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sparc: Optimize strlen using techniques from powerpc implementation.
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David S. Miller committed Mar 9, 2010
1 parent 2fe000d commit 462a522
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5 changes: 5 additions & 0 deletions ChangeLog
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Expand Up @@ -6,6 +6,11 @@

* sysdeps/sparc/sparc32/memcpy.S: Fix build.

* sysdeps/sparc/sparc32/strlen.S: Optimize.
* sysdeps/sparc/sparc64/strlen.S: Likewise.
* sysdeps/sparc/sparc32/sparcv9/strlen.S (ASI_PNF, ASI_BLK_P,
XCC): Delete definitions, not needed.

2010-03-07 Ulrich Drepper <drepper@redhat.com>

* sysdeps/unix/sysv/linux/internal_statvfs.c (__statvfs_getflags):
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3 changes: 0 additions & 3 deletions sysdeps/sparc/sparc32/sparcv9/strlen.S
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@@ -1,4 +1 @@
#define ASI_PNF 0x82
#define ASI_BLK_P 0xf0
#define XCC icc
#include <sparc64/strlen.S>
128 changes: 49 additions & 79 deletions sysdeps/sparc/sparc32/strlen.S
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@@ -1,8 +1,9 @@
/* Determine the length of a string.
For SPARC v7.
Copyright (C) 1996, 1999, 2003 Free Software Foundation, Inc.
Copyright (C) 1996, 1999, 2003, 2010 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jj@ultra.linux.cz>.
Contributed by Jakub Jelinek <jj@ultra.linux.cz> and
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
Expand All @@ -21,86 +22,55 @@

#include <sysdep.h>

/* Normally, this uses ((xword - 0x01010101) & 0x80808080) test
to find out if any byte in xword could be zero. This is fast, but
also gives false alarm for any byte in range 0x81-0xff. It does
not matter for correctness, as if this test tells us there could
be some zero byte, we check it byte by byte, but if bytes with
high bits set are common in the strings, then this will give poor
performance. You can #define EIGHTBIT_NOT_RARE and the algorithm
will use one tick slower, but more precise test
((xword - 0x01010101) & (~xword) & 0x80808080),
which does not give any false alarms (but if some bits are set,
one cannot assume from it which bytes are zero and which are not).
It is yet to be measured, what is the correct default for glibc
in these days for an average user.
*/

.text
.align 4

ENTRY(strlen)
mov %o0, %o1
andcc %o0, 3, %g0
be 20f
sethi %hi(0x80808080), %o4

ldub [%o0], %o5
cmp %o5, 0
be 21f
add %o0, 1, %o0
andcc %o0, 3, %g0
be 4f
or %o4, %lo(0x80808080), %o3
ldub [%o0], %o5
cmp %o5, 0
be 22f
add %o0, 1, %o0
andcc %o0, 3, %g0
be 5f
sethi %hi(0x01010101), %o4
ldub [%o0], %o5
cmp %o5, 0
be 23f
add %o0, 1, %o0
b 11f
or %o4, %lo(0x01010101), %o2
21: retl
mov 0, %o0
22: retl
mov 1, %o0
23: retl
mov 2, %o0

20: or %o4, %lo(0x80808080), %o3
4: sethi %hi(0x01010101), %o4
5: or %o4, %lo(0x01010101), %o2
11: ld [%o0], %o5
12: sub %o5, %o2, %o4
#ifdef EIGHTBIT_NOT_RARE
andn %o4, %o5, %o4
#endif
andcc %o4, %o3, %g0
be 11b
add %o0, 4, %o0

srl %o5, 24, %g5
andcc %g5, 0xff, %g0
be 13f
add %o0, -4, %o4
srl %o5, 16, %g5
andcc %g5, 0xff, %g0
be 13f
add %o4, 1, %o4
srl %o5, 8, %g5
andcc %g5, 0xff, %g0
be 13f
add %o4, 1, %o4
andcc %o5, 0xff, %g0
bne,a 12b
ld [%o0], %o5
add %o4, 1, %o4
13: retl
sub %o4, %o1, %o0
mov %o0, %o1
andn %o0, 0x3, %o0

ld [%o0], %o5
and %o1, 0x3, %g1
mov -1, %g5

sethi %hi(0x01010101), %o2
sll %g1, 3, %g1

or %o2, %lo(0x01010101), %o2
srl %g5, %g1, %g2

orn %o5, %g2, %o5
sll %o2, 7, %o3
10: add %o0, 4, %o0

andn %o3, %o5, %g1
sub %o5, %o2, %g2

andcc %g1, %g2, %g0
be,a 10b
ld [%o0], %o5

srl %o5, 24, %g1

andcc %g1, 0xff, %g0
be 90f
sub %o0, 4, %o0

srl %o5, 16, %g2

andcc %g2, 0xff, %g0
be 90f
add %o0, 1, %o0

srl %o5, 8, %g1

andcc %g1, 0xff, %g0
be 90f
add %o0, 1, %o0

add %o0, 1, %o0

90: retl
sub %o0, %o1, %o0
END(strlen)
libc_hidden_builtin_def (strlen)
210 changes: 61 additions & 149 deletions sysdeps/sparc/sparc64/strlen.S
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@@ -1,8 +1,9 @@
/* Determine the length of a string. For SPARC v9.
Copyright (C) 1998, 1999, 2003 Free Software Foundation, Inc.
Copyright (C) 1998, 1999, 2003, 2010 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jan Vondrak <jvon4518@ss1000.ms.mff.cuni.cz> and
Jakub Jelinek <jj@ultra.linux.cz>.
Contributed by Jan Vondrak <jvon4518@ss1000.ms.mff.cuni.cz>,
Jakub Jelinek <jj@ultra.linux.cz>, and
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
Expand All @@ -20,155 +21,66 @@
02111-1307 USA. */

#include <sysdep.h>
#include <asm/asi.h>

/* Normally, this uses
((xword - 0x0101010101010101) & 0x8080808080808080) test
to find out if any byte in xword could be zero. This is fast, but
also gives false alarm for any byte in range 0x81-0xff. It does
not matter for correctness, as if this test tells us there could
be some zero byte, we check it byte by byte, but if bytes with
high bits set are common in the strings, then this will give poor
performance. You can #define EIGHTBIT_NOT_RARE and the algorithm
will use one tick slower, but more precise test
((xword - 0x0101010101010101) & (~xword) & 0x8080808080808080),
which does not give any false alarms (but if some bits are set,
one cannot assume from it which bytes are zero and which are not).
It is yet to be measured, what is the correct default for glibc
in these days for an average user.
*/

.register %g2, #scratch
.register %g3, #scratch

.text
.align 32
ENTRY(strlen)
sethi %hi(0x01010101), %g1 /* IEU0 Group */
ldub [%o0], %o3 /* Load */
or %g1, %lo(0x01010101), %g1 /* IEU0 Group */
mov %o0, %o1 /* IEU1 */

sllx %g1, 32, %g4 /* IEU0 Group */
andcc %o0, 7, %g0 /* IEU1 */
or %g1, %g4, %g1 /* IEU0 Group */
brz,pn %o3, 13f /* CTI+IEU1 */

sllx %g1, 7, %g4 /* IEU0 Group */
bne,a,pn %icc, 15f /* CTI */
add %o0, 1, %o0 /* IEU1 */
/* %g1 = 0x0101010101010101 *
* %g4 = 0x8080808080808080 *
* %o0 = string pointer *
* %o1 = start of string */
1: ldx [%o0], %o3 /* Load Group */

add %o0, 8, %o0 /* IEU1 */
2: sub %o3, %g1, %o2 /* IEU0 Group */
#ifdef EIGHTBIT_NOT_RARE
andn %o2, %o3, %o5 /* IEU0 Group */
ldxa [%o0] ASI_PNF, %o3 /* Load */
andcc %o5, %g4, %g0 /* IEU1 Group */
#else
ldxa [%o0] ASI_PNF, %o3 /* Load */
andcc %o2, %g4, %g0 /* IEU1 Group */
#endif

be,pt %xcc, 2b /* CTI */
add %o0, 8, %o0 /* IEU0 */
addcc %o2, %g1, %g5 /* IEU1 Group */
#ifdef EIGHTBIT_NOT_RARE
srlx %o5, 32, %o5 /* IEU0 */

3: andcc %o5, %g4, %g0 /* IEU1 Group */
#else
srlx %o2, 32, %o2 /* IEU0 */

3: andcc %o2, %g4, %g0 /* IEU1 Group */
#endif
be,pn %xcc, 4f /* CTI */
srlx %g5, 56, %o2 /* IEU0 */
andcc %o2, 0xff, %g0 /* IEU1 Group */

be,pn %icc, 12f /* CTI */
srlx %g5, 48, %o2 /* IEU0 */
andcc %o2, 0xff, %g0 /* IEU1 Group */
be,pn %icc, 11f /* CTI */

srlx %g5, 40, %o2 /* IEU0 */
andcc %o2, 0xff, %g0 /* IEU1 Group */
be,pn %icc, 10f /* CTI */
srlx %g5, 32, %o2 /* IEU0 */

andcc %o2, 0xff, %g0 /* IEU1 Group */
be,pn %icc, 9f /* CTI */
4: srlx %g5, 24, %o2 /* IEU0 */
andcc %o2, 0xff, %g0 /* IEU1 Group */

be,pn %icc, 8f /* CTI */
srlx %g5, 16, %o2 /* IEU0 */
andcc %o2, 0xff, %g0 /* IEU1 Group */
be,pn %icc, 7f /* CTI */

srlx %g5, 8, %o2 /* IEU0 */
andcc %o2, 0xff, %g0 /* IEU1 Group */
be,pn %icc, 6f /* CTI */
sub %o3, %g1, %o2 /* IEU0 */

andcc %g5, 0xff, %g0 /* IEU1 Group */
be,pn %icc, 5f /* CTI */
ldxa [%o0] ASI_PNF, %o3 /* Load */
andcc %o2, %g4, %g0 /* IEU1 Group */

be,pt %xcc, 2b /* CTI */
add %o0, 8, %o0 /* IEU0 */
addcc %o2, %g1, %g5 /* IEU1 Group */
ba,pt %xcc, 3b /* CTI */

srlx %o2, 32, %o2 /* IEU0 */
5: add %o0, -9, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */

6: add %o0, -10, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */
7: add %o0, -11, %o0 /* IEU0 Group */

retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */
8: add %o0, -12, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */

sub %o0, %o1, %o0 /* IEU0 */
9: add %o0, -13, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */

10: add %o0, -14, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */
11: add %o0, -15, %o0 /* IEU0 Group */

retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */
12: add %o0, -16, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */

sub %o0, %o1, %o0 /* IEU0 */
13: retl /* CTI+IEU1 Group */
mov 0, %o0 /* IEU0 */
nop

15: ldub [%o0], %o3 /* Load Group */
16: andcc %o0, 7, %g0 /* IEU1 */
be,pn %icc, 1b /* CTI */
nop /* IEU0 Group */

add %o0, 1, %o0 /* IEU1 */
andcc %o3, 0xff, %g0 /* IEU1 Group */
bne,a,pt %icc, 16b /* CTI */
lduba [%o0] ASI_PNF, %o3 /* Load */

add %o0, -1, %o0 /* IEU0 Group */
retl /* CTI+IEU1 Group */
sub %o0, %o1, %o0 /* IEU0 */
mov %o0, %o1
andn %o0, 0x7, %o0

ldx [%o0], %o5
and %o1, 0x7, %g1
mov -1, %g5

sethi %hi(0x01010101), %o2
sll %g1, 3, %g1

or %o2, %lo(0x01010101), %o2
srlx %g5, %g1, %o3

sllx %o2, 32, %g1
sethi %hi(0x0000ff00), %g5

orn %o5, %o3, %o5
or %o2, %g1, %o2

sllx %o2, 7, %o3
10: add %o0, 8, %o0

andn %o3, %o5, %g1
sub %o5, %o2, %g2

andcc %g1, %g2, %g0
be,a,pt %xcc, 10b
ldx [%o0], %o5
srlx %o5, 32, %g1

andn %o3, %g1, %o4
sub %g1, %o2, %g2

add %o0, 4, %g3
andcc %o4, %g2, %g0
movne %icc, %g1, %o5

move %icc, %g3, %o0
or %g5, %lo(0x0000ff00), %g5
mov 3 - 8, %g2

andcc %o5, %g5, %g0
srlx %o5, 16, %g1
move %icc, 2 - 8, %g2

andcc %g1, 0xff, %g0
srl %o5, 24, %o5
move %icc, 1 - 8, %g2

movrz %o5, 0 - 8, %g2
sub %o0, %o1, %o0

retl
add %o0, %g2, %o0
END(strlen)
libc_hidden_builtin_def (strlen)

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