diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src')
| -rw-r--r-- | compiler/rustc_mir_transform/src/lib.rs | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs index 43c5b3873b9..ce9043ec287 100644 --- a/compiler/rustc_mir_transform/src/lib.rs +++ b/compiler/rustc_mir_transform/src/lib.rs @@ -566,17 +566,28 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { body, &[ &check_alignment::CheckAlignment, - &lower_slice_len::LowerSliceLenCalls, // has to be done before inlining, otherwise actual call will be almost always inlined. Also simple, so can just do first + // Before inlining: trim down MIR with passes to reduce inlining work. + + // Has to be done before inlining, otherwise actual call will be almost always inlined. + // Also simple, so can just do first + &lower_slice_len::LowerSliceLenCalls, + // Perform inlining, which may add a lot of code. &inline::Inline, - // Substitutions during inlining may introduce switch on enums with uninhabited branches. + // Code from other crates may have storage markers, so this needs to happen after inlining. + &remove_storage_markers::RemoveStorageMarkers, + // Inlining and substitution may introduce ZST and useless drops. + &remove_zsts::RemoveZsts, + &remove_unneeded_drops::RemoveUnneededDrops, + // Type substitution may create uninhabited enums. &uninhabited_enum_branching::UninhabitedEnumBranching, &unreachable_prop::UnreachablePropagation, &o1(simplify::SimplifyCfg::AfterUninhabitedEnumBranching), - &remove_storage_markers::RemoveStorageMarkers, - &remove_zsts::RemoveZsts, - &normalize_array_len::NormalizeArrayLen, // has to run after `slice::len` lowering + // Inlining may have introduced a lot of redundant code and a large move pattern. + // Now, we need to shrink the generated MIR. + + // Has to run after `slice::len` lowering + &normalize_array_len::NormalizeArrayLen, &const_goto::ConstGoto, - &remove_unneeded_drops::RemoveUnneededDrops, &ref_prop::ReferencePropagation, &sroa::ScalarReplacementOfAggregates, &match_branches::MatchBranchSimplification, |