Improve polymorphic loads on single slots.

src/hydrogen-instructions.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 938 matching lines @@
     case IS_SYMBOL:
       *mask = kIsSymbolMask;
       *tag = kSymbolTag;
       return;
     default:
       UNREACHABLE();
   }
 }
 
 
-void HCheckMap::PrintDataTo(StringStream* stream) {
+void HCheckMaps::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
-  stream->Add(" %p", *map());
-  if (mode() == REQUIRE_EXACT_MAP) {
-    stream->Add(" [EXACT]");
-  } else if (!has_element_transitions_) {
-    stream->Add(" [EXACT*]");
-  } else {
-    stream->Add(" [MATCH ELEMENTS]");
+  stream->Add(" [%p", *map_set()->first());
+  for (int i = 1; i < map_set()->length(); ++i) {
+    stream->Add(",%p", *map_set()->at(i));
   }
+  stream->Add("]");
 }
 
 
 void HCheckFunction::PrintDataTo(StringStream* stream) {
   value()->PrintNameTo(stream);
   stream->Add(" %p", *target());
 }
 
 
 const char* HCheckInstanceType::GetCheckName() {
@@ skipping 883 matching lines @@
 
 
 // Implementation of type inference and type conversions. Calculates
 // the inferred type of this instruction based on the input operands.
 
 HType HValue::CalculateInferredType() {
   return type_;
 }
 
 
-HType HCheckMap::CalculateInferredType() {
+HType HCheckMaps::CalculateInferredType() {
   return value()->type();
 }
 
 
 HType HCheckFunction::CalculateInferredType() {
   return value()->type();
 }
 
 
 HType HCheckNonSmi::CalculateInferredType() {
@@ skipping 404 matching lines @@
 
 
 void HCheckPrototypeMaps::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal