mir-opt: Do not transform non-int type in match_branches

2 files changed, 61 insertions, 0 deletions

diff --git a/tests/mir-opt/matches_reduce_branches.match_non_int_failed.MatchBranchSimplification.diff b/tests/mir-opt/matches_reduce_branches.match_non_int_failed.MatchBranchSimplification.diff
new file mode 100644
index 00000000000..81e900a34c0
--- /dev/null
+++ b/tests/mir-opt/matches_reduce_branches.match_non_int_failed.MatchBranchSimplification.diff
@@ -0,0 +1,29 @@
+- // MIR for `match_non_int_failed` before MatchBranchSimplification
++ // MIR for `match_non_int_failed` after MatchBranchSimplification
+  
+  fn match_non_int_failed(_1: char) -> u8 {
+      let mut _0: u8;
+  
+      bb0: {
+          switchInt(copy _1) -> [97: bb1, 98: bb2, otherwise: bb3];
+      }
+  
+      bb1: {
+          _0 = const 97_u8;
+          goto -> bb4;
+      }
+  
+      bb2: {
+          _0 = const 98_u8;
+          goto -> bb4;
+      }
+  
+      bb3: {
+          unreachable;
+      }
+  
+      bb4: {
+          return;
+      }
+  }
+  
diff --git a/tests/mir-opt/matches_reduce_branches.rs b/tests/mir-opt/matches_reduce_branches.rs
index 3372ae2f2a6..19611a843c6 100644
--- a/tests/mir-opt/matches_reduce_branches.rs
+++ b/tests/mir-opt/matches_reduce_branches.rs
@@ -628,6 +628,37 @@ fn match_i128_u128(i: EnumAi128) -> u128 {
     }
 }
 
+// EMIT_MIR matches_reduce_branches.match_non_int_failed.MatchBranchSimplification.diff
+#[custom_mir(dialect = "runtime")]
+fn match_non_int_failed(i: char) -> u8 {
+    // CHECK-LABEL: fn match_non_int_failed(
+    // CHECK: switchInt
+    // CHECK: return
+    mir! {
+        {
+            match i {
+                'a' => bb1,
+                'b' => bb2,
+                _ => unreachable_bb,
+            }
+        }
+        bb1 = {
+            RET = 97;
+            Goto(ret)
+        }
+        bb2 = {
+            RET = 98;
+            Goto(ret)
+        }
+        unreachable_bb = {
+            Unreachable()
+        }
+        ret = {
+            Return()
+        }
+    }
+}
+
 fn main() {
     let _ = foo(None);
     let _ = foo(Some(()));
@@ -665,4 +696,5 @@ fn main() {
     let _ = match_i128_u128(EnumAi128::A);
 
     let _ = my_is_some(None);
+    let _ = match_non_int_failed('a');
 }