glibc/sysdeps/x86_64/fpu/multiarch/s_truncf.c
Joseph Myers ae8372d7e4 Add SSE4.1 trunc, truncf (bug 20142).
This patch adds SSE4.1 versions of trunc and truncf, using the roundsd
/ roundss instructions, similar to the versions of ceil, floor, rint
and nearbyint functions we already have.  In my testing with the glibc
benchtests these are about 30% faster than the C versions for double,
20% faster for float.

Tested for x86_64.

	[BZ #20142]
	* sysdeps/x86_64/fpu/multiarch/Makefile (libm-sysdep_routines):
	Add s_trunc-c, s_truncf-c, s_trunc-sse4_1 and s_truncf-sse4_1.
	* sysdeps/x86_64/fpu/multiarch/s_trunc-c.c: New file.
	* sysdeps/x86_64/fpu/multiarch/s_trunc-sse4_1.S: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_trunc.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_truncf-c.c: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_truncf-sse4_1.S: Likewise.
	* sysdeps/x86_64/fpu/multiarch/s_truncf.c: Likewise.
2017-09-20 16:54:05 +00:00

30 lines
1.1 KiB
C

/* Multiple versions of __truncf.
Copyright (C) 2017 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
<http://www.gnu.org/licenses/>. */
#define truncf __redirect_truncf
#define __truncf __redirect___truncf
#include <math.h>
#undef truncf
#undef __truncf
#define SYMBOL_NAME truncf
#include "ifunc-sse4_1.h"
libc_ifunc_redirected (__redirect_truncf, __truncf, IFUNC_SELECTOR ());
weak_alias (__truncf, truncf)