From 461e07822a3cdfac8a27c3d891fb05404805166e Mon Sep 17 00:00:00 2001
From: Andrew Noyes <andrew@weaselab.dev>
Date: Sat, 29 Jun 2024 15:10:05 -0700
Subject: [PATCH] 32-bit x86 simd for the other scan16 too

---
 ConflictSet.cpp | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/ConflictSet.cpp b/ConflictSet.cpp
index df9be5e..9c2d62b 100644
--- a/ConflictSet.cpp
+++ b/ConflictSet.cpp
@@ -1895,6 +1895,20 @@ inline __attribute((always_inline)) bool scan16(const InternalVersionT *vs,
   conflict &= end == 16 ? -1 : (uint64_t(1) << (end << 2)) - 1;
   conflict >>= begin << 2;
   return !conflict;
+#elif INTERNAL_VERSION_32_BIT && defined(HAS_AVX)
+  __m128i w4[4];
+  memcpy(w4, vs, sizeof(w4));
+  uint32_t rv;
+  memcpy(&rv, &readVersion, sizeof(rv));
+  const auto rvVec = _mm_set1_epi32(rv);
+  const auto zero = _mm_setzero_si128();
+  uint32_t conflict = 0;
+  for (int i = 0; i < 4; ++i) {
+    conflict |= _mm_movemask_ps(_mm_cmpgt_epi32(_mm_sub_epi32(w4[i], rvVec), zero)) << (i * 4);
+  }
+  conflict &= (1 << end) - 1;
+  conflict >>= begin;
+  return !conflict;
 #else
   uint64_t conflict = 0;
   for (int i = 0; i < 16; ++i) {