Do graphic cards have instruction sets of their own? I assume they do, but I have been wondering if they are proprietary or if there is some sort of open standard.
Is every GPU instruction preceded by a CPU instruction or is it seamless?
That is, does OpenGL or DirectX call on the driver layer via the CPU which then sends a GPU instruction down the bus or is it more elaborate?
AMD Graphics Core Next (GCN)
https://en.wikipedia.org/wiki/Graphics_Core_Next
The first generation is called "Southern Islands".
The wiki page links to AMD specs that document the ISA, e.g.: http://developer.amd.com/wordpress/media/2012/12/AMD_Southern_Islands_Instruction_Set_Architecture.pdf
There is even an open RTL implementation called MIAOW https://github.com/VerticalResearchGroup/miaow, although it likely infringes some IP which AMD has merely chosen to tolerated in silence for now (source).
SPIR-V
https://en.wikipedia.org/wiki/Standard_Portable_Intermediate_Representation is a Krhonos standard intermediate language.
It is likely designed to be similar to existing GPU ISAs, so that it will be more implementable and have better adoption, so it should give a good idea of actual GPU ISAs.
And if this standard does catch on, as it seem to be the case due to adoption in Vulkan and OpenCL 2.1, future implementations are likely be designed to implement is closely to have better performance.
How to obtain and modify PTX
How to create or manipulate GPU assembler?
Related
https://computergraphics.stackexchange.com/questions/7809/what-does-gpu-assembly-look-like
