Merged r17451 into 3.21 branch.

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 4dc80226f295efd8850efa45c319867cffb4ff90..06bb33abc011b6b27161418c6a17854ad993f8a0 100644
--- a/src/mips/lithium-mips.cc
+++ b/src/mips/lithium-mips.cc
@@ -1906,8 +1906,9 @@ LInstruction* LChunkBuilder::DoChange(HChange* instr) {
     } else if (to.IsSmi()) {
       HValue* val = instr->value();
       LOperand* value = UseRegister(val);
-      LInstruction* result =
-          DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
+      LInstruction* result = val->CheckFlag(HInstruction::kUint32)
+          ? DefineSameAsFirst(new(zone()) LUint32ToSmi(value))
+          : DefineSameAsFirst(new(zone()) LInteger32ToSmi(value));
       if (val->HasRange() && val->range()->IsInSmiRange()) {
         return result;
       }