Talk:CPU FLAGS X86

USE flag groups
Many pages on this wiki reference CPU_FLAGS_X86, they should probably refer to this article in some way for the users who which to optimize their systems.

I've seeded it with the news item that introduces this use flag group since it is probably a good place to start.


 * In the years since this discussion was started, we now have links to the USE_EXPAND page, which explains this concept. I believe this discussion can be closed now. --Maffblaster (talk) 23:20, 8 February 2022 (UTC)

CPU_FLAGS_* for other architectures
I think PowerPC, ARM, MIPS and SPARC should also have support for such a feature. Who's with me? I can already provide a PowerPC machine. Grepwood (talk) 12:18, 17 April 2018 (UTC)


 * The CPU_FLAGS_ARM and CPU_FLAGS_PPC variables have been added.
 * I'm not sure about MIPS or SPARC... Fturco (talk) 11:50, 29 March 2020 (UTC)


 * If such existed I guess they would be listed in profiles/base/make.defaults
 * BTW: Thanks for adjusting my typo
 * --Charles17 (talk) 12:10, 29 March 2020 (UTC)

CPU/CPU_FLAGS_X86 public table
Over the past year I've been requested by clients to provide images of ready to use Gentoo systems tailored for specific systems. Often a time, I have to ask my clients to run a livecd of whatever on the target machine, compile cpuinfo2cpuflags, run it and mail me the output, in order to ensure the correct and best optimizations. If we could collect information about sepcific CPUs and their CPU_FLAGS_X86, we could reduce the amount of such queries made to people like me. Where would be a good place to host such a publically accessible table? Grepwood (talk) 12:18, 17 April 2018 (UTC)


 * Not sure if you still require this but if you wanted to record such a thing then the best place would be a page like Safe CFLAGS but for CPU FLAGS on the wiki so it's easily found by anyone in the community.
 * Immolo (talk) 11:30, 24 April 2023 (UTC)

Python script
I think the following sentences should be removed: "To help users enable the correct USE flags, a Python script is provided that generates the correct value using /proc/cpuinfo. It can be found in the app-portage/cpuid2cpuflags package."

On my system the app-portage/cpuid2cpuflags-6 package contains no Python script at all, just the /usr/bin/cpuid2cpuflags executable.

Can anyone confirm this?

Fturco (talk) 15:49, 23 July 2019 (UTC)


 * That sentence seems to apply to version 1 which is still in the tree. --Charles17 (talk) 05:55, 24 July 2019 (UTC)


 * OK, I added that info to the wiki article. Thank you! Fturco (talk) 10:22, 24 July 2019 (UTC)

Saving deprecated USE_flags still needed?
Is the CPU_FLAGS_X86 section still needed? Guess it's time to remove it. What do you think?--Charles17 (talk) 16:03, 28 November 2019 (UTC)


 * There are still several packages using USE instead of CPU_FLAGS_X86, CPU_FLAGS_ARM or CPU_FLAGS_PPC.
 * , for example, still relies on the  and   USE flags
 * Fturco (talk) 12:01, 29 March 2020 (UTC)