From 97be5d4d200755c5077684e6ea003d3c452b0b4a Mon Sep 17 00:00:00 2001
From: Hendrik Leppkes <h.leppkes@gmail.com>
Date: Wed, 14 Oct 2015 23:20:09 +0200
Subject: [PATCH] w32pthreads: fix mingw build on x86 with -msse2 or higher

When SSE2 or higher compiler optimizations are used, mingw uses
the _mm_mfence intrinsic for MemoryBarrier, however it doesn't include
the appropriate headers automatically.
---
 compat/w32pthreads.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/compat/w32pthreads.h b/compat/w32pthreads.h
index c25a191f21..3a2f68f2d5 100644
--- a/compat/w32pthreads.h
+++ b/compat/w32pthreads.h
@@ -39,6 +39,11 @@
 #include <windows.h>
 #include <process.h>
 
+/* MinGW requires the intrinsics header for the pthread_once fallback code */
+#if _WIN32_WINNT < 0x0600 && defined(__MINGW32__)
+#include <intrin.h>
+#endif
+
 #include "libavutil/attributes.h"
 #include "libavutil/common.h"
 #include "libavutil/internal.h"
-- 
2.11.0