diff --git a/doc/sf/ccmath.qbk b/doc/sf/ccmath.qbk index d0d6a41a5a..c53b063e57 100644 --- a/doc/sf/ccmath.qbk +++ b/doc/sf/ccmath.qbk @@ -149,6 +149,12 @@ All of the following functions require C++17 or greater. template inline constexpr Promoted hypot(Arithmetic1 x, Arithmetic2 y) noexcept + template + inline constexpr Real fdim(Real x, Real y) noexcept + + template + inline constexpr Promoted fdim(Arithmetic1 x, Arithmetic2 y) noexcept + } // Namespaces [endsect] [/section:ccmath Constexpr CMath] diff --git a/include/boost/math/ccmath/ccmath.hpp b/include/boost/math/ccmath/ccmath.hpp index b2ef415d09..6f02ca6022 100644 --- a/include/boost/math/ccmath/ccmath.hpp +++ b/include/boost/math/ccmath/ccmath.hpp @@ -30,5 +30,6 @@ #include #include #include +#include #endif // BOOST_MATH_CCMATH_HPP diff --git a/include/boost/math/ccmath/fdim.hpp b/include/boost/math/ccmath/fdim.hpp new file mode 100644 index 0000000000..5b03d05c89 --- /dev/null +++ b/include/boost/math/ccmath/fdim.hpp @@ -0,0 +1,100 @@ +// (C) Copyright Matt Borland 2022. +// Use, modification and distribution are subject to the +// Boost Software License, Version 1.0. (See accompanying file +// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +#ifndef BOOST_MATH_CCMATH_FDIM_HPP +#define BOOST_MATH_CCMATH_FDIM_HPP + +#include +#include +#include +#include +#include + +namespace boost::math::ccmath { + +namespace detail { + +template +inline constexpr T fdim_impl(const T x, const T y) noexcept +{ + if (x <= y) + { + return 0; + } + else if ((y < 0) && (x > (std::numeric_limits::max)() + y)) + { + return std::numeric_limits::infinity(); + } + else + { + return x - y; + } +} + +} // Namespace detail + +template , bool> = true> +inline constexpr Real fdim(Real x, Real y) noexcept +{ + if (BOOST_MATH_IS_CONSTANT_EVALUATED(x)) + { + return boost::math::ccmath::isnan(x) ? std::numeric_limits::quiet_NaN() : + boost::math::ccmath::isnan(y) ? std::numeric_limits::quiet_NaN() : + boost::math::ccmath::detail::fdim_impl(x, y); + } + else + { + using std::fdim; + return fdim(x, y); + } +} + +template +inline constexpr auto fdim(T1 x, T2 y) noexcept +{ + if (BOOST_MATH_IS_CONSTANT_EVALUATED(x)) + { + // If the type is an integer (e.g. epsilon == 0) then set the epsilon value to 1 so that type is at a minimum + // cast to double + constexpr auto T1p = std::numeric_limits::epsilon() > 0 ? std::numeric_limits::epsilon() : 1; + constexpr auto T2p = std::numeric_limits::epsilon() > 0 ? std::numeric_limits::epsilon() : 1; + + using promoted_type = + #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS + std::conditional_t>>>; + #else + >>; + #endif + + return boost::math::ccmath::fdim(promoted_type(x), promoted_type(y)); + } + else + { + using std::fdim; + return fdim(x, y); + } +} + +inline constexpr float fdimf(float x, float y) noexcept +{ + return boost::math::ccmath::fdim(x, y); +} + +#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS +inline constexpr long double fdiml(long double x, long double y) noexcept +{ + return boost::math::ccmath::fdim(x, y); +} +#endif + +} // Namespace boost::math::ccmath + +#endif // BOOST_MATH_CCMATH_FDIM_HPP diff --git a/test/Jamfile.v2 b/test/Jamfile.v2 index f6b633c860..63a3086a80 100644 --- a/test/Jamfile.v2 +++ b/test/Jamfile.v2 @@ -144,6 +144,7 @@ test-suite special_fun : [ run ccmath_remainder_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ] [ run ccmath_copysign_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ] [ run ccmath_hypot_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ] + [ run ccmath_fdim_test.cpp ../../test/build//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] ] [ run log1p_expm1_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework ] [ run powm1_sqrtp1m1_test.cpp test_instances//test_instances pch_light ../../test/build//boost_unit_test_framework ] [ run special_functions_test.cpp ../../test/build//boost_unit_test_framework ] diff --git a/test/ccmath_fdim_test.cpp b/test/ccmath_fdim_test.cpp new file mode 100644 index 0000000000..f5f688d534 --- /dev/null +++ b/test/ccmath_fdim_test.cpp @@ -0,0 +1,54 @@ +// (C) Copyright Matt Borland 2022. +// Use, modification and distribution are subject to the +// Boost Software License, Version 1.0. (See accompanying file +// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef BOOST_HAS_FLOAT128 +#include +#endif + +template +constexpr void test() +{ + static_assert(boost::math::ccmath::isnan(boost::math::ccmath::fdim(std::numeric_limits::quiet_NaN(), T(1))), "If x is NaN, NaN is returned"); + static_assert(boost::math::ccmath::isnan(boost::math::ccmath::fdim(T(1), std::numeric_limits::quiet_NaN())), "If y is NaN, NaN is returned"); + + static_assert(boost::math::ccmath::fdim(T(4), T(1)) == T(3)); + static_assert(boost::math::ccmath::fdim(T(1), T(4)) == T(0)); + static_assert(boost::math::ccmath::fdim(T(4), T(-1)) == T(5)); + static_assert(boost::math::ccmath::fdim(T(1), T(-4)) == T(5)); + + static_assert(boost::math::ccmath::isinf(boost::math::ccmath::fdim(std::numeric_limits::infinity(), T(-1)))); +} + +#if !defined(BOOST_MATH_NO_CONSTEXPR_DETECTION) && !defined(BOOST_MATH_USING_BUILTIN_CONSTANT_P) +int main() +{ + test(); + test(); + + #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS + test(); + #endif + + #ifdef BOOST_HAS_FLOAT128 + test(); + #endif + + return 0; +} +#else +int main() +{ + return 0; +} +#endif diff --git a/test/compile_test/ccmath_fdim_incl_test.cpp b/test/compile_test/ccmath_fdim_incl_test.cpp new file mode 100644 index 0000000000..39e8874d2e --- /dev/null +++ b/test/compile_test/ccmath_fdim_incl_test.cpp @@ -0,0 +1,16 @@ +// (C) Copyright Matt Borland 2022. +// Use, modification and distribution are subject to the +// Boost Software License, Version 1.0. (See accompanying file +// LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) + +#include +#include "test_compile_result.hpp" + +void compile_and_link_test() +{ + check_result(boost::math::ccmath::fdim(1.0f, 1.0f)); + check_result(boost::math::ccmath::fdim(1.0, 1.0)); +#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS + check_result(boost::math::ccmath::fdim(1.0l, 1.0l)); +#endif +}