[patch] Fix PR tree-optimization/50412

Richard Guenther richard.guenther@gmail.com
Fri Sep 23 22:17:00 GMT 2011


On Sun, Sep 18, 2011 at 11:00 AM, Ira Rosen <ira.rosen@linaro.org> wrote:
> Hi,
>
> Strided accesses of single element or with gaps may require creation
> of epilogue loop. At the moment we don't support peeling for outer
> loops, therefore, we should not allow such strided accesses in outer
> loops.
>
> Bootstrapped and tested on powerpc64-suse-linux.
> Committed to trunk.
>
> Now testing for 4.6.
> OK for 4.6 when the testing completes?

Ok.

Thanks,
Richard.

> Thanks,
> Ira
>
> ChangeLog:
>
>        PR tree-optimization/50412
>        * tree-vect-data-refs.c (vect_analyze_group_access): Fail for
>        acceses that require epilogue loop if vectorizing outer loop.
>
> testsuite/ChangeLog:
>
>        PR tree-optimization/50412
>        * gfortran.dg/vect/pr50412.f90: New.
>
>
>
> Index: tree-vect-data-refs.c
> ===================================================================
> --- tree-vect-data-refs.c       (revision 178939)
> +++ tree-vect-data-refs.c       (working copy)
> @@ -2060,7 +2060,11 @@ vect_analyze_group_access (struct data_reference *
>   HOST_WIDE_INT dr_step = TREE_INT_CST_LOW (step);
>   HOST_WIDE_INT stride, last_accessed_element = 1;
>   bool slp_impossible = false;
> +  struct loop *loop = NULL;
>
> +  if (loop_vinfo)
> +    loop = LOOP_VINFO_LOOP (loop_vinfo);
> +
>   /* For interleaving, STRIDE is STEP counted in elements, i.e., the
> size of the
>      interleaving group (including gaps).  */
>   stride = dr_step / type_size;
> @@ -2090,11 +2094,18 @@ vect_analyze_group_access (struct data_reference *
>
>          if (loop_vinfo)
>            {
> -             LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
> -
>              if (vect_print_dump_info (REPORT_DETAILS))
>                fprintf (vect_dump, "Data access with gaps requires scalar "
>                                    "epilogue loop");
> +              if (loop->inner)
> +                {
> +                  if (vect_print_dump_info (REPORT_DETAILS))
> +                    fprintf (vect_dump, "Peeling for outer loop is not"
> +                                        " supported");
> +                  return false;
> +                }
> +
> +              LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
>            }
>
>          return true;
> @@ -2277,10 +2288,17 @@ vect_analyze_group_access (struct data_reference *
>       /* There is a gap in the end of the group.  */
>       if (stride - last_accessed_element > 0 && loop_vinfo)
>        {
> -         LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
>          if (vect_print_dump_info (REPORT_DETAILS))
>            fprintf (vect_dump, "Data access with gaps requires scalar "
>                                "epilogue loop");
> +          if (loop->inner)
> +            {
> +              if (vect_print_dump_info (REPORT_DETAILS))
> +                fprintf (vect_dump, "Peeling for outer loop is not supported");
> +              return false;
> +            }
> +
> +          LOOP_VINFO_PEELING_FOR_GAPS (loop_vinfo) = true;
>        }
>     }
> Index: testsuite/gfortran.dg/vect/pr50412.f90
> ===================================================================
> --- testsuite/gfortran.dg/vect/pr50412.f90      (revision 0)
> +++ testsuite/gfortran.dg/vect/pr50412.f90      (revision 0)
> @@ -0,0 +1,12 @@
> +! { dg-do compile }
> +
> +      DOUBLE PRECISION AK,AI,AAE
> +      COMMON/com/AK(36),AI(4,4),AAE(8,4),ii,jj
> +      DO 20 II=1,4
> +        DO 21 JJ=1,4
> +          AK(n)=AK(n)-AAE(I,II)*AI(II,JJ)
> +   21   CONTINUE
> +   20 CONTINUE
> +      END
> +
> +! { dg-final { cleanup-tree-dump "vect" } }
>



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