Revert "Merge arguments branch to bleeding merge."

src/x64/full-codegen-x64.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 208 matching lines @@
     __ lea(rdx,
            Operand(rbp, StandardFrameConstants::kCallerSPOffset + offset));
     __ push(rdx);
     __ Push(Smi::FromInt(scope()->num_parameters()));
     // Arguments to ArgumentsAccessStub:
     //   function, receiver address, parameter count.
     // The stub will rewrite receiver and parameter count if the previous
     // stack frame was an arguments adapter frame.
     ArgumentsAccessStub stub(
         is_strict_mode() ? ArgumentsAccessStub::NEW_STRICT
-                         : ArgumentsAccessStub::NEW_NON_STRICT_SLOW);
+                         : ArgumentsAccessStub::NEW_NON_STRICT);
     __ CallStub(&stub);
 
+    Variable* arguments_shadow = scope()->arguments_shadow();
+    if (arguments_shadow != NULL) {
+      // Store new arguments object in both "arguments" and ".arguments" slots.
+      __ movq(rcx, rax);
+      Move(arguments_shadow->AsSlot(), rcx, rbx, rdx);
+    }
     Move(arguments->AsSlot(), rax, rbx, rdx);
   }
 
   if (FLAG_trace) {
     __ CallRuntime(Runtime::kTraceEnter, 0);
   }
 
   // Visit the declarations and body unless there is an illegal
   // redeclaration.
   if (scope()->HasIllegalRedeclaration()) {
@@ skipping 122 matching lines @@
 
 void FullCodeGenerator::StackValueContext::Plug(Slot* slot) const {
   MemOperand slot_operand = codegen()->EmitSlotSearch(slot, result_register());
   __ push(slot_operand);
 }
 
 
 void FullCodeGenerator::TestContext::Plug(Slot* slot) const {
   codegen()->Move(result_register(), slot);
   codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
-  codegen()->DoTest(true_label_, false_label_, fall_through_);
+  codegen()->DoTest(this);
 }
 
 
 void FullCodeGenerator::EffectContext::Plug(Heap::RootListIndex index) const {
 }
 
 
 void FullCodeGenerator::AccumulatorValueContext::Plug(
     Heap::RootListIndex index) const {
   __ LoadRoot(result_register(), index);
@@ skipping 12 matching lines @@
                                           true_label_,
                                           false_label_);
   if (index == Heap::kUndefinedValueRootIndex ||
       index == Heap::kNullValueRootIndex ||
       index == Heap::kFalseValueRootIndex) {
     if (false_label_ != fall_through_) __ jmp(false_label_);
   } else if (index == Heap::kTrueValueRootIndex) {
     if (true_label_ != fall_through_) __ jmp(true_label_);
   } else {
     __ LoadRoot(result_register(), index);
-    codegen()->DoTest(true_label_, false_label_, fall_through_);
+    codegen()->DoTest(this);
   }
 }
 
 
 void FullCodeGenerator::EffectContext::Plug(Handle<Object> lit) const {
 }
 
 
 void FullCodeGenerator::AccumulatorValueContext::Plug(
     Handle<Object> lit) const {
@@ skipping 24 matching lines @@
     }
   } else if (lit->IsSmi()) {
     if (Smi::cast(*lit)->value() == 0) {
       if (false_label_ != fall_through_) __ jmp(false_label_);
     } else {
       if (true_label_ != fall_through_) __ jmp(true_label_);
     }
   } else {
     // For simplicity we always test the accumulator register.
     __ Move(result_register(), lit);
-    codegen()->DoTest(true_label_, false_label_, fall_through_);
+    codegen()->DoTest(this);
   }
 }
 
 
 void FullCodeGenerator::EffectContext::DropAndPlug(int count,
                                                    Register reg) const {
   ASSERT(count > 0);
   __ Drop(count);
 }
 
@@ skipping 15 matching lines @@
 }
 
 
 void FullCodeGenerator::TestContext::DropAndPlug(int count,
                                                  Register reg) const {
   ASSERT(count > 0);
   // For simplicity we always test the accumulator register.
   __ Drop(count);
   __ Move(result_register(), reg);
   codegen()->PrepareForBailoutBeforeSplit(TOS_REG, false, NULL, NULL);
-  codegen()->DoTest(true_label_, false_label_, fall_through_);
+  codegen()->DoTest(this);
 }
 
 
 void FullCodeGenerator::EffectContext::Plug(Label* materialize_true,
                                             Label* materialize_false) const {
   ASSERT(materialize_true == materialize_false);
   __ bind(materialize_true);
 }
 
 
@@ skipping 54 matching lines @@
                                           true_label_,
                                           false_label_);
   if (flag) {
     if (true_label_ != fall_through_) __ jmp(true_label_);
   } else {
     if (false_label_ != fall_through_) __ jmp(false_label_);
   }
 }
 
 
-void FullCodeGenerator::DoTest(Label* if_true,
+void FullCodeGenerator::DoTest(Expression* condition,
+                               Label* if_true,
                                Label* if_false,
                                Label* fall_through) {
   ToBooleanStub stub;
   __ push(result_register());
   __ CallStub(&stub);
   __ testq(rax, rax);
   // The stub returns nonzero for true.
   Split(not_zero, if_true, if_false, fall_through);
 }
 
@@ skipping 633 matching lines @@
           EmitCallIC(ic, RelocInfo::CODE_TARGET, GetPropertyId(property));
           __ jmp(done);
         }
       }
     }
   }
 }
 
 
 void FullCodeGenerator::EmitVariableLoad(Variable* var) {
-  // Three cases: non-this global variables, lookup slots, and all other
-  // types of slots.
+  // Four cases: non-this global variables, lookup slots, all other
+  // types of slots, and parameters that rewrite to explicit property
+  // accesses on the arguments object.
   Slot* slot = var->AsSlot();
-  ASSERT((var->is_global() && !var->is_this()) == (slot == NULL));
+  Property* property = var->AsProperty();
 
-  if (slot == NULL) {
+  if (var->is_global() && !var->is_this()) {
     Comment cmnt(masm_, "Global variable");
     // Use inline caching. Variable name is passed in rcx and the global
     // object on the stack.
     __ Move(rcx, var->name());
     __ movq(rax, GlobalObjectOperand());
     Handle<Code> ic = isolate()->builtins()->LoadIC_Initialize();
     EmitCallIC(ic, RelocInfo::CODE_TARGET_CONTEXT, AstNode::kNoNumber);
     context()->Plug(rax);
 
   } else if (slot != NULL && slot->type() == Slot::LOOKUP) {
     Label done, slow;
 
     // Generate code for loading from variables potentially shadowed
     // by eval-introduced variables.
     EmitDynamicLoadFromSlotFastCase(slot, NOT_INSIDE_TYPEOF, &slow, &done);
 
     __ bind(&slow);
     Comment cmnt(masm_, "Lookup slot");
     __ push(rsi);  // Context.
     __ Push(var->name());
     __ CallRuntime(Runtime::kLoadContextSlot, 2);
     __ bind(&done);
 
     context()->Plug(rax);
 
-  } else {
+  } else if (slot != NULL) {
     Comment cmnt(masm_, (slot->type() == Slot::CONTEXT)
                             ? "Context slot"
                             : "Stack slot");
     if (var->mode() == Variable::CONST) {
       // Constants may be the hole value if they have not been initialized.
       // Unhole them.
       Label done;
       MemOperand slot_operand = EmitSlotSearch(slot, rax);
       __ movq(rax, slot_operand);
       __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
       __ j(not_equal, &done, Label::kNear);
       __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
       __ bind(&done);
       context()->Plug(rax);
     } else {
       context()->Plug(slot);
     }
+
+  } else {
+    Comment cmnt(masm_, "Rewritten parameter");
+    ASSERT_NOT_NULL(property);
+    // Rewritten parameter accesses are of the form "slot[literal]".
+
+    // Assert that the object is in a slot.
+    Variable* object_var = property->obj()->AsVariableProxy()->AsVariable();
+    ASSERT_NOT_NULL(object_var);
+    Slot* object_slot = object_var->AsSlot();
+    ASSERT_NOT_NULL(object_slot);
+
+    // Load the object.
+    MemOperand object_loc = EmitSlotSearch(object_slot, rax);
+    __ movq(rdx, object_loc);
+
+    // Assert that the key is a smi.
+    Literal* key_literal = property->key()->AsLiteral();
+    ASSERT_NOT_NULL(key_literal);
+    ASSERT(key_literal->handle()->IsSmi());
+
+    // Load the key.
+    __ Move(rax, key_literal->handle());
+
+    // Do a keyed property load.
+    Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Initialize();
+    EmitCallIC(ic, RelocInfo::CODE_TARGET, GetPropertyId(property));
+    context()->Plug(rax);
   }
 }
 
 
 void FullCodeGenerator::VisitRegExpLiteral(RegExpLiteral* expr) {
   Comment cmnt(masm_, "[ RegExpLiteral");
   Label materialized;
   // Registers will be used as follows:
   // rdi = JS function.
   // rcx = literals array.
@@ skipping 212 matching lines @@
 void FullCodeGenerator::VisitAssignment(Assignment* expr) {
   Comment cmnt(masm_, "[ Assignment");
   // Invalid left-hand sides are rewritten to have a 'throw ReferenceError'
   // on the left-hand side.
   if (!expr->target()->IsValidLeftHandSide()) {
     VisitForEffect(expr->target());
     return;
   }
 
   // Left-hand side can only be a property, a global or a (parameter or local)
-  // slot.
+  // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* property = expr->target()->AsProperty();
   if (property != NULL) {
     assign_type = (property->key()->IsPropertyName())
         ? NAMED_PROPERTY
         : KEYED_PROPERTY;
   }
 
   // Evaluate LHS expression.
   switch (assign_type) {
     case VARIABLE:
       // Nothing to do here.
       break;
     case NAMED_PROPERTY:
       if (expr->is_compound()) {
         // We need the receiver both on the stack and in the accumulator.
         VisitForAccumulatorValue(property->obj());
         __ push(result_register());
       } else {
         VisitForStackValue(property->obj());
       }
       break;
     case KEYED_PROPERTY: {
       if (expr->is_compound()) {
-        VisitForStackValue(property->obj());
-        VisitForAccumulatorValue(property->key());
+        if (property->is_arguments_access()) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          MemOperand slot_operand =
+              EmitSlotSearch(obj_proxy->var()->AsSlot(), rcx);
+          __ push(slot_operand);
+          __ Move(rax, property->key()->AsLiteral()->handle());
+        } else {
+          VisitForStackValue(property->obj());
+          VisitForAccumulatorValue(property->key());
+        }
         __ movq(rdx, Operand(rsp, 0));
         __ push(rax);
       } else {
-        VisitForStackValue(property->obj());
-        VisitForStackValue(property->key());
+        if (property->is_arguments_access()) {
+          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
+          MemOperand slot_operand =
+              EmitSlotSearch(obj_proxy->var()->AsSlot(), rcx);
+          __ push(slot_operand);
+          __ Push(property->key()->AsLiteral()->handle());
+        } else {
+          VisitForStackValue(property->obj());
+          VisitForStackValue(property->key());
+        }
       }
       break;
     }
   }
 
   // For compound assignments we need another deoptimization point after the
   // variable/property load.
   if (expr->is_compound()) {
     { AccumulatorValueContext context(this);
       switch (assign_type) {
@@ skipping 146 matching lines @@
 
 void FullCodeGenerator::EmitAssignment(Expression* expr, int bailout_ast_id) {
   // Invalid left-hand sides are rewritten to have a 'throw
   // ReferenceError' on the left-hand side.
   if (!expr->IsValidLeftHandSide()) {
     VisitForEffect(expr);
     return;
   }
 
   // Left-hand side can only be a property, a global or a (parameter or local)
-  // slot.
+  // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* prop = expr->AsProperty();
   if (prop != NULL) {
     assign_type = (prop->key()->IsPropertyName())
         ? NAMED_PROPERTY
         : KEYED_PROPERTY;
   }
 
   switch (assign_type) {
@@ skipping 10 matching lines @@
       __ pop(rax);  // Restore value.
       __ Move(rcx, prop->key()->AsLiteral()->handle());
       Handle<Code> ic = is_strict_mode()
           ? isolate()->builtins()->StoreIC_Initialize_Strict()
           : isolate()->builtins()->StoreIC_Initialize();
       EmitCallIC(ic, RelocInfo::CODE_TARGET, AstNode::kNoNumber);
       break;
     }
     case KEYED_PROPERTY: {
       __ push(rax);  // Preserve value.
-      VisitForStackValue(prop->obj());
-      VisitForAccumulatorValue(prop->key());
-      __ movq(rcx, rax);
-      __ pop(rdx);
+      if (prop->is_synthetic()) {
+        ASSERT(prop->obj()->AsVariableProxy() != NULL);
+        ASSERT(prop->key()->AsLiteral() != NULL);
+        { AccumulatorValueContext for_object(this);
+          EmitVariableLoad(prop->obj()->AsVariableProxy()->var());
+        }
+        __ movq(rdx, rax);
+        __ Move(rcx, prop->key()->AsLiteral()->handle());
+      } else {
+        VisitForStackValue(prop->obj());
+        VisitForAccumulatorValue(prop->key());
+        __ movq(rcx, rax);
+        __ pop(rdx);
+      }
       __ pop(rax);  // Restore value.
       Handle<Code> ic = is_strict_mode()
           ? isolate()->builtins()->KeyedStoreIC_Initialize_Strict()
           : isolate()->builtins()->KeyedStoreIC_Initialize();
       EmitCallIC(ic, RelocInfo::CODE_TARGET, AstNode::kNoNumber);
       break;
     }
   }
   PrepareForBailoutForId(bailout_ast_id, TOS_REG);
   context()->Plug(rax);
 }
 
 
 void FullCodeGenerator::EmitVariableAssignment(Variable* var,
                                                Token::Value op) {
+  // Left-hand sides that rewrite to explicit property accesses do not reach
+  // here.
   ASSERT(var != NULL);
   ASSERT(var->is_global() || var->AsSlot() != NULL);
 
   if (var->is_global()) {
     ASSERT(!var->is_this());
     // Assignment to a global variable.  Use inline caching for the
     // assignment.  Right-hand-side value is passed in rax, variable name in
     // rcx, and the global object on the stack.
     __ Move(rcx, var->name());
     __ movq(rdx, GlobalObjectOperand());
@@ skipping 1934 matching lines @@
   SetSourcePosition(expr->position());
 
   // Invalid left-hand-sides are rewritten to have a 'throw
   // ReferenceError' as the left-hand side.
   if (!expr->expression()->IsValidLeftHandSide()) {
     VisitForEffect(expr->expression());
     return;
   }
 
   // Expression can only be a property, a global or a (parameter or local)
-  // slot.
+  // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* prop = expr->expression()->AsProperty();
   // In case of a property we use the uninitialized expression context
   // of the key to detect a named property.
   if (prop != NULL) {
     assign_type =
         (prop->key()->IsPropertyName()) ? NAMED_PROPERTY : KEYED_PROPERTY;
   }
 
   // Evaluate expression and get value.
   if (assign_type == VARIABLE) {
     ASSERT(expr->expression()->AsVariableProxy()->var() != NULL);
     AccumulatorValueContext context(this);
     EmitVariableLoad(expr->expression()->AsVariableProxy()->var());
   } else {
     // Reserve space for result of postfix operation.
     if (expr->is_postfix() && !context()->IsEffect()) {
       __ Push(Smi::FromInt(0));
     }
     if (assign_type == NAMED_PROPERTY) {
       VisitForAccumulatorValue(prop->obj());
       __ push(rax);  // Copy of receiver, needed for later store.
       EmitNamedPropertyLoad(prop);
     } else {
-      VisitForStackValue(prop->obj());
-      VisitForAccumulatorValue(prop->key());
+      if (prop->is_arguments_access()) {
+        VariableProxy* obj_proxy = prop->obj()->AsVariableProxy();
+        MemOperand slot_operand =
+            EmitSlotSearch(obj_proxy->var()->AsSlot(), rcx);
+        __ push(slot_operand);
+        __ Move(rax, prop->key()->AsLiteral()->handle());
+      } else {
+        VisitForStackValue(prop->obj());
+        VisitForAccumulatorValue(prop->key());
+      }
       __ movq(rdx, Operand(rsp, 0));  // Leave receiver on stack
       __ push(rax);  // Copy of key, needed for later store.
       EmitKeyedPropertyLoad(prop);
     }
   }
 
   // We need a second deoptimization point after loading the value
   // in case evaluating the property load my have a side effect.
   if (assign_type == VARIABLE) {
     PrepareForBailout(expr->expression(), TOS_REG);
@@ skipping 498 matching lines @@
   __ ret(0);
 }
 
 
 #undef __
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64