Created attachment 438500 [details] ebuild for microcode-data ver 2016/06/07 Intel has released a new version of the microcode for x86 cpu: https://downloadcenter.intel.com/download/26083/Linux-Processor-Microcode-Data-File?product=873 I've renamed the last ebuild and updated the url, seems to work without problems here (~x86_64).
Thanks for the report. Fixed in http://gitweb.gentoo.org/repo/gentoo.git/commit/?id=be80f0b97c58400faf2fe0631bd7542dc38f2105