[Mesa-dev] [PATCH] llvmpipe: fix lp_test_arit denorm handling

[Roland Scheidegger]

Am 09.12.2014 um 06:40 schrieb Matt Turner:
> On Mon, Nov 24, 2014 at 2:37 PM,  <sroland at vmware.com> wrote:
>> From: Roland Scheidegger <sroland at vmware.com>
>>
>> llvmpipe disables denorms on purpose (on x86/sse only), because denorms are
>> generally neither required nor desired for graphic apis (and in case of d3d10,
>> they are forbidden).
>> However, this caused some arithmetic tests using denorms to fail on some
>> systems, because the reference did not generate the same results anymore.
>> (It did not fail on all systems - behavior of these math functions is sort
>> of undefined when called with non-standard floating point mode, hence the
>> result differing depending on implementation and in particular the sse
>> capabilities.)
>> So, for the reference, simply flush all (input/output) denorms manually
>> to zero in this case.
>>
>> This fixes https://urldefense.proofpoint.com/v2/url?u=https-3A__bugs.freedesktop.org_show-5Fbug.cgi-3Fid-3D67672&d=AAIBaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=kfA7P5Lq_Kc8RiA_OyaBMl6jeaxCRiOubj10LmlV8gI&s=23wd53B39EpRPW3XV9e2YRxGyVl3wa7ZHICdUTzoPt0&e= .
>> ---
> 
> Can we pick this to 10.4? I've had a Gentoo bug open about this
> failure for since 10.0.
> 
> (commit 8148a06b8fdb734f7f9a11ce787ee6505939fdaa in master)
> 

Well I guess why not. It's not like it actually fixes a bug in the
driver (just fixes the test) so it shouldn't hurt in any case neither :-).

Roland