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/* Optimized memcmp implementation for PowerPC476.
Copyright (C) 2010-2013 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>
/* memcmp
r3:source1 address, return equality
r4:source2 address
r5:byte count
Check 2 words from src1 and src2. If unequal jump to end and
return src1 > src2 or src1 < src2.
If count = zero check bytes before zero counter and then jump to end and
return src1 > src2, src1 < src2 or src1 = src2.
If src1 = src2 and no null, repeat. */
EALIGN (memcmp, 5, 0)
srwi. r6,r5,5
beq L(preword2_count_loop)
mtctr r6
clrlwi r5,r5,27
L(word8_compare_loop):
lwz r10,0(r3)
lwz r6,4(r3)
lwz r8,0(r4)
lwz r9,4(r4)
cmplw cr5,r8,r10
cmplw cr1,r9,r6
bne cr5,L(st2)
bne cr1,L(st1)
lwz r10,8(r3)
lwz r6,12(r3)
lwz r8,8(r4)
lwz r9,12(r4)
cmplw cr5,r8,r10
cmplw cr1,r9,r6
bne cr5,L(st2)
bne cr1,L(st1)
lwz r10,16(r3)
lwz r6,20(r3)
lwz r8,16(r4)
lwz r9,20(r4)
cmplw cr5,r8,r10
cmplw cr1,r9,r6
bne cr5,L(st2)
bne cr1,L(st1)
lwz r10,24(r3)
lwz r6,28(r3)
addi r3,r3,0x20
lwz r8,24(r4)
lwz r9,28(r4)
addi r4,r4,0x20
cmplw cr5,r8,r10
cmplw cr1,r9,r6
bne cr5,L(st2)
bne cr1,L(st1)
bdnz L(word8_compare_loop)
L(preword2_count_loop):
srwi. r6,r5,3
beq L(prebyte_count_loop)
mtctr r6
clrlwi r5,r5,29
L(word2_count_loop):
lwz r10,0(r3)
lwz r6,4(r3)
addi r3,r3,0x08
lwz r8,0(r4)
lwz r9,4(r4)
addi r4,r4,0x08
cmplw cr5,r8,r10
cmplw cr1,r9,r6
bne cr5,L(st2)
bne cr1,L(st1)
bdnz L(word2_count_loop)
L(prebyte_count_loop):
addi r5,r5,1
mtctr r5
bdz L(end_memcmp)
L(byte_count_loop):
lbz r6,0(r3)
addi r3,r3,0x01
lbz r8,0(r4)
addi r4,r4,0x01
cmplw cr5,r8,r6
bne cr5,L(st2)
bdnz L(byte_count_loop)
L(end_memcmp):
addi r3,r0,0
blr
L(l_r):
addi r3,r0,1
blr
L(st1):
blt cr1,L(l_r)
addi r3,r0,-1
blr
L(st2):
blt cr5,L(l_r)
addi r3,r0,-1
blr
END (memcmp)
libc_hidden_builtin_def (memcmp)
weak_alias (memcmp,bcmp)
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