From abdc839367e3f9a27e864907b2bf6b6a9d232b89 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Sun, 3 Apr 2016 10:41:28 +0200
Subject: [PATCH] Workaround for old gcc versions missing
 _mm256_broadcastsi128_si256()

Some old gcc versions define vbroadcasti128 as
_mm_broadcastsi128_si256() not _mm256_broadcastsi128_si256().

Detect this, and use _mm_broadcastsi128_si256() in that case.
---
 configure.ac | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 656bec2a..782a4b4e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -379,7 +379,17 @@ AS_IF([test "x$EMSCRIPTEN" = "x"],[
 ]], [[ __m256i x = _mm256_abs_epi8(_mm256_setzero_si256()); ]])],
     [AC_MSG_RESULT(yes)
      AC_DEFINE([HAVE_AVX2INTRIN_H], [1], [AVX2 is available])
-     AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS_AVX="-mavx2"])],
+     AX_CHECK_COMPILE_FLAG([-mavx2], [CFLAGS_AVX="-mavx2"])
+     AC_MSG_CHECKING(if _mm256_broadcastsi128_si256 is correctly defined)
+     AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
+#pragma GCC target("avx2")
+#include <immintrin.h>
+     ]], [[ __m256i y = _mm256_broadcastsi128_si256(_mm_setzero_si128()); ]])],
+       [AC_MSG_RESULT(yes)],
+       [AC_MSG_RESULT(no)
+        AC_DEFINE([_mm256_broadcastsi128_si256], [_mm_broadcastsi128_si256],
+                  [Define to the local name of _mm256_broadcastsi128_si256])])
+     ],
     [AC_MSG_RESULT(no)])
   CFLAGS="$oldcflags"