Changeset 179477 in webkit for trunk/Source/JavaScriptCore/dfg/DFGNode.h

Timestamp:

Feb 2, 2015, 10:15:44 AM (11 years ago)

Author:

[email protected]

Message:

Converting Flushes and PhantomLocals to Phantoms requires an OSR availability analysis rather than just using the SetLocal's child
​https://bugs.webkit.org/show_bug.cgi?id=141107

Reviewed by Michael Saboff.

See the bugzilla for a discussion of the problem. This addresses the problem by ensuring
that Flushes are always strength-reduced to PhantomLocals, and CPS rethreading does a mini
OSR availability analysis to determine the right MovHint value to use for the Phantom.

• dfg/DFGCPSRethreadingPhase.cpp:

(JSC::DFG::CPSRethreadingPhase::CPSRethreadingPhase):
(JSC::DFG::CPSRethreadingPhase::freeUnnecessaryNodes):
(JSC::DFG::CPSRethreadingPhase::clearVariables):
(JSC::DFG::CPSRethreadingPhase::canonicalizeFlushOrPhantomLocalFor):
(JSC::DFG::CPSRethreadingPhase::canonicalizeLocalsInBlock):
(JSC::DFG::CPSRethreadingPhase::clearVariablesAtHeadAndTail): Deleted.

• dfg/DFGNode.h:

(JSC::DFG::Node::convertPhantomToPhantomLocal):
(JSC::DFG::Node::convertFlushToPhantomLocal):
(JSC::DFG::Node::convertToPhantomLocal): Deleted.

• dfg/DFGStrengthReductionPhase.cpp:

(JSC::DFG::StrengthReductionPhase::handleNode):

• tests/stress/inline-call-that-doesnt-use-all-args.js: Added.

(foo):
(bar):
(baz):

File:

• trunk/Source/JavaScriptCore/dfg/DFGNode.h (modified) (3 diffs)

trunk/Source/JavaScriptCore/dfg/DFGNode.h

@@ -1 +1 @@
 /*
- * Copyright (C) 2011, 2012, 2013, 2014 Apple Inc. All rights reserved.
+ * Copyright (C) 2011-2015 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -539 +539 @@
     }
     
-    void convertToPhantomLocal()
+    void convertPhantomToPhantomLocal()
     {
         ASSERT(m_op == Phantom && (child1()->op() == Phi || child1()->op() == SetLocal || child1()->op() == SetArgument));
@@ -545 +545 @@
         m_opInfo = child1()->m_opInfo; // Copy the variableAccessData.
         children.setChild1(Edge());
+    }
+    
+    void convertFlushToPhantomLocal()
+    {
+        ASSERT(m_op == Flush);
+        m_op = PhantomLocal;
+        children = AdjacencyList();
     }