Support symbol comparison in crankshaft.

src/hydrogen.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 4816 matching lines @@
 
       ast_context()->ReturnValue(expr->is_postfix() ? before : after);
     }
 
   } else {
     return Bailout("invalid lhs in count operation");
   }
 }
 
 
+HCompareSymbolEq* HGraphBuilder::BuildSymbolCompare(HValue* left,
+                                                    HValue* right,
+                                                    Token::Value op) {
+  ASSERT(op == Token::EQ || op == Token::EQ_STRICT);
+  AddInstruction(new(zone()) HCheckNonSmi(left));
+  AddInstruction(HCheckInstanceType::NewIsSymbol(left));
+  AddInstruction(new(zone()) HCheckNonSmi(right));
+  AddInstruction(HCheckInstanceType::NewIsSymbol(right));
+  return new(zone()) HCompareSymbolEq(left, right, op);
+}
+
+
 HStringCharCodeAt* HGraphBuilder::BuildStringCharCodeAt(HValue* string,
                                                         HValue* index) {
   AddInstruction(new(zone()) HCheckNonSmi(string));
   AddInstruction(HCheckInstanceType::NewIsString(string));
   HStringLength* length = new(zone()) HStringLength(string);
   AddInstruction(length);
   AddInstruction(new(zone()) HBoundsCheck(index, length));
   return new(zone()) HStringCharCodeAt(string, index);
 }
 
@@ skipping 299 matching lines @@
         AddInstruction(HCheckInstanceType::NewIsJSObjectOrJSFunction(left));
         AddInstruction(new(zone()) HCheckNonSmi(right));
         AddInstruction(HCheckInstanceType::NewIsJSObjectOrJSFunction(right));
         instr = new(zone()) HCompareJSObjectEq(left, right);
         break;
       }
       default:
         return Bailout("Unsupported non-primitive compare");
         break;
     }
+  } else if (type_info.IsString() && oracle()->IsSymbolCompare(expr) &&
+             (op == Token::EQ || op == Token::EQ_STRICT)) {
+    instr = BuildSymbolCompare(left, right, op);
   } else {
     HCompare* compare = new(zone()) HCompare(left, right, op);
     Representation r = ToRepresentation(type_info);
     compare->SetInputRepresentation(r);
     instr = compare;
   }
   instr->set_position(expr->position());
   ast_context()->ReturnInstruction(instr, expr->id());
 }
 
@@ skipping 935 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal