This shares the code for std::gcd and std::experimental::gcd, and
similarly for lcm.
I realised I'd mixed up the gcd.cc and lcm.cc tests so this patch also
swaps them around.
* doc/xml/manual/status_cxx2017.xml: Update gcd/lcm status.
* doc/html/*: Regenerate.
* include/experimental/numeric (__abs): Move to <numeric>.
(gcd, lcm): Use __detail::gcd and __detail::lcm.
* include/std/numeric (__detail::__abs_integral)
(__detail::__gcd, __detail::__lcm): Define.
(gcd, lcm): Define for C++17.
* testsuite/26_numerics/gcd/1.cc: New test.
* testsuite/26_numerics/lcm/1.cc: New test.
* testsuite/experimental/numeric/gcd.cc: Swap contents with ...
* testsuite/experimental/numeric/lcd.cc: ... this.
Tested powerpc64le-linux, committed to trunk.
commit 56efd86de7a7bbcfe43fe1c20979e06eb5e49802
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Mon Oct 3 17:09:10 2016 +0100
Define std::gcd and std::lcm for C++17
* doc/xml/manual/status_cxx2017.xml: Update gcd/lcm status.
* doc/html/*: Regenerate.
* include/experimental/numeric (__abs): Move to <numeric>.
(gcd, lcm): Use __detail::gcd and __detail::lcm.
* include/std/numeric (__detail::__abs_integral)
(__detail::__gcd, __detail::__lcm): Define.
(gcd, lcm): Define for C++17.
* testsuite/26_numerics/gcd/1.cc: New test.
* testsuite/26_numerics/lcm/1.cc: New test.
* testsuite/experimental/numeric/gcd.cc: Swap contents with ...
* testsuite/experimental/numeric/lcd.cc: ... this.
diff --git a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
index feed085..9f47b349 100644
--- a/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
+++ b/libstdc++-v3/doc/xml/manual/status_cxx2017.xml
@@ -615,14 +615,13 @@ Feature-testing recommendations for C++</link>.
</row>
<row>
- <?dbhtml bgcolor="#C8B0B0" ?>
<entry> Adopt Selected Library Fundamentals V2 Components for C++17
</entry>
<entry>
<link xmlns:xlink="http://www.w3.org/1999/xlink";
xlink:href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0295r0.pdf";>
P0295R0
</link>
</entry>
- <entry align="center"> No </entry>
+ <entry align="center"> 7 </entry>
<entry><code> __cpp_lib_gcd >= 201606 </code>,
<code> __cpp_lib_lcm >= 201606 </code>
</entry>
diff --git a/libstdc++-v3/include/experimental/numeric
b/libstdc++-v3/include/experimental/numeric
index 5089772..6d1dc21 100644
--- a/libstdc++-v3/include/experimental/numeric
+++ b/libstdc++-v3/include/experimental/numeric
@@ -52,44 +52,24 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
#define __cpp_lib_experimental_gcd_lcm 201411
- // std::abs is not constexpr and doesn't support unsigned integers.
- template<typename _Tp>
- constexpr
- enable_if_t<__and_<is_integral<_Tp>, is_signed<_Tp>>::value, _Tp>
- __abs(_Tp __val)
- { return __val < 0 ? -__val : __val; }
-
- template<typename _Tp>
- constexpr
- enable_if_t<__and_<is_integral<_Tp>, is_unsigned<_Tp>>::value, _Tp>
- __abs(_Tp __val)
- { return __val; }
-
- // Greatest common divisor
+ /// Greatest common divisor
template<typename _Mn, typename _Nn>
constexpr common_type_t<_Mn, _Nn>
gcd(_Mn __m, _Nn __n)
{
static_assert(is_integral<_Mn>::value, "arguments to gcd are integers");
static_assert(is_integral<_Nn>::value, "arguments to gcd are integers");
-
- return __m == 0 ? fundamentals_v2::__abs(__n)
- : __n == 0 ? fundamentals_v2::__abs(__m)
- : fundamentals_v2::gcd(__n, __m % __n);
+ return std::__detail::__gcd(__m, __n);
}
- // Least common multiple
+ /// Least common multiple
template<typename _Mn, typename _Nn>
constexpr common_type_t<_Mn, _Nn>
lcm(_Mn __m, _Nn __n)
{
static_assert(is_integral<_Mn>::value, "arguments to lcm are integers");
static_assert(is_integral<_Nn>::value, "arguments to lcm are integers");
-
- return (__m != 0 && __n != 0)
- ? (fundamentals_v2::__abs(__m) / fundamentals_v2::gcd(__m, __n))
- * fundamentals_v2::__abs(__n)
- : 0;
+ return std::__detail::__lcm(__m, __n);
}
_GLIBCXX_END_NAMESPACE_VERSION
diff --git a/libstdc++-v3/include/std/numeric b/libstdc++-v3/include/std/numeric
index 47a7cb8..7b1ab98 100644
--- a/libstdc++-v3/include/std/numeric
+++ b/libstdc++-v3/include/std/numeric
@@ -74,4 +74,83 @@
* math functions.
*/
+#if __cplusplus >= 201402L
+#include <type_traits>
+
+namespace std _GLIBCXX_VISIBILITY(default)
+{
+namespace __detail
+{
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+ // std::abs is not constexpr and doesn't support unsigned integers.
+ template<typename _Tp>
+ constexpr
+ enable_if_t<__and_<is_integral<_Tp>, is_signed<_Tp>>::value, _Tp>
+ __abs_integral(_Tp __val)
+ { return __val < 0 ? -__val : __val; }
+
+ template<typename _Tp>
+ constexpr
+ enable_if_t<__and_<is_integral<_Tp>, is_unsigned<_Tp>>::value, _Tp>
+ __abs_integral(_Tp __val)
+ { return __val; }
+
+ template<typename _Mn, typename _Nn>
+ constexpr common_type_t<_Mn, _Nn>
+ __gcd(_Mn __m, _Nn __n)
+ {
+ return __m == 0 ? __detail::__abs_integral(__n)
+ : __n == 0 ? __detail::__abs_integral(__m)
+ : __detail::__gcd(__n, __m % __n);
+ }
+
+ /// Least common multiple
+ template<typename _Mn, typename _Nn>
+ constexpr common_type_t<_Mn, _Nn>
+ __lcm(_Mn __m, _Nn __n)
+ {
+ return (__m != 0 && __n != 0)
+ ? (__detail::__abs_integral(__m) / __detail::__gcd(__m, __n))
+ * __detail::__abs_integral(__n)
+ : 0;
+ }
+
+_GLIBCXX_END_NAMESPACE_VERSION
+}
+
+_GLIBCXX_BEGIN_NAMESPACE_VERSION
+
+#if __cplusplus > 201402L
+
+#define __cpp_lib_gcd 201606
+ /// Greatest common divisor
+ template<typename _Mn, typename _Nn>
+ constexpr common_type_t<_Mn, _Nn>
+ gcd(_Mn __m, _Nn __n)
+ {
+ static_assert(is_integral<_Mn>::value, "arguments to gcd are integers");
+ static_assert(is_integral<_Nn>::value, "arguments to gcd are integers");
+ return __detail::__gcd(__m, __n);
+ }
+
+#define __cpp_lib_lcm 201606
+ /// Least common multiple
+ template<typename _Mn, typename _Nn>
+ constexpr common_type_t<_Mn, _Nn>
+ lcm(_Mn __m, _Nn __n)
+ {
+ static_assert(is_integral<_Mn>::value, "arguments to lcm are integers");
+ static_assert(is_integral<_Nn>::value, "arguments to lcm are integers");
+ return __detail::__lcm(__m, __n);
+ }
+
+#endif // C++17
+
+_GLIBCXX_END_NAMESPACE_VERSION
+} // namespace std
+
+#endif // C++14
+
+
#endif /* _GLIBCXX_NUMERIC */
diff --git a/libstdc++-v3/testsuite/26_numerics/gcd/1.cc
b/libstdc++-v3/testsuite/26_numerics/gcd/1.cc
new file mode 100644
index 0000000..8e16257
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/gcd/1.cc
@@ -0,0 +1,44 @@
+// Copyright (C) 2015-2016 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-options "-std=gnu++1z" }
+// { dg-do compile { target c++1z } }
+
+#include <numeric>
+
+#ifndef __cpp_lib_gcd
+# error "Feature-test macro for gcd missing"
+#elif __cpp_lib_gcd != 201606
+# error "Feature-test macro for gcd has wrong value"
+#endif
+
+using std::gcd;
+
+static_assert( gcd(1071, 462) == 21, "" );
+static_assert( gcd(2000, 20) == 20, "" );
+static_assert( gcd(2011, 17) == 1, "GCD of two primes is 1" );
+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(1u, 2) == 1, "unsigned and signed");
+static_assert(gcd(3, 4u) == 1, "signed and unsigned");
+static_assert(gcd(5u, 6u) == 1, "unsigned and unsigned");
+
+static_assert( std::is_same_v<decltype(gcd(1l, 1)), long> );
+static_assert( std::is_same_v<decltype(gcd(1ul, 1ull)), unsigned long long> );
diff --git a/libstdc++-v3/testsuite/26_numerics/lcm/1.cc
b/libstdc++-v3/testsuite/26_numerics/lcm/1.cc
new file mode 100644
index 0000000..caa2032
--- /dev/null
+++ b/libstdc++-v3/testsuite/26_numerics/lcm/1.cc
@@ -0,0 +1,41 @@
+// Copyright (C) 2015-2016 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-options "-std=gnu++1z" }
+// { dg-do compile { target c++1z } }
+
+#include <numeric>
+
+#ifndef __cpp_lib_lcm
+# error "Feature-test macro for lcm missing"
+#elif __cpp_lib_lcm != 201606
+# error "Feature-test macro for lcm has wrong value"
+#endif
+
+using std::lcm;
+
+static_assert(lcm(21, 6) == 42, "");
+static_assert(lcm(41, 0) == 0, "LCD with zero is zero");
+static_assert(lcm(0, 7) == 0, "LCD with zero is zero");
+static_assert(lcm(0, 0) == 0, "no division by zero");
+
+static_assert(lcm(1u, 2) == 2, "unsigned and signed");
+static_assert(lcm(3, 4u) == 12, "signed and unsigned");
+static_assert(lcm(5u, 6u) == 30, "unsigned and unsigned");
+
+static_assert( std::is_same_v<decltype(lcm(1l, 1)), long> );
+static_assert( std::is_same_v<decltype(lcm(1ul, 1ull)), unsigned long long> );
diff --git a/libstdc++-v3/testsuite/experimental/numeric/gcd.cc
b/libstdc++-v3/testsuite/experimental/numeric/gcd.cc
index b3345dc..d90c152 100644
--- a/libstdc++-v3/testsuite/experimental/numeric/gcd.cc
+++ b/libstdc++-v3/testsuite/experimental/numeric/gcd.cc
@@ -19,13 +19,16 @@
#include <experimental/numeric>
-using std::experimental::fundamentals_v2::lcm;
+using std::experimental::fundamentals_v2::gcd;
-static_assert(lcm(21, 6) == 42, "");
-static_assert(lcm(41, 0) == 0, "LCD with zero is zero");
-static_assert(lcm(0, 7) == 0, "LCD with zero is zero");
-static_assert(lcm(0, 0) == 0, "no division by zero");
+static_assert( gcd(1071, 462) == 21, "" );
+static_assert( gcd(2000, 20) == 20, "" );
+static_assert( gcd(2011, 17) == 1, "GCD of two primes is 1" );
+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(lcm(1u, 2) == 2, "unsigned and signed");
-static_assert(lcm(3, 4u) == 12, "signed and unsigned");
-static_assert(lcm(5u, 6u) == 30, "unsigned and unsigned");
+static_assert(gcd(1u, 2) == 1, "unsigned and signed");
+static_assert(gcd(3, 4u) == 1, "signed and unsigned");
+static_assert(gcd(5u, 6u) == 1, "unsigned and unsigned");
diff --git a/libstdc++-v3/testsuite/experimental/numeric/lcm.cc
b/libstdc++-v3/testsuite/experimental/numeric/lcm.cc
index d90c152..b3345dc 100644
--- a/libstdc++-v3/testsuite/experimental/numeric/lcm.cc
+++ b/libstdc++-v3/testsuite/experimental/numeric/lcm.cc
@@ -19,16 +19,13 @@
#include <experimental/numeric>
-using std::experimental::fundamentals_v2::gcd;
+using std::experimental::fundamentals_v2::lcm;
-static_assert( gcd(1071, 462) == 21, "" );
-static_assert( gcd(2000, 20) == 20, "" );
-static_assert( gcd(2011, 17) == 1, "GCD of two primes is 1" );
-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(lcm(21, 6) == 42, "");
+static_assert(lcm(41, 0) == 0, "LCD with zero is zero");
+static_assert(lcm(0, 7) == 0, "LCD with zero is zero");
+static_assert(lcm(0, 0) == 0, "no division by zero");
-static_assert(gcd(1u, 2) == 1, "unsigned and signed");
-static_assert(gcd(3, 4u) == 1, "signed and unsigned");
-static_assert(gcd(5u, 6u) == 1, "unsigned and unsigned");
+static_assert(lcm(1u, 2) == 2, "unsigned and signed");
+static_assert(lcm(3, 4u) == 12, "signed and unsigned");
+static_assert(lcm(5u, 6u) == 30, "unsigned and unsigned");
