xref: /petsc/src/mat/impls/aij/seq/fdaij.c (revision a8971b879276cca6863383fabd428e6708b69100)
1 
2 #include <../src/mat/impls/aij/seq/aij.h>
3 #include <../src/mat/impls/baij/seq/baij.h>
4 
5 /*
6     This routine is shared by SeqAIJ and SeqBAIJ matrices,
7     since it operators only on the nonzero structure of the elements or blocks.
8 */
9 #undef __FUNCT__
10 #define __FUNCT__ "MatFDColoringCreate_SeqXAIJ"
11 PetscErrorCode MatFDColoringCreate_SeqXAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
12 {
13   PetscErrorCode ierr;
14   PetscInt       bs,nis=iscoloring->n,m=mat->rmap->n;
15   PetscBool      isBAIJ;
16 
17   PetscFunctionBegin;
18   /* set default brows and bcols for speedup inserting the dense matrix into sparse Jacobian */
19   ierr = MatGetBlockSize(mat,&bs);CHKERRQ(ierr);
20   ierr = PetscObjectTypeCompare((PetscObject)mat,MATSEQBAIJ,&isBAIJ);CHKERRQ(ierr);
21   if (isBAIJ) {
22     c->brows = m;
23     c->bcols = 1;
24   } else { /* seqaij matrix */
25     /* bcols is chosen s.t. dy-array takes 50% of memory space as mat */
26     Mat_SeqAIJ *spA = (Mat_SeqAIJ*)mat->data;
27     PetscReal  mem;
28     PetscInt   nz,brows,bcols;
29 
30     bs    = 1; /* only bs=1 is supported for SeqAIJ matrix */
31 
32     nz    = spA->nz;
33     mem   = nz*(sizeof(PetscScalar) + sizeof(PetscInt)) + 3*m*sizeof(PetscInt);
34     bcols = (PetscInt)(0.5*mem /(m*sizeof(PetscScalar)));
35     brows = 1000/bcols;
36     if (bcols > nis) bcols = nis;
37     if (brows == 0 || brows > m) brows = m;
38     c->brows = brows;
39     c->bcols = bcols;
40   }
41 
42   c->M       = mat->rmap->N/bs;   /* set total rows, columns and local rows */
43   c->N       = mat->cmap->N/bs;
44   c->m       = mat->rmap->N/bs;
45   c->rstart  = 0;
46   c->ncolors = nis;
47   c->ctype   = IS_COLORING_GHOSTED;
48   PetscFunctionReturn(0);
49 }
50 
51 #undef __FUNCT__
52 #define __FUNCT__ "MatFDColoringSetUpBlocked_AIJ_Private"
53 PetscErrorCode MatFDColoringSetUpBlocked_AIJ_Private(Mat mat,MatFDColoring c,PetscInt nz)
54 {
55   PetscErrorCode ierr;
56   PetscInt       i,j,nrows,nbcols=0,brows=c->brows,bcols=c->bcols,mbs=c->m,*row_start,*nrows_new,nz_new,row_end,nis=c->ncolors;
57   PetscInt       *color_start;
58   MatEntry       *Jentry_new,*Jentry=c->matentry;
59 
60   PetscFunctionBegin;
61   if (brows < 1 || brows > mbs) brows = mbs;
62   ierr = PetscMalloc((nis+1)*sizeof(PetscInt),&color_start);CHKERRQ(ierr);
63   color_start[0] = 0;
64   for (i=0; i<nis; i++) color_start[i+1] = c->nrows[i] + color_start[i];
65 
66   ierr = PetscMalloc(nz*sizeof(MatEntry),&Jentry_new);CHKERRQ(ierr);
67   ierr = PetscMalloc(bcols*sizeof(PetscInt),&row_start);CHKERRQ(ierr);
68   ierr = PetscMalloc(nis*sizeof(PetscInt),&nrows_new);CHKERRQ(ierr);
69 
70   nz_new  = 0;
71   for (i=0; i<nis; i+=bcols) { /* loop over colors */
72     if (i + bcols > nis) bcols = nis - i;
73 
74     row_end = brows;
75     if (row_end > mbs) row_end = mbs;
76     for (j=0; j<bcols; j++) row_start[j] = 0;
77     while (row_end <= mbs) {   /* loop over block rows */
78       for (j=0; j<bcols; j++) {       /* loop over block columns */
79         nrows = c->nrows[i+j];
80         nz    = color_start[i+j];
81         while (row_start[j] < nrows) {
82           if (Jentry[nz].row >= row_end) {
83             color_start[i+j] = nz;
84             break;
85           } else { /* copy Jentry[nz] to Jentry_new[nz_new] */
86             Jentry_new[nz_new].row     = Jentry[nz].row + j*mbs; /* index in dy-array */
87             Jentry_new[nz_new].col     = Jentry[nz].col;
88             Jentry_new[nz_new].valaddr = Jentry[nz].valaddr;
89             nz_new++; nz++; row_start[j]++;
90           }
91         }
92       }
93       if (row_end == mbs) break;
94       row_end += brows;
95       if (row_end > mbs) row_end = mbs;
96     }
97     nrows_new[nbcols++] = nz_new;
98   }
99   for (i=nbcols-1; i>0; i--) nrows_new[i] -= nrows_new[i-1];
100   ierr = PetscFree(c->nrows);CHKERRQ(ierr);
101   c->nrows = nrows_new;
102 
103   ierr = PetscFree(Jentry);CHKERRQ(ierr);
104   c->matentry = Jentry_new;
105   ierr = PetscMalloc(c->bcols*mat->rmap->n*sizeof(PetscScalar),&c->dy);CHKERRQ(ierr);
106   ierr = PetscFree(row_start);CHKERRQ(ierr);
107   ierr = PetscFree(color_start);CHKERRQ(ierr);
108   PetscFunctionReturn(0);
109 }
110 
111 #undef __FUNCT__
112 #define __FUNCT__ "MatFDColoringSetUp_SeqXAIJ"
113 PetscErrorCode MatFDColoringSetUp_SeqXAIJ(Mat mat,ISColoring iscoloring,MatFDColoring c)
114 {
115   PetscErrorCode ierr;
116   PetscInt       i,n,nrows,mbs=c->m,j,k,m,ncols,col,nis=iscoloring->n,*rowhit,bs,bs2,*spidx,nz;
117   const PetscInt *is,*row,*ci,*cj;
118   IS             *isa;
119   PetscBool      isBAIJ;
120   PetscScalar    *A_val,**valaddrhit;
121   MatEntry       *Jentry;
122 
123   PetscFunctionBegin;
124   ierr = ISColoringGetIS(iscoloring,PETSC_IGNORE,&isa);CHKERRQ(ierr);
125 
126   ierr = MatGetBlockSize(mat,&bs);CHKERRQ(ierr);
127   ierr = PetscObjectTypeCompare((PetscObject)mat,MATSEQBAIJ,&isBAIJ);CHKERRQ(ierr);
128   if (isBAIJ) {
129     Mat_SeqBAIJ *spA = (Mat_SeqBAIJ*)mat->data;
130     A_val = spA->a;
131     nz    = spA->nz;
132   } else {
133     Mat_SeqAIJ  *spA = (Mat_SeqAIJ*)mat->data;
134     A_val = spA->a;
135     nz    = spA->nz;
136     bs    = 1; /* only bs=1 is supported for SeqAIJ matrix */
137   }
138 
139   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->ncolumns);CHKERRQ(ierr);
140   ierr       = PetscMalloc(nis*sizeof(PetscInt*),&c->columns);CHKERRQ(ierr);
141   ierr       = PetscMalloc(nis*sizeof(PetscInt),&c->nrows);CHKERRQ(ierr);
142   ierr       = PetscLogObjectMemory((PetscObject)c,3*nis*sizeof(PetscInt));CHKERRQ(ierr);
143 
144   ierr       = PetscMalloc(nz*sizeof(MatEntry),&Jentry);CHKERRQ(ierr);
145   ierr       = PetscLogObjectMemory((PetscObject)c,nz*sizeof(MatEntry));CHKERRQ(ierr);
146   c->matentry = Jentry;
147 
148   if (isBAIJ) {
149     ierr = MatGetColumnIJ_SeqBAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
150   } else {
151     ierr = MatGetColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
152   }
153 
154   ierr = PetscMalloc2(c->m,PetscInt,&rowhit,c->m,PetscScalar*,&valaddrhit);CHKERRQ(ierr);
155   ierr = PetscMemzero(rowhit,c->m*sizeof(PetscInt));CHKERRQ(ierr);
156 
157   nz = 0;
158   for (i=0; i<nis; i++) { /* loop over colors */
159     ierr = ISGetLocalSize(isa[i],&n);CHKERRQ(ierr);
160     ierr = ISGetIndices(isa[i],&is);CHKERRQ(ierr);
161 
162     c->ncolumns[i] = n;
163     if (n) {
164       ierr = PetscMalloc(n*sizeof(PetscInt),&c->columns[i]);CHKERRQ(ierr);
165       ierr = PetscLogObjectMemory((PetscObject)c,n*sizeof(PetscInt));CHKERRQ(ierr);
166       ierr = PetscMemcpy(c->columns[i],is,n*sizeof(PetscInt));CHKERRQ(ierr);
167     } else {
168       c->columns[i] = 0;
169     }
170 
171     /* fast, crude version requires O(N*N) work */
172     bs2   = bs*bs;
173     nrows = 0;
174     for (j=0; j<n; j++) {  /* loop over columns */
175       col    = is[j];
176       row    = cj + ci[col];
177       m      = ci[col+1] - ci[col];
178       nrows += m;
179       for (k=0; k<m; k++) {  /* loop over columns marking them in rowhit */
180         rowhit[*row]       = col + 1;
181         valaddrhit[*row++] = &A_val[bs2*spidx[ci[col] + k]];
182       }
183     }
184     c->nrows[i] = nrows; /* total num of rows for this color */
185 
186     for (j=0; j<mbs; j++) { /* loop over rows */
187       if (rowhit[j]) {
188         Jentry[nz].row     = j;              /* local row index */
189         Jentry[nz].col     = rowhit[j] - 1;  /* local column index */
190         Jentry[nz].valaddr = valaddrhit[j];  /* address of mat value for this entry */
191         nz++;
192         rowhit[j] = 0.0;                     /* zero rowhit for reuse */
193       }
194     }
195     ierr = ISRestoreIndices(isa[i],&is);CHKERRQ(ierr);
196   }
197 
198   if (c->bcols > 1) {  /* reorder Jentry for faster MatFDColoringApply() */
199     ierr = MatFDColoringSetUpBlocked_AIJ_Private(mat,c,nz);CHKERRQ(ierr);
200   }
201 
202   if (isBAIJ) {
203     ierr = MatRestoreColumnIJ_SeqBAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
204     ierr = PetscMalloc(bs*mat->rmap->n*sizeof(PetscScalar),&c->dy);CHKERRQ(ierr);
205   } else {
206     ierr = MatRestoreColumnIJ_SeqAIJ_Color(mat,0,PETSC_FALSE,PETSC_FALSE,&ncols,&ci,&cj,&spidx,NULL);CHKERRQ(ierr);
207   }
208   ierr = PetscFree2(rowhit,valaddrhit);CHKERRQ(ierr);
209   ierr = ISColoringRestoreIS(iscoloring,&isa);CHKERRQ(ierr);
210 
211   ierr = VecCreateGhost(PetscObjectComm((PetscObject)mat),mat->rmap->n,PETSC_DETERMINE,0,NULL,&c->vscale);CHKERRQ(ierr);
212   PetscFunctionReturn(0);
213 }
214