added check for sin(3*Pi/2)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@1640 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 13 insertions, 0 deletions

diff --git a/tests/tsin.c b/tests/tsin.c
index e2c7eb897..b302b025c 100644
--- a/tests/tsin.c
+++ b/tests/tsin.c
@@ -70,6 +70,7 @@ main (int argc, char *argv[])
   check53 (1.00591265847407274059,  8.446508805292128885e-1, GMP_RNDN);
 
   mpfr_init2 (x, 2);
+
   mpfr_set_d (x, 0.5, GMP_RNDN);
   mpfr_sin (x, x, GMP_RNDD);
   if (mpfr_get_d(x) != 0.375)
@@ -77,6 +78,18 @@ main (int argc, char *argv[])
       fprintf (stderr, "mpfr_sin(0.5, GMP_RNDD) failed with precision=2\n");
       exit (1);
     }
+
+  /* bug found by Kevin Ryde */
+  mpfr_const_pi (x, GMP_RNDN);
+  mpfr_mul_ui (x, x, 3L, GMP_RNDN);
+  mpfr_div_ui (x, x, 2L, GMP_RNDN);
+  mpfr_sin (x, x, GMP_RNDN);
+  if (mpfr_cmp_ui (x, 0) >= 0)
+    {
+      fprintf (stderr, "Error: wrong sign for sin(3*Pi/2)\n");
+      exit (1);
+    }
+
   mpfr_clear (x);
 
   test_generic (2, 100, 80);