Changeset 43339 in webkit for trunk/JavaScriptCore/parser/Nodes.cpp

Timestamp:

May 7, 2009, 1:27:58 AM (16 years ago)

Author:

[email protected]

Message:

2009-05-07 Gavin Barraclough <​[email protected]>

Reviewed by NOBODY (OOPS!).

Enable op_strcat across += assignments. This patch allows the lhs of a read/modify node
to be included within the concatenation operation, and also modifies the implementation
of the concatenation to attempt to reuse and cat onto the leftmost string, rather than
always allocating a new empty output string to copy into (as was previously the behaviour).

~0.5% progression, due to a 3%-3.5% progression on the string tests (particularly validate).

• parser/Nodes.cpp: (JSC::BinaryOpNode::emitStrcat): (JSC::emitReadModifyAssignment): (JSC::ReadModifyResolveNode::emitBytecode): (JSC::ReadModifyDotNode::emitBytecode): (JSC::ReadModifyBracketNode::emitBytecode):
• parser/Nodes.h:
• runtime/Operations.h: (JSC::concatenateStrings):
• runtime/UString.cpp: (JSC::UString::reserveCapacity):
• runtime/UString.h:

File:

• trunk/JavaScriptCore/parser/Nodes.cpp (modified) (11 diffs)

trunk/JavaScriptCore/parser/Nodes.cpp

@@ -1176 +1176 @@
 // least one left child that is also an add that can be determined to be operating on strings.
 //
-// Fixme: This method should correctly support concatenation on read-modify nodes (+=)
-//        but disabling this due to performance degradation (op_strcat needs to be able
-//        to append to the existing string).
-//
-RegisterID* BinaryOpNode::emitStrcat(BytecodeGenerator& generator, RegisterID* dst, RegisterID* lhs)
+RegisterID* BinaryOpNode::emitStrcat(BytecodeGenerator& generator, RegisterID* dst, RegisterID* lhs, ReadModifyResolveNode* emitExpressionInfoForMe)
 {
     ASSERT(isAdd());
@@ -1257 +1253 @@
     ASSERT(temporaryRegisters.size() >= 3);
 
+    // Certain read-modify nodes require expression info to be emitted *after* m_right has been generated.
+    // If this is required the node is passed as 'emitExpressionInfoForMe'; do so now.
+    if (emitExpressionInfoForMe)
+        generator.emitExpressionInfo(emitExpressionInfoForMe->divot(), emitExpressionInfoForMe->startOffset(), emitExpressionInfoForMe->endOffset());
+
     // If there is an assignment convert the lhs now.  This will also copy lhs to
     // the temporary register we allocated for it.
@@ -1409 +1410 @@
 
 // FIXME: should this be moved to be a method on BytecodeGenerator?
-static ALWAYS_INLINE RegisterID* emitReadModifyAssignment(BytecodeGenerator& generator, RegisterID* dst, RegisterID* src1, RegisterID* src2, Operator oper, OperandTypes types)
+static ALWAYS_INLINE RegisterID* emitReadModifyAssignment(BytecodeGenerator& generator, RegisterID* dst, RegisterID* src1, ExpressionNode* m_right, Operator oper, OperandTypes types, ReadModifyResolveNode* emitExpressionInfoForMe = 0)
 {
     OpcodeID opcodeID;
@@ -1420 +1421 @@
             break;
         case OpPlusEq:
+            if (m_right->isAdd() && m_right->resultDescriptor().definitelyIsString())
+                return static_cast<AddNode*>(m_right)->emitStrcat(generator, dst, src1, emitExpressionInfoForMe);
             opcodeID = op_add;
             break;
@@ -1450 +1453 @@
             return dst;
     }
-    
+
+    RegisterID* src2 = generator.emitNode(m_right);
+
+    // Certain read-modify nodes require expression info to be emitted *after* m_right has been generated.
+    // If this is required the node is passed as 'emitExpressionInfoForMe'; do so now.
+    if (emitExpressionInfoForMe)
+        generator.emitExpressionInfo(emitExpressionInfoForMe->divot(), emitExpressionInfoForMe->startOffset(), emitExpressionInfoForMe->endOffset());
+
     return generator.emitBinaryOp(opcodeID, dst, src1, src2, types);
 }
@@ -1458 +1468 @@
     if (RegisterID* local = generator.registerFor(m_ident)) {
         if (generator.isLocalConstant(m_ident)) {
-            RegisterID* src2 = generator.emitNode(m_right.get());
-            return emitReadModifyAssignment(generator, generator.finalDestination(dst), local, src2, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+            return emitReadModifyAssignment(generator, generator.finalDestination(dst), local, m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
         }
         
@@ -1465 +1474 @@
             RefPtr<RegisterID> result = generator.newTemporary();
             generator.emitMove(result.get(), local);
-            RegisterID* src2 = generator.emitNode(m_right.get());
-            emitReadModifyAssignment(generator, result.get(), result.get(), src2, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+            emitReadModifyAssignment(generator, result.get(), result.get(), m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
             generator.emitMove(local, result.get());
             return generator.moveToDestinationIfNeeded(dst, result.get());
         }
         
-        RegisterID* src2 = generator.emitNode(m_right.get());
-        RegisterID* result = emitReadModifyAssignment(generator, local, local, src2, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+        RegisterID* result = emitReadModifyAssignment(generator, local, local, m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
         return generator.moveToDestinationIfNeeded(dst, result);
     }
@@ -1481 +1488 @@
     if (generator.findScopedProperty(m_ident, index, depth, true, globalObject) && index != missingSymbolMarker()) {
         RefPtr<RegisterID> src1 = generator.emitGetScopedVar(generator.tempDestination(dst), depth, index, globalObject);
-        RegisterID* src2 = generator.emitNode(m_right.get());
-        RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), src2, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+        RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
         generator.emitPutScopedVar(depth, index, result, globalObject);
         return result;
@@ -1490 +1496 @@
     generator.emitExpressionInfo(divot() - startOffset() + m_ident.size(), m_ident.size(), 0);
     RefPtr<RegisterID> base = generator.emitResolveWithBase(generator.newTemporary(), src1.get(), m_ident);
-    RegisterID* src2 = generator.emitNode(m_right.get());
-    generator.emitExpressionInfo(divot(), startOffset(), endOffset());
-    RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), src2, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+    RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()), this);
     return generator.emitPutById(base.get(), m_ident, result);
 }
@@ -1579 +1583 @@
     generator.emitExpressionInfo(divot() - m_subexpressionDivotOffset, startOffset() - m_subexpressionDivotOffset, m_subexpressionEndOffset);
     RefPtr<RegisterID> value = generator.emitGetById(generator.tempDestination(dst), base.get(), m_ident);
-    RegisterID* change = generator.emitNode(m_right.get());
-    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), change, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
 
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());
@@ -1651 +1654 @@
     generator.emitExpressionInfo(divot() - m_subexpressionDivotOffset, startOffset() - m_subexpressionDivotOffset, m_subexpressionEndOffset);
     RefPtr<RegisterID> value = generator.emitGetByVal(generator.tempDestination(dst), base.get(), property.get());
-    RegisterID* change = generator.emitNode(m_right.get());
-    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), change, m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
+    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), m_right.get(), m_operator, OperandTypes(ResultType::unknownType(), m_right->resultDescriptor()));
 
     generator.emitExpressionInfo(divot(), startOffset(), endOffset());