Global Instruction Selection BPF example

Code Generation Common Infrastructure
1

Hi,

Porting GlobalISel to A New Target — LLVM 16.0.0git documentation recommends these slides https://llvm.org/devmtg/2017-10/slides/Bogner-Nandakumar-Sanders-Head%20First%20into%20GlobalISel.pdf (presented in video 2017 LLVM Developers’ Meeting: J. Bogner & A. Nandakumar & D. Sanders “Tutorial: GlobalISel ” - YouTube)

In the slides and video, BPF is taken as an example and Global Instruction Selection is explained. I tried to follow it to add Global Instruction Selection for a new Target but I am not seeing any of the functions mentioned on Slide 18 in BPF target llvm source.

getRegBankInfo()
getLegalizerInfo()
etc.

I am using llvm 14 version. Which llvm version is the video referring to whose BPF Target source matches to whatever is presented?

Thanks

2

The talk didn’t correspond to any specific released version. No BPF GlobalISel support was ever added as far as I know. In tree, only AArch64 and AMDGPU have any any substantial support.

1 Like
3

I see. The talk specifically mentioned BPF as being the easiest to implement as it has less lines of code.

Good to know that it was never added, otherwise, I would have been searching.