xref: /petsc/src/ksp/pc/impls/pbjacobi/pbjacobi.c (revision 22612f2f7cceb60caedd65384cdf99fc989f2aeb)
1 #define PETSCKSP_DLL
2 
3 /*
4    Include files needed for the PBJacobi preconditioner:
5      pcimpl.h - private include file intended for use by all preconditioners
6 */
7 
8 #include "private/pcimpl.h"   /*I "petscpc.h" I*/
9 
10 /*
11    Private context (data structure) for the PBJacobi preconditioner.
12 */
13 typedef struct {
14   PetscScalar *diag;
15   PetscInt    bs,mbs;
16 } PC_PBJacobi;
17 
18 /*
19    Currently only implemented for baij matrices and directly access baij
20   data structures.
21 */
22 #include "src/mat/impls/baij/mpi/mpibaij.h"
23 #include "src/inline/ilu.h"
24 
25 #undef __FUNCT__
26 #define __FUNCT__ "PCApply_PBJacobi_2"
27 static PetscErrorCode PCApply_PBJacobi_2(PC pc,Vec x,Vec y)
28 {
29   PC_PBJacobi    *jac = (PC_PBJacobi*)pc->data;
30   PetscErrorCode ierr;
31   PetscInt       i,m = jac->mbs;
32   PetscScalar    *diag = jac->diag,x0,x1,*xx,*yy;
33 
34   PetscFunctionBegin;
35   ierr = VecGetArray(x,&xx);CHKERRQ(ierr);
36   ierr = VecGetArray(y,&yy);CHKERRQ(ierr);
37   for (i=0; i<m; i++) {
38     x0 = xx[2*i]; x1 = xx[2*i+1];
39     yy[2*i]   = diag[0]*x0 + diag[2]*x1;
40     yy[2*i+1] = diag[1]*x0 + diag[3]*x1;
41     diag     += 4;
42   }
43   ierr = VecRestoreArray(x,&xx);CHKERRQ(ierr);
44   ierr = VecRestoreArray(y,&yy);CHKERRQ(ierr);
45   ierr = PetscLogFlops(6*m);CHKERRQ(ierr);
46   PetscFunctionReturn(0);
47 }
48 #undef __FUNCT__
49 #define __FUNCT__ "PCApply_PBJacobi_3"
50 static PetscErrorCode PCApply_PBJacobi_3(PC pc,Vec x,Vec y)
51 {
52   PC_PBJacobi    *jac = (PC_PBJacobi*)pc->data;
53   PetscErrorCode ierr;
54   PetscInt       i,m = jac->mbs;
55   PetscScalar    *diag = jac->diag,x0,x1,x2,*xx,*yy;
56 
57   PetscFunctionBegin;
58   ierr = VecGetArray(x,&xx);CHKERRQ(ierr);
59   ierr = VecGetArray(y,&yy);CHKERRQ(ierr);
60   for (i=0; i<m; i++) {
61     x0 = xx[3*i]; x1 = xx[3*i+1]; x2 = xx[3*i+2];
62     yy[3*i]   = diag[0]*x0 + diag[3]*x1 + diag[6]*x2;
63     yy[3*i+1] = diag[1]*x0 + diag[4]*x1 + diag[7]*x2;
64     yy[3*i+2] = diag[2]*x0 + diag[5]*x1 + diag[8]*x2;
65     diag     += 9;
66   }
67   ierr = VecRestoreArray(x,&xx);CHKERRQ(ierr);
68   ierr = VecRestoreArray(y,&yy);CHKERRQ(ierr);
69   ierr = PetscLogFlops(15*m);CHKERRQ(ierr);
70   PetscFunctionReturn(0);
71 }
72 #undef __FUNCT__
73 #define __FUNCT__ "PCApply_PBJacobi_4"
74 static PetscErrorCode PCApply_PBJacobi_4(PC pc,Vec x,Vec y)
75 {
76   PC_PBJacobi    *jac = (PC_PBJacobi*)pc->data;
77   PetscErrorCode ierr;
78   PetscInt       i,m = jac->mbs;
79   PetscScalar    *diag = jac->diag,x0,x1,x2,x3,*xx,*yy;
80 
81   PetscFunctionBegin;
82   ierr = VecGetArray(x,&xx);CHKERRQ(ierr);
83   ierr = VecGetArray(y,&yy);CHKERRQ(ierr);
84   for (i=0; i<m; i++) {
85     x0 = xx[4*i]; x1 = xx[4*i+1]; x2 = xx[4*i+2]; x3 = xx[4*i+3];
86     yy[4*i]   = diag[0]*x0 + diag[4]*x1 + diag[8]*x2  + diag[12]*x3;
87     yy[4*i+1] = diag[1]*x0 + diag[5]*x1 + diag[9]*x2  + diag[13]*x3;
88     yy[4*i+2] = diag[2]*x0 + diag[6]*x1 + diag[10]*x2 + diag[14]*x3;
89     yy[4*i+3] = diag[3]*x0 + diag[7]*x1 + diag[11]*x2 + diag[15]*x3;
90     diag     += 16;
91   }
92   ierr = VecRestoreArray(x,&xx);CHKERRQ(ierr);
93   ierr = VecRestoreArray(y,&yy);CHKERRQ(ierr);
94   ierr = PetscLogFlops(28*m);CHKERRQ(ierr);
95   PetscFunctionReturn(0);
96 }
97 #undef __FUNCT__
98 #define __FUNCT__ "PCApply_PBJacobi_5"
99 static PetscErrorCode PCApply_PBJacobi_5(PC pc,Vec x,Vec y)
100 {
101   PC_PBJacobi    *jac = (PC_PBJacobi*)pc->data;
102   PetscErrorCode ierr;
103   PetscInt       i,m = jac->mbs;
104   PetscScalar    *diag = jac->diag,x0,x1,x2,x3,x4,*xx,*yy;
105 
106   PetscFunctionBegin;
107   ierr = VecGetArray(x,&xx);CHKERRQ(ierr);
108   ierr = VecGetArray(y,&yy);CHKERRQ(ierr);
109   for (i=0; i<m; i++) {
110     x0 = xx[5*i]; x1 = xx[5*i+1]; x2 = xx[5*i+2]; x3 = xx[5*i+3]; x4 = xx[5*i+4];
111     yy[5*i]   = diag[0]*x0 + diag[5]*x1 + diag[10]*x2  + diag[15]*x3 + diag[20]*x4;
112     yy[5*i+1] = diag[1]*x0 + diag[6]*x1 + diag[11]*x2  + diag[16]*x3 + diag[21]*x4;
113     yy[5*i+2] = diag[2]*x0 + diag[7]*x1 + diag[12]*x2 + diag[17]*x3 + diag[22]*x4;
114     yy[5*i+3] = diag[3]*x0 + diag[8]*x1 + diag[13]*x2 + diag[18]*x3 + diag[23]*x4;
115     yy[5*i+4] = diag[4]*x0 + diag[9]*x1 + diag[14]*x2 + diag[19]*x3 + diag[24]*x4;
116     diag     += 25;
117   }
118   ierr = VecRestoreArray(x,&xx);CHKERRQ(ierr);
119   ierr = VecRestoreArray(y,&yy);CHKERRQ(ierr);
120   ierr = PetscLogFlops(45*m);CHKERRQ(ierr);
121   PetscFunctionReturn(0);
122 }
123 /* -------------------------------------------------------------------------- */
124 #undef __FUNCT__
125 #define __FUNCT__ "PCSetUp_PBJacobi"
126 static PetscErrorCode PCSetUp_PBJacobi(PC pc)
127 {
128   PC_PBJacobi    *jac = (PC_PBJacobi*)pc->data;
129   PetscErrorCode ierr;
130   PetscMPIInt    size;
131   PetscTruth     seqbaij,mpibaij,baij;
132   Mat            A = pc->pmat;
133   Mat_SeqBAIJ    *a;
134 
135   PetscFunctionBegin;
136   ierr = PetscTypeCompare((PetscObject)pc->pmat,MATSEQBAIJ,&seqbaij);CHKERRQ(ierr);
137   ierr = PetscTypeCompare((PetscObject)pc->pmat,MATMPIBAIJ,&mpibaij);CHKERRQ(ierr);
138   ierr = PetscTypeCompare((PetscObject)pc->pmat,MATBAIJ,&baij);CHKERRQ(ierr);
139   if (!seqbaij && !mpibaij && !baij) {
140     SETERRQ(PETSC_ERR_SUP,"Currently only supports BAIJ matrices");
141   }
142   ierr = MPI_Comm_size(pc->comm,&size);CHKERRQ(ierr);
143   if (mpibaij || (baij && (size > 1))) A = ((Mat_MPIBAIJ*)A->data)->A;
144   if (A->rmap.n != A->cmap.n) SETERRQ(PETSC_ERR_SUP,"Supported only for square matrices and square storage");
145 
146   ierr        =  MatSeqBAIJInvertBlockDiagonal(A);CHKERRQ(ierr);
147   a           = (Mat_SeqBAIJ*)A->data;
148   jac->diag   = a->idiag;
149   jac->bs     = A->rmap.bs;
150   jac->mbs    = a->mbs;
151   switch (jac->bs){
152     case 2:
153       pc->ops->apply = PCApply_PBJacobi_2;
154       break;
155     case 3:
156       pc->ops->apply = PCApply_PBJacobi_3;
157       break;
158     case 4:
159       pc->ops->apply = PCApply_PBJacobi_4;
160       break;
161     case 5:
162       pc->ops->apply = PCApply_PBJacobi_5;
163       break;
164     default:
165       SETERRQ1(PETSC_ERR_SUP,"not supported for block size %D",jac->bs);
166   }
167 
168   PetscFunctionReturn(0);
169 }
170 /* -------------------------------------------------------------------------- */
171 #undef __FUNCT__
172 #define __FUNCT__ "PCDestroy_PBJacobi"
173 static PetscErrorCode PCDestroy_PBJacobi(PC pc)
174 {
175   PC_PBJacobi    *jac = (PC_PBJacobi*)pc->data;
176   PetscErrorCode ierr;
177 
178   PetscFunctionBegin;
179   /*
180       Free the private data structure that was hanging off the PC
181   */
182   ierr = PetscFree(jac);CHKERRQ(ierr);
183   PetscFunctionReturn(0);
184 }
185 /* -------------------------------------------------------------------------- */
186 /*MC
187      PCPBJACOBI - Point block Jacobi
188 
189    Level: beginner
190 
191   Concepts: point block Jacobi
192 
193    Notes: Only implemented for the BAIJ matrix formats.
194 
195 .seealso:  PCCreate(), PCSetType(), PCType (for list of available types), PC
196 
197 M*/
198 
199 EXTERN_C_BEGIN
200 #undef __FUNCT__
201 #define __FUNCT__ "PCCreate_PBJacobi"
202 PetscErrorCode PETSCKSP_DLLEXPORT PCCreate_PBJacobi(PC pc)
203 {
204   PC_PBJacobi    *jac;
205   PetscErrorCode ierr;
206 
207   PetscFunctionBegin;
208 
209   /*
210      Creates the private data structure for this preconditioner and
211      attach it to the PC object.
212   */
213   ierr      = PetscNewLog(pc,PC_PBJacobi,&jac);CHKERRQ(ierr);
214   pc->data  = (void*)jac;
215 
216   /*
217      Initialize the pointers to vectors to ZERO; these will be used to store
218      diagonal entries of the matrix for fast preconditioner application.
219   */
220   jac->diag          = 0;
221 
222   /*
223       Set the pointers for the functions that are provided above.
224       Now when the user-level routines (such as PCApply(), PCDestroy(), etc.)
225       are called, they will automatically call these functions.  Note we
226       choose not to provide a couple of these functions since they are
227       not needed.
228   */
229   pc->ops->apply               = 0; /*set depending on the block size */
230   pc->ops->applytranspose      = 0;
231   pc->ops->setup               = PCSetUp_PBJacobi;
232   pc->ops->destroy             = PCDestroy_PBJacobi;
233   pc->ops->setfromoptions      = 0;
234   pc->ops->view                = 0;
235   pc->ops->applyrichardson     = 0;
236   pc->ops->applysymmetricleft  = 0;
237   pc->ops->applysymmetricright = 0;
238   PetscFunctionReturn(0);
239 }
240 EXTERN_C_END
241 
242 
243