Hi
tested x86_64-linux multilib, committed to mainline. A similar fix will
go in 4_7-branch too.
Thanks,
Paolo.
////////////////////////
2012-10-24 Haakan Younes <hyou...@google.com>
Paolo Carlini <paolo.carl...@oracle.com>
PR libstdc++/55047
* include/bits/random.h (exponential_distribution<>::operator):
Fix formula to std::log(result_type(1) - __aurng()).
* include/bits/random.tcc: Likewise, everywhere.
Index: include/bits/random.tcc
===================================================================
--- include/bits/random.tcc (revision 192718)
+++ include/bits/random.tcc (working copy)
@@ -1,6 +1,6 @@
// random number generation (out of line) -*- C++ -*-
-// Copyright (C) 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+// Copyright (C) 2009-2012 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
@@ -1187,7 +1187,7 @@
double __cand;
do
- __cand = std::floor(std::log(__aurng()) / __param._M_log_1_p);
+ __cand = std::floor(std::log(1.0 - __aurng()) / __param._M_log_1_p);
while (__cand >= __thr);
return result_type(__cand + __naf);
@@ -1217,7 +1217,8 @@
{
double __cand;
do
- __cand = std::floor(std::log(__aurng()) / __param._M_log_1_p);
+ __cand = std::floor(std::log(1.0 - __aurng())
+ / __param._M_log_1_p);
while (__cand >= __thr);
*__f++ = __cand + __naf;
@@ -1464,7 +1465,7 @@
do
{
const double __u = __c * __aurng();
- const double __e = -std::log(__aurng());
+ const double __e = -std::log(1.0 - __aurng());
double __w = 0.0;
@@ -1496,7 +1497,7 @@
__x = 1;
else
{
- const double __v = -std::log(__aurng());
+ const double __v = -std::log(1.0 - __aurng());
const double __y = __param._M_d
+ __v * __2cx / __param._M_d;
__x = std::ceil(__y);
@@ -1655,7 +1656,7 @@
do
{
- const double __e = -std::log(__aurng());
+ const double __e = -std::log(1.0 - __aurng());
__sum += __e / (__t - __x);
__x += 1;
}
@@ -1723,7 +1724,7 @@
__reject = __y >= __param._M_d1;
if (!__reject)
{
- const double __e = -std::log(__aurng());
+ const double __e = -std::log(1.0 - __aurng());
__x = std::floor(__y);
__v = -__e - __n * __n / 2 + __param._M_c;
}
@@ -1735,15 +1736,15 @@
__reject = __y >= __param._M_d2;
if (!__reject)
{
- const double __e = -std::log(__aurng());
+ const double __e = -std::log(1.0 - __aurng());
__x = std::floor(-__y);
__v = -__e - __n * __n / 2;
}
}
else if (__u <= __a123)
{
- const double __e1 = -std::log(__aurng());
- const double __e2 = -std::log(__aurng());
+ const double __e1 = -std::log(1.0 - __aurng());
+ const double __e2 = -std::log(1.0 - __aurng());
const double __y = __param._M_d1
+ 2 * __s1s * __e1 / __param._M_d1;
@@ -1754,8 +1755,8 @@
}
else
{
- const double __e1 = -std::log(__aurng());
- const double __e2 = -std::log(__aurng());
+ const double __e1 = -std::log(1.0 - __aurng());
+ const double __e2 = -std::log(1.0 - __aurng());
const double __y = __param._M_d2
+ 2 * __s2s * __e1 / __param._M_d2;
@@ -1869,7 +1870,7 @@
__detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
__aurng(__urng);
while (__f != __t)
- *__f++ = -std::log(__aurng()) / __p.lambda();
+ *__f++ = -std::log(result_type(1) - __aurng()) / __p.lambda();
}
template<typename _RealType, typename _CharT, typename _Traits>
@@ -2628,7 +2629,7 @@
{
__detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
__aurng(__urng);
- return __p.b() * std::pow(-std::log(__aurng()),
+ return __p.b() * std::pow(-std::log(result_type(1) - __aurng()),
result_type(1) / __p.a());
}
@@ -2644,10 +2645,11 @@
__glibcxx_function_requires(_ForwardIteratorConcept<_ForwardIterator>)
__detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
__aurng(__urng);
- auto inv_a = result_type(1) / __p.a();
+ auto __inv_a = result_type(1) / __p.a();
while (__f != __t)
- *__f++ = __p.b() * std::pow(-std::log(__aurng()), inv_a);
+ *__f++ = __p.b() * std::pow(-std::log(result_type(1) - __aurng()),
+ __inv_a);
}
template<typename _RealType, typename _CharT, typename _Traits>
@@ -2704,7 +2706,8 @@
{
__detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
__aurng(__urng);
- return __p.a() - __p.b() * std::log(-std::log(__aurng()));
+ return __p.a() - __p.b() * std::log(-std::log(result_type(1)
+ - __aurng()));
}
template<typename _RealType>
@@ -2721,7 +2724,8 @@
__aurng(__urng);
while (__f != __t)
- *__f++ = __p.a() - __p.b() * std::log(-std::log(__aurng()));
+ *__f++ = __p.a() - __p.b() * std::log(-std::log(result_type(1)
+ - __aurng()));
}
template<typename _RealType, typename _CharT, typename _Traits>
Index: include/bits/random.h
===================================================================
--- include/bits/random.h (revision 192718)
+++ include/bits/random.h (working copy)
@@ -1,6 +1,6 @@
// random number generation -*- C++ -*-
-// Copyright (C) 2009, 2010, 2011, 2012 Free Software Foundation, Inc.
+// Copyright (C) 2009-2012 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
@@ -4748,7 +4748,7 @@
{
__detail::_Adaptor<_UniformRandomNumberGenerator, result_type>
__aurng(__urng);
- return -std::log(__aurng()) / __p.lambda();
+ return -std::log(result_type(1) - __aurng()) / __p.lambda();
}
template<typename _ForwardIterator,
