Bug 150511 – Air needs a late register liveness phase that calls Special::reportUsedRegisters()

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

[Filip Pizlo]

Otherwise, stackmaps will think that no registers are in use.

[Filip Pizlo]

Created attachment 264462 [details]
the patch

[Saam Barati]

Comment on attachment 264462 [details]
the patch

View in context: https://bugs.webkit.org/attachment.cgi?id=264462&action=review

LGTM

> Source/JavaScriptCore/b3/air/AirGenerate.cpp:79
> +    recordUsedRegisters(code);

Do we cache the results of the used registers?
If not, maybe a better name would be just reportUsedRegisters like the function name?

> Source/JavaScriptCore/b3/air/AirRecordUsedRegisters.cpp:67
> +

Style: I think we can drop the new lines at the end of the file.

> Source/JavaScriptCore/b3/air/AirRecordUsedRegisters.h:35
> +// This allocates StackSlots to places on the stack. It first allocates the pinned ones in index

Is this really what this phase does?

[Filip Pizlo]

(In reply to comment #2)
> Comment on attachment 264462 [details]
> the patch
> 
> View in context:
> https://bugs.webkit.org/attachment.cgi?id=264462&action=review
> 
> LGTM
> 
> > Source/JavaScriptCore/b3/air/AirGenerate.cpp:79
> > +    recordUsedRegisters(code);
> 
> Do we cache the results of the used registers?
> If not, maybe a better name would be just reportUsedRegisters like the
> function name?

Good point.

> 
> > Source/JavaScriptCore/b3/air/AirRecordUsedRegisters.cpp:67
> > +
> 
> Style: I think we can drop the new lines at the end of the file.

OK.

> 
> > Source/JavaScriptCore/b3/air/AirRecordUsedRegisters.h:35
> > +// This allocates StackSlots to places on the stack. It first allocates the pinned ones in index
> 
> Is this really what this phase does?

Ooops!

[Filip Pizlo]

Landed in http://trac.webkit.org/changeset/191845