Branch: refs/heads/main
Home: https://github.com/WebKit/WebKit
Commit: 2ee637ac017724a626b7a6899db0e31ab305483b
https://github.com/WebKit/WebKit/commit/2ee637ac017724a626b7a6899db0e31ab305483b
Author: Yusuke Suzuki <[email protected]>
Date: 2026-10-10 (Sat, 10 Oct 2026)
Changed paths:
A JSTests/stress/ftl-map-set-with-deleted-entries.js
M Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp
Log Message:
-----------
[JSC] Tighten FTL lowering of Map and Set lookup and iteration
https://bugs.webkit.org/show_bug.cgi?id=326779
rdar://problem/189487375
Reviewed by Sosuke Suzuki.
compileMapGetImpl compared every probed key against the deleted-entry marker.
The marker is a VM-private Symbol that is never a key and is neither a string
nor a BigInt, so every key-type case already sends it to the next entry in
the chain. Drop the extra compare and branch from each probe.
Also, compileMapIteratorNext marks the first-call, closed, end-of-table, and
deleted-entry cases as rare, and reuses the empty-sentinel block for the
closed iterator instead of feeding the phis the same values twice.
Test: JSTests/stress/ftl-map-set-with-deleted-entries.js
* JSTests/stress/ftl-map-set-with-deleted-entries.js: Added.
(shouldBe):
(getUntyped):
* Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp:
(JSC::FTL::DFG::LowerDFGToB3::compileCompareStrictEq):
Canonical link: https://commits.webkit.org/323315@main
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