On Sun, Jan 18, 2015 at 3:23 PM, Michał Górny <mgo...@gentoo.org> wrote: > Dnia 2015-01-18, o godz. 15:15:22 > Matt Turner <matts...@gentoo.org> napisał(a): > >> On Sun, Jan 18, 2015 at 12:44 PM, Michał Górny <mgo...@gentoo.org> wrote: >> > Hello, >> > >> > I would like to commit the following flags as cpu_flags_x86_desc. >> > The list combines global USE flags with some local USE flags I've been >> > able to find. >> > >> > >> > 3dnow - Use the 3DNow! instruction set >> > 3dnowext - Use the Enhanced 3DNow! instruction set >> > aes-ni - Enable support for Intel's AES instruction set (aes in cpuinfo) >> > avx - Adds support for Advanced Vector Extensions instructions >> > avx2 - Adds support for Advanced Vector Extensions 2 instructions >> > fma - Use the Fused Multiply Add instruction set >> >> There are fma3 and fma4 instruction sets. We need to determine which >> one the packages that have this flag are actually using and name the >> flag appropriately. > > Ok then: > > fma3 - Use the Fused Multiply Add v3 instruction set > fma4 - Use the Fused Multiply Add v4 instruction set
They're not actually versions 3 and 4, like SSE. The number is the number of arguments the instructions take. I'd just remove the 'v' from the description and call it good. See http://en.wikipedia.org/wiki/FMA_instruction_set for more information.
