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|
/* Optimized memchr with sse2
Copyright (C) 2011-2022 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
<https://www.gnu.org/licenses/>. */
#if IS_IN (libc)
# include <sysdep.h>
# 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 4
# define STR1 PARMS
# define STR2 STR1+4
# ifndef USE_AS_RAWMEMCHR
# define LEN STR2+4
# define RETURN POP(%edi); ret; CFI_PUSH(%edi);
# endif
# ifndef MEMCHR
# define MEMCHR __memchr_sse2_bsf
# endif
.text
ENTRY (MEMCHR)
mov STR1(%esp), %ecx
movd STR2(%esp), %xmm1
# ifndef USE_AS_RAWMEMCHR
mov LEN(%esp), %edx
test %edx, %edx
jz L(return_null_1)
# endif
mov %ecx, %eax
punpcklbw %xmm1, %xmm1
punpcklbw %xmm1, %xmm1
and $63, %ecx
pshufd $0, %xmm1, %xmm1
cmp $48, %ecx
ja L(crosscache)
movdqu (%eax), %xmm0
pcmpeqb %xmm1, %xmm0
/* Check if there is a match. */
pmovmskb %xmm0, %ecx
test %ecx, %ecx
je L(unaligned_no_match_1)
/* Check which byte is a match. */
bsf %ecx, %ecx
# ifndef USE_AS_RAWMEMCHR
sub %ecx, %edx
jbe L(return_null_1)
# endif
add %ecx, %eax
ret
.p2align 4
L(unaligned_no_match_1):
# ifndef USE_AS_RAWMEMCHR
sub $16, %edx
jbe L(return_null_1)
PUSH (%edi)
lea 16(%eax), %edi
and $15, %eax
and $-16, %edi
add %eax, %edx
# else
lea 16(%eax), %edx
and $-16, %edx
# endif
jmp L(loop_prolog)
.p2align 4
L(return_null_1):
xor %eax, %eax
ret
# ifndef USE_AS_RAWMEMCHR
CFI_POP (%edi)
# endif
.p2align 4
L(crosscache):
/* Handle unaligned string. */
# ifndef USE_AS_RAWMEMCHR
PUSH (%edi)
mov %eax, %edi
and $15, %ecx
and $-16, %edi
movdqa (%edi), %xmm0
# else
mov %eax, %edx
and $15, %ecx
and $-16, %edx
movdqa (%edx), %xmm0
# endif
pcmpeqb %xmm1, %xmm0
/* Check if there is a match. */
pmovmskb %xmm0, %eax
/* Remove the leading bytes. */
sar %cl, %eax
test %eax, %eax
je L(unaligned_no_match)
/* Check which byte is a match. */
bsf %eax, %eax
# ifndef USE_AS_RAWMEMCHR
sub %eax, %edx
jbe L(return_null)
add %edi, %eax
add %ecx, %eax
RETURN
# else
add %edx, %eax
add %ecx, %eax
ret
# endif
.p2align 4
L(unaligned_no_match):
# ifndef USE_AS_RAWMEMCHR
/* Calculate the last acceptable address and check for possible
addition overflow by using satured math:
edx = ecx + edx
edx |= -(edx < ecx) */
add %ecx, %edx
sbb %eax, %eax
or %eax, %edx
sub $16, %edx
jbe L(return_null)
add $16, %edi
# else
add $16, %edx
# endif
.p2align 4
/* Loop start on aligned string. */
L(loop_prolog):
# ifndef USE_AS_RAWMEMCHR
sub $64, %edx
jbe L(exit_loop)
movdqa (%edi), %xmm0
# else
movdqa (%edx), %xmm0
# endif
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
# ifndef USE_AS_RAWMEMCHR
movdqa 16(%edi), %xmm2
# else
movdqa 16(%edx), %xmm2
# endif
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches16)
# ifndef USE_AS_RAWMEMCHR
movdqa 32(%edi), %xmm3
# else
movdqa 32(%edx), %xmm3
# endif
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches32)
# ifndef USE_AS_RAWMEMCHR
movdqa 48(%edi), %xmm4
# else
movdqa 48(%edx), %xmm4
# endif
pcmpeqb %xmm1, %xmm4
# ifndef USE_AS_RAWMEMCHR
add $64, %edi
# else
add $64, %edx
# endif
pmovmskb %xmm4, %eax
test %eax, %eax
jnz L(matches0)
# ifndef USE_AS_RAWMEMCHR
test $0x3f, %edi
# else
test $0x3f, %edx
# endif
jz L(align64_loop)
# ifndef USE_AS_RAWMEMCHR
sub $64, %edx
jbe L(exit_loop)
movdqa (%edi), %xmm0
# else
movdqa (%edx), %xmm0
# endif
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
# ifndef USE_AS_RAWMEMCHR
movdqa 16(%edi), %xmm2
# else
movdqa 16(%edx), %xmm2
# endif
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches16)
# ifndef USE_AS_RAWMEMCHR
movdqa 32(%edi), %xmm3
# else
movdqa 32(%edx), %xmm3
# endif
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches32)
# ifndef USE_AS_RAWMEMCHR
movdqa 48(%edi), %xmm3
# else
movdqa 48(%edx), %xmm3
# endif
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
# ifndef USE_AS_RAWMEMCHR
add $64, %edi
# else
add $64, %edx
# endif
test %eax, %eax
jnz L(matches0)
# ifndef USE_AS_RAWMEMCHR
mov %edi, %ecx
and $-64, %edi
and $63, %ecx
add %ecx, %edx
# else
and $-64, %edx
# endif
.p2align 4
L(align64_loop):
# ifndef USE_AS_RAWMEMCHR
sub $64, %edx
jbe L(exit_loop)
movdqa (%edi), %xmm0
movdqa 16(%edi), %xmm2
movdqa 32(%edi), %xmm3
movdqa 48(%edi), %xmm4
# else
movdqa (%edx), %xmm0
movdqa 16(%edx), %xmm2
movdqa 32(%edx), %xmm3
movdqa 48(%edx), %xmm4
# endif
pcmpeqb %xmm1, %xmm0
pcmpeqb %xmm1, %xmm2
pcmpeqb %xmm1, %xmm3
pcmpeqb %xmm1, %xmm4
pmaxub %xmm0, %xmm3
pmaxub %xmm2, %xmm4
pmaxub %xmm3, %xmm4
pmovmskb %xmm4, %eax
# ifndef USE_AS_RAWMEMCHR
add $64, %edi
# else
add $64, %edx
# endif
test %eax, %eax
jz L(align64_loop)
# ifndef USE_AS_RAWMEMCHR
sub $64, %edi
# else
sub $64, %edx
# endif
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches16)
# ifndef USE_AS_RAWMEMCHR
movdqa 32(%edi), %xmm3
# else
movdqa 32(%edx), %xmm3
# endif
pcmpeqb %xmm1, %xmm3
# ifndef USE_AS_RAWMEMCHR
pcmpeqb 48(%edi), %xmm1
# else
pcmpeqb 48(%edx), %xmm1
# endif
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches32)
pmovmskb %xmm1, %eax
bsf %eax, %eax
# ifndef USE_AS_RAWMEMCHR
lea 48(%edi, %eax), %eax
RETURN
# else
lea 48(%edx, %eax), %eax
ret
# endif
# ifndef USE_AS_RAWMEMCHR
.p2align 4
L(exit_loop):
add $64, %edx
cmp $32, %edx
jbe L(exit_loop_32)
movdqa (%edi), %xmm0
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches)
movdqa 16(%edi), %xmm2
pcmpeqb %xmm1, %xmm2
pmovmskb %xmm2, %eax
test %eax, %eax
jnz L(matches16)
movdqa 32(%edi), %xmm3
pcmpeqb %xmm1, %xmm3
pmovmskb %xmm3, %eax
test %eax, %eax
jnz L(matches32_1)
cmp $48, %edx
jbe L(return_null)
pcmpeqb 48(%edi), %xmm1
pmovmskb %xmm1, %eax
test %eax, %eax
jnz L(matches48_1)
xor %eax, %eax
RETURN
.p2align 4
L(exit_loop_32):
movdqa (%edi), %xmm0
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %eax
test %eax, %eax
jnz L(matches_1)
cmp $16, %edx
jbe L(return_null)
pcmpeqb 16(%edi), %xmm1
pmovmskb %xmm1, %eax
test %eax, %eax
jnz L(matches16_1)
xor %eax, %eax
RETURN
# endif
.p2align 4
L(matches0):
bsf %eax, %eax
# ifndef USE_AS_RAWMEMCHR
lea -16(%eax, %edi), %eax
RETURN
# else
lea -16(%eax, %edx), %eax
ret
# endif
.p2align 4
L(matches):
bsf %eax, %eax
# ifndef USE_AS_RAWMEMCHR
add %edi, %eax
RETURN
# else
add %edx, %eax
ret
# endif
.p2align 4
L(matches16):
bsf %eax, %eax
# ifndef USE_AS_RAWMEMCHR
lea 16(%eax, %edi), %eax
RETURN
# else
lea 16(%eax, %edx), %eax
ret
# endif
.p2align 4
L(matches32):
bsf %eax, %eax
# ifndef USE_AS_RAWMEMCHR
lea 32(%eax, %edi), %eax
RETURN
# else
lea 32(%eax, %edx), %eax
ret
# endif
# ifndef USE_AS_RAWMEMCHR
.p2align 4
L(matches_1):
bsf %eax, %eax
sub %eax, %edx
jbe L(return_null)
add %edi, %eax
RETURN
.p2align 4
L(matches16_1):
sub $16, %edx
bsf %eax, %eax
sub %eax, %edx
jbe L(return_null)
lea 16(%edi, %eax), %eax
RETURN
.p2align 4
L(matches32_1):
sub $32, %edx
bsf %eax, %eax
sub %eax, %edx
jbe L(return_null)
lea 32(%edi, %eax), %eax
RETURN
.p2align 4
L(matches48_1):
sub $48, %edx
bsf %eax, %eax
sub %eax, %edx
jbe L(return_null)
lea 48(%edi, %eax), %eax
RETURN
# endif
.p2align 4
L(return_null):
xor %eax, %eax
# ifndef USE_AS_RAWMEMCHR
RETURN
# else
ret
# endif
END (MEMCHR)
#endif
|
