1 files changed, 19 insertions, 0 deletions
diff --git a/compiler/rustc_middle/src/mir/interpret/allocation/tests.rs b/compiler/rustc_middle/src/mir/interpret/allocation/tests.rs
new file mode 100644
index 000000000..c9c3c50c5
--- /dev/null
+++ b/compiler/rustc_middle/src/mir/interpret/allocation/tests.rs
@@ -0,0 +1,19 @@
+use super::*;
+
+#[test]
+fn uninit_mask() {
+    let mut mask = InitMask::new(Size::from_bytes(500), false);
+    assert!(!mask.get(Size::from_bytes(499)));
+    mask.set_range(alloc_range(Size::from_bytes(499), Size::from_bytes(1)), true);
+    assert!(mask.get(Size::from_bytes(499)));
+    mask.set_range((100..256).into(), true);
+    for i in 0..100 {
+        assert!(!mask.get(Size::from_bytes(i)), "{i} should not be set");
+    }
+    for i in 100..256 {
+        assert!(mask.get(Size::from_bytes(i)), "{i} should be set");
+    }
+    for i in 256..499 {
+        assert!(!mask.get(Size::from_bytes(i)), "{i} should not be set");
+    }
+}