1 /* Test mpn_divrem_1 and mpn_preinv_divrem_1.
2
3 Copyright 2003 Free Software Foundation, Inc.
4
5 This file is part of the GNU MP Library test suite.
6
7 The GNU MP Library test suite is free software; you can redistribute it
8 and/or modify it under the terms of the GNU General Public License as
9 published by the Free Software Foundation; either version 3 of the License,
10 or (at your option) any later version.
11
12 The GNU MP Library test suite is distributed in the hope that it will be
13 useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 Public License for more details.
16
17 You should have received a copy of the GNU General Public License along with
18 the GNU MP Library test suite. If not, see https://www.gnu.org/licenses/. */
19
20 #include <stdio.h>
21 #include <stdlib.h>
22
23 #include "gmp-impl.h"
24 #include "tests.h"
25
26
27 void
check_data(void)28 check_data (void)
29 {
30 static const struct {
31 mp_limb_t n[1];
32 mp_size_t nsize;
33 mp_limb_t d;
34 mp_size_t qxn;
35 mp_limb_t want_q[5];
36 mp_limb_t want_r;
37 } data[] = {
38 { { 0 }, 1, 1, 0,
39 { 0 }, 0},
40
41 { { 5 }, 1, 2, 0,
42 { 2 }, 1},
43
44 /* Exercises the q update in the nl == constant 0 case of
45 udiv_qrnnd_preinv3. Test case copied from t-fat.c. */
46 { { 287 }, 1, 7, 1,
47 { 0, 41 }, 0 },
48
49 #if GMP_NUMB_BITS == 32
50 { { 0x3C }, 1, 0xF2, 1,
51 { 0x3F789854, 0 }, 0x98 },
52 #endif
53
54 #if GMP_NUMB_BITS == 64
55 { { 0x3C }, 1, 0xF2, 1,
56 { CNST_LIMB(0x3F789854A0CB1B81), 0 }, 0x0E },
57
58 /* This case exposed some wrong code generated by SGI cc on mips64 irix
59 6.5 with -n32 -O2, in the fractional loop for normalized divisor
60 using udiv_qrnnd_preinv. A test "x>al" in one of the sub_ddmmss
61 expansions came out wrong, leading to an incorrect quotient. */
62 { { CNST_LIMB(0x3C00000000000000) }, 1, CNST_LIMB(0xF200000000000000), 1,
63 { CNST_LIMB(0x3F789854A0CB1B81), 0 }, CNST_LIMB(0x0E00000000000000) },
64 #endif
65 };
66
67 mp_limb_t dinv, got_r, got_q[numberof(data[0].want_q)];
68 mp_size_t qsize;
69 int i, shift;
70
71 for (i = 0; i < numberof (data); i++)
72 {
73 qsize = data[i].nsize + data[i].qxn;
74 ASSERT_ALWAYS (qsize <= numberof (got_q));
75
76 got_r = mpn_divrem_1 (got_q, data[i].qxn, data[i].n, data[i].nsize,
77 data[i].d);
78 if (got_r != data[i].want_r
79 || refmpn_cmp (got_q, data[i].want_q, qsize) != 0)
80 {
81 printf ("mpn_divrem_1 wrong at data[%d]\n", i);
82 bad:
83 mpn_trace (" n", data[i].n, data[i].nsize);
84 printf (" nsize=%ld\n", (long) data[i].nsize);
85 mp_limb_trace (" d", data[i].d);
86 printf (" qxn=%ld\n", (long) data[i].qxn);
87 mpn_trace (" want q", data[i].want_q, qsize);
88 mpn_trace (" got q", got_q, qsize);
89 mp_limb_trace (" want r", data[i].want_r);
90 mp_limb_trace (" got r", got_r);
91 abort ();
92 }
93
94 /* test if available */
95 #if USE_PREINV_DIVREM_1 || HAVE_NATIVE_mpn_preinv_divrem_1
96 shift = refmpn_count_leading_zeros (data[i].d);
97 dinv = refmpn_invert_limb (data[i].d << shift);
98 got_r = mpn_preinv_divrem_1 (got_q, data[i].qxn,
99 data[i].n, data[i].nsize,
100 data[i].d, dinv, shift);
101 if (got_r != data[i].want_r
102 || refmpn_cmp (got_q, data[i].want_q, qsize) != 0)
103 {
104 printf ("mpn_preinv divrem_1 wrong at data[%d]\n", i);
105 printf (" shift=%d\n", shift);
106 mp_limb_trace (" dinv", dinv);
107 goto bad;
108 }
109 #endif
110 }
111 }
112
113 int
main(void)114 main (void)
115 {
116 tests_start ();
117 mp_trace_base = -16;
118
119 check_data ();
120
121 tests_end ();
122 exit (0);
123 }
124