[interpreter] Add accumulator use description to bytecodes.

test/unittests/interpreter/bytecodes-unittest.cc

 // Copyright 2015 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 <vector>
 
 #include "src/v8.h"
 
 #include "src/interpreter/bytecodes.h"
 #include "test/unittests/test-utils.h"
@@ skipping 262 matching lines @@
   CHECK(!Bytecodes::OperandScaleRequiresPrefixBytecode(OperandScale::kSingle));
   CHECK(Bytecodes::OperandScaleRequiresPrefixBytecode(OperandScale::kDouble));
   CHECK(
       Bytecodes::OperandScaleRequiresPrefixBytecode(OperandScale::kQuadruple));
   CHECK(Bytecodes::OperandScaleToPrefixBytecode(OperandScale::kDouble) ==
         Bytecode::kWide);
   CHECK(Bytecodes::OperandScaleToPrefixBytecode(OperandScale::kQuadruple) ==
         Bytecode::kExtraWide);
 }
 
+TEST(AccumulatorUse, LogicalOperators) {
+  CHECK_EQ(AccumulatorUse::kNone | AccumulatorUse::kRead,
+           AccumulatorUse::kRead);
+  CHECK_EQ(AccumulatorUse::kRead | AccumulatorUse::kWrite,
+           AccumulatorUse::kReadWrite);
+  CHECK_EQ(AccumulatorUse::kRead & AccumulatorUse::kReadWrite,
+           AccumulatorUse::kRead);
+  CHECK_EQ(AccumulatorUse::kRead & AccumulatorUse::kWrite,
+           AccumulatorUse::kNone);
+}
+
+TEST(AccumulatorUse, SampleBytecodes) {
+  CHECK(Bytecodes::ReadsAccumulator(Bytecode::kStar));
+  CHECK(!Bytecodes::WritesAccumulator(Bytecode::kStar));
+  CHECK_EQ(Bytecodes::GetAccumulatorUse(Bytecode::kStar),
+           AccumulatorUse::kRead);
+  CHECK(!Bytecodes::ReadsAccumulator(Bytecode::kLdar));
+  CHECK(Bytecodes::WritesAccumulator(Bytecode::kLdar));
+  CHECK_EQ(Bytecodes::GetAccumulatorUse(Bytecode::kLdar),
+           AccumulatorUse::kWrite);
+  CHECK(Bytecodes::ReadsAccumulator(Bytecode::kAdd));
+  CHECK(Bytecodes::WritesAccumulator(Bytecode::kAdd));
+  CHECK_EQ(Bytecodes::GetAccumulatorUse(Bytecode::kAdd),
+           AccumulatorUse::kReadWrite);
+}
+
+TEST(AccumulatorUse, AccumulatorUseToString) {
+  std::set<std::string> names;
+  names.insert(Bytecodes::AccumulatorUseToString(AccumulatorUse::kNone));
+  names.insert(Bytecodes::AccumulatorUseToString(AccumulatorUse::kRead));
+  names.insert(Bytecodes::AccumulatorUseToString(AccumulatorUse::kWrite));
+  names.insert(Bytecodes::AccumulatorUseToString(AccumulatorUse::kReadWrite));
+  CHECK_EQ(names.size(), 4);

[rmcilroy, 2016/04/05 12:59:23]

Not sure what this is testing? 

[oth, 2016/04/05 14:12:10]

It tests the associated names of the AccumulatorUse enumeration are unique. It
avoids AccumulatorUseToString showing up as untouched by the code coverage
tooling so is one less thing anyone has to glance at.

+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8