mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-26 20:51:11 +00:00
202 lines
4.7 KiB
ArmAsm
202 lines
4.7 KiB
ArmAsm
/* Compare two strings for differences.
|
|
For SPARC v9.
|
|
Copyright (C) 2011 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by David S. Miller <davem@davemloft.net>
|
|
|
|
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>
|
|
#include <asm/asi.h>
|
|
|
|
#ifndef XCC
|
|
.register %g2, #scratch
|
|
.register %g3, #scratch
|
|
.register %g6, #scratch
|
|
#endif
|
|
|
|
#define rSTR1 %o0
|
|
#define rSTR2 %o1
|
|
#define r0101 %o2 /* 0x0101010101010101 */
|
|
#define r8080 %o3 /* 0x8080808080808080 */
|
|
#define rSTRXOR %o4
|
|
#define rWORD1 %o5
|
|
#define rTMP1 %g1
|
|
#define rTMP2 %g2
|
|
#define rWORD2 %g3
|
|
#define rSLL %g4
|
|
#define rSRL %g5
|
|
#define rBARREL %g6
|
|
|
|
/* There are two cases, either the two pointers are aligned
|
|
* identically or they are not. If they have the same
|
|
* alignment we can use the normal full speed loop. Otherwise
|
|
* we have to use the barrel-shifter version.
|
|
*/
|
|
|
|
.text
|
|
.align 32
|
|
ENTRY(strcmp)
|
|
or rSTR2, rSTR1, rTMP1
|
|
sethi %hi(0x80808080), r8080
|
|
|
|
andcc rTMP1, 0x7, %g0
|
|
bne,pn %icc, .Lmaybe_barrel_shift
|
|
or r8080, %lo(0x80808080), r8080
|
|
ldx [rSTR1], rWORD1
|
|
|
|
sub rSTR2, rSTR1, rSTR2
|
|
sllx r8080, 32, rTMP1
|
|
|
|
ldx [rSTR1 + rSTR2], rWORD2
|
|
or r8080, rTMP1, r8080
|
|
|
|
ba,pt %xcc, .Laligned_loop_entry
|
|
srlx r8080, 7, r0101
|
|
|
|
.align 32
|
|
.Laligned_loop_entry:
|
|
.Laligned_loop:
|
|
add rSTR1, 8, rSTR1
|
|
|
|
sub rWORD1, r0101, rTMP2
|
|
xorcc rWORD1, rWORD2, rSTRXOR
|
|
bne,pn %xcc, .Lcommon_endstring
|
|
|
|
andn r8080, rWORD1, rTMP1
|
|
|
|
ldxa [rSTR1] ASI_PNF, rWORD1
|
|
andcc rTMP1, rTMP2, %g0
|
|
be,a,pt %xcc, .Laligned_loop
|
|
|
|
ldxa [rSTR1 + rSTR2] ASI_PNF, rWORD2
|
|
|
|
.Lcommon_equal:
|
|
retl
|
|
mov 0, %o0
|
|
|
|
/* All loops terminate here once they find an unequal word.
|
|
* If a zero byte appears in the word before the first unequal
|
|
* byte, we must report zero. Otherwise we report '1' or '-1'
|
|
* depending upon whether the first mis-matching byte is larger
|
|
* in the first string or the second, respectively.
|
|
*
|
|
* First we compute a 64-bit mask value that has "0x01" in
|
|
* each byte where a zero exists in rWORD1. rSTRXOR holds the
|
|
* value (rWORD1 ^ rWORD2). Therefore, if considered as an
|
|
* unsigned quantity, our "0x01" mask value is "greater than"
|
|
* rSTRXOR then a zero terminating byte comes first and
|
|
* therefore we report '0'.
|
|
*
|
|
* The formula for this mask is:
|
|
*
|
|
* mask_tmp1 = ~rWORD1 & 0x8080808080808080;
|
|
* mask_tmp2 = ((rWORD1 & 0x7f7f7f7f7f7f7f7f) +
|
|
* 0x7f7f7f7f7f7f7f7f);
|
|
*
|
|
* mask = ((mask_tmp1 & ~mask_tmp2) >> 7);
|
|
*/
|
|
.Lcommon_endstring:
|
|
andn rWORD1, r8080, rTMP2
|
|
or r8080, 1, %o1
|
|
|
|
mov 1, %o0
|
|
sub rTMP2, %o1, rTMP2
|
|
|
|
cmp rWORD1, rWORD2
|
|
andn rTMP1, rTMP2, rTMP1
|
|
|
|
movleu %xcc, -1, %o0
|
|
srlx rTMP1, 7, rTMP1
|
|
|
|
cmp rTMP1, rSTRXOR
|
|
retl
|
|
movgu %xcc, 0, %o0
|
|
|
|
.Lmaybe_barrel_shift:
|
|
sub rSTR2, rSTR1, rSTR2
|
|
sllx r8080, 32, rTMP1
|
|
|
|
or r8080, rTMP1, r8080
|
|
and rSTR1, 0x7, rTMP2
|
|
|
|
srlx r8080, 7, r0101
|
|
andn rSTR1, 0x7, rSTR1
|
|
|
|
ldxa [rSTR1] ASI_PNF, rWORD1
|
|
andcc rSTR2, 0x7, rSLL
|
|
sll rTMP2, 3, rSTRXOR
|
|
|
|
bne,pn %icc, .Lneed_barrel_shift
|
|
mov -1, rTMP1
|
|
ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
|
|
|
|
srlx rTMP1, rSTRXOR, rTMP2
|
|
|
|
orn rWORD1, rTMP2, rWORD1
|
|
ba,pt %xcc, .Laligned_loop_entry
|
|
orn rBARREL, rTMP2, rWORD2
|
|
|
|
.Lneed_barrel_shift:
|
|
sllx rSLL, 3, rSLL
|
|
andn rSTR2, 0x7, rSTR2
|
|
|
|
ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
|
|
mov 64, rTMP2
|
|
sub rTMP2, rSLL, rSRL
|
|
|
|
srlx rTMP1, rSTRXOR, rTMP1
|
|
add rSTR2, 8, rSTR2
|
|
|
|
orn rWORD1, rTMP1, rWORD1
|
|
sllx rBARREL, rSLL, rWORD2
|
|
ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
|
|
|
|
add rSTR1, 8, rSTR1
|
|
sub rWORD1, r0101, rTMP2
|
|
|
|
srlx rBARREL, rSRL, rSTRXOR
|
|
|
|
or rWORD2, rSTRXOR, rWORD2
|
|
|
|
orn rWORD2, rTMP1, rWORD2
|
|
ba,pt %xcc, .Lbarrel_shift_loop_entry
|
|
andn r8080, rWORD1, rTMP1
|
|
|
|
.Lbarrel_shift_loop:
|
|
sllx rBARREL, rSLL, rWORD2
|
|
ldxa [rSTR1 + rSTR2] ASI_PNF, rBARREL
|
|
|
|
add rSTR1, 8, rSTR1
|
|
sub rWORD1, r0101, rTMP2
|
|
|
|
srlx rBARREL, rSRL, rSTRXOR
|
|
andn r8080, rWORD1, rTMP1
|
|
|
|
or rWORD2, rSTRXOR, rWORD2
|
|
|
|
.Lbarrel_shift_loop_entry:
|
|
xorcc rWORD1, rWORD2, rSTRXOR
|
|
bne,pn %xcc, .Lcommon_endstring
|
|
|
|
andcc rTMP1, rTMP2, %g0
|
|
be,a,pt %xcc, .Lbarrel_shift_loop
|
|
ldxa [rSTR1] ASI_PNF, rWORD1
|
|
|
|
retl
|
|
mov 0, %o0
|
|
END(strcmp)
|
|
libc_hidden_builtin_def (strcmp)
|