Bug 170459 – Don't need to Air::reportUsedRegisters for wasm at -O1

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

[Filip Pizlo]

Patch forthcoming.

[Filip Pizlo]

Created attachment 306181 [details]
the patch

[Saam Barati]

Comment on attachment 306181 [details]
the patch

View in context: https://bugs.webkit.org/attachment.cgi?id=306181&action=review

r=me

> Source/JavaScriptCore/b3/B3StackmapGenerationParams.h:63
> +    // NOTE: This will report bogus information if you did proc.setNeedsUsedRegisters(false).

Can we make it crash, at least in debug builds?

> Source/JavaScriptCore/b3/air/AirLiveness.h:42
> +        SuperSamplerScope samplingScope(false);
> +        WTF::Liveness<Adapter>::compute();

Is the reason for this change just so you can time it?

[Filip Pizlo]

(In reply to Saam Barati from comment #2)
> Comment on attachment 306181 [details]
> the patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=306181&action=review
> 
> r=me
> 
> > Source/JavaScriptCore/b3/B3StackmapGenerationParams.h:63
> > +    // NOTE: This will report bogus information if you did proc.setNeedsUsedRegisters(false).
> 
> Can we make it crash, at least in debug builds?

I'll add an assertion.

> 
> > Source/JavaScriptCore/b3/air/AirLiveness.h:42
> > +        SuperSamplerScope samplingScope(false);
> > +        WTF::Liveness<Adapter>::compute();
> 
> Is the reason for this change just so you can time it?

Yeah, it was just for timing.

There was a prior patch where I had done this same hack and then lost it.  It's super useful.

[Filip Pizlo]

Landed in https://trac.webkit.org/changeset/214887/webkit