mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-01 17:30:07 +00:00
2b778ceb40
I used these shell commands: ../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright (cd ../glibc && git commit -am"[this commit message]") and then ignored the output, which consisted lines saying "FOO: warning: copyright statement not found" for each of 6694 files FOO. I then removed trailing white space from benchtests/bench-pthread-locks.c and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this diagnostic from Savannah: remote: *** pre-commit check failed ... remote: *** error: lines with trailing whitespace found remote: error: hook declined to update refs/heads/master
127 lines
3.2 KiB
C
127 lines
3.2 KiB
C
/* Round to nearest integer value, rounding halfway cases to even.
|
|
ldbl-96 version.
|
|
Copyright (C) 2016-2021 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <math.h>
|
|
#include <math_private.h>
|
|
#include <libm-alias-ldouble.h>
|
|
#include <stdint.h>
|
|
|
|
#define BIAS 0x3fff
|
|
#define MANT_DIG 64
|
|
#define MAX_EXP (2 * BIAS + 1)
|
|
|
|
long double
|
|
__roundevenl (long double x)
|
|
{
|
|
uint16_t se;
|
|
uint32_t hx, lx;
|
|
GET_LDOUBLE_WORDS (se, hx, lx, x);
|
|
int exponent = se & 0x7fff;
|
|
if (exponent >= BIAS + MANT_DIG - 1)
|
|
{
|
|
/* Integer, infinity or NaN. */
|
|
if (exponent == MAX_EXP)
|
|
/* Infinity or NaN; quiet signaling NaNs. */
|
|
return x + x;
|
|
else
|
|
return x;
|
|
}
|
|
else if (exponent >= BIAS + MANT_DIG - 32)
|
|
{
|
|
/* Not necessarily an integer; integer bit is in low word.
|
|
Locate the bits with exponents 0 and -1. */
|
|
int int_pos = (BIAS + MANT_DIG - 1) - exponent;
|
|
int half_pos = int_pos - 1;
|
|
uint32_t half_bit = 1U << half_pos;
|
|
uint32_t int_bit = 1U << int_pos;
|
|
if ((lx & (int_bit | (half_bit - 1))) != 0)
|
|
{
|
|
/* No need to test whether HALF_BIT is set. */
|
|
lx += half_bit;
|
|
if (lx < half_bit)
|
|
{
|
|
hx++;
|
|
if (hx == 0)
|
|
{
|
|
hx = 0x80000000;
|
|
se++;
|
|
}
|
|
}
|
|
}
|
|
lx &= ~(int_bit - 1);
|
|
}
|
|
else if (exponent == BIAS + MANT_DIG - 33)
|
|
{
|
|
/* Not necessarily an integer; integer bit is bottom of high
|
|
word, half bit is top of low word. */
|
|
if (((hx & 1) | (lx & 0x7fffffff)) != 0)
|
|
{
|
|
lx += 0x80000000;
|
|
if (lx < 0x80000000)
|
|
{
|
|
hx++;
|
|
if (hx == 0)
|
|
{
|
|
hx = 0x80000000;
|
|
se++;
|
|
}
|
|
}
|
|
}
|
|
lx = 0;
|
|
}
|
|
else if (exponent >= BIAS)
|
|
{
|
|
/* At least 1; not necessarily an integer, integer bit and half
|
|
bit are in the high word. Locate the bits with exponents 0
|
|
and -1. */
|
|
int int_pos = (BIAS + MANT_DIG - 33) - exponent;
|
|
int half_pos = int_pos - 1;
|
|
uint32_t half_bit = 1U << half_pos;
|
|
uint32_t int_bit = 1U << int_pos;
|
|
if (((hx & (int_bit | (half_bit - 1))) | lx) != 0)
|
|
{
|
|
hx += half_bit;
|
|
if (hx < half_bit)
|
|
{
|
|
hx = 0x80000000;
|
|
se++;
|
|
}
|
|
}
|
|
hx &= ~(int_bit - 1);
|
|
lx = 0;
|
|
}
|
|
else if (exponent == BIAS - 1 && (hx > 0x80000000 || lx != 0))
|
|
{
|
|
/* Interval (0.5, 1). */
|
|
se = (se & 0x8000) | 0x3fff;
|
|
hx = 0x80000000;
|
|
lx = 0;
|
|
}
|
|
else
|
|
{
|
|
/* Rounds to 0. */
|
|
se &= 0x8000;
|
|
hx = 0;
|
|
lx = 0;
|
|
}
|
|
SET_LDOUBLE_WORDS (x, se, hx, lx);
|
|
return x;
|
|
}
|
|
libm_alias_ldouble (__roundeven, roundeven)
|