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Diffstat (limited to 'tests/tsub_ui.c')
| -rw-r--r-- | tests/tsub_ui.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/tests/tsub_ui.c b/tests/tsub_ui.c new file mode 100644 index 0000000..1d27fd9 --- /dev/null +++ b/tests/tsub_ui.c @@ -0,0 +1,144 @@ +/* Test file for mpfr_sub_ui + +Copyright 2000, 2001, 2002, 2003, 2004, 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 <stdio.h> +#include <stdlib.h> +#include <float.h> + +#include "mpfr-test.h" + +/* checks that x-y gives the right results with 53 bits of precision */ +static void +check3 (const char *xs, unsigned long y, mpfr_rnd_t rnd_mode, const char *zs) +{ + mpfr_t xx,zz; + + mpfr_inits2 (53, xx, zz, (mpfr_ptr) 0); + mpfr_set_str1 (xx, xs); + mpfr_sub_ui (zz, xx, y, rnd_mode); + if (mpfr_cmp_str1(zz, zs)) + { + printf ("expected sum is %s, got ", zs); + mpfr_print_binary(zz); + printf ("\nmpfr_sub_ui failed for x=%s y=%lu with rnd_mode=%s\n", + xs, y, mpfr_print_rnd_mode (rnd_mode)); + exit (1); + } + mpfr_clears (xx, zz, (mpfr_ptr) 0); +} + +/* FastTwoSum: if EXP(x) >= EXP(y), u = o(x+y), v = o(u-x), w = o(y-v), + then x + y = u + w +thus if u = o(y-x), v = o(u+x), w = o(v-y), then y-x = u-w */ +static void +check_two_sum (mpfr_prec_t p) +{ + unsigned int x; + mpfr_t y, u, v, w; + mpfr_rnd_t rnd; + int inexact; + + mpfr_inits2 (p, y, u, v, w, (mpfr_ptr) 0); + do + { + x = randlimb (); + } + while (x < 1); + mpfr_urandomb (y, RANDS); + rnd = MPFR_RNDN; + inexact = mpfr_sub_ui (u, y, x, rnd); + mpfr_add_ui (v, u, x, rnd); + mpfr_sub (w, v, y, rnd); + /* as u - (y-x) = w, we should have inexact and w of same sign */ + if (((inexact == 0) && mpfr_cmp_ui (w, 0)) || + ((inexact > 0) && (mpfr_cmp_ui (w, 0) <= 0)) || + ((inexact < 0) && (mpfr_cmp_ui (w, 0) >= 0))) + { + printf ("Wrong inexact flag for prec=%u, rnd=%s\n", + (unsigned int) p, mpfr_print_rnd_mode (rnd)); + printf ("x=%u\n", x); + printf ("y="); mpfr_print_binary(y); puts (""); + printf ("u="); mpfr_print_binary(u); puts (""); + printf ("v="); mpfr_print_binary(v); puts (""); + printf ("w="); mpfr_print_binary(w); puts (""); + printf ("inexact = %d\n", inexact); + exit (1); + } + mpfr_clears (y, u, v, w, (mpfr_ptr) 0); +} + +static void +check_nans (void) +{ + mpfr_t x, y; + + mpfr_init2 (x, 123L); + mpfr_init2 (y, 123L); + + /* nan - 1 == nan */ + mpfr_set_nan (x); + mpfr_sub_ui (y, x, 1L, MPFR_RNDN); + MPFR_ASSERTN (mpfr_nan_p (y)); + + /* +inf - 1 == +inf */ + mpfr_set_inf (x, 1); + mpfr_sub_ui (y, x, 1L, MPFR_RNDN); + MPFR_ASSERTN (mpfr_inf_p (y)); + MPFR_ASSERTN (mpfr_sgn (y) > 0); + + /* -inf - 1 == -inf */ + mpfr_set_inf (x, -1); + mpfr_sub_ui (y, x, 1L, MPFR_RNDN); + MPFR_ASSERTN (mpfr_inf_p (y)); + MPFR_ASSERTN (mpfr_sgn (y) < 0); + + mpfr_clear (x); + mpfr_clear (y); +} + +#define TEST_FUNCTION mpfr_sub_ui +#define INTEGER_TYPE unsigned long +#define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS) +#include "tgeneric_ui.c" + +int +main (int argc, char *argv[]) +{ + mpfr_prec_t p; + int k; + + tests_start_mpfr (); + + check_nans (); + + for (p=2; p<200; p++) + for (k=0; k<200; k++) + check_two_sum (p); + + check3 ("0.9999999999", 1, MPFR_RNDN, + "-10000000827403709990903735160827636718750e-50"); + + test_generic_ui (2, 1000, 100); + + tests_end_mpfr (); + return 0; +} |