coth.c, sech.c: a rounding mode was incorrect.

tests/tcoth.c: added underflowed_cothinf test.
tests/tsech.c: added overflowed_sech0 test.


git-svn-id: svn://scm.gforge.inria.fr/svn/mpfr/trunk@4570 280ebfd0-de03-0410-8827-d642c229c3f4

4 files changed, 148 insertions, 2 deletions

diff --git a/coth.c b/coth.c
index c54ef82eb..bbbcdd63b 100644
--- a/coth.c
+++ b/coth.c
@@ -31,7 +31,7 @@ MA 02110-1301, USA. */
 #define FUNCTION mpfr_coth
 #define INVERSE  mpfr_tanh
 #define ACTION_NAN(y) do { MPFR_SET_NAN(y); MPFR_RET_NAN; } while (1)
-#define ACTION_INF(y) return mpfr_set_si (y, MPFR_IS_POS(x) ? 1 : -1, GMP_RNDN)
+#define ACTION_INF(y) return mpfr_set_si (y, MPFR_IS_POS(x) ? 1 : -1, rnd_mode)
 #define ACTION_ZERO(y,x) do { MPFR_SET_SAME_SIGN(y,x); MPFR_SET_ZERO(y); \
                               MPFR_RET(0); } while (1)
 
diff --git a/sech.c b/sech.c
index 7e3ff4939..cdfa5fb82 100644
--- a/sech.c
+++ b/sech.c
@@ -30,7 +30,7 @@ MA 02110-1301, USA. */
 #define INVERSE  mpfr_cosh
 #define ACTION_NAN(y) do { MPFR_SET_NAN(y); MPFR_RET_NAN; } while (1)
 #define ACTION_INF(y) return mpfr_set_ui (y, 0, GMP_RNDN)
-#define ACTION_ZERO(y,x) return mpfr_set_ui (y, 1, GMP_RNDN)
+#define ACTION_ZERO(y,x) return mpfr_set_ui (y, 1, rnd_mode)
 /* for x near 0, sech(x) = 1 - x^2/2 + ..., more precisely |sech(x)-1| <= x^2/2
    for |x| <= 1. The tiny action is the same as for cos(x). */
 #define ACTION_TINY(y,x,r) \
diff --git a/tests/tcoth.c b/tests/tcoth.c
index 60d30cde0..064771eb6 100644
--- a/tests/tcoth.c
+++ b/tests/tcoth.c
@@ -131,6 +131,72 @@ check_bugs (void)
   mpfr_clear (y);
 }
 
+static void
+underflowed_cothinf (void)
+{
+  mpfr_t x, y;
+  int i, inex, rnd, err = 0;
+  mp_exp_t old_emin;
+
+  old_emin = mpfr_get_emin ();
+
+  mpfr_init2 (x, 8);
+  mpfr_init2 (y, 8);
+
+  for (i = -1; i <= 1; i += 2)
+    RND_LOOP (rnd)
+      {
+        mpfr_set_inf (x, i);
+        mpfr_clear_flags ();
+        set_emin (2);  /* 1 is not representable. */
+        inex = mpfr_coth (x, x, rnd);
+        set_emin (old_emin);
+        if (! mpfr_underflow_p ())
+          {
+            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
+                    "  The underflow flag is not set.\n",
+                    i, mpfr_print_rnd_mode (rnd));
+            err = 1;
+          }
+        mpfr_set_si (y, (i < 0 && rnd == GMP_RNDD) ||
+                        (i > 0 && rnd == GMP_RNDU) ? 2 : 0, GMP_RNDN);
+        if (i < 0)
+          mpfr_neg (y, y, GMP_RNDN);
+        if (! (mpfr_equal_p (x, y) &&
+               MPFR_MULT_SIGN (MPFR_SIGN (x), MPFR_SIGN (y)) > 0))
+          {
+            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
+                    "  Got ", i, mpfr_print_rnd_mode (rnd));
+            mpfr_print_binary (x);
+            printf (" instead of ");
+            mpfr_print_binary (y);
+            printf (".\n");
+            err = 1;
+          }
+        if ((rnd == GMP_RNDD ||
+             (i > 0 && (rnd == GMP_RNDN || rnd == GMP_RNDZ))) && inex >= 0)
+          {
+            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
+                    "  The inexact value must be negative.\n",
+                    i, mpfr_print_rnd_mode (rnd));
+            err = 1;
+          }
+        if ((rnd == GMP_RNDU ||
+             (i < 0 && (rnd == GMP_RNDN || rnd == GMP_RNDZ))) && inex <= 0)
+          {
+            printf ("Error in underflowed_cothinf (i = %d, rnd = %s):\n"
+                    "  The inexact value must be positive.\n",
+                    i, mpfr_print_rnd_mode (rnd));
+            err = 1;
+          }
+      }
+
+  if (err)
+    exit (1);
+  mpfr_clear (x);
+  mpfr_clear (y);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -139,6 +205,7 @@ main (int argc, char *argv[])
   check_specials ();
   check_bugs ();
   test_generic (2, 200, 10);
+  underflowed_cothinf ();
 
   tests_end_mpfr ();
   return 0;
diff --git a/tests/tsech.c b/tests/tsech.c
index 40b113698..e35a114b9 100644
--- a/tests/tsech.c
+++ b/tests/tsech.c
@@ -96,6 +96,84 @@ check_specials (void)
   mpfr_clear (y);
 }
 
+static void
+overflowed_sech0 (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_sech (x, x, rnd);
+            if ((i == 0 || emax < 0 || rnd == GMP_RNDN || rnd == GMP_RNDU) &&
+                ! mpfr_overflow_p ())
+              {
+                printf ("Error in overflowed_sech0 (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_sech0 (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_sech0 (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_sech0 (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_sech0 (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[])
 {
@@ -103,6 +181,7 @@ main (int argc, char *argv[])
 
   check_specials ();
   test_generic (2, 200, 10);
+  overflowed_sech0 ();
 
   tests_end_mpfr ();
   return 0;