diff --git a/include/llvm/ADT/BitVector.h b/include/llvm/ADT/BitVector.h
index 9dcb9e106f2..1940fd3900e 100644
--- a/include/llvm/ADT/BitVector.h
+++ b/include/llvm/ADT/BitVector.h
@@ -127,6 +127,12 @@ public:
     return false;
   }
 
+  /// all - Returns true if all bits are set.
+  bool all() const {
+    // TODO: Optimize this.
+    return count() == size();
+  }
+
   /// none - Returns true if none of the bits are set.
   bool none() const {
     return !any();
diff --git a/include/llvm/ADT/SmallBitVector.h b/include/llvm/ADT/SmallBitVector.h
index 3441d0a90c9..b15b3ee0418 100644
--- a/include/llvm/ADT/SmallBitVector.h
+++ b/include/llvm/ADT/SmallBitVector.h
@@ -187,6 +187,13 @@ public:
     return getPointer()->any();
   }
 
+  /// all - Returns true if all bits are set.
+  bool all() const {
+    if (isSmall())
+      return getSmallBits() == (uintptr_t(1) << getSmallSize()) - 1;
+    return getPointer()->all();
+  }
+
   /// none - Returns true if none of the bits are set.
   bool none() const {
     if (isSmall())
diff --git a/unittests/ADT/BitVectorTest.cpp b/unittests/ADT/BitVectorTest.cpp
index a9fc133c72e..fa663121a8a 100644
--- a/unittests/ADT/BitVectorTest.cpp
+++ b/unittests/ADT/BitVectorTest.cpp
@@ -22,6 +22,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Vec.count());
   EXPECT_EQ(0U, Vec.size());
   EXPECT_FALSE(Vec.any());
+  EXPECT_TRUE(Vec.all());
   EXPECT_TRUE(Vec.none());
   EXPECT_TRUE(Vec.empty());
 
@@ -29,6 +30,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(5U, Vec.count());
   EXPECT_EQ(5U, Vec.size());
   EXPECT_TRUE(Vec.any());
+  EXPECT_TRUE(Vec.all());
   EXPECT_FALSE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
@@ -36,6 +38,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(5U, Vec.count());
   EXPECT_EQ(11U, Vec.size());
   EXPECT_TRUE(Vec.any());
+  EXPECT_FALSE(Vec.all());
   EXPECT_FALSE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
@@ -43,6 +46,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(6U, Inv.count());
   EXPECT_EQ(11U, Inv.size());
   EXPECT_TRUE(Inv.any());
+  EXPECT_FALSE(Inv.all());
   EXPECT_FALSE(Inv.none());
   EXPECT_FALSE(Inv.empty());
 
@@ -123,6 +127,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Vec.count());
   EXPECT_EQ(130U, Vec.size());
   EXPECT_FALSE(Vec.any());
+  EXPECT_FALSE(Vec.all());
   EXPECT_TRUE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
@@ -130,6 +135,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Inv.count());
   EXPECT_EQ(0U, Inv.size());
   EXPECT_FALSE(Inv.any());
+  EXPECT_TRUE(Inv.all());
   EXPECT_TRUE(Inv.none());
   EXPECT_TRUE(Inv.empty());
 
@@ -137,6 +143,7 @@ TEST(BitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Vec.count());
   EXPECT_EQ(0U, Vec.size());
   EXPECT_FALSE(Vec.any());
+  EXPECT_TRUE(Vec.all());
   EXPECT_TRUE(Vec.none());
   EXPECT_TRUE(Vec.empty());
 }
diff --git a/unittests/ADT/SmallBitVectorTest.cpp b/unittests/ADT/SmallBitVectorTest.cpp
index 9c69aad5a97..c4dda9e88d4 100644
--- a/unittests/ADT/SmallBitVectorTest.cpp
+++ b/unittests/ADT/SmallBitVectorTest.cpp
@@ -19,6 +19,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Vec.count());
   EXPECT_EQ(0U, Vec.size());
   EXPECT_FALSE(Vec.any());
+  EXPECT_TRUE(Vec.all());
   EXPECT_TRUE(Vec.none());
   EXPECT_TRUE(Vec.empty());
 
@@ -26,6 +27,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(5U, Vec.count());
   EXPECT_EQ(5U, Vec.size());
   EXPECT_TRUE(Vec.any());
+  EXPECT_TRUE(Vec.all());
   EXPECT_FALSE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
@@ -33,6 +35,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(5U, Vec.count());
   EXPECT_EQ(11U, Vec.size());
   EXPECT_TRUE(Vec.any());
+  EXPECT_FALSE(Vec.all());
   EXPECT_FALSE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
@@ -40,6 +43,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(6U, Inv.count());
   EXPECT_EQ(11U, Inv.size());
   EXPECT_TRUE(Inv.any());
+  EXPECT_FALSE(Inv.all());
   EXPECT_FALSE(Inv.none());
   EXPECT_FALSE(Inv.empty());
 
@@ -120,6 +124,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Vec.count());
   EXPECT_EQ(130U, Vec.size());
   EXPECT_FALSE(Vec.any());
+  EXPECT_FALSE(Vec.all());
   EXPECT_TRUE(Vec.none());
   EXPECT_FALSE(Vec.empty());
 
@@ -127,6 +132,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Inv.count());
   EXPECT_EQ(0U, Inv.size());
   EXPECT_FALSE(Inv.any());
+  EXPECT_TRUE(Inv.all());
   EXPECT_TRUE(Inv.none());
   EXPECT_TRUE(Inv.empty());
 
@@ -134,6 +140,7 @@ TEST(SmallBitVectorTest, TrivialOperation) {
   EXPECT_EQ(0U, Vec.count());
   EXPECT_EQ(0U, Vec.size());
   EXPECT_FALSE(Vec.any());
+  EXPECT_TRUE(Vec.all());
   EXPECT_TRUE(Vec.none());
   EXPECT_TRUE(Vec.empty());
 }