Re: [gentoo-dev] Moving CPU flags into USE_EXPAND

[Alexis Ballier]

On Mon, 19 Jan 2015 23:43:19 -0800
Christopher Head <chead@×××××.ca> wrote:

> On Wed, 14 Jan 2015 11:01:16 -0800
> Zac Medico <zmedico@g.o> wrote:
>
> > Why should we have to foresee the future? We can easily add support
> > for new flags in CPU_FLAGS_* variables at any time.
>
> Ah, what I meant was that whoever maintains this flag list only needs
> to forsee the present—when AMD or Intel adds a new instruction set
> extension, you add a flag for it to the variable immediately, whether
> or not any package actually uses it yet. Why? Here’s why:
>
> Case 1: flags are added only as packages need them. This is pretty
> much what we have today, only without the USE-expand feature. Every
> time a package adds support for a new CPU feature, it gets a new USE
> flag, and I see it in my emerge output.
[...]

you will not see it if no package use it.


Alexis.