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/* This is a software fixed-point library.

   Copyright (C) 2007, 2009 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under

the terms of the GNU General Public License as published by the Free

Software Foundation; either version 3, or (at your option) any later

version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY

WARRANTY; without even the implied warranty of MERCHANTABILITY or

FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

for more details.

Under Section 7 of GPL version 3, you are granted additional

permissions described in the GCC Runtime Library Exception, version

3.1, as published by the Free Software Foundation.

You should have received a copy of the GNU General Public License and

a copy of the GCC Runtime Library Exception along with this program;

see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see

<http://www.gnu.org/licenses/>.  */

/* This implements fixed-point arithmetic.

   Contributed by Chao-ying Fu  <fu@mips.com>.  */

/* To use this file, we need to define one of the following:

   QQ_MODE, UQQ_MODE, HQ_MODE, UHQ_MODE, SQ_MODE, USQ_MODE, DQ_MODE, UDQ_MODE,

   TQ_MODE, UTQ_MODE, HA_MODE, UHA_MODE, SA_MODE, USA_MODE, DA_MODE, UDA_MODE,

   TA_MODE, UTA_MODE.

   Then, all operators for this machine mode will be created.

   Or, we need to define FROM_* TO_* for conversions from one mode to another

   mode.  The mode could be one of the following:

   Fract: QQ, UQQ, HQ, UHQ, SQ, USQ, DQ, UDQ, TQ, UTQ

   Accum: HA, UHA, SA, USA, DA, UDA, TA, UTA

   Signed integer: QI, HI, SI, DI, TI

   Unsigned integer: UQI, UHI, USI, UDI, UTI

   Floating-point: SF, DF

   Ex: If we define FROM_QQ and TO_SI, the conversion from QQ to SI is

   generated.  */

#include "tconfig.h"

#include "tsystem.h"

#include "coretypes.h"

#include "tm.h"

#ifndef MIN_UNITS_PER_WORD

#define MIN_UNITS_PER_WORD UNITS_PER_WORD

#endif

#include "config/fixed-bit.h"

#if defined(FIXED_ADD) && defined(L_add)

FIXED_C_TYPE

FIXED_ADD (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  z = x + y;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_ADD */

#if defined(FIXED_SSADD) && defined(L_ssadd)

FIXED_C_TYPE

FIXED_SSADD (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  z = x + y;

  if ((((x ^ y) >> I_F_BITS) & 1) == 0)

    {

      if (((z ^ x) >> I_F_BITS) & 1)

        {

          z = 1;

          z = z << I_F_BITS;

          if (x >= 0)

            z--;

        }

    }

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_SSADD */

#if defined(FIXED_USADD) && defined(L_usadd)

FIXED_C_TYPE

FIXED_USADD (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  z = x + y;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  if (z < x || z < y) /* max */

    {

       z = -1;

#if HAVE_PADDING_BITS

       z = z << PADDING_BITS;

       z = z >> PADDING_BITS;

#endif

    }

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_USADD */

#if defined(FIXED_SUB) && defined(L_sub)

FIXED_C_TYPE

FIXED_SUB (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  z = x - y;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_SUB */

#if defined(FIXED_SSSUB) && defined(L_sssub)

FIXED_C_TYPE

FIXED_SSSUB (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  z = x - y;

  if (((x ^ y) >> I_F_BITS) & 1)

    {

      if (((z ^ x) >> I_F_BITS) & 1)

        {

          z = 1;

          z = z << I_F_BITS;

          if (x >= 0)

            z--;

        }

    }

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_SSSUB */

#if defined(FIXED_USSUB) && defined(L_ussub)

FIXED_C_TYPE

FIXED_USSUB (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  z = x - y;

  if (x < y)

    z = 0;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_USSUB */

#if defined(FIXED_SATURATE1) && defined(L_saturate1)

void

FIXED_SATURATE1 (DINT_C_TYPE *a)

{

  DINT_C_TYPE max, min;

  max = (DINT_C_TYPE)1 << I_F_BITS;

  max = max - 1;

#if MODE_UNSIGNED == 0

  min = (DINT_C_TYPE)1 << (2 * FIXED_WIDTH - 1);

  min = min >> (2 * FIXED_WIDTH - 1 - I_F_BITS);

#else

  min = 0;

#endif

  if (*a > max)

    *a = max;

  else if (*a < min)

    *a = min;

}

#endif /* FIXED_SATURATE1 */

#if defined(FIXED_SATURATE2) && defined(L_saturate2)

void

FIXED_SATURATE2 (INT_C_TYPE *high, INT_C_TYPE *low)

{

  INT_C_TYPE r_max, s_max, r_min, s_min;

  r_max = 0;

#if (MODE_UNSIGNED == 0) || HAVE_PADDING_BITS

  s_max = (INT_C_TYPE)1 << I_F_BITS;

  s_max = s_max - 1;

#else

  s_max = -1;

#endif

#if MODE_UNSIGNED == 0

  r_min = -1;

  s_min = (INT_C_TYPE)1 << (FIXED_WIDTH - 1);

  s_min = s_min >> (FIXED_WIDTH - 1 - I_F_BITS);

#else

  r_min = 0;

  s_min = 0;

#endif

  if (*high > r_max

      || (*high == r_max && (UINT_C_TYPE)(*low) > (UINT_C_TYPE)s_max))

    {

      *high = r_max;

      *low = s_max;

    }

  else if (*high < r_min ||

           (*high == r_min && (UINT_C_TYPE)(*low) < (UINT_C_TYPE)s_min))

    {

      *high = r_min;

      *low = s_min;

    }

}

#endif /* FIXED_SATURATE2 */

#if defined(FIXED_MULHELPER) && defined(L_mulhelper)

FIXED_C_TYPE

FIXED_MULHELPER (FIXED_C_TYPE a, FIXED_C_TYPE b, word_type satp)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y;

#if defined (DINT_C_TYPE)

  INT_C_TYPE z;

  DINT_C_TYPE dx, dy, dz;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  dx = (DINT_C_TYPE) x;

  dy = (DINT_C_TYPE) y;

  dz = dx * dy;

  /* Round the result by adding (1 << (FBITS -1)).  */

  dz += ((DINT_C_TYPE) 1 << (FBITS - 1));

  dz = dz >> FBITS;

  if (satp)

    FIXED_SATURATE1 (&dz);

  z = (INT_C_TYPE) dz;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

#else /* No DINT_C_TYPE */

  /* The result of multiplication expands to two INT_C_TYPE.  */

  INTunion aa, bb;

  INTunion a_high, a_low, b_high, b_low;

  INTunion high_high, high_low, low_high, low_low;

  INTunion r, s, temp1, temp2;

  INT_C_TYPE carry = 0;

  INT_C_TYPE z;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  /* Decompose a and b.  */

  aa.ll = x;

  bb.ll = y;

  a_high.s.low = aa.s.high;

  a_high.s.high = 0;

  a_low.s.low = aa.s.low;

  a_low.s.high = 0;

  b_high.s.low = bb.s.high;

  b_high.s.high = 0;

  b_low.s.low = bb.s.low;

  b_low.s.high = 0;

  /* Perform four multiplications.  */

  low_low.ll = a_low.ll * b_low.ll;

  low_high.ll = a_low.ll * b_high.ll;

  high_low.ll = a_high.ll * b_low.ll;

  high_high.ll = a_high.ll * b_high.ll;

  /* Accumulate four results to {r, s}.  */

  temp1.s.high = high_low.s.low;

  temp1.s.low = 0;

  s.ll = low_low.ll + temp1.ll;

  if ((UINT_C_TYPE) s.ll < (UINT_C_TYPE) low_low.ll

      || (UINT_C_TYPE) s.ll < (UINT_C_TYPE) temp1.ll)

    carry ++; /* Carry.  */

  temp1.ll = s.ll;

  temp2.s.high = low_high.s.low;

  temp2.s.low = 0;

  s.ll = temp1.ll + temp2.ll;

  if ((UINT_C_TYPE) s.ll < (UINT_C_TYPE) temp1.ll

      || (UINT_C_TYPE) s.ll < (UINT_C_TYPE) temp2.ll)

    carry ++; /* Carry.  */

  temp1.s.low = high_low.s.high;

  temp1.s.high = 0;

  r.ll = high_high.ll + temp1.ll;

  temp1.s.low = low_high.s.high;

  temp1.s.high = 0;

  r.ll = r.ll + temp1.ll + carry;

#if MODE_UNSIGNED == 0

  /* For signed types, we need to add neg(y) to r, if x < 0.  */

  if (x < 0)

    r.ll = r.ll - y;

  /* We need to add neg(x) to r, if y < 0.  */

  if (y < 0)

    r.ll = r.ll - x;

#endif

  /* Round the result by adding (1 << (FBITS -1)).  */

  temp1.ll = s.ll;

  s.ll += ((INT_C_TYPE) 1 << (FBITS -1));

  if ((UINT_C_TYPE) s.ll < (UINT_C_TYPE) temp1.ll

      || (UINT_C_TYPE) s.ll < (UINT_C_TYPE) ((INT_C_TYPE) 1 << (FBITS -1)))

    r.ll += 1;

  /* Shift right the result by FBITS.  */

#if FBITS == FIXED_WIDTH

  /* This happens only for unsigned types without any padding bits.

     So, it is safe to set r.ll to 0 as it is logically shifted right.  */

  s.ll = r.ll;

  r.ll = 0;

#else

  s.ll = ((UINT_C_TYPE)s.ll) >> FBITS;

  temp1.ll = r.ll << (FIXED_WIDTH - FBITS);

  s.ll = s.ll | temp1.ll;

  r.ll = r.ll >> FBITS;

#endif

  if (satp)

    FIXED_SATURATE2 (&r.ll, &s.ll);

  z = (INT_C_TYPE) s.ll;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

#endif

}

#endif /* FIXED_MULHELPER */

#if defined(FIXED_MUL) && defined(L_mul)

FIXED_C_TYPE

FIXED_MUL (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_MULHELPER (a, b, 0);

}

#endif /* FIXED_MUL */

#if defined(FIXED_SSMUL) && defined(L_ssmul)

FIXED_C_TYPE

FIXED_SSMUL (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_MULHELPER (a, b, 1);

}

#endif /* FIXED_SSMUL */

#if defined(FIXED_USMUL) && defined(L_usmul)

FIXED_C_TYPE

FIXED_USMUL (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_MULHELPER (a, b, 1);

}

#endif /* FIXED_USMUL */

#if defined(FIXED_DIVHELPER) && defined(L_divhelper)

FIXED_C_TYPE

FIXED_DIVHELPER (FIXED_C_TYPE a, FIXED_C_TYPE b, word_type satp)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y;

  INT_C_TYPE z;

#if defined (DINT_C_TYPE)

  DINT_C_TYPE dx, dy, dz;

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  dx = (DINT_C_TYPE) x;

  dy = (DINT_C_TYPE) y;

  dx = dx << FBITS;

  dz = dx / dy;

  if (satp)

    FIXED_SATURATE1 (&dz);

  z = (INT_C_TYPE) dz;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

#else /* No DINT_C_TYPE */

  INT_C_TYPE pos_a, pos_b, r, s;

  INT_C_TYPE quo_r, quo_s, mod, temp;

  word_type i;

#if MODE_UNSIGNED == 0

  word_type num_of_neg = 0;

#endif

  memcpy (&x, &a, FIXED_SIZE);

  memcpy (&y, &b, FIXED_SIZE);

  pos_a = x;

  pos_b = y;

#if MODE_UNSIGNED == 0

  /* If a < 0, negate a.  */

  if (pos_a < 0)

    {

      pos_a = -pos_a;

      num_of_neg ++;

    }

  /* If b < 0, negate b.  */

  if (pos_b < 0)

    {

      pos_b = -pos_b;

      num_of_neg ++;

    }

#endif

  /* Left shift pos_a to {r, s} by FBITS.  */

#if FBITS == FIXED_WIDTH

  /* This happens only for unsigned types without any padding bits.  */

  r = pos_a;

  s = 0;

#else

  s = pos_a << FBITS;

  r = pos_a >> (FIXED_WIDTH - FBITS);

#endif

  /* Unsigned divide r by pos_b to quo_r.  The remainder is in mod.  */

  quo_r = (UINT_C_TYPE)r / (UINT_C_TYPE)pos_b;

  mod = (UINT_C_TYPE)r % (UINT_C_TYPE)pos_b;

  quo_s = 0;

  for (i = 0; i < FIXED_WIDTH; i++)

    {

      /* Record the leftmost bit of mod.  */

      word_type leftmost_mode = (mod >> (FIXED_WIDTH - 1)) & 1;

      /* Shift left mod by 1 bit.  */

      mod = mod << 1;

      /* Test the leftmost bit of s to add to mod.  */

      if ((s >> (FIXED_WIDTH - 1)) & 1)

        mod ++;

      /* Shift left quo_s by 1 bit.  */

      quo_s = quo_s << 1;

      /* Try to calculate (mod - pos_b).  */

      temp = mod - pos_b;

      if (leftmost_mode || (UINT_C_TYPE)mod >= (UINT_C_TYPE)pos_b)

        {

          quo_s ++;

          mod = temp;

        }

      /* Shift left s by 1 bit.  */

      s = s << 1;

    }

#if MODE_UNSIGNED == 0

    if (num_of_neg == 1)

      {

        quo_s = -quo_s;

        if (quo_s == 0)

          quo_r = -quo_r;

        else

          quo_r = ~quo_r;

      }

#endif

  if (satp)

    FIXED_SATURATE2 (&quo_r, &quo_s);

  z = quo_s;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

#endif

}

#endif /* FIXED_DIVHELPER */

#if defined(FIXED_DIV) && defined(L_div)

FIXED_C_TYPE

FIXED_DIV (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_DIVHELPER (a, b, 0);

}

#endif /* FIXED_DIV */

#if defined(FIXED_UDIV) && defined(L_udiv)

FIXED_C_TYPE

FIXED_UDIV (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_DIVHELPER (a, b, 0);

}

#endif /* FIXED_UDIV */

#if defined(FIXED_SSDIV) && defined(L_ssdiv)

FIXED_C_TYPE

FIXED_SSDIV (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_DIVHELPER (a, b, 1);

}

#endif /* FIXED_SSDIV */

#if defined(FIXED_USDIV) && defined(L_usdiv)

FIXED_C_TYPE

FIXED_USDIV (FIXED_C_TYPE a, FIXED_C_TYPE b)

{

  return FIXED_DIVHELPER (a, b, 1);

}

#endif /* FIXED_USDIV */

#if defined(FIXED_NEG) && defined(L_neg)

FIXED_C_TYPE

FIXED_NEG (FIXED_C_TYPE a)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, z;

  memcpy (&x, &a, FIXED_SIZE);

  z = -x;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_NEG */

#if defined(FIXED_SSNEG) && defined(L_ssneg)

FIXED_C_TYPE

FIXED_SSNEG (FIXED_C_TYPE a)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, y, z;

  memcpy (&y, &a, FIXED_SIZE);

  x = 0;

  z = x - y;

  if (((x ^ y) >> I_F_BITS) & 1)

    {

      if (((z ^ x) >> I_F_BITS) & 1)

        {

          z = 1;

          z = z << I_F_BITS;

          if (x >= 0)

            z--;

        }

    }

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_SSNEG */

#if defined(FIXED_USNEG) && defined(L_usneg)

FIXED_C_TYPE

FIXED_USNEG (FIXED_C_TYPE a __attribute__ ((__unused__)))

{

  FIXED_C_TYPE c;

  INT_C_TYPE z;

  z = 0;

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_USNEG */

#if defined(FIXED_ASHLHELPER) && defined(L_ashlhelper)

FIXED_C_TYPE

FIXED_ASHLHELPER (FIXED_C_TYPE a, word_type b, word_type satp)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, z;

#if defined (DINT_C_TYPE)

  DINT_C_TYPE dx, dz;

  memcpy (&x, &a, FIXED_SIZE);

  dx = (DINT_C_TYPE) x;

  if (b >= FIXED_WIDTH)

    dz = dx << FIXED_WIDTH;

  else

    dz = dx << b;

  if (satp)

    FIXED_SATURATE1 (&dz);

  z = (INT_C_TYPE) dz;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

#else /* No DINT_C_TYPE */

  INT_C_TYPE r, s;

  memcpy (&x, &a, FIXED_SIZE);

  /* We need to shift left x by b bits to {r, s}.  */

  if (b >= FIXED_WIDTH)

    {

      r = b;

      s = 0;

    }

  else

    {

      s = x << b;

      r = x >> (FIXED_WIDTH - b);

    }

  if (satp)

    FIXED_SATURATE2 (&r, &s);

  z = s;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

#endif

}

#endif /* FIXED_ASHLHELPER */

#if defined(FIXED_ASHL) && defined(L_ashl)

FIXED_C_TYPE

FIXED_ASHL (FIXED_C_TYPE a, word_type b)

{

  return FIXED_ASHLHELPER (a, b, 0);

}

#endif /* FIXED_ASHL */

#if defined(FIXED_ASHR) && defined(L_ashr)

FIXED_C_TYPE

FIXED_ASHR (FIXED_C_TYPE a, word_type b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, z;

  memcpy (&x, &a, FIXED_SIZE);

  z = x >> b;

#if HAVE_PADDING_BITS

  z = z << PADDING_BITS;

  z = z >> PADDING_BITS;

#endif

  memcpy (&c, &z, FIXED_SIZE);

  return c;

}

#endif /* FIXED_ASHR */

#if defined(FIXED_LSHR) && defined(L_lshr)

FIXED_C_TYPE

FIXED_LSHR (FIXED_C_TYPE a, word_type b)

{

  FIXED_C_TYPE c;

  INT_C_TYPE x, z;

  memcpy (&x, &a, FIXED_SIZE);

  z = x >> b;

#if HAVE_PADDING_BITS