diff options
Diffstat (limited to 'benchtests/bench-strstr.c')
| -rw-r--r-- | benchtests/bench-strstr.c | 220 |
1 files changed, 137 insertions, 83 deletions
diff --git a/benchtests/bench-strstr.c b/benchtests/bench-strstr.c index 2e67812..31309b2 100644 --- a/benchtests/bench-strstr.c +++ b/benchtests/bench-strstr.c @@ -16,63 +16,140 @@ License along with the GNU C Library; if not, see <http://www.gnu.org/licenses/>. */ +#define MIN_PAGE_SIZE 131072 #define TEST_MAIN #define TEST_NAME "strstr" #include "bench-string.h" - -#define STRSTR simple_strstr -#define libc_hidden_builtin_def(X) -#define __strnlen strnlen -#include "../string/strstr.c" - - +static const char input[] = +"This manual is written with the assumption that you are at least " +"somewhat familiar with the C programming language and basic programming " +"concepts. Specifically, familiarity with ISO standard C (*note ISO " +"C::), rather than “traditional” pre-ISO C dialects, is assumed.\n" + +" The GNU C Library includes several “header files”, each of which " +"provides definitions and declarations for a group of related facilities; " +"this information is used by the C compiler when processing your program. " +"For example, the header file ‘stdio.h’ declares facilities for " +"performing input and output, and the header file ‘string.h’ declares " +"string processing utilities. The organization of this manual generally " +"follows the same division as the header files.\n" + +" If you are reading this manual for the first time, you should read " +"all of the introductory material and skim the remaining chapters. There " +"are a _lot_ of functions in the GNU C Library and it’s not realistic to " +"expect that you will be able to remember exactly _how_ to use each and " +"every one of them. It’s more important to become generally familiar " +"with the kinds of facilities that the library provides, so that when you " +"are writing your programs you can recognize _when_ to make use of " +"library functions, and _where_ in this manual you can find more specific " +"information about them.\n"; + +/* Simple yet efficient strstr - for needles < 32 bytes it is 2-4 times + faster than the optimized twoway_strstr. */ static char * -stupid_strstr (const char *s1, const char *s2) +basic_strstr (const char *s1, const char *s2) { - ssize_t s1len = strlen (s1); - ssize_t s2len = strlen (s2); + size_t i; + int c = s2[0]; - if (s2len > s1len) - return NULL; + if (c == 0) + return (char*)s1; - for (ssize_t i = 0; i <= s1len - s2len; ++i) + for ( ; s1[0] != '\0'; s1++) { - size_t j; - for (j = 0; j < s2len; ++j) - if (s1[i + j] != s2[j]) + if (s1[0] != c) + continue; + for (i = 1; s2[i] != 0; i++) + if (s1[i] != s2[i]) break; - if (j == s2len) - return (char *) s1 + i; + if (s2[i] == '\0') + return (char*)s1; } return NULL; } +#define RETURN_TYPE char * +#define AVAILABLE(h, h_l, j, n_l) \ + (((j) + (n_l) <= (h_l)) \ + || ((h_l) += __strnlen ((void*)((h) + (h_l)), (n_l) + 512), \ + (j) + (n_l) <= (h_l))) +#define CHECK_EOL (1) +#define RET0_IF_0(a) if (!a) goto ret0 +#define FASTSEARCH(S,C,N) (void*) strchr ((void*)(S), (C)) +#define LONG_NEEDLE_THRESHOLD 32U +#define __strnlen strnlen +#include "string/str-two-way.h" + +/* Optimized Two-way implementation from GLIBC 2.29. */ +static char * +twoway_strstr (const char *haystack, const char *needle) +{ + size_t needle_len; /* Length of NEEDLE. */ + size_t haystack_len; /* Known minimum length of HAYSTACK. */ + + /* Handle empty NEEDLE special case. */ + if (needle[0] == '\0') + return (char *) haystack; + + /* Skip until we find the first matching char from NEEDLE. */ + haystack = strchr (haystack, needle[0]); + if (haystack == NULL || needle[1] == '\0') + return (char *) haystack; + + /* Ensure HAYSTACK length is at least as long as NEEDLE length. + Since a match may occur early on in a huge HAYSTACK, use strnlen + and read ahead a few cachelines for improved performance. */ + needle_len = strlen (needle); + haystack_len = __strnlen (haystack, needle_len + 256); + if (haystack_len < needle_len) + return NULL; + + /* Check whether we have a match. This improves performance since we avoid + the initialization overhead of the two-way algorithm. */ + if (memcmp (haystack, needle, needle_len) == 0) + return (char *) haystack; + + /* Perform the search. Abstract memory is considered to be an array + of 'unsigned char' values, not an array of 'char' values. See + ISO C 99 section 6.2.6.1. */ + if (needle_len < LONG_NEEDLE_THRESHOLD) + return two_way_short_needle ((const unsigned char *) haystack, + haystack_len, + (const unsigned char *) needle, needle_len); + return two_way_long_needle ((const unsigned char *) haystack, haystack_len, + (const unsigned char *) needle, needle_len); +} typedef char *(*proto_t) (const char *, const char *); -IMPL (stupid_strstr, 0) -IMPL (simple_strstr, 0) IMPL (strstr, 1) - +IMPL (twoway_strstr, 0) +IMPL (basic_strstr, 0) static void do_one_test (impl_t *impl, const char *s1, const char *s2, char *exp_result) { size_t i, iters = INNER_LOOP_ITERS; timing_t start, stop, cur; + char *res; TIMING_NOW (start); for (i = 0; i < iters; ++i) - { - CALL (impl, s1, s2); - } + res = CALL (impl, s1, s2); TIMING_NOW (stop); TIMING_DIFF (cur, start, stop); TIMING_PRINT_MEAN ((double) cur, (double) iters); + + if (res != exp_result) + { + error (0, 0, "Wrong result in function %s %s %s", impl->name, + res, exp_result); + ret = 1; + } } @@ -83,36 +160,42 @@ do_test (size_t align1, size_t align2, size_t len1, size_t len2, char *s1 = (char *) (buf1 + align1); char *s2 = (char *) (buf2 + align2); - static const char d[] = "1234567890abcdef"; -#define dl (sizeof (d) - 1) - char *ss2 = s2; - for (size_t l = len2; l > 0; l = l > dl ? l - dl : 0) - { - size_t t = l > dl ? dl : l; - ss2 = mempcpy (ss2, d, t); - } - s2[len2] = '\0'; + size_t size = sizeof (input) - 1; + size_t pos = (len1 + len2) % size; - if (fail) + char *ss2 = s2; + for (size_t l = len2; l > 0; l = l > size ? l - size : 0) { - char *ss1 = s1; - for (size_t l = len1; l > 0; l = l > dl ? l - dl : 0) + size_t t = l > size ? size : l; + if (pos + t <= size) + ss2 = mempcpy (ss2, input + pos, t); + else { - size_t t = l > dl ? dl : l; - memcpy (ss1, d, t); - ++ss1[len2 > 7 ? 7 : len2 - 1]; - ss1 += t; + ss2 = mempcpy (ss2, input + pos, size - pos); + ss2 = mempcpy (ss2, input, t - (size - pos)); } } - else + s2[len2] = '\0'; + + char *ss1 = s1; + for (size_t l = len1; l > 0; l = l > size ? l - size : 0) { - memset (s1, '0', len1); - memcpy (s1 + len1 - len2, s2, len2); + size_t t = l > size ? size : l; + memcpy (ss1, input, t); + ss1 += t; } + + if (!fail) + memcpy (s1 + len1 - len2, s2, len2); s1[len1] = '\0'; - printf ("Length %4zd/%zd, alignment %2zd/%2zd, %s:", - len1, len2, align1, align2, fail ? "fail" : "found"); + /* Remove any accidental matches except for the last if !fail. */ + for (ss1 = basic_strstr (s1, s2); ss1; ss1 = basic_strstr (ss1 + 1, s2)) + if (fail || ss1 != s1 + len1 - len2) + ++ss1[len2 / 2]; + + printf ("Length %4zd/%3zd, alignment %2zd/%2zd, %s:", + len1, len2, align1, align2, fail ? "fail " : "found"); FOR_EACH_IMPL (impl, 0) do_one_test (impl, s1, s2, fail ? NULL : s1 + len1 - len2); @@ -130,48 +213,19 @@ test_main (void) printf ("\t%s", impl->name); putchar ('\n'); - for (size_t klen = 2; klen < 32; ++klen) - for (size_t hlen = 2 * klen; hlen < 16 * klen; hlen += klen) + for (size_t hlen = 64; hlen <= 256; hlen += 32) + for (size_t klen = 1; klen <= 16; klen++) { - do_test (0, 0, hlen, klen, 0); - do_test (0, 0, hlen, klen, 1); - do_test (0, 3, hlen, klen, 0); - do_test (0, 3, hlen, klen, 1); - do_test (0, 9, hlen, klen, 0); + do_test (1, 3, hlen, klen, 0); do_test (0, 9, hlen, klen, 1); - do_test (0, 15, hlen, klen, 0); - do_test (0, 15, hlen, klen, 1); - - do_test (3, 0, hlen, klen, 0); - do_test (3, 0, hlen, klen, 1); - do_test (3, 3, hlen, klen, 0); - do_test (3, 3, hlen, klen, 1); - do_test (3, 9, hlen, klen, 0); - do_test (3, 9, hlen, klen, 1); - do_test (3, 15, hlen, klen, 0); - do_test (3, 15, hlen, klen, 1); - - do_test (9, 0, hlen, klen, 0); - do_test (9, 0, hlen, klen, 1); - do_test (9, 3, hlen, klen, 0); - do_test (9, 3, hlen, klen, 1); - do_test (9, 9, hlen, klen, 0); - do_test (9, 9, hlen, klen, 1); - do_test (9, 15, hlen, klen, 0); - do_test (9, 15, hlen, klen, 1); - - do_test (15, 0, hlen, klen, 0); - do_test (15, 0, hlen, klen, 1); - do_test (15, 3, hlen, klen, 0); - do_test (15, 3, hlen, klen, 1); - do_test (15, 9, hlen, klen, 0); - do_test (15, 9, hlen, klen, 1); - do_test (15, 15, hlen, klen, 0); - do_test (15, 15, hlen, klen, 1); } - do_test (0, 0, page_size - 1, 16, 0); - do_test (0, 0, page_size - 1, 16, 1); + for (size_t hlen = 256; hlen <= 65536; hlen *= 2) + for (size_t klen = 16; klen <= 256; klen *= 2) + { + do_test (1, 11, hlen, klen, 0); + do_test (14, 5, hlen, klen, 1); + } return ret; } |