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[/] [openrisc/] [tags/] [gnu-src/] [gcc-4.5.1/] [gcc-4.5.1-or32-1.0rc1/] [libgcc/] [config/] [libbid/] [bid64_rem.c] - Diff between revs 272 and 338

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/* Copyright (C) 2007, 2009  Free Software Foundation, Inc.
/* Copyright (C) 2007, 2009  Free Software Foundation, Inc.
 
 
This file is part of GCC.
This file is part of GCC.
 
 
GCC is free software; you can redistribute it and/or modify it under
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
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 3, or (at your option) any later
Software Foundation; either version 3, or (at your option) any later
version.
version.
 
 
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.
for more details.
 
 
Under Section 7 of GPL version 3, you are granted additional
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
3.1, as published by the Free Software Foundation.
 
 
You should have received a copy of the GNU General Public License and
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;
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
<http://www.gnu.org/licenses/>.  */
<http://www.gnu.org/licenses/>.  */
 
 
/*****************************************************************************
/*****************************************************************************
 *    BID64 remainder
 *    BID64 remainder
 *****************************************************************************
 *****************************************************************************
 *
 *
 *  Algorithm description:
 *  Algorithm description:
 *
 *
 *  if(exponent_x < exponent_y)
 *  if(exponent_x < exponent_y)
 *    scale coefficient_y so exponents are aligned
 *    scale coefficient_y so exponents are aligned
 *    perform coefficient divide (64-bit integer divide), unless
 *    perform coefficient divide (64-bit integer divide), unless
 *            coefficient_y is longer than 64 bits (clearly larger
 *            coefficient_y is longer than 64 bits (clearly larger
 *                                               than coefficient_x)
 *                                               than coefficient_x)
 *  else  // exponent_x > exponent_y
 *  else  // exponent_x > exponent_y
 *     use a loop to scale coefficient_x to 18_digits, divide by
 *     use a loop to scale coefficient_x to 18_digits, divide by
 *         coefficient_y (64-bit integer divide), calculate remainder
 *         coefficient_y (64-bit integer divide), calculate remainder
 *         as new_coefficient_x and repeat until final remainder is obtained
 *         as new_coefficient_x and repeat until final remainder is obtained
 *         (when new_exponent_x < exponent_y)
 *         (when new_exponent_x < exponent_y)
 *
 *
 ****************************************************************************/
 ****************************************************************************/
 
 
#include "bid_internal.h"
#include "bid_internal.h"
 
 
#define MAX_FORMAT_DIGITS     16
#define MAX_FORMAT_DIGITS     16
#define DECIMAL_EXPONENT_BIAS 398
#define DECIMAL_EXPONENT_BIAS 398
#define MASK_BINARY_EXPONENT  0x7ff0000000000000ull
#define MASK_BINARY_EXPONENT  0x7ff0000000000000ull
#define BINARY_EXPONENT_BIAS  0x3ff
#define BINARY_EXPONENT_BIAS  0x3ff
#define UPPER_EXPON_LIMIT     51
#define UPPER_EXPON_LIMIT     51
 
 
#if DECIMAL_CALL_BY_REFERENCE
#if DECIMAL_CALL_BY_REFERENCE
 
 
void
void
bid64_rem (UINT64 * pres, UINT64 * px,
bid64_rem (UINT64 * pres, UINT64 * px,
           UINT64 *
           UINT64 *
           py _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
           py _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
  UINT64 x, y;
  UINT64 x, y;
#else
#else
 
 
UINT64
UINT64
bid64_rem (UINT64 x,
bid64_rem (UINT64 x,
           UINT64 y _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
           UINT64 y _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
#endif
#endif
  UINT128 CY;
  UINT128 CY;
  UINT64 sign_x, sign_y, coefficient_x, coefficient_y, res;
  UINT64 sign_x, sign_y, coefficient_x, coefficient_y, res;
  UINT64 Q, R, R2, T, valid_y, valid_x;
  UINT64 Q, R, R2, T, valid_y, valid_x;
  int_float tempx;
  int_float tempx;
  int exponent_x, exponent_y, bin_expon, e_scale;
  int exponent_x, exponent_y, bin_expon, e_scale;
  int digits_x, diff_expon;
  int digits_x, diff_expon;
 
 
#if DECIMAL_CALL_BY_REFERENCE
#if DECIMAL_CALL_BY_REFERENCE
  x = *px;
  x = *px;
  y = *py;
  y = *py;
#endif
#endif
 
 
  valid_y = unpack_BID64 (&sign_y, &exponent_y, &coefficient_y, y);
  valid_y = unpack_BID64 (&sign_y, &exponent_y, &coefficient_y, y);
  valid_x = unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x);
  valid_x = unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x);
 
 
  // unpack arguments, check for NaN or Infinity
  // unpack arguments, check for NaN or Infinity
  if (!valid_x) {
  if (!valid_x) {
    // x is Inf. or NaN or 0
    // x is Inf. or NaN or 0
#ifdef SET_STATUS_FLAGS
#ifdef SET_STATUS_FLAGS
    if ((y & SNAN_MASK64) == SNAN_MASK64)       // y is sNaN
    if ((y & SNAN_MASK64) == SNAN_MASK64)       // y is sNaN
      __set_status_flags (pfpsf, INVALID_EXCEPTION);
      __set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
#endif
 
 
    // test if x is NaN
    // test if x is NaN
    if ((x & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
    if ((x & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
#ifdef SET_STATUS_FLAGS
#ifdef SET_STATUS_FLAGS
      if (((x & SNAN_MASK64) == SNAN_MASK64))
      if (((x & SNAN_MASK64) == SNAN_MASK64))
        __set_status_flags (pfpsf, INVALID_EXCEPTION);
        __set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
#endif
      res = coefficient_x & QUIET_MASK64;;
      res = coefficient_x & QUIET_MASK64;;
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
    // x is Infinity?
    // x is Infinity?
    if ((x & 0x7800000000000000ull) == 0x7800000000000000ull) {
    if ((x & 0x7800000000000000ull) == 0x7800000000000000ull) {
      if (((y & NAN_MASK64) != NAN_MASK64)) {
      if (((y & NAN_MASK64) != NAN_MASK64)) {
#ifdef SET_STATUS_FLAGS
#ifdef SET_STATUS_FLAGS
        __set_status_flags (pfpsf, INVALID_EXCEPTION);
        __set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
#endif
        // return NaN
        // return NaN
        res = 0x7c00000000000000ull;
        res = 0x7c00000000000000ull;
        BID_RETURN (res);
        BID_RETURN (res);
      }
      }
    }
    }
    // x is 0
    // x is 0
    // return x if y != 0
    // return x if y != 0
    if (((y & 0x7800000000000000ull) < 0x7800000000000000ull) &&
    if (((y & 0x7800000000000000ull) < 0x7800000000000000ull) &&
        coefficient_y) {
        coefficient_y) {
      if ((y & 0x6000000000000000ull) == 0x6000000000000000ull)
      if ((y & 0x6000000000000000ull) == 0x6000000000000000ull)
        exponent_y = (y >> 51) & 0x3ff;
        exponent_y = (y >> 51) & 0x3ff;
      else
      else
        exponent_y = (y >> 53) & 0x3ff;
        exponent_y = (y >> 53) & 0x3ff;
 
 
      if (exponent_y < exponent_x)
      if (exponent_y < exponent_x)
        exponent_x = exponent_y;
        exponent_x = exponent_y;
 
 
      x = exponent_x;
      x = exponent_x;
      x <<= 53;
      x <<= 53;
 
 
      res = x | sign_x;
      res = x | sign_x;
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
 
 
  }
  }
  if (!valid_y) {
  if (!valid_y) {
    // y is Inf. or NaN
    // y is Inf. or NaN
 
 
    // test if y is NaN
    // test if y is NaN
    if ((y & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
    if ((y & 0x7c00000000000000ull) == 0x7c00000000000000ull) {
#ifdef SET_STATUS_FLAGS
#ifdef SET_STATUS_FLAGS
      if (((y & SNAN_MASK64) == SNAN_MASK64))
      if (((y & SNAN_MASK64) == SNAN_MASK64))
        __set_status_flags (pfpsf, INVALID_EXCEPTION);
        __set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
#endif
      res = coefficient_y & QUIET_MASK64;;
      res = coefficient_y & QUIET_MASK64;;
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
    // y is Infinity?
    // y is Infinity?
    if ((y & 0x7800000000000000ull) == 0x7800000000000000ull) {
    if ((y & 0x7800000000000000ull) == 0x7800000000000000ull) {
      res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
      res = very_fast_get_BID64 (sign_x, exponent_x, coefficient_x);
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
    // y is 0, return NaN
    // y is 0, return NaN
    {
    {
#ifdef SET_STATUS_FLAGS
#ifdef SET_STATUS_FLAGS
      __set_status_flags (pfpsf, INVALID_EXCEPTION);
      __set_status_flags (pfpsf, INVALID_EXCEPTION);
#endif
#endif
      res = 0x7c00000000000000ull;
      res = 0x7c00000000000000ull;
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
  }
  }
 
 
 
 
  diff_expon = exponent_x - exponent_y;
  diff_expon = exponent_x - exponent_y;
  if (diff_expon <= 0) {
  if (diff_expon <= 0) {
    diff_expon = -diff_expon;
    diff_expon = -diff_expon;
 
 
    if (diff_expon > 16) {
    if (diff_expon > 16) {
      // |x|<|y| in this case
      // |x|<|y| in this case
      res = x;
      res = x;
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
    // set exponent of y to exponent_x, scale coefficient_y
    // set exponent of y to exponent_x, scale coefficient_y
    T = power10_table_128[diff_expon].w[0];
    T = power10_table_128[diff_expon].w[0];
    __mul_64x64_to_128 (CY, coefficient_y, T);
    __mul_64x64_to_128 (CY, coefficient_y, T);
 
 
    if (CY.w[1] || CY.w[0] > (coefficient_x << 1)) {
    if (CY.w[1] || CY.w[0] > (coefficient_x << 1)) {
      res = x;
      res = x;
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
 
 
    Q = coefficient_x / CY.w[0];
    Q = coefficient_x / CY.w[0];
    R = coefficient_x - Q * CY.w[0];
    R = coefficient_x - Q * CY.w[0];
 
 
    R2 = R + R;
    R2 = R + R;
    if (R2 > CY.w[0] || (R2 == CY.w[0] && (Q & 1))) {
    if (R2 > CY.w[0] || (R2 == CY.w[0] && (Q & 1))) {
      R = CY.w[0] - R;
      R = CY.w[0] - R;
      sign_x ^= 0x8000000000000000ull;
      sign_x ^= 0x8000000000000000ull;
    }
    }
 
 
    res = very_fast_get_BID64 (sign_x, exponent_x, R);
    res = very_fast_get_BID64 (sign_x, exponent_x, R);
    BID_RETURN (res);
    BID_RETURN (res);
  }
  }
 
 
 
 
  while (diff_expon > 0) {
  while (diff_expon > 0) {
    // get number of digits in coeff_x
    // get number of digits in coeff_x
    tempx.d = (float) coefficient_x;
    tempx.d = (float) coefficient_x;
    bin_expon = ((tempx.i >> 23) & 0xff) - 0x7f;
    bin_expon = ((tempx.i >> 23) & 0xff) - 0x7f;
    digits_x = estimate_decimal_digits[bin_expon];
    digits_x = estimate_decimal_digits[bin_expon];
    // will not use this test, dividend will have 18 or 19 digits
    // will not use this test, dividend will have 18 or 19 digits
    //if(coefficient_x >= power10_table_128[digits_x].w[0])
    //if(coefficient_x >= power10_table_128[digits_x].w[0])
    //      digits_x++;
    //      digits_x++;
 
 
    e_scale = 18 - digits_x;
    e_scale = 18 - digits_x;
    if (diff_expon >= e_scale) {
    if (diff_expon >= e_scale) {
      diff_expon -= e_scale;
      diff_expon -= e_scale;
    } else {
    } else {
      e_scale = diff_expon;
      e_scale = diff_expon;
      diff_expon = 0;
      diff_expon = 0;
    }
    }
 
 
    // scale dividend to 18 or 19 digits
    // scale dividend to 18 or 19 digits
    coefficient_x *= power10_table_128[e_scale].w[0];
    coefficient_x *= power10_table_128[e_scale].w[0];
 
 
    // quotient
    // quotient
    Q = coefficient_x / coefficient_y;
    Q = coefficient_x / coefficient_y;
    // remainder
    // remainder
    coefficient_x -= Q * coefficient_y;
    coefficient_x -= Q * coefficient_y;
 
 
    // check for remainder == 0
    // check for remainder == 0
    if (!coefficient_x) {
    if (!coefficient_x) {
      res = very_fast_get_BID64_small_mantissa (sign_x, exponent_y, 0);
      res = very_fast_get_BID64_small_mantissa (sign_x, exponent_y, 0);
      BID_RETURN (res);
      BID_RETURN (res);
    }
    }
  }
  }
 
 
  R2 = coefficient_x + coefficient_x;
  R2 = coefficient_x + coefficient_x;
  if (R2 > coefficient_y || (R2 == coefficient_y && (Q & 1))) {
  if (R2 > coefficient_y || (R2 == coefficient_y && (Q & 1))) {
    coefficient_x = coefficient_y - coefficient_x;
    coefficient_x = coefficient_y - coefficient_x;
    sign_x ^= 0x8000000000000000ull;
    sign_x ^= 0x8000000000000000ull;
  }
  }
 
 
  res = very_fast_get_BID64 (sign_x, exponent_y, coefficient_x);
  res = very_fast_get_BID64 (sign_x, exponent_y, coefficient_x);
  BID_RETURN (res);
  BID_RETURN (res);
 
 
}
}
 
 

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