1 files changed, 81 insertions, 1 deletions

diff --git a/tests/tacos.c b/tests/tacos.c
index 62b372ba9..aaa3a1f1a 100644
--- a/tests/tacos.c
+++ b/tests/tacos.c
@@ -1,6 +1,6 @@
 /* Test file for mpfr_acos.
 
-Copyright 2001, 2002, 2003 Free Software Foundation.
+Copyright 2001, 2002, 2003, 2004 Free Software Foundation.
 Contributed by Mathieu Dutour.
 
 This file is part of the MPFR Library.
@@ -28,13 +28,47 @@ MA 02111-1307, USA. */
 #define TEST_FUNCTION mpfr_acos
 #include "tgeneric.c"
 
+static void
+special (void)
+{
+  mpfr_t x, y;
+  
+  mpfr_init2 (x, 32);
+  mpfr_init2 (y, 32);
+
+  mpfr_set_str_binary (x, "0.10001000001001011000100001E-6");
+  mpfr_acos (y, x, GMP_RNDN);
+  mpfr_set_str_binary (x, "1.10001111111111110001110110001");
+  if (mpfr_cmp (x, y))
+    {
+      printf ("Error in mpfr_acos (1)\n");
+      exit (1);
+    }
+
+  mpfr_set_str_binary (x, "-0.01101011110111100111010011001011");
+  mpfr_acos (y, x, GMP_RNDZ);
+  mpfr_set_str_binary (x, "10.0000000101111000011101000101");
+  if (mpfr_cmp (x, y))
+    {
+      printf ("Error in mpfr_acos (2)\n");
+      mpfr_print_binary (y); printf ("\n");
+      exit (1);
+    }
+
+  mpfr_clear (y);
+  mpfr_clear (x);
+}
+
 int
 main (void)
 {
   mpfr_t x, y;
+  mp_rnd_t r;
 
   tests_start_mpfr ();
 
+  special ();
+
   mpfr_init (x);
   mpfr_init (y);
 
@@ -54,6 +88,52 @@ main (void)
       exit (1);
     }
 
+  mpfr_set_si (x, -2, GMP_RNDN);
+  mpfr_acos (y, x, GMP_RNDN);
+  if (mpfr_nan_p(y) == 0)
+    {
+      printf ("Error: acos(-2) != NaN\n");
+      exit (1);
+    }
+
+  /* acos (1) = 0 */
+  mpfr_set_ui (x, 1, GMP_RNDN);
+  mpfr_acos (y, x, GMP_RNDN);
+  if (mpfr_cmp_ui (y, 0) || mpfr_sgn (y) < 0)
+    {
+      printf ("Error: acos(1) != +0.0\n");
+      exit (1);
+    }
+
+  /* acos (0) = Pi/2 */
+  for (r = 0; r < 4; r++)
+    {
+      mpfr_set_ui (x, 0, GMP_RNDN); /* exact */
+      mpfr_acos (y, x, r);
+      mpfr_const_pi (x, r);
+      mpfr_div_2exp (x, x, 1, GMP_RNDN); /* exact */
+      if (mpfr_cmp (x, y))
+        {
+          printf ("Error: acos(0) != Pi/2 for rnd=%s\n",
+                  mpfr_print_rnd_mode (r));
+          exit (1);
+        }
+    }
+
+  /* acos (-1) = Pi */
+  for (r = 0; r < 4; r++)
+    {
+      mpfr_set_si (x, -1, GMP_RNDN); /* exact */
+      mpfr_acos (y, x, r);
+      mpfr_const_pi (x, r);
+      if (mpfr_cmp (x, y))
+        {
+          printf ("Error: acos(1) != Pi for rnd=%s\n",
+                  mpfr_print_rnd_mode (r));
+          exit (1);
+        }
+    }
+
   test_generic (2, 100, 7);
 
   mpfr_clear (x);