Macros MPFR_EXP_INVALID (invalid exponent value) and MPFR_EXP_CHECK

added. Code update to use MPFR_GET_EXP and MPFR_SET_EXP instead of
MPFR_EXP to allow more bug detection related to special values.
Macros MPFR_SET_NAN, MPFR_SET_INF, MPFR_SET_ZERO and MPFR_INIT set
the exponent of the number to MPFR_EXP_INVALID if MPFR_EXP_CHECK
is defined. Compile with -DMPFR_EXP_CHECK and make check to see
the potential problems; currently, 40 of 76 tests fail.


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2301 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 7 insertions, 6 deletions

diff --git a/sub.c b/sub.c
index 37689c65f..bdf3b3c20 100644
--- a/sub.c
+++ b/sub.c
@@ -1,6 +1,6 @@
 /* mpfr_sub -- subtract two floating-point numbers
 
-Copyright 2001, 2002 Free Software Foundation.
+Copyright 2001, 2002, 2003 Free Software Foundation.
 Contributed by the Spaces project, INRIA Lorraine.
 
 This file is part of the MPFR Library.
@@ -90,22 +90,23 @@ mpfr_sub (mpfr_ptr a, mpfr_srcptr b, mpfr_srcptr c, mp_rnd_t rnd_mode)
     }
   else
     { /* signs differ, it's an addition */
-      if (MPFR_EXP(b) < MPFR_EXP(c))
+      mp_exp_t eb, ec;
+      eb = MPFR_GET_EXP (b);
+      ec = MPFR_GET_EXP (c);
+      if (eb < ec)
         { /* exchange rounding modes towards +/- infinity */
           int inexact;
           if (rnd_mode == GMP_RNDU)
             rnd_mode = GMP_RNDD;
           else if (rnd_mode == GMP_RNDD)
             rnd_mode = GMP_RNDU;
-          inexact = mpfr_add1(a, c, b, rnd_mode,
-                              (mp_exp_unsigned_t) MPFR_EXP(c) - MPFR_EXP(b));
+          inexact = mpfr_add1(a, c, b, rnd_mode, (mp_exp_unsigned_t) ec - eb);
           MPFR_CHANGE_SIGN(a);
           return -inexact;
         }
       else
         {
-          return mpfr_add1(a, b, c, rnd_mode,
-                           (mp_exp_unsigned_t) MPFR_EXP(b) - MPFR_EXP(c));
+          return mpfr_add1(a, b, c, rnd_mode, (mp_exp_unsigned_t) eb - ec);
         }
     }
 }