1113179 - SIMD.int32x4 / SIMD.float32x4 should not have a type set with unknownProperties.

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Nicolas B. Pierron [:nbp]]

Currently, to make SIMD.int32x4 / SIMD.float32x4 callable, we create these objects with the Function as a proto [1]. Due to this trick, we flag the typeSet as having unknownProperties [2], which cause addType to flag the type set of int32x4 / float32x4 objects to be AnyObject [3].

This makes IonMonkey unable to predict what is the function which should be used for the function call (Bug 1112154), and force us to "guard; load; typebarrier" before every SIMD function call (Bug 1112155).

[1] http://dxr.mozilla.org/mozilla-central/source/js/src/builtin/SIMD.cpp#250,257
[2] http://dxr.mozilla.org/mozilla-central/source/js/src/jsinfer.cpp#4470-4478
[3] http://dxr.mozilla.org/mozilla-central/source/js/src/jsinfer.cpp#552-556,566-567

Comment 1

[Nicolas B. Pierron [:nbp]]

Attachment: SIMD types are now created as Singleton objects.

Comment 2

[Benjamin Bouvier [:bbouvier] (inactive)]

Comment on attachment 8538571 [details] [diff] [review]
SIMD types are now created as Singleton objects.

Review of attachment 8538571 [details] [diff] [review]:
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Good catch!

Comment 3

[Nicolas B. Pierron [:nbp]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/f078e3258ffd

Comment 4

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/f078e3258ffd