On Thu, Dec 12, 2013 at 10:53:02AM +0100, Thomas Schwinge wrote:
> On Thu, 5 Sep 2013 18:11:05 +0200, Jakub Jelinek <ja...@redhat.com> wrote:
> > 3) I figured out we need to tell the runtime library not just
> > address, size and kind, but also alignment (we won't need that for
> > the #pragma omp declare target global vars though), so that the
> > runtime library can properly align it. As TYPE_ALIGN/DECL_ALIGN
> > is in bits and is 32 bit wide, when that is in bytes and we only care
> > about power of twos, I've decided to encode it in the upper 5 bits
> > of the kind (lower 3 bits are used for OMP_CLAUSE_MAP_* kind).
>
> Unfortunately, this scheme breaks down with OpenACC: we need an
> additional bit to codify a flag for present_or_* map clauses (meaning:
> only map the data (allocate/to/from/tofrom, as for OpenMP) if not already
> present on the device).
The OpenMP behavior is always only map the data (allocate/to/from/tofrom)
if not already mapped on the device. So what behavior does OpenACC have
if present_or_* isn't present?
Jakub
