1 files changed, 85 insertions, 0 deletions
diff --git a/llvm/unittests/ADT/EquivalenceClassesTest.cpp b/llvm/unittests/ADT/EquivalenceClassesTest.cpp
new file mode 100644
index 00000000000..57d588a4c51
--- /dev/null
+++ b/llvm/unittests/ADT/EquivalenceClassesTest.cpp
@@ -0,0 +1,85 @@
+//=== llvm/unittest/ADT/EquivalenceClassesTest.cpp - the structure 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/EquivalenceClasses.h"
+#include "gtest/gtest.h"
+
+using namespace llvm;
+
+namespace llvm {
+
+TEST(EquivalenceClassesTest, NoMerges) {
+  EquivalenceClasses<int> EqClasses;
+  // Until we merged any sets, check that every element is only equivalent to
+  // itself.
+  for (int i = 0; i < 3; i++)
+    for (int j = 0; j < 3; j++)
+      if (i == j)
+        EXPECT_TRUE(EqClasses.isEquivalent(i, j));
+      else
+        EXPECT_FALSE(EqClasses.isEquivalent(i, j));
+}
+
+TEST(EquivalenceClassesTest, SimpleMerge1) {
+  EquivalenceClasses<int> EqClasses;
+  // Check that once we merge (A, B), (B, C), (C, D), then all elements belong
+  // to one set.
+  EqClasses.unionSets(0, 1);
+  EqClasses.unionSets(1, 2);
+  EqClasses.unionSets(2, 3);
+  for (int i = 0; i < 4; ++i)
+    for (int j = 0; j < 4; ++j)
+      EXPECT_TRUE(EqClasses.isEquivalent(i, j));
+}
+
+TEST(EquivalenceClassesTest, SimpleMerge2) {
+  EquivalenceClasses<int> EqClasses;
+  // Check that once we merge (A, B), (C, D), (A, C), then all elements belong
+  // to one set.
+  EqClasses.unionSets(0, 1);
+  EqClasses.unionSets(2, 3);
+  EqClasses.unionSets(0, 2);
+  for (int i = 0; i < 4; ++i)
+    for (int j = 0; j < 4; ++j)
+      EXPECT_TRUE(EqClasses.isEquivalent(i, j));
+}
+
+TEST(EquivalenceClassesTest, TwoSets) {
+  EquivalenceClasses<int> EqClasses;
+  // Form sets of odd and even numbers, check that we split them into these
+  // two sets correcrly.
+  for (int i = 0; i < 30; i += 2)
+    EqClasses.unionSets(0, i);
+  for (int i = 1; i < 30; i += 2)
+    EqClasses.unionSets(1, i);
+
+  for (int i = 0; i < 30; i++)
+    for (int j = 0; j < 30; j++)
+      if (i % 2 == j % 2)
+        EXPECT_TRUE(EqClasses.isEquivalent(i, j));
+      else
+        EXPECT_FALSE(EqClasses.isEquivalent(i, j));
+}
+
+TEST(EquivalenceClassesTest, MultipleSets) {
+  EquivalenceClasses<int> EqClasses;
+  // Split numbers from [0, 100) into sets so that values in the same set have
+  // equal remainders (mod 17).
+  for (int i = 0; i < 100; i++)
+    EqClasses.unionSets(i % 17, i);
+
+  for (int i = 0; i < 100; i++)
+    for (int j = 0; j < 100; j++)
+      if (i % 17 == j % 17)
+        EXPECT_TRUE(EqClasses.isEquivalent(i, j));
+      else
+        EXPECT_FALSE(EqClasses.isEquivalent(i, j));
+}
+
+} // llvm