Hi,
On Tue, Aug 06, 2024 at 02:11:45PM -0600, Jeff Law wrote:
> On 8/6/24 1:50 PM, Florian Weimer wrote:
> >* Jeff Law via Gcc:
> >
> >>On 8/5/24 4:23 PM, Mark Wielaard wrote:
> >>
> >>>It was suggested to just ignore the machine has rvv since it isn't
> >>>1.0
> >>>compliant. So it is now configured --with-arch=rv64gc --with-abi=lp64d
> >>>--with-multilib-list=lp64d but that didn't really change any of the
> >>>testresults since the rvv vector tests are still all run.
> >
> >>Quite possibly because the damn thing claims it's "V", but in fact
> >>it's not compatible with the V1.0 spec. Sadly it's a common problem
> >>for these V0.7.1 systems.
> >
> >I've seen kernel patches floating around that mask the __riscv_hwprobe
> >flags for those machines. Haven't they been merged?
> Dunno. I know there's patches out there, but no clue if they're
> been merged and if there's all the bits needed to build a new kernel
> that'll work on that system.
The pioneer box is still running the Fedora 38 (vendor) kernel linux
6.1.31 which doesn't seem to have the riscv_hwprobe system call yet.
But I don't fully understand how the gcc testsuite detects whether rvv
is implemented. e.g. rvv.exp seems to just check whether the target is
RISC-V and if so just executes all tests assuming it can just set
-march=rv64gcv* and/or -mrvv-* and run the tests:
# Exit immediately if this isn't a RISC-V target.
if ![istarget riscv*-*-*] then {
return
}
Should that test be more precise? Or is there some other test that is?
I do see some of the runtime tests have:
/* { dg-do run { target { riscv_v } } } */
How exactly does that work? How does it determine the riscv_v target?
> Ours has been so flaky that we don't use it much.
I put an extra fan on it. It has been pretty stable. Last couple of
days it has been doing back-to-back gcc bootstaps. Which now take ~5
hours about half of the time it is actually using 64 cores at the same
time, but it is also running a lot of time just one or a few cores.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84402
Cheers,
Mark
