commit f37746ed8cccdeced75f8a4def20b1e8e6e8edf3
author mhahnenberg@apple.com <mhahnenberg@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Mon Mar 10 22:21:44 2014 +0000
committer mhahnenberg@apple.com <mhahnenberg@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc> Mon Mar 10 22:21:44 2014 +0000
tree 4d237a6e80887141da0d79fdd9100c0e284c84ab
parent 312efcd765c63ead8816e18cc08da99ed6f0c8e2

Remove ConditionalStore barrier
https://bugs.webkit.org/show_bug.cgi?id=130040

Reviewed by Geoffrey Garen.

ConditionalStoreBarrier was created when barriers were much more expensive. Now that 
they're cheap(er), we can get rid of them. This also allows us to get rid of the write 
barrier logic in emitPutTransitionStub because we always will have executed a write barrier 
on the base object in the case where we are allocating and storing a new Butterfly into it. 
Previously, a ConditionalStoreBarrier might or might not have barrier-ed the base object, 
so we'd have to emit a write barrier in the transition case.

This is performance neutral on the benchmarks we track.

* dfg/DFGAbstractInterpreterInlines.h:
(JSC::DFG::AbstractInterpreter<AbstractStateType>::executeEffects):
* dfg/DFGClobberize.h:
(JSC::DFG::clobberize):
* dfg/DFGConstantFoldingPhase.cpp:
(JSC::DFG::ConstantFoldingPhase::foldConstants):
(JSC::DFG::ConstantFoldingPhase::emitPutByOffset):
* dfg/DFGFixupPhase.cpp:
(JSC::DFG::FixupPhase::fixupNode):
(JSC::DFG::FixupPhase::insertStoreBarrier):
* dfg/DFGNode.h:
(JSC::DFG::Node::isStoreBarrier):
* dfg/DFGNodeType.h:
* dfg/DFGPredictionPropagationPhase.cpp:
(JSC::DFG::PredictionPropagationPhase::propagate):
* dfg/DFGSafeToExecute.h:
(JSC::DFG::safeToExecute):
* dfg/DFGSpeculativeJIT.cpp:
(JSC::DFG::SpeculativeJIT::compileStoreBarrier):
* dfg/DFGSpeculativeJIT32_64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* dfg/DFGSpeculativeJIT64.cpp:
(JSC::DFG::SpeculativeJIT::compile):
* ftl/FTLCapabilities.cpp:
(JSC::FTL::canCompile):
* ftl/FTLLowerDFGToLLVM.cpp:
(JSC::FTL::LowerDFGToLLVM::compileNode):
* jit/Repatch.cpp:
(JSC::emitPutTransitionStub):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@165407 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/JavaScriptCore/dfg/DFGFixupPhase.cpp

diff --git a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
index 689b7ac..3c67923 100644
--- a/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
+++ b/Source/JavaScriptCore/dfg/DFGFixupPhase.cpp
@@ -578,7 +578,7 @@
             case Array::Arguments:
                 fixEdge<KnownCellUse>(child1);
                 fixEdge<Int32Use>(child2);
-                insertStoreBarrier(m_indexInBlock, child1, child3);
+                insertStoreBarrier(m_indexInBlock, child1);
                 break;
             default:
                 fixEdge<KnownCellUse>(child1);
@@ -616,7 +616,7 @@
                 break;
             case Array::Contiguous:
             case Array::ArrayStorage:
-                insertStoreBarrier(m_indexInBlock, node->child1(), node->child2());
+                insertStoreBarrier(m_indexInBlock, node->child1());
                 break;
             default:
                 break;
@@ -809,7 +809,7 @@
 
         case PutClosureVar: {
             fixEdge<KnownCellUse>(node->child1());
-            insertStoreBarrier(m_indexInBlock, node->child1(), node->child3());
+            insertStoreBarrier(m_indexInBlock, node->child1());
             break;
         }
 
@@ -853,7 +853,7 @@
         case PutByIdFlush:
         case PutByIdDirect: {
             fixEdge<CellUse>(node->child1());
-            insertStoreBarrier(m_indexInBlock, node->child1(), node->child2());
+            insertStoreBarrier(m_indexInBlock, node->child1());
             break;
         }
 
@@ -892,13 +892,13 @@
             if (!node->child1()->hasStorageResult())
                 fixEdge<KnownCellUse>(node->child1());
             fixEdge<KnownCellUse>(node->child2());
-            insertStoreBarrier(m_indexInBlock, node->child2(), node->child3());
+            insertStoreBarrier(m_indexInBlock, node->child2());
             break;
         }
             
         case MultiPutByOffset: {
             fixEdge<CellUse>(node->child1());
-            insertStoreBarrier(m_indexInBlock, node->child1(), node->child2());
+            insertStoreBarrier(m_indexInBlock, node->child1());
             break;
         }
             
@@ -966,8 +966,8 @@
                 m_indexInBlock, SpecNone, WeakJSConstant, node->origin, 
                 OpInfo(m_graph.globalObjectFor(node->origin.semantic)));
             Node* barrierNode = m_graph.addNode(
-                SpecNone, ConditionalStoreBarrier, m_currentNode->origin, 
-                Edge(globalObjectNode, KnownCellUse), Edge(node->child1().node(), UntypedUse));
+                SpecNone, StoreBarrier, m_currentNode->origin, 
+                Edge(globalObjectNode, KnownCellUse));
             m_insertionSet.insert(m_indexInBlock, barrierNode);
             break;
         }
@@ -1041,7 +1041,6 @@
         case ExtractOSREntryLocal:
         case LoopHint:
         case StoreBarrier:
-        case ConditionalStoreBarrier:
         case StoreBarrierWithNullCheck:
         case FunctionReentryWatchpoint:
         case TypedArrayWatchpoint:
@@ -1618,15 +1617,9 @@
         edge.setUseKind(useKind);
     }
     
-    void insertStoreBarrier(unsigned indexInBlock, Edge child1, Edge child2 = Edge())
+    void insertStoreBarrier(unsigned indexInBlock, Edge child1)
     {
-        Node* barrierNode;
-        if (!child2)
-            barrierNode = m_graph.addNode(SpecNone, StoreBarrier, m_currentNode->origin, Edge(child1.node(), child1.useKind()));
-        else {
-            barrierNode = m_graph.addNode(SpecNone, ConditionalStoreBarrier, m_currentNode->origin, 
-                Edge(child1.node(), child1.useKind()), Edge(child2.node(), child2.useKind()));
-        }
+        Node* barrierNode = m_graph.addNode(SpecNone, StoreBarrier, m_currentNode->origin, child1);
         m_insertionSet.insert(indexInBlock, barrierNode);
     }