On March 6, 2017 6:55:10 PM GMT+01:00, Alexander Monakov <amona...@ispras.ru> wrote: >On Mon, 6 Mar 2017, Richard Biener wrote: >> >I am not a lawyer and this is not legal advice. >> > >> >Generating SPIR-V output would not cause that output to become GPLv3 >> >licensed. However, linking the result against the GCC support >> >libraries, as is normally required for any program generated by GCC, >> >and then distributing the resulting executable to other people, >would >> >require you to use an eligible compilation process (as defined by >the >> >GCC Runtime Library Exception license that you cite). What this >means >> >in practice is that you can not take SPIR-V, do further processing >it >> >using a proprietary compiler, link the result with the GCC runtime >> >libraries, and then distribute the resulting program to anybody >else. >> > >> >I don't think it is necessary to determine whether SPIR-V is "target >> >code" or "intermediate representation" to draw that conclusion. >> >> Note we already have the HSAIL and PTX backends which have the very >same >> (non-)problem. Both invoke a proprietary compiler for final >compilation. > >Sorry, to me this statement sounds a bit ambiguous, so allow me to >clarify: >there is no mandatory invocation of proprietary code generators taking >place as >part of GCC invocation (I think there's none at all in case of HSAIL, >and in >case of PTX it's done for the purpose of syntax checking and can be >omitted). > >Translation of HSAIL/PTX assembly to GPU binary code takes place when >the >host executable runs, on user's machine, by invoking corresponding >libraries (in >case of PTX it's NVIDIA's CUDA driver library). > >There is no support for translating HSAIL/PTX on the developer's >machine and >linking the resulting GPU binary code into GCC-produced executable.
Yes, the final compilation taking part 'after' distribution might be a working loophole here. Not sure if that was intended though (and both PTX and HSAIL and up being dynamically linked with libgomp). I suppose some bits of clarifying documentation would be nice here. Richard. >Hope that helps. >Alexander
