[petsc-dev] I am getting this error ...

[Satish Balay]

Multiple e-mail threads on the same issue (:

As suggested in my earlier thread - add -mp=gpu to both CPPFLAGS and CFLAGS [or LDFLAGS]

Satish

-------
Executing: cc  -o /tmp/petsc-Vvs8_T/config.setCompilers/conftest   -g -DLANDAU_DIM=2 -DLANDAU_MAX_SPECIES=10 -DLANDAU_MAX_Q=4 /tmp/petsc-Vvs8_T/config.setCompilers/conftest.o
Possible ERROR while running linker:
stderr:
nvc-Warning-The -gpu option has no effect unless a language-specific option to enable GPU code generation is used (e.g.: -acc, -mp=gpu, -stdpar, -cuda)


On Thu, 4 Nov 2021, Mark Adams wrote:

> It is CPPFLAGS. I seem to get the same behavior.
> 
> FWIW, I did get this response from NERSc but I don't know how to interpret
> it.
> 
> He seems to be saying that I don't need -mp=gpu for the device compiler
> (nvcc). He seems to think that I am adding -gpu.
> 
> nvcc -- The device compiler does not need any of those flags because it
> already knows that it's being fed cuda code. The warning you're seeing is
> coming from nvc (which is the host / CPU side compiler) if you're in the
> PrgEnv-nvidia environment. You should not need to add -mp=gpu and -cuda,
> please just add the -cuda flag (to your host code) not to the device code.
> 
> I will try to talk with this guy again.
> 
> Thanks,
> 
> 
> On Thu, Nov 4, 2021 at 4:11 PM Barry Smith <bsmith at petsc.dev> wrote:
> 
> >
> >   Yes, you need to use the CPPFLAGS which maybe called CPPCFLAGS I am not
> > sure
> >
> >
> > On Nov 4, 2021, at 3:23 PM, Mark Adams <mfadams at lbl.gov> wrote:
> >
> > Ah, CCFLAGS does not seem to work.
> >
> > On Thu, Nov 4, 2021 at 3:07 PM Barry Smith <bsmith at petsc.dev> wrote:
> >
> >>
> >>   You have to pass in the flag to turn off the bitching about -gpu to the
> >> C preprocessor, not the C compiler.
> >>
> >>
> >> stderr:
> >> nvc-Warning-The -gpu option has no effect unless a language-specific
> >> option to enable GPU code generation is used (e.g.: -acc, -mp=gpu, -stdpar,
> >> -cuda)
> >> Source:
> >> #include "confdefs.h"
> >> #include "conffix.h"
> >> #include <stdlib.h>
> >>
> >>
> >>
> >> > On Nov 4, 2021, at 2:49 PM, Mark Adams <mfadams at lbl.gov> wrote:
> >> >
> >> > on Perlmutter with nvhpc:
> >> >
> >> >               Defined make macro "CPP" to "cc --use cpp32"
> >> > Preprocessing source:
> >> > #include "confdefs.h"
> >> > #include "conffix.h"
> >> > #include <stdlib.h>
> >> >
> >> > Executing: cc --use cpp32  -I/tmp/petsc-jV9U1b/config.setCompilers
> >> /tmp/petsc-jV9U1b/config.setCompilers/conftest.c
> >> > Possible ERROR while running preprocessor: exit code 1
> >> > stderr:
> >> > nvc-Error-Unknown switch: --use
> >> > Source:
> >> > <configure.log>
> >>
> >> <configure.log>
> >
> >
> >
>