[PATCH] D127474: [SelectionDAG] fold Op0 - (X * MulC) --> Op0 + (X << log2(-MulC))

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:2524
+      SDValue Res = TLO.DAG.getNode(
+          Op.getOpcode() == ISD::ADD ? ISD::SUB : ISD::ADD, dl, VT, Y, Shl);
+      return TLO.CombineTo(Op, Res);
----------------
Might be better to pass ISD::SUB or ISD::ADD from the caller instead of re-inspecting the opcode.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D127474/new/

https://reviews.llvm.org/D127474