ICC error on __m256 access

Hi, I have this simple program where I try to store a floating point number in a __m256 variable from AVX

#include <stdio.h>
#include <stdlib.h>

#include <x86intrin.h>


#ifndef __AVX__
#error AVX not defined
#endif

int main( int argc, char *argv[] )
{
        __m256 RR;
        __m256 BB;

        RR.m256_f32[0] = 1.0;
        BB.m256_f32[0] = 1.0;

        return 0;
}

But when I compile with ICC i get:

$ icc -march=native -g -O0 -std=c99 -g intel_test_a.c -o intel_test_a -rdynamic -ldl

intel_test_a.c(42): error: expression must have struct or union type

        RR.m256_f32[0] = 1.0;

        ^

intel_test_a.c(43): error: expression must have struct or union type

        BB.m256_f32[0] = 1.0;

        ^

compilation aborted for intel_test_a.c (code 2)

just wonder what I'm doing wrong? I am using linux (debian).

Thanks