diff --git a/llvm/lib/CodeGen/TypePromotion.cpp b/llvm/lib/CodeGen/TypePromotion.cpp
--- a/llvm/lib/CodeGen/TypePromotion.cpp
+++ b/llvm/lib/CodeGen/TypePromotion.cpp
@@ -484,7 +484,10 @@
         continue;
 
       if (auto *Const = dyn_cast<ConstantInt>(Op)) {
-        Constant *NewConst = (SafeWrap.contains(I) && i == 1)
+        // For ICmp, the constant can be on the LHS or RHS. For Add/Sub the
+        // constant we checked for sext is on the RHS.
+        Constant *NewConst = (SafeWrap.contains(I) &&
+                              (I->getOpcode() == Instruction::ICmp || i == 1))
                                  ? ConstantExpr::getSExt(Const, ExtTy)
                                  : ConstantExpr::getZExt(Const, ExtTy);
         I->setOperand(i, NewConst);