bench: cross-library Pauli-propagation benchmark, with truncation-accuracy measurement

.github/workflows/ci.yml

@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v4
 
       # Toolchain for the cargo-fmt / cargo-check / cargo-clippy hooks.
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@1.98.0
         with:
           components: rustfmt, clippy
 
@@ -59,7 +59,9 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@1.98.0
+        with:
+          components: rustfmt, clippy
 
       - uses: Swatinem/rust-cache@v2
 
@@ -85,7 +87,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@1.98.0
         with:
           targets: wasm32-unknown-unknown
 
@@ -101,7 +103,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@1.98.0
 
       - uses: Swatinem/rust-cache@v2
 
@@ -128,7 +130,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@1.98.0
 
       - uses: Swatinem/rust-cache@v2
 

.github/workflows/license-headers.yml

@@ -12,5 +12,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - uses: jdx/mise-action@v2
+
       - name: Check SPDX headers
-        uses: korandoru/hawkeye@v6
+        run: mise exec -- hawkeye check --config licenserc.toml

.github/workflows/rust-docs.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: dtolnay/rust-toolchain@1.98.0
 
       - uses: Swatinem/rust-cache@v2
 

benchmarks/README.md

@@ -87,3 +87,19 @@ uv run --with matplotlib python benchmarks/plot_branch_coalesce.py \
 - `plot_branch_coalesce.py` — left panel: time vs `m` (log-log); right panel:
   sort-merge speedup `t_hash / t_sortmerge` vs `m`, with the crossover line and
   the "hash wins" band.
+
+# Cross-library Pauli propagation
+
+`ppvm` against [PauliPropagation.jl][xpp], [PauliStrings.jl][xps], Qiskit's
+[pauli-prop][xqk] and Algorithmiq's [monoprop][xmp], on TFIM Trotter and
+Heisenberg autocorrelator workloads, all single-threaded and all validated to
+propagate the identical operator term-for-term before anything is timed.
+
+Lives in [`cross-library/`](cross-library/README.md) — see that README for the
+circuit spec, the shared environment contract, the per-engine caveats (notably
+that monoprop is parallel unless capped), and a measured run.
+
+[xpp]: https://github.com/MSRudolph/PauliPropagation.jl
+[xps]: https://github.com/nicolasloizeau/PauliStrings.jl
+[xqk]: https://github.com/Qiskit/pauli-prop
+[xmp]: https://github.com/Algorithmiq/monoprop