Zack Rusin Talks About Gallium3D's TGSI IR

[phoronix]

Phoronix: Zack Rusin Talks About Gallium3D's TGSI IR

Lately there's been a lot of talk about Gallium3D's IR known as TGSI, or Tokenized Gallium Shader Instructions, and attempts by some to replace this intermediate representation. Efforts toward improving TGSI are not particularly new, but it's been going on for a while and then just earlier this month a new shader and compiler stack was proposed by LunarG. As part of the LunarGLASS proposal, the LLVM IR would be used as a replacement to TGSI...

http://www.phoronix.com/vr.php?view=ODcyOQ

[markg85]

I was under the impression that all video cards work on one thing at the lowest level: TGSI, but now it seems like even there is fragmentation where ATI has a specific set of "TGSI" (IR) functions..

More info on this subject would be nice, just to understand a little what it all is ^_^

[bridgman]

Zack is talking about the IL used by our proprietary driver stack, which has been around for years. The driver stack converts GL shaders, DX shaders, and OpenCL programs to a common IL then the shader compiler processes that down to optimized hardware instructions.

Every HW vendor has something similar; ours just happens to be exposed and documented as part of the Stream initiative, and we happen to use the same IL for graphics and compute (not sure if other vendors do that).

I think Zack suggested that the NVidia equivalent is also exposed as part of PTX but not sure.