diff --git a/compiler/rustc_codegen_llvm/src/builder.rs b/compiler/rustc_codegen_llvm/src/builder.rs
index 63e59ea13fc35..24dadfd960e7e 100644
--- a/compiler/rustc_codegen_llvm/src/builder.rs
+++ b/compiler/rustc_codegen_llvm/src/builder.rs
@@ -1132,14 +1132,12 @@ impl<'a, 'll, 'tcx> BuilderMethods<'a, 'tcx> for Builder<'a, 'll, 'tcx> {
         &mut self,
         op: rustc_codegen_ssa::common::AtomicRmwBinOp,
         dst: &'ll Value,
-        mut src: &'ll Value,
+        src: &'ll Value,
         order: rustc_codegen_ssa::common::AtomicOrdering,
     ) -> &'ll Value {
         // The only RMW operation that LLVM supports on pointers is compare-exchange.
-        if self.val_ty(src) == self.type_ptr()
-            && op != rustc_codegen_ssa::common::AtomicRmwBinOp::AtomicXchg
-        {
-            src = self.ptrtoint(src, self.type_isize());
+        if self.val_ty(src) == self.type_ptr() {
+            assert_eq!(op, rustc_codegen_ssa::common::AtomicRmwBinOp::AtomicXchg);
         }
         unsafe {
             llvm::LLVMBuildAtomicRMW(
diff --git a/compiler/rustc_codegen_ssa/src/common.rs b/compiler/rustc_codegen_ssa/src/common.rs
index 44a2434238dad..36a13c6469dad 100644
--- a/compiler/rustc_codegen_ssa/src/common.rs
+++ b/compiler/rustc_codegen_ssa/src/common.rs
@@ -42,7 +42,7 @@ pub enum RealPredicate {
     RealPredicateTrue,
 }
 
-#[derive(Copy, Clone, PartialEq)]
+#[derive(Copy, Clone, PartialEq, Debug)]
 pub enum AtomicRmwBinOp {
     AtomicXchg,
     AtomicAdd,