Changeset 129316 in webkit for trunk/Source/JavaScriptCore/dfg/DFGAbstractState.cpp

Timestamp:

Sep 23, 2012, 3:48:19 PM (13 years ago)

Author:

[email protected]

Message:

CSE for access to closure variables (get_/put_scoped_var)
​https://bugs.webkit.org/show_bug.cgi?id=97414

Reviewed by Oliver Hunt.

I separated loading a scope from loading its storage pointer, so we can
CSE the storage pointer load. Then, I copied the global var CSE and adjusted
it for closure vars.

• dfg/DFGAbstractState.cpp:

(JSC::DFG::AbstractState::execute): Renamed GetScopeChain => GetScope to
reflect renames from a few weeks ago.

Added a case for the storage pointer load, similar to object storage pointer load.

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::parseBlock): Added an independent node for
the storage pointer.

• dfg/DFGCSEPhase.cpp:

(JSC::DFG::CSEPhase::scopedVarLoadElimination):
(CSEPhase):
(JSC::DFG::CSEPhase::scopedVarStoreElimination):
(JSC::DFG::CSEPhase::getScopeLoadElimination):
(JSC::DFG::CSEPhase::getScopeRegistersLoadElimination):
(JSC::DFG::CSEPhase::setLocalStoreElimination):
(JSC::DFG::CSEPhase::performNodeCSE): Copied globalVarLoad/StoreElimination
and adapted the same logic to closure vars.

• dfg/DFGNode.h:

(JSC::DFG::Node::hasScopeChainDepth):
(JSC::DFG::Node::scope):
(Node):

• dfg/DFGNodeType.h:

(DFG): GetScopedVar and GetGlobalVar are no longer MustGenerate. I'm not
sure why they ever were. But these are simple load operations so, if they're
unused, they're truly dead.

• dfg/DFGPredictionPropagationPhase.cpp:

(JSC::DFG::PredictionPropagationPhase::propagate):

• dfg/DFGSpeculativeJIT32_64.cpp:

(JSC::DFG::SpeculativeJIT::compile):

• dfg/DFGSpeculativeJIT64.cpp:

(JSC::DFG::SpeculativeJIT::compile): Updated for renames and split-out
node for getting the storage pointer.

File:

• trunk/Source/JavaScriptCore/dfg/DFGAbstractState.cpp (modified) (1 diff)

trunk/Source/JavaScriptCore/dfg/DFGAbstractState.cpp

@@ -1263 +1263 @@
         break;
             
-    case GetScopeChain:
+    case GetScope:
         node.setCanExit(false);
         forNode(nodeIndex).set(SpecCellOther);
         break;
-            
+
+    case GetScopeRegisters:
+        node.setCanExit(false);
+        forNode(node.child1()).filter(SpecCell);
+        forNode(nodeIndex).clear(); // The result is not a JS value.
+        break;
+
     case GetScopedVar:
         node.setCanExit(false);