Special instructions for OS X

Newer versions of OS X ship broken versions of the gnu binutils. They are deprecated in favor of clang, which as of 3.10.3 can be used to get a fairly performant and correct ATLAS install. Add the flag ``--force-clang=/path/to/clang'' to your configure line so that ATLAS knows clang is your native compiler. If you have a fortran compiler using the name gfortran, then this is all that is necessary. If it is installed in a different name (even a close one like gfortran-5), then you should also add: ``-C if /path/to/f77comp''. If you have no fortran compiler, see Section [*].

Note that more recent GNU tar releases have become incompatible with OS X's native tar. If you have difficulty untarring the tarfiles, you may need to use gnu tar rather than OS X tar. On many OS X systems, GNU tar is available as gtar.

R. Clint Whaley 2016-07-28