diff --git a/tests/codegen-llvm/issues/saturating-sub-index-139759.rs b/tests/codegen-llvm/issues/saturating-sub-index-139759.rs new file mode 100644 index 0000000000000..eac2f4d306b93 --- /dev/null +++ b/tests/codegen-llvm/issues/saturating-sub-index-139759.rs @@ -0,0 +1,19 @@ +// Test that calculating an index with saturating subtraction from an in-bounds +// index doesn't generate another bounds check. + +//@ compile-flags: -Copt-level=3 +//@ min-llvm-version: 21 + +#![crate_type = "lib"] + +// CHECK-LABEL: @bounds_check_is_elided +#[no_mangle] +pub fn bounds_check_is_elided(s: &[i32], index: usize) -> i32 { + // CHECK-NOT: panic_bounds_check + if index < s.len() { + let lower_bound = index.saturating_sub(1); + s[lower_bound] + } else { + -1 + } +}