[Bug libstdc++/68397] std::tr1::expint fails in __expint_En_cont_frac for some long double arguments due to low __max_iter value

[emsr at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68397

--- Comment #3 from emsr at gcc dot gnu.org ---
Author: emsr
Date: Thu Apr 20 15:41:59 2017
New Revision: 247027

URL: https://gcc.gnu.org/viewcvs?rev=247027&root=gcc&view=rev
Log:
2017-04-20  Edward Smith-Rowland  <3dw...@verizon.net>

        PR libstdc++/68397 std::tr1::expint fails ... long double arguments.
        * include/tr1/exp_integral.tcc: Increase iteration limits.
        * testsuite/tr1/5_numerical_facilities/special_functions/15_expint/
        pr68397.cc: New test.
        * testsuite/special_functions/14_expint/pr68397.cc: New test.

Added:
    trunk/libstdc++-v3/testsuite/special_functions/14_expint/pr68397.cc
   
trunk/libstdc++-v3/testsuite/tr1/5_numerical_facilities/special_functions/15_expint/pr68397.cc
Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/include/tr1/exp_integral.tcc