exp2.c: use MPFR_SMALL_INPUT_AFTER_SAVE_EXPO instead of

MPFR_FAST_COMPUTE_IF_SMALL_INPUT since 1 (__gmpfr_one) isn't
necessarily representable.
tests/texp2.c: added overflowed_exp2_0 test.


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@4565 280ebfd0-de03-0410-8827-d642c229c3f4

1 files changed, 80 insertions, 0 deletions

diff --git a/tests/texp2.c b/tests/texp2.c
index 47ba741a3..dadd0f651 100644
--- a/tests/texp2.c
+++ b/tests/texp2.c
@@ -137,6 +137,84 @@ exp_range (void)
   mpfr_clear (x);
 }
 
+static void
+overflowed_exp2_0 (void)
+{
+  mpfr_t x, y;
+  int emax, i, inex, rnd, err = 0;
+  mp_exp_t old_emax;
+
+  old_emax = mpfr_get_emax ();
+
+  mpfr_init2 (x, 8);
+  mpfr_init2 (y, 8);
+
+  for (emax = -1; emax <= 0; emax++)
+    {
+      mpfr_set_ui_2exp (y, 1, emax, GMP_RNDN);
+      mpfr_nextbelow (y);
+      set_emax (emax);  /* 1 is not representable. */
+      /* and if emax < 0, 1 - eps is not representable either. */
+      for (i = -1; i <= 1; i++)
+        RND_LOOP (rnd)
+        {
+          mpfr_set_si_2exp (x, i, -512 * ABS (i), GMP_RNDN);
+          mpfr_clear_flags ();
+          inex = mpfr_exp2 (x, x, rnd);
+          if ((i >= 0 || emax < 0 || rnd == GMP_RNDN || rnd == GMP_RNDU) &&
+              ! mpfr_overflow_p ())
+            {
+              printf ("Error in overflowed_exp2_0 (i = %d, rnd = %s):\n"
+                      "  The overflow flag is not set.\n",
+                      i, mpfr_print_rnd_mode (rnd));
+              err = 1;
+            }
+          if (rnd == GMP_RNDZ || rnd == GMP_RNDD)
+            {
+              if (inex >= 0)
+                {
+                  printf ("Error in overflowed_exp2_0 (i = %d, rnd = %s):\n"
+                          "  The inexact value must be negative.\n",
+                          i, mpfr_print_rnd_mode (rnd));
+                  err = 1;
+                }
+              if (! mpfr_equal_p (x, y))
+                {
+                  printf ("Error in overflowed_exp2_0 (i = %d, rnd = %s):\n"
+                          "  Got ", i, mpfr_print_rnd_mode (rnd));
+                  mpfr_print_binary (x);
+                  printf (" instead of 0.11111111E%d.\n", emax);
+                  err = 1;
+                }
+            }
+          else
+            {
+              if (inex <= 0)
+                {
+                  printf ("Error in overflowed_exp2_0 (i = %d, rnd = %s):\n"
+                          "  The inexact value must be positive.\n",
+                          i, mpfr_print_rnd_mode (rnd));
+                  err = 1;
+                }
+              if (! (mpfr_inf_p (x) && MPFR_SIGN (x) > 0))
+                {
+                  printf ("Error in overflowed_exp2_0 (i = %d, rnd = %s):\n"
+                          "  Got ", i, mpfr_print_rnd_mode (rnd));
+                  mpfr_print_binary (x);
+                  printf (" instead of +Inf.\n");
+                  err = 1;
+                }
+            }
+        }
+      set_emax (old_emax);
+    }
+
+  if (err)
+    exit (1);
+  mpfr_clear (x);
+  mpfr_clear (y);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -270,6 +348,8 @@ main (int argc, char *argv[])
   mpfr_clear (x);
   mpfr_clear (y);
 
+  overflowed_exp2_0 ();
+
   tests_end_mpfr ();
   return 0;
 }