[tests/tnorm.c] added test exposing bug in underflow case

git-svn-id: svn://scm.gforge.inria.fr/svn/mpc/trunk@1080 211d60ee-9f03-0410-a15a-8952a2c7a4e4

1 files changed, 75 insertions, 1 deletions

diff --git a/tests/tnorm.c b/tests/tnorm.c
index 7cd53e6..23d76df 100644
--- a/tests/tnorm.c
+++ b/tests/tnorm.c
@@ -1,6 +1,6 @@
 /* tnorm -- test file for mpc_norm.
 
-Copyright (C) 2008 INRIA
+Copyright (C) 2008, 2011 INRIA
 
 This file is part of GNU MPC.
 
@@ -20,6 +20,79 @@ along with this program. If not, see http://www.gnu.org/licenses/ .
 
 #include "mpc-tests.h"
 
+static void
+test_underflow (void)
+{
+  mpfr_exp_t emin = mpfr_get_emin ();
+  mpc_t z;
+  mpfr_t f;
+  int inex;
+  
+  mpfr_set_emin (-1); /* smallest positive number is 0.5*2^emin = 0.25 */
+  mpc_init2 (z, 10);
+  mpfr_set_ui_2exp (mpc_realref (z), 1023, -11, MPFR_RNDN); /* exact */
+  mpfr_set_ui_2exp (mpc_imagref (z), 1023, -11, MPFR_RNDN); /* exact */
+  mpfr_init2 (f, 10);
+
+  inex = mpc_norm (f, z, MPFR_RNDZ); /* should give 511/1024 */
+  if (inex >= 0)
+    {
+      printf ("Error in underflow case (1)\n");
+      printf ("expected inex < 0, got %d\n", inex);
+      exit (1);
+    }
+  if (mpfr_cmp_ui_2exp (f, 511, -10) != 0)
+    {
+      printf ("Error in underflow case (1)\n");
+      printf ("got      ");
+      mpfr_dump (f);
+      printf ("expected ");
+      mpfr_set_ui_2exp (f, 511, -10, MPFR_RNDZ);
+      mpfr_dump (f);
+      exit (1);
+    }
+
+  inex = mpc_norm (f, z, MPFR_RNDN); /* should give 511/1024 */
+  if (inex >= 0)
+    {
+      printf ("Error in underflow case (2)\n");
+      printf ("expected inex < 0, got %d\n", inex);
+      exit (1);
+    }
+  if (mpfr_cmp_ui_2exp (f, 511, -10) != 0)
+    {
+      printf ("Error in underflow case (2)\n");
+      printf ("got      ");
+      mpfr_dump (f);
+      printf ("expected ");
+      mpfr_set_ui_2exp (f, 511, -10, MPFR_RNDZ);
+      mpfr_dump (f);
+      exit (1);
+    }
+
+  inex = mpc_norm (f, z, MPFR_RNDU); /* should give 1023/2048 */
+  if (inex <= 0)
+    {
+      printf ("Error in underflow case (3)\n");
+      printf ("expected inex > 0, got %d\n", inex);
+      exit (1);
+    }
+  if (mpfr_cmp_ui_2exp (f, 1023, -11) != 0)
+    {
+      printf ("Error in underflow case (3)\n");
+      printf ("got      ");
+      mpfr_dump (f);
+      printf ("expected ");
+      mpfr_set_ui_2exp (f, 1023, -11, MPFR_RNDZ);
+      mpfr_dump (f);
+      exit (1);
+    }
+
+  mpc_clear (z);
+  mpfr_clear (f);
+  mpfr_set_emin (emin);
+}
+
 int
 main (void)
 {
@@ -29,6 +102,7 @@ main (void)
 
   data_check (f, "norm.dat");
   tgeneric (f, 2, 1024, 1, 4096);
+  test_underflow ();
 
   test_end ();