1/* Test mpf_div.
2
3Copyright 2004 Free Software Foundation, Inc.
4
5This file is part of the GNU MP Library.
6
7The GNU MP Library is free software; you can redistribute it and/or modify
8it under the terms of the GNU Lesser General Public License as published by
9the Free Software Foundation; either version 3 of the License, or (at your
10option) any later version.
11
12The GNU MP Library is distributed in the hope that it will be useful, but
13WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
15License for more details.
16
17You should have received a copy of the GNU Lesser General Public License
18along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */
19
20#include <stdio.h>
21#include <stdlib.h>
22#include "gmp.h"
23#include "gmp-impl.h"
24#include "tests.h"
25
26
27void
28check_one (const char *desc, mpf_ptr got, mpf_srcptr u, mpf_srcptr v)
29{
30  if (! refmpf_validate_division ("mpf_div", got, u, v))
31    {
32      mp_trace_base = -16;
33      mpf_trace ("  u", u);
34      mpf_trace ("  v", v);
35      printf    ("  %s\n", desc);
36      abort ();
37    }
38}
39
40void
41check_rand (void)
42{
43  unsigned long  min_prec = __GMPF_BITS_TO_PREC (1);
44  gmp_randstate_ptr  rands = RANDS;
45  unsigned long  prec;
46  mpf_t  got, u, v;
47  int    i;
48
49  mpf_init (got);
50  mpf_init (u);
51  mpf_init (v);
52
53  /* separate */
54  for (i = 0; i < 100; i++)
55    {
56      /* got precision */
57      prec = min_prec + gmp_urandomm_ui (rands, 15L);
58      refmpf_set_prec_limbs (got, prec);
59
60      /* u */
61      prec = min_prec + gmp_urandomm_ui (rands, 15L);
62      refmpf_set_prec_limbs (u, prec);
63      do {
64        mpf_random2 (u, PREC(u), (mp_exp_t) 20);
65      } while (SIZ(u) == 0);
66      if (gmp_urandomb_ui (rands, 1L))
67        mpf_neg (u, u);
68
69      /* v */
70      prec = min_prec + gmp_urandomm_ui (rands, 15L);
71      refmpf_set_prec_limbs (v, prec);
72      do {
73        mpf_random2 (v, PREC(v), (mp_exp_t) 20);
74      } while (SIZ(v) == 0);
75      if (gmp_urandomb_ui (rands, 1L))
76        mpf_neg (v, v);
77
78      switch (i % 3) {
79      case 0:
80        mpf_div (got, u, v);
81        check_one ("separate", got, u, v);
82        break;
83      case 1:
84        prec = refmpf_set_overlap (got, u);
85        mpf_div (got, got, v);
86        check_one ("dst == u", got, u, v);
87        mpf_set_prec_raw (got, prec);
88        break;
89      case 2:
90        prec = refmpf_set_overlap (got, v);
91        mpf_div (got, u, got);
92        check_one ("dst == v", got, u, v);
93        mpf_set_prec_raw (got, prec);
94        break;
95      }
96    }
97
98  mpf_clear (got);
99  mpf_clear (u);
100  mpf_clear (v);
101}
102
103/* Exercise calls mpf(x,x,x) */
104void
105check_reuse_three (void)
106{
107  unsigned long  min_prec = __GMPF_BITS_TO_PREC (1);
108  gmp_randstate_ptr  rands = RANDS;
109  unsigned long  result_prec, input_prec, set_prec;
110  mpf_t  got;
111  int    i;
112
113  mpf_init (got);
114
115  for (i = 0; i < 8; i++)
116    {
117      result_prec = min_prec + gmp_urandomm_ui (rands, 15L);
118      input_prec = min_prec + gmp_urandomm_ui (rands, 15L);
119
120      set_prec = MAX (result_prec, input_prec);
121      refmpf_set_prec_limbs (got, set_prec);
122
123      /* input, non-zero, possibly negative */
124      PREC(got) = input_prec;
125      do {
126        mpf_random2 (got, input_prec, (mp_exp_t) 20);
127      } while (SIZ(got) == 0);
128      if (gmp_urandomb_ui (rands, 1L))
129        mpf_neg (got, got);
130
131      PREC(got) = result_prec;
132
133      mpf_div (got, got, got);
134
135      /* expect exactly 1.0 always */
136      ASSERT_ALWAYS (mpf_cmp_ui (got, 1L) == 0);
137
138      PREC(got) = set_prec;
139    }
140
141  mpf_clear (got);
142}
143
144void
145check_various (void)
146{
147  mpf_t got, u, v;
148
149  mpf_init (got);
150  mpf_init (u);
151  mpf_init (v);
152
153  /* 100/4 == 25 */
154  mpf_set_prec (got, 20L);
155  mpf_set_ui (u, 100L);
156  mpf_set_ui (v, 4L);
157  mpf_div (got, u, v);
158  MPF_CHECK_FORMAT (got);
159  ASSERT_ALWAYS (mpf_cmp_ui (got, 25L) == 0);
160
161  /* 1/(2^n+1), a case where truncating the divisor would be wrong */
162  mpf_set_prec (got, 500L);
163  mpf_set_prec (v, 900L);
164  mpf_set_ui (v, 1L);
165  mpf_mul_2exp (v, v, 800L);
166  mpf_add_ui (v, v, 1L);
167  mpf_div (got, u, v);
168  check_one ("1/2^n+1, separate", got, u, v);
169
170  mpf_clear (got);
171  mpf_clear (u);
172  mpf_clear (v);
173}
174
175int
176main (void)
177{
178  tests_start ();
179
180  check_various ();
181  check_rand ();
182  check_reuse_three ();
183
184  tests_end ();
185  exit (0);
186}
187