On Mon, Nov 21, 2016 at 8:25 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Wed, Nov 16, 2016 at 09:14:57PM -0600, Bill Schmidt wrote:
>> 2016-11-16 Bill Schmidt <wschm...@linux.vnet.ibm.com>
>> Richard Biener <rguent...@suse.de>
>>
>> PR tree-optimization/77848
>> * tree-if-conv.c (tree_if_conversion): Always version loops unless
>> the user specified -ftree-loop-if-convert.
>
> This broke the attached testcase.
>
>> --- gcc/tree-if-conv.c (revision 242521)
>> +++ gcc/tree-if-conv.c (working copy)
>> @@ -2803,10 +2803,12 @@ tree_if_conversion (struct loop *loop)
>> || loop->dont_vectorize))
>> goto cleanup;
>>
>> - /* Either version this loop, or if the pattern is right for outer-loop
>> - vectorization, version the outer loop. In the latter case we will
>> - still if-convert the original inner loop. */
>> - if ((any_pred_load_store || any_complicated_phi)
>> + /* Since we have no cost model, always version loops unless the user
>> + specified -ftree-loop-if-convert. Either version this loop, or if
>> + the pattern is right for outer-loop vectorization, version the
>> + outer loop. In the latter case we will still if-convert the
>> + original inner loop. */
>> + if (flag_tree_loop_if_convert != 1
>> && !version_loop_for_if_conversion
>> (versionable_outer_loop_p (loop_outer (loop))
>> ? loop_outer (loop) : loop))
>
> If there are masked loads/stores (and I assume also the complicated phi
> stuff, but haven't verified), then it isn't just some kind of optimization
> to version the loop based on LOOP_VECTORIZED ifn, it is a requirement
> - MASK_LOAD/MASK_STORE aren't supported for scalar code, so they can only
> appear in the vectorized version. Fixed by reverting that - if
> -ftree-loop-if-convert we'll do what we used to do before, without it
> we do what you've added, i.e. version always.
>
> The rest is just formatting fix, the too large argument that forces
> call's ( on the next line and even misindented is IMHO much cleaner
> if a temporary is used.
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
Thanks,
Richard.
> 2016-11-21 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/78445
> * tree-if-conv.c (tree_if_conversion): If any_pred_load_store or
> any_complicated_phi, version loop even if flag_tree_loop_if_convert is
> 1. Formatting fix.
>
> * gcc.dg/pr78445.c: New test.
>
> --- gcc/tree-if-conv.c.jj 2016-11-17 18:08:12.000000000 +0100
> +++ gcc/tree-if-conv.c 2016-11-21 17:28:30.807242395 +0100
> @@ -2804,15 +2804,20 @@ tree_if_conversion (struct loop *loop)
> goto cleanup;
>
> /* Since we have no cost model, always version loops unless the user
> - specified -ftree-loop-if-convert. Either version this loop, or if
> - the pattern is right for outer-loop vectorization, version the
> - outer loop. In the latter case we will still if-convert the
> - original inner loop. */
> - if (flag_tree_loop_if_convert != 1
> - && !version_loop_for_if_conversion
> - (versionable_outer_loop_p (loop_outer (loop))
> - ? loop_outer (loop) : loop))
> - goto cleanup;
> + specified -ftree-loop-if-convert or unless versioning is required.
> + Either version this loop, or if the pattern is right for outer-loop
> + vectorization, version the outer loop. In the latter case we will
> + still if-convert the original inner loop. */
> + if (any_pred_load_store
> + || any_complicated_phi
> + || flag_tree_loop_if_convert != 1)
> + {
> + struct loop *vloop
> + = (versionable_outer_loop_p (loop_outer (loop))
> + ? loop_outer (loop) : loop);
> + if (!version_loop_for_if_conversion (vloop))
> + goto cleanup;
> + }
>
> /* Now all statements are if-convertible. Combine all the basic
> blocks into one huge basic block doing the if-conversion
> --- gcc/testsuite/gcc.dg/pr78445.c.jj 2016-11-21 17:30:58.534400256 +0100
> +++ gcc/testsuite/gcc.dg/pr78445.c 2016-11-21 17:30:41.000000000 +0100
> @@ -0,0 +1,19 @@
> +/* PR tree-optimization/78445 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -ftree-loop-if-convert -ftree-vectorize" } */
> +/* { dg-additional-options "-mavx2" { target { i?86-*-* x86_64-*-* } } } */
> +
> +int a;
> +
> +void
> +foo (int x, int *y)
> +{
> + while (a != 0)
> + if (x != 0)
> + {
> + *y = a;
> + x = *y;
> + }
> + else
> + x = a;
> +}
>
>
> Jakub
