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In <boost/cstdfloat.hpp>, fixed the 128-bit float helper function pown(). Do some additional cleanup.

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This commit is contained in:
ckormanyos
2014-02-24 21:38:00 +01:00
parent 88dddb0710
commit 05134be404
1 changed files with 26 additions and 19 deletions
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45
include/boost/math/cstdfloat/cstdfloat_cmath.hpp
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@@ -74,11 +74,11 @@
else if(p == static_cast<integer_type>(4)) { const float_type x2 = (x * x); return (x2 * x2); }
else
{
integer_type p2(p);
// The variable xn stores the binary powers of x.
float_type result = x;
float_type xn = x;
float_type result(((p % integer_type(2)) != integer_type(0)) ? x : float_type(1));
float_type xn (x);
integer_type p2 = p;
while(integer_type(p2 /= 2) != integer_type(0))
{
@@ -181,7 +181,6 @@
{
// Patch the expq() function for a subset of broken GCC compilers
// like GCC 4.7, 4.8 on MinGW.
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
// Use an order-36 polynomial approximation of the exponential function
// in the range of (-ln2 < x < ln2). Scale the argument to this range
@@ -198,6 +197,8 @@
// x^23, x^24, x^25, x^26, x^27, x^28, x^29, x^30, x^31, x^32,
// x^33, x^34, x^35, x^36}, x]
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
// Scale the argument x to the range (-ln2 < x < ln2).
BOOST_CONSTEXPR_OR_CONST float_type one_over_ln2 = float_type(BOOST_FLOAT128_C(1.44269504088896340735992468100189213742664595415299));
const float_type x_over_ln2 = x * one_over_ln2;
@@ -214,12 +215,12 @@
}
// Check if the argument is very near an integer.
const boost::int_fast32_t nn = ((n < static_cast<boost::int_fast32_t>(0)) ? -n : n);
const float_type floor_of_x = ::BOOST_CSTDFLOAT_FLOAT128_FLOOR(x);
if(BOOST_CSTDFLOAT_FLOAT128_FABS(x - n) < float_type(BOOST_CSTDFLOAT_FLOAT128_EPS * nn))
if(::BOOST_CSTDFLOAT_FLOAT128_FABS(x - floor_of_x) < float_type(BOOST_CSTDFLOAT_FLOAT128_EPS))
{
// Return e^n for arguments very near an integer.
return boost::math::cstdfloat::detail::pown(BOOST_FLOAT128_C(2.71828182845904523536028747135266249775724709369996), n);
return boost::math::cstdfloat::detail::pown(BOOST_FLOAT128_C(2.71828182845904523536028747135266249775724709369996), static_cast<boost::int_fast32_t>(floor_of_x));
}
// Compute the scaled argument alpha.
@@ -281,42 +282,48 @@
{
// Patch the sinhq() function for a subset of broken GCC compilers
// like GCC 4.7, 4.8 on MinGW.
const boost::math::cstdfloat::detail::float_internal128_t ex = ::BOOST_CSTDFLOAT_FLOAT128_EXP(x);
return (ex - (boost::math::cstdfloat::detail::float_internal128_t(1) / ex)) / 2;
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
const float_type ex = ::BOOST_CSTDFLOAT_FLOAT128_EXP(x);
return (ex - (float_type(1) / ex)) / 2;
}
inline boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_COSH (boost::math::cstdfloat::detail::float_internal128_t x)
{
// Patch the coshq() function for a subset of broken GCC compilers
// like GCC 4.7, 4.8 on MinGW.
const boost::math::cstdfloat::detail::float_internal128_t ex = ::BOOST_CSTDFLOAT_FLOAT128_EXP(x);
return (ex + (boost::math::cstdfloat::detail::float_internal128_t(1) / ex)) / 2;
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
const float_type ex = ::BOOST_CSTDFLOAT_FLOAT128_EXP(x);
return (ex + (float_type(1) / ex)) / 2;
}
inline boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_TANH (boost::math::cstdfloat::detail::float_internal128_t x)
{
// Patch the tanhq() function for a subset of broken GCC compilers
// like GCC 4.7, 4.8 on MinGW.
const boost::math::cstdfloat::detail::float_internal128_t ex_plus = ::BOOST_CSTDFLOAT_FLOAT128_EXP(x);
const boost::math::cstdfloat::detail::float_internal128_t ex_minus = (boost::math::cstdfloat::detail::float_internal128_t(1) / ex_plus);
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
const float_type ex_plus = ::BOOST_CSTDFLOAT_FLOAT128_EXP(x);
const float_type ex_minus = (float_type(1) / ex_plus);
return (ex_plus - ex_minus) / (ex_plus + ex_minus);
}
inline boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_ASINH(boost::math::cstdfloat::detail::float_internal128_t x) throw()
{
// Patch the asinh() function since quadmath does not have it.
return ::BOOST_CSTDFLOAT_FLOAT128_LOG(x + ::BOOST_CSTDFLOAT_FLOAT128_SQRT((x * x) + boost::math::cstdfloat::detail::float_internal128_t(1)));
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
return ::BOOST_CSTDFLOAT_FLOAT128_LOG(x + ::BOOST_CSTDFLOAT_FLOAT128_SQRT((x * x) + float_type(1)));
}
inline boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_ACOSH(boost::math::cstdfloat::detail::float_internal128_t x) throw()
{
// Patch the acosh() function since quadmath does not have it.
const boost::math::cstdfloat::detail::float_internal128_t zp(x + boost::math::cstdfloat::detail::float_internal128_t(1));
const boost::math::cstdfloat::detail::float_internal128_t zm(x - boost::math::cstdfloat::detail::float_internal128_t(1));
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
const float_type zp(x + float_type(1));
const float_type zm(x - float_type(1));
return ::BOOST_CSTDFLOAT_FLOAT128_LOG(x + (zp * ::BOOST_CSTDFLOAT_FLOAT128_SQRT(zm / zp)));
}
inline boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_ATANH(boost::math::cstdfloat::detail::float_internal128_t x) throw()
{
// Patch the atanh() function since quadmath does not have it.
return ( ::BOOST_CSTDFLOAT_FLOAT128_LOG(boost::math::cstdfloat::detail::float_internal128_t(1) + x)
- ::BOOST_CSTDFLOAT_FLOAT128_LOG(boost::math::cstdfloat::detail::float_internal128_t(1) - x)) / 2;
typedef boost::math::cstdfloat::detail::float_internal128_t float_type;
return ( ::BOOST_CSTDFLOAT_FLOAT128_LOG(float_type(1) + x)
- ::BOOST_CSTDFLOAT_FLOAT128_LOG(float_type(1) - x)) / 2;
}
extern "C" boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_FMOD (boost::math::cstdfloat::detail::float_internal128_t, boost::math::cstdfloat::detail::float_internal128_t) throw();
extern "C" boost::math::cstdfloat::detail::float_internal128_t BOOST_CSTDFLOAT_FLOAT128_ATAN2 (boost::math::cstdfloat::detail::float_internal128_t, boost::math::cstdfloat::detail::float_internal128_t) throw();