[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: 950720: netCDF problem

>Organization: IBM
>Keywords: 199507201733.AA28655

Hi Chris,

> netCDF version 2.3.1
> AIX    version 3.2.5
> XLF    version 3.2.2.1
>   
> RISC System/6000 model 590
>   
> I'm using netCDF 2.3.1 which I downloaded from your anon server this
> afternoon. The application code has been supplied by a customer for me
> to run a benchmark - I can send the code if needed.

You must mean netcdf 2.3.2, if you downloaded it this afternoon from
ftp.unidata.ucar.edu.  As far as I know, there is no 2.3.1 version
available.  You can see the version number by looking at the file VERSION in
the top-level of the netCDF source directory.

The version of AIX/XLF you are using had a compiler/optimizer bug for which
there was a workaround, described in our netCDF Frequently Asked Questions
list at the URL http://www.unidata.ucar.edu/packages/netcdf/faq.html#aix

 12. Is there a problem with building netCDF under AIX 3.2? 

     We have observed a problem with the optimizer in the C compiler of AIX
     3.2. The default for our configure script is to specify optimization by
     using the "-O" compiler flag, but that causes the netCDF library to be
     built incorrectly under AIX 3.2, with the symptom that "make test" will
     fail even though there are no compile or link errors when building from
     source.

     A workaround is to build the netCDF library with CFLAGS="" (or "-g")
     explicitly, by setting the environment variable CFLAGS to "" or "-g"
     before invoking configure, or by using one of the other methods
     suggested in the INSTALL file to prevent the use of the "-O" flag for
     compilation.

     The specific file that is incorrectly compiled with "-O" is
     libsrc/string.c, so another workaround is to recompile that file
     without "-O".

     Delete the ncgen and ncdump executables before rebuilding, so they will
     get rebuilt using the new library.

     NOTE: This is no longer a problem on AIX 4.1.2. 

If you had run "make test" after building the netCDF library with "make
all", you would have seen a test failure that is a symptom of this problem.
If after following the workaround suggested above and relinking with the new
library you still see the problem, please let us know.  Thanks.

> There were no errors shown during the compilation and linking of either
> netCDF or the application.

The optimization error only shows up in the output of "make test".

______________________________________________________________________________

Russ Rew                                           UCAR Unidata Program
address@hidden                              http://www.unidata.ucar.edu