[committed] jit: add gcc_jit_type_get_vector

[David Malcolm]

On Thu, 2017-08-17 at 09:15 +1200, Michael Cree wrote:
> On Wed, Aug 16, 2017 at 10:01:57AM -0400, David Malcolm wrote:
> > On Wed, 2017-08-16 at 21:58 +1200, Michael Cree wrote:
> > > 
> > > But I have hit a problem which I suspect is a bug in the gcc
> > > optimiser.
> > > 
> > > In the vein of your example above, but working on uint8_t pixel
> > > data
> > > and adding saturation, the jit compiler segfaults in the
> > > optimiser. I
> > > provide below the gimple produced by the function that causes the
> > > problem (I presume that is more useful than the code calling the
> > > gcc_jit routines), 
> > 
> > There's actually a handy entrypoint for generating minimal
> > reproducers
> > for such crashes:
> >   gcc_jit_context_dump_reproducer_to_file
> > 
> > https://gcc.gnu.org/onlinedocs/jit/topics/contexts.html#gcc_jit_con
> > text_dump_reproducer_to_file
> > 
> > Can you add a call to that to your code (after the context is fully
> > populated), and see if the resulting .c file leads to the crash
> > when
> > run?  If so, can you post the .c file here please (or attach it to
> > bugzilla), and hopefully I can then reproduce it at my end.
> 
> Attached.
> 
> Cheers
> Michael.

Thanks.  I'm able to reproduce the crash using that; am investigating.

Dave