v8/test/mjsunit/regress/regress-460917.js
Mathias Bynens 26c00f4a4c [elements] Rename FAST elements kinds
The `FAST_` prefix doesn’t make much sense — they’re all just different cases
with their own optimizations. Packedness being implicit (e.g. `FAST_ELEMENTS`
vs. `FAST_HOLEY_ELEMENTS`) is not ideal, either.

This patch renames the FAST elements kinds as follows:

- e.g. FAST_ELEMENTS => PACKED_ELEMENTS
- e.g. FAST_HOLEY_ELEMENTS => HOLEY_ELEMENTS

The following exceptions are left intact, for lack of a better name:

- FAST_SLOPPY_ARGUMENTS_ELEMENTS
- SLOW_SLOPPY_ARGUMENTS_ELEMENTS
- FAST_STRING_WRAPPER_ELEMENTS
- SLOW_STRING_WRAPPER_ELEMENTS

This makes it easier to reason about elements kinds, and less confusing to
explain how they’re used.

R=jkummerow@chromium.org, cbruni@chromium.org
BUG=v8:6548

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ie7c6bee85583c3d84b730f7aebbd70c1efa38af9
Reviewed-on: https://chromium-review.googlesource.com/556032
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Mathias Bynens <mathias@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46361}
2017-06-30 13:31:44 +00:00

36 lines
1.0 KiB
JavaScript

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// Flags: --allow-natives-syntax
function boom(a1, a2) {
// Do something with a2 that needs a map check (for DOUBLE_ELEMENTS).
var s = a2[0];
// Emit a load that transitions a1 to PACKED_ELEMENTS.
var t = a1[0];
// Emit a store to a2 that assumes DOUBLE_ELEMENTS.
// The map check is considered redundant and will be eliminated.
a2[0] = 0.3;
}
// Prepare type feedback for the "t = a1[0]" load: fast elements.
var fast_elem = new Array(1);
fast_elem[0] = "tagged";
boom(fast_elem, [1]);
// Prepare type feedback for the "a2[0] = 0.3" store: double elements.
var double_elem = new Array(1);
double_elem[0] = 0.1;
boom(double_elem, double_elem);
// Reset |double_elem| and go have a party.
double_elem = new Array(10);
double_elem[0] = 0.1;
%OptimizeFunctionOnNextCall(boom);
boom(double_elem, double_elem);
assertEquals(0.3, double_elem[0]);
assertEquals(undefined, double_elem[1]);