This is the mail archive of the
mailing list for the GCC project.
Re: OpenACC in GCC - how does it not violate the license?
- From: Jeff Hammond <jeff dot science at gmail dot com>
- To: Jeff Law <law at redhat dot com>
- Cc: Alec Teal <a dot teal at warwick dot ac dot uk>, GCC <gcc at gcc dot gnu dot org>
- Date: Sun, 17 Nov 2013 08:32:35 -0600
- Subject: Re: OpenACC in GCC - how does it not violate the license?
- Authentication-results: sourceware.org; auth=none
- References: <52884CE8 dot 2050002 at warwick dot ac dot uk> <52885287 dot 9030202 at redhat dot com>
> On Nov 16, 2013, at 11:22 PM, Jeff Law <firstname.lastname@example.org> wrote:
>> On 11/16/13 21:58, Alec Teal wrote:
>> Now while great, is this true!? Nvidia (IIRC, this was like a year ago
>> though) don't even give out the instruction set for their GPUs, can we
>> have GCC targeting closed things? Also there (must be and is) a Cuda
>> runtime, wouldn't we need an open runtime to link against?
> The various projects looking at supporting OpenACC are, to the best of my knowledge, targeting PTX, which is a virtual ISA from NVidia which is published.
> Going from PTX to the actual instructions for the particular GPU is the job of a runtime system which would be provided by NVidia.
If one wants to tilt at these windmills, we should belabor the lack of open documentation of the microcode corresponding to the x86 instruction set.
> However, there's no reason why OpenACC couldn't target the host CPU or another GPU. In fact, that's what I'd initially do if I were working on this.
>> This is by no means an accusation, I'm sure he's doing fine work; but
>> he's doing something I didn't think the GPLv3 allowed (so I want to be
>> corrected) he seems to have added something that requires a closed
>> runtime for a target with a closed instruction set - probably for Nvidia
>> (as he is responsible for "strategic partnerships" with them)
> To answer that question you'd need to talk to your lawyer.