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Revert of Restore per-TypedArray-class length accessors as a perf workaround (patchset #2 id:20001 of https://codereview.chromium.org/1624383003/ )

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Reason for revert:
This patch actually seemed to cause a further GameBoy regression! Reverting it seems to address the regression.

Original issue's description:
> Restore per-TypedArray-class length accessors as a perf workaround
>
> This patch is a workaround to the performance regression caused by
> implementing the ES2015 TypedArray prototype chain: Include a
> per-TypedArray-subclass length getter so that the superclass getter does
> not become polymorphic. The patch appears to fix a regression in the
> Gameboy Octane benchmark.
>
> BUG=chromium:579905
> R=adamk
> LOG=Y
>
> Committed: https://crrev.com/03ce7711e474a0ef74f723b30ae1527c89dec010
> Cr-Commit-Position: refs/heads/master@{#33501}

R=adamk@chromium.org
BUG=chromium:579905,chromium:593634
LOG=Y

Review URL: https://codereview.chromium.org/1812143004

Cr-Commit-Position: refs/heads/master@{#34906}
This commit is contained in:
littledan 2016-03-18 11:29:02 -07:00 committed by Commit bot
parent 3245d74490
commit 0d2e28cb24
2 changed files with 3 additions and 18 deletions
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11
src/js/typedarray.js
View File

@ -281,14 +281,6 @@ function NAMEConstructor(arg1, arg2, arg3) {
}
}
// TODO(littledan): Remove this performance workaround BUG(chromium:579905)
function NAME_GetLength() {
if (!(%_ClassOf(this) === 'NAME')) {
throw MakeTypeError(kIncompatibleMethodReceiver, "NAME.length", this);
}
return %_TypedArrayGetLength(this);
}
function NAMESubArray(begin, end) {
var beginInt = TO_INTEGER(begin);
if (!IS_UNDEFINED(end)) {
@ -888,9 +880,6 @@ macro SETUP_TYPED_ARRAY(ARRAY_ID, NAME, ELEMENT_SIZE)
%AddNamedProperty(GlobalNAME.prototype,
"BYTES_PER_ELEMENT", ELEMENT_SIZE,
READ_ONLY | DONT_ENUM | DONT_DELETE);
// TODO(littledan): Remove this performance workaround BUG(chromium:579905)
utils.InstallGetter(GlobalNAME.prototype, "length", NAME_GetLength,
DONT_ENUM | DONT_DELETE);
endmacro
TYPED_ARRAYS(SETUP_TYPED_ARRAY)

10
test/mjsunit/es6/typedarray-proto.js
View File

@ -28,17 +28,13 @@ assertEquals(TypedArrayPrototype.__proto__, Object.prototype);
let classProperties = new Set([
"length", "name", "arguments", "caller", "prototype", "BYTES_PER_ELEMENT"
]);
let instanceProperties = new Set([
"BYTES_PER_ELEMENT", "constructor", "prototype",
// length is also an instance property as a temporary workaround to
// BUG(chromium:579905). TODO(littledan): remove the workaround
"length"
]);
let instanceProperties = new Set(["BYTES_PER_ELEMENT", "constructor", "prototype"]);
function functionProperties(object) {
return Object.getOwnPropertyNames(object).filter(function(name) {
return typeof Object.getOwnPropertyDescriptor(object, name).value
== "function" && name != 'constructor';
== "function"
&& name != 'constructor' && name != 'subarray';
});
}