/* Test file for mpfr_div_ui. Copyright 1999-2015 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 void check (const char *ds, unsigned long u, mpfr_rnd_t rnd, const char *es) { mpfr_t x, y; mpfr_init2 (x, 53); mpfr_init2 (y, 53); mpfr_set_str1 (x, ds); mpfr_div_ui (y, x, u, rnd); if (mpfr_cmp_str1 (y, es)) { printf ("mpfr_div_ui failed for x=%s, u=%lu, rnd=%s\n", ds, u, mpfr_print_rnd_mode (rnd)); printf ("expected result is %s, got", es); mpfr_out_str(stdout, 10, 0, y, MPFR_RNDN); exit (1); } mpfr_clear (x); mpfr_clear (y); } static void special (void) { mpfr_t x, y; unsigned xprec, yprec; mpfr_init (x); mpfr_init (y); mpfr_set_prec (x, 32); mpfr_set_prec (y, 32); mpfr_set_ui (x, 1, MPFR_RNDN); mpfr_div_ui (y, x, 3, MPFR_RNDN); mpfr_set_prec (x, 100); mpfr_set_prec (y, 100); mpfr_urandomb (x, RANDS); mpfr_div_ui (y, x, 123456, MPFR_RNDN); mpfr_set_ui (x, 0, MPFR_RNDN); mpfr_div_ui (y, x, 123456789, MPFR_RNDN); if (mpfr_cmp_ui (y, 0)) { printf ("mpfr_div_ui gives non-zero for 0/ui\n"); exit (1); } /* bug found by Norbert Mueller, 21 Aug 2001 */ mpfr_set_prec (x, 110); mpfr_set_prec (y, 60); mpfr_set_str_binary (x, "0.110101110011111110011111001110011001110111000000111110001000111011000011E-44"); mpfr_div_ui (y, x, 17, MPFR_RNDN); mpfr_set_str_binary (x, "0.11001010100101100011101110000001100001010110101001010011011E-48"); if (mpfr_cmp (x, y)) { printf ("Error in x/17 for x=1/16!\n"); printf ("Expected "); mpfr_out_str (stdout, 2, 0, x, MPFR_RNDN); printf ("\nGot "); mpfr_out_str (stdout, 2, 0, y, MPFR_RNDN); printf ("\n"); exit (1); } /* corner case */ mpfr_set_prec (x, 2 * mp_bits_per_limb); mpfr_set_prec (y, 2); mpfr_set_ui (x, 4, MPFR_RNDN); mpfr_nextabove (x); mpfr_div_ui (y, x, 2, MPFR_RNDN); /* exactly in the middle */ MPFR_ASSERTN(mpfr_cmp_ui (y, 2) == 0); mpfr_set_prec (x, 3 * mp_bits_per_limb); mpfr_set_prec (y, 2); mpfr_set_ui (x, 2, MPFR_RNDN); mpfr_nextabove (x); mpfr_div_ui (y, x, 2, MPFR_RNDN); MPFR_ASSERTN(mpfr_cmp_ui (y, 1) == 0); mpfr_set_prec (x, 3 * mp_bits_per_limb); mpfr_set_prec (y, 2); mpfr_set_si (x, -4, MPFR_RNDN); mpfr_nextbelow (x); mpfr_div_ui (y, x, 2, MPFR_RNDD); MPFR_ASSERTN(mpfr_cmp_si (y, -3) == 0); for (xprec = 53; xprec <= 128; xprec++) { mpfr_set_prec (x, xprec); mpfr_set_str_binary (x, "0.1100100100001111110011111000000011011100001100110111E2"); for (yprec = 53; yprec <= 128; yprec++) { mpfr_set_prec (y, yprec); mpfr_div_ui (y, x, 1, MPFR_RNDN); if (mpfr_cmp(x,y)) { printf ("division by 1.0 fails for xprec=%u, yprec=%u\n", xprec, yprec); printf ("expected "); mpfr_print_binary (x); puts (""); printf ("got "); mpfr_print_binary (y); puts (""); exit (1); } } } /* Bug reported by Mark Dickinson, 6 Nov 2007 */ mpfr_set_si (x, 0, MPFR_RNDN); mpfr_set_si (y, -1, MPFR_RNDN); mpfr_div_ui (y, x, 4, MPFR_RNDN); MPFR_ASSERTN(MPFR_IS_ZERO(y) && MPFR_IS_POS(y)); mpfr_clear (x); mpfr_clear (y); } static void check_inexact (void) { mpfr_t x, y, z; mpfr_prec_t px, py; int inexact, cmp; unsigned long int u; int rnd; mpfr_init (x); mpfr_init (y); mpfr_init (z); for (px=2; px<300; px++) { mpfr_set_prec (x, px); mpfr_urandomb (x, RANDS); do { u = randlimb (); } while (u == 0); for (py=2; py<300; py++) { mpfr_set_prec (y, py); mpfr_set_prec (z, py + mp_bits_per_limb); for (rnd = 0; rnd < MPFR_RND_MAX; rnd++) { inexact = mpfr_div_ui (y, x, u, (mpfr_rnd_t) rnd); if (mpfr_mul_ui (z, y, u, (mpfr_rnd_t) rnd)) { printf ("z <- y * u should be exact for u=%lu\n", u); printf ("y="); mpfr_print_binary (y); puts (""); printf ("z="); mpfr_print_binary (z); puts (""); exit (1); } cmp = mpfr_cmp (z, x); if (((inexact == 0) && (cmp != 0)) || ((inexact > 0) && (cmp <= 0)) || ((inexact < 0) && (cmp >= 0))) { printf ("Wrong inexact flag for u=%lu, rnd=%s\n", u, mpfr_print_rnd_mode ((mpfr_rnd_t) rnd)); printf ("x="); mpfr_print_binary (x); puts (""); printf ("y="); mpfr_print_binary (y); puts (""); exit (1); } } } } mpfr_clear (x); mpfr_clear (y); mpfr_clear (z); } #define TEST_FUNCTION mpfr_div_ui #define ULONG_ARG2 #define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS) #include "tgeneric.c" int main (int argc, char **argv) { mpfr_t x; tests_start_mpfr (); special (); check_inexact (); check("1.0", 3, MPFR_RNDN, "3.3333333333333331483e-1"); check("1.0", 3, MPFR_RNDZ, "3.3333333333333331483e-1"); check("1.0", 3, MPFR_RNDU, "3.3333333333333337034e-1"); check("1.0", 3, MPFR_RNDD, "3.3333333333333331483e-1"); check("1.0", 2116118, MPFR_RNDN, "4.7256343927890600483e-7"); check("1.098612288668109782", 5, MPFR_RNDN, "0.21972245773362195087"); mpfr_init2 (x, 53); mpfr_set_ui (x, 3, MPFR_RNDD); mpfr_log (x, x, MPFR_RNDD); mpfr_div_ui (x, x, 5, MPFR_RNDD); if (mpfr_cmp_str1 (x, "0.21972245773362189536")) { printf ("Error in mpfr_div_ui for x=ln(3), u=5\n"); exit (1); } mpfr_clear (x); test_generic (2, 200, 100); tests_end_mpfr (); return 0; }