MLIR Dialects for Multi-Threading GCC

[Nicholas Krause]

Greetings All,

Seems the LLVM side has made a multi threaded pass manager in MLIR:
https://mlir.llvm.org/docs/WritingAPass/

It also seems to have fixed a lot of the issues around my research in
SSA. There are two ways to look into using MLIR either:

a) Write a dialect of it for GIMPLE
b) Use the ideas but implement them internally in GCC rewriting passes
into the core infrastructure as need be

Not sure if other people think its a good idea or there are license issues,
Nick