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Modernise log1p/expm1 to mostly use their std:: equivalents.

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Add support for <cstdfloat> types as well.
Extend tests for better coverage.
This commit is contained in:
jzmaddock
2025-04-19 13:35:23 +01:00
parent b0200e41d1
commit 54b057bb51
6 changed files with 523 additions and 392 deletions
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98
include/boost/math/special_functions/expm1.hpp
View File

@@ -15,6 +15,14 @@
#ifndef BOOST_MATH_HAS_NVRTC
#if defined __has_include
# if __cplusplus > 202002L || _MSVC_LANG > 202002L
# if __has_include (<stdfloat>)
# include <stdfloat>
# endif
# endif
#endif
#include <boost/math/tools/series.hpp>
#include <boost/math/tools/precision.hpp>
#include <boost/math/tools/big_constant.hpp>
@@ -37,7 +45,8 @@
#pragma GCC system_header
#endif
namespace boost{ namespace math{
namespace boost {
namespace math {
namespace detail
{
@@ -51,7 +60,8 @@ namespace detail
typedef T result_type;
BOOST_MATH_GPU_ENABLED expm1_series(T x)
: k(0), m_x(x), m_term(1) {}
: k(0), m_x(x), m_term(1) {
}
BOOST_MATH_GPU_ENABLED T operator()()
{
@@ -273,15 +283,9 @@ BOOST_MATH_GPU_ENABLED inline typename tools::promote_args<T>::type expm1(T x, c
tag_type(), forwarding_policy()), "boost::math::expm1<%1%>(%1%)");
}
#ifdef expm1
# ifndef BOOST_HAS_expm1
# define BOOST_HAS_expm1
# endif
# undef expm1
#endif
#if defined(BOOST_HAS_EXPM1) && !(defined(__osf__) && defined(__DECCXX_VER))
# ifdef BOOST_MATH_USE_C99
//
// Since we now live in a post C++11 world, we can always defer to std::expm1 when appropriate:
//
template <class Policy>
BOOST_MATH_GPU_ENABLED inline float expm1(float x, const Policy&)
{
@@ -295,7 +299,7 @@ BOOST_MATH_GPU_ENABLED inline float expm1(float x, const Policy&)
if (x >= tools::log_max_value<float>())
return policies::raise_overflow_error<float>("boost::math::expm1<%1%>(%1%)", nullptr, Policy());
}
return ::expm1f(x);
return std::expm1(x);
}
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
template <class Policy>
@@ -311,42 +315,9 @@ inline long double expm1(long double x, const Policy&)
if (x >= tools::log_max_value<long double>())
return policies::raise_overflow_error<long double>("boost::math::expm1<%1%>(%1%)", nullptr, Policy());
}
return ::expm1l(x);
return std::expm1(x);
}
#endif
# else
template <class Policy>
inline float expm1(float x, const Policy&)
{
BOOST_MATH_IF_CONSTEXPR(Policy::domain_error_type::value != boost::math::policies::ignore_error && Policy::domain_error_type::value != boost::math::policies::errno_on_error)
{
if ((boost::math::isnan)(x))
return policies::raise_domain_error<float>("boost::math::expm1<%1%>(%1%)", "expm1 requires a finite argument, but got %1%", x, Policy());
}
BOOST_MATH_IF_CONSTEXPR(Policy::overflow_error_type::value != boost::math::policies::ignore_error && Policy::overflow_error_type::value != boost::math::policies::errno_on_error)
{
if (x >= tools::log_max_value<float>())
return policies::raise_overflow_error<float>("boost::math::expm1<%1%>(%1%)", nullptr, Policy());
}
return static_cast<float>(::expm1(x));
}
template <class Policy>
inline typename std::enable_if<sizeof(double) == sizeof(long double), long double>::type expm1(long double x, const Policy&)
{
BOOST_MATH_IF_CONSTEXPR(Policy::domain_error_type::value != boost::math::policies::ignore_error && Policy::domain_error_type::value != boost::math::policies::errno_on_error)
{
if ((boost::math::isnan)(x))
return policies::raise_domain_error<long double>("boost::math::expm1<%1%>(%1%)", "expm1 requires a finite argument, but got %1%", x, Policy());
}
BOOST_MATH_IF_CONSTEXPR(Policy::overflow_error_type::value != boost::math::policies::ignore_error && Policy::overflow_error_type::value != boost::math::policies::errno_on_error)
{
if (x >= tools::log_max_value<float>())
return policies::raise_overflow_error<long double>("boost::math::expm1<%1%>(%1%)", nullptr, Policy());
}
return ::expm1(x);
}
# endif
template <class Policy>
BOOST_MATH_GPU_ENABLED inline double expm1(double x, const Policy&)
{
@@ -360,16 +331,45 @@ BOOST_MATH_GPU_ENABLED inline double expm1(double x, const Policy&)
if (x >= tools::log_max_value<double>())
return policies::raise_overflow_error<double>("boost::math::expm1<%1%>(%1%)", nullptr, Policy());
}
return ::expm1(x);
return std::expm1(x);
}
#endif
template <class T>
BOOST_MATH_GPU_ENABLED inline typename tools::promote_args<T>::type expm1(T x)
{
return expm1(x, policies::policy<>());
}
//
// Specific width floating point types:
//
#ifdef __STDCPP_FLOAT32_T__
template <class Policy>
BOOST_MATH_GPU_ENABLED inline std::float32_t expm1(std::float32_t x, const Policy& pol)
{
return boost::math::expm1(static_cast<float>(x), pol);
}
#endif
#ifdef __STDCPP_FLOAT64_T__
template <class Policy>
BOOST_MATH_GPU_ENABLED inline std::float64_t expm1(std::float64_t x, const Policy& pol)
{
return boost::math::expm1(static_cast<double>(x), pol);
}
#endif
#ifdef __STDCPP_FLOAT128_T__
template <class Policy>
BOOST_MATH_GPU_ENABLED inline std::float128_t expm1(std::float128_t x, const Policy& pol)
{
if constexpr (std::numeric_limits<long double>::digits == std::numeric_limits<std::float128_t>::digits)
{
return boost::math::expm1(static_cast<long double>(x), pol);
}
else
{
return boost::math::detail::expm1_imp(x, boost::math::integral_constant<int, 113>(), pol);
}
}
#endif
} // namespace math
} // namespace boost

115
include/boost/math/special_functions/log1p.hpp
View File

@@ -12,6 +12,14 @@
#pragma warning(disable:4702) // Unreachable code (release mode only warning)
#endif
#if defined __has_include
# if __cplusplus > 202002L || _MSVC_LANG > 202002L
# if __has_include (<stdfloat>)
# include <stdfloat>
# endif
# endif
#endif
#include <boost/math/tools/config.hpp>
#include <boost/math/tools/series.hpp>
#include <boost/math/tools/rational.hpp>
@@ -289,15 +297,6 @@ BOOST_MATH_GPU_ENABLED inline typename tools::promote_args<T>::type log1p(T x, c
detail::log1p_imp(static_cast<value_type>(x), forwarding_policy(), tag_type()), "boost::math::log1p<%1%>(%1%)");
}
#ifdef log1p
# ifndef BOOST_HAS_LOG1P
# define BOOST_HAS_LOG1P
# endif
# undef log1p
#endif
#if defined(BOOST_HAS_LOG1P) && !(defined(__osf__) && defined(__DECCXX_VER))
# ifdef BOOST_MATH_USE_C99
template <class Policy>
BOOST_MATH_GPU_ENABLED inline float log1p(float x, const Policy& pol)
{
@@ -307,7 +306,7 @@ BOOST_MATH_GPU_ENABLED inline float log1p(float x, const Policy& pol)
if(x == -1)
return -policies::raise_overflow_error<float>(
"log1p<%1%>(%1%)", nullptr, pol);
return ::log1pf(x);
return std::log1p(x);
}
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
template <class Policy>
@@ -319,20 +318,7 @@ BOOST_MATH_GPU_ENABLED inline long double log1p(long double x, const Policy& pol
if(x == -1)
return -policies::raise_overflow_error<long double>(
"log1p<%1%>(%1%)", nullptr, pol);
return ::log1pl(x);
}
#endif
#else
template <class Policy>
inline float log1p(float x, const Policy& pol)
{
if(x < -1)
return policies::raise_domain_error<float>(
"log1p<%1%>(%1%)", "log1p(x) requires x > -1, but got x = %1%.", x, pol);
if(x == -1)
return -policies::raise_overflow_error<float>(
"log1p<%1%>(%1%)", nullptr, pol);
return ::log1p(x);
return std::log1p(x);
}
#endif
template <class Policy>
@@ -344,56 +330,8 @@ BOOST_MATH_GPU_ENABLED inline double log1p(double x, const Policy& pol)
if(x == -1)
return -policies::raise_overflow_error<double>(
"log1p<%1%>(%1%)", nullptr, pol);
return ::log1p(x);
return std::log1p(x);
}
#elif defined(_MSC_VER) && (BOOST_MSVC >= 1400)
//
// You should only enable this branch if you are absolutely sure
// that your compilers optimizer won't mess this code up!!
// Currently tested with VC8 and Intel 9.1.
//
template <class Policy>
inline double log1p(double x, const Policy& pol)
{
if(x < -1)
return policies::raise_domain_error<double>(
"log1p<%1%>(%1%)", "log1p(x) requires x > -1, but got x = %1%.", x, pol);
if(x == -1)
return -policies::raise_overflow_error<double>(
"log1p<%1%>(%1%)", nullptr, pol);
double u = 1+x;
if(u == 1.0)
return x;
else
return ::log(u)*(x/(u-1.0));
}
template <class Policy>
inline float log1p(float x, const Policy& pol)
{
return static_cast<float>(boost::math::log1p(static_cast<double>(x), pol));
}
#ifndef _WIN32_WCE
//
// For some reason this fails to compile under WinCE...
// Needs more investigation.
//
template <class Policy>
inline long double log1p(long double x, const Policy& pol)
{
if(x < -1)
return policies::raise_domain_error<long double>(
"log1p<%1%>(%1%)", "log1p(x) requires x > -1, but got x = %1%.", x, pol);
if(x == -1)
return -policies::raise_overflow_error<long double>(
"log1p<%1%>(%1%)", nullptr, pol);
long double u = 1+x;
if(u == 1.0)
return x;
else
return ::logl(u)*(x/(u-1.0));
}
#endif
#endif
template <class T>
BOOST_MATH_GPU_ENABLED inline typename tools::promote_args<T>::type log1p(T x)
@@ -441,6 +379,37 @@ BOOST_MATH_GPU_ENABLED inline typename tools::promote_args<T>::type log1pmx(T x)
return log1pmx(x, policies::policy<>());
}
//
// Specific width floating point types:
//
#ifdef __STDCPP_FLOAT32_T__
template <class Policy>
BOOST_MATH_GPU_ENABLED inline std::float32_t log1p(std::float32_t x, const Policy& pol)
{
return boost::math::log1p(static_cast<float>(x), pol);
}
#endif
#ifdef __STDCPP_FLOAT64_T__
template <class Policy>
BOOST_MATH_GPU_ENABLED inline std::float64_t log1p(std::float64_t x, const Policy& pol)
{
return boost::math::log1p(static_cast<double>(x), pol);
}
#endif
#ifdef __STDCPP_FLOAT128_T__
template <class Policy>
BOOST_MATH_GPU_ENABLED inline std::float128_t log1p(std::float128_t x, const Policy& pol)
{
if constexpr (std::numeric_limits<long double>::digits == std::numeric_limits<std::float128_t>::digits)
{
return boost::math::log1p(static_cast<long double>(x), pol);
}
else
{
return boost::math::detail::log1p_imp(x, pol, boost::math::integral_constant<int, 113>());
}
}
#endif
} // namespace math
} // namespace boost

4
include_private/boost/math/tools/test.hpp
View File

@@ -167,7 +167,7 @@ test_result<typename calculate_result_type<A>::value_type> test(const A& a, F1 t
print_row(row, std::cerr);
BOOST_ERROR("Unexpected non-finite result");
}
if(err > 0.5)
if(err > 0.5f)
{
std::cerr << "CAUTION: Gross error found at entry " << i << ".\n";
std::cerr << "Found: " << point << " Expected " << expected << " Error: " << err << std::endl;
@@ -240,7 +240,7 @@ test_result<Real> test_hetero(const A& a, F1 test_func, F2 expect_func)
print_row(row, std::cerr);
BOOST_ERROR("Unexpected non-finite result");
}
if(err > 0.5)
if(err > 0.5f)
{
std::cerr << "CAUTION: Gross error found at entry " << i << ".\n";
std::cerr << "Found: " << point << " Expected " << expected << " Error: " << err << std::endl;

2
test/Jamfile.v2
View File

@@ -178,6 +178,8 @@ test-suite special_fun :
[ run ccmath_fma_test.cpp /boost/test//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] $(float128_type) ]
[ run ccmath_signbit_test.cpp /boost/test//boost_unit_test_framework : : : [ requires cxx17_if_constexpr ] $(float128_type) ]
[ run log1p_expm1_test.cpp test_instances//test_instances pch_light /boost/test//boost_unit_test_framework ]
[ run log1p_expm1_extra_test.cpp pch_light /boost/test//boost_unit_test_framework ]
[ run log1p_expm1_stdfloat_test.cpp pch_light /boost/test//boost_unit_test_framework ]
[ run powm1_sqrtp1m1_test.cpp test_instances//test_instances pch_light /boost/test//boost_unit_test_framework ]
[ run git_issue_705.cpp /boost/test//boost_unit_test_framework ]
[ run git_issue_810.cpp /boost/test//boost_unit_test_framework ]

73
test/log1p_expm1_extra_test.cpp Normal file
View File

@@ -0,0 +1,73 @@
// Copyright John Maddock 2005.
// Copyright Paul A. Bristow 2010
// 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 <pch_light.hpp>
#define SC_(x) static_cast<T>(BOOST_STRINGIZE(x))
#define BOOST_MATH_OVERFLOW_ERROR_POLICY ignore_error
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
#include <boost/test/tools/floating_point_comparison.hpp>
#include <boost/math/special_functions/log1p.hpp>
#include <boost/math/special_functions/expm1.hpp>
#include "log1p_expm1_test.hpp"
#include <boost/multiprecision/cpp_bin_float.hpp>
//
// DESCRIPTION:
// ~~~~~~~~~~~~
//
// This file tests the functions log1p and expm1. The accuracy tests
// use values generated with NTL::RR at 1000-bit precision
// and our generic versions of these functions.
//
// Note that this tests the generic versions of our functions using
// software emulated types. This ensures these still get tested
// even though we mostly defer to std::expm1 and std::log1p at
// these precisions nowadays
//
void expected_results()
{
//
// Define the max and mean errors expected for
// various compilers and platforms.
//
//
// Catch all cases come last:
//
add_expected_result(
".*", // compiler
".*", // stdlib
".*", // platform
".*", // test type(s)
".*", // test data group
".*", // test function
4, // Max Peek error
3); // Max mean error
//
// Finish off by printing out the compiler/stdlib/platform names,
// we do this to make it easier to mark up expected error rates.
//
std::cout << "Tests run with " << BOOST_COMPILER << ", "
<< BOOST_STDLIB << ", " << BOOST_PLATFORM << std::endl;
}
BOOST_AUTO_TEST_CASE( test_main )
{
expected_results();
BOOST_MATH_CONTROL_FP;
test(boost::multiprecision::cpp_bin_float_single(0), "cpp_bin_float_single");
test(boost::multiprecision::cpp_bin_float_double(0), "cpp_bin_float_double");
test(boost::multiprecision::cpp_bin_float_double_extended(0), "cpp_bin_float_double_extended");
test(boost::multiprecision::cpp_bin_float_quad(0), "cpp_bin_float_quad");
}

87
test/log1p_expm1_stdfloat_test.cpp Normal file
View File

@@ -0,0 +1,87 @@
// Copyright John Maddock 2005.
// Copyright Paul A. Bristow 2010
// 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 <pch_light.hpp>
#if defined __has_include
# if __cplusplus > 202002L || _MSVC_LANG > 202002L
# if __has_include (<stdfloat>)
# include <stdfloat>
# endif
# endif
#endif
#define SC_(x) static_cast<T>(BOOST_MATH_BIG_CONSTANT(T, 128, x))
#define BOOST_MATH_OVERFLOW_ERROR_POLICY ignore_error
#define BOOST_TEST_MAIN
#include <boost/test/unit_test.hpp>
#include <boost/test/tools/floating_point_comparison.hpp>
#include <boost/math/special_functions/log1p.hpp>
#include <boost/math/special_functions/expm1.hpp>
#include <boost/math/tools/big_constant.hpp>
#include "log1p_expm1_test.hpp"
//
// DESCRIPTION:
// ~~~~~~~~~~~~
//
// This file tests the functions log1p and expm1. The accuracy tests
// use values generated with NTL::RR at 1000-bit precision
// and our generic versions of these functions.
//
// Note that this tests the generic versions of our functions using
// software emulated types. This ensures these still get tested
// even though we mostly defer to std::expm1 and std::log1p at
// these precisions nowadays
//
void expected_results()
{
//
// Define the max and mean errors expected for
// various compilers and platforms.
//
//
// Catch all cases come last:
//
add_expected_result(
".*", // compiler
".*", // stdlib
".*", // platform
".*", // test type(s)
".*", // test data group
".*", // test function
4, // Max Peek error
3); // Max mean error
//
// Finish off by printing out the compiler/stdlib/platform names,
// we do this to make it easier to mark up expected error rates.
//
std::cout << "Tests run with " << BOOST_COMPILER << ", "
<< BOOST_STDLIB << ", " << BOOST_PLATFORM << std::endl;
}
BOOST_AUTO_TEST_CASE( test_main )
{
expected_results();
BOOST_MATH_CONTROL_FP;
#ifdef __STDCPP_FLOAT32_T__
test(std::float32_t(0), "std::float32_t");
#endif
#ifdef __STDCPP_FLOAT64_T__
test(std::float64_t(0), "std::float64_t");
#endif
#ifdef __STDCPP_FLOAT128_T__
// As of gcc-13 this does not work as float128_t has no std::math function overloads
//test(std::float128_t(0), "std::float128_t");
#endif
}