+/* Test file for mpfr_nextabove, mpfr_nextbelow, mpfr_nexttoward.
+
+Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+Contributed by the Arenaire and Cacao projects, INRIA.
+
+This file is part of the GNU MPFR Library.
+
+The GNU MPFR Library is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or (at your
+option) any later version.
+
+The GNU MPFR Library is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with the GNU MPFR Library; see the file COPYING.LIB. If not, write to
+the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+MA 02110-1301, USA. */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "mpfr-test.h"
+
+/* Generic tests for mpfr_nextabove and mpfr_nextbelow */
+static void
+generic_abovebelow (void)
+{
+ int i;
+
+ for (i = 0; i < 20000; i++)
+ {
+ mpfr_t x, y, z, t;
+ mp_prec_t prec;
+ int neg, below;
+
+ prec = (randlimb () % 300) + MPFR_PREC_MIN;
+ mpfr_inits2 (prec, x, y, z, (mpfr_ptr) 0);
+ mpfr_init2 (t, 3);
+
+ /* special tests (executed once is enough) */
+ if (i == 0)
+ {
+ mpfr_set_nan (x);
+ mpfr_nextabove (x);
+ MPFR_ASSERTN(mpfr_nan_p (x));
+ mpfr_nextbelow (x);
+ MPFR_ASSERTN(mpfr_nan_p (x));
+ mpfr_nexttoward (x, y);
+ MPFR_ASSERTN(mpfr_nan_p (x));
+ mpfr_set_ui (y, 1, GMP_RNDN);
+ mpfr_nexttoward (y, x);
+ MPFR_ASSERTN(mpfr_nan_p (y));
+ mpfr_set_ui (x, 1, GMP_RNDN);
+ mpfr_set_ui (y, 1, GMP_RNDN);
+ mpfr_nexttoward (x, y);
+ MPFR_ASSERTN(mpfr_cmp_ui (x, 1) == 0);
+ }
+
+ do
+ mpfr_urandomb (x, RANDS);
+ while (mpfr_cmp_ui (x, 0) == 0);
+ neg = randlimb () & 1;
+ if (neg)
+ mpfr_neg (x, x, GMP_RNDN);
+ mpfr_set (y, x, GMP_RNDN);
+ below = randlimb () & 1;
+ if (below)
+ mpfr_nextbelow (y);
+ else
+ mpfr_nextabove (y);
+ mpfr_set_si (t, below ? -5 : 5, GMP_RNDN);
+ mpfr_mul_2si (t, t, (mpfr_get_exp) (x) - prec - 3, GMP_RNDN);
+ /* t = (1/2 + 1/8) ulp(x) */
+ mpfr_add (z, x, t, GMP_RNDN);
+ if (!mpfr_number_p (y) || mpfr_cmp (y, z) != 0)
+ {
+ printf ("Error in mpfr_next%s for\n",
+ below ? "below" : "above");
+ mpfr_out_str (stdout, 2, 0, x, GMP_RNDN);
+ printf (", got\n");
+ mpfr_out_str (stdout, 2, 0, y, GMP_RNDN);
+ printf (" instead of\n");
+ mpfr_out_str (stdout, 2, 0, z, GMP_RNDN);
+ printf ("\n");
+ exit (1);
+ }
+ mpfr_clears (x, y, z, t, (mpfr_ptr) 0);
+ }
+}
+
+static void
+inverse_test (void)
+{
+ static const char *tests[] = { "0", "1", "2", "3.1", "Inf" };
+ int i, neg, below;
+ mp_prec_t prec;
+
+ for (i = 0; i < (int) (sizeof(tests) / sizeof(tests[0])); i++)
+ for (neg = 0; neg <= 1; neg++)
+ for (below = 0; below <= 1; below++)
+ for (prec = MPFR_PREC_MIN; prec < 200; prec += 3)
+ {
+ mpfr_t x, y;
+ int sign;
+
+ mpfr_inits2 (prec, x, y, (mpfr_ptr) 0);
+ mpfr_set_str (x, tests[i], 10, GMP_RNDN);
+ if (neg)
+ mpfr_neg (x, x, GMP_RNDN);
+ mpfr_set (y, x, GMP_RNDN);
+ if (below)
+ mpfr_nextbelow (y);
+ else
+ mpfr_nextabove (y);
+ sign = MPFR_SIGN (y);
+ if (!(neg == below && mpfr_inf_p (x))) /* then x = y */
+ {
+ if (mpfr_cmp (x, y) == 0)
+ {
+ printf ("Error in inverse_test for %s, neg = %d,"
+ " below = %d, prec = %d: x = y", tests[i],
+ neg, below, (int) prec);
+ printf ("\nx = ");
+ mpfr_out_str (stdout, 2, 0, x, GMP_RNDN);
+ printf ("\ny = ");
+ mpfr_out_str (stdout, 2, 0, y, GMP_RNDN);
+ printf ("\n");
+ exit (1);
+ }
+ mpfr_nexttoward (y, x);
+ if (mpfr_cmp_ui (y, 0) == 0 && MPFR_SIGN (y) != sign)
+ {
+ printf ("Sign error in inverse_test for %s, neg = %d,"
+ " below = %d, prec = %d\n", tests[i], neg,
+ below, (int) prec);
+ mpfr_out_str (stdout, 2, 0, y, GMP_RNDN);
+ printf ("\n");
+ exit (1);
+ }
+ }
+ if (mpfr_cmp (x, y) != 0)
+ {
+ printf ("Error in inverse_test for %s, neg = %d, below = %d,"
+ " prec = %d", tests[i], neg, below, (int) prec);
+ printf ("\nx = ");
+ mpfr_out_str (stdout, 2, 0, x, GMP_RNDN);
+ printf ("\ny = ");
+ mpfr_out_str (stdout, 2, 0, y, GMP_RNDN);
+ printf ("\n");
+ exit (1);
+ }
+ mpfr_clears (x, y, (mpfr_ptr) 0);
+ }
+}
+
+int
+main (void)
+{
+ tests_start_mpfr ();
+ generic_abovebelow ();
+ inverse_test ();
+ tests_end_mpfr ();
+ return 0;
+}