From 2176c9387e24cb269e25126ef44dc53faef3cff1 Mon Sep 17 00:00:00 2001
From: 87 <dev@87flowers.com>
Date: Sat, 16 Aug 2025 22:41:55 +0100
Subject: [PATCH] Add performance warning comment for vpcompressw

closes https://github.com/official-stockfish/Stockfish/pull/6237

No functional change
---
 src/movegen.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/movegen.cpp b/src/movegen.cpp
index 10adc70be..697a83cdf 100644
--- a/src/movegen.cpp
+++ b/src/movegen.cpp
@@ -37,6 +37,7 @@ namespace {
 #if defined(USE_AVX512ICL)
 
 inline Move* write_moves(Move* moveList, uint32_t mask, __m512i vector) {
+    // Avoid _mm512_mask_compressstoreu_epi16() as it's 256 uOps on Zen4
     _mm512_storeu_si512(reinterpret_cast<__m512i*>(moveList),
                         _mm512_maskz_compress_epi16(mask, vector));
     return moveList + popcount(mask);