diff options
| -rw-r--r-- | library/core/src/slice/rotate.rs | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/library/core/src/slice/rotate.rs b/library/core/src/slice/rotate.rs index fa8c238f8e7..1d7b8633979 100644 --- a/library/core/src/slice/rotate.rs +++ b/library/core/src/slice/rotate.rs @@ -71,7 +71,9 @@ pub unsafe fn ptr_rotate<T>(mut left: usize, mut mid: *mut T, mut right: usize) if (right == 0) || (left == 0) { return; } - if (left + right < 24) || (mem::size_of::<T>() > mem::size_of::<[usize; 4]>()) { + if !cfg!(feature = "optimize_for_size") + && ((left + right < 24) || (mem::size_of::<T>() > mem::size_of::<[usize; 4]>())) + { // Algorithm 1 // Microbenchmarks indicate that the average performance for random shifts is better all // the way until about `left + right == 32`, but the worst case performance breaks even @@ -158,7 +160,9 @@ pub unsafe fn ptr_rotate<T>(mut left: usize, mut mid: *mut T, mut right: usize) } return; // `T` is not a zero-sized type, so it's okay to divide by its size. - } else if cmp::min(left, right) <= mem::size_of::<BufType>() / mem::size_of::<T>() { + } else if !cfg!(feature = "optimize_for_size") + && cmp::min(left, right) <= mem::size_of::<BufType>() / mem::size_of::<T>() + { // Algorithm 2 // The `[T; 0]` here is to ensure this is appropriately aligned for T let mut rawarray = MaybeUninit::<(BufType, [T; 0])>::uninit(); |