MIPS: DummyUse if Representation::Tagged()+Type::Smi() to Representation::Smi()

src/mips/lithium-mips.cc

Index: src/mips/lithium-mips.cc
diff --git a/src/mips/lithium-mips.cc b/src/mips/lithium-mips.cc
index 5ceca4970098dc92cf7e761e452e3e39882e618e..a2587a7ca59c15947a55abb7a4739691ba7f626f 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1781,6 +1781,9 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
+      if (val->type().IsSmi()) {
+        return DefineSameAsFirst(new(zone()) LDummyUse(value));
+      }
       return AssignEnvironment(
           DefineSameAsFirst(new(zone()) LCheckSmiAndReturn(value)));
     } else {