Changeset 36976 in webkit for trunk/JavaScriptCore/kjs/nodes.cpp

Timestamp:

Sep 26, 2008, 6:44:15 PM (17 years ago)

Author:

[email protected]

Message:

2008-09-26 Gavin Barraclough <​[email protected]>

Reviewed by Maciej Stachowiak & Oliver Hunt.

Add support for reusing temporary JSNumberCells. This change is based on the observation
that if the result of certain operations is a JSNumberCell and is consumed by a subsequent
operation that would produce a JSNumberCell, we can reuse the object rather than allocating
a fresh one. E.g. given the expression ((a * b) * c), we can statically determine that
(a * b) will have a numeric result (or else it will have thrown an exception), so the result
will either be a JSNumberCell or a JSImmediate.

This patch changes three areas of JSC:

• The AST now tracks type information about the result of each node.
• This information is consumed in bytecode compilation, and certain bytecode operations now carry the statically determined type information about their operands.
• CTI uses the information in a number of fashions:
  • Where an operand to certain arithmetic operations is reusable, it will plant code to try to perform the operation in JIT code & reuse the cell, where appropriate.
  • Where it can be statically determined that an operand can only be numeric (typically the result of another arithmetic operation) the code will not redundantly check that the JSCell is a JSNumberCell.
  • Where either of the operands to an add are non-numeric do not plant an optimized arithmetic code path, just call straight out to the C function.

+6% Sunspider (10% progression on 3D, 16% progression on math, 60% progression on access-nbody),
+1% v8-tests (improvements in raytrace & crypto)

• VM/CTI.cpp: Add optimized code generation with reuse of temporary JSNumberCells.
• VM/CTI.h:
• kjs/JSNumberCell.h:
• masm/X86Assembler.h:

• VM/CodeBlock.cpp: Add type information to specific bytecodes.
• VM/CodeGenerator.cpp:
• VM/CodeGenerator.h:
• VM/Machine.cpp:

• kjs/nodes.cpp: Track static type information for nodes.
• kjs/nodes.h:
• kjs/ResultDescriptor.h: (Added)
• JavaScriptCore.xcodeproj/project.pbxproj:

File:

• trunk/JavaScriptCore/kjs/nodes.cpp (modified) (16 diffs)

trunk/JavaScriptCore/kjs/nodes.cpp

@@ -142 +142 @@
 Node::Node(JSGlobalData* globalData)
     : ParserRefCounted(globalData)
-    , m_expectedReturnType(ObjectType)
-{
-    m_line = globalData->lexer->lineNo();
-}
-
-Node::Node(JSGlobalData* globalData, JSType expectedReturn)
-    : ParserRefCounted(globalData)
-    , m_expectedReturnType(expectedReturn)
 {
     m_line = globalData->lexer->lineNo();
@@ -664 +656 @@
                 return 0;
             RefPtr<RegisterID> r0 = generator.emitUnexpectedLoad(generator.finalDestination(dst), (m_operator == OpPlusPlus) ? 1.0 : -1.0);
-            return generator.emitBinaryOp(op_add, r0.get(), local, r0.get());
+            return generator.emitBinaryOp(op_add, r0.get(), local, r0.get(), OperandTypes());
         }
 
@@ -755 +747 @@
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(m_expr1.get(), m_rightHasAssignments, m_expr2->isPure(generator));
     RegisterID* src2 = generator.emitNode(m_expr2.get());
-    return generator.emitBinaryOp(opcode, generator.finalDestination(dst, src1.get()), src1.get(), src2);
+    return generator.emitBinaryOp(opcode, generator.finalDestination(dst, src1.get()), src1.get(), src2, OperandTypes(m_expr1->resultDescriptor(), m_expr2->resultDescriptor()));
 }
 
@@ -781 +773 @@
     RefPtr<RegisterID> src1 = generator.emitNodeForLeftHandSide(m_expr1.get(), m_rightHasAssignments, m_expr2->isPure(generator));
     RegisterID* src2 = generator.emitNode(m_expr2.get());
-    return generator.emitBinaryOp(opcode(), generator.finalDestination(dst, src1.get()), src2, src1.get());
+    return generator.emitBinaryOp(opcode(), generator.finalDestination(dst, src1.get()), src2, src1.get(), OperandTypes(m_expr2->resultDescriptor(), m_expr1->resultDescriptor()));
 }
 
@@ -789 +781 @@
     RegisterID* src2 = generator.emitNode(m_expr2.get());
     generator.emitExpressionInfo(m_divot, m_startOffset, m_endOffset);
-    return generator.emitBinaryOp(opcode(), generator.finalDestination(dst, src1.get()), src1.get(), src2);
+    return generator.emitBinaryOp(opcode(), generator.finalDestination(dst, src1.get()), src1.get(), src2, OperandTypes(m_expr1->resultDescriptor(), m_expr2->resultDescriptor()));
 }
 
@@ -847 +839 @@
 
 // FIXME: should this be moved to be a method on CodeGenerator?
-static ALWAYS_INLINE RegisterID* emitReadModifyAssignment(CodeGenerator& generator, RegisterID* dst, RegisterID* src1, RegisterID* src2, Operator oper)
+static ALWAYS_INLINE RegisterID* emitReadModifyAssignment(CodeGenerator& generator, RegisterID* dst, RegisterID* src1, RegisterID* src2, Operator oper, OperandTypes types)
 {
     OpcodeID opcode;
@@ -889 +881 @@
     }
     
-    return generator.emitBinaryOp(opcode, dst, src1, src2);
+    return generator.emitBinaryOp(opcode, dst, src1, src2, types);
 }
 
@@ -897 +889 @@
         if (generator.isLocalConstant(m_ident)) {
             RegisterID* src2 = generator.emitNode(m_right.get());
-            return emitReadModifyAssignment(generator, generator.finalDestination(dst), local, src2, m_operator);
+            return emitReadModifyAssignment(generator, generator.finalDestination(dst), local, src2, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
         }
         
@@ -904 +896 @@
             generator.emitMove(result.get(), local);
             RegisterID* src2 = generator.emitNode(m_right.get());
-            emitReadModifyAssignment(generator, result.get(), result.get(), src2, m_operator);
+            emitReadModifyAssignment(generator, result.get(), result.get(), src2, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
             generator.emitMove(local, result.get());
             return generator.moveToDestinationIfNeeded(dst, result.get());
@@ -910 +902 @@
         
         RegisterID* src2 = generator.emitNode(m_right.get());
-        RegisterID* result = emitReadModifyAssignment(generator, local, local, src2, m_operator);
+        RegisterID* result = emitReadModifyAssignment(generator, local, local, src2, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
         return generator.moveToDestinationIfNeeded(dst, result);
     }
@@ -920 +912 @@
         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);
+        RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), src2, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
         generator.emitPutScopedVar(depth, index, result, globalObject);
         return result;
@@ -930 +922 @@
     RegisterID* src2 = generator.emitNode(m_right.get());
     generator.emitExpressionInfo(m_divot, m_startOffset, m_endOffset);
-    RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), src2, m_operator);
+    RegisterID* result = emitReadModifyAssignment(generator, generator.finalDestination(dst, src1.get()), src1.get(), src2, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
     return generator.emitPutById(base.get(), m_ident, result);
 }
@@ -986 +978 @@
     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);
+    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), change, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
 
     generator.emitExpressionInfo(m_divot, m_startOffset, m_endOffset);
@@ -1021 +1013 @@
     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);
+    RegisterID* updatedValue = emitReadModifyAssignment(generator, generator.finalDestination(dst, value.get()), value.get(), change, m_operator, OperandTypes(ResultType::unknown(), m_right->resultDescriptor()));
 
     generator.emitExpressionInfo(m_divot, m_startOffset, m_endOffset);
@@ -1568 +1560 @@
             RefPtr<RegisterID> clauseVal = generator.newTemporary();
             generator.emitNode(clauseVal.get(), list->getClause()->expr());
-            generator.emitBinaryOp(op_stricteq, clauseVal.get(), clauseVal.get(), switchExpression);
+            generator.emitBinaryOp(op_stricteq, clauseVal.get(), clauseVal.get(), switchExpression, OperandTypes());
             labelVector.append(generator.newLabel());
             generator.emitJumpIfTrue(clauseVal.get(), labelVector[labelVector.size() - 1].get());
@@ -1576 +1568 @@
             RefPtr<RegisterID> clauseVal = generator.newTemporary();
             generator.emitNode(clauseVal.get(), list->getClause()->expr());
-            generator.emitBinaryOp(op_stricteq, clauseVal.get(), clauseVal.get(), switchExpression);
+            generator.emitBinaryOp(op_stricteq, clauseVal.get(), clauseVal.get(), switchExpression, OperandTypes());
             labelVector.append(generator.newLabel());
             generator.emitJumpIfTrue(clauseVal.get(), labelVector[labelVector.size() - 1].get());