avutil: add alignment needed for AVX-512

libavutil/mem.c

@@ -61,7 +61,7 @@ void  free(void *ptr);
 
 #include "mem_internal.h"
 
-#define ALIGN (HAVE_AVX ? 32 : 16)
+#define ALIGN (HAVE_AVX512 ? 64 : (HAVE_AVX ? 32 : 16))
 
 /* NOTE: if you want to override these functions with your own
  * implementations (not recommended) you have to link libav* as

libavutil/x86/cpu.c

@@ -246,6 +246,8 @@ size_t ff_get_cpu_max_align_x86(void)
 {
     int flags = av_get_cpu_flags();
 
+    if (flags & AV_CPU_FLAG_AVX512)
+        return 64;
     if (flags & (AV_CPU_FLAG_AVX2      |
                  AV_CPU_FLAG_AVX       |
                  AV_CPU_FLAG_XOP       |