diff options
| -rw-r--r-- | compiler/rustc_mir_transform/src/unreachable_enum_branching.rs | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/compiler/rustc_mir_transform/src/unreachable_enum_branching.rs b/compiler/rustc_mir_transform/src/unreachable_enum_branching.rs index 52bd0bea37d..66b6235eb93 100644 --- a/compiler/rustc_mir_transform/src/unreachable_enum_branching.rs +++ b/compiler/rustc_mir_transform/src/unreachable_enum_branching.rs @@ -175,7 +175,10 @@ impl<'tcx> MirPass<'tcx> for UnreachableEnumBranching { // ``` let otherwise_is_last_variant = !otherwise_is_empty_unreachable && allowed_variants.len() == 1 - && check_successors(&body.basic_blocks, targets.otherwise()); + // Despite the LLVM issue, we hope that small enum can still be transformed. + // This is valuable for both `a <= b` and `if let Some/Ok(v)`. + && (targets.all_targets().len() <= 3 + || check_successors(&body.basic_blocks, targets.otherwise())); let replace_otherwise_to_unreachable = otherwise_is_last_variant || (!otherwise_is_empty_unreachable && allowed_variants.is_empty()); |