[all-commits] [llvm/llvm-project] f21d78: [mlir] Tighten the rules around folding TensorLoadOp

[Nicolas Vasilache via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f21d78633a3d09d1bac904cf4b97f9f7e66b3094
      https://github.com/llvm/llvm-project/commit/f21d78633a3d09d1bac904cf4b97f9f7e66b3094
  Author: Nicolas Vasilache <nicolas.vasilache at gmail.com>
  Date:   2021-03-04 (Thu, 04 Mar 2021)

  Changed paths:
    M mlir/lib/Dialect/StandardOps/IR/Ops.cpp

  Log Message:
  -----------
  [mlir] Tighten the rules around folding TensorLoadOp

`tensor_load(tensor_to_memref(x)) -> x` is an incorrect folding because it ignores potential aliasing.

This revision approximates no-aliasing by restricting the folding to occur only when tensor_to_memref
is immediately preceded by tensor_load in the same block. This is a conservative step back towards
correctness until better alias analysis becomes available.

Context: https://llvm.discourse.group/t/properly-using-bufferization-related-passes/2913/6

Differential Revision: https://reviews.llvm.org/D97957