OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
1338118928
gcc/libgcc/config/libbid/bid128_next.c
Richard Sandiford ac1dca3cab Update copyright years in libgcc/ 
From-SVN: r206295
2014-01-02 22:25:22 +00:00

644 lines
22 KiB
C
Raw Blame History

/* Copyright (C) 2007-2014 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/>. */
#define BID_128RES
#include "bid_internal.h"
/*****************************************************************************
* BID128 nextup
****************************************************************************/
#if DECIMAL_CALL_BY_REFERENCE
void
bid128_nextup (UINT128 * pres,
UINT128 *
px _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
UINT128 x = *px;
#else
UINT128
bid128_nextup (UINT128 x _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
_EXC_INFO_PARAM) {
#endif
UINT128 res;
UINT64 x_sign;
UINT64 x_exp;
int exp;
BID_UI64DOUBLE tmp1;
int x_nr_bits;
int q1, ind;
UINT128 C1; // C1.w[1], C1.w[0] represent x_signif_hi, x_signif_lo (UINT64)
BID_SWAP128 (x);
// unpack the argument
x_sign = x.w[1] & MASK_SIGN; // 0 for positive, MASK_SIGN for negative
C1.w[1] = x.w[1] & MASK_COEFF;
C1.w[0] = x.w[0];
// check for NaN or Infinity
if ((x.w[1] & MASK_SPECIAL) == MASK_SPECIAL) {
// x is special
if ((x.w[1] & MASK_NAN) == MASK_NAN) { // x is NAN
// if x = NaN, then res = Q (x)
// check first for non-canonical NaN payload
if (((x.w[1] & 0x00003fffffffffffull) > 0x0000314dc6448d93ull) ||
(((x.w[1] & 0x00003fffffffffffull) == 0x0000314dc6448d93ull)
&& (x.w[0] > 0x38c15b09ffffffffull))) {
x.w[1] = x.w[1] & 0xffffc00000000000ull;
x.w[0] = 0x0ull;
}
if ((x.w[1] & MASK_SNAN) == MASK_SNAN) { // x is SNAN
// set invalid flag
*pfpsf |= INVALID_EXCEPTION;
// return quiet (x)
res.w[1] = x.w[1] & 0xfc003fffffffffffull; // clear out also G[6]-G[16]
res.w[0] = x.w[0];
} else { // x is QNaN
// return x
res.w[1] = x.w[1] & 0xfc003fffffffffffull; // clear out G[6]-G[16]
res.w[0] = x.w[0];
}
} else { // x is not NaN, so it must be infinity
if (!x_sign) { // x is +inf
res.w[1] = 0x7800000000000000ull; // +inf
res.w[0] = 0x0000000000000000ull;
} else { // x is -inf
res.w[1] = 0xdfffed09bead87c0ull; // -MAXFP = -999...99 * 10^emax
res.w[0] = 0x378d8e63ffffffffull;
}
}
BID_RETURN (res);
}
// check for non-canonical values (treated as zero)
if ((x.w[1] & 0x6000000000000000ull) == 0x6000000000000000ull) { // G0_G1=11
// non-canonical
x_exp = (x.w[1] << 2) & MASK_EXP; // biased and shifted left 49 bits
C1.w[1] = 0; // significand high
C1.w[0] = 0; // significand low
} else { // G0_G1 != 11
x_exp = x.w[1] & MASK_EXP; // biased and shifted left 49 bits
if (C1.w[1] > 0x0001ed09bead87c0ull ||
(C1.w[1] == 0x0001ed09bead87c0ull
&& C1.w[0] > 0x378d8e63ffffffffull)) {
// x is non-canonical if coefficient is larger than 10^34 -1
C1.w[1] = 0;
C1.w[0] = 0;
} else { // canonical
;
}
}
if ((C1.w[1] == 0x0ull) && (C1.w[0] == 0x0ull)) {
// x is +/-0
res.w[1] = 0x0000000000000000ull; // +1 * 10^emin
res.w[0] = 0x0000000000000001ull;
} else { // x is not special and is not zero
if (x.w[1] == 0x5fffed09bead87c0ull
&& x.w[0] == 0x378d8e63ffffffffull) {
// x = +MAXFP = 999...99 * 10^emax
res.w[1] = 0x7800000000000000ull; // +inf
res.w[0] = 0x0000000000000000ull;
} else if (x.w[1] == 0x8000000000000000ull
&& x.w[0] == 0x0000000000000001ull) {
// x = -MINFP = 1...99 * 10^emin
res.w[1] = 0x8000000000000000ull; // -0
res.w[0] = 0x0000000000000000ull;
} else { // -MAXFP <= x <= -MINFP - 1 ulp OR MINFP <= x <= MAXFP - 1 ulp
// can add/subtract 1 ulp to the significand
// Note: we could check here if x >= 10^34 to speed up the case q1 = 34
// q1 = nr. of decimal digits in x
// determine first the nr. of bits in x
if (C1.w[1] == 0) {
if (C1.w[0] >= 0x0020000000000000ull) { // x >= 2^53
// split the 64-bit value in two 32-bit halves to avoid rnd errors
if (C1.w[0] >= 0x0000000100000000ull) { // x >= 2^32
tmp1.d = (double) (C1.w[0] >> 32); // exact conversion
x_nr_bits =
33 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) -
0x3ff);
} else { // x < 2^32
tmp1.d = (double) (C1.w[0]); // exact conversion
x_nr_bits =
1 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) -
0x3ff);
}
} else { // if x < 2^53
tmp1.d = (double) C1.w[0]; // exact conversion
x_nr_bits =
1 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) - 0x3ff);
}
} else { // C1.w[1] != 0 => nr. bits = 64 + nr_bits (C1.w[1])
tmp1.d = (double) C1.w[1]; // exact conversion
x_nr_bits =
65 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) - 0x3ff);
}
q1 = nr_digits[x_nr_bits - 1].digits;
if (q1 == 0) {
q1 = nr_digits[x_nr_bits - 1].digits1;
if (C1.w[1] > nr_digits[x_nr_bits - 1].threshold_hi
|| (C1.w[1] == nr_digits[x_nr_bits - 1].threshold_hi
&& C1.w[0] >= nr_digits[x_nr_bits - 1].threshold_lo))
q1++;
}
// if q1 < P34 then pad the significand with zeros
if (q1 < P34) {
exp = (x_exp >> 49) - 6176;
if (exp + 6176 > P34 - q1) {
ind = P34 - q1; // 1 <= ind <= P34 - 1
// pad with P34 - q1 zeros, until exponent = emin
// C1 = C1 * 10^ind
if (q1 <= 19) { // 64-bit C1
if (ind <= 19) { // 64-bit 10^ind and 64-bit C1
__mul_64x64_to_128MACH (C1, C1.w[0], ten2k64[ind]);
} else { // 128-bit 10^ind and 64-bit C1
__mul_128x64_to_128 (C1, C1.w[0], ten2k128[ind - 20]);
}
} else { // C1 is (most likely) 128-bit
if (ind <= 14) { // 64-bit 10^ind and 128-bit C1 (most likely)
__mul_128x64_to_128 (C1, ten2k64[ind], C1);
} else if (ind <= 19) { // 64-bit 10^ind and 64-bit C1 (q1 <= 19)
__mul_64x64_to_128MACH (C1, C1.w[0], ten2k64[ind]);
} else { // 128-bit 10^ind and 64-bit C1 (C1 must be 64-bit)
__mul_128x64_to_128 (C1, C1.w[0], ten2k128[ind - 20]);
}
}
x_exp = x_exp - ((UINT64) ind << 49);
} else { // pad with zeros until the exponent reaches emin
ind = exp + 6176;
// C1 = C1 * 10^ind
if (ind <= 19) { // 1 <= P34 - q1 <= 19 <=> 15 <= q1 <= 33
if (q1 <= 19) { // 64-bit C1, 64-bit 10^ind
__mul_64x64_to_128MACH (C1, C1.w[0], ten2k64[ind]);
} else { // 20 <= q1 <= 33 => 128-bit C1, 64-bit 10^ind
__mul_128x64_to_128 (C1, ten2k64[ind], C1);
}
} else { // if 20 <= P34 - q1 <= 33 <=> 1 <= q1 <= 14 =>
// 64-bit C1, 128-bit 10^ind
__mul_128x64_to_128 (C1, C1.w[0], ten2k128[ind - 20]);
}
x_exp = EXP_MIN;
}
}
if (!x_sign) { // x > 0
// add 1 ulp (add 1 to the significand)
C1.w[0]++;
if (C1.w[0] == 0)
C1.w[1]++;
if (C1.w[1] == 0x0001ed09bead87c0ull && C1.w[0] == 0x378d8e6400000000ull) { // if C1 = 10^34
C1.w[1] = 0x0000314dc6448d93ull; // C1 = 10^33
C1.w[0] = 0x38c15b0a00000000ull;
x_exp = x_exp + EXP_P1;
}
} else { // x < 0
// subtract 1 ulp (subtract 1 from the significand)
C1.w[0]--;
if (C1.w[0] == 0xffffffffffffffffull)
C1.w[1]--;
if (x_exp != 0 && C1.w[1] == 0x0000314dc6448d93ull && C1.w[0] == 0x38c15b09ffffffffull) { // if C1 = 10^33 - 1
C1.w[1] = 0x0001ed09bead87c0ull; // C1 = 10^34 - 1
C1.w[0] = 0x378d8e63ffffffffull;
x_exp = x_exp - EXP_P1;
}
}
// assemble the result
res.w[1] = x_sign | x_exp | C1.w[1];
res.w[0] = C1.w[0];
} // end -MAXFP <= x <= -MINFP - 1 ulp OR MINFP <= x <= MAXFP - 1 ulp
} // end x is not special and is not zero
BID_RETURN (res);
}
/*****************************************************************************
* BID128 nextdown
****************************************************************************/
#if DECIMAL_CALL_BY_REFERENCE
void
bid128_nextdown (UINT128 * pres,
UINT128 *
px _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) {
UINT128 x = *px;
#else
UINT128
bid128_nextdown (UINT128 x _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
_EXC_INFO_PARAM) {
#endif
UINT128 res;
UINT64 x_sign;
UINT64 x_exp;
int exp;
BID_UI64DOUBLE tmp1;
int x_nr_bits;
int q1, ind;
UINT128 C1; // C1.w[1], C1.w[0] represent x_signif_hi, x_signif_lo (UINT64)
BID_SWAP128 (x);
// unpack the argument
x_sign = x.w[1] & MASK_SIGN; // 0 for positive, MASK_SIGN for negative
C1.w[1] = x.w[1] & MASK_COEFF;
C1.w[0] = x.w[0];
// check for NaN or Infinity
if ((x.w[1] & MASK_SPECIAL) == MASK_SPECIAL) {
// x is special
if ((x.w[1] & MASK_NAN) == MASK_NAN) { // x is NAN
// if x = NaN, then res = Q (x)
// check first for non-canonical NaN payload
if (((x.w[1] & 0x00003fffffffffffull) > 0x0000314dc6448d93ull) ||
(((x.w[1] & 0x00003fffffffffffull) == 0x0000314dc6448d93ull)
&& (x.w[0] > 0x38c15b09ffffffffull))) {
x.w[1] = x.w[1] & 0xffffc00000000000ull;
x.w[0] = 0x0ull;
}
if ((x.w[1] & MASK_SNAN) == MASK_SNAN) { // x is SNAN
// set invalid flag
*pfpsf |= INVALID_EXCEPTION;
// return quiet (x)
res.w[1] = x.w[1] & 0xfc003fffffffffffull; // clear out also G[6]-G[16]
res.w[0] = x.w[0];
} else { // x is QNaN
// return x
res.w[1] = x.w[1] & 0xfc003fffffffffffull; // clear out G[6]-G[16]
res.w[0] = x.w[0];
}
} else { // x is not NaN, so it must be infinity
if (!x_sign) { // x is +inf
res.w[1] = 0x5fffed09bead87c0ull; // +MAXFP = +999...99 * 10^emax
res.w[0] = 0x378d8e63ffffffffull;
} else { // x is -inf
res.w[1] = 0xf800000000000000ull; // -inf
res.w[0] = 0x0000000000000000ull;
}
}
BID_RETURN (res);
}
// check for non-canonical values (treated as zero)
if ((x.w[1] & 0x6000000000000000ull) == 0x6000000000000000ull) { // G0_G1=11
// non-canonical
x_exp = (x.w[1] << 2) & MASK_EXP; // biased and shifted left 49 bits
C1.w[1] = 0; // significand high
C1.w[0] = 0; // significand low
} else { // G0_G1 != 11
x_exp = x.w[1] & MASK_EXP; // biased and shifted left 49 bits
if (C1.w[1] > 0x0001ed09bead87c0ull ||
(C1.w[1] == 0x0001ed09bead87c0ull
&& C1.w[0] > 0x378d8e63ffffffffull)) {
// x is non-canonical if coefficient is larger than 10^34 -1
C1.w[1] = 0;
C1.w[0] = 0;
} else { // canonical
;
}
}
if ((C1.w[1] == 0x0ull) && (C1.w[0] == 0x0ull)) {
// x is +/-0
res.w[1] = 0x8000000000000000ull; // -1 * 10^emin
res.w[0] = 0x0000000000000001ull;
} else { // x is not special and is not zero
if (x.w[1] == 0xdfffed09bead87c0ull
&& x.w[0] == 0x378d8e63ffffffffull) {
// x = -MAXFP = -999...99 * 10^emax
res.w[1] = 0xf800000000000000ull; // -inf
res.w[0] = 0x0000000000000000ull;
} else if (x.w[1] == 0x0ull && x.w[0] == 0x0000000000000001ull) { // +MINFP
res.w[1] = 0x0000000000000000ull; // +0
res.w[0] = 0x0000000000000000ull;
} else { // -MAXFP <= x <= -MINFP - 1 ulp OR MINFP <= x <= MAXFP - 1 ulp
// can add/subtract 1 ulp to the significand
// Note: we could check here if x >= 10^34 to speed up the case q1 = 34
// q1 = nr. of decimal digits in x
// determine first the nr. of bits in x
if (C1.w[1] == 0) {
if (C1.w[0] >= 0x0020000000000000ull) { // x >= 2^53
// split the 64-bit value in two 32-bit halves to avoid rnd errors
if (C1.w[0] >= 0x0000000100000000ull) { // x >= 2^32
tmp1.d = (double) (C1.w[0] >> 32); // exact conversion
x_nr_bits =
33 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) -
0x3ff);
} else { // x < 2^32
tmp1.d = (double) (C1.w[0]); // exact conversion
x_nr_bits =
1 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) -
0x3ff);
}
} else { // if x < 2^53
tmp1.d = (double) C1.w[0]; // exact conversion
x_nr_bits =
1 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) - 0x3ff);
}
} else { // C1.w[1] != 0 => nr. bits = 64 + nr_bits (C1.w[1])
tmp1.d = (double) C1.w[1]; // exact conversion
x_nr_bits =
65 + ((((unsigned int) (tmp1.ui64 >> 52)) & 0x7ff) - 0x3ff);
}
q1 = nr_digits[x_nr_bits - 1].digits;
if (q1 == 0) {
q1 = nr_digits[x_nr_bits - 1].digits1;
if (C1.w[1] > nr_digits[x_nr_bits - 1].threshold_hi
|| (C1.w[1] == nr_digits[x_nr_bits - 1].threshold_hi
&& C1.w[0] >= nr_digits[x_nr_bits - 1].threshold_lo))
q1++;
}
// if q1 < P then pad the significand with zeros
if (q1 < P34) {
exp = (x_exp >> 49) - 6176;
if (exp + 6176 > P34 - q1) {
ind = P34 - q1; // 1 <= ind <= P34 - 1
// pad with P34 - q1 zeros, until exponent = emin
// C1 = C1 * 10^ind
if (q1 <= 19) { // 64-bit C1
if (ind <= 19) { // 64-bit 10^ind and 64-bit C1
__mul_64x64_to_128MACH (C1, C1.w[0], ten2k64[ind]);
} else { // 128-bit 10^ind and 64-bit C1
__mul_128x64_to_128 (C1, C1.w[0], ten2k128[ind - 20]);
}
} else { // C1 is (most likely) 128-bit
if (ind <= 14) { // 64-bit 10^ind and 128-bit C1 (most likely)
__mul_128x64_to_128 (C1, ten2k64[ind], C1);
} else if (ind <= 19) { // 64-bit 10^ind and 64-bit C1 (q1 <= 19)
__mul_64x64_to_128MACH (C1, C1.w[0], ten2k64[ind]);
} else { // 128-bit 10^ind and 64-bit C1 (C1 must be 64-bit)
__mul_128x64_to_128 (C1, C1.w[0], ten2k128[ind - 20]);
}
}
x_exp = x_exp - ((UINT64) ind << 49);
} else { // pad with zeros until the exponent reaches emin
ind = exp + 6176;
// C1 = C1 * 10^ind
if (ind <= 19) { // 1 <= P34 - q1 <= 19 <=> 15 <= q1 <= 33
if (q1 <= 19) { // 64-bit C1, 64-bit 10^ind
__mul_64x64_to_128MACH (C1, C1.w[0], ten2k64[ind]);
} else { // 20 <= q1 <= 33 => 128-bit C1, 64-bit 10^ind
__mul_128x64_to_128 (C1, ten2k64[ind], C1);
}
} else { // if 20 <= P34 - q1 <= 33 <=> 1 <= q1 <= 14 =>
// 64-bit C1, 128-bit 10^ind
__mul_128x64_to_128 (C1, C1.w[0], ten2k128[ind - 20]);
}
x_exp = EXP_MIN;
}
}
if (x_sign) { // x < 0
// add 1 ulp (add 1 to the significand)
C1.w[0]++;
if (C1.w[0] == 0)
C1.w[1]++;
if (C1.w[1] == 0x0001ed09bead87c0ull && C1.w[0] == 0x378d8e6400000000ull) { // if C1 = 10^34
C1.w[1] = 0x0000314dc6448d93ull; // C1 = 10^33
C1.w[0] = 0x38c15b0a00000000ull;
x_exp = x_exp + EXP_P1;
}
} else { // x > 0
// subtract 1 ulp (subtract 1 from the significand)
C1.w[0]--;
if (C1.w[0] == 0xffffffffffffffffull)
C1.w[1]--;
if (x_exp != 0 && C1.w[1] == 0x0000314dc6448d93ull && C1.w[0] == 0x38c15b09ffffffffull) { // if C1 = 10^33 - 1
C1.w[1] = 0x0001ed09bead87c0ull; // C1 = 10^34 - 1
C1.w[0] = 0x378d8e63ffffffffull;
x_exp = x_exp - EXP_P1;
}
}
// assemble the result
res.w[1] = x_sign | x_exp | C1.w[1];
res.w[0] = C1.w[0];
} // end -MAXFP <= x <= -MINFP - 1 ulp OR MINFP <= x <= MAXFP - 1 ulp
} // end x is not special and is not zero
BID_RETURN (res);
}
/*****************************************************************************
* BID128 nextafter
****************************************************************************/
#if DECIMAL_CALL_BY_REFERENCE
void
bid128_nextafter (UINT128 * pres, UINT128 * px,
UINT128 *
py _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM)
{
UINT128 x = *px;
UINT128 y = *py;
UINT128 xnswp = *px;
UINT128 ynswp = *py;
#else
UINT128
bid128_nextafter (UINT128 x,
UINT128 y _EXC_FLAGS_PARAM _EXC_MASKS_PARAM
_EXC_INFO_PARAM) {
UINT128 xnswp = x;
UINT128 ynswp = y;
#endif
UINT128 res;
UINT128 tmp1, tmp2, tmp3;
FPSC tmp_fpsf = 0; // dummy fpsf for calls to comparison functions
int res1, res2;
UINT64 x_exp;
BID_SWAP128 (x);
BID_SWAP128 (y);
// check for NaNs
if (((x.w[1] & MASK_SPECIAL) == MASK_SPECIAL)
|| ((y.w[1] & MASK_SPECIAL) == MASK_SPECIAL)) {
// x is special or y is special
if ((x.w[1] & MASK_NAN) == MASK_NAN) { // x is NAN
// if x = NaN, then res = Q (x)
// check first for non-canonical NaN payload
if (((x.w[1] & 0x00003fffffffffffull) > 0x0000314dc6448d93ull) ||
(((x.w[1] & 0x00003fffffffffffull) == 0x0000314dc6448d93ull)
&& (x.w[0] > 0x38c15b09ffffffffull))) {
x.w[1] = x.w[1] & 0xffffc00000000000ull;
x.w[0] = 0x0ull;
}
if ((x.w[1] & MASK_SNAN) == MASK_SNAN) { // x is SNAN
// set invalid flag
*pfpsf |= INVALID_EXCEPTION;
// return quiet (x)
res.w[1] = x.w[1] & 0xfc003fffffffffffull; // clear out also G[6]-G[16]
res.w[0] = x.w[0];
} else { // x is QNaN
// return x
res.w[1] = x.w[1] & 0xfc003fffffffffffull; // clear out G[6]-G[16]
res.w[0] = x.w[0];
if ((y.w[1] & MASK_SNAN) == MASK_SNAN) { // y is SNAN
// set invalid flag
*pfpsf |= INVALID_EXCEPTION;
}
}
BID_RETURN (res)
} else if ((y.w[1] & MASK_NAN) == MASK_NAN) { // y is NAN
// if x = NaN, then res = Q (x)
// check first for non-canonical NaN payload
if (((y.w[1] & 0x00003fffffffffffull) > 0x0000314dc6448d93ull) ||
(((y.w[1] & 0x00003fffffffffffull) == 0x0000314dc6448d93ull)
&& (y.w[0] > 0x38c15b09ffffffffull))) {
y.w[1] = y.w[1] & 0xffffc00000000000ull;
y.w[0] = 0x0ull;
}
if ((y.w[1] & MASK_SNAN) == MASK_SNAN) { // y is SNAN
// set invalid flag
*pfpsf |= INVALID_EXCEPTION;
// return quiet (x)
res.w[1] = y.w[1] & 0xfc003fffffffffffull; // clear out also G[6]-G[16]
res.w[0] = y.w[0];
} else { // x is QNaN
// return x
res.w[1] = y.w[1] & 0xfc003fffffffffffull; // clear out G[6]-G[16]
res.w[0] = y.w[0];
}
BID_RETURN (res)
} else { // at least one is infinity
if ((x.w[1] & MASK_ANY_INF) == MASK_INF) { // x = inf
x.w[1] = x.w[1] & (MASK_SIGN | MASK_INF);
x.w[0] = 0x0ull;
}
if ((y.w[1] & MASK_ANY_INF) == MASK_INF) { // y = inf
y.w[1] = y.w[1] & (MASK_SIGN | MASK_INF);
y.w[0] = 0x0ull;
}
}
}
// neither x nor y is NaN
// if not infinity, check for non-canonical values x (treated as zero)
if ((x.w[1] & MASK_ANY_INF) != MASK_INF) { // x != inf
if ((x.w[1] & 0x6000000000000000ull) == 0x6000000000000000ull) { // G0_G1=11
// non-canonical
x_exp = (x.w[1] << 2) & MASK_EXP; // biased and shifted left 49 bits
x.w[1] = (x.w[1] & MASK_SIGN) | x_exp;
x.w[0] = 0x0ull;
} else { // G0_G1 != 11
x_exp = x.w[1] & MASK_EXP; // biased and shifted left 49 bits
if ((x.w[1] & MASK_COEFF) > 0x0001ed09bead87c0ull ||
((x.w[1] & MASK_COEFF) == 0x0001ed09bead87c0ull
&& x.w[0] > 0x378d8e63ffffffffull)) {
// x is non-canonical if coefficient is larger than 10^34 -1
x.w[1] = (x.w[1] & MASK_SIGN) | x_exp;
x.w[0] = 0x0ull;
} else { // canonical
;
}
}
}
// no need to check for non-canonical y
// neither x nor y is NaN
tmp_fpsf = *pfpsf; // save fpsf
#if DECIMAL_CALL_BY_REFERENCE
bid128_quiet_equal (&res1, &xnswp,
&ynswp _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
bid128_quiet_greater (&res2, &xnswp,
&ynswp _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
#else
res1 =
bid128_quiet_equal (xnswp,
ynswp _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
res2 =
bid128_quiet_greater (xnswp,
ynswp _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
#endif
*pfpsf = tmp_fpsf; // restore fpsf
if (res1) { // x = y
// return x with the sign of y
res.w[1] =
(x.w[1] & 0x7fffffffffffffffull) | (y.
w[1] & 0x8000000000000000ull);
res.w[0] = x.w[0];
} else if (res2) { // x > y
#if DECIMAL_CALL_BY_REFERENCE
bid128_nextdown (&res,
&xnswp _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
#else
res =
bid128_nextdown (xnswp _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
#endif
BID_SWAP128 (res);
} else { // x < y
#if DECIMAL_CALL_BY_REFERENCE
bid128_nextup (&res,
&xnswp _EXC_FLAGS_ARG _EXC_MASKS_ARG _EXC_INFO_ARG);
#else
res =
bid128_nextup (xnswp _EXC_FLAGS_ARG _EXC_MASKS_ARG _EXC_INFO_ARG);
#endif
BID_SWAP128 (res);
}
// if the operand x is finite but the result is infinite, signal
// overflow and inexact
if (((x.w[1] & MASK_SPECIAL) != MASK_SPECIAL)
&& ((res.w[1] & MASK_SPECIAL) == MASK_SPECIAL)) {
// set the inexact flag
*pfpsf |= INEXACT_EXCEPTION;
// set the overflow flag
*pfpsf |= OVERFLOW_EXCEPTION;
}
// if the result is in (-10^emin, 10^emin), and is different from the
// operand x, signal underflow and inexact
tmp1.w[HIGH_128W] = 0x0000314dc6448d93ull;
tmp1.w[LOW_128W] = 0x38c15b0a00000000ull; // +100...0[34] * 10^emin
tmp2.w[HIGH_128W] = res.w[1] & 0x7fffffffffffffffull;
tmp2.w[LOW_128W] = res.w[0];
tmp3.w[HIGH_128W] = res.w[1];
tmp3.w[LOW_128W] = res.w[0];
tmp_fpsf = *pfpsf; // save fpsf
#if DECIMAL_CALL_BY_REFERENCE
bid128_quiet_greater (&res1, &tmp1,
&tmp2 _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
bid128_quiet_not_equal (&res2, &xnswp,
&tmp3 _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
#else
res1 =
bid128_quiet_greater (tmp1,
tmp2 _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
res2 =
bid128_quiet_not_equal (xnswp,
tmp3 _EXC_FLAGS_ARG _EXC_MASKS_ARG
_EXC_INFO_ARG);
#endif
*pfpsf = tmp_fpsf; // restore fpsf
if (res1 && res2) {
// set the inexact flag
*pfpsf |= INEXACT_EXCEPTION;
// set the underflow flag
*pfpsf |= UNDERFLOW_EXCEPTION;
}
BID_RETURN (res);
}
Reference in New Issue View Git Blame Copy Permalink