[PATCH] D22975: Add new nodes for computing the Newton series

[Evandro Menezes via llvm-commits]

evandro added a comment.

Thank you.


================
Comment at: llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp:14695
@@ -14655,1 +14694,3 @@
+              ? buildSqrtNROneConst(Op, Est, Iterations, Flags, Reciprocal)
+              : buildSqrtNRTwoConst(Op, Est, Iterations, Flags, Reciprocal);
     }
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n.bozhenov wrote:
> A more consistent way to choose a refinement method would be to replace the boolean UseOneConstNR value with some enum, let the target set this enum and choose the refinement method based on the enum value.
> 
> Yet another option would be to return an already refined value from ARMTargetLowering::getRsqrtEstimate and set Iterations to 0. In this case we wouldn't need the buildSqrtNRNative function.
> 
I like this suggestion.  I'll explore it and get back to y'all.


Repository:
  rL LLVM

https://reviews.llvm.org/D22975