blob: 36229dc2409681a68eb092737f13c49fe26278df (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// REQUIRES: long_tests
// UNSUPPORTED: c++98, c++03
// Not a portable test
// <__hash_table>
// size_t __next_hash_pow2(size_t n);
// If n <= 1, return n. If n is a power of 2, return n.
// Otherwise, return the next power of 2.
#include <__hash_table>
#include <unordered_map>
#include <cassert>
#include <iostream>
bool
is_power_of_two(unsigned long n)
{
return __builtin_popcount(n) == 1;
}
void test_next_pow2_val(size_t n)
{
std::size_t npow2 = std::__next_hash_pow2(n);
assert(is_power_of_two(npow2) && npow2 > n);
}
void
test_next_pow2()
{
assert(!is_power_of_two(0));
assert(is_power_of_two(1));
assert(is_power_of_two(2));
assert(!is_power_of_two(3));
assert(std::__next_hash_pow2(0) == 0);
assert(std::__next_hash_pow2(1) == 1);
for (std::size_t n = 2; n < (sizeof(std::size_t) * 8 - 1); ++n)
{
std::size_t pow2 = 1ULL << n;
assert(std::__next_hash_pow2(pow2) == pow2);
}
test_next_pow2_val(3);
test_next_pow2_val(7);
test_next_pow2_val(9);
test_next_pow2_val(15);
test_next_pow2_val(127);
test_next_pow2_val(129);
}
// Note: this is only really useful when run with -fsanitize=undefined.
void
fuzz_unordered_map_reserve(unsigned num_inserts,
unsigned num_reserve1,
unsigned num_reserve2)
{
std::unordered_map<uint64_t, unsigned long> m;
m.reserve(num_reserve1);
for (unsigned I = 0; I < num_inserts; ++I) m[I] = 0;
m.reserve(num_reserve2);
assert(m.bucket_count() >= num_reserve2);
}
int main()
{
test_next_pow2();
for (unsigned num_inserts = 0; num_inserts <= 64; ++num_inserts)
for (unsigned num_reserve1 = 1; num_reserve1 <= 64; ++num_reserve1)
for (unsigned num_reserve2 = 1; num_reserve2 <= 64; ++num_reserve2)
fuzz_unordered_map_reserve(num_inserts, num_reserve1, num_reserve2);
return 0;
}
|
