Merge webkit.org at r50258 : Initial merge by git.

Change-Id: I1a9e1dc4ed654b69174ad52a4f031a07240f37b0

3 files changed, 121 insertions, 41 deletions

diff --git a/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
index 8951ce3..04dae15 100644
--- a/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.cpp
@@ -608,8 +608,9 @@ void ALWAYS_INLINE BytecodeGenerator::rewindUnaryOp()
 
 PassRefPtr<Label> BytecodeGenerator::emitJump(Label* target)
 {
+    size_t begin = instructions().size();
     emitOpcode(target->isForward() ? op_jmp : op_loop);
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return target;
 }
 
@@ -624,10 +625,12 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(RegisterID* cond, Label* tar
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindBinaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_loop_if_less);
             instructions().append(src1Index);
             instructions().append(src2Index);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_lesseq && !target->isForward()) {
@@ -639,10 +642,12 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(RegisterID* cond, Label* tar
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindBinaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_loop_if_lesseq);
             instructions().append(src1Index);
             instructions().append(src2Index);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_eq_null && target->isForward()) {
@@ -653,9 +658,11 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(RegisterID* cond, Label* tar
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindUnaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jeq_null);
             instructions().append(srcIndex);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_neq_null && target->isForward()) {
@@ -666,16 +673,20 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(RegisterID* cond, Label* tar
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindUnaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jneq_null);
             instructions().append(srcIndex);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     }
 
+    size_t begin = instructions().size();
+
     emitOpcode(target->isForward() ? op_jtrue : op_loop_if_true);
     instructions().append(cond->index());
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return target;
 }
 
@@ -692,10 +703,12 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* ta
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindBinaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jnless);
             instructions().append(src1Index);
             instructions().append(src2Index);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_lesseq) {
@@ -707,10 +720,12 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* ta
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindBinaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jnlesseq);
             instructions().append(src1Index);
             instructions().append(src2Index);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_not) {
@@ -721,9 +736,11 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* ta
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindUnaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jtrue);
             instructions().append(srcIndex);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_eq_null) {
@@ -734,9 +751,11 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* ta
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindUnaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jneq_null);
             instructions().append(srcIndex);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     } else if (m_lastOpcodeID == op_neq_null) {
@@ -747,34 +766,41 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* ta
 
         if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
             rewindUnaryOp();
+
+            size_t begin = instructions().size();
             emitOpcode(op_jeq_null);
             instructions().append(srcIndex);
-            instructions().append(target->offsetFrom(instructions().size()));
+            instructions().append(target->bind(begin, instructions().size()));
             return target;
         }
     }
 
+    size_t begin = instructions().size();
     emitOpcode(op_jfalse);
     instructions().append(cond->index());
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return target;
 }
 
 PassRefPtr<Label> BytecodeGenerator::emitJumpIfNotFunctionCall(RegisterID* cond, Label* target)
 {
+    size_t begin = instructions().size();
+
     emitOpcode(op_jneq_ptr);
     instructions().append(cond->index());
     instructions().append(m_scopeChain->globalObject()->d()->callFunction);
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return target;
 }
 
 PassRefPtr<Label> BytecodeGenerator::emitJumpIfNotFunctionApply(RegisterID* cond, Label* target)
 {
+    size_t begin = instructions().size();
+
     emitOpcode(op_jneq_ptr);
     instructions().append(cond->index());
     instructions().append(m_scopeChain->globalObject()->d()->applyFunction);
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return target;
 }
 
@@ -1255,6 +1281,19 @@ RegisterID* BytecodeGenerator::emitDeleteById(RegisterID* dst, RegisterID* base,
 
 RegisterID* BytecodeGenerator::emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
 {
+    for (size_t i = m_forInContextStack.size(); i > 0; i--) {
+        ForInContext& context = m_forInContextStack[i - 1];
+        if (context.propertyRegister == property) {
+            emitOpcode(op_get_by_pname);
+            instructions().append(dst->index());
+            instructions().append(base->index());
+            instructions().append(property->index());
+            instructions().append(context.expectedSubscriptRegister->index());
+            instructions().append(context.iterRegister->index());
+            instructions().append(context.indexRegister->index());
+            return dst;
+        }
+    }
     emitOpcode(op_get_by_val);
     instructions().append(dst->index());
     instructions().append(base->index());
@@ -1718,6 +1757,8 @@ PassRefPtr<Label> BytecodeGenerator::emitComplexJumpScopes(Label* target, Contro
         }
 
         if (nNormalScopes) {
+            size_t begin = instructions().size();
+
             // We need to remove a number of dynamic scopes to get to the next
             // finally block
             emitOpcode(op_jmp_scopes);
@@ -1726,14 +1767,14 @@ PassRefPtr<Label> BytecodeGenerator::emitComplexJumpScopes(Label* target, Contro
             // If topScope == bottomScope then there isn't actually a finally block
             // left to emit, so make the jmp_scopes jump directly to the target label
             if (topScope == bottomScope) {
-                instructions().append(target->offsetFrom(instructions().size()));
+                instructions().append(target->bind(begin, instructions().size()));
                 return target;
             }
 
             // Otherwise we just use jmp_scopes to pop a group of scopes and go
             // to the next instruction
             RefPtr<Label> nextInsn = newLabel();
-            instructions().append(nextInsn->offsetFrom(instructions().size()));
+            instructions().append(nextInsn->bind(begin, instructions().size()));
             emitLabel(nextInsn.get());
         }
 
@@ -1758,27 +1799,47 @@ PassRefPtr<Label> BytecodeGenerator::emitJumpScopes(Label* target, int targetSco
     if (m_finallyDepth)
         return emitComplexJumpScopes(target, &m_scopeContextStack.last(), &m_scopeContextStack.last() - scopeDelta);
 
+    size_t begin = instructions().size();
+
     emitOpcode(op_jmp_scopes);
     instructions().append(scopeDelta);
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return target;
 }
 
-RegisterID* BytecodeGenerator::emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target)
+RegisterID* BytecodeGenerator::emitGetPropertyNames(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, Label* breakTarget)
 {
+    size_t begin = instructions().size();
+
+    emitOpcode(op_get_pnames);
+    instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(i->index());
+    instructions().append(size->index());
+    instructions().append(breakTarget->bind(begin, instructions().size()));
+    return dst;
+}
+
+RegisterID* BytecodeGenerator::emitNextPropertyName(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, RegisterID* iter, Label* target)
+{
+    size_t begin = instructions().size();
+
     emitOpcode(op_next_pname);
     instructions().append(dst->index());
+    instructions().append(base->index());
+    instructions().append(i->index());
+    instructions().append(size->index());
     instructions().append(iter->index());
-    instructions().append(target->offsetFrom(instructions().size()));
+    instructions().append(target->bind(begin, instructions().size()));
     return dst;
 }
 
 RegisterID* BytecodeGenerator::emitCatch(RegisterID* targetRegister, Label* start, Label* end)
 {
 #if ENABLE(JIT)
-    HandlerInfo info = { start->offsetFrom(0), end->offsetFrom(0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth, CodeLocationLabel() };
+    HandlerInfo info = { start->bind(0, 0), end->bind(0, 0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth, CodeLocationLabel() };
 #else
-    HandlerInfo info = { start->offsetFrom(0), end->offsetFrom(0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth };
+    HandlerInfo info = { start->bind(0, 0), end->bind(0, 0), instructions().size(), m_dynamicScopeDepth + m_baseScopeDepth };
 #endif
 
     m_codeBlock->addExceptionHandler(info);
@@ -1798,9 +1859,11 @@ RegisterID* BytecodeGenerator::emitNewError(RegisterID* dst, ErrorType type, JSV
 
 PassRefPtr<Label> BytecodeGenerator::emitJumpSubroutine(RegisterID* retAddrDst, Label* finally)
 {
+    size_t begin = instructions().size();
+
     emitOpcode(op_jsr);
     instructions().append(retAddrDst->index());
-    instructions().append(finally->offsetFrom(instructions().size()));
+    instructions().append(finally->bind(begin, instructions().size()));
     emitLabel(newLabel().get()); // Record the fact that the next instruction is implicitly labeled, because op_sret will return to it.
     return finally;
 }
@@ -1870,7 +1933,7 @@ static void prepareJumpTableForImmediateSwitch(SimpleJumpTable& jumpTable, int32
         // We're emitting this after the clause labels should have been fixed, so 
         // the labels should not be "forward" references
         ASSERT(!labels[i]->isForward());
-        jumpTable.add(keyForImmediateSwitch(nodes[i], min, max), labels[i]->offsetFrom(switchAddress)); 
+        jumpTable.add(keyForImmediateSwitch(nodes[i], min, max), labels[i]->bind(switchAddress, switchAddress + 3)); 
     }
 }
 
@@ -1896,7 +1959,7 @@ static void prepareJumpTableForCharacterSwitch(SimpleJumpTable& jumpTable, int32
         // We're emitting this after the clause labels should have been fixed, so 
         // the labels should not be "forward" references
         ASSERT(!labels[i]->isForward());
-        jumpTable.add(keyForCharacterSwitch(nodes[i], min, max), labels[i]->offsetFrom(switchAddress)); 
+        jumpTable.add(keyForCharacterSwitch(nodes[i], min, max), labels[i]->bind(switchAddress, switchAddress + 3)); 
     }
 }
 
@@ -1910,7 +1973,7 @@ static void prepareJumpTableForStringSwitch(StringJumpTable& jumpTable, int32_t
         ASSERT(nodes[i]->isString());
         UString::Rep* clause = static_cast<StringNode*>(nodes[i])->value().ustring().rep();
         OffsetLocation location;
-        location.branchOffset = labels[i]->offsetFrom(switchAddress);
+        location.branchOffset = labels[i]->bind(switchAddress, switchAddress + 3);
         jumpTable.offsetTable.add(clause, location);
     }
 }
@@ -1921,23 +1984,23 @@ void BytecodeGenerator::endSwitch(uint32_t clauseCount, RefPtr<Label>* labels, E
     m_switchContextStack.removeLast();
     if (switchInfo.switchType == SwitchInfo::SwitchImmediate) {
         instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfImmediateSwitchJumpTables();
-        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->offsetFrom(switchInfo.bytecodeOffset + 3);
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
 
         SimpleJumpTable& jumpTable = m_codeBlock->addImmediateSwitchJumpTable();
-        prepareJumpTableForImmediateSwitch(jumpTable, switchInfo.bytecodeOffset + 3, clauseCount, labels, nodes, min, max);
+        prepareJumpTableForImmediateSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes, min, max);
     } else if (switchInfo.switchType == SwitchInfo::SwitchCharacter) {
         instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfCharacterSwitchJumpTables();
-        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->offsetFrom(switchInfo.bytecodeOffset + 3);
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
         
         SimpleJumpTable& jumpTable = m_codeBlock->addCharacterSwitchJumpTable();
-        prepareJumpTableForCharacterSwitch(jumpTable, switchInfo.bytecodeOffset + 3, clauseCount, labels, nodes, min, max);
+        prepareJumpTableForCharacterSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes, min, max);
     } else {
         ASSERT(switchInfo.switchType == SwitchInfo::SwitchString);
         instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfStringSwitchJumpTables();
-        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->offsetFrom(switchInfo.bytecodeOffset + 3);
+        instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
 
         StringJumpTable& jumpTable = m_codeBlock->addStringSwitchJumpTable();
-        prepareJumpTableForStringSwitch(jumpTable, switchInfo.bytecodeOffset + 3, clauseCount, labels, nodes);
+        prepareJumpTableForStringSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes);
     }
 }
 
diff --git a/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/JavaScriptCore/bytecompiler/BytecodeGenerator.h
index 1a83ce9..4648fb5 100644
--- a/JavaScriptCore/bytecompiler/BytecodeGenerator.h
+++ b/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -61,6 +61,13 @@ namespace JSC {
         FinallyContext finallyContext;
     };
 
+    struct ForInContext {
+        RefPtr<RegisterID> expectedSubscriptRegister;
+        RefPtr<RegisterID> iterRegister;
+        RefPtr<RegisterID> indexRegister;
+        RefPtr<RegisterID> propertyRegister;
+    };
+
     class BytecodeGenerator : public FastAllocBase {
     public:
         typedef DeclarationStacks::VarStack VarStack;
@@ -312,8 +319,8 @@ namespace JSC {
         PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
         void emitSubroutineReturn(RegisterID* retAddrSrc);
 
-        RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base) { return emitUnaryOp(op_get_pnames, dst, base); }
-        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target);
+        RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, Label* breakTarget);
+        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, RegisterID* iter, Label* target);
 
         RegisterID* emitCatch(RegisterID*, Label* start, Label* end);
         void emitThrow(RegisterID* exc) { emitUnaryNoDstOp(op_throw, exc); }
@@ -331,6 +338,17 @@ namespace JSC {
         void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
         void popFinallyContext();
 
+        void pushOptimisedForIn(RegisterID* expectedBase, RegisterID* iter, RegisterID* index, RegisterID* propertyRegister)
+        {
+            ForInContext context = { expectedBase, iter, index, propertyRegister };
+            m_forInContextStack.append(context);
+        }
+
+        void popOptimisedForIn()
+        {
+            m_forInContextStack.removeLast();
+        }
+
         LabelScope* breakTarget(const Identifier&);
         LabelScope* continueTarget(const Identifier&);
 
@@ -467,6 +485,7 @@ namespace JSC {
 
         Vector<ControlFlowContext> m_scopeContextStack;
         Vector<SwitchInfo> m_switchContextStack;
+        Vector<ForInContext> m_forInContextStack;
 
         int m_nextGlobalIndex;
         int m_nextParameterIndex;
diff --git a/JavaScriptCore/bytecompiler/Label.h b/JavaScriptCore/bytecompiler/Label.h
index 0b3d038..8cab1db 100644
--- a/JavaScriptCore/bytecompiler/Label.h
+++ b/JavaScriptCore/bytecompiler/Label.h
@@ -51,19 +51,17 @@ namespace JSC {
             m_location = location;
 
             unsigned size = m_unresolvedJumps.size();
-            for (unsigned i = 0; i < size; ++i) {
-                unsigned j = m_unresolvedJumps[i];
-                m_codeBlock->instructions()[j].u.operand = m_location - j;
-            }
+            for (unsigned i = 0; i < size; ++i)
+                m_codeBlock->instructions()[m_unresolvedJumps[i].second].u.operand = m_location - m_unresolvedJumps[i].first;
         }
 
-        int offsetFrom(int location) const
+        int bind(int opcode, int offset) const
         {
             if (m_location == invalidLocation) {
-                m_unresolvedJumps.append(location);
+                m_unresolvedJumps.append(std::make_pair(opcode, offset));
                 return 0;
             }
-            return m_location - location;
+            return m_location - opcode;
         }
 
         void ref() { ++m_refCount; }
@@ -77,7 +75,7 @@ namespace JSC {
         bool isForward() const { return m_location == invalidLocation; }
 
     private:
-        typedef Vector<int, 8> JumpVector;
+        typedef Vector<std::pair<int, int>, 8> JumpVector;
 
         static const unsigned invalidLocation = UINT_MAX;