Auto merge of #99667 - ouz-a:some_branch, r=oli-obk

Optimize `UnDerefer`

Addresses the performance [issues](https://github.com/rust-lang/rust/pull/98145#issuecomment-1183548597) faced here.

r? `@oli-obk`
This commit is contained in:
bors 2022-07-29 07:11:50 +00:00
commit 7dfdd64433
7 changed files with 22 additions and 28 deletions

View File

@ -215,7 +215,7 @@ fn do_mir_borrowck<'a, 'tcx>(
let (move_data, move_errors): (MoveData<'tcx>, Vec<(Place<'tcx>, MoveError<'tcx>)>) =
match MoveData::gather_moves(&body, tcx, param_env) {
Ok(move_data) => (move_data, Vec::new()),
Ok((_, move_data)) => (move_data, Vec::new()),
Err((move_data, move_errors)) => (move_data, move_errors),
};
let promoted_errors = promoted

View File

@ -1,3 +1,4 @@
use crate::move_paths::FxHashMap;
use crate::un_derefer::UnDerefer;
use rustc_index::vec::IndexVec;
use rustc_middle::mir::tcx::RvalueInitializationState;
@ -206,10 +207,13 @@ impl<'b, 'a, 'tcx> Gatherer<'b, 'a, 'tcx> {
}
}
pub type MoveDat<'tcx> = Result<
(FxHashMap<Local, Place<'tcx>>, MoveData<'tcx>),
(MoveData<'tcx>, Vec<(Place<'tcx>, MoveError<'tcx>)>),
>;
impl<'a, 'tcx> MoveDataBuilder<'a, 'tcx> {
fn finalize(
self,
) -> Result<MoveData<'tcx>, (MoveData<'tcx>, Vec<(Place<'tcx>, MoveError<'tcx>)>)> {
fn finalize(self) -> MoveDat<'tcx> {
debug!("{}", {
debug!("moves for {:?}:", self.body.span);
for (j, mo) in self.data.moves.iter_enumerated() {
@ -222,7 +226,11 @@ impl<'a, 'tcx> MoveDataBuilder<'a, 'tcx> {
"done dumping moves"
});
if !self.errors.is_empty() { Err((self.data, self.errors)) } else { Ok(self.data) }
if self.errors.is_empty() {
Ok((self.un_derefer.derefer_sidetable, self.data))
} else {
Err((self.data, self.errors))
}
}
}
@ -230,7 +238,7 @@ pub(super) fn gather_moves<'tcx>(
body: &Body<'tcx>,
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
) -> Result<MoveData<'tcx>, (MoveData<'tcx>, Vec<(Place<'tcx>, MoveError<'tcx>)>)> {
) -> MoveDat<'tcx> {
let mut builder = MoveDataBuilder::new(body, tcx, param_env);
builder.gather_args();

View File

@ -1,3 +1,4 @@
use crate::move_paths::builder::MoveDat;
use rustc_data_structures::fx::FxHashMap;
use rustc_index::vec::IndexVec;
use rustc_middle::mir::*;
@ -386,7 +387,7 @@ impl<'tcx> MoveData<'tcx> {
body: &Body<'tcx>,
tcx: TyCtxt<'tcx>,
param_env: ParamEnv<'tcx>,
) -> Result<Self, (Self, Vec<(Place<'tcx>, MoveError<'tcx>)>)> {
) -> MoveDat<'tcx> {
builder::gather_moves(body, tcx, param_env)
}

View File

@ -30,7 +30,7 @@ impl<'tcx> MirPass<'tcx> for SanityCheck {
}
let param_env = tcx.param_env(def_id);
let move_data = MoveData::gather_moves(body, tcx, param_env).unwrap();
let (_, move_data) = MoveData::gather_moves(body, tcx, param_env).unwrap();
let mdpe = MoveDataParamEnv { move_data, param_env };
if has_rustc_mir_with(tcx, def_id, sym::rustc_peek_maybe_init).is_some() {

View File

@ -9,6 +9,7 @@ pub struct UnDerefer<'tcx> {
}
impl<'tcx> UnDerefer<'tcx> {
#[inline]
pub fn derefer(&self, place: PlaceRef<'tcx>, body: &Body<'tcx>) -> Option<Place<'tcx>> {
let reffed = self.derefer_sidetable.get(&place.local)?;
@ -18,19 +19,4 @@ impl<'tcx> UnDerefer<'tcx> {
}
Some(new_place)
}
pub fn ref_finder(&mut self, body: &Body<'tcx>) {
for (_bb, data) in body.basic_blocks().iter_enumerated() {
for stmt in data.statements.iter() {
match stmt.kind {
StatementKind::Assign(box (place, Rvalue::CopyForDeref(reffed))) => {
if body.local_decls[place.local].is_deref_temp() {
self.derefer_sidetable.insert(place.local, reffed);
}
}
_ => (),
}
}
}
}
}

View File

@ -28,20 +28,19 @@ impl<'tcx> MirPass<'tcx> for ElaborateDrops {
fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
debug!("elaborate_drops({:?} @ {:?})", body.source, body.span);
let mut un_derefer = UnDerefer { tcx: tcx, derefer_sidetable: Default::default() };
un_derefer.ref_finder(body);
let def_id = body.source.def_id();
let param_env = tcx.param_env_reveal_all_normalized(def_id);
let move_data = match MoveData::gather_moves(body, tcx, param_env) {
let (side_table, move_data) = match MoveData::gather_moves(body, tcx, param_env) {
Ok(move_data) => move_data,
Err((move_data, _)) => {
tcx.sess.delay_span_bug(
body.span,
"No `move_errors` should be allowed in MIR borrowck",
);
move_data
(Default::default(), move_data)
}
};
let un_derefer = UnDerefer { tcx: tcx, derefer_sidetable: side_table };
let elaborate_patch = {
let body = &*body;
let env = MoveDataParamEnv { move_data, param_env };

View File

@ -21,7 +21,7 @@ pub struct RemoveUninitDrops;
impl<'tcx> MirPass<'tcx> for RemoveUninitDrops {
fn run_pass(&self, tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
let param_env = tcx.param_env(body.source.def_id());
let Ok(move_data) = MoveData::gather_moves(body, tcx, param_env) else {
let Ok((_,move_data)) = MoveData::gather_moves(body, tcx, param_env) else {
// We could continue if there are move errors, but there's not much point since our
// init data isn't complete.
return;