Avoid potential integer overflows and improve consistency. This should

fix bug #13918 "Segfault with precision = MPFR_PREC_MAX on 32-bit".
Note: this problem appeared in MPFR 3.0.0 when the precision type (now
mpfr_prec_t) was changed to a signed integer.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@8025 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 2 insertions, 2 deletions

diff --git a/src/agm.c b/src/agm.c
index 141a44cec..ed5cb0b8e 100644
--- a/src/agm.c
+++ b/src/agm.c
@@ -91,7 +91,7 @@ mpfr_agm (mpfr_ptr r, mpfr_srcptr op2, mpfr_srcptr op1, mpfr_rnd_t rnd_mode)
   q = MPFR_PREC(r);
   p = q + MPFR_INT_CEIL_LOG2(q) + 15;
   MPFR_ASSERTD (p >= 7); /* see algorithms.tex */
-  s = (p - 1) / GMP_NUMB_BITS + 1;
+  s = MPFR_PREC2LIMBS (p);
 
   /* b (op2) and a (op1) are the 2 operands but we want b >= a */
   compare = mpfr_cmp (op1, op2);
@@ -285,7 +285,7 @@ mpfr_agm (mpfr_ptr r, mpfr_srcptr op2, mpfr_srcptr op1, mpfr_rnd_t rnd_mode)
 
       /* Next iteration */
       MPFR_ZIV_NEXT (loop, p);
-      s = (p - 1) / GMP_NUMB_BITS + 1;
+      s = MPFR_PREC2LIMBS (p);
     }
   MPFR_ZIV_FREE (loop);