Reviewers: Christian Plesner Hansen, Message: Small code-review. Untangled a check that shouldn't be bound to Boyer-Moore. Pretty much no influence on performance of benchmarks, as they are typically either all-ASCII or all-non-ASCII.
Description: Test for non-ASCII character in a needle used on an ASCII string is now handled first instead of only in the unrelated table-construction of Boyer-Moore. Please review this at http://codereview.chromium.org/7300 Affected files: M src/runtime.cc Index: src/runtime.cc diff --git a/src/runtime.cc b/src/runtime.cc index c7cbb1bd42381ee127b55ab0473e06d0c6c1286c..b094307519d1ed62363ea094c55d9972164b3e09 100644 --- a/src/runtime.cc +++ b/src/runtime.cc @@ -996,8 +996,8 @@ static BMGoodSuffixBuffers bmgs_buffers; // Compute the bad-char table for Boyer-Moore in the static buffer. // Return false if the pattern contains non-ASCII characters that cannot be // in the searched string. -template <typename pchar, bool check_ascii> -static bool BoyerMoorePopulateBadCharTable(Vector<const pchar> pattern, +template <typename pchar> +static void BoyerMoorePopulateBadCharTable(Vector<const pchar> pattern, int start) { // Run forwards to populate bad_char_table, so that *last* instance // of character equivalence class is the one registered. @@ -1006,14 +1006,8 @@ static bool BoyerMoorePopulateBadCharTable(Vector<const pchar> pattern, bad_char_occurence[i] = start - 1; } for (int i = start; i < pattern.length(); i++) { - uc32 c = pattern[i]; - bad_char_occurence[c % kBMAlphabetSize] = i; - if (check_ascii && - c > String::kMaxAsciiCharCode) { - return false; - } + bad_char_occurence[pattern[i] % kBMAlphabetSize] = i; } - return true; } template <typename pchar> @@ -1081,13 +1075,7 @@ static int BoyerMooreIndexOf(Vector<const schar> subject, int start = m < kBMMaxShift ? 0 : m - kBMMaxShift; int len = m - start; - if (sizeof(pchar) > 1 && sizeof(schar) == 1) { - BoyerMoorePopulateBadCharTable<pchar, true>(pattern, start); - } else { - if (!BoyerMoorePopulateBadCharTable<pchar, false>(pattern, start)) { - return -1; - } - } + BoyerMoorePopulateBadCharTable(pattern, start); int badness = 0; // How bad we are doing without a good-suffix table. int idx; // No matches found prior to this index. @@ -1201,6 +1189,17 @@ static int StringMatchStrategy(Vector<const schar> sub, int start_index) { ASSERT(pat.length() > 1); + // We have an ASCII haystack and a non-ASCII needle. Check if there + // really is a non-ASCII character in the needle and bail out if there + // is. + if (sizeof(pchar) > 1 && sizeof(schar) == 1) { + for (int i = 0; i < pat.length(); i++) { + uc16 c = pat[i]; + if (c > String::kMaxAsciiCharCode) { + return -1; + } + } + } // For small searches, a complex sort is not worth the setup overhead. bool complete; int idx = SimpleIndexOf(sub, pat, start_index, complete); --~--~---------~--~----~------------~-------~--~----~ v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev -~----------~----~----~----~------~----~------~--~---
