doc: add some implementation details on parametric integer programming
[isl.git] / isl_seq.c
blob757e7294058143ce4b2c5e08e337fdbf1430432e
1 /*
2 * Copyright 2008-2009 Katholieke Universiteit Leuven
4 * Use of this software is governed by the GNU LGPLv2.1 license
6 * Written by Sven Verdoolaege, K.U.Leuven, Departement
7 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8 */
10 #include <isl_ctx_private.h>
11 #include <isl/seq.h>
13 void isl_seq_clr(isl_int *p, unsigned len)
15 int i;
16 for (i = 0; i < len; ++i)
17 isl_int_set_si(p[i], 0);
20 void isl_seq_set(isl_int *p, isl_int v, unsigned len)
22 int i;
23 for (i = 0; i < len; ++i)
24 isl_int_set(p[i], v);
27 void isl_seq_neg(isl_int *dst, isl_int *src, unsigned len)
29 int i;
30 for (i = 0; i < len; ++i)
31 isl_int_neg(dst[i], src[i]);
34 void isl_seq_cpy(isl_int *dst, isl_int *src, unsigned len)
36 int i;
37 for (i = 0; i < len; ++i)
38 isl_int_set(dst[i], src[i]);
41 void isl_seq_submul(isl_int *dst, isl_int f, isl_int *src, unsigned len)
43 int i;
44 for (i = 0; i < len; ++i)
45 isl_int_submul(dst[i], f, src[i]);
48 void isl_seq_swp_or_cpy(isl_int *dst, isl_int *src, unsigned len)
50 int i;
51 for (i = 0; i < len; ++i)
52 isl_int_swap_or_set(dst[i], src[i]);
55 void isl_seq_scale(isl_int *dst, isl_int *src, isl_int m, unsigned len)
57 int i;
58 for (i = 0; i < len; ++i)
59 isl_int_mul(dst[i], src[i], m);
62 void isl_seq_scale_down(isl_int *dst, isl_int *src, isl_int m, unsigned len)
64 int i;
65 for (i = 0; i < len; ++i)
66 isl_int_divexact(dst[i], src[i], m);
69 void isl_seq_cdiv_q(isl_int *dst, isl_int *src, isl_int m, unsigned len)
71 int i;
72 for (i = 0; i < len; ++i)
73 isl_int_cdiv_q(dst[i], src[i], m);
76 void isl_seq_fdiv_q(isl_int *dst, isl_int *src, isl_int m, unsigned len)
78 int i;
79 for (i = 0; i < len; ++i)
80 isl_int_fdiv_q(dst[i], src[i], m);
83 void isl_seq_fdiv_r(isl_int *dst, isl_int *src, isl_int m, unsigned len)
85 int i;
86 for (i = 0; i < len; ++i)
87 isl_int_fdiv_r(dst[i], src[i], m);
90 void isl_seq_combine(isl_int *dst, isl_int m1, isl_int *src1,
91 isl_int m2, isl_int *src2, unsigned len)
93 int i;
94 isl_int tmp;
96 isl_int_init(tmp);
97 for (i = 0; i < len; ++i) {
98 isl_int_mul(tmp, m1, src1[i]);
99 isl_int_addmul(tmp, m2, src2[i]);
100 isl_int_set(dst[i], tmp);
102 isl_int_clear(tmp);
106 * Let d = dst[pos] and s = src[pos]
107 * dst is replaced by |s| dst - sgn(s)d src
109 void isl_seq_elim(isl_int *dst, isl_int *src, unsigned pos, unsigned len,
110 isl_int *m)
112 isl_int a;
113 isl_int b;
115 if (isl_int_is_zero(dst[pos]))
116 return;
118 isl_int_init(a);
119 isl_int_init(b);
121 isl_int_gcd(a, src[pos], dst[pos]);
122 isl_int_divexact(b, dst[pos], a);
123 if (isl_int_is_pos(src[pos]))
124 isl_int_neg(b, b);
125 isl_int_divexact(a, src[pos], a);
126 isl_int_abs(a, a);
127 isl_seq_combine(dst, a, dst, b, src, len);
129 if (m)
130 isl_int_mul(*m, *m, a);
132 isl_int_clear(a);
133 isl_int_clear(b);
136 int isl_seq_eq(isl_int *p1, isl_int *p2, unsigned len)
138 int i;
139 for (i = 0; i < len; ++i)
140 if (isl_int_ne(p1[i], p2[i]))
141 return 0;
142 return 1;
145 int isl_seq_cmp(isl_int *p1, isl_int *p2, unsigned len)
147 int i;
148 int cmp;
149 for (i = 0; i < len; ++i)
150 if ((cmp = isl_int_cmp(p1[i], p2[i])) != 0)
151 return cmp;
152 return 0;
155 int isl_seq_is_neg(isl_int *p1, isl_int *p2, unsigned len)
157 int i;
159 for (i = 0; i < len; ++i) {
160 if (isl_int_abs_ne(p1[i], p2[i]))
161 return 0;
162 if (isl_int_is_zero(p1[i]))
163 continue;
164 if (isl_int_eq(p1[i], p2[i]))
165 return 0;
167 return 1;
170 int isl_seq_first_non_zero(isl_int *p, unsigned len)
172 int i;
174 for (i = 0; i < len; ++i)
175 if (!isl_int_is_zero(p[i]))
176 return i;
177 return -1;
180 int isl_seq_last_non_zero(isl_int *p, unsigned len)
182 int i;
184 for (i = len - 1; i >= 0; --i)
185 if (!isl_int_is_zero(p[i]))
186 return i;
187 return -1;
190 int isl_seq_abs_min_non_zero(isl_int *p, unsigned len)
192 int i, min = isl_seq_first_non_zero(p, len);
193 if (min < 0)
194 return -1;
195 for (i = min + 1; i < len; ++i) {
196 if (isl_int_is_zero(p[i]))
197 continue;
198 if (isl_int_abs_lt(p[i], p[min]))
199 min = i;
201 return min;
204 void isl_seq_gcd(isl_int *p, unsigned len, isl_int *gcd)
206 int i, min = isl_seq_abs_min_non_zero(p, len);
208 if (min < 0) {
209 isl_int_set_si(*gcd, 0);
210 return;
212 isl_int_abs(*gcd, p[min]);
213 for (i = 0; isl_int_cmp_si(*gcd, 1) > 0 && i < len; ++i) {
214 if (i == min)
215 continue;
216 if (isl_int_is_zero(p[i]))
217 continue;
218 isl_int_gcd(*gcd, *gcd, p[i]);
222 void isl_seq_normalize(struct isl_ctx *ctx, isl_int *p, unsigned len)
224 if (len == 0)
225 return;
226 isl_seq_gcd(p, len, &ctx->normalize_gcd);
227 if (!isl_int_is_zero(ctx->normalize_gcd) &&
228 !isl_int_is_one(ctx->normalize_gcd))
229 isl_seq_scale_down(p, p, ctx->normalize_gcd, len);
232 void isl_seq_lcm(isl_int *p, unsigned len, isl_int *lcm)
234 int i;
236 if (len == 0) {
237 isl_int_set_si(*lcm, 1);
238 return;
240 isl_int_set(*lcm, p[0]);
241 for (i = 1; i < len; ++i)
242 isl_int_lcm(*lcm, *lcm, p[i]);
245 void isl_seq_inner_product(isl_int *p1, isl_int *p2, unsigned len,
246 isl_int *prod)
248 int i;
249 if (len == 0) {
250 isl_int_set_si(*prod, 0);
251 return;
253 isl_int_mul(*prod, p1[0], p2[0]);
254 for (i = 1; i < len; ++i)
255 isl_int_addmul(*prod, p1[i], p2[i]);
258 uint32_t isl_seq_hash(isl_int *p, unsigned len, uint32_t hash)
260 int i;
261 for (i = 0; i < len; ++i) {
262 if (isl_int_is_zero(p[i]))
263 continue;
264 hash *= 16777619;
265 hash ^= (i & 0xFF);
266 hash = isl_int_hash(p[i], hash);
268 return hash;
271 uint32_t isl_seq_get_hash(isl_int *p, unsigned len)
273 uint32_t hash = isl_hash_init();
275 return isl_seq_hash(p, len, hash);
278 uint32_t isl_seq_get_hash_bits(isl_int *p, unsigned len, unsigned bits)
280 uint32_t hash;
282 hash = isl_seq_get_hash(p, len);
283 return isl_hash_bits(hash, bits);