Adding Smi support to Add, Sub, Mul, and Bitwise

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 20 matching lines @@
 namespace internal {
 
 void HCanonicalizePhase::Run() {
   const ZoneList<HBasicBlock*>* blocks(graph()->blocks());
   // Before removing no-op instructions, save their semantic value.
   // We must be careful not to set the flag unnecessarily, because GVN
   // cannot identify two instructions when their flag value differs.
   for (int i = 0; i < blocks->length(); ++i) {
     for (HInstructionIterator it(blocks->at(i)); !it.Done(); it.Advance()) {
       HInstruction* instr = it.Current();
-      if (instr->IsArithmeticBinaryOperation() &&
-          instr->representation().IsInteger32() &&
-          instr->HasAtLeastOneUseWithFlagAndNoneWithout(
-              HInstruction::kTruncatingToInt32)) {
-        instr->SetFlag(HInstruction::kAllUsesTruncatingToInt32);
+      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);
+          }
+        }
       }
     }
   }
   // 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