1 #include <../src/ksp/pc/impls/vpbjacobi/vpbjacobi.h> 2 3 static PetscErrorCode PCApply_VPBJacobi(PC pc, Vec x, Vec y) 4 { 5 PC_VPBJacobi *jac = (PC_VPBJacobi *)pc->data; 6 PetscInt i, ncnt = 0; 7 const MatScalar *diag = jac->diag; 8 PetscInt ib, jb, bs; 9 const PetscScalar *xx; 10 PetscScalar *yy, x0, x1, x2, x3, x4, x5, x6; 11 PetscInt nblocks; 12 const PetscInt *bsizes; 13 14 PetscFunctionBegin; 15 PetscCall(MatGetVariableBlockSizes(pc->pmat, &nblocks, &bsizes)); 16 PetscCall(VecGetArrayRead(x, &xx)); 17 PetscCall(VecGetArray(y, &yy)); 18 for (i = 0; i < nblocks; i++) { 19 bs = bsizes[i]; 20 switch (bs) { 21 case 1: 22 yy[ncnt] = *diag * xx[ncnt]; 23 break; 24 case 2: 25 x0 = xx[ncnt]; 26 x1 = xx[ncnt + 1]; 27 yy[ncnt] = diag[0] * x0 + diag[2] * x1; 28 yy[ncnt + 1] = diag[1] * x0 + diag[3] * x1; 29 break; 30 case 3: 31 x0 = xx[ncnt]; 32 x1 = xx[ncnt + 1]; 33 x2 = xx[ncnt + 2]; 34 yy[ncnt] = diag[0] * x0 + diag[3] * x1 + diag[6] * x2; 35 yy[ncnt + 1] = diag[1] * x0 + diag[4] * x1 + diag[7] * x2; 36 yy[ncnt + 2] = diag[2] * x0 + diag[5] * x1 + diag[8] * x2; 37 break; 38 case 4: 39 x0 = xx[ncnt]; 40 x1 = xx[ncnt + 1]; 41 x2 = xx[ncnt + 2]; 42 x3 = xx[ncnt + 3]; 43 yy[ncnt] = diag[0] * x0 + diag[4] * x1 + diag[8] * x2 + diag[12] * x3; 44 yy[ncnt + 1] = diag[1] * x0 + diag[5] * x1 + diag[9] * x2 + diag[13] * x3; 45 yy[ncnt + 2] = diag[2] * x0 + diag[6] * x1 + diag[10] * x2 + diag[14] * x3; 46 yy[ncnt + 3] = diag[3] * x0 + diag[7] * x1 + diag[11] * x2 + diag[15] * x3; 47 break; 48 case 5: 49 x0 = xx[ncnt]; 50 x1 = xx[ncnt + 1]; 51 x2 = xx[ncnt + 2]; 52 x3 = xx[ncnt + 3]; 53 x4 = xx[ncnt + 4]; 54 yy[ncnt] = diag[0] * x0 + diag[5] * x1 + diag[10] * x2 + diag[15] * x3 + diag[20] * x4; 55 yy[ncnt + 1] = diag[1] * x0 + diag[6] * x1 + diag[11] * x2 + diag[16] * x3 + diag[21] * x4; 56 yy[ncnt + 2] = diag[2] * x0 + diag[7] * x1 + diag[12] * x2 + diag[17] * x3 + diag[22] * x4; 57 yy[ncnt + 3] = diag[3] * x0 + diag[8] * x1 + diag[13] * x2 + diag[18] * x3 + diag[23] * x4; 58 yy[ncnt + 4] = diag[4] * x0 + diag[9] * x1 + diag[14] * x2 + diag[19] * x3 + diag[24] * x4; 59 break; 60 case 6: 61 x0 = xx[ncnt]; 62 x1 = xx[ncnt + 1]; 63 x2 = xx[ncnt + 2]; 64 x3 = xx[ncnt + 3]; 65 x4 = xx[ncnt + 4]; 66 x5 = xx[ncnt + 5]; 67 yy[ncnt] = diag[0] * x0 + diag[6] * x1 + diag[12] * x2 + diag[18] * x3 + diag[24] * x4 + diag[30] * x5; 68 yy[ncnt + 1] = diag[1] * x0 + diag[7] * x1 + diag[13] * x2 + diag[19] * x3 + diag[25] * x4 + diag[31] * x5; 69 yy[ncnt + 2] = diag[2] * x0 + diag[8] * x1 + diag[14] * x2 + diag[20] * x3 + diag[26] * x4 + diag[32] * x5; 70 yy[ncnt + 3] = diag[3] * x0 + diag[9] * x1 + diag[15] * x2 + diag[21] * x3 + diag[27] * x4 + diag[33] * x5; 71 yy[ncnt + 4] = diag[4] * x0 + diag[10] * x1 + diag[16] * x2 + diag[22] * x3 + diag[28] * x4 + diag[34] * x5; 72 yy[ncnt + 5] = diag[5] * x0 + diag[11] * x1 + diag[17] * x2 + diag[23] * x3 + diag[29] * x4 + diag[35] * x5; 73 break; 74 case 7: 75 x0 = xx[ncnt]; 76 x1 = xx[ncnt + 1]; 77 x2 = xx[ncnt + 2]; 78 x3 = xx[ncnt + 3]; 79 x4 = xx[ncnt + 4]; 80 x5 = xx[ncnt + 5]; 81 x6 = xx[ncnt + 6]; 82 yy[ncnt] = diag[0] * x0 + diag[7] * x1 + diag[14] * x2 + diag[21] * x3 + diag[28] * x4 + diag[35] * x5 + diag[42] * x6; 83 yy[ncnt + 1] = diag[1] * x0 + diag[8] * x1 + diag[15] * x2 + diag[22] * x3 + diag[29] * x4 + diag[36] * x5 + diag[43] * x6; 84 yy[ncnt + 2] = diag[2] * x0 + diag[9] * x1 + diag[16] * x2 + diag[23] * x3 + diag[30] * x4 + diag[37] * x5 + diag[44] * x6; 85 yy[ncnt + 3] = diag[3] * x0 + diag[10] * x1 + diag[17] * x2 + diag[24] * x3 + diag[31] * x4 + diag[38] * x5 + diag[45] * x6; 86 yy[ncnt + 4] = diag[4] * x0 + diag[11] * x1 + diag[18] * x2 + diag[25] * x3 + diag[32] * x4 + diag[39] * x5 + diag[46] * x6; 87 yy[ncnt + 5] = diag[5] * x0 + diag[12] * x1 + diag[19] * x2 + diag[26] * x3 + diag[33] * x4 + diag[40] * x5 + diag[47] * x6; 88 yy[ncnt + 6] = diag[6] * x0 + diag[13] * x1 + diag[20] * x2 + diag[27] * x3 + diag[34] * x4 + diag[41] * x5 + diag[48] * x6; 89 break; 90 default: 91 for (ib = 0; ib < bs; ib++) { 92 PetscScalar rowsum = 0; 93 for (jb = 0; jb < bs; jb++) rowsum += diag[ib + jb * bs] * xx[ncnt + jb]; 94 yy[ncnt + ib] = rowsum; 95 } 96 } 97 ncnt += bsizes[i]; 98 diag += bsizes[i] * bsizes[i]; 99 } 100 PetscCall(VecRestoreArrayRead(x, &xx)); 101 PetscCall(VecRestoreArray(y, &yy)); 102 PetscFunctionReturn(0); 103 } 104 105 PETSC_INTERN PetscErrorCode PCSetUp_VPBJacobi_Host(PC pc) 106 { 107 PC_VPBJacobi *jac = (PC_VPBJacobi *)pc->data; 108 Mat A = pc->pmat; 109 MatFactorError err; 110 PetscInt i, nsize = 0, nlocal; 111 PetscInt nblocks; 112 const PetscInt *bsizes; 113 114 PetscFunctionBegin; 115 PetscCall(MatGetVariableBlockSizes(pc->pmat, &nblocks, &bsizes)); 116 PetscCall(MatGetLocalSize(pc->pmat, &nlocal, NULL)); 117 PetscCheck(!nlocal || nblocks, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Must call MatSetVariableBlockSizes() before using PCVPBJACOBI"); 118 if (!jac->diag) { 119 for (i = 0; i < nblocks; i++) nsize += bsizes[i] * bsizes[i]; 120 PetscCall(PetscMalloc1(nsize, &jac->diag)); 121 } 122 PetscCall(MatInvertVariableBlockDiagonal(A, nblocks, bsizes, jac->diag)); 123 PetscCall(MatFactorGetError(A, &err)); 124 if (err) pc->failedreason = (PCFailedReason)err; 125 pc->ops->apply = PCApply_VPBJacobi; 126 PetscFunctionReturn(0); 127 } 128 129 static PetscErrorCode PCSetUp_VPBJacobi(PC pc) 130 { 131 PetscFunctionBegin; 132 /* In PCCreate_VPBJacobi() pmat might have not been set, so we wait to the last minute to do the dispatch */ 133 #if defined(PETSC_HAVE_CUDA) 134 PetscBool isCuda; 135 PetscCall(PetscObjectTypeCompareAny((PetscObject)pc->pmat, &isCuda, MATSEQAIJCUSPARSE, MATMPIAIJCUSPARSE, "")); 136 #endif 137 #if defined(PETSC_HAVE_KOKKOS_KERNELS) 138 PetscBool isKok; 139 PetscCall(PetscObjectTypeCompareAny((PetscObject)pc->pmat, &isKok, MATSEQAIJKOKKOS, MATMPIAIJKOKKOS, "")); 140 #endif 141 142 #if defined(PETSC_HAVE_CUDA) 143 if (isCuda) PetscCall(PCSetUp_VPBJacobi_CUDA(pc)); 144 else 145 #endif 146 #if defined(PETSC_HAVE_KOKKOS_KERNELS) 147 if (isKok) 148 PetscCall(PCSetUp_VPBJacobi_Kokkos(pc)); 149 else 150 #endif 151 { 152 PetscCall(PCSetUp_VPBJacobi_Host(pc)); 153 } 154 PetscFunctionReturn(0); 155 } 156 157 PETSC_INTERN PetscErrorCode PCDestroy_VPBJacobi(PC pc) 158 { 159 PC_VPBJacobi *jac = (PC_VPBJacobi *)pc->data; 160 161 PetscFunctionBegin; 162 /* 163 Free the private data structure that was hanging off the PC 164 */ 165 PetscCall(PetscFree(jac->diag)); 166 PetscCall(PetscFree(pc->data)); 167 PetscFunctionReturn(0); 168 } 169 170 /*MC 171 PCVPBJACOBI - Variable size point block Jacobi preconditioner 172 173 Level: beginner 174 175 Notes: 176 See `PCJACOBI` for point Jacobi preconditioning, `PCPBJACOBI` for fixed point block size, and `PCBJACOBI` for large size blocks 177 178 This works for `MATAIJ` matrices 179 180 Uses dense LU factorization with partial pivoting to invert the blocks; if a zero pivot 181 is detected a PETSc error is generated. 182 183 One must call `MatSetVariableBlockSizes()` to use this preconditioner 184 185 Developer Notes: 186 This should support the `PCSetErrorIfFailure()` flag set to `PETSC_TRUE` to allow 187 the factorization to continue even after a zero pivot is found resulting in a Nan and hence 188 terminating `KSP` with a `KSP_DIVERGED_NANORINF` allowing 189 a nonlinear solver/ODE integrator to recover without stopping the program as currently happens. 190 191 Perhaps should provide an option that allows generation of a valid preconditioner 192 even if a block is singular as the `PCJACOBI` does. 193 194 .seealso: `MatSetVariableBlockSizes()`, `PCCreate()`, `PCSetType()`, `PCType`, `PC`, `PCJACOBI`, `PCPBJACOBI`, `PCBJACOBI` 195 M*/ 196 197 PETSC_EXTERN PetscErrorCode PCCreate_VPBJacobi(PC pc) 198 { 199 PC_VPBJacobi *jac; 200 201 PetscFunctionBegin; 202 /* 203 Creates the private data structure for this preconditioner and 204 attach it to the PC object. 205 */ 206 PetscCall(PetscNew(&jac)); 207 pc->data = (void *)jac; 208 209 /* 210 Initialize the pointers to vectors to ZERO; these will be used to store 211 diagonal entries of the matrix for fast preconditioner application. 212 */ 213 jac->diag = NULL; 214 215 /* 216 Set the pointers for the functions that are provided above. 217 Now when the user-level routines (such as PCApply(), PCDestroy(), etc.) 218 are called, they will automatically call these functions. Note we 219 choose not to provide a couple of these functions since they are 220 not needed. 221 */ 222 pc->ops->apply = PCApply_VPBJacobi; 223 pc->ops->applytranspose = NULL; 224 pc->ops->setup = PCSetUp_VPBJacobi; 225 pc->ops->destroy = PCDestroy_VPBJacobi; 226 pc->ops->setfromoptions = NULL; 227 pc->ops->applyrichardson = NULL; 228 pc->ops->applysymmetricleft = NULL; 229 pc->ops->applysymmetricright = NULL; 230 PetscFunctionReturn(0); 231 } 232