2c40c5250b
This adds missing test coverage for corner cases of SpeculativeNumberAdd and SpeculativeNumberSubtract inside of SimplifiedLowering. This was discovered to be untested by the coverage bot. Bug: v8:8015 Change-Id: I7355b1b840a76bc12bd911adb6c2d88f05d816c5 Reviewed-on: https://chromium-review.googlesource.com/1236256 Reviewed-by: Sigurd Schneider <sigurds@chromium.org> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Cr-Commit-Position: refs/heads/master@{#56090}
63 lines
2.0 KiB
JavaScript
63 lines
2.0 KiB
JavaScript
// Copyright 2018 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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// This tests that NumberAdd passes on the right truncations
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// even if it figures out during SimplifiedLowering that it
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// can indeed do a Word32 operation (based on the feedback
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// baked in for its inputs by other operators).
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(function() {
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// We need a + with Number feedback to get to a NumberAdd
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// during the typed lowering pass of TurboFan's frontend.
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function foo(x, y) { return x + y; }
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foo(0.1, 0.2);
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foo(0.1, 0.2);
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// Now we need to fool TurboFan to think that it has to
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// perform the `foo(x,-1)` on Float64 values until the
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// very last moment (after the RETYPE phase of the
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// SimplifiedLowering) where it realizes that the inputs
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// and outputs of the NumberAdd allow it perform the
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// operation on Word32.
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function bar(x) {
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x = Math.trunc(foo(x - 1, 1));
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return foo(x, -1);
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}
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assertEquals(0, bar(1));
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assertEquals(1, bar(2));
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%OptimizeFunctionOnNextCall(bar);
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assertEquals(2, bar(3));
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})();
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// This tests that SpeculativeNumberAdd can still lower to
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// Int32Add in SimplifiedLowering, which requires some magic
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// to make sure that SpeculativeNumberAdd survives to that
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// point, especially the JSTypedLowering needs to be unable
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// to tell that the inputs to SpeculativeNumberAdd are non
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// String primitives.
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(function() {
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// We need a function that has a + with feedback Number or
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// NumberOrOddball, but for whose inputs the JSTypedLowering
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// cannot reduce it to NumberAdd (with SpeculativeToNumber
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// conversions). We achieve this utilizing an object literal
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// indirection here.
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function baz(x) {
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return {x}.x + x;
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}
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baz(null);
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baz(undefined);
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// Now we just need to truncate the result.
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function foo(x) {
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return baz(1) | 0;
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}
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assertEquals(2, foo());
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assertEquals(2, foo());
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%OptimizeFunctionOnNextCall(foo);
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assertEquals(2, foo());
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})();
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