[interpeter] Move to table based peephole optimizer.

src/interpreter/bytecode-peephole-optimizer.h

-// Copyright 2015 the V8 project authors. All rights reserved.
+// Copyright 2016 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_INTERPRETER_BYTECODE_PEEPHOLE_OPTIMIZER_H_
 #define V8_INTERPRETER_BYTECODE_PEEPHOLE_OPTIMIZER_H_
 
 #include "src/interpreter/bytecode-pipeline.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
 class ConstantArrayBuilder;
 
+#define PEEPHOLE_NON_JUMP_ACTION_LIST(V)            \
+  V(DefaultAction)                                  \
+  V(UpdateLastAction)                               \
+  V(ElideCurrentAction)                             \
+  V(ElideCurrentIfOperand0MatchesAction)            \
+  V(ElideCurrentIfLoadingNameConstantAction)        \
+  V(ElideLastAction)                                \
+  V(ChangeBytecodeAction)                           \
+  V(TransformLdaStarToLdrLdarAction)                \
+  V(TransformLdaSmiBinaryOpToBinaryOpWithSmiAction) \
+  V(TransformLdaZeroBinaryOpToBinaryOpWithZeroAction)
+
+#define PEEPHOLE_JUMP_ACTION_LIST(V) \
+  V(DefaultJumpAction)               \
+  V(UpdateLastJumpAction)            \
+  V(ChangeJumpBytecodeAction)        \
+  V(ElideLastBeforeJumpAction)
+
+#define PEEPHOLE_ACTION_LIST(V)    \
+  PEEPHOLE_NON_JUMP_ACTION_LIST(V) \
+  PEEPHOLE_JUMP_ACTION_LIST(V)
+
+// Actions to take when a pair of bytes is encountered. A handler
+// exists for each action.
+enum class PeepholeAction : uint8_t {
+#define DECLARE_PEEPHOLE_ACTION(Action) k##Action,
+  PEEPHOLE_ACTION_LIST(DECLARE_PEEPHOLE_ACTION)
+#undef DECLARE_PEEPHOLE_ACTION
+};
+
+// Tuple of action to take when pair of bytecodes is encountered and
+// optional data to invoke handler with.
+struct PeepholeActionAndData final {
+  // Action to take when tuple of bytecodes encountered.
+  PeepholeAction action;
+
+  // Replacement bytecode (if valid).
+  Bytecode bytecode;
+};
+
 // An optimization stage for performing peephole optimizations on
 // generated bytecode. The optimizer may buffer one bytecode
 // internally.
 class BytecodePeepholeOptimizer final : public BytecodePipelineStage,
                                         public ZoneObject {
  public:
   BytecodePeepholeOptimizer(ConstantArrayBuilder* constant_array_builder,
                             BytecodePipelineStage* next_stage);
 
   // BytecodePipelineStage interface.
   void Write(BytecodeNode* node) override;
   void WriteJump(BytecodeNode* node, BytecodeLabel* label) override;
   void BindLabel(BytecodeLabel* label) override;
   void BindLabel(const BytecodeLabel& target, BytecodeLabel* label) override;
   Handle<BytecodeArray> ToBytecodeArray(
       int fixed_register_count, int parameter_count,
       Handle<FixedArray> handler_table) override;
 
  private:
-  BytecodeNode* OptimizeAndEmitLast(BytecodeNode* current);
-  BytecodeNode* Optimize(BytecodeNode* current);
+#define DECLARE_ACTION(Action)          \
+  void Action(BytecodeNode* const node, \
+              const PeepholeActionAndData* const action_data = nullptr);
+  PEEPHOLE_ACTION_LIST(DECLARE_ACTION)
+#undef DECLARE_ACTION
+
+  void Optimize(BytecodeNode* const node);
   void Flush();
-
-  void TryToRemoveLastExpressionPosition(const BytecodeNode* const current);
-  bool TransformCurrentBytecode(BytecodeNode* const current);
-  bool TransformLastAndCurrentBytecodes(BytecodeNode* const current);
-  bool CanElideCurrent(const BytecodeNode* const current) const;
-  bool CanElideLast(const BytecodeNode* const current) const;
   bool CanElideLastBasedOnSourcePosition(
       const BytecodeNode* const current) const;
-
-  // Simple substitution methods.
-  bool RemoveToBooleanFromJump(BytecodeNode* const current);
-  bool RemoveToBooleanFromLogicalNot(BytecodeNode* const current);
-
   void InvalidateLast();
   bool LastIsValid() const;
   void SetLast(const BytecodeNode* const node);
 
-  bool LastBytecodePutsNameInAccumulator() const;
-
   Handle<Object> GetConstantForIndexOperand(const BytecodeNode* const node,
                                             int index) const;
 
+  BytecodePipelineStage* next_stage() const { return next_stage_; }
+  BytecodeNode* last() { return &last_; }
+
   ConstantArrayBuilder* constant_array_builder_;
   BytecodePipelineStage* next_stage_;
   BytecodeNode last_;
 
   DISALLOW_COPY_AND_ASSIGN(BytecodePeepholeOptimizer);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_PEEPHOLE_OPTIMIZER_H_