From 7ff55cc6500e7a32204ffe774d00797f18153547 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C5=91rinc?= <pap.lorinc@gmail.com>
Date: Wed, 15 Jul 2026 13:12:05 -0700
Subject: [PATCH] bench: add fixed-width SipHash benchmarks

Benchmark 32-byte hashes and inputs consisting of a 32-byte hash plus a 32-bit index with SipHash-2-4 and SipHash-1-3-UJ.
The UJ benchmark zero-extends the index into one 64-bit normal block.
Keep all four measurements together after shared correctness coverage and before changing `CCoinsMap`'s hasher.

Co-authored-by: Pieter Wuille <pieter@wuille.net>
---
 src/bench/crypto_hash.cpp | 52 ++++++++++++++++++++++++++++++++++++---
 1 file changed, 49 insertions(+), 3 deletions(-)

diff --git a/src/bench/crypto_hash.cpp b/src/bench/crypto_hash.cpp
index 4d0660db580..827448974fb 100644
--- a/src/bench/crypto_hash.cpp
+++ b/src/bench/crypto_hash.cpp
@@ -190,10 +190,10 @@ static void SHA512(benchmark::Bench& bench)
     });
 }
 
-static void SipHash_32b(benchmark::Bench& bench)
+static void SipHash24_32b(benchmark::Bench& bench)
 {
     FastRandomContext rng{/*fDeterministic=*/true};
-    PresaltedSipHasher presalted_sip_hasher(rng.rand64(), rng.rand64());
+    PresaltedSipHasher presalted_sip_hasher{rng.rand64(), rng.rand64()};
     auto val{rng.rand256()};
     auto i{0U};
     bench.run([&] {
@@ -203,6 +203,49 @@ static void SipHash_32b(benchmark::Bench& bench)
     });
 }
 
+static void SipHash24_36b(benchmark::Bench& bench)
+{
+    FastRandomContext rng{/*fDeterministic=*/true};
+    PresaltedSipHasher presalted_sip_hasher{rng.rand64(), rng.rand64()};
+    auto val{rng.rand256()};
+    uint32_t extra{rng.rand32()};
+    auto i{0U};
+    bench.run([&] {
+        ankerl::nanobench::doNotOptimizeAway(presalted_sip_hasher(val, extra));
+        ++i;
+        val.data()[i % uint256::size()] ^= i & 0xFF;
+        extra += i;
+    });
+}
+
+static void SipHash13UJ_32b(benchmark::Bench& bench)
+{
+    FastRandomContext rng{/*fDeterministic=*/true};
+    SipHasher13UJ sip_hasher{rng.rand64(), rng.rand64()};
+    auto val{rng.rand256()};
+    auto i{0U};
+    bench.run([&] {
+        ankerl::nanobench::doNotOptimizeAway(sip_hasher.Hash(val));
+        ++i;
+        val.data()[i % uint256::size()] ^= i & 0xFF;
+    });
+}
+
+static void SipHash13UJ_36b(benchmark::Bench& bench)
+{
+    FastRandomContext rng{/*fDeterministic=*/true};
+    SipHasher13UJ sip_hasher{rng.rand64(), rng.rand64()};
+    auto val{rng.rand256()};
+    uint32_t extra{rng.rand32()};
+    auto i{0U};
+    bench.run([&] {
+        ankerl::nanobench::doNotOptimizeAway(sip_hasher.Hash(val, uint64_t{extra}));
+        ++i;
+        val.data()[i % uint256::size()] ^= i & 0xFF;
+        extra += i;
+    });
+}
+
 static void MuHash(benchmark::Bench& bench)
 {
     MuHash3072 acc;
@@ -273,7 +316,10 @@ BENCHMARK(SHA256_32b_STANDARD);
 BENCHMARK(SHA256_32b_SSE4);
 BENCHMARK(SHA256_32b_AVX2);
 BENCHMARK(SHA256_32b_SHANI);
-BENCHMARK(SipHash_32b);
+BENCHMARK(SipHash24_32b);
+BENCHMARK(SipHash24_36b);
+BENCHMARK(SipHash13UJ_32b);
+BENCHMARK(SipHash13UJ_36b);
 BENCHMARK(SHA256D64_1024_STANDARD);
 BENCHMARK(SHA256D64_1024_SSE4);
 BENCHMARK(SHA256D64_1024_AVX2);