Re: [PATCH, PR tree-optimization/68327] Compute vectype for live phi nodes when copmputing VF

[Richard Biener <richard dot guenther at gmail dot com>]

On Fri, Nov 20, 2015 at 4:10 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
> On 20 Nov 14:31, Ilya Enkovich wrote:
>> 2015-11-20 14:28 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>> > On Wed, Nov 18, 2015 at 2:53 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>> >> 2015-11-18 16:44 GMT+03:00 Richard Biener <richard.guenther@gmail.com>:
>> >>> On Wed, Nov 18, 2015 at 12:34 PM, Ilya Enkovich <enkovich.gnu@gmail.com> wrote:
>> >>>> Hi,
>> >>>>
>> >>>> When we compute vectypes we skip non-relevant phi nodes.  But we process non-relevant alive statements and thus may need vectype of non-relevant live phi node to compute mask vectype.  This patch enables vectype computation for live phi nodes.  Botostrapped and regtested on x86_64-unknown-linux-gnu.  OK for trunk?
>> >>>
>> >>> Hmm.  What breaks if you instead skip all !relevant stmts and not
>> >>> compute vectype for life but not relevant ones?  We won't ever
>> >>> "vectorize" !relevant ones, that is, we don't need their vector type.
>> >>
>> >> I tried it and got regression in SLP.  It expected non-null vectype
>> >> for non-releveant but live statement. Regression was in
>> >> gcc/gcc/testsuite/gfortran.fortran-torture/execute/pr43390.f90
>> >
>> > Because somebody put a vector type check before
>> >
>> >   if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
>> >     return false;
>> >
>> > @@ -7590,6 +7651,9 @@ vectorizable_comparison (gimple *stmt, g
>> >    tree mask_type;
>> >    tree mask;
>> >
>> > +  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
>> > +    return false;
>> > +
>> >    if (!VECTOR_BOOLEAN_TYPE_P (vectype))
>> >      return false;
>> >
>> > @@ -7602,8 +7666,6 @@ vectorizable_comparison (gimple *stmt, g
>> >      ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
>> >
>> >    gcc_assert (ncopies >= 1);
>> > -  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
>> > -    return false;
>> >
>> >    if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def
>> >        && !(STMT_VINFO_DEF_TYPE (stmt_info) == vect_nested_cycle
>> >
>> > fixes this particular fallout for me.
>>
>> I'll try it.
>
> With this fix it works fine, thanks!  Bootstrapped and regtested on x86_64-unknown-linux-gnu.  OK for trunk?

Ok.

Thanks,
Richard.

> Ilya
> --
> gcc/
>
> 2015-11-20  Ilya Enkovich  <enkovich.gnu@gmail.com>
>             Richard Biener  <rguenther@suse.de>
>
>         * tree-vect-loop.c (vect_determine_vectorization_factor): Don't
>         compute vectype for non-relevant mask producers.
>         * gcc/tree-vect-stmts.c (vectorizable_comparison): Check stmt
>         relevance earlier.
>
> gcc/testsuite/
>
> 2015-11-20  Ilya Enkovich  <enkovich.gnu@gmail.com>
>
>         * gcc.dg/pr68327.c: New test.
>
>
> diff --git a/gcc/testsuite/gcc.dg/pr68327.c b/gcc/testsuite/gcc.dg/pr68327.c
> new file mode 100644
> index 0000000..c3e6a94
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/pr68327.c
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O3" } */
> +
> +int a, d;
> +char b, c;
> +
> +void
> +fn1 ()
> +{
> +  int i = 0;
> +  for (; i < 1; i++)
> +    d = 1;
> +  for (; b; b++)
> +    a = 1 && (d & b);
> +}
> diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
> index 80937ec..592372d 100644
> --- a/gcc/tree-vect-loop.c
> +++ b/gcc/tree-vect-loop.c
> @@ -439,7 +439,8 @@ vect_determine_vectorization_factor (loop_vec_info loop_vinfo)
>                  compute a factor.  */
>               if (TREE_CODE (scalar_type) == BOOLEAN_TYPE)
>                 {
> -                 mask_producers.safe_push (stmt_info);
> +                 if (STMT_VINFO_RELEVANT_P (stmt_info))
> +                   mask_producers.safe_push (stmt_info);
>                   bool_result = true;
>
>                   if (gimple_code (stmt) == GIMPLE_ASSIGN
> diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
> index 0f64aaf..3723b26 100644
> --- a/gcc/tree-vect-stmts.c
> +++ b/gcc/tree-vect-stmts.c
> @@ -7546,6 +7546,9 @@ vectorizable_comparison (gimple *stmt, gimple_stmt_iterator *gsi,
>    tree mask_type;
>    tree mask;
>
> +  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
> +    return false;
> +
>    if (!VECTOR_BOOLEAN_TYPE_P (vectype))
>      return false;
>
> @@ -7558,9 +7561,6 @@ vectorizable_comparison (gimple *stmt, gimple_stmt_iterator *gsi,
>      ncopies = LOOP_VINFO_VECT_FACTOR (loop_vinfo) / nunits;
>
>    gcc_assert (ncopies >= 1);
> -  if (!STMT_VINFO_RELEVANT_P (stmt_info) && !bb_vinfo)
> -    return false;
> -
>    if (STMT_VINFO_DEF_TYPE (stmt_info) != vect_internal_def
>        && !(STMT_VINFO_DEF_TYPE (stmt_info) == vect_nested_cycle
>            && reduc_def))