[turbofan] Eliminate redundant masking operations for word8/word16 stores.

src/compiler/machine-operator.cc

 // 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.
 
 #include "src/compiler/machine-operator.h"
 
 #include "src/base/lazy-instance.h"
 #include "src/compiler/opcodes.h"
 #include "src/compiler/operator.h"
 
@@ skipping 28 matching lines @@
   return base::hash_combine(rep.machine_type(), rep.write_barrier_kind());
 }
 
 
 std::ostream& operator<<(std::ostream& os, StoreRepresentation rep) {
   return os << "(" << rep.machine_type() << " : " << rep.write_barrier_kind()
             << ")";
 }
 
 
+StoreRepresentation const& StoreRepresentationOf(Operator const* op) {
+  DCHECK_EQ(IrOpcode::kStore, op->opcode());
+  return OpParameter<StoreRepresentation>(op);
+}
+
+
 #define PURE_OP_LIST(V)                                                       \
   V(Word32And, Operator::kAssociative | Operator::kCommutative, 2, 1)         \
   V(Word32Or, Operator::kAssociative | Operator::kCommutative, 2, 1)          \
   V(Word32Xor, Operator::kAssociative | Operator::kCommutative, 2, 1)         \
   V(Word32Shl, Operator::kNoProperties, 2, 1)                                 \
   V(Word32Shr, Operator::kNoProperties, 2, 1)                                 \
   V(Word32Sar, Operator::kNoProperties, 2, 1)                                 \
   V(Word32Ror, Operator::kNoProperties, 2, 1)                                 \
   V(Word32Equal, Operator::kCommutative, 2, 1)                                \
   V(Word64And, Operator::kAssociative | Operator::kCommutative, 2, 1)         \
@@ skipping 167 matching lines @@
     default:
       break;
   }
   UNREACHABLE();
   return NULL;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8