Status of clang-llvm builds? Related to powerpc-spe.

[Joel Sherrill]

On Sat, Jan 23, 2021, 3:36 AM Hesham Almatary <hesham.almatary at cl.cam.ac.uk>
wrote:

> On Fri, 22 Jan 2021 at 21:30, <dufault at hda.com> wrote:
> >
> > Actually, replying to myself:
> >
> > I bet the context-switching code is broken for platforms that use the
> SPE via a Freescale library.  That's something I'll need to look at.
> >
> > > On Jan 22, 2021, at 14:26 , Peter Dufault <dufault at hda.com> wrote:
> > >
> > > Signed PGP part
> > > The PowerPC Signal Processing Engine (powerpc-spe) is now gone from
> gcc and therefore from RTEMS (on the master branch).  It *appears* to be
> supported with Clang/LLVM on FreeBSD, apparently primarily to support some
> Amiga platforms (I think), I think it's supported beginning in FreeBSD 12.
> > >
> > > RTEMS has appropriately pulled out support for the SPE.  Since in the
> applications I use the SPE is used via libraries from
> Motorola/Freescale/... that may be OK, but having support for the
> architecture would "look good" to my clients.
> > >
> > > I'm not going to push for a project to switch to LLVM for the SPE
> targets, I don't have either the time or the money and I'm not going to ask
> my clients to fund it.  But I do want to know:
> > >
> > > - What's the status of Clang/LLVM and RTEMS?  Is it production-ready
> and production-used on certain (RISCV?) platforms?
>
> I don't think so (at least for RISC-V). Currently, it relies on users
> knowing how to build and teach LLVM about other externally-built libs
> such as newlib and compiler-rt (libgcc). Also, I had to add an RTEMS
> driver [1] to the backend and that's not upstream AFAIR.
> We will need to teach RSB to build all of that (currently it has a
> target for LLVM), newlib, compiler-rt and install a sysroot and a
> config file that includes paths to the installed libs. Additionally,
> to get C++ support, the relative libs will also need to be built
> manually/separately.
>

Is this any better with the sparc? Gaisler did work for ESA to support llvm
and I think they are shipping llvm with their RCC package.

>
> [1]
> https://github.com/CTSRD-CHERI/llvm-project/blob/master/clang/lib/Driver/ToolChains/RTEMS.cpp
>
> >
> > > - Does anybody know anything the quality of the "powerpc-spe" support
> in Clang/LLVM?
> > >
> > > This is must an exploratory question.  I don't have a plan to work on
> this soon.
> > >
> > > Peter
> > > -----------------
> > > Peter Dufault
> > > HD Associates, Inc.      Software and System Engineering
> > >
> > > This email is delivered through the public internet using protocols
> subject to interception and tampering.
> > >
> > >
> > >
> >
> > Peter
> > -----------------
> > Peter Dufault
> > HD Associates, Inc.      Software and System Engineering
> >
> > This email is delivered through the public internet using protocols
> subject to interception and tampering.
> >
> > _______________________________________________
> > devel mailing list
> > devel at rtems.org
> > http://lists.rtems.org/mailman/listinfo/devel
> _______________________________________________
> devel mailing list
> devel at rtems.org
> http://lists.rtems.org/mailman/listinfo/devel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rtems.org/pipermail/devel/attachments/20210123/2dc28af1/attachment.html>