/* Test file for mpfr_subnormalize. Copyright 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc. Contributed by the AriC and Caramel 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 3 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.LESSER. If not, see http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include "mpfr-test.h" static const struct { const char *in; int i; mpfr_rnd_t rnd; const char *out; int j; } tab[] = { /* 4th field: use the mpfr_dump format, in case of error. */ {"1E1", 0, MPFR_RNDN, "0.100000000E2", 0}, {"1E1", -1, MPFR_RNDZ, "0.100000000E2", -1}, {"1E1", -1, MPFR_RNDD, "0.100000000E2", -1}, {"1E1", 1, MPFR_RNDU, "0.100000000E2", 1}, {"0.10000E-10", 0, MPFR_RNDN, "0.100000000E-10", 0}, {"0.10001E-10", 0, MPFR_RNDN, "0.100000000E-10", -1}, {"0.11001E-10", 0, MPFR_RNDN, "0.100000000E-9", 1}, {"0.11001E-10", 0, MPFR_RNDZ, "0.100000000E-10", -1}, {"0.11001E-10", 0, MPFR_RNDU, "0.100000000E-9", 1}, {"0.11000E-10", 0, MPFR_RNDN, "0.100000000E-9", 1}, {"0.11000E-10", -1, MPFR_RNDN, "0.100000000E-9", 1}, {"0.11000E-10", 1, MPFR_RNDN, "0.100000000E-10", -1}, {"0.11111E-8", 0, MPFR_RNDN, "0.100000000E-7", 1}, {"0.10111E-8", 0, MPFR_RNDN, "0.110000000E-8", 1}, {"0.11110E-8", -1, MPFR_RNDN, "0.100000000E-7", 1}, {"0.10110E-8", 1, MPFR_RNDN, "0.101000000E-8", -1} }; static void check1 (void) { mpfr_t x; int i, j, k, s, old_inex, tiny, expj; mpfr_exp_t emin, emax; unsigned int expflags, flags; 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 == MPFR_RNDN); s++) for (k = 0; k <= 1; k++) { mpfr_set_str (x, tab[i].in, 2, MPFR_RNDN); old_inex = tab[i].i; expj = tab[i].j; if (s) { mpfr_neg (x, x, MPFR_RNDN); old_inex = - old_inex; expj = - expj; } if (k && old_inex) old_inex = old_inex < 0 ? INT_MIN : INT_MAX; tiny = MPFR_GET_EXP (x) <= -3; mpfr_clear_flags (); j = mpfr_subnormalize (x, old_inex, tab[i].rnd); expflags = (tiny ? MPFR_FLAGS_UNDERFLOW : 0) | (expj ? MPFR_FLAGS_INEXACT : 0); flags = __gmpfr_flags; if (s) mpfr_neg (x, x, MPFR_RNDN); if (mpfr_cmp_str (x, tab[i].out, 2, MPFR_RNDN) != 0 || flags != expflags || ! SAME_SIGN (j, expj)) { 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, MPFR_RNDN); mpfr_dump (x); printf ("Expected flags = %u, got %u\n", expflags, flags); printf ("Expected ternary value = %d, got %d\n", expj, j); 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; mpfr_exp_t emin; emin = mpfr_get_emin (); mpfr_init2 (x, 32); mpfr_init2 (y, 32); mpfr_init2 (z, 32); mpfr_set_ui (x, 0xC0000000U, MPFR_RNDN); mpfr_neg (x, x, MPFR_RNDN); mpfr_set_ui (y, 0xFFFFFFFEU, MPFR_RNDN); mpfr_set_exp (x, 0); mpfr_set_exp (y, 0); mpfr_set_emin (-29); tern = mpfr_mul (z, x, y, MPFR_RNDN); /* z = -0.BFFFFFFE, tern > 0 */ tern = mpfr_subnormalize (z, tern, MPFR_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; mpfr_exp_t emin; emin = mpfr_get_emin (); mpfr_init2 (x, 32); mpfr_init2 (y, 32); mpfr_init2 (z, 32); mpfr_set_ui (x, 0xBFFFFFFFU, MPFR_RNDN); /* 3221225471/2^32 */ mpfr_set_ui (y, 0x80000001U, MPFR_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, MPFR_RNDN); MPFR_ASSERTN (tern < 0 && mpfr_cmp_ui_2exp (z, 3, -3) == 0); tern = mpfr_subnormalize (z, tern, MPFR_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, MPFR_RNDN); MPFR_ASSERTN (tern > 0 && mpfr_cmp_ui_2exp (z, 3, -3) == 0); tern = mpfr_subnormalize (z, tern, MPFR_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, MPFR_RNDN); tern = mpfr_subnormalize (z, 0, MPFR_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; }