fixed bug in mpfr_sin (possible wrong inexact flag for rounding to nearest)

added items in NEWS and TODO


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@3705 280ebfd0-de03-0410-8827-d642c229c3f4

4 files changed, 11 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index 6f8c42ce3..0457b7b69 100644
--- a/NEWS
+++ b/NEWS
@@ -38,6 +38,7 @@ Changes from version 2.1.1 to version 2.2.0:
   features.
 - Thread safe (if built with --enable-thread-safe).
 - Logging facility.
+- Change in the semantics of mpfr_out_str/mpfr_get_str when n_digits=0.
 
 Changes from version 2.1.0 to version 2.1.1:
 - Better way to detect the GMP library.
diff --git a/TODO b/TODO
index 93ae0ca97..b0a076164 100644
--- a/TODO
+++ b/TODO
@@ -203,6 +203,9 @@ New functions to implement:
   - radians
   - sqrtpi
 
+- mpfr_frexp(mpfr_t rop, mp_exp_t *n, mpfr_t op, mp_rnd_t rnd) suggested by
+  Steve Kargl <sgk@troutmask.apl.washington.edu> Sun, 7 Aug 2005
+
 ##############################################################################
 Efficiency:
 ##############################################################################
diff --git a/sin.c b/sin.c
index a8fa1358d..96d341083 100644
--- a/sin.c
+++ b/sin.c
@@ -162,7 +162,10 @@ mpfr_sin (mpfr_ptr y, mpfr_srcptr x, mp_rnd_t rnd_mode)
 	{
 	  /* the absolute error on c is at most 2^(3-m-EXP(c)) */
 	  e = 2 * MPFR_GET_EXP (c) + m - 3;
-	  if (mpfr_can_round (c, e, GMP_RNDZ, rnd_mode, precy))
+	  if (mpfr_can_round (c, e, GMP_RNDZ, GMP_RNDZ,
+                              precy + (rnd_mode == GMP_RNDN)))
+            /* WARNING: need one more bit for rounding to nearest,
+               to be able to get the inexact flag correct */
 	    break;
 
 	  /* check for huge cancellation (Near 0) */
diff --git a/tests/tsin.c b/tests/tsin.c
index 5d8bfe65d..6919bc9f4 100644
--- a/tests/tsin.c
+++ b/tests/tsin.c
@@ -21,6 +21,7 @@ MA 02110-1301, USA. */
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h> /* for strlen */
 
 #include "mpfr-test.h"
 
@@ -185,7 +186,7 @@ check_regression ()
   mp_prec_t p;
   int i;
 
-  p = strlen (xs) -2 - 3;
+  p = strlen (xs) - 2 - 3;
   mpfr_inits2 (p, x, y, NULL);
 
   mpfr_set_str (x, xs, 2, GMP_RNDN);
@@ -208,6 +209,7 @@ main (int argc, char *argv[])
 
   tests_start_mpfr ();
 
+  check_regression ();
   check_nans ();
 
   /* worst case from PhD thesis of Vincent Lefe`vre: x=8980155785351021/2^54 */
@@ -280,7 +282,6 @@ main (int argc, char *argv[])
 
   test_generic (2, 100, 20);
   test_sign ();
-  check_regression ();
 
   tests_end_mpfr ();
   return 0;