[Bug tree-optimization/41881] Complete unrolling (inner) versus vectorization of reduction

[rguenth at gcc dot gnu dot org]

------- Comment #4 from rguenth at gcc dot gnu dot org  2009-10-30 22:50 -------
But:

static unsigned int
tree_complete_unroll_inner (void)
{
  unsigned ret = 0;

  loop_optimizer_init (LOOPS_NORMAL
                       | LOOPS_HAVE_RECORDED_EXITS);
  if (number_of_loops () > 1)
    {
      scev_initialize ();
      ret = tree_unroll_loops_completely (optimize >= 3, false);

so it will not allow the body to increase in code-size when not
compiling with -O3.  Unrolling the loop in your example does
increase code size.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41881