[Mlir-commits] [mlir] [MLIR][TOSA] Add --tosa-remove-redundant-transposes pass (PR #108260)

[Arteen Abrishami]

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+//===- TosaRemoveRedundantTransposes.cpp
+//------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// ----------
+// Motivation:
+// ----------
+
+// Some legalization pathways introduce redundant tosa.TRANSPOSE
+// operations that result in avoidable data movement. For example,
+// PyTorch -> TOSA contains a lot of unnecessary transposes due
+// to conversions between NCHW and NHWC.
+
+// We wish to remove all the ones that we can, since in general
+// it is possible to remove the overwhelming majority.
+
+// -------------------
+// High-Level Overview:
+// -------------------
+
+// The pass begins at a downstream transpose with some perms tensor.
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arteen1000 wrote:

I used `perms` because that is what the `tosa.TRANSPOSE` operator argument calls it, so I was aligning with that.

https://github.com/llvm/llvm-project/pull/108260