Fix default type feedback returned from the oracle

src/hydrogen.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 9226 matching lines @@
     instr->set_position(expr->position());
     return ast_context()->ReturnControl(instr, expr->id());
   }
 
   Handle<Type> left_type = expr->left()->lower_type();
   Handle<Type> right_type = expr->right()->lower_type();
   Handle<Type> combined_type = expr->combined_type();
   Representation combined_rep = ToRepresentation(combined_type);
   Representation left_rep = ToRepresentation(left_type);
   Representation right_rep = ToRepresentation(right_type);
-  // Check if this expression was ever executed according to type feedback.
-  // Note that for the special typeof/null/undefined cases we get unknown here.
-  if (combined_type->Is(Type::None())) {
-    AddSoftDeoptimize();
-    combined_type = left_type = right_type = handle(Type::Any(), isolate());
-  }
 
   CHECK_ALIVE(VisitForValue(expr->left()));
   CHECK_ALIVE(VisitForValue(expr->right()));
 
   HValue* context = environment()->LookupContext();
   HValue* right = Pop();
   HValue* left = Pop();
   Token::Value op = expr->op();
 
   HTypeof* typeof_expr = NULL;
@@ skipping 46 matching lines @@
       HInstanceOf* result = new(zone()) HInstanceOf(context, left, right);
       result->set_position(expr->position());
       return ast_context()->ReturnInstruction(result, expr->id());
     } else {
       Add<HCheckFunction>(right, target);
       HInstanceOfKnownGlobal* result =
           new(zone()) HInstanceOfKnownGlobal(context, left, target);
       result->set_position(expr->position());
       return ast_context()->ReturnInstruction(result, expr->id());
     }
+
+    // Code below assumes that we don't fall through.
+    UNREACHABLE();
   } else if (op == Token::IN) {
     HIn* result = new(zone()) HIn(context, left, right);
     result->set_position(expr->position());
     return ast_context()->ReturnInstruction(result, expr->id());
-  } else if (combined_type->Is(Type::Receiver())) {
+  }
+
+  // Cases handled below depend on collected type feedback. They should
+  // soft deoptimize when there is no type feedback.
+  if (combined_type->Is(Type::None())) {
+    AddSoftDeoptimize();
+    combined_type = left_type = right_type = handle(Type::Any(), isolate());
+  }
+
+  if (combined_type->Is(Type::Receiver())) {
     switch (op) {
       case Token::EQ:
       case Token::EQ_STRICT: {
         // Can we get away with map check and not instance type check?
         if (combined_type->IsClass()) {
           Handle<Map> map = combined_type->AsClass();
           AddCheckMapsWithTransitions(left, map);
           AddCheckMapsWithTransitions(right, map);
           HCompareObjectEqAndBranch* result =
               new(zone()) HCompareObjectEqAndBranch(left, right);
@@ skipping 1686 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal