[Bug tree-optimization/77848] Gimple if-conversion results in redundant comparisons

[rguenther at suse dot de]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77848

--- Comment #10 from rguenther at suse dot de <rguenther at suse dot de> ---
On Fri, 4 Nov 2016, wschmidt at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77848
> 
> --- Comment #8 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
> FYI, the patch I am testing is:
> 
> Index: gcc/tree-if-conv.c
> ===================================================================
> --- gcc/tree-if-conv.c  (revision 241802)
> +++ gcc/tree-if-conv.c  (working copy)
> @@ -2767,8 +2767,7 @@ tree_if_conversion (struct loop *loop)
>           || loop->dont_vectorize))
>      goto cleanup;
> 
> -  if ((any_pred_load_store || any_complicated_phi)
> -      && !version_loop_for_if_conversion (loop))
> +  if (flag_tree_loop_vectorize && !version_loop_for_if_conversion (loop))
>      goto cleanup;

can any_pred_load_store or any_complicated_phi never be true without
flag_tree_loop_vectorize?

Btw, I think we should simply guard if-conversion with
flag_tree_loop_vectorize... (given it has no cost model)

Richard.

>    /* Now all statements are if-convertible.  Combine all the basic
> 
>