[PATCH] D33143: [Polly][Simplify] Remove identical write removal. NFC.

[Michael Kruse via Phabricator via llvm-commits]

Meinersbur created this revision.
Meinersbur added a project: Polly.

Removal of overwritten writes currently encompasses all the cases of the identical write removal.

Identical write removal might still be superior when partial writes (in preparation) do not share exactly the same domain, but can be merged into a single write. However, this could be implemented with overwritten write removal as well.

The identical write removal algorithm could be extended to handle all cases of overwritten removal, but with O(n^3) performance characteristic.

There is an observable behavioral change in that the last, instead of the first, MemoryAccess is kept. This should not affect the generated code, however.


https://reviews.llvm.org/D33143

Files:
  lib/Transform/Simplify.cpp
  overwritten.ll
  test/Simplify/identical.ll
  test/Simplify/identical_3phi.ll
  test/Simplify/identical_3phi___%for---%return.jscop
  test/Simplify/identical_3phi___%for---%return.jscop.transformed
  test/Simplify/identical___%for---%return.jscop
  test/Simplify/identical___%for---%return.jscop.transformed
  test/Simplify/overwritten_3phi.ll
  test/Simplify/overwritten_3phi___%for---%return.jscop
  test/Simplify/overwritten_3phi___%for---%return.jscop.transformed
  test/Simplify/overwritten_scalar.ll
  test/Simplify/overwritten_scalar___%for---%return.jscop
  test/Simplify/overwritten_scalar___%for---%return.jscop.transformed

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