[webkit-reviews] review granted: [Bug 185670] Constant fold CheckTypeInfoFlags on ImplementsDefaultHasInstance : [Attachment 340466] patch

[bugzilla-daemon at webkit.org]

Yusuke Suzuki <utatane.tea at gmail.com> has granted Saam Barati
<sbarati at apple.com>'s request for review:
Bug 185670: Constant fold CheckTypeInfoFlags on ImplementsDefaultHasInstance
https://bugs.webkit.org/show_bug.cgi?id=185670

Attachment 340466: patch

https://bugs.webkit.org/attachment.cgi?id=340466&action=review




--- Comment #3 from Yusuke Suzuki <utatane.tea at gmail.com> ---
Comment on attachment 340466
  --> https://bugs.webkit.org/attachment.cgi?id=340466
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=340466&action=review

r=me with comments

> JSTests/ChangeLog:35
> +2018-05-15  Saam Barati  <sbarati at apple.com>
> +
> +	   OverridesHasInstance should not rely on OSR exit information and
should be in ConstantFoldingPhase
> +	   https://bugs.webkit.org/show_bug.cgi?id=154832
> +
> +	   Reviewed by NOBODY (OOPS!).
> +
> +	   * microbenchmarks/constant-fold-check-type-info-flags.js: Added.
> +	   (clobber):
> +	   (C):
> +	   (D):
> +	   (foo):
> +	   (access):
> +	   (theClass):
> +	   * stress/dont-constant-fold-check-type-info-on-bound-function.js:
Added.
> +	   (C):
> +	   (foo):

This is not related to this patch.

> Source/JavaScriptCore/dfg/DFGAbstractInterpreterInlines.h:3449
> +	   if (node->typeInfoOperand() != ImplementsDefaultHasInstance)

While CheckTypeInfoFlags is used only for ImplementsDefaultHasInstance right
now, this folding rules can be applied to the other TypeInfoFlags (except for
speculated type based folding).
Can we relax this check? Or can we have FIXME for that?

> Source/JavaScriptCore/dfg/DFGConstantFoldingPhase.cpp:812
> +		   if (node->typeInfoOperand() != ImplementsDefaultHasInstance)
> +		       break;

Ditto.