Add optimized x86-64 implementation of strnlen.

While at it, beef up the test suite for strnlen and add performance
tests for it, too.
This commit is contained in:
Ulrich Drepper 2010-07-26 08:37:08 -07:00
parent 8e96b93aa7
commit 24fb0f88ed
6 changed files with 301 additions and 20 deletions

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@ -1,3 +1,12 @@
2010-07-26 Ulrich Drepper <drepper@redhat.com>
* string/test-strnlen.c: New file.
* string/Makefile (strop-tests): Add strnlen.
* string/tester.c (test_strnlen): Add a few more test cases.
* string/tst-strlen.c: Better error reporting.
* sysdeps/x86_64/strnlen.S: New file.
2010-07-24 Ulrich Drepper <drepper@redhat.com> 2010-07-24 Ulrich Drepper <drepper@redhat.com>
* sysdeps/x86_64/multiarch/strstr.c (__m128i_strloadu_tolower): Use * sysdeps/x86_64/multiarch/strstr.c (__m128i_strloadu_tolower): Use

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@ -49,7 +49,7 @@ o-objects.ob := memcpy.o memset.o memchr.o
strop-tests := memchr memcmp memcpy memmove mempcpy memset memccpy \ strop-tests := memchr memcmp memcpy memmove mempcpy memset memccpy \
stpcpy stpncpy strcat strchr strcmp strcpy strcspn \ stpcpy stpncpy strcat strchr strcmp strcpy strcspn \
strlen strncmp strncpy strpbrk strrchr strspn memmem \ strlen strncmp strncpy strpbrk strrchr strspn memmem \
strstr strcasestr strstr strcasestr strnlen
tests := tester inl-tester noinl-tester testcopy test-ffs \ tests := tester inl-tester noinl-tester testcopy test-ffs \
tst-strlen stratcliff tst-svc tst-inlcall \ tst-strlen stratcliff tst-svc tst-inlcall \
bug-strncat1 bug-strspn1 bug-strpbrk1 tst-bswap \ bug-strncat1 bug-strspn1 bug-strpbrk1 tst-bswap \

197
string/test-strnlen.c Normal file
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@ -0,0 +1,197 @@
/* Test and measure strlen functions.
Copyright (C) 1999, 2002, 2003, 2005, 2010 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Written by Jakub Jelinek <jakub@redhat.com>, 1999.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#define TEST_MAIN
#include "test-string.h"
typedef size_t (*proto_t) (const char *, size_t);
size_t simple_strnlen (const char *, size_t);
IMPL (simple_strnlen, 0)
IMPL (strnlen, 1)
size_t
simple_strnlen (const char *s, size_t maxlen)
{
size_t i;
for (i = 0; i < maxlen && s[i]; ++i);
return i;
}
static void
do_one_test (impl_t *impl, const char *s, size_t maxlen, size_t exp_len)
{
size_t len = CALL (impl, s, maxlen);
if (len != exp_len)
{
error (0, 0, "Wrong result in function %s %zd %zd", impl->name,
len, exp_len);
ret = 1;
return;
}
if (HP_TIMING_AVAIL)
{
hp_timing_t start __attribute ((unused));
hp_timing_t stop __attribute ((unused));
hp_timing_t best_time = ~ (hp_timing_t) 0;
size_t i;
for (i = 0; i < 32; ++i)
{
HP_TIMING_NOW (start);
CALL (impl, s, maxlen);
HP_TIMING_NOW (stop);
HP_TIMING_BEST (best_time, start, stop);
}
printf ("\t%zd", (size_t) best_time);
}
}
static void
do_test (size_t align, size_t len, size_t maxlen, int max_char)
{
size_t i;
align &= 7;
if (align + len >= page_size)
return;
for (i = 0; i < len; ++i)
buf1[align + i] = 1 + 7 * i % max_char;
buf1[align + len] = 0;
if (HP_TIMING_AVAIL)
printf ("Length %4zd, alignment %2zd:", len, align);
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, (char *) (buf1 + align), maxlen, MIN (len, maxlen));
if (HP_TIMING_AVAIL)
putchar ('\n');
}
static void
do_random_tests (void)
{
size_t i, j, n, align, len;
unsigned char *p = buf1 + page_size - 512;
for (n = 0; n < ITERATIONS; n++)
{
align = random () & 15;
len = random () & 511;
if (len + align > 510)
len = 511 - align - (random () & 7);
j = len + align + 64;
if (j > 512)
j = 512;
for (i = 0; i < j; i++)
{
if (i == len + align)
p[i] = 0;
else
{
p[i] = random () & 255;
if (i >= align && i < len + align && !p[i])
p[i] = (random () & 127) + 1;
}
}
FOR_EACH_IMPL (impl, 1)
{
if (len > 0
&& CALL (impl, (char *) (p + align), len - 1) != len - 1)
{
error (0, 0, "Iteration %zd (limited) - wrong result in function %s (%zd) %zd != %zd, p %p",
n, impl->name, align,
CALL (impl, (char *) (p + align), len - 1), len - 1, p);
ret = 1;
}
if (CALL (impl, (char *) (p + align), len) != len)
{
error (0, 0, "Iteration %zd (exact) - wrong result in function %s (%zd) %zd != %zd, p %p",
n, impl->name, align,
CALL (impl, (char *) (p + align), len), len, p);
ret = 1;
}
if (CALL (impl, (char *) (p + align), len + 1) != len)
{
error (0, 0, "Iteration %zd (long) - wrong result in function %s (%zd) %zd != %zd, p %p",
n, impl->name, align,
CALL (impl, (char *) (p + align), len + 1), len, p);
ret = 1;
}
}
}
}
int
test_main (void)
{
size_t i;
test_init ();
printf ("%20s", "");
FOR_EACH_IMPL (impl, 0)
printf ("\t%s", impl->name);
putchar ('\n');
for (i = 1; i < 8; ++i)
{
do_test (0, i, i - 1, 127);
do_test (0, i, i, 127);
do_test (0, i, i + 1, 127);
}
for (i = 1; i < 8; ++i)
{
do_test (i, i, i - 1, 127);
do_test (i, i, i, 127);
do_test (i, i, i + 1, 127);
}
for (i = 2; i <= 10; ++i)
{
do_test (0, 1 << i, 5000, 127);
do_test (1, 1 << i, 5000, 127);
}
for (i = 1; i < 8; ++i)
do_test (0, i, 5000, 255);
for (i = 1; i < 8; ++i)
do_test (i, i, 5000, 255);
for (i = 2; i <= 10; ++i)
{
do_test (0, 1 << i, 5000, 255);
do_test (1, 1 << i, 5000, 255);
}
do_random_tests ();
return ret;
}
#include "../test-skeleton.c"

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@ -1,5 +1,5 @@
/* Tester for string functions. /* Tester for string functions.
Copyright (C) 1995-2001, 2003, 2005, 2008 Free Software Foundation, Inc. Copyright (C) 1995-2001, 2003, 2005, 2008, 2010 Free Software Foundation, Inc.
This file is part of the GNU C Library. This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or The GNU C Library is free software; you can redistribute it and/or
@ -441,20 +441,21 @@ test_strnlen (void)
check (strnlen ("", 10) == 0, 1); /* Empty. */ check (strnlen ("", 10) == 0, 1); /* Empty. */
check (strnlen ("a", 10) == 1, 2); /* Single char. */ check (strnlen ("a", 10) == 1, 2); /* Single char. */
check (strnlen ("abcd", 10) == 4, 3); /* Multiple chars. */ check (strnlen ("abcd", 10) == 4, 3); /* Multiple chars. */
check (strnlen ("foo", (size_t)-1) == 3, 4); /* limits of n. */ check (strnlen ("foo", (size_t) -1) == 3, 4); /* limits of n. */
check (strnlen ("abcd", 0) == 0, 5); /* Restricted. */
check (strnlen ("abcd", 1) == 1, 6); /* Restricted. */
check (strnlen ("abcd", 2) == 2, 7); /* Restricted. */
check (strnlen ("abcd", 3) == 3, 8); /* Restricted. */
check (strnlen ("abcd", 4) == 4, 9); /* Restricted. */
{ char buf[4096];
char buf[4096]; for (int i = 0; i < 0x100; ++i)
int i; {
char *p; char *p = (char *) ((unsigned long int)(buf + 0xff) & ~0xff) + i;
for (i=0; i < 0x100; i++) strcpy (p, "OK");
{ strcpy (p + 3, "BAD/WRONG");
p = (char *) ((unsigned long int)(buf + 0xff) & ~0xff) + i; check (strnlen (p, 100) == 2, 10 + i);
strcpy (p, "OK"); }
strcpy (p+3, "BAD/WRONG");
check (strnlen (p, 100) == 2, 5+i);
}
}
} }
static void static void
@ -988,7 +989,7 @@ test_memcmp (void)
int cnt = 1; int cnt = 1;
char one[21]; char one[21];
char two[21]; char two[21];
it = "memcmp"; it = "memcmp";
check(memcmp("a", "a", 1) == 0, cnt++); /* Identity. */ check(memcmp("a", "a", 1) == 0, cnt++); /* Identity. */
check(memcmp("abc", "abc", 3) == 0, cnt++); /* Multicharacter. */ check(memcmp("abc", "abc", 3) == 0, cnt++); /* Multicharacter. */

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@ -31,11 +31,21 @@ main(int argc, char *argv[])
buf[words * 4 + 3] = (last & 8) != 0 ? 'e' : '\0'; buf[words * 4 + 3] = (last & 8) != 0 ? 'e' : '\0';
buf[words * 4 + 4] = '\0'; buf[words * 4 + 4] = '\0';
if (strlen (buf) != words * 4 + lens[last] if (strlen (buf) != words * 4 + lens[last])
|| strnlen (buf, -1) != words * 4 + lens[last])
{ {
printf ("failed for base=%Zu, words=%Zu, and last=%Zu\n", printf ("\
base, words, last); strlen failed for base=%Zu, words=%Zu, and last=%Zu (is %zd, expected %zd)\n",
base, words, last,
strlen (buf), words * 4 + lens[last]);
return 1;
}
if (strnlen (buf, -1) != words * 4 + lens[last])
{
printf ("\
strnlen failed for base=%Zu, words=%Zu, and last=%Zu (is %zd, expected %zd)\n",
base, words, last,
strnlen (buf, -1), words * 4 + lens[last]);
return 1; return 1;
} }
} }

64
sysdeps/x86_64/strnlen.S Normal file
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@ -0,0 +1,64 @@
/* strnlen(str,maxlen) -- determine the length of the string STR up to MAXLEN.
Copyright (C) 2010 Free Software Foundation, Inc.
Contributed by Ulrich Drepper <drepper@redhat.com>.
This file is part of the GNU C Library.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <sysdep.h>
.text
ENTRY(__strnlen)
movq %rsi, %rax
testq %rsi, %rsi
jz 3f
pxor %xmm2, %xmm2
movq %rdi, %rcx
movq %rdi, %r8
movq $16, %r9
andq $~15, %rdi
movdqa %xmm2, %xmm1
pcmpeqb (%rdi), %xmm2
orl $0xffffffff, %r10d
subq %rdi, %rcx
shll %cl, %r10d
subq %rcx, %r9
pmovmskb %xmm2, %edx
andl %r10d, %edx
jnz 1f
subq %r9, %rsi
jbe 3f
2: movdqa 16(%rdi), %xmm0
leaq 16(%rdi), %rdi
pcmpeqb %xmm1, %xmm0
pmovmskb %xmm0, %edx
testl %edx, %edx
jnz 1f
subq $16, %rsi
jnbe 2b
3: ret
1: subq %r8, %rdi
bsfl %edx, %edx
addq %rdi, %rdx
cmpq %rdx, %rax
cmovnbq %rdx, %rax
ret
END(__strnlen)
weak_alias (__strnlen, strnlen)
libc_hidden_def (strnlen)