linux/arch/sparc64/lib/strlen_user.S
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

96 lines
1.8 KiB
ArmAsm

/* strlen_user.S: Sparc64 optimized strlen_user code
*
* Return length of string in userspace including terminating 0
* or 0 for error
*
* Copyright (C) 1991,1996 Free Software Foundation
* Copyright (C) 1996,1999 David S. Miller (davem@redhat.com)
* Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
*/
#include <asm/asi.h>
#define LO_MAGIC 0x01010101
#define HI_MAGIC 0x80808080
.align 4
.global __strlen_user, __strnlen_user
__strlen_user:
sethi %hi(32768), %o1
__strnlen_user:
mov %o1, %g1
mov %o0, %o1
andcc %o0, 3, %g0
be,pt %icc, 9f
sethi %hi(HI_MAGIC), %o4
10: lduba [%o0] %asi, %o5
brz,pn %o5, 21f
add %o0, 1, %o0
andcc %o0, 3, %g0
be,pn %icc, 4f
or %o4, %lo(HI_MAGIC), %o3
11: lduba [%o0] %asi, %o5
brz,pn %o5, 22f
add %o0, 1, %o0
andcc %o0, 3, %g0
be,pt %icc, 13f
srl %o3, 7, %o2
12: lduba [%o0] %asi, %o5
brz,pn %o5, 23f
add %o0, 1, %o0
ba,pt %icc, 2f
15: lda [%o0] %asi, %o5
9: or %o4, %lo(HI_MAGIC), %o3
4: srl %o3, 7, %o2
13: lda [%o0] %asi, %o5
2: sub %o5, %o2, %o4
andcc %o4, %o3, %g0
bne,pn %icc, 82f
add %o0, 4, %o0
sub %o0, %o1, %g2
81: cmp %g2, %g1
blu,pt %icc, 13b
mov %o0, %o4
ba,a,pt %xcc, 1f
/* Check every byte. */
82: srl %o5, 24, %g7
andcc %g7, 0xff, %g0
be,pn %icc, 1f
add %o0, -3, %o4
srl %o5, 16, %g7
andcc %g7, 0xff, %g0
be,pn %icc, 1f
add %o4, 1, %o4
srl %o5, 8, %g7
andcc %g7, 0xff, %g0
be,pn %icc, 1f
add %o4, 1, %o4
andcc %o5, 0xff, %g0
bne,pt %icc, 81b
sub %o0, %o1, %g2
add %o4, 1, %o4
1: retl
sub %o4, %o1, %o0
21: retl
mov 1, %o0
22: retl
mov 2, %o0
23: retl
mov 3, %o0
.section .fixup,#alloc,#execinstr
.align 4
30:
retl
clr %o0
.section __ex_table,#alloc
.align 4
.word 10b, 30b
.word 11b, 30b
.word 12b, 30b
.word 15b, 30b
.word 13b, 30b