Optimized memchr, memrchr, rawmemchr for x86-32

1 files changed, 79 insertions, 0 deletions

diff --git a/sysdeps/i386/i686/multiarch/memrchr.S b/sysdeps/i386/i686/multiarch/memrchr.S
new file mode 100644
index 0000000000..8e5b2c50a2
--- /dev/null
+++ b/sysdeps/i386/i686/multiarch/memrchr.S
@@ -0,0 +1,79 @@
+/* Multiple versions of memrchr
+   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>
+
+#ifndef  NOT_IN_libc
+	.section	.gnu.linkonce.t.__i686.get_pc_thunk.bx,"ax",@progbits
+	.globl	__i686.get_pc_thunk.bx
+	.hidden	__i686.get_pc_thunk.bx
+	.p2align 4
+	.type	__i686.get_pc_thunk.bx,@function
+__i686.get_pc_thunk.bx:
+	movl	(%esp), %ebx
+	ret
+
+# define CFI_POP(REG) \
+	cfi_adjust_cfa_offset (-4); \
+	cfi_restore (REG)
+
+# define CFI_PUSH(REG) \
+	cfi_adjust_cfa_offset (4); \
+	cfi_rel_offset (REG, 0)
+
+	.text
+ENTRY(__memrchr)
+	.type	__memrchr, @gnu_indirect_function
+	pushl	%ebx
+	CFI_PUSH (%ebx)
+	call	__i686.get_pc_thunk.bx
+	addl	$_GLOBAL_OFFSET_TABLE_, %ebx
+	cmpl	$0, KIND_OFFSET+__cpu_features@GOTOFF(%ebx)
+	jne	1f
+	call	__init_cpu_features
+
+1:	testl	$bit_SSE2, CPUID_OFFSET+index_SSE2+__cpu_features@GOTOFF(%ebx)
+	jz	2f
+	testl	$bit_Slow_BSF, FEATURE_OFFSET+index_Slow_BSF+__cpu_features@GOTOFF(%ebx)
+	jz	3f
+
+	leal	__memrchr_sse2@GOTOFF(%ebx), %eax
+	popl	%ebx
+	CFI_POP	(%ebx)
+	ret
+
+	CFI_PUSH (%ebx)
+
+2:	leal	__memrchr_ia32@GOTOFF(%ebx), %eax
+	popl	%ebx
+	CFI_POP	(%ebx)
+	ret
+
+	CFI_PUSH (%ebx)
+
+3:	leal	__memrchr_sse2_bsf@GOTOFF(%ebx), %eax
+	popl	%ebx
+	CFI_POP	(%ebx)
+	ret
+END(__memrchr)
+
+weak_alias(__memrchr, memrchr)
+#endif