[PATCH] D135736: [mlir][MemRef] Make reinterpret_cast(extract_strided_metadata) more robust

[Quentin Colombet via Phabricator via llvm-commits]

qcolombet created this revision.
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Prior to this patch the canonicalization pattern that turns `reinterpret_cast(extract_strided_metadata)` into `cast` was only applied when all the input operands of the `reinterpret_cast` are exactly all the output results of the `extract_strided_metadata`.

This missed simplification opportunities when the values would have hold the same constant values, but yet, come from different actual values.

E.g., prior to this patch, a pattern of the form:

  %base, %offset = extract_strided_metadata %source : memref<i16>
  reinterpret_cast %base to offset:[0]

Wouldn't have been simplified into a simple cast, because %offset is not directly the same value object as 0.

This patch teaches this pattern how to check if the constant values match what the results of the extract_strided_metadata operation would have hold.

Note: This patch will be helpful to keep nice MLIR outputs when I push the patch to do the forwarding of statically known information as part of a folding of `extract_strided_metadata`.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D135736

Files:
  mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
  mlir/test/Dialect/MemRef/canonicalize.mlir

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