Attempt to fix compare performance regression.

src/ic.cc

 // Copyright 2006-2009 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 2115 matching lines @@
     case OBJECTS: return "OBJECTS";
     case GENERIC: return "GENERIC";
     default:
       UNREACHABLE();
       return NULL;
   }
 }
 
 
 CompareIC::State CompareIC::TargetState(State state,
+                                        bool has_inlined_smi_code,
                                         Handle<Object> x,
                                         Handle<Object> y) {
-  if (state != UNINITIALIZED) return GENERIC;
-  if (x->IsSmi() && y->IsSmi()) return SMIS;
-  if (x->IsNumber() && y->IsNumber()) return HEAP_NUMBERS;
+  if (!has_inlined_smi_code && state != UNINITIALIZED) return GENERIC;
+  if (state == UNINITIALIZED && x->IsSmi() && y->IsSmi()) return SMIS;
+  if ((state == UNINITIALIZED || (state == SMIS && has_inlined_smi_code)) &&
+      x->IsNumber() && y->IsNumber()) return HEAP_NUMBERS;

[fschneider, 2010/12/11 15:18:46]

Would the condition 
(state == UNINITIALIZED || state == SMIS) &&
x->IsNumber() &&
y->IsNumber())

be sufficient here? So that we always go from SMI to HEAP_NUMBER before going to
GENERIC.

   if (op_ != Token::EQ && op_ != Token::EQ_STRICT) return GENERIC;
-  if (x->IsJSObject() && y->IsJSObject()) return OBJECTS;
+  if (state == UNINITIALIZED &&
+      x->IsJSObject() && y->IsJSObject()) return OBJECTS;
   return GENERIC;
 }
 
 
 // Used from ic_<arch>.cc.
 Code* CompareIC_Miss(Arguments args) {
   NoHandleAllocation na;
   ASSERT(args.length() == 3);
   CompareIC ic(static_cast<Token::Value>(Smi::cast(args[2])->value()));
   ic.UpdateCaches(args.at<Object>(0), args.at<Object>(1));
   return ic.target();
 }
 
 
 static Address IC_utilities[] = {
 #define ADDR(name) FUNCTION_ADDR(name),
     IC_UTIL_LIST(ADDR)
     NULL
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal