diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src/lib.rs')
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index c0a09b7a761..c42888d8791 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -613,6 +613,15 @@ fn inner_optimized_mir(tcx: TyCtxt<'_>, did: LocalDefId) -> Body<'_> { return body; } + // If `mir_drops_elaborated_and_const_checked` found that the current body has unsatisfiable + // predicates, it will shrink the MIR to a single `unreachable` terminator. + // More generally, if MIR is a lone `unreachable`, there is nothing to optimize. + if let TerminatorKind::Unreachable = body.basic_blocks[START_BLOCK].terminator().kind + && body.basic_blocks[START_BLOCK].statements.is_empty() + { + return body; + } + run_optimization_passes(tcx, &mut body); body |