On 09 Jan 16:02, Jakub Jelinek wrote:
> On Fri, Jan 09, 2015 at 05:57:02PM +0300, Ilya Verbin wrote:
> > If one (by mistake) calls a non-target function from the target region, the
> > offload compiler crashes in input_overwrite_node. This is because
> > compute_ltrans_boundary during streaming-out includes to SET the
> > non-offloadable nodes, called from offloadable nodes.
> > Probably it's possible to ignore such incorrect nodes (and edges) in
> > streaming-out, but such a situation can not appear in a correct OpenMP 4.0
> > program, therefore I've added a check to scan_omp_1_stmt.
>
> Unlike variables, the spec last time I've checked isn't all that clear about
> that.
I think that GCC shouldn't allow such calls, at least for non-external
functions. Otherwise why the 'declare target' directive is needed at all?
As for external functions, it's an open question, e.g. for MIC it's OK to have
in target region a call to a function from a native library, like printf.
> > --- a/gcc/omp-low.c
> > +++ b/gcc/omp-low.c
> > @@ -2818,6 +2818,19 @@ scan_omp_1_stmt (gimple_stmt_iterator *gsi, bool
> > *handled_ops_p,
> > default:
> > break;
> > }
> > + else if (!DECL_EXTERNAL (fndecl)
> > + && !cgraph_node::get_create (fndecl)->offloadable)
>
> What about if fndecl is defined in the current TU, but as global symbol and
> can be
> interposed (e.g. is in a shared library and not hidden in there), the local
> function
> definition is without target attribute but the definition used at runtime is
> not?
I believe that if it is defined in the current TU and is used in a target
region, then it should be declared as target in current TU too.
> > + {
> > + omp_context *octx;
> > + if (cgraph_node::get (current_function_decl)->offloadable)
> > + remove = true;
> > + for (octx = ctx; octx && !remove; octx = octx->outer)
> > + if (is_targetreg_ctx (octx))
> > + remove = true;
> > + if (remove)
> > + error_at (gimple_location (stmt), "function called from "
> > + "target region, but not marked as 'declare target'");
>
> %<declare target%> ?
Fixed.
-- Ilya
