Auto merge of #119499 - cjgillot:dtm-opt, r=nnethercote

Two small bitset optimisations
This commit is contained in:
bors 2024-01-06 11:54:15 +00:00
commit efb3f11087
2 changed files with 15 additions and 18 deletions

View File

@ -1699,14 +1699,15 @@ impl<R: Idx, C: Idx> BitMatrix<R, C> {
let (read_start, read_end) = self.range(read);
let (write_start, write_end) = self.range(write);
let words = &mut self.words[..];
let mut changed = false;
let mut changed = 0;
for (read_index, write_index) in iter::zip(read_start..read_end, write_start..write_end) {
let word = words[write_index];
let new_word = word | words[read_index];
words[write_index] = new_word;
changed |= word != new_word;
// See `bitwise` for the rationale.
changed |= word ^ new_word;
}
changed
changed != 0
}
/// Adds the bits from `with` to the bits from row `write`, and
@ -1715,14 +1716,7 @@ impl<R: Idx, C: Idx> BitMatrix<R, C> {
assert!(write.index() < self.num_rows);
assert_eq!(with.domain_size(), self.num_columns);
let (write_start, write_end) = self.range(write);
let mut changed = false;
for (read_index, write_index) in iter::zip(0..with.words.len(), write_start..write_end) {
let word = self.words[write_index];
let new_word = word | with.words[read_index];
self.words[write_index] = new_word;
changed |= word != new_word;
}
changed
bitwise(&mut self.words[write_start..write_end], &with.words, |a, b| a | b)
}
/// Sets every cell in `row` to true.

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@ -942,6 +942,7 @@ fn compute_storage_conflicts<'mir, 'tcx>(
body,
saved_locals: saved_locals,
local_conflicts: BitMatrix::from_row_n(&ineligible_locals, body.local_decls.len()),
eligible_storage_live: BitSet::new_empty(body.local_decls.len()),
};
requires_storage.visit_reachable_with(body, &mut visitor);
@ -978,6 +979,8 @@ struct StorageConflictVisitor<'mir, 'tcx, 's> {
// FIXME(tmandry): Consider using sparse bitsets here once we have good
// benchmarks for coroutines.
local_conflicts: BitMatrix<Local, Local>,
// We keep this bitset as a buffer to avoid reallocating memory.
eligible_storage_live: BitSet<Local>,
}
impl<'mir, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'mir, 'tcx, R>
@ -1009,19 +1012,19 @@ impl<'mir, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'mir, 'tcx, R>
impl StorageConflictVisitor<'_, '_, '_> {
fn apply_state(&mut self, flow_state: &BitSet<Local>, loc: Location) {
// Ignore unreachable blocks.
if self.body.basic_blocks[loc.block].terminator().kind == TerminatorKind::Unreachable {
if let TerminatorKind::Unreachable = self.body.basic_blocks[loc.block].terminator().kind {
return;
}
let mut eligible_storage_live = flow_state.clone();
eligible_storage_live.intersect(&**self.saved_locals);
self.eligible_storage_live.clone_from(flow_state);
self.eligible_storage_live.intersect(&**self.saved_locals);
for local in eligible_storage_live.iter() {
self.local_conflicts.union_row_with(&eligible_storage_live, local);
for local in self.eligible_storage_live.iter() {
self.local_conflicts.union_row_with(&self.eligible_storage_live, local);
}
if eligible_storage_live.count() > 1 {
trace!("at {:?}, eligible_storage_live={:?}", loc, eligible_storage_live);
if self.eligible_storage_live.count() > 1 {
trace!("at {:?}, eligible_storage_live={:?}", loc, self.eligible_storage_live);
}
}
}