On 9 June 2016 at 14:31, Jakub Jelinek <ja...@redhat.com> wrote:
> On Thu, Jun 09, 2016 at 02:18:44PM +0200, Christophe Lyon wrote:
>> On 8 June 2016 at 16:50, Jakub Jelinek <ja...@redhat.com> wrote:
>> > On Wed, Jun 08, 2016 at 04:44:00PM +0200, Christophe Lyon wrote:
>> >> I've tried the attached patch (which does only dg-options ->
>> >> dg-additional-options).
>> >> For GCC, it's better, except that on arm-none-eabi qemu complains about
>> >> an illegal instruction when asked to use arm926 and GCC is configured with
>> >> the default cpu. Maybe that's because check_vect does not have the
>> >> expected
>> >
>> > check_vect installs a SIGILL handler and if the insn is invalid, excepts
>> > a signal to be raised. Is that not the case with qemu? Or is qemu just
>> > being too noisy?
>> >
>> qemu complains when executing check_vect's prologue, which contains
>> movw r1, #35712
>> which is not supported either on arm926.
>
> Bet it depends if this happens before the signal(SIGILL, sig_ill_handler);
> call or after it. If before, then I guess you'd better rewrite the
> long long a = 0, b = 1;
> asm ("vorr %P0, %P1, %P2"
> : "=w" (a)
> : "0" (a), "w" (b));
> if (a != 1)
Of course you are right: it happens just before the call to signal,
to build the sig_ill_handler address in r1.
So it's not even a problem with rewriting the asm.
> fully into inline asm, if after, then it is likely either just too noisy
> qemu, or misdesigned issue in qemu.
>
> Jakub
