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Attempting to work round the dodgy std::numeric_limits<long double> on

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some BSDs.


[SVN r35345]
This commit is contained in:
Daniel James
2006-09-26 20:35:58 +00:00
parent eb5ef5e134
commit 26473491c4
2 changed files with 98 additions and 47 deletions
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84
hash/test/hash_float_test.cpp
View File

@@ -24,12 +24,12 @@ void float_tests(char const* name, T* = 0)
std::cerr<<"\n"
<<"Testing " BOOST_STRINGIZE(HASH_NAMESPACE) "::hash<"<<name<<">\n"
<<"\n"
<<"std::numeric_limits<T>::digits = "
<<std::numeric_limits<T>::digits<<"\n"
<<"std::numeric_limits<int>::digits = "
<<std::numeric_limits<int>::digits<<"\n"
<<"std::numeric_limits<std::size_t>::digits = "
<<std::numeric_limits<std::size_t>::digits<<"\n"
<<"boost::hash_detail::float_limits<T>::digits = "
<<boost::hash_detail::float_limits<T>::digits<<"\n"
<<"boost::hash_detail::float_limits<int>::digits = "
<<boost::hash_detail::float_limits<int>::digits<<"\n"
<<"boost::hash_detail::float_limits<std::size_t>::digits = "
<<boost::hash_detail::float_limits<std::size_t>::digits<<"\n"
<<"\n"
;
@@ -50,11 +50,11 @@ void float_tests(char const* name, T* = 0)
#if defined(__BORLANDC__)
std::cerr<<"Not running infinity checks on Borland, as it causes it to crash.\n";
#else
if(std::numeric_limits<T>::has_infinity) {
if(boost::hash_detail::float_limits<T>::has_infinity) {
T infinity = -log(zero);
T infinity2 = (T) 1. / zero;
T infinity3 = (T) -1. / minus_zero;
T infinity4 = std::numeric_limits<T>::infinity();
T infinity4 = boost::hash_detail::float_limits<T>::infinity();
T minus_infinity = log(zero);
T minus_infinity2 = (T) -1. / zero;
@@ -84,26 +84,26 @@ void float_tests(char const* name, T* = 0)
// This should really be 'has_denorm == denorm_present' but some
// compilers don't have 'denorm_present'. See also a later use.
if(std::numeric_limits<T>::has_denorm) {
if(x1(std::numeric_limits<T>::denorm_min()) == x1(infinity)) {
if(boost::hash_detail::float_limits<T>::has_denorm) {
if(x1(boost::hash_detail::float_limits<T>::denorm_min()) == x1(infinity)) {
std::cerr<<"x1(denorm_min) == x1(infinity) == "<<x1(infinity)<<"\n";
}
if(x1(std::numeric_limits<T>::denorm_min()) == x1(minus_infinity)) {
if(x1(boost::hash_detail::float_limits<T>::denorm_min()) == x1(minus_infinity)) {
std::cerr<<"x1(denorm_min) == x1(-infinity) == "<<x1(minus_infinity)<<"\n";
}
}
if(std::numeric_limits<T>::has_quiet_NaN) {
if(x1(std::numeric_limits<T>::quiet_NaN()) == x1(infinity)) {
if(boost::hash_detail::float_limits<T>::has_quiet_NaN) {
if(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) == x1(infinity)) {
std::cerr<<"x1(quiet_NaN) == x1(infinity) == "<<x1(infinity)<<"\n";
}
if(x1(std::numeric_limits<T>::quiet_NaN()) == x1(minus_infinity)) {
if(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) == x1(minus_infinity)) {
std::cerr<<"x1(quiet_NaN) == x1(-infinity) == "<<x1(minus_infinity)<<"\n";
}
}
}
#endif
T max = (std::numeric_limits<T>::max)();
T max = (boost::hash_detail::float_limits<T>::max)();
T half_max = max / 2;
T quarter_max = max / 4;
T three_quarter_max = max - quarter_max;
@@ -132,50 +132,50 @@ void float_tests(char const* name, T* = 0)
BOOST_TEST(x1(v1) == HASH_NAMESPACE::hash_value(v1));
BOOST_TEST(x1(v2) == HASH_NAMESPACE::hash_value(v2));
BOOST_TEST(x1(std::numeric_limits<T>::epsilon()) ==
HASH_NAMESPACE::hash_value(std::numeric_limits<T>::epsilon()));
BOOST_TEST(x1(boost::hash_detail::float_limits<T>::epsilon()) ==
HASH_NAMESPACE::hash_value(boost::hash_detail::float_limits<T>::epsilon()));
BOOST_TEST(std::numeric_limits<T>::epsilon() != (T) 0);
if(x1(std::numeric_limits<T>::epsilon()) == x1((T) 0))
BOOST_TEST(boost::hash_detail::float_limits<T>::epsilon() != (T) 0);
if(x1(boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 0))
std::cerr<<"x1(epsilon) == x1(0) == "<<x1((T) 0)<<"\n";
BOOST_TEST(-std::numeric_limits<T>::epsilon() != (T) 0);
if(x1(-std::numeric_limits<T>::epsilon()) == x1((T) 0))
BOOST_TEST(-boost::hash_detail::float_limits<T>::epsilon() != (T) 0);
if(x1(-boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 0))
std::cerr<<"x1(-epsilon) == x1(0) == "<<x1((T) 0)<<"\n";
BOOST_TEST((T) 1 + std::numeric_limits<T>::epsilon() != (T) 1);
if(x1((T) 1 + std::numeric_limits<T>::epsilon()) == x1((T) 1))
BOOST_TEST((T) 1 + boost::hash_detail::float_limits<T>::epsilon() != (T) 1);
if(x1((T) 1 + boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 1))
std::cerr<<"x1(1 + epsilon) == x1(1) == "<<x1((T) 1)<<"\n";
BOOST_TEST((T) 1 - std::numeric_limits<T>::epsilon() != (T) 1);
if(x1((T) 1 - std::numeric_limits<T>::epsilon()) == x1((T) 1))
BOOST_TEST((T) 1 - boost::hash_detail::float_limits<T>::epsilon() != (T) 1);
if(x1((T) 1 - boost::hash_detail::float_limits<T>::epsilon()) == x1((T) 1))
std::cerr<<"x1(1 - epsilon) == x1(1) == "<<x1((T) 1)<<"\n";
BOOST_TEST((T) -1 + std::numeric_limits<T>::epsilon() != (T) -1);
if(x1((T) -1 + std::numeric_limits<T>::epsilon()) == x1((T) -1))
BOOST_TEST((T) -1 + boost::hash_detail::float_limits<T>::epsilon() != (T) -1);
if(x1((T) -1 + boost::hash_detail::float_limits<T>::epsilon()) == x1((T) -1))
std::cerr<<"x1(-1 + epsilon) == x1(-1) == "<<x1((T) -1)<<"\n";
BOOST_TEST((T) -1 - std::numeric_limits<T>::epsilon() != (T) -1);
if(x1((T) -1 - std::numeric_limits<T>::epsilon()) == x1((T) -1))
BOOST_TEST((T) -1 - boost::hash_detail::float_limits<T>::epsilon() != (T) -1);
if(x1((T) -1 - boost::hash_detail::float_limits<T>::epsilon()) == x1((T) -1))
std::cerr<<"x1(-1 - epsilon) == x1(-1) == "<<x1((T) -1)<<"\n";
// As before.
if(std::numeric_limits<T>::has_denorm) {
if(x1(std::numeric_limits<T>::denorm_min()) == x1(zero)) {
if(boost::hash_detail::float_limits<T>::has_denorm) {
if(x1(boost::hash_detail::float_limits<T>::denorm_min()) == x1(zero)) {
std::cerr<<"x1(denorm_min) == x1(zero) == "<<x1(zero)<<"\n";
}
#if !BOOST_WORKAROUND(__DECCXX_VER,<70190006)
// The Tru64/CXX standard library prior to 7.1 contains a bug in the
// specialization of std::numeric_limits::denorm_min() for long
// specialization of boost::hash_detail::float_limits::denorm_min() for long
// doubles which causes this test to fail.
if(x1(std::numeric_limits<T>::denorm_min()) !=
HASH_NAMESPACE::hash_value(std::numeric_limits<T>::denorm_min()))
if(x1(boost::hash_detail::float_limits<T>::denorm_min()) !=
HASH_NAMESPACE::hash_value(boost::hash_detail::float_limits<T>::denorm_min()))
{
std::cerr<<"x1(std::numeric_limits<T>::denorm_min()) = "
<< x1(std::numeric_limits<T>::denorm_min())
<< "\nhash_value(std::numeric_limits<T>::denorm_min()) = "
std::cerr<<"x1(boost::hash_detail::float_limits<T>::denorm_min()) = "
<< x1(boost::hash_detail::float_limits<T>::denorm_min())
<< "\nhash_value(boost::hash_detail::float_limits<T>::denorm_min()) = "
<< HASH_NAMESPACE::hash_value(
std::numeric_limits<T>::denorm_min())
boost::hash_detail::float_limits<T>::denorm_min())
<< "\nx1(0) = "<<x1(0)<<"\n";
}
#endif
@@ -183,12 +183,12 @@ void float_tests(char const* name, T* = 0)
// NaN also causes borland to crash.
#if !defined(__BORLANDC__)
if(std::numeric_limits<T>::has_quiet_NaN) {
if(x1(std::numeric_limits<T>::quiet_NaN()) == x1(1.0)) {
if(boost::hash_detail::float_limits<T>::has_quiet_NaN) {
if(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) == x1(1.0)) {
std::cerr<<"x1(quiet_NaN) == x1(1.0) == "<<x1(1.0)<<"\n";
}
BOOST_TEST(x1(std::numeric_limits<T>::quiet_NaN()) ==
HASH_NAMESPACE::hash_value(std::numeric_limits<T>::quiet_NaN()));
BOOST_TEST(x1(boost::hash_detail::float_limits<T>::quiet_NaN()) ==
HASH_NAMESPACE::hash_value(boost::hash_detail::float_limits<T>::quiet_NaN()));
}
#endif
}

61
include/boost/functional/detail/hash_float.hpp
View File

@@ -35,10 +35,61 @@
# endif
#endif
// On FreeBSD and OpenBSD, numeric_limits is not reliable for long doubles, but
// the macros defined in <float.h> are. I don't know if this is also be the case for
// other BSDs, but using the macros if they're available seems like the best
// choice.
#if defined(__FreeBSD__) || defined(__NetBSD__) && \
defined(__OpenBSD__) || defined(__DragonFly__)
#include <float.h>
#endif
namespace boost
{
namespace hash_detail
{
template <class T>
struct float_limits : std::numeric_limits<T> {};
#if defined(__FreeBSD__) || defined(__NetBSD__) && \
defined(__OpenBSD__) || defined(__DragonFly__)
template <>
struct float_limits<long double>
: std::numeric_limits<long double>
{
#if defined(LDBL_EPSILON)
static long double epsilon() {
return LDBL_EPSILON;
}
#endif
#if defined(LDBL_MANT_DIG)
BOOST_STATIC_CONSTANT(int, digits = LDBL_MANT_DIG);
#endif
#if defined(LDBL_MAX)
static long double (max)() {
return LDBL_MAX;
}
#endif
#if defined(LDBL_MIN)
static long double (min)() {
return LDBL_MIN;
}
#endif
#if defined(LDBL_MAX_EXP)
BOOST_STATIC_CONSTANT(int, max_exponent = LDBL_MAX_EXP);
#endif
#if defined(LDBL_MIN_EXP)
BOOST_STATIC_CONSTANT(int, min_exponent = LDBL_MIN_EXP);
#endif
};
#endif // __FreeBSD__/__NetBSD__/__OpenBSD__/__DragonFly__
inline void hash_float_combine(std::size_t& seed, std::size_t value)
{
seed ^= value + (seed<<6) + (seed>>2);
@@ -63,19 +114,19 @@ namespace boost
//BOOST_ASSERT(0 <= v && v < 0.5);
v = boost::hash_detail::call_ldexp(v,
std::numeric_limits<std::size_t>::digits + 1);
float_limits<std::size_t>::digits + 1);
std::size_t seed = static_cast<std::size_t>(v);
v -= seed;
// ceiling(digits(T) * log2(radix(T))/ digits(size_t)) - 1;
std::size_t const length
= (std::numeric_limits<T>::digits *
boost::static_log2<std::numeric_limits<T>::radix>::value - 1)
/ std::numeric_limits<std::size_t>::digits;
= (float_limits<T>::digits *
boost::static_log2<float_limits<T>::radix>::value - 1)
/ float_limits<std::size_t>::digits;
for(std::size_t i = 0; i < length; ++i)
{
v = boost::hash_detail::call_ldexp(v, std::numeric_limits<std::size_t>::digits);
v = boost::hash_detail::call_ldexp(v, float_limits<std::size_t>::digits);
std::size_t part = static_cast<std::size_t>(v);
v -= part;
hash_float_combine(seed, part);