[WHLSL] Avoid visiting the full AST in computeDimensions

• Component: WebGPU
• Status: RESOLVED FIXED

[Robin Morisset]

We only need to look at the attributes of function definitions, nothing else.
And currently we spend a couple of milliseconds in computeDimensions.

[Robin Morisset]

Created attachment 375466 [details]
Patch

2ms -> 0.002ms for that pass.

[Myles C. Maxfield]

Comment on attachment 375466 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=375466&action=review

> Source/WebCore/Modules/webgpu/WHLSL/WHLSLComputeDimensions.cpp:52
> +                if (&functionDefinition == &entryPoint) {

Can we move this check outside of the nearest for loop?

[Robin Morisset]

(In reply to Myles C. Maxfield from comment #2)
> Comment on attachment 375466 [details]
> Patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=375466&action=review
> 
> > Source/WebCore/Modules/webgpu/WHLSL/WHLSLComputeDimensions.cpp:52
> > +                if (&functionDefinition == &entryPoint) {
> 
> Can we move this check outside of the nearest for loop?

Not easily: the loop has two jobs, both computing the dimensions for the entry point and verifying that no function has multiple NumThreads attributes.
So we can't just "continue;" in the case where &functionDefinition != &entryPoint.

[WebKit Commit Bot]

Comment on attachment 375466 [details]
Patch

Clearing flags on attachment: 375466

Committed r248194: <https://trac.webkit.org/changeset/248194>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/53888075>