[webkit-reviews] review granted: [Bug 69114] DFG does not speculate aggressively enough on put_by_id : [Attachment 109353] the patch - fix style and merge

[bugzilla-daemon at webkit.org]

Oliver Hunt <oliver at apple.com> has granted Filip Pizlo <fpizlo at apple.com>'s
request for review:
Bug 69114: DFG does not speculate aggressively enough on put_by_id
https://bugs.webkit.org/show_bug.cgi?id=69114

Attachment 109353: the patch - fix style and merge
https://bugs.webkit.org/attachment.cgi?id=109353&action=review

------- Additional Comments from Oliver Hunt <oliver at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=109353&action=review


r=me, but you should probably drop the write barrier if the cell is already in
the old generation

> Source/JavaScriptCore/dfg/DFGJITCodeGenerator.cpp:270
> +void JITCodeGenerator::writeBarrier(GPRReg ownerGPR, JSCell* value,
WriteBarrierUseKind useKind, GPRReg scratch1, GPRReg scratch2)

if value is a cell you can do a generation check (Heap::isMarked()) you can
avoid planting this write barrier entirely