diff options
| -rw-r--r-- | libstdc++-v3/ChangeLog | 12 | ||||
| -rw-r--r-- | libstdc++-v3/include/tr1/random | 2 | ||||
| -rw-r--r-- | libstdc++-v3/include/tr1/random.tcc | 79 |
3 files changed, 65 insertions, 28 deletions
diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog index 0da5ecd..b9420e0 100644 --- a/libstdc++-v3/ChangeLog +++ b/libstdc++-v3/ChangeLog @@ -1,3 +1,15 @@ +2006-07-14 Paolo Carlini <pcarlini@suse.de> + + * include/tr1/random.tcc (struct _To_Unsigned_Type): Add. + (subtract_with_carry<>::seed(_Gen&, false_type)): Use an + unsigned type in the loop, fix factor multiplier, take g + invocations modulo 2^32. + + * include/tr1/random.tcc (subtract_with_carry<>:: + seed(unsigned long)): Fix value == 0 special case. + + * include/tr1/random (struct _Shift): Fix for large shifts. + 2006-07-13 Paolo Carlini <pcarlini@suse.de> * testsuite/performance/21_strings/string_copy_cons_and_dest.cc: New. diff --git a/libstdc++-v3/include/tr1/random b/libstdc++-v3/include/tr1/random index f90c8d1..5810986 100644 --- a/libstdc++-v3/include/tr1/random +++ b/libstdc++-v3/include/tr1/random @@ -125,7 +125,7 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) } template<typename _UIntType, int __w, bool = - __w != std::numeric_limits<_UIntType>::digits> + __w < std::numeric_limits<_UIntType>::digits> struct _Shift { static const _UIntType __value = 0; }; diff --git a/libstdc++-v3/include/tr1/random.tcc b/libstdc++-v3/include/tr1/random.tcc index fe77abb..a3c263d 100644 --- a/libstdc++-v3/include/tr1/random.tcc +++ b/libstdc++-v3/include/tr1/random.tcc @@ -102,6 +102,28 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) 2 + std::numeric_limits<_RealType>::digits * 3010/10000; }; + template<typename _ValueT> + struct _To_Unsigned_Type + { typedef _ValueT _Type; }; + + template<> + struct _To_Unsigned_Type<short> + { typedef unsigned short _Type; }; + + template<> + struct _To_Unsigned_Type<int> + { typedef unsigned int _Type; }; + + template<> + struct _To_Unsigned_Type<long> + { typedef unsigned long _Type; }; + +#ifdef _GLIBCXX_USE_LONG_LONG + template<> + struct _To_Unsigned_Type<long long> + { typedef unsigned long long _Type; }; +#endif + } // namespace _Private @@ -347,6 +369,9 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) subtract_with_carry<_IntType, __m, __s, __r>:: seed(unsigned long __value) { + if (__value == 0) + __value = 19780503; + std::tr1::linear_congruential<unsigned long, 40014, 0, 2147483563> __lcg(__value); @@ -357,35 +382,35 @@ _GLIBCXX_BEGIN_NAMESPACE(tr1) _M_p = 0; } - // - // This implementation differs from the tr1 spec because the tr1 spec refused - // to make any sense to me: the exponent of the factor in the spec goes from - // 1 to (n-1), but it would only make sense to me if it went from 0 to (n-1). - // - // This algorithm is still problematic because it can overflow left right and - // center. - // template<typename _IntType, _IntType __m, int __s, int __r> template<class _Gen> - void - subtract_with_carry<_IntType, __m, __s, __r>:: - seed(_Gen& __gen, false_type) - { - const int __n = (std::numeric_limits<_IntType>::digits + 31) / 32; - for (int __i = 0; __i < long_lag; ++__i) - { - _M_x[__i] = 0; - unsigned long __factor = 1; - for (int __j = 0; __j < __n; ++__j) - { - _M_x[__i] += __gen() * __factor; - __factor *= 0x80000000; - } - _M_x[__i] = _Private::__mod<_IntType, 1, 0, modulus>(_M_x[__i]); - } - _M_carry = (_M_x[long_lag - 1] == 0) ? 1 : 0; - _M_p = 0; - } + void + subtract_with_carry<_IntType, __m, __s, __r>:: + seed(_Gen& __gen, false_type) + { + const int __n = (std::numeric_limits<_IntType>::digits + 31) / 32; + + typedef typename _Private::_Select<(sizeof(unsigned) == 4), + unsigned, unsigned long>::_Type _UInt32Type; + + typedef typename _Private::_To_Unsigned_Type<_IntType>::_Type + _UIntType; + + for (int __i = 0; __i < long_lag; ++__i) + { + _UIntType __tmp = 0; + _UIntType __factor = 1; + for (int __j = 0; __j < __n; ++__j) + { + __tmp += (_Private::__mod<_UInt32Type, 1, 0, 0>(__gen()) + * __factor); + __factor *= _Private::_Shift<_UIntType, 32>::__value; + } + _M_x[__i] = _Private::__mod<_UIntType, 1, 0, modulus>(__tmp); + } + _M_carry = (_M_x[long_lag - 1] == 0) ? 1 : 0; + _M_p = 0; + } template<typename _IntType, _IntType __m, int __s, int __r> typename subtract_with_carry<_IntType, __m, __s, __r>::result_type |