Changeset 120974 in webkit for trunk/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp

Timestamp:

Jun 21, 2012, 3:55:42 PM (13 years ago)

Author:

[email protected]

Message:

DFG should inline 'new Array()'
​https://bugs.webkit.org/show_bug.cgi?id=89632

Reviewed by Geoffrey Garen.

This adds support for treating InternalFunction like intrinsics. The code
to do so is actually quite clean, so I don't feel bad about perpetuating
the InternalFunction vs. JSFunction-with-NativeExecutable dichotomy.

Currently this newfound power is only used to inline 'new Array()'.

• dfg/DFGByteCodeParser.cpp:

(ByteCodeParser):
(JSC::DFG::ByteCodeParser::handleCall):
(JSC::DFG::ByteCodeParser::handleConstantInternalFunction):
(DFG):

• dfg/DFGGraph.h:

(JSC::DFG::Graph::isInternalFunctionConstant):
(JSC::DFG::Graph::valueOfInternalFunctionConstant):

File:

• trunk/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp (modified) (7 diffs)

trunk/Source/JavaScriptCore/dfg/DFGByteCodeParser.cpp

@@ -29 +29 @@
 #if ENABLE(DFG_JIT)
 
+#include "ArrayConstructor.h"
 #include "CallLinkStatus.h"
 #include "CodeBlock.h"
@@ -96 +97 @@
     // Handle intrinsic functions. Return true if it succeeded, false if we need to plant a call.
     bool handleIntrinsic(bool usesResult, int resultOperand, Intrinsic, int registerOffset, int argumentCountIncludingThis, SpeculatedType prediction);
+    bool handleConstantInternalFunction(bool usesResult, int resultOperand, InternalFunction*, int registerOffset, int argumentCountIncludingThis, SpeculatedType prediction, CodeSpecializationKind);
     void handleGetByOffset(
         int destinationOperand, SpeculatedType, NodeIndex base, unsigned identifierNumber,
@@ -1129 +1131 @@
     
     NodeIndex callTarget = get(currentInstruction[1].u.operand);
-    enum { ConstantFunction, LinkedFunction, UnknownFunction } callType;
+    enum {
+        ConstantFunction,
+        ConstantInternalFunction,
+        LinkedFunction,
+        UnknownFunction
+    } callType;
             
     CallLinkStatus callLinkStatus = CallLinkStatus::computeFor(
@@ -1151 +1158 @@
                 m_graph.valueOfFunctionConstant(callTarget),
                 m_graph.valueOfFunctionConstant(callTarget)->executable());
+#endif
+    } else if (m_graph.isInternalFunctionConstant(callTarget)) {
+        callType = ConstantInternalFunction;
+#if DFG_ENABLE(DEBUG_VERBOSE)
+        dataLog("Call at [@%lu, bc#%u] has an internal function constant: %p.\n",
+                m_graph.size(), m_currentIndex,
+                m_graph.valueOfInternalFunctionConstant(callTarget));
 #endif
     } else if (callLinkStatus.isSet() && !callLinkStatus.couldTakeSlowPath()
@@ -1184 +1198 @@
             nextOffset += OPCODE_LENGTH(op_call_put_result);
         }
+
+        if (callType == ConstantInternalFunction) {
+            if (handleConstantInternalFunction(usesResult, resultOperand, m_graph.valueOfInternalFunctionConstant(callTarget), registerOffset, argumentCountIncludingThis, prediction, kind))
+                return;
+            
+            // Can only handle this using the generic call handler.
+            addCall(interpreter, currentInstruction, op);
+            return;
+        }
+        
         JSFunction* expectedFunction;
         Intrinsic intrinsic;
@@ -1215 +1239 @@
             return;
     }
-            
+    
     addCall(interpreter, currentInstruction, op);
 }
@@ -1570 +1594 @@
         return false;
     }
+}
+
+bool ByteCodeParser::handleConstantInternalFunction(
+    bool usesResult, int resultOperand, InternalFunction* function, int registerOffset,
+    int argumentCountIncludingThis, SpeculatedType prediction, CodeSpecializationKind kind)
+{
+    // If we ever find that we have a lot of internal functions that we specialize for,
+    // then we should probably have some sort of hashtable dispatch, or maybe even
+    // dispatch straight through the MethodTable of the InternalFunction. But for now,
+    // it seems that this case is hit infrequently enough, and the number of functions
+    // we know about is small enough, that having just a linear cascade of if statements
+    // is good enough.
+    
+    UNUSED_PARAM(registerOffset); // Remove this once we do more things to the arguments.
+    UNUSED_PARAM(prediction); // Remove this once we do more things.
+    UNUSED_PARAM(kind); // Remove this once we do more things.
+    
+    if (function->classInfo() == &ArrayConstructor::s_info) {
+        // We could handle this but don't for now.
+        if (argumentCountIncludingThis != 1)
+            return false;
+        
+        setIntrinsicResult(
+            usesResult, resultOperand,
+            addToGraph(Node::VarArg, NewArray, OpInfo(0), OpInfo(0)));
+        return true;
+    }
+    
+    return false;
 }