[Bug c++/64631] New: error: âlgammal_râ was not declared in this scope

["mathieu.malaterre at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64631

            Bug ID: 64631
           Summary: error: âlgammal_râ was not declared in this scope
           Product: gcc
           Version: 4.9.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mathieu.malaterre at gmail dot com

Created attachment 34464
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34464&action=edit
demo

I cannot compile the following pseudo code (see attachment) it fails with:

$ g++ -ffast-math foo.cxx
In file included from /usr/include/math.h:432:0,
                 from foo.cxx:3:
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function âdouble
lgamma(double)â:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:260:41: error:
âlgamma_râ was not declared in this scope
   return lgamma_r (__d, &__local_signgam);
                                         ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function âfloat
lgammaf(float)â:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:269:42: error:
âlgammaf_râ was not declared in this scope
   return lgammaf_r (__d, &__local_signgam);
                                          ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function âlong
double lgammal(long double)â:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:279:42: error:
âlgammal_râ was not declared in this scope
   return lgammal_r (__d, &__local_signgam);
                                          ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function âdouble
gamma(double)â:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:293:41: error:
âlgamma_râ was not declared in this scope
   return lgamma_r (__d, &__local_signgam);
                                         ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function âfloat
gammaf(float)â:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:302:42: error:
âlgammaf_râ was not declared in this scope
   return lgammaf_r (__d, &__local_signgam);
                                          ^
/usr/include/x86_64-linux-gnu/bits/math-finite.h: In function âlong
double gammal(long double)â:
/usr/include/x86_64-linux-gnu/bits/math-finite.h:312:42: error:
âlgammal_râ was not declared in this scope
   return lgammal_r (__d, &__local_signgam);