Add support for FAST_COMPUTE_IS_SMALL_INPUT.

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@3552 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 4 insertions, 1 deletions

diff --git a/sin.c b/sin.c
index b3c40322c..47e3b7842 100644
--- a/sin.c
+++ b/sin.c
@@ -128,11 +128,14 @@ mpfr_sin (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd_mode)
 	}
     }
 
+  /* sin(x) = x - x^3/6 + ... so the error is < 2^(3*EXP(x)-2) */
+  MPFR_FAST_COMPUTE_IF_SMALL_INPUT (y, x, -2*MPFR_GET_EXP (x)+2,0,rnd_mode, );
+
   /* Compute initial precision */
   precy = MPFR_PREC (y);
   m = precy + MPFR_INT_CEIL_LOG2 (precy) + 13;
   e = MPFR_GET_EXP (x);
-  m += (e < 0) ? -2*e : e;  
+  m += (e < 0) ? -2*e : e;
 
   sign = mpfr_sin_sign (x);
   mpfr_init2 (c, m);