Introduce needsCleanup() for APFloat and APInt.

This is needed in clang so one can check if the object needs the
destructor called after its memory was freed. This is useful when
creating many APInt/APFloat objects with placement new, where the
overhead of tracking the pointers for cleanup is significant.

llvm-svn: 183100

llvm/include/llvm/ADT/APFloat.h

@@ -201,6 +201,9 @@ public:
 
   /// @}
 
+  /// \brief Returns whether this instance allocated memory.
+  bool needsCleanup() const { return partCount() > 1; }
+
   /// \name Convenience "constructors"
   /// @{
 

llvm/include/llvm/ADT/APInt.h

@@ -293,7 +293,7 @@ public:
 
   /// \brief Destructor.
   ~APInt() {
-    if (!isSingleWord())
+    if (needsCleanup())
       delete[] pVal;
   }
 
@@ -303,6 +303,9 @@ public:
   ///  method Read).
   explicit APInt() : BitWidth(1) {}
 
+  /// \brief Returns whether this instance allocated memory.
+  bool needsCleanup() const { return !isSingleWord(); }
+
   /// Used to insert APInt objects, or objects that contain APInt objects, into
   ///  FoldingSets.
   void Profile(FoldingSetNodeID &id) const;

llvm/lib/Support/APFloat.cpp

@@ -580,7 +580,7 @@ APFloat::initialize(const fltSemantics *ourSemantics)
 void
 APFloat::freeSignificand()
 {
-  if (partCount() > 1)
+  if (needsCleanup())
     delete [] significand.parts;
 }