On Fri, Sep 25, 2020 at 10:41:05AM -0500, will schmidt wrote:
> On Thu, 2020-09-24 at 19:40 -0500, Segher Boessenkool wrote:
> > > +++ b/gcc/testsuite/gcc.target/powerpc/vsx-load-element-extend-
> > > char.c
> > > @@ -0,0 +1,168 @@
> > > +/*
> > > + * Test of vec_xl_sext and vec_xl_zext (load into rightmost
> > > + * vector element and zero/sign extend). */
> > > +
> > > +/* { dg-do compile {target power10_ok} } */
> > > +/* { dg-do run {target power10_hw} } */
> > > +/* { dg-require-effective-target power10_ok } */
> > > +/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
> >
> > If you dg_require it, why test it on the "dg-do compile" line? It
> > will
> > *work* with it of course, but it is puzzling :-)
>
> I've had both compile-time and run-time versions of the test. In this
> case I wanted to try to handle both, so compile when I can compile it,
> and run when I can run it, etc.
>
> If that combo doesn't work the way I expect it to, i'll need to split
> them out into separate tests.
It works, but it does the same thing as
/* { dg-do compile } */
/* { dg-do run {target power10_hw} } */
/* { dg-require-effective-target power10_ok } */
/* { dg-options "-mdejagnu-cpu=power10 -O2" } */
(so just that first line simplified).
> > > +/* { dg-do compile {target power10_ok} } */
> > > +/* { dg-do run {target power10_hw} } */
> > > +/* { dg-require-effective-target power10_ok } */
> > > +/* { dg-options "-mdejagnu-cpu=power10 -O0" } */
> >
> > Please comment here what that -O0 is for? So that we still know when
> > we
> > read it decades from now ;-)
>
> I've got it commented at least once, I'll make sure to get all the
> instances covered.
Ah I didn't see that one instance.
> > > +/* { dg-final { scan-assembler-times {\mlxvrwx\M} 2 } } */
> > > +/* { dg-final { scan-assembler-times {\mlwax\M} 0 } } */
> >
> > Maybe all of {\mlwa} here?
>
> lwax was sufficient for what I sniff-tested. I'll double-check.
Yes, but lwa and lwaux can happen as well... With a scan-assembler-not
(which this is equivalent to), it is a good idea to throw a wide net in
general. If the compiler starts using (say) lwa, you won't notice
otherwise.
(The particular regex I gave also catches lwat and lwarx, but do we
actually care? :-) )
Segher
