1248930 - Use Int32Value in ArrayBufferObject::BYTE_LENGTH_SLOT.

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Tooru Fujisawa [:arai]]

Currently ArrayBufferObject::BYTE_LENGTH_SLOT slot is using DoubleValue, but byteLength property should fit into Int32, and using Int32Value should be better for inlining in bug 1165053.

Comment 1

[Tooru Fujisawa [:arai]]

Attachment: Use Int32Value in ArrayBufferObject::BYTE_LENGTH_SLOT.

Just replacing DoubleValue with Int32Value works.
Green on try run: https://treeherder.mozilla.org/#/jobs?repo=try&revision=6427abbbd86e

Comment 2

[Till Schneidereit [:till]]

Note that per spec byteLength should be clamped using ToLength, so be in the range of [0,2^53). That we don't currently support lengths above Int32 is something we should fix, not further cement in our code.

Comment 3

[Lars T Hansen [:lth]]

IMVHO there's so much code that needs to change if we move away from the int32 assumption that it's better to at least be consistent, if we're not going to make that change straight away.

cc'ing Waldo on the theory that he might have opinions.

Comment 4

[Jeff Walden [:Waldo]]

I kinda suggested this in bug 1165053.  :-)  I agree being consistent -- and more efficient/faster for now, as well -- is good.  (And if we extend to the 2**53 limit at some point, it wouldn't surprise me if we encoded it not as a double value anyway.)

Comment 5

[Tooru Fujisawa [:arai]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/58cb45035b724e5114c5fac236291badce35e41c
Bug 1248930 - Use Int32Value in ArrayBufferObject::BYTE_LENGTH_SLOT. r=lth

Comment 6

[Phil Ringnalda (:philor)]

https://hg.mozilla.org/mozilla-central/rev/58cb45035b72