[interpreter] Bytecode register optimizer.

test/unittests/interpreter/bytecode-array-iterator-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 "src/v8.h"
 
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "test/unittests/test-utils.h"
 
@@ skipping 29 matching lines @@
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(heap_num_1)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(zero)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_0)
       .StoreAccumulatorInRegister(reg_0)
       .LoadLiteral(smi_1)
       .StoreAccumulatorInRegister(reg_1)
       .LoadAccumulatorWithRegister(reg_0)
+      .BinaryOperation(Token::Value::ADD, reg_0)
       .StoreAccumulatorInRegister(reg_1)
       .LoadNamedProperty(reg_1, name, feedback_slot)
       .BinaryOperation(Token::Value::ADD, reg_0)
       .StoreAccumulatorInRegister(param)
       .CallRuntimeForPair(Runtime::kLoadLookupSlotForCall, param, 1, reg_0)
       .ForInPrepare(reg_0)
       .CallRuntime(Runtime::kLoadIC_Miss, reg_0, 1)
       .Debugger()
       .LoadGlobal(name, 0x10000000, TypeofMode::NOT_INSIDE_TYPEOF)
       .Return();
@@ skipping 89 matching lines @@
   iterator.Advance();
 
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
   CHECK(!iterator.done());
   offset += Bytecodes::Size(Bytecode::kLdar, OperandScale::kSingle);
   iterator.Advance();
 
+  CHECK_EQ(iterator.current_bytecode(), Bytecode::kAdd);
+  CHECK_EQ(iterator.current_offset(), offset);
+  CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
+  CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_0.index());
+  CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
+  CHECK(!iterator.done());
+  offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
+  iterator.Advance();
+
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kStar);
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK_EQ(iterator.GetRegisterOperand(0).index(), reg_1.index());
   CHECK_EQ(iterator.GetRegisterOperandRange(0), 1);
   CHECK(!iterator.done());
   offset += Bytecodes::Size(Bytecode::kStar, OperandScale::kSingle);
   iterator.Advance();
 
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kLdaNamedProperty);
@@ skipping 78 matching lines @@
   CHECK_EQ(iterator.current_offset(), offset);
   CHECK_EQ(iterator.current_operand_scale(), OperandScale::kSingle);
   CHECK(!iterator.done());
   iterator.Advance();
   CHECK(iterator.done());
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8