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Re: [Qemu-devel] [PATCH v1 7/9] tests/tcg: add float_madds test to multi
From: |
Alex Bennée |
Subject: |
Re: [Qemu-devel] [PATCH v1 7/9] tests/tcg: add float_madds test to multiarch |
Date: |
Wed, 18 Sep 2019 12:33:18 +0100 |
User-agent: |
mu4e 1.3.4; emacs 27.0.50 |
Richard Henderson <address@hidden> writes:
> On 9/17/19 5:00 PM, Alex Bennée wrote:
>>>> + add_f32_const(0x8p-152);
>>>> + add_f32_const(0x8p-152);
>>>> + add_f32_const(0x8p-152);
>>>
>>> Why are you adding 3 of the same?
>>
>> To replicate the 1841491 test case where the same number is used for
>> a/b/c
>
> Then we really ought to be more explicit about that.
I guess - I was hoping to piggy back on the general case. Maybe we
should just split that into a separate test case. We can at least re-use
the format and flag printing code and drop the behind the scenes magic
to "join" the constant table with extra test values.
> You're not doing full permutations on the sets of numbers, so does
> incrementing
> a random index really test what you intended?
I did initially do the full permutation but for madds it all adds up
quite quickly. The shuffle we do here is a bit of a comprise, so it
shuffles the various nan forms before nans with -inf and -large and
finally a bunch of real numbers (subnormals in the middle). It gives a
reasonably broad coverage without going nuts.
>
>>>> +#if defined(__arm__)
>>>> + r = __builtin_fmaf(a, b, c);
>>>> +#else
>>>> + r = __builtin_fmaf(a, b, c);
>>>> +#endif
>>>
>>> Eh?
>>
>> Ahh I was going to hardcode the arm madd instruction in as the builtin
>> wasn't expanding. I tried setting -march in the CFLAGS but that didn't
>> trigger it either on my buster arm-hf compiler. Any ideas how to get the
>> compiler to do the right thing?
>
> I think you want -mfpu=neon-vfpv4.
Ahh that worked. I would have hoped that v8 would be enough to spit out
aarch32 code which has to have VFPv4 for A profile right?
Anyway I'll use that for now.
>
>
> r~
--
Alex Bennée
[Qemu-devel] [PATCH v1 9/9] tests/tcg: add refs for PPC float_[convs|madds] tests (FAILS TESTS), Alex Bennée, 2019/09/17
Re: [Qemu-devel] [PATCH v1 0/9] testing/next (docker, podman, float), no-reply, 2019/09/18