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/*
Copyright (c) 2011, Intel Corporation
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef L
# define L(label) .L##label
#endif
#ifndef cfi_startproc
# define cfi_startproc .cfi_startproc
#endif
#ifndef cfi_endproc
# define cfi_endproc .cfi_endproc
#endif
#ifndef cfi_rel_offset
# define cfi_rel_offset(reg, off) .cfi_rel_offset reg, off
#endif
#ifndef cfi_restore
# define cfi_restore(reg) .cfi_restore reg
#endif
#ifndef cfi_adjust_cfa_offset
# define cfi_adjust_cfa_offset(off) .cfi_adjust_cfa_offset off
#endif
#ifndef ENTRY
# define ENTRY(name) \
.type name, @function; \
.globl name; \
.p2align 4; \
name: \
cfi_startproc
#endif
#ifndef END
# define END(name) \
cfi_endproc; \
.size name, .-name
#endif
#define CFI_PUSH(REG) \
cfi_adjust_cfa_offset (4); \
cfi_rel_offset (REG, 0)
#define CFI_POP(REG) \
cfi_adjust_cfa_offset (-4); \
cfi_restore (REG)
#define PUSH(REG) pushl REG; CFI_PUSH (REG)
#define POP(REG) popl REG; CFI_POP (REG)
#define PARMS 8
#define ENTRANCE PUSH(%edi)
#define RETURN POP (%edi); ret; CFI_PUSH (%edi);
#define STR1 PARMS
#define STR2 STR1+4
.text
ENTRY (strchr)
ENTRANCE
mov STR1(%esp), %ecx
movd STR2(%esp), %xmm1
pxor %xmm2, %xmm2
mov %ecx, %edi
punpcklbw %xmm1, %xmm1
punpcklbw %xmm1, %xmm1
/* ECX has OFFSET. */
and $15, %ecx
pshufd $0, %xmm1, %xmm1
je L(loop)
/* Handle unaligned string. */
and $-16, %edi
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
pcmpeqb %xmm1, %xmm0
/* Find where NULL is. */
pmovmskb %xmm2, %edx
/* Check if there is a match. */
pmovmskb %xmm0, %eax
/* Remove the leading bytes. */
sarl %cl, %edx
sarl %cl, %eax
test %eax, %eax
jz L(unaligned_no_match)
add %ecx, %edi
test %edx, %edx
jz L(match_case1)
jmp L(match_case2)
.p2align 4
L(unaligned_no_match):
test %edx, %edx
jne L(return_null)
pxor %xmm2, %xmm2
add $16, %edi
.p2align 4
/* Loop start on aligned string. */
L(loop):
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
test %edx, %edx
jnz L(return_null)
add $16, %edi
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
test %edx, %edx
jnz L(return_null)
add $16, %edi
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
test %edx, %edx
jnz L(return_null)
add $16, %edi
movdqa (%edi), %xmm0
pcmpeqb %xmm0, %xmm2
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm2, %edx
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
test %edx, %edx
jnz L(return_null)
add $16, %edi
jmp L(loop)
L(matches):
/* There is a match. First find where NULL is. */
test %edx, %edx
jz L(match_case1)
.p2align 4
L(match_case2):
test %al, %al
jz L(match_higth_case2)
mov %al, %cl
and $15, %cl
jnz L(match_case2_4)
mov %dl, %ch
and $15, %ch
jnz L(return_null)
test $0x10, %al
jnz L(Exit5)
test $0x10, %dl
jnz L(return_null)
test $0x20, %al
jnz L(Exit6)
test $0x20, %dl
jnz L(return_null)
test $0x40, %al
jnz L(Exit7)
test $0x40, %dl
jnz L(return_null)
lea 7(%edi), %eax
RETURN
.p2align 4
L(match_case2_4):
test $0x01, %al
jnz L(Exit1)
test $0x01, %dl
jnz L(return_null)
test $0x02, %al
jnz L(Exit2)
test $0x02, %dl
jnz L(return_null)
test $0x04, %al
jnz L(Exit3)
test $0x04, %dl
jnz L(return_null)
lea 3(%edi), %eax
RETURN
.p2align 4
L(match_higth_case2):
test %dl, %dl
jnz L(return_null)
mov %ah, %cl
and $15, %cl
jnz L(match_case2_12)
mov %dh, %ch
and $15, %ch
jnz L(return_null)
test $0x10, %ah
jnz L(Exit13)
test $0x10, %dh
jnz L(return_null)
test $0x20, %ah
jnz L(Exit14)
test $0x20, %dh
jnz L(return_null)
test $0x40, %ah
jnz L(Exit15)
test $0x40, %dh
jnz L(return_null)
lea 15(%edi), %eax
RETURN
.p2align 4
L(match_case2_12):
test $0x01, %ah
jnz L(Exit9)
test $0x01, %dh
jnz L(return_null)
test $0x02, %ah
jnz L(Exit10)
test $0x02, %dh
jnz L(return_null)
test $0x04, %ah
jnz L(Exit11)
test $0x04, %dh
jnz L(return_null)
lea 11(%edi), %eax
RETURN
.p2align 4
L(match_case1):
test %al, %al
jz L(match_higth_case1)
test $0x01, %al
jnz L(Exit1)
test $0x02, %al
jnz L(Exit2)
test $0x04, %al
jnz L(Exit3)
test $0x08, %al
jnz L(Exit4)
test $0x10, %al
jnz L(Exit5)
test $0x20, %al
jnz L(Exit6)
test $0x40, %al
jnz L(Exit7)
lea 7(%edi), %eax
RETURN
.p2align 4
L(match_higth_case1):
test $0x01, %ah
jnz L(Exit9)
test $0x02, %ah
jnz L(Exit10)
test $0x04, %ah
jnz L(Exit11)
test $0x08, %ah
jnz L(Exit12)
test $0x10, %ah
jnz L(Exit13)
test $0x20, %ah
jnz L(Exit14)
test $0x40, %ah
jnz L(Exit15)
lea 15(%edi), %eax
RETURN
.p2align 4
L(Exit1):
lea (%edi), %eax
RETURN
.p2align 4
L(Exit2):
lea 1(%edi), %eax
RETURN
.p2align 4
L(Exit3):
lea 2(%edi), %eax
RETURN
.p2align 4
L(Exit4):
lea 3(%edi), %eax
RETURN
.p2align 4
L(Exit5):
lea 4(%edi), %eax
RETURN
.p2align 4
L(Exit6):
lea 5(%edi), %eax
RETURN
.p2align 4
L(Exit7):
lea 6(%edi), %eax
RETURN
.p2align 4
L(Exit9):
lea 8(%edi), %eax
RETURN
.p2align 4
L(Exit10):
lea 9(%edi), %eax
RETURN
.p2align 4
L(Exit11):
lea 10(%edi), %eax
RETURN
.p2align 4
L(Exit12):
lea 11(%edi), %eax
RETURN
.p2align 4
L(Exit13):
lea 12(%edi), %eax
RETURN
.p2align 4
L(Exit14):
lea 13(%edi), %eax
RETURN
.p2align 4
L(Exit15):
lea 14(%edi), %eax
RETURN
.p2align 4
L(return_null):
xor %eax, %eax
RETURN
END (strchr)
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