1 files changed, 38 insertions, 0 deletions
diff --git a/tests/codegen/binary-search-index-no-bound-check.rs b/tests/codegen/binary-search-index-no-bound-check.rs
new file mode 100644
index 000000000..c1766a4a4
--- /dev/null
+++ b/tests/codegen/binary-search-index-no-bound-check.rs
@@ -0,0 +1,38 @@
+// compile-flags: -O
+// ignore-debug: the debug assertions get in the way
+#![crate_type = "lib"]
+
+// Make sure no bounds checks are emitted when slicing or indexing
+// with an index from `binary_search`.
+
+// CHECK-LABEL: @binary_search_index_no_bounds_check
+#[no_mangle]
+pub fn binary_search_index_no_bounds_check(s: &[u8]) -> u8 {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_index_len_fail
+    if let Ok(idx) = s.binary_search(&b'\\') {
+        s[idx]
+    } else {
+        42
+    }
+}
+
+// Similarly, check that `partition_point` is known to return a valid fencepost.
+
+// CHECK-LABEL: @unknown_split
+#[no_mangle]
+pub fn unknown_split(x: &[i32], i: usize) -> (&[i32], &[i32]) {
+    // This just makes sure that the subsequent function is looking for the
+    // absence of something that might actually be there.
+
+    // CHECK: call core::panicking::panic
+    x.split_at(i)
+}
+
+// CHECK-LABEL: @partition_point_split_no_bounds_check
+#[no_mangle]
+pub fn partition_point_split_no_bounds_check(x: &[i32], needle: i32) -> (&[i32], &[i32]) {
+    // CHECK-NOT: call core::panicking::panic
+    let i = x.partition_point(|p| p < &needle);
+    x.split_at(i)
+}