Delete dead code from HOptimizedGraphBuilder::VisitCompareOperation

src/hydrogen.cc

 // Copyright 2013 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 8321 matching lines @@
     return ast_context()->ReturnControl(result, expr->id());
   } else if (combined_type->Is(Type::String())) {
     BuildCheckHeapObject(left);
     AddInstruction(HCheckInstanceType::NewIsString(left, zone()));
     BuildCheckHeapObject(right);
     AddInstruction(HCheckInstanceType::NewIsString(right, zone()));
     HStringCompareAndBranch* result =
         New<HStringCompareAndBranch>(left, right, op);
     result->set_position(expr->position());
     return ast_context()->ReturnControl(result, expr->id());
-  } else if (combined_type->NumClasses() == 1 && Token::IsEqualityOp(op)) {

[rossberg, 2013/10/15 10:49:18]

This case isn't actually entirely dead, since it would be taken if combined_type
was e.g. String \/ Class(m). OTOH, it would also do the wrong thing in that
case... 8-{

-    BuildCheckHeapObject(left);
-    BuildCheckMap(left, combined_type->Classes().Current());
-    BuildCheckHeapObject(right);
-    BuildCheckMap(right, combined_type->Classes().Current());
-    HCompareObjectEqAndBranch* result =
-        New<HCompareObjectEqAndBranch>(left, right);
-    result->set_position(expr->position());
-    return ast_context()->ReturnInstruction(result, expr->id());
-  } else if (combined_type->Is(Type::Receiver()) && Token::IsEqualityOp(op)) {
-    BuildCheckHeapObject(left);
-    AddInstruction(HCheckInstanceType::NewIsSpecObject(left, zone()));
-    BuildCheckHeapObject(right);
-    AddInstruction(HCheckInstanceType::NewIsSpecObject(right, zone()));
-    HCompareObjectEqAndBranch* result =
-        New<HCompareObjectEqAndBranch>(left, right);
-    result->set_position(expr->position());
-    return ast_context()->ReturnInstruction(result, expr->id());
   } else {
     if (combined_rep.IsTagged() || combined_rep.IsNone()) {
       HCompareGeneric* result =
           new(zone()) HCompareGeneric(context, left, right, op);
       result->set_observed_input_representation(1, left_rep);
       result->set_observed_input_representation(2, right_rep);
       result->set_position(expr->position());
       return ast_context()->ReturnInstruction(result, expr->id());
     } else {
       HCompareNumericAndBranch* result =
@@ skipping 1515 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal