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:   PetscMalloc1(n,&(a->array_head));

 15:   a->array            = a->array_head;
 16:   a->local_remaining  = n;
 17:   a->local_used       = 0;
 18:   a->total_array_size = 0;
 19:   a->more_space       = NULL;

 21:   if (*list) {
 22:     (*list)->more_space = a;
 23:     a->total_array_size = (*list)->total_array_size;
 24:   }

 26:   a->total_array_size += n;
 27:   *list                =  a;
 28:   return(0);
 29: }

 33: PetscErrorCode PetscFreeSpaceContiguous(PetscFreeSpaceList *head,PetscInt *space)
 34: {
 35:   PetscFreeSpaceList a;
 36:   PetscErrorCode     ierr;

 39:   while ((*head)) {
 40:     a      =  (*head)->more_space;
 41:      PetscMemcpy(space,(*head)->array_head,((*head)->local_used)*sizeof(PetscInt));
 42:     space += (*head)->local_used;
 43:      PetscFree((*head)->array_head);
 44:      PetscFree(*head);
 45:     *head  =  a;
 46:   }
 47:   return(0);
 48: }

 50: /*
 51:   PetscFreeSpaceContiguous_LU -
 52:     Copy a linket list obtained from matrix symbolic ILU or LU factorization into a contiguous array
 53:   that enables an efficient matrix triangular solve.

 55:    Input Parameters:
 56: +  head - linked list of column indices obtained from matrix symbolic ILU or LU factorization
 57: .  space - an allocated int array with length nnz of factored matrix.
 58: .  n - order of the matrix
 59: .  bi - row pointer of factored matrix L with length n+1.
 60: -  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.

 62:    Output Parameter:
 63: .  space - column indices are copied into this int array with contiguous layout of L and U

 65:    See MatILUFactorSymbolic_SeqAIJ_ilu0() for detailed data structure of L and U
 66: */
 69: PetscErrorCode PetscFreeSpaceContiguous_LU(PetscFreeSpaceList *head,PetscInt *space,PetscInt n,PetscInt *bi,PetscInt *bdiag)
 70: {
 71:   PetscFreeSpaceList a;
 72:   PetscErrorCode     ierr;
 73:   PetscInt           row,nnz,*bj,*array,total,bi_temp;
 74:   PetscInt           nnzL,nnzU;

 77:   bi_temp = bi[n];
 78:   row     = 0;
 79:   total   = 0;
 80:   nnzL    = bdiag[0];
 81:   while ((*head)) {
 82:     total += (*head)->local_used;
 83:     array  = (*head)->array_head;

 85:     while (row < n) {
 86:       if (bi[row+1] > total) break;
 87:       /* copy array entries into bj for this row */
 88:       nnz = bi[row+1] - bi[row];
 89:       /* set bi[row] for new datastruct */
 90:       if (row == 0) {
 91:         bi[row] = 0;
 92:       } else {
 93:         bi[row] = bi[row-1] + nnzL; /* nnzL of previous row */
 94:       }

 96:       /* L part */
 97:       nnzL = bdiag[row];
 98:       bj   = space+bi[row];
 99:       PetscMemcpy(bj,array,nnzL*sizeof(PetscInt));

101:       /* diagonal entry */
102:       bdiag[row]        = bi_temp - 1;
103:       space[bdiag[row]] = row;

105:       /* U part */
106:       nnzU    = nnz - nnzL;
107:       bi_temp = bi_temp - nnzU;
108:       nnzU--;       /* exclude diagonal */
109:       bj     = space + bi_temp;
110:       PetscMemcpy(bj,array+nnzL+1,nnzU*sizeof(PetscInt));
111:       array += nnz;
112:       row++;
113:     }

115:     a     = (*head)->more_space;
116:     PetscFree((*head)->array_head);
117:     PetscFree(*head);
118:     *head = a;
119:   }
120:   if (n) {
121:     bi[n]    = bi[n-1] + nnzL;
122:     bdiag[n] = bdiag[n-1]-1;
123:   }
124:   return(0);
125: }

127: /*
128:   PetscFreeSpaceContiguous_Cholesky -
129:     Copy a linket list obtained from matrix symbolic ICC or Cholesky factorization into a contiguous array
130:   that enables an efficient matrix triangular solve.

132:    Input Parameters:
133: +  head - linked list of column indices obtained from matrix symbolic ICC or Cholesky factorization
134: .  space - an allocated int array with length nnz of factored matrix.
135: .  n - order of the matrix
136: .  ui - row pointer of factored matrix with length n+1. All entries are set based on the traditional layout U matrix.
137: -  udiag - int array of length n.

139:    Output Parameter:
140: +  space - column indices are copied into this int array with contiguous layout of U, with diagonal located as the last entry in each row
141: -  udiag - indices of diagonal entries

143:    See MatICCFactorSymbolic_SeqAIJ_newdatastruct() for detailed description.
144: */

148: PetscErrorCode PetscFreeSpaceContiguous_Cholesky(PetscFreeSpaceList *head,PetscInt *space,PetscInt n,PetscInt *ui,PetscInt *udiag)
149: {
150:   PetscFreeSpaceList a;
151:   PetscErrorCode     ierr;
152:   PetscInt           row,nnz,*uj,*array,total;

155:   row   = 0;
156:   total = 0;
157:   while (*head) {
158:     total += (*head)->local_used;
159:     array  = (*head)->array_head;

161:     while (row < n) {
162:       if (ui[row+1] > total) break;
163:       udiag[row] = ui[row+1] - 1;     /* points to the last entry of U(row,:) */
164:       nnz        = ui[row+1] - ui[row] - 1; /* exclude diagonal */
165:       uj         = space + ui[row];
166:       PetscMemcpy(uj,array+1,nnz*sizeof(PetscInt));
167:       uj[nnz]    = array[0]; /* diagonal */
168:       array     += nnz + 1;
169:       row++;
170:     }

172:     a     = (*head)->more_space;
173:     PetscFree((*head)->array_head);
174:     PetscFree(*head);
175:     *head = a;
176:   }
177:   return(0);
178: }

182: PetscErrorCode PetscFreeSpaceDestroy(PetscFreeSpaceList head)
183: {
184:   PetscFreeSpaceList a;
185:   PetscErrorCode     ierr;

188:   while ((head)) {
189:     a    = (head)->more_space;
190:     PetscFree((head)->array_head);
191:     PetscFree(head);
192:     head = a;
193:   }
194:   return(0);
195: }