[src/next.c] Improved handling of special values.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@8952 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 23 insertions, 18 deletions

diff --git a/src/next.c b/src/next.c
index c6ff1d891..dbf86dc28 100644
--- a/src/next.c
+++ b/src/next.c
@@ -26,15 +26,18 @@ http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
 void
 mpfr_nexttozero (mpfr_ptr x)
 {
-  if (MPFR_UNLIKELY(MPFR_IS_INF(x)))
+  if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x)))
     {
-      mpfr_setmax (x, __gmpfr_emax);
-      return;
-    }
-  else if (MPFR_UNLIKELY( MPFR_IS_ZERO(x) ))
-    {
-      MPFR_CHANGE_SIGN(x);
-      mpfr_setmin (x, __gmpfr_emin);
+      if (MPFR_IS_INF (x))
+        {
+          mpfr_setmax (x, __gmpfr_emax);
+        }
+      else
+        {
+          MPFR_ASSERTN (MPFR_IS_ZERO (x));
+          MPFR_CHANGE_SIGN(x);
+          mpfr_setmin (x, __gmpfr_emin);
+        }
     }
   else
     {
@@ -46,10 +49,11 @@ mpfr_nexttozero (mpfr_ptr x)
       MPFR_UNSIGNED_MINUS_MODULO (sh, MPFR_PREC(x));
       xp = MPFR_MANT(x);
       mpn_sub_1 (xp, xp, xn, MPFR_LIMB_ONE << sh);
-      if (MPFR_UNLIKELY( MPFR_LIMB_MSB(xp[xn-1]) == 0) )
-        { /* was an exact power of two: not normalized any more */
+      if (MPFR_UNLIKELY (MPFR_LIMB_MSB (xp[xn-1]) == 0))
+        { /* was an exact power of two: not normalized any more,
+             thus do not use MPFR_GET_EXP. */
           mpfr_exp_t exp = MPFR_EXP (x);
-          if (MPFR_UNLIKELY(exp == __gmpfr_emin))
+          if (MPFR_UNLIKELY (exp == __gmpfr_emin))
             MPFR_SET_ZERO(x);
           else
             {
@@ -66,10 +70,11 @@ mpfr_nexttozero (mpfr_ptr x)
 void
 mpfr_nexttoinf (mpfr_ptr x)
 {
-  if (MPFR_UNLIKELY(MPFR_IS_INF(x)))
-    return;
-  else if (MPFR_UNLIKELY(MPFR_IS_ZERO(x)))
-    mpfr_setmin (x, __gmpfr_emin);
+  if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (x)))
+    {
+      if (MPFR_IS_ZERO (x))
+        mpfr_setmin (x, __gmpfr_emin);
+    }
   else
     {
       mp_size_t xn;
@@ -79,12 +84,12 @@ mpfr_nexttoinf (mpfr_ptr x)
       xn = MPFR_LIMB_SIZE (x);
       MPFR_UNSIGNED_MINUS_MODULO (sh, MPFR_PREC(x));
       xp = MPFR_MANT(x);
-      if (MPFR_UNLIKELY( mpn_add_1 (xp, xp, xn, MPFR_LIMB_ONE << sh)) )
+      if (MPFR_UNLIKELY (mpn_add_1 (xp, xp, xn, MPFR_LIMB_ONE << sh)))
         /* got 1.0000... */
         {
           mpfr_exp_t exp = MPFR_EXP (x);
-          if (MPFR_UNLIKELY(exp == __gmpfr_emax))
-            MPFR_SET_INF(x);
+          if (MPFR_UNLIKELY (exp == __gmpfr_emax))
+            MPFR_SET_INF (x);
           else
             {
               MPFR_SET_EXP (x, exp + 1);