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- /* Copyright (C) 2007-2022 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/>. */
- #include "bid_internal.h"
- #define MAX_FORMAT_DIGITS 16
- #define DECIMAL_EXPONENT_BIAS 398
- #define MAX_DECIMAL_EXPONENT 767
- #if DECIMAL_CALL_BY_REFERENCE
- void
- bid64_quantize (UINT64 * pres, UINT64 * px,
- UINT64 *
- py _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
- _EXC_INFO_PARAM) {
- UINT64 x, y;
- #else
- UINT64
- bid64_quantize (UINT64 x,
- UINT64 y _RND_MODE_PARAM _EXC_FLAGS_PARAM
- _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
- #endif
- UINT128 CT;
- UINT64 sign_x, sign_y, coefficient_x, coefficient_y, remainder_h, C64,
- valid_x;
- UINT64 tmp, carry, res;
- int_float tempx;
- int exponent_x, exponent_y, digits_x, extra_digits, amount, amount2;
- int expon_diff, total_digits, bin_expon_cx;
- unsigned rmode, status;
- #if DECIMAL_CALL_BY_REFERENCE
- #if !DECIMAL_GLOBAL_ROUNDING
- _IDEC_round rnd_mode = *prnd_mode;
- #endif
- x = *px;
- y = *py;
- #endif
- valid_x = unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x);
- // unpack arguments, check for NaN or Infinity
- if (!unpack_BID64 (&sign_y, &exponent_y, &coefficient_y, y)) {
- // Inf. or NaN or 0
- #ifdef SET_STATUS_FLAGS
- if ((x & SNAN_MASK64) == SNAN_MASK64) // y is sNaN
- __set_status_flags (pfpsf, INVALID_EXCEPTION);
- #endif
- // x=Inf, y=Inf?
- if (((coefficient_x << 1) == 0xf000000000000000ull)
- && ((coefficient_y << 1) == 0xf000000000000000ull)) {
- res = coefficient_x;
- BID_RETURN (res);
- }
- // Inf or NaN?
- if ((y & 0x7800000000000000ull) == 0x7800000000000000ull) {
- #ifdef SET_STATUS_FLAGS
- if (((y & 0x7e00000000000000ull) == 0x7e00000000000000ull) // sNaN
- || (((y & 0x7c00000000000000ull) == 0x7800000000000000ull) && //Inf
- ((x & 0x7c00000000000000ull) < 0x7800000000000000ull)))
- __set_status_flags (pfpsf, INVALID_EXCEPTION);
- #endif
- if ((y & NAN_MASK64) != NAN_MASK64)
- coefficient_y = 0;
- if ((x & NAN_MASK64) != NAN_MASK64) {
- res = 0x7c00000000000000ull | (coefficient_y & QUIET_MASK64);
- if (((y & NAN_MASK64) != NAN_MASK64) && ((x & NAN_MASK64) == 0x7800000000000000ull))
- res = x;
- BID_RETURN (res);
- }
- }
- }
- // unpack arguments, check for NaN or Infinity
- if (!valid_x) {
- // x is Inf. or NaN or 0
- // Inf or NaN?
- if ((x & 0x7800000000000000ull) == 0x7800000000000000ull) {
- #ifdef SET_STATUS_FLAGS
- if (((x & 0x7e00000000000000ull) == 0x7e00000000000000ull) // sNaN
- || ((x & 0x7c00000000000000ull) == 0x7800000000000000ull)) //Inf
- __set_status_flags (pfpsf, INVALID_EXCEPTION);
- #endif
- if ((x & NAN_MASK64) != NAN_MASK64)
- coefficient_x = 0;
- res = 0x7c00000000000000ull | (coefficient_x & QUIET_MASK64);
- BID_RETURN (res);
- }
- res = very_fast_get_BID64_small_mantissa (sign_x, exponent_y, 0);
- BID_RETURN (res);
- }
- // get number of decimal digits in coefficient_x
- tempx.d = (float) coefficient_x;
- bin_expon_cx = ((tempx.i >> 23) & 0xff) - 0x7f;
- digits_x = estimate_decimal_digits[bin_expon_cx];
- if (coefficient_x >= power10_table_128[digits_x].w[0])
- digits_x++;
- expon_diff = exponent_x - exponent_y;
- total_digits = digits_x + expon_diff;
- // check range of scaled coefficient
- if ((UINT32) (total_digits + 1) <= 17) {
- if (expon_diff >= 0) {
- coefficient_x *= power10_table_128[expon_diff].w[0];
- res = very_fast_get_BID64 (sign_x, exponent_y, coefficient_x);
- BID_RETURN (res);
- }
- // must round off -expon_diff digits
- extra_digits = -expon_diff;
- #ifndef IEEE_ROUND_NEAREST_TIES_AWAY
- #ifndef IEEE_ROUND_NEAREST
- rmode = rnd_mode;
- if (sign_x && (unsigned) (rmode - 1) < 2)
- rmode = 3 - rmode;
- #else
- rmode = 0;
- #endif
- #else
- rmode = 0;
- #endif
- coefficient_x += round_const_table[rmode][extra_digits];
- // get P*(2^M[extra_digits])/10^extra_digits
- __mul_64x64_to_128 (CT, coefficient_x,
- reciprocals10_64[extra_digits]);
- // now get P/10^extra_digits: shift C64 right by M[extra_digits]-128
- amount = short_recip_scale[extra_digits];
- C64 = CT.w[1] >> amount;
- #ifndef IEEE_ROUND_NEAREST_TIES_AWAY
- #ifndef IEEE_ROUND_NEAREST
- if (rnd_mode == 0)
- #endif
- if (C64 & 1) {
- // check whether fractional part of initial_P/10^extra_digits
- // is exactly .5
- // this is the same as fractional part of
- // (initial_P + 0.5*10^extra_digits)/10^extra_digits is exactly zero
- // get remainder
- amount2 = 64 - amount;
- remainder_h = 0;
- remainder_h--;
- remainder_h >>= amount2;
- remainder_h = remainder_h & CT.w[1];
- // test whether fractional part is 0
- if (!remainder_h && (CT.w[0] < reciprocals10_64[extra_digits])) {
- C64--;
- }
- }
- #endif
- #ifdef SET_STATUS_FLAGS
- status = INEXACT_EXCEPTION;
- // get remainder
- remainder_h = CT.w[1] << (64 - amount);
- switch (rmode) {
- case ROUNDING_TO_NEAREST:
- case ROUNDING_TIES_AWAY:
- // test whether fractional part is 0
- if ((remainder_h == 0x8000000000000000ull)
- && (CT.w[0] < reciprocals10_64[extra_digits]))
- status = EXACT_STATUS;
- break;
- case ROUNDING_DOWN:
- case ROUNDING_TO_ZERO:
- if (!remainder_h && (CT.w[0] < reciprocals10_64[extra_digits]))
- status = EXACT_STATUS;
- //if(!C64 && rmode==ROUNDING_DOWN) sign_s=sign_y;
- break;
- default:
- // round up
- __add_carry_out (tmp, carry, CT.w[0],
- reciprocals10_64[extra_digits]);
- if ((remainder_h >> (64 - amount)) + carry >=
- (((UINT64) 1) << amount))
- status = EXACT_STATUS;
- break;
- }
- __set_status_flags (pfpsf, status);
- #endif
- res = very_fast_get_BID64_small_mantissa (sign_x, exponent_y, C64);
- BID_RETURN (res);
- }
- if (total_digits < 0) {
- #ifdef SET_STATUS_FLAGS
- __set_status_flags (pfpsf, INEXACT_EXCEPTION);
- #endif
- C64 = 0;
- #ifndef IEEE_ROUND_NEAREST_TIES_AWAY
- #ifndef IEEE_ROUND_NEAREST
- rmode = rnd_mode;
- if (sign_x && (unsigned) (rmode - 1) < 2)
- rmode = 3 - rmode;
- if (rmode == ROUNDING_UP)
- C64 = 1;
- #endif
- #endif
- res = very_fast_get_BID64_small_mantissa (sign_x, exponent_y, C64);
- BID_RETURN (res);
- }
- // else more than 16 digits in coefficient
- #ifdef SET_STATUS_FLAGS
- __set_status_flags (pfpsf, INVALID_EXCEPTION);
- #endif
- res = 0x7c00000000000000ull;
- BID_RETURN (res);
- }
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