[PATCH] D134260: [AArch64] Add GPR rr instructions to isAssociativeAndCommutative

[Dave Green via Phabricator via llvm-commits]

dmgreen added a comment.

The swift-return test shows it best, where it changes:

  ; CHECK:  add     [[TMP:x.*]], x0, x1
  ; CHECK:  add     [[TMP]], [[TMP]], x2
  ; CHECK:  add     [[TMP]], [[TMP]], x3
  ; CHECK:  add     x0, [[TMP]], x4

To:

  ; CHECK:  add     [[TMP:x.*]], x0, x1
  ; CHECK:  add     [[TMP2:x.*]], x2, x3
  ; CHECK:  add     [[TMP]], [[TMP]], [[TMP2]]
  ; CHECK:  add     x0, [[TMP]], x4

This allow the first two operations to be executed in parallel. This reassociation in the machine combiner is what this patch now allows.


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  https://reviews.llvm.org/D134260/new/

https://reviews.llvm.org/D134260