1 files changed, 70 insertions, 0 deletions

diff --git a/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs b/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs
new file mode 100644
index 00000000000..1e2c25babe0
--- /dev/null
+++ b/tests/codegen-llvm/issues/issue-73396-bounds-check-after-position.rs
@@ -0,0 +1,70 @@
+//@ compile-flags: -Copt-level=3
+#![crate_type = "lib"]
+
+// Make sure no bounds checks are emitted when slicing or indexing
+// with an index from `position()` or `rposition()`.
+
+// CHECK-LABEL: @position_slice_to_no_bounds_check
+#[no_mangle]
+pub fn position_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: panic_bounds_check
+    // CHECK-NOT: unreachable
+    if let Some(idx) = s.iter().position(|b| *b == b'\\') { &s[..idx] } else { s }
+}
+
+// CHECK-LABEL: @position_slice_from_no_bounds_check
+#[no_mangle]
+pub fn position_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: panic_bounds_check
+    // CHECK-NOT: unreachable
+    if let Some(idx) = s.iter().position(|b| *b == b'\\') { &s[idx..] } else { s }
+}
+
+// CHECK-LABEL: @position_index_no_bounds_check
+#[no_mangle]
+pub fn position_index_no_bounds_check(s: &[u8]) -> u8 {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: panic_bounds_check
+    // CHECK-NOT: unreachable
+    if let Some(idx) = s.iter().position(|b| *b == b'\\') { s[idx] } else { 42 }
+}
+// CHECK-LABEL: @rposition_slice_to_no_bounds_check
+#[no_mangle]
+pub fn rposition_slice_to_no_bounds_check(s: &[u8]) -> &[u8] {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: panic_bounds_check
+    // CHECK-NOT: unreachable
+    if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { &s[..idx] } else { s }
+}
+
+// CHECK-LABEL: @rposition_slice_from_no_bounds_check
+#[no_mangle]
+pub fn rposition_slice_from_no_bounds_check(s: &[u8]) -> &[u8] {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: panic_bounds_check
+    // CHECK-NOT: unreachable
+    if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { &s[idx..] } else { s }
+}
+
+// CHECK-LABEL: @rposition_index_no_bounds_check
+#[no_mangle]
+pub fn rposition_index_no_bounds_check(s: &[u8]) -> u8 {
+    // CHECK-NOT: panic
+    // CHECK-NOT: slice_start_index_len_fail
+    // CHECK-NOT: slice_end_index_len_fail
+    // CHECK-NOT: panic_bounds_check
+    // CHECK-NOT: unreachable
+    if let Some(idx) = s.iter().rposition(|b| *b == b'\\') { s[idx] } else { 42 }
+}