Add support for untagged LoadField, StoreField, LoadElement, and StoreElement simplfied operators. …

src/compiler/simplified-operator.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 #define V8_COMPILER_SIMPLIFIED_OPERATOR_H_
 
 #include "src/compiler/machine-operator.h"
 #include "src/compiler/opcodes.h"
 #include "src/zone.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
-// An access descriptor for loads/stores from/to fixed structures
-// like field accesses of heap objects.
+// An access descriptor for loads/stores of fixed structures like field
+// accesses of heap objects. Accesses from either tagged or untagged base
+// pointers are supported; untagging is done automatically during lowering.
 struct FieldAccess {
-  int offset;
-  Handle<Name> name;  // debug only.
-  Type* type;
-  MachineRepresentation representation;
+  bool base_is_tagged;  // {true} if the base pointer is tagged.
+  int offset;           // offset of the field, without tag.
+  Handle<Name> name;    // debugging only.
+  Type* type;           // type of the field.
+  MachineRepresentation representation;  // machine representation of field.
 };
 
 
-// An access descriptor for loads/stores of indexed structures
-// like characters in strings or off-heap backing stores.
+// An access descriptor for loads/stores of indexed structures like characters
+// in strings or off-heap backing stores. Accesses from either tagged or
+// untagged base pointers are supported; untagging is done automatically during
+// lowering.
 struct ElementAccess {
-  int header_size;
-  Type* type;
-  MachineRepresentation representation;
+  bool base_is_tagged;  // {true} if the base pointer is tagged.
+  int header_size;      // size of the header, without tag.
+  Type* type;           // type of the element.
+  MachineRepresentation representation;  // machine representation of element.
 };
 
 
 // If the accessed object is not a heap object, add this to the header_size.
 static const int kNonHeapObjectHeaderSize = kHeapObjectTag;
 
 
 // Specialization for static parameters of type {FieldAccess}.
 template <>
 struct StaticParameterTraits<const FieldAccess> {
   static OStream& PrintTo(OStream& os, const FieldAccess& val) {  // NOLINT
     return os << val.offset;
   }
   static int HashCode(const FieldAccess& val) {
     return (val.offset < 16) | (val.representation & 0xffff);
   }
   static bool Equals(const FieldAccess& a, const FieldAccess& b) {
-    return a.offset == b.offset && a.representation == b.representation &&
-           a.type->Is(b.type);
+    return a.base_is_tagged == b.base_is_tagged && a.offset == b.offset &&
+           a.representation == b.representation && a.type->Is(b.type);
   }
 };
 
 
 // Specialization for static parameters of type {ElementAccess}.
 template <>
 struct StaticParameterTraits<const ElementAccess> {
   static OStream& PrintTo(OStream& os, const ElementAccess& val) {  // NOLINT
     return os << val.header_size;
   }
   static int HashCode(const ElementAccess& val) {
     return (val.header_size < 16) | (val.representation & 0xffff);
   }
   static bool Equals(const ElementAccess& a, const ElementAccess& b) {
-    return a.header_size == b.header_size &&
+    return a.base_is_tagged == b.base_is_tagged &&
+           a.header_size == b.header_size &&
            a.representation == b.representation && a.type->Is(b.type);
   }
 };
 
 
 inline const FieldAccess FieldAccessOf(Operator* op) {
   ASSERT(op->opcode() == IrOpcode::kLoadField ||
          op->opcode() == IrOpcode::kStoreField);
   return static_cast<Operator1<FieldAccess>*>(op)->parameter();
 }
@@ skipping 92 matching lines @@
 #undef SIMPLE
 
  private:
   Zone* zone_;
 };
 }
 }
 }  // namespace v8::internal::compiler
 
 #endif  // V8_COMPILER_SIMPLIFIED_OPERATOR_H_