diff options
Diffstat (limited to 'compiler/rustc_mir_transform/src')
| -rw-r--r-- | compiler/rustc_mir_transform/src/coroutine/by_move_body.rs | 5 | ||||
| -rw-r--r-- | compiler/rustc_mir_transform/src/dest_prop.rs | 113 |
2 files changed, 49 insertions, 69 deletions
diff --git a/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs b/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs index ebe8d2eff4f..cf39c136b01 100644 --- a/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs +++ b/compiler/rustc_mir_transform/src/coroutine/by_move_body.rs @@ -207,11 +207,12 @@ pub fn coroutine_by_move_body_def_id<'tcx>( let mut by_move_body = body.clone(); MakeByMoveBody { tcx, field_remapping, by_move_coroutine_ty }.visit_body(&mut by_move_body); - dump_mir(tcx, false, "coroutine_by_move", &0, &by_move_body, |_, _| Ok(())); - let body_def = tcx.create_def(coroutine_def_id, kw::Empty, DefKind::SyntheticCoroutineBody); + // This will always be `{closure#1}`, since the original coroutine is `{closure#0}`. + let body_def = tcx.create_def(parent_def_id, kw::Empty, DefKind::SyntheticCoroutineBody); by_move_body.source = mir::MirSource::from_instance(InstanceKind::Item(body_def.def_id().to_def_id())); + dump_mir(tcx, false, "built", &"after", &by_move_body, |_, _| Ok(())); // Inherited from the by-ref coroutine. body_def.codegen_fn_attrs(tcx.codegen_fn_attrs(coroutine_def_id).clone()); diff --git a/compiler/rustc_mir_transform/src/dest_prop.rs b/compiler/rustc_mir_transform/src/dest_prop.rs index 8940a21d7fa..67bee36b8a5 100644 --- a/compiler/rustc_mir_transform/src/dest_prop.rs +++ b/compiler/rustc_mir_transform/src/dest_prop.rs @@ -163,7 +163,8 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation { fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) { let def_id = body.source.def_id(); - let mut allocations = Allocations::default(); + let mut candidates = Candidates::default(); + let mut write_info = WriteInfo::default(); trace!(func = ?tcx.def_path_str(def_id)); let borrowed = rustc_mir_dataflow::impls::borrowed_locals(body); @@ -191,12 +192,7 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation { loop { // PERF: Can we do something smarter than recalculating the candidates and liveness // results? - let mut candidates = find_candidates( - body, - &borrowed, - &mut allocations.candidates, - &mut allocations.candidates_reverse, - ); + candidates.reset_and_find(body, &borrowed); trace!(?candidates); dest_prop_mir_dump(tcx, body, &points, &live, round_count); @@ -204,7 +200,7 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation { &mut candidates, &points, &live, - &mut allocations.write_info, + &mut write_info, body, ); @@ -253,20 +249,8 @@ impl<'tcx> crate::MirPass<'tcx> for DestinationPropagation { } } -/// Container for the various allocations that we need. -/// -/// We store these here and hand out `&mut` access to them, instead of dropping and recreating them -/// frequently. Everything with a `&'alloc` lifetime points into here. -#[derive(Default)] -struct Allocations { - candidates: FxIndexMap<Local, Vec<Local>>, - candidates_reverse: FxIndexMap<Local, Vec<Local>>, - write_info: WriteInfo, - // PERF: Do this for `MaybeLiveLocals` allocations too. -} - -#[derive(Debug)] -struct Candidates<'alloc> { +#[derive(Debug, Default)] +struct Candidates { /// The set of candidates we are considering in this optimization. /// /// We will always merge the key into at most one of its values. @@ -281,11 +265,12 @@ struct Candidates<'alloc> { /// /// We will still report that we would like to merge `_1` and `_2` in an attempt to allow us to /// remove that assignment. - c: &'alloc mut FxIndexMap<Local, Vec<Local>>, + c: FxIndexMap<Local, Vec<Local>>, + /// A reverse index of the `c` set; if the `c` set contains `a => Place { local: b, proj }`, /// then this contains `b => a`. // PERF: Possibly these should be `SmallVec`s? - reverse: &'alloc mut FxIndexMap<Local, Vec<Local>>, + reverse: FxIndexMap<Local, Vec<Local>>, } ////////////////////////////////////////////////////////// @@ -358,19 +343,40 @@ impl<'a, 'tcx> MutVisitor<'tcx> for Merger<'a, 'tcx> { // // This section enforces bullet point 2 -struct FilterInformation<'a, 'body, 'alloc, 'tcx> { - body: &'body Body<'tcx>, +struct FilterInformation<'a, 'tcx> { + body: &'a Body<'tcx>, points: &'a DenseLocationMap, live: &'a SparseIntervalMatrix<Local, PointIndex>, - candidates: &'a mut Candidates<'alloc>, - write_info: &'alloc mut WriteInfo, + candidates: &'a mut Candidates, + write_info: &'a mut WriteInfo, at: Location, } // We first implement some utility functions which we will expose removing candidates according to // different needs. Throughout the liveness filtering, the `candidates` are only ever accessed // through these methods, and not directly. -impl<'alloc> Candidates<'alloc> { +impl Candidates { + /// Collects the candidates for merging. + /// + /// This is responsible for enforcing the first and third bullet point. + fn reset_and_find<'tcx>(&mut self, body: &Body<'tcx>, borrowed: &BitSet<Local>) { + self.c.clear(); + self.reverse.clear(); + let mut visitor = FindAssignments { body, candidates: &mut self.c, borrowed }; + visitor.visit_body(body); + // Deduplicate candidates. + for (_, cands) in self.c.iter_mut() { + cands.sort(); + cands.dedup(); + } + // Generate the reverse map. + for (src, cands) in self.c.iter() { + for dest in cands.iter().copied() { + self.reverse.entry(dest).or_default().push(*src); + } + } + } + /// Just `Vec::retain`, but the condition is inverted and we add debugging output fn vec_filter_candidates( src: Local, @@ -445,7 +451,7 @@ enum CandidateFilter { Remove, } -impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx> { +impl<'a, 'tcx> FilterInformation<'a, 'tcx> { /// Filters the set of candidates to remove those that conflict. /// /// The steps we take are exactly those that are outlined at the top of the file. For each @@ -463,12 +469,12 @@ impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx> { /// before the statement/terminator will correctly report locals that are read in the /// statement/terminator to be live. We are additionally conservative by treating all written to /// locals as also being read from. - fn filter_liveness<'b>( - candidates: &mut Candidates<'alloc>, + fn filter_liveness( + candidates: &mut Candidates, points: &DenseLocationMap, live: &SparseIntervalMatrix<Local, PointIndex>, - write_info_alloc: &'alloc mut WriteInfo, - body: &'b Body<'tcx>, + write_info: &mut WriteInfo, + body: &Body<'tcx>, ) { let mut this = FilterInformation { body, @@ -477,7 +483,7 @@ impl<'a, 'body, 'alloc, 'tcx> FilterInformation<'a, 'body, 'alloc, 'tcx> { candidates, // We don't actually store anything at this scope, we just keep things here to be able // to reuse the allocation. - write_info: write_info_alloc, + write_info, // Doesn't matter what we put here, will be overwritten before being used at: Location::START, }; @@ -734,40 +740,13 @@ fn places_to_candidate_pair<'tcx>( Some((a, b)) } -/// Collects the candidates for merging -/// -/// This is responsible for enforcing the first and third bullet point. -fn find_candidates<'alloc, 'tcx>( - body: &Body<'tcx>, - borrowed: &BitSet<Local>, - candidates: &'alloc mut FxIndexMap<Local, Vec<Local>>, - candidates_reverse: &'alloc mut FxIndexMap<Local, Vec<Local>>, -) -> Candidates<'alloc> { - candidates.clear(); - candidates_reverse.clear(); - let mut visitor = FindAssignments { body, candidates, borrowed }; - visitor.visit_body(body); - // Deduplicate candidates - for (_, cands) in candidates.iter_mut() { - cands.sort(); - cands.dedup(); - } - // Generate the reverse map - for (src, cands) in candidates.iter() { - for dest in cands.iter().copied() { - candidates_reverse.entry(dest).or_default().push(*src); - } - } - Candidates { c: candidates, reverse: candidates_reverse } -} - -struct FindAssignments<'a, 'alloc, 'tcx> { +struct FindAssignments<'a, 'tcx> { body: &'a Body<'tcx>, - candidates: &'alloc mut FxIndexMap<Local, Vec<Local>>, + candidates: &'a mut FxIndexMap<Local, Vec<Local>>, borrowed: &'a BitSet<Local>, } -impl<'tcx> Visitor<'tcx> for FindAssignments<'_, '_, 'tcx> { +impl<'tcx> Visitor<'tcx> for FindAssignments<'_, 'tcx> { fn visit_statement(&mut self, statement: &Statement<'tcx>, _: Location) { if let StatementKind::Assign(box ( lhs, @@ -819,9 +798,9 @@ fn is_local_required(local: Local, body: &Body<'_>) -> bool { ///////////////////////////////////////////////////////// // MIR Dump -fn dest_prop_mir_dump<'body, 'tcx>( +fn dest_prop_mir_dump<'tcx>( tcx: TyCtxt<'tcx>, - body: &'body Body<'tcx>, + body: &Body<'tcx>, points: &DenseLocationMap, live: &SparseIntervalMatrix<Local, PointIndex>, round: usize, |