diff options
| author | Paolo Carlini <pcarlini@suse.de> | 2006-10-29 10:49:07 +0000 |
|---|---|---|
| committer | Paolo Carlini <paolo@gcc.gnu.org> | 2006-10-29 10:49:07 +0000 |
| commit | a8db47cb5889a381d0a40c903243a9945299fbb9 (patch) | |
| tree | b119b574ab746f5b26e56348069fe2d4875f0d75 | |
| parent | a7a53ca582735ec356bb273b2d17aee0274896d1 (diff) | |
| download | gcc-a8db47cb5889a381d0a40c903243a9945299fbb9.zip gcc-a8db47cb5889a381d0a40c903243a9945299fbb9.tar.gz gcc-a8db47cb5889a381d0a40c903243a9945299fbb9.tar.bz2 | |
re PR libstdc++/29520 (tr1: discrete_distributions vs large floating point values)
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
| -rw-r--r-- | libstdc++-v3/ChangeLog | 12 | ||||
| -rw-r--r-- | libstdc++-v3/include/tr1/random | 3 | ||||
| -rw-r--r-- | libstdc++-v3/include/tr1/random.tcc | 42 |
3 files changed, 53 insertions, 4 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index cb13016..a6a0589 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -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> * include/tr1/array (array<>::_M_at): New. diff --git a/libstdc++-v3/include/tr1/random b/libstdc++-v3/include/tr1/random index 9d1aa84..9114d80 100644 --- a/libstdc++-v3/include/tr1/random +++ b/libstdc++-v3/include/tr1/random @@ -1759,8 +1759,7 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) 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 diff --git a/libstdc++-v3/include/tr1/random.tcc b/libstdc++-v3/include/tr1/random.tcc index 8624f12..67d79ed 100644 --- a/libstdc++-v3/include/tr1/random.tcc +++ b/libstdc++-v3/include/tr1/random.tcc @@ -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, typename _CharT, typename _Traits> std::basic_ostream<_CharT, _Traits>& @@ -841,6 +863,12 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) { _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 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) __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 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) { _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 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) + 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; |