[DAG Combiner] Fix the native computation of the Newton series for reciprocals
The generic infrastructure to compute the Newton series for reciprocal and
reciprocal square root was conceived to allow a target to compute the series
itself. However, the original code did not properly consider this condition
if returned by a target. This patch addresses the issues to allow a target
to compute the series on its own.
Differential revision: https://reviews.llvm.org/D22975
llvm-svn: 286523
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index d54c76e..22f7110 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -9637,9 +9637,10 @@
return RefinementSteps;
}
-SDValue PPCTargetLowering::getRsqrtEstimate(SDValue Operand, SelectionDAG &DAG,
- int Enabled, int &RefinementSteps,
- bool &UseOneConstNR) const {
+SDValue PPCTargetLowering::getSqrtEstimate(SDValue Operand, SelectionDAG &DAG,
+ int Enabled, int &RefinementSteps,
+ bool &UseOneConstNR,
+ bool Reciprocal) const {
EVT VT = Operand.getValueType();
if ((VT == MVT::f32 && Subtarget.hasFRSQRTES()) ||
(VT == MVT::f64 && Subtarget.hasFRSQRTE()) ||
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
index 2944e99..689a2e6 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -968,9 +968,9 @@
SDValue DAGCombineTruncBoolExt(SDNode *N, DAGCombinerInfo &DCI) const;
SDValue combineFPToIntToFP(SDNode *N, DAGCombinerInfo &DCI) const;
- SDValue getRsqrtEstimate(SDValue Operand, SelectionDAG &DAG, int Enabled,
- int &RefinementSteps,
- bool &UseOneConstNR) const override;
+ SDValue getSqrtEstimate(SDValue Operand, SelectionDAG &DAG, int Enabled,
+ int &RefinementSteps, bool &UseOneConstNR,
+ bool Reciprocal) const override;
SDValue getRecipEstimate(SDValue Operand, SelectionDAG &DAG, int Enabled,
int &RefinementSteps) const override;
unsigned combineRepeatedFPDivisors() const override;