gcc/testsuite/gcc.dg/pr87320.c

/* PR tree-optimization/87320 */
/* { dg-do run } */
/* { dg-require-effective-target alloca } */
/* { dg-options "-O3" } */
/* { dg-additional-options "-mavx" { target avx_runtime } } */

static void __attribute__ ((noinline))
transpose_vector (unsigned long n)
{
  unsigned long data[2 * n];
  for (unsigned long i = 0; i < 2 * n; i++)
    data[i] = 4 * i + 2;

  unsigned long transposed[n];
  for (unsigned long i = 0; i < n; i++)
    transposed[i] = data[2 * i];

  for (unsigned long i = 0; i < n; i++)
    if (transposed[i] != 8 * i + 2)
      __builtin_abort ();
}

int
main ()
{
  transpose_vector (4);
  transpose_vector (120);
  return 0;
}