Eliminate intentional conversion from Smi to Int32 in HMul

src/hydrogen-canonicalize.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 30 matching lines @@
       if (instr->IsArithmeticBinaryOperation()) {
         if (instr->representation().IsInteger32()) {
           if (instr->HasAtLeastOneUseWithFlagAndNoneWithout(
                   HInstruction::kTruncatingToInt32)) {
             instr->SetFlag(HInstruction::kAllUsesTruncatingToInt32);
           }
         } else if (instr->representation().IsSmi()) {
           if (instr->HasAtLeastOneUseWithFlagAndNoneWithout(
                   HInstruction::kTruncatingToSmi)) {
             instr->SetFlag(HInstruction::kAllUsesTruncatingToSmi);
+          } else if (instr->HasAtLeastOneUseWithFlagAndNoneWithout(
+                         HInstruction::kTruncatingToInt32)) {
+            // Avoid redundant minus zero check
+            instr->SetFlag(HInstruction::kAllUsesTruncatingToInt32);
           }
         }
       }
     }
   }
   // Perform actual Canonicalization pass.
   for (int i = 0; i < blocks->length(); ++i) {
     for (HInstructionIterator it(blocks->at(i)); !it.Done(); it.Advance()) {
       HInstruction* instr = it.Current();
       HValue* value = instr->Canonicalize();
       if (value != instr) instr->DeleteAndReplaceWith(value);
     }
   }
 }
 
 } }  // namespace v8::internal