[Rd] OpenMP problem with 64-bit Rtools

[Radford Neal]

> On Fri, Aug 21, 2015 at 8:38 PM, Radford Neal <radford at cs.toronto.edu> wrote:
>
> > The reason for this appears to be that the omp.h file included is
> > appropriate only for the 32-bit version of the openMP library.  As
> > far as I can see, there is no 64-bit version of this include file
> > in the stuff installed with Rtools.

On Sat, Aug 22, 2015 at 01:30:51AM +0200, Jeroen Ooms wrote:

> This particular behavior exists in all builds of mingw-w64, not rtools
> per se. We might get a better answer in the mingw-w64-public mailing
> list.

A comment near the front of omp.h says "These two structures get
edited by the libgomp build process to reflect the shape of the two
types".  So presumably it is possible to generate the 64-bit version,
and presumably this must have been done in order to compile the 64-bit
version of the OpenMP library that is supplied with Rtools.

Maybe there's no provision in the build process for having two omp.h
files at once, though...

   Radford