[PATCH] D133471: [DAGCombiner][X86] Fold (sub (subcarry X, 0, Carry), Y) -> (subcarry X, Y, Carry)

[Sanjay Patel via Phabricator via llvm-commits]

spatel added a reviewer: deadalnix.
spatel added a comment.

Is the transform still profitable if the subcarry has another use? (not sure how to write a test for that)

In IR, it looks like we'd reduce the equivalent of "subcarry X, 0, Carry" to "usubo X, Carry". Are those the same semantics for this node? And would that simpler transform make sense in SDAG too?


Repository:
  rG LLVM Github Monorepo

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https://reviews.llvm.org/D133471