There are two issues.
1. gcc actually does not use __ppc__ and __ppc64__ but __PPC__ and
__PPC64__. The tests of __ILP32__ and __LP64__ are sufficient for gcc.
2. clang defines __GNU__ and defines both __ppc64__ and __ppc__ when
targeting ppc64. This makes CARES_SIZEOF_LONG to be 4 on a ppc64 system
when building with clang.
My patch is two change the order of the checks so that we check the
64-bit case first.
GCC specific adjustments:
- check __ILP32__ before 32 and 64bit processor architectures in
order to detect ILP32 programming model on 64 bit processors
which, of course, also support LP64 programming model, when using
gcc 4.7 or newer.
- keep 32bit processor architecture checks in order to support gcc
versions older than 4.7 which don't define __ILP32__
- check __LP64__ for gcc 3.3 and newer, while keeping 64bit processor
architecture checks for older versions which don't define __LP64__
Doug Kwan
Yang Tse
Daniel Stenberg