xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision 52c87ff2747de67dfdd6ccb0bd18d7d7f8d26768)
1 
2 #ifdef PETSC_RCS_HEADER
3 static char vcid[] = "$Id: fdmpiaij.c,v 1.10 1997/07/09 20:54:04 balay Exp bsmith $";
4 #endif
5 
6 #include "src/mat/impls/aij/mpi/mpiaij.h"
7 #include "src/vec/vecimpl.h"
8 #include "petsc.h"
9 
10 extern int CreateColmap_MPIAIJ_Private(Mat);
11 extern int MatGetColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
12 extern int MatRestoreColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
13 
14 #undef __FUNC__
15 #define __FUNC__ "MatFDColoringCreate_MPIAIJ" /* ADIC Ignore */
16 int MatFDColoringCreate_MPIAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
17 {
18   Mat_MPIAIJ *aij = (Mat_MPIAIJ *) mat->data;
19   int        i,*is,n,nrows,j,k,m,*rows = 0,ierr,*A_ci,*A_cj,ncols,col,flg;
20   int        nis = iscoloring->n,*ncolsonproc,size,nctot,*cols,*disp,*B_ci,*B_cj;
21   int        *rowhit, M = mat->m,cstart = aij->cstart, cend = aij->cend,colb;
22   int        *columnsforrow;
23   IS         *isa = iscoloring->is;
24   PetscTruth done;
25 
26   c->M             = mat->M;  /* set the global rows and columns and local rows */
27   c->N             = mat->N;
28   c->m             = mat->m;
29   c->rstart        = aij->rstart;
30 
31   c->ncolors       = nis;
32   c->ncolumns      = (int *) PetscMalloc( nis*sizeof(int) );   CHKPTRQ(c->ncolumns);
33   c->columns       = (int **) PetscMalloc( nis*sizeof(int *)); CHKPTRQ(c->columns);
34   c->nrows         = (int *) PetscMalloc( nis*sizeof(int) );   CHKPTRQ(c->nrows);
35   c->rows          = (int **) PetscMalloc( nis*sizeof(int *)); CHKPTRQ(c->rows);
36   c->columnsforrow = (int **) PetscMalloc( nis*sizeof(int *)); CHKPTRQ(c->columnsforrow);
37   PLogObjectMemory(c,5*nis*sizeof(int));
38 
39   /* Allow access to data structures of local part of matrix */
40   if (!aij->colmap) {
41     ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
42   }
43   /*
44       Calls the _SeqAIJ() version of these routines to make sure it does not
45      get the reduced (by inodes) version of I and J
46   */
47   ierr = MatGetColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done); CHKERRQ(ierr);
48   ierr = MatGetColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done); CHKERRQ(ierr);
49 
50   MPI_Comm_size(mat->comm,&size);
51   ncolsonproc = (int *) PetscMalloc( 2*size*sizeof(int *) ); CHKPTRQ(ncolsonproc);
52   disp        = ncolsonproc + size;
53 
54   rowhit        = (int *) PetscMalloc( (M+1)*sizeof(int) ); CHKPTRQ(rowhit);
55   columnsforrow = (int *) PetscMalloc( (M+1)*sizeof(int) );CHKPTRQ(columnsforrow);
56 
57   /*
58      Temporary option to allow for debugging/testing
59   */
60   ierr = OptionsHasName(0,"-matfdcoloring_slow",&flg);
61 
62   for ( i=0; i<nis; i++ ) {
63     ierr = ISGetSize(isa[i],&n); CHKERRQ(ierr);
64     ierr = ISGetIndices(isa[i],&is); CHKERRQ(ierr);
65     c->ncolumns[i] = n;
66     c->ncolumns[i] = n;
67     if (n) {
68       c->columns[i]  = (int *) PetscMalloc( n*sizeof(int) ); CHKPTRQ(c->columns[i]);
69       PLogObjectMemory(c,n*sizeof(int));
70       PetscMemcpy(c->columns[i],is,n*sizeof(int));
71     } else {
72       c->columns[i]  = 0;
73     }
74 
75     /* Determine the total (parallel) number of columns of this color */
76     MPI_Allgather(&n,1,MPI_INT,ncolsonproc,1,MPI_INT,mat->comm);
77     nctot = 0; for ( j=0; j<size; j++ ) {nctot += ncolsonproc[j];}
78     if (!nctot) SETERRQ(1,0,"Invalid coloring");
79 
80     disp[0] = 0;
81     for ( j=1; j<size; j++ ) {
82       disp[j] = disp[j-1] + ncolsonproc[j-1];
83     }
84 
85     /* Get complete list of columns for color on each processor */
86     cols = (int *) PetscMalloc( nctot*sizeof(int) ); CHKPTRQ(cols);
87     MPI_Allgatherv(is,n,MPI_INT,cols,ncolsonproc,disp,MPI_INT,mat->comm);
88 
89 /*
90 for ( j=0; j<nctot; j++ ) {
91   printf("color %d %d col %d\n",i,j,cols[j]);
92 }
93 */
94 
95     /*
96        Mark all rows affect by these columns
97     */
98     if (flg) {/*-----------------------------------------------------------------------------*/
99       /* crude, slow version */
100       PetscMemzero(rowhit,M*sizeof(int));
101       /* loop over columns*/
102       for ( j=0; j<nctot; j++ ) {
103         col  = cols[j];
104         if (col >= cstart && col < cend) {
105           /* column is in diagonal block of matrix */
106           rows = A_cj + A_ci[col-cstart];
107           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
108         } else {
109           colb = aij->colmap[col] - 1;
110           if (colb == -1) {
111             m = 0;
112           } else {
113             rows = B_cj + B_ci[colb];
114             m    = B_ci[colb+1] - B_ci[colb];
115           }
116         }
117         /* loop over columns marking them in rowhit */
118         for ( k=0; k<m; k++ ) {
119           rowhit[*rows++] = col + 1;
120         }
121       }
122 
123 /*
124 printf("for col %d found rows \n",i);
125 for ( j=0; j<M; j++ ) printf("rhow hit %d %d\n",j,rowhit[j]);
126 */
127 
128       /* count the number of hits */
129       nrows = 0;
130       for ( j=0; j<M; j++ ) {
131         if (rowhit[j]) nrows++;
132       }
133       c->nrows[i]         = nrows;
134       c->rows[i]          = (int *) PetscMalloc((nrows+1)*sizeof(int)); CHKPTRQ(c->rows[i]);
135       c->columnsforrow[i] = (int *) PetscMalloc((nrows+1)*sizeof(int)); CHKPTRQ(c->columnsforrow[i]);
136       PLogObjectMemory(c,2*(nrows+1)*sizeof(int));
137       nrows = 0;
138       for ( j=0; j<M; j++ ) {
139         if (rowhit[j]) {
140           c->rows[i][nrows]           = j;
141           c->columnsforrow[i][nrows] = rowhit[j] - 1;
142           nrows++;
143         }
144       }
145     } else {/*-------------------------------------------------------------------------------*/
146       /* efficient version, using rowhit as a linked list */
147       int currentcol,fm,mfm;
148       rowhit[M] = M;
149       nrows     = 0;
150       /* loop over columns*/
151       for ( j=0; j<nctot; j++ ) {
152         col  = cols[j];
153         if (col >= cstart && col < cend) {
154           /* column is in diagonal block of matrix */
155           rows = A_cj + A_ci[col-cstart];
156           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
157         } else {
158           colb = aij->colmap[col] - 1;
159           if (colb == -1) {
160             m = 0;
161           } else {
162             rows = B_cj + B_ci[colb];
163             m    = B_ci[colb+1] - B_ci[colb];
164           }
165         }
166         /* loop over columns marking them in rowhit */
167         fm    = M; /* fm points to first entry in linked list */
168         for ( k=0; k<m; k++ ) {
169           currentcol = *rows++;
170 	  /* is it already in the list? */
171           do {
172             mfm  = fm;
173             fm   = rowhit[fm];
174           } while (fm < currentcol);
175           /* not in list so add it */
176           if (fm != currentcol) {
177             nrows++;
178             columnsforrow[currentcol] = col;
179             /* next three lines insert new entry into linked list */
180             rowhit[mfm]               = currentcol;
181             rowhit[currentcol]        = fm;
182             fm                        = currentcol;
183             /* fm points to present position in list since we know the columns are sorted */
184           } else {
185             SETERRQ(1,0,"Invalid coloring");
186           }
187         }
188       }
189       c->nrows[i]         = nrows;
190       c->rows[i]          = (int *)PetscMalloc((nrows+1)*sizeof(int));CHKPTRQ(c->rows[i]);
191       c->columnsforrow[i] = (int *)PetscMalloc((nrows+1)*sizeof(int));CHKPTRQ(c->columnsforrow[i]);
192       PLogObjectMemory(c,(nrows+1)*sizeof(int));
193       /* now store the linked list of rows into c->rows[i] */
194       nrows = 0;
195       fm    = rowhit[M];
196       do {
197         c->rows[i][nrows]            = fm;
198         c->columnsforrow[i][nrows++] = columnsforrow[fm];
199         fm                           = rowhit[fm];
200       } while (fm < M);
201     } /* ---------------------------------------------------------------------------------------*/
202     PetscFree(cols);
203   }
204   PetscFree(rowhit);
205   PetscFree(columnsforrow);
206   PetscFree(ncolsonproc);
207   ierr = MatRestoreColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done); CHKERRQ(ierr);
208   ierr = MatRestoreColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done); CHKERRQ(ierr);
209 
210   c->scale  = (Scalar *) PetscMalloc( 2*mat->N*sizeof(Scalar) ); CHKPTRQ(c->scale);
211   PLogObjectMemory(c,2*mat->N*sizeof(Scalar));
212   c->wscale = c->scale + mat->N;
213   return 0;
214 }
215 
216