fixed bug in exp(-eps) for rounding toward zero (test was also wrong...)

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@3844 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 15 insertions, 1 deletions

diff --git a/tests/texp.c b/tests/texp.c
index d398ca2ad..82c0217c3 100644
--- a/tests/texp.c
+++ b/tests/texp.c
@@ -339,12 +339,16 @@ check_special ()
   if (mpfr_cmp_ui_2exp (y, 3, -2))
     {
       printf ("Error for exp(-1/16), prec=2, RNDD\n");
+      printf ("expected 0.11, got ");
+      mpfr_dump (y);
       exit (1);
     }
   test_exp (y, x, GMP_RNDZ);
-  if (mpfr_cmp_ui (y, 1))
+  if (mpfr_cmp_ui_2exp (y, 3, -2))
     {
       printf ("Error for exp(-1/16), prec=2, RNDZ\n");
+      printf ("expected 0.11, got ");
+      mpfr_dump (y);
       exit (1);
     }
   mpfr_set_str_binary (x, "0.1E-3");
@@ -426,6 +430,16 @@ check_special ()
       mpfr_out_str (stdout, 16, 0, x, GMP_RNDN); putchar ('\n');
     }
 
+  /* bug found by Guillaume Melquiond, 13 Sep 2005 */
+  mpfr_set_prec (x, 53);
+  mpfr_set_str_binary (x, "-1E-400");
+  mpfr_exp (x, x, GMP_RNDZ);
+  if (mpfr_cmp_ui (x, 1) == 0)
+    {
+      printf ("Error for exp(-2^(-400))\n");
+      exit (1);
+    }
+
   mpfr_clear (x);
   mpfr_clear (y);
   mpfr_clear (z);