benches: expand argon2 benchmarks varying p_cost

Additionally, use a set instead of trying to avoid repeating a
particular set of params by hand.

benches/src/argon2.rs

@@ -1,3 +1,5 @@
+use std::collections::HashSet;
+
 use argon2::*;
 use criterion::{black_box, criterion_group, criterion_main, Criterion};
 use pprof::criterion::{Output, PProfProfiler};
@@ -26,46 +28,26 @@ fn bench_default_params(c: &mut Criterion) {
     }
 }
 
-fn bench_vary_m(c: &mut Criterion) {
-    let t_cost = 4;
-    let p_cost = 4;
-    for m_cost in [2 * 1024, 16 * 1024, 64 * 1024, 256 * 1024] {
-        let test_name = format!("argon2id V0x13 m={m_cost} t={t_cost} p={p_cost}");
-        c.bench_function(&test_name, |b| {
-            let mut out = [0u8; 32];
-            let params = Params::new(m_cost, t_cost, p_cost, Some(32)).unwrap();
-            let argon2 = Argon2::new(Algorithm::Argon2id, Version::V0x13, params);
-            b.iter(|| {
-                argon2
-                    .hash_password_into(black_box(BENCH_PASSWORD), black_box(BENCH_SALT), &mut out)
-                    .unwrap()
-            })
-        });
+fn bench_vary_params(c: &mut Criterion) {
+    let mut tests = HashSet::new();
+    // Vary `m_cost`.
+    for m_cost in [2 * 1024, 16 * 1024, 32 * 1024, 64 * 1024, 256 * 1024] {
+        tests.insert((m_cost, 4, 4));
     }
-}
-
-fn bench_vary_t(c: &mut Criterion) {
-    let m_cost = 32 * 1024;
-    let p_cost = 4;
-    for t_cost in [2, 8, 16, 24] {
-        let test_name = format!("argon2id V0x13 m={m_cost} t={t_cost} p={p_cost}");
-        c.bench_function(&test_name, |b| {
-            let mut out = [0u8; 32];
-            let params = Params::new(m_cost, t_cost, p_cost, Some(32)).unwrap();
-            let argon2 = Argon2::new(Algorithm::Argon2id, Version::V0x13, params);
-            b.iter(|| {
-                argon2
-                    .hash_password_into(black_box(BENCH_PASSWORD), black_box(BENCH_SALT), &mut out)
-                    .unwrap()
-            })
-        });
+    // Vary `t_cost`.
+    for t_cost in [1, 2, 4, 8, 16] {
+        tests.insert((32 * 1024, t_cost, 4));
     }
-}
-
-fn bench_vary_p(c: &mut Criterion) {
-    let m_cost = 32 * 1024;
-    let t_cost = 4;
-    for p_cost in [2, 8, 16, 64] {
+    // Vary `p_cost`.
+    for p_cost in [1, 2, 4, 8, 16] {
+        for m_mib in [256 * 1024, 1024 * 1024] {
+            tests.insert((m_mib, 1, p_cost));
+        }
+        for t_cost in [1, 2, 4] {
+            tests.insert((32 * 1024, t_cost, p_cost));
+        }
+    }
+    for (m_cost, t_cost, p_cost) in tests {
         let test_name = format!("argon2id V0x13 m={m_cost} t={t_cost} p={p_cost}");
         c.bench_function(&test_name, |b| {
             let mut out = [0u8; 32];
@@ -85,8 +67,6 @@ criterion_group!(
     config = Criterion::default().with_profiler(PProfProfiler::new(300, Output::Flamegraph(None)));
     targets =
     bench_default_params,
-    bench_vary_m,
-    bench_vary_t,
-    bench_vary_p,
+    bench_vary_params,
 );
 criterion_main!(benches);