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Re: Math errors


On Fri, Jan 3, 2020 at 1:30 AM Szabolcs Nagy <Szabolcs.Nagy@arm.com> wrote:
>
> On 03/01/2020 02:18, Alistair Francis wrote:
> > On Mon, Dec 30, 2019 at 2:29 PM Joseph Myers <joseph@codesourcery.com> wrote:
> >>
> >> On Mon, 30 Dec 2019, Joseph Myers wrote:
> >>
> >>> On Mon, 30 Dec 2019, Alistair Francis wrote:
> >>>
> >>>> Hey,
> >>>>
> >>>> I'm running the `make check` tests on RV32 inside QEMU and about 800
> >>>> math tests are failing with errors along these lines:
> >>>
> >>> You need to generate libm-test-ulps for RV32 ("make regen-ulps") (also
> >>> remember to create a corresponding libm-test-ulps-name file for use in
> >>> generating the table in the manual).
> >>
> >> I should add: first try renaming the RV64 libm-test-ulps to make it
> >> generic for both RV32 and RV64.  You should only need a separate file for
> >> RV32 if there is a clear reason for different results between the two.
> >
> > Thanks Joseph,
> >
> > I moved the RV64 one to be generic and that seems to fix most of the
> > math tests. I tried `make regen-ulps` after that, just to be sure, and
> > it didn't generate a diff.
>
> regen-ulps should create a math/NewUlps file.
> (details are in math/README.libm-test)

Yep, I just meant that I diffed that to the RV64 one.

>
> >
> > There are a handful of math tests that seem to fail, but if I manually
> > run the test a few times I will eventually get a pass. Any hints on
> > what to do there?
>
> flaky math test is not normal, you need to investigate.

It turns out that there is a difference between libm-test-ulps for
RV32 and RV64. The gen-libm-test.py script was failing to run as I
don't have Python2 installed, so the file wasn't being updated. If I
manually run the script with Python3 I can generate a libm-test-ulps
file that is somewhat different to the RV64 one.

I'm running the tests now, but hopefully that fixes the failing math test cases.

Alistair

>
> >
> > Alistair
> >
> >>
> >> --
> >> Joseph S. Myers
> >> joseph@codesourcery.com
>


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