[RoadMap] Multi-Backend Refactoring/Decoupling

[SiriusNEO]

@SiriusNEO @LeiWang1999

TileLang currently supports multiple backends (CUDA, ROCm, etc.), but the codebase has become deeply coupled with specific backends. This tight coupling makes it difficult to add new backends and maintain existing ones.

This roadmap tracks our recent efforts on this refactoring. We will gradually refactor and reorganize the codebase to reduce backend coupling, establishing clear abstractions and interfaces that make it easy to integrate new backends.

• [Refactor][Build] Separate CMakeLists into different backends #2114
• [Refactor][CodeGen] Refactor CodeGen part for multi-backend decoupling #2121
• [Refactor][Backend] Split tl.copy lowering by backend #2138
• [Backend] Refactor Transform Pipeline to support different backends #2189
  • [Backend] Promote PassPipeline to backend sub-folder and cleanup Metal Leftover #2291
  • [Backend][Transform] Move backend-specific transforms into separate namespaces #2297

[petersktang]

Build error with USE_CUDA=ON USE_ROCM=ON USE_LLVM=ON TILELANG_USE_CUDA_STUBS=ON

Error in CMakeLists.txt:
IMPORTED_LOCATION not set for imported target "CUDA::cuda_driver"
configuration "Release".

Details in PR #2114

[ShanSimu]

When will this refactor be completed?

[SiriusNEO]

@ShanSimu Ideally, the main work is almost done, but further cleanup is still needed. Our ultimate goal is to successfully rebase the other hardware branches (Ascend, metalx, MUSA) onto the existing architecture.