xref: /llvm-project/llvm/unittests/Support/ParallelTest.cpp (revision fea8c073561f21ac0fea7f961287bf6b7dcf9f96)
1 //===- llvm/unittest/Support/ParallelTest.cpp -----------------------------===//
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 /// \file
10 /// Parallel.h unit tests.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #include "llvm/Support/Parallel.h"
15 #include "gtest/gtest.h"
16 #include <array>
17 #include <random>
18 
19 uint32_t array[1024 * 1024];
20 
21 using namespace llvm;
22 
23 // Tests below are hanging up on mingw. Investigating.
24 #if !defined(__MINGW32__)
25 
26 TEST(Parallel, sort) {
27   std::mt19937 randEngine;
28   std::uniform_int_distribution<uint32_t> dist;
29 
30   for (auto &i : array)
31     i = dist(randEngine);
32 
33   parallelSort(std::begin(array), std::end(array));
34   ASSERT_TRUE(llvm::is_sorted(array));
35 }
36 
37 TEST(Parallel, parallel_for) {
38   // We need to test the case with a TaskSize > 1. We are white-box testing
39   // here. The TaskSize is calculated as (End - Begin) / 1024 at the time of
40   // writing.
41   uint32_t range[2050];
42   std::fill(range, range + 2050, 1);
43   parallelFor(0, 2049, [&range](size_t I) { ++range[I]; });
44 
45   uint32_t expected[2049];
46   std::fill(expected, expected + 2049, 2);
47   ASSERT_TRUE(std::equal(range, range + 2049, expected));
48   // Check that we don't write past the end of the requested range.
49   ASSERT_EQ(range[2049], 1u);
50 }
51 
52 TEST(Parallel, TransformReduce) {
53   // Sum an empty list, check that it works.
54   auto identity = [](uint32_t v) { return v; };
55   uint32_t sum = parallelTransformReduce(ArrayRef<uint32_t>(), 0U,
56                                          std::plus<uint32_t>(), identity);
57   EXPECT_EQ(sum, 0U);
58 
59   // Sum the lengths of these strings in parallel.
60   const char *strs[] = {"a", "ab", "abc", "abcd", "abcde", "abcdef"};
61   size_t lenSum =
62       parallelTransformReduce(strs, static_cast<size_t>(0), std::plus<size_t>(),
63                               [](const char *s) { return strlen(s); });
64   EXPECT_EQ(lenSum, static_cast<size_t>(21));
65 
66   // Check that we handle non-divisible task sizes as above.
67   uint32_t range[2050];
68   std::fill(std::begin(range), std::end(range), 1);
69   sum = parallelTransformReduce(range, 0U, std::plus<uint32_t>(), identity);
70   EXPECT_EQ(sum, 2050U);
71 
72   std::fill(std::begin(range), std::end(range), 2);
73   sum = parallelTransformReduce(range, 0U, std::plus<uint32_t>(), identity);
74   EXPECT_EQ(sum, 4100U);
75 
76   // Avoid one large task.
77   uint32_t range2[3060];
78   std::fill(std::begin(range2), std::end(range2), 1);
79   sum = parallelTransformReduce(range2, 0U, std::plus<uint32_t>(), identity);
80   EXPECT_EQ(sum, 3060U);
81 }
82 
83 TEST(Parallel, ForEachError) {
84   int nums[] = {1, 2, 3, 4, 5, 6};
85   Error e = parallelForEachError(nums, [](int v) -> Error {
86     if ((v & 1) == 0)
87       return createStringError(std::errc::invalid_argument, "asdf");
88     return Error::success();
89   });
90   EXPECT_TRUE(e.isA<ErrorList>());
91   std::string errText = toString(std::move(e));
92   EXPECT_EQ(errText, std::string("asdf\nasdf\nasdf"));
93 }
94 
95 TEST(Parallel, TaskGroupSequentialFor) {
96   size_t Count = 0;
97   {
98     parallel::TaskGroup tg;
99     for (size_t Idx = 0; Idx < 500; Idx++)
100       tg.spawn([&Count, Idx]() { EXPECT_EQ(Count++, Idx); }, true);
101   }
102   EXPECT_EQ(Count, 500ul);
103 }
104 
105 #endif
106