http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47032
Peter O'Gorman <pogma at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |pogma at gcc dot gnu.org
--- Comment #8 from Peter O'Gorman <pogma at gcc dot gnu.org> 2011-02-08
20:43:18 UTC ---
(In reply to comment #7)
> (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.
As far as I can tell the problem is that the configure tests for long double
functions don't #include <math.h>, changing the AC_CHECK_LIB to AC_LINK_IFELSE
that #includes math.h and uses the symbol should give correct results.
