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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
// template <class T>
// constexpr T log2p1(T x) noexcept;
// If x == 0, 0; otherwise one plus the base-2 logarithm of x, with any fractional part discarded.
// Remarks: This function shall not participate in overload resolution unless
// T is an unsigned integer type
#include <bit>
#include <cstdint>
#include <cassert>
#include "test_macros.h"
class A{};
enum E1 : unsigned char { rEd };
enum class E2 : unsigned char { red };
template <typename T>
constexpr bool constexpr_test()
{
return std::log2p1(T(0)) == T(0)
&& std::log2p1(T(1)) == T(1)
&& std::log2p1(T(2)) == T(2)
&& std::log2p1(T(3)) == T(2)
&& std::log2p1(T(4)) == T(3)
&& std::log2p1(T(5)) == T(3)
&& std::log2p1(T(6)) == T(3)
&& std::log2p1(T(7)) == T(3)
&& std::log2p1(T(8)) == T(4)
&& std::log2p1(T(9)) == T(4)
;
}
template <typename T>
void runtime_test()
{
ASSERT_SAME_TYPE(T, decltype(std::log2p1(T(0))));
ASSERT_NOEXCEPT( std::log2p1(T(0)));
assert( std::log2p1(T(0)) == T(0));
assert( std::log2p1(T(1)) == T(1));
assert( std::log2p1(T(2)) == T(2));
assert( std::log2p1(T(3)) == T(2));
assert( std::log2p1(T(4)) == T(3));
assert( std::log2p1(T(5)) == T(3));
assert( std::log2p1(T(6)) == T(3));
assert( std::log2p1(T(7)) == T(3));
assert( std::log2p1(T(8)) == T(4));
assert( std::log2p1(T(9)) == T(4));
assert( std::log2p1(T(121)) == T(7));
assert( std::log2p1(T(122)) == T(7));
assert( std::log2p1(T(123)) == T(7));
assert( std::log2p1(T(124)) == T(7));
assert( std::log2p1(T(125)) == T(7));
assert( std::log2p1(T(126)) == T(7));
assert( std::log2p1(T(127)) == T(7));
assert( std::log2p1(T(128)) == T(8));
assert( std::log2p1(T(129)) == T(8));
assert( std::log2p1(T(130)) == T(8));
}
int main()
{
{
auto lambda = [](auto x) -> decltype(std::log2p1(x)) {};
using L = decltype(lambda);
static_assert( std::is_invocable_v<L, unsigned char>, "");
static_assert( std::is_invocable_v<L, unsigned int>, "");
static_assert( std::is_invocable_v<L, unsigned long>, "");
static_assert( std::is_invocable_v<L, unsigned long long>, "");
static_assert( std::is_invocable_v<L, uint8_t>, "");
static_assert( std::is_invocable_v<L, uint16_t>, "");
static_assert( std::is_invocable_v<L, uint32_t>, "");
static_assert( std::is_invocable_v<L, uint64_t>, "");
static_assert( std::is_invocable_v<L, size_t>, "");
static_assert( std::is_invocable_v<L, uintmax_t>, "");
static_assert( std::is_invocable_v<L, uintptr_t>, "");
static_assert(!std::is_invocable_v<L, int>, "");
static_assert(!std::is_invocable_v<L, signed int>, "");
static_assert(!std::is_invocable_v<L, long>, "");
static_assert(!std::is_invocable_v<L, long long>, "");
static_assert(!std::is_invocable_v<L, int8_t>, "");
static_assert(!std::is_invocable_v<L, int16_t>, "");
static_assert(!std::is_invocable_v<L, int32_t>, "");
static_assert(!std::is_invocable_v<L, int64_t>, "");
static_assert(!std::is_invocable_v<L, ptrdiff_t>, "");
static_assert(!std::is_invocable_v<L, bool>, "");
static_assert(!std::is_invocable_v<L, signed char>, "");
static_assert(!std::is_invocable_v<L, char16_t>, "");
static_assert(!std::is_invocable_v<L, char32_t>, "");
#ifndef _LIBCPP_HAS_NO_INT128
static_assert( std::is_invocable_v<L, __uint128_t>, "");
static_assert(!std::is_invocable_v<L, __int128_t>, "");
#endif
static_assert(!std::is_invocable_v<L, A>, "");
static_assert(!std::is_invocable_v<L, E1>, "");
static_assert(!std::is_invocable_v<L, E2>, "");
}
static_assert(constexpr_test<unsigned char>(), "");
static_assert(constexpr_test<unsigned short>(), "");
static_assert(constexpr_test<unsigned>(), "");
static_assert(constexpr_test<unsigned long>(), "");
static_assert(constexpr_test<unsigned long long>(), "");
static_assert(constexpr_test<uint8_t>(), "");
static_assert(constexpr_test<uint16_t>(), "");
static_assert(constexpr_test<uint32_t>(), "");
static_assert(constexpr_test<uint64_t>(), "");
static_assert(constexpr_test<size_t>(), "");
static_assert(constexpr_test<uintmax_t>(), "");
static_assert(constexpr_test<uintptr_t>(), "");
#ifndef _LIBCPP_HAS_NO_INT128
static_assert(constexpr_test<__uint128_t>(), "");
#endif
runtime_test<unsigned char>();
runtime_test<unsigned>();
runtime_test<unsigned short>();
runtime_test<unsigned long>();
runtime_test<unsigned long long>();
runtime_test<uint8_t>();
runtime_test<uint16_t>();
runtime_test<uint32_t>();
runtime_test<uint64_t>();
runtime_test<size_t>();
runtime_test<uintmax_t>();
runtime_test<uintptr_t>();
#ifndef _LIBCPP_HAS_NO_INT128
runtime_test<__uint128_t>();
{
__uint128_t val = 128;
val <<= 32;
assert( std::log2p1(val-1) == 39);
assert( std::log2p1(val) == 40);
assert( std::log2p1(val+1) == 40);
val <<= 2;
assert( std::log2p1(val-1) == 41);
assert( std::log2p1(val) == 42);
assert( std::log2p1(val+1) == 42);
val <<= 3;
assert( std::log2p1(val-1) == 44);
assert( std::log2p1(val) == 45);
assert( std::log2p1(val+1) == 45);
}
#endif
}