Reland of [turbofan] Restore basic write barrier elimination.

src/compiler/simplified-operator.cc

 // Copyright 2012 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.
 
 #include "src/compiler/simplified-operator.h"
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 #include "src/types.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
+size_t hash_value(BaseTaggedness base_taggedness) {
+  return static_cast<uint8_t>(base_taggedness);
+}
+
 std::ostream& operator<<(std::ostream& os, BaseTaggedness base_taggedness) {
   switch (base_taggedness) {
     case kUntaggedBase:
       return os << "untagged base";
     case kTaggedBase:
       return os << "tagged base";
   }
   UNREACHABLE();
   return os;
 }
@@ skipping 51 matching lines @@
 
 
 BufferAccess const BufferAccessOf(const Operator* op) {
   DCHECK(op->opcode() == IrOpcode::kLoadBuffer ||
          op->opcode() == IrOpcode::kStoreBuffer);
   return OpParameter<BufferAccess>(op);
 }
 
 
 bool operator==(FieldAccess const& lhs, FieldAccess const& rhs) {
+  // On purpose we don't include the write barrier kind here, as this method is
+  // really only relevant for eliminating loads and they don't care about the
+  // write barrier mode.
   return lhs.base_is_tagged == rhs.base_is_tagged && lhs.offset == rhs.offset &&
          lhs.machine_type == rhs.machine_type;
 }
 
 
 bool operator!=(FieldAccess const& lhs, FieldAccess const& rhs) {
   return !(lhs == rhs);
 }
 
 
 size_t hash_value(FieldAccess const& access) {
+  // On purpose we don't include the write barrier kind here, as this method is
+  // really only relevant for eliminating loads and they don't care about the
+  // write barrier mode.
   return base::hash_combine(access.base_is_tagged, access.offset,
                             access.machine_type);
 }
 
 
 std::ostream& operator<<(std::ostream& os, FieldAccess const& access) {
   os << "[" << access.base_is_tagged << ", " << access.offset << ", ";
 #ifdef OBJECT_PRINT
   Handle<Name> name;
   if (access.name.ToHandle(&name)) {
     name->Print(os);
     os << ", ";
   }
 #endif
   access.type->PrintTo(os);
-  os << ", " << access.machine_type << "]";
+  os << ", " << access.machine_type << ", " << access.write_barrier_kind << "]";
   return os;
 }
 
 
 bool operator==(ElementAccess const& lhs, ElementAccess const& rhs) {
+  // On purpose we don't include the write barrier kind here, as this method is
+  // really only relevant for eliminating loads and they don't care about the
+  // write barrier mode.
   return lhs.base_is_tagged == rhs.base_is_tagged &&
          lhs.header_size == rhs.header_size &&
          lhs.machine_type == rhs.machine_type;
 }
 
 
 bool operator!=(ElementAccess const& lhs, ElementAccess const& rhs) {
   return !(lhs == rhs);
 }
 
 
 size_t hash_value(ElementAccess const& access) {
+  // On purpose we don't include the write barrier kind here, as this method is
+  // really only relevant for eliminating loads and they don't care about the
+  // write barrier mode.
   return base::hash_combine(access.base_is_tagged, access.header_size,
                             access.machine_type);
 }
 
 
 std::ostream& operator<<(std::ostream& os, ElementAccess const& access) {
   os << access.base_is_tagged << ", " << access.header_size << ", ";
   access.type->PrintTo(os);
-  os << ", " << access.machine_type;
+  os << ", " << access.machine_type << ", " << access.write_barrier_kind;
   return os;
 }
 
 
 const FieldAccess& FieldAccessOf(const Operator* op) {
   DCHECK_NOT_NULL(op);
   DCHECK(op->opcode() == IrOpcode::kLoadField ||
          op->opcode() == IrOpcode::kStoreField);
   return OpParameter<FieldAccess>(op);
 }
@@ skipping 168 matching lines @@
         Operator1<Type>(IrOpcode::k##Name, Operator::kNoThrow | properties,    \
                         #Name, value_input_count, 1, control_input_count,      \
                         output_count, 1, 0, access);                           \
   }
 ACCESS_OP_LIST(ACCESS)
 #undef ACCESS
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8