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

[Ilya Enkovich]

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.

Thanks,
Ilya

>
> Richard.
>
>> Ilya
>>
>>>
>>> Richard.
>>>
>>>> Thanks,
>>>> Ilya