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Re: Failure in math/test-float-vlen8-avx2-log.out
- From: Carlos O'Donell <carlos at redhat dot com>
- To: Paul Pluzhnikov <ppluzhnikov at google dot com>, GLIBC Devel <libc-alpha at sourceware dot org>
- Date: Sat, 19 May 2018 20:30:41 -0400
- Subject: Re: Failure in math/test-float-vlen8-avx2-log.out
- References: <CAPC3xarhW9odKuqaao5dS4jaeaDrYQqpPsABvoO1rGWJmLt=OA@mail.gmail.com> <CALoOobMy_GPPEO+aksh-z=WsTZAq=jr-VuoF_+1nqN6bhZDk1Q@mail.gmail.com>
On 05/19/2018 04:04 PM, Paul Pluzhnikov wrote:
> Greetings,
>
> I am seeing failure in math/test-float-vlen8-avx2-log.
> Is that a real failure, or should ulps be updated?
>
> Thanks,
>
> $ cat math/test-float-vlen8-avx2-log.out
> testing float (vector length 8)
> Failure: Test: log_vlen8_avx2 (0xb.0d5dfp-4)
> Result:
> is: -3.69957983e-01 -0x1.7ad644p-2
> should be: -3.69957894e-01 -0x1.7ad63ep-2
> difference: 8.94069672e-08 0x1.800000p-24
> ulp : 3.0000
> max.ulp : 2.0000
> Maximal error of `log_vlen8_avx2'
> is : 3 ulp
> accepted: 2 ulp
>
> Test suite completed:
> 36 test cases plus 0 tests for exception flags and
> 0 tests for errno executed.
> 2 errors occurred.
>
>
> $ cat /proc/cpuinfo
> processor : 0
> vendor_id : AuthenticAMD
I haven't seen this failure, but I also haven't tried
the CPU you're using.
Given that this is an AMD CPU, a difference of 1 ULP
from 2 to 3 for log is OK. Real errors generally show
up as thousands of ULPs error.
I would submit an ULPs update patch for review and state
the hardware you used.
--
Cheers,
Carlos.