On Thu, May 11, 2017 at 2:14 PM, Richard Biener
<richard.guent...@gmail.com> wrote:
> On Thu, May 11, 2017 at 1:15 PM, Robin Dapp <rd...@linux.vnet.ibm.com> wrote:
>> Included the requested changes in the patches (to follow). I removed
>> the alignment count check now altogether.
>>
>>> I'm not sure why you test for unlimited_cost_model here as I said
>>> elsewhere I'm not sure
>>> what not cost modeling means for static decisions. The purpose of
>>> unlimited_cost_model
>>> is to always vectorize when possible and omit the runtime
>>> profitability check. So for peeling
>>> I'd just always use the cost model. Thus please drop this check.
>>
>> Without that, I get one additional FAIL gcc.dg/vect/slp-25.c for x86.
>> It is caused by choosing no peeling (inside costs 0) over peeling for
>> known alignment with unlimited cost model (inside costs 0 as well).
>> Costs 0 for no peeling are caused by count == 0 or rather ncopies = vf /
>> nunits == 4 / 8 == 0 in record_stmt_costs (). Shouldn't always hold
>> ncopies > 0? Even 0.5 would have worked here to make no peeling more
>> expensive than 0.
>
> That's odd. I can't get
>
> Index: gcc/tree-vect-stmts.c
> ===================================================================
> --- gcc/tree-vect-stmts.c (revision 247882)
> +++ gcc/tree-vect-stmts.c (working copy)
> @@ -95,6 +96,7 @@ record_stmt_cost (stmt_vector_for_cost *
> enum vect_cost_for_stmt kind, stmt_vec_info stmt_info,
> int misalign, enum vect_cost_model_location where)
> {
> + gcc_assert (count > 0);
> if (body_cost_vec)
> {
> tree vectype = stmt_info ? stmt_vectype (stmt_info) : NULL_TREE;
>
> to ICE with the testcase (unpatched trunk)
>
> Where's that record_stmt_cost call done? You can't simply use vf/nunits
> for SLP.
Ah, of course needs -fvect-cost-model.
I'll investigate.
Richard.
> Richard.
>
>> Test suite on s390x is clean.
>>
>> Regards
>> Robin
>>
