Ping On Fri, Nov 15, 2013 at 7:45 PM, Andrey Turetskiy <andrey.turets...@gmail.com> wrote: > Let's suppose, we are going to run target gcc driver from lto-wrapper. > How could a list of offload targets be passed there from option > parser? > In my opinion, the simpliest way to do it is to use environment > variable. Would you agree with such approach? > > On Fri, Nov 8, 2013 at 6:34 PM, Jakub Jelinek <ja...@redhat.com> wrote: >> On Fri, Nov 08, 2013 at 06:26:53PM +0400, Andrey Turetskiy wrote: >>> Thanks. >>> And a few questions about compiler options: >>> 1) You've mentioned two options for offloading: >>> -foffload-target=<set of targets> - to specify targets for offloading >>> -foffload-target-<target name>=<set of options> - to specify >>> compiler options for different targets >>> Do we really need two options to set up offloading? >>> What do you think about, in my opinion, more compact way: >>> -foffload-<target name> - if I want to offload for 'target name', >>> but I don't want to specify any options >>> -foffload-<target-name>=<set of options> - enable offloading for >>> 'target name' and set options >>> And compilation for several targets would look like: >>> gcc -fopenmp -foffload-mic="-O3 -msse -m64" -foffload-ptx >>> -foffload-hsail="-O2 -m32" file.c >> >> I don't think it is a good idea to include the target name before = >> in the name of the option, but perhaps you can use two =s: >> -foffloat-target=x86_64-k1om-linux="-O2 -mtune=foobar' >> -foffloat-target=ptx-none >> >>> 2) If user doesn't specify target options directly, is target >>> compilation done without any option or compiler uses those host >>> options which are suitable for target? >> >> I think I've said that earlier, non-target specific options from original >> compilation should be copied over, target specific options discarded, >> and the command line supplied overrides appended to that. >> >>> 3) Am I understand right, that options for different targets should be >>> stored in different sections in fat object file, and than lto frontend >>> should read theese options and run target compilation with them? >> >> No, I'd store in the LTO target IL only the original host compilation >> options that weren't target specific (opt* has some flags what is target >> specific and what is not), so say -O2 -ftree-vrp would go there, >> but say -march=corei7-avx would not. And the -foffload-target= options >> would only matter during linking. >> >> Jakub > > > > -- > Best regards, > Andrey Turetskiy
-- Best regards, Andrey Turetskiy
