view libgsmefr/basic_op.h @ 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 9b05bbc23b8a
children
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/*
 * This version of basic_op.h for GSM-EFR codec has been created at
 * Themyscira Wireless with the aim of performance improvement.
 * The original version contained only function declarations,
 * resulting in a function call for every elementary operation;
 * the present version implements most of these operations as inline
 * functions.  (Further update: for extra speed-up, some inline
 * function implementations have been lifted from PacketVideo AMR
 * version, aka libopencore-amrnb.)
 *
 * Elimination of Overflow flag: examination of EFR code reveals that
 * both Carry and Overflow flags are accessed outside of basicop2.c
 * only in g_pitch.c, as part of a code sequence that uses L_macNs.
 * Since the Overflow flag is not checked anywhere else, we can eliminate
 * its setting from all other elementary operation functions, saving
 * some cycles and code size.
 *
 * Non-portability: we assume real target machines, not hypothetical
 * ones.  Specifically, we assume that >> does an arithmetic right shift
 * (sign bit fill).
 */

/* for the few functions that still use them */
extern __thread Flag Overflow;
extern __thread Flag Carry;

#define MAX_32 (Word32)0x7fffffff
#define MIN_32 (Word32)0x80000000

#define MAX_16 (Word16)0x7fff
#define MIN_16 (Word16)0x8000

/* likely and unlikely conditional paths */

#define	likely(x)	__builtin_expect(!!(x), 1)
#define	unlikely(x)	__builtin_expect(!!(x), 0)

/* Word16 operations */

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : add                                                     |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Performs the addition (var1+var2) with overflow control and saturation;|
 |    the 16 bit result is set at +32767 when overflow occurs or at -32768   |
 |    when underflow occurs.                                                 |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   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.                |
 |___________________________________________________________________________|
*/

static inline Word16 add (Word16 var1, Word16 var2)
{
    Word32 L_sum;

    L_sum = (Word32) var1 + var2;
    if (unlikely(L_sum > MAX_16))
        return MAX_16;
    else if (unlikely(L_sum < MIN_16))
        return MIN_16;
    else
        return L_sum;
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : sub                                                     |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Performs the subtraction (var1+var2) with overflow control and satu-   |
 |    ration; the 16 bit result is set at +32767 when overflow occurs or at  |
 |    -32768 when underflow occurs.                                          |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   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.                |
 |___________________________________________________________________________|
*/

static inline Word16 sub (Word16 var1, Word16 var2)
{
    Word32 L_diff;

    L_diff = (Word32) var1 - var2;
    if (unlikely(L_diff > MAX_16))
        return MAX_16;
    else if (unlikely(L_diff < MIN_16))
        return MIN_16;
    else
        return L_diff;
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : abs_s                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Absolute value of var1; abs_s(-32768) = 32767.                         |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             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 0000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/

static inline Word16 abs_s (Word16 var1)
{
    Word16 y = var1 - (var1 < 0);
    y = y ^ (y >> 15);
    return (y);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : shl                                                     |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Arithmetically shift the 16 bit input var1 left var2 positions.Zero fill|
 |   the var2 LSB of the result. If var2 is negative, arithmetically shift   |
 |   var1 right by -var2 with sign extension. Saturate the result in case of |
 |   underflows or overflows.                                                |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   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.                |
 |___________________________________________________________________________|
*/

static inline Word16 shl (Word16 var1, Word16 var2)
{
    Word16 var_out;

    if (unlikely(var2 < 0)) {
        if (unlikely(var2 < -15))
            var2 = -15;
        var2 = -var2;
        var_out = var1 >> var2;
    } else {
        if (unlikely(var2 > 15))
            var2 = 15;
        var_out = var1 << var2;
        if (unlikely(var_out >> var2 != var1))
        {
            var_out = (var1 >> 15) ^ MAX_16;
        }
    }
    return var_out;
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : shr                                                     |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Arithmetically shift the 16 bit input var1 right var2 positions with    |
 |   sign extension. If var2 is negative, arithmetically shift var1 left by  |
 |   -var2 with sign extension. Saturate the result in case of underflows or |
 |   overflows.                                                              |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   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.                |
 |___________________________________________________________________________|
*/

static inline Word16 shr (Word16 var1, Word16 var2)
{
    Word16 var_out;

    if (unlikely(var2 < 0)) {
        if (unlikely(var2 < -15))
            var2 = -15;
        var2 = -var2;
        var_out = var1 << var2;
        if (unlikely(var_out >> var2 != var1))
        {
            var_out = (var1 >> 15) ^ MAX_16;
        }
    } else {
        if (unlikely(var2 > 15))
            var2 = 15;
        var_out = var1 >> var2;
    }
    return var_out;
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : mult                                                    |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Performs the multiplication of var1 by var2 and gives a 16 bit result  |
 |    which is scaled i.e.:                                                  |
 |             mult(var1,var2) = extract_l(L_shr((var1 times var2),15)) and  |
 |             mult(-32768,-32768) = 32767.                                  |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   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.                |
 |___________________________________________________________________________|
*/

static inline Word16 mult (Word16 var1, Word16 var2)
{
    register Word32 product;

    product = ((Word32) var1 * var2) >> 15;

    /* Saturate result (if necessary). */
    /* var1 * var2 >0x00007fff is the only case */
    /* that saturation occurs. */

    if (unlikely(product > 0x00007fff))
        product = (Word32) MAX_16;

    /* Return the product as a 16 bit value by type casting Word32 to Word16 */

    return ((Word16) product);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : negate                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Negate var1 with saturation, saturate in the case where input is -32768:|
 |                negate(var1) = sub(0,var1).                                |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             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.                |
 |___________________________________________________________________________|
*/

static inline Word16 negate (Word16 var1)
{
    Word16 var_out;

    var_out = (var1 == MIN_16) ? MAX_16 : -var1;
    return (var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : extract_h                                               |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Return the 16 MSB of L_var1.                                            |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1                                                                 |
 |             32 bit long signed integer (Word32 ) whose value falls in the |
 |             range : 0x8000 0000 <= L_var1 <= 0x7fff ffff.                 |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/

static inline Word16 extract_h (Word32 L_var1)
{
    Word16 var_out;

    var_out = (Word16) (L_var1 >> 16);
    return (var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : extract_l                                               |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Return the 16 LSB of L_var1.                                            |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1                                                                 |
 |             32 bit long signed integer (Word32 ) whose value falls in the |
 |             range : 0x8000 0000 <= L_var1 <= 0x7fff ffff.                 |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/

static inline Word16 extract_l (Word32 L_var1)
{
    Word16 var_out;

    var_out = (Word16) L_var1;
    return (var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : round                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Round the lower 16 bits of the 32 bit input number into the MS 16 bits  |
 |   with saturation. Shift the resulting bits right by 16 and return the 16 |
 |   bit number:                                                             |
 |               round(L_var1) = extract_h(L_add(L_var1,32768))              |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1                                                                 |
 |             32 bit long signed integer (Word32 ) whose value falls in the |
 |             range : 0x8000 0000 <= L_var1 <= 0x7fff ffff.                 |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0xffff 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/

static inline Word16 round (Word32 L_var1)
{
    if (unlikely(L_var1 >= 0x7fff8000))
        return MAX_16;
    else
        return (L_var1 + 0x8000) >> 16;
}

/* Word32 operations */

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_add                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   32 bits addition of the two 32 bits variables (L_var1+L_var2) with      |
 |   overflow control and saturation; the result is set at +2147483647 when  |
 |   overflow occurs or at -2147483648 when underflow occurs.                |
 |                                                                           |
 |   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.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_add (Word32 L_var1, Word32 L_var2)
{
    Word32 L_var_out;

    L_var_out = L_var1 + L_var2;

    if (((L_var1 ^ L_var2) & MIN_32) == 0)
    {
        if ((L_var_out ^ L_var1) & MIN_32)
        {
            L_var_out = (L_var1 < 0) ? MIN_32 : MAX_32;
        }
    }
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_sub                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   32 bits subtraction of the two 32 bits variables (L_var1-L_var2) with   |
 |   overflow control and saturation; the result is set at +2147483647 when  |
 |   overflow occurs or at -2147483648 when underflow occurs.                |
 |                                                                           |
 |   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.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_sub (Word32 L_var1, Word32 L_var2)
{
    Word32 L_var_out;

    L_var_out = L_var1 - L_var2;

    if (((L_var1 ^ L_var2) & MIN_32) != 0)
    {
        if ((L_var_out ^ L_var1) & MIN_32)
        {
            L_var_out = (L_var1 < 0) ? MIN_32 : MAX_32;
        }
    }
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_mult                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   L_mult is the 32 bit result of the multiplication of var1 times var2    |
 |   with one shift left i.e.:                                               |
 |        L_mult(var1,var2) = L_shl((var1 times var2),1) and                   |
 |        L_mult(-32768,-32768) = 2147483647.                                |
 |                                                                           |
 |   Complexity weight : 1                                                   |
 |                                                                           |
 |   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 :                                                          |
 |                                                                           |
 |    L_var_out                                                              |
 |             32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var_out <= 0x7fff ffff.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_mult (Word16 var1, Word16 var2)
{
    register Word32 L_product;

    L_product = (Word32) var1 * var2;

    if (likely(L_product != (Word32) 0x40000000))
    {
        L_product <<= 1;          /* Multiply by 2 */
    }
    else
    {
        Overflow = 1;
        L_product = MAX_32;
    }

    return (L_product);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_mac                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Multiply var1 by var2 and shift the result left by 1. Add the 32 bit    |
 |   result to L_var3 with saturation, return a 32 bit result:               |
 |        L_mac(L_var3,var1,var2) = L_add(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.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_mac (Word32 L_var3, Word16 var1, Word16 var2)
{
    Word32 L_var_out;
    Word32 L_product;

    L_product = L_mult (var1, var2);
    L_var_out = L_add (L_var3, L_product);
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_msu                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Multiply var1 by var2 and shift the result left by 1. Subtract the 32   |
 |   bit result to L_var3 with saturation, return a 32 bit result:           |
 |        L_msu(L_var3,var1,var2) = L_sub(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.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_msu (Word32 L_var3, Word16 var1, Word16 var2)
{
    Word32 L_var_out;
    Word32 L_product;

    L_product = L_mult (var1, var2);
    L_var_out = L_sub (L_var3, L_product);
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_negate                                                |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Negate the 32 bit variable L_var1 with saturation; saturate in the case |
 |   where input is -2147483648 (0x8000 0000).                               |
 |                                                                           |
 |   Complexity weight : 2                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1   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.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_negate (Word32 L_var1)
{
    Word32 L_var_out;

    L_var_out = (L_var1 == MIN_32) ? MAX_32 : -L_var1;
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_shl                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Arithmetically shift the 32 bit input L_var1 left var2 positions. Zero  |
 |   fill the var2 LSB of the result. If var2 is negative, arithmetically    |
 |   shift L_var1 right by -var2 with sign extension. Saturate the result in |
 |   case of underflows or overflows.                                        |
 |                                                                           |
 |   Complexity weight : 2                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1   32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var3 <= 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 <= L_var_out <= 0x7fff ffff.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_shl (Word32 L_var1, Word16 var2)
{
    Word32 L_var_out;

    if (unlikely(var2 < 0)) {
        if (unlikely(var2 < -31))
            var2 = -31;
        var2 = -var2;
        L_var_out = L_var1 >> var2;
    } else {
        if (unlikely(var2 > 31))
            var2 = 31;
        L_var_out = L_var1 << var2;
        if (unlikely(L_var_out >> var2 != L_var1))
            L_var_out = (L_var1 >> 31) ^ MAX_32;
    }
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_shr                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Arithmetically shift the 32 bit input L_var1 right var2 positions with  |
 |   sign extension. If var2 is negative, arithmetically shift L_var1 left   |
 |   by -var2 and zero fill the -var2 LSB of the result. Saturate the result |
 |   in case of underflows or overflows.                                     |
 |                                                                           |
 |   Complexity weight : 2                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1   32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= L_var3 <= 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 <= L_var_out <= 0x7fff ffff.              |
 |___________________________________________________________________________|
*/

static inline Word32 L_shr (Word32 L_var1, Word16 var2)
{
    Word32 L_var_out;

    if (unlikely(var2 < 0)) {
        if (unlikely(var2 < -31))
            var2 = -31;
        var2 = -var2;
        L_var_out = L_var1 << var2;
        if (unlikely(L_var_out >> var2 != L_var1))
            L_var_out = (L_var1 >> 31) ^ MAX_32;
    } else {
        if (unlikely(var2 > 31))
            var2 = 31;
        L_var_out = L_var1 >> var2;
    }
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_deposit_h                                             |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Deposit the 16 bit var1 into the 16 MS bits of the 32 bit output. The   |
 |   16 LS bits of the output are zeroed.                                    |
 |                                                                           |
 |   Complexity weight : 2                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             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 0000.                |
 |___________________________________________________________________________|
*/

static inline Word32 L_deposit_h (Word16 var1)
{
    Word32 L_var_out;

    L_var_out = (Word32) var1 << 16;
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_deposit_l                                             |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Deposit the 16 bit var1 into the 16 LS bits of the 32 bit output. The   |
 |   16 MS bits of the output are sign extended.                             |
 |                                                                           |
 |   Complexity weight : 2                                                   |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             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 : 0xFFFF 8000 <= var_out <= 0x0000 7fff.                |
 |___________________________________________________________________________|
*/

static inline Word32 L_deposit_l (Word16 var1)
{
    Word32 L_var_out;

    L_var_out = (Word32) var1;
    return (L_var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : L_abs                                                   |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |    Absolute value of L_var1; Saturate in case where the input is          |
 |                                                               -214783648  |
 |                                                                           |
 |   Complexity weight : 3                                                   |
 |                                                                           |
 |   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 : 0x0000 0000 <= var_out <= 0x7fff ffff.                |
 |___________________________________________________________________________|
*/

static inline Word32 L_abs (Word32 L_var1)
{
    Word32 L_var_out;

    if (L_var1 == MIN_32)
    {
        L_var_out = MAX_32;
    }
    else
    {
        if (L_var1 < 0)
        {
            L_var_out = -L_var1;
        }
        else
        {
            L_var_out = L_var1;
        }
    }

    return (L_var_out);
}

/* additional ops */

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : mult_r                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Same as mult with rounding, i.e.:                                       |
 |     mult_r(var1,var2) = extract_l(L_shr(((var1 * var2) + 16384),15)) and  |
 |     mult_r(-32768,-32768) = 32767.                                        |
 |                                                                           |
 |   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.                |
 |___________________________________________________________________________|
*/

static inline Word16 mult_r (Word16 var1, Word16 var2)
{
    Word16 var_out;
    Word32 L_product_arr;

    L_product_arr = (Word32) var1 *(Word32) var2;       /* product */
    L_product_arr += (Word32) 0x00004000L;      /* round */
    L_product_arr &= (Word32) 0xffff8000L;
    L_product_arr >>= 15;       /* shift */

    if (unlikely(L_product_arr > MAX_16))
        return MAX_16;
    else if (unlikely(L_product_arr < MIN_16))
        return MIN_16;
    else
        return L_product_arr;
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : norm_s                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Produces the number of left shift needed to normalize the 16 bit varia- |
 |   ble var1 for positive values on the interval with minimum of 16384 and  |
 |   maximum of 32767, and for negative values on the interval with minimum  |
 |   of -32768 and maximum of -16384; in order to normalize the result, the  |
 |   following operation must be done :                                      |
 |                    norm_var1 = shl(var1,norm_s(var1)).                    |
 |                                                                           |
 |   Complexity weight : 15                                                  |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    var1                                                                   |
 |             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 0000 <= var_out <= 0x0000 000f.                |
 |___________________________________________________________________________|
*/

static inline Word16 norm_s (Word16 var1)
{
    Word16 var_out;

    if (var1 == 0)
    {
        var_out = 0;
    }
    else
    {
        if (var1 == (Word16) 0xffff)
        {
            var_out = 15;
        }
        else
        {
            if (var1 < 0)
            {
                var1 = ~var1;
            }
            for (var_out = 0; var1 < 0x4000; var_out++)
            {
                var1 <<= 1;
            }
        }
    }

    return (var_out);
}

/*___________________________________________________________________________
 |                                                                           |
 |   Function Name : norm_l                                                  |
 |                                                                           |
 |   Purpose :                                                               |
 |                                                                           |
 |   Produces the number of left shifts needed to normalize the 32 bit varia-|
 |   ble L_var1 for positive values on the interval with minimum of          |
 |   1073741824 and maximum of 2147483647, and for negative values on the in-|
 |   terval with minimum of -2147483648 and maximum of -1073741824; in order |
 |   to normalize the result, the following operation must be done :         |
 |                   norm_L_var1 = L_shl(L_var1,norm_l(L_var1)).             |
 |                                                                           |
 |   Complexity weight : 30                                                  |
 |                                                                           |
 |   Inputs :                                                                |
 |                                                                           |
 |    L_var1                                                                 |
 |             32 bit long signed integer (Word32) whose value falls in the  |
 |             range : 0x8000 0000 <= var1 <= 0x7fff ffff.                   |
 |                                                                           |
 |   Outputs :                                                               |
 |                                                                           |
 |    none                                                                   |
 |                                                                           |
 |   Return Value :                                                          |
 |                                                                           |
 |    var_out                                                                |
 |             16 bit short signed integer (Word16) whose value falls in the |
 |             range : 0x0000 0000 <= var_out <= 0x0000 001f.                |
 |___________________________________________________________________________|
*/

static inline Word16 norm_l (Word32 L_var1)
{
    Word16 var_out;

    if (L_var1 == 0)
    {
        var_out = 0;
    }
    else
    {
        if (L_var1 == (Word32) 0xffffffffL)
        {
            var_out = 31;
        }
        else
        {
            if (L_var1 < 0)
            {
                L_var1 = ~L_var1;
            }
            for (var_out = 0; L_var1 < (Word32) 0x40000000L; var_out++)
            {
                L_var1 <<= 1;
            }
        }
    }

    return (var_out);
}

/* ETSI functions that aren't inlined */

Word32 L_macNs (Word32 L_var3, Word16 var1, Word16 var2); /* Mac without
                                                             sat, 1   */
Word32 L_msuNs (Word32 L_var3, Word16 var1, Word16 var2); /* Msu without
                                                             sat, 1   */
Word32 L_add_c (Word32 L_var1, Word32 L_var2);  /* Long add with c, 2 */
Word32 L_sub_c (Word32 L_var1, Word32 L_var2);  /* Long sub with c, 2 */
Word16 shr_r (Word16 var1, Word16 var2);        /* Shift right with
                                                   round, 2           */
Word16 mac_r (Word32 L_var3, Word16 var1, Word16 var2); /* Mac with
                                                           rounding,2 */
Word16 msu_r (Word32 L_var3, Word16 var1, Word16 var2); /* Msu with
                                                           rounding,2 */
Word32 L_shr_r (Word32 L_var1, Word16 var2); /* Long shift right with
                                                round,  3             */
Word32 L_sat (Word32 L_var1);            /* Long saturation,       4  */
Word16 div_s (Word16 var1, Word16 var2); /* Short division,       18  */