/* strlen.S: Sparc optimized strlen code | |
* Hand optimized from GNU libc's strlen | |
* Copyright (C) 1991,1996 Free Software Foundation | |
* Copyright (C) 1996,2008 David S. Miller (davem@davemloft.net) | |
* Copyright (C) 1996, 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz) | |
*/ | |
#include <linux/linkage.h> | |
#include <asm/asm.h> | |
#define LO_MAGIC 0x01010101 | |
#define HI_MAGIC 0x80808080 | |
.text | |
ENTRY(strlen) | |
mov %o0, %o1 | |
andcc %o0, 3, %g0 | |
BRANCH32(be, pt, 9f) | |
sethi %hi(HI_MAGIC), %o4 | |
ldub [%o0], %o5 | |
BRANCH_REG_ZERO(pn, %o5, 11f) | |
add %o0, 1, %o0 | |
andcc %o0, 3, %g0 | |
BRANCH32(be, pn, 4f) | |
or %o4, %lo(HI_MAGIC), %o3 | |
ldub [%o0], %o5 | |
BRANCH_REG_ZERO(pn, %o5, 12f) | |
add %o0, 1, %o0 | |
andcc %o0, 3, %g0 | |
BRANCH32(be, pt, 5f) | |
sethi %hi(LO_MAGIC), %o4 | |
ldub [%o0], %o5 | |
BRANCH_REG_ZERO(pn, %o5, 13f) | |
add %o0, 1, %o0 | |
BRANCH32(ba, pt, 8f) | |
or %o4, %lo(LO_MAGIC), %o2 | |
9: | |
or %o4, %lo(HI_MAGIC), %o3 | |
4: | |
sethi %hi(LO_MAGIC), %o4 | |
5: | |
or %o4, %lo(LO_MAGIC), %o2 | |
8: | |
ld [%o0], %o5 | |
2: | |
sub %o5, %o2, %o4 | |
andcc %o4, %o3, %g0 | |
BRANCH32(be, pt, 8b) | |
add %o0, 4, %o0 | |
/* Check every byte. */ | |
srl %o5, 24, %g7 | |
andcc %g7, 0xff, %g0 | |
BRANCH32(be, pn, 1f) | |
add %o0, -4, %o4 | |
srl %o5, 16, %g7 | |
andcc %g7, 0xff, %g0 | |
BRANCH32(be, pn, 1f) | |
add %o4, 1, %o4 | |
srl %o5, 8, %g7 | |
andcc %g7, 0xff, %g0 | |
BRANCH32(be, pn, 1f) | |
add %o4, 1, %o4 | |
andcc %o5, 0xff, %g0 | |
BRANCH32_ANNUL(bne, pt, 2b) | |
ld [%o0], %o5 | |
add %o4, 1, %o4 | |
1: | |
retl | |
sub %o4, %o1, %o0 | |
11: | |
retl | |
mov 0, %o0 | |
12: | |
retl | |
mov 1, %o0 | |
13: | |
retl | |
mov 2, %o0 | |
ENDPROC(strlen) |