Replace HCheckPrototypeMaps by explicit map checks of constant values.

src/x64/lithium-x64.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1902 matching lines @@
 }
 
 
 LInstruction* LChunkBuilder::DoCheckInstanceType(HCheckInstanceType* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   LCheckInstanceType* result = new(zone()) LCheckInstanceType(value);
   return AssignEnvironment(result);
 }
 
 
-LInstruction* LChunkBuilder::DoCheckPrototypeMaps(HCheckPrototypeMaps* instr) {
-  LUnallocated* temp = NULL;
-  if (!instr->CanOmitPrototypeChecks()) temp = TempRegister();
-  LCheckPrototypeMaps* result = new(zone()) LCheckPrototypeMaps(temp);
-  if (instr->CanOmitPrototypeChecks()) return result;
-  return AssignEnvironment(result);
-}
-
-
 LInstruction* LChunkBuilder::DoCheckFunction(HCheckFunction* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckFunction(value));
 }
 
 
 LInstruction* LChunkBuilder::DoCheckMaps(HCheckMaps* instr) {
   LOperand* value = NULL;
   if (!instr->CanOmitMapChecks()) value = UseRegisterAtStart(instr->value());
   LCheckMaps* result = new(zone()) LCheckMaps(value);
@@ skipping 602 matching lines @@
 LInstruction* LChunkBuilder::DoLoadFieldByIndex(HLoadFieldByIndex* instr) {
   LOperand* object = UseRegister(instr->object());
   LOperand* index = UseTempRegister(instr->index());
   return DefineSameAsFirst(new(zone()) LLoadFieldByIndex(object, index));
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64