ImutAVLTree now allocates tree nodes from the BumpPtrAllocator using

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

diff --git a/include/llvm/ADT/BitVector.h b/include/llvm/ADT/BitVector.h
index 6418f7f66b4b1c1e2da1a8b19d2153e46cd451a7..927cfa9f7869ab83645e78d1ed85cc8c4a1eb95b 100644 (file)
--- a/include/llvm/ADT/BitVector.h
+++ b/include/llvm/ADT/BitVector.h
@@ -57,7 +57,7 @@ public:
     }
 
     operator bool() const {
-      return (*WordRef) & (1L << BitPos);
+      return ((*WordRef) & (1L << BitPos)) ? true : false;
     }
   };
 
@@ -185,8 +185,18 @@ public:
       grow(N);
       init_words(&Bits[OldCapacity], (Capacity-OldCapacity), t);
     }
+    
+    // Set any old unused bits that are now included in the BitVector. This 
+    // may set bits that are not included in the new vector, but we will clear 
+    // them back out below.
+    if (N > Size)
+      set_unused_bits(t);
+    
+    // Update the size, and clear out any bits that are now unused
+    unsigned OldSize = Size;
     Size = N;
-    clear_unused_bits();
+    if (t || N < OldSize)
+      clear_unused_bits();
   }
 
   void reserve(unsigned N) {
@@ -249,12 +259,23 @@ public:
 
   // Comparison operators.
   bool operator==(const BitVector &RHS) const {
-    if (Size != RHS.Size)
-      return false;
-
-    for (unsigned i = 0; i < NumBitWords(size()); ++i)
+    unsigned ThisWords = NumBitWords(size());
+    unsigned RHSWords  = NumBitWords(RHS.size());
+    unsigned i;
+    for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
       if (Bits[i] != RHS.Bits[i])
         return false;
+    
+    // Verify that any extra words are all zeros.
+    if (i != ThisWords) {
+      for (; i != ThisWords; ++i)
+        if (Bits[i])
+          return false;
+    } else if (i != RHSWords) {
+      for (; i != RHSWords; ++i)
+        if (RHS.Bits[i])
+          return false;
+    }
     return true;
   }
 
@@ -264,9 +285,18 @@ public:
 
   // Intersection, union, disjoint union.
   BitVector operator&=(const BitVector &RHS) {
-    assert(Size == RHS.Size && "Illegal operation!");
-    for (unsigned i = 0; i < NumBitWords(size()); ++i)
+    unsigned ThisWords = NumBitWords(size());
+    unsigned RHSWords  = NumBitWords(RHS.size());
+    unsigned i;
+    for (i = 0; i != std::min(ThisWords, RHSWords); ++i)
       Bits[i] &= RHS.Bits[i];
+    
+    // Any bits that are just in this bitvector become zero, because they aren't
+    // in the RHS bit vector.  Any words only in RHS are ignored because they
+    // are already zero in the LHS.
+    for (; i != ThisWords; ++i)
+      Bits[i] = 0;
+    
     return *this;
   }
 
@@ -297,7 +327,7 @@ public:
     }
   
     // Grow the bitvector to have enough elements.
-    Capacity = NumBitWords(Size);
+    Capacity = RHSWords;
     BitWord *NewBits = new BitWord[Capacity];
     std::copy(RHS.Bits, &RHS.Bits[RHSWords], NewBits);
 
@@ -312,16 +342,27 @@ private:
   unsigned NumBitWords(unsigned S) const {
     return (S + BITWORD_SIZE-1) / BITWORD_SIZE;
   }
-
-  // Clear the unused top bits in the high word.
-  void clear_unused_bits() {
+  
+  // Set the unused bits in the high words.
+  void set_unused_bits(bool t = true) {
+    //  Set high words first.
+    unsigned UsedWords = NumBitWords(Size);
+    if (Capacity > UsedWords)
+      init_words(&Bits[UsedWords], (Capacity-UsedWords), t);
+    
+    //  Then set any stray high bits of the last used word.
     unsigned ExtraBits = Size % BITWORD_SIZE;
     if (ExtraBits) {
-      unsigned index = Size / BITWORD_SIZE;
-      Bits[index] &= ~(~0L << ExtraBits);
+      Bits[UsedWords-1] &= ~(~0L << ExtraBits);
+      Bits[UsedWords-1] |= (0 - (BitWord)t) << ExtraBits;
     }
   }
 
+  // Clear the unused bits in the high words.
+  void clear_unused_bits() {
+    set_unused_bits(false);
+  }
+
   void grow(unsigned NewSize) {
     unsigned OldCapacity = Capacity;
     Capacity = NumBitWords(NewSize);