1061741 - Remove type slot in typed arrays

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

Typed arrays have a slot storing their Scalar::Type, which can be easily computed from the array's clasp instead.  The attached patch removes this slot, which also allows typed arrays to use a smaller size class and be able to store 32 more bytes of data inline.

Comment 1

[Steve Fink [:sfink] [:s:]]

Comment on attachment 8482772 [details] [diff] [review]
patch

Review of attachment 8482772 [details] [diff] [review]:
-----------------------------------------------------------------

::: js/src/vm/SharedTypedArrayObject.h
@@ +106,5 @@
> +inline Scalar::Type
> +SharedTypedArrayObject::type() const
> +{
> +    JS_ASSERT(IsSharedTypedArrayClass(getClass()));
> +    return (Scalar::Type) (getClass() - &classes[0]);

static_cast<Scalar::Type>()

Comment 2

[Brian Hackett [Laid off!]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/01da8d5ed02d

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/01da8d5ed02d