[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

Arseny Solokha <asolokha at gmx dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |asolokha at gmx dot com

--- Comment #27 from Arseny Solokha <asolokha at gmx dot com> ---
Is it still an issue?

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

--- Comment #28 from Richard Biener <rguenth at gcc dot gnu.org> ---
Yes, the original issue is still present.

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

--- Comment #29 from Richard Biener <rguenth at gcc dot gnu.org> ---
So a testcase for missed outer loop induction SLP (and nested cycle SLP) is
for example

int a[1024];
void foo (unsigned n)
{
  for (int i = 0; i < 1020; i += 4)
    {
      int suma = a[i];
      int sumb = a[i+1];
      int sumc = a[i+2];
      int sumd = a[i+3];
      for (unsigned j = 0; j < 17; ++j)
        {
          suma = (suma ^ i) + 1;
          sumb = (sumb ^ i) + 2;
          sumc = (sumc ^ i) + 3;
          sumd = (sumd ^ i) + 4;
        }
      a[i] = suma;
      a[i+1] = sumb;
      a[i+2] = sumc;
      a[i+3] = sumd;
    }
}

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

--- Comment #30 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #29)
> So a testcase for missed outer loop induction SLP (and nested cycle SLP) is
> for example
> 
> int a[1024];
> void foo (unsigned n)
> {
>   for (int i = 0; i < 1020; i += 4)
>     {
>       int suma = a[i];
>       int sumb = a[i+1];
>       int sumc = a[i+2];
>       int sumd = a[i+3];
>       for (unsigned j = 0; j < 17; ++j)
>         {
>           suma = (suma ^ i) + 1;
>           sumb = (sumb ^ i) + 2;
>           sumc = (sumc ^ i) + 3;
>           sumd = (sumd ^ i) + 4;
>         }
>       a[i] = suma;
>       a[i+1] = sumb;
>       a[i+2] = sumc;
>       a[i+3] = sumd;
>     }
> }

Actually this is still not an inner loop induction in outer loop vectorization.
But missed nested cycle SLP handling.  I have a patch for this in testing.

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

--- Comment #31 from Richard Biener <rguenth at gcc dot gnu.org> ---
The following is a testcase triggering the

      /* FORNOW: outer loop induction with SLP not supported.  */
      if (STMT_SLP_TYPE (stmt_info))
        return false;

test:

double image[40];

void
foo (void)
{
  for (int i = 0; i < 20; i++)
    {
      double suma = 0;
      double sumb = 0;
      for (int j = 0; j < 40; j++)
        {
          suma += j+i;
          sumb += j+i;
        }
      image[2*i] = suma;
      image[2*i+1] = sumb;
    }
}

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

--- Comment #32 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:ac6affba97130bcbffb21bd9f8ca53c7aac89551

commit r11-4652-gac6affba97130bcbffb21bd9f8ca53c7aac89551
Author: Richard Biener <rguenther@suse.de>
Date:   Tue Nov 3 11:52:47 2020 +0100

    tree-optimization/80928 - SLP vectorize nested loop induction

    This adds SLP vectorization of nested inductions.

    2020-11-03  Richard Biener <rguenther@suse.de>

            PR tree-optimization/80928
            * tree-vect-loop.c (vectorizable_induction): SLP vectorize
            nested inductions.

            * gcc.dg/vect/vect-outer-slp-2.c: New testcase.
            * gcc.dg/vect/vect-outer-slp-3.c: Likewise.

[Bug tree-optimization/80928] SLP vectorization does not handle induction in outer loop vectorization

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80928

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #33 from Richard Biener <rguenth at gcc dot gnu.org> ---
Now fixed.