Actual source code: freespace.c
2: #include <../src/mat/utils/freespace.h>
6: PetscErrorCode PetscFreeSpaceGet(PetscInt n,PetscFreeSpaceList *list)
7: {
8: PetscFreeSpaceList a;
9: PetscErrorCode ierr;
12: PetscMalloc(sizeof(struct _Space),&a);
13: PetscMalloc(n*sizeof(PetscInt),&(a->array_head));
14: a->array = a->array_head;
15: a->local_remaining = n;
16: a->local_used = 0;
17: a->total_array_size = 0;
18: a->more_space = NULL;
20: if (*list) {
21: (*list)->more_space = a;
22: a->total_array_size = (*list)->total_array_size;
23: }
25: a->total_array_size += n;
26: *list = a;
27: return(0);
28: }
32: PetscErrorCode PetscFreeSpaceContiguous(PetscFreeSpaceList *head,PetscInt *space)
33: {
34: PetscFreeSpaceList a;
35: PetscErrorCode ierr;
38: while ((*head)) {
39: a = (*head)->more_space;
40: PetscMemcpy(space,(*head)->array_head,((*head)->local_used)*sizeof(PetscInt));
41: space += (*head)->local_used;
42: PetscFree((*head)->array_head);
43: PetscFree(*head);
44: *head = a;
45: }
46: return(0);
47: }
49: /*
50: PetscFreeSpaceContiguous_LU -
51: Copy a linket list obtained from matrix symbolic ILU or LU factorization into a contiguous array
52: that enables an efficient matrix triangular solve.
54: Input Parameters:
55: + head - linked list of column indices obtained from matrix symbolic ILU or LU factorization
56: . space - an allocated int array with length nnz of factored matrix.
57: . n - order of the matrix
58: . bi - row pointer of factored matrix L with length n+1.
59: - bdiag - int array of length n+1. bdiag[i] points to diagonal of U(i,:), and bdiag[n] points to entry of U(n-1,0)-1.
61: Output Parameter:
62: . space - column indices are copied into this int array with contiguous layout of L and U
64: See MatILUFactorSymbolic_SeqAIJ_ilu0() for detailed data structure of L and U
65: */
68: PetscErrorCode PetscFreeSpaceContiguous_LU(PetscFreeSpaceList *head,PetscInt *space,PetscInt n,PetscInt *bi,PetscInt *bdiag)
69: {
70: PetscFreeSpaceList a;
71: PetscErrorCode ierr;
72: PetscInt row,nnz,*bj,*array,total,bi_temp;
73: PetscInt nnzL,nnzU;
76: bi_temp = bi[n];
77: row = 0;
78: total = 0;
79: nnzL = bdiag[0];
80: while ((*head)!=NULL) {
81: total += (*head)->local_used;
82: array = (*head)->array_head;
83:
84: while (row < n) {
85: if (bi[row+1] > total) break;
86: /* copy array entries into bj for this row */
87: nnz = bi[row+1] - bi[row];
88: /* set bi[row] for new datastruct */
89: if (row == 0 ){
90: bi[row] = 0;
91: } else {
92: bi[row] = bi[row-1] + nnzL; /* nnzL of previous row */
93: }
95: /* L part */
96: nnzL = bdiag[row];
97: bj = space+bi[row];
98: PetscMemcpy(bj,array,nnzL*sizeof(PetscInt));
99:
100: /* diagonal entry */
101: bdiag[row] = bi_temp - 1;
102: space[bdiag[row]] = row;
104: /* U part */
105: nnzU = nnz - nnzL;
106: bi_temp = bi_temp - nnzU;
107: nnzU --; /* exclude diagonal */
108: bj = space + bi_temp;
109: PetscMemcpy(bj,array+nnzL+1,nnzU*sizeof(PetscInt));
110: array += nnz;
111: row++;
112: }
114: a = (*head)->more_space;
115: PetscFree((*head)->array_head);
116: PetscFree(*head);
117: *head = a;
118: }
119: bi[n] = bi[n-1] + nnzL;
120: bdiag[n] = bdiag[n-1]-1;
121: return(0);
122: }
124: /*
125: PetscFreeSpaceContiguous_Cholesky -
126: Copy a linket list obtained from matrix symbolic ICC or Cholesky factorization into a contiguous array
127: that enables an efficient matrix triangular solve.
129: Input Parameters:
130: + head - linked list of column indices obtained from matrix symbolic ICC or Cholesky factorization
131: . space - an allocated int array with length nnz of factored matrix.
132: . n - order of the matrix
133: . ui - row pointer of factored matrix with length n+1. All entries are set based on the traditional layout U matrix.
134: - udiag - int array of length n.
136: Output Parameter:
137: + space - column indices are copied into this int array with contiguous layout of U, with diagonal located as the last entry in each row
138: - udiag - indices of diagonal entries
140: See MatICCFactorSymbolic_SeqAIJ_newdatastruct() for detailed description.
141: */
145: PetscErrorCode PetscFreeSpaceContiguous_Cholesky(PetscFreeSpaceList *head,PetscInt *space,PetscInt n,PetscInt *ui,PetscInt *udiag)
146: {
147: PetscFreeSpaceList a;
148: PetscErrorCode ierr;
149: PetscInt row,nnz,*uj,*array,total;
152: row = 0;
153: total = 0;
154: while (*head) {
155: total += (*head)->local_used;
156: array = (*head)->array_head;
157:
158: while (row < n){
159: if (ui[row+1] > total) break;
160: udiag[row] = ui[row+1] - 1; /* points to the last entry of U(row,:) */
161: nnz = ui[row+1] - ui[row] - 1; /* exclude diagonal */
162: uj = space + ui[row];
163: PetscMemcpy(uj,array+1,nnz*sizeof(PetscInt));
164: uj[nnz] = array[0]; /* diagonal */
165: array += nnz + 1;
166: row++;
167: }
169: a = (*head)->more_space;
170: PetscFree((*head)->array_head);
171: PetscFree(*head);
172: *head = a;
173: }
174: return(0);
175: }
179: PetscErrorCode PetscFreeSpaceDestroy(PetscFreeSpaceList head)
180: {
181: PetscFreeSpaceList a;
182: PetscErrorCode ierr;
185: while ((head)!=NULL) {
186: a = (head)->more_space;
187: PetscFree((head)->array_head);
188: PetscFree(head);
189: head = a;
190: }
191: return(0);
192: }