Re: Fwd: [RFC][gomp4] Offloading patches (2/3): Add tables generation

[Bernd Schmidt <bernds@codesourcery.com>]

On 01/28/2014 01:52 PM, Ilya Verbin wrote:
> The table is used in libgomp (see my patch [1]), as proposed by Jakub
> (see [2]).  The idea is that the order of entries in the host and
> target tables must be identical.  This allows to set up one-to-one
> correspondence between host and target addresses.

I was worried the answer was going to be something like this. These are 
produced by two different compilers/linkers, aren't they? This seems 
really fragile to me and a recipe for hard-to-debug silent failures.

For ptx, I think we can create both tables at the same time in the 
image-generating tool, so I'm hoping that it won't be a problem. I'll 
let you know what I find, but it would still be nice to come up with 
something more robust.

> Could you please describe how functions would be invoked on
> PTX?

First we let the driver compile and load all the ptx code, then we'd 
call a cuda library function with the name of the function passed as a 
string. So I guess the host table would contain pointers to the host 
version of the functions, and the target table would contain a pointer 
to the name.


Bernd