Bug 144317 – DFG+FTL should generate efficient code for branching on a string's boolean value.

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

[Andreas Kling]

We shouldn't drop out to operationConvertJSValueToBoolean if we know the value to be a string.

[Andreas Kling]

Created attachment 251830 [details]
Proposed patch

All right, let's see if I got this right.

[Geoffrey Garen]

Comment on attachment 251830 [details]
Proposed patch

r=me

Can has FTL?

[Filip Pizlo]

Comment on attachment 251830 [details]
Proposed patch

This needs to have the FTL implementation as well.  Otherwise you're actually reducing FTL coverage with this patch.

So, please implement both DFG and FTL functionality in the same patch.

[Andreas Kling]

(In reply to comment #3)
> Comment on attachment 251830 [details]
> Proposed patch
> 
> This needs to have the FTL implementation as well.  Otherwise you're
> actually reducing FTL coverage with this patch.
> 
> So, please implement both DFG and FTL functionality in the same patch.

FTL already uses boolify() to implement compileBranch(). boolify() knows how to handle StringUse and generates nice code for it. Doesn't this mean that the FTL support is already in-place?

[Filip Pizlo]

(In reply to comment #4)
> (In reply to comment #3)
> > Comment on attachment 251830 [details]
> > Proposed patch
> > 
> > This needs to have the FTL implementation as well.  Otherwise you're
> > actually reducing FTL coverage with this patch.
> > 
> > So, please implement both DFG and FTL functionality in the same patch.
> 
> FTL already uses boolify() to implement compileBranch(). boolify() knows how
> to handle StringUse and generates nice code for it. Doesn't this mean that
> the FTL support is already in-place?

Oh!  That's true.

[Filip Pizlo]

Comment on attachment 251830 [details]
Proposed patch

View in context: https://bugs.webkit.org/attachment.cgi?id=251830&action=review

> LayoutTests/ChangeLog:3
> +        DFG should generate efficient code for branching on a string's boolean value.

Please make sure you note that this is about both DFG and FTL.  Either change the bug title, or put some blurb in the changelog.

[Andreas Kling]

Committed r183495: <http://trac.webkit.org/changeset/183495>