glibc/sysdeps/x86_64/multiarch/memcmp-sse2.S

/* memcmp with SSE2.
   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/>.  */

#if IS_IN (libc)
# define memcmp __memcmp_sse2

# ifdef SHARED
#  undef libc_hidden_builtin_def
#  define libc_hidden_builtin_def(name)
# endif

# undef weak_alias
# define weak_alias(ignored1, ignored2)
#endif

#include <sysdeps/x86_64/memcmp.S>
x86-64: Implement memcmp family IFUNC selectors in C Implement memcmp 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 memcmp family functions within libc. * sysdeps/x86_64/multiarch/Makefile (sysdep_routines): Add memcmp-sse2. * sysdeps/x86_64/multiarch/ifunc-memcmp.h: New file. * sysdeps/x86_64/multiarch/memcmp-sse2.S: Likewise. * sysdeps/x86_64/multiarch/memcmp.c: Likewise. * sysdeps/x86_64/multiarch/wmemcmp.c: Likewise. * sysdeps/x86_64/multiarch/memcmp.S: Removed. * sysdeps/x86_64/multiarch/wmemcmp.S: Likewise. 2017-06-15 15:49:43 +00:00			`/* memcmp with SSE2.`
			`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/>. */`

			`#if IS_IN (libc)`
			`# define memcmp __memcmp_sse2`

			`# ifdef SHARED`
			`# undef libc_hidden_builtin_def`
			`# define libc_hidden_builtin_def(name)`
			`# endif`

			`# undef weak_alias`
			`# define weak_alias(ignored1, ignored2)`
			`#endif`

			`#include <sysdeps/x86_64/memcmp.S>`