Overflow support.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1578 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 38 insertions, 38 deletions

diff --git a/mul_ui.c b/mul_ui.c
index c997c41d9..b18937667 100644
--- a/mul_ui.c
+++ b/mul_ui.c
@@ -19,7 +19,6 @@ along with the MPFR Library; see the file COPYING.LIB.  If not, write to
 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 MA 02111-1307, USA. */
 
-#include <stdio.h>
 #include "gmp.h"
 #include "gmp-impl.h"
 #include "longlong.h"
@@ -29,86 +28,87 @@ MA 02111-1307, USA. */
 int
 mpfr_mul_ui (mpfr_ptr y, mpfr_srcptr x, unsigned long int u, mp_rnd_t rnd_mode)
 {
-  mp_limb_t *my, *old_my;
-  unsigned long xn, yn, cnt, c;
-  int inexact;
+  mp_limb_t *yp, *old_yp;
+  mp_size_t xn, yn;
+  int cnt, c, inexact;
   TMP_DECL(marker);
 
   if (MPFR_IS_NAN(x))
     {
-      MPFR_CLEAR_FLAGS(y);
       MPFR_SET_NAN(y);
-      return 1; /* a NaN is always inexact */
+      MPFR_RET_NAN;
     }
 
   if (MPFR_IS_INF(x)) 
     {
-      MPFR_CLEAR_FLAGS(y);
-      if (u) 
-	{ 
-	  MPFR_SET_INF(y); 
-	  if (MPFR_SIGN(y) != MPFR_SIGN(x))
-	    MPFR_CHANGE_SIGN(y);
-	  return 0; /* infinity is exact */
+      if (u != 0)
+	{
+          MPFR_CLEAR_FLAGS(y);
+          MPFR_SET_INF(y);
+          MPFR_SET_SAME_SIGN(y, x);
+          MPFR_RET(0); /* infinity is exact */
 	}
       else /* 0 * infinity */
 	{
 	  MPFR_SET_NAN(y);
-	  return 1; /* NaN is inexact */
+          MPFR_RET_NAN;
 	}
     }
 
-  if (MPFR_IS_ZERO(x) || !u) 
+  MPFR_CLEAR_FLAGS(y);
+
+  if (u == 0 || MPFR_IS_ZERO(x))
     {
-      MPFR_CLEAR_FLAGS(y);
       MPFR_SET_ZERO(y);
-      return 0; /* zero is exact */
+      MPFR_SET_SAME_SIGN(y, x);
+      MPFR_RET(0); /* zero is exact */
     }
 
-  MPFR_CLEAR_FLAGS(y);
-
   if (u == 1)
     return mpfr_set (y, x, rnd_mode);
 
   TMP_MARK(marker);
-  my = MPFR_MANT(y);
+  yp = MPFR_MANT(y);
   yn = (MPFR_PREC(y) - 1) / BITS_PER_MP_LIMB + 1;
   xn = (MPFR_PREC(x) - 1) / BITS_PER_MP_LIMB + 1;
 
-  old_my = my;
+  old_yp = yp;
 
+  MPFR_ASSERTN(xn < MP_SIZE_T_MAX);
   if (yn < xn + 1)
-    my = (mp_ptr) TMP_ALLOC ((xn + 1) * BYTES_PER_MP_LIMB);
+    yp = (mp_ptr) TMP_ALLOC ((size_t) (xn + 1) * BYTES_PER_MP_LIMB);
 
-  my[xn] = mpn_mul_1 (my, MPFR_MANT(x), xn, u);
-  
-  /* x * u is stored in my[xn], ..., my[0] */
+  yp[xn] = mpn_mul_1 (yp, MPFR_MANT(x), xn, u);
+
+  /* x * u is stored in yp[xn], ..., yp[0] */
 
   /* since the case u=1 was treated above, we have u >= 2, thus
-     my[xn] >= 1 since x was msb-normalized */
-  MPFR_ASSERTN(my[xn] != 0);
-  count_leading_zeros(cnt, my[xn]);
-  mpn_lshift (my, my, xn + 1, cnt);
+     yp[xn] >= 1 since x was msb-normalized */
+  MPFR_ASSERTN(yp[xn] != 0);
+  count_leading_zeros(cnt, yp[xn]);
+  mpn_lshift (yp, yp, xn + 1, cnt);
 
-  /* now my[xn], ..., my[0] is msb-normalized too, and has at most
+  /* now yp[xn], ..., yp[0] is msb-normalized too, and has at most
      PREC(x) + (BITS_PER_MP_LIMB - cnt) non-zero bits */
 
-  c = mpfr_round_raw (old_my, my, (xn + 1) * BITS_PER_MP_LIMB,
+  c = mpfr_round_raw (old_yp, yp, (mp_prec_t) (xn + 1) * BITS_PER_MP_LIMB,
 		      (MPFR_SIGN(x) < 0), MPFR_PREC(y), rnd_mode, &inexact);
 
-  MPFR_EXP(y) = MPFR_EXP(x) + BITS_PER_MP_LIMB - cnt; 
+  cnt = BITS_PER_MP_LIMB - cnt;
 
   if (c) /* rounded result is 1.0000000000000000... */
     {
-      old_my[yn-1] = MP_LIMB_T_HIGHBIT;
-      MPFR_EXP(y) ++;
+      old_yp[yn-1] = MP_LIMB_T_HIGHBIT;
+      cnt++;
     }
 
-  /* set sign */
-  if (MPFR_SIGN(y) * MPFR_SIGN(x) < 0)
-    MPFR_CHANGE_SIGN(y);
-
   TMP_FREE(marker);
 
+  if (__mpfr_emax < MPFR_EMAX_MIN + cnt || MPFR_EXP(x) > __mpfr_emax - cnt)
+    return mpfr_set_overflow(y, rnd_mode, MPFR_SIGN(x));
+
+  MPFR_EXP(y) = MPFR_EXP(x) + cnt;
+  MPFR_SET_SAME_SIGN(y, x);
+
   return inexact;
 }