xref: /petsc/src/ksp/pc/impls/mg/smg.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
1 
2 /*
3      Additive Multigrid V Cycle routine
4 */
5 #include <petsc/private/pcmgimpl.h>
6 
7 PetscErrorCode PCMGACycle_Private(PC pc,PC_MG_Levels **mglevels,PetscBool transpose,PetscBool matapp)
8 {
9   PetscInt       i,l = mglevels[0]->levels;
10 
11   PetscFunctionBegin;
12   /* compute RHS on each level */
13   for (i=l-1; i>0; i--) {
14     if (mglevels[i]->eventinterprestrict) PetscCall(PetscLogEventBegin(mglevels[i]->eventinterprestrict,0,0,0,0));
15     if (!transpose) {
16       if (matapp) PetscCall(MatMatRestrict(mglevels[i]->restrct,mglevels[i]->B,&mglevels[i-1]->B));
17       else PetscCall(MatRestrict(mglevels[i]->restrct,mglevels[i]->b,mglevels[i-1]->b));
18     } else {
19       if (matapp) PetscCall(MatMatRestrict(mglevels[i]->interpolate,mglevels[i]->B,&mglevels[i-1]->B));
20       else PetscCall(MatRestrict(mglevels[i]->interpolate,mglevels[i]->b,mglevels[i-1]->b));
21     }
22     if (mglevels[i]->eventinterprestrict) PetscCall(PetscLogEventEnd(mglevels[i]->eventinterprestrict,0,0,0,0));
23   }
24   /* solve separately on each level */
25   for (i=0; i<l; i++) {
26     if (matapp) {
27       if (!mglevels[i]->X) {
28         PetscCall(MatDuplicate(mglevels[i]->B,MAT_DO_NOT_COPY_VALUES,&mglevels[i]->X));
29       } else {
30         PetscCall(MatZeroEntries(mglevels[i]->X));
31       }
32     } else {
33       PetscCall(VecZeroEntries(mglevels[i]->x));
34     }
35     if (mglevels[i]->eventsmoothsolve) PetscCall(PetscLogEventBegin(mglevels[i]->eventsmoothsolve,0,0,0,0));
36     if (!transpose) {
37       if (matapp) {
38         PetscCall(KSPMatSolve(mglevels[i]->smoothd,mglevels[i]->B,mglevels[i]->X));
39         PetscCall(KSPCheckSolve(mglevels[i]->smoothd,pc,NULL));
40       } else {
41         PetscCall(KSPSolve(mglevels[i]->smoothd,mglevels[i]->b,mglevels[i]->x));
42         PetscCall(KSPCheckSolve(mglevels[i]->smoothd,pc,mglevels[i]->x));
43       }
44     } else {
45       PetscCheck(!matapp,PetscObjectComm((PetscObject)pc),PETSC_ERR_SUP,"Not supported");
46       PetscCall(KSPSolveTranspose(mglevels[i]->smoothu,mglevels[i]->b,mglevels[i]->x));
47       PetscCall(KSPCheckSolve(mglevels[i]->smoothu,pc,mglevels[i]->x));
48     }
49     if (mglevels[i]->eventsmoothsolve) PetscCall(PetscLogEventEnd(mglevels[i]->eventsmoothsolve,0,0,0,0));
50   }
51   for (i=1; i<l; i++) {
52     if (mglevels[i]->eventinterprestrict) PetscCall(PetscLogEventBegin(mglevels[i]->eventinterprestrict,0,0,0,0));
53     if (!transpose) {
54       if (matapp) PetscCall(MatMatInterpolateAdd(mglevels[i]->interpolate,mglevels[i-1]->X,mglevels[i]->X,&mglevels[i]->X));
55       else PetscCall(MatInterpolateAdd(mglevels[i]->interpolate,mglevels[i-1]->x,mglevels[i]->x,mglevels[i]->x));
56     } else {
57       if (matapp) PetscCall(MatMatInterpolateAdd(mglevels[i]->restrct,mglevels[i-1]->X,mglevels[i]->X,&mglevels[i]->X));
58       else PetscCall(MatInterpolateAdd(mglevels[i]->restrct,mglevels[i-1]->x,mglevels[i]->x,mglevels[i]->x));
59     }
60     if (mglevels[i]->eventinterprestrict) PetscCall(PetscLogEventEnd(mglevels[i]->eventinterprestrict,0,0,0,0));
61   }
62   PetscFunctionReturn(0);
63 }
64