glibc/sysdeps/x86_64/multiarch/strrchr.c
H.J. Lu d2538b9156 x86-64: Optimize strrchr/wcsrchr with AVX2
Optimize strrchr/wcsrchr with AVX2 to check 32 bytes with vector
instructions.  It is as fast as SSE2 version for small data sizes
and up to 1X faster for large data sizes on Haswell.  Select AVX2
version on AVX2 machines where vzeroupper is preferred and AVX
unaligned load is fast.

	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	strrchr-sse2, strrchr-avx2, wcsrchr-sse2 and wcsrchr-avx2.
	* sysdeps/x86_64/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add tests for __strrchr_avx2,
	__strrchr_sse2, __wcsrchr_avx2 and __wcsrchr_sse2.
	* sysdeps/x86_64/multiarch/strrchr-avx2.S: New file.
	* sysdeps/x86_64/multiarch/strrchr-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/strrchr.c: Likewise.
	* sysdeps/x86_64/multiarch/wcsrchr-avx2.S: Likewise.
	* sysdeps/x86_64/multiarch/wcsrchr-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/wcsrchr.c: Likewise.
2017-06-09 05:45:52 -07:00

35 lines
1.2 KiB
C

/* Multiple versions of strrchr.
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 multiple versions only for the definition in libc. */
#if IS_IN (libc)
# define strrchr __redirect_strrchr
# include <string.h>
# undef strrchr
# define SYMBOL_NAME strrchr
# include "ifunc-avx2.h"
libc_ifunc_redirected (__redirect_strrchr, strrchr, IFUNC_SELECTOR ());
weak_alias (strrchr, rindex);
# ifdef SHARED
__hidden_ver1 (strrchr, __GI_strrchr, __redirect_strrchr)
__attribute__((visibility ("hidden")));
# endif
#endif