comparison gcc/lambda-mat.c @ 0:a06113de4d67

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author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
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1 /* Integer matrix math routines
2 Copyright (C) 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc.
3 Contributed by Daniel Berlin <dberlin@dberlin.org>.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "tm.h"
25 #include "ggc.h"
26 #include "tree.h"
27 #include "tree-flow.h"
28 #include "lambda.h"
29
30 static void lambda_matrix_get_column (lambda_matrix, int, int,
31 lambda_vector);
32
33 /* Allocate a matrix of M rows x N cols. */
34
35 lambda_matrix
36 lambda_matrix_new (int m, int n)
37 {
38 lambda_matrix mat;
39 int i;
40
41 mat = GGC_NEWVEC (lambda_vector, m);
42
43 for (i = 0; i < m; i++)
44 mat[i] = lambda_vector_new (n);
45
46 return mat;
47 }
48
49 /* Copy the elements of M x N matrix MAT1 to MAT2. */
50
51 void
52 lambda_matrix_copy (lambda_matrix mat1, lambda_matrix mat2,
53 int m, int n)
54 {
55 int i;
56
57 for (i = 0; i < m; i++)
58 lambda_vector_copy (mat1[i], mat2[i], n);
59 }
60
61 /* Store the N x N identity matrix in MAT. */
62
63 void
64 lambda_matrix_id (lambda_matrix mat, int size)
65 {
66 int i, j;
67
68 for (i = 0; i < size; i++)
69 for (j = 0; j < size; j++)
70 mat[i][j] = (i == j) ? 1 : 0;
71 }
72
73 /* Return true if MAT is the identity matrix of SIZE */
74
75 bool
76 lambda_matrix_id_p (lambda_matrix mat, int size)
77 {
78 int i, j;
79 for (i = 0; i < size; i++)
80 for (j = 0; j < size; j++)
81 {
82 if (i == j)
83 {
84 if (mat[i][j] != 1)
85 return false;
86 }
87 else
88 {
89 if (mat[i][j] != 0)
90 return false;
91 }
92 }
93 return true;
94 }
95
96 /* Negate the elements of the M x N matrix MAT1 and store it in MAT2. */
97
98 void
99 lambda_matrix_negate (lambda_matrix mat1, lambda_matrix mat2, int m, int n)
100 {
101 int i;
102
103 for (i = 0; i < m; i++)
104 lambda_vector_negate (mat1[i], mat2[i], n);
105 }
106
107 /* Take the transpose of matrix MAT1 and store it in MAT2.
108 MAT1 is an M x N matrix, so MAT2 must be N x M. */
109
110 void
111 lambda_matrix_transpose (lambda_matrix mat1, lambda_matrix mat2, int m, int n)
112 {
113 int i, j;
114
115 for (i = 0; i < n; i++)
116 for (j = 0; j < m; j++)
117 mat2[i][j] = mat1[j][i];
118 }
119
120
121 /* Add two M x N matrices together: MAT3 = MAT1+MAT2. */
122
123 void
124 lambda_matrix_add (lambda_matrix mat1, lambda_matrix mat2,
125 lambda_matrix mat3, int m, int n)
126 {
127 int i;
128
129 for (i = 0; i < m; i++)
130 lambda_vector_add (mat1[i], mat2[i], mat3[i], n);
131 }
132
133 /* MAT3 = CONST1 * MAT1 + CONST2 * MAT2. All matrices are M x N. */
134
135 void
136 lambda_matrix_add_mc (lambda_matrix mat1, int const1,
137 lambda_matrix mat2, int const2,
138 lambda_matrix mat3, int m, int n)
139 {
140 int i;
141
142 for (i = 0; i < m; i++)
143 lambda_vector_add_mc (mat1[i], const1, mat2[i], const2, mat3[i], n);
144 }
145
146 /* Multiply two matrices: MAT3 = MAT1 * MAT2.
147 MAT1 is an M x R matrix, and MAT2 is R x N. The resulting MAT2
148 must therefore be M x N. */
149
150 void
151 lambda_matrix_mult (lambda_matrix mat1, lambda_matrix mat2,
152 lambda_matrix mat3, int m, int r, int n)
153 {
154
155 int i, j, k;
156
157 for (i = 0; i < m; i++)
158 {
159 for (j = 0; j < n; j++)
160 {
161 mat3[i][j] = 0;
162 for (k = 0; k < r; k++)
163 mat3[i][j] += mat1[i][k] * mat2[k][j];
164 }
165 }
166 }
167
168 /* Get column COL from the matrix MAT and store it in VEC. MAT has
169 N rows, so the length of VEC must be N. */
170
171 static void
172 lambda_matrix_get_column (lambda_matrix mat, int n, int col,
173 lambda_vector vec)
174 {
175 int i;
176
177 for (i = 0; i < n; i++)
178 vec[i] = mat[i][col];
179 }
180
181 /* Delete rows r1 to r2 (not including r2). */
182
183 void
184 lambda_matrix_delete_rows (lambda_matrix mat, int rows, int from, int to)
185 {
186 int i;
187 int dist;
188 dist = to - from;
189
190 for (i = to; i < rows; i++)
191 mat[i - dist] = mat[i];
192
193 for (i = rows - dist; i < rows; i++)
194 mat[i] = NULL;
195 }
196
197 /* Swap rows R1 and R2 in matrix MAT. */
198
199 void
200 lambda_matrix_row_exchange (lambda_matrix mat, int r1, int r2)
201 {
202 lambda_vector row;
203
204 row = mat[r1];
205 mat[r1] = mat[r2];
206 mat[r2] = row;
207 }
208
209 /* Add a multiple of row R1 of matrix MAT with N columns to row R2:
210 R2 = R2 + CONST1 * R1. */
211
212 void
213 lambda_matrix_row_add (lambda_matrix mat, int n, int r1, int r2, int const1)
214 {
215 int i;
216
217 if (const1 == 0)
218 return;
219
220 for (i = 0; i < n; i++)
221 mat[r2][i] += const1 * mat[r1][i];
222 }
223
224 /* Negate row R1 of matrix MAT which has N columns. */
225
226 void
227 lambda_matrix_row_negate (lambda_matrix mat, int n, int r1)
228 {
229 lambda_vector_negate (mat[r1], mat[r1], n);
230 }
231
232 /* Multiply row R1 of matrix MAT with N columns by CONST1. */
233
234 void
235 lambda_matrix_row_mc (lambda_matrix mat, int n, int r1, int const1)
236 {
237 int i;
238
239 for (i = 0; i < n; i++)
240 mat[r1][i] *= const1;
241 }
242
243 /* Exchange COL1 and COL2 in matrix MAT. M is the number of rows. */
244
245 void
246 lambda_matrix_col_exchange (lambda_matrix mat, int m, int col1, int col2)
247 {
248 int i;
249 int tmp;
250 for (i = 0; i < m; i++)
251 {
252 tmp = mat[i][col1];
253 mat[i][col1] = mat[i][col2];
254 mat[i][col2] = tmp;
255 }
256 }
257
258 /* Add a multiple of column C1 of matrix MAT with M rows to column C2:
259 C2 = C2 + CONST1 * C1. */
260
261 void
262 lambda_matrix_col_add (lambda_matrix mat, int m, int c1, int c2, int const1)
263 {
264 int i;
265
266 if (const1 == 0)
267 return;
268
269 for (i = 0; i < m; i++)
270 mat[i][c2] += const1 * mat[i][c1];
271 }
272
273 /* Negate column C1 of matrix MAT which has M rows. */
274
275 void
276 lambda_matrix_col_negate (lambda_matrix mat, int m, int c1)
277 {
278 int i;
279
280 for (i = 0; i < m; i++)
281 mat[i][c1] *= -1;
282 }
283
284 /* Multiply column C1 of matrix MAT with M rows by CONST1. */
285
286 void
287 lambda_matrix_col_mc (lambda_matrix mat, int m, int c1, int const1)
288 {
289 int i;
290
291 for (i = 0; i < m; i++)
292 mat[i][c1] *= const1;
293 }
294
295 /* Compute the inverse of the N x N matrix MAT and store it in INV.
296
297 We don't _really_ compute the inverse of MAT. Instead we compute
298 det(MAT)*inv(MAT), and we return det(MAT) to the caller as the function
299 result. This is necessary to preserve accuracy, because we are dealing
300 with integer matrices here.
301
302 The algorithm used here is a column based Gauss-Jordan elimination on MAT
303 and the identity matrix in parallel. The inverse is the result of applying
304 the same operations on the identity matrix that reduce MAT to the identity
305 matrix.
306
307 When MAT is a 2 x 2 matrix, we don't go through the whole process, because
308 it is easily inverted by inspection and it is a very common case. */
309
310 static int lambda_matrix_inverse_hard (lambda_matrix, lambda_matrix, int);
311
312 int
313 lambda_matrix_inverse (lambda_matrix mat, lambda_matrix inv, int n)
314 {
315 if (n == 2)
316 {
317 int a, b, c, d, det;
318 a = mat[0][0];
319 b = mat[1][0];
320 c = mat[0][1];
321 d = mat[1][1];
322 inv[0][0] = d;
323 inv[0][1] = -c;
324 inv[1][0] = -b;
325 inv[1][1] = a;
326 det = (a * d - b * c);
327 if (det < 0)
328 {
329 det *= -1;
330 inv[0][0] *= -1;
331 inv[1][0] *= -1;
332 inv[0][1] *= -1;
333 inv[1][1] *= -1;
334 }
335 return det;
336 }
337 else
338 return lambda_matrix_inverse_hard (mat, inv, n);
339 }
340
341 /* If MAT is not a special case, invert it the hard way. */
342
343 static int
344 lambda_matrix_inverse_hard (lambda_matrix mat, lambda_matrix inv, int n)
345 {
346 lambda_vector row;
347 lambda_matrix temp;
348 int i, j;
349 int determinant;
350
351 temp = lambda_matrix_new (n, n);
352 lambda_matrix_copy (mat, temp, n, n);
353 lambda_matrix_id (inv, n);
354
355 /* Reduce TEMP to a lower triangular form, applying the same operations on
356 INV which starts as the identity matrix. N is the number of rows and
357 columns. */
358 for (j = 0; j < n; j++)
359 {
360 row = temp[j];
361
362 /* Make every element in the current row positive. */
363 for (i = j; i < n; i++)
364 if (row[i] < 0)
365 {
366 lambda_matrix_col_negate (temp, n, i);
367 lambda_matrix_col_negate (inv, n, i);
368 }
369
370 /* Sweep the upper triangle. Stop when only the diagonal element in the
371 current row is nonzero. */
372 while (lambda_vector_first_nz (row, n, j + 1) < n)
373 {
374 int min_col = lambda_vector_min_nz (row, n, j);
375 lambda_matrix_col_exchange (temp, n, j, min_col);
376 lambda_matrix_col_exchange (inv, n, j, min_col);
377
378 for (i = j + 1; i < n; i++)
379 {
380 int factor;
381
382 factor = -1 * row[i];
383 if (row[j] != 1)
384 factor /= row[j];
385
386 lambda_matrix_col_add (temp, n, j, i, factor);
387 lambda_matrix_col_add (inv, n, j, i, factor);
388 }
389 }
390 }
391
392 /* Reduce TEMP from a lower triangular to the identity matrix. Also compute
393 the determinant, which now is simply the product of the elements on the
394 diagonal of TEMP. If one of these elements is 0, the matrix has 0 as an
395 eigenvalue so it is singular and hence not invertible. */
396 determinant = 1;
397 for (j = n - 1; j >= 0; j--)
398 {
399 int diagonal;
400
401 row = temp[j];
402 diagonal = row[j];
403
404 /* The matrix must not be singular. */
405 gcc_assert (diagonal);
406
407 determinant = determinant * diagonal;
408
409 /* If the diagonal is not 1, then multiply the each row by the
410 diagonal so that the middle number is now 1, rather than a
411 rational. */
412 if (diagonal != 1)
413 {
414 for (i = 0; i < j; i++)
415 lambda_matrix_col_mc (inv, n, i, diagonal);
416 for (i = j + 1; i < n; i++)
417 lambda_matrix_col_mc (inv, n, i, diagonal);
418
419 row[j] = diagonal = 1;
420 }
421
422 /* Sweep the lower triangle column wise. */
423 for (i = j - 1; i >= 0; i--)
424 {
425 if (row[i])
426 {
427 int factor = -row[i];
428 lambda_matrix_col_add (temp, n, j, i, factor);
429 lambda_matrix_col_add (inv, n, j, i, factor);
430 }
431
432 }
433 }
434
435 return determinant;
436 }
437
438 /* Decompose a N x N matrix MAT to a product of a lower triangular H
439 and a unimodular U matrix such that MAT = H.U. N is the size of
440 the rows of MAT. */
441
442 void
443 lambda_matrix_hermite (lambda_matrix mat, int n,
444 lambda_matrix H, lambda_matrix U)
445 {
446 lambda_vector row;
447 int i, j, factor, minimum_col;
448
449 lambda_matrix_copy (mat, H, n, n);
450 lambda_matrix_id (U, n);
451
452 for (j = 0; j < n; j++)
453 {
454 row = H[j];
455
456 /* Make every element of H[j][j..n] positive. */
457 for (i = j; i < n; i++)
458 {
459 if (row[i] < 0)
460 {
461 lambda_matrix_col_negate (H, n, i);
462 lambda_vector_negate (U[i], U[i], n);
463 }
464 }
465
466 /* Stop when only the diagonal element is nonzero. */
467 while (lambda_vector_first_nz (row, n, j + 1) < n)
468 {
469 minimum_col = lambda_vector_min_nz (row, n, j);
470 lambda_matrix_col_exchange (H, n, j, minimum_col);
471 lambda_matrix_row_exchange (U, j, minimum_col);
472
473 for (i = j + 1; i < n; i++)
474 {
475 factor = row[i] / row[j];
476 lambda_matrix_col_add (H, n, j, i, -1 * factor);
477 lambda_matrix_row_add (U, n, i, j, factor);
478 }
479 }
480 }
481 }
482
483 /* Given an M x N integer matrix A, this function determines an M x
484 M unimodular matrix U, and an M x N echelon matrix S such that
485 "U.A = S". This decomposition is also known as "right Hermite".
486
487 Ref: Algorithm 2.1 page 33 in "Loop Transformations for
488 Restructuring Compilers" Utpal Banerjee. */
489
490 void
491 lambda_matrix_right_hermite (lambda_matrix A, int m, int n,
492 lambda_matrix S, lambda_matrix U)
493 {
494 int i, j, i0 = 0;
495
496 lambda_matrix_copy (A, S, m, n);
497 lambda_matrix_id (U, m);
498
499 for (j = 0; j < n; j++)
500 {
501 if (lambda_vector_first_nz (S[j], m, i0) < m)
502 {
503 ++i0;
504 for (i = m - 1; i >= i0; i--)
505 {
506 while (S[i][j] != 0)
507 {
508 int sigma, factor, a, b;
509
510 a = S[i-1][j];
511 b = S[i][j];
512 sigma = (a * b < 0) ? -1: 1;
513 a = abs (a);
514 b = abs (b);
515 factor = sigma * (a / b);
516
517 lambda_matrix_row_add (S, n, i, i-1, -factor);
518 lambda_matrix_row_exchange (S, i, i-1);
519
520 lambda_matrix_row_add (U, m, i, i-1, -factor);
521 lambda_matrix_row_exchange (U, i, i-1);
522 }
523 }
524 }
525 }
526 }
527
528 /* Given an M x N integer matrix A, this function determines an M x M
529 unimodular matrix V, and an M x N echelon matrix S such that "A =
530 V.S". This decomposition is also known as "left Hermite".
531
532 Ref: Algorithm 2.2 page 36 in "Loop Transformations for
533 Restructuring Compilers" Utpal Banerjee. */
534
535 void
536 lambda_matrix_left_hermite (lambda_matrix A, int m, int n,
537 lambda_matrix S, lambda_matrix V)
538 {
539 int i, j, i0 = 0;
540
541 lambda_matrix_copy (A, S, m, n);
542 lambda_matrix_id (V, m);
543
544 for (j = 0; j < n; j++)
545 {
546 if (lambda_vector_first_nz (S[j], m, i0) < m)
547 {
548 ++i0;
549 for (i = m - 1; i >= i0; i--)
550 {
551 while (S[i][j] != 0)
552 {
553 int sigma, factor, a, b;
554
555 a = S[i-1][j];
556 b = S[i][j];
557 sigma = (a * b < 0) ? -1: 1;
558 a = abs (a);
559 b = abs (b);
560 factor = sigma * (a / b);
561
562 lambda_matrix_row_add (S, n, i, i-1, -factor);
563 lambda_matrix_row_exchange (S, i, i-1);
564
565 lambda_matrix_col_add (V, m, i-1, i, factor);
566 lambda_matrix_col_exchange (V, m, i, i-1);
567 }
568 }
569 }
570 }
571 }
572
573 /* When it exists, return the first nonzero row in MAT after row
574 STARTROW. Otherwise return rowsize. */
575
576 int
577 lambda_matrix_first_nz_vec (lambda_matrix mat, int rowsize, int colsize,
578 int startrow)
579 {
580 int j;
581 bool found = false;
582
583 for (j = startrow; (j < rowsize) && !found; j++)
584 {
585 if ((mat[j] != NULL)
586 && (lambda_vector_first_nz (mat[j], colsize, startrow) < colsize))
587 found = true;
588 }
589
590 if (found)
591 return j - 1;
592 return rowsize;
593 }
594
595 /* Calculate the projection of E sub k to the null space of B. */
596
597 void
598 lambda_matrix_project_to_null (lambda_matrix B, int rowsize,
599 int colsize, int k, lambda_vector x)
600 {
601 lambda_matrix M1, M2, M3, I;
602 int determinant;
603
604 /* Compute c(I-B^T inv(B B^T) B) e sub k. */
605
606 /* M1 is the transpose of B. */
607 M1 = lambda_matrix_new (colsize, colsize);
608 lambda_matrix_transpose (B, M1, rowsize, colsize);
609
610 /* M2 = B * B^T */
611 M2 = lambda_matrix_new (colsize, colsize);
612 lambda_matrix_mult (B, M1, M2, rowsize, colsize, rowsize);
613
614 /* M3 = inv(M2) */
615 M3 = lambda_matrix_new (colsize, colsize);
616 determinant = lambda_matrix_inverse (M2, M3, rowsize);
617
618 /* M2 = B^T (inv(B B^T)) */
619 lambda_matrix_mult (M1, M3, M2, colsize, rowsize, rowsize);
620
621 /* M1 = B^T (inv(B B^T)) B */
622 lambda_matrix_mult (M2, B, M1, colsize, rowsize, colsize);
623 lambda_matrix_negate (M1, M1, colsize, colsize);
624
625 I = lambda_matrix_new (colsize, colsize);
626 lambda_matrix_id (I, colsize);
627
628 lambda_matrix_add_mc (I, determinant, M1, 1, M2, colsize, colsize);
629
630 lambda_matrix_get_column (M2, colsize, k - 1, x);
631
632 }
633
634 /* Multiply a vector VEC by a matrix MAT.
635 MAT is an M*N matrix, and VEC is a vector with length N. The result
636 is stored in DEST which must be a vector of length M. */
637
638 void
639 lambda_matrix_vector_mult (lambda_matrix matrix, int m, int n,
640 lambda_vector vec, lambda_vector dest)
641 {
642 int i, j;
643
644 lambda_vector_clear (dest, m);
645 for (i = 0; i < m; i++)
646 for (j = 0; j < n; j++)
647 dest[i] += matrix[i][j] * vec[j];
648 }
649
650 /* Print out an M x N matrix MAT to OUTFILE. */
651
652 void
653 print_lambda_matrix (FILE * outfile, lambda_matrix matrix, int m, int n)
654 {
655 int i;
656
657 for (i = 0; i < m; i++)
658 print_lambda_vector (outfile, matrix[i], n);
659 fprintf (outfile, "\n");
660 }
661