[webkit-reviews] review denied: [Bug 64068] DFG JIT unnecessarily boxes and unboxes values during silent spilling : [Attachment 99951] the patch

[bugzilla-daemon at webkit.org]

Gavin Barraclough <barraclough at apple.com> has denied Filip Pizlo
<fpizlo at apple.com>'s request for review:
Bug 64068: DFG JIT unnecessarily boxes and unboxes values during silent
spilling
https://bugs.webkit.org/show_bug.cgi?id=64068

Attachment 99951: the patch
https://bugs.webkit.org/attachment.cgi?id=99951&action=review

------- Additional Comments from Gavin Barraclough <barraclough at apple.com>
Hi Filip, I think there may be a subtle bug in this code.  When a register is
silently spilled it is only actually written out to memory if it needs to be
spilled (hasn't already been).	This means that if you have values in registers
XMM0 & XMM1, and XMM0 has already been spilled as a boxed value, then after the
silent spill one of the values in memory will be boxed and the other won't.  As
such, you need to handle this in the silentFillFPR.  If the register
needsSpill() then it is unboxed, if not the value in memory is boxed.  Also,
please expand on the ChangeLog entry.