[Interpreter] Optimize the Register Optimizer.

src/interpreter/bytecode-pipeline.h

 // 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.
 
 #ifndef V8_INTERPRETER_BYTECODE_PIPELINE_H_
 #define V8_INTERPRETER_BYTECODE_PIPELINE_H_
 
 #include "src/base/compiler-specific.h"
 #include "src/globals.h"
 #include "src/interpreter/bytecode-register-allocator.h"
@@ skipping 77 matching lines @@
     position_type_ = PositionType::kExpression;
     source_position_ = source_position;
   }
 
   // Forces an instance into an expression position.
   void ForceExpressionPosition(int source_position) {
     position_type_ = PositionType::kExpression;
     source_position_ = source_position;
   }
 
-  // Clones a source position. The current instance is expected to be
-  // invalid.
-  void Clone(const BytecodeSourceInfo& other) {
-    DCHECK(!is_valid());
-    position_type_ = other.position_type_;
-    source_position_ = other.source_position_;
-  }
-
   int source_position() const {
     DCHECK(is_valid());
     return source_position_;
   }
 
   bool is_statement() const {
     return position_type_ == PositionType::kStatement;
   }
   bool is_expression() const {
     return position_type_ == PositionType::kExpression;
@@ skipping 19 matching lines @@
   enum class PositionType : uint8_t { kNone, kExpression, kStatement };
 
   PositionType position_type_;
   int source_position_;
 };
 
 // A container for a generated bytecode, it's operands, and source information.
 // These must be allocated by a BytecodeNodeAllocator instance.
 class V8_EXPORT_PRIVATE BytecodeNode final : NON_EXPORTED_BASE(ZoneObject) {
  public:
-  INLINE(BytecodeNode(const Bytecode bytecode,
-                      BytecodeSourceInfo* source_info = nullptr))
+  INLINE(BytecodeNode(Bytecode bytecode,
+                      BytecodeSourceInfo source_info = BytecodeSourceInfo()))
       : bytecode_(bytecode),
         operand_count_(0),
-        operand_scale_(OperandScale::kSingle) {
+        operand_scale_(OperandScale::kSingle),
+        source_info_(source_info) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), operand_count());
-    AttachSourceInfo(source_info);
   }
 
-  INLINE(BytecodeNode(const Bytecode bytecode, uint32_t operand0,
-                      BytecodeSourceInfo* source_info = nullptr))
+  INLINE(BytecodeNode(Bytecode bytecode, uint32_t operand0,
+                      BytecodeSourceInfo source_info = BytecodeSourceInfo()))
       : bytecode_(bytecode),
         operand_count_(1),
-        operand_scale_(OperandScale::kSingle) {
+        operand_scale_(OperandScale::kSingle),
+        source_info_(source_info) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), operand_count());
     SetOperand(0, operand0);
-    AttachSourceInfo(source_info);
   }
 
-  INLINE(BytecodeNode(const Bytecode bytecode, uint32_t operand0,
-                      uint32_t operand1,
-                      BytecodeSourceInfo* source_info = nullptr))
+  INLINE(BytecodeNode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
+                      BytecodeSourceInfo source_info = BytecodeSourceInfo()))
       : bytecode_(bytecode),
         operand_count_(2),
-        operand_scale_(OperandScale::kSingle) {
+        operand_scale_(OperandScale::kSingle),
+        source_info_(source_info) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), operand_count());
     SetOperand(0, operand0);
     SetOperand(1, operand1);
-    AttachSourceInfo(source_info);
   }
 
-  INLINE(BytecodeNode(const Bytecode bytecode, uint32_t operand0,
-                      uint32_t operand1, uint32_t operand2,
-                      BytecodeSourceInfo* source_info = nullptr))
+  INLINE(BytecodeNode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
+                      uint32_t operand2,
+                      BytecodeSourceInfo source_info = BytecodeSourceInfo()))
       : bytecode_(bytecode),
         operand_count_(3),
-        operand_scale_(OperandScale::kSingle) {
+        operand_scale_(OperandScale::kSingle),
+        source_info_(source_info) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), operand_count());
     SetOperand(0, operand0);
     SetOperand(1, operand1);
     SetOperand(2, operand2);
-    AttachSourceInfo(source_info);
   }
 
-  INLINE(BytecodeNode(const Bytecode bytecode, uint32_t operand0,
-                      uint32_t operand1, uint32_t operand2, uint32_t operand3,
-                      BytecodeSourceInfo* source_info = nullptr))
+  INLINE(BytecodeNode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
+                      uint32_t operand2, uint32_t operand3,
+                      BytecodeSourceInfo source_info = BytecodeSourceInfo()))
       : bytecode_(bytecode),
         operand_count_(4),
-        operand_scale_(OperandScale::kSingle) {
+        operand_scale_(OperandScale::kSingle),
+        source_info_(source_info) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), operand_count());
     SetOperand(0, operand0);
     SetOperand(1, operand1);
     SetOperand(2, operand2);
     SetOperand(3, operand3);
-    AttachSourceInfo(source_info);
   }
 
-  BytecodeNode(const BytecodeNode& other);
-  BytecodeNode& operator=(const BytecodeNode& other);
-
   // Replace the bytecode of this node with |bytecode| and keep the operands.
   void replace_bytecode(Bytecode bytecode) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode_),
               Bytecodes::NumberOfOperands(bytecode));
     bytecode_ = bytecode;
   }
+
   void set_bytecode(Bytecode bytecode) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), 0);
     bytecode_ = bytecode;
     operand_count_ = 0;
     operand_scale_ = OperandScale::kSingle;
   }
+
   void set_bytecode(Bytecode bytecode, uint32_t operand0) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), 1);
     bytecode_ = bytecode;
     operand_count_ = 1;
     operand_scale_ = OperandScale::kSingle;
     SetOperand(0, operand0);
   }
+
   void set_bytecode(Bytecode bytecode, uint32_t operand0, uint32_t operand1) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), 2);
     bytecode_ = bytecode;
     operand_count_ = 2;
     operand_scale_ = OperandScale::kSingle;
     SetOperand(0, operand0);
     SetOperand(1, operand1);
   }
+
   void set_bytecode(Bytecode bytecode, uint32_t operand0, uint32_t operand1,
                     uint32_t operand2) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), 3);
     bytecode_ = bytecode;
     operand_count_ = 3;
     operand_scale_ = OperandScale::kSingle;
     SetOperand(0, operand0);
     SetOperand(1, operand1);
     SetOperand(2, operand2);
   }
 
-  // Clone |other|.
-  void Clone(const BytecodeNode* const other);
-
   // Print to stream |os|.
   void Print(std::ostream& os) const;
 
   // Transform to a node representing |new_bytecode| which has one
   // operand more than the current bytecode.
   void Transform(Bytecode new_bytecode, uint32_t extra_operand) {
     DCHECK_EQ(Bytecodes::NumberOfOperands(new_bytecode),
               Bytecodes::NumberOfOperands(bytecode()) + 1);
     DCHECK(Bytecodes::NumberOfOperands(bytecode()) < 1 ||
            Bytecodes::GetOperandType(new_bytecode, 0) ==
                Bytecodes::GetOperandType(bytecode(), 0));
     DCHECK(Bytecodes::NumberOfOperands(bytecode()) < 2 ||
            Bytecodes::GetOperandType(new_bytecode, 1) ==
                Bytecodes::GetOperandType(bytecode(), 1));
     DCHECK(Bytecodes::NumberOfOperands(bytecode()) < 3 ||
            Bytecodes::GetOperandType(new_bytecode, 2) ==
                Bytecodes::GetOperandType(bytecode(), 2));
     DCHECK(Bytecodes::NumberOfOperands(bytecode()) < 4);
 
     bytecode_ = new_bytecode;
     operand_count_++;
     SetOperand(operand_count() - 1, extra_operand);
   }
 
-  // Updates the operand at |operand_index| to |operand|.
-  void UpdateOperand(int operand_index, uint32_t operand) {
-    DCHECK_LE(operand_index, Bytecodes::NumberOfOperands(bytecode()));
-    operands_[operand_index] = operand;
-    if ((Bytecodes::OperandIsScalableSignedByte(bytecode(), operand_index) &&
-         Bytecodes::ScaleForSignedOperand(operand) != operand_scale_) ||
-        (Bytecodes::OperandIsScalableUnsignedByte(bytecode(), operand_index) &&
-         Bytecodes::ScaleForUnsignedOperand(operand) != operand_scale_)) {
-      UpdateScale();
-    }
-  }
-
   Bytecode bytecode() const { return bytecode_; }
 
   uint32_t operand(int i) const {
     DCHECK_LT(i, operand_count());
     return operands_[i];
   }
   const uint32_t* operands() const { return operands_; }
 
   int operand_count() const { return operand_count_; }
   OperandScale operand_scale() const { return operand_scale_; }
 
   const BytecodeSourceInfo& source_info() const { return source_info_; }
-  BytecodeSourceInfo* source_info_ptr() { return &source_info_; }
+  void set_source_info(BytecodeSourceInfo source_info) {
+    source_info_ = source_info;
+  }
 
   bool operator==(const BytecodeNode& other) const;
   bool operator!=(const BytecodeNode& other) const { return !(*this == other); }
 
  private:
-  INLINE(void AttachSourceInfo(BytecodeSourceInfo* source_info)) {
-    if (source_info && source_info->is_valid()) {
-      // Statement positions need to be emitted immediately.  Expression
-      // positions can be pushed back until a bytecode is found that can
-      // throw (if expression position filtering is turned on). We only
-      // invalidate the existing source position information if it is used.
-      if (source_info->is_statement() ||
-          !FLAG_ignition_filter_expression_positions ||
-          !Bytecodes::IsWithoutExternalSideEffects(bytecode())) {
-        source_info_.Clone(*source_info);
-        source_info->set_invalid();
-      }
-    }
-  }
-
   INLINE(void UpdateScaleForOperand(int operand_index, uint32_t operand)) {
     if (Bytecodes::OperandIsScalableSignedByte(bytecode(), operand_index)) {
       operand_scale_ =
           std::max(operand_scale_, Bytecodes::ScaleForSignedOperand(operand));
     } else if (Bytecodes::OperandIsScalableUnsignedByte(bytecode(),
                                                         operand_index)) {
       operand_scale_ =
           std::max(operand_scale_, Bytecodes::ScaleForUnsignedOperand(operand));
     }
   }
 
   INLINE(void SetOperand(int operand_index, uint32_t operand)) {
     operands_[operand_index] = operand;
     UpdateScaleForOperand(operand_index, operand);
   }
 
-  void UpdateScale() {
-    operand_scale_ = OperandScale::kSingle;
-    for (int i = 0; i < operand_count(); i++) {
-      UpdateScaleForOperand(i, operands_[i]);
-    }
-  }
-
   Bytecode bytecode_;
   uint32_t operands_[Bytecodes::kMaxOperands];
   int operand_count_;
   OperandScale operand_scale_;
   BytecodeSourceInfo source_info_;
 };
 
 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
                                            const BytecodeSourceInfo& info);
 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os,
                                            const BytecodeNode& node);
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_BYTECODE_PIPELINE_H_