mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-17 18:40:14 +00:00
1d280d9f1e
Use C comments throughout. Line up operands column with tabs. * sysdeps/powerpc/strchr.S: Likewise. * sysdeps/powerpc/strcmp.S: Likewise. * sysdeps/powerpc/strcpy.S: Likewise. * sysdeps/powerpc/strlen.S: Likewise. * sysdeps/powerpc/memset.S: Define & use symbolic register names. Use C comments throughout. Line up operands column with tabs. * sysdeps/powerpc/strchr.S: Likewise. * sysdeps/powerpc/strcmp.S: Likewise. * sysdeps/powerpc/strcpy.S: Likewise. * sysdeps/powerpc/strlen.S: Likewise.
114 lines
3.0 KiB
ArmAsm
114 lines
3.0 KiB
ArmAsm
/* Optimized strcmp implementation for PowerPC.
|
|
Copyright (C) 1997, 1999, 2000 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include <sysdep.h>
|
|
|
|
/* See strlen.s for comments on how the end-of-string testing works. */
|
|
|
|
/* int [r3] strcmp (const char *s1 [r3], const char *s2 [r4]) */
|
|
|
|
EALIGN (strcmp, 4, 0)
|
|
|
|
#define rTMP r0
|
|
#define rRTN r3 /* return value */
|
|
#define rSTR1 r3 /* first string arg */
|
|
#define rSTR2 r4 /* second string arg */
|
|
#define rWORD1 r5 /* current word in s1 */
|
|
#define rWORD2 r6 /* current word in s2 */
|
|
#define rFEFE r7 /* constant 0xfefefeff (-0x01010101) */
|
|
#define r7F7F r8 /* constant 0x7f7f7f7f */
|
|
#define rNEG r9 /* ~(word in s1 | 0x7f7f7f7f) */
|
|
#define rBITDIF r10 /* bits that differ in s1 & s2 words */
|
|
|
|
or rTMP, rSTR2, rSTR1
|
|
clrlwi. rTMP, rTMP, 30
|
|
lis rFEFE, -0x101
|
|
bne L(unaligned)
|
|
|
|
lwz rWORD1, 0(rSTR1)
|
|
lwz rWORD2, 0(rSTR2)
|
|
lis r7F7F, 0x7f7f
|
|
addi rFEFE, rFEFE, -0x101
|
|
addi r7F7F, r7F7F, 0x7f7f
|
|
b L(g1)
|
|
|
|
L(g0): lwzu rWORD1, 4(rSTR1)
|
|
bne cr1, L(different)
|
|
lwzu rWORD2, 4(rSTR2)
|
|
L(g1): add rTMP, rFEFE, rWORD1
|
|
nor rNEG, r7F7F, rWORD1
|
|
and. rTMP, rTMP, rNEG
|
|
cmpw cr1, rWORD1, rWORD2
|
|
beq+ L(g0)
|
|
L(endstring):
|
|
/* OK. We've hit the end of the string. We need to be careful that
|
|
we don't compare two strings as different because of gunk beyond
|
|
the end of the strings... */
|
|
and rTMP, r7F7F, rWORD1
|
|
beq cr1, L(equal)
|
|
add rTMP, rTMP, r7F7F
|
|
xor. rBITDIF, rWORD1, rWORD2
|
|
andc rNEG, rNEG, rTMP
|
|
blt- L(highbit)
|
|
cntlzw rBITDIF, rBITDIF
|
|
cntlzw rNEG, rNEG
|
|
addi rNEG, rNEG, 7
|
|
cmpw cr1, rNEG, rBITDIF
|
|
sub rRTN, rWORD1, rWORD2
|
|
bgelr+ cr1
|
|
L(equal):
|
|
li rRTN, 0
|
|
blr
|
|
|
|
L(different):
|
|
lwz rWORD1, -4(rSTR1)
|
|
xor. rBITDIF, rWORD1, rWORD2
|
|
sub rRTN, rWORD1, rWORD2
|
|
bgelr+
|
|
L(highbit):
|
|
ori rRTN, rWORD2, 1
|
|
blr
|
|
|
|
|
|
/* Oh well. In this case, we just do a byte-by-byte comparison. */
|
|
.align 4
|
|
L(unaligned):
|
|
lbz rWORD1, 0(rSTR1)
|
|
lbz rWORD2, 0(rSTR2)
|
|
b L(u1)
|
|
|
|
L(u0): lbzu rWORD1, 1(rSTR1)
|
|
bne- L(u4)
|
|
lbzu rWORD2, 1(rSTR2)
|
|
L(u1): cmpwi cr1, rWORD1, 0
|
|
beq- cr1, L(u3)
|
|
cmpw rWORD1, rWORD2
|
|
bne- L(u3)
|
|
lbzu rWORD1, 1(rSTR1)
|
|
lbzu rWORD2, 1(rSTR2)
|
|
cmpwi cr1, rWORD1, 0
|
|
cmpw rWORD1, rWORD2
|
|
bne+ cr1, L(u0)
|
|
L(u3): sub rRTN, rWORD1, rWORD2
|
|
blr
|
|
L(u4): lbz rWORD1, -1(rSTR1)
|
|
sub rRTN, rWORD1, rWORD2
|
|
blr
|
|
END(strcmp)
|