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| author | Maxim Kuvyrkov <maxim@codesourcery.com> | 2012-05-28 22:46:07 -0700 |
|---|---|---|
| committer | Maxim Kuvyrkov <maxim@codesourcery.com> | 2012-08-21 18:07:47 -0700 |
| commit | bcca089526c6859e775243731037a469aec3065c (patch) | |
| tree | 646370482233fa52fcb5311b066f65fef2946d84 | |
| parent | 99677e575504ec526546501b1fdb86221493768a (diff) | |
| download | glibc-bcca089526c6859e775243731037a469aec3065c.zip glibc-bcca089526c6859e775243731037a469aec3065c.tar.gz glibc-bcca089526c6859e775243731037a469aec3065c.tar.bz2 | |
Micro-optimize critical path of strstr, strcase and memmem.
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | string/str-two-way.h | 11 | ||||
| -rw-r--r-- | string/strcasestr.c | 1 | ||||
| -rw-r--r-- | string/strstr.c | 1 |
4 files changed, 18 insertions, 1 deletions
@@ -1,5 +1,11 @@ 2012-08-21 Maxim Kuvyrkov <maxim@codesourcery.com> + * string/str-two-way.h (AVAILABLE1_USES_J): New macro, define default. + (two_way_short_needle): Use it. + * string/{strstr.c, strcasestr.c} (AVAILABLE1_USES_J): Define. + +2012-08-21 Maxim Kuvyrkov <maxim@codesourcery.com> + * string/str-two-way.h (two_way_short_needle): Use pointers instead of array references. * string/strcasestr.c (TOLOWER): Make side-effect safe. diff --git a/string/str-two-way.h b/string/str-two-way.h index 1b7a8ba..59609b8 100644 --- a/string/str-two-way.h +++ b/string/str-two-way.h @@ -84,6 +84,9 @@ #ifndef RET0_IF_0 # define RET0_IF_0(a) /* nothing */ #endif +#ifndef AVAILABLE1_USES_J +# define AVAILABLE1_USES_J (1) +#endif /* Perform a critical factorization of NEEDLE, of length NEEDLE_LEN. Return the index of the first byte in the right half, and set @@ -295,12 +298,17 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len, != (haystack_char = CANON_ELEMENT (*phaystack++))) { RET0_IF_0 (haystack_char); +#if AVAILABLE1_USES_J ++j; +#endif continue; } - /* Calculate J. */ +#if !AVAILABLE1_USES_J + /* Calculate J if it wasn't kept up-to-date in the first-character + loop. */ j = phaystack - &haystack[suffix] - 1; +#endif /* Scan for matches in right half. */ i = suffix + 1; @@ -497,6 +505,7 @@ two_way_long_needle (const unsigned char *haystack, size_t haystack_len, #undef AVAILABLE #undef AVAILABLE1 #undef AVAILABLE2 +#undef AVAILABLE1_USES_J #undef CANON_ELEMENT #undef CMP_FUNC #undef RET0_IF_0 diff --git a/string/strcasestr.c b/string/strcasestr.c index b6458ae..9467b7a 100644 --- a/string/strcasestr.c +++ b/string/strcasestr.c @@ -46,6 +46,7 @@ #define AVAILABLE1(h, h_l, j, n_l) (true) #define AVAILABLE2(h, h_l, j, n_l) AVAILABLE (h, h_l, j, n_l) #define RET0_IF_0(a) if (!a) goto ret0 +#define AVAILABLE1_USES_J (0) #define CANON_ELEMENT(c) TOLOWER (c) #define CMP_FUNC(p1, p2, l) \ __strncasecmp ((const char *) (p1), (const char *) (p2), l) diff --git a/string/strstr.c b/string/strstr.c index ec2a1e9..cfed771 100644 --- a/string/strstr.c +++ b/string/strstr.c @@ -38,6 +38,7 @@ #define AVAILABLE1(h, h_l, j, n_l) (true) #define AVAILABLE2(h, h_l, j, n_l) AVAILABLE (h, h_l, j, n_l) #define RET0_IF_0(a) if (!a) goto ret0 +#define AVAILABLE1_USES_J (0) #include "str-two-way.h" #undef strstr |