xref: /llvm-project/llvm/unittests/ADT/EquivalenceClassesTest.cpp (revision 2946cd701067404b99c39fb29dc9c74bd7193eb3)
1 //=== llvm/unittest/ADT/EquivalenceClassesTest.cpp - the structure tests --===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "llvm/ADT/EquivalenceClasses.h"
10 #include "gtest/gtest.h"
11 
12 using namespace llvm;
13 
14 namespace llvm {
15 
16 TEST(EquivalenceClassesTest, NoMerges) {
17   EquivalenceClasses<int> EqClasses;
18   // Until we merged any sets, check that every element is only equivalent to
19   // itself.
20   for (int i = 0; i < 3; i++)
21     for (int j = 0; j < 3; j++)
22       if (i == j)
23         EXPECT_TRUE(EqClasses.isEquivalent(i, j));
24       else
25         EXPECT_FALSE(EqClasses.isEquivalent(i, j));
26 }
27 
28 TEST(EquivalenceClassesTest, SimpleMerge1) {
29   EquivalenceClasses<int> EqClasses;
30   // Check that once we merge (A, B), (B, C), (C, D), then all elements belong
31   // to one set.
32   EqClasses.unionSets(0, 1);
33   EqClasses.unionSets(1, 2);
34   EqClasses.unionSets(2, 3);
35   for (int i = 0; i < 4; ++i)
36     for (int j = 0; j < 4; ++j)
37       EXPECT_TRUE(EqClasses.isEquivalent(i, j));
38 }
39 
40 TEST(EquivalenceClassesTest, SimpleMerge2) {
41   EquivalenceClasses<int> EqClasses;
42   // Check that once we merge (A, B), (C, D), (A, C), then all elements belong
43   // to one set.
44   EqClasses.unionSets(0, 1);
45   EqClasses.unionSets(2, 3);
46   EqClasses.unionSets(0, 2);
47   for (int i = 0; i < 4; ++i)
48     for (int j = 0; j < 4; ++j)
49       EXPECT_TRUE(EqClasses.isEquivalent(i, j));
50 }
51 
52 TEST(EquivalenceClassesTest, TwoSets) {
53   EquivalenceClasses<int> EqClasses;
54   // Form sets of odd and even numbers, check that we split them into these
55   // two sets correcrly.
56   for (int i = 0; i < 30; i += 2)
57     EqClasses.unionSets(0, i);
58   for (int i = 1; i < 30; i += 2)
59     EqClasses.unionSets(1, i);
60 
61   for (int i = 0; i < 30; i++)
62     for (int j = 0; j < 30; j++)
63       if (i % 2 == j % 2)
64         EXPECT_TRUE(EqClasses.isEquivalent(i, j));
65       else
66         EXPECT_FALSE(EqClasses.isEquivalent(i, j));
67 }
68 
69 TEST(EquivalenceClassesTest, MultipleSets) {
70   EquivalenceClasses<int> EqClasses;
71   // Split numbers from [0, 100) into sets so that values in the same set have
72   // equal remainders (mod 17).
73   for (int i = 0; i < 100; i++)
74     EqClasses.unionSets(i % 17, i);
75 
76   for (int i = 0; i < 100; i++)
77     for (int j = 0; j < 100; j++)
78       if (i % 17 == j % 17)
79         EXPECT_TRUE(EqClasses.isEquivalent(i, j));
80       else
81         EXPECT_FALSE(EqClasses.isEquivalent(i, j));
82 }
83 
84 } // llvm
85