Merge arguments branch to bleeding edge (second try).

src/ia32/full-codegen-ia32.cc

Index: src/ia32/full-codegen-ia32.cc
diff --git a/src/ia32/full-codegen-ia32.cc b/src/ia32/full-codegen-ia32.cc
index 871179400378e66d39e25898e5bd0cd21a5e9c3d..a9857bf9272036ac25a5fda30853ff4f6f15bd51 100644
--- a/src/ia32/full-codegen-ia32.cc
+++ b/src/ia32/full-codegen-ia32.cc
@@ -218,20 +218,21 @@ void FullCodeGenerator::Generate(CompilationInfo* info) {
            Operand(ebp, StandardFrameConstants::kCallerSPOffset + offset));
     __ push(edx);
     __ SafePush(Immediate(Smi::FromInt(scope()->num_parameters())));
-    // Arguments to ArgumentsAccessStub:
+    // Arguments to ArgumentsAccessStub and/or New...:
     //   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);
+    ArgumentsAccessStub::Type type;
+    if (is_strict_mode()) {
+      type = ArgumentsAccessStub::NEW_STRICT;
+    } else if (function()->has_duplicate_parameters()) {
+      type = ArgumentsAccessStub::NEW_NON_STRICT_SLOW;
+    } else {
+      type = ArgumentsAccessStub::NEW_NON_STRICT_FAST;
+    }
+    ArgumentsAccessStub stub(type);
     __ CallStub(&stub);
 
-    Variable* arguments_shadow = scope()->arguments_shadow();
-    if (arguments_shadow != NULL) {
-      __ mov(ecx, eax);  // Duplicate result.
-      Move(arguments_shadow->AsSlot(), ecx, ebx, edx);
-    }
     Move(arguments->AsSlot(), eax, ebx, edx);
   }
 
@@ -1209,13 +1210,12 @@ void FullCodeGenerator::EmitDynamicLoadFromSlotFastCase(
 
 
 void FullCodeGenerator::EmitVariableLoad(Variable* var) {
-  // 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.
+  // Three cases: non-this global variables, lookup slots, and all other
+  // types of slots.
   Slot* slot = var->AsSlot();
-  Property* property = var->AsProperty();
+  ASSERT((var->is_global() && !var->is_this()) == (slot == NULL));
 
-  if (var->is_global() && !var->is_this()) {
+  if (slot == NULL) {
     Comment cmnt(masm_, "Global variable");
     // Use inline caching. Variable name is passed in ecx and the global
     // object on the stack.
@@ -1225,7 +1225,7 @@ void FullCodeGenerator::EmitVariableLoad(Variable* var) {
     EmitCallIC(ic, RelocInfo::CODE_TARGET_CONTEXT, AstNode::kNoNumber);
     context()->Plug(eax);
 
-  } else if (slot != NULL && slot->type() == Slot::LOOKUP) {
+  } else if (slot->type() == Slot::LOOKUP) {
     Label done, slow;
 
     // Generate code for loading from variables potentially shadowed
@@ -1241,7 +1241,7 @@ void FullCodeGenerator::EmitVariableLoad(Variable* var) {
 
     context()->Plug(eax);
 
-  } else if (slot != NULL) {
+  } else {
     Comment cmnt(masm_, (slot->type() == Slot::CONTEXT)
                             ? "Context slot"
                             : "Stack slot");
@@ -1259,36 +1259,6 @@ void FullCodeGenerator::EmitVariableLoad(Variable* var) {
     } 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, eax);
-    __ mov(edx, 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.
-    __ SafeSet(eax, Immediate(key_literal->handle()));
-
-    // Do a keyed property load.
-    Handle<Code> ic = isolate()->builtins()->KeyedLoadIC_Initialize();
-    EmitCallIC(ic, RelocInfo::CODE_TARGET, GetPropertyId(property));
-
-    // Drop key and object left on the stack by IC.
-    context()->Plug(eax);
   }
 }
 
@@ -1521,7 +1491,7 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
   }
 
   // Left-hand side can only be a property, a global or a (parameter or local)
-  // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
+  // slot.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* property = expr->target()->AsProperty();
@@ -1547,29 +1517,13 @@ void FullCodeGenerator::VisitAssignment(Assignment* expr) {
       break;
     case KEYED_PROPERTY: {
       if (expr->is_compound()) {
-        if (property->is_arguments_access()) {
-          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
-          MemOperand slot_operand =
-              EmitSlotSearch(obj_proxy->var()->AsSlot(), ecx);
-          __ push(slot_operand);
-          __ SafeSet(eax, Immediate(property->key()->AsLiteral()->handle()));
-        } else {
-          VisitForStackValue(property->obj());
-          VisitForAccumulatorValue(property->key());
-        }
+        VisitForStackValue(property->obj());
+        VisitForAccumulatorValue(property->key());
         __ mov(edx, Operand(esp, 0));
         __ push(eax);
       } else {
-        if (property->is_arguments_access()) {
-          VariableProxy* obj_proxy = property->obj()->AsVariableProxy();
-          MemOperand slot_operand =
-              EmitSlotSearch(obj_proxy->var()->AsSlot(), ecx);
-          __ push(slot_operand);
-          __ SafePush(Immediate(property->key()->AsLiteral()->handle()));
-        } else {
-          VisitForStackValue(property->obj());
-          VisitForStackValue(property->key());
-        }
+        VisitForStackValue(property->obj());
+        VisitForStackValue(property->key());
       }
       break;
     }
@@ -1773,7 +1727,7 @@ void FullCodeGenerator::EmitAssignment(Expression* expr, int bailout_ast_id) {
   }
 
   // Left-hand side can only be a property, a global or a (parameter or local)
-  // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
+  // slot.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* prop = expr->AsProperty();
@@ -1833,8 +1787,6 @@ void FullCodeGenerator::EmitAssignment(Expression* expr, int bailout_ast_id) {
 
 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);
 
@@ -3787,7 +3739,7 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
   }
 
   // Expression can only be a property, a global or a (parameter or local)
-  // slot. Variables with rewrite to .arguments are treated as KEYED_PROPERTY.
+  // slot.
   enum LhsKind { VARIABLE, NAMED_PROPERTY, KEYED_PROPERTY };
   LhsKind assign_type = VARIABLE;
   Property* prop = expr->expression()->AsProperty();
@@ -3814,16 +3766,8 @@ void FullCodeGenerator::VisitCountOperation(CountOperation* expr) {
       __ push(eax);
       EmitNamedPropertyLoad(prop);
     } else {
-      if (prop->is_arguments_access()) {
-        VariableProxy* obj_proxy = prop->obj()->AsVariableProxy();
-        MemOperand slot_operand =
-            EmitSlotSearch(obj_proxy->var()->AsSlot(), ecx);
-        __ push(slot_operand);
-        __ SafeSet(eax, Immediate(prop->key()->AsLiteral()->handle()));
-      } else {
-        VisitForStackValue(prop->obj());
-        VisitForAccumulatorValue(prop->key());
-      }
+      VisitForStackValue(prop->obj());
+      VisitForAccumulatorValue(prop->key());
       __ mov(edx, Operand(esp, 0));
       __ push(eax);
       EmitKeyedPropertyLoad(prop);