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

llvm-svn: 276751

3 files changed, 180 insertions, 0 deletions

diff --git a/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.not_integral1.fail.cpp b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.not_integral1.fail.cpp
new file mode 100644
index 00000000000..585e40bac8a
--- /dev/null
+++ b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.not_integral1.fail.cpp
@@ -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);
+}
diff --git a/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.not_integral2.fail.cpp b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.not_integral2.fail.cpp
new file mode 100644
index 00000000000..7a2709aa93b
--- /dev/null
+++ b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.not_integral2.fail.cpp
@@ -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);
+}
diff --git a/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
new file mode 100644
index 00000000000..84625cd6532
--- /dev/null
+++ b/libcxx/test/std/numerics/numeric.ops/numeric.ops.gcd/gcd.pass.cpp
@@ -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)));
+}