FreeCalypso > hg > gsm-codec-lib
view libgsmefr/basicops.c @ 467:ad032051166a
doc: AMR-EFR-hybrid-emu new article
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Sun, 12 May 2024 23:54:43 +0000 |
| parents | 1c514150c033 |
| children |
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/* * This C module is a stripped-down version made from ETSI basicop2.c, * reduced to just those functions which we are not inlining. */ /*___________________________________________________________________________ | | | Include-Files | |___________________________________________________________________________| */ #include <stdint.h> #include "typedef.h" #include "namespace.h" #include "basic_op.h" /*___________________________________________________________________________ | | | Functions | |___________________________________________________________________________| */ /*___________________________________________________________________________ | | | Function Name : L_macNs | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Add the 32 bit | | result to L_var3 without saturation, return a 32 bit result. Generate | | carry and overflow values : | | L_macNs(L_var3,var1,var2) = L_add_c(L_var3,L_mult(var1,var2)). | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_macNs (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; L_var_out = L_mult (var1, var2); L_var_out = L_add_c (L_var3, L_var_out); return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_msuNs | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Subtract the 32 | | bit result from L_var3 without saturation, return a 32 bit result. Ge- | | nerate carry and overflow values : | | L_msuNs(L_var3,var1,var2) = L_sub_c(L_var3,L_mult(var1,var2)). | | | | Complexity weight : 1 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_msuNs (Word32 L_var3, Word16 var1, Word16 var2) { Word32 L_var_out; L_var_out = L_mult (var1, var2); L_var_out = L_sub_c (L_var3, L_var_out); return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_add_c | | | | Purpose : | | | | Performs 32 bits addition of the two 32 bits variables (L_var1+L_var2+C)| | with carry. No saturation. Generate carry and Overflow values. The car- | | ry and overflow values are binary variables which can be tested and as- | | signed values. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | L_var2 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_add_c (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; Word32 L_test; Flag carry_int = 0; L_var_out = L_var1 + L_var2 + Carry; L_test = L_var1 + L_var2; if ((L_var1 > 0) && (L_var2 > 0) && (L_test < 0)) { Overflow = 1; carry_int = 0; } else { if ((L_var1 < 0) && (L_var2 < 0)) { if (L_test >= 0) { Overflow = 1; carry_int = 1; } else { Overflow = 0; carry_int = 1; } } else { if (((L_var1 ^ L_var2) < 0) && (L_test >= 0)) { Overflow = 0; carry_int = 1; } else { Overflow = 0; carry_int = 0; } } } if (Carry) { if (L_test == MAX_32) { Overflow = 1; Carry = carry_int; } else { if (L_test == (Word32) 0xFFFFFFFFL) { Carry = 1; } else { Carry = carry_int; } } } else { Carry = carry_int; } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_sub_c | | | | Purpose : | | | | Performs 32 bits subtraction of the two 32 bits variables with carry | | (borrow) : L_var1-L_var2-C. No saturation. Generate carry and Overflow | | values. The carry and overflow values are binary variables which can | | be tested and assigned values. | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var1 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | L_var2 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var_out <= 0x7fff ffff. | | | | Caution : | | | | In some cases the Carry flag has to be cleared or set before using | | operators which take into account its value. | |___________________________________________________________________________| */ Word32 L_sub_c (Word32 L_var1, Word32 L_var2) { Word32 L_var_out; Word32 L_test; Flag carry_int = 0; if (Carry) { Carry = 0; if (L_var2 != MIN_32) { L_var_out = L_add_c (L_var1, -L_var2); } else { L_var_out = L_var1 - L_var2; if (L_var1 > 0L) { Overflow = 1; Carry = 0; } } } else { L_var_out = L_var1 - L_var2 - (Word32) 0X00000001L; L_test = L_var1 - L_var2; if ((L_test < 0) && (L_var1 > 0) && (L_var2 < 0)) { Overflow = 1; carry_int = 0; } else if ((L_test > 0) && (L_var1 < 0) && (L_var2 > 0)) { Overflow = 1; carry_int = 1; } else if ((L_test > 0) && ((L_var1 ^ L_var2) > 0)) { Overflow = 0; carry_int = 1; } if (L_test == MIN_32) { Overflow = 1; Carry = carry_int; } else { Carry = carry_int; } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : shr_r | | | | Purpose : | | | | Same as shr(var1,var2) but with rounding. Saturate the result in case of| | underflows or overflows : | | - If var2 is greater than zero : | | if (sub(shl(shr(var1,var2),1),shr(var1,sub(var2,1)))) | | is equal to zero | | then | | shr_r(var1,var2) = shr(var1,var2) | | else | | shr_r(var1,var2) = add(shr(var1,var2),1) | | - If var2 is less than or equal to zero : | | shr_r(var1,var2) = shr(var1,var2). | | | | Complexity weight : 2 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ Word16 shr_r (Word16 var1, Word16 var2) { Word16 var_out; if (var2 > 15) { var_out = 0; } else { var_out = shr (var1, var2); if (var2 > 0) { if ((var1 & ((Word16) 1 << (var2 - 1))) != 0) { var_out++; } } } return (var_out); } /*___________________________________________________________________________ | | | Function Name : mac_r | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Add the 32 bit | | result to L_var3 with saturation. Round the LS 16 bits of the result | | into the MS 16 bits with saturation and shift the result right by 16. | | Return a 16 bit result. | | mac_r(L_var3,var1,var2) = round(L_mac(L_var3,var1,var2)) | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 8000 <= L_var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ Word16 mac_r (Word32 L_var3, Word16 var1, Word16 var2) { Word16 var_out; L_var3 = L_mac (L_var3, var1, var2); L_var3 = L_add (L_var3, (Word32) 0x00008000L); var_out = extract_h (L_var3); return (var_out); } /*___________________________________________________________________________ | | | Function Name : msu_r | | | | Purpose : | | | | Multiply var1 by var2 and shift the result left by 1. Subtract the 32 | | bit result to L_var3 with saturation. Round the LS 16 bits of the res- | | ult into the MS 16 bits with saturation and shift the result right by | | 16. Return a 16 bit result. | | msu_r(L_var3,var1,var2) = round(L_msu(L_var3,var1,var2)) | | | | Complexity weight : 2 | | | | Inputs : | | | | L_var3 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= L_var3 <= 0x7fff ffff. | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 8000 <= L_var_out <= 0x0000 7fff. | |___________________________________________________________________________| */ Word16 msu_r (Word32 L_var3, Word16 var1, Word16 var2) { Word16 var_out; L_var3 = L_msu (L_var3, var1, var2); L_var3 = L_add (L_var3, (Word32) 0x00008000L); var_out = extract_h (L_var3); return (var_out); } /*___________________________________________________________________________ | | | Function Name : L_shr_r | | | | Purpose : | | | | Same as L_shr(L_var1,var2) but with rounding. Saturate the result in | | case of underflows or overflows : | | - If var2 is greater than zero : | | if (L_sub(L_shl(L_shr(L_var1,var2),1),L_shr(L_var1,sub(var2,1))))| | is equal to zero | | then | | L_shr_r(L_var1,var2) = L_shr(L_var1,var2) | | else | | L_shr_r(L_var1,var2) = L_add(L_shr(L_var1,var2),1) | | - If var2 is less than or equal to zero : | | L_shr_r(L_var1,var2) = L_shr(L_var1,var2). | | | | Complexity weight : 3 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 0x7fff ffff. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0xffff 8000 <= var1 <= 0x0000 7fff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ Word32 L_shr_r (Word32 L_var1, Word16 var2) { Word32 L_var_out; if (var2 > 31) { L_var_out = 0; } else { L_var_out = L_shr (L_var1, var2); if (var2 > 0) { if ((L_var1 & ((Word32) 1 << (var2 - 1))) != 0) { L_var_out++; } } } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : L_sat | | | | Purpose : | | | | 32 bit L_var1 is set to 2147483647 if an overflow occured or to | | -2147483648 if an underflow occured on the most recent L_add_c, | | L_sub_c, L_macNs or L_msuNs operations. The carry and overflow values | | are binary values which can be tested and assigned values. | | | | Complexity weight : 4 | | | | Inputs : | | | | L_var1 | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var1 <= 0x7fff ffff. | | | | Outputs : | | | | none | | | | Return Value : | | | | L_var_out | | 32 bit long signed integer (Word32) whose value falls in the | | range : 0x8000 0000 <= var_out <= 0x7fff ffff. | |___________________________________________________________________________| */ Word32 L_sat (Word32 L_var1) { Word32 L_var_out; L_var_out = L_var1; if (Overflow) { if (Carry) { L_var_out = MIN_32; } else { L_var_out = MAX_32; } Carry = 0; Overflow = 0; } return (L_var_out); } /*___________________________________________________________________________ | | | Function Name : div_s | | | | Purpose : | | | | Produces a result which is the fractional integer division of var1 by | | var2; var1 and var2 must be positive and var2 must be greater or equal | | to var1; the result is positive (leading bit equal to 0) and truncated | | to 16 bits. | | If var1 = var2 then div(var1,var2) = 32767. | | | | Complexity weight : 18 | | | | Inputs : | | | | var1 | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var1 <= var2 and var2 != 0. | | | | var2 | | 16 bit short signed integer (Word16) whose value falls in the | | range : var1 <= var2 <= 0x0000 7fff and var2 != 0. | | | | Outputs : | | | | none | | | | Return Value : | | | | var_out | | 16 bit short signed integer (Word16) whose value falls in the | | range : 0x0000 0000 <= var_out <= 0x0000 7fff. | | It's a Q15 value (point between b15 and b14). | |___________________________________________________________________________| */ Word16 div_s (Word16 var1, Word16 var2) { Word16 var_out = 0; Word16 iteration; Word32 L_num; Word32 L_denom; #if 0 if ((var1 > var2) || (var1 < 0) || (var2 < 0)) { printf ("Division Error var1=%d var2=%d\n", var1, var2); exit (0); } if (var2 == 0) { printf ("Division by 0, Fatal error \n"); exit (0); } #endif if (var1 == 0) { var_out = 0; } else { if (var1 == var2) { var_out = MAX_16; } else { L_num = L_deposit_l (var1); L_denom = L_deposit_l (var2); for (iteration = 0; iteration < 15; iteration++) { var_out <<= 1; L_num <<= 1; if (L_num >= L_denom) { L_num = L_sub (L_num, L_denom); var_out = add (var_out, 1); } } } } return (var_out); }