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[v3] libstdc++/29520
- From: Paolo Carlini <pcarlini at suse dot de>
- To: "'gcc-patches at gcc dot gnu dot org'" <gcc-patches at gcc dot gnu dot org>
- Date: Sun, 29 Oct 2006 11:52:17 +0100
- Subject: [v3] libstdc++/29520
Hi,
tested x86-linux, committed mainline and 4_2.
Paolo.
//////////////
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.
Index: include/tr1/random
===================================================================
--- include/tr1/random (revision 118104)
+++ include/tr1/random (working copy)
@@ -1759,8 +1759,7 @@
template<class _UniformRandomNumberGenerator>
result_type
- operator()(_UniformRandomNumberGenerator& __urng)
- { return result_type(std::ceil(std::log(__urng()) / _M_log_p)); }
+ operator()(_UniformRandomNumberGenerator& __urng);
/**
* Inserts a %geometric_distribution random number distribution
Index: include/tr1/random.tcc
===================================================================
--- include/tr1/random.tcc (revision 118104)
+++ include/tr1/random.tcc (working copy)
@@ -768,6 +768,28 @@
}
+ 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,
typename _CharT, typename _Traits>
std::basic_ostream<_CharT, _Traits>&
@@ -841,6 +863,12 @@
{
_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);
// sqrt(pi / 2)
const _RealType __spi_2 = 1.2533141373155002512078826424055226L;
@@ -899,9 +927,11 @@
__reject = (__w - __e - __x * _M_lm_thr
> _M_lfm - std::tr1::lgamma(__x + __m + 1));
+ __reject |= __x + __m >= __thr;
+
} while (__reject);
- return _IntType(__x + __m + 0.5);
+ return result_type(__x + __m + __naf);
}
else
#endif
@@ -1055,6 +1085,12 @@
{
_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 __pa = __np / _M_t;
@@ -1127,10 +1163,12 @@
+ std::tr1::lgamma(_M_t - (__np + __x) + 1);
__reject = __v > _M_lf - __lfx + __x * _M_lp1p;
}
+
+ __reject |= __x + __np >= __thr;
}
while (__reject);
- __x += __np + 0.5;
+ __x += __np + __naf;
const _IntType __z = _M_waiting(__urng, _M_t - _IntType(__x));
__ret = _IntType(__x) + __z;