mpfr-impl.h: avoid a compiler bug under Mac OS X Tiger + Xcode (&x == &x

is false) that makes tset_d fail; this problem was introduced in r5880.
[merged -c 5883 from trunk]


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/branches/2.4@5884 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 8 insertions, 5 deletions

diff --git a/mpfr-impl.h b/mpfr-impl.h
index 2721d6d5e..9692ae5b9 100644
--- a/mpfr-impl.h
+++ b/mpfr-impl.h
@@ -407,18 +407,21 @@ typedef union ieee_double_extract Ieee_double_extract;
                          ((((Ieee_double_extract *)&(x))->s.manl != 0) || \
                          (((Ieee_double_extract *)&(x))->s.manh != 0)))
 #else
-/* Below, the &(x) == &(x) allows to make sure that x is a lvalue
-   without (probably) any warning from the compiler. */
-# define DOUBLE_ISINF(x) (&(x) == &(x) && ((x) > DBL_MAX || (x) < -DBL_MAX))
+/* Below, the &(x) == &(x) || &(x) != &(x) allows to make sure that x
+   is a lvalue without (probably) any warning from the compiler.  The
+   &(x) != &(x) is needed to avoid a failure under Mac OS X 10.4.11
+   (with Xcode 2.4.1, i.e. the latest one). */
+# define LVALUE(x) (&(x) == &(x) || &(x) != &(x))
+# define DOUBLE_ISINF(x) (LVALUE(x) && ((x) > DBL_MAX || (x) < -DBL_MAX))
 # ifdef MPFR_NANISNAN
 /* Avoid MIPSpro / IRIX64 / gcc -ffast-math (incorrect) optimizations.
    The + must not be replaced by a ||. With gcc -ffast-math, NaN is
    regarded as a positive number or something like that; the second
    test catches this case. */
 #  define DOUBLE_ISNAN(x) \
-    (&(x) == &(x) && !((((x) >= 0.0) + ((x) <= 0.0)) && -(x)*(x) <= 0.0))
+    (LVALUE(x) && !((((x) >= 0.0) + ((x) <= 0.0)) && -(x)*(x) <= 0.0))
 # else
-#  define DOUBLE_ISNAN(x) (&(x) == &(x) && (x) != (x))
+#  define DOUBLE_ISNAN(x) (LVALUE(x) && (x) != (x))
 # endif
 #endif