diff options
Diffstat (limited to 'string/str-two-way.h')
| -rw-r--r-- | string/str-two-way.h | 58 |
1 files changed, 28 insertions, 30 deletions
diff --git a/string/str-two-way.h b/string/str-two-way.h index dcf1d65aaf..523d946c59 100644 --- a/string/str-two-way.h +++ b/string/str-two-way.h @@ -1,5 +1,5 @@ /* Byte-wise substring search, using the Two-Way algorithm. - Copyright (C) 2008-2016 Free Software Foundation, Inc. + Copyright (C) 2008-2018 Free Software Foundation, Inc. This file is part of the GNU C Library. Written by Eric Blake <ebb9@byu.net>, 2008. @@ -281,50 +281,50 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len, } else { - const unsigned char *phaystack = &haystack[suffix]; + const unsigned char *phaystack; /* The comparison always starts from needle[suffix], so cache it and use an optimized first-character loop. */ unsigned char needle_suffix = CANON_ELEMENT (needle[suffix]); -#if CHECK_EOL - /* We start matching from the SUFFIX'th element, so make sure we - don't hit '\0' before that. */ - if (haystack_len < suffix + 1 - && !AVAILABLE (haystack, haystack_len, 0, suffix + 1)) - return NULL; -#endif - /* The two halves of needle are distinct; no extra memory is required, and any mismatch results in a maximal shift. */ period = MAX (suffix, needle_len - suffix) + 1; j = 0; - while (1 -#if !CHECK_EOL - && AVAILABLE (haystack, haystack_len, j, needle_len) -#endif - ) + while (AVAILABLE (haystack, haystack_len, j, needle_len)) { unsigned char haystack_char; const unsigned char *pneedle; - /* TODO: The first-character loop can be sped up by adapting - longword-at-a-time implementation of memchr/strchr. */ - if (needle_suffix + phaystack = &haystack[suffix + j]; + +#ifdef FASTSEARCH + if (*phaystack++ != needle_suffix) + { + phaystack = FASTSEARCH (phaystack, needle_suffix, + haystack_len - needle_len - j); + if (phaystack == NULL) + goto ret0; + j = phaystack - &haystack[suffix]; + phaystack++; + } +#else + while (needle_suffix != (haystack_char = CANON_ELEMENT (*phaystack++))) { RET0_IF_0 (haystack_char); -#if !CHECK_EOL +# if !CHECK_EOL ++j; -#endif - continue; + if (!AVAILABLE (haystack, haystack_len, j, needle_len)) + goto ret0; +# endif } -#if CHECK_EOL +# if CHECK_EOL /* Calculate J if it wasn't kept up-to-date in the first-character loop. */ j = phaystack - &haystack[suffix] - 1; +# endif #endif - /* Scan for matches in right half. */ i = suffix + 1; pneedle = &needle[i]; @@ -338,6 +338,11 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len, } ++i; } +#if CHECK_EOL + /* Update minimal length of haystack. */ + if (phaystack > haystack + haystack_len) + haystack_len = phaystack - haystack; +#endif if (needle_len <= i) { /* Scan for matches in left half. */ @@ -360,13 +365,6 @@ two_way_short_needle (const unsigned char *haystack, size_t haystack_len, } else j += i - suffix + 1; - -#if CHECK_EOL - if (!AVAILABLE (haystack, haystack_len, j, needle_len)) - break; -#endif - - phaystack = &haystack[suffix + j]; } } ret0: __attribute__ ((unused)) |