Remove duplicate switch targets

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/mir-opt/instcombine_duplicate_switch_targets.rs b/tests/mir-opt/instcombine_duplicate_switch_targets.rs
new file mode 100644
index 00000000000..ef3b487afa3
--- /dev/null
+++ b/tests/mir-opt/instcombine_duplicate_switch_targets.rs
@@ -0,0 +1,27 @@
+#![feature(custom_mir, core_intrinsics)]
+#![crate_type = "lib"]
+
+use std::intrinsics::mir::*;
+
+// unit-test: InstCombine
+
+// EMIT_MIR instcombine_duplicate_switch_targets.assert_zero.InstCombine.diff
+#[custom_mir(dialect = "runtime", phase = "post-cleanup")]
+pub unsafe fn assert_zero(x: u8) -> u8 {
+    mir!(
+        {
+            match x {
+                0 => retblock,
+                1 => unreachable,
+                _ => unreachable,
+            }
+        }
+        unreachable = {
+            Unreachable()
+        }
+        retblock = {
+            RET = x;
+            Return()
+        }
+    )
+}