[RFC] TensorIR: A schedulable IR for TVM

[yzh119]

@Hzfengsy

TensorIR:

with tir.block([10]) as vi:
    B[vi] = A0[vi]
with tir.block([10]) as vi:
    B[vi + 10] = A1[vi]
with tir.block([10]) as vi:
    B[vi + 20] = A2[vi]

The critical improvement is performance. In TIR we optimize the program by deprecating the if branch, which is impossible in the TE schedule.

This looks confusing to me because there is no example showing how to schedule the three blocks.

I’m curious if TIR’s Block construct is strong enough to support holistic fusion like Rammer and HFuse, where different Block has heterogeneous workload but we can fuse them in a single kernel. If so we can make such fusion a primitive in TIR schedule and enlarge the auto-scheduling search space.