xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision 3a40ed3dce77c081171d005ae1a6ff4bb9d13b6f)
1 
2 #ifdef PETSC_RCS_HEADER
3 static char vcid[] = "$Id: fdmpiaij.c,v 1.12 1997/08/22 15:13:39 bsmith 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"
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   PetscFunctionBegin;
27   c->M             = mat->M;  /* set the global rows and columns and local rows */
28   c->N             = mat->N;
29   c->m             = mat->m;
30   c->rstart        = aij->rstart;
31 
32   c->ncolors       = nis;
33   c->ncolumns      = (int *) PetscMalloc( nis*sizeof(int) );   CHKPTRQ(c->ncolumns);
34   c->columns       = (int **) PetscMalloc( nis*sizeof(int *)); CHKPTRQ(c->columns);
35   c->nrows         = (int *) PetscMalloc( nis*sizeof(int) );   CHKPTRQ(c->nrows);
36   c->rows          = (int **) PetscMalloc( nis*sizeof(int *)); CHKPTRQ(c->rows);
37   c->columnsforrow = (int **) PetscMalloc( nis*sizeof(int *)); CHKPTRQ(c->columnsforrow);
38   PLogObjectMemory(c,5*nis*sizeof(int));
39 
40   /* Allow access to data structures of local part of matrix */
41   if (!aij->colmap) {
42     ierr = CreateColmap_MPIAIJ_Private(mat);CHKERRQ(ierr);
43   }
44   /*
45       Calls the _SeqAIJ() version of these routines to make sure it does not
46      get the reduced (by inodes) version of I and J
47   */
48   ierr = MatGetColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done); CHKERRQ(ierr);
49   ierr = MatGetColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done); CHKERRQ(ierr);
50 
51   MPI_Comm_size(mat->comm,&size);
52   ncolsonproc = (int *) PetscMalloc( 2*size*sizeof(int *) ); CHKPTRQ(ncolsonproc);
53   disp        = ncolsonproc + size;
54 
55   rowhit        = (int *) PetscMalloc( (M+1)*sizeof(int) ); CHKPTRQ(rowhit);
56   columnsforrow = (int *) PetscMalloc( (M+1)*sizeof(int) );CHKPTRQ(columnsforrow);
57 
58   /*
59      Temporary option to allow for debugging/testing
60   */
61   ierr = OptionsHasName(0,"-matfdcoloring_slow",&flg);
62 
63   for ( i=0; i<nis; i++ ) {
64     ierr = ISGetSize(isa[i],&n); CHKERRQ(ierr);
65     ierr = ISGetIndices(isa[i],&is); CHKERRQ(ierr);
66     c->ncolumns[i] = n;
67     c->ncolumns[i] = n;
68     if (n) {
69       c->columns[i]  = (int *) PetscMalloc( n*sizeof(int) ); CHKPTRQ(c->columns[i]);
70       PLogObjectMemory(c,n*sizeof(int));
71       PetscMemcpy(c->columns[i],is,n*sizeof(int));
72     } else {
73       c->columns[i]  = 0;
74     }
75 
76     /* Determine the total (parallel) number of columns of this color */
77     MPI_Allgather(&n,1,MPI_INT,ncolsonproc,1,MPI_INT,mat->comm);
78     nctot = 0; for ( j=0; j<size; j++ ) {nctot += ncolsonproc[j];}
79     if (!nctot) SETERRQ(1,0,"Invalid coloring");
80 
81     disp[0] = 0;
82     for ( j=1; j<size; j++ ) {
83       disp[j] = disp[j-1] + ncolsonproc[j-1];
84     }
85 
86     /* Get complete list of columns for color on each processor */
87     cols = (int *) PetscMalloc( nctot*sizeof(int) ); CHKPTRQ(cols);
88     MPI_Allgatherv(is,n,MPI_INT,cols,ncolsonproc,disp,MPI_INT,mat->comm);
89 
90 /*
91 for ( j=0; j<nctot; j++ ) {
92   printf("color %d %d col %d\n",i,j,cols[j]);
93 }
94 */
95 
96     /*
97        Mark all rows affect by these columns
98     */
99     if (flg) {/*-----------------------------------------------------------------------------*/
100       /* crude, slow version */
101       PetscMemzero(rowhit,M*sizeof(int));
102       /* loop over columns*/
103       for ( j=0; j<nctot; j++ ) {
104         col  = cols[j];
105         if (col >= cstart && col < cend) {
106           /* column is in diagonal block of matrix */
107           rows = A_cj + A_ci[col-cstart];
108           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
109         } else {
110           colb = aij->colmap[col] - 1;
111           if (colb == -1) {
112             m = 0;
113           } else {
114             rows = B_cj + B_ci[colb];
115             m    = B_ci[colb+1] - B_ci[colb];
116           }
117         }
118         /* loop over columns marking them in rowhit */
119         for ( k=0; k<m; k++ ) {
120           rowhit[*rows++] = col + 1;
121         }
122       }
123 
124 /*
125 printf("for col %d found rows \n",i);
126 for ( j=0; j<M; j++ ) printf("rhow hit %d %d\n",j,rowhit[j]);
127 */
128 
129       /* count the number of hits */
130       nrows = 0;
131       for ( j=0; j<M; j++ ) {
132         if (rowhit[j]) nrows++;
133       }
134       c->nrows[i]         = nrows;
135       c->rows[i]          = (int *) PetscMalloc((nrows+1)*sizeof(int)); CHKPTRQ(c->rows[i]);
136       c->columnsforrow[i] = (int *) PetscMalloc((nrows+1)*sizeof(int)); CHKPTRQ(c->columnsforrow[i]);
137       PLogObjectMemory(c,2*(nrows+1)*sizeof(int));
138       nrows = 0;
139       for ( j=0; j<M; j++ ) {
140         if (rowhit[j]) {
141           c->rows[i][nrows]           = j;
142           c->columnsforrow[i][nrows] = rowhit[j] - 1;
143           nrows++;
144         }
145       }
146     } else {/*-------------------------------------------------------------------------------*/
147       /* efficient version, using rowhit as a linked list */
148       int currentcol,fm,mfm;
149       rowhit[M] = M;
150       nrows     = 0;
151       /* loop over columns*/
152       for ( j=0; j<nctot; j++ ) {
153         col  = cols[j];
154         if (col >= cstart && col < cend) {
155           /* column is in diagonal block of matrix */
156           rows = A_cj + A_ci[col-cstart];
157           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
158         } else {
159           colb = aij->colmap[col] - 1;
160           if (colb == -1) {
161             m = 0;
162           } else {
163             rows = B_cj + B_ci[colb];
164             m    = B_ci[colb+1] - B_ci[colb];
165           }
166         }
167         /* loop over columns marking them in rowhit */
168         fm    = M; /* fm points to first entry in linked list */
169         for ( k=0; k<m; k++ ) {
170           currentcol = *rows++;
171 	  /* is it already in the list? */
172           do {
173             mfm  = fm;
174             fm   = rowhit[fm];
175           } while (fm < currentcol);
176           /* not in list so add it */
177           if (fm != currentcol) {
178             nrows++;
179             columnsforrow[currentcol] = col;
180             /* next three lines insert new entry into linked list */
181             rowhit[mfm]               = currentcol;
182             rowhit[currentcol]        = fm;
183             fm                        = currentcol;
184             /* fm points to present position in list since we know the columns are sorted */
185           } else {
186             SETERRQ(1,0,"Invalid coloring");
187           }
188         }
189       }
190       c->nrows[i]         = nrows;
191       c->rows[i]          = (int *)PetscMalloc((nrows+1)*sizeof(int));CHKPTRQ(c->rows[i]);
192       c->columnsforrow[i] = (int *)PetscMalloc((nrows+1)*sizeof(int));CHKPTRQ(c->columnsforrow[i]);
193       PLogObjectMemory(c,(nrows+1)*sizeof(int));
194       /* now store the linked list of rows into c->rows[i] */
195       nrows = 0;
196       fm    = rowhit[M];
197       do {
198         c->rows[i][nrows]            = fm;
199         c->columnsforrow[i][nrows++] = columnsforrow[fm];
200         fm                           = rowhit[fm];
201       } while (fm < M);
202     } /* ---------------------------------------------------------------------------------------*/
203     PetscFree(cols);
204   }
205   PetscFree(rowhit);
206   PetscFree(columnsforrow);
207   PetscFree(ncolsonproc);
208   ierr = MatRestoreColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done); CHKERRQ(ierr);
209   ierr = MatRestoreColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done); CHKERRQ(ierr);
210 
211   c->scale  = (Scalar *) PetscMalloc( 2*mat->N*sizeof(Scalar) ); CHKPTRQ(c->scale);
212   PLogObjectMemory(c,2*mat->N*sizeof(Scalar));
213   c->wscale = c->scale + mat->N;
214   PetscFunctionReturn(0);
215 }
216 
217