From c7af338e6fa95dd9877a19be74b94f471233d75b Mon Sep 17 00:00:00 2001 From: Scott McMurray Date: Fri, 30 Sep 2022 23:39:15 -0700 Subject: Tell LLVM that `partition_point` returns a valid fencepost This was already done for a successful `binary_search`, but this way `partition_point` can get similar optimizations. --- .../codegen/binary-search-index-no-bound-check.rs | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'src/test/codegen') diff --git a/src/test/codegen/binary-search-index-no-bound-check.rs b/src/test/codegen/binary-search-index-no-bound-check.rs index 2deabcaa6c2..c1766a4a44a 100644 --- a/src/test/codegen/binary-search-index-no-bound-check.rs +++ b/src/test/codegen/binary-search-index-no-bound-check.rs @@ -16,3 +16,23 @@ pub fn binary_search_index_no_bounds_check(s: &[u8]) -> u8 { 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) +} -- cgit 1.4.1-3-g733a5