[Interpreter] Remove all Ldr style bytecodes and replace with Star lookahead.

src/interpreter/mkpeephole.cc

 // 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.
 
 #include <array>
 #include <fstream>
 #include <map>
 #include <string>
 #include <vector>
 
@@ skipping 61 matching lines @@
   std::array<size_t, kNumberOfBytecodes> row_map_;
 };
 
 const char* PeepholeActionTableWriter::kIndent = "  ";
 const char* PeepholeActionTableWriter::kNamespaceElements[] = {"v8", "internal",
                                                                "interpreter"};
 
 // static
 PeepholeActionAndData PeepholeActionTableWriter::LookupActionAndData(
     Bytecode last, Bytecode current) {
-  // Optimize various accumulator loads followed by store accumulator
-  // to an equivalent register load and loading the accumulator with
-  // the register. The latter accumulator load can often be elided as
-  // it is side-effect free and often followed by another accumulator
-  // load so can be elided.
-  if (current == Bytecode::kStar) {
-    switch (last) {
-      case Bytecode::kLdaGlobal:
-        return {PeepholeAction::kTransformLdaStarToLdrLdarAction,
-                Bytecode::kLdrGlobal};
-      case Bytecode::kLdaContextSlot:
-        return {PeepholeAction::kTransformLdaStarToLdrLdarAction,
-                Bytecode::kLdrContextSlot};
-      case Bytecode::kLdaCurrentContextSlot:
-        return {PeepholeAction::kTransformLdaStarToLdrLdarAction,
-                Bytecode::kLdrCurrentContextSlot};
-      case Bytecode::kLdaUndefined:
-        return {PeepholeAction::kTransformLdaStarToLdrLdarAction,
-                Bytecode::kLdrUndefined};
-      default:
-        break;
-    }
-  }
-
   // ToName bytecodes can be replaced by Star with the same output register if
   // the value in the accumulator is already a name.
   if (current == Bytecode::kToName && Bytecodes::PutsNameInAccumulator(last)) {
     return {PeepholeAction::kChangeBytecodeAction, Bytecode::kStar};
   }
 
   // Nop are placeholders for holding source position information and can be
   // elided if there is no source information.
   if (last == Bytecode::kNop) {
     if (Bytecodes::IsJump(current)) {
@@ skipping 258 matching lines @@
 
   std::ofstream ofs(argv[1], std::ofstream::trunc);
   v8::internal::interpreter::PeepholeActionTableWriter writer;
   writer.BuildTable();
   writer.Write(ofs);
   ofs.flush();
   ofs.close();
 
   return 0;
 }