[interpreter] Introduce fused bytecodes for common sequences.

test/unittests/interpreter/bytecode-array-builder-unittest.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/v8.h"
 
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "src/interpreter/bytecode-register-allocator.h"
 #include "test/unittests/test-utils.h"
@@ skipping 29 matching lines @@
   // Emit constant loads.
   builder.LoadLiteral(Smi::FromInt(0))
       .StoreAccumulatorInRegister(reg)
       .LoadLiteral(Smi::FromInt(8))
       .StoreAccumulatorInRegister(reg)
       .LoadLiteral(Smi::FromInt(10000000))
       .StoreAccumulatorInRegister(reg)
       .LoadLiteral(factory->NewStringFromStaticChars("A constant"))
       .StoreAccumulatorInRegister(reg)
       .LoadUndefined()
-      .StoreAccumulatorInRegister(reg)
+      .Debugger()  // Prevent peephole optimization LdaNull, Star -> LdrNull.
       .LoadNull()
       .StoreAccumulatorInRegister(reg)
       .LoadTheHole()
       .StoreAccumulatorInRegister(reg)
       .LoadTrue()
       .StoreAccumulatorInRegister(reg)
       .LoadFalse()
       .StoreAccumulatorInRegister(wide);
 
   builder.StackCheck(0)
@@ skipping 281 matching lines @@
     }
     i += prefix_offset + Bytecodes::Size(final_bytecode, operand_scale);
   }
 
   // Insert entry for illegal bytecode as this is never willingly emitted.
   scorecard[Bytecodes::ToByte(Bytecode::kIllegal)] = 1;
 
   // Insert entry for nop bytecode as this often gets optimized out.
   scorecard[Bytecodes::ToByte(Bytecode::kNop)] = 1;
 
+  // Insert entries for bytecodes only emiited by peephole optimizer.
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrNamedProperty)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrKeyedProperty)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrGlobal)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrContextSlot)] = 1;
+  scorecard[Bytecodes::ToByte(Bytecode::kLdrUndefined)] = 1;
+
   // Check return occurs at the end and only once in the BytecodeArray.
   CHECK_EQ(final_bytecode, Bytecode::kReturn);
   CHECK_EQ(scorecard[Bytecodes::ToByte(final_bytecode)], 1);
 
 #define CHECK_BYTECODE_PRESENT(Name, ...)                                \
   /* Check Bytecode is marked in scorecard, unless it's a debug break */ \
   if (!Bytecodes::IsDebugBreak(Bytecode::k##Name)) {                     \
     CHECK_GE(scorecard[Bytecodes::ToByte(Bytecode::k##Name)], 1);        \
   }
   BYTECODE_LIST(CHECK_BYTECODE_PRESENT)
@@ skipping 358 matching lines @@
     iterator.Advance();
   }
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
   iterator.Advance();
   CHECK(iterator.done());
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8