Add mod, copysign, abs operations to APFloat.

Implement some constant folding in SelectionDAG and
DAGCombiner using APFloat.  Remove double versions
of constructor and getValue from ConstantFPSDNode.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41664 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/CodeGen/SelectionDAGNodes.h

@@ -1147,33 +1147,26 @@ public:
 class ConstantFPSDNode : public SDNode {
   APFloat Value;
   virtual void ANCHOR();  // Out-of-line virtual method to give class a home.
+  // Longterm plan: replace all uses of getValue with getValueAPF, remove
+  // getValue, rename getValueAPF to getValue.
 protected:
   friend class SelectionDAG;
-  ConstantFPSDNode(bool isTarget, double val, MVT::ValueType VT)
-    : SDNode(isTarget ? ISD::TargetConstantFP : ISD::ConstantFP,
-             getSDVTList(VT)), 
-             Value(VT==MVT::f64 ? APFloat(val) : APFloat((float)val)) {
-  }
   ConstantFPSDNode(bool isTarget, const APFloat& val, MVT::ValueType VT)
     : SDNode(isTarget ? ISD::TargetConstantFP : ISD::ConstantFP,
              getSDVTList(VT)), Value(val) {
   }
 public:
 
-  // Longterm plan: replace all uses of getValue with getValueAPF, remove
-  // getValue, rename getValueAPF to getValue.
-  double getValue() const { 
-    if ( getValueType(0)==MVT::f64)
-      return Value.convertToDouble();
-    else
-      return Value.convertToFloat();
-  }
   const APFloat& getValueAPF() const { return Value; }
 
   /// 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.
   /// As such, this method can be used to do an exact bit-for-bit comparison of
   /// two floating point values.
+
+  /// We leave the version with the double argument here because it's just so
+  /// convenient to write "2.0" and the like.  Without this function we'd 
+  /// have to duplicate its logic everywhere it's called.
   bool isExactlyValue(double V) const { 
     if (getValueType(0)==MVT::f64)
       return isExactlyValue(APFloat(V));