Changeset 92736 in webkit

Timestamp:

Aug 9, 2011 6:12:28 PM (13 years ago)

Author:

fpizlo@apple.com

Message:

DFG JIT does not speculative integers as aggressively as it should
​https://bugs.webkit.org/show_bug.cgi?id=65949

Reviewed by Gavin Barraclough.

Added a tree walk to propagate integer predictions through arithmetic
expressions.

This is a 71% speed-up on Kraken's imaging-gaussian-blur, which
translates to a 19% speed-up on Kraken overall. It's neutral on
other benchmarks.

• dfg/DFGByteCodeParser.cpp:

(JSC::DFG::ByteCodeParser::predictInt32):

Location:

trunk/Source/JavaScriptCore

Files:

• ChangeLog (modified) (1 diff)
• dfg/DFGByteCodeParser.cpp (modified) (2 diffs)

trunk/Source/JavaScriptCore/ChangeLog

@@ +1 @@
+2011-08-09  Filip Pizlo  <fpizlo@apple.com>
+
+        DFG JIT does not speculative integers as aggressively as it should
+        https://bugs.webkit.org/show_bug.cgi?id=65949
+
+        Reviewed by Gavin Barraclough.
+        
+        Added a tree walk to propagate integer predictions through arithmetic
+        expressions.
+        
+        This is a 71% speed-up on Kraken's imaging-gaussian-blur, which
+        translates to a 19% speed-up on Kraken overall.  It's neutral on
+        other benchmarks.
+
+        * dfg/DFGByteCodeParser.cpp:
+        (JSC::DFG::ByteCodeParser::predictInt32):
+
 2011-08-09  Filip Pizlo  <fpizlo@apple.com>
 

trunk/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp

@@ -436 +436 @@
     void predictInt32(NodeIndex nodeIndex)
     {
-        Node* nodePtr = &m_graph[nodeIndex];
-
-        if (nodePtr->op == ValueToNumber)
-            nodePtr = &m_graph[nodePtr->child1()];
-
-        if (nodePtr->op == ValueToInt32)
-            nodePtr = &m_graph[nodePtr->child1()];
+        ASSERT(m_reusableNodeStack.isEmpty());
+        m_reusableNodeStack.append(&m_graph[nodeIndex]);
         
-        m_graph.predict(*nodePtr, PredictInt32);
+        do {
+            Node* nodePtr = m_reusableNodeStack.last();
+            m_reusableNodeStack.removeLast();
+            
+            if (nodePtr->op == ValueToNumber)
+                nodePtr = &m_graph[nodePtr->child1()];
+            
+            if (nodePtr->op == ValueToInt32)
+                nodePtr = &m_graph[nodePtr->child1()];
+            
+            switch (nodePtr->op) {
+            case ArithAdd:
+            case ArithSub:
+            case ArithMul:
+            case ValueAdd:
+                m_reusableNodeStack.append(&m_graph[nodePtr->child1()]);
+                m_reusableNodeStack.append(&m_graph[nodePtr->child2()]);
+                break;
+            default:
+                m_graph.predict(*nodePtr, PredictInt32);
+                break;
+            }
+        } while (!m_reusableNodeStack.isEmpty());
     }
 
@@ -517 +534 @@
     Vector<PhiStackEntry, 16> m_argumentPhiStack;
     Vector<PhiStackEntry, 16> m_localPhiStack;
+    
+    Vector<Node*, 16> m_reusableNodeStack;
 };