1 //===----------------------------------------------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 // UNSUPPORTED: c++03, c++11, c++14, c++17
10 
11 // template <class T>
12 //   constexpr int rotr(T x, unsigned int s) noexcept;
13 
14 // Remarks: This function shall not participate in overload resolution unless
15 //  T is an unsigned integer type
16 
17 #include <bit>
18 #include <cstdint>
19 #include <type_traits>
20 #include <cassert>
21 
22 #include "test_macros.h"
23 
24 class A{};
25 enum       E1 : unsigned char { rEd };
26 enum class E2 : unsigned char { red };
27 
28 template <typename T>
constexpr_test()29 constexpr bool constexpr_test()
30 {
31     const T max = std::numeric_limits<T>::max();
32 
33     return std::rotr(T(128), 0) == T(128)
34        &&  std::rotr(T(128), 1) == T( 64)
35        &&  std::rotr(T(128), 2) == T( 32)
36        &&  std::rotr(T(128), 3) == T( 16)
37        &&  std::rotr(T(128), 4) == T(  8)
38        &&  std::rotr(T(128), 5) == T(  4)
39        &&  std::rotr(T(128), 6) == T(  2)
40        &&  std::rotr(T(128), 7) == T(  1)
41        &&  std::rotr(max, 0)  == max
42        &&  std::rotr(max, 1)  == max
43        &&  std::rotr(max, 2)  == max
44        &&  std::rotr(max, 3)  == max
45        &&  std::rotr(max, 4)  == max
46        &&  std::rotr(max, 5)  == max
47        &&  std::rotr(max, 6)  == max
48        &&  std::rotr(max, 7)  == max
49       ;
50 }
51 
52 
53 template <typename T>
runtime_test()54 void runtime_test()
55 {
56     ASSERT_SAME_TYPE(T, decltype(std::rotr(T(0), 0)));
57     ASSERT_NOEXCEPT(             std::rotr(T(0), 0));
58     const T max = std::numeric_limits<T>::max();
59     const T val = std::numeric_limits<T>::max() - 1;
60 
61     const T uppers [] = {
62         max,              // not used
63         max - max,        // 000 .. 0
64         max - (max >> 1), // 800 .. 0
65         max - (max >> 2), // C00 .. 0
66         max - (max >> 3), // E00 .. 0
67         max - (max >> 4), // F00 .. 0
68         max - (max >> 5), // F80 .. 0
69         max - (max >> 6), // FC0 .. 0
70         max - (max >> 7), // FE0 .. 0
71         };
72 
73     assert( std::rotr(val, 0) == val);
74     assert( std::rotr(val, 1) == T((val >> 1) +  uppers[1]));
75     assert( std::rotr(val, 2) == T((val >> 2) +  uppers[2]));
76     assert( std::rotr(val, 3) == T((val >> 3) +  uppers[3]));
77     assert( std::rotr(val, 4) == T((val >> 4) +  uppers[4]));
78     assert( std::rotr(val, 5) == T((val >> 5) +  uppers[5]));
79     assert( std::rotr(val, 6) == T((val >> 6) +  uppers[6]));
80     assert( std::rotr(val, 7) == T((val >> 7) +  uppers[7]));
81 }
82 
main(int,char **)83 int main(int, char**)
84 {
85 
86     {
87     auto lambda = [](auto x) -> decltype(std::rotr(x, 1U)) {};
88     using L = decltype(lambda);
89 
90     static_assert( std::is_invocable_v<L, unsigned char>, "");
91     static_assert( std::is_invocable_v<L, unsigned int>, "");
92     static_assert( std::is_invocable_v<L, unsigned long>, "");
93     static_assert( std::is_invocable_v<L, unsigned long long>, "");
94 
95     static_assert( std::is_invocable_v<L, uint8_t>, "");
96     static_assert( std::is_invocable_v<L, uint16_t>, "");
97     static_assert( std::is_invocable_v<L, uint32_t>, "");
98     static_assert( std::is_invocable_v<L, uint64_t>, "");
99     static_assert( std::is_invocable_v<L, size_t>, "");
100 
101     static_assert( std::is_invocable_v<L, uintmax_t>, "");
102     static_assert( std::is_invocable_v<L, uintptr_t>, "");
103 
104 
105     static_assert(!std::is_invocable_v<L, int>, "");
106     static_assert(!std::is_invocable_v<L, signed int>, "");
107     static_assert(!std::is_invocable_v<L, long>, "");
108     static_assert(!std::is_invocable_v<L, long long>, "");
109 
110     static_assert(!std::is_invocable_v<L, int8_t>, "");
111     static_assert(!std::is_invocable_v<L, int16_t>, "");
112     static_assert(!std::is_invocable_v<L, int32_t>, "");
113     static_assert(!std::is_invocable_v<L, int64_t>, "");
114     static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
115 
116     static_assert(!std::is_invocable_v<L, bool>, "");
117     static_assert(!std::is_invocable_v<L, signed char>, "");
118     static_assert(!std::is_invocable_v<L, char16_t>, "");
119     static_assert(!std::is_invocable_v<L, char32_t>, "");
120 
121 #ifndef _LIBCPP_HAS_NO_INT128
122     static_assert( std::is_invocable_v<L, __uint128_t>, "");
123     static_assert(!std::is_invocable_v<L,  __int128_t>, "");
124 #endif
125 
126     static_assert(!std::is_invocable_v<L, A, unsigned>, "");
127     static_assert(!std::is_invocable_v<L, E1, unsigned>, "");
128     static_assert(!std::is_invocable_v<L, E2, unsigned>, "");
129     }
130 
131     static_assert(constexpr_test<unsigned char>(),      "");
132     static_assert(constexpr_test<unsigned short>(),     "");
133     static_assert(constexpr_test<unsigned>(),           "");
134     static_assert(constexpr_test<unsigned long>(),      "");
135     static_assert(constexpr_test<unsigned long long>(), "");
136 
137     static_assert(constexpr_test<uint8_t>(),   "");
138     static_assert(constexpr_test<uint16_t>(),  "");
139     static_assert(constexpr_test<uint32_t>(),  "");
140     static_assert(constexpr_test<uint64_t>(),  "");
141     static_assert(constexpr_test<size_t>(),    "");
142     static_assert(constexpr_test<uintmax_t>(), "");
143     static_assert(constexpr_test<uintptr_t>(), "");
144 
145 #ifndef _LIBCPP_HAS_NO_INT128
146     static_assert(constexpr_test<__uint128_t>(),        "");
147 #endif
148 
149 
150     runtime_test<unsigned char>();
151     runtime_test<unsigned>();
152     runtime_test<unsigned short>();
153     runtime_test<unsigned long>();
154     runtime_test<unsigned long long>();
155 
156     runtime_test<uint8_t>();
157     runtime_test<uint16_t>();
158     runtime_test<uint32_t>();
159     runtime_test<uint64_t>();
160     runtime_test<size_t>();
161     runtime_test<uintmax_t>();
162     runtime_test<uintptr_t>();
163 
164 
165 #ifndef _LIBCPP_HAS_NO_INT128
166     runtime_test<__uint128_t>();
167 
168     {
169     __uint128_t val = 168; // 0xA8 (aka 10101000)
170 
171     assert( std::rotr(val, 128) == 168);
172     val <<= 32;
173     assert( std::rotr(val,  32) == 168);
174     val <<= 2;
175     assert( std::rotr(val,  33) == 336);
176     val <<= 3;
177     assert( std::rotr(val,  38) ==  84);
178     assert( std::rotr(val, 166) ==  84);
179     }
180 #endif
181 
182     return 0;
183 }
184