Optimized memcmp and wmemcmp for x86-64 and x86-32

1 files changed, 47 insertions, 0 deletions

diff --git a/sysdeps/x86_64/multiarch/wmemcmp.S b/sysdeps/x86_64/multiarch/wmemcmp.S
new file mode 100644
index 0000000000..7c3b7ed178
--- /dev/null
+++ b/sysdeps/x86_64/multiarch/wmemcmp.S
@@ -0,0 +1,47 @@
+/* Multiple versions of wmemcmp
+   Copyright (C)  2011 Free Software Foundation, Inc.
+   Contributed by Intel Corporation.
+   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, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <sysdep.h>
+#include <init-arch.h>
+
+/* Define multiple versions only for the definition in libc. */
+#ifndef NOT_IN_libc
+	.text
+ENTRY(wmemcmp)
+	.type	wmemcmp, @gnu_indirect_function
+	cmpl	$0, KIND_OFFSET+__cpu_features(%rip)
+	jne	1f
+	call	__init_cpu_features
+
+1:	testl	$bit_SSSE3, __cpu_features+CPUID_OFFSET+index_SSSE3(%rip)
+	jnz	2f
+	leaq	__wmemcmp_sse2(%rip), %rax
+	ret
+
+2:	testl	$bit_SSE4_1, __cpu_features+CPUID_OFFSET+index_SSE4_1(%rip)
+	jz	3f
+	leaq	__wmemcmp_sse4_1(%rip), %rax
+	ret
+
+3:	leaq	__wmemcmp_ssse3(%rip), %rax
+	ret
+
+END(wmemcmp)
+#endif