1/*
2 * Copyright 2008-2009 Katholieke Universiteit Leuven
3 *
4 * Use of this software is governed by the MIT license
5 *
6 * Written by Sven Verdoolaege, K.U.Leuven, Departement
7 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium
8 */
9
10#include <isl_ctx_private.h>
11#include <isl_map_private.h>
12#include <isl/space.h>
13#include <isl/seq.h>
14#include <isl_mat_private.h>
15#include <isl_space_private.h>
16#include <isl_val_private.h>
17
18isl_ctx *isl_mat_get_ctx(__isl_keep isl_mat *mat)
19{
20	return mat ? mat->ctx : NULL;
21}
22
23struct isl_mat *isl_mat_alloc(struct isl_ctx *ctx,
24	unsigned n_row, unsigned n_col)
25{
26	int i;
27	struct isl_mat *mat;
28
29	mat = isl_alloc_type(ctx, struct isl_mat);
30	if (!mat)
31		return NULL;
32
33	mat->row = NULL;
34	mat->block = isl_blk_alloc(ctx, n_row * n_col);
35	if (isl_blk_is_error(mat->block))
36		goto error;
37	mat->row = isl_alloc_array(ctx, isl_int *, n_row);
38	if (n_row && !mat->row)
39		goto error;
40
41	for (i = 0; i < n_row; ++i)
42		mat->row[i] = mat->block.data + i * n_col;
43
44	mat->ctx = ctx;
45	isl_ctx_ref(ctx);
46	mat->ref = 1;
47	mat->n_row = n_row;
48	mat->n_col = n_col;
49	mat->max_col = n_col;
50	mat->flags = 0;
51
52	return mat;
53error:
54	isl_blk_free(ctx, mat->block);
55	free(mat);
56	return NULL;
57}
58
59struct isl_mat *isl_mat_extend(struct isl_mat *mat,
60	unsigned n_row, unsigned n_col)
61{
62	int i;
63	isl_int *old;
64	isl_int **row;
65
66	if (!mat)
67		return NULL;
68
69	if (mat->max_col >= n_col && mat->n_row >= n_row) {
70		if (mat->n_col < n_col)
71			mat->n_col = n_col;
72		return mat;
73	}
74
75	if (mat->max_col < n_col) {
76		struct isl_mat *new_mat;
77
78		if (n_row < mat->n_row)
79			n_row = mat->n_row;
80		new_mat = isl_mat_alloc(mat->ctx, n_row, n_col);
81		if (!new_mat)
82			goto error;
83		for (i = 0; i < mat->n_row; ++i)
84			isl_seq_cpy(new_mat->row[i], mat->row[i], mat->n_col);
85		isl_mat_free(mat);
86		return new_mat;
87	}
88
89	mat = isl_mat_cow(mat);
90	if (!mat)
91		goto error;
92
93	old = mat->block.data;
94	mat->block = isl_blk_extend(mat->ctx, mat->block, n_row * mat->max_col);
95	if (isl_blk_is_error(mat->block))
96		goto error;
97	row = isl_realloc_array(mat->ctx, mat->row, isl_int *, n_row);
98	if (n_row && !row)
99		goto error;
100	mat->row = row;
101
102	for (i = 0; i < mat->n_row; ++i)
103		mat->row[i] = mat->block.data + (mat->row[i] - old);
104	for (i = mat->n_row; i < n_row; ++i)
105		mat->row[i] = mat->block.data + i * mat->max_col;
106	mat->n_row = n_row;
107	if (mat->n_col < n_col)
108		mat->n_col = n_col;
109
110	return mat;
111error:
112	isl_mat_free(mat);
113	return NULL;
114}
115
116__isl_give isl_mat *isl_mat_sub_alloc6(isl_ctx *ctx, isl_int **row,
117	unsigned first_row, unsigned n_row, unsigned first_col, unsigned n_col)
118{
119	int i;
120	struct isl_mat *mat;
121
122	mat = isl_alloc_type(ctx, struct isl_mat);
123	if (!mat)
124		return NULL;
125	mat->row = isl_alloc_array(ctx, isl_int *, n_row);
126	if (n_row && !mat->row)
127		goto error;
128	for (i = 0; i < n_row; ++i)
129		mat->row[i] = row[first_row+i] + first_col;
130	mat->ctx = ctx;
131	isl_ctx_ref(ctx);
132	mat->ref = 1;
133	mat->n_row = n_row;
134	mat->n_col = n_col;
135	mat->block = isl_blk_empty();
136	mat->flags = ISL_MAT_BORROWED;
137	return mat;
138error:
139	free(mat);
140	return NULL;
141}
142
143__isl_give isl_mat *isl_mat_sub_alloc(__isl_keep isl_mat *mat,
144	unsigned first_row, unsigned n_row, unsigned first_col, unsigned n_col)
145{
146	if (!mat)
147		return NULL;
148	return isl_mat_sub_alloc6(mat->ctx, mat->row, first_row, n_row,
149				  first_col, n_col);
150}
151
152void isl_mat_sub_copy(struct isl_ctx *ctx, isl_int **dst, isl_int **src,
153	unsigned n_row, unsigned dst_col, unsigned src_col, unsigned n_col)
154{
155	int i;
156
157	for (i = 0; i < n_row; ++i)
158		isl_seq_cpy(dst[i]+dst_col, src[i]+src_col, n_col);
159}
160
161void isl_mat_sub_neg(struct isl_ctx *ctx, isl_int **dst, isl_int **src,
162	unsigned n_row, unsigned dst_col, unsigned src_col, unsigned n_col)
163{
164	int i;
165
166	for (i = 0; i < n_row; ++i)
167		isl_seq_neg(dst[i]+dst_col, src[i]+src_col, n_col);
168}
169
170struct isl_mat *isl_mat_copy(struct isl_mat *mat)
171{
172	if (!mat)
173		return NULL;
174
175	mat->ref++;
176	return mat;
177}
178
179struct isl_mat *isl_mat_dup(struct isl_mat *mat)
180{
181	int i;
182	struct isl_mat *mat2;
183
184	if (!mat)
185		return NULL;
186	mat2 = isl_mat_alloc(mat->ctx, mat->n_row, mat->n_col);
187	if (!mat2)
188		return NULL;
189	for (i = 0; i < mat->n_row; ++i)
190		isl_seq_cpy(mat2->row[i], mat->row[i], mat->n_col);
191	return mat2;
192}
193
194struct isl_mat *isl_mat_cow(struct isl_mat *mat)
195{
196	struct isl_mat *mat2;
197	if (!mat)
198		return NULL;
199
200	if (mat->ref == 1 && !ISL_F_ISSET(mat, ISL_MAT_BORROWED))
201		return mat;
202
203	mat2 = isl_mat_dup(mat);
204	isl_mat_free(mat);
205	return mat2;
206}
207
208void *isl_mat_free(struct isl_mat *mat)
209{
210	if (!mat)
211		return NULL;
212
213	if (--mat->ref > 0)
214		return NULL;
215
216	if (!ISL_F_ISSET(mat, ISL_MAT_BORROWED))
217		isl_blk_free(mat->ctx, mat->block);
218	isl_ctx_deref(mat->ctx);
219	free(mat->row);
220	free(mat);
221
222	return NULL;
223}
224
225int isl_mat_rows(__isl_keep isl_mat *mat)
226{
227	return mat ? mat->n_row : -1;
228}
229
230int isl_mat_cols(__isl_keep isl_mat *mat)
231{
232	return mat ? mat->n_col : -1;
233}
234
235int isl_mat_get_element(__isl_keep isl_mat *mat, int row, int col, isl_int *v)
236{
237	if (!mat)
238		return -1;
239	if (row < 0 || row >= mat->n_row)
240		isl_die(mat->ctx, isl_error_invalid, "row out of range",
241			return -1);
242	if (col < 0 || col >= mat->n_col)
243		isl_die(mat->ctx, isl_error_invalid, "column out of range",
244			return -1);
245	isl_int_set(*v, mat->row[row][col]);
246	return 0;
247}
248
249/* Extract the element at row "row", oolumn "col" of "mat".
250 */
251__isl_give isl_val *isl_mat_get_element_val(__isl_keep isl_mat *mat,
252	int row, int col)
253{
254	isl_ctx *ctx;
255
256	if (!mat)
257		return NULL;
258	ctx = isl_mat_get_ctx(mat);
259	if (row < 0 || row >= mat->n_row)
260		isl_die(ctx, isl_error_invalid, "row out of range",
261			return NULL);
262	if (col < 0 || col >= mat->n_col)
263		isl_die(ctx, isl_error_invalid, "column out of range",
264			return NULL);
265	return isl_val_int_from_isl_int(ctx, mat->row[row][col]);
266}
267
268__isl_give isl_mat *isl_mat_set_element(__isl_take isl_mat *mat,
269	int row, int col, isl_int v)
270{
271	mat = isl_mat_cow(mat);
272	if (!mat)
273		return NULL;
274	if (row < 0 || row >= mat->n_row)
275		isl_die(mat->ctx, isl_error_invalid, "row out of range",
276			goto error);
277	if (col < 0 || col >= mat->n_col)
278		isl_die(mat->ctx, isl_error_invalid, "column out of range",
279			goto error);
280	isl_int_set(mat->row[row][col], v);
281	return mat;
282error:
283	isl_mat_free(mat);
284	return NULL;
285}
286
287__isl_give isl_mat *isl_mat_set_element_si(__isl_take isl_mat *mat,
288	int row, int col, int v)
289{
290	mat = isl_mat_cow(mat);
291	if (!mat)
292		return NULL;
293	if (row < 0 || row >= mat->n_row)
294		isl_die(mat->ctx, isl_error_invalid, "row out of range",
295			goto error);
296	if (col < 0 || col >= mat->n_col)
297		isl_die(mat->ctx, isl_error_invalid, "column out of range",
298			goto error);
299	isl_int_set_si(mat->row[row][col], v);
300	return mat;
301error:
302	isl_mat_free(mat);
303	return NULL;
304}
305
306/* Replace the element at row "row", column "col" of "mat" by "v".
307 */
308__isl_give isl_mat *isl_mat_set_element_val(__isl_take isl_mat *mat,
309	int row, int col, __isl_take isl_val *v)
310{
311	if (!v)
312		return isl_mat_free(mat);
313	if (!isl_val_is_int(v))
314		isl_die(isl_val_get_ctx(v), isl_error_invalid,
315			"expecting integer value", goto error);
316	mat = isl_mat_set_element(mat, row, col, v->n);
317	isl_val_free(v);
318	return mat;
319error:
320	isl_val_free(v);
321	return isl_mat_free(mat);
322}
323
324__isl_give isl_mat *isl_mat_diag(isl_ctx *ctx, unsigned n_row, isl_int d)
325{
326	int i;
327	struct isl_mat *mat;
328
329	mat = isl_mat_alloc(ctx, n_row, n_row);
330	if (!mat)
331		return NULL;
332	for (i = 0; i < n_row; ++i) {
333		isl_seq_clr(mat->row[i], i);
334		isl_int_set(mat->row[i][i], d);
335		isl_seq_clr(mat->row[i]+i+1, n_row-(i+1));
336	}
337
338	return mat;
339}
340
341__isl_give isl_mat *isl_mat_identity(isl_ctx *ctx, unsigned n_row)
342{
343	if (!ctx)
344		return NULL;
345	return isl_mat_diag(ctx, n_row, ctx->one);
346}
347
348struct isl_vec *isl_mat_vec_product(struct isl_mat *mat, struct isl_vec *vec)
349{
350	int i;
351	struct isl_vec *prod;
352
353	if (!mat || !vec)
354		goto error;
355
356	isl_assert(mat->ctx, mat->n_col == vec->size, goto error);
357
358	prod = isl_vec_alloc(mat->ctx, mat->n_row);
359	if (!prod)
360		goto error;
361
362	for (i = 0; i < prod->size; ++i)
363		isl_seq_inner_product(mat->row[i], vec->el, vec->size,
364					&prod->block.data[i]);
365	isl_mat_free(mat);
366	isl_vec_free(vec);
367	return prod;
368error:
369	isl_mat_free(mat);
370	isl_vec_free(vec);
371	return NULL;
372}
373
374__isl_give isl_vec *isl_mat_vec_inverse_product(__isl_take isl_mat *mat,
375	__isl_take isl_vec *vec)
376{
377	struct isl_mat *vec_mat;
378	int i;
379
380	if (!mat || !vec)
381		goto error;
382	vec_mat = isl_mat_alloc(vec->ctx, vec->size, 1);
383	if (!vec_mat)
384		goto error;
385	for (i = 0; i < vec->size; ++i)
386		isl_int_set(vec_mat->row[i][0], vec->el[i]);
387	vec_mat = isl_mat_inverse_product(mat, vec_mat);
388	isl_vec_free(vec);
389	if (!vec_mat)
390		return NULL;
391	vec = isl_vec_alloc(vec_mat->ctx, vec_mat->n_row);
392	if (vec)
393		for (i = 0; i < vec->size; ++i)
394			isl_int_set(vec->el[i], vec_mat->row[i][0]);
395	isl_mat_free(vec_mat);
396	return vec;
397error:
398	isl_mat_free(mat);
399	isl_vec_free(vec);
400	return NULL;
401}
402
403struct isl_vec *isl_vec_mat_product(struct isl_vec *vec, struct isl_mat *mat)
404{
405	int i, j;
406	struct isl_vec *prod;
407
408	if (!mat || !vec)
409		goto error;
410
411	isl_assert(mat->ctx, mat->n_row == vec->size, goto error);
412
413	prod = isl_vec_alloc(mat->ctx, mat->n_col);
414	if (!prod)
415		goto error;
416
417	for (i = 0; i < prod->size; ++i) {
418		isl_int_set_si(prod->el[i], 0);
419		for (j = 0; j < vec->size; ++j)
420			isl_int_addmul(prod->el[i], vec->el[j], mat->row[j][i]);
421	}
422	isl_mat_free(mat);
423	isl_vec_free(vec);
424	return prod;
425error:
426	isl_mat_free(mat);
427	isl_vec_free(vec);
428	return NULL;
429}
430
431struct isl_mat *isl_mat_aff_direct_sum(struct isl_mat *left,
432	struct isl_mat *right)
433{
434	int i;
435	struct isl_mat *sum;
436
437	if (!left || !right)
438		goto error;
439
440	isl_assert(left->ctx, left->n_row == right->n_row, goto error);
441	isl_assert(left->ctx, left->n_row >= 1, goto error);
442	isl_assert(left->ctx, left->n_col >= 1, goto error);
443	isl_assert(left->ctx, right->n_col >= 1, goto error);
444	isl_assert(left->ctx,
445	    isl_seq_first_non_zero(left->row[0]+1, left->n_col-1) == -1,
446	    goto error);
447	isl_assert(left->ctx,
448	    isl_seq_first_non_zero(right->row[0]+1, right->n_col-1) == -1,
449	    goto error);
450
451	sum = isl_mat_alloc(left->ctx, left->n_row, left->n_col + right->n_col - 1);
452	if (!sum)
453		goto error;
454	isl_int_lcm(sum->row[0][0], left->row[0][0], right->row[0][0]);
455	isl_int_divexact(left->row[0][0], sum->row[0][0], left->row[0][0]);
456	isl_int_divexact(right->row[0][0], sum->row[0][0], right->row[0][0]);
457
458	isl_seq_clr(sum->row[0]+1, sum->n_col-1);
459	for (i = 1; i < sum->n_row; ++i) {
460		isl_int_mul(sum->row[i][0], left->row[0][0], left->row[i][0]);
461		isl_int_addmul(sum->row[i][0],
462				right->row[0][0], right->row[i][0]);
463		isl_seq_scale(sum->row[i]+1, left->row[i]+1, left->row[0][0],
464				left->n_col-1);
465		isl_seq_scale(sum->row[i]+left->n_col,
466				right->row[i]+1, right->row[0][0],
467				right->n_col-1);
468	}
469
470	isl_int_divexact(left->row[0][0], sum->row[0][0], left->row[0][0]);
471	isl_int_divexact(right->row[0][0], sum->row[0][0], right->row[0][0]);
472	isl_mat_free(left);
473	isl_mat_free(right);
474	return sum;
475error:
476	isl_mat_free(left);
477	isl_mat_free(right);
478	return NULL;
479}
480
481static void exchange(struct isl_mat *M, struct isl_mat **U,
482	struct isl_mat **Q, unsigned row, unsigned i, unsigned j)
483{
484	int r;
485	for (r = row; r < M->n_row; ++r)
486		isl_int_swap(M->row[r][i], M->row[r][j]);
487	if (U) {
488		for (r = 0; r < (*U)->n_row; ++r)
489			isl_int_swap((*U)->row[r][i], (*U)->row[r][j]);
490	}
491	if (Q)
492		isl_mat_swap_rows(*Q, i, j);
493}
494
495static void subtract(struct isl_mat *M, struct isl_mat **U,
496	struct isl_mat **Q, unsigned row, unsigned i, unsigned j, isl_int m)
497{
498	int r;
499	for (r = row; r < M->n_row; ++r)
500		isl_int_submul(M->row[r][j], m, M->row[r][i]);
501	if (U) {
502		for (r = 0; r < (*U)->n_row; ++r)
503			isl_int_submul((*U)->row[r][j], m, (*U)->row[r][i]);
504	}
505	if (Q) {
506		for (r = 0; r < (*Q)->n_col; ++r)
507			isl_int_addmul((*Q)->row[i][r], m, (*Q)->row[j][r]);
508	}
509}
510
511static void oppose(struct isl_mat *M, struct isl_mat **U,
512	struct isl_mat **Q, unsigned row, unsigned col)
513{
514	int r;
515	for (r = row; r < M->n_row; ++r)
516		isl_int_neg(M->row[r][col], M->row[r][col]);
517	if (U) {
518		for (r = 0; r < (*U)->n_row; ++r)
519			isl_int_neg((*U)->row[r][col], (*U)->row[r][col]);
520	}
521	if (Q)
522		isl_seq_neg((*Q)->row[col], (*Q)->row[col], (*Q)->n_col);
523}
524
525/* Given matrix M, compute
526 *
527 *		M U = H
528 *		M   = H Q
529 *
530 * with U and Q unimodular matrices and H a matrix in column echelon form
531 * such that on each echelon row the entries in the non-echelon column
532 * are non-negative (if neg == 0) or non-positive (if neg == 1)
533 * and stricly smaller (in absolute value) than the entries in the echelon
534 * column.
535 * If U or Q are NULL, then these matrices are not computed.
536 */
537struct isl_mat *isl_mat_left_hermite(struct isl_mat *M, int neg,
538	struct isl_mat **U, struct isl_mat **Q)
539{
540	isl_int c;
541	int row, col;
542
543	if (U)
544		*U = NULL;
545	if (Q)
546		*Q = NULL;
547	if (!M)
548		goto error;
549	M = isl_mat_cow(M);
550	if (!M)
551		goto error;
552	if (U) {
553		*U = isl_mat_identity(M->ctx, M->n_col);
554		if (!*U)
555			goto error;
556	}
557	if (Q) {
558		*Q = isl_mat_identity(M->ctx, M->n_col);
559		if (!*Q)
560			goto error;
561	}
562
563	col = 0;
564	isl_int_init(c);
565	for (row = 0; row < M->n_row; ++row) {
566		int first, i, off;
567		first = isl_seq_abs_min_non_zero(M->row[row]+col, M->n_col-col);
568		if (first == -1)
569			continue;
570		first += col;
571		if (first != col)
572			exchange(M, U, Q, row, first, col);
573		if (isl_int_is_neg(M->row[row][col]))
574			oppose(M, U, Q, row, col);
575		first = col+1;
576		while ((off = isl_seq_first_non_zero(M->row[row]+first,
577						       M->n_col-first)) != -1) {
578			first += off;
579			isl_int_fdiv_q(c, M->row[row][first], M->row[row][col]);
580			subtract(M, U, Q, row, col, first, c);
581			if (!isl_int_is_zero(M->row[row][first]))
582				exchange(M, U, Q, row, first, col);
583			else
584				++first;
585		}
586		for (i = 0; i < col; ++i) {
587			if (isl_int_is_zero(M->row[row][i]))
588				continue;
589			if (neg)
590				isl_int_cdiv_q(c, M->row[row][i], M->row[row][col]);
591			else
592				isl_int_fdiv_q(c, M->row[row][i], M->row[row][col]);
593			if (isl_int_is_zero(c))
594				continue;
595			subtract(M, U, Q, row, col, i, c);
596		}
597		++col;
598	}
599	isl_int_clear(c);
600
601	return M;
602error:
603	if (Q) {
604		isl_mat_free(*Q);
605		*Q = NULL;
606	}
607	if (U) {
608		isl_mat_free(*U);
609		*U = NULL;
610	}
611	isl_mat_free(M);
612	return NULL;
613}
614
615struct isl_mat *isl_mat_right_kernel(struct isl_mat *mat)
616{
617	int i, rank;
618	struct isl_mat *U = NULL;
619	struct isl_mat *K;
620
621	mat = isl_mat_left_hermite(mat, 0, &U, NULL);
622	if (!mat || !U)
623		goto error;
624
625	for (i = 0, rank = 0; rank < mat->n_col; ++rank) {
626		while (i < mat->n_row && isl_int_is_zero(mat->row[i][rank]))
627			++i;
628		if (i >= mat->n_row)
629			break;
630	}
631	K = isl_mat_alloc(U->ctx, U->n_row, U->n_col - rank);
632	if (!K)
633		goto error;
634	isl_mat_sub_copy(K->ctx, K->row, U->row, U->n_row, 0, rank, U->n_col-rank);
635	isl_mat_free(mat);
636	isl_mat_free(U);
637	return K;
638error:
639	isl_mat_free(mat);
640	isl_mat_free(U);
641	return NULL;
642}
643
644struct isl_mat *isl_mat_lin_to_aff(struct isl_mat *mat)
645{
646	int i;
647	struct isl_mat *mat2;
648
649	if (!mat)
650		return NULL;
651	mat2 = isl_mat_alloc(mat->ctx, 1+mat->n_row, 1+mat->n_col);
652	if (!mat2)
653		goto error;
654	isl_int_set_si(mat2->row[0][0], 1);
655	isl_seq_clr(mat2->row[0]+1, mat->n_col);
656	for (i = 0; i < mat->n_row; ++i) {
657		isl_int_set_si(mat2->row[1+i][0], 0);
658		isl_seq_cpy(mat2->row[1+i]+1, mat->row[i], mat->n_col);
659	}
660	isl_mat_free(mat);
661	return mat2;
662error:
663	isl_mat_free(mat);
664	return NULL;
665}
666
667/* Given two matrices M1 and M2, return the block matrix
668 *
669 *	[ M1  0  ]
670 *	[ 0   M2 ]
671 */
672__isl_give isl_mat *isl_mat_diagonal(__isl_take isl_mat *mat1,
673	__isl_take isl_mat *mat2)
674{
675	int i;
676	isl_mat *mat;
677
678	if (!mat1 || !mat2)
679		goto error;
680
681	mat = isl_mat_alloc(mat1->ctx, mat1->n_row + mat2->n_row,
682				       mat1->n_col + mat2->n_col);
683	if (!mat)
684		goto error;
685	for (i = 0; i < mat1->n_row; ++i) {
686		isl_seq_cpy(mat->row[i], mat1->row[i], mat1->n_col);
687		isl_seq_clr(mat->row[i] + mat1->n_col, mat2->n_col);
688	}
689	for (i = 0; i < mat2->n_row; ++i) {
690		isl_seq_clr(mat->row[mat1->n_row + i], mat1->n_col);
691		isl_seq_cpy(mat->row[mat1->n_row + i] + mat1->n_col,
692						    mat2->row[i], mat2->n_col);
693	}
694	isl_mat_free(mat1);
695	isl_mat_free(mat2);
696	return mat;
697error:
698	isl_mat_free(mat1);
699	isl_mat_free(mat2);
700	return NULL;
701}
702
703static int row_first_non_zero(isl_int **row, unsigned n_row, unsigned col)
704{
705	int i;
706
707	for (i = 0; i < n_row; ++i)
708		if (!isl_int_is_zero(row[i][col]))
709			return i;
710	return -1;
711}
712
713static int row_abs_min_non_zero(isl_int **row, unsigned n_row, unsigned col)
714{
715	int i, min = row_first_non_zero(row, n_row, col);
716	if (min < 0)
717		return -1;
718	for (i = min + 1; i < n_row; ++i) {
719		if (isl_int_is_zero(row[i][col]))
720			continue;
721		if (isl_int_abs_lt(row[i][col], row[min][col]))
722			min = i;
723	}
724	return min;
725}
726
727static void inv_exchange(struct isl_mat *left, struct isl_mat *right,
728	unsigned i, unsigned j)
729{
730	left = isl_mat_swap_rows(left, i, j);
731	right = isl_mat_swap_rows(right, i, j);
732}
733
734static void inv_oppose(
735	struct isl_mat *left, struct isl_mat *right, unsigned row)
736{
737	isl_seq_neg(left->row[row]+row, left->row[row]+row, left->n_col-row);
738	isl_seq_neg(right->row[row], right->row[row], right->n_col);
739}
740
741static void inv_subtract(struct isl_mat *left, struct isl_mat *right,
742	unsigned row, unsigned i, isl_int m)
743{
744	isl_int_neg(m, m);
745	isl_seq_combine(left->row[i]+row,
746			left->ctx->one, left->row[i]+row,
747			m, left->row[row]+row,
748			left->n_col-row);
749	isl_seq_combine(right->row[i], right->ctx->one, right->row[i],
750			m, right->row[row], right->n_col);
751}
752
753/* Compute inv(left)*right
754 */
755struct isl_mat *isl_mat_inverse_product(struct isl_mat *left,
756	struct isl_mat *right)
757{
758	int row;
759	isl_int a, b;
760
761	if (!left || !right)
762		goto error;
763
764	isl_assert(left->ctx, left->n_row == left->n_col, goto error);
765	isl_assert(left->ctx, left->n_row == right->n_row, goto error);
766
767	if (left->n_row == 0) {
768		isl_mat_free(left);
769		return right;
770	}
771
772	left = isl_mat_cow(left);
773	right = isl_mat_cow(right);
774	if (!left || !right)
775		goto error;
776
777	isl_int_init(a);
778	isl_int_init(b);
779	for (row = 0; row < left->n_row; ++row) {
780		int pivot, first, i, off;
781		pivot = row_abs_min_non_zero(left->row+row, left->n_row-row, row);
782		if (pivot < 0) {
783			isl_int_clear(a);
784			isl_int_clear(b);
785			isl_assert(left->ctx, pivot >= 0, goto error);
786		}
787		pivot += row;
788		if (pivot != row)
789			inv_exchange(left, right, pivot, row);
790		if (isl_int_is_neg(left->row[row][row]))
791			inv_oppose(left, right, row);
792		first = row+1;
793		while ((off = row_first_non_zero(left->row+first,
794					left->n_row-first, row)) != -1) {
795			first += off;
796			isl_int_fdiv_q(a, left->row[first][row],
797					left->row[row][row]);
798			inv_subtract(left, right, row, first, a);
799			if (!isl_int_is_zero(left->row[first][row]))
800				inv_exchange(left, right, row, first);
801			else
802				++first;
803		}
804		for (i = 0; i < row; ++i) {
805			if (isl_int_is_zero(left->row[i][row]))
806				continue;
807			isl_int_gcd(a, left->row[row][row], left->row[i][row]);
808			isl_int_divexact(b, left->row[i][row], a);
809			isl_int_divexact(a, left->row[row][row], a);
810			isl_int_neg(b, b);
811			isl_seq_combine(left->row[i] + i,
812					a, left->row[i] + i,
813					b, left->row[row] + i,
814					left->n_col - i);
815			isl_seq_combine(right->row[i], a, right->row[i],
816					b, right->row[row], right->n_col);
817		}
818	}
819	isl_int_clear(b);
820
821	isl_int_set(a, left->row[0][0]);
822	for (row = 1; row < left->n_row; ++row)
823		isl_int_lcm(a, a, left->row[row][row]);
824	if (isl_int_is_zero(a)){
825		isl_int_clear(a);
826		isl_assert(left->ctx, 0, goto error);
827	}
828	for (row = 0; row < left->n_row; ++row) {
829		isl_int_divexact(left->row[row][row], a, left->row[row][row]);
830		if (isl_int_is_one(left->row[row][row]))
831			continue;
832		isl_seq_scale(right->row[row], right->row[row],
833				left->row[row][row], right->n_col);
834	}
835	isl_int_clear(a);
836
837	isl_mat_free(left);
838	return right;
839error:
840	isl_mat_free(left);
841	isl_mat_free(right);
842	return NULL;
843}
844
845void isl_mat_col_scale(struct isl_mat *mat, unsigned col, isl_int m)
846{
847	int i;
848
849	for (i = 0; i < mat->n_row; ++i)
850		isl_int_mul(mat->row[i][col], mat->row[i][col], m);
851}
852
853void isl_mat_col_combine(struct isl_mat *mat, unsigned dst,
854	isl_int m1, unsigned src1, isl_int m2, unsigned src2)
855{
856	int i;
857	isl_int tmp;
858
859	isl_int_init(tmp);
860	for (i = 0; i < mat->n_row; ++i) {
861		isl_int_mul(tmp, m1, mat->row[i][src1]);
862		isl_int_addmul(tmp, m2, mat->row[i][src2]);
863		isl_int_set(mat->row[i][dst], tmp);
864	}
865	isl_int_clear(tmp);
866}
867
868struct isl_mat *isl_mat_right_inverse(struct isl_mat *mat)
869{
870	struct isl_mat *inv;
871	int row;
872	isl_int a, b;
873
874	mat = isl_mat_cow(mat);
875	if (!mat)
876		return NULL;
877
878	inv = isl_mat_identity(mat->ctx, mat->n_col);
879	inv = isl_mat_cow(inv);
880	if (!inv)
881		goto error;
882
883	isl_int_init(a);
884	isl_int_init(b);
885	for (row = 0; row < mat->n_row; ++row) {
886		int pivot, first, i, off;
887		pivot = isl_seq_abs_min_non_zero(mat->row[row]+row, mat->n_col-row);
888		if (pivot < 0) {
889			isl_int_clear(a);
890			isl_int_clear(b);
891			isl_assert(mat->ctx, pivot >= 0, goto error);
892		}
893		pivot += row;
894		if (pivot != row)
895			exchange(mat, &inv, NULL, row, pivot, row);
896		if (isl_int_is_neg(mat->row[row][row]))
897			oppose(mat, &inv, NULL, row, row);
898		first = row+1;
899		while ((off = isl_seq_first_non_zero(mat->row[row]+first,
900						    mat->n_col-first)) != -1) {
901			first += off;
902			isl_int_fdiv_q(a, mat->row[row][first],
903						    mat->row[row][row]);
904			subtract(mat, &inv, NULL, row, row, first, a);
905			if (!isl_int_is_zero(mat->row[row][first]))
906				exchange(mat, &inv, NULL, row, row, first);
907			else
908				++first;
909		}
910		for (i = 0; i < row; ++i) {
911			if (isl_int_is_zero(mat->row[row][i]))
912				continue;
913			isl_int_gcd(a, mat->row[row][row], mat->row[row][i]);
914			isl_int_divexact(b, mat->row[row][i], a);
915			isl_int_divexact(a, mat->row[row][row], a);
916			isl_int_neg(a, a);
917			isl_mat_col_combine(mat, i, a, i, b, row);
918			isl_mat_col_combine(inv, i, a, i, b, row);
919		}
920	}
921	isl_int_clear(b);
922
923	isl_int_set(a, mat->row[0][0]);
924	for (row = 1; row < mat->n_row; ++row)
925		isl_int_lcm(a, a, mat->row[row][row]);
926	if (isl_int_is_zero(a)){
927		isl_int_clear(a);
928		goto error;
929	}
930	for (row = 0; row < mat->n_row; ++row) {
931		isl_int_divexact(mat->row[row][row], a, mat->row[row][row]);
932		if (isl_int_is_one(mat->row[row][row]))
933			continue;
934		isl_mat_col_scale(inv, row, mat->row[row][row]);
935	}
936	isl_int_clear(a);
937
938	isl_mat_free(mat);
939
940	return inv;
941error:
942	isl_mat_free(mat);
943	isl_mat_free(inv);
944	return NULL;
945}
946
947struct isl_mat *isl_mat_transpose(struct isl_mat *mat)
948{
949	struct isl_mat *transpose = NULL;
950	int i, j;
951
952	if (!mat)
953		return NULL;
954
955	if (mat->n_col == mat->n_row) {
956		mat = isl_mat_cow(mat);
957		if (!mat)
958			return NULL;
959		for (i = 0; i < mat->n_row; ++i)
960			for (j = i + 1; j < mat->n_col; ++j)
961				isl_int_swap(mat->row[i][j], mat->row[j][i]);
962		return mat;
963	}
964	transpose = isl_mat_alloc(mat->ctx, mat->n_col, mat->n_row);
965	if (!transpose)
966		goto error;
967	for (i = 0; i < mat->n_row; ++i)
968		for (j = 0; j < mat->n_col; ++j)
969			isl_int_set(transpose->row[j][i], mat->row[i][j]);
970	isl_mat_free(mat);
971	return transpose;
972error:
973	isl_mat_free(mat);
974	return NULL;
975}
976
977struct isl_mat *isl_mat_swap_cols(struct isl_mat *mat, unsigned i, unsigned j)
978{
979	int r;
980
981	mat = isl_mat_cow(mat);
982	if (!mat)
983		return NULL;
984	isl_assert(mat->ctx, i < mat->n_col, goto error);
985	isl_assert(mat->ctx, j < mat->n_col, goto error);
986
987	for (r = 0; r < mat->n_row; ++r)
988		isl_int_swap(mat->row[r][i], mat->row[r][j]);
989	return mat;
990error:
991	isl_mat_free(mat);
992	return NULL;
993}
994
995struct isl_mat *isl_mat_swap_rows(struct isl_mat *mat, unsigned i, unsigned j)
996{
997	isl_int *t;
998
999	if (!mat)
1000		return NULL;
1001	mat = isl_mat_cow(mat);
1002	if (!mat)
1003		return NULL;
1004	t = mat->row[i];
1005	mat->row[i] = mat->row[j];
1006	mat->row[j] = t;
1007	return mat;
1008}
1009
1010__isl_give isl_mat *isl_mat_product(__isl_take isl_mat *left,
1011	__isl_take isl_mat *right)
1012{
1013	int i, j, k;
1014	struct isl_mat *prod;
1015
1016	if (!left || !right)
1017		goto error;
1018	isl_assert(left->ctx, left->n_col == right->n_row, goto error);
1019	prod = isl_mat_alloc(left->ctx, left->n_row, right->n_col);
1020	if (!prod)
1021		goto error;
1022	if (left->n_col == 0) {
1023		for (i = 0; i < prod->n_row; ++i)
1024			isl_seq_clr(prod->row[i], prod->n_col);
1025		isl_mat_free(left);
1026		isl_mat_free(right);
1027		return prod;
1028	}
1029	for (i = 0; i < prod->n_row; ++i) {
1030		for (j = 0; j < prod->n_col; ++j) {
1031			isl_int_mul(prod->row[i][j],
1032				    left->row[i][0], right->row[0][j]);
1033			for (k = 1; k < left->n_col; ++k)
1034				isl_int_addmul(prod->row[i][j],
1035					    left->row[i][k], right->row[k][j]);
1036		}
1037	}
1038	isl_mat_free(left);
1039	isl_mat_free(right);
1040	return prod;
1041error:
1042	isl_mat_free(left);
1043	isl_mat_free(right);
1044	return NULL;
1045}
1046
1047/* Replace the variables x in the rows q by x' given by x = M x',
1048 * with M the matrix mat.
1049 *
1050 * If the number of new variables is greater than the original
1051 * number of variables, then the rows q have already been
1052 * preextended.  If the new number is smaller, then the coefficients
1053 * of the divs, which are not changed, need to be shifted down.
1054 * The row q may be the equalities, the inequalities or the
1055 * div expressions.  In the latter case, has_div is true and
1056 * we need to take into account the extra denominator column.
1057 */
1058static int preimage(struct isl_ctx *ctx, isl_int **q, unsigned n,
1059	unsigned n_div, int has_div, struct isl_mat *mat)
1060{
1061	int i;
1062	struct isl_mat *t;
1063	int e;
1064
1065	if (mat->n_col >= mat->n_row)
1066		e = 0;
1067	else
1068		e = mat->n_row - mat->n_col;
1069	if (has_div)
1070		for (i = 0; i < n; ++i)
1071			isl_int_mul(q[i][0], q[i][0], mat->row[0][0]);
1072	t = isl_mat_sub_alloc6(mat->ctx, q, 0, n, has_div, mat->n_row);
1073	t = isl_mat_product(t, mat);
1074	if (!t)
1075		return -1;
1076	for (i = 0; i < n; ++i) {
1077		isl_seq_swp_or_cpy(q[i] + has_div, t->row[i], t->n_col);
1078		isl_seq_cpy(q[i] + has_div + t->n_col,
1079			    q[i] + has_div + t->n_col + e, n_div);
1080		isl_seq_clr(q[i] + has_div + t->n_col + n_div, e);
1081	}
1082	isl_mat_free(t);
1083	return 0;
1084}
1085
1086/* Replace the variables x in bset by x' given by x = M x', with
1087 * M the matrix mat.
1088 *
1089 * If there are fewer variables x' then there are x, then we perform
1090 * the transformation in place, which that, in principle,
1091 * this frees up some extra variables as the number
1092 * of columns remains constant, but we would have to extend
1093 * the div array too as the number of rows in this array is assumed
1094 * to be equal to extra.
1095 */
1096struct isl_basic_set *isl_basic_set_preimage(struct isl_basic_set *bset,
1097	struct isl_mat *mat)
1098{
1099	struct isl_ctx *ctx;
1100
1101	if (!bset || !mat)
1102		goto error;
1103
1104	ctx = bset->ctx;
1105	bset = isl_basic_set_cow(bset);
1106	if (!bset)
1107		goto error;
1108
1109	isl_assert(ctx, bset->dim->nparam == 0, goto error);
1110	isl_assert(ctx, 1+bset->dim->n_out == mat->n_row, goto error);
1111	isl_assert(ctx, mat->n_col > 0, goto error);
1112
1113	if (mat->n_col > mat->n_row) {
1114		bset = isl_basic_set_extend(bset, 0, mat->n_col-1, 0, 0, 0);
1115		if (!bset)
1116			goto error;
1117	} else if (mat->n_col < mat->n_row) {
1118		bset->dim = isl_space_cow(bset->dim);
1119		if (!bset->dim)
1120			goto error;
1121		bset->dim->n_out -= mat->n_row - mat->n_col;
1122	}
1123
1124	if (preimage(ctx, bset->eq, bset->n_eq, bset->n_div, 0,
1125			isl_mat_copy(mat)) < 0)
1126		goto error;
1127
1128	if (preimage(ctx, bset->ineq, bset->n_ineq, bset->n_div, 0,
1129			isl_mat_copy(mat)) < 0)
1130		goto error;
1131
1132	if (preimage(ctx, bset->div, bset->n_div, bset->n_div, 1, mat) < 0)
1133		goto error2;
1134
1135	ISL_F_CLR(bset, ISL_BASIC_SET_NO_IMPLICIT);
1136	ISL_F_CLR(bset, ISL_BASIC_SET_NO_REDUNDANT);
1137	ISL_F_CLR(bset, ISL_BASIC_SET_NORMALIZED);
1138	ISL_F_CLR(bset, ISL_BASIC_SET_NORMALIZED_DIVS);
1139	ISL_F_CLR(bset, ISL_BASIC_SET_ALL_EQUALITIES);
1140
1141	bset = isl_basic_set_simplify(bset);
1142	bset = isl_basic_set_finalize(bset);
1143
1144	return bset;
1145error:
1146	isl_mat_free(mat);
1147error2:
1148	isl_basic_set_free(bset);
1149	return NULL;
1150}
1151
1152struct isl_set *isl_set_preimage(struct isl_set *set, struct isl_mat *mat)
1153{
1154	struct isl_ctx *ctx;
1155	int i;
1156
1157	set = isl_set_cow(set);
1158	if (!set)
1159		return NULL;
1160
1161	ctx = set->ctx;
1162	for (i = 0; i < set->n; ++i) {
1163		set->p[i] = isl_basic_set_preimage(set->p[i],
1164						    isl_mat_copy(mat));
1165		if (!set->p[i])
1166			goto error;
1167	}
1168	if (mat->n_col != mat->n_row) {
1169		set->dim = isl_space_cow(set->dim);
1170		if (!set->dim)
1171			goto error;
1172		set->dim->n_out += mat->n_col;
1173		set->dim->n_out -= mat->n_row;
1174	}
1175	isl_mat_free(mat);
1176	ISL_F_CLR(set, ISL_SET_NORMALIZED);
1177	return set;
1178error:
1179	isl_set_free(set);
1180	isl_mat_free(mat);
1181	return NULL;
1182}
1183
1184/* Replace the variables x starting at pos in the rows q
1185 * by x' with x = M x' with M the matrix mat.
1186 * That is, replace the corresponding coefficients c by c M.
1187 */
1188static int transform(isl_ctx *ctx, isl_int **q, unsigned n,
1189	unsigned pos, __isl_take isl_mat *mat)
1190{
1191	int i;
1192	isl_mat *t;
1193
1194	t = isl_mat_sub_alloc6(ctx, q, 0, n, pos, mat->n_row);
1195	t = isl_mat_product(t, mat);
1196	if (!t)
1197		return -1;
1198	for (i = 0; i < n; ++i)
1199		isl_seq_swp_or_cpy(q[i] + pos, t->row[i], t->n_col);
1200	isl_mat_free(t);
1201	return 0;
1202}
1203
1204/* Replace the variables x of type "type" starting at "first" in "bset"
1205 * by x' with x = M x' with M the matrix trans.
1206 * That is, replace the corresponding coefficients c by c M.
1207 *
1208 * The transformation matrix should be a square matrix.
1209 */
1210__isl_give isl_basic_set *isl_basic_set_transform_dims(
1211	__isl_take isl_basic_set *bset, enum isl_dim_type type, unsigned first,
1212	__isl_take isl_mat *trans)
1213{
1214	isl_ctx *ctx;
1215	unsigned pos;
1216
1217	bset = isl_basic_set_cow(bset);
1218	if (!bset || !trans)
1219		goto error;
1220
1221	ctx = isl_basic_set_get_ctx(bset);
1222	if (trans->n_row != trans->n_col)
1223		isl_die(trans->ctx, isl_error_invalid,
1224			"expecting square transformation matrix", goto error);
1225	if (first + trans->n_row > isl_basic_set_dim(bset, type))
1226		isl_die(trans->ctx, isl_error_invalid,
1227			"oversized transformation matrix", goto error);
1228
1229	pos = isl_basic_set_offset(bset, type) + first;
1230
1231	if (transform(ctx, bset->eq, bset->n_eq, pos, isl_mat_copy(trans)) < 0)
1232		goto error;
1233	if (transform(ctx, bset->ineq, bset->n_ineq, pos,
1234		      isl_mat_copy(trans)) < 0)
1235		goto error;
1236	if (transform(ctx, bset->div, bset->n_div, 1 + pos,
1237		      isl_mat_copy(trans)) < 0)
1238		goto error;
1239
1240	ISL_F_CLR(bset, ISL_BASIC_SET_NORMALIZED);
1241	ISL_F_CLR(bset, ISL_BASIC_SET_NORMALIZED_DIVS);
1242
1243	isl_mat_free(trans);
1244	return bset;
1245error:
1246	isl_mat_free(trans);
1247	isl_basic_set_free(bset);
1248	return NULL;
1249}
1250
1251void isl_mat_print_internal(__isl_keep isl_mat *mat, FILE *out, int indent)
1252{
1253	int i, j;
1254
1255	if (!mat) {
1256		fprintf(out, "%*snull mat\n", indent, "");
1257		return;
1258	}
1259
1260	if (mat->n_row == 0)
1261		fprintf(out, "%*s[]\n", indent, "");
1262
1263	for (i = 0; i < mat->n_row; ++i) {
1264		if (!i)
1265			fprintf(out, "%*s[[", indent, "");
1266		else
1267			fprintf(out, "%*s[", indent+1, "");
1268		for (j = 0; j < mat->n_col; ++j) {
1269			if (j)
1270			    fprintf(out, ",");
1271			isl_int_print(out, mat->row[i][j], 0);
1272		}
1273		if (i == mat->n_row-1)
1274			fprintf(out, "]]\n");
1275		else
1276			fprintf(out, "]\n");
1277	}
1278}
1279
1280void isl_mat_dump(__isl_keep isl_mat *mat)
1281{
1282	isl_mat_print_internal(mat, stderr, 0);
1283}
1284
1285struct isl_mat *isl_mat_drop_cols(struct isl_mat *mat, unsigned col, unsigned n)
1286{
1287	int r;
1288
1289	if (n == 0)
1290		return mat;
1291
1292	mat = isl_mat_cow(mat);
1293	if (!mat)
1294		return NULL;
1295
1296	if (col != mat->n_col-n) {
1297		for (r = 0; r < mat->n_row; ++r)
1298			isl_seq_cpy(mat->row[r]+col, mat->row[r]+col+n,
1299					mat->n_col - col - n);
1300	}
1301	mat->n_col -= n;
1302	return mat;
1303}
1304
1305struct isl_mat *isl_mat_drop_rows(struct isl_mat *mat, unsigned row, unsigned n)
1306{
1307	int r;
1308
1309	mat = isl_mat_cow(mat);
1310	if (!mat)
1311		return NULL;
1312
1313	for (r = row; r+n < mat->n_row; ++r)
1314		mat->row[r] = mat->row[r+n];
1315
1316	mat->n_row -= n;
1317	return mat;
1318}
1319
1320__isl_give isl_mat *isl_mat_insert_cols(__isl_take isl_mat *mat,
1321				unsigned col, unsigned n)
1322{
1323	isl_mat *ext;
1324
1325	if (!mat)
1326		return NULL;
1327	if (n == 0)
1328		return mat;
1329
1330	ext = isl_mat_alloc(mat->ctx, mat->n_row, mat->n_col + n);
1331	if (!ext)
1332		goto error;
1333
1334	isl_mat_sub_copy(mat->ctx, ext->row, mat->row, mat->n_row, 0, 0, col);
1335	isl_mat_sub_copy(mat->ctx, ext->row, mat->row, mat->n_row,
1336				col + n, col, mat->n_col - col);
1337
1338	isl_mat_free(mat);
1339	return ext;
1340error:
1341	isl_mat_free(mat);
1342	return NULL;
1343}
1344
1345__isl_give isl_mat *isl_mat_insert_zero_cols(__isl_take isl_mat *mat,
1346	unsigned first, unsigned n)
1347{
1348	int i;
1349
1350	if (!mat)
1351		return NULL;
1352	mat = isl_mat_insert_cols(mat, first, n);
1353	if (!mat)
1354		return NULL;
1355
1356	for (i = 0; i < mat->n_row; ++i)
1357		isl_seq_clr(mat->row[i] + first, n);
1358
1359	return mat;
1360}
1361
1362__isl_give isl_mat *isl_mat_add_zero_cols(__isl_take isl_mat *mat, unsigned n)
1363{
1364	if (!mat)
1365		return NULL;
1366
1367	return isl_mat_insert_zero_cols(mat, mat->n_col, n);
1368}
1369
1370__isl_give isl_mat *isl_mat_insert_rows(__isl_take isl_mat *mat,
1371				unsigned row, unsigned n)
1372{
1373	isl_mat *ext;
1374
1375	if (!mat)
1376		return NULL;
1377	if (n == 0)
1378		return mat;
1379
1380	ext = isl_mat_alloc(mat->ctx, mat->n_row + n, mat->n_col);
1381	if (!ext)
1382		goto error;
1383
1384	isl_mat_sub_copy(mat->ctx, ext->row, mat->row, row, 0, 0, mat->n_col);
1385	isl_mat_sub_copy(mat->ctx, ext->row + row + n, mat->row + row,
1386				mat->n_row - row, 0, 0, mat->n_col);
1387
1388	isl_mat_free(mat);
1389	return ext;
1390error:
1391	isl_mat_free(mat);
1392	return NULL;
1393}
1394
1395__isl_give isl_mat *isl_mat_add_rows(__isl_take isl_mat *mat, unsigned n)
1396{
1397	if (!mat)
1398		return NULL;
1399
1400	return isl_mat_insert_rows(mat, mat->n_row, n);
1401}
1402
1403__isl_give isl_mat *isl_mat_insert_zero_rows(__isl_take isl_mat *mat,
1404	unsigned row, unsigned n)
1405{
1406	int i;
1407
1408	mat = isl_mat_insert_rows(mat, row, n);
1409	if (!mat)
1410		return NULL;
1411
1412	for (i = 0; i < n; ++i)
1413		isl_seq_clr(mat->row[row + i], mat->n_col);
1414
1415	return mat;
1416}
1417
1418__isl_give isl_mat *isl_mat_add_zero_rows(__isl_take isl_mat *mat, unsigned n)
1419{
1420	if (!mat)
1421		return NULL;
1422
1423	return isl_mat_insert_zero_rows(mat, mat->n_row, n);
1424}
1425
1426void isl_mat_col_submul(struct isl_mat *mat,
1427			int dst_col, isl_int f, int src_col)
1428{
1429	int i;
1430
1431	for (i = 0; i < mat->n_row; ++i)
1432		isl_int_submul(mat->row[i][dst_col], f, mat->row[i][src_col]);
1433}
1434
1435void isl_mat_col_add(__isl_keep isl_mat *mat, int dst_col, int src_col)
1436{
1437	int i;
1438
1439	if (!mat)
1440		return;
1441
1442	for (i = 0; i < mat->n_row; ++i)
1443		isl_int_add(mat->row[i][dst_col],
1444			    mat->row[i][dst_col], mat->row[i][src_col]);
1445}
1446
1447void isl_mat_col_mul(struct isl_mat *mat, int dst_col, isl_int f, int src_col)
1448{
1449	int i;
1450
1451	for (i = 0; i < mat->n_row; ++i)
1452		isl_int_mul(mat->row[i][dst_col], f, mat->row[i][src_col]);
1453}
1454
1455struct isl_mat *isl_mat_unimodular_complete(struct isl_mat *M, int row)
1456{
1457	int r;
1458	struct isl_mat *H = NULL, *Q = NULL;
1459
1460	if (!M)
1461		return NULL;
1462
1463	isl_assert(M->ctx, M->n_row == M->n_col, goto error);
1464	M->n_row = row;
1465	H = isl_mat_left_hermite(isl_mat_copy(M), 0, NULL, &Q);
1466	M->n_row = M->n_col;
1467	if (!H)
1468		goto error;
1469	for (r = 0; r < row; ++r)
1470		isl_assert(M->ctx, isl_int_is_one(H->row[r][r]), goto error);
1471	for (r = row; r < M->n_row; ++r)
1472		isl_seq_cpy(M->row[r], Q->row[r], M->n_col);
1473	isl_mat_free(H);
1474	isl_mat_free(Q);
1475	return M;
1476error:
1477	isl_mat_free(H);
1478	isl_mat_free(Q);
1479	isl_mat_free(M);
1480	return NULL;
1481}
1482
1483__isl_give isl_mat *isl_mat_concat(__isl_take isl_mat *top,
1484	__isl_take isl_mat *bot)
1485{
1486	struct isl_mat *mat;
1487
1488	if (!top || !bot)
1489		goto error;
1490
1491	isl_assert(top->ctx, top->n_col == bot->n_col, goto error);
1492	if (top->n_row == 0) {
1493		isl_mat_free(top);
1494		return bot;
1495	}
1496	if (bot->n_row == 0) {
1497		isl_mat_free(bot);
1498		return top;
1499	}
1500
1501	mat = isl_mat_alloc(top->ctx, top->n_row + bot->n_row, top->n_col);
1502	if (!mat)
1503		goto error;
1504	isl_mat_sub_copy(mat->ctx, mat->row, top->row, top->n_row,
1505			 0, 0, mat->n_col);
1506	isl_mat_sub_copy(mat->ctx, mat->row + top->n_row, bot->row, bot->n_row,
1507			 0, 0, mat->n_col);
1508	isl_mat_free(top);
1509	isl_mat_free(bot);
1510	return mat;
1511error:
1512	isl_mat_free(top);
1513	isl_mat_free(bot);
1514	return NULL;
1515}
1516
1517int isl_mat_is_equal(__isl_keep isl_mat *mat1, __isl_keep isl_mat *mat2)
1518{
1519	int i;
1520
1521	if (!mat1 || !mat2)
1522		return -1;
1523
1524	if (mat1->n_row != mat2->n_row)
1525		return 0;
1526
1527	if (mat1->n_col != mat2->n_col)
1528		return 0;
1529
1530	for (i = 0; i < mat1->n_row; ++i)
1531		if (!isl_seq_eq(mat1->row[i], mat2->row[i], mat1->n_col))
1532			return 0;
1533
1534	return 1;
1535}
1536
1537__isl_give isl_mat *isl_mat_from_row_vec(__isl_take isl_vec *vec)
1538{
1539	struct isl_mat *mat;
1540
1541	if (!vec)
1542		return NULL;
1543	mat = isl_mat_alloc(vec->ctx, 1, vec->size);
1544	if (!mat)
1545		goto error;
1546
1547	isl_seq_cpy(mat->row[0], vec->el, vec->size);
1548
1549	isl_vec_free(vec);
1550	return mat;
1551error:
1552	isl_vec_free(vec);
1553	return NULL;
1554}
1555
1556__isl_give isl_mat *isl_mat_vec_concat(__isl_take isl_mat *top,
1557	__isl_take isl_vec *bot)
1558{
1559	return isl_mat_concat(top, isl_mat_from_row_vec(bot));
1560}
1561
1562__isl_give isl_mat *isl_mat_move_cols(__isl_take isl_mat *mat,
1563	unsigned dst_col, unsigned src_col, unsigned n)
1564{
1565	isl_mat *res;
1566
1567	if (!mat)
1568		return NULL;
1569	if (n == 0 || dst_col == src_col)
1570		return mat;
1571
1572	res = isl_mat_alloc(mat->ctx, mat->n_row, mat->n_col);
1573	if (!res)
1574		goto error;
1575
1576	if (dst_col < src_col) {
1577		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1578				 0, 0, dst_col);
1579		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1580				 dst_col, src_col, n);
1581		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1582				 dst_col + n, dst_col, src_col - dst_col);
1583		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1584				 src_col + n, src_col + n,
1585				 res->n_col - src_col - n);
1586	} else {
1587		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1588				 0, 0, src_col);
1589		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1590				 src_col, src_col + n, dst_col - src_col);
1591		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1592				 dst_col, src_col, n);
1593		isl_mat_sub_copy(res->ctx, res->row, mat->row, mat->n_row,
1594				 dst_col + n, dst_col + n,
1595				 res->n_col - dst_col - n);
1596	}
1597	isl_mat_free(mat);
1598
1599	return res;
1600error:
1601	isl_mat_free(mat);
1602	return NULL;
1603}
1604
1605void isl_mat_gcd(__isl_keep isl_mat *mat, isl_int *gcd)
1606{
1607	int i;
1608	isl_int g;
1609
1610	isl_int_set_si(*gcd, 0);
1611	if (!mat)
1612		return;
1613
1614	isl_int_init(g);
1615	for (i = 0; i < mat->n_row; ++i) {
1616		isl_seq_gcd(mat->row[i], mat->n_col, &g);
1617		isl_int_gcd(*gcd, *gcd, g);
1618	}
1619	isl_int_clear(g);
1620}
1621
1622__isl_give isl_mat *isl_mat_scale_down(__isl_take isl_mat *mat, isl_int m)
1623{
1624	int i;
1625
1626	if (isl_int_is_one(m))
1627		return mat;
1628
1629	mat = isl_mat_cow(mat);
1630	if (!mat)
1631		return NULL;
1632
1633	for (i = 0; i < mat->n_row; ++i)
1634		isl_seq_scale_down(mat->row[i], mat->row[i], m, mat->n_col);
1635
1636	return mat;
1637}
1638
1639__isl_give isl_mat *isl_mat_scale_down_row(__isl_take isl_mat *mat, int row,
1640	isl_int m)
1641{
1642	if (isl_int_is_one(m))
1643		return mat;
1644
1645	mat = isl_mat_cow(mat);
1646	if (!mat)
1647		return NULL;
1648
1649	isl_seq_scale_down(mat->row[row], mat->row[row], m, mat->n_col);
1650
1651	return mat;
1652}
1653
1654__isl_give isl_mat *isl_mat_normalize(__isl_take isl_mat *mat)
1655{
1656	isl_int gcd;
1657
1658	if (!mat)
1659		return NULL;
1660
1661	isl_int_init(gcd);
1662	isl_mat_gcd(mat, &gcd);
1663	mat = isl_mat_scale_down(mat, gcd);
1664	isl_int_clear(gcd);
1665
1666	return mat;
1667}
1668
1669__isl_give isl_mat *isl_mat_normalize_row(__isl_take isl_mat *mat, int row)
1670{
1671	mat = isl_mat_cow(mat);
1672	if (!mat)
1673		return NULL;
1674
1675	isl_seq_normalize(mat->ctx, mat->row[row], mat->n_col);
1676
1677	return mat;
1678}
1679
1680/* Number of initial non-zero columns.
1681 */
1682int isl_mat_initial_non_zero_cols(__isl_keep isl_mat *mat)
1683{
1684	int i;
1685
1686	if (!mat)
1687		return -1;
1688
1689	for (i = 0; i < mat->n_col; ++i)
1690		if (row_first_non_zero(mat->row, mat->n_row, i) < 0)
1691			break;
1692
1693	return i;
1694}
1695