Improve polymorphic loads on single slots.

src/ia32/lithium-ia32.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
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@@ skipping 1770 matching lines @@
   // want the value in a register.  If the target gets promoted before we
   // emit code, we will still get the register but will do an immediate
   // compare instead of the cell compare.  This is safe.
   LOperand* value = Isolate::Current()->heap()->InNewSpace(*instr->target())
       ? UseRegisterAtStart(instr->value())
       : UseAtStart(instr->value());
   return AssignEnvironment(new(zone()) LCheckFunction(value));
 }
 
 
-LInstruction* LChunkBuilder::DoCheckMap(HCheckMap* instr) {
+LInstruction* LChunkBuilder::DoCheckMaps(HCheckMaps* instr) {
   LOperand* value = UseRegisterAtStart(instr->value());
-  LCheckMap* result = new(zone()) LCheckMap(value);
+  LCheckMaps* result = new(zone()) LCheckMaps(value);
   return AssignEnvironment(result);
 }
 
 
 LInstruction* LChunkBuilder::DoClampToUint8(HClampToUint8* instr) {
   HValue* value = instr->value();
   Representation input_rep = value->representation();
   if (input_rep.IsDouble()) {
     LOperand* reg = UseRegister(value);
     return DefineAsRegister(new(zone()) LClampDToUint8(reg));
@@ skipping 612 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_IA32