On Wed, 8 Apr 2020 at 11:48, Richard Sandiford
<richard.sandiford@arm.com> wrote:
>
> Christophe Lyon via Gcc-patches <gcc-patches@gcc.gnu.org> writes:
> > Hi,
> >
> > While checking Martin's fix for PR ipa/94445, he made me realize that
> > the cmse-15.c testcase still fails at -Os because ICF means that we
> > generate
> > nonsecure2:
> >         b       nonsecure0
> >
> > which is OK, but does not match the currently expected
> > nonsecure2:
> > ...
> >         bl      __gnu_cmse_nonsecure_call
> >
> > (see https://gcc.gnu.org/pipermail/gcc-patches/2020-April/543190.html)
> >
> > The test has already different expectations for v8-M and v8.1-M.
> >
> > I've decided to try to use check-function-bodies to account for the
> > different possibilities:
> > - v8-M vs v8.1-M via two different prefixes
> > - code generation variants (-0?) via multiple regexps
> >
> > I've tested that the test now passes with --target-board=-march=armv8-m.main
> > and --target-board=-march=armv8.1-m.main.
> >
> > I feel this a bit too much of a burden for the purpose, maybe there's
> > a better way of handling all these alternatives (in particular,
> > there's a lot of duplication since the expected code for the secure*
> > functions is the same for v8-M and v8.1-M).
>
> FWIW, an alternative is to give multiple versions with the same prefix
> and use { target ... } to select between them.  E.g.:
>
> /*
> ** foo:   { target a }
> **      ...
> */
> /*
> ** foo:   { target { ! a } }
> **      ...
> */
>

Ha indeed, that makes it simpler. Thanks for the example, I hadn't
fully understand how to use that scheme: I tried to add a third
alternative (different prefix) with no selector for cases where no
distinction was needed, but I realized that all alternatives need
their full matching description.

However, {target { ! a } } does not work as is, so the attached patch
uses a non-greedy regexp to avoid trying "! a }" instead of "target {
! a }"

If OK, maybe I should commit that as two separate patches?

Thanks

Christophe


> Thanks,
> Richard