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1 //===----------------------------------------------------------------------===//
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 // test unsigned long long to_ullong() const;
10 
11 #include <bitset>
12 #include <algorithm>
13 #include <type_traits>
14 #include <climits>
15 #include <cassert>
16 
17 #include "test_macros.h"
18 
19 template <std::size_t N>
test_to_ullong()20 void test_to_ullong() {
21     const std::size_t M = sizeof(unsigned long long) * CHAR_BIT < N ? sizeof(unsigned long long) * CHAR_BIT : N;
22     const bool is_M_zero = std::integral_constant<bool, M == 0>::value; // avoid compiler warnings
23     const std::size_t X = is_M_zero ? sizeof(unsigned long long) * CHAR_BIT - 1 : sizeof(unsigned long long) * CHAR_BIT - M;
24     const unsigned long long max = is_M_zero ? 0 : (unsigned long long)(-1) >> X;
25     unsigned long long tests[] = {
26         0,
27         std::min<unsigned long long>(1, max),
28         std::min<unsigned long long>(2, max),
29         std::min<unsigned long long>(3, max),
30         std::min(max, max-3),
31         std::min(max, max-2),
32         std::min(max, max-1),
33         max
34     };
35     for (std::size_t i = 0; i < sizeof(tests)/sizeof(tests[0]); ++i) {
36         unsigned long long j = tests[i];
37         std::bitset<N> v(j);
38         assert(j == v.to_ullong());
39     }
40     { // test values bigger than can fit into the bitset
41         const unsigned long long val = 0x55AAAAFFFFAAAA55ULL;
42         const bool canFit = N < sizeof(unsigned long long) * CHAR_BIT;
43         const unsigned long long mask = canFit ? (1ULL << (canFit ? N : 0)) - 1 : (unsigned long long)(-1); // avoid compiler warnings
44         std::bitset<N> v(val);
45         assert(v.to_ullong() == (val & mask)); // we shouldn't return bit patterns from outside the limits of the bitset.
46     }
47 }
48 
main(int,char **)49 int main(int, char**) {
50 //     test_to_ullong<0>();
51     test_to_ullong<1>();
52     test_to_ullong<31>();
53     test_to_ullong<32>();
54     test_to_ullong<33>();
55     test_to_ullong<63>();
56     test_to_ullong<64>();
57     test_to_ullong<65>();
58     test_to_ullong<1000>();
59 
60     return 0;
61 }
62