Nouveau Developer Working On NIR For SPIR-V Compute, Step Towards Vulkan In The Future

[phoronix]

Phoronix: Nouveau Developer Working On NIR For SPIR-V Compute, Step Towards Vulkan In The Future

There's some exciting news for open-source NVIDIA "Nouveau" driver users this holiday season!..

http://www.phoronix.com/scan.php?page=news_item&px=NIR-Nouveau-Starts

[crymsonpheonix]

It's nice to see that they're using NIR like Intel and AMD are doing, and not trying to parse SPIR-V directly into their backend IR. That plan was always crazy and duplicated all of the code that Intel and AMD have invested in and validated for getting SPIR-V working with their drivers. This should also make getting GL 4.6 on nouveau easier, since they'll be able to just plug in the work that AMD and Intel are doing.

[mulenmar]

This should also make getting GL 4.6 on nouveau easier, since they'll be able to just plug in the work that AMD and Intel are doing.

Shhhh! nVidia will realize they're helping the nouveau devs and will suddenly remember to make their code useless without the blob-driver and signed firmware!

[Anvil]

Shhhh! nVidia will realize they're helping the nouveau devs and will suddenly remember to make their code useless without the blob-driver and signed firmware!

this may sound Good but my bets still lots of people will still need the closed source drivers, the opensource ones will never be able to seriously compete

[remm]

I don't get why Red Hat invests in Nouveau, since unfortunately it will never work without some minimal cooperation from NVidia (releasing firmware, which now isn't happening at all).

[discordian]

It's nice to see that they're using NIR like Intel and AMD are doing, and not trying to parse SPIR-V directly into their backend IR. That plan was always crazy and duplicated all of the code that Intel and AMD have invested in and validated for getting SPIR-V working with their drivers. This should also make getting GL 4.6 on nouveau easier, since they'll be able to just plug in the work that AMD and Intel are doing.

Honest question: Why is "aNother IR" necessary and was created in the first place?
There might be valid technical reasons for that, but I guess if *some other* company would have created it instead of using SPIR-V there would be a big backlash.

[discordian]

Shhhh! nVidia will realize they're helping the nouveau devs and will suddenly remember to make their code useless without the blob-driver and signed firmware!

Let us all thank for NVidia, who gives purpose for countless lives and ensures we can read posts like the one quoted. Amen!

[FireBurn]

Honest question: Why is "aNother IR" necessary and was created in the first place?
There might be valid technical reasons for that, but I guess if *some other* company would have created it instead of using SPIR-V there would be a big backlash.

There was a whole discussion on it when it was first created, basically NIR was created to be typeless and built for SSA (Static single assignment) which allows for more standard compiler optimizations. Then SPIR-V came along and it was determined that NIR would allow both GLSL & SPIR-V shaders to be represented and it wouldn't be much overhead to translate between the two, the theory being that a translation layer is less compute time than running optimizations on different IRs and NIR allowed for the most optimization

This all from memory by the way so apologies if I've mis-remembered stuff

[crymsonpheonix]

There was a whole discussion on it when it was first created, basically NIR was created to be typeless and built for SSA (Static single assignment) which allows for more standard compiler optimizations. Then SPIR-V came along and it was determined that NIR would allow both GLSL & SPIR-V shaders to be represented and it wouldn't be much overhead to translate between the two, the theory being that a translation layer is less compute time than running optimizations on different IRs and NIR allowed for the most optimization

This all from memory by the way so apologies if I've mis-remembered stuff

Pretty close. SPIR-V is not an optimizing IR, it's an interchange format. One anology to use would be that SPIR-V is like JSON, and NIR is like arrays and hash tables. No one directly edits JSON, no one tries to optimize SPIR-V, you convert it into an IR that is meant for optimiziations, like NIR or LLVM-IR (for example), and no one attempts to programatically edit JSON, you convert it into native containers (arrays and hash tables) and modify those.

Small nit, "NIR" is "New IR" not "aNother IR"