1422851 - Add CacheIR instruction GuardIsTypedArray

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P3)

Description

[Matthew Gaudet (he/him) [:mgaudet]]

From Bug 1419372: 

> This is fine, but for typed arrays we could consider adding a GuardIsTypedArray
> CacheIR instruction (that does something like [0]) and emitting it instead of
> GuardShape.
> 
> The idea is this: typed array objects with different element types (say 
> Int32Array and Int8Array) have a different js::Class* and therefore get a 
> different Shape, but this IC stub works exactly the same for each
> TypedArrayObject. So GuardIsTypedArray would be a more generic guard that 
> would accept all typed arrays.
> 
> [0] https://searchfox.org/mozilla-central/rev/477ac066b565ae0eb3519875581a62dfb1430e98/js/src/jit/CodeGenerator.cpp#12029-12034


Follow up is to of course use the guard in HasPropIRGenerator::tryAttachTypedArray.

Comment 1

[André Bargull [:anba]]

Attachment: Bug 1422851 - Part 1: Add GuardIsTypedArray CacheIR instruction. r=jandem!

Add GuardIsTypedArray CacheIR instruction and transpile it for Warp. The
implementation follows existing guard instructions like
MGuardIsNotArrayBufferMaybeShared.

Comment 2

[André Bargull [:anba]]

Attachment: Bug 1422851 - Part 2: Split LoadTypedArrayElementExistsResult CacheIR instruction. r=jandem!

Split LoadTypedArrayElementExistsResult into TypedArray and TypedObject specific
instructions in preparation for part 3, which will transpile the TypedArray
instruction.

Depends on D91107

Comment 3

[André Bargull [:anba]]

Attachment: Bug 1422851 - Part 3: Transpile LoadTypedArrayElementExistsResult. r=jandem!

Transpile LoadTypedArrayElementExistsResult to make use of the transpiled
GuardIsTypedArray instruction from part 1.

Depends on D91108

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5cf1e63bb834
Part 1: Add GuardIsTypedArray CacheIR instruction. r=jandem
https://hg.mozilla.org/integration/autoland/rev/f3e8c7058df6
Part 2: Split LoadTypedArrayElementExistsResult CacheIR instruction. r=jandem
https://hg.mozilla.org/integration/autoland/rev/828cb455bafd
Part 3: Transpile LoadTypedArrayElementExistsResult. r=jandem

Comment 5

[Andreea Pavel [:apavel]]

https://hg.mozilla.org/mozilla-central/rev/5cf1e63bb834
https://hg.mozilla.org/mozilla-central/rev/f3e8c7058df6
https://hg.mozilla.org/mozilla-central/rev/828cb455bafd