Re: [PATCH] gdb.trace: Add a testcase for tdesc in tfile.

[Marcin KoÅcielnicki <koriakin at 0x04 dot net>]

On 12/02/16 19:49, Antoine Tremblay wrote:
> Marcin KoÅcielnicki writes:
>
> > On 12/02/16 19:31, Antoine Tremblay wrote:
> > > Marcin KoÅcielnicki writes:
> > >
> > > > On 11/02/16 14:00, Pedro Alves wrote:
> > > > > On 02/11/2016 10:14 AM, Marcin KoÅcielnicki wrote:
> > > > > > This tests whether $ymm15 can be correctly collected and printed from
> > > > > > tfile.  It covers:
> > > > > >
> > > > > > - storing tdesc in tfile (without that, $ymm15 doesn't exist)
> > > > > > - ax_pseudo_register_collect for x86 (without that, $ymm15 cannot be
> > > > > >      collected)
> > > > > > - register order in tfile_fetch_registers (without that, $ymm15h is
> > > > > >      fetched from wrong position)
> > > > > > - off-by-one in tfile_fetch_registers (without that, $ymm15h is
> > > > > >      incorrectly considered to be out of bounds)
> > > > > > - using proper tdesc in encoding tracepoint actions (without that,
> > > > > >      internal error happens due to $ymm15h being
> > > > >
> > > > > OK once prereqs are in.
> > > > >
> > > > > Thanks,
> > > > > Pedro Alves
> > > >
> > > > Thanks, pushed.
> > >
> > > Hi,
> > >     I've been trying to run this test on x86 but I get the following error
> > >     while compiling tfile-avx.c :
> > >
> > >    binutils-gdb/build-x86/gdb/testsuite/../../../gdb/testsuite/gdb.trace/tfile-avx.c:38:19: error: invalid register name for 'a'
> > >     register __v8si a asm("ymm15") = {
> > >                      ^
> > >
> > >     I've also noticed the same error on the buildbot results see:
> > >     http://gdb-build.sergiodj.net/builders/Debian-x86_64-m64/builds/2928/steps/test%20gdb/logs/stdio
> > >
> > >     My cpu (Intel(R) Core(TM) i7-4600M ) supports avx, cat /proc/cpuinfo
> > >     shows avx and a gdb print $ymm15 returns something...
> > >
> > >     This is with gcc 4.8.4...
> > >
> > >     Am I missing something?
> > >
> > > Regards,
> > > Antoine
> >
> > Ugh.  It seems you need a newer gcc to recognize "ymm15" as a register
> > name - 4.8.2 seems to want it called "xmm15" - sort of incorrect, but
> > close enough.  gcc 5.3 still accepts that, so perhaps we should change
> > it to xmm15 for the sake of older compilers, even if it harms readability?
>
> Would xmm15 still work on newer gccs ? If so I would guess it's a good
> idea to change it given that our own buildbot test machines seem to test
> with an older gcc...?

Both xmm15 and ymm15 work just fine on gcc 4.9.3 and 5.3.0, which are 
the only ones I have around right now.  So, let's do it.
> Maybe adding a note of it in the test... or if there's a way to check
> for the gcc version ?

I'll throw in a comment.
> I actually can't find the gcc doc where those names are defined at the
> moment would you have that handy by any chance?

gcc/config/i386/i386.h, ADDITIONAL_REGISTER_NAMES.
> Regards,
> Antoine