On 11/16/16 9:08 AM, Richard Biener wrote:
> On Tue, Nov 15, 2016 at 9:03 PM, Bill Schmidt
> <wschm...@linux.vnet.ibm.com> wrote:
>> - if ((any_pred_load_store || any_complicated_phi)
>> - && !version_loop_for_if_conversion (loop))
>> + /* Since we have no cost model, always version loops if vectorization
>> + is enabled. 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. */
>> + /* FIXME: When SLP vectorization can handle if-conversion on its own,
>> + predicate all of if-conversion on flag_tree_loop_vectorize. */
>> + if ((any_pred_load_store || any_complicated_phi ||
>> flag_tree_loop_vectorize)
> I'd say given fun->has_force_vectorize_loops this should be
>
> 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;
> and thus always version if the user didnt' specify -ftree-loop-if-convert
> (-ftree-loop-if-convert-stores is dead, I forgot to remove uses).
>
> Can you as a first patch (after fixing the minor things above) commit
> the patch w/o changing the condition under which we version
> (but _do_ version the outer loop if possible?). This should be a strict
> improvement enabling more outer loop vectorization.
Done and committed. Thanks!
>
> The 2nd patch can then fix the PR and change the condition.
>
> Thus, ok with the nits fixed and the condition unchanged.
>
> Can you re-test the 2nd part with my suggested changed predicate?
Yes, the new predicate works fine. New patch below, bootstrapped and tested
on powerpc64le-unknown-linux-gnu, with only the bb-slp-cond-1.c regressions
previously discussed. Is this ok for trunk?
Thanks,
Bill
>
> Thanks,
> Richard.
>
[gcc]
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.
[gcc/testsuite]
2016-11-16 Bill Schmidt <wschm...@linux.vnet.ibm.com>
Richard Biener <rguent...@suse.de>
PR tree-optimization/77848
* gfortran.dg/vect/pr77848.f: New test.
Index: gcc/testsuite/gfortran.dg/vect/pr77848.f
===================================================================
--- gcc/testsuite/gfortran.dg/vect/pr77848.f (revision 0)
+++ gcc/testsuite/gfortran.dg/vect/pr77848.f (working copy)
@@ -0,0 +1,24 @@
+! PR 77848: Verify versioning is on when vectorization fails
+! { dg-do compile }
+! { dg-options "-O3 -ffast-math -fdump-tree-ifcvt -fdump-tree-vect-details" }
+
+ subroutine sub(x,a,n,m)
+ implicit none
+ real*8 x(*),a(*),atemp
+ integer i,j,k,m,n
+ real*8 s,t,u,v
+ do j=1,m
+ atemp=0.d0
+ do i=1,n
+ if (abs(a(i)).gt.atemp) then
+ atemp=a(i)
+ k = i
+ end if
+ enddo
+ call dummy(atemp,k)
+ enddo
+ return
+ end
+
+! { dg-final { scan-tree-dump "LOOP_VECTORIZED" "ifcvt" } }
+! { dg-final { scan-tree-dump "vectorized 0 loops in function" "vect" } }
Index: gcc/tree-if-conv.c
===================================================================
--- 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))
