Use APFloat internally for ConstantFPSDNode.

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

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);
 }
 
 //===----------------------------------------------------------------------===//