[TensorExpr] Nuke DepTracker and findAllNeededTensors. (#54997)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54997
DepTracker was used to automatically pull in dependent computations from
output ones. While it seems quite convenient, it's led to several
architectural issues, which are fixed in this stack.
DepTracker worked on Tensors, which is a pair of Buf and Stmt. However,
Stmt could become stale and there was no way to reliably update the
corresponding tensor. We're now using Bufs and Stmts directly and moving
away from using Tensors to avoid these problems.
Removing DepTracker allowed to unify Loads and FunctionCalls, which
essentially were duplicates of each other.
Test Plan: Imported from OSS
Reviewed By: navahgar
Differential Revision: D27446414
Pulled By: ZolotukhinM
fbshipit-source-id: a2a32749d5b28beed92a601da33d126c0a2cf399
Author
Mikhail Zolotukhin
