[llvm] r345452 - [TargetLowering] Move LegalizeDAG FP_TO_UINT handling to TargetLowering::expandFP_TO_UINT. NFCI.

[Simon Pilgrim via llvm-commits]

Author: rksimon
Date: Sat Oct 27 05:15:58 2018
New Revision: 345452

URL: http://llvm.org/viewvc/llvm-project?rev=345452&view=rev
Log:
[TargetLowering] Move LegalizeDAG FP_TO_UINT handling to TargetLowering::expandFP_TO_UINT. NFCI.

First step towards fixing PR17686 and adding vector support.

Modified:
    llvm/trunk/include/llvm/CodeGen/TargetLowering.h
    llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
    llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp

Modified: llvm/trunk/include/llvm/CodeGen/TargetLowering.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/TargetLowering.h?rev=345452&r1=345451&r2=345452&view=diff
==============================================================================
--- llvm/trunk/include/llvm/CodeGen/TargetLowering.h (original)
+++ llvm/trunk/include/llvm/CodeGen/TargetLowering.h Sat Oct 27 05:15:58 2018
@@ -3663,6 +3663,12 @@ public:
   /// \returns True, if the expansion was successful, false otherwise
   bool expandFP_TO_SINT(SDNode *N, SDValue &Result, SelectionDAG &DAG) const;
 
+  /// Expand float to UINT conversion
+  /// \param N Node to expand
+  /// \param Result output after conversion
+  /// \returns True, if the expansion was successful, false otherwise
+  bool expandFP_TO_UINT(SDNode *N, SDValue &Result, SelectionDAG &DAG) const;
+
   /// Expand UINT(i64) to double(f64) conversion
   /// \param N Node to expand
   /// \param Result output after conversion

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp?rev=345452&r1=345451&r2=345452&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp Sat Oct 27 05:15:58 2018
@@ -2877,29 +2877,10 @@ bool SelectionDAGLegalize::ExpandNode(SD
     if (TLI.expandFP_TO_SINT(Node, Tmp1, DAG))
       Results.push_back(Tmp1);
     break;
-  case ISD::FP_TO_UINT: {
-    SDValue True, False;
-    EVT VT =  Node->getOperand(0).getValueType();
-    EVT NVT = Node->getValueType(0);
-    APFloat apf(DAG.EVTToAPFloatSemantics(VT),
-                APInt::getNullValue(VT.getSizeInBits()));
-    APInt x = APInt::getSignMask(NVT.getSizeInBits());
-    (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
-    Tmp1 = DAG.getConstantFP(apf, dl, VT);
-    Tmp2 = DAG.getSetCC(dl, getSetCCResultType(VT),
-                        Node->getOperand(0),
-                        Tmp1, ISD::SETLT);
-    True = DAG.getNode(ISD::FP_TO_SINT, dl, NVT, Node->getOperand(0));
-    // TODO: Should any fast-math-flags be set for the FSUB?
-    False = DAG.getNode(ISD::FP_TO_SINT, dl, NVT,
-                        DAG.getNode(ISD::FSUB, dl, VT,
-                                    Node->getOperand(0), Tmp1));
-    False = DAG.getNode(ISD::XOR, dl, NVT, False,
-                        DAG.getConstant(x, dl, NVT));
-    Tmp1 = DAG.getSelect(dl, NVT, Tmp2, True, False);
-    Results.push_back(Tmp1);
+  case ISD::FP_TO_UINT:
+    if (TLI.expandFP_TO_UINT(Node, Tmp1, DAG))
+      Results.push_back(Tmp1);
     break;
-  }
   case ISD::VAARG:
     Results.push_back(DAG.expandVAArg(Node));
     Results.push_back(Results[0].getValue(1));

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp?rev=345452&r1=345451&r2=345452&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/TargetLowering.cpp Sat Oct 27 05:15:58 2018
@@ -4137,6 +4137,37 @@ bool TargetLowering::expandFP_TO_SINT(SD
   return true;
 }
 
+bool TargetLowering::expandFP_TO_UINT(SDNode *Node, SDValue &Result,
+                                      SelectionDAG &DAG) const {
+  SDLoc dl(SDValue(Node, 0));
+  SDValue Src = Node->getOperand(0);
+
+  EVT SrcVT = Src.getValueType();
+  EVT DstVT = Node->getValueType(0);
+  EVT SetCCVT =
+      getSetCCResultType(DAG.getDataLayout(), *DAG.getContext(), SrcVT);
+
+  // Expand based on maximum range of FP_TO_SINT:
+  // True = fp_to_sint(Src)
+  // False = 0x8000000000000000 + fp_to_sint(Src - 0x8000000000000000)
+  // Result = select (Src < 0x8000000000000000), True, False
+  APFloat apf(DAG.EVTToAPFloatSemantics(SrcVT),
+              APInt::getNullValue(SrcVT.getScalarSizeInBits()));
+  APInt x = APInt::getSignMask(DstVT.getScalarSizeInBits());
+  (void)apf.convertFromAPInt(x, false, APFloat::rmNearestTiesToEven);
+
+  SDValue Tmp1 = DAG.getConstantFP(apf, dl, SrcVT);
+  SDValue Tmp2 = DAG.getSetCC(dl, SetCCVT, Src, Tmp1, ISD::SETLT);
+  SDValue True = DAG.getNode(ISD::FP_TO_SINT, dl, DstVT, Src);
+  // TODO: Should any fast-math-flags be set for the FSUB?
+  SDValue False = DAG.getNode(ISD::FP_TO_SINT, dl, DstVT,
+                              DAG.getNode(ISD::FSUB, dl, SrcVT, Src, Tmp1));
+  False =
+      DAG.getNode(ISD::XOR, dl, DstVT, False, DAG.getConstant(x, dl, DstVT));
+  Result = DAG.getSelect(dl, DstVT, Tmp2, True, False);
+  return true;
+}
+
 bool TargetLowering::expandUINT_TO_FP(SDNode *Node, SDValue &Result,
                                       SelectionDAG &DAG) const {
   SDValue Src = Node->getOperand(0);