Update gcc.target/powerpc/pr92132-fp test for power7 and older

[Segher Boessenkool]

On Mon, Feb 17, 2020 at 02:48:20PM -0600, will schmidt wrote:
> On Thu, 2020-02-13 at 17:23 -0600, Segher Boessenkool wrote:
> > On Thu, Feb 13, 2020 at 04:41:09PM -0600, will schmidt wrote:
> > > -/* { dg-final { scan-tree-dump-times "LOOP VECTORIZED" 14 "vect" }
> > > } */
> > > +/* { dg-final { scan-tree-dump-times "LOOP VECTORIZED" 14 "vect" {
> > > target p8vector_hw } } } */
> > 
> > That actually checks if the hardware is p8 or later, while what you
> > care
> > about is what options are compiled with.  Say, if running on a p8 but
> > compiling for a p7 this will fail?
> 
> Right...
> 
> I did some experimentation and havn't come up with anything I'm
> completely satisfied with.   The powerpc_p8vector_ok check doesn't
> fail out like I'd expect it to on a power7 target.

What we usually do is duplicate the test, run one for p7, and the other
for p8.  This isn't nice at all.

> Ok, so it appears check_effective_target_powerpc_p8vector_ok () inserts
> a "-mpower8-vector" option as part of it's test, so as long as the
> compiler on a power7 system is able to generate power8 code, that
> power8-vector check will pass, even if we have not otherwise indicated
> power8 in our test incantation.

Yes, that is what the *_ok mean: whether we can compile code for that
target.  This isn't usually useful at all.

> I'll think on this one some more...

If the test can be disabled at the source code level, there are _ARCH_PWR8
and friends.  Maybe we want some dejagnu effective targets that just test
some of those defines?


Segher