Add BitVector::anyCommon().

The existing operation (A & B).any() is very slow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156760 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/include/llvm/ADT/BitVector.h b/include/llvm/ADT/BitVector.h
index 7e0b5ba371..bf6d76fbcc 100644
--- a/include/llvm/ADT/BitVector.h
+++ b/include/llvm/ADT/BitVector.h
@@ -272,6 +272,16 @@ public:
     return (*this)[Idx];
   }
 
+  /// Test if any common bits are set.
+  bool anyCommon(const BitVector &RHS) const {
+    unsigned ThisWords = NumBitWords(size());
+    unsigned RHSWords  = NumBitWords(RHS.size());
+    for (unsigned i = 0, e = std::min(ThisWords, RHSWords); i != e; ++i)
+      if (Bits[i] & RHS.Bits[i])
+        return true;
+    return false;
+  }
+
   // Comparison operators.
   bool operator==(const BitVector &RHS) const {
     unsigned ThisWords = NumBitWords(size());