diff --git a/include/llvm/ADT/SmallBitVector.h b/include/llvm/ADT/SmallBitVector.h
index fe9bef9..86949b2 100644
--- a/include/llvm/ADT/SmallBitVector.h
+++ b/include/llvm/ADT/SmallBitVector.h
@@ -426,6 +426,40 @@
     return *this;
   }
 
+  /// reset - Reset bits that are set in RHS. Same as *this &= ~RHS.
+  SmallBitVector &reset(const SmallBitVector &RHS) {
+    if (isSmall() && RHS.isSmall())
+      setSmallBits(getSmallBits() & ~RHS.getSmallBits());
+    else if (!isSmall() && !RHS.isSmall())
+      getPointer()->reset(*RHS.getPointer());
+    else
+      for (unsigned i = 0, e = std::min(size(), RHS.size()); i != e; ++i)
+        if (RHS.test(i))
+          reset(i);
+
+    return *this;
+  }
+
+  /// test - Check if (This - RHS) is zero.
+  /// This is the same as reset(RHS) and any().
+  bool test(const SmallBitVector &RHS) const {
+    if (isSmall() && RHS.isSmall())
+      return (getSmallBits() & ~RHS.getSmallBits()) != 0;
+    if (!isSmall() && !RHS.isSmall())
+      return getPointer()->test(*RHS.getPointer());
+
+    unsigned i, e;
+    for (i = 0, e = std::min(size(), RHS.size()); i != e; ++i)
+      if (test(i) && !RHS.test(i))
+        return true;
+
+    for (e = size(); i != e; ++i)
+      if (test(i))
+        return true;
+
+    return false;
+  }
+
   SmallBitVector &operator|=(const SmallBitVector &RHS) {
     resize(std::max(size(), RHS.size()));
     if (isSmall())
diff --git a/unittests/ADT/BitVectorTest.cpp b/unittests/ADT/BitVectorTest.cpp
index 85e1594..d7cde89 100644
--- a/unittests/ADT/BitVectorTest.cpp
+++ b/unittests/ADT/BitVectorTest.cpp
@@ -357,5 +357,41 @@
   EXPECT_TRUE( E.test(32));
   EXPECT_FALSE(E.test(33));
 }
+
+TYPED_TEST(BitVectorTest, CompoundTestReset) {
+  TypeParam A(50, true);
+  TypeParam B(50, false);
+
+  TypeParam C(100, true);
+  TypeParam D(100, false);
+
+  EXPECT_FALSE(A.test(A));
+  EXPECT_TRUE(A.test(B));
+  EXPECT_FALSE(A.test(C));
+  EXPECT_TRUE(A.test(D));
+  EXPECT_FALSE(B.test(A));
+  EXPECT_FALSE(B.test(B));
+  EXPECT_FALSE(B.test(C));
+  EXPECT_FALSE(B.test(D));
+  EXPECT_TRUE(C.test(A));
+  EXPECT_TRUE(C.test(B));
+  EXPECT_FALSE(C.test(C));
+  EXPECT_TRUE(C.test(D));
+
+  A.reset(B);
+  A.reset(D);
+  EXPECT_TRUE(A.all());
+  A.reset(A);
+  EXPECT_TRUE(A.none());
+  A.set();
+  A.reset(C);
+  EXPECT_TRUE(A.none());
+  A.set();
+
+  C.reset(A);
+  EXPECT_EQ(50, C.find_first());
+  C.reset(C);
+  EXPECT_TRUE(C.none());
+}
 }
 #endif