diff --git a/llvm/unittests/Support/IntegersSubsetTest.cpp b/llvm/unittests/Support/IntegersSubsetTest.cpp
new file mode 100644
index 0000000..5de1f7c
--- /dev/null
+++ b/llvm/unittests/Support/IntegersSubsetTest.cpp
@@ -0,0 +1,180 @@
+//===- llvm/unittest/Support/IntegersSubsetTest.cpp - IntegersSubset tests ===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/APInt.h"
+#include "llvm/Support/IntegersSubset.h" 
+#include "llvm/Support/IntegersSubsetMapping.h"
+
+#include "gtest/gtest.h"
+
+#include <vector>
+
+using namespace llvm;
+
+namespace {
+  
+  class Int : public APInt {
+  public:
+    Int(uint64_t V) : APInt(64, V) {}
+    bool operator < (const APInt& RHS) const { return ult(RHS); }
+    bool operator > (const APInt& RHS) const { return ugt(RHS); }
+    bool operator <= (const APInt& RHS) const { return ule(RHS); }
+    bool operator >= (const APInt& RHS) const { return uge(RHS); }
+  };
+  
+  typedef IntRange<Int> Range;
+  typedef IntegersSubsetGeneric<Int> Subset;
+  typedef IntegersSubsetMapping<unsigned,Subset,Int> Mapping;
+  
+  TEST(IntegersSubsetTest, GeneralTest) {
+    
+    // Test construction.
+
+    std::vector<Range> Ranges;
+    Ranges.reserve(3);
+
+    // Initialize Subset as union of three pairs:
+    // { {0, 8}, {10, 18}, {20, 28} }
+    for (unsigned i = 0; i < 3; ++i)
+      Ranges.push_back(Range(Int(i*10), Int(i*10 + 8)));
+
+    Subset TheSubset(Ranges);
+    
+    for (unsigned i = 0; i < 3; ++i) {
+      EXPECT_EQ(TheSubset.getItem(i).getLow(), Int(i*10));
+      EXPECT_EQ(TheSubset.getItem(i).getHigh(), Int(i*10 + 8));
+    }
+    
+    EXPECT_EQ(TheSubset.getNumItems(), 3ULL);
+    
+    // Test belonging to range.
+    
+    EXPECT_TRUE(TheSubset.isSatisfies(Int(5)));
+    EXPECT_FALSE(TheSubset.isSatisfies(Int(9)));
+    
+    // Test when subset contains the only item.
+    
+    Ranges.clear();
+    Ranges.push_back(Range(Int(10), Int(10)));
+    
+    Subset TheSingleNumber(Ranges);
+    
+    EXPECT_TRUE(TheSingleNumber.isSingleNumber());
+    
+    Ranges.push_back(Range(Int(12), Int(15)));
+    
+    Subset NotASingleNumber(Ranges);
+    
+    EXPECT_FALSE(NotASingleNumber.isSingleNumber());
+    
+    // Test when subset contains items that are not a ranges but
+    // the single numbers.
+    
+    Ranges.clear();
+    Ranges.push_back(Range(Int(10), Int(10)));
+    Ranges.push_back(Range(Int(15), Int(19)));
+    
+    Subset WithSingleNumberItems(Ranges);
+    
+    EXPECT_TRUE(WithSingleNumberItems.isSingleNumber(0));
+    EXPECT_FALSE(WithSingleNumberItems.isSingleNumber(1));
+    
+    // Test size of subset. Note subset itself may be not optimized (improper),
+    // so it may contain duplicates, and the size of subset { {0, 9} {5, 9} }
+    // will 15 instead of 10.
+    
+    Ranges.clear();
+    Ranges.push_back(Range(Int(0), Int(9)));
+    Ranges.push_back(Range(Int(5), Int(9)));
+    
+    Subset NotOptimizedSubset(Ranges);
+    
+    EXPECT_EQ(NotOptimizedSubset.getSize(), 15ULL);
+
+    // Test access to a single value.
+    // getSingleValue(idx) method represents subset as flat numbers collection,
+    // so subset { {0, 3}, {8, 10} } will represented as array
+    // { 0, 1, 2, 3, 8, 9, 10 }.
+    
+    Ranges.clear();
+    Ranges.push_back(Range(Int(0), Int(3)));
+    Ranges.push_back(Range(Int(8), Int(10)));
+    
+    Subset OneMoreSubset(Ranges);
+    
+    EXPECT_EQ(OneMoreSubset.getSingleValue(5), Int(9));
+  }
+  
+  TEST(IntegersSubsetTest, MappingTest) {
+
+    Mapping::Cases TheCases;
+    
+    unsigned Successors[3] = {0, 1, 2};
+    
+    // Test construction.
+    
+    Mapping TheMapping;
+    for (unsigned i = 0; i < 3; ++i)
+      TheMapping.add(Int(10*i), Int(10*i + 9), Successors + i);
+    TheMapping.add(Int(111), Int(222), Successors);
+    TheMapping.removeItem(--TheMapping.end());
+    
+    TheMapping.getCases(TheCases);
+    
+    EXPECT_EQ(TheCases.size(), 3ULL);
+    
+    for (unsigned i = 0; i < 3; ++i) {
+      Mapping::Cases::iterator CaseIt = TheCases.begin();
+      std::advance(CaseIt, i);  
+      EXPECT_EQ(CaseIt->first, Successors + i);
+      EXPECT_EQ(CaseIt->second.getNumItems(), 1ULL);
+      EXPECT_EQ(CaseIt->second.getItem(0), Range(Int(10*i), Int(10*i + 9)));
+    }
+    
+    // Test verification.
+    
+    Mapping ImproperMapping;
+    ImproperMapping.add(Int(10), Int(11), Successors + 0);
+    ImproperMapping.add(Int(11), Int(12), Successors + 1);
+    
+    Mapping::RangeIterator ErrItem;
+    EXPECT_FALSE(ImproperMapping.verify(ErrItem));
+    EXPECT_EQ(ErrItem, --ImproperMapping.end());
+    
+    Mapping ProperMapping;
+    ProperMapping.add(Int(10), Int(11), Successors + 0);
+    ProperMapping.add(Int(12), Int(13), Successors + 1);
+    
+    EXPECT_TRUE(ProperMapping.verify(ErrItem));
+    
+    // Test optimization.
+    
+    Mapping ToBeOptimized;
+    
+    for (unsigned i = 0; i < 3; ++i) {
+      ToBeOptimized.add(Int(i * 10), Int(i * 10 + 1), Successors + i);
+      ToBeOptimized.add(Int(i * 10 + 2), Int(i * 10 + 9), Successors + i);
+    }
+    
+    ToBeOptimized.optimize();
+    
+    TheCases.clear();
+    ToBeOptimized.getCases(TheCases);
+    
+    EXPECT_EQ(TheCases.size(), 3ULL);
+    
+    for (unsigned i = 0; i < 3; ++i) {
+      Mapping::Cases::iterator CaseIt = TheCases.begin();
+      std::advance(CaseIt, i);  
+      EXPECT_EQ(CaseIt->first, Successors + i);
+      EXPECT_EQ(CaseIt->second.getNumItems(), 1ULL);
+      EXPECT_EQ(CaseIt->second.getItem(0), Range(Int(i * 10), Int(i * 10 + 9)));
+    }
+  }
+}