linux/arch/sparc/lib/strlen.S
David S. Miller ae984d72e0 sparc: Unify strlen assembler.
Use the new asm/asm.h header to help commonize the
strlen assembler between 32-bit and 64-bit

While we're here, use proper linux/linkage.h macros
instead of by-hand stuff.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-09 01:07:09 -08:00

80 lines
1.5 KiB
ArmAsm

/* 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)