dev-libs/atlas (3.5.11 tested) will build if the CPU detection is fixed. On my system, $CFLAGS doesn't contain anything that identifies the processor, so I hacked together a test to see if $CHOST contains "x86_64" and outputs "2" to the output file. Need to add ~amd64 to KEYWORDS too. Reproducible: Always Steps to Reproduce:
New version 3.6.0 in CVS with ~amd64, thanks!