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re PR libstdc++/29520 (tr1: discrete_distributions vs large floating point values)

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2006-10-29  Paolo Carlini  <pcarlini@suse.de>
	
	PR libstdc++/29520
	* include/tr1/random (geometric_distribution<>::
	operator()(_UniformRandomNumberGenerator&)): Only declare.
	* include/tr1/random.tcc (geometric_distribution<>::
	operator()(_UniformRandomNumberGenerator&),
	poisson_distribution<>::operator()(_UniformRandomNumberGenerator&),
	binomial_distribution<>::operator()(_UniformRandomNumberGenerator&)):
	Reject candidate floating point values not convertible to the
	result_type.

From-SVN: r118135
This commit is contained in:
Paolo Carlini 2006-10-29 10:49:07 +00:00 • committed by Paolo Carlini
parent a7a53ca582
commit a8db47cb58
3 changed files with 53 additions and 4 deletions
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12
libstdc++-v3/ChangeLog
View file

@ -1,3 +1,15 @@
2006-10-29 Paolo Carlini <pcarlini@suse.de>
PR libstdc++/29520
* include/tr1/random (geometric_distribution<>::
operator()(_UniformRandomNumberGenerator&)): Only declare.
* include/tr1/random.tcc (geometric_distribution<>::
operator()(_UniformRandomNumberGenerator&),
poisson_distribution<>::operator()(_UniformRandomNumberGenerator&),
binomial_distribution<>::operator()(_UniformRandomNumberGenerator&)):
Reject candidate floating point values not convertible to the
result_type.
2006-10-28 Paolo Carlini <pcarlini@suse.de> 2006-10-28 Paolo Carlini <pcarlini@suse.de>
* include/tr1/array (array<>::_M_at): New. * include/tr1/array (array<>::_M_at): New.

3
libstdc++-v3/include/tr1/random
View file

@ -1759,8 +1759,7 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1)
template<class _UniformRandomNumberGenerator> template<class _UniformRandomNumberGenerator>
result_type result_type
operator()(_UniformRandomNumberGenerator& __urng) operator()(_UniformRandomNumberGenerator& __urng);
{ return result_type(std::ceil(std::log(__urng()) / _M_log_p)); }
/** /**
* Inserts a %geometric_distribution random number distribution * Inserts a %geometric_distribution random number distribution

42
libstdc++-v3/include/tr1/random.tcc
View file

@ -768,6 +768,28 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1)
} }
template<typename _IntType, typename _RealType>
template<class _UniformRandomNumberGenerator>
typename geometric_distribution<_IntType, _RealType>::result_type
geometric_distribution<_IntType, _RealType>::
operator()(_UniformRandomNumberGenerator& __urng)
{
// About the epsilon thing see this thread:
// http://gcc.gnu.org/ml/gcc-patches/2006-10/msg00971.html
const _RealType __naf =
(1 - std::numeric_limits<_RealType>::epsilon()) / 2;
// The largest _RealType convertible to _IntType.
const _RealType __thr =
std::numeric_limits<_IntType>::max() + __naf;
_RealType __cand;
do
__cand = std::ceil(std::log(__urng()) / _M_log_p);
while (__cand >= __thr);
return result_type(__cand + __naf);
}
template<typename _IntType, typename _RealType, template<typename _IntType, typename _RealType,
typename _CharT, typename _Traits> typename _CharT, typename _Traits>
std::basic_ostream<_CharT, _Traits>& std::basic_ostream<_CharT, _Traits>&
@ -841,6 +863,12 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1)
{ {
_RealType __x; _RealType __x;
// See comments above...
const _RealType __naf =
(1 - std::numeric_limits<_RealType>::epsilon()) / 2;
const _RealType __thr =
std::numeric_limits<_IntType>::max() + __naf;
const _RealType __m = std::floor(_M_mean); const _RealType __m = std::floor(_M_mean);
// sqrt(pi / 2) // sqrt(pi / 2)
const _RealType __spi_2 = 1.2533141373155002512078826424055226L; const _RealType __spi_2 = 1.2533141373155002512078826424055226L;
@ -899,9 +927,11 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1)
__reject = (__w - __e - __x * _M_lm_thr __reject = (__w - __e - __x * _M_lm_thr
> _M_lfm - std::tr1::lgamma(__x + __m + 1)); > _M_lfm - std::tr1::lgamma(__x + __m + 1));
__reject |= __x + __m >= __thr;
} while (__reject); } while (__reject);
return _IntType(__x + __m + 0.5); return result_type(__x + __m + __naf);
} }
else else
#endif #endif
@ -1055,6 +1085,12 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1)
{ {
_RealType __x; _RealType __x;
// See comments above...
const _RealType __naf =
(1 - std::numeric_limits<_RealType>::epsilon()) / 2;
const _RealType __thr =
std::numeric_limits<_IntType>::max() + __naf;
const _RealType __np = std::floor(_M_t * __p12); const _RealType __np = std::floor(_M_t * __p12);
const _RealType __pa = __np / _M_t; const _RealType __pa = __np / _M_t;
@ -1127,10 +1163,12 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1)
+ std::tr1::lgamma(_M_t - (__np + __x) + 1); + std::tr1::lgamma(_M_t - (__np + __x) + 1);
__reject = __v > _M_lf - __lfx + __x * _M_lp1p; __reject = __v > _M_lf - __lfx + __x * _M_lp1p;
} }
__reject |= __x + __np >= __thr;
} }
while (__reject); while (__reject);
__x += __np + 0.5; __x += __np + __naf;
const _IntType __z = _M_waiting(__urng, _M_t - _IntType(__x)); const _IntType __z = _M_waiting(__urng, _M_t - _IntType(__x));
__ret = _IntType(__x) + __z; __ret = _IntType(__x) + __z;