glibc/sysdeps/x86_64/fpu/fesetround.c
Paul Eggert 2b778ceb40 Update copyright dates with scripts/update-copyrights
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
2021-01-02 12:17:34 -08:00

49 lines
1.5 KiB
C

/* Set current rounding direction.
Copyright (C) 2001-2021 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 <fenv.h>
int
__fesetround (int round)
{
unsigned short int cw;
int mxcsr;
if ((round & ~0xc00) != 0)
/* ROUND is no valid rounding mode. */
return 1;
/* First set the x87 FPU. */
asm ("fnstcw %0" : "=m" (*&cw));
cw &= ~0xc00;
cw |= round;
asm ("fldcw %0" : : "m" (*&cw));
/* And now the MSCSR register for SSE, the precision is at different bit
positions in the different units, we need to shift it 3 bits. */
asm ("stmxcsr %0" : "=m" (*&mxcsr));
mxcsr &= ~ 0x6000;
mxcsr |= round << 3;
asm ("ldmxcsr %0" : : "m" (*&mxcsr));
return 0;
}
libm_hidden_def (__fesetround)
weak_alias (__fesetround, fesetround)
libm_hidden_weak (fesetround)