diff --git a/tests/mir-opt/combine_transmutes.adt_transmutes.InstSimplify.diff b/tests/mir-opt/instsimplify/combine_transmutes.adt_transmutes.InstSimplify.diff
similarity index 100%
rename from tests/mir-opt/combine_transmutes.adt_transmutes.InstSimplify.diff
rename to tests/mir-opt/instsimplify/combine_transmutes.adt_transmutes.InstSimplify.diff
diff --git a/tests/mir-opt/combine_transmutes.identity_transmutes.InstSimplify.diff b/tests/mir-opt/instsimplify/combine_transmutes.identity_transmutes.InstSimplify.diff
similarity index 100%
rename from tests/mir-opt/combine_transmutes.identity_transmutes.InstSimplify.diff
rename to tests/mir-opt/instsimplify/combine_transmutes.identity_transmutes.InstSimplify.diff
diff --git a/tests/mir-opt/combine_transmutes.integer_transmutes.InstSimplify.diff b/tests/mir-opt/instsimplify/combine_transmutes.integer_transmutes.InstSimplify.diff
similarity index 100%
rename from tests/mir-opt/combine_transmutes.integer_transmutes.InstSimplify.diff
rename to tests/mir-opt/instsimplify/combine_transmutes.integer_transmutes.InstSimplify.diff
diff --git a/tests/mir-opt/combine_transmutes.rs b/tests/mir-opt/instsimplify/combine_transmutes.rs
similarity index 65%
rename from tests/mir-opt/combine_transmutes.rs
rename to tests/mir-opt/instsimplify/combine_transmutes.rs
index 89ec0a08a01..b8e15da905b 100644
--- a/tests/mir-opt/combine_transmutes.rs
+++ b/tests/mir-opt/instsimplify/combine_transmutes.rs
@@ -1,4 +1,3 @@
-// skip-filecheck
 // unit-test: InstSimplify
 // compile-flags: -C panic=abort
 
@@ -11,6 +10,10 @@
 
 // EMIT_MIR combine_transmutes.identity_transmutes.InstSimplify.diff
 pub unsafe fn identity_transmutes() {
+    // CHECK-LABEL: fn identity_transmutes(
+    // CHECK-NOT: as i32 (Transmute);
+    // CHECK-NOT: as Vec<i32> (Transmute);
+
     // These are nops and should be removed
     let _a = transmute::<i32, i32>(1);
     let _a = transmute::<Vec<i32>, Vec<i32>>(Vec::new());
@@ -19,6 +22,16 @@ pub unsafe fn identity_transmutes() {
 #[custom_mir(dialect = "runtime", phase = "initial")]
 // EMIT_MIR combine_transmutes.integer_transmutes.InstSimplify.diff
 pub unsafe fn integer_transmutes() {
+    // CHECK-LABEL: fn integer_transmutes(
+    // CHECK-NOT: _i32 as u32 (Transmute);
+    // CHECK: _i32 as u32 (IntToInt);
+    // CHECK: _i32 as i64 (Transmute);
+    // CHECK-NOT: _u64 as i64 (Transmute);
+    // CHECK: _u64 as i64 (IntToInt);
+    // CHECK: _u64 as u32 (Transmute);
+    // CHECK-NOT: _isize as usize (Transmute);
+    // CHECK: _isize as usize (IntToInt);
+
     mir! {
         {
             let A = CastTransmute::<i32, u32>(1); // Can be a cast
@@ -33,6 +46,14 @@ pub unsafe fn integer_transmutes() {
 
 // EMIT_MIR combine_transmutes.adt_transmutes.InstSimplify.diff
 pub unsafe fn adt_transmutes() {
+    // CHECK-LABEL: fn adt_transmutes(
+    // CHECK: as u8 (Transmute);
+    // CHECK: ({{_.*}}.0: i16);
+    // CHECK: as u16 (Transmute);
+    // CHECK: as u32 (Transmute);
+    // CHECK: as i32 (Transmute);
+    // CHECK: ({{_.*}}.1: std::mem::ManuallyDrop<std::string::String>);
+
     let _a: u8 = transmute(Some(std::num::NonZeroU8::MAX));
     let _a: i16 = transmute(std::num::Wrapping(0_i16));
     let _a: u16 = transmute(std::num::Wrapping(0_i16));