832329 - Beef up definite properties analysis for Prototype library's create() method

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

The definite properties analysis used to determine which properties will definitely be possessed by an object created with 'new' doesn't pattern match sufficiently well to deal with the initialize.apply() call in Class.create().  With bug 638794 fixed this is all that's left to do to get definite properties in these objects, which gives a boost of about 23% to our v8-raytrace score (8166 -> 100044, x86/darwin).

Comment 1

[Jan de Mooij [:jandem]]

Comment on attachment 703914 [details] [diff] [review]
patch

Review of attachment 703914 [details] [diff] [review]:
-----------------------------------------------------------------

Nice.

::: js/src/jsinfer.cpp
@@ +4997,5 @@
> +             *   could cause 'this' to escape.
> +             *
> +             * - The accessed property is either already a definite property or
> +             *   is not later added as one. Since the definite properties are
> +             *   added to the object at theh point of its creation, reading a

Nit: "the" typo

@@ +4998,5 @@
> +             *
> +             * - The accessed property is either already a definite property or
> +             *   is not later added as one. Since the definite properties are
> +             *   added to the object at theh point of its creation, reading a
> +             *   definite property before it is unassigned could incorrectly hit.

Nit: s/unassigned/assigned

@@ +5016,5 @@
> +            Shape *shape = type->proto ? type->proto->nativeLookup(cx, id) : NULL;
> +            if (shape && shape->hasSlot()) {
> +                Value protov = type->proto->getSlot(shape->slot());
> +                TypeSet *types = script->analysis()->bytecodeTypes(pc);
> +                types->addType(cx, GetValueType(cx, protov));

This deserves a comment.

Comment 2

[Brian Hackett [Laid off!]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/5c56910fa445

Comment 3

[(no longer active)]

https://hg.mozilla.org/mozilla-central/rev/5c56910fa445