[Bug target/63503] [AArch64] A57 executes fused multiply-add poorly in some situations

[e.menezes at samsung dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63503

--- Comment #4 from Evandro Menezes <e.menezes at samsung dot com> ---
Here's a simplified code to reproduce these results:

double sum(double *A, double *B, int n) 
{
  int i;
  double res = 0;

  for (i = 0; i < n; i++)
    res += A [i] * B [i];

  return res;
}