1 files changed, 22 insertions, 9 deletions
diff --git a/Source/JavaScriptCore/dfg/DFGOSRAvailabilityAnalysisPhase.h b/Source/JavaScriptCore/dfg/DFGOSRAvailabilityAnalysisPhase.h
index 28bf505da..2433c040e 100644
--- a/Source/JavaScriptCore/dfg/DFGOSRAvailabilityAnalysisPhase.h
+++ b/Source/JavaScriptCore/dfg/DFGOSRAvailabilityAnalysisPhase.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Apple Inc. All rights reserved.
+ * Copyright (C) 2013, 2014 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -23,13 +23,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
  */
 
-#ifndef DFGOSRAvailabilityAnalysisPhase_h
-#define DFGOSRAvailabilityAnalysisPhase_h
-
-#include <wtf/Platform.h>
+#pragma once
 
 #if ENABLE(DFG_JIT)
 
+#include "DFGBasicBlock.h"
 #include "DFGCommon.h"
 
 namespace JSC { namespace DFG {
@@ -37,13 +35,28 @@ namespace JSC { namespace DFG {
 class Graph;
 
 // Computes BasicBlock::ssa->availabiltiyAtHead/Tail. This is a forward flow type inference
-// over MovHints and SetLocals.
+// over MovHints and SetLocals. This analysis is run directly by the Plan for preparing for
+// lowering to B3 IR, but it can also be used as a utility. Note that if you run it before
+// stack layout, all of the flush availability will omit the virtual register - but it will
+// tell you the format.
 
 bool performOSRAvailabilityAnalysis(Graph&);
 
+// Local calculator for figuring out the availability at any node in a basic block. Requires
+// having run the availability analysis.
+class LocalOSRAvailabilityCalculator {
+public:
+    LocalOSRAvailabilityCalculator(Graph&);
+    ~LocalOSRAvailabilityCalculator();
+    
+    void beginBlock(BasicBlock*);
+    void endBlock(BasicBlock*); // Useful if you want to get data for the end of the block. You don't need to call this if you did beginBlock() and then executeNode() for every node.
+    void executeNode(Node*);
+    
+    AvailabilityMap m_availability;
+    Graph& m_graph;
+};
+
 } } // namespace JSC::DFG
 
 #endif // ENABLE(DFG_JIT)
-
-#endif // DFGOSRAvailabilityAnalysisPhase_h
-