From 93d8f8eefe14aca5ca5750049f042b58801b55d8 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Tue, 30 Dec 2025 09:52:00 +0100
Subject: [PATCH] Using _mm_add_epi8(a, a) is cleaner than the shift+mask

---
 src/libsodium/crypto_ipcrypt/ipcrypt_aesni.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/libsodium/crypto_ipcrypt/ipcrypt_aesni.c b/src/libsodium/crypto_ipcrypt/ipcrypt_aesni.c
index 73cf7ce0..e86081b3 100644
--- a/src/libsodium/crypto_ipcrypt/ipcrypt_aesni.c
+++ b/src/libsodium/crypto_ipcrypt/ipcrypt_aesni.c
@@ -317,10 +317,8 @@ static void
 pfx_shift_left(uint8_t ip16[16])
 {
     BlockVec       v       = LOAD128(ip16);
-    const BlockVec mask_fe = _mm_set1_epi8((char) 0xfe);
-    const BlockVec mask_01 = _mm_set1_epi8(0x01);
-    const BlockVec shl     = _mm_and_si128(_mm_slli_epi16(v, 1), mask_fe);
-    const BlockVec msb     = _mm_and_si128(_mm_srli_epi16(v, 7), mask_01);
+    const BlockVec shl     = _mm_add_epi8(v, v);
+    const BlockVec msb     = _mm_and_si128(_mm_srli_epi16(v, 7), _mm_set1_epi8(0x01));
     const BlockVec carries = _mm_srli_si128(msb, 1);
     v                      = _mm_or_si128(shl, carries);
     STORE128(ip16, v);