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Add optimized x86-64 implementation of strnlen.
While at it, beef up the test suite for strnlen and add performance tests for it, too.
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Ulrich Drepper
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Jul 26, 2010
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -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); | ||
|
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||
| IMPL (simple_strnlen, 0) | ||
| IMPL (strnlen, 1) | ||
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| size_t | ||
| simple_strnlen (const char *s, size_t maxlen) | ||
| { | ||
| size_t i; | ||
|
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||
| 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); | ||
| } | ||
|
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| 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; | ||
|
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| align &= 7; | ||
| if (align + len >= page_size) | ||
| return; | ||
|
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| for (i = 0; i < len; ++i) | ||
| buf1[align + i] = 1 + 7 * i % max_char; | ||
| buf1[align + len] = 0; | ||
|
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| if (HP_TIMING_AVAIL) | ||
| printf ("Length %4zd, alignment %2zd:", len, align); | ||
|
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| FOR_EACH_IMPL (impl, 0) | ||
| do_one_test (impl, (char *) (buf1 + align), maxlen, MIN (len, maxlen)); | ||
|
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||
| 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; | ||
|
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||
| 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; | ||
|
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||
| 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; | ||
| } | ||
| } | ||
|
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||
| 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; | ||
| } | ||
| } | ||
| } | ||
| } | ||
|
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| int | ||
| test_main (void) | ||
| { | ||
| size_t i; | ||
|
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| test_init (); | ||
|
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| printf ("%20s", ""); | ||
| FOR_EACH_IMPL (impl, 0) | ||
| printf ("\t%s", impl->name); | ||
| putchar ('\n'); | ||
|
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| 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); | ||
| } | ||
|
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| 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); | ||
| } | ||
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| for (i = 2; i <= 10; ++i) | ||
| { | ||
| do_test (0, 1 << i, 5000, 127); | ||
| do_test (1, 1 << i, 5000, 127); | ||
| } | ||
|
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| for (i = 1; i < 8; ++i) | ||
| do_test (0, i, 5000, 255); | ||
|
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| for (i = 1; i < 8; ++i) | ||
| do_test (i, i, 5000, 255); | ||
|
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| for (i = 2; i <= 10; ++i) | ||
| { | ||
| do_test (0, 1 << i, 5000, 255); | ||
| do_test (1, 1 << i, 5000, 255); | ||
| } | ||
|
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||
| do_random_tests (); | ||
| return ret; | ||
| } | ||
|
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||
| #include "../test-skeleton.c" |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -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. */ | ||
|
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||
| #include <sysdep.h> | ||
|
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||
|
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| .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 | ||
|
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| 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 | ||
|
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| 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) |