-#endif
- mpfr_t n; mpfr_init(n);
-], [AC_MSG_RESULT([yes])], [AC_MSG_RESULT([buggy but acceptable])])],
- [AC_MSG_RESULT([no]); have_gmp=no])
- LIBS="$saved_LIBS"
-fi
-CFLAGS="$saved_CFLAGS"
+ #endif
+ ], [AC_MSG_RESULT([yes])], [AC_MSG_RESULT([no]); have_gmp=no])
+
+ if test x"$have_gmp" = xyes; then
+ saved_LIBS="$LIBS"
+ LIBS="$LIBS $gmplibs"
+ dnl MPFR 2.2.0 is acceptable but buggy, MPFR 2.2.1 is better.
+ AC_MSG_CHECKING([for correct version of mpfr.h])
+ AC_TRY_LINK([#include <gmp.h>
+ #include <mpfr.h>],[
+ #if MPFR_VERSION < MPFR_VERSION_NUM(2,2,0)
+ choke me
+ #endif
+ mpfr_t n; mpfr_init(n);
+ mpfr_t x; mpfr_init(x);
+ int t;
+ mpfr_atan2 (n, n, x, GMP_RNDN);
+ mpfr_erfc (n, x, GMP_RNDN);
+ mpfr_subnormalize (x, t, GMP_RNDN);
+ ], [AC_TRY_LINK([#include <gmp.h>
+ #include <mpfr.h>],[
+ #if MPFR_VERSION < MPFR_VERSION_NUM(2,2,1)
+ choke me
+ #endif
+ mpfr_t n; mpfr_init(n);
+ ], [AC_MSG_RESULT([yes])], [AC_MSG_RESULT([buggy but acceptable])])],
+ [AC_MSG_RESULT([no]); have_gmp=no])
+ LIBS="$saved_LIBS"
+ fi
+ CFLAGS="$saved_CFLAGS"