Re: [PATCH 09/11] x86: rework CONFIG_GENERIC_CPU compiler flags

[Arnd Bergmann]

On Thu, Dec 5, 2024, at 09:13, Andy Shevchenko wrote:
> On Wed, Dec 04, 2024 at 03:33:19PM -0800, Linus Torvalds wrote:
>> On Wed, 4 Dec 2024 at 11:44, Arnd Bergmann <arnd@xxxxxxxx> wrote:
>
> ...
>
>> Will that work when you cross-compile? No. Do we care? Also no. It's
>> basically a simple "you want to optimize for your own local machine"
>> switch.
>
> Maybe it's okay for 64-bit machines, but for cross-compiling for 32-bit on
> 64-bit. I dunno what '-march=native -m32' (or equivalent) will give in such
> cases.

>From the compiler's perspective this is nothing special, it just
builds a 32-bit binary that can use any instruction supported in
32-bit mode of that 64-bit CPU, the same as the 32-bit CONFIG_MCORE2
option that I disallow in patch 04/11.

     Arnd