[src/div.c] further improvement in mpfr_div_1()

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@11109 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 6 insertions, 6 deletions

diff --git a/src/div.c b/src/div.c
index f2351df97..25eccae0d 100644
--- a/src/div.c
+++ b/src/div.c
@@ -48,16 +48,16 @@ mpfr_div_1 (mpfr_ptr q, mpfr_srcptr u, mpfr_srcptr v, mpfr_rnd_t rnd_mode)
   if ((extra = (u0 >= v0)))
     u0 -= v0;
 
-#if GMP_NUMB_BITS == 64 /* __gmpfr_invert_limb only exists for 64-bit for now */
+#if GMP_NUMB_BITS == 64 /* __gmpfr_invert_limb_approx only exists for 64-bit */
   /* first try with an approximate quotient */
-  mp_limb_t inv = __gmpfr_invert_limb (v0);
+  mp_limb_t inv = __gmpfr_invert_limb_approx (v0);
   umul_ppmm (q0, sb, u0, inv);
   q0 = (q0 + u0) >> extra;
   /* before the >> extra shift, q0 + u0 does not exceed the true quotient
-     floor(u'0*2^GMP_NUMB_BITS/v0), with error at most 1, which means the rational
-     quotient q satisfies q0 + u0 <= q < q0 + u0 + 2. We can round correctly except
-     when the last sh-1 bits of q0 are now 000..000 or 111..111. */
-  if (MPFR_LIKELY(((q0 + 1) & (mask >> 1)) > 1))
+     floor(u'0*2^GMP_NUMB_BITS/v0), with error at most 2, which means the rational
+     quotient q satisfies q0 + u0 <= q < q0 + u0 + 3. We can round correctly except
+     when the last sh-1 bits of q0 are 000..000 or 111..111 or 111..110. */
+  if (MPFR_LIKELY(((q0 + 2) & (mask >> 1)) > 2))
     {
       rb = q0 & (MPFR_LIMB_ONE << (sh - 1));
       sb = 1; /* result cannot be exact when we can round with an approximation */