Created attachment 205402 [details]
This patch ( https://github.com/xianyi/OpenBLAS/pull/2170 ) fixes build for PPC970 target. Since most people that run FreeBSD on powerpc64 use PowerPC 970 CPU's, switch to it by default and add non-default option to optimize for POWER6.
Technically, it would require bumping PORTREVISION, but considering low popularity of powerpc64 platform, I didn't do it. Do you require it?