Re: [testsuite] Add missing dg-require-effective-target alloca to gcc testsuite

[Tom de Vries <Tom_deVries at mentor dot com>]

On 28/03/17 10:23, Thomas Schwinge wrote:
> Hi!
>
> On Thu, 23 Mar 2017 16:46:19 +0100, Tom de Vries <Tom_deVries@mentor.com> wrote:
> > I've run the gcc testsuite for target nvptx-none and ran into "test for
> > excess errors" FAILs due to:
> > ...
> > sorry, unimplemented: target cannot support alloca.
> > ...
> >
> > This patch marks those testcases as requiring alloca.
>
> I observed that this test case:
>
> > --- gcc/testsuite/gcc.dg/torture/pr71881.c (revision 246278)
> > +++ gcc/testsuite/gcc.dg/torture/pr71881.c (working copy)
> > @@ -1,4 +1,5 @@
> >  /* { dg-do compile } */
> > +/* { dg-require-effective-target alloca } */
> >  /* { dg-additional-options "-g" } */
>
> ... as well as this test case:
>
> > --- gcc/testsuite/gcc.c-torture/compile/pr79413.c (revision 246278)
> > +++ gcc/testsuite/gcc.c-torture/compile/pr79413.c (working copy)
> > @@ -1,3 +1,4 @@
> > +/* { dg-require-effective-target alloca } */
> >  /* PR c/79413 */
>
> ... previously did PASS for anything but "-O0" (that is, any "alloca"
> usage got optimized away).  Now changed as follows:
>
>     [-FAIL:-]{+UNSUPPORTED:+} gcc.c-torture/compile/pr79413.c   -O0  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.c-torture/compile/pr79413.c   -O1  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.c-torture/compile/pr79413.c   -O2  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.c-torture/compile/pr79413.c   -O3 -g  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.c-torture/compile/pr79413.c   -Os  [-(test for excess errors)-]
>
>     [-FAIL:-]{+UNSUPPORTED:+} gcc.dg/torture/pr71881.c   -O0  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.dg/torture/pr71881.c   -O1  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.dg/torture/pr71881.c   -O2  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.dg/torture/pr71881.c   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.dg/torture/pr71881.c   -O3 -g  [-(test for excess errors)-]
>     [-PASS:-]{+UNSUPPORTED:+} gcc.dg/torture/pr71881.c   -Os  [-(test for excess errors)-]
>
> Would it be useful to XFAIL these for "-O0" only (along with a comment),
> so that we continue testing that any "alloca" usage gets optimized away?
> (Just an idea.)

I'd say that makes sense for test-cases which have the purpose of 
testing whether alloca is optimized away at certain optimization levels, 
but not for random test cases.

Thanks,
- Tom