On Mon, 27 Sept 2021 at 19:16, L A Walsh <gcc@xxxxxxxxx> wrote: > > On 2021/09/27 10:13, Segher Boessenkool wrote: > > On Mon, Sep 27, 2021 at 02:55:28PM +0200, Vincent Lefevre wrote: > > > >> On 2021-09-17 12:53:25 -0500, Segher Boessenkool wrote: > >> > >>> For x86 -march=something is the same as -march=native, _if_ the compiler > >>> knows about your CPU. > >>> > ---- > I have a question, as someone reading this conversation .... > > If one is using cross-compilation -- as it sounded like the original > author might be doing, what could the compiler know about the target > machine? Only what you tell it. > Is there some sort of "profile-this-cpu-for-pertinent-options" binary > or compiler-option that one should(or could) run on the target > machine in order that the correct compiler switches be set? > > Otherwise, it would seem that -march=native would only be useful for > the (probably majority of) cases where one is compiling for their own > machine (?). Yes, -march=native is for native compilation, not cross compilation. The clue is in the name :-)
