mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-15 09:30:06 +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
84 lines
2.8 KiB
C
84 lines
2.8 KiB
C
/* Round to nearest integer. PowerPC64 version.
|
|
Copyright (C) 2019-2021 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, see <https://www.gnu.org/licenses/>. */
|
|
|
|
#define NO_MATH_REDIRECT
|
|
#define lroundf __redirect_llround
|
|
#define __lroundf __redirect___lround
|
|
#include <math.h>
|
|
#undef lroundf
|
|
#undef __lroundf
|
|
#include <libm-alias-float.h>
|
|
#include <math-barriers.h>
|
|
|
|
long long int
|
|
__llroundf (float x)
|
|
{
|
|
#ifdef _ARCH_PWR5X
|
|
double r = __builtin_round (x);
|
|
/* Prevent gcc from calling llround directly when compiled with
|
|
-fno-math-errno by inserting a barrier. */
|
|
math_opt_barrier (r);
|
|
return r;
|
|
#else
|
|
/* IEEE 1003.1 llroundf function. IEEE specifies "roundf to the nearest
|
|
integer value, rounding halfway cases away from zero, regardless of
|
|
the current rounding mode." However PowerPC Architecture defines
|
|
"roundf to Nearest" as "Choose the best approximation. In case of a
|
|
tie, choose the one that is even (least significant bit o).".
|
|
So we can't use the PowerPC "round to Nearest" mode. Instead we set
|
|
"round toward Zero" mode and round by adding +-0.5 before rounding
|
|
to the integer value.
|
|
|
|
It is necessary to detect when x is (+-)0x1.fffffffffffffp-2
|
|
because adding +-0.5 in this case will cause an erroneous shift,
|
|
carry and round. We simply return 0 if 0.5 > x > -0.5. Likewise
|
|
if x is and odd number between +-(2^23 and 2^24-1) a shift and
|
|
carry will erroneously round if biased with +-0.5. Therefore if x
|
|
is greater/less than +-2^23 we don't need to bias the number with
|
|
+-0.5. */
|
|
|
|
float ax = fabsf (x);
|
|
|
|
if (ax < 0.5f)
|
|
return 0;
|
|
|
|
if (ax < 0x1p+23f)
|
|
{
|
|
/* Test whether an integer to avoid spurious "inexact". */
|
|
float t = ax + 0x1p+23f;
|
|
t = t - 0x1p+23f;
|
|
if (ax != t)
|
|
{
|
|
ax = ax + 0.5f;
|
|
if (x < 0.0f)
|
|
ax = -fabs (ax);
|
|
x = ax;
|
|
}
|
|
}
|
|
|
|
long int ret;
|
|
__asm__ ("fctidz %0, %1" : "=d" (ret) : "d" (x));
|
|
return ret;
|
|
#endif
|
|
}
|
|
#ifndef __llroundf
|
|
strong_alias (__llroundf, __lroundf)
|
|
libm_alias_float (__llround, lround)
|
|
libm_alias_float (__llround, llround)
|
|
#endif
|