-C acg /full/path/to/your/gcc
If you specify only the name and not the path (eg., ``-C alg gcc-4.4'', then ATLAS will search for the named compiler in your PATH variable. The safest approach is to give the full path to the compiler if gcc choice is critical to you. If you want also specify the gfortran to use, additionally add the flag:
-C if /full/path/to/your/gfortran
IMPORTANT NOTE: If you use a different gcc than preferred version,
you may reduce performance. Therefore once
your build is finished, you should make sure to compare your achieved
performance against what ATLAS's architectural defaults achieved. See
Section for details on how to do this.
If you can tolerate a long install time, you may also
want to tell ATLAS not to use the architectural defaults, as described
in Section
.
R. Clint Whaley 2016-07-28