Implement LCM and GCD for C++17. Same code as for Library Fundamentals TS.

llvm-svn: 276751
This commit is contained in:
Marshall Clow 2016-07-26 14:29:45 +00:00
parent ab581e79aa
commit 19b4035f29
9 changed files with 426 additions and 5 deletions

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@ -2431,7 +2431,7 @@ __rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIt
template<typename _Integral>
inline _LIBCPP_INLINE_VISIBILITY
_Integral
__gcd(_Integral __x, _Integral __y)
__algo_gcd(_Integral __x, _Integral __y)
{
do
{
@ -2456,7 +2456,7 @@ __rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _Ran
_VSTD::swap_ranges(__first, __middle, __middle);
return __middle;
}
const difference_type __g = _VSTD::__gcd(__m1, __m2);
const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
for (_RandomAccessIterator __p = __first + __g; __p != __first;)
{
value_type __t(_VSTD::move(*--__p));

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@ -53,6 +53,12 @@ template <class InputIterator, class OutputIterator, class BinaryOperation>
template <class ForwardIterator, class T>
void iota(ForwardIterator first, ForwardIterator last, T value);
template <class M, class N>
constexpr common_type_t<M,N> gcd(M m, N n); // C++17
template <class M, class N>
constexpr common_type_t<M,N> lcm(M m, N n); // C++17
} // std
*/
@ -192,6 +198,62 @@ iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value_)
*__first = __value_;
}
#if _LIBCPP_STD_VER > 14
template <typename _Tp, bool _IsSigned = is_signed<_Tp>::value> struct __abs;
template <typename _Tp>
struct __abs<_Tp, true> {
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
_Tp operator()(_Tp __t) const noexcept { return __t >= 0 ? __t : -__t; }
};
template <typename _Tp>
struct __abs<_Tp, false> {
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
_Tp operator()(_Tp __t) const noexcept { return __t; }
};
template<class _Tp>
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
_Tp __gcd(_Tp __m, _Tp __n)
{
static_assert((!is_signed<_Tp>::value), "" );
return __n == 0 ? __m : __gcd<_Tp>(__n, __m % __n);
}
template<class _Tp, class _Up>
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
common_type_t<_Tp,_Up>
gcd(_Tp __m, _Up __n)
{
static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to gcd must be integer types");
using _Rp = common_type_t<_Tp,_Up>;
using _Wp = make_unsigned_t<_Rp>;
return static_cast<_Rp>(__gcd(static_cast<_Wp>(__abs<_Tp>()(__m)),
static_cast<_Wp>(__abs<_Up>()(__n))));
}
template<class _Tp, class _Up>
_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
common_type_t<_Tp,_Up>
lcm(_Tp __m, _Up __n)
{
static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to lcm must be integer types");
if (__m == 0 || __n == 0)
return 0;
using _Rp = common_type_t<_Tp,_Up>;
_Rp __val1 = __abs<_Tp>()(__m) / gcd(__m,__n);
_Up __val2 = __abs<_Up>()(__n);
_LIBCPP_ASSERT((numeric_limits<_Rp>::max() / __val1 > __val2), "Overflow in lcm");
return __val1 * __val2;
}
#endif /* _LIBCPP_STD_VER > 14 */
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP_NUMERIC

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@ -0,0 +1,24 @@
//===----------------------------------------------------------------------===//
//
// 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
// <numeric>
// template<class _M, class _N>
// constexpr common_type_t<_M,_N> gcd(_M __m, _N __n)
// Remarks: If either M or N is not an integer type, the program is ill-formed.
#include <numeric>
int main()
{
std::gcd(2.0, 4);
}

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@ -0,0 +1,24 @@
//===----------------------------------------------------------------------===//
//
// 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
// <numeric>
// template<class _M, class _N>
// constexpr common_type_t<_M,_N> gcd(_M __m, _N __n)
// Remarks: If either M or N is not an integer type, the program is ill-formed.
#include <numeric>
int main()
{
std::gcd(4, 6.0);
}

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@ -0,0 +1,132 @@
//===----------------------------------------------------------------------===//
//
// 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
// <numeric>
// template<class _M, class _N>
// constexpr common_type_t<_M,_N> gcd(_M __m, _N __n)
#include <numeric>
#include <cassert>
#include <cstdlib> // for rand()
#include <iostream>
constexpr struct {
int x;
int y;
int expect;
} Cases[] = {
{0, 0, 0},
{1, 0, 1},
{0, 1, 1},
{1, 1, 1},
{2, 3, 1},
{2, 4, 2},
{36, 17, 1},
{36, 18, 18}
};
template <typename Input1, typename Input2, typename Output>
constexpr bool test0(Input1 in1, Input2 in2, Output out)
{
static_assert((std::is_same<Output, decltype(std::gcd(in1, in2))>::value), "" );
static_assert((std::is_same<Output, decltype(std::gcd(in2, in1))>::value), "" );
return out == std::gcd(in1, in2) ? true : (std::abort(), false);
}
template <typename Input1, typename Input2 = Input1>
constexpr bool do_test(int dummy = 0)
{
using S1 = typename std::make_signed<Input1>::type;
using S2 = typename std::make_signed<Input2>::type;
using U1 = typename std::make_unsigned<Input1>::type;
using U2 = typename std::make_unsigned<Input2>::type;
bool accumulate = true;
for (auto TC : Cases) {
{ // Test with two signed types
using Output = std::common_type_t<S1, S2>;
accumulate &= test0<S1, S2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S1, S2, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<S1, S2, Output>(TC.x, -TC.y, TC.expect);
accumulate &= test0<S1, S2, Output>(-TC.x, -TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(TC.x, -TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(-TC.x, -TC.y, TC.expect);
}
{ // test with two unsigned types
using Output = std::common_type_t<U1, U2>;
accumulate &= test0<U1, U2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<U2, U1, Output>(TC.x, TC.y, TC.expect);
}
{ // Test with mixed signs
using Output = std::common_type_t<S1, U2>;
accumulate &= test0<S1, U2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<U2, S1, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S1, U2, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<U2, S1, Output>(TC.x, -TC.y, TC.expect);
}
{ // Test with mixed signs
using Output = std::common_type_t<S2, U1>;
accumulate &= test0<S2, U1, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<U1, S2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S2, U1, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<U1, S2, Output>(TC.x, -TC.y, TC.expect);
}
}
return accumulate;
}
int main()
{
auto non_cce = std::rand(); // a value that can't possibly be constexpr
static_assert(do_test<signed char>(), "");
static_assert(do_test<short>(), "");
static_assert(do_test<int>(), "");
static_assert(do_test<long>(), "");
static_assert(do_test<long long>(), "");
assert(do_test<signed char>(non_cce));
assert(do_test<short>(non_cce));
assert(do_test<int>(non_cce));
assert(do_test<long>(non_cce));
assert(do_test<long long>(non_cce));
static_assert(do_test< int8_t>(), "");
static_assert(do_test<int16_t>(), "");
static_assert(do_test<int32_t>(), "");
static_assert(do_test<int64_t>(), "");
assert(do_test< int8_t>(non_cce));
assert(do_test<int16_t>(non_cce));
assert(do_test<int32_t>(non_cce));
assert(do_test<int64_t>(non_cce));
static_assert(do_test<signed char, int>(), "");
static_assert(do_test<int, signed char>(), "");
static_assert(do_test<short, int>(), "");
static_assert(do_test<int, short>(), "");
static_assert(do_test<int, long>(), "");
static_assert(do_test<long, int>(), "");
static_assert(do_test<int, long long>(), "");
static_assert(do_test<long long, int>(), "");
assert((do_test<signed char, int>(non_cce)));
assert((do_test<int, signed char>(non_cce)));
assert((do_test<short, int>(non_cce)));
assert((do_test<int, short>(non_cce)));
assert((do_test<int, long>(non_cce)));
assert((do_test<long, int>(non_cce)));
assert((do_test<int, long long>(non_cce)));
assert((do_test<long long, int>(non_cce)));
}

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@ -0,0 +1,24 @@
//===----------------------------------------------------------------------===//
//
// 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
// <numeric>
// template<class _M, class _N>
// constexpr common_type_t<_M,_N> lcm(_M __m, _N __n)
// Remarks: If either M or N is not an integer type, the program is ill-formed.
#include <numeric>
int main()
{
std::lcm(2.0, 4);
}

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@ -0,0 +1,24 @@
//===----------------------------------------------------------------------===//
//
// 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
// <numeric>
// template<class _M, class _N>
// constexpr common_type_t<_M,_N> lcm(_M __m, _N __n)
// Remarks: If either M or N is not an integer type, the program is ill-formed.
#include <numeric>
int main()
{
std::lcm(4, 6.0);
}

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@ -0,0 +1,131 @@
//===----------------------------------------------------------------------===//
//
// 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
// <numeric>
// template<class _M, class _N>
// constexpr common_type_t<_M,_N> gcd(_M __m, _N __n)
#include <numeric>
#include <cassert>
#include <cstdlib>
#include <iostream>
constexpr struct {
int x;
int y;
int expect;
} Cases[] = {
{0, 0, 0},
{1, 0, 0},
{0, 1, 0},
{1, 1, 1},
{2, 3, 6},
{2, 4, 4},
{3, 17, 51},
{36, 18, 36}
};
template <typename Input1, typename Input2, typename Output>
constexpr bool test0(Input1 in1, Input2 in2, Output out)
{
static_assert((std::is_same<Output, decltype(std::lcm(Input1(0), Input2(0)))>::value), "" );
static_assert((std::is_same<Output, decltype(std::lcm(Input2(0), Input1(0)))>::value), "" );
return out == std::lcm(in1, in2) ? true : (std::abort(), false);
}
template <typename Input1, typename Input2 = Input1>
constexpr bool do_test(int dummy = 0)
{
using S1 = typename std::make_signed<Input1>::type;
using S2 = typename std::make_signed<Input2>::type;
using U1 = typename std::make_unsigned<Input1>::type;
using U2 = typename std::make_unsigned<Input2>::type;
bool accumulate = true;
for (auto TC : Cases) {
{ // Test with two signed types
using Output = std::common_type_t<S1, S2>;
accumulate &= test0<S1, S2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S1, S2, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<S1, S2, Output>(TC.x, -TC.y, TC.expect);
accumulate &= test0<S1, S2, Output>(-TC.x, -TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(TC.x, -TC.y, TC.expect);
accumulate &= test0<S2, S1, Output>(-TC.x, -TC.y, TC.expect);
}
{ // test with two unsigned types
using Output = std::common_type_t<U1, U2>;
accumulate &= test0<U1, U2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<U2, U1, Output>(TC.x, TC.y, TC.expect);
}
{ // Test with mixed signs
using Output = std::common_type_t<S1, U2>;
accumulate &= test0<S1, U2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<U2, S1, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S1, U2, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<U2, S1, Output>(TC.x, -TC.y, TC.expect);
}
{ // Test with mixed signs
using Output = std::common_type_t<S2, U1>;
accumulate &= test0<S2, U1, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<U1, S2, Output>(TC.x, TC.y, TC.expect);
accumulate &= test0<S2, U1, Output>(-TC.x, TC.y, TC.expect);
accumulate &= test0<U1, S2, Output>(TC.x, -TC.y, TC.expect);
}
}
return accumulate;
}
int main()
{
auto non_cce = std::rand(); // a value that can't possibly be constexpr
static_assert(do_test<signed char>(), "");
static_assert(do_test<short>(), "");
static_assert(do_test<int>(), "");
static_assert(do_test<long>(), "");
static_assert(do_test<long long>(), "");
assert(do_test<signed char>(non_cce));
assert(do_test<short>(non_cce));
assert(do_test<int>(non_cce));
assert(do_test<long>(non_cce));
assert(do_test<long long>(non_cce));
static_assert(do_test< int8_t>(), "");
static_assert(do_test<int16_t>(), "");
static_assert(do_test<int32_t>(), "");
static_assert(do_test<int64_t>(), "");
assert(do_test< int8_t>(non_cce));
assert(do_test<int16_t>(non_cce));
assert(do_test<int32_t>(non_cce));
assert(do_test<int64_t>(non_cce));
static_assert(do_test<signed char, int>(), "");
static_assert(do_test<int, signed char>(), "");
static_assert(do_test<short, int>(), "");
static_assert(do_test<int, short>(), "");
static_assert(do_test<int, long>(), "");
static_assert(do_test<long, int>(), "");
static_assert(do_test<int, long long>(), "");
static_assert(do_test<long long, int>(), "");
assert((do_test<signed char, int>(non_cce)));
assert((do_test<int, signed char>(non_cce)));
assert((do_test<short, int>(non_cce)));
assert((do_test<int, short>(non_cce)));
assert((do_test<int, long>(non_cce)));
assert((do_test<long, int>(non_cce)));
assert((do_test<int, long long>(non_cce)));
assert((do_test<long long, int>(non_cce)));
}

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@ -108,14 +108,14 @@
<tr><td><a href="http://wg21.link/p0181r1">p0181r1</a></td><td>LWG</td><td>Ordered by Default</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0209r2">p0209r2</a></td><td>LWG</td><td>make_from_tuple: apply for construction</td><td>Oulu</td><td>Complete</td><td>3.9</td></tr>
<tr><td><a href="http://wg21.link/p0219r1">p0219r1</a></td><td>LWG</td><td>Relative Paths for Filesystem</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0254r2">p0254r2</a></td><td>LWG</td><td>Integrating std::string_view and std::string</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0254r2">p0254r2</a></td><td>LWG</td><td>Integrating std::string_view and std::string</td><td>Oulu</td><td>Complete</td><td>4.0</td></tr>
<tr><td><a href="http://wg21.link/p0258r2">p0258r2</a></td><td>LWG</td><td>has_unique_object_representations</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0295r0">p0295r0</a></td><td>LWG</td><td>Adopt Selected Library Fundamentals V2 Components for C++17</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0295r0">p0295r0</a></td><td>LWG</td><td>Adopt Selected Library Fundamentals V2 Components for C++17</td><td>Oulu</td><td>Complete</td><td>4.0</td></tr>
<tr><td><a href="http://wg21.link/p0302r1">p0302r1</a></td><td>LWG</td><td>Removing Allocator Support in std::function</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0307r2">p0307r2</a></td><td>LWG</td><td>Making Optional Greater Equal Again</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0336r1">p0336r1</a></td><td>LWG</td><td>Better Names for Parallel Execution Policies in C++17</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0337r0">p0337r0</a></td><td>LWG</td><td>Delete operator= for polymorphic_allocator</td><td>Oulu</td><td>Complete</td><td>3.9</td></tr>
<tr><td><a href="http://wg21.link/p0346r1">p0346r1</a></td><td>LWG</td><td>A &lt;random&gt; Nomenclature Tweak</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0346r1">p0346r1</a></td><td>LWG</td><td>A &lt;random&gt; Nomenclature Tweak</td><td>Oulu</td><td>Complete</td><td>3.9</td></tr>
<tr><td><a href="http://wg21.link/p0358r1">p0358r1</a></td><td>LWG</td><td>Fixes for not_fn</td><td>Oulu</td><td>Complete</td><td>3.9</td></tr>
<tr><td><a href="http://wg21.link/p0371r1">p0371r1</a></td><td>LWG</td><td>Temporarily discourage memory_order_consume</td><td>Oulu</td><td></td><td></td></tr>
<tr><td><a href="http://wg21.link/p0392r0">p0392r0</a></td><td>LWG</td><td>Adapting string_view by filesystem paths</td><td>Oulu</td><td>Complete</td><td>4.0</td></tr>