Use APFloat internally for ConstantFPSDNode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41372 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/SelectionDAGNodes.h

@@ -23,6 +23,7 @@
 #include "llvm/ADT/FoldingSet.h"
 #include "llvm/ADT/GraphTraits.h"
 #include "llvm/ADT/iterator"
+#include "llvm/ADT/APFloat.h"
 #include "llvm/CodeGen/ValueTypes.h"
 #include "llvm/Support/DataTypes.h"
 #include <cassert>
@@ -1144,17 +1145,17 @@ public:
 };
 
 class ConstantFPSDNode : public SDNode {
-  double Value;
+  APFloat Value;
   virtual void ANCHOR();  // Out-of-line virtual method to give class a home.
 protected:
   friend class SelectionDAG;
   ConstantFPSDNode(bool isTarget, double val, MVT::ValueType VT)
     : SDNode(isTarget ? ISD::TargetConstantFP : ISD::ConstantFP,
-             getSDVTList(VT)), Value(val) {
+             getSDVTList(VT)), Value(APFloat(val)) {
   }
 public:
 
-  double getValue() const { return Value; }
+  double getValue() const { return Value.convertToDouble(); }
 
   /// isExactlyValue - We don't rely on operator== working on double values, as
   /// it returns true for things that are clearly not equal, like -0.0 and 0.0.

lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -49,7 +49,7 @@ static SDVTList makeVTList(const MVT::ValueType *VTs, unsigned NumVTs) {
 /// As such, this method can be used to do an exact bit-for-bit comparison of
 /// two floating point values.
 bool ConstantFPSDNode::isExactlyValue(double V) const {
-  return DoubleToBits(V) == DoubleToBits(Value);
+  return Value == APFloat(V);
 }
 
 //===----------------------------------------------------------------------===//