Weird warning

[Marcel Keller <M.Keller@xxxxxxxxxxxxx>]

Hi,

Running avx-bug.cpp compiled with GCC 6.2 and -mavx results in a 
segfault here. The same happens with avx-bug2.cpp, but there I get the 
following warning when compiling:

avx-bug2.cpp: In function ‘int main()’:
avx-bug2.cpp:6:22: warning: ignoring attributes on template argument 
‘__m256i {aka __vector(4) long long int}’ [-Wignored-attributes]
   std::vector<__m256i> v(10000);
                      ^

I'm a bit confused what I should do about the warning and why it doesn't 
appear in the functionally equivalent code.

Best regards,
Marcel

#include <vector>
#include <immintrin.h>

struct U {
  __m256i a;
};

int main()
{
  std::vector<U> v(10000);
}

#include <vector>
#include <immintrin.h>

int main()
{
  std::vector<__m256i> v(10000);
}