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[JSC] Allow quick DFG/FTL tier-up recovery after reinstall#60373

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webkit-commit-queue merged 1 commit intoWebKit:mainfrom
hyjorc1:eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool
Mar 13, 2026
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[JSC] Allow quick DFG/FTL tier-up recovery after reinstall#60373
webkit-commit-queue merged 1 commit intoWebKit:mainfrom
hyjorc1:eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool

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@hyjorc1 hyjorc1 commented Mar 11, 2026 •
edited by webkit-early-warning-system
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f92b82d

[JSC] Allow quick DFG/FTL tier-up recovery after reinstall
https://bugs.webkit.org/show_bug.cgi?id=309687
rdar://172290040

Reviewed by Dan Hecht.

Quick tier-up reduces the optimization threshold for functions that have
previously run JIT code successfully, letting them re-tier faster after
jettison.

Previously didInstallDFGCode() and didInstallFTLCode() were one-shot:
once the flag was cleared by a jettison, subsequent reinstalls could not
recover it. This patch allows recovery on reinstall.

A jettison is a profiling event — the speculation failure reveals type
information that baseline JIT captures, and a re-compile against those
richer profiles is likely more stable. Penalizing it permanently was
counterproductive.

Canonical link: https://commits.webkit.org/309230@main

f05e49d

Misc iOS, visionOS, tvOS & watchOS macOS Linux Windows Apple Internal
✅ 🧪 style   🛠 ios   🛠 mac   🛠 wpe   🛠 win ⏳ 🛠 ios-apple
  🛠 ios-sim   🛠 mac-AS-debug   🧪 wpe-wk2   🧪 win-tests ⏳ 🛠 mac-apple
✅ 🧪 webkitperl   🧪 ios-wk2   🧪 api-mac   🧪 api-wpe ⏳ 🛠 vision-apple
  🧪 ios-wk2-wpt   🧪 api-mac-debug   🛠 gtk3-libwebrtc
✅ 🛠 🧪 jsc   🧪 api-ios   🧪 mac-wk1   🛠 gtk
✅ 🛠 🧪 jsc-debug-arm64   🛠 ios-safer-cpp   🧪 mac-wk2   🧪 gtk-wk2
  🛠 vision   🧪 mac-AS-debug-wk2   🧪 api-gtk
✅ 🛠 🧪 merge   🛠 vision-sim   🧪 mac-wk2-stress   🛠 playstation
⏳ 🧪 vision-wk2   🧪 mac-intel-wk2   🛠 jsc-armv7
  🛠 tv   🛠 mac-safer-cpp   🧪 jsc-armv7-tests
  🛠 tv-sim
  🛠 watch
  🛠 watch-sim

@hyjorc1 hyjorc1 requested a review from a team as a code owner March 11, 2026 17:02
@hyjorc1 hyjorc1 self-assigned this Mar 11, 2026
@hyjorc1 hyjorc1 added the New Bugs Unclassified bugs are placed in this component until the correct component can be determined. label Mar 11, 2026
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webkit-early-warning-system commented Mar 11, 2026 •
edited
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EWS run on previous version of this PR (hash e811034)

Details

Misc iOS, visionOS, tvOS & watchOS macOS Linux Windows Apple Internal
✅ 🧪 style ✅ 🛠 ios   🛠 mac ✅ 🛠 wpe   🛠 win ⏳ 🛠 ios-apple
  🛠 ios-sim ✅ 🛠 mac-AS-debug   🧪 wpe-wk2   🧪 win-tests ⏳ 🛠 mac-apple
✅ 🧪 webkitperl   🧪 ios-wk2   🧪 api-mac   🧪 api-wpe ⏳ 🛠 vision-apple
  🧪 ios-wk2-wpt   🧪 api-mac-debug ✅ 🛠 gtk3-libwebrtc
✅ 🛠 🧪 jsc   🧪 api-ios   🧪 mac-wk1 ✅ 🛠 gtk
✅ 🛠 🧪 jsc-debug-arm64   🛠 ios-safer-cpp   🧪 mac-wk2   🧪 gtk-wk2
  🛠 vision   🧪 mac-AS-debug-wk2   🧪 api-gtk
  🛠 vision-sim   🧪 mac-wk2-stress   🛠 playstation
⏳ 🧪 vision-wk2   🧪 mac-intel-wk2 ✅ 🛠 jsc-armv7
✅ 🛠 tv   🛠 mac-safer-cpp   🧪 jsc-armv7-tests
  🛠 tv-sim
  🛠 watch
  🛠 watch-sim

dhecht
dhecht approved these changes Mar 11, 2026
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r=me with nits

@hyjorc1 hyjorc1 force-pushed the eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool branch from e811034 to fd31306 Compare March 11, 2026 17:32
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webkit-early-warning-system commented Mar 11, 2026 •
edited
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EWS run on previous version of this PR (hash fd31306)

Details

Misc iOS, visionOS, tvOS & watchOS macOS Linux Windows Apple Internal
✅ 🧪 style ✅ 🛠 ios ✅ 🛠 mac ✅ 🛠 wpe ✅ 🛠 win ⏳ 🛠 ios-apple
✅ 🛠 ios-sim ✅ 🛠 mac-AS-debug ✅ 🧪 wpe-wk2 ✅ 🧪 win-tests ⏳ 🛠 mac-apple
✅ 🧪 webkitperl ✅ 🧪 ios-wk2 ✅ 🧪 api-mac ✅ 🧪 api-wpe ⏳ 🛠 vision-apple
✅ 🧪 ios-wk2-wpt ✅ 🧪 api-mac-debug ✅ 🛠 gtk3-libwebrtc
✅ 🛠 🧪 jsc ✅ 🧪 api-ios ✅ 🧪 mac-wk1 ✅ 🛠 gtk
✅ 🛠 🧪 jsc-debug-arm64 ✅ 🛠 ios-safer-cpp ✅ 🧪 mac-wk2 ✅ 🧪 gtk-wk2
✅ 🛠 vision ✅ 🧪 mac-AS-debug-wk2 ✅ 🧪 api-gtk
✅ 🛠 vision-sim ✅ 🧪 mac-wk2-stress ✅ 🛠 playstation
✅ 🧪 vision-wk2 ✅ 🧪 mac-intel-wk2 ✅ 🛠 jsc-armv7
✅ 🛠 tv ✅ 🛠 mac-safer-cpp   🧪 jsc-armv7-tests
✅ 🛠 tv-sim
✅ 🛠 watch
✅ 🛠 watch-sim

@hyjorc1 hyjorc1 added safe-merge-queue Applied to automatically send a pull-request to merge-queue after passing EWS checks and removed safe-merge-queue Applied to automatically send a pull-request to merge-queue after passing EWS checks labels Mar 11, 2026
@hyjorc1 hyjorc1 changed the title [JSC] Simplify quick DFG/FTL tier-up flags from TriState to bool [JSC] Allow quick DFG/FTL tier-up recovery after reinstall Mar 13, 2026
@hyjorc1 hyjorc1 force-pushed the eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool branch from fd31306 to 6c169c0 Compare March 13, 2026 15:46
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webkit-early-warning-system commented Mar 13, 2026 •
edited
Loading

EWS run on previous version of this PR (hash 6c169c0)

Details

Misc iOS, visionOS, tvOS & watchOS macOS Linux Windows Apple Internal
✅ 🧪 style ✅ 🛠 ios ✅ 🛠 mac ✅ 🛠 wpe   🛠 win ✅ 🛠 ios-apple
✅ 🛠 ios-sim ✅ 🛠 mac-AS-debug ✅ 🧪 wpe-wk2   🧪 win-tests ⏳ 🛠 mac-apple
✅ 🧪 webkitperl ✅ 🧪 ios-wk2 ✅ 🧪 api-mac ✅ 🧪 api-wpe ✅ 🛠 vision-apple
  🧪 ios-wk2-wpt   🧪 api-mac-debug ✅ 🛠 gtk3-libwebrtc
✅ 🛠 🧪 jsc ✅ 🧪 api-ios ✅ 🧪 mac-wk1 ✅ 🛠 gtk
✅ 🛠 🧪 jsc-debug-arm64   🛠 ios-safer-cpp ✅ 🧪 mac-wk2 ✅ 🧪 gtk-wk2
✅ 🛠 vision ✅ 🧪 mac-AS-debug-wk2 ✅ 🧪 api-gtk
  🛠 🧪 merge ✅ 🛠 vision-sim ✅ 🧪 mac-wk2-stress ✅ 🛠 playstation
✅ 🧪 vision-wk2 ✅ 🧪 mac-intel-wk2 ✅ 🛠 jsc-armv7
✅ 🛠 tv ✅ 🛠 mac-safer-cpp   🧪 jsc-armv7-tests
✅ 🛠 tv-sim
✅ 🛠 watch
✅ 🛠 watch-sim

@hyjorc1 hyjorc1 added the merge-queue Applied to send a pull request to merge-queue label Mar 13, 2026
@webkit-commit-queue webkit-commit-queue force-pushed the eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool branch from 6c169c0 to f6e4343 Compare March 13, 2026 19:08
@hyjorc1 hyjorc1 added merge-queue Applied to send a pull request to merge-queue and removed merge-queue Applied to send a pull request to merge-queue labels Mar 13, 2026
@hyjorc1 hyjorc1 force-pushed the eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool branch from f6e4343 to f05e49d Compare March 13, 2026 19:51
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webkit-early-warning-system commented Mar 13, 2026 •
edited
Loading

EWS run on current version of this PR (hash f05e49d)

Details

Misc iOS, visionOS, tvOS & watchOS macOS Linux Windows Apple Internal
✅ 🧪 style   🛠 ios   🛠 mac   🛠 wpe   🛠 win ⏳ 🛠 ios-apple
  🛠 ios-sim   🛠 mac-AS-debug   🧪 wpe-wk2   🧪 win-tests ⏳ 🛠 mac-apple
✅ 🧪 webkitperl   🧪 ios-wk2   🧪 api-mac   🧪 api-wpe ⏳ 🛠 vision-apple
  🧪 ios-wk2-wpt   🧪 api-mac-debug   🛠 gtk3-libwebrtc
✅ 🛠 🧪 jsc   🧪 api-ios   🧪 mac-wk1   🛠 gtk
✅ 🛠 🧪 jsc-debug-arm64   🛠 ios-safer-cpp   🧪 mac-wk2   🧪 gtk-wk2
  🛠 vision   🧪 mac-AS-debug-wk2   🧪 api-gtk
✅ 🛠 🧪 merge   🛠 vision-sim   🧪 mac-wk2-stress   🛠 playstation
⏳ 🧪 vision-wk2   🧪 mac-intel-wk2   🛠 jsc-armv7
  🛠 tv   🛠 mac-safer-cpp   🧪 jsc-armv7-tests
  🛠 tv-sim
  🛠 watch
  🛠 watch-sim

@webkit-early-warning-system
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webkit-early-warning-system commented Mar 13, 2026

EWS run on previous version of this PR (hash f6e4343)

Details

Misc iOS, visionOS, tvOS & watchOS macOS Linux Windows Apple Internal
⏳ 🧪 style ⏳ 🛠 ios ⏳ 🛠 mac ⏳ 🛠 wpe ⏳ 🛠 win ⏳ 🛠 ios-apple
⏳ 🧪 bindings ⏳ 🛠 ios-sim ⏳ 🛠 mac-AS-debug ⏳ 🧪 wpe-wk2 ⏳ 🧪 win-tests ⏳ 🛠 mac-apple
⏳ 🧪 webkitperl ⏳ 🧪 ios-wk2 ⏳ 🧪 api-mac ⏳ 🧪 api-wpe ⏳ 🛠 vision-apple
⏳ 🧪 webkitpy ⏳ 🧪 ios-wk2-wpt ⏳ 🧪 api-mac-debug ⏳ 🛠 gtk3-libwebrtc
⏳ 🛠 🧪 jsc ⏳ 🧪 api-ios ⏳ 🧪 mac-wk1 ⏳ 🛠 gtk
⏳ 🛠 🧪 jsc-debug-arm64 ⏳ 🛠 ios-safer-cpp ⏳ 🧪 mac-wk2 ⏳ 🧪 gtk-wk2
⏳ 🧪 services ⏳ 🛠 vision ⏳ 🧪 mac-AS-debug-wk2 ⏳ 🧪 api-gtk
  🛠 🧪 merge ⏳ 🛠 vision-sim ⏳ 🧪 mac-wk2-stress ⏳ 🛠 playstation
⏳ 🧪 vision-wk2 ⏳ 🧪 mac-intel-wk2 ⏳ 🛠 jsc-armv7
⏳ 🛠 tv ⏳ 🛠 mac-safer-cpp ⏳ 🧪 jsc-armv7-tests
⏳ 🛠 tv-sim
⏳ 🛠 watch
⏳ 🛠 watch-sim

@hyjorc1 hyjorc1 added the merge-queue Applied to send a pull request to merge-queue label Mar 13, 2026
@hyjorc1
[JSC] Allow quick DFG/FTL tier-up recovery after reinstall
f92b82d 
https://bugs.webkit.org/show_bug.cgi?id=309687
rdar://172290040

Reviewed by Dan Hecht.

Quick tier-up reduces the optimization threshold for functions that have
previously run JIT code successfully, letting them re-tier faster after
jettison.

Previously didInstallDFGCode() and didInstallFTLCode() were one-shot:
once the flag was cleared by a jettison, subsequent reinstalls could not
recover it. This patch allows recovery on reinstall.

A jettison is a profiling event — the speculation failure reveals type
information that baseline JIT captures, and a re-compile against those
richer profiles is likely more stable. Penalizing it permanently was
counterproductive.

Canonical link: https://commits.webkit.org/309230@main
@webkit-commit-queue webkit-commit-queue force-pushed the eng/JSC-Simplify-quick-DFG-FTL-tier-up-flags-from-TriState-to-bool branch from f05e49d to f92b82d Compare March 13, 2026 20:30
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webkit-commit-queue commented Mar 13, 2026

Committed 309230@main (f92b82d): https://commits.webkit.org/309230@main

Reviewed commits have been landed. Closing PR #60373 and removing active labels.

@webkit-commit-queue webkit-commit-queue merged commit f92b82d into WebKit:main Mar 13, 2026
@webkit-commit-queue webkit-commit-queue removed the merge-queue Applied to send a pull request to merge-queue label Mar 13, 2026
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