05507cc3ea
This change rewrites regexps like (ab|ac|z|ad|ae|af) into (a[b-f]|z). We can only reorder disjunctions like this for case-dependent regexps. For case-independent regexps, the disjunctions should be pre-sorted for best results. R=yangguo@chromium.org BUG=chromium:482998 LOG=n Review URL: https://codereview.chromium.org/1180433003 Cr-Commit-Position: refs/heads/master@{#28902}
23 lines
641 B
JavaScript
23 lines
641 B
JavaScript
// Copyright 2015 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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// Should not time out. Running time 0.5s vs. 120s before the change.
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function collapse() {
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var src = "(?:";
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for (var i = 128; i < 0x1000; i++) {
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src += "a" + String.fromCharCode(i) + "|";
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}
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src += "aa)";
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var collapsible = new RegExp(src);
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var subject = "zzzzzzz" + String.fromCharCode(3000);
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for (var i = 0; i < 1000; i++) {
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subject += "xxxxxxx";
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}
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for (var i = 0; i < 2000; i++) {
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assertFalse(collapsible.test(subject));
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}
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}
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collapse();
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