implement inexact flag

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1255 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 7 insertions, 4 deletions

diff --git a/div_2exp.c b/div_2exp.c
index e518f6518..0a400a002 100644
--- a/div_2exp.c
+++ b/div_2exp.c
@@ -25,7 +25,7 @@ MA 02111-1307, USA. */
 #include "mpfr.h"
 #include "mpfr-impl.h"
 
-void
+int
 #if __STDC__
 mpfr_div_2exp (mpfr_ptr y, mpfr_srcptr x, unsigned long int n, mp_rnd_t rnd_mode)
 #else
@@ -36,9 +36,12 @@ mpfr_div_2exp (y, x, n, rnd_mode)
      mp_rnd_t rnd_mode;
 #endif
 {
+  int inexact = 0;
+
   /* Important particular case */ 
-  if (y != x) mpfr_set(y, x, rnd_mode);
-  MPFR_EXP(y) -= n; 
-  return; 
+  if (y != x)
+    inexact = mpfr_set (y, x, rnd_mode);
+  return ((MPFR_EXP(y) -= n) < __mpfr_emin)
+    ? mpfr_set_underflow (y, rnd_mode, MPFR_SIGN(y)) : inexact;
 }