Changeset 223614 in webkit for trunk/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp

Timestamp:

Oct 18, 2017, 10:41:55 AM (8 years ago)

Author:

[email protected]

Message:

The compiler should always register a structure when it adds its transitionWatchPointSet.
​https://bugs.webkit.org/show_bug.cgi?id=178420
<rdar://problem/34814024>

Reviewed by Saam Barati and Filip Pizlo.

JSTests:

• stress/regress-178420.js: Added.

(new.Array.10000.map):

Source/JavaScriptCore:

Instead of invoking addLazily() to add a structure's transitionWatchpointSet, we
now invoke Graph::registerAndWatchStructureTransition() on the structure.
registerAndWatchStructureTransition() both registers the structure and add its
transitionWatchpointSet to the plan desired watchpoints.

Graph::registerAndWatchStructureTransition() is based on Graph::registerStructure()
except registerAndWatchStructureTransition() adds the structure's
transitionWatchpointSet unconditionally.

• dfg/DFGArgumentsEliminationPhase.cpp:
• dfg/DFGArrayMode.cpp:

(JSC::DFG::ArrayMode::refine const):

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::handleIntrinsicCall):

• dfg/DFGFixupPhase.cpp:

(JSC::DFG::FixupPhase::fixupNode):

• dfg/DFGGraph.cpp:

(JSC::DFG::Graph::registerAndWatchStructureTransition):

• dfg/DFGGraph.h:

• dfg/DFGSpeculativeJIT.cpp:

(JSC::DFG::SpeculativeJIT::compileGetByValOnString):

• The second set of addLazily()s is redundant. This set is executed only when prototypeChainIsSane is true, and prototypeChainIsSane can only be true if and only if we've executed the if statement above it. That preceding if statement already registerAndWatchStructureTransition() the same 2 structures. Hence, this second set can be deleted.

• dfg/DFGWatchpointCollectionPhase.cpp:

(JSC::DFG::WatchpointCollectionPhase::addLazily):

• Deleted an unused function.

• ftl/FTLLowerDFGToB3.cpp:

(JSC::FTL::DFG::LowerDFGToB3::compileStringCharAt):

File:

• trunk/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/ftl/FTLLowerDFGToB3.cpp

@@ -5760 +5760 @@
                 // https://bugs.webkit.org/show_bug.cgi?id=144668
                 
-                m_graph.watchpoints().addLazily(globalObject->stringPrototype()->structure()->transitionWatchpointSet());
-                m_graph.watchpoints().addLazily(globalObject->objectPrototype()->structure()->transitionWatchpointSet());
-                
+                m_graph.registerAndWatchStructureTransition(globalObject->stringPrototype()->structure());
+                m_graph.registerAndWatchStructureTransition(globalObject->objectPrototype()->structure());
+
                 prototypeChainIsSane = globalObject->stringPrototypeChainIsSane();
             }