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Issue 3665 Allocation site pretenuring degrades performance in Ember
Starred by 17 users Project Member Reported by, Oct 30 2014 Back to list
Status: Assigned
HW: ----
OS: All
Priority: Medium
Type: Bug

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v8:3664 tracks deoptimizations caused by weak references. With disabled weak references, allocation site pretenuring is the next common cause of deoptimization.

"Complex List" test at runs
- 185.11ms without weak references, with allocation site pretenuring (--js-flags="--noweak-embedded-objects-in-optimized-code --noweak-embedded-maps-in-optimized-code")
- 169.57ms without weak references and without allocation site pretenuring (--js-flags="--noweak-embedded-objects-in-optimized-code --noweak-embedded-maps-in-optimized-code --noallocation-site-pretenuring")
Project Member Comment 1 by, Oct 30 2014
Blocking: v8:2935
Project Member Comment 2 by, Apr 29 2015
Status: Assigned
Comment 3 by, Nov 14 2015
Any progress on this?
Project Member Comment 4 by, Nov 15 2015
Yes, months ago we tried disabling allocation site pretenuring, so that none of these deopts occur. The performance effect was negligible. Deopts occurred in those functions anyway, for other reasons.
Project Member Comment 5 by, Oct 8
Blockedon: 5459
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