The x32 ABI is a new linux ABI which aims at bringin the best from the 32 and 64 worlds. More informations can be found on the following websites:
With the attached patch, atlas builds fine and no problem have been encountered so far (however I didn't test it extensively)
The atlas build system passes unconditionally either -m32 or -m64 as flag to the toolchain. With x32, the correct flag is -mx32
So the proposed patch add a new possible value (48, for sure not ideal) for the '-b' switch. In this case, it passes the correct flag.
The number 48 may not be the best choice, but