[webkit-reviews] review denied: [Bug 63173] DFG non-speculative JIT lacks basic optimizations for GetById and GetByVal : [Attachment 98231] the patch (more style fixes)

[bugzilla-daemon at webkit.org]

Gavin Barraclough <barraclough at apple.com> has denied Filip Pizlo
<fpizlo at apple.com>'s request for review:
Bug 63173: DFG non-speculative JIT lacks basic optimizations for GetById and
GetByVal
https://bugs.webkit.org/show_bug.cgi?id=63173

Attachment 98231: the patch (more style fixes)
https://bugs.webkit.org/attachment.cgi?id=98231&action=review

------- Additional Comments from Gavin Barraclough <barraclough at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=98231&action=review

Please fix comments above, as discussed!

> Source/JavaScriptCore/dfg/DFGNonSpeculativeJIT.cpp:502
> +	   NodeIndex alias = node.child3;

The alias optimization is unsafe on the non-speculative path.
This assumes that between subsequent GetByVals to the same location, the value
/ array has not changed.  We ensure this is true on the speculative path by
restricting generation of operations that would trigger side-effects, but do
not do so on the non-speculative path.

> Source/JavaScriptCore/dfg/DFGNonSpeculativeJIT.cpp:586
> +	   cachedGetById(baseGPR, resultGPR, node.identifierNumber());

The code generation for this method is going to generate two calls, please
refactor to make one call.