On Fri, Sep 20, 2024 at 6:50 PM Thomas Schwinge <tschwi...@baylibre.com> wrote:
>
> Hi!
>
> (This is orthogonal to yesterday's
> "GCC 15: nvptx '-mptx=3.1' multilib variants are deprecated".)
>
> We'd like to raise nvptx code generation from PTX ISA 6.0, sm_30 "Kepler"
> to default PTX ISA 7.3, sm_52 "Maxwell", therefore CUDA 11.3 (2021-04).
> This is, primarily, so that we're able to use 'alloca' and related stack
> manipulation instructions, and improve upon the current:
>
> sorry ("target cannot support alloca");
>
> I see, for example:
>
> - Ubuntu 22.04 "jammy" LTS has 11.5.1-1ubuntu1 packaged
> - Debian 12 "stable" ("bookworm", 2023-06) has 11.8.89~11.8.0-5~deb12u1
> packaged
>
> ..., and sm_52 "Maxwell" has been supported as of CUDA 6.5 (2014-08), and
> thus supported by most Nvidia GPUs of the last decade, approximately.
>
> The question is, whether we continue to build by default also the current
> sm_30 "Kepler" multilib variants (to be available for use via
> building/linking with '-march=sm_30'), or if that's truly obsolete by
> now, and need no longer be available by default? (It has been deprecated
> for a long time, and sm_3x "Kepler architecture support is removed from
> CUDA 12.0", 2022-12.) There's always the 'configure'-time
> '--with-arch=sm_30' if you (additionally to sm_52) still need your target
> libraries built for sm_30 multilib variants; I would argue that's
> sufficient?
I seem to have Turing so the change works for me; How would the user
experience be with using the sm_30 multilib?
Richard.
>
> Grüße
> Thomas
