[Mlir-commits] [mlir] [MLIR][Transforms] add eliminate-explicit-rounding pass (PR #93443)

[Jianhui Li]

Jianhui-Li wrote:

I think it makes sense to modify the PR slightly so that it only removes the extf/truncf pair if they have the "fastmath=contract" attribute, and followed by future PRs which mark these attributes for extf/truncf op introduced by various promotion passes.  This is exactly what suggested by https://github.com/llvm/llvm-project/pull/93443#issuecomment-2138154222.

This mean that we all agree to extend the "fastmath=contract" semantics to MLIR extf/truncf op and allow MLIR optimization to remove the rounding effects associated with these two ops.  

We also need to consider whether and how user specified compiler options on "fastmath" impacts the promotion passes to set "fastmath=contract" for extf/truncf. But I think it is a global issue and need to discussed in separate thread (or please let us know if there is already such one!). 

https://github.com/llvm/llvm-project/pull/93443