Add strcpy-stosb.S hjl/pr22353/master

1 files changed, 66 insertions, 0 deletions

diff --git a/sysdeps/i386/i686/multiarch/strcpy-stosb.S b/sysdeps/i386/i686/multiarch/strcpy-stosb.S
new file mode 100644
index 0000000000..36e4412fad
--- /dev/null
+++ b/sysdeps/i386/i686/multiarch/strcpy-stosb.S
@@ -0,0 +1,66 @@
+/* strcpy/strcpy optimized with stosb.
+   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 <sysdep.h>
+
+#define PARMS	4+8	/* space for 2 saved regs */
+#define DEST	PARMS
+#define SRC	DEST+4
+
+#ifndef USE_AS_STPCPY
+# define STRCPY __strcpy_stosb
+#endif
+
+	.text
+ENTRY (STRCPY)
+	pushl	%edi
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (%edi, 4)
+	pushl	%esi
+	cfi_adjust_cfa_offset (4)
+	cfi_rel_offset (%esi, 0)
+
+	movl	DEST(%esp), %edi
+	movl	SRC(%esp), %esi
+
+#ifndef USE_AS_STPCPY
+	movl	%edi, %edx
+#endif
+
+L(repeat):
+	lodsb
+	stosb
+	testb	%al,%al
+	jne	L(repeat)
+
+#ifdef USE_AS_STPCPY
+	leal	-1(%edi), %eax
+#else
+	movl	%edx, %eax
+#endif
+
+	popl	%esi
+	cfi_adjust_cfa_offset (-4)
+	cfi_restore (%esi)
+	popl	%edi
+	cfi_adjust_cfa_offset (-4)
+	cfi_restore (%edi)
+
+	ret
+END (STRCPY)