[PATCH] D156778: [SelectionDAG] Improve `isKnownToBeAPowerOfTwo`

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:4069
+      case ISD::ZERO_EXTEND:
+      case ISD::ANY_EXTEND:
+        V = V.getOperand(0);
----------------
Looking through ANY_EXTEND is probably broken


================
Comment at: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp:4136-4137
+  if (Val.getOpcode() == ISD::SELECT || Val.getOpcode() == ISD::VSELECT)
+    return isKnownToBeAPowerOfTwo(Val.getOperand(1), Depth + 1) &&
+           isKnownToBeAPowerOfTwo(Val.getOperand(2), Depth + 1);
+
----------------
try RHS first


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D156778/new/

https://reviews.llvm.org/D156778