--- a/js/src/jit/IonAnalysis.cpp
+++ b/js/src/jit/IonAnalysis.cpp
@@ -3952,59 +3952,54 @@ MDefinition* jit::ConvertLinearSum(TempA
                                    const LinearSum& sum, bool convertConstant) {
   MDefinition* def = nullptr;
 
   for (size_t i = 0; i < sum.numTerms(); i++) {
     LinearTerm term = sum.term(i);
     MOZ_ASSERT(!term.term->isConstant());
     if (term.scale == 1) {
       if (def) {
-        def = MAdd::New(alloc, def, term.term);
-        def->toAdd()->setInt32Specialization();
+        def = MAdd::New(alloc, def, term.term, MIRType::Int32);
         block->insertAtEnd(def->toInstruction());
         def->computeRange(alloc);
       } else {
         def = term.term;
       }
     } else if (term.scale == -1) {
       if (!def) {
         def = MConstant::New(alloc, Int32Value(0));
         block->insertAtEnd(def->toInstruction());
         def->computeRange(alloc);
       }
-      def = MSub::New(alloc, def, term.term);
-      def->toSub()->setInt32Specialization();
+      def = MSub::New(alloc, def, term.term, MIRType::Int32);
       block->insertAtEnd(def->toInstruction());
       def->computeRange(alloc);
     } else {
       MOZ_ASSERT(term.scale != 0);
       MConstant* factor = MConstant::New(alloc, Int32Value(term.scale));
       block->insertAtEnd(factor);
-      MMul* mul = MMul::New(alloc, term.term, factor);
-      mul->setInt32Specialization();
+      MMul* mul = MMul::New(alloc, term.term, factor, MIRType::Int32);
       block->insertAtEnd(mul);
       mul->computeRange(alloc);
       if (def) {
-        def = MAdd::New(alloc, def, mul);
-        def->toAdd()->setInt32Specialization();
+        def = MAdd::New(alloc, def, mul, MIRType::Int32);
         block->insertAtEnd(def->toInstruction());
         def->computeRange(alloc);
       } else {
         def = mul;
       }
     }
   }
 
   if (convertConstant && sum.constant()) {
     MConstant* constant = MConstant::New(alloc, Int32Value(sum.constant()));
     block->insertAtEnd(constant);
     constant->computeRange(alloc);
     if (def) {
-      def = MAdd::New(alloc, def, constant);
-      def->toAdd()->setInt32Specialization();
+      def = MAdd::New(alloc, def, constant, MIRType::Int32);
       block->insertAtEnd(def->toInstruction());
       def->computeRange(alloc);
     } else {
       def = constant;
     }
   }
 
   if (!def) {
@@ -4062,18 +4057,17 @@ MCompare* jit::ConvertLinearInequality(T
         rhsDef->computeRange(alloc);
         break;
       }
     }
 
     MDefinition* constant = MConstant::New(alloc, Int32Value(lhs.constant()));
     block->insertAtEnd(constant->toInstruction());
     constant->computeRange(alloc);
-    lhsDef = MAdd::New(alloc, lhsDef, constant);
-    lhsDef->toAdd()->setInt32Specialization();
+    lhsDef = MAdd::New(alloc, lhsDef, constant, MIRType::Int32);
     block->insertAtEnd(lhsDef->toInstruction());
     lhsDef->computeRange(alloc);
   } while (false);
 
   if (!rhsDef) {
     rhsDef = MConstant::New(alloc, Int32Value(0));
     block->insertAtEnd(rhsDef->toInstruction());
     rhsDef->computeRange(alloc);