On Mon, 2008-04-28 at 07:47 -0700, Mark Mitchell wrote:
> Joel Sherrill wrote:
>
> >> 1. Make these tests say something about what capability they require,
> >> with a dg-require directive, and then write autoconf-style tests run by
> >> the testsuite to determine whether the current compiler has that
> >> capability. For example, add a "dg-require-hard-float" directive, and
> >> probe the compiler to see whether it can generate hard float, given all
> >> the options in play.
Defining proc check_effective_target_whatever makes it possible
to use "dg-require-effective-target whatever", or combinations
of whatever with other effective targets. The proc can compile,
and optionally run, a configuration test with the current set of
options. I suppose it could even be used before and after
dg-options to make sure that the test files compiled with those
options will be compatible with support files compiled without
those options, as in
/* { dg-require-effective-target hard_float } */
/* { dg-options "-O2 -mcpu=405" } */
/* { dg-require-effective-target hard_float && ppc405 } */
> > That will not work on at least the *-rtems* configurations.
> > We use one multilib'ed toolset configuration to support
> > all variants within a family. So for the PowerPC, we actually
> > do have support for [4567]xx, [58]xxx, etc. m68k includes
> > coldfire, etc.
>
> There's no reason that we can't probe once per multilib. There are
> already probes like that in the testsuite. The autoconfy-ness just
> needs to be per-multilib.
Right, the effective-target tests are usually run per-multilib.
> > I think this would work. If you ended up with compiler
> > settings that didn't match what the test required, then
> > it could exit. How should it exit in this case?
>
> Just by doing "return 0;" from "main".
>
> > For the case we have been looking at, -mcpu=405 results
> > in __PPC405__ being defined. If you are writing a CPU model
> > specific test, you should know what the macro generated is.
> >
> > #if !defined(__PPC405__)
> > XXX -- ?? what to do?
> > #endif
>
> Here:
>
> #if !defined(__PPC405__)
> int main() { return 0; }
> #else
> /* The real test goes here. */
> #endif
>
> > Would this work on the scan tests which look for particular
> > assembly instructions?
>
> Probably not. Though, I suppose:
>
> #if !defined(__PPC405__)
> asm("haha here is a 405 insn");
> #else
> /* The real test goes here. */
> #endif
>
> might...
It's easier, though, to just skip the test.
Janis
