From e68d8cea9b41947664b36803cd901651ded6f5f6 Mon Sep 17 00:00:00 2001
From: Matthias Hochsteger <mhochsteger@cerbsim.com>
Date: Wed, 16 Dec 2020 10:57:20 +0100
Subject: [PATCH] workaround for missing intrinsic on GCC 7

---
 libsrc/core/simd_avx.hpp | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/libsrc/core/simd_avx.hpp b/libsrc/core/simd_avx.hpp
index f089a0b2..3f83dae6 100644
--- a/libsrc/core/simd_avx.hpp
+++ b/libsrc/core/simd_avx.hpp
@@ -11,6 +11,15 @@
 
 namespace ngcore
 {
+
+#if defined(__GNUC__) && (__GNUC__ == 7)
+  // GCC7 does not have intrinsic _mm256_set_m128i, see
+  // https://stackoverflow.com/questions/32630458/setting-m256i-to-the-value-of-two-m128i-values
+  NETGEN_INLINE auto _mm256_set_m128i(__m128i v0, __m128i v1) {
+      return _mm256_insertf128_si256(_mm256_castsi128_si256(v1), (v0), 1);
+  }
+#endif // defined(__GNUC__) && (__GNUC__ == 7)
+
 #if defined(__AVX2__)
   NETGEN_INLINE __m256i my_mm256_cmpgt_epi64 (__m256i a, __m256i b)
   {