glibc/sysdeps/x86_64/multiarch/ifunc-unaligned-ssse3.h
H.J. Lu 5a103908c0 x86-64: Implement strcpy family IFUNC selectors in C
Implement strcpy family IFUNC selectors in C.

All internal calls within libc.so can use IFUNC on x86-64 since unlike
x86, x86-64 supports PC-relative addressing to access the GOT entry so
that it can call via PLT without using an extra register.  For libc.a,
we can't use IFUNC for functions which are called before IFUNC has been
initialized.  Use IFUNC internally reduces the icache footprint since
libc.so and other codes in the process use the same implementations.
This patch uses IFUNC for strcpy family functions within libc.

	* sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add
	strcpy-sse2 and stpcpy-sse2.
	* sysdeps/x86_64/multiarch/ifunc-unaligned-ssse3.h: New file.
	* sysdeps/x86_64/multiarch/stpcpy-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/stpcpy.c: Likewise.
	* sysdeps/x86_64/multiarch/stpncpy.c: Likewise.
	* sysdeps/x86_64/multiarch/strcpy-sse2.S: Likewise.
	* sysdeps/x86_64/multiarch/strcpy.c: Likewise.
	* sysdeps/x86_64/multiarch/strncpy.c: Likewise.
	* sysdeps/x86_64/multiarch/stpcpy.S: Removed.
	* sysdeps/x86_64/multiarch/stpncpy.S: Likewise.
	* sysdeps/x86_64/multiarch/strcpy.S: Likewise.
	* sysdeps/x86_64/multiarch/strncpy.S: Likewise.
	* sysdeps/x86_64/multiarch/stpncpy-c.c (weak_alias): New.
	(libc_hidden_def): Always defined as empty.
	* sysdeps/x86_64/multiarch/strncpy-c.c (libc_hidden_builtin_def):
	Always Defined as empty.
2017-06-12 09:06:09 -07:00

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1.5 KiB
C

/* Common definition for ifunc selections optimized with SSE2, unaligned
SSE2 and SSSE3.
All versions must be listed in ifunc-impl-list.c.
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/>. */
#include <init-arch.h>
extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2) attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (sse2_unaligned)
attribute_hidden;
extern __typeof (REDIRECT_NAME) OPTIMIZE (ssse3) attribute_hidden;
static inline void *
IFUNC_SELECTOR (void)
{
const struct cpu_features* cpu_features = __get_cpu_features ();
if (CPU_FEATURES_ARCH_P (cpu_features, Fast_Unaligned_Load))
return OPTIMIZE (sse2_unaligned);
if (CPU_FEATURES_CPU_P (cpu_features, SSSE3))
return OPTIMIZE (ssse3);
return OPTIMIZE (sse2);
}