Use ahash for IndexMap and IndexSet hasher (#12935)

The ahash hasher offers better performace as a drop in replacement for
the stdlib hash algorithm. This is a large reason we use the hashbrown
crate for our HashMap type in Qiskit (along with rayon support). The
indexmap crate doesn't use ahash by default however, so we typically
switch to it anywhere we use IndexMap or IndexSet to match the lookup
performance of hashbrown in places where we need to preserve insertion
order. However, there were a couple of spots where we missed this in the
rust code, this commit corrects these oversights.

Cargo.toml

@@ -23,6 +23,7 @@ ndarray = "^0.15.6"
 numpy = "0.21.0"
 smallvec = "1.13"
 thiserror = "1.0"
+ahash = "0.8.11"
 
 # Most of the crates don't need the feature `extension-module`, since only `qiskit-pyext` builds an
 # actual C extension (the feature disables linking in `libpython`, which is forbidden in Python

crates/accelerate/Cargo.toml

@@ -15,7 +15,7 @@ numpy.workspace = true
 rand = "0.8"
 rand_pcg = "0.3"
 rand_distr = "0.4.3"
-ahash = "0.8.11"
+ahash.workspace = true
 num-traits = "0.2"
 num-complex.workspace = true
 num-bigint.workspace = true

crates/accelerate/src/synthesis/clifford/greedy_synthesis.rs

@@ -10,6 +10,7 @@
 // copyright notice, and modified files need to carry a notice indicating
 // that they have been altered from the originals.
 
+use ahash::RandomState;
 use indexmap::IndexSet;
 use ndarray::{s, ArrayView2};
 use smallvec::smallvec;
@@ -102,7 +103,7 @@ pub struct GreedyCliffordSynthesis<'a> {
     symplectic_matrix: SymplecticMatrix,
 
     /// Unprocessed qubits.
-    unprocessed_qubits: IndexSet<usize>,
+    unprocessed_qubits: IndexSet<usize, RandomState>,
 }
 
 impl GreedyCliffordSynthesis<'_> {
@@ -121,7 +122,7 @@ impl GreedyCliffordSynthesis<'_> {
             smat: tableau.slice(s![.., 0..2 * num_qubits]).to_owned(),
         };
 
-        let unprocessed_qubits: IndexSet<usize> = (0..num_qubits).collect();
+        let unprocessed_qubits = (0..num_qubits).collect();
 
         Ok(GreedyCliffordSynthesis {
             tableau,

crates/qasm3/Cargo.toml

@@ -14,3 +14,4 @@ pyo3.workspace = true
 indexmap.workspace = true
 hashbrown.workspace = true
 oq3_semantics = "0.6.0"
+ahash.workspace = true

crates/qasm3/src/build.rs

@@ -13,6 +13,8 @@
 use pyo3::prelude::*;
 use pyo3::types::{PySequence, PyString, PyTuple};
 
+use ahash::RandomState;
+
 use hashbrown::HashMap;
 use indexmap::IndexMap;
 
@@ -190,8 +192,9 @@ impl BuilderState {
         let qubits = if let Some(asg_qubits) = barrier.qubits().as_ref() {
             // We want any deterministic order for easier circuit reproducibility in Python space,
             // and to include each seen qubit once.  This simply maintains insertion order.
-            let mut qubits = IndexMap::<*const ::pyo3::ffi::PyObject, Py<PyAny>>::with_capacity(
+            let mut qubits = IndexMap::<*const ::pyo3::ffi::PyObject, Py<PyAny>, RandomState>::with_capacity_and_hasher(
                 asg_qubits.len(),
+                RandomState::default()
             );
             for qarg in asg_qubits.iter() {
                 let qarg = expr::expect_gate_operand(qarg)?;