improved coverage test

git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@2713 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 23 insertions, 0 deletions

diff --git a/tests/tmul.c b/tests/tmul.c
index 9cd2ce08c..e825effda 100644
--- a/tests/tmul.c
+++ b/tests/tmul.c
@@ -257,6 +257,7 @@ static void
 check_max(void)
 {
   mpfr_t xx, yy, zz;
+  mp_exp_t emin;
 
   mpfr_init2(xx, 4);
   mpfr_init2(yy, 4);
@@ -297,6 +298,28 @@ check_max(void)
       exit(1);
     }
 
+  /* check underflow */
+  emin = mpfr_get_emin ();
+  mpfr_set_emin (0);
+  mpfr_set_str_binary (xx, "0.1E0");
+  mpfr_set_str_binary (yy, "0.1E0");
+  mpfr_mul (zz, xx, yy, GMP_RNDN);
+  /* exact result is 0.1E-1, which should round to 0 */
+  MPFR_ASSERTN(mpfr_cmp_ui (zz, 0) == 0 && MPFR_IS_POS(zz));
+  mpfr_set_emin (emin);
+  
+  /* coverage test for mpfr_powerof2_raw */
+  emin = mpfr_get_emin ();
+  mpfr_set_emin (0);
+  mpfr_set_prec (xx, mp_bits_per_limb + 1);
+  mpfr_set_str_binary (xx, "0.1E0");
+  mpfr_nextabove (xx);
+  mpfr_set_str_binary (yy, "0.1E0");
+  mpfr_mul (zz, xx, yy, GMP_RNDN);
+  /* exact result is just above 0.1E-1, which should round to minfloat */
+  MPFR_ASSERTN(mpfr_cmp (zz, yy) == 0);
+  mpfr_set_emin (emin);
+  
   mpfr_clear(xx);
   mpfr_clear(yy);
   mpfr_clear(zz);