_S_gcd(intmax_t __m, intmax_t __n) noexcept
{
// Duration only allows positive periods so we don't need to
- // support negative values here (unlike __static_gcd and std::gcd).
+ // handle negative values here (unlike __static_gcd and std::gcd).
+#if __cplusplus >= 201402L
+ while (__m != 0 && __n != 0)
+ {
+ intmax_t __rem = __m % __n;
+ __m = __n;
+ __n = __rem;
+ }
+ return __m + __n;
+#else
+ // C++11 doesn't allow loops in constexpr functions, but this
+ // recursive version can be more expensive to evaluate.
return (__m == 0) ? __n : (__n == 0) ? __m : _S_gcd(__n, __m % __n);
+#endif
}
// _GLIBCXX_RESOLVE_LIB_DEFECTS
#if __cplusplus >= 201402L
#include <type_traits>
+#include <bit>
namespace std _GLIBCXX_VISIBILITY(default)
{
template<typename _Up> void __absu(bool) = delete;
- // GCD implementation
+ // GCD implementation, using Stein's algorithm
template<typename _Tp>
constexpr _Tp
__gcd(_Tp __m, _Tp __n)
{
static_assert(is_unsigned<_Tp>::value, "type must be unsigned");
- return __m == 0 ? __n
- : __n == 0 ? __m
- : __detail::__gcd(__n, _Tp(__m % __n));
+
+ if (__m == 0)
+ return __n;
+ if (__n == 0)
+ return __m;
+
+ const int __i = std::__countr_zero(__m);
+ __m >>= __i;
+ const int __j = std::__countr_zero(__n);
+ __n >>= __j;
+ const int __k = __i < __j ? __i : __j; // min(i, j)
+
+ while (true)
+ {
+ if (__m > __n)
+ {
+ _Tp __tmp = __m;
+ __m = __n;
+ __n = __tmp;
+ }
+
+ __n -= __m;
+
+ if (__n == 0)
+ return __m << __k;
+
+ __n >>= std::__countr_zero(__n);
+ }
}
// LCM implementation
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
-// { dg-options "-std=gnu++17" }
// { dg-do compile { target c++17 } }
#include <numeric>
#endif
using std::gcd;
+using std::is_same_v;
static_assert( gcd(1071, 462) == 21, "" );
static_assert( gcd(2000, 20) == 20, "" );
static_assert( gcd(200, 200) == 200, "GCD of equal numbers is that number" );
static_assert( gcd(0, 13) == 13, "GCD of any number and 0 is that number" );
static_assert( gcd(29, 0) == 29, "GCD of any number and 0 is that number" );
-static_assert( gcd(0, 0) == 0, "" );
+static_assert( gcd(0, 0) == 0, "Zarro Boogs found" );
static_assert(gcd(1u, 2) == 1, "unsigned and signed");
+static_assert(gcd(9, 6u) == 3, "unsigned and signed");
static_assert(gcd(3, 4u) == 1, "signed and unsigned");
+static_assert(gcd(32u, 24) == 8, "signed and unsigned");
+static_assert(gcd(1u, -2) == 1, "unsigned and negative");
+static_assert(gcd(-21, 28u) == 7, "unsigned and negative");
+static_assert(gcd(-3, 4u) == 1, "negative and unsigned");
+static_assert(gcd(33u, -44) == 11, "negative and unsigned");
static_assert(gcd(5u, 6u) == 1, "unsigned and unsigned");
+static_assert(gcd(54u, 36u) == 18, "unsigned and unsigned");
+static_assert(gcd(-5, -6) == 1, "negative and negative");
+static_assert(gcd(-50, -60) == 10, "negative and negative");
-static_assert( std::is_same_v<decltype(gcd(1l, 1)), long> );
-static_assert( std::is_same_v<decltype(gcd(1ul, 1ull)), unsigned long long> );
+static_assert( is_same_v<decltype(gcd(1l, 1)), long> );
+static_assert( is_same_v<decltype(gcd(1ul, 1ull)), unsigned long long> );
--- /dev/null
+// Copyright (C) 2015-2020 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library. This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-do run { target c++17 } }
+
+#include <numeric>
+#include <climits>
+#include <testsuite_hooks.h>
+
+constexpr struct testcase { unsigned long long p, q, r; } testcases[] = {
+ { 5, 8, 1 },
+ { 6, 35, 1 },
+ { 30, 42, 6 },
+ { 24, 60, 12 },
+ { 55, 144, 1 },
+ { 105, 252, 21 },
+ { 253, 22121, 11 },
+ { 1386, 3213, 63 },
+ { 2028, 2049, 3 },
+ { 46391, 62527, 2017 },
+ { 63245986, 39088169, 1 },
+ { 77160074263, 47687519812, 1 },
+ { 77160074264, 47687519812, 4 },
+};
+
+template<typename P, typename Q>
+constexpr bool
+check(P p, Q q, unsigned long long r)
+{
+ using R = std::common_type_t<P, Q>;
+ static_assert( std::is_same_v<decltype(std::gcd(p, q)), R> );
+ static_assert( std::is_same_v<decltype(std::gcd(q, p)), R> );
+ R r1 = std::gcd(p, q);
+ // Check non-negative, so conversion to unsigned long doesn't alter value.
+ VERIFY( r1 >= 0 );
+ // Check for expected result
+ VERIFY( (unsigned long long)r1 == r );
+ // Check reversing arguments doesn't change result
+ VERIFY( std::gcd(q, p) == r1 );
+
+ P pabs = p < 0 ? -p : p;
+ VERIFY( std::gcd(p, p) == pabs );
+ VERIFY( std::gcd(0, p) == pabs );
+ VERIFY( std::gcd(p, 0) == pabs );
+ VERIFY( std::gcd(1, p) == 1 );
+ VERIFY( std::gcd(p, 1) == 1 );
+ Q qabs = q < 0 ? -q : q;
+ VERIFY( std::gcd(q, q) == qabs );
+ VERIFY( std::gcd(0, q) == qabs );
+ VERIFY( std::gcd(q, 0) == qabs );
+ VERIFY( std::gcd(1, q) == 1 );
+ VERIFY( std::gcd(q, 1) == 1 );
+ VERIFY( std::gcd(r, r) == r );
+ VERIFY( std::gcd(0, r) == r );
+ VERIFY( std::gcd(r, 0) == r );
+ VERIFY( std::gcd(1, r) == 1 );
+ VERIFY( std::gcd(r, 1) == 1 );
+
+ return true;
+}
+
+constexpr bool
+test01()
+{
+ for (auto t : testcases)
+ {
+ check(t.p, t.q, t.r);
+
+ if (t.p <= LONG_MAX && t.q <= LONG_MAX)
+ {
+ check( (long)t.p, (long)t.p, t.p);
+ check(-(long)t.p, (long)t.p, t.p);
+ check(-(long)t.p, -(long)t.p, t.p);
+
+ check( (long)t.p, t.q, t.r);
+ check(-(long)t.p, t.q, t.r);
+
+ check(t.p, (long)t.q, t.r);
+ check(t.p, -(long)t.q, t.r);
+
+ check( (long)t.p, (long)t.q, t.r);
+ check( (long)t.p, -(long)t.q, t.r);
+ check(-(long)t.p, (long)t.q, t.r);
+ check(-(long)t.p, -(long)t.q, t.r);
+ }
+
+ if (t.p <= INT_MAX && t.q <= INT_MAX)
+ {
+ check((long)t.p, (int)t.q, t.r);
+ check(-(int)t.p, (long)t.q, t.r);
+
+ check( (int)t.p, (unsigned)t.q, t.r);
+ check(-(int)t.p, (unsigned)t.q, t.r);
+
+ check(-(int)t.p, -(int)t.q, t.r);
+ check(-(int)t.p, -(long)t.q, t.r);
+ }
+
+ if (t.p <= SHRT_MAX && t.q <= SHRT_MAX)
+ {
+ check( (long)t.p, (short)t.q, t.r);
+ check(-(short)t.p, (long)t.q, t.r);
+
+ check( (short)t.p, (unsigned short)t.q, t.r);
+ check(-(short)t.p, (unsigned short)t.q, t.r);
+
+ check(-(short)t.p, -(short)t.q, t.r);
+ check(-(short)t.p, -(long)t.q, t.r);
+ }
+ }
+ return true;
+}
+
+
+int main()
+{
+ static_assert( test01() ); // constexpr
+ VERIFY( test01() ); // non-constexpr
+}
std::gcd<const int&, const int&>(0.1, 0.1); // { dg-error "from here" }
}
-// { dg-error "must be integers" "" { target *-*-* } 134 }
-// { dg-error "must be integers" "" { target *-*-* } 135 }
-// { dg-error "must not be bool" "" { target *-*-* } 136 }
-// { dg-error "must not be bool" "" { target *-*-* } 137 }
+// { dg-error "must be integers" "" { target *-*-* } 160 }
+// { dg-error "must be integers" "" { target *-*-* } 161 }
+// { dg-error "must not be bool" "" { target *-*-* } 162 }
+// { dg-error "must not be bool" "" { target *-*-* } 163 }
// { dg-prune-output "deleted function" }
// { dg-prune-output "incomplete type .*make_unsigned" }
std::lcm<const int&, const int&>(0.1, 0.1); // { dg-error "from here" }
}
-// { dg-error "must be integers" "" { target *-*-* } 148 }
-// { dg-error "must be integers" "" { target *-*-* } 149 }
-// { dg-error "must not be bool" "" { target *-*-* } 150 }
-// { dg-error "must not be bool" "" { target *-*-* } 151 }
+// { dg-error "must be integers" "" { target *-*-* } 174 }
+// { dg-error "must be integers" "" { target *-*-* } 175 }
+// { dg-error "must not be bool" "" { target *-*-* } 176 }
+// { dg-error "must not be bool" "" { target *-*-* } 177 }
// { dg-prune-output "deleted function" }
// { dg-prune-output "incomplete type .*make_unsigned" }
// { dg-do compile { target c++14 } }
#include <experimental/numeric>
+#include <experimental/type_traits>
+
+#ifndef __cpp_lib_experimental_gcd_lcm
+# error "Feature-test macro for gcd missing"
+#elif __cpp_lib_experimental_gcd_lcm != 201411
+# error "Feature-test macro for gcd has wrong value"
+#endif
using std::experimental::fundamentals_v2::gcd;
+using std::experimental::is_same_v;
static_assert( gcd(1071, 462) == 21, "" );
static_assert( gcd(2000, 20) == 20, "" );
static_assert( gcd(200, 200) == 200, "GCD of equal numbers is that number" );
static_assert( gcd(0, 13) == 13, "GCD of any number and 0 is that number" );
static_assert( gcd(29, 0) == 29, "GCD of any number and 0 is that number" );
-static_assert( gcd(0, 0) == 0, "" );
+static_assert( gcd(0, 0) == 0, "Zarro Boogs found" );
static_assert(gcd(1u, 2) == 1, "unsigned and signed");
+static_assert(gcd(9, 6u) == 3, "unsigned and signed");
static_assert(gcd(3, 4u) == 1, "signed and unsigned");
+static_assert(gcd(32u, 24) == 8, "signed and unsigned");
+static_assert(gcd(1u, -2) == 1, "unsigned and negative");
+static_assert(gcd(-21, 28u) == 7, "unsigned and negative");
+static_assert(gcd(-3, 4u) == 1, "negative and unsigned");
+static_assert(gcd(33u, -44) == 11, "negative and unsigned");
static_assert(gcd(5u, 6u) == 1, "unsigned and unsigned");
+static_assert(gcd(54u, 36u) == 18, "unsigned and unsigned");
+static_assert(gcd(-5, -6) == 1, "negative and negative");
+static_assert(gcd(-50, -60) == 10, "negative and negative");
+
+static_assert( is_same_v<decltype(gcd(1l, 1)), long>, "" );
+static_assert( is_same_v<decltype(gcd(1ul, 1ull)), unsigned long long>, "" );
+
+#include <climits>
+#include <testsuite_hooks.h>
+
+constexpr struct testcase { unsigned long long p, q, r; } testcases[] = {
+ { 5, 8, 1 },
+ { 6, 35, 1 },
+ { 30, 42, 6 },
+ { 24, 60, 12 },
+ { 55, 144, 1 },
+ { 105, 252, 21 },
+ { 253, 22121, 11 },
+ { 1386, 3213, 63 },
+ { 2028, 2049, 3 },
+ { 46391, 62527, 2017 },
+ { 63245986, 39088169, 1 },
+ { 77160074263, 47687519812, 1 },
+ { 77160074264, 47687519812, 4 },
+};
+
+template<typename P, typename Q>
+constexpr bool
+check(P p, Q q, unsigned long long r)
+{
+ using R = std::common_type_t<P, Q>;
+ static_assert( is_same_v<decltype(gcd(p, q)), R>, "" );
+ static_assert( is_same_v<decltype(gcd(q, p)), R>, "" );
+ R r1 = gcd(p, q);
+ // Check non-negative, so conversion to unsigned long doesn't alter value.
+ VERIFY( r1 >= 0 );
+ // Check for expected result
+ VERIFY( (unsigned long long)r1 == r );
+ // Check reversing arguments doesn't change result
+ VERIFY( gcd(q, p) == r1 );
+
+ P pabs = p < 0 ? -p : p;
+ VERIFY( gcd(p, p) == pabs );
+ VERIFY( gcd(0, p) == pabs );
+ VERIFY( gcd(p, 0) == pabs );
+ VERIFY( gcd(1, p) == 1 );
+ VERIFY( gcd(p, 1) == 1 );
+ Q qabs = q < 0 ? -q : q;
+ VERIFY( gcd(q, q) == qabs );
+ VERIFY( gcd(0, q) == qabs );
+ VERIFY( gcd(q, 0) == qabs );
+ VERIFY( gcd(1, q) == 1 );
+ VERIFY( gcd(q, 1) == 1 );
+ VERIFY( gcd(r, r) == r );
+ VERIFY( gcd(0, r) == r );
+ VERIFY( gcd(r, 0) == r );
+ VERIFY( gcd(1, r) == 1 );
+ VERIFY( gcd(r, 1) == 1 );
+
+ return true;
+}
+
+constexpr bool
+test01()
+{
+ for (auto t : testcases)
+ {
+ check(t.p, t.q, t.r);
+
+ if (t.p <= LONG_MAX && t.q <= LONG_MAX)
+ {
+ check( (long)t.p, (long)t.p, t.p);
+ check(-(long)t.p, (long)t.p, t.p);
+ check(-(long)t.p, -(long)t.p, t.p);
+
+ check( (long)t.p, t.q, t.r);
+ check(-(long)t.p, t.q, t.r);
+
+ check(t.p, (long)t.q, t.r);
+ check(t.p, -(long)t.q, t.r);
+
+ check( (long)t.p, (long)t.q, t.r);
+ check( (long)t.p, -(long)t.q, t.r);
+ check(-(long)t.p, (long)t.q, t.r);
+ check(-(long)t.p, -(long)t.q, t.r);
+ }
+
+ if (t.p <= INT_MAX && t.q <= INT_MAX)
+ {
+ check((long)t.p, (int)t.q, t.r);
+ check(-(int)t.p, (long)t.q, t.r);
+
+ check( (int)t.p, (unsigned)t.q, t.r);
+ check(-(int)t.p, (unsigned)t.q, t.r);
+
+ check(-(int)t.p, -(int)t.q, t.r);
+ check(-(int)t.p, -(long)t.q, t.r);
+ }
+
+ if (t.p <= SHRT_MAX && t.q <= SHRT_MAX)
+ {
+ check( (long)t.p, (short)t.q, t.r);
+ check(-(short)t.p, (long)t.q, t.r);
+
+ check( (short)t.p, (unsigned short)t.q, t.r);
+ check(-(short)t.p, (unsigned short)t.q, t.r);
+
+ check(-(short)t.p, -(short)t.q, t.r);
+ check(-(short)t.p, -(long)t.q, t.r);
+ }
+ }
+ return true;
+}
+
+
+int main()
+{
+ static_assert( test01() ); // constexpr
+ VERIFY( test01() ); // non-constexpr
+}
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