xref: /petsc/src/mat/impls/aij/mpi/fdmpiaij.c (revision da0e36291a7faffe80bfe1f7d38bec47da9a7fbe)
1 /*$Id: fdmpiaij.c,v 1.33 2000/05/15 18:42:52 bsmith Exp bsmith $*/
2 
3 #include "src/mat/impls/aij/mpi/mpiaij.h"
4 #include "src/vec/vecimpl.h"
5 
6 EXTERN int CreateColmap_MPIAIJ_Private(Mat);
7 EXTERN int MatGetColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
8 EXTERN int MatRestoreColumnIJ_SeqAIJ(Mat,int,PetscTruth,int*,int**,int**,PetscTruth*);
9 
10 #undef __FUNC__
11 #define __FUNC__ /*<a name=""></a>*/"MatFDColoringCreate_MPIAIJ"
12 int MatFDColoringCreate_MPIAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
13 {
14   Mat_MPIAIJ *aij = (Mat_MPIAIJ*)mat->data;
15   int        i,*is,n,nrows,j,k,m,*rows = 0,ierr,*A_ci,*A_cj,ncols,col;
16   int        nis = iscoloring->n,*ncolsonproc,size,nctot,*cols,*disp,*B_ci,*B_cj;
17   int        *rowhit,M = mat->m,cstart = aij->cstart,cend = aij->cend,colb;
18   int        *columnsforrow,l;
19   IS         *isa = iscoloring->is;
20   PetscTruth done,flg;
21 
22   PetscFunctionBegin;
23   if (!mat->assembled) {
24     SETERRQ(PETSC_ERR_ARG_WRONGSTATE,1,"Matrix must be assembled first; MatAssemblyBegin/End();");
25   }
26 
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   ierr          = MPI_Comm_size(mat->comm,&size);CHKERRQ(ierr);
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(PETSC_NULL,"-matfdcoloring_slow",&flg);CHKERRQ(ierr);
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       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(int));CHKERRQ(ierr);
72     } else {
73       c->columns[i]  = 0;
74     }
75 
76     /* Determine the total (parallel) number of columns of this color */
77     ierr = MPI_Allgather(&n,1,MPI_INT,ncolsonproc,1,MPI_INT,mat->comm);CHKERRQ(ierr);
78     nctot = 0; for (j=0; j<size; j++) {nctot += ncolsonproc[j];}
79     if (!nctot) SETERRQ(PETSC_ERR_PLIB,0,"Invalid coloring of matrix detected");
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     ierr = MPI_Allgatherv(is,n,MPI_INT,cols,ncolsonproc,disp,MPI_INT,mat->comm);CHKERRQ(ierr);
89 
90     /*
91        Mark all rows affect by these columns
92     */
93     if (flg) {/*-----------------------------------------------------------------------------*/
94       /* crude, slow version */
95       ierr = PetscMemzero(rowhit,M*sizeof(int));CHKERRQ(ierr);
96       /* loop over columns*/
97       for (j=0; j<nctot; j++) {
98         col  = cols[j];
99         if (col >= cstart && col < cend) {
100           /* column is in diagonal block of matrix */
101           rows = A_cj + A_ci[col-cstart];
102           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
103         } else {
104 #if defined (PETSC_USE_CTABLE)
105           ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr)
106 	  colb --;
107 #else
108           colb = aij->colmap[col] - 1;
109 #endif
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       /* count the number of hits */
124       nrows = 0;
125       for (j=0; j<M; j++) {
126         if (rowhit[j]) nrows++;
127       }
128       c->nrows[i]         = nrows;
129       c->rows[i]          = (int*)PetscMalloc((nrows+1)*sizeof(int));CHKPTRQ(c->rows[i]);
130       c->columnsforrow[i] = (int*)PetscMalloc((nrows+1)*sizeof(int));CHKPTRQ(c->columnsforrow[i]);
131       PLogObjectMemory(c,2*(nrows+1)*sizeof(int));
132       nrows = 0;
133       for (j=0; j<M; j++) {
134         if (rowhit[j]) {
135           c->rows[i][nrows]           = j;
136           c->columnsforrow[i][nrows] = rowhit[j] - 1;
137           nrows++;
138         }
139       }
140     } else {/*-------------------------------------------------------------------------------*/
141       /* efficient version, using rowhit as a linked list */
142       int currentcol,fm,mfm;
143       rowhit[M] = M;
144       nrows     = 0;
145       /* loop over columns*/
146       for (j=0; j<nctot; j++) {
147         col  = cols[j];
148         if (col >= cstart && col < cend) {
149           /* column is in diagonal block of matrix */
150           rows = A_cj + A_ci[col-cstart];
151           m    = A_ci[col-cstart+1] - A_ci[col-cstart];
152         } else {
153 #if defined (PETSC_USE_CTABLE)
154 	  ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
155           colb --;
156 #else
157           colb = aij->colmap[col] - 1;
158 #endif
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(PETSC_ERR_PLIB,0,"Invalid coloring of matrix detected");
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     ierr = PetscFree(cols);CHKERRQ(ierr);
203   }
204 
205   /* Optimize by adding the vscale, and scaleforrow[][] fields */
206   /*
207        vscale will contain the "diagonal" on processor scalings followed by the off processor
208   */
209   ierr = VecCreateGhost(mat->comm,aij->A->m,PETSC_DETERMINE,aij->B->n,aij->garray,&c->vscale);CHKERRQ(ierr)
210   c->vscaleforrow   = (int**)PetscMalloc(c->ncolors*sizeof(int*));CHKPTRQ(c->vscaleforrow);
211   for (k=0; k<c->ncolors; k++) {
212     c->vscaleforrow[k] = (int*)PetscMalloc((c->nrows[k]+1)*sizeof(int));CHKPTRQ(c->vscaleforrow[k]);
213     for (l=0; l<c->nrows[k]; l++) {
214       col = c->columnsforrow[k][l];
215       if (col >= cstart && col < cend) {
216         /* column is in diagonal block of matrix */
217         colb = col - cstart;
218       } else {
219         /* column  is in "off-processor" part */
220 #if defined (PETSC_USE_CTABLE)
221         ierr = PetscTableFind(aij->colmap,col+1,&colb);CHKERRQ(ierr);
222         colb --;
223 #else
224         colb = aij->colmap[col] - 1;
225 #endif
226         colb += cend - cstart;
227       }
228       c->vscaleforrow[k][l] = colb;
229     }
230   }
231 
232   ierr = PetscFree(rowhit);CHKERRQ(ierr);
233   ierr = PetscFree(columnsforrow);CHKERRQ(ierr);
234   ierr = PetscFree(ncolsonproc);CHKERRQ(ierr);
235   ierr = MatRestoreColumnIJ_SeqAIJ(aij->A,0,PETSC_FALSE,&ncols,&A_ci,&A_cj,&done);CHKERRQ(ierr);
236   ierr = MatRestoreColumnIJ_SeqAIJ(aij->B,0,PETSC_FALSE,&ncols,&B_ci,&B_cj,&done);CHKERRQ(ierr);
237   PetscFunctionReturn(0);
238 }
239 
240