Re: MIPS-specific porting issue

[Mathieu Malaterre <malat@debian.org>]

Salut Stéphane,

On Fri, Dec 3, 2021 at 10:19 AM Stéphane Glondu <glondu@debian.org> wrote:
>
> Dear MIPS porters,
>
> I am debugging ocaml-mirage-crypto build on mipsel.
>
> It uses the following code:
>
> > #if defined (__i386__) || defined (__x86_64__)
> >   return Val_long (__rdtsc ());
> > #elif defined (__arm__) || defined (__aarch64__)
> >   return Val_long (read_virtual_count ());
> > #elif defined(__powerpc64__)
> >   return Val_long (read_cycle_counter ());
> > #elif defined(__riscv) && (64 == __riscv_xlen)
> >   return Val_long (rdcycle64 ());
> > #elif defined (__s390x__)
> >   return Val_long (getticks ());
> > #else
> > #error ("No known cycle-counting instruction.")
> > #endif
>
> I have trouble finding a suitable implementation for this on mipsel.
> Would you have a hint?

All I could find is this code (untested):

https://salsa.debian.org/science-team/nfft/-/blob/debian/master/include/cycle.h#L485-507