1edb46cc04
This improves the general Array constructor call performance (w/o usable AllocationSite feedback) in TurboFan by ~2x, i.e. for example invoking the Array constructor like this var a = Array.call(undefined, n); instead of var a = Array(n); such that the CallIC doesn't know that it's eventually calling the Array constructor. It also thus changes the single argument Array constructor to always return holey arrays. Previously the single argument case for the Array constructor was somehow trying to dynamically detect 0 and in that case returned a packed array instead of a holey one. That adds quite a lot of churn, and doesn't seem to be very useful, especially since this might lead to unnecessary feedback pollution later. R=mvstanton@chromium.org Bug: v8:2229, v8:5269, v8:6399 Change-Id: I3d7cb9bd975ec0e491e3cdbcf1230185cfd1e3de Reviewed-on: https://chromium-review.googlesource.com/565721 Reviewed-by: Michael Stanton <mvstanton@chromium.org> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org> Commit-Queue: Benedikt Meurer <bmeurer@chromium.org> Cr-Commit-Position: refs/heads/master@{#46538}
68 lines
2.2 KiB
JavaScript
68 lines
2.2 KiB
JavaScript
// Copyright 2013 the V8 project authors. All rights reserved.
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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// * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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// * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following
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// disclaimer in the documentation and/or other materials provided
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// with the distribution.
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// * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived
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// from this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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// Flags: --allow-natives-syntax --expose-gc --noalways-opt
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function isHoley(obj) {
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if (%HasHoleyElements(obj)) return true;
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return false;
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}
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function assertHoley(obj, name_opt) {
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assertEquals(true, isHoley(obj), name_opt);
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}
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function create_array(arg) {
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return new Array(arg);
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}
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obj = create_array(0);
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assertHoley(obj);
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create_array(0);
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%OptimizeFunctionOnNextCall(create_array);
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obj = create_array(10);
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assertHoley(obj);
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// The code below would assert in debug or crash in release
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function f(length) {
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return new Array(length)
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}
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f(0);
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f(0);
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%OptimizeFunctionOnNextCall(f);
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var a = f(10);
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function g(a) {
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return a[0];
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}
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var b = [0];
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g(b);
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g(b);
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assertEquals(undefined, g(a));
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