http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47032
--- Comment #7 from Ralf Wildenhues <rwild at gcc dot gnu.org> 2011-02-04 05:16:15 UTC --- (In reply to comment #3) > libgfortran/configure.ac has lines of the form (note I wrapped the line) > > AC_CHECK_LIB([m],[copysignl],[AC_DEFINE([HAVE_COPYSIGNL],[1],\ > [libm includes copysignl])]) > > So, configure is already checking if libm contains the > the "long double functions". The problem appears to be > that AC_CHECK_LIB is a compile only test, and these tests > appear to pass on AIX. AC_CHECK_LIB uses a link test, not a compile test.
