platform_bionic/libc/arch-x86/generic/string/strcat.S
Varvara Rainchik 5a92284167 Add 32-bit Silvermont-optimized string/memory functions.
Add following functions:
bcopy, memcpy, memmove, memset, bzero, memcmp, wmemcmp, strlen,
strcpy, strncpy, stpcpy, stpncpy.
Create new directories inside arch-x86 to specify architecture: atom,
silvermont and generic (non atom or silvermont architectures are treated like generic).
Due to introducing optimized versions of stpcpy and stpncpy,
c-implementations of these functions are moved from
common for architectures makefile to arm and mips specific makefiles.

Change-Id: I990f8061c3e9bca1f154119303da9e781c5d086e
Signed-off-by: Varvara Rainchik <varvara.rainchik@intel.com>
2014-05-12 13:56:59 -07:00

74 lines
1.5 KiB
ArmAsm

/* $OpenBSD: strcat.S,v 1.8 2005/08/07 11:30:38 espie Exp $ */
/*
* Written by J.T. Conklin <jtc@netbsd.org>.
* Public domain.
*/
#include <private/bionic_asm.h>
#if defined(APIWARN)
#APP
.section .gnu.warning.strcat
.ascii "warning: strcat() is almost always misused, please use strlcat()"
#NO_APP
#endif
/*
* NOTE: I've unrolled the loop eight times: large enough to make a
* significant difference, and small enough not to totally trash the
* cache.
*/
ENTRY(strcat)
pushl %edi /* save edi */
movl 8(%esp),%edi /* dst address */
movl 12(%esp),%edx /* src address */
pushl %edi /* push destination address */
cld /* set search forward */
xorl %eax,%eax /* set search for null terminator */
movl $-1,%ecx /* set search for lots of characters */
repne /* search! */
scasb
leal -1(%edi),%ecx /* correct dst address */
.align 2,0x90
L1: movb (%edx),%al /* unroll loop, but not too much */
movb %al,(%ecx)
testb %al,%al
jz L2
movb 1(%edx),%al
movb %al,1(%ecx)
testb %al,%al
jz L2
movb 2(%edx),%al
movb %al,2(%ecx)
testb %al,%al
jz L2
movb 3(%edx),%al
movb %al,3(%ecx)
testb %al,%al
jz L2
movb 4(%edx),%al
movb %al,4(%ecx)
testb %al,%al
jz L2
movb 5(%edx),%al
movb %al,5(%ecx)
testb %al,%al
jz L2
movb 6(%edx),%al
movb %al,6(%ecx)
testb %al,%al
jz L2
movb 7(%edx),%al
movb %al,7(%ecx)
addl $8,%edx
addl $8,%ecx
testb %al,%al
jnz L1
L2: popl %eax /* pop destination address */
popl %edi /* restore edi */
ret
END(strcat)