Skip to content

Commit

Permalink
fix: nondeterminism in lazify-measure (#766)
Browse files Browse the repository at this point in the history
Co-authored-by: Agustín Borgna <[email protected]>
  • Loading branch information
doug-q and ABorgna authored Feb 12, 2025
1 parent 0e78663 commit d2ad66d
Showing 1 changed file with 6 additions and 2 deletions.
8 changes: 6 additions & 2 deletions tket2-hseries/src/lazify_measure.rs
Original file line number Diff line number Diff line change
Expand Up @@ -125,7 +125,10 @@ impl LazifyMeasureRewrite {
Self::check_signature(node, QSystemOp::LazyMeasure, hugr.get_optype(node))?;

let subgraph = SiblingSubgraph::from_node(node, &hugr);
let uses = hugr.linked_inputs(node, 0).collect_vec();
// SimpleReplacement adds edges in a nondeterministic order. This
// results in linked_inputs returning items in a nondeterministic
// order. We sort them here to restore determinism.
let uses = hugr.linked_inputs(node, 0).sorted().collect_vec();
let (lazy_measure_node, replacement) = {
let bool_uses = uses.len();
let mut builder =
Expand Down Expand Up @@ -165,7 +168,8 @@ impl LazifyMeasureRewrite {
Self::check_signature(node, QSystemOp::LazyMeasureReset, hugr.get_optype(node))?;

let subgraph = SiblingSubgraph::from_node(node, &hugr);
let uses = hugr.linked_inputs(node, 1).collect_vec();
// See comment in try_new_measure
let uses = hugr.linked_inputs(node, 1).sorted().collect_vec();
let (lazy_measure_reset_node, replacement) = {
let bool_uses = uses.len();
let mut builder = {
Expand Down

0 comments on commit d2ad66d

Please sign in to comment.