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...017 um 02:05 schrieb Ilia Mirkin: > On Mon, Jun 12, 2017 at 7:57 PM, Roland Scheidegger <sroland at vmware.com> wrote: >> FWIW surely on nv50 you could keep a single mad instruction for umad >> (sad maybe too?). (I'm actually wondering if the hw really can't do >> unfused float multiply+add as a single instruction but I know next to >> nothing about nvidia hw...) > > The compiler should reassociate a mul + add into a mad where possible. > In actuality, IMAD is actually super-slow... allegedly slower than > IMUL + IADD. Not sure why. Maxwell adde...

...esselation...) For 1/9: Reviewed-by: Roland Scheidegger <sroland at vmware.com> 2/9 has a typo in the commit short log ("Instrutions"). FWIW surely on nv50 you could keep a single mad instruction for umad (sad maybe too?). (I'm actually wondering if the hw really can't do unfused float multiply+add as a single instruction but I know next to nothing about nvidia hw...) Roland Am 12.06.2017 um 12:42 schrieb Nicolai Hähnle: > On 11.06.2017 20:42, Karol Herbst wrote: >> Running Tomb Raider on Nouveau I found some flicker caused by ignoring >> precise >>...

On Mon, Jun 12, 2017 at 7:57 PM, Roland Scheidegger <sroland at vmware.com> wrote: > FWIW surely on nv50 you could keep a single mad instruction for umad > (sad maybe too?). (I'm actually wondering if the hw really can't do > unfused float multiply+add as a single instruction but I know next to > nothing about nvidia hw...) The compiler should reassociate a mul + add into a mad where possible. In actuality, IMAD is actually super-slow... allegedly slower than IMUL + IADD. Not sure why. Maxwell added a XMAD operation which...

...sure where maybe under Modifiers or some such. Roland > > 2/9 has a typo in the commit short log ("Instrutions"). > > FWIW surely on nv50 you could keep a single mad instruction for umad > (sad maybe too?). (I'm actually wondering if the hw really can't do > unfused float multiply+add as a single instruction but I know next to > nothing about nvidia hw...) > > Roland > > Am 12.06.2017 um 12:42 schrieb Nicolai Hähnle: >> On 11.06.2017 20:42, Karol Herbst wrote: >>> Running Tomb Raider on Nouveau I found some flicker caused by i...

> On Feb 11, 2016, at 12:43 AM, via llvm-dev <Alexander G. Riccio> wrote: > > I don’t think that we can agree to abstract code guidelines without knowing what it means in practice for the codebase. If you’re interested in this, please include a diff that shows the impact to the headers, and we should also measure what happens to the performance of the generated compiler. > >

Running Tomb Raider on Nouveau I found some flicker caused by ignoring precise modifiers on variables inside Nouveau. This series add precise/invariant handling to TGSI, which can be then used by drivers to disable certain unsafe optimisations which may otherwise alter calculations, which depend on having the same result across shaders. This series fixes this bug in Tomb Raider and one CTS test