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14#include "mpi-internal.h"
15#include "longlong.h"
16
17void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den);
18void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor);
19
20void mpi_fdiv_r(MPI rem, MPI dividend, MPI divisor)
21{
22 int divisor_sign = divisor->sign;
23 MPI temp_divisor = NULL;
24
25
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27
28
29 if (rem == divisor) {
30 temp_divisor = mpi_copy(divisor);
31 divisor = temp_divisor;
32 }
33
34 mpi_tdiv_r(rem, dividend, divisor);
35
36 if (((divisor_sign?1:0) ^ (dividend->sign?1:0)) && rem->nlimbs)
37 mpi_add(rem, rem, divisor);
38
39 if (temp_divisor)
40 mpi_free(temp_divisor);
41}
42
43void mpi_fdiv_q(MPI quot, MPI dividend, MPI divisor)
44{
45 MPI tmp = mpi_alloc(mpi_get_nlimbs(quot));
46 mpi_fdiv_qr(quot, tmp, dividend, divisor);
47 mpi_free(tmp);
48}
49
50void mpi_fdiv_qr(MPI quot, MPI rem, MPI dividend, MPI divisor)
51{
52 int divisor_sign = divisor->sign;
53 MPI temp_divisor = NULL;
54
55 if (quot == divisor || rem == divisor) {
56 temp_divisor = mpi_copy(divisor);
57 divisor = temp_divisor;
58 }
59
60 mpi_tdiv_qr(quot, rem, dividend, divisor);
61
62 if ((divisor_sign ^ dividend->sign) && rem->nlimbs) {
63 mpi_sub_ui(quot, quot, 1);
64 mpi_add(rem, rem, divisor);
65 }
66
67 if (temp_divisor)
68 mpi_free(temp_divisor);
69}
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77
78void mpi_tdiv_r(MPI rem, MPI num, MPI den)
79{
80 mpi_tdiv_qr(NULL, rem, num, den);
81}
82
83void mpi_tdiv_qr(MPI quot, MPI rem, MPI num, MPI den)
84{
85 mpi_ptr_t np, dp;
86 mpi_ptr_t qp, rp;
87 mpi_size_t nsize = num->nlimbs;
88 mpi_size_t dsize = den->nlimbs;
89 mpi_size_t qsize, rsize;
90 mpi_size_t sign_remainder = num->sign;
91 mpi_size_t sign_quotient = num->sign ^ den->sign;
92 unsigned int normalization_steps;
93 mpi_limb_t q_limb;
94 mpi_ptr_t marker[5];
95 int markidx = 0;
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97
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100
101 rsize = nsize + 1;
102 mpi_resize(rem, rsize);
103
104 qsize = rsize - dsize;
105 if (qsize <= 0) {
106 if (num != rem) {
107 rem->nlimbs = num->nlimbs;
108 rem->sign = num->sign;
109 MPN_COPY(rem->d, num->d, nsize);
110 }
111 if (quot) {
112
113
114
115 quot->nlimbs = 0;
116 quot->sign = 0;
117 }
118 return;
119 }
120
121 if (quot)
122 mpi_resize(quot, qsize);
123
124
125 np = num->d;
126 dp = den->d;
127 rp = rem->d;
128
129
130 if (dsize == 1) {
131 mpi_limb_t rlimb;
132 if (quot) {
133 qp = quot->d;
134 rlimb = mpihelp_divmod_1(qp, np, nsize, dp[0]);
135 qsize -= qp[qsize - 1] == 0;
136 quot->nlimbs = qsize;
137 quot->sign = sign_quotient;
138 } else
139 rlimb = mpihelp_mod_1(np, nsize, dp[0]);
140 rp[0] = rlimb;
141 rsize = rlimb != 0?1:0;
142 rem->nlimbs = rsize;
143 rem->sign = sign_remainder;
144 return;
145 }
146
147
148 if (quot) {
149 qp = quot->d;
150
151
152
153 if (qp == np) {
154 np = marker[markidx++] = mpi_alloc_limb_space(nsize);
155 MPN_COPY(np, qp, nsize);
156 }
157 } else
158 qp = rp + dsize;
159
160 normalization_steps = count_leading_zeros(dp[dsize - 1]);
161
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165
166 if (normalization_steps) {
167 mpi_ptr_t tp;
168 mpi_limb_t nlimb;
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174 tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
175 mpihelp_lshift(tp, dp, dsize, normalization_steps);
176 dp = tp;
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181
182 nlimb = mpihelp_lshift(rp, np, nsize, normalization_steps);
183 if (nlimb) {
184 rp[nsize] = nlimb;
185 rsize = nsize + 1;
186 } else
187 rsize = nsize;
188 } else {
189
190
191
192 if (dp == rp || (quot && (dp == qp))) {
193 mpi_ptr_t tp;
194
195 tp = marker[markidx++] = mpi_alloc_limb_space(dsize);
196 MPN_COPY(tp, dp, dsize);
197 dp = tp;
198 }
199
200
201 if (rp != np)
202 MPN_COPY(rp, np, nsize);
203
204 rsize = nsize;
205 }
206
207 q_limb = mpihelp_divrem(qp, 0, rp, rsize, dp, dsize);
208
209 if (quot) {
210 qsize = rsize - dsize;
211 if (q_limb) {
212 qp[qsize] = q_limb;
213 qsize += 1;
214 }
215
216 quot->nlimbs = qsize;
217 quot->sign = sign_quotient;
218 }
219
220 rsize = dsize;
221 MPN_NORMALIZE(rp, rsize);
222
223 if (normalization_steps && rsize) {
224 mpihelp_rshift(rp, rp, rsize, normalization_steps);
225 rsize -= rp[rsize - 1] == 0?1:0;
226 }
227
228 rem->nlimbs = rsize;
229 rem->sign = sign_remainder;
230 while (markidx) {
231 markidx--;
232 mpi_free_limb_space(marker[markidx]);
233 }
234}
235