d8d8f8b316
Adds constant folding for the StringConcat bytecode to NativeContextSpecialization. Can reduce operator to either a fully folded constant string, or a JSAdd or a StringConcat with a reduced number of operators. BUG=v8:6243, chromium:738312 Change-Id: I6b2be6a3d95230a23f3c7390a4f7be5181c49a2a Reviewed-on: https://chromium-review.googlesource.com/559146 Commit-Queue: Ross McIlroy <rmcilroy@chromium.org> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org> Reviewed-by: Jaroslav Sevcik <jarin@chromium.org> Cr-Commit-Position: refs/heads/master@{#46461}
38 lines
834 B
JavaScript
38 lines
834 B
JavaScript
// Copyright 2017 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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// Flags: --allow-natives-syntax
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var foo = 'foo';
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var bar = 'bar';
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var a;
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var b;
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var c;
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var d;
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function baz() { return 'baz'; }
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function test(arg) {
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// All operands are constant folded by native context
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// specialization / inlining.
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a = '"' + foo + '-' + bar + '"';
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b = '"' + foo + '-' + baz() + '"';
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// Reduce down to a JSAdd of folded constant + arg.
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c = foo + bar + arg;
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// Reduces to a StringConcat with three operands.
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d = '"' + foo + arg + bar + '"';
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}
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test('boo');
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%OptimizeFunctionOnNextCall(test);
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test('baa');
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assertEquals('"foo-bar"', a);
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assertEquals('"foo-baz"', b);
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assertEquals('foobarbaa', c);
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assertEquals('"foobaabar"', d);
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