Fix PR1816, by correcting the broken definition of APInt::countTrailingZeros.

[oota-llvm.git] / include / llvm / ADT / SmallPtrSet.h

diff --git a/include/llvm/ADT/SmallPtrSet.h b/include/llvm/ADT/SmallPtrSet.h
index 9f975af07c56b2a62a7dc6de9dada70c17e6255e..ec7b78e359366174d22ea8ae00298b3d3a9a31eb 100644 (file)
--- a/include/llvm/ADT/SmallPtrSet.h
+++ b/include/llvm/ADT/SmallPtrSet.h
@@ -43,7 +43,7 @@ class SmallPtrSetImpl {
 protected:
   /// CurArray - This is the current set of buckets.  If it points to
   /// SmallArray, then the set is in 'small mode'.
-  void **CurArray;
+  const void **CurArray;
   /// CurArraySize - The allocated size of CurArray, always a power of two.
   /// Note that CurArray points to an array that has CurArraySize+1 elements in
   /// it, so that the end iterator actually points to valid memory.
@@ -52,7 +52,7 @@ protected:
   // If small, this is # elts allocated consequtively
   unsigned NumElements;
   unsigned NumTombstones;
-  void *SmallArray[1];  // Must be last ivar.
+  const void *SmallArray[1];  // Must be last ivar.
 
   // Helper to copy construct a SmallPtrSet.
   SmallPtrSetImpl(const SmallPtrSetImpl& that);
@@ -67,10 +67,7 @@ public:
     CurArray[SmallSize] = 0;
     clear();
   }
-  ~SmallPtrSetImpl() {
-    if (!isSmall())
-      delete[] CurArray;
-  }
+  ~SmallPtrSetImpl();
   
   bool empty() const { return size() == 0; }
   unsigned size() const { return NumElements; }
@@ -83,31 +80,34 @@ public:
   }
   
   void clear() {
+    // If the capacity of the array is huge, and the # elements used is small,
+    // shrink the array.
+    if (!isSmall() && NumElements*4 < CurArraySize && CurArraySize > 32)
+      return shrink_and_clear();
+    
     // Fill the array with empty markers.
     memset(CurArray, -1, CurArraySize*sizeof(void*));
     NumElements = 0;
     NumTombstones = 0;
   }
   
-  /// insert - This returns true if the pointer was new to the set, false if it
-  /// was already in the set.
-  bool insert(void *Ptr);
-  
-  template <typename IterT>
-  void insert(IterT I, IterT E) {
-    for (; I != E; ++I)
-      insert((void*)*I);
-  }
+protected:
+  /// insert_imp - This returns true if the pointer was new to the set, false if
+  /// it was already in the set.  This is hidden from the client so that the
+  /// derived class can check that the right type of pointer is passed in.
+  bool insert_imp(const void * Ptr);
   
-  /// erase - If the set contains the specified pointer, remove it and return
-  /// true, otherwise return false.
-  bool erase(void *Ptr);
+  /// erase_imp - If the set contains the specified pointer, remove it and
+  /// return true, otherwise return false.  This is hidden from the client so
+  /// that the derived class can check that the right type of pointer is passed
+  /// in.
+  bool erase_imp(const void * Ptr);
   
-  bool count(void *Ptr) const {
+  bool count_imp(const void * Ptr) const {
     if (isSmall()) {
       // Linear search for the item.
-      for (void *const *APtr = SmallArray, *const *E = SmallArray+NumElements;
-           APtr != E; ++APtr)
+      for (const void *const *APtr = SmallArray,
+                      *const *E = SmallArray+NumElements; APtr != E; ++APtr)
         if (*APtr == Ptr)
           return true;
       return false;
@@ -120,10 +120,11 @@ public:
 private:
   bool isSmall() const { return CurArray == &SmallArray[0]; }
 
-  unsigned Hash(void *Ptr) const {
+  unsigned Hash(const void *Ptr) const {
     return ((uintptr_t)Ptr >> 4) & (CurArraySize-1);
   }
-  void * const *FindBucketFor(void *Ptr) const;
+  const void * const *FindBucketFor(const void *Ptr) const;
+  void shrink_and_clear();
   
   /// Grow - Allocate a larger backing store for the buckets and move it over.
   void Grow();
@@ -137,9 +138,9 @@ protected:
 /// instances of SmallPtrSetIterator.
 class SmallPtrSetIteratorImpl {
 protected:
-  void *const *Bucket;
+  const void *const *Bucket;
 public:
-  SmallPtrSetIteratorImpl(void *const *BP) : Bucket(BP) {
+  SmallPtrSetIteratorImpl(const void *const *BP) : Bucket(BP) {
     AdvanceIfNotValid();
   }
   
@@ -165,12 +166,12 @@ protected:
 template<typename PtrTy>
 class SmallPtrSetIterator : public SmallPtrSetIteratorImpl {
 public:
-  SmallPtrSetIterator(void *const *BP) : SmallPtrSetIteratorImpl(BP) {}
+  SmallPtrSetIterator(const void *const *BP) : SmallPtrSetIteratorImpl(BP) {}
 
   // Most methods provided by baseclass.
   
-  PtrTy operator*() const {
-    return static_cast<PtrTy>(*Bucket);
+  const PtrTy operator*() const {
+    return static_cast<const PtrTy>(const_cast<void*>(*Bucket));
   }
   
   inline SmallPtrSetIterator& operator++() {          // Preincrement
@@ -229,6 +230,23 @@ public:
     insert(I, E);
   }
   
+  /// insert - This returns true if the pointer was new to the set, false if it
+  /// was already in the set.
+  bool insert(PtrType Ptr) { return insert_imp(Ptr); }
+  
+  /// erase - If the set contains the specified pointer, remove it and return
+  /// true, otherwise return false.
+  bool erase(PtrType Ptr) { return erase_imp(Ptr); }
+  
+  /// count - Return true if the specified pointer is in the set.
+  bool count(PtrType Ptr) const { return count_imp(Ptr); }
+  
+  template <typename IterT>
+  void insert(IterT I, IterT E) {
+    for (; I != E; ++I)
+      insert(*I);
+  }
+  
   typedef SmallPtrSetIterator<PtrType> iterator;
   typedef SmallPtrSetIterator<PtrType> const_iterator;
   inline iterator begin() const {