Add support for MPFR_FAST_COMPUTE_IS_SMALL_INPUT

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@3553 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 4 insertions, 1 deletions

diff --git a/log1p.c b/log1p.c
index ca98975ed..6180ef225 100644
--- a/log1p.c
+++ b/log1p.c
@@ -61,7 +61,10 @@ mpfr_log1p (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd_mode)
 	  MPFR_RET (0);
 	}
     }
-  
+
+  /* log(1+x) = x-x^2/2 + ... so the error is < 2^(2*EXP(x)-1) */
+  MPFR_FAST_COMPUTE_IF_SMALL_INPUT (y, x, -MPFR_GET_EXP (x)+1,0,rnd_mode,);
+
   comp = mpfr_cmp_si (x, -1);
   /* log1p(x) is undefined for x < -1 */
   if (MPFR_UNLIKELY(comp <= 0))