--- /dev/null
+/* Test file for mpfr_subnormalize.
+
+Copyright 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 <limits.h>
+
+#include "mpfr-test.h"
+
+static const struct {
+ const char *in;
+ int i;
+ mp_rnd_t rnd;
+ const char *out;
+} tab[] ={
+ {"1E1", 0, GMP_RNDN, "1E1"},
+ {"1E1", -1, GMP_RNDZ, "1E1"},
+ {"1E1", -1, GMP_RNDD, "1E1"},
+ {"1E1", 1, GMP_RNDU, "1E1"},
+ {"0.10000E-10", 0, GMP_RNDN, "0.1E-10"},
+ {"0.10001E-10", 0, GMP_RNDN, "0.1E-10"},
+ {"0.11001E-10", 0, GMP_RNDN, "0.1E-9"},
+ {"0.11001E-10", 0, GMP_RNDZ, "0.1E-10"},
+ {"0.11001E-10", 0, GMP_RNDU, "0.1E-9"},
+ {"0.11000E-10", 0, GMP_RNDN, "0.1E-9"},
+ {"0.11000E-10", -1, GMP_RNDN, "0.1E-9"},
+ {"0.11000E-10", 1, GMP_RNDN, "0.1E-10"},
+ {"0.11111E-8", 0, GMP_RNDN, "0.10E-7"},
+ {"0.10111E-8", 0, GMP_RNDN, "0.11E-8"},
+ {"0.11110E-8", -1, GMP_RNDN, "0.10E-7"},
+ {"0.10110E-8", 1, GMP_RNDN, "0.101E-8"}
+};
+
+static void
+check1 (void)
+{
+ mpfr_t x;
+ int i, j, k, s, old_inex;
+ mp_exp_t emin, emax;
+
+ emin = mpfr_get_emin ();
+ emax = mpfr_get_emax ();
+
+ mpfr_set_default_prec (9);
+ mpfr_set_emin (-10);
+ mpfr_set_emax (10);
+
+ mpfr_init (x);
+ for (i = 0; i < (sizeof (tab) / sizeof (tab[0])); i++)
+ for (s = 0; s <= (tab[i].rnd == GMP_RNDN); s++)
+ for (k = 0; k <= 1; k++)
+ {
+ mpfr_set_str (x, tab[i].in, 2, GMP_RNDN);
+ old_inex = tab[i].i;
+ if (s)
+ {
+ mpfr_neg (x, x, GMP_RNDN);
+ old_inex = - old_inex;
+ }
+ if (k && old_inex)
+ old_inex = old_inex < 0 ? INT_MIN : INT_MAX;
+ j = mpfr_subnormalize (x, old_inex, tab[i].rnd);
+ /* TODO: test j. */
+ if (s)
+ mpfr_neg (x, x, GMP_RNDN);
+ if (mpfr_cmp_str (x, tab[i].out, 2, GMP_RNDN) != 0)
+ {
+ const char *sgn = s ? "-" : "";
+ printf ("Error for i = %d (old_inex = %d), k = %d, x = %s%s\n"
+ "Expected: %s%s\nGot: ", i, old_inex, k,
+ sgn, tab[i].in, sgn, tab[i].out);
+ if (s)
+ mpfr_neg (x, x, GMP_RNDN);
+ mpfr_dump (x);
+ exit (1);
+ }
+ }
+ mpfr_clear (x);
+
+ MPFR_ASSERTN (mpfr_get_emin () == -10);
+ MPFR_ASSERTN (mpfr_get_emax () == 10);
+
+ set_emin (emin);
+ set_emax (emax);
+}
+
+/* bug found by Kevin P. Rauch on 22 Oct 2007 */
+static void
+check2 (void)
+{
+ mpfr_t x, y, z;
+ int tern;
+ mp_exp_t emin;
+
+ emin = mpfr_get_emin ();
+
+ mpfr_init2 (x, 32);
+ mpfr_init2 (y, 32);
+ mpfr_init2 (z, 32);
+
+ mpfr_set_ui (x, 0xC0000000U, GMP_RNDN);
+ mpfr_neg (x, x, GMP_RNDN);
+ mpfr_set_ui (y, 0xFFFFFFFEU, GMP_RNDN);
+ mpfr_set_exp (x, 0);
+ mpfr_set_exp (y, 0);
+ mpfr_set_emin (-29);
+
+ tern = mpfr_mul (z, x, y, GMP_RNDN);
+ /* z = -0.BFFFFFFE, tern > 0 */
+
+ tern = mpfr_subnormalize (z, tern, GMP_RNDN);
+ /* z should be -0.75 */
+ MPFR_ASSERTN (tern < 0 && mpfr_cmp_si_2exp (z, -3, -2) == 0);
+
+ mpfr_clear (x);
+ mpfr_clear (y);
+ mpfr_clear (z);
+
+ MPFR_ASSERTN (mpfr_get_emin () == -29);
+
+ set_emin (emin);
+}
+
+/* bug found by Kevin P. Rauch on 22 Oct 2007 */
+static void
+check3 (void)
+{
+ mpfr_t x, y, z;
+ int tern;
+ mp_exp_t emin;
+
+ emin = mpfr_get_emin ();
+
+ mpfr_init2 (x, 32);
+ mpfr_init2 (y, 32);
+ mpfr_init2 (z, 32);
+
+ mpfr_set_ui (x, 0xBFFFFFFFU, GMP_RNDN); /* 3221225471/2^32 */
+ mpfr_set_ui (y, 0x80000001U, GMP_RNDN); /* 2147483649/2^32 */
+ mpfr_set_exp (x, 0);
+ mpfr_set_exp (y, 0);
+ mpfr_set_emin (-1);
+
+ /* the exact product is 6917529028714823679/2^64, which is rounded to
+ 3/8 = 0.375, which is smaller, thus tern < 0 */
+ tern = mpfr_mul (z, x, y, GMP_RNDN);
+ MPFR_ASSERTN (tern < 0 && mpfr_cmp_ui_2exp (z, 3, -3) == 0);
+
+ tern = mpfr_subnormalize (z, tern, GMP_RNDN);
+ /* since emin = -1, and EXP(z)=-1, z should be rounded to precision
+ EXP(z)-emin+1 = 1, i.e., z should be a multiple of the smallest possible
+ positive representable value with emin=-1, which is 1/4. The two
+ possible values are 1/4 and 2/4, which are at equal distance of z.
+ But since tern < 0, we should choose the largest value, i.e., 2/4. */
+ MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 1, -1) == 0);
+
+ /* here is another test for the alternate case, where z was rounded up
+ first, thus we have to round down */
+ mpfr_set_str_binary (x, "0.11111111111010110101011011011011");
+ mpfr_set_str_binary (y, "0.01100000000001111100000000001110");
+ tern = mpfr_mul (z, x, y, GMP_RNDN);
+ MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 3, -3) == 0);
+ tern = mpfr_subnormalize (z, tern, GMP_RNDN);
+ MPFR_ASSERTN (tern < 0 && mpfr_cmp_ui_2exp (z, 1, -2) == 0);
+
+ /* finally the case where z was exact, which we simulate here */
+ mpfr_set_ui_2exp (z, 3, -3, GMP_RNDN);
+ tern = mpfr_subnormalize (z, 0, GMP_RNDN);
+ MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 1, -1) == 0);
+
+ mpfr_clear (x);
+ mpfr_clear (y);
+ mpfr_clear (z);
+
+ MPFR_ASSERTN (mpfr_get_emin () == -1);
+
+ set_emin (emin);
+}
+
+int
+main (int argc, char *argv[])
+{
+ tests_start_mpfr ();
+
+ check1 ();
+ check2 ();
+ check3 ();
+
+ tests_end_mpfr ();
+ return 0;
+}
projects / msp430-gcc.git / blobdiff