Preserve resolve_obligations_as_possible temporary allocation across calls

This commit is contained in:
Lukas Wirth 2023-08-10 20:11:03 +02:00
parent 05b0612051
commit c1c8e787d2

View file

@ -143,6 +143,9 @@ pub(crate) struct InferenceTable<'a> {
var_unification_table: ChalkInferenceTable,
type_variable_table: Vec<TypeVariableFlags>,
pending_obligations: Vec<Canonicalized<InEnvironment<Goal>>>,
/// Double buffer used in [`Self::resolve_obligations_as_possible`] to cut down on
/// temporary allocations.
resolve_obligations_buffer: Vec<Canonicalized<InEnvironment<Goal>>>,
}
pub(crate) struct InferenceTableSnapshot {
@ -159,6 +162,7 @@ impl<'a> InferenceTable<'a> {
var_unification_table: ChalkInferenceTable::new(),
type_variable_table: Vec::new(),
pending_obligations: Vec::new(),
resolve_obligations_buffer: Vec::new(),
}
}
@ -510,10 +514,10 @@ impl<'a> InferenceTable<'a> {
pub(crate) fn resolve_obligations_as_possible(&mut self) {
let _span = profile::span("resolve_obligations_as_possible");
let mut changed = true;
let mut obligations = Vec::new();
while changed {
changed = false;
let mut obligations = mem::take(&mut self.resolve_obligations_buffer);
while mem::take(&mut changed) {
mem::swap(&mut self.pending_obligations, &mut obligations);
for canonicalized in obligations.drain(..) {
if !self.check_changed(&canonicalized) {
self.pending_obligations.push(canonicalized);
@ -528,6 +532,8 @@ impl<'a> InferenceTable<'a> {
self.register_obligation_in_env(uncanonical);
}
}
self.resolve_obligations_buffer = obligations;
self.resolve_obligations_buffer.clear();
}
pub(crate) fn fudge_inference<T: TypeFoldable<Interner>>(