simply set to zero the non-significant bits, don't call mpfr_round_raw

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@341 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 10 insertions, 8 deletions

diff --git a/random.c b/random.c
index a4d32a8fb..8eaf563c3 100644
--- a/random.c
+++ b/random.c
@@ -24,12 +24,12 @@ mpfr_random(x)
      mpfr_ptr x; 
 #endif    
 {
-  mp_limb_t *xp; unsigned long xs, i, cnt; 
+  mp_limb_t *xp; unsigned long xn, i, cnt, prec=PREC(x); 
 
-  xp = MANT(x); 
-  xs = ABSSIZE(x); 
+  xp = MANT(x);
+  xn = (prec-1)/BITS_PER_MP_LIMB + 1;
 
-  for (i = 0; i < xs; i++)
+  for (i = 0; i < xn; i++)
     {
       /* random() c/sh/ould be replaced by a homemade random number generator.
 	 Indeed, if on Linux random is a good RNG, this is definitely not
@@ -37,11 +37,13 @@ mpfr_random(x)
       xp[i] = random();
     }
   
-  count_leading_zeros(cnt, xp[xs - 1]); 
-  if (cnt) mpn_lshift(xp, xp, xs, cnt); 
+  count_leading_zeros(cnt, xp[xn - 1]); 
+  if (cnt) mpn_lshift(xp, xp, xn, cnt); 
   EXP(x) = -cnt; 
-  mpfr_round_raw(xp, xp, PREC(x), (SIGN(x)<0), PREC(x), random()&3);
-  /* ignore any possible carry (this is sheer laziness). */
+
+  cnt = xn*BITS_PER_MP_LIMB - prec; 
+  /* cnt is the number of non significant bits in the low limb */
+  xp[0] &= ~((((mp_limb_t)1)<<cnt) - 1);
 }
 
 void