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annotate libgsmhr1/mathhalf.c @ 503:3654df24451f

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libgsmhr1/mathdp31.[ch]: import original
author Mychaela Falconia <falcon@freecalypso.org>
date Wed, 19 Jun 2024 01:16:47 +0000
parents b0333fa167c3
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
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1 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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2 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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3 * File Name: mathhalf.c
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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4 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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5 * Purpose: Contains functions which implement the primitive
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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6 * arithmetic operations.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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7 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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8 * The functions in this file are listed below. Some of them are
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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9 * defined in terms of other basic operations. One of the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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10 * routines, saturate() is static. This is not a basic
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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11 * operation, and is not referenced outside the scope of this
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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12 * file.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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13 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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14 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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15 * abs_s()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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16 * add()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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17 * divide_s()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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18 * extract_h()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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19 * extract_l()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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20 * L_abs()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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21 * L_add()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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22 * L_deposit_h()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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23 * L_deposit_l()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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24 * L_mac()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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25 * L_msu()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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26 * L_mult()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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27 * L_negate()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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28 * L_shift_r()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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29 * L_shl()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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30 * L_shr()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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31 * L_sub()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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32 * mac_r()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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33 * msu_r()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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34 * mult()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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35 * mult_r()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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36 * negate()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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37 * norm_l()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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38 * norm_s()
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Mychaela Falconia <falcon@freecalypso.org>
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39 * round()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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40 * saturate()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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41 * shift_r()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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42 * shl()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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43 * shr()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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44 * sub()
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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45 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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46 **************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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47
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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48 /*_________________________________________________________________________
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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49 | |
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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50 | Include Files |
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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51 |_________________________________________________________________________|
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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52 */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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53
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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54 #include "typedefs.h"
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b0333fa167c3 libgsmhr1: compile mathhalf.c
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55 #include "namespace.h"
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66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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56 #include "mathhalf.h"
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57
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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58 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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59 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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60 * FUNCTION NAME: saturate
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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61 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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62 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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63 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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64 * Limit the 32 bit input to the range of a 16 bit word.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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65 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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66 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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67 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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68 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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69 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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70 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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71 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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72 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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73 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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74 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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75 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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76 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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77 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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78 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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79 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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80 * swOut
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Mychaela Falconia <falcon@freecalypso.org>
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81 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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parents:
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82 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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83 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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84 *
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Mychaela Falconia <falcon@freecalypso.org>
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85 * KEYWORDS: saturation, limiting, limit, saturate, 16 bits
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Mychaela Falconia <falcon@freecalypso.org>
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86 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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87 *************************************************************************/
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Mychaela Falconia <falcon@freecalypso.org>
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88
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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89 static Shortword saturate(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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90 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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91 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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92
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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93 if (L_var1 > SW_MAX)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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94 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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95 swOut = SW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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96 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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97 else if (L_var1 < SW_MIN)
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98 {
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99 swOut = SW_MIN;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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100 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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101 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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102 swOut = (Shortword) L_var1; /* automatic type conversion */
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103 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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104 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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105
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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106 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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107 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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108 * FUNCTION NAME: abs_s
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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109 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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110 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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111 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
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112 * Take the absolute value of the 16 bit input. An input of
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
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113 * -0x8000 results in a return value of 0x7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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114 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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115 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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116 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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117 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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118 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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119 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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120 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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121 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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122 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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123 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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124 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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125 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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126 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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127 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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128 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
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129 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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130 * 0x0000 0000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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131 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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132 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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133 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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134 * Take the absolute value of the 16 bit input. An input of
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
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135 * -0x8000 results in a return value of 0x7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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136 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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137 * KEYWORDS: absolute value, abs
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
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diff changeset
138 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
139 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
140
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
141 Shortword abs_s(Shortword var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
142 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
143 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
144
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
145 if (var1 == SW_MIN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
146 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
147 swOut = SW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
148 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
149 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
150 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
151 if (var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
152 swOut = -var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
153 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
154 swOut = var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
155 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
156 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
157 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
158
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
159 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
160 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
161 * FUNCTION NAME: add
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
162 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
163 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
164 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
165 * Perform the addition of the two 16 bit input variable with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
166 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
167 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
168 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
169 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
170 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
171 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
172 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
173 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
174 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
175 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
176 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
177 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
178 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
179 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
180 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
181 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
182 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
183 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
184 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
185 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
186 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
187 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
188 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
189 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
190 * Perform the addition of the two 16 bit input variable with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
191 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
192 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
193 * swOut = var1 + var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
194 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
195 * swOut is set to 0x7fff if the operation results in an
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
196 * overflow. swOut is set to 0x8000 if the operation results
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
197 * in an underflow.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
198 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
199 * KEYWORDS: add, addition
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
200 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
201 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
202
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
203 Shortword add(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
204 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
205 Longword L_sum;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
206 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
207
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
208 L_sum = (Longword) var1 + var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
209 swOut = saturate(L_sum);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
210 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
211 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
212
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
213 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
214 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
215 * FUNCTION NAME: divide_s
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
216 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
217 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
218 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
219 * Divide var1 by var2. Note that both must be positive, and
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
220 * var1 >= var2. The output is set to 0 if invalid input is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
221 * provided.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
222 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
223 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
224 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
225 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
226 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
227 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
228 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
229 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
230 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
231 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
232 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
233 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
234 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
235 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
236 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
237 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
238 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
239 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
240 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
241 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
242 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
243 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
244 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
245 * In the case where var1==var2 the function returns 0x7fff. The output
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
246 * is undefined for invalid inputs. This implementation returns zero
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
247 * and issues a warning via stdio if invalid input is presented.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
248 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
249 * KEYWORDS: divide
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
250 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
251 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
252
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
253 Shortword divide_s(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
254 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
255 Longword L_div;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
256 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
257
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
258 if (var1 < 0 || var2 < 0 || var1 > var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
259 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
260 /* undefined output for invalid input into divide_s */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
261 return (0);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
262 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
263
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
264 if (var1 == var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
265 return (0x7fff);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
266
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
267 L_div = ((0x00008000L * (Longword) var1) / (Longword) var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
268 swOut = saturate(L_div);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
269 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
270 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
271
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
272 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
273 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
274 * FUNCTION NAME: extract_h
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
275 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
276 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
277 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
278 * Extract the 16 MS bits of a 32 bit Longword. Return the 16 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
279 * number as a Shortword. This is used as a "truncation" of a fractional
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
280 * number.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
281 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
282 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
283 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
284 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
285 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
286 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
287 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
288 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
289 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
290 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
291 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
292 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
293 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
294 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
295 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
296 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
297 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
298 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
299 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
300 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
301 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
302 * KEYWORDS: assign, truncate
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
303 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
304 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
305
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
306 Shortword extract_h(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
307 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
308 Shortword var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
309
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
310 var2 = (Shortword) (0x0000ffffL & (L_var1 >> 16));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
311 return (var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
312 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
313
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
314 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
315 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
316 * FUNCTION NAME: extract_l
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
317 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
318 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
319 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
320 * Extract the 16 LS bits of a 32 bit Longword. Return the 16 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
321 * number as a Shortword. The upper portion of the input Longword
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
322 * has no impact whatsoever on the output.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
323 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
324 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
325 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
326 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
327 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
328 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
329 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
330 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
331 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
332 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
333 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
334 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
335 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
336 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
337 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
338 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
339 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
340 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
341 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
342 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
343 * KEYWORDS: extract, assign
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
344 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
345 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
346
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
347 Shortword extract_l(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
348 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
349 Shortword var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
350
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
351 var2 = (Shortword) (0x0000ffffL & L_var1);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
352 return (var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
353 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
354
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
355 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
356 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
357 * FUNCTION NAME: L_abs
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
358 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
359 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
360 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
361 * Take the absolute value of the 32 bit input. An input of
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
362 * -0x8000 0000 results in a return value of 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
363 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
364 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
365 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
366 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
367 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
368 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
369 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
370 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
371 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
372 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
373 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
374 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
375 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
376 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
377 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
378 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
379 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
380 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
381 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
382 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
383 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
384 * KEYWORDS: absolute value, abs
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
385 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
386 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
387 Longword L_abs(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
388 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
389 Longword L_Out;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
390
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
391 if (L_var1 == LW_MIN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
392 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
393 L_Out = LW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
394 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
395 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
396 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
397 if (L_var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
398 L_Out = -L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
399 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
400 L_Out = L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
401 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
402 return (L_Out);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
403 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
404
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
405 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
406 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
407 * FUNCTION NAME: L_add
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
408 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
409 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
410 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
411 * Perform the addition of the two 32 bit input variables with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
412 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
413 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
414 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
415 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
416 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
417 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
418 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
419 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
420 * L_var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
421 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
422 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
423 * 0x8000 0000 <= L_var2 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
424 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
425 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
426 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
427 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
428 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
429 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
430 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
431 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
432 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
433 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
434 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
435 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
436 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
437 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
438 * Perform the addition of the two 32 bit input variables with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
439 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
440 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
441 * L_Out = L_var1 + L_var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
442 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
443 * L_Out is set to 0x7fff ffff if the operation results in an
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
444 * overflow. L_Out is set to 0x8000 0000 if the operation
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
445 * results in an underflow.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
446 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
447 * KEYWORDS: add, addition
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
448 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
449 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
450 Longword L_add(Longword L_var1, Longword L_var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
451 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
452
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
453 Longword L_Sum,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
454 L_SumLow,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
455 L_SumHigh;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
456
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
457 L_Sum = L_var1 + L_var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
458
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
459 if ((L_var1 > 0 && L_var2 > 0) || (L_var1 < 0 && L_var2 < 0))
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
460 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
461
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
462 /* an overflow is possible */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
463
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
464 L_SumLow = (L_var1 & 0xffff) + (L_var2 & 0xffff);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
465 L_SumHigh = ((L_var1 >> 16) & 0xffff) + ((L_var2 >> 16) & 0xffff);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
466 if (L_SumLow & 0x10000)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
467 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
468 /* carry into high word is set */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
469 L_SumHigh += 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
470 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
471
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
472 /* update sum only if there is an overflow or underflow */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
473 /*------------------------------------------------------*/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
474
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
475 if ((0x10000 & L_SumHigh) && !(0x8000 & L_SumHigh))
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
476 L_Sum = LW_MIN; /* underflow */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
477 else if (!(0x10000 & L_SumHigh) && (0x8000 & L_SumHigh))
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
478 L_Sum = LW_MAX; /* overflow */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
479 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
480
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
481 return (L_Sum);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
482
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
483 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
484
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
485 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
486 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
487 * FUNCTION NAME: L_deposit_h
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
488 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
489 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
490 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
491 * Put the 16 bit input into the 16 MSB's of the output Longword. The
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
492 * LS 16 bits are zeroed.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
493 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
494 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
495 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
496 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
497 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
498 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
499 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
500 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
501 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
502 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
503 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
504 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
505 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
506 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
507 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
508 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
509 * 0x8000 0000 <= L_var1 <= 0x7fff 0000.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
510 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
511 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
512 * KEYWORDS: deposit, assign, fractional assign
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
513 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
514 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
515
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
516 Longword L_deposit_h(Shortword var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
517 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
518 Longword L_var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
519
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
520 L_var2 = (Longword) var1 << 16;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
521 return (L_var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
522 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
523
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
524 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
525 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
526 * FUNCTION NAME: L_deposit_l
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
527 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
528 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
529 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
530 * Put the 16 bit input into the 16 LSB's of the output Longword with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
531 * sign extension i.e. the top 16 bits are set to either 0 or 0xffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
532 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
533 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
534 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
535 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
536 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
537 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
538 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
539 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
540 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
541 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
542 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
543 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
544 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
545 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
546 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
547 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
548 * 0xffff 8000 <= L_var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
549 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
550 * KEYWORDS: deposit, assign
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
551 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
552 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
553
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
554 Longword L_deposit_l(Shortword var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
555 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
556 Longword L_Out;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
557
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
558 L_Out = var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
559 return (L_Out);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
560 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
561
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
562 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
563 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
564 * FUNCTION NAME: L_mac
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
565 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
566 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
567 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
568 * Multiply accumulate. Fractionally multiply two 16 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
569 * numbers together with saturation. Add that result to the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
570 * 32 bit input with saturation. Return the 32 bit result.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
571 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
572 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
573 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
574 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
575 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
576 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
577 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
578 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
579 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
580 * L_var3
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
581 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
582 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
583 * 0x8000 0000 <= L_var2 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
584 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
585 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
586 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
587 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
588 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
589 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
590 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
591 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
592 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
593 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
594 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
595 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
596 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
597 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
598 * Fractionally multiply two 16 bit numbers together with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
599 * saturation. The only numbers which will cause saturation on
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
600 * the multiply are 0x8000 * 0x8000.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
601 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
602 * Add that result to the 32 bit input with saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
603 * Return the 32 bit result.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
604 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
605 * Please note that this is not a true multiply accumulate as
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
606 * most processors would implement it. The 0x8000*0x8000
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
607 * causes and overflow for this instruction. On most
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
608 * processors this would cause an overflow only if the 32 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
609 * input added to it were positive or zero.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
610 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
611 * KEYWORDS: mac, multiply accumulate
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
612 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
613 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
614
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
615 Longword L_mac(Longword L_var3, Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
616 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
617 return (L_add(L_var3, L_mult(var1, var2)));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
618 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
619
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
620 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
621 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
622 * FUNCTION NAME: L_msu
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
623 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
624 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
625 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
626 * Multiply and subtract. Fractionally multiply two 16 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
627 * numbers together with saturation. Subtract that result from
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
628 * the 32 bit input with saturation. Return the 32 bit result.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
629 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
630 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
631 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
632 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
633 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
634 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
635 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
636 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
637 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
638 * L_var3
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
639 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
640 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
641 * 0x8000 0000 <= L_var2 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
642 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
643 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
644 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
645 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
646 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
647 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
648 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
649 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
650 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
651 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
652 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
653 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
654 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
655 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
656 * Fractionally multiply two 16 bit numbers together with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
657 * saturation. The only numbers which will cause saturation on
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
658 * the multiply are 0x8000 * 0x8000.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
659 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
660 * Subtract that result from the 32 bit input with saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
661 * Return the 32 bit result.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
662 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
663 * Please note that this is not a true multiply accumulate as
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
664 * most processors would implement it. The 0x8000*0x8000
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
665 * causes and overflow for this instruction. On most
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
666 * processors this would cause an overflow only if the 32 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
667 * input added to it were negative or zero.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
668 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
669 * KEYWORDS: mac, multiply accumulate, msu
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
670 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
671 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
672
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
673 Longword L_msu(Longword L_var3, Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
674 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
675 return (L_sub(L_var3, L_mult(var1, var2)));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
676 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
677
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
678 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
679 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
680 * FUNCTION NAME: L_mult
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
681 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
682 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
683 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
684 * Perform a fractional multipy of the two 16 bit input numbers
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
685 * with saturation. Output a 32 bit number.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
686 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
687 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
688 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
689 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
690 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
691 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
692 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
693 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
694 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
695 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
696 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
697 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
698 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
699 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
700 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
701 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
702 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
703 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
704 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
705 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
706 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
707 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
708 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
709 * Multiply the two the two 16 bit input numbers. If the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
710 * result is within this range, left shift the result by one
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
711 * and output the 32 bit number. The only possible overflow
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
712 * occurs when var1==var2==-0x8000. In this case output
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
713 * 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
714 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
715 * KEYWORDS: multiply, mult, mpy
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
716 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
717 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
718
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
719 Longword L_mult(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
720 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
721 Longword L_product;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
722
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
723 if (var1 == SW_MIN && var2 == SW_MIN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
724 L_product = LW_MAX; /* overflow */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
725 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
726 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
727 L_product = (Longword) var1 *var2; /* integer multiply */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
728
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
729 L_product = L_product << 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
730 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
731 return (L_product);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
732 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
733
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
734 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
735 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
736 * FUNCTION NAME: L_negate
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
737 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
738 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
739 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
740 * Negate the 32 bit input. 0x8000 0000's negated value is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
741 * 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
742 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
743 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
744 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
745 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
746 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
747 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
748 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
749 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
750 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
751 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
752 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
753 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
754 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
755 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
756 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
757 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
758 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
759 * 0x8000 0001 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
760 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
761 * KEYWORDS: negate, negative
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
762 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
763 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
764
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
765 Longword L_negate(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
766 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
767 Longword L_Out;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
768
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
769 if (L_var1 == LW_MIN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
770 L_Out = LW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
771 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
772 L_Out = -L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
773 return (L_Out);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
774 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
775
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
776 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
777 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
778 * FUNCTION NAME: L_shift_r
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
779 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
780 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
781 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
782 * Shift and round. Perform a shift right. After shifting, use
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
783 * the last bit shifted out of the LSB to round the result up
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
784 * or down.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
785 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
786 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
787 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
788 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
789 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
790 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
791 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
792 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
793 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
794 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
795 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
796 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
797 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
798 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
799 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
800 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
801 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
802 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
803 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
804 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
805 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
806 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
807 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
808 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
809 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
810 * Shift and round. Perform a shift right. After shifting, use
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
811 * the last bit shifted out of the LSB to round the result up
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
812 * or down. This is just like shift_r above except that the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
813 * input/output is 32 bits as opposed to 16.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
814 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
815 * if var2 is positve perform a arithmetic left shift
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
816 * with saturation (see L_shl() above).
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
817 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
818 * If var2 is zero simply return L_var1.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
819 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
820 * If var2 is negative perform a arithmetic right shift (L_shr)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
821 * of L_var1 by (-var2)+1. Add the LS bit of the result to
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
822 * L_var1 shifted right (L_shr) by -var2.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
823 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
824 * Note that there is no constraint on var2, so if var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
825 * -0xffff 8000 then -var2 is 0x0000 8000, not 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
826 * This is the reason the L_shl function is used.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
827 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
828 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
829 * KEYWORDS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
830 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
831 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
832
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
833 Longword L_shift_r(Longword L_var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
834 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
835 Longword L_Out,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
836 L_rnd;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
837
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
838 if (var2 < -31)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
839 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
840 L_Out = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
841 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
842 else if (var2 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
843 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
844 /* right shift */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
845 L_rnd = L_shl(L_var1, var2 + 1) & 0x1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
846 L_Out = L_add(L_shl(L_var1, var2), L_rnd);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
847 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
848 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
849 L_Out = L_shl(L_var1, var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
850
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
851 return (L_Out);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
852 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
853
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
854 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
855 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
856 * FUNCTION NAME: L_shl
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
857 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
858 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
859 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
860 * Arithmetic shift left (or right).
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
861 * Arithmetically shift the input left by var2. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
862 * negative then an arithmetic shift right (L_shr) of L_var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
863 * -var2 is performed.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
864 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
865 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
866 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
867 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
868 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
869 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
870 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
871 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
872 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
873 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
874 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
875 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
876 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
877 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
878 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
879 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
880 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
881 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
882 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
883 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
884 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
885 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
886 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
887 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
888 * Arithmetically shift the 32 bit input left by var2. This
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
889 * operation maintains the sign of the input number. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
890 * negative then an arithmetic shift right (L_shr) of L_var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
891 * -var2 is performed. See description of L_shr for details.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
892 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
893 * Equivalent to the Full-Rate GSM ">> n" operation. Note that
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
894 * ANSI-C does not guarantee operation of the C ">>" or "<<"
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
895 * operator for negative numbers.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
896 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
897 * KEYWORDS: shift, arithmetic shift left,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
898 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
899 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
900
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
901 Longword L_shl(Longword L_var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
902 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
903
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
904 Longword L_Mask,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
905 L_Out;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
906 int i,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
907 iOverflow = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
908
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
909 if (var2 == 0 || L_var1 == 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
910 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
911 L_Out = L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
912 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
913 else if (var2 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
914 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
915 if (var2 <= -31)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
916 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
917 if (L_var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
918 L_Out = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
919 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
920 L_Out = 0xffffffffL;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
921 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
922 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
923 L_Out = L_shr(L_var1, -var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
924 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
925 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
926 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
927
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
928 if (var2 >= 31)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
929 iOverflow = 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
930
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
931 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
932 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
933
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
934 if (L_var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
935 L_Mask = LW_SIGN; /* sign bit mask */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
936 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
937 L_Mask = 0x0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
938 L_Out = L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
939 for (i = 0; i < var2 && !iOverflow; i++)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
940 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
941 /* check the sign bit */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
942 L_Out = (L_Out & 0x7fffffffL) << 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
943 if ((L_Mask ^ L_Out) & LW_SIGN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
944 iOverflow = 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
945 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
946 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
947
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
948 if (iOverflow)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
949 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
950 /* saturate */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
951 if (L_var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
952 L_Out = LW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
953 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
954 L_Out = LW_MIN;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
955 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
956 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
957
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
958 return (L_Out);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
959 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
960
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
961 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
962 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
963 * FUNCTION NAME: L_shr
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
964 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
965 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
966 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
967 * Arithmetic shift right (or left).
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
968 * Arithmetically shift the input right by var2. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
969 * negative then an arithmetic shift left (shl) of var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
970 * -var2 is performed.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
971 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
972 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
973 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
974 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
975 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
976 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
977 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
978 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
979 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
980 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
981 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
982 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
983 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
984 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
985 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
986 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
987 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
988 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
989 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
990 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
991 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
992 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
993 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
994 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
995 * Arithmetically shift the input right by var2. This
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
996 * operation maintains the sign of the input number. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
997 * negative then an arithmetic shift left (shl) of L_var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
998 * -var2 is performed. See description of L_shl for details.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
999 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1000 * The input is a 32 bit number, as is the output.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1001 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1002 * Equivalent to the Full-Rate GSM ">> n" operation. Note that
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1003 * ANSI-C does not guarantee operation of the C ">>" or "<<"
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1004 * operator for negative numbers.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1005 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1006 * KEYWORDS: shift, arithmetic shift right,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1007 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1008 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1009
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1010 Longword L_shr(Longword L_var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1011 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1012
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1013 Longword L_Mask,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1014 L_Out;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1015
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1016 if (var2 == 0 || L_var1 == 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1017 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1018 L_Out = L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1019 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1020 else if (var2 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1021 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1022 /* perform a left shift */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1023 /*----------------------*/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1024 if (var2 <= -31)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1025 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1026 /* saturate */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1027 if (L_var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1028 L_Out = LW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1029 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1030 L_Out = LW_MIN;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1031 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1032 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1033 L_Out = L_shl(L_var1, -var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1034 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1035 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1036 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1037
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1038 if (var2 >= 31)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1039 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1040 if (L_var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1041 L_Out = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1042 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1043 L_Out = 0xffffffffL;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1044 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1045 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1046 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1047 L_Mask = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1048
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1049 if (L_var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1050 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1051 L_Mask = ~L_Mask << (32 - var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1052 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1053
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1054 L_var1 >>= var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1055 L_Out = L_Mask | L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1056 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1057 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1058 return (L_Out);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1059 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1060
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1061 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1062 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1063 * FUNCTION NAME: L_sub
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1064 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1065 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1066 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1067 * Perform the subtraction of the two 32 bit input variables with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1068 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1069 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1070 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1071 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1072 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1073 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1074 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1075 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1076 * L_var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1077 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1078 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1079 * 0x8000 0000 <= L_var2 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1080 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1081 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1082 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1083 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1084 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1085 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1086 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1087 * L_Out
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1088 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1089 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1090 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1091 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1092 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1093 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1094 * Perform the subtraction of the two 32 bit input variables with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1095 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1096 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1097 * L_Out = L_var1 - L_var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1098 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1099 * L_Out is set to 0x7fff ffff if the operation results in an
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1100 * overflow. L_Out is set to 0x8000 0000 if the operation
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1101 * results in an underflow.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1102 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1103 * KEYWORDS: sub, subtraction
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1104 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1105 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1106 Longword L_sub(Longword L_var1, Longword L_var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1107 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1108 Longword L_Sum;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1109
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1110 /* check for overflow */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1111 if ((L_var1 > 0 && L_var2 < 0) || (L_var1 < 0 && L_var2 > 0))
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1112 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1113 if (L_var2 == LW_MIN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1114 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1115 L_Sum = L_add(L_var1, LW_MAX);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1116 L_Sum = L_add(L_Sum, 1);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1117 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1118 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1119 L_Sum = L_add(L_var1, -L_var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1120 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1121 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1122 { /* no overflow possible */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1123 L_Sum = L_var1 - L_var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1124 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1125 return (L_Sum);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1126 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1127
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1128 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1129 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1130 * FUNCTION NAME:mac_r
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1131 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1132 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1133 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1134 * Multiply accumulate and round. Fractionally multiply two 16
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1135 * bit numbers together with saturation. Add that result to
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1136 * the 32 bit input with saturation. Finally round the result
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1137 * into a 16 bit number.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1138 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1139 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1140 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1141 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1142 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1143 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1144 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1145 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1146 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1147 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1148 * L_var3
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1149 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1150 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1151 * 0x8000 0000 <= L_var2 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1152 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1153 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1154 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1155 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1156 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1157 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1158 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1159 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1160 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1161 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1162 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1163 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1164 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1165 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1166 * Fractionally multiply two 16 bit numbers together with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1167 * saturation. The only numbers which will cause saturation on
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1168 * the multiply are 0x8000 * 0x8000.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1169 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1170 * Add that result to the 32 bit input with saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1171 * Round the 32 bit result by adding 0x0000 8000 to the input.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1172 * The result may overflow due to the add. If so, the result
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1173 * is saturated. The 32 bit rounded number is then shifted
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1174 * down 16 bits and returned as a Shortword.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1175 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1176 * Please note that this is not a true multiply accumulate as
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1177 * most processors would implement it. The 0x8000*0x8000
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1178 * causes and overflow for this instruction. On most
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1179 * processors this would cause an overflow only if the 32 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1180 * input added to it were positive or zero.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1181 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1182 * KEYWORDS: mac, multiply accumulate, macr
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1183 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1184 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1185
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1186 Shortword mac_r(Longword L_var3, Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1187 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1188 return (round(L_add(L_var3, L_mult(var1, var2))));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1189 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1190
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1191 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1192 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1193 * FUNCTION NAME: msu_r
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1194 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1195 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1196 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1197 * Multiply subtract and round. Fractionally multiply two 16
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1198 * bit numbers together with saturation. Subtract that result from
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1199 * the 32 bit input with saturation. Finally round the result
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1200 * into a 16 bit number.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1201 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1202 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1203 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1204 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1205 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1206 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1207 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1208 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1209 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1210 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1211 * L_var3
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1212 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1213 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1214 * 0x8000 0000 <= L_var2 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1215 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1216 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1217 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1218 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1219 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1220 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1221 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1222 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1223 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1224 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1225 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1226 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1227 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1228 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1229 * Fractionally multiply two 16 bit numbers together with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1230 * saturation. The only numbers which will cause saturation on
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1231 * the multiply are 0x8000 * 0x8000.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1232 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1233 * Subtract that result from the 32 bit input with saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1234 * Round the 32 bit result by adding 0x0000 8000 to the input.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1235 * The result may overflow due to the add. If so, the result
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1236 * is saturated. The 32 bit rounded number is then shifted
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1237 * down 16 bits and returned as a Shortword.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1238 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1239 * Please note that this is not a true multiply accumulate as
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1240 * most processors would implement it. The 0x8000*0x8000
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1241 * causes and overflow for this instruction. On most
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1242 * processors this would cause an overflow only if the 32 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1243 * input added to it were positive or zero.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1244 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1245 * KEYWORDS: mac, multiply accumulate, macr
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1246 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1247 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1248
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1249 Shortword msu_r(Longword L_var3, Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1250 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1251 return (round(L_sub(L_var3, L_mult(var1, var2))));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1252 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1253
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1254 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1255 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1256 * FUNCTION NAME: mult
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1257 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1258 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1259 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1260 * Perform a fractional multipy of the two 16 bit input numbers
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1261 * with saturation and truncation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1262 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1263 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1264 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1265 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1266 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1267 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1268 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1269 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1270 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1271 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1272 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1273 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1274 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1275 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1276 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1277 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1278 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1279 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1280 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1281 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1282 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1283 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1284 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1285 * Perform a fractional multipy of the two 16 bit input
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1286 * numbers. If var1 == var2 == -0x8000, output 0x7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1287 * Otherwise output var1*var2 >> 15. The output is a
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1288 * 16 bit number.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1289 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1290 * KEYWORDS: mult, mulitply, mpy
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1291 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1292 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1293
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1294 Shortword mult(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1295 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1296 Longword L_product;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1297 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1298
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1299 L_product = L_mult(var1, var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1300 swOut = extract_h(L_product);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1301 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1302 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1303
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1304 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1305 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1306 * FUNCTION NAME: mult_r
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1307 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1308 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1309 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1310 * Perform a fractional multipy and round of the two 16 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1311 * input numbers with saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1312 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1313 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1314 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1315 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1316 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1317 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1318 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1319 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1320 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1321 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1322 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1323 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1324 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1325 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1326 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1327 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1328 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1329 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1330 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1331 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1332 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1333 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1334 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1335 * This routine is defined as the concatenation of the multiply
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1336 * operation and the round operation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1337 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1338 * The fractional multiply (L_mult) produces a saturated 32 bit
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1339 * output. This is followed by a an add of 0x0000 8000 to the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1340 * 32 bit result. The result may overflow due to the add. If
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1341 * so, the result is saturated. The 32 bit rounded number is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1342 * then shifted down 16 bits and returned as a Shortword.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1343 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1344 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1345 * KEYWORDS: multiply and round, round, mult_r, mpyr
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1346 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1347 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1348
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1349
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1350 Shortword mult_r(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1351 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1352 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1353
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1354 swOut = round(L_mult(var1, var2));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1355 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1356 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1357
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1358 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1359 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1360 * FUNCTION NAME: negate
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1361 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1362 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1363 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1364 * Negate the 16 bit input. 0x8000's negated value is 0x7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1365 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1366 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1367 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1368 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1369 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1370 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1371 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1372 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1373 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1374 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1375 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1376 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1377 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1378 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1379 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1380 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1381 * 0xffff 8001 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1382 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1383 * KEYWORDS: negate, negative, invert
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1384 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1385 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1386
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1387 Shortword negate(Shortword var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1388 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1389 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1390
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1391 if (var1 == SW_MIN)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1392 swOut = SW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1393 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1394 swOut = -var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1395 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1396 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1397
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1398 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1399 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1400 * FUNCTION NAME: norm_l
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1401 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1402 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1403 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1404 * Get normalize shift count:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1405 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1406 * A 32 bit number is input (possiblly unnormalized). Output
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1407 * the positive (or zero) shift count required to normalize the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1408 * input.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1409 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1410 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1411 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1412 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1413 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1414 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1415 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1416 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1417 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1418 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1419 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1420 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1421 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1422 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1423 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1424 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1425 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1426 * 0 <= swOut <= 31
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1427 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1428 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1429 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1430 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1431 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1432 * Get normalize shift count:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1433 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1434 * A 32 bit number is input (possiblly unnormalized). Output
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1435 * the positive (or zero) shift count required to normalize the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1436 * input.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1437 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1438 * If zero in input, return 0 as the shift count.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1439 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1440 * For non-zero numbers, count the number of left shift
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1441 * required to get the number to fall into the range:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1442 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1443 * 0x4000 0000 >= normlzd number >= 0x7fff ffff (positive number)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1444 * or
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1445 * 0x8000 0000 <= normlzd number < 0xc000 0000 (negative number)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1446 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1447 * Return the number of shifts.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1448 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1449 * This instruction corresponds exactly to the Full-Rate "norm"
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1450 * instruction.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1451 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1452 * KEYWORDS: norm, normalization
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1453 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1454 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1455
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1456 Shortword norm_l(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1457 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1458
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1459 Shortword swShiftCnt;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1460
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1461 if (L_var1 != 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1462 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1463 if (!(L_var1 & LW_SIGN))
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1464 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1465
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1466 /* positive input */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1467 for (swShiftCnt = 0; !(L_var1 <= LW_MAX && L_var1 >= 0x40000000L);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1468 swShiftCnt++)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1469 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1470 L_var1 = L_var1 << 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1471 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1472
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1473 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1474 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1475 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1476 /* negative input */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1477 for (swShiftCnt = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1478 !(L_var1 >= LW_MIN && L_var1 < (Longword) 0xc0000000L);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1479 swShiftCnt++)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1480 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1481 L_var1 = L_var1 << 1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1482 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1483 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1484 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1485 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1486 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1487 swShiftCnt = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1488 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1489 return (swShiftCnt);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1490 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1491
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1492 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1493 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1494 * FUNCTION NAME: norm_s
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1495 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1496 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1497 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1498 * Get normalize shift count:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1499 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1500 * A 16 bit number is input (possiblly unnormalized). Output
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1501 * the positive (or zero) shift count required to normalize the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1502 * input.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1503 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1504 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1505 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1506 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1507 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1508 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1509 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1510 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1511 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1512 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1513 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1514 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1515 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1516 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1517 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1518 * 0 <= swOut <= 15
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1519 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1520 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1521 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1522 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1523 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1524 * Get normalize shift count:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1525 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1526 * A 16 bit number is input (possiblly unnormalized). Output
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1527 * the positive (or zero) shift count required to normalize the
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1528 * input.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1529 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1530 * If zero in input, return 0 as the shift count.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1531 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1532 * For non-zero numbers, count the number of left shift
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1533 * required to get the number to fall into the range:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1534 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1535 * 0x4000 >= normlzd number >= 0x7fff (positive number)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1536 * or
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1537 * 0x8000 <= normlzd number < 0xc000 (negative number)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1538 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1539 * Return the number of shifts.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1540 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1541 * This instruction corresponds exactly to the Full-Rate "norm"
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1542 * instruction.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1543 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1544 * KEYWORDS: norm, normalization
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1545 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1546 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1547
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1548 Shortword norm_s(Shortword var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1549 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1550
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1551 short swShiftCnt;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1552 Longword L_var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1553
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1554 L_var1 = L_deposit_h(var1);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1555 swShiftCnt = norm_l(L_var1);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1556 return (swShiftCnt);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1557 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1558
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1559 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1560 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1561 * FUNCTION NAME: round
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1562 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1563 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1564 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1565 * Round the 32 bit Longword into a 16 bit shortword with saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1566 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1567 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1568 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1569 * L_var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1570 * 32 bit long signed integer (Longword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1571 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1572 * 0x8000 0000 <= L_var1 <= 0x7fff ffff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1573 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1574 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1575 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1576 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1577 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1578 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1579 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1580 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1581 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1582 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1583 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1584 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1585 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1586 * Perform a two's complement round on the input Longword with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1587 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1588 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1589 * This is equivalent to adding 0x0000 8000 to the input. The
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1590 * result may overflow due to the add. If so, the result is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1591 * saturated. The 32 bit rounded number is then shifted down
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1592 * 16 bits and returned as a Shortword.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1593 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1594 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1595 * KEYWORDS: round
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1596 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1597 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1598
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1599 Shortword round(Longword L_var1)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1600 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1601 Longword L_Prod;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1602
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1603 L_Prod = L_add(L_var1, 0x00008000L); /* round MSP */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1604 return (extract_h(L_Prod));
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1605 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1606
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1607 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1608 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1609 * FUNCTION NAME: shift_r
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1610 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1611 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1612 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1613 * Shift and round. Perform a shift right. After shifting, use
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1614 * the last bit shifted out of the LSB to round the result up
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1615 * or down.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1616 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1617 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1618 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1619 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1620 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1621 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1622 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1623 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1624 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1625 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1626 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1627 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1628 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1629 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1630 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1631 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1632 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1633 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1634 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1635 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1636 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1637 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1638 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1639 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1640 * Shift and round. Perform a shift right. After shifting, use
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1641 * the last bit shifted out of the LSB to round the result up
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1642 * or down.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1643 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1644 * If var2 is positive perform a arithmetic left shift
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1645 * with saturation (see shl() above).
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1646 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1647 * If var2 is zero simply return var1.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1648 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1649 * If var2 is negative perform a arithmetic right shift (shr)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1650 * of var1 by (-var2)+1. Add the LS bit of the result to var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1651 * shifted right (shr) by -var2.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1652 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1653 * Note that there is no constraint on var2, so if var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1654 * -0xffff 8000 then -var2 is 0x0000 8000, not 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1655 * This is the reason the shl function is used.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1656 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1657 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1658 * KEYWORDS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1659 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1660 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1661
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1662 Shortword shift_r(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1663 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1664 Shortword swOut,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1665 swRnd;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1666
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1667 if (var2 >= 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1668 swOut = shl(var1, var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1669 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1670 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1671
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1672 /* right shift */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1673
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1674 if (var2 < -15)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1675 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1676
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1677 swOut = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1678
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1679 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1680 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1681 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1682
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1683 swRnd = shl(var1, var2 + 1) & 0x1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1684 swOut = add(shl(var1, var2), swRnd);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1685
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1686 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1687 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1688 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1689 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1690
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1691 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1692 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1693 * FUNCTION NAME: shl
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1694 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1695 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1696 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1697 * Arithmetically shift the input left by var2.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1698 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1699 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1700 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1701 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1702 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1703 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1704 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1705 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1706 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1707 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1708 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1709 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1710 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1711 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1712 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1713 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1714 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1715 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1716 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1717 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1718 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1719 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1720 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1721 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1722 * If Arithmetically shift the input left by var2. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1723 * negative then an arithmetic shift right (shr) of var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1724 * -var2 is performed. See description of shr for details.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1725 * When an arithmetic shift left is performed the var2 LS bits
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1726 * are zero filled.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1727 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1728 * The only exception is if the left shift causes an overflow
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1729 * or underflow. In this case the LS bits are not modified.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1730 * The number returned is 0x8000 in the case of an underflow or
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1731 * 0x7fff in the case of an overflow.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1732 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1733 * The shl is equivalent to the Full-Rate GSM "<< n" operation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1734 * Note that ANSI-C does not guarantee operation of the C ">>"
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1735 * or "<<" operator for negative numbers - it is not specified
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1736 * whether this shift is an arithmetic or logical shift.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1737 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1738 * KEYWORDS: asl, arithmetic shift left, shift
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1739 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1740 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1741
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1742 Shortword shl(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1743 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1744 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1745 Longword L_Out;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1746
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1747 if (var2 == 0 || var1 == 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1748 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1749 swOut = var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1750 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1751 else if (var2 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1752 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1753
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1754 /* perform a right shift */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1755 /*-----------------------*/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1756
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1757 if (var2 <= -15)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1758 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1759 if (var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1760 swOut = (Shortword) 0xffff;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1761 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1762 swOut = 0x0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1763 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1764 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1765 swOut = shr(var1, -var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1766
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1767 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1768 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1769 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1770 /* var2 > 0 */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1771 if (var2 >= 15)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1772 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1773 /* saturate */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1774 if (var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1775 swOut = SW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1776 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1777 swOut = SW_MIN;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1778 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1779 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1780 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1781
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1782 L_Out = (Longword) var1 *(1 << var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1783
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1784 swOut = (Shortword) L_Out; /* copy low portion to swOut, overflow
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1785 * could have hpnd */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1786 if (swOut != L_Out)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1787 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1788 /* overflow */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1789 if (var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1790 swOut = SW_MAX; /* saturate */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1791 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1792 swOut = SW_MIN; /* saturate */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1793 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1794 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1795 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1796 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1797 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1798
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1799 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1800 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1801 * FUNCTION NAME: shr
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1802 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1803 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1804 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1805 * Arithmetic shift right (or left).
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1806 * Arithmetically shift the input right by var2. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1807 * negative then an arithmetic shift left (shl) of var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1808 * -var2 is performed.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1809 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1810 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1811 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1812 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1813 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1814 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1815 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1816 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1817 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1818 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1819 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1820 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1821 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1822 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1823 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1824 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1825 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1826 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1827 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1828 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1829 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1830 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1831 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1832 * Arithmetically shift the input right by var2. This
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1833 * operation maintains the sign of the input number. If var2 is
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1834 * negative then an arithmetic shift left (shl) of var1 by
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1835 * -var2 is performed. See description of shl for details.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1836 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1837 * Equivalent to the Full-Rate GSM ">> n" operation. Note that
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1838 * ANSI-C does not guarantee operation of the C ">>" or "<<"
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1839 * operator for negative numbers.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1840 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1841 * KEYWORDS: shift, arithmetic shift right,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1842 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1843 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1844
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1845 Shortword shr(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1846 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1847
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1848 Shortword swMask,
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1849 swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1850
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1851 if (var2 == 0 || var1 == 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1852 swOut = var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1853
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1854 else if (var2 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1855 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1856 /* perform an arithmetic left shift */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1857 /*----------------------------------*/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1858 if (var2 <= -15)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1859 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1860 /* saturate */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1861 if (var1 > 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1862 swOut = SW_MAX;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1863 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1864 swOut = SW_MIN;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1865 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1866 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1867 swOut = shl(var1, -var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1868 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1869
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1870 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1871 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1872
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1873 /* positive shift count */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1874 /*----------------------*/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1875
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1876 if (var2 >= 15)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1877 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1878 if (var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1879 swOut = (Shortword) 0xffff;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1880 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1881 swOut = 0x0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1882 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1883 else
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1884 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1885 /* take care of sign extension */
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1886 /*-----------------------------*/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1887
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1888 swMask = 0;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1889 if (var1 < 0)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1890 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1891 swMask = ~swMask << (16 - var2);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1892 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1893
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1894 var1 >>= var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1895 swOut = swMask | var1;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1896
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1897 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1898 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1899 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1900 }
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1901
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1902 /***************************************************************************
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1903 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1904 * FUNCTION NAME: sub
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1905 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1906 * PURPOSE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1907 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1908 * Perform the subtraction of the two 16 bit input variable with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1909 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1910 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1911 * INPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1912 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1913 * var1
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1914 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1915 * falls in the range 0xffff 8000 <= var1 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1916 * var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1917 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1918 * falls in the range 0xffff 8000 <= var2 <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1919 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1920 * OUTPUTS:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1921 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1922 * none
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1923 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1924 * RETURN VALUE:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1925 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1926 * swOut
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1927 * 16 bit short signed integer (Shortword) whose value
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1928 * falls in the range
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1929 * 0xffff 8000 <= swOut <= 0x0000 7fff.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1930 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1931 * IMPLEMENTATION:
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1932 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1933 * Perform the subtraction of the two 16 bit input variable with
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1934 * saturation.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1935 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1936 * swOut = var1 - var2
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1937 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1938 * swOut is set to 0x7fff if the operation results in an
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1939 * overflow. swOut is set to 0x8000 if the operation results
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1940 * in an underflow.
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1941 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1942 * KEYWORDS: sub, subtraction
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1943 *
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1944 *************************************************************************/
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1945 Shortword sub(Shortword var1, Shortword var2)
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1946 {
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1947 Longword L_diff;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1948 Shortword swOut;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1949
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1950 L_diff = (Longword) var1 - var2;
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1951 swOut = saturate(L_diff);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1952
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1953 return (swOut);
66fb1fd032e6 libgsmhr1/mathhalf.[ch]: import original
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1954 }