[netCDF #NPG-935647]: Netcdf 3.6.3 with Powerpc64: cputype error

> Hi,
> 
> I am trying to build a 64-bit version of netcdf (3.6.3) in a powerpc64
> system (Mac G5). I am using gcc and gfortran 4.4.0 on Mac OS X 10.5.6.
> To ensure compilation in 64-bit mode I use -mpowerpc64 -m64 as compiler
> flags. I was told in the gcc mailing list that I should use both to have
> a 64-bit executable in powerpc64. While just -mpowerpc64 is fine,
> whenever I include -m64 the netcdf compilation exits with a cputype error:
> 
> a(netcdf.o) cputype (18) does not match previous archive members cputype
> (16777234) (all members must match)
> 
> Searching on the support mailing list I found similar problems. I have
> tested some of the suggestions, including:
> 
> * Using "-arch ppc -m64" instead of -mpowerpc64: doesn't work, gcc does
> not recognize the -arch option (?).
> 
> * Using the configure option --enable-64bit: also doesn't work,
> configure says that option is unrecognized.
> 
> 
> How do you suggest I compile netcdf for powerpc64? It works fine if I
> don't specify the 64-bit options, but I need to link it with a program
> that has to be 64-bit.
> 
> Thanks!
> 
> Tiago

Howdy Tiago!

I don't have a powerpc system to experiment with, and I don't know the answer 
to your questions.

However, I see something here, on this gcc page about the powerpc:
http://gcc.gnu.org/onlinedocs/gcc/RS_002f6000-and-PowerPC-Options.html

It says:
"The -mpowerpc option allows GCC to generate instructions that are found only 
in the 32-bit subset of the PowerPC architecture."

and...

"The -mpowerpc64 option allows GCC to generate the additional 64-bit 
instructions that are found in the full PowerPC64 architecture and to treat 
GPRs as 64-bit, doubleword quantities. GCC defaults to -mno-powerpc64."

So perhaps you want to use -mpowerpc64.

However, in general, the answer is to first figure out what command line 
options you need using some simple test case, before trying them on netCDF. If 
you can't get it to work on a simple test case, it is not going to work with 
the rather complex netCDF build system.

Good luck, and please let us know if you solve this problem, so that we can 
make the solution available to other netCDF users.

Thanks,

Ed

Ticket Details
===================
Ticket ID: NPG-935647
Department: Support netCDF
Priority: Normal
Status: Closed