[Boost-bugs] [Boost C++ Libraries] #10104: program aborts with log1p(-2.0Q)

Subject: [Boost-bugs] [Boost C++ Libraries] #10104: program aborts with log1p(-2.0Q)
From: Boost C++ Libraries (noreply_at_[hidden])
Date: 2014-06-07 12:49:49

#10104: program aborts with log1p(-2.0Q)
----------------------------------------+----------------------------
 Reporter:  Charles Karney <charles@…>  |      Owner:  johnmaddock
     Type:  Bugs                        |     Status:  new
Milestone:  To Be Determined            |  Component:  multiprecision
  Version:  Boost 1.54.0                |   Severity:  Problem
 Keywords:                              |
----------------------------------------+----------------------------
 The math functions, e.g., log1p, for float128 do not handle parameters
 outside the normal domain.  Thus sqrt(-2.0Q) produces a nan as does
 log1p(-2.0), but log1p(-2.0Q) crashes.  (Similar remarks apply to hypot
 and probably other similarly defined functions.)


 {{{
 #include <iostream>
 #include <cmath>
 #include <boost/multiprecision/float128.hpp>
 #include <boost/math/special_functions/log1p.hpp>

 int main() {
   double x = -2;
   boost::multiprecision::float128 y = -2;

   std::cout << std::sqrt(x) << "\n" << std::log1p(x) << "\n";
   std::cout << sqrt(y) << "\n";
   std::cout << boost::math::log1p(y) << "\n";
 }
 }}}
 produces
 {{{
 -nan
 -nan
 -nan
 terminate called after throwing an instance of
 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<std::domain_error>
 >'
   what():  Error in function
 boost::math::log1p<N5boost14multiprecision6numberINS0_8backends16float128_backendELNS0_26expression_template_optionE0EEE>(N5boost14multiprecision6numberINS0_8backends16float128_backendELNS0_26expression_template_optionE0EEE):
 log1p(x) requires x > -1, but got x = -2.
 Aborted (core dumped)
 }}}

-- 
Ticket URL: <https://svn.boost.org/trac/boost/ticket/10104>
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