[PATCH] D144789: [DAG] Match select(icmp(x,y),sub(x,y),sub(y,x)) -> abd(x,y) patterns

[Noah Goldstein via Phabricator via llvm-commits]

goldstein.w.n added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:11807
+        N1.getOperand(0) == N2.getOperand(1) && 
+        N1.getOperand(1) == N2.getOperand(0)) {
+      bool IsSigned = isSignedIntSetCC(CC);
----------------
Maybe there should be one-use checks? Is `abd` more efficient if the sub operations are already needed?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D144789/new/

https://reviews.llvm.org/D144789