Properly consider Double inputs for representation inference

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 2230 matching lines @@
   Representation rep = representation();
   for (int i = 1; i <= 2; ++i) {
     Representation input_rep = observed_input_representation(i);
     if (input_rep.is_more_general_than(rep)) rep = input_rep;
   }
   // If any of the actual input representation is more general than what we
   // have so far but not Tagged, use that representation instead.
   Representation left_rep = left()->representation();
   Representation right_rep = right()->representation();
 
-  if (left_rep.is_more_general_than(rep) &&
-      left()->CheckFlag(kFlexibleRepresentation)) {
+  if (left_rep.is_more_general_than(rep) && !left_rep.IsTagged()) {
     rep = left_rep;
   }
-  if (right_rep.is_more_general_than(rep) &&
-      right()->CheckFlag(kFlexibleRepresentation)) {
+  if (right_rep.is_more_general_than(rep) && !right_rep.IsTagged()) {
     rep = right_rep;
   }
   // Consider observed output representation, but ignore it if it's Double,
   // this instruction is not a division, and all its uses are truncating
   // to Integer32.
   if (observed_output_representation_.is_more_general_than(rep) &&
       !IgnoreObservedOutputRepresentation(rep)) {
     rep = observed_output_representation_;
   }
   return rep;
@@ skipping 1341 matching lines @@
 
 
 void HCheckFunction::Verify() {
   HInstruction::Verify();
   ASSERT(HasNoUses());
 }
 
 #endif
 
 } }  // namespace v8::internal