Fix handling of -0 in the unary-op IC and avoid repeated patching/transitions.

src/ic.cc

 // Copyright 2011 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 2182 matching lines @@
   if (operand_type.IsSmi()) {
     return SMI;
   } else if (operand_type.IsNumber()) {
     return HEAP_NUMBER;
   } else {
     return GENERIC;
   }
 }
 
 
-TRUnaryOpIC::TypeInfo TRUnaryOpIC::JoinTypes(TRUnaryOpIC::TypeInfo x,
-                                             TRUnaryOpIC::TypeInfo y) {
-  return x >= y ? x : y;
+TRUnaryOpIC::TypeInfo TRUnaryOpIC::ComputeNewType(
+    TRUnaryOpIC::TypeInfo type,
+    TRUnaryOpIC::TypeInfo previous) {
+  switch (previous) {
+    case TRUnaryOpIC::UNINITIALIZED:
+      return type;
+    case TRUnaryOpIC::SMI:
+      return (type == TRUnaryOpIC::GENERIC)
+          ? TRUnaryOpIC::GENERIC
+          : TRUnaryOpIC::HEAP_NUMBER;
+    case TRUnaryOpIC::HEAP_NUMBER:
+      return TRUnaryOpIC::GENERIC;
+    case TRUnaryOpIC::GENERIC:
+      // We should never do patching if we are in GENERIC state.
+      UNREACHABLE();
+      return TRUnaryOpIC::GENERIC;
+  }
 }
 
 
 void TRBinaryOpIC::patch(Code* code) {
   set_target(code);
 }
 
 
 const char* TRBinaryOpIC::GetName(TypeInfo type_info) {
   switch (type_info) {
@@ skipping 91 matching lines @@
   ASSERT(args.length() == 4);
 
   HandleScope scope(isolate);
   Handle<Object> operand = args.at<Object>(0);
   int key = Smi::cast(args[1])->value();
   Token::Value op = static_cast<Token::Value>(Smi::cast(args[2])->value());
   TRUnaryOpIC::TypeInfo previous_type =
       static_cast<TRUnaryOpIC::TypeInfo>(Smi::cast(args[3])->value());
 
   TRUnaryOpIC::TypeInfo type = TRUnaryOpIC::GetTypeInfo(operand);
-  type = TRUnaryOpIC::JoinTypes(type, previous_type);
+  type = TRUnaryOpIC::ComputeNewType(type, previous_type);
 
   Handle<Code> code = GetTypeRecordingUnaryOpStub(key, type);
   if (!code.is_null()) {
     if (FLAG_trace_ic) {
       PrintF("[TypeRecordingUnaryOpIC (%s->%s)#%s]\n",
              TRUnaryOpIC::GetName(previous_type),
              TRUnaryOpIC::GetName(type),
              Token::Name(op));
     }
     TRUnaryOpIC ic(isolate);
@@ skipping 210 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal