Properly sum costs in tree-vect-loop.c (PR tree-optimization/90973).

Hi.

That's a thinko that's pre-approved by Richi.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Thanks,
Martin

gcc/ChangeLog:

2019-06-24  Martin Liska  <mliska@suse.cz>

	PR tree-optimization/90973
	* tree-vect-loop.c (vect_get_known_peeling_cost): Sum retval
	of prologue and epilogue.
---
 gcc/tree-vect-loop.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

On Tue, 2019-06-25 at 10:16 +0200, Martin Liška wrote:
> Hi.
> 
> That's a thinko that's pre-approved by Richi.
> 
> Patch can bootstrap on x86_64-linux-gnu and survives regression
> tests.
> 
> Thanks,
> Martin
> 
> gcc/ChangeLog:
> 
> 2019-06-24  Martin Liska  <mliska@suse.cz>
> 
> 	PR tree-optimization/90973
> 	* tree-vect-loop.c (vect_get_known_peeling_cost): Sum retval
> 	of prologue and epilogue.
> ---
>  gcc/tree-vect-loop.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

> diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
> index d3facf67bf9..489bee65397 100644
> --- a/gcc/tree-vect-loop.c
> +++ b/gcc/tree-vect-loop.c
> @@ -3405,8 +3405,8 @@ vect_get_known_peeling_cost (loop_vec_info loop_vinfo, int peel_iters_prologue,
>           iterations are unknown, count a taken branch per peeled loop.  */
>        retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
>  				 NULL, 0, vect_prologue);
> -      retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
> -				 NULL, 0, vect_epilogue);
> +      retval += record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
                                     ^^^^^^^^^^^^^^^^^^
Should this be epilogue_cost_vec?

> +				  NULL, 0, vect_epilogue);

(caveat: I'm purely going by symmetry here)

On Tue, Jun 25, 2019 at 10:50 AM David Malcolm <dmalcolm@redhat.com> wrote:
>
> On Tue, 2019-06-25 at 10:16 +0200, Martin Liška wrote:
> > Hi.
> >
> > That's a thinko that's pre-approved by Richi.
> >
> > Patch can bootstrap on x86_64-linux-gnu and survives regression
> > tests.
> >
> > Thanks,
> > Martin
> >
> > gcc/ChangeLog:
> >
> > 2019-06-24  Martin Liska  <mliska@suse.cz>
> >
> >       PR tree-optimization/90973
> >       * tree-vect-loop.c (vect_get_known_peeling_cost): Sum retval
> >       of prologue and epilogue.
> > ---
> >  gcc/tree-vect-loop.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
>
> > diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
> > index d3facf67bf9..489bee65397 100644
> > --- a/gcc/tree-vect-loop.c
> > +++ b/gcc/tree-vect-loop.c
> > @@ -3405,8 +3405,8 @@ vect_get_known_peeling_cost (loop_vec_info loop_vinfo, int peel_iters_prologue,
> >           iterations are unknown, count a taken branch per peeled loop.  */
> >        retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
> >                                NULL, 0, vect_prologue);
> > -      retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
> > -                              NULL, 0, vect_epilogue);
> > +      retval += record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
>                                      ^^^^^^^^^^^^^^^^^^
> Should this be epilogue_cost_vec?

I think so.

> > +                               NULL, 0, vect_epilogue);
>
> (caveat: I'm purely going by symmetry here)

On 6/25/19 4:18 PM, Richard Biener wrote:
> On Tue, Jun 25, 2019 at 10:50 AM David Malcolm <dmalcolm@redhat.com> wrote:
>>
>> On Tue, 2019-06-25 at 10:16 +0200, Martin Liška wrote:
>>> Hi.
>>>
>>> That's a thinko that's pre-approved by Richi.
>>>
>>> Patch can bootstrap on x86_64-linux-gnu and survives regression
>>> tests.
>>>
>>> Thanks,
>>> Martin
>>>
>>> gcc/ChangeLog:
>>>
>>> 2019-06-24  Martin Liska  <mliska@suse.cz>
>>>
>>>       PR tree-optimization/90973
>>>       * tree-vect-loop.c (vect_get_known_peeling_cost): Sum retval
>>>       of prologue and epilogue.
>>> ---
>>>  gcc/tree-vect-loop.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>>> diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
>>> index d3facf67bf9..489bee65397 100644
>>> --- a/gcc/tree-vect-loop.c
>>> +++ b/gcc/tree-vect-loop.c
>>> @@ -3405,8 +3405,8 @@ vect_get_known_peeling_cost (loop_vec_info loop_vinfo, int peel_iters_prologue,
>>>           iterations are unknown, count a taken branch per peeled loop.  */
>>>        retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
>>>                                NULL, 0, vect_prologue);
>>> -      retval = record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
>>> -                              NULL, 0, vect_epilogue);
>>> +      retval += record_stmt_cost (prologue_cost_vec, 1, cond_branch_taken,
>>                                      ^^^^^^^^^^^^^^^^^^
>> Should this be epilogue_cost_vec?
> 
> I think so.
> 
>>> +                               NULL, 0, vect_epilogue);
>>
>> (caveat: I'm purely going by symmetry here)

I've got a patch that I've been testing. I'll install it if it survives
regression tests.

Thanks,
Martin