isl_multi_union_pw_aff_zero: check that input is not a parameter space
[isl.git] / isl_local.c
blob7725af9d0064811da1428cea07336d9e4db51078
1 /*
2 * Copyright 2014 Ecole Normale Superieure
4 * Use of this software is governed by the MIT license
6 * Written by Sven Verdoolaege,
7 * Ecole Normale Superieure, 45 rue d'Ulm, 75230 Paris, France
8 */
10 #include <isl_mat_private.h>
11 #include <isl_seq.h>
13 /* Given a matrix "div" representing local variables,
14 * does the variable at position "pos" have an explicit representation?
16 isl_bool isl_local_div_is_known(__isl_keep isl_mat *div, int pos)
18 if (!div)
19 return isl_bool_error;
20 if (pos < 0 || pos >= div->n_row)
21 isl_die(isl_mat_get_ctx(div), isl_error_invalid,
22 "position out of bounds", return isl_bool_error);
23 return !isl_int_is_zero(div->row[pos][0]);
26 /* Compare two matrices representing local variables, defined over
27 * the same space.
29 * Return -1 if "div1" is "smaller" than "div2", 1 if "div1" is "greater"
30 * than "div2" and 0 if they are equal.
32 * The order is fairly arbitrary. We do "prefer" divs that only involve
33 * earlier dimensions in the sense that we consider matrices where
34 * the first differing div involves earlier dimensions to be smaller.
36 int isl_local_cmp(__isl_keep isl_mat *div1, __isl_keep isl_mat *div2)
38 int i;
39 int cmp;
40 int known1, known2;
41 int last1, last2;
42 int n_col;
44 if (div1 == div2)
45 return 0;
46 if (!div1)
47 return -1;
48 if (!div2)
49 return 1;
51 if (div1->n_row != div2->n_row)
52 return div1->n_row - div2->n_row;
54 n_col = isl_mat_cols(div1);
55 for (i = 0; i < div1->n_row; ++i) {
56 known1 = isl_local_div_is_known(div1, i);
57 known2 = isl_local_div_is_known(div2, i);
58 if (!known1 && !known2)
59 continue;
60 if (!known1)
61 return 1;
62 if (!known2)
63 return -1;
64 last1 = isl_seq_last_non_zero(div1->row[i] + 1, n_col - 1);
65 last2 = isl_seq_last_non_zero(div2->row[i] + 1, n_col - 1);
66 if (last1 != last2)
67 return last1 - last2;
68 cmp = isl_seq_cmp(div1->row[i], div2->row[i], n_col);
69 if (cmp != 0)
70 return cmp;
73 return 0;