[PATCH] D152260: [DAGCombiner] Use generalized pattern matcher in visitFMA to support vp.fma.

[Yeting Kuo via Phabricator via llvm-commits]

fakepaper56 added inline comments.


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Comment at: llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp:6819
   // fneg is removable even if it has multiple uses.
-  if (Op.getOpcode() == ISD::FNEG) {
+  if (Op.getOpcode() == ISD::FNEG || Op.getOpcode() == ISD::VP_FNEG) {
     Cost = NegatibleCost::Cheaper;
----------------
luke wrote:
> Is the negation of VP_FNEG still operand 0 if the mask isn't all ones or the EVL is less than the vector width?
The behavior for inactive elements is undefined, so I think we don't need to care them.


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  https://reviews.llvm.org/D152260/new/

https://reviews.llvm.org/D152260