Created attachment 395388 [details, diff] patch to omit CPU_FLAGS_X86="sse" from libvpx-1.3.0.ebuild In media-libs/libvpx there is REQUIRED_USE"cpu_flags_x86_sse? ( cpu_flags_x86_sse2 )" This is not very useful, since it means that users whose CPU can do sse but not sse2 (like AMD's athlon) and set CPU_FLAGS_X86 according to their processor's capabilities get an error when trying to emerge the package. They can fix it for this package by setting the value -cpu_flags_x86_sse in package.use. But this is strange for the user's cpu and also plays not well with temporarily overriding CPU_FLAGS_X86 in environment (e.g. when building binary packages for a different architecture). There is a much better solution: 1. If every sse2 system can also do sse (I suppose that this is true), one can just omit cpu_flags_x86_sse completely (because in this case, it is pointless for the ebuild), and let cpu_flags_x86_sse2 imply the current behaviour of cpu_flags_x86_sse (patch attached). 2. If the asumption of 1. is false or you possibly want to support some exotic sse2 systems which cannot do sse, you can additionally add a REQUIRED_USE, but in the opposite direction, which in contrast to the current solution hurts only users of such (probably rare) systems: REQUIRED_USE"cpu_flags_x86_sse2? ( cpu_flags_x86_sse )" In addition (I do not want to open a separate bug report for this), one should similarly also avoid the other two REQUIRED_USE restriction (that sse3 uses sse2 and that sse2 uses mmx) and make sse3 automatically imply sse2, and sse2 automatically imply mmx. However, in this case, the patch would be a bit longer. I will create and append it upon request.
I'm sorry but you're late to the party :). revision 1.17 date: 2015-02-02 15:33:55 +0100; author: mgorny; state: Exp; lines: +3 -3; commitid: 347954cf8ad24567; Bug #498364: disable USE=sse implicitly without sse2 rather than forcing non-SSE2 users to enable SSE2.
