add some simple test cases in tadd_d.c and friends

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@4837 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 32 insertions, 0 deletions

diff --git a/tests/td_sub.c b/tests/td_sub.c
index 732684ea9..a51a8c632 100644
--- a/tests/td_sub.c
+++ b/tests/td_sub.c
@@ -63,9 +63,41 @@ check_nans (void)
 int
 main (int argc, char *argv[])
 {
+  mpfr_t x, y, z;
+  double d;
+  int inexact;
+
   MPFR_TEST_USE_RANDS ();
   tests_start_mpfr ();
 
+  /* check with enough precision */
+  mpfr_init2 (x, IEEE_DBL_MANT_DIG);
+  mpfr_init2 (y, IEEE_DBL_MANT_DIG);
+  mpfr_init2 (z, IEEE_DBL_MANT_DIG);
+  
+  mpfr_set_str (y, "4096", 10, GMP_RNDN);
+  d = 0.125;
+  mpfr_clear_flags ();
+  inexact = mpfr_d_sub (x, d, y, GMP_RNDN);
+  if (inexact != 0)
+    {
+      printf ("Inexact flag error in mpfr_d_sub\n");
+      exit (1);
+    }
+  mpfr_set_str (z, "-4095.875", 10, GMP_RNDN);
+  if (mpfr_cmp (z, x))
+    {
+      printf ("Error in mpfr_d_sub (");
+      mpfr_out_str (stdout, 10, 7, y, GMP_RNDN);
+      printf (" + %.20g)\nexpected ", d);
+      mpfr_out_str (stdout, 10, 0, z, GMP_RNDN);
+      printf ("\ngot     ");
+      mpfr_out_str (stdout, 10, 0, x, GMP_RNDN);
+      printf ("\n");
+      exit (1);
+    }
+  mpfr_clears (x, y, z, (void *)0);
+
   check_nans ();
 
   test_generic (2, 1000, 100);