Optimize x86-64 rawmemchr and add test

This commit is contained in:
Ulrich Drepper 2011-10-19 22:22:29 -04:00
parent d9a4d2ab27
commit 855d156018
4 changed files with 198 additions and 5 deletions

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@ -1,5 +1,10 @@
2011-10-19 Ulrich Drepper <drepper@gmail.com>
* sysdeps/x86_64/multiarch/rawmemchr.S: Small optimization to safe an
instruction.
* string/Makefile (strop-tests): Add rawmemchr.
* string/test-rawmemchr.c: New file.
* sysdeps/x86_64/multiarch/init-arch.h: Define bit_AVX and index_AVX.
* sysdeps/x86_64/multiarch/strcmp-sse42.S: New file. Split out from...
* sysdeps/x86_64/multiarch/strcmp.S: ...here. Include strcmp-sse42.S

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@ -50,7 +50,7 @@ strop-tests := memchr memcmp memcpy memmove mempcpy memset memccpy \
stpcpy stpncpy strcat strchr strcmp strcpy strcspn \
strlen strncmp strncpy strpbrk strrchr strspn memmem \
strstr strcasestr strnlen strcasecmp strncasecmp \
strncat
strncat rawmemchr
tests := tester inl-tester noinl-tester testcopy test-ffs \
tst-strlen stratcliff tst-svc tst-inlcall \
bug-strncat1 bug-strspn1 bug-strpbrk1 tst-bswap \

189
string/test-rawmemchr.c Normal file
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@ -0,0 +1,189 @@
/* Test and measure memchr functions.
Copyright (C) 1999,2002,2003,2005,2009,2011 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. */
#include <assert.h>
#define TEST_MAIN
#include "test-string.h"
typedef char *(*proto_t) (const char *, int);
char *simple_rawmemchr (const char *, int);
IMPL (simple_rawmemchr, 0)
IMPL (rawmemchr, 1)
char *
simple_rawmemchr (const char *s, int c)
{
while (1)
if (*s++ == (char) c)
return (char *) s - 1;
return NULL;
}
static void
do_one_test (impl_t *impl, const char *s, int c, char *exp_res)
{
char *res = CALL (impl, s, c);
if (res != exp_res)
{
error (0, 0, "Wrong result in function %s %p %p", impl->name,
res, exp_res);
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, c);
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 pos, size_t len, int seek_char)
{
size_t i;
char *result;
align &= 7;
if (align + len >= page_size)
return;
for (i = 0; i < len; ++i)
{
buf1[align + i] = 1 + 23 * i % 127;
if (buf1[align + i] == seek_char)
buf1[align + i] = seek_char + 1;
}
buf1[align + len] = 0;
assert (pos < len);
buf1[align + pos] = seek_char;
buf1[align + len] = -seek_char;
result = (char *) (buf1 + align + pos);
if (HP_TIMING_AVAIL)
printf ("Length %4zd, alignment %2zd:", pos, align);
FOR_EACH_IMPL (impl, 0)
do_one_test (impl, (char *) (buf1 + align), seek_char, result);
if (HP_TIMING_AVAIL)
putchar ('\n');
}
static void
do_random_tests (void)
{
size_t i, j, n, align, pos, len;
int seek_char;
char *result;
unsigned char *p = buf1 + page_size - 512;
for (n = 0; n < ITERATIONS; n++)
{
align = random () & 15;
pos = random () & 511;
if (pos + align >= 512)
pos = 511 - align - (random () & 7);
len = random () & 511;
if (len + align >= 512)
len = 512 - align - (random () & 7);
if (pos >= len)
continue;
seek_char = random () & 255;
j = len + align + 64;
if (j > 512)
j = 512;
for (i = 0; i < j; i++)
{
if (i == pos + align)
p[i] = seek_char;
else
{
p[i] = random () & 255;
if (i < pos + align && p[i] == seek_char)
p[i] = seek_char + 13;
}
}
assert (pos < len);
size_t r = random ();
if ((r & 31) == 0)
len = ~(uintptr_t) (p + align) - ((r >> 5) & 31);
result = (char *) (p + pos + align);
FOR_EACH_IMPL (impl, 1)
if (CALL (impl, (char *) (p + align), seek_char) != result)
{
error (0, 0, "Iteration %zd - wrong result in function %s (%zd, %d, %zd, %zd) %p != %p, p %p",
n, impl->name, align, seek_char, len, pos,
CALL (impl, (char *) (p + align), seek_char),
result, 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 < 7; ++i)
{
do_test (0, 16 << i, 2048, 23);
do_test (i, 64, 256, 23);
do_test (0, 16 << i, 2048, 0);
do_test (i, 64, 256, 0);
}
for (i = 1; i < 32; ++i)
{
do_test (0, i, i + 1, 23);
do_test (0, i, i + 1, 0);
}
do_random_tests ();
return ret;
}
#include "../test-skeleton.c"

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@ -50,12 +50,11 @@ __rawmemchr_sse42:
CALL_MCOUNT
movd %esi, %xmm1
movq %rdi, %rcx
punpcklbw %xmm1, %xmm1
pxor %xmm2, %xmm2
andq $~15, %rdi
punpcklbw %xmm1, %xmm1
orl $0xffffffff, %esi
pshufb %xmm2, %xmm1
movdqa (%rdi), %xmm0
pshufd $0, %xmm1, %xmm1
subq %rdi, %rcx
pcmpeqb %xmm1, %xmm0
shl %cl, %esi