xref: /petsc/src/mat/impls/aij/seq/aij.c (revision ef87514f82c7b25b6fb8e051605bd2db44a73083)
1 /*
2     Defines the basic matrix operations for the AIJ (compressed row)
3   matrix storage format.
4 */
5 
6 #include <../src/mat/impls/aij/seq/aij.h> /*I "petscmat.h" I*/
7 #include <petscblaslapack.h>
8 #include <petscbt.h>
9 #include <petsc/private/kernels/blocktranspose.h>
10 
11 /* defines MatSetValues_Seq_Hash(), MatAssemblyEnd_Seq_Hash(), MatSetUp_Seq_Hash() */
12 #define TYPE AIJ
13 #define TYPE_BS
14 #include "../src/mat/impls/aij/seq/seqhashmatsetvalues.h"
15 #include "../src/mat/impls/aij/seq/seqhashmat.h"
16 #undef TYPE
17 #undef TYPE_BS
18 
19 static PetscErrorCode MatSeqAIJSetTypeFromOptions(Mat A)
20 {
21   PetscBool flg;
22   char      type[256];
23 
24   PetscFunctionBegin;
25   PetscObjectOptionsBegin((PetscObject)A);
26   PetscCall(PetscOptionsFList("-mat_seqaij_type", "Matrix SeqAIJ type", "MatSeqAIJSetType", MatSeqAIJList, "seqaij", type, 256, &flg));
27   if (flg) PetscCall(MatSeqAIJSetType(A, type));
28   PetscOptionsEnd();
29   PetscFunctionReturn(PETSC_SUCCESS);
30 }
31 
32 static PetscErrorCode MatGetColumnReductions_SeqAIJ(Mat A, PetscInt type, PetscReal *reductions)
33 {
34   PetscInt    i, m, n;
35   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
36 
37   PetscFunctionBegin;
38   PetscCall(MatGetSize(A, &m, &n));
39   PetscCall(PetscArrayzero(reductions, n));
40   if (type == NORM_2) {
41     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscAbsScalar(aij->a[i] * aij->a[i]);
42   } else if (type == NORM_1) {
43     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscAbsScalar(aij->a[i]);
44   } else if (type == NORM_INFINITY) {
45     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] = PetscMax(PetscAbsScalar(aij->a[i]), reductions[aij->j[i]]);
46   } else if (type == REDUCTION_SUM_REALPART || type == REDUCTION_MEAN_REALPART) {
47     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscRealPart(aij->a[i]);
48   } else if (type == REDUCTION_SUM_IMAGINARYPART || type == REDUCTION_MEAN_IMAGINARYPART) {
49     for (i = 0; i < aij->i[m]; i++) reductions[aij->j[i]] += PetscImaginaryPart(aij->a[i]);
50   } else SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Unknown reduction type");
51 
52   if (type == NORM_2) {
53     for (i = 0; i < n; i++) reductions[i] = PetscSqrtReal(reductions[i]);
54   } else if (type == REDUCTION_MEAN_REALPART || type == REDUCTION_MEAN_IMAGINARYPART) {
55     for (i = 0; i < n; i++) reductions[i] /= m;
56   }
57   PetscFunctionReturn(PETSC_SUCCESS);
58 }
59 
60 static PetscErrorCode MatFindOffBlockDiagonalEntries_SeqAIJ(Mat A, IS *is)
61 {
62   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
63   PetscInt        i, m = A->rmap->n, cnt = 0, bs = A->rmap->bs;
64   const PetscInt *jj = a->j, *ii = a->i;
65   PetscInt       *rows;
66 
67   PetscFunctionBegin;
68   for (i = 0; i < m; i++) {
69     if ((ii[i] != ii[i + 1]) && ((jj[ii[i]] < bs * (i / bs)) || (jj[ii[i + 1] - 1] > bs * ((i + bs) / bs) - 1))) cnt++;
70   }
71   PetscCall(PetscMalloc1(cnt, &rows));
72   cnt = 0;
73   for (i = 0; i < m; i++) {
74     if ((ii[i] != ii[i + 1]) && ((jj[ii[i]] < bs * (i / bs)) || (jj[ii[i + 1] - 1] > bs * ((i + bs) / bs) - 1))) {
75       rows[cnt] = i;
76       cnt++;
77     }
78   }
79   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, cnt, rows, PETSC_OWN_POINTER, is));
80   PetscFunctionReturn(PETSC_SUCCESS);
81 }
82 
83 PetscErrorCode MatFindZeroDiagonals_SeqAIJ_Private(Mat A, PetscInt *nrows, PetscInt **zrows)
84 {
85   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
86   const MatScalar *aa;
87   PetscInt         i, m = A->rmap->n, cnt = 0;
88   const PetscInt  *ii = a->i, *jj = a->j, *diag;
89   PetscInt        *rows;
90 
91   PetscFunctionBegin;
92   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
93   PetscCall(MatMarkDiagonal_SeqAIJ(A));
94   diag = a->diag;
95   for (i = 0; i < m; i++) {
96     if ((diag[i] >= ii[i + 1]) || (jj[diag[i]] != i) || (aa[diag[i]] == 0.0)) cnt++;
97   }
98   PetscCall(PetscMalloc1(cnt, &rows));
99   cnt = 0;
100   for (i = 0; i < m; i++) {
101     if ((diag[i] >= ii[i + 1]) || (jj[diag[i]] != i) || (aa[diag[i]] == 0.0)) rows[cnt++] = i;
102   }
103   *nrows = cnt;
104   *zrows = rows;
105   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
106   PetscFunctionReturn(PETSC_SUCCESS);
107 }
108 
109 static PetscErrorCode MatFindZeroDiagonals_SeqAIJ(Mat A, IS *zrows)
110 {
111   PetscInt nrows, *rows;
112 
113   PetscFunctionBegin;
114   *zrows = NULL;
115   PetscCall(MatFindZeroDiagonals_SeqAIJ_Private(A, &nrows, &rows));
116   PetscCall(ISCreateGeneral(PetscObjectComm((PetscObject)A), nrows, rows, PETSC_OWN_POINTER, zrows));
117   PetscFunctionReturn(PETSC_SUCCESS);
118 }
119 
120 static PetscErrorCode MatFindNonzeroRows_SeqAIJ(Mat A, IS *keptrows)
121 {
122   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
123   const MatScalar *aa;
124   PetscInt         m = A->rmap->n, cnt = 0;
125   const PetscInt  *ii;
126   PetscInt         n, i, j, *rows;
127 
128   PetscFunctionBegin;
129   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
130   *keptrows = NULL;
131   ii        = a->i;
132   for (i = 0; i < m; i++) {
133     n = ii[i + 1] - ii[i];
134     if (!n) {
135       cnt++;
136       goto ok1;
137     }
138     for (j = ii[i]; j < ii[i + 1]; j++) {
139       if (aa[j] != 0.0) goto ok1;
140     }
141     cnt++;
142   ok1:;
143   }
144   if (!cnt) {
145     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
146     PetscFunctionReturn(PETSC_SUCCESS);
147   }
148   PetscCall(PetscMalloc1(A->rmap->n - cnt, &rows));
149   cnt = 0;
150   for (i = 0; i < m; i++) {
151     n = ii[i + 1] - ii[i];
152     if (!n) continue;
153     for (j = ii[i]; j < ii[i + 1]; j++) {
154       if (aa[j] != 0.0) {
155         rows[cnt++] = i;
156         break;
157       }
158     }
159   }
160   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
161   PetscCall(ISCreateGeneral(PETSC_COMM_SELF, cnt, rows, PETSC_OWN_POINTER, keptrows));
162   PetscFunctionReturn(PETSC_SUCCESS);
163 }
164 
165 PetscErrorCode MatDiagonalSet_SeqAIJ(Mat Y, Vec D, InsertMode is)
166 {
167   Mat_SeqAIJ        *aij = (Mat_SeqAIJ *)Y->data;
168   PetscInt           i, m = Y->rmap->n;
169   const PetscInt    *diag;
170   MatScalar         *aa;
171   const PetscScalar *v;
172   PetscBool          missing;
173 
174   PetscFunctionBegin;
175   if (Y->assembled) {
176     PetscCall(MatMissingDiagonal_SeqAIJ(Y, &missing, NULL));
177     if (!missing) {
178       diag = aij->diag;
179       PetscCall(VecGetArrayRead(D, &v));
180       PetscCall(MatSeqAIJGetArray(Y, &aa));
181       if (is == INSERT_VALUES) {
182         for (i = 0; i < m; i++) aa[diag[i]] = v[i];
183       } else {
184         for (i = 0; i < m; i++) aa[diag[i]] += v[i];
185       }
186       PetscCall(MatSeqAIJRestoreArray(Y, &aa));
187       PetscCall(VecRestoreArrayRead(D, &v));
188       PetscFunctionReturn(PETSC_SUCCESS);
189     }
190     PetscCall(MatSeqAIJInvalidateDiagonal(Y));
191   }
192   PetscCall(MatDiagonalSet_Default(Y, D, is));
193   PetscFunctionReturn(PETSC_SUCCESS);
194 }
195 
196 PetscErrorCode MatGetRowIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *m, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
197 {
198   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
199   PetscInt    i, ishift;
200 
201   PetscFunctionBegin;
202   if (m) *m = A->rmap->n;
203   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
204   ishift = 0;
205   if (symmetric && A->structurally_symmetric != PETSC_BOOL3_TRUE) {
206     PetscCall(MatToSymmetricIJ_SeqAIJ(A->rmap->n, a->i, a->j, PETSC_TRUE, ishift, oshift, (PetscInt **)ia, (PetscInt **)ja));
207   } else if (oshift == 1) {
208     PetscInt *tia;
209     PetscInt  nz = a->i[A->rmap->n];
210     /* malloc space and  add 1 to i and j indices */
211     PetscCall(PetscMalloc1(A->rmap->n + 1, &tia));
212     for (i = 0; i < A->rmap->n + 1; i++) tia[i] = a->i[i] + 1;
213     *ia = tia;
214     if (ja) {
215       PetscInt *tja;
216       PetscCall(PetscMalloc1(nz + 1, &tja));
217       for (i = 0; i < nz; i++) tja[i] = a->j[i] + 1;
218       *ja = tja;
219     }
220   } else {
221     *ia = a->i;
222     if (ja) *ja = a->j;
223   }
224   PetscFunctionReturn(PETSC_SUCCESS);
225 }
226 
227 PetscErrorCode MatRestoreRowIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
228 {
229   PetscFunctionBegin;
230   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
231   if ((symmetric && A->structurally_symmetric != PETSC_BOOL3_TRUE) || oshift == 1) {
232     PetscCall(PetscFree(*ia));
233     if (ja) PetscCall(PetscFree(*ja));
234   }
235   PetscFunctionReturn(PETSC_SUCCESS);
236 }
237 
238 PetscErrorCode MatGetColumnIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
239 {
240   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
241   PetscInt    i, *collengths, *cia, *cja, n = A->cmap->n, m = A->rmap->n;
242   PetscInt    nz = a->i[m], row, *jj, mr, col;
243 
244   PetscFunctionBegin;
245   *nn = n;
246   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
247   if (symmetric) {
248     PetscCall(MatToSymmetricIJ_SeqAIJ(A->rmap->n, a->i, a->j, PETSC_TRUE, 0, oshift, (PetscInt **)ia, (PetscInt **)ja));
249   } else {
250     PetscCall(PetscCalloc1(n, &collengths));
251     PetscCall(PetscMalloc1(n + 1, &cia));
252     PetscCall(PetscMalloc1(nz, &cja));
253     jj = a->j;
254     for (i = 0; i < nz; i++) collengths[jj[i]]++;
255     cia[0] = oshift;
256     for (i = 0; i < n; i++) cia[i + 1] = cia[i] + collengths[i];
257     PetscCall(PetscArrayzero(collengths, n));
258     jj = a->j;
259     for (row = 0; row < m; row++) {
260       mr = a->i[row + 1] - a->i[row];
261       for (i = 0; i < mr; i++) {
262         col = *jj++;
263 
264         cja[cia[col] + collengths[col]++ - oshift] = row + oshift;
265       }
266     }
267     PetscCall(PetscFree(collengths));
268     *ia = cia;
269     *ja = cja;
270   }
271   PetscFunctionReturn(PETSC_SUCCESS);
272 }
273 
274 PetscErrorCode MatRestoreColumnIJ_SeqAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
275 {
276   PetscFunctionBegin;
277   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
278 
279   PetscCall(PetscFree(*ia));
280   PetscCall(PetscFree(*ja));
281   PetscFunctionReturn(PETSC_SUCCESS);
282 }
283 
284 /*
285  MatGetColumnIJ_SeqAIJ_Color() and MatRestoreColumnIJ_SeqAIJ_Color() are customized from
286  MatGetColumnIJ_SeqAIJ() and MatRestoreColumnIJ_SeqAIJ() by adding an output
287  spidx[], index of a->a, to be used in MatTransposeColoringCreate_SeqAIJ() and MatFDColoringCreate_SeqXAIJ()
288 */
289 PetscErrorCode MatGetColumnIJ_SeqAIJ_Color(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscInt *spidx[], PetscBool *done)
290 {
291   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
292   PetscInt        i, *collengths, *cia, *cja, n = A->cmap->n, m = A->rmap->n;
293   PetscInt        nz = a->i[m], row, mr, col, tmp;
294   PetscInt       *cspidx;
295   const PetscInt *jj;
296 
297   PetscFunctionBegin;
298   *nn = n;
299   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
300 
301   PetscCall(PetscCalloc1(n, &collengths));
302   PetscCall(PetscMalloc1(n + 1, &cia));
303   PetscCall(PetscMalloc1(nz, &cja));
304   PetscCall(PetscMalloc1(nz, &cspidx));
305   jj = a->j;
306   for (i = 0; i < nz; i++) collengths[jj[i]]++;
307   cia[0] = oshift;
308   for (i = 0; i < n; i++) cia[i + 1] = cia[i] + collengths[i];
309   PetscCall(PetscArrayzero(collengths, n));
310   jj = a->j;
311   for (row = 0; row < m; row++) {
312     mr = a->i[row + 1] - a->i[row];
313     for (i = 0; i < mr; i++) {
314       col         = *jj++;
315       tmp         = cia[col] + collengths[col]++ - oshift;
316       cspidx[tmp] = a->i[row] + i; /* index of a->j */
317       cja[tmp]    = row + oshift;
318     }
319   }
320   PetscCall(PetscFree(collengths));
321   *ia    = cia;
322   *ja    = cja;
323   *spidx = cspidx;
324   PetscFunctionReturn(PETSC_SUCCESS);
325 }
326 
327 PetscErrorCode MatRestoreColumnIJ_SeqAIJ_Color(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscInt *spidx[], PetscBool *done)
328 {
329   PetscFunctionBegin;
330   PetscCall(MatRestoreColumnIJ_SeqAIJ(A, oshift, symmetric, inodecompressed, n, ia, ja, done));
331   PetscCall(PetscFree(*spidx));
332   PetscFunctionReturn(PETSC_SUCCESS);
333 }
334 
335 static PetscErrorCode MatSetValuesRow_SeqAIJ(Mat A, PetscInt row, const PetscScalar v[])
336 {
337   Mat_SeqAIJ  *a  = (Mat_SeqAIJ *)A->data;
338   PetscInt    *ai = a->i;
339   PetscScalar *aa;
340 
341   PetscFunctionBegin;
342   PetscCall(MatSeqAIJGetArray(A, &aa));
343   PetscCall(PetscArraycpy(aa + ai[row], v, ai[row + 1] - ai[row]));
344   PetscCall(MatSeqAIJRestoreArray(A, &aa));
345   PetscFunctionReturn(PETSC_SUCCESS);
346 }
347 
348 /*
349     MatSeqAIJSetValuesLocalFast - An optimized version of MatSetValuesLocal() for SeqAIJ matrices with several assumptions
350 
351       -   a single row of values is set with each call
352       -   no row or column indices are negative or (in error) larger than the number of rows or columns
353       -   the values are always added to the matrix, not set
354       -   no new locations are introduced in the nonzero structure of the matrix
355 
356      This does NOT assume the global column indices are sorted
357 
358 */
359 
360 #include <petsc/private/isimpl.h>
361 PetscErrorCode MatSeqAIJSetValuesLocalFast(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
362 {
363   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
364   PetscInt        low, high, t, row, nrow, i, col, l;
365   const PetscInt *rp, *ai = a->i, *ailen = a->ilen, *aj = a->j;
366   PetscInt        lastcol = -1;
367   MatScalar      *ap, value, *aa;
368   const PetscInt *ridx = A->rmap->mapping->indices, *cidx = A->cmap->mapping->indices;
369 
370   PetscFunctionBegin;
371   PetscCall(MatSeqAIJGetArray(A, &aa));
372   row  = ridx[im[0]];
373   rp   = aj + ai[row];
374   ap   = aa + ai[row];
375   nrow = ailen[row];
376   low  = 0;
377   high = nrow;
378   for (l = 0; l < n; l++) { /* loop over added columns */
379     col   = cidx[in[l]];
380     value = v[l];
381 
382     if (col <= lastcol) low = 0;
383     else high = nrow;
384     lastcol = col;
385     while (high - low > 5) {
386       t = (low + high) / 2;
387       if (rp[t] > col) high = t;
388       else low = t;
389     }
390     for (i = low; i < high; i++) {
391       if (rp[i] == col) {
392         ap[i] += value;
393         low = i + 1;
394         break;
395       }
396     }
397   }
398   PetscCall(MatSeqAIJRestoreArray(A, &aa));
399   return PETSC_SUCCESS;
400 }
401 
402 PetscErrorCode MatSetValues_SeqAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
403 {
404   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
405   PetscInt   *rp, k, low, high, t, ii, row, nrow, i, col, l, rmax, N;
406   PetscInt   *imax = a->imax, *ai = a->i, *ailen = a->ilen;
407   PetscInt   *aj = a->j, nonew = a->nonew, lastcol = -1;
408   MatScalar  *ap = NULL, value = 0.0, *aa;
409   PetscBool   ignorezeroentries = a->ignorezeroentries;
410   PetscBool   roworiented       = a->roworiented;
411 
412   PetscFunctionBegin;
413   PetscCall(MatSeqAIJGetArray(A, &aa));
414   for (k = 0; k < m; k++) { /* loop over added rows */
415     row = im[k];
416     if (row < 0) continue;
417     PetscCheck(row < A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, row, A->rmap->n - 1);
418     rp = PetscSafePointerPlusOffset(aj, ai[row]);
419     if (!A->structure_only) ap = PetscSafePointerPlusOffset(aa, ai[row]);
420     rmax = imax[row];
421     nrow = ailen[row];
422     low  = 0;
423     high = nrow;
424     for (l = 0; l < n; l++) { /* loop over added columns */
425       if (in[l] < 0) continue;
426       PetscCheck(in[l] < A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, in[l], A->cmap->n - 1);
427       col = in[l];
428       if (v && !A->structure_only) value = roworiented ? v[l + k * n] : v[k + l * m];
429       if (!A->structure_only && value == 0.0 && ignorezeroentries && is == ADD_VALUES && row != col) continue;
430 
431       if (col <= lastcol) low = 0;
432       else high = nrow;
433       lastcol = col;
434       while (high - low > 5) {
435         t = (low + high) / 2;
436         if (rp[t] > col) high = t;
437         else low = t;
438       }
439       for (i = low; i < high; i++) {
440         if (rp[i] > col) break;
441         if (rp[i] == col) {
442           if (!A->structure_only) {
443             if (is == ADD_VALUES) {
444               ap[i] += value;
445               (void)PetscLogFlops(1.0);
446             } else ap[i] = value;
447           }
448           low = i + 1;
449           goto noinsert;
450         }
451       }
452       if (value == 0.0 && ignorezeroentries && row != col) goto noinsert;
453       if (nonew == 1) goto noinsert;
454       PetscCheck(nonew != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero at (%" PetscInt_FMT ",%" PetscInt_FMT ") in the matrix", row, col);
455       if (A->structure_only) {
456         MatSeqXAIJReallocateAIJ_structure_only(A, A->rmap->n, 1, nrow, row, col, rmax, ai, aj, rp, imax, nonew, MatScalar);
457       } else {
458         MatSeqXAIJReallocateAIJ(A, A->rmap->n, 1, nrow, row, col, rmax, aa, ai, aj, rp, ap, imax, nonew, MatScalar);
459       }
460       N = nrow++ - 1;
461       a->nz++;
462       high++;
463       /* shift up all the later entries in this row */
464       PetscCall(PetscArraymove(rp + i + 1, rp + i, N - i + 1));
465       rp[i] = col;
466       if (!A->structure_only) {
467         PetscCall(PetscArraymove(ap + i + 1, ap + i, N - i + 1));
468         ap[i] = value;
469       }
470       low = i + 1;
471     noinsert:;
472     }
473     ailen[row] = nrow;
474   }
475   PetscCall(MatSeqAIJRestoreArray(A, &aa));
476   PetscFunctionReturn(PETSC_SUCCESS);
477 }
478 
479 static PetscErrorCode MatSetValues_SeqAIJ_SortedFullNoPreallocation(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
480 {
481   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
482   PetscInt   *rp, k, row;
483   PetscInt   *ai = a->i;
484   PetscInt   *aj = a->j;
485   MatScalar  *aa, *ap;
486 
487   PetscFunctionBegin;
488   PetscCheck(!A->was_assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot call on assembled matrix.");
489   PetscCheck(m * n + a->nz <= a->maxnz, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of entries in matrix will be larger than maximum nonzeros allocated for %" PetscInt_FMT " in MatSeqAIJSetTotalPreallocation()", a->maxnz);
490 
491   PetscCall(MatSeqAIJGetArray(A, &aa));
492   for (k = 0; k < m; k++) { /* loop over added rows */
493     row = im[k];
494     rp  = aj + ai[row];
495     ap  = PetscSafePointerPlusOffset(aa, ai[row]);
496 
497     PetscCall(PetscMemcpy(rp, in, n * sizeof(PetscInt)));
498     if (!A->structure_only) {
499       if (v) {
500         PetscCall(PetscMemcpy(ap, v, n * sizeof(PetscScalar)));
501         v += n;
502       } else {
503         PetscCall(PetscMemzero(ap, n * sizeof(PetscScalar)));
504       }
505     }
506     a->ilen[row]  = n;
507     a->imax[row]  = n;
508     a->i[row + 1] = a->i[row] + n;
509     a->nz += n;
510   }
511   PetscCall(MatSeqAIJRestoreArray(A, &aa));
512   PetscFunctionReturn(PETSC_SUCCESS);
513 }
514 
515 /*@
516   MatSeqAIJSetTotalPreallocation - Sets an upper bound on the total number of expected nonzeros in the matrix.
517 
518   Input Parameters:
519 + A       - the `MATSEQAIJ` matrix
520 - nztotal - bound on the number of nonzeros
521 
522   Level: advanced
523 
524   Notes:
525   This can be called if you will be provided the matrix row by row (from row zero) with sorted column indices for each row.
526   Simply call `MatSetValues()` after this call to provide the matrix entries in the usual manner. This matrix may be used
527   as always with multiple matrix assemblies.
528 
529 .seealso: [](ch_matrices), `Mat`, `MatSetOption()`, `MAT_SORTED_FULL`, `MatSetValues()`, `MatSeqAIJSetPreallocation()`
530 @*/
531 PetscErrorCode MatSeqAIJSetTotalPreallocation(Mat A, PetscInt nztotal)
532 {
533   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
534 
535   PetscFunctionBegin;
536   PetscCall(PetscLayoutSetUp(A->rmap));
537   PetscCall(PetscLayoutSetUp(A->cmap));
538   a->maxnz = nztotal;
539   if (!a->imax) { PetscCall(PetscMalloc1(A->rmap->n, &a->imax)); }
540   if (!a->ilen) {
541     PetscCall(PetscMalloc1(A->rmap->n, &a->ilen));
542   } else {
543     PetscCall(PetscMemzero(a->ilen, A->rmap->n * sizeof(PetscInt)));
544   }
545 
546   /* allocate the matrix space */
547   PetscCall(PetscShmgetAllocateArray(A->rmap->n + 1, sizeof(PetscInt), (void **)&a->i));
548   PetscCall(PetscShmgetAllocateArray(nztotal, sizeof(PetscInt), (void **)&a->j));
549   a->free_ij = PETSC_TRUE;
550   if (A->structure_only) {
551     a->free_a = PETSC_FALSE;
552   } else {
553     PetscCall(PetscShmgetAllocateArray(nztotal, sizeof(PetscScalar), (void **)&a->a));
554     a->free_a = PETSC_TRUE;
555   }
556   a->i[0]           = 0;
557   A->ops->setvalues = MatSetValues_SeqAIJ_SortedFullNoPreallocation;
558   A->preallocated   = PETSC_TRUE;
559   PetscFunctionReturn(PETSC_SUCCESS);
560 }
561 
562 static PetscErrorCode MatSetValues_SeqAIJ_SortedFull(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
563 {
564   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
565   PetscInt   *rp, k, row;
566   PetscInt   *ai = a->i, *ailen = a->ilen;
567   PetscInt   *aj = a->j;
568   MatScalar  *aa, *ap;
569 
570   PetscFunctionBegin;
571   PetscCall(MatSeqAIJGetArray(A, &aa));
572   for (k = 0; k < m; k++) { /* loop over added rows */
573     row = im[k];
574     PetscCheck(n <= a->imax[row], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Preallocation for row %" PetscInt_FMT " does not match number of columns provided", n);
575     rp = aj + ai[row];
576     ap = aa + ai[row];
577     if (!A->was_assembled) PetscCall(PetscMemcpy(rp, in, n * sizeof(PetscInt)));
578     if (!A->structure_only) {
579       if (v) {
580         PetscCall(PetscMemcpy(ap, v, n * sizeof(PetscScalar)));
581         v += n;
582       } else {
583         PetscCall(PetscMemzero(ap, n * sizeof(PetscScalar)));
584       }
585     }
586     ailen[row] = n;
587     a->nz += n;
588   }
589   PetscCall(MatSeqAIJRestoreArray(A, &aa));
590   PetscFunctionReturn(PETSC_SUCCESS);
591 }
592 
593 static PetscErrorCode MatGetValues_SeqAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], PetscScalar v[])
594 {
595   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
596   PetscInt        *rp, k, low, high, t, row, nrow, i, col, l, *aj = a->j;
597   PetscInt        *ai = a->i, *ailen = a->ilen;
598   const MatScalar *ap, *aa;
599 
600   PetscFunctionBegin;
601   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
602   for (k = 0; k < m; k++) { /* loop over rows */
603     row = im[k];
604     if (row < 0) {
605       v += n;
606       continue;
607     } /* negative row */
608     PetscCheck(row < A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row too large: row %" PetscInt_FMT " max %" PetscInt_FMT, row, A->rmap->n - 1);
609     rp   = PetscSafePointerPlusOffset(aj, ai[row]);
610     ap   = PetscSafePointerPlusOffset(aa, ai[row]);
611     nrow = ailen[row];
612     for (l = 0; l < n; l++) { /* loop over columns */
613       if (in[l] < 0) {
614         v++;
615         continue;
616       } /* negative column */
617       PetscCheck(in[l] < A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column too large: col %" PetscInt_FMT " max %" PetscInt_FMT, in[l], A->cmap->n - 1);
618       col  = in[l];
619       high = nrow;
620       low  = 0; /* assume unsorted */
621       while (high - low > 5) {
622         t = (low + high) / 2;
623         if (rp[t] > col) high = t;
624         else low = t;
625       }
626       for (i = low; i < high; i++) {
627         if (rp[i] > col) break;
628         if (rp[i] == col) {
629           *v++ = ap[i];
630           goto finished;
631         }
632       }
633       *v++ = 0.0;
634     finished:;
635     }
636   }
637   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
638   PetscFunctionReturn(PETSC_SUCCESS);
639 }
640 
641 static PetscErrorCode MatView_SeqAIJ_Binary(Mat mat, PetscViewer viewer)
642 {
643   Mat_SeqAIJ        *A = (Mat_SeqAIJ *)mat->data;
644   const PetscScalar *av;
645   PetscInt           header[4], M, N, m, nz, i;
646   PetscInt          *rowlens;
647 
648   PetscFunctionBegin;
649   PetscCall(PetscViewerSetUp(viewer));
650 
651   M  = mat->rmap->N;
652   N  = mat->cmap->N;
653   m  = mat->rmap->n;
654   nz = A->nz;
655 
656   /* write matrix header */
657   header[0] = MAT_FILE_CLASSID;
658   header[1] = M;
659   header[2] = N;
660   header[3] = nz;
661   PetscCall(PetscViewerBinaryWrite(viewer, header, 4, PETSC_INT));
662 
663   /* fill in and store row lengths */
664   PetscCall(PetscMalloc1(m, &rowlens));
665   for (i = 0; i < m; i++) rowlens[i] = A->i[i + 1] - A->i[i];
666   if (PetscDefined(USE_DEBUG)) {
667     PetscInt mnz = 0;
668 
669     for (i = 0; i < m; i++) mnz += rowlens[i];
670     PetscCheck(nz == mnz, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Row lens %" PetscInt_FMT " do not sum to nz %" PetscInt_FMT, mnz, nz);
671   }
672   PetscCall(PetscViewerBinaryWrite(viewer, rowlens, m, PETSC_INT));
673   PetscCall(PetscFree(rowlens));
674   /* store column indices */
675   PetscCall(PetscViewerBinaryWrite(viewer, A->j, nz, PETSC_INT));
676   /* store nonzero values */
677   PetscCall(MatSeqAIJGetArrayRead(mat, &av));
678   PetscCall(PetscViewerBinaryWrite(viewer, av, nz, PETSC_SCALAR));
679   PetscCall(MatSeqAIJRestoreArrayRead(mat, &av));
680 
681   /* write block size option to the viewer's .info file */
682   PetscCall(MatView_Binary_BlockSizes(mat, viewer));
683   PetscFunctionReturn(PETSC_SUCCESS);
684 }
685 
686 static PetscErrorCode MatView_SeqAIJ_ASCII_structonly(Mat A, PetscViewer viewer)
687 {
688   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
689   PetscInt    i, k, m = A->rmap->N;
690 
691   PetscFunctionBegin;
692   PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
693   for (i = 0; i < m; i++) {
694     PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
695     for (k = a->i[i]; k < a->i[i + 1]; k++) PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ") ", a->j[k]));
696     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
697   }
698   PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
699   PetscFunctionReturn(PETSC_SUCCESS);
700 }
701 
702 extern PetscErrorCode MatSeqAIJFactorInfo_Matlab(Mat, PetscViewer);
703 
704 static PetscErrorCode MatView_SeqAIJ_ASCII(Mat A, PetscViewer viewer)
705 {
706   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
707   const PetscScalar *av;
708   PetscInt           i, j, m = A->rmap->n;
709   const char        *name;
710   PetscViewerFormat  format;
711 
712   PetscFunctionBegin;
713   if (A->structure_only) {
714     PetscCall(MatView_SeqAIJ_ASCII_structonly(A, viewer));
715     PetscFunctionReturn(PETSC_SUCCESS);
716   }
717 
718   PetscCall(PetscViewerGetFormat(viewer, &format));
719   // By petsc's rule, even PETSC_VIEWER_ASCII_INFO_DETAIL doesn't print matrix entries
720   if (format == PETSC_VIEWER_ASCII_FACTOR_INFO || format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) PetscFunctionReturn(PETSC_SUCCESS);
721 
722   /* trigger copy to CPU if needed */
723   PetscCall(MatSeqAIJGetArrayRead(A, &av));
724   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
725   if (format == PETSC_VIEWER_ASCII_MATLAB) {
726     PetscInt nofinalvalue = 0;
727     if (m && ((a->i[m] == a->i[m - 1]) || (a->j[a->nz - 1] != A->cmap->n - 1))) {
728       /* Need a dummy value to ensure the dimension of the matrix. */
729       nofinalvalue = 1;
730     }
731     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
732     PetscCall(PetscViewerASCIIPrintf(viewer, "%% Size = %" PetscInt_FMT " %" PetscInt_FMT " \n", m, A->cmap->n));
733     PetscCall(PetscViewerASCIIPrintf(viewer, "%% Nonzeros = %" PetscInt_FMT " \n", a->nz));
734 #if defined(PETSC_USE_COMPLEX)
735     PetscCall(PetscViewerASCIIPrintf(viewer, "zzz = zeros(%" PetscInt_FMT ",4);\n", a->nz + nofinalvalue));
736 #else
737     PetscCall(PetscViewerASCIIPrintf(viewer, "zzz = zeros(%" PetscInt_FMT ",3);\n", a->nz + nofinalvalue));
738 #endif
739     PetscCall(PetscViewerASCIIPrintf(viewer, "zzz = [\n"));
740 
741     for (i = 0; i < m; i++) {
742       for (j = a->i[i]; j < a->i[i + 1]; j++) {
743 #if defined(PETSC_USE_COMPLEX)
744         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e %18.16e\n", i + 1, a->j[j] + 1, (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
745 #else
746         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e\n", i + 1, a->j[j] + 1, (double)a->a[j]));
747 #endif
748       }
749     }
750     if (nofinalvalue) {
751 #if defined(PETSC_USE_COMPLEX)
752       PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e %18.16e\n", m, A->cmap->n, 0., 0.));
753 #else
754       PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT "  %18.16e\n", m, A->cmap->n, 0.0));
755 #endif
756     }
757     PetscCall(PetscObjectGetName((PetscObject)A, &name));
758     PetscCall(PetscViewerASCIIPrintf(viewer, "];\n %s = spconvert(zzz);\n", name));
759     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
760   } else if (format == PETSC_VIEWER_ASCII_COMMON) {
761     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
762     for (i = 0; i < m; i++) {
763       PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
764       for (j = a->i[i]; j < a->i[i + 1]; j++) {
765 #if defined(PETSC_USE_COMPLEX)
766         if (PetscImaginaryPart(a->a[j]) > 0.0 && PetscRealPart(a->a[j]) != 0.0) {
767           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
768         } else if (PetscImaginaryPart(a->a[j]) < 0.0 && PetscRealPart(a->a[j]) != 0.0) {
769           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)-PetscImaginaryPart(a->a[j])));
770         } else if (PetscRealPart(a->a[j]) != 0.0) {
771           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
772         }
773 #else
774         if (a->a[j] != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
775 #endif
776       }
777       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
778     }
779     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
780   } else if (format == PETSC_VIEWER_ASCII_SYMMODU) {
781     PetscInt nzd = 0, fshift = 1, *sptr;
782     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
783     PetscCall(PetscMalloc1(m + 1, &sptr));
784     for (i = 0; i < m; i++) {
785       sptr[i] = nzd + 1;
786       for (j = a->i[i]; j < a->i[i + 1]; j++) {
787         if (a->j[j] >= i) {
788 #if defined(PETSC_USE_COMPLEX)
789           if (PetscImaginaryPart(a->a[j]) != 0.0 || PetscRealPart(a->a[j]) != 0.0) nzd++;
790 #else
791           if (a->a[j] != 0.0) nzd++;
792 #endif
793         }
794       }
795     }
796     sptr[m] = nzd + 1;
797     PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT "\n\n", m, nzd));
798     for (i = 0; i < m + 1; i += 6) {
799       if (i + 4 < m) {
800         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2], sptr[i + 3], sptr[i + 4], sptr[i + 5]));
801       } else if (i + 3 < m) {
802         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2], sptr[i + 3], sptr[i + 4]));
803       } else if (i + 2 < m) {
804         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2], sptr[i + 3]));
805       } else if (i + 1 < m) {
806         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1], sptr[i + 2]));
807       } else if (i < m) {
808         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " %" PetscInt_FMT "\n", sptr[i], sptr[i + 1]));
809       } else {
810         PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT "\n", sptr[i]));
811       }
812     }
813     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
814     PetscCall(PetscFree(sptr));
815     for (i = 0; i < m; i++) {
816       for (j = a->i[i]; j < a->i[i + 1]; j++) {
817         if (a->j[j] >= i) PetscCall(PetscViewerASCIIPrintf(viewer, " %" PetscInt_FMT " ", a->j[j] + fshift));
818       }
819       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
820     }
821     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
822     for (i = 0; i < m; i++) {
823       for (j = a->i[i]; j < a->i[i + 1]; j++) {
824         if (a->j[j] >= i) {
825 #if defined(PETSC_USE_COMPLEX)
826           if (PetscImaginaryPart(a->a[j]) != 0.0 || PetscRealPart(a->a[j]) != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " %18.16e %18.16e ", (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
827 #else
828           if (a->a[j] != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " %18.16e ", (double)a->a[j]));
829 #endif
830         }
831       }
832       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
833     }
834     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
835   } else if (format == PETSC_VIEWER_ASCII_DENSE) {
836     PetscInt    cnt = 0, jcnt;
837     PetscScalar value;
838 #if defined(PETSC_USE_COMPLEX)
839     PetscBool realonly = PETSC_TRUE;
840 
841     for (i = 0; i < a->i[m]; i++) {
842       if (PetscImaginaryPart(a->a[i]) != 0.0) {
843         realonly = PETSC_FALSE;
844         break;
845       }
846     }
847 #endif
848 
849     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
850     for (i = 0; i < m; i++) {
851       jcnt = 0;
852       for (j = 0; j < A->cmap->n; j++) {
853         if (jcnt < a->i[i + 1] - a->i[i] && j == a->j[cnt]) {
854           value = a->a[cnt++];
855           jcnt++;
856         } else {
857           value = 0.0;
858         }
859 #if defined(PETSC_USE_COMPLEX)
860         if (realonly) {
861           PetscCall(PetscViewerASCIIPrintf(viewer, " %7.5e ", (double)PetscRealPart(value)));
862         } else {
863           PetscCall(PetscViewerASCIIPrintf(viewer, " %7.5e+%7.5e i ", (double)PetscRealPart(value), (double)PetscImaginaryPart(value)));
864         }
865 #else
866         PetscCall(PetscViewerASCIIPrintf(viewer, " %7.5e ", (double)value));
867 #endif
868       }
869       PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
870     }
871     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
872   } else if (format == PETSC_VIEWER_ASCII_MATRIXMARKET) {
873     PetscInt fshift = 1;
874     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
875 #if defined(PETSC_USE_COMPLEX)
876     PetscCall(PetscViewerASCIIPrintf(viewer, "%%%%MatrixMarket matrix coordinate complex general\n"));
877 #else
878     PetscCall(PetscViewerASCIIPrintf(viewer, "%%%%MatrixMarket matrix coordinate real general\n"));
879 #endif
880     PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", m, A->cmap->n, a->nz));
881     for (i = 0; i < m; i++) {
882       for (j = a->i[i]; j < a->i[i + 1]; j++) {
883 #if defined(PETSC_USE_COMPLEX)
884         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT " %g %g\n", i + fshift, a->j[j] + fshift, (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
885 #else
886         PetscCall(PetscViewerASCIIPrintf(viewer, "%" PetscInt_FMT " %" PetscInt_FMT " %g\n", i + fshift, a->j[j] + fshift, (double)a->a[j]));
887 #endif
888       }
889     }
890     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
891   } else {
892     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
893     if (A->factortype) {
894       for (i = 0; i < m; i++) {
895         PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
896         /* L part */
897         for (j = a->i[i]; j < a->i[i + 1]; j++) {
898 #if defined(PETSC_USE_COMPLEX)
899           if (PetscImaginaryPart(a->a[j]) > 0.0) {
900             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
901           } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
902             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)(-PetscImaginaryPart(a->a[j]))));
903           } else {
904             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
905           }
906 #else
907           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
908 #endif
909         }
910         /* diagonal */
911         j = a->diag[i];
912 #if defined(PETSC_USE_COMPLEX)
913         if (PetscImaginaryPart(a->a[j]) > 0.0) {
914           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(1 / a->a[j]), (double)PetscImaginaryPart(1 / a->a[j])));
915         } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
916           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(1 / a->a[j]), (double)(-PetscImaginaryPart(1 / a->a[j]))));
917         } else {
918           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(1 / a->a[j])));
919         }
920 #else
921         PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)(1 / a->a[j])));
922 #endif
923 
924         /* U part */
925         for (j = a->diag[i + 1] + 1; j < a->diag[i]; j++) {
926 #if defined(PETSC_USE_COMPLEX)
927           if (PetscImaginaryPart(a->a[j]) > 0.0) {
928             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
929           } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
930             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)(-PetscImaginaryPart(a->a[j]))));
931           } else {
932             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
933           }
934 #else
935           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
936 #endif
937         }
938         PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
939       }
940     } else {
941       for (i = 0; i < m; i++) {
942         PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i));
943         for (j = a->i[i]; j < a->i[i + 1]; j++) {
944 #if defined(PETSC_USE_COMPLEX)
945           if (PetscImaginaryPart(a->a[j]) > 0.0) {
946             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)PetscImaginaryPart(a->a[j])));
947           } else if (PetscImaginaryPart(a->a[j]) < 0.0) {
948             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i)", a->j[j], (double)PetscRealPart(a->a[j]), (double)-PetscImaginaryPart(a->a[j])));
949           } else {
950             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)PetscRealPart(a->a[j])));
951           }
952 #else
953           PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", a->j[j], (double)a->a[j]));
954 #endif
955         }
956         PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
957       }
958     }
959     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
960   }
961   PetscCall(PetscViewerFlush(viewer));
962   PetscFunctionReturn(PETSC_SUCCESS);
963 }
964 
965 #include <petscdraw.h>
966 static PetscErrorCode MatView_SeqAIJ_Draw_Zoom(PetscDraw draw, void *Aa)
967 {
968   Mat                A = (Mat)Aa;
969   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
970   PetscInt           i, j, m = A->rmap->n;
971   int                color;
972   PetscReal          xl, yl, xr, yr, x_l, x_r, y_l, y_r;
973   PetscViewer        viewer;
974   PetscViewerFormat  format;
975   const PetscScalar *aa;
976 
977   PetscFunctionBegin;
978   PetscCall(PetscObjectQuery((PetscObject)A, "Zoomviewer", (PetscObject *)&viewer));
979   PetscCall(PetscViewerGetFormat(viewer, &format));
980   PetscCall(PetscDrawGetCoordinates(draw, &xl, &yl, &xr, &yr));
981 
982   /* loop over matrix elements drawing boxes */
983   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
984   if (format != PETSC_VIEWER_DRAW_CONTOUR) {
985     PetscDrawCollectiveBegin(draw);
986     /* Blue for negative, Cyan for zero and  Red for positive */
987     color = PETSC_DRAW_BLUE;
988     for (i = 0; i < m; i++) {
989       y_l = m - i - 1.0;
990       y_r = y_l + 1.0;
991       for (j = a->i[i]; j < a->i[i + 1]; j++) {
992         x_l = a->j[j];
993         x_r = x_l + 1.0;
994         if (PetscRealPart(aa[j]) >= 0.) continue;
995         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
996       }
997     }
998     color = PETSC_DRAW_CYAN;
999     for (i = 0; i < m; i++) {
1000       y_l = m - i - 1.0;
1001       y_r = y_l + 1.0;
1002       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1003         x_l = a->j[j];
1004         x_r = x_l + 1.0;
1005         if (aa[j] != 0.) continue;
1006         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
1007       }
1008     }
1009     color = PETSC_DRAW_RED;
1010     for (i = 0; i < m; i++) {
1011       y_l = m - i - 1.0;
1012       y_r = y_l + 1.0;
1013       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1014         x_l = a->j[j];
1015         x_r = x_l + 1.0;
1016         if (PetscRealPart(aa[j]) <= 0.) continue;
1017         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
1018       }
1019     }
1020     PetscDrawCollectiveEnd(draw);
1021   } else {
1022     /* use contour shading to indicate magnitude of values */
1023     /* first determine max of all nonzero values */
1024     PetscReal minv = 0.0, maxv = 0.0;
1025     PetscInt  nz = a->nz, count = 0;
1026     PetscDraw popup;
1027 
1028     for (i = 0; i < nz; i++) {
1029       if (PetscAbsScalar(aa[i]) > maxv) maxv = PetscAbsScalar(aa[i]);
1030     }
1031     if (minv >= maxv) maxv = minv + PETSC_SMALL;
1032     PetscCall(PetscDrawGetPopup(draw, &popup));
1033     PetscCall(PetscDrawScalePopup(popup, minv, maxv));
1034 
1035     PetscDrawCollectiveBegin(draw);
1036     for (i = 0; i < m; i++) {
1037       y_l = m - i - 1.0;
1038       y_r = y_l + 1.0;
1039       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1040         x_l   = a->j[j];
1041         x_r   = x_l + 1.0;
1042         color = PetscDrawRealToColor(PetscAbsScalar(aa[count]), minv, maxv);
1043         PetscCall(PetscDrawRectangle(draw, x_l, y_l, x_r, y_r, color, color, color, color));
1044         count++;
1045       }
1046     }
1047     PetscDrawCollectiveEnd(draw);
1048   }
1049   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1050   PetscFunctionReturn(PETSC_SUCCESS);
1051 }
1052 
1053 #include <petscdraw.h>
1054 static PetscErrorCode MatView_SeqAIJ_Draw(Mat A, PetscViewer viewer)
1055 {
1056   PetscDraw draw;
1057   PetscReal xr, yr, xl, yl, h, w;
1058   PetscBool isnull;
1059 
1060   PetscFunctionBegin;
1061   PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
1062   PetscCall(PetscDrawIsNull(draw, &isnull));
1063   if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
1064 
1065   xr = A->cmap->n;
1066   yr = A->rmap->n;
1067   h  = yr / 10.0;
1068   w  = xr / 10.0;
1069   xr += w;
1070   yr += h;
1071   xl = -w;
1072   yl = -h;
1073   PetscCall(PetscDrawSetCoordinates(draw, xl, yl, xr, yr));
1074   PetscCall(PetscObjectCompose((PetscObject)A, "Zoomviewer", (PetscObject)viewer));
1075   PetscCall(PetscDrawZoom(draw, MatView_SeqAIJ_Draw_Zoom, A));
1076   PetscCall(PetscObjectCompose((PetscObject)A, "Zoomviewer", NULL));
1077   PetscCall(PetscDrawSave(draw));
1078   PetscFunctionReturn(PETSC_SUCCESS);
1079 }
1080 
1081 PetscErrorCode MatView_SeqAIJ(Mat A, PetscViewer viewer)
1082 {
1083   PetscBool iascii, isbinary, isdraw;
1084 
1085   PetscFunctionBegin;
1086   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
1087   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
1088   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
1089   if (iascii) PetscCall(MatView_SeqAIJ_ASCII(A, viewer));
1090   else if (isbinary) PetscCall(MatView_SeqAIJ_Binary(A, viewer));
1091   else if (isdraw) PetscCall(MatView_SeqAIJ_Draw(A, viewer));
1092   PetscCall(MatView_SeqAIJ_Inode(A, viewer));
1093   PetscFunctionReturn(PETSC_SUCCESS);
1094 }
1095 
1096 PetscErrorCode MatAssemblyEnd_SeqAIJ(Mat A, MatAssemblyType mode)
1097 {
1098   Mat_SeqAIJ *a      = (Mat_SeqAIJ *)A->data;
1099   PetscInt    fshift = 0, i, *ai = a->i, *aj = a->j, *imax = a->imax;
1100   PetscInt    m = A->rmap->n, *ip, N, *ailen = a->ilen, rmax = 0, n;
1101   MatScalar  *aa    = a->a, *ap;
1102   PetscReal   ratio = 0.6;
1103 
1104   PetscFunctionBegin;
1105   if (mode == MAT_FLUSH_ASSEMBLY) PetscFunctionReturn(PETSC_SUCCESS);
1106   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1107   if (A->was_assembled && A->ass_nonzerostate == A->nonzerostate) {
1108     /* we need to respect users asking to use or not the inodes routine in between matrix assemblies */
1109     PetscCall(MatAssemblyEnd_SeqAIJ_Inode(A, mode));
1110     PetscFunctionReturn(PETSC_SUCCESS);
1111   }
1112 
1113   if (m) rmax = ailen[0]; /* determine row with most nonzeros */
1114   for (i = 1; i < m; i++) {
1115     /* move each row back by the amount of empty slots (fshift) before it*/
1116     fshift += imax[i - 1] - ailen[i - 1];
1117     rmax = PetscMax(rmax, ailen[i]);
1118     if (fshift) {
1119       ip = aj + ai[i];
1120       ap = aa + ai[i];
1121       N  = ailen[i];
1122       PetscCall(PetscArraymove(ip - fshift, ip, N));
1123       if (!A->structure_only) PetscCall(PetscArraymove(ap - fshift, ap, N));
1124     }
1125     ai[i] = ai[i - 1] + ailen[i - 1];
1126   }
1127   if (m) {
1128     fshift += imax[m - 1] - ailen[m - 1];
1129     ai[m] = ai[m - 1] + ailen[m - 1];
1130   }
1131   /* reset ilen and imax for each row */
1132   a->nonzerorowcnt = 0;
1133   if (A->structure_only) {
1134     PetscCall(PetscFree(a->imax));
1135     PetscCall(PetscFree(a->ilen));
1136   } else { /* !A->structure_only */
1137     for (i = 0; i < m; i++) {
1138       ailen[i] = imax[i] = ai[i + 1] - ai[i];
1139       a->nonzerorowcnt += ((ai[i + 1] - ai[i]) > 0);
1140     }
1141   }
1142   a->nz = ai[m];
1143   PetscCheck(!fshift || a->nounused != -1, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unused space detected in matrix: %" PetscInt_FMT " X %" PetscInt_FMT ", %" PetscInt_FMT " unneeded", m, A->cmap->n, fshift);
1144   PetscCall(MatMarkDiagonal_SeqAIJ(A)); // since diagonal info is used a lot, it is helpful to set them up at the end of assembly
1145   a->diagonaldense = PETSC_TRUE;
1146   n                = PetscMin(A->rmap->n, A->cmap->n);
1147   for (i = 0; i < n; i++) {
1148     if (a->diag[i] >= ai[i + 1]) {
1149       a->diagonaldense = PETSC_FALSE;
1150       break;
1151     }
1152   }
1153   PetscCall(PetscInfo(A, "Matrix size: %" PetscInt_FMT " X %" PetscInt_FMT "; storage space: %" PetscInt_FMT " unneeded,%" PetscInt_FMT " used\n", m, A->cmap->n, fshift, a->nz));
1154   PetscCall(PetscInfo(A, "Number of mallocs during MatSetValues() is %" PetscInt_FMT "\n", a->reallocs));
1155   PetscCall(PetscInfo(A, "Maximum nonzeros in any row is %" PetscInt_FMT "\n", rmax));
1156 
1157   A->info.mallocs += a->reallocs;
1158   a->reallocs         = 0;
1159   A->info.nz_unneeded = (PetscReal)fshift;
1160   a->rmax             = rmax;
1161 
1162   if (!A->structure_only) PetscCall(MatCheckCompressedRow(A, a->nonzerorowcnt, &a->compressedrow, a->i, m, ratio));
1163   PetscCall(MatAssemblyEnd_SeqAIJ_Inode(A, mode));
1164   PetscFunctionReturn(PETSC_SUCCESS);
1165 }
1166 
1167 static PetscErrorCode MatRealPart_SeqAIJ(Mat A)
1168 {
1169   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1170   PetscInt    i, nz = a->nz;
1171   MatScalar  *aa;
1172 
1173   PetscFunctionBegin;
1174   PetscCall(MatSeqAIJGetArray(A, &aa));
1175   for (i = 0; i < nz; i++) aa[i] = PetscRealPart(aa[i]);
1176   PetscCall(MatSeqAIJRestoreArray(A, &aa));
1177   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1178   PetscFunctionReturn(PETSC_SUCCESS);
1179 }
1180 
1181 static PetscErrorCode MatImaginaryPart_SeqAIJ(Mat A)
1182 {
1183   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1184   PetscInt    i, nz = a->nz;
1185   MatScalar  *aa;
1186 
1187   PetscFunctionBegin;
1188   PetscCall(MatSeqAIJGetArray(A, &aa));
1189   for (i = 0; i < nz; i++) aa[i] = PetscImaginaryPart(aa[i]);
1190   PetscCall(MatSeqAIJRestoreArray(A, &aa));
1191   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1192   PetscFunctionReturn(PETSC_SUCCESS);
1193 }
1194 
1195 PetscErrorCode MatZeroEntries_SeqAIJ(Mat A)
1196 {
1197   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1198   MatScalar  *aa;
1199 
1200   PetscFunctionBegin;
1201   PetscCall(MatSeqAIJGetArrayWrite(A, &aa));
1202   PetscCall(PetscArrayzero(aa, a->i[A->rmap->n]));
1203   PetscCall(MatSeqAIJRestoreArrayWrite(A, &aa));
1204   PetscCall(MatSeqAIJInvalidateDiagonal(A));
1205   PetscFunctionReturn(PETSC_SUCCESS);
1206 }
1207 
1208 static PetscErrorCode MatReset_SeqAIJ(Mat A)
1209 {
1210   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1211 
1212   PetscFunctionBegin;
1213   if (A->hash_active) {
1214     A->ops[0] = a->cops;
1215     PetscCall(PetscHMapIJVDestroy(&a->ht));
1216     PetscCall(PetscFree(a->dnz));
1217     A->hash_active = PETSC_FALSE;
1218   }
1219 
1220   PetscCall(PetscLogObjectState((PetscObject)A, "Rows=%" PetscInt_FMT ", Cols=%" PetscInt_FMT ", NZ=%" PetscInt_FMT, A->rmap->n, A->cmap->n, a->nz));
1221   PetscCall(MatSeqXAIJFreeAIJ(A, &a->a, &a->j, &a->i));
1222   PetscCall(ISDestroy(&a->row));
1223   PetscCall(ISDestroy(&a->col));
1224   PetscCall(PetscFree(a->diag));
1225   PetscCall(PetscFree(a->ibdiag));
1226   PetscCall(PetscFree(a->imax));
1227   PetscCall(PetscFree(a->ilen));
1228   PetscCall(PetscFree(a->ipre));
1229   PetscCall(PetscFree3(a->idiag, a->mdiag, a->ssor_work));
1230   PetscCall(PetscFree(a->solve_work));
1231   PetscCall(ISDestroy(&a->icol));
1232   PetscCall(PetscFree(a->saved_values));
1233   PetscCall(PetscFree2(a->compressedrow.i, a->compressedrow.rindex));
1234   PetscCall(MatDestroy_SeqAIJ_Inode(A));
1235   PetscFunctionReturn(PETSC_SUCCESS);
1236 }
1237 
1238 static PetscErrorCode MatResetHash_SeqAIJ(Mat A)
1239 {
1240   PetscFunctionBegin;
1241   PetscCall(MatReset_SeqAIJ(A));
1242   PetscCall(MatCreate_SeqAIJ_Inode(A));
1243   PetscCall(MatSetUp_Seq_Hash(A));
1244   A->nonzerostate++;
1245   PetscFunctionReturn(PETSC_SUCCESS);
1246 }
1247 
1248 PetscErrorCode MatDestroy_SeqAIJ(Mat A)
1249 {
1250   PetscFunctionBegin;
1251   PetscCall(MatReset_SeqAIJ(A));
1252   PetscCall(PetscFree(A->data));
1253 
1254   /* MatMatMultNumeric_SeqAIJ_SeqAIJ_Sorted may allocate this.
1255      That function is so heavily used (sometimes in an hidden way through multnumeric function pointers)
1256      that is hard to properly add this data to the MatProduct data. We free it here to avoid
1257      users reusing the matrix object with different data to incur in obscure segmentation faults
1258      due to different matrix sizes */
1259   PetscCall(PetscObjectCompose((PetscObject)A, "__PETSc__ab_dense", NULL));
1260 
1261   PetscCall(PetscObjectChangeTypeName((PetscObject)A, NULL));
1262   PetscCall(PetscObjectComposeFunction((PetscObject)A, "PetscMatlabEnginePut_C", NULL));
1263   PetscCall(PetscObjectComposeFunction((PetscObject)A, "PetscMatlabEngineGet_C", NULL));
1264   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJSetColumnIndices_C", NULL));
1265   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatStoreValues_C", NULL));
1266   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatRetrieveValues_C", NULL));
1267   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqsbaij_C", NULL));
1268   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqbaij_C", NULL));
1269   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijperm_C", NULL));
1270   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijsell_C", NULL));
1271 #if defined(PETSC_HAVE_MKL_SPARSE)
1272   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijmkl_C", NULL));
1273 #endif
1274 #if defined(PETSC_HAVE_CUDA)
1275   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijcusparse_C", NULL));
1276   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijcusparse_seqaij_C", NULL));
1277   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaij_seqaijcusparse_C", NULL));
1278 #endif
1279 #if defined(PETSC_HAVE_HIP)
1280   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijhipsparse_C", NULL));
1281   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijhipsparse_seqaij_C", NULL));
1282   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaij_seqaijhipsparse_C", NULL));
1283 #endif
1284 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
1285   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijkokkos_C", NULL));
1286 #endif
1287   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijcrl_C", NULL));
1288 #if defined(PETSC_HAVE_ELEMENTAL)
1289   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_elemental_C", NULL));
1290 #endif
1291 #if defined(PETSC_HAVE_SCALAPACK)
1292   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_scalapack_C", NULL));
1293 #endif
1294 #if defined(PETSC_HAVE_HYPRE)
1295   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_hypre_C", NULL));
1296   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_transpose_seqaij_seqaij_C", NULL));
1297 #endif
1298   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqdense_C", NULL));
1299   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqsell_C", NULL));
1300   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_is_C", NULL));
1301   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatIsTranspose_C", NULL));
1302   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatIsHermitianTranspose_C", NULL));
1303   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJSetPreallocation_C", NULL));
1304   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatResetPreallocation_C", NULL));
1305   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatResetHash_C", NULL));
1306   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJSetPreallocationCSR_C", NULL));
1307   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatReorderForNonzeroDiagonal_C", NULL));
1308   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_is_seqaij_C", NULL));
1309   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqdense_seqaij_C", NULL));
1310   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaij_seqaij_C", NULL));
1311   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqAIJKron_C", NULL));
1312   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSetPreallocationCOO_C", NULL));
1313   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSetValuesCOO_C", NULL));
1314   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatFactorGetSolverType_C", NULL));
1315   /* these calls do not belong here: the subclasses Duplicate/Destroy are wrong */
1316   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaijsell_seqaij_C", NULL));
1317   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaijperm_seqaij_C", NULL));
1318   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqaij_seqaijviennacl_C", NULL));
1319   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijviennacl_seqdense_C", NULL));
1320   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatProductSetFromOptions_seqaijviennacl_seqaij_C", NULL));
1321   PetscFunctionReturn(PETSC_SUCCESS);
1322 }
1323 
1324 PetscErrorCode MatSetOption_SeqAIJ(Mat A, MatOption op, PetscBool flg)
1325 {
1326   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1327 
1328   PetscFunctionBegin;
1329   switch (op) {
1330   case MAT_ROW_ORIENTED:
1331     a->roworiented = flg;
1332     break;
1333   case MAT_KEEP_NONZERO_PATTERN:
1334     a->keepnonzeropattern = flg;
1335     break;
1336   case MAT_NEW_NONZERO_LOCATIONS:
1337     a->nonew = (flg ? 0 : 1);
1338     break;
1339   case MAT_NEW_NONZERO_LOCATION_ERR:
1340     a->nonew = (flg ? -1 : 0);
1341     break;
1342   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1343     a->nonew = (flg ? -2 : 0);
1344     break;
1345   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1346     a->nounused = (flg ? -1 : 0);
1347     break;
1348   case MAT_IGNORE_ZERO_ENTRIES:
1349     a->ignorezeroentries = flg;
1350     break;
1351   case MAT_SPD:
1352   case MAT_SYMMETRIC:
1353   case MAT_STRUCTURALLY_SYMMETRIC:
1354   case MAT_HERMITIAN:
1355   case MAT_SYMMETRY_ETERNAL:
1356   case MAT_STRUCTURE_ONLY:
1357   case MAT_STRUCTURAL_SYMMETRY_ETERNAL:
1358   case MAT_SPD_ETERNAL:
1359     /* if the diagonal matrix is square it inherits some of the properties above */
1360     break;
1361   case MAT_FORCE_DIAGONAL_ENTRIES:
1362   case MAT_IGNORE_OFF_PROC_ENTRIES:
1363   case MAT_USE_HASH_TABLE:
1364     PetscCall(PetscInfo(A, "Option %s ignored\n", MatOptions[op]));
1365     break;
1366   case MAT_USE_INODES:
1367     PetscCall(MatSetOption_SeqAIJ_Inode(A, MAT_USE_INODES, flg));
1368     break;
1369   case MAT_SUBMAT_SINGLEIS:
1370     A->submat_singleis = flg;
1371     break;
1372   case MAT_SORTED_FULL:
1373     if (flg) A->ops->setvalues = MatSetValues_SeqAIJ_SortedFull;
1374     else A->ops->setvalues = MatSetValues_SeqAIJ;
1375     break;
1376   case MAT_FORM_EXPLICIT_TRANSPOSE:
1377     A->form_explicit_transpose = flg;
1378     break;
1379   default:
1380     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "unknown option %d", op);
1381   }
1382   PetscFunctionReturn(PETSC_SUCCESS);
1383 }
1384 
1385 static PetscErrorCode MatGetDiagonal_SeqAIJ(Mat A, Vec v)
1386 {
1387   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1388   PetscInt           i, j, n, *ai = a->i, *aj = a->j;
1389   PetscScalar       *x;
1390   const PetscScalar *aa;
1391 
1392   PetscFunctionBegin;
1393   PetscCall(VecGetLocalSize(v, &n));
1394   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
1395   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
1396   if (A->factortype == MAT_FACTOR_ILU || A->factortype == MAT_FACTOR_LU) {
1397     PetscInt *diag = a->diag;
1398     PetscCall(VecGetArrayWrite(v, &x));
1399     for (i = 0; i < n; i++) x[i] = 1.0 / aa[diag[i]];
1400     PetscCall(VecRestoreArrayWrite(v, &x));
1401     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1402     PetscFunctionReturn(PETSC_SUCCESS);
1403   }
1404 
1405   PetscCall(VecGetArrayWrite(v, &x));
1406   for (i = 0; i < n; i++) {
1407     x[i] = 0.0;
1408     for (j = ai[i]; j < ai[i + 1]; j++) {
1409       if (aj[j] == i) {
1410         x[i] = aa[j];
1411         break;
1412       }
1413     }
1414   }
1415   PetscCall(VecRestoreArrayWrite(v, &x));
1416   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1417   PetscFunctionReturn(PETSC_SUCCESS);
1418 }
1419 
1420 #include <../src/mat/impls/aij/seq/ftn-kernels/fmult.h>
1421 PetscErrorCode MatMultTransposeAdd_SeqAIJ(Mat A, Vec xx, Vec zz, Vec yy)
1422 {
1423   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1424   const MatScalar   *aa;
1425   PetscScalar       *y;
1426   const PetscScalar *x;
1427   PetscInt           m = A->rmap->n;
1428 #if !defined(PETSC_USE_FORTRAN_KERNEL_MULTTRANSPOSEAIJ)
1429   const MatScalar  *v;
1430   PetscScalar       alpha;
1431   PetscInt          n, i, j;
1432   const PetscInt   *idx, *ii, *ridx = NULL;
1433   Mat_CompressedRow cprow    = a->compressedrow;
1434   PetscBool         usecprow = cprow.use;
1435 #endif
1436 
1437   PetscFunctionBegin;
1438   if (zz != yy) PetscCall(VecCopy(zz, yy));
1439   PetscCall(VecGetArrayRead(xx, &x));
1440   PetscCall(VecGetArray(yy, &y));
1441   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
1442 
1443 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTTRANSPOSEAIJ)
1444   fortranmulttransposeaddaij_(&m, x, a->i, a->j, aa, y);
1445 #else
1446   if (usecprow) {
1447     m    = cprow.nrows;
1448     ii   = cprow.i;
1449     ridx = cprow.rindex;
1450   } else {
1451     ii = a->i;
1452   }
1453   for (i = 0; i < m; i++) {
1454     idx = a->j + ii[i];
1455     v   = aa + ii[i];
1456     n   = ii[i + 1] - ii[i];
1457     if (usecprow) {
1458       alpha = x[ridx[i]];
1459     } else {
1460       alpha = x[i];
1461     }
1462     for (j = 0; j < n; j++) y[idx[j]] += alpha * v[j];
1463   }
1464 #endif
1465   PetscCall(PetscLogFlops(2.0 * a->nz));
1466   PetscCall(VecRestoreArrayRead(xx, &x));
1467   PetscCall(VecRestoreArray(yy, &y));
1468   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1469   PetscFunctionReturn(PETSC_SUCCESS);
1470 }
1471 
1472 PetscErrorCode MatMultTranspose_SeqAIJ(Mat A, Vec xx, Vec yy)
1473 {
1474   PetscFunctionBegin;
1475   PetscCall(VecSet(yy, 0.0));
1476   PetscCall(MatMultTransposeAdd_SeqAIJ(A, xx, yy, yy));
1477   PetscFunctionReturn(PETSC_SUCCESS);
1478 }
1479 
1480 #include <../src/mat/impls/aij/seq/ftn-kernels/fmult.h>
1481 
1482 PetscErrorCode MatMult_SeqAIJ(Mat A, Vec xx, Vec yy)
1483 {
1484   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1485   PetscScalar       *y;
1486   const PetscScalar *x;
1487   const MatScalar   *a_a;
1488   PetscInt           m = A->rmap->n;
1489   const PetscInt    *ii, *ridx = NULL;
1490   PetscBool          usecprow = a->compressedrow.use;
1491 
1492 #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
1493   #pragma disjoint(*x, *y, *aa)
1494 #endif
1495 
1496   PetscFunctionBegin;
1497   if (a->inode.use && a->inode.checked) {
1498     PetscCall(MatMult_SeqAIJ_Inode(A, xx, yy));
1499     PetscFunctionReturn(PETSC_SUCCESS);
1500   }
1501   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1502   PetscCall(VecGetArrayRead(xx, &x));
1503   PetscCall(VecGetArray(yy, &y));
1504   ii = a->i;
1505   if (usecprow) { /* use compressed row format */
1506     PetscCall(PetscArrayzero(y, m));
1507     m    = a->compressedrow.nrows;
1508     ii   = a->compressedrow.i;
1509     ridx = a->compressedrow.rindex;
1510     PetscPragmaUseOMPKernels(parallel for)
1511     for (PetscInt i = 0; i < m; i++) {
1512       PetscInt           n   = ii[i + 1] - ii[i];
1513       const PetscInt    *aj  = a->j + ii[i];
1514       const PetscScalar *aa  = a_a + ii[i];
1515       PetscScalar        sum = 0.0;
1516       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1517       /* for (j=0; j<n; j++) sum += (*aa++)*x[*aj++]; */
1518       y[*ridx++] = sum;
1519     }
1520   } else { /* do not use compressed row format */
1521 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTAIJ)
1522     fortranmultaij_(&m, x, ii, a->j, a_a, y);
1523 #else
1524     PetscPragmaUseOMPKernels(parallel for)
1525     for (PetscInt i = 0; i < m; i++) {
1526       PetscInt           n   = ii[i + 1] - ii[i];
1527       const PetscInt    *aj  = a->j + ii[i];
1528       const PetscScalar *aa  = a_a + ii[i];
1529       PetscScalar        sum = 0.0;
1530       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1531       y[i] = sum;
1532     }
1533 #endif
1534   }
1535   PetscCall(PetscLogFlops(2.0 * a->nz - a->nonzerorowcnt));
1536   PetscCall(VecRestoreArrayRead(xx, &x));
1537   PetscCall(VecRestoreArray(yy, &y));
1538   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1539   PetscFunctionReturn(PETSC_SUCCESS);
1540 }
1541 
1542 // HACK!!!!! Used by src/mat/tests/ex170.c
1543 PETSC_EXTERN PetscErrorCode MatMultMax_SeqAIJ(Mat A, Vec xx, Vec yy)
1544 {
1545   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1546   PetscScalar       *y;
1547   const PetscScalar *x;
1548   const MatScalar   *aa, *a_a;
1549   PetscInt           m = A->rmap->n;
1550   const PetscInt    *aj, *ii, *ridx   = NULL;
1551   PetscInt           n, i, nonzerorow = 0;
1552   PetscScalar        sum;
1553   PetscBool          usecprow = a->compressedrow.use;
1554 
1555 #if defined(PETSC_HAVE_PRAGMA_DISJOINT)
1556   #pragma disjoint(*x, *y, *aa)
1557 #endif
1558 
1559   PetscFunctionBegin;
1560   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1561   PetscCall(VecGetArrayRead(xx, &x));
1562   PetscCall(VecGetArray(yy, &y));
1563   if (usecprow) { /* use compressed row format */
1564     m    = a->compressedrow.nrows;
1565     ii   = a->compressedrow.i;
1566     ridx = a->compressedrow.rindex;
1567     for (i = 0; i < m; i++) {
1568       n   = ii[i + 1] - ii[i];
1569       aj  = a->j + ii[i];
1570       aa  = a_a + ii[i];
1571       sum = 0.0;
1572       nonzerorow += (n > 0);
1573       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1574       /* for (j=0; j<n; j++) sum += (*aa++)*x[*aj++]; */
1575       y[*ridx++] = sum;
1576     }
1577   } else { /* do not use compressed row format */
1578     ii = a->i;
1579     for (i = 0; i < m; i++) {
1580       n   = ii[i + 1] - ii[i];
1581       aj  = a->j + ii[i];
1582       aa  = a_a + ii[i];
1583       sum = 0.0;
1584       nonzerorow += (n > 0);
1585       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1586       y[i] = sum;
1587     }
1588   }
1589   PetscCall(PetscLogFlops(2.0 * a->nz - nonzerorow));
1590   PetscCall(VecRestoreArrayRead(xx, &x));
1591   PetscCall(VecRestoreArray(yy, &y));
1592   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1593   PetscFunctionReturn(PETSC_SUCCESS);
1594 }
1595 
1596 // HACK!!!!! Used by src/mat/tests/ex170.c
1597 PETSC_EXTERN PetscErrorCode MatMultAddMax_SeqAIJ(Mat A, Vec xx, Vec yy, Vec zz)
1598 {
1599   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1600   PetscScalar       *y, *z;
1601   const PetscScalar *x;
1602   const MatScalar   *aa, *a_a;
1603   PetscInt           m = A->rmap->n, *aj, *ii;
1604   PetscInt           n, i, *ridx = NULL;
1605   PetscScalar        sum;
1606   PetscBool          usecprow = a->compressedrow.use;
1607 
1608   PetscFunctionBegin;
1609   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1610   PetscCall(VecGetArrayRead(xx, &x));
1611   PetscCall(VecGetArrayPair(yy, zz, &y, &z));
1612   if (usecprow) { /* use compressed row format */
1613     if (zz != yy) PetscCall(PetscArraycpy(z, y, m));
1614     m    = a->compressedrow.nrows;
1615     ii   = a->compressedrow.i;
1616     ridx = a->compressedrow.rindex;
1617     for (i = 0; i < m; i++) {
1618       n   = ii[i + 1] - ii[i];
1619       aj  = a->j + ii[i];
1620       aa  = a_a + ii[i];
1621       sum = y[*ridx];
1622       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1623       z[*ridx++] = sum;
1624     }
1625   } else { /* do not use compressed row format */
1626     ii = a->i;
1627     for (i = 0; i < m; i++) {
1628       n   = ii[i + 1] - ii[i];
1629       aj  = a->j + ii[i];
1630       aa  = a_a + ii[i];
1631       sum = y[i];
1632       PetscSparseDenseMaxDot(sum, x, aa, aj, n);
1633       z[i] = sum;
1634     }
1635   }
1636   PetscCall(PetscLogFlops(2.0 * a->nz));
1637   PetscCall(VecRestoreArrayRead(xx, &x));
1638   PetscCall(VecRestoreArrayPair(yy, zz, &y, &z));
1639   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1640   PetscFunctionReturn(PETSC_SUCCESS);
1641 }
1642 
1643 #include <../src/mat/impls/aij/seq/ftn-kernels/fmultadd.h>
1644 PetscErrorCode MatMultAdd_SeqAIJ(Mat A, Vec xx, Vec yy, Vec zz)
1645 {
1646   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1647   PetscScalar       *y, *z;
1648   const PetscScalar *x;
1649   const MatScalar   *a_a;
1650   const PetscInt    *ii, *ridx = NULL;
1651   PetscInt           m        = A->rmap->n;
1652   PetscBool          usecprow = a->compressedrow.use;
1653 
1654   PetscFunctionBegin;
1655   if (a->inode.use && a->inode.checked) {
1656     PetscCall(MatMultAdd_SeqAIJ_Inode(A, xx, yy, zz));
1657     PetscFunctionReturn(PETSC_SUCCESS);
1658   }
1659   PetscCall(MatSeqAIJGetArrayRead(A, &a_a));
1660   PetscCall(VecGetArrayRead(xx, &x));
1661   PetscCall(VecGetArrayPair(yy, zz, &y, &z));
1662   if (usecprow) { /* use compressed row format */
1663     if (zz != yy) PetscCall(PetscArraycpy(z, y, m));
1664     m    = a->compressedrow.nrows;
1665     ii   = a->compressedrow.i;
1666     ridx = a->compressedrow.rindex;
1667     for (PetscInt i = 0; i < m; i++) {
1668       PetscInt           n   = ii[i + 1] - ii[i];
1669       const PetscInt    *aj  = a->j + ii[i];
1670       const PetscScalar *aa  = a_a + ii[i];
1671       PetscScalar        sum = y[*ridx];
1672       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1673       z[*ridx++] = sum;
1674     }
1675   } else { /* do not use compressed row format */
1676     ii = a->i;
1677 #if defined(PETSC_USE_FORTRAN_KERNEL_MULTADDAIJ)
1678     fortranmultaddaij_(&m, x, ii, a->j, a_a, y, z);
1679 #else
1680     PetscPragmaUseOMPKernels(parallel for)
1681     for (PetscInt i = 0; i < m; i++) {
1682       PetscInt           n   = ii[i + 1] - ii[i];
1683       const PetscInt    *aj  = a->j + ii[i];
1684       const PetscScalar *aa  = a_a + ii[i];
1685       PetscScalar        sum = y[i];
1686       PetscSparseDensePlusDot(sum, x, aa, aj, n);
1687       z[i] = sum;
1688     }
1689 #endif
1690   }
1691   PetscCall(PetscLogFlops(2.0 * a->nz));
1692   PetscCall(VecRestoreArrayRead(xx, &x));
1693   PetscCall(VecRestoreArrayPair(yy, zz, &y, &z));
1694   PetscCall(MatSeqAIJRestoreArrayRead(A, &a_a));
1695   PetscFunctionReturn(PETSC_SUCCESS);
1696 }
1697 
1698 /*
1699      Adds diagonal pointers to sparse matrix nonzero structure.
1700 */
1701 PetscErrorCode MatMarkDiagonal_SeqAIJ(Mat A)
1702 {
1703   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1704   PetscInt    i, j, m = A->rmap->n;
1705   PetscBool   alreadySet = PETSC_TRUE;
1706 
1707   PetscFunctionBegin;
1708   if (!a->diag) {
1709     PetscCall(PetscMalloc1(m, &a->diag));
1710     alreadySet = PETSC_FALSE;
1711   }
1712   for (i = 0; i < A->rmap->n; i++) {
1713     /* If A's diagonal is already correctly set, this fast track enables cheap and repeated MatMarkDiagonal_SeqAIJ() calls */
1714     if (alreadySet) {
1715       PetscInt pos = a->diag[i];
1716       if (pos >= a->i[i] && pos < a->i[i + 1] && a->j[pos] == i) continue;
1717     }
1718 
1719     a->diag[i] = a->i[i + 1];
1720     for (j = a->i[i]; j < a->i[i + 1]; j++) {
1721       if (a->j[j] == i) {
1722         a->diag[i] = j;
1723         break;
1724       }
1725     }
1726   }
1727   PetscFunctionReturn(PETSC_SUCCESS);
1728 }
1729 
1730 static PetscErrorCode MatShift_SeqAIJ(Mat A, PetscScalar v)
1731 {
1732   Mat_SeqAIJ     *a    = (Mat_SeqAIJ *)A->data;
1733   const PetscInt *diag = (const PetscInt *)a->diag;
1734   const PetscInt *ii   = (const PetscInt *)a->i;
1735   PetscInt        i, *mdiag = NULL;
1736   PetscInt        cnt = 0; /* how many diagonals are missing */
1737 
1738   PetscFunctionBegin;
1739   if (!A->preallocated || !a->nz) {
1740     PetscCall(MatSeqAIJSetPreallocation(A, 1, NULL));
1741     PetscCall(MatShift_Basic(A, v));
1742     PetscFunctionReturn(PETSC_SUCCESS);
1743   }
1744 
1745   if (a->diagonaldense) {
1746     cnt = 0;
1747   } else {
1748     PetscCall(PetscCalloc1(A->rmap->n, &mdiag));
1749     for (i = 0; i < A->rmap->n; i++) {
1750       if (i < A->cmap->n && diag[i] >= ii[i + 1]) { /* 'out of range' rows never have diagonals */
1751         cnt++;
1752         mdiag[i] = 1;
1753       }
1754     }
1755   }
1756   if (!cnt) {
1757     PetscCall(MatShift_Basic(A, v));
1758   } else {
1759     PetscScalar       *olda = a->a; /* preserve pointers to current matrix nonzeros structure and values */
1760     PetscInt          *oldj = a->j, *oldi = a->i;
1761     PetscBool          free_a = a->free_a, free_ij = a->free_ij;
1762     const PetscScalar *Aa;
1763 
1764     PetscCall(MatSeqAIJGetArrayRead(A, &Aa)); // sync the host
1765     PetscCall(MatSeqAIJRestoreArrayRead(A, &Aa));
1766 
1767     a->a = NULL;
1768     a->j = NULL;
1769     a->i = NULL;
1770     /* increase the values in imax for each row where a diagonal is being inserted then reallocate the matrix data structures */
1771     for (i = 0; i < PetscMin(A->rmap->n, A->cmap->n); i++) a->imax[i] += mdiag[i];
1772     PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(A, 0, a->imax));
1773 
1774     /* copy old values into new matrix data structure */
1775     for (i = 0; i < A->rmap->n; i++) {
1776       PetscCall(MatSetValues(A, 1, &i, a->imax[i] - mdiag[i], &oldj[oldi[i]], &olda[oldi[i]], ADD_VALUES));
1777       if (i < A->cmap->n) PetscCall(MatSetValue(A, i, i, v, ADD_VALUES));
1778     }
1779     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
1780     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
1781     if (free_a) PetscCall(PetscShmgetDeallocateArray((void **)&olda));
1782     if (free_ij) PetscCall(PetscShmgetDeallocateArray((void **)&oldj));
1783     if (free_ij) PetscCall(PetscShmgetDeallocateArray((void **)&oldi));
1784   }
1785   PetscCall(PetscFree(mdiag));
1786   a->diagonaldense = PETSC_TRUE;
1787   PetscFunctionReturn(PETSC_SUCCESS);
1788 }
1789 
1790 /*
1791      Checks for missing diagonals
1792 */
1793 PetscErrorCode MatMissingDiagonal_SeqAIJ(Mat A, PetscBool *missing, PetscInt *d)
1794 {
1795   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
1796   PetscInt   *diag, *ii = a->i, i;
1797 
1798   PetscFunctionBegin;
1799   *missing = PETSC_FALSE;
1800   if (A->rmap->n > 0 && !ii) {
1801     *missing = PETSC_TRUE;
1802     if (d) *d = 0;
1803     PetscCall(PetscInfo(A, "Matrix has no entries therefore is missing diagonal\n"));
1804   } else {
1805     PetscInt n;
1806     n    = PetscMin(A->rmap->n, A->cmap->n);
1807     diag = a->diag;
1808     for (i = 0; i < n; i++) {
1809       if (diag[i] >= ii[i + 1]) {
1810         *missing = PETSC_TRUE;
1811         if (d) *d = i;
1812         PetscCall(PetscInfo(A, "Matrix is missing diagonal number %" PetscInt_FMT "\n", i));
1813         break;
1814       }
1815     }
1816   }
1817   PetscFunctionReturn(PETSC_SUCCESS);
1818 }
1819 
1820 #include <petscblaslapack.h>
1821 #include <petsc/private/kernels/blockinvert.h>
1822 
1823 /*
1824     Note that values is allocated externally by the PC and then passed into this routine
1825 */
1826 static PetscErrorCode MatInvertVariableBlockDiagonal_SeqAIJ(Mat A, PetscInt nblocks, const PetscInt *bsizes, PetscScalar *diag)
1827 {
1828   PetscInt        n = A->rmap->n, i, ncnt = 0, *indx, j, bsizemax = 0, *v_pivots;
1829   PetscBool       allowzeropivot, zeropivotdetected = PETSC_FALSE;
1830   const PetscReal shift = 0.0;
1831   PetscInt        ipvt[5];
1832   PetscCount      flops = 0;
1833   PetscScalar     work[25], *v_work;
1834 
1835   PetscFunctionBegin;
1836   allowzeropivot = PetscNot(A->erroriffailure);
1837   for (i = 0; i < nblocks; i++) ncnt += bsizes[i];
1838   PetscCheck(ncnt == n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Total blocksizes %" PetscInt_FMT " doesn't match number matrix rows %" PetscInt_FMT, ncnt, n);
1839   for (i = 0; i < nblocks; i++) bsizemax = PetscMax(bsizemax, bsizes[i]);
1840   PetscCall(PetscMalloc1(bsizemax, &indx));
1841   if (bsizemax > 7) PetscCall(PetscMalloc2(bsizemax, &v_work, bsizemax, &v_pivots));
1842   ncnt = 0;
1843   for (i = 0; i < nblocks; i++) {
1844     for (j = 0; j < bsizes[i]; j++) indx[j] = ncnt + j;
1845     PetscCall(MatGetValues(A, bsizes[i], indx, bsizes[i], indx, diag));
1846     switch (bsizes[i]) {
1847     case 1:
1848       *diag = 1.0 / (*diag);
1849       break;
1850     case 2:
1851       PetscCall(PetscKernel_A_gets_inverse_A_2(diag, shift, allowzeropivot, &zeropivotdetected));
1852       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1853       PetscCall(PetscKernel_A_gets_transpose_A_2(diag));
1854       break;
1855     case 3:
1856       PetscCall(PetscKernel_A_gets_inverse_A_3(diag, shift, allowzeropivot, &zeropivotdetected));
1857       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1858       PetscCall(PetscKernel_A_gets_transpose_A_3(diag));
1859       break;
1860     case 4:
1861       PetscCall(PetscKernel_A_gets_inverse_A_4(diag, shift, allowzeropivot, &zeropivotdetected));
1862       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1863       PetscCall(PetscKernel_A_gets_transpose_A_4(diag));
1864       break;
1865     case 5:
1866       PetscCall(PetscKernel_A_gets_inverse_A_5(diag, ipvt, work, shift, allowzeropivot, &zeropivotdetected));
1867       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1868       PetscCall(PetscKernel_A_gets_transpose_A_5(diag));
1869       break;
1870     case 6:
1871       PetscCall(PetscKernel_A_gets_inverse_A_6(diag, shift, allowzeropivot, &zeropivotdetected));
1872       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1873       PetscCall(PetscKernel_A_gets_transpose_A_6(diag));
1874       break;
1875     case 7:
1876       PetscCall(PetscKernel_A_gets_inverse_A_7(diag, shift, allowzeropivot, &zeropivotdetected));
1877       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1878       PetscCall(PetscKernel_A_gets_transpose_A_7(diag));
1879       break;
1880     default:
1881       PetscCall(PetscKernel_A_gets_inverse_A(bsizes[i], diag, v_pivots, v_work, allowzeropivot, &zeropivotdetected));
1882       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1883       PetscCall(PetscKernel_A_gets_transpose_A_N(diag, bsizes[i]));
1884     }
1885     ncnt += bsizes[i];
1886     diag += bsizes[i] * bsizes[i];
1887     flops += 2 * PetscPowInt64(bsizes[i], 3) / 3;
1888   }
1889   PetscCall(PetscLogFlops(flops));
1890   if (bsizemax > 7) PetscCall(PetscFree2(v_work, v_pivots));
1891   PetscCall(PetscFree(indx));
1892   PetscFunctionReturn(PETSC_SUCCESS);
1893 }
1894 
1895 /*
1896    Negative shift indicates do not generate an error if there is a zero diagonal, just invert it anyways
1897 */
1898 static PetscErrorCode MatInvertDiagonal_SeqAIJ(Mat A, PetscScalar omega, PetscScalar fshift)
1899 {
1900   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
1901   PetscInt         i, *diag, m = A->rmap->n;
1902   const MatScalar *v;
1903   PetscScalar     *idiag, *mdiag;
1904 
1905   PetscFunctionBegin;
1906   if (a->idiagvalid) PetscFunctionReturn(PETSC_SUCCESS);
1907   PetscCall(MatMarkDiagonal_SeqAIJ(A));
1908   diag = a->diag;
1909   if (!a->idiag) { PetscCall(PetscMalloc3(m, &a->idiag, m, &a->mdiag, m, &a->ssor_work)); }
1910 
1911   mdiag = a->mdiag;
1912   idiag = a->idiag;
1913   PetscCall(MatSeqAIJGetArrayRead(A, &v));
1914   if (omega == 1.0 && PetscRealPart(fshift) <= 0.0) {
1915     for (i = 0; i < m; i++) {
1916       mdiag[i] = v[diag[i]];
1917       if (!PetscAbsScalar(mdiag[i])) { /* zero diagonal */
1918         if (PetscRealPart(fshift)) {
1919           PetscCall(PetscInfo(A, "Zero diagonal on row %" PetscInt_FMT "\n", i));
1920           A->factorerrortype             = MAT_FACTOR_NUMERIC_ZEROPIVOT;
1921           A->factorerror_zeropivot_value = 0.0;
1922           A->factorerror_zeropivot_row   = i;
1923         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Zero diagonal on row %" PetscInt_FMT, i);
1924       }
1925       idiag[i] = 1.0 / v[diag[i]];
1926     }
1927     PetscCall(PetscLogFlops(m));
1928   } else {
1929     for (i = 0; i < m; i++) {
1930       mdiag[i] = v[diag[i]];
1931       idiag[i] = omega / (fshift + v[diag[i]]);
1932     }
1933     PetscCall(PetscLogFlops(2.0 * m));
1934   }
1935   a->idiagvalid = PETSC_TRUE;
1936   PetscCall(MatSeqAIJRestoreArrayRead(A, &v));
1937   PetscFunctionReturn(PETSC_SUCCESS);
1938 }
1939 
1940 PetscErrorCode MatSOR_SeqAIJ(Mat A, Vec bb, PetscReal omega, MatSORType flag, PetscReal fshift, PetscInt its, PetscInt lits, Vec xx)
1941 {
1942   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
1943   PetscScalar       *x, d, sum, *t, scale;
1944   const MatScalar   *v, *idiag = NULL, *mdiag, *aa;
1945   const PetscScalar *b, *bs, *xb, *ts;
1946   PetscInt           n, m = A->rmap->n, i;
1947   const PetscInt    *idx, *diag;
1948 
1949   PetscFunctionBegin;
1950   if (a->inode.use && a->inode.checked && omega == 1.0 && fshift == 0.0) {
1951     PetscCall(MatSOR_SeqAIJ_Inode(A, bb, omega, flag, fshift, its, lits, xx));
1952     PetscFunctionReturn(PETSC_SUCCESS);
1953   }
1954   its = its * lits;
1955 
1956   if (fshift != a->fshift || omega != a->omega) a->idiagvalid = PETSC_FALSE; /* must recompute idiag[] */
1957   if (!a->idiagvalid) PetscCall(MatInvertDiagonal_SeqAIJ(A, omega, fshift));
1958   a->fshift = fshift;
1959   a->omega  = omega;
1960 
1961   diag  = a->diag;
1962   t     = a->ssor_work;
1963   idiag = a->idiag;
1964   mdiag = a->mdiag;
1965 
1966   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
1967   PetscCall(VecGetArray(xx, &x));
1968   PetscCall(VecGetArrayRead(bb, &b));
1969   /* We count flops by assuming the upper triangular and lower triangular parts have the same number of nonzeros */
1970   if (flag == SOR_APPLY_UPPER) {
1971     /* apply (U + D/omega) to the vector */
1972     bs = b;
1973     for (i = 0; i < m; i++) {
1974       d   = fshift + mdiag[i];
1975       n   = a->i[i + 1] - diag[i] - 1;
1976       idx = a->j + diag[i] + 1;
1977       v   = aa + diag[i] + 1;
1978       sum = b[i] * d / omega;
1979       PetscSparseDensePlusDot(sum, bs, v, idx, n);
1980       x[i] = sum;
1981     }
1982     PetscCall(VecRestoreArray(xx, &x));
1983     PetscCall(VecRestoreArrayRead(bb, &b));
1984     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
1985     PetscCall(PetscLogFlops(a->nz));
1986     PetscFunctionReturn(PETSC_SUCCESS);
1987   }
1988 
1989   PetscCheck(flag != SOR_APPLY_LOWER, PETSC_COMM_SELF, PETSC_ERR_SUP, "SOR_APPLY_LOWER is not implemented");
1990   if (flag & SOR_EISENSTAT) {
1991     /* Let  A = L + U + D; where L is lower triangular,
1992     U is upper triangular, E = D/omega; This routine applies
1993 
1994             (L + E)^{-1} A (U + E)^{-1}
1995 
1996     to a vector efficiently using Eisenstat's trick.
1997     */
1998     scale = (2.0 / omega) - 1.0;
1999 
2000     /*  x = (E + U)^{-1} b */
2001     for (i = m - 1; i >= 0; i--) {
2002       n   = a->i[i + 1] - diag[i] - 1;
2003       idx = a->j + diag[i] + 1;
2004       v   = aa + diag[i] + 1;
2005       sum = b[i];
2006       PetscSparseDenseMinusDot(sum, x, v, idx, n);
2007       x[i] = sum * idiag[i];
2008     }
2009 
2010     /*  t = b - (2*E - D)x */
2011     v = aa;
2012     for (i = 0; i < m; i++) t[i] = b[i] - scale * (v[*diag++]) * x[i];
2013 
2014     /*  t = (E + L)^{-1}t */
2015     ts   = t;
2016     diag = a->diag;
2017     for (i = 0; i < m; i++) {
2018       n   = diag[i] - a->i[i];
2019       idx = a->j + a->i[i];
2020       v   = aa + a->i[i];
2021       sum = t[i];
2022       PetscSparseDenseMinusDot(sum, ts, v, idx, n);
2023       t[i] = sum * idiag[i];
2024       /*  x = x + t */
2025       x[i] += t[i];
2026     }
2027 
2028     PetscCall(PetscLogFlops(6.0 * m - 1 + 2.0 * a->nz));
2029     PetscCall(VecRestoreArray(xx, &x));
2030     PetscCall(VecRestoreArrayRead(bb, &b));
2031     PetscFunctionReturn(PETSC_SUCCESS);
2032   }
2033   if (flag & SOR_ZERO_INITIAL_GUESS) {
2034     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
2035       for (i = 0; i < m; i++) {
2036         n   = diag[i] - a->i[i];
2037         idx = a->j + a->i[i];
2038         v   = aa + a->i[i];
2039         sum = b[i];
2040         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2041         t[i] = sum;
2042         x[i] = sum * idiag[i];
2043       }
2044       xb = t;
2045       PetscCall(PetscLogFlops(a->nz));
2046     } else xb = b;
2047     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {
2048       for (i = m - 1; i >= 0; i--) {
2049         n   = a->i[i + 1] - diag[i] - 1;
2050         idx = a->j + diag[i] + 1;
2051         v   = aa + diag[i] + 1;
2052         sum = xb[i];
2053         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2054         if (xb == b) {
2055           x[i] = sum * idiag[i];
2056         } else {
2057           x[i] = (1 - omega) * x[i] + sum * idiag[i]; /* omega in idiag */
2058         }
2059       }
2060       PetscCall(PetscLogFlops(a->nz)); /* assumes 1/2 in upper */
2061     }
2062     its--;
2063   }
2064   while (its--) {
2065     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
2066       for (i = 0; i < m; i++) {
2067         /* lower */
2068         n   = diag[i] - a->i[i];
2069         idx = a->j + a->i[i];
2070         v   = aa + a->i[i];
2071         sum = b[i];
2072         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2073         t[i] = sum; /* save application of the lower-triangular part */
2074         /* upper */
2075         n   = a->i[i + 1] - diag[i] - 1;
2076         idx = a->j + diag[i] + 1;
2077         v   = aa + diag[i] + 1;
2078         PetscSparseDenseMinusDot(sum, x, v, idx, n);
2079         x[i] = (1. - omega) * x[i] + sum * idiag[i]; /* omega in idiag */
2080       }
2081       xb = t;
2082       PetscCall(PetscLogFlops(2.0 * a->nz));
2083     } else xb = b;
2084     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {
2085       for (i = m - 1; i >= 0; i--) {
2086         sum = xb[i];
2087         if (xb == b) {
2088           /* whole matrix (no checkpointing available) */
2089           n   = a->i[i + 1] - a->i[i];
2090           idx = a->j + a->i[i];
2091           v   = aa + a->i[i];
2092           PetscSparseDenseMinusDot(sum, x, v, idx, n);
2093           x[i] = (1. - omega) * x[i] + (sum + mdiag[i] * x[i]) * idiag[i];
2094         } else { /* lower-triangular part has been saved, so only apply upper-triangular */
2095           n   = a->i[i + 1] - diag[i] - 1;
2096           idx = a->j + diag[i] + 1;
2097           v   = aa + diag[i] + 1;
2098           PetscSparseDenseMinusDot(sum, x, v, idx, n);
2099           x[i] = (1. - omega) * x[i] + sum * idiag[i]; /* omega in idiag */
2100         }
2101       }
2102       if (xb == b) {
2103         PetscCall(PetscLogFlops(2.0 * a->nz));
2104       } else {
2105         PetscCall(PetscLogFlops(a->nz)); /* assumes 1/2 in upper */
2106       }
2107     }
2108   }
2109   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2110   PetscCall(VecRestoreArray(xx, &x));
2111   PetscCall(VecRestoreArrayRead(bb, &b));
2112   PetscFunctionReturn(PETSC_SUCCESS);
2113 }
2114 
2115 static PetscErrorCode MatGetInfo_SeqAIJ(Mat A, MatInfoType flag, MatInfo *info)
2116 {
2117   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
2118 
2119   PetscFunctionBegin;
2120   info->block_size   = 1.0;
2121   info->nz_allocated = a->maxnz;
2122   info->nz_used      = a->nz;
2123   info->nz_unneeded  = (a->maxnz - a->nz);
2124   info->assemblies   = A->num_ass;
2125   info->mallocs      = A->info.mallocs;
2126   info->memory       = 0; /* REVIEW ME */
2127   if (A->factortype) {
2128     info->fill_ratio_given  = A->info.fill_ratio_given;
2129     info->fill_ratio_needed = A->info.fill_ratio_needed;
2130     info->factor_mallocs    = A->info.factor_mallocs;
2131   } else {
2132     info->fill_ratio_given  = 0;
2133     info->fill_ratio_needed = 0;
2134     info->factor_mallocs    = 0;
2135   }
2136   PetscFunctionReturn(PETSC_SUCCESS);
2137 }
2138 
2139 static PetscErrorCode MatZeroRows_SeqAIJ(Mat A, PetscInt N, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
2140 {
2141   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2142   PetscInt           i, m = A->rmap->n - 1;
2143   const PetscScalar *xx;
2144   PetscScalar       *bb, *aa;
2145   PetscInt           d = 0;
2146 
2147   PetscFunctionBegin;
2148   if (x && b) {
2149     PetscCall(VecGetArrayRead(x, &xx));
2150     PetscCall(VecGetArray(b, &bb));
2151     for (i = 0; i < N; i++) {
2152       PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2153       if (rows[i] >= A->cmap->n) continue;
2154       bb[rows[i]] = diag * xx[rows[i]];
2155     }
2156     PetscCall(VecRestoreArrayRead(x, &xx));
2157     PetscCall(VecRestoreArray(b, &bb));
2158   }
2159 
2160   PetscCall(MatSeqAIJGetArray(A, &aa));
2161   if (a->keepnonzeropattern) {
2162     for (i = 0; i < N; i++) {
2163       PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2164       PetscCall(PetscArrayzero(&aa[a->i[rows[i]]], a->ilen[rows[i]]));
2165     }
2166     if (diag != 0.0) {
2167       for (i = 0; i < N; i++) {
2168         d = rows[i];
2169         if (rows[i] >= A->cmap->n) continue;
2170         PetscCheck(a->diag[d] < a->i[d + 1], PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Matrix is missing diagonal entry in the zeroed row %" PetscInt_FMT, d);
2171       }
2172       for (i = 0; i < N; i++) {
2173         if (rows[i] >= A->cmap->n) continue;
2174         aa[a->diag[rows[i]]] = diag;
2175       }
2176     }
2177   } else {
2178     if (diag != 0.0) {
2179       for (i = 0; i < N; i++) {
2180         PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2181         if (a->ilen[rows[i]] > 0) {
2182           if (rows[i] >= A->cmap->n) {
2183             a->ilen[rows[i]] = 0;
2184           } else {
2185             a->ilen[rows[i]]    = 1;
2186             aa[a->i[rows[i]]]   = diag;
2187             a->j[a->i[rows[i]]] = rows[i];
2188           }
2189         } else if (rows[i] < A->cmap->n) { /* in case row was completely empty */
2190           PetscCall(MatSetValues_SeqAIJ(A, 1, &rows[i], 1, &rows[i], &diag, INSERT_VALUES));
2191         }
2192       }
2193     } else {
2194       for (i = 0; i < N; i++) {
2195         PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2196         a->ilen[rows[i]] = 0;
2197       }
2198     }
2199     A->nonzerostate++;
2200   }
2201   PetscCall(MatSeqAIJRestoreArray(A, &aa));
2202   PetscUseTypeMethod(A, assemblyend, MAT_FINAL_ASSEMBLY);
2203   PetscFunctionReturn(PETSC_SUCCESS);
2204 }
2205 
2206 static PetscErrorCode MatZeroRowsColumns_SeqAIJ(Mat A, PetscInt N, const PetscInt rows[], PetscScalar diag, Vec x, Vec b)
2207 {
2208   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2209   PetscInt           i, j, m = A->rmap->n - 1, d = 0;
2210   PetscBool          missing, *zeroed, vecs = PETSC_FALSE;
2211   const PetscScalar *xx;
2212   PetscScalar       *bb, *aa;
2213 
2214   PetscFunctionBegin;
2215   if (!N) PetscFunctionReturn(PETSC_SUCCESS);
2216   PetscCall(MatSeqAIJGetArray(A, &aa));
2217   if (x && b) {
2218     PetscCall(VecGetArrayRead(x, &xx));
2219     PetscCall(VecGetArray(b, &bb));
2220     vecs = PETSC_TRUE;
2221   }
2222   PetscCall(PetscCalloc1(A->rmap->n, &zeroed));
2223   for (i = 0; i < N; i++) {
2224     PetscCheck(rows[i] >= 0 && rows[i] <= m, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", rows[i]);
2225     PetscCall(PetscArrayzero(PetscSafePointerPlusOffset(aa, a->i[rows[i]]), a->ilen[rows[i]]));
2226 
2227     zeroed[rows[i]] = PETSC_TRUE;
2228   }
2229   for (i = 0; i < A->rmap->n; i++) {
2230     if (!zeroed[i]) {
2231       for (j = a->i[i]; j < a->i[i + 1]; j++) {
2232         if (a->j[j] < A->rmap->n && zeroed[a->j[j]]) {
2233           if (vecs) bb[i] -= aa[j] * xx[a->j[j]];
2234           aa[j] = 0.0;
2235         }
2236       }
2237     } else if (vecs && i < A->cmap->N) bb[i] = diag * xx[i];
2238   }
2239   if (x && b) {
2240     PetscCall(VecRestoreArrayRead(x, &xx));
2241     PetscCall(VecRestoreArray(b, &bb));
2242   }
2243   PetscCall(PetscFree(zeroed));
2244   if (diag != 0.0) {
2245     PetscCall(MatMissingDiagonal_SeqAIJ(A, &missing, &d));
2246     if (missing) {
2247       for (i = 0; i < N; i++) {
2248         if (rows[i] >= A->cmap->N) continue;
2249         PetscCheck(!a->nonew || rows[i] < d, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Matrix is missing diagonal entry in row %" PetscInt_FMT " (%" PetscInt_FMT ")", d, rows[i]);
2250         PetscCall(MatSetValues_SeqAIJ(A, 1, &rows[i], 1, &rows[i], &diag, INSERT_VALUES));
2251       }
2252     } else {
2253       for (i = 0; i < N; i++) aa[a->diag[rows[i]]] = diag;
2254     }
2255   }
2256   PetscCall(MatSeqAIJRestoreArray(A, &aa));
2257   PetscUseTypeMethod(A, assemblyend, MAT_FINAL_ASSEMBLY);
2258   PetscFunctionReturn(PETSC_SUCCESS);
2259 }
2260 
2261 PetscErrorCode MatGetRow_SeqAIJ(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
2262 {
2263   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2264   const PetscScalar *aa;
2265 
2266   PetscFunctionBegin;
2267   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2268   *nz = a->i[row + 1] - a->i[row];
2269   if (v) *v = PetscSafePointerPlusOffset((PetscScalar *)aa, a->i[row]);
2270   if (idx) {
2271     if (*nz && a->j) *idx = a->j + a->i[row];
2272     else *idx = NULL;
2273   }
2274   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2275   PetscFunctionReturn(PETSC_SUCCESS);
2276 }
2277 
2278 PetscErrorCode MatRestoreRow_SeqAIJ(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
2279 {
2280   PetscFunctionBegin;
2281   PetscFunctionReturn(PETSC_SUCCESS);
2282 }
2283 
2284 static PetscErrorCode MatNorm_SeqAIJ(Mat A, NormType type, PetscReal *nrm)
2285 {
2286   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
2287   const MatScalar *v;
2288   PetscReal        sum = 0.0;
2289   PetscInt         i, j;
2290 
2291   PetscFunctionBegin;
2292   PetscCall(MatSeqAIJGetArrayRead(A, &v));
2293   if (type == NORM_FROBENIUS) {
2294 #if defined(PETSC_USE_REAL___FP16)
2295     PetscBLASInt one = 1, nz = a->nz;
2296     PetscCallBLAS("BLASnrm2", *nrm = BLASnrm2_(&nz, v, &one));
2297 #else
2298     for (i = 0; i < a->nz; i++) {
2299       sum += PetscRealPart(PetscConj(*v) * (*v));
2300       v++;
2301     }
2302     *nrm = PetscSqrtReal(sum);
2303 #endif
2304     PetscCall(PetscLogFlops(2.0 * a->nz));
2305   } else if (type == NORM_1) {
2306     PetscReal *tmp;
2307     PetscInt  *jj = a->j;
2308     PetscCall(PetscCalloc1(A->cmap->n + 1, &tmp));
2309     *nrm = 0.0;
2310     for (j = 0; j < a->nz; j++) {
2311       tmp[*jj++] += PetscAbsScalar(*v);
2312       v++;
2313     }
2314     for (j = 0; j < A->cmap->n; j++) {
2315       if (tmp[j] > *nrm) *nrm = tmp[j];
2316     }
2317     PetscCall(PetscFree(tmp));
2318     PetscCall(PetscLogFlops(PetscMax(a->nz - 1, 0)));
2319   } else if (type == NORM_INFINITY) {
2320     *nrm = 0.0;
2321     for (j = 0; j < A->rmap->n; j++) {
2322       const PetscScalar *v2 = PetscSafePointerPlusOffset(v, a->i[j]);
2323       sum                   = 0.0;
2324       for (i = 0; i < a->i[j + 1] - a->i[j]; i++) {
2325         sum += PetscAbsScalar(*v2);
2326         v2++;
2327       }
2328       if (sum > *nrm) *nrm = sum;
2329     }
2330     PetscCall(PetscLogFlops(PetscMax(a->nz - 1, 0)));
2331   } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_SUP, "No support for two norm");
2332   PetscCall(MatSeqAIJRestoreArrayRead(A, &v));
2333   PetscFunctionReturn(PETSC_SUCCESS);
2334 }
2335 
2336 static PetscErrorCode MatIsTranspose_SeqAIJ(Mat A, Mat B, PetscReal tol, PetscBool *f)
2337 {
2338   Mat_SeqAIJ      *aij = (Mat_SeqAIJ *)A->data, *bij = (Mat_SeqAIJ *)B->data;
2339   PetscInt        *adx, *bdx, *aii, *bii, *aptr, *bptr;
2340   const MatScalar *va, *vb;
2341   PetscInt         ma, na, mb, nb, i;
2342 
2343   PetscFunctionBegin;
2344   PetscCall(MatGetSize(A, &ma, &na));
2345   PetscCall(MatGetSize(B, &mb, &nb));
2346   if (ma != nb || na != mb) {
2347     *f = PETSC_FALSE;
2348     PetscFunctionReturn(PETSC_SUCCESS);
2349   }
2350   PetscCall(MatSeqAIJGetArrayRead(A, &va));
2351   PetscCall(MatSeqAIJGetArrayRead(B, &vb));
2352   aii = aij->i;
2353   bii = bij->i;
2354   adx = aij->j;
2355   bdx = bij->j;
2356   PetscCall(PetscMalloc1(ma, &aptr));
2357   PetscCall(PetscMalloc1(mb, &bptr));
2358   for (i = 0; i < ma; i++) aptr[i] = aii[i];
2359   for (i = 0; i < mb; i++) bptr[i] = bii[i];
2360 
2361   *f = PETSC_TRUE;
2362   for (i = 0; i < ma; i++) {
2363     while (aptr[i] < aii[i + 1]) {
2364       PetscInt    idc, idr;
2365       PetscScalar vc, vr;
2366       /* column/row index/value */
2367       idc = adx[aptr[i]];
2368       idr = bdx[bptr[idc]];
2369       vc  = va[aptr[i]];
2370       vr  = vb[bptr[idc]];
2371       if (i != idr || PetscAbsScalar(vc - vr) > tol) {
2372         *f = PETSC_FALSE;
2373         goto done;
2374       } else {
2375         aptr[i]++;
2376         if (B || i != idc) bptr[idc]++;
2377       }
2378     }
2379   }
2380 done:
2381   PetscCall(PetscFree(aptr));
2382   PetscCall(PetscFree(bptr));
2383   PetscCall(MatSeqAIJRestoreArrayRead(A, &va));
2384   PetscCall(MatSeqAIJRestoreArrayRead(B, &vb));
2385   PetscFunctionReturn(PETSC_SUCCESS);
2386 }
2387 
2388 static PetscErrorCode MatIsHermitianTranspose_SeqAIJ(Mat A, Mat B, PetscReal tol, PetscBool *f)
2389 {
2390   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data, *bij = (Mat_SeqAIJ *)B->data;
2391   PetscInt   *adx, *bdx, *aii, *bii, *aptr, *bptr;
2392   MatScalar  *va, *vb;
2393   PetscInt    ma, na, mb, nb, i;
2394 
2395   PetscFunctionBegin;
2396   PetscCall(MatGetSize(A, &ma, &na));
2397   PetscCall(MatGetSize(B, &mb, &nb));
2398   if (ma != nb || na != mb) {
2399     *f = PETSC_FALSE;
2400     PetscFunctionReturn(PETSC_SUCCESS);
2401   }
2402   aii = aij->i;
2403   bii = bij->i;
2404   adx = aij->j;
2405   bdx = bij->j;
2406   va  = aij->a;
2407   vb  = bij->a;
2408   PetscCall(PetscMalloc1(ma, &aptr));
2409   PetscCall(PetscMalloc1(mb, &bptr));
2410   for (i = 0; i < ma; i++) aptr[i] = aii[i];
2411   for (i = 0; i < mb; i++) bptr[i] = bii[i];
2412 
2413   *f = PETSC_TRUE;
2414   for (i = 0; i < ma; i++) {
2415     while (aptr[i] < aii[i + 1]) {
2416       PetscInt    idc, idr;
2417       PetscScalar vc, vr;
2418       /* column/row index/value */
2419       idc = adx[aptr[i]];
2420       idr = bdx[bptr[idc]];
2421       vc  = va[aptr[i]];
2422       vr  = vb[bptr[idc]];
2423       if (i != idr || PetscAbsScalar(vc - PetscConj(vr)) > tol) {
2424         *f = PETSC_FALSE;
2425         goto done;
2426       } else {
2427         aptr[i]++;
2428         if (B || i != idc) bptr[idc]++;
2429       }
2430     }
2431   }
2432 done:
2433   PetscCall(PetscFree(aptr));
2434   PetscCall(PetscFree(bptr));
2435   PetscFunctionReturn(PETSC_SUCCESS);
2436 }
2437 
2438 PetscErrorCode MatDiagonalScale_SeqAIJ(Mat A, Vec ll, Vec rr)
2439 {
2440   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2441   const PetscScalar *l, *r;
2442   PetscScalar        x;
2443   MatScalar         *v;
2444   PetscInt           i, j, m = A->rmap->n, n = A->cmap->n, M, nz = a->nz;
2445   const PetscInt    *jj;
2446 
2447   PetscFunctionBegin;
2448   if (ll) {
2449     /* The local size is used so that VecMPI can be passed to this routine
2450        by MatDiagonalScale_MPIAIJ */
2451     PetscCall(VecGetLocalSize(ll, &m));
2452     PetscCheck(m == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Left scaling vector wrong length");
2453     PetscCall(VecGetArrayRead(ll, &l));
2454     PetscCall(MatSeqAIJGetArray(A, &v));
2455     for (i = 0; i < m; i++) {
2456       x = l[i];
2457       M = a->i[i + 1] - a->i[i];
2458       for (j = 0; j < M; j++) (*v++) *= x;
2459     }
2460     PetscCall(VecRestoreArrayRead(ll, &l));
2461     PetscCall(PetscLogFlops(nz));
2462     PetscCall(MatSeqAIJRestoreArray(A, &v));
2463   }
2464   if (rr) {
2465     PetscCall(VecGetLocalSize(rr, &n));
2466     PetscCheck(n == A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Right scaling vector wrong length");
2467     PetscCall(VecGetArrayRead(rr, &r));
2468     PetscCall(MatSeqAIJGetArray(A, &v));
2469     jj = a->j;
2470     for (i = 0; i < nz; i++) (*v++) *= r[*jj++];
2471     PetscCall(MatSeqAIJRestoreArray(A, &v));
2472     PetscCall(VecRestoreArrayRead(rr, &r));
2473     PetscCall(PetscLogFlops(nz));
2474   }
2475   PetscCall(MatSeqAIJInvalidateDiagonal(A));
2476   PetscFunctionReturn(PETSC_SUCCESS);
2477 }
2478 
2479 PetscErrorCode MatCreateSubMatrix_SeqAIJ(Mat A, IS isrow, IS iscol, PetscInt csize, MatReuse scall, Mat *B)
2480 {
2481   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data, *c;
2482   PetscInt          *smap, i, k, kstart, kend, oldcols = A->cmap->n, *lens;
2483   PetscInt           row, mat_i, *mat_j, tcol, first, step, *mat_ilen, sum, lensi;
2484   const PetscInt    *irow, *icol;
2485   const PetscScalar *aa;
2486   PetscInt           nrows, ncols;
2487   PetscInt          *starts, *j_new, *i_new, *aj = a->j, *ai = a->i, ii, *ailen = a->ilen;
2488   MatScalar         *a_new, *mat_a, *c_a;
2489   Mat                C;
2490   PetscBool          stride;
2491 
2492   PetscFunctionBegin;
2493   PetscCall(ISGetIndices(isrow, &irow));
2494   PetscCall(ISGetLocalSize(isrow, &nrows));
2495   PetscCall(ISGetLocalSize(iscol, &ncols));
2496 
2497   PetscCall(PetscObjectTypeCompare((PetscObject)iscol, ISSTRIDE, &stride));
2498   if (stride) {
2499     PetscCall(ISStrideGetInfo(iscol, &first, &step));
2500   } else {
2501     first = 0;
2502     step  = 0;
2503   }
2504   if (stride && step == 1) {
2505     /* special case of contiguous rows */
2506     PetscCall(PetscMalloc2(nrows, &lens, nrows, &starts));
2507     /* loop over new rows determining lens and starting points */
2508     for (i = 0; i < nrows; i++) {
2509       kstart    = ai[irow[i]];
2510       kend      = kstart + ailen[irow[i]];
2511       starts[i] = kstart;
2512       for (k = kstart; k < kend; k++) {
2513         if (aj[k] >= first) {
2514           starts[i] = k;
2515           break;
2516         }
2517       }
2518       sum = 0;
2519       while (k < kend) {
2520         if (aj[k++] >= first + ncols) break;
2521         sum++;
2522       }
2523       lens[i] = sum;
2524     }
2525     /* create submatrix */
2526     if (scall == MAT_REUSE_MATRIX) {
2527       PetscInt n_cols, n_rows;
2528       PetscCall(MatGetSize(*B, &n_rows, &n_cols));
2529       PetscCheck(n_rows == nrows && n_cols == ncols, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Reused submatrix wrong size");
2530       PetscCall(MatZeroEntries(*B));
2531       C = *B;
2532     } else {
2533       PetscInt rbs, cbs;
2534       PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2535       PetscCall(MatSetSizes(C, nrows, ncols, PETSC_DETERMINE, PETSC_DETERMINE));
2536       PetscCall(ISGetBlockSize(isrow, &rbs));
2537       PetscCall(ISGetBlockSize(iscol, &cbs));
2538       PetscCall(MatSetBlockSizes(C, rbs, cbs));
2539       PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
2540       PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(C, 0, lens));
2541     }
2542     c = (Mat_SeqAIJ *)C->data;
2543 
2544     /* loop over rows inserting into submatrix */
2545     PetscCall(MatSeqAIJGetArrayWrite(C, &a_new)); // Not 'a_new = c->a-new', since that raw usage ignores offload state of C
2546     j_new = c->j;
2547     i_new = c->i;
2548     PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2549     for (i = 0; i < nrows; i++) {
2550       ii    = starts[i];
2551       lensi = lens[i];
2552       if (lensi) {
2553         for (k = 0; k < lensi; k++) *j_new++ = aj[ii + k] - first;
2554         PetscCall(PetscArraycpy(a_new, aa + starts[i], lensi));
2555         a_new += lensi;
2556       }
2557       i_new[i + 1] = i_new[i] + lensi;
2558       c->ilen[i]   = lensi;
2559     }
2560     PetscCall(MatSeqAIJRestoreArrayWrite(C, &a_new)); // Set C's offload state properly
2561     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2562     PetscCall(PetscFree2(lens, starts));
2563   } else {
2564     PetscCall(ISGetIndices(iscol, &icol));
2565     PetscCall(PetscCalloc1(oldcols, &smap));
2566     PetscCall(PetscMalloc1(1 + nrows, &lens));
2567     for (i = 0; i < ncols; i++) {
2568       PetscCheck(icol[i] < oldcols, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Requesting column beyond largest column icol[%" PetscInt_FMT "] %" PetscInt_FMT " >= A->cmap->n %" PetscInt_FMT, i, icol[i], oldcols);
2569       smap[icol[i]] = i + 1;
2570     }
2571 
2572     /* determine lens of each row */
2573     for (i = 0; i < nrows; i++) {
2574       kstart  = ai[irow[i]];
2575       kend    = kstart + a->ilen[irow[i]];
2576       lens[i] = 0;
2577       for (k = kstart; k < kend; k++) {
2578         if (smap[aj[k]]) lens[i]++;
2579       }
2580     }
2581     /* Create and fill new matrix */
2582     if (scall == MAT_REUSE_MATRIX) {
2583       PetscBool equal;
2584 
2585       c = (Mat_SeqAIJ *)((*B)->data);
2586       PetscCheck((*B)->rmap->n == nrows && (*B)->cmap->n == ncols, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Cannot reuse matrix. wrong size");
2587       PetscCall(PetscArraycmp(c->ilen, lens, (*B)->rmap->n, &equal));
2588       PetscCheck(equal, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Cannot reuse matrix. wrong number of nonzeros");
2589       PetscCall(PetscArrayzero(c->ilen, (*B)->rmap->n));
2590       C = *B;
2591     } else {
2592       PetscInt rbs, cbs;
2593       PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
2594       PetscCall(MatSetSizes(C, nrows, ncols, PETSC_DETERMINE, PETSC_DETERMINE));
2595       PetscCall(ISGetBlockSize(isrow, &rbs));
2596       PetscCall(ISGetBlockSize(iscol, &cbs));
2597       if (rbs > 1 || cbs > 1) PetscCall(MatSetBlockSizes(C, rbs, cbs));
2598       PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
2599       PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(C, 0, lens));
2600     }
2601     PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2602 
2603     c = (Mat_SeqAIJ *)C->data;
2604     PetscCall(MatSeqAIJGetArrayWrite(C, &c_a)); // Not 'c->a', since that raw usage ignores offload state of C
2605     for (i = 0; i < nrows; i++) {
2606       row      = irow[i];
2607       kstart   = ai[row];
2608       kend     = kstart + a->ilen[row];
2609       mat_i    = c->i[i];
2610       mat_j    = PetscSafePointerPlusOffset(c->j, mat_i);
2611       mat_a    = PetscSafePointerPlusOffset(c_a, mat_i);
2612       mat_ilen = c->ilen + i;
2613       for (k = kstart; k < kend; k++) {
2614         if ((tcol = smap[a->j[k]])) {
2615           *mat_j++ = tcol - 1;
2616           *mat_a++ = aa[k];
2617           (*mat_ilen)++;
2618         }
2619       }
2620     }
2621     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2622     /* Free work space */
2623     PetscCall(ISRestoreIndices(iscol, &icol));
2624     PetscCall(PetscFree(smap));
2625     PetscCall(PetscFree(lens));
2626     /* sort */
2627     for (i = 0; i < nrows; i++) {
2628       PetscInt ilen;
2629 
2630       mat_i = c->i[i];
2631       mat_j = PetscSafePointerPlusOffset(c->j, mat_i);
2632       mat_a = PetscSafePointerPlusOffset(c_a, mat_i);
2633       ilen  = c->ilen[i];
2634       PetscCall(PetscSortIntWithScalarArray(ilen, mat_j, mat_a));
2635     }
2636     PetscCall(MatSeqAIJRestoreArrayWrite(C, &c_a));
2637   }
2638 #if defined(PETSC_HAVE_DEVICE)
2639   PetscCall(MatBindToCPU(C, A->boundtocpu));
2640 #endif
2641   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
2642   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
2643 
2644   PetscCall(ISRestoreIndices(isrow, &irow));
2645   *B = C;
2646   PetscFunctionReturn(PETSC_SUCCESS);
2647 }
2648 
2649 static PetscErrorCode MatGetMultiProcBlock_SeqAIJ(Mat mat, MPI_Comm subComm, MatReuse scall, Mat *subMat)
2650 {
2651   Mat B;
2652 
2653   PetscFunctionBegin;
2654   if (scall == MAT_INITIAL_MATRIX) {
2655     PetscCall(MatCreate(subComm, &B));
2656     PetscCall(MatSetSizes(B, mat->rmap->n, mat->cmap->n, mat->rmap->n, mat->cmap->n));
2657     PetscCall(MatSetBlockSizesFromMats(B, mat, mat));
2658     PetscCall(MatSetType(B, MATSEQAIJ));
2659     PetscCall(MatDuplicateNoCreate_SeqAIJ(B, mat, MAT_COPY_VALUES, PETSC_TRUE));
2660     *subMat = B;
2661   } else {
2662     PetscCall(MatCopy_SeqAIJ(mat, *subMat, SAME_NONZERO_PATTERN));
2663   }
2664   PetscFunctionReturn(PETSC_SUCCESS);
2665 }
2666 
2667 static PetscErrorCode MatILUFactor_SeqAIJ(Mat inA, IS row, IS col, const MatFactorInfo *info)
2668 {
2669   Mat_SeqAIJ *a = (Mat_SeqAIJ *)inA->data;
2670   Mat         outA;
2671   PetscBool   row_identity, col_identity;
2672 
2673   PetscFunctionBegin;
2674   PetscCheck(info->levels == 0, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only levels=0 supported for in-place ilu");
2675 
2676   PetscCall(ISIdentity(row, &row_identity));
2677   PetscCall(ISIdentity(col, &col_identity));
2678 
2679   outA             = inA;
2680   outA->factortype = MAT_FACTOR_LU;
2681   PetscCall(PetscFree(inA->solvertype));
2682   PetscCall(PetscStrallocpy(MATSOLVERPETSC, &inA->solvertype));
2683 
2684   PetscCall(PetscObjectReference((PetscObject)row));
2685   PetscCall(ISDestroy(&a->row));
2686 
2687   a->row = row;
2688 
2689   PetscCall(PetscObjectReference((PetscObject)col));
2690   PetscCall(ISDestroy(&a->col));
2691 
2692   a->col = col;
2693 
2694   /* Create the inverse permutation so that it can be used in MatLUFactorNumeric() */
2695   PetscCall(ISDestroy(&a->icol));
2696   PetscCall(ISInvertPermutation(col, PETSC_DECIDE, &a->icol));
2697 
2698   if (!a->solve_work) { /* this matrix may have been factored before */
2699     PetscCall(PetscMalloc1(inA->rmap->n + 1, &a->solve_work));
2700   }
2701 
2702   PetscCall(MatMarkDiagonal_SeqAIJ(inA));
2703   if (row_identity && col_identity) {
2704     PetscCall(MatLUFactorNumeric_SeqAIJ_inplace(outA, inA, info));
2705   } else {
2706     PetscCall(MatLUFactorNumeric_SeqAIJ_InplaceWithPerm(outA, inA, info));
2707   }
2708   PetscFunctionReturn(PETSC_SUCCESS);
2709 }
2710 
2711 PetscErrorCode MatScale_SeqAIJ(Mat inA, PetscScalar alpha)
2712 {
2713   Mat_SeqAIJ  *a = (Mat_SeqAIJ *)inA->data;
2714   PetscScalar *v;
2715   PetscBLASInt one = 1, bnz;
2716 
2717   PetscFunctionBegin;
2718   PetscCall(MatSeqAIJGetArray(inA, &v));
2719   PetscCall(PetscBLASIntCast(a->nz, &bnz));
2720   PetscCallBLAS("BLASscal", BLASscal_(&bnz, &alpha, v, &one));
2721   PetscCall(PetscLogFlops(a->nz));
2722   PetscCall(MatSeqAIJRestoreArray(inA, &v));
2723   PetscCall(MatSeqAIJInvalidateDiagonal(inA));
2724   PetscFunctionReturn(PETSC_SUCCESS);
2725 }
2726 
2727 PetscErrorCode MatDestroySubMatrix_Private(Mat_SubSppt *submatj)
2728 {
2729   PetscInt i;
2730 
2731   PetscFunctionBegin;
2732   if (!submatj->id) { /* delete data that are linked only to submats[id=0] */
2733     PetscCall(PetscFree4(submatj->sbuf1, submatj->ptr, submatj->tmp, submatj->ctr));
2734 
2735     for (i = 0; i < submatj->nrqr; ++i) PetscCall(PetscFree(submatj->sbuf2[i]));
2736     PetscCall(PetscFree3(submatj->sbuf2, submatj->req_size, submatj->req_source1));
2737 
2738     if (submatj->rbuf1) {
2739       PetscCall(PetscFree(submatj->rbuf1[0]));
2740       PetscCall(PetscFree(submatj->rbuf1));
2741     }
2742 
2743     for (i = 0; i < submatj->nrqs; ++i) PetscCall(PetscFree(submatj->rbuf3[i]));
2744     PetscCall(PetscFree3(submatj->req_source2, submatj->rbuf2, submatj->rbuf3));
2745     PetscCall(PetscFree(submatj->pa));
2746   }
2747 
2748 #if defined(PETSC_USE_CTABLE)
2749   PetscCall(PetscHMapIDestroy(&submatj->rmap));
2750   if (submatj->cmap_loc) PetscCall(PetscFree(submatj->cmap_loc));
2751   PetscCall(PetscFree(submatj->rmap_loc));
2752 #else
2753   PetscCall(PetscFree(submatj->rmap));
2754 #endif
2755 
2756   if (!submatj->allcolumns) {
2757 #if defined(PETSC_USE_CTABLE)
2758     PetscCall(PetscHMapIDestroy(&submatj->cmap));
2759 #else
2760     PetscCall(PetscFree(submatj->cmap));
2761 #endif
2762   }
2763   PetscCall(PetscFree(submatj->row2proc));
2764 
2765   PetscCall(PetscFree(submatj));
2766   PetscFunctionReturn(PETSC_SUCCESS);
2767 }
2768 
2769 PetscErrorCode MatDestroySubMatrix_SeqAIJ(Mat C)
2770 {
2771   Mat_SeqAIJ  *c       = (Mat_SeqAIJ *)C->data;
2772   Mat_SubSppt *submatj = c->submatis1;
2773 
2774   PetscFunctionBegin;
2775   PetscCall((*submatj->destroy)(C));
2776   PetscCall(MatDestroySubMatrix_Private(submatj));
2777   PetscFunctionReturn(PETSC_SUCCESS);
2778 }
2779 
2780 /* Note this has code duplication with MatDestroySubMatrices_SeqBAIJ() */
2781 static PetscErrorCode MatDestroySubMatrices_SeqAIJ(PetscInt n, Mat *mat[])
2782 {
2783   PetscInt     i;
2784   Mat          C;
2785   Mat_SeqAIJ  *c;
2786   Mat_SubSppt *submatj;
2787 
2788   PetscFunctionBegin;
2789   for (i = 0; i < n; i++) {
2790     C       = (*mat)[i];
2791     c       = (Mat_SeqAIJ *)C->data;
2792     submatj = c->submatis1;
2793     if (submatj) {
2794       if (--((PetscObject)C)->refct <= 0) {
2795         PetscCall(PetscFree(C->factorprefix));
2796         PetscCall((*submatj->destroy)(C));
2797         PetscCall(MatDestroySubMatrix_Private(submatj));
2798         PetscCall(PetscFree(C->defaultvectype));
2799         PetscCall(PetscFree(C->defaultrandtype));
2800         PetscCall(PetscLayoutDestroy(&C->rmap));
2801         PetscCall(PetscLayoutDestroy(&C->cmap));
2802         PetscCall(PetscHeaderDestroy(&C));
2803       }
2804     } else {
2805       PetscCall(MatDestroy(&C));
2806     }
2807   }
2808 
2809   /* Destroy Dummy submatrices created for reuse */
2810   PetscCall(MatDestroySubMatrices_Dummy(n, mat));
2811 
2812   PetscCall(PetscFree(*mat));
2813   PetscFunctionReturn(PETSC_SUCCESS);
2814 }
2815 
2816 static PetscErrorCode MatCreateSubMatrices_SeqAIJ(Mat A, PetscInt n, const IS irow[], const IS icol[], MatReuse scall, Mat *B[])
2817 {
2818   PetscInt i;
2819 
2820   PetscFunctionBegin;
2821   if (scall == MAT_INITIAL_MATRIX) PetscCall(PetscCalloc1(n + 1, B));
2822 
2823   for (i = 0; i < n; i++) PetscCall(MatCreateSubMatrix_SeqAIJ(A, irow[i], icol[i], PETSC_DECIDE, scall, &(*B)[i]));
2824   PetscFunctionReturn(PETSC_SUCCESS);
2825 }
2826 
2827 static PetscErrorCode MatIncreaseOverlap_SeqAIJ(Mat A, PetscInt is_max, IS is[], PetscInt ov)
2828 {
2829   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
2830   PetscInt        row, i, j, k, l, ll, m, n, *nidx, isz, val;
2831   const PetscInt *idx;
2832   PetscInt        start, end, *ai, *aj, bs = (A->rmap->bs > 0 && A->rmap->bs == A->cmap->bs) ? A->rmap->bs : 1;
2833   PetscBT         table;
2834 
2835   PetscFunctionBegin;
2836   m  = A->rmap->n / bs;
2837   ai = a->i;
2838   aj = a->j;
2839 
2840   PetscCheck(ov >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "illegal negative overlap value used");
2841 
2842   PetscCall(PetscMalloc1(m + 1, &nidx));
2843   PetscCall(PetscBTCreate(m, &table));
2844 
2845   for (i = 0; i < is_max; i++) {
2846     /* Initialize the two local arrays */
2847     isz = 0;
2848     PetscCall(PetscBTMemzero(m, table));
2849 
2850     /* Extract the indices, assume there can be duplicate entries */
2851     PetscCall(ISGetIndices(is[i], &idx));
2852     PetscCall(ISGetLocalSize(is[i], &n));
2853 
2854     if (bs > 1) {
2855       /* Enter these into the temp arrays. I.e., mark table[row], enter row into new index */
2856       for (j = 0; j < n; ++j) {
2857         if (!PetscBTLookupSet(table, idx[j] / bs)) nidx[isz++] = idx[j] / bs;
2858       }
2859       PetscCall(ISRestoreIndices(is[i], &idx));
2860       PetscCall(ISDestroy(&is[i]));
2861 
2862       k = 0;
2863       for (j = 0; j < ov; j++) { /* for each overlap */
2864         n = isz;
2865         for (; k < n; k++) { /* do only those rows in nidx[k], which are not done yet */
2866           for (ll = 0; ll < bs; ll++) {
2867             row   = bs * nidx[k] + ll;
2868             start = ai[row];
2869             end   = ai[row + 1];
2870             for (l = start; l < end; l++) {
2871               val = aj[l] / bs;
2872               if (!PetscBTLookupSet(table, val)) nidx[isz++] = val;
2873             }
2874           }
2875         }
2876       }
2877       PetscCall(ISCreateBlock(PETSC_COMM_SELF, bs, isz, nidx, PETSC_COPY_VALUES, is + i));
2878     } else {
2879       /* Enter these into the temp arrays. I.e., mark table[row], enter row into new index */
2880       for (j = 0; j < n; ++j) {
2881         if (!PetscBTLookupSet(table, idx[j])) nidx[isz++] = idx[j];
2882       }
2883       PetscCall(ISRestoreIndices(is[i], &idx));
2884       PetscCall(ISDestroy(&is[i]));
2885 
2886       k = 0;
2887       for (j = 0; j < ov; j++) { /* for each overlap */
2888         n = isz;
2889         for (; k < n; k++) { /* do only those rows in nidx[k], which are not done yet */
2890           row   = nidx[k];
2891           start = ai[row];
2892           end   = ai[row + 1];
2893           for (l = start; l < end; l++) {
2894             val = aj[l];
2895             if (!PetscBTLookupSet(table, val)) nidx[isz++] = val;
2896           }
2897         }
2898       }
2899       PetscCall(ISCreateGeneral(PETSC_COMM_SELF, isz, nidx, PETSC_COPY_VALUES, is + i));
2900     }
2901   }
2902   PetscCall(PetscBTDestroy(&table));
2903   PetscCall(PetscFree(nidx));
2904   PetscFunctionReturn(PETSC_SUCCESS);
2905 }
2906 
2907 static PetscErrorCode MatPermute_SeqAIJ(Mat A, IS rowp, IS colp, Mat *B)
2908 {
2909   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
2910   PetscInt        i, nz = 0, m = A->rmap->n, n = A->cmap->n;
2911   const PetscInt *row, *col;
2912   PetscInt       *cnew, j, *lens;
2913   IS              icolp, irowp;
2914   PetscInt       *cwork = NULL;
2915   PetscScalar    *vwork = NULL;
2916 
2917   PetscFunctionBegin;
2918   PetscCall(ISInvertPermutation(rowp, PETSC_DECIDE, &irowp));
2919   PetscCall(ISGetIndices(irowp, &row));
2920   PetscCall(ISInvertPermutation(colp, PETSC_DECIDE, &icolp));
2921   PetscCall(ISGetIndices(icolp, &col));
2922 
2923   /* determine lengths of permuted rows */
2924   PetscCall(PetscMalloc1(m + 1, &lens));
2925   for (i = 0; i < m; i++) lens[row[i]] = a->i[i + 1] - a->i[i];
2926   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
2927   PetscCall(MatSetSizes(*B, m, n, m, n));
2928   PetscCall(MatSetBlockSizesFromMats(*B, A, A));
2929   PetscCall(MatSetType(*B, ((PetscObject)A)->type_name));
2930   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*B, 0, lens));
2931   PetscCall(PetscFree(lens));
2932 
2933   PetscCall(PetscMalloc1(n, &cnew));
2934   for (i = 0; i < m; i++) {
2935     PetscCall(MatGetRow_SeqAIJ(A, i, &nz, &cwork, &vwork));
2936     for (j = 0; j < nz; j++) cnew[j] = col[cwork[j]];
2937     PetscCall(MatSetValues_SeqAIJ(*B, 1, &row[i], nz, cnew, vwork, INSERT_VALUES));
2938     PetscCall(MatRestoreRow_SeqAIJ(A, i, &nz, &cwork, &vwork));
2939   }
2940   PetscCall(PetscFree(cnew));
2941 
2942   (*B)->assembled = PETSC_FALSE;
2943 
2944 #if defined(PETSC_HAVE_DEVICE)
2945   PetscCall(MatBindToCPU(*B, A->boundtocpu));
2946 #endif
2947   PetscCall(MatAssemblyBegin(*B, MAT_FINAL_ASSEMBLY));
2948   PetscCall(MatAssemblyEnd(*B, MAT_FINAL_ASSEMBLY));
2949   PetscCall(ISRestoreIndices(irowp, &row));
2950   PetscCall(ISRestoreIndices(icolp, &col));
2951   PetscCall(ISDestroy(&irowp));
2952   PetscCall(ISDestroy(&icolp));
2953   if (rowp == colp) PetscCall(MatPropagateSymmetryOptions(A, *B));
2954   PetscFunctionReturn(PETSC_SUCCESS);
2955 }
2956 
2957 PetscErrorCode MatCopy_SeqAIJ(Mat A, Mat B, MatStructure str)
2958 {
2959   PetscFunctionBegin;
2960   /* If the two matrices have the same copy implementation, use fast copy. */
2961   if (str == SAME_NONZERO_PATTERN && (A->ops->copy == B->ops->copy)) {
2962     Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
2963     Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;
2964     const PetscScalar *aa;
2965 
2966     PetscCall(MatSeqAIJGetArrayRead(A, &aa));
2967     PetscCheck(a->i[A->rmap->n] == b->i[B->rmap->n], PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Number of nonzeros in two matrices are different %" PetscInt_FMT " != %" PetscInt_FMT, a->i[A->rmap->n], b->i[B->rmap->n]);
2968     PetscCall(PetscArraycpy(b->a, aa, a->i[A->rmap->n]));
2969     PetscCall(PetscObjectStateIncrease((PetscObject)B));
2970     PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
2971   } else {
2972     PetscCall(MatCopy_Basic(A, B, str));
2973   }
2974   PetscFunctionReturn(PETSC_SUCCESS);
2975 }
2976 
2977 PETSC_INTERN PetscErrorCode MatSeqAIJGetArray_SeqAIJ(Mat A, PetscScalar *array[])
2978 {
2979   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
2980 
2981   PetscFunctionBegin;
2982   *array = a->a;
2983   PetscFunctionReturn(PETSC_SUCCESS);
2984 }
2985 
2986 PETSC_INTERN PetscErrorCode MatSeqAIJRestoreArray_SeqAIJ(Mat A, PetscScalar *array[])
2987 {
2988   PetscFunctionBegin;
2989   *array = NULL;
2990   PetscFunctionReturn(PETSC_SUCCESS);
2991 }
2992 
2993 /*
2994    Computes the number of nonzeros per row needed for preallocation when X and Y
2995    have different nonzero structure.
2996 */
2997 PetscErrorCode MatAXPYGetPreallocation_SeqX_private(PetscInt m, const PetscInt *xi, const PetscInt *xj, const PetscInt *yi, const PetscInt *yj, PetscInt *nnz)
2998 {
2999   PetscInt i, j, k, nzx, nzy;
3000 
3001   PetscFunctionBegin;
3002   /* Set the number of nonzeros in the new matrix */
3003   for (i = 0; i < m; i++) {
3004     const PetscInt *xjj = PetscSafePointerPlusOffset(xj, xi[i]), *yjj = PetscSafePointerPlusOffset(yj, yi[i]);
3005     nzx    = xi[i + 1] - xi[i];
3006     nzy    = yi[i + 1] - yi[i];
3007     nnz[i] = 0;
3008     for (j = 0, k = 0; j < nzx; j++) {                  /* Point in X */
3009       for (; k < nzy && yjj[k] < xjj[j]; k++) nnz[i]++; /* Catch up to X */
3010       if (k < nzy && yjj[k] == xjj[j]) k++;             /* Skip duplicate */
3011       nnz[i]++;
3012     }
3013     for (; k < nzy; k++) nnz[i]++;
3014   }
3015   PetscFunctionReturn(PETSC_SUCCESS);
3016 }
3017 
3018 PetscErrorCode MatAXPYGetPreallocation_SeqAIJ(Mat Y, Mat X, PetscInt *nnz)
3019 {
3020   PetscInt    m = Y->rmap->N;
3021   Mat_SeqAIJ *x = (Mat_SeqAIJ *)X->data;
3022   Mat_SeqAIJ *y = (Mat_SeqAIJ *)Y->data;
3023 
3024   PetscFunctionBegin;
3025   /* Set the number of nonzeros in the new matrix */
3026   PetscCall(MatAXPYGetPreallocation_SeqX_private(m, x->i, x->j, y->i, y->j, nnz));
3027   PetscFunctionReturn(PETSC_SUCCESS);
3028 }
3029 
3030 PetscErrorCode MatAXPY_SeqAIJ(Mat Y, PetscScalar a, Mat X, MatStructure str)
3031 {
3032   Mat_SeqAIJ *x = (Mat_SeqAIJ *)X->data, *y = (Mat_SeqAIJ *)Y->data;
3033 
3034   PetscFunctionBegin;
3035   if (str == UNKNOWN_NONZERO_PATTERN || (PetscDefined(USE_DEBUG) && str == SAME_NONZERO_PATTERN)) {
3036     PetscBool e = x->nz == y->nz ? PETSC_TRUE : PETSC_FALSE;
3037     if (e) {
3038       PetscCall(PetscArraycmp(x->i, y->i, Y->rmap->n + 1, &e));
3039       if (e) {
3040         PetscCall(PetscArraycmp(x->j, y->j, y->nz, &e));
3041         if (e) str = SAME_NONZERO_PATTERN;
3042       }
3043     }
3044     if (!e) PetscCheck(str != SAME_NONZERO_PATTERN, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MatStructure is not SAME_NONZERO_PATTERN");
3045   }
3046   if (str == SAME_NONZERO_PATTERN) {
3047     const PetscScalar *xa;
3048     PetscScalar       *ya, alpha = a;
3049     PetscBLASInt       one = 1, bnz;
3050 
3051     PetscCall(PetscBLASIntCast(x->nz, &bnz));
3052     PetscCall(MatSeqAIJGetArray(Y, &ya));
3053     PetscCall(MatSeqAIJGetArrayRead(X, &xa));
3054     PetscCallBLAS("BLASaxpy", BLASaxpy_(&bnz, &alpha, xa, &one, ya, &one));
3055     PetscCall(MatSeqAIJRestoreArrayRead(X, &xa));
3056     PetscCall(MatSeqAIJRestoreArray(Y, &ya));
3057     PetscCall(PetscLogFlops(2.0 * bnz));
3058     PetscCall(MatSeqAIJInvalidateDiagonal(Y));
3059     PetscCall(PetscObjectStateIncrease((PetscObject)Y));
3060   } else if (str == SUBSET_NONZERO_PATTERN) { /* nonzeros of X is a subset of Y's */
3061     PetscCall(MatAXPY_Basic(Y, a, X, str));
3062   } else {
3063     Mat       B;
3064     PetscInt *nnz;
3065     PetscCall(PetscMalloc1(Y->rmap->N, &nnz));
3066     PetscCall(MatCreate(PetscObjectComm((PetscObject)Y), &B));
3067     PetscCall(PetscObjectSetName((PetscObject)B, ((PetscObject)Y)->name));
3068     PetscCall(MatSetLayouts(B, Y->rmap, Y->cmap));
3069     PetscCall(MatSetType(B, ((PetscObject)Y)->type_name));
3070     PetscCall(MatAXPYGetPreallocation_SeqAIJ(Y, X, nnz));
3071     PetscCall(MatSeqAIJSetPreallocation(B, 0, nnz));
3072     PetscCall(MatAXPY_BasicWithPreallocation(B, Y, a, X, str));
3073     PetscCall(MatHeaderMerge(Y, &B));
3074     PetscCall(MatSeqAIJCheckInode(Y));
3075     PetscCall(PetscFree(nnz));
3076   }
3077   PetscFunctionReturn(PETSC_SUCCESS);
3078 }
3079 
3080 PETSC_INTERN PetscErrorCode MatConjugate_SeqAIJ(Mat mat)
3081 {
3082 #if defined(PETSC_USE_COMPLEX)
3083   Mat_SeqAIJ  *aij = (Mat_SeqAIJ *)mat->data;
3084   PetscInt     i, nz;
3085   PetscScalar *a;
3086 
3087   PetscFunctionBegin;
3088   nz = aij->nz;
3089   PetscCall(MatSeqAIJGetArray(mat, &a));
3090   for (i = 0; i < nz; i++) a[i] = PetscConj(a[i]);
3091   PetscCall(MatSeqAIJRestoreArray(mat, &a));
3092 #else
3093   PetscFunctionBegin;
3094 #endif
3095   PetscFunctionReturn(PETSC_SUCCESS);
3096 }
3097 
3098 static PetscErrorCode MatGetRowMaxAbs_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3099 {
3100   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3101   PetscInt         i, j, m = A->rmap->n, *ai, *aj, ncols, n;
3102   PetscReal        atmp;
3103   PetscScalar     *x;
3104   const MatScalar *aa, *av;
3105 
3106   PetscFunctionBegin;
3107   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3108   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3109   aa = av;
3110   ai = a->i;
3111   aj = a->j;
3112 
3113   PetscCall(VecGetArrayWrite(v, &x));
3114   PetscCall(VecGetLocalSize(v, &n));
3115   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3116   for (i = 0; i < m; i++) {
3117     ncols = ai[1] - ai[0];
3118     ai++;
3119     x[i] = 0;
3120     for (j = 0; j < ncols; j++) {
3121       atmp = PetscAbsScalar(*aa);
3122       if (PetscAbsScalar(x[i]) < atmp) {
3123         x[i] = atmp;
3124         if (idx) idx[i] = *aj;
3125       }
3126       aa++;
3127       aj++;
3128     }
3129   }
3130   PetscCall(VecRestoreArrayWrite(v, &x));
3131   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3132   PetscFunctionReturn(PETSC_SUCCESS);
3133 }
3134 
3135 static PetscErrorCode MatGetRowSumAbs_SeqAIJ(Mat A, Vec v)
3136 {
3137   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3138   PetscInt         i, j, m = A->rmap->n, *ai, ncols, n;
3139   PetscScalar     *x;
3140   const MatScalar *aa, *av;
3141 
3142   PetscFunctionBegin;
3143   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3144   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3145   aa = av;
3146   ai = a->i;
3147 
3148   PetscCall(VecGetArrayWrite(v, &x));
3149   PetscCall(VecGetLocalSize(v, &n));
3150   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3151   for (i = 0; i < m; i++) {
3152     ncols = ai[1] - ai[0];
3153     ai++;
3154     x[i] = 0;
3155     for (j = 0; j < ncols; j++) {
3156       x[i] += PetscAbsScalar(*aa);
3157       aa++;
3158     }
3159   }
3160   PetscCall(VecRestoreArrayWrite(v, &x));
3161   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3162   PetscFunctionReturn(PETSC_SUCCESS);
3163 }
3164 
3165 static PetscErrorCode MatGetRowMax_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3166 {
3167   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3168   PetscInt         i, j, m = A->rmap->n, *ai, *aj, ncols, n;
3169   PetscScalar     *x;
3170   const MatScalar *aa, *av;
3171 
3172   PetscFunctionBegin;
3173   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3174   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3175   aa = av;
3176   ai = a->i;
3177   aj = a->j;
3178 
3179   PetscCall(VecGetArrayWrite(v, &x));
3180   PetscCall(VecGetLocalSize(v, &n));
3181   PetscCheck(n == A->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3182   for (i = 0; i < m; i++) {
3183     ncols = ai[1] - ai[0];
3184     ai++;
3185     if (ncols == A->cmap->n) { /* row is dense */
3186       x[i] = *aa;
3187       if (idx) idx[i] = 0;
3188     } else { /* row is sparse so already KNOW maximum is 0.0 or higher */
3189       x[i] = 0.0;
3190       if (idx) {
3191         for (j = 0; j < ncols; j++) { /* find first implicit 0.0 in the row */
3192           if (aj[j] > j) {
3193             idx[i] = j;
3194             break;
3195           }
3196         }
3197         /* in case first implicit 0.0 in the row occurs at ncols-th column */
3198         if (j == ncols && j < A->cmap->n) idx[i] = j;
3199       }
3200     }
3201     for (j = 0; j < ncols; j++) {
3202       if (PetscRealPart(x[i]) < PetscRealPart(*aa)) {
3203         x[i] = *aa;
3204         if (idx) idx[i] = *aj;
3205       }
3206       aa++;
3207       aj++;
3208     }
3209   }
3210   PetscCall(VecRestoreArrayWrite(v, &x));
3211   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3212   PetscFunctionReturn(PETSC_SUCCESS);
3213 }
3214 
3215 static PetscErrorCode MatGetRowMinAbs_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3216 {
3217   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3218   PetscInt         i, j, m = A->rmap->n, *ai, *aj, ncols, n;
3219   PetscScalar     *x;
3220   const MatScalar *aa, *av;
3221 
3222   PetscFunctionBegin;
3223   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3224   aa = av;
3225   ai = a->i;
3226   aj = a->j;
3227 
3228   PetscCall(VecGetArrayWrite(v, &x));
3229   PetscCall(VecGetLocalSize(v, &n));
3230   PetscCheck(n == m, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector, %" PetscInt_FMT " vs. %" PetscInt_FMT " rows", m, n);
3231   for (i = 0; i < m; i++) {
3232     ncols = ai[1] - ai[0];
3233     ai++;
3234     if (ncols == A->cmap->n) { /* row is dense */
3235       x[i] = *aa;
3236       if (idx) idx[i] = 0;
3237     } else { /* row is sparse so already KNOW minimum is 0.0 or higher */
3238       x[i] = 0.0;
3239       if (idx) { /* find first implicit 0.0 in the row */
3240         for (j = 0; j < ncols; j++) {
3241           if (aj[j] > j) {
3242             idx[i] = j;
3243             break;
3244           }
3245         }
3246         /* in case first implicit 0.0 in the row occurs at ncols-th column */
3247         if (j == ncols && j < A->cmap->n) idx[i] = j;
3248       }
3249     }
3250     for (j = 0; j < ncols; j++) {
3251       if (PetscAbsScalar(x[i]) > PetscAbsScalar(*aa)) {
3252         x[i] = *aa;
3253         if (idx) idx[i] = *aj;
3254       }
3255       aa++;
3256       aj++;
3257     }
3258   }
3259   PetscCall(VecRestoreArrayWrite(v, &x));
3260   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3261   PetscFunctionReturn(PETSC_SUCCESS);
3262 }
3263 
3264 static PetscErrorCode MatGetRowMin_SeqAIJ(Mat A, Vec v, PetscInt idx[])
3265 {
3266   Mat_SeqAIJ      *a = (Mat_SeqAIJ *)A->data;
3267   PetscInt         i, j, m = A->rmap->n, ncols, n;
3268   const PetscInt  *ai, *aj;
3269   PetscScalar     *x;
3270   const MatScalar *aa, *av;
3271 
3272   PetscFunctionBegin;
3273   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3274   PetscCall(MatSeqAIJGetArrayRead(A, &av));
3275   aa = av;
3276   ai = a->i;
3277   aj = a->j;
3278 
3279   PetscCall(VecGetArrayWrite(v, &x));
3280   PetscCall(VecGetLocalSize(v, &n));
3281   PetscCheck(n == m, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
3282   for (i = 0; i < m; i++) {
3283     ncols = ai[1] - ai[0];
3284     ai++;
3285     if (ncols == A->cmap->n) { /* row is dense */
3286       x[i] = *aa;
3287       if (idx) idx[i] = 0;
3288     } else { /* row is sparse so already KNOW minimum is 0.0 or lower */
3289       x[i] = 0.0;
3290       if (idx) { /* find first implicit 0.0 in the row */
3291         for (j = 0; j < ncols; j++) {
3292           if (aj[j] > j) {
3293             idx[i] = j;
3294             break;
3295           }
3296         }
3297         /* in case first implicit 0.0 in the row occurs at ncols-th column */
3298         if (j == ncols && j < A->cmap->n) idx[i] = j;
3299       }
3300     }
3301     for (j = 0; j < ncols; j++) {
3302       if (PetscRealPart(x[i]) > PetscRealPart(*aa)) {
3303         x[i] = *aa;
3304         if (idx) idx[i] = *aj;
3305       }
3306       aa++;
3307       aj++;
3308     }
3309   }
3310   PetscCall(VecRestoreArrayWrite(v, &x));
3311   PetscCall(MatSeqAIJRestoreArrayRead(A, &av));
3312   PetscFunctionReturn(PETSC_SUCCESS);
3313 }
3314 
3315 static PetscErrorCode MatInvertBlockDiagonal_SeqAIJ(Mat A, const PetscScalar **values)
3316 {
3317   Mat_SeqAIJ     *a = (Mat_SeqAIJ *)A->data;
3318   PetscInt        i, bs = PetscAbs(A->rmap->bs), mbs = A->rmap->n / bs, ipvt[5], bs2 = bs * bs, *v_pivots, ij[7], *IJ, j;
3319   MatScalar      *diag, work[25], *v_work;
3320   const PetscReal shift = 0.0;
3321   PetscBool       allowzeropivot, zeropivotdetected = PETSC_FALSE;
3322 
3323   PetscFunctionBegin;
3324   allowzeropivot = PetscNot(A->erroriffailure);
3325   if (a->ibdiagvalid) {
3326     if (values) *values = a->ibdiag;
3327     PetscFunctionReturn(PETSC_SUCCESS);
3328   }
3329   PetscCall(MatMarkDiagonal_SeqAIJ(A));
3330   if (!a->ibdiag) { PetscCall(PetscMalloc1(bs2 * mbs, &a->ibdiag)); }
3331   diag = a->ibdiag;
3332   if (values) *values = a->ibdiag;
3333   /* factor and invert each block */
3334   switch (bs) {
3335   case 1:
3336     for (i = 0; i < mbs; i++) {
3337       PetscCall(MatGetValues(A, 1, &i, 1, &i, diag + i));
3338       if (PetscAbsScalar(diag[i] + shift) < PETSC_MACHINE_EPSILON) {
3339         if (allowzeropivot) {
3340           A->factorerrortype             = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3341           A->factorerror_zeropivot_value = PetscAbsScalar(diag[i]);
3342           A->factorerror_zeropivot_row   = i;
3343           PetscCall(PetscInfo(A, "Zero pivot, row %" PetscInt_FMT " pivot %g tolerance %g\n", i, (double)PetscAbsScalar(diag[i]), (double)PETSC_MACHINE_EPSILON));
3344         } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_MAT_LU_ZRPVT, "Zero pivot, row %" PetscInt_FMT " pivot %g tolerance %g", i, (double)PetscAbsScalar(diag[i]), (double)PETSC_MACHINE_EPSILON);
3345       }
3346       diag[i] = (PetscScalar)1.0 / (diag[i] + shift);
3347     }
3348     break;
3349   case 2:
3350     for (i = 0; i < mbs; i++) {
3351       ij[0] = 2 * i;
3352       ij[1] = 2 * i + 1;
3353       PetscCall(MatGetValues(A, 2, ij, 2, ij, diag));
3354       PetscCall(PetscKernel_A_gets_inverse_A_2(diag, shift, allowzeropivot, &zeropivotdetected));
3355       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3356       PetscCall(PetscKernel_A_gets_transpose_A_2(diag));
3357       diag += 4;
3358     }
3359     break;
3360   case 3:
3361     for (i = 0; i < mbs; i++) {
3362       ij[0] = 3 * i;
3363       ij[1] = 3 * i + 1;
3364       ij[2] = 3 * i + 2;
3365       PetscCall(MatGetValues(A, 3, ij, 3, ij, diag));
3366       PetscCall(PetscKernel_A_gets_inverse_A_3(diag, shift, allowzeropivot, &zeropivotdetected));
3367       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3368       PetscCall(PetscKernel_A_gets_transpose_A_3(diag));
3369       diag += 9;
3370     }
3371     break;
3372   case 4:
3373     for (i = 0; i < mbs; i++) {
3374       ij[0] = 4 * i;
3375       ij[1] = 4 * i + 1;
3376       ij[2] = 4 * i + 2;
3377       ij[3] = 4 * i + 3;
3378       PetscCall(MatGetValues(A, 4, ij, 4, ij, diag));
3379       PetscCall(PetscKernel_A_gets_inverse_A_4(diag, shift, allowzeropivot, &zeropivotdetected));
3380       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3381       PetscCall(PetscKernel_A_gets_transpose_A_4(diag));
3382       diag += 16;
3383     }
3384     break;
3385   case 5:
3386     for (i = 0; i < mbs; i++) {
3387       ij[0] = 5 * i;
3388       ij[1] = 5 * i + 1;
3389       ij[2] = 5 * i + 2;
3390       ij[3] = 5 * i + 3;
3391       ij[4] = 5 * i + 4;
3392       PetscCall(MatGetValues(A, 5, ij, 5, ij, diag));
3393       PetscCall(PetscKernel_A_gets_inverse_A_5(diag, ipvt, work, shift, allowzeropivot, &zeropivotdetected));
3394       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3395       PetscCall(PetscKernel_A_gets_transpose_A_5(diag));
3396       diag += 25;
3397     }
3398     break;
3399   case 6:
3400     for (i = 0; i < mbs; i++) {
3401       ij[0] = 6 * i;
3402       ij[1] = 6 * i + 1;
3403       ij[2] = 6 * i + 2;
3404       ij[3] = 6 * i + 3;
3405       ij[4] = 6 * i + 4;
3406       ij[5] = 6 * i + 5;
3407       PetscCall(MatGetValues(A, 6, ij, 6, ij, diag));
3408       PetscCall(PetscKernel_A_gets_inverse_A_6(diag, shift, allowzeropivot, &zeropivotdetected));
3409       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3410       PetscCall(PetscKernel_A_gets_transpose_A_6(diag));
3411       diag += 36;
3412     }
3413     break;
3414   case 7:
3415     for (i = 0; i < mbs; i++) {
3416       ij[0] = 7 * i;
3417       ij[1] = 7 * i + 1;
3418       ij[2] = 7 * i + 2;
3419       ij[3] = 7 * i + 3;
3420       ij[4] = 7 * i + 4;
3421       ij[5] = 7 * i + 5;
3422       ij[6] = 7 * i + 6;
3423       PetscCall(MatGetValues(A, 7, ij, 7, ij, diag));
3424       PetscCall(PetscKernel_A_gets_inverse_A_7(diag, shift, allowzeropivot, &zeropivotdetected));
3425       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3426       PetscCall(PetscKernel_A_gets_transpose_A_7(diag));
3427       diag += 49;
3428     }
3429     break;
3430   default:
3431     PetscCall(PetscMalloc3(bs, &v_work, bs, &v_pivots, bs, &IJ));
3432     for (i = 0; i < mbs; i++) {
3433       for (j = 0; j < bs; j++) IJ[j] = bs * i + j;
3434       PetscCall(MatGetValues(A, bs, IJ, bs, IJ, diag));
3435       PetscCall(PetscKernel_A_gets_inverse_A(bs, diag, v_pivots, v_work, allowzeropivot, &zeropivotdetected));
3436       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
3437       PetscCall(PetscKernel_A_gets_transpose_A_N(diag, bs));
3438       diag += bs2;
3439     }
3440     PetscCall(PetscFree3(v_work, v_pivots, IJ));
3441   }
3442   a->ibdiagvalid = PETSC_TRUE;
3443   PetscFunctionReturn(PETSC_SUCCESS);
3444 }
3445 
3446 static PetscErrorCode MatSetRandom_SeqAIJ(Mat x, PetscRandom rctx)
3447 {
3448   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)x->data;
3449   PetscScalar a, *aa;
3450   PetscInt    m, n, i, j, col;
3451 
3452   PetscFunctionBegin;
3453   if (!x->assembled) {
3454     PetscCall(MatGetSize(x, &m, &n));
3455     for (i = 0; i < m; i++) {
3456       for (j = 0; j < aij->imax[i]; j++) {
3457         PetscCall(PetscRandomGetValue(rctx, &a));
3458         col = (PetscInt)(n * PetscRealPart(a));
3459         PetscCall(MatSetValues(x, 1, &i, 1, &col, &a, ADD_VALUES));
3460       }
3461     }
3462   } else {
3463     PetscCall(MatSeqAIJGetArrayWrite(x, &aa));
3464     for (i = 0; i < aij->nz; i++) PetscCall(PetscRandomGetValue(rctx, aa + i));
3465     PetscCall(MatSeqAIJRestoreArrayWrite(x, &aa));
3466   }
3467   PetscCall(MatAssemblyBegin(x, MAT_FINAL_ASSEMBLY));
3468   PetscCall(MatAssemblyEnd(x, MAT_FINAL_ASSEMBLY));
3469   PetscFunctionReturn(PETSC_SUCCESS);
3470 }
3471 
3472 /* Like MatSetRandom_SeqAIJ, but do not set values on columns in range of [low, high) */
3473 PetscErrorCode MatSetRandomSkipColumnRange_SeqAIJ_Private(Mat x, PetscInt low, PetscInt high, PetscRandom rctx)
3474 {
3475   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)x->data;
3476   PetscScalar a;
3477   PetscInt    m, n, i, j, col, nskip;
3478 
3479   PetscFunctionBegin;
3480   nskip = high - low;
3481   PetscCall(MatGetSize(x, &m, &n));
3482   n -= nskip; /* shrink number of columns where nonzeros can be set */
3483   for (i = 0; i < m; i++) {
3484     for (j = 0; j < aij->imax[i]; j++) {
3485       PetscCall(PetscRandomGetValue(rctx, &a));
3486       col = (PetscInt)(n * PetscRealPart(a));
3487       if (col >= low) col += nskip; /* shift col rightward to skip the hole */
3488       PetscCall(MatSetValues(x, 1, &i, 1, &col, &a, ADD_VALUES));
3489     }
3490   }
3491   PetscCall(MatAssemblyBegin(x, MAT_FINAL_ASSEMBLY));
3492   PetscCall(MatAssemblyEnd(x, MAT_FINAL_ASSEMBLY));
3493   PetscFunctionReturn(PETSC_SUCCESS);
3494 }
3495 
3496 static struct _MatOps MatOps_Values = {MatSetValues_SeqAIJ,
3497                                        MatGetRow_SeqAIJ,
3498                                        MatRestoreRow_SeqAIJ,
3499                                        MatMult_SeqAIJ,
3500                                        /*  4*/ MatMultAdd_SeqAIJ,
3501                                        MatMultTranspose_SeqAIJ,
3502                                        MatMultTransposeAdd_SeqAIJ,
3503                                        NULL,
3504                                        NULL,
3505                                        NULL,
3506                                        /* 10*/ NULL,
3507                                        MatLUFactor_SeqAIJ,
3508                                        NULL,
3509                                        MatSOR_SeqAIJ,
3510                                        MatTranspose_SeqAIJ,
3511                                        /*1 5*/ MatGetInfo_SeqAIJ,
3512                                        MatEqual_SeqAIJ,
3513                                        MatGetDiagonal_SeqAIJ,
3514                                        MatDiagonalScale_SeqAIJ,
3515                                        MatNorm_SeqAIJ,
3516                                        /* 20*/ NULL,
3517                                        MatAssemblyEnd_SeqAIJ,
3518                                        MatSetOption_SeqAIJ,
3519                                        MatZeroEntries_SeqAIJ,
3520                                        /* 24*/ MatZeroRows_SeqAIJ,
3521                                        NULL,
3522                                        NULL,
3523                                        NULL,
3524                                        NULL,
3525                                        /* 29*/ MatSetUp_Seq_Hash,
3526                                        NULL,
3527                                        NULL,
3528                                        NULL,
3529                                        NULL,
3530                                        /* 34*/ MatDuplicate_SeqAIJ,
3531                                        NULL,
3532                                        NULL,
3533                                        MatILUFactor_SeqAIJ,
3534                                        NULL,
3535                                        /* 39*/ MatAXPY_SeqAIJ,
3536                                        MatCreateSubMatrices_SeqAIJ,
3537                                        MatIncreaseOverlap_SeqAIJ,
3538                                        MatGetValues_SeqAIJ,
3539                                        MatCopy_SeqAIJ,
3540                                        /* 44*/ MatGetRowMax_SeqAIJ,
3541                                        MatScale_SeqAIJ,
3542                                        MatShift_SeqAIJ,
3543                                        MatDiagonalSet_SeqAIJ,
3544                                        MatZeroRowsColumns_SeqAIJ,
3545                                        /* 49*/ MatSetRandom_SeqAIJ,
3546                                        MatGetRowIJ_SeqAIJ,
3547                                        MatRestoreRowIJ_SeqAIJ,
3548                                        MatGetColumnIJ_SeqAIJ,
3549                                        MatRestoreColumnIJ_SeqAIJ,
3550                                        /* 54*/ MatFDColoringCreate_SeqXAIJ,
3551                                        NULL,
3552                                        NULL,
3553                                        MatPermute_SeqAIJ,
3554                                        NULL,
3555                                        /* 59*/ NULL,
3556                                        MatDestroy_SeqAIJ,
3557                                        MatView_SeqAIJ,
3558                                        NULL,
3559                                        NULL,
3560                                        /* 64*/ NULL,
3561                                        MatMatMatMultNumeric_SeqAIJ_SeqAIJ_SeqAIJ,
3562                                        NULL,
3563                                        NULL,
3564                                        NULL,
3565                                        /* 69*/ MatGetRowMaxAbs_SeqAIJ,
3566                                        MatGetRowMinAbs_SeqAIJ,
3567                                        NULL,
3568                                        NULL,
3569                                        NULL,
3570                                        /* 74*/ NULL,
3571                                        MatFDColoringApply_AIJ,
3572                                        NULL,
3573                                        NULL,
3574                                        NULL,
3575                                        /* 79*/ MatFindZeroDiagonals_SeqAIJ,
3576                                        NULL,
3577                                        NULL,
3578                                        NULL,
3579                                        MatLoad_SeqAIJ,
3580                                        /* 84*/ NULL,
3581                                        NULL,
3582                                        NULL,
3583                                        NULL,
3584                                        NULL,
3585                                        /* 89*/ NULL,
3586                                        NULL,
3587                                        MatMatMultNumeric_SeqAIJ_SeqAIJ,
3588                                        NULL,
3589                                        NULL,
3590                                        /* 94*/ MatPtAPNumeric_SeqAIJ_SeqAIJ_SparseAxpy,
3591                                        NULL,
3592                                        NULL,
3593                                        MatMatTransposeMultNumeric_SeqAIJ_SeqAIJ,
3594                                        NULL,
3595                                        /* 99*/ MatProductSetFromOptions_SeqAIJ,
3596                                        NULL,
3597                                        NULL,
3598                                        MatConjugate_SeqAIJ,
3599                                        NULL,
3600                                        /*104*/ MatSetValuesRow_SeqAIJ,
3601                                        MatRealPart_SeqAIJ,
3602                                        MatImaginaryPart_SeqAIJ,
3603                                        NULL,
3604                                        NULL,
3605                                        /*109*/ MatMatSolve_SeqAIJ,
3606                                        NULL,
3607                                        MatGetRowMin_SeqAIJ,
3608                                        NULL,
3609                                        MatMissingDiagonal_SeqAIJ,
3610                                        /*114*/ NULL,
3611                                        NULL,
3612                                        NULL,
3613                                        NULL,
3614                                        NULL,
3615                                        /*119*/ NULL,
3616                                        NULL,
3617                                        NULL,
3618                                        NULL,
3619                                        MatGetMultiProcBlock_SeqAIJ,
3620                                        /*124*/ MatFindNonzeroRows_SeqAIJ,
3621                                        MatGetColumnReductions_SeqAIJ,
3622                                        MatInvertBlockDiagonal_SeqAIJ,
3623                                        MatInvertVariableBlockDiagonal_SeqAIJ,
3624                                        NULL,
3625                                        /*129*/ NULL,
3626                                        NULL,
3627                                        NULL,
3628                                        MatTransposeMatMultNumeric_SeqAIJ_SeqAIJ,
3629                                        MatTransposeColoringCreate_SeqAIJ,
3630                                        /*134*/ MatTransColoringApplySpToDen_SeqAIJ,
3631                                        MatTransColoringApplyDenToSp_SeqAIJ,
3632                                        NULL,
3633                                        NULL,
3634                                        MatRARtNumeric_SeqAIJ_SeqAIJ,
3635                                        /*139*/ NULL,
3636                                        NULL,
3637                                        NULL,
3638                                        MatFDColoringSetUp_SeqXAIJ,
3639                                        MatFindOffBlockDiagonalEntries_SeqAIJ,
3640                                        MatCreateMPIMatConcatenateSeqMat_SeqAIJ,
3641                                        /*145*/ MatDestroySubMatrices_SeqAIJ,
3642                                        NULL,
3643                                        NULL,
3644                                        MatCreateGraph_Simple_AIJ,
3645                                        NULL,
3646                                        /*150*/ MatTransposeSymbolic_SeqAIJ,
3647                                        MatEliminateZeros_SeqAIJ,
3648                                        MatGetRowSumAbs_SeqAIJ,
3649                                        NULL,
3650                                        NULL,
3651                                        /*155*/ NULL,
3652                                        MatCopyHashToXAIJ_Seq_Hash};
3653 
3654 static PetscErrorCode MatSeqAIJSetColumnIndices_SeqAIJ(Mat mat, PetscInt *indices)
3655 {
3656   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
3657   PetscInt    i, nz, n;
3658 
3659   PetscFunctionBegin;
3660   nz = aij->maxnz;
3661   n  = mat->rmap->n;
3662   for (i = 0; i < nz; i++) aij->j[i] = indices[i];
3663   aij->nz = nz;
3664   for (i = 0; i < n; i++) aij->ilen[i] = aij->imax[i];
3665   PetscFunctionReturn(PETSC_SUCCESS);
3666 }
3667 
3668 /*
3669  * Given a sparse matrix with global column indices, compact it by using a local column space.
3670  * The result matrix helps saving memory in other algorithms, such as MatPtAPSymbolic_MPIAIJ_MPIAIJ_scalable()
3671  */
3672 PetscErrorCode MatSeqAIJCompactOutExtraColumns_SeqAIJ(Mat mat, ISLocalToGlobalMapping *mapping)
3673 {
3674   Mat_SeqAIJ   *aij = (Mat_SeqAIJ *)mat->data;
3675   PetscHMapI    gid1_lid1;
3676   PetscHashIter tpos;
3677   PetscInt      gid, lid, i, ec, nz = aij->nz;
3678   PetscInt     *garray, *jj = aij->j;
3679 
3680   PetscFunctionBegin;
3681   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3682   PetscAssertPointer(mapping, 2);
3683   /* use a table */
3684   PetscCall(PetscHMapICreateWithSize(mat->rmap->n, &gid1_lid1));
3685   ec = 0;
3686   for (i = 0; i < nz; i++) {
3687     PetscInt data, gid1 = jj[i] + 1;
3688     PetscCall(PetscHMapIGetWithDefault(gid1_lid1, gid1, 0, &data));
3689     if (!data) {
3690       /* one based table */
3691       PetscCall(PetscHMapISet(gid1_lid1, gid1, ++ec));
3692     }
3693   }
3694   /* form array of columns we need */
3695   PetscCall(PetscMalloc1(ec, &garray));
3696   PetscHashIterBegin(gid1_lid1, tpos);
3697   while (!PetscHashIterAtEnd(gid1_lid1, tpos)) {
3698     PetscHashIterGetKey(gid1_lid1, tpos, gid);
3699     PetscHashIterGetVal(gid1_lid1, tpos, lid);
3700     PetscHashIterNext(gid1_lid1, tpos);
3701     gid--;
3702     lid--;
3703     garray[lid] = gid;
3704   }
3705   PetscCall(PetscSortInt(ec, garray)); /* sort, and rebuild */
3706   PetscCall(PetscHMapIClear(gid1_lid1));
3707   for (i = 0; i < ec; i++) PetscCall(PetscHMapISet(gid1_lid1, garray[i] + 1, i + 1));
3708   /* compact out the extra columns in B */
3709   for (i = 0; i < nz; i++) {
3710     PetscInt gid1 = jj[i] + 1;
3711     PetscCall(PetscHMapIGetWithDefault(gid1_lid1, gid1, 0, &lid));
3712     lid--;
3713     jj[i] = lid;
3714   }
3715   PetscCall(PetscLayoutDestroy(&mat->cmap));
3716   PetscCall(PetscHMapIDestroy(&gid1_lid1));
3717   PetscCall(PetscLayoutCreateFromSizes(PetscObjectComm((PetscObject)mat), ec, ec, 1, &mat->cmap));
3718   PetscCall(ISLocalToGlobalMappingCreate(PETSC_COMM_SELF, mat->cmap->bs, mat->cmap->n, garray, PETSC_OWN_POINTER, mapping));
3719   PetscCall(ISLocalToGlobalMappingSetType(*mapping, ISLOCALTOGLOBALMAPPINGHASH));
3720   PetscFunctionReturn(PETSC_SUCCESS);
3721 }
3722 
3723 /*@
3724   MatSeqAIJSetColumnIndices - Set the column indices for all the rows
3725   in the matrix.
3726 
3727   Input Parameters:
3728 + mat     - the `MATSEQAIJ` matrix
3729 - indices - the column indices
3730 
3731   Level: advanced
3732 
3733   Notes:
3734   This can be called if you have precomputed the nonzero structure of the
3735   matrix and want to provide it to the matrix object to improve the performance
3736   of the `MatSetValues()` operation.
3737 
3738   You MUST have set the correct numbers of nonzeros per row in the call to
3739   `MatCreateSeqAIJ()`, and the columns indices MUST be sorted.
3740 
3741   MUST be called before any calls to `MatSetValues()`
3742 
3743   The indices should start with zero, not one.
3744 
3745 .seealso: [](ch_matrices), `Mat`, `MATSEQAIJ`
3746 @*/
3747 PetscErrorCode MatSeqAIJSetColumnIndices(Mat mat, PetscInt *indices)
3748 {
3749   PetscFunctionBegin;
3750   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3751   PetscAssertPointer(indices, 2);
3752   PetscUseMethod(mat, "MatSeqAIJSetColumnIndices_C", (Mat, PetscInt *), (mat, indices));
3753   PetscFunctionReturn(PETSC_SUCCESS);
3754 }
3755 
3756 static PetscErrorCode MatStoreValues_SeqAIJ(Mat mat)
3757 {
3758   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
3759   size_t      nz  = aij->i[mat->rmap->n];
3760 
3761   PetscFunctionBegin;
3762   PetscCheck(aij->nonew, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatSetOption(A,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);first");
3763 
3764   /* allocate space for values if not already there */
3765   if (!aij->saved_values) { PetscCall(PetscMalloc1(nz + 1, &aij->saved_values)); }
3766 
3767   /* copy values over */
3768   PetscCall(PetscArraycpy(aij->saved_values, aij->a, nz));
3769   PetscFunctionReturn(PETSC_SUCCESS);
3770 }
3771 
3772 /*@
3773   MatStoreValues - Stashes a copy of the matrix values; this allows reusing of the linear part of a Jacobian, while recomputing only the
3774   nonlinear portion.
3775 
3776   Logically Collect
3777 
3778   Input Parameter:
3779 . mat - the matrix (currently only `MATAIJ` matrices support this option)
3780 
3781   Level: advanced
3782 
3783   Example Usage:
3784 .vb
3785     Using SNES
3786     Create Jacobian matrix
3787     Set linear terms into matrix
3788     Apply boundary conditions to matrix, at this time matrix must have
3789       final nonzero structure (i.e. setting the nonlinear terms and applying
3790       boundary conditions again will not change the nonzero structure
3791     MatSetOption(mat, MAT_NEW_NONZERO_LOCATIONS, PETSC_FALSE);
3792     MatStoreValues(mat);
3793     Call SNESSetJacobian() with matrix
3794     In your Jacobian routine
3795       MatRetrieveValues(mat);
3796       Set nonlinear terms in matrix
3797 
3798     Without `SNESSolve()`, i.e. when you handle nonlinear solve yourself:
3799     // build linear portion of Jacobian
3800     MatSetOption(mat, MAT_NEW_NONZERO_LOCATIONS, PETSC_FALSE);
3801     MatStoreValues(mat);
3802     loop over nonlinear iterations
3803        MatRetrieveValues(mat);
3804        // call MatSetValues(mat,...) to set nonliner portion of Jacobian
3805        // call MatAssemblyBegin/End() on matrix
3806        Solve linear system with Jacobian
3807     endloop
3808 .ve
3809 
3810   Notes:
3811   Matrix must already be assembled before calling this routine
3812   Must set the matrix option `MatSetOption`(mat,`MAT_NEW_NONZERO_LOCATIONS`,`PETSC_FALSE`); before
3813   calling this routine.
3814 
3815   When this is called multiple times it overwrites the previous set of stored values
3816   and does not allocated additional space.
3817 
3818 .seealso: [](ch_matrices), `Mat`, `MatRetrieveValues()`
3819 @*/
3820 PetscErrorCode MatStoreValues(Mat mat)
3821 {
3822   PetscFunctionBegin;
3823   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3824   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3825   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3826   PetscUseMethod(mat, "MatStoreValues_C", (Mat), (mat));
3827   PetscFunctionReturn(PETSC_SUCCESS);
3828 }
3829 
3830 static PetscErrorCode MatRetrieveValues_SeqAIJ(Mat mat)
3831 {
3832   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
3833   PetscInt    nz  = aij->i[mat->rmap->n];
3834 
3835   PetscFunctionBegin;
3836   PetscCheck(aij->nonew, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatSetOption(A,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);first");
3837   PetscCheck(aij->saved_values, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatStoreValues(A);first");
3838   /* copy values over */
3839   PetscCall(PetscArraycpy(aij->a, aij->saved_values, nz));
3840   PetscFunctionReturn(PETSC_SUCCESS);
3841 }
3842 
3843 /*@
3844   MatRetrieveValues - Retrieves the copy of the matrix values that was stored with `MatStoreValues()`
3845 
3846   Logically Collect
3847 
3848   Input Parameter:
3849 . mat - the matrix (currently only `MATAIJ` matrices support this option)
3850 
3851   Level: advanced
3852 
3853 .seealso: [](ch_matrices), `Mat`, `MatStoreValues()`
3854 @*/
3855 PetscErrorCode MatRetrieveValues(Mat mat)
3856 {
3857   PetscFunctionBegin;
3858   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
3859   PetscCheck(mat->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
3860   PetscCheck(!mat->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
3861   PetscUseMethod(mat, "MatRetrieveValues_C", (Mat), (mat));
3862   PetscFunctionReturn(PETSC_SUCCESS);
3863 }
3864 
3865 /*@
3866   MatCreateSeqAIJ - Creates a sparse matrix in `MATSEQAIJ` (compressed row) format
3867   (the default parallel PETSc format).  For good matrix assembly performance
3868   the user should preallocate the matrix storage by setting the parameter `nz`
3869   (or the array `nnz`).
3870 
3871   Collective
3872 
3873   Input Parameters:
3874 + comm - MPI communicator, set to `PETSC_COMM_SELF`
3875 . m    - number of rows
3876 . n    - number of columns
3877 . nz   - number of nonzeros per row (same for all rows)
3878 - nnz  - array containing the number of nonzeros in the various rows
3879          (possibly different for each row) or NULL
3880 
3881   Output Parameter:
3882 . A - the matrix
3883 
3884   Options Database Keys:
3885 + -mat_no_inode            - Do not use inodes
3886 - -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3887 
3888   Level: intermediate
3889 
3890   Notes:
3891   It is recommend to use `MatCreateFromOptions()` instead of this routine
3892 
3893   If `nnz` is given then `nz` is ignored
3894 
3895   The `MATSEQAIJ` format, also called
3896   compressed row storage, is fully compatible with standard Fortran
3897   storage.  That is, the stored row and column indices can begin at
3898   either one (as in Fortran) or zero.
3899 
3900   Specify the preallocated storage with either `nz` or `nnz` (not both).
3901   Set `nz` = `PETSC_DEFAULT` and `nnz` = `NULL` for PETSc to control dynamic memory
3902   allocation.
3903 
3904   By default, this format uses inodes (identical nodes) when possible, to
3905   improve numerical efficiency of matrix-vector products and solves. We
3906   search for consecutive rows with the same nonzero structure, thereby
3907   reusing matrix information to achieve increased efficiency.
3908 
3909 .seealso: [](ch_matrices), `Mat`, [Sparse Matrix Creation](sec_matsparse), `MatCreate()`, `MatCreateAIJ()`, `MatSetValues()`, `MatSeqAIJSetColumnIndices()`, `MatCreateSeqAIJWithArrays()`
3910 @*/
3911 PetscErrorCode MatCreateSeqAIJ(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], Mat *A)
3912 {
3913   PetscFunctionBegin;
3914   PetscCall(MatCreate(comm, A));
3915   PetscCall(MatSetSizes(*A, m, n, m, n));
3916   PetscCall(MatSetType(*A, MATSEQAIJ));
3917   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*A, nz, nnz));
3918   PetscFunctionReturn(PETSC_SUCCESS);
3919 }
3920 
3921 /*@
3922   MatSeqAIJSetPreallocation - For good matrix assembly performance
3923   the user should preallocate the matrix storage by setting the parameter nz
3924   (or the array nnz).  By setting these parameters accurately, performance
3925   during matrix assembly can be increased by more than a factor of 50.
3926 
3927   Collective
3928 
3929   Input Parameters:
3930 + B   - The matrix
3931 . nz  - number of nonzeros per row (same for all rows)
3932 - nnz - array containing the number of nonzeros in the various rows
3933          (possibly different for each row) or NULL
3934 
3935   Options Database Keys:
3936 + -mat_no_inode            - Do not use inodes
3937 - -mat_inode_limit <limit> - Sets inode limit (max limit=5)
3938 
3939   Level: intermediate
3940 
3941   Notes:
3942   If `nnz` is given then `nz` is ignored
3943 
3944   The `MATSEQAIJ` format also called
3945   compressed row storage, is fully compatible with standard Fortran
3946   storage.  That is, the stored row and column indices can begin at
3947   either one (as in Fortran) or zero.  See the users' manual for details.
3948 
3949   Specify the preallocated storage with either `nz` or `nnz` (not both).
3950   Set nz = `PETSC_DEFAULT` and `nnz` = `NULL` for PETSc to control dynamic memory
3951   allocation.
3952 
3953   You can call `MatGetInfo()` to get information on how effective the preallocation was;
3954   for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3955   You can also run with the option -info and look for messages with the string
3956   malloc in them to see if additional memory allocation was needed.
3957 
3958   Developer Notes:
3959   Use nz of `MAT_SKIP_ALLOCATION` to not allocate any space for the matrix
3960   entries or columns indices
3961 
3962   By default, this format uses inodes (identical nodes) when possible, to
3963   improve numerical efficiency of matrix-vector products and solves. We
3964   search for consecutive rows with the same nonzero structure, thereby
3965   reusing matrix information to achieve increased efficiency.
3966 
3967 .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateAIJ()`, `MatSetValues()`, `MatSeqAIJSetColumnIndices()`, `MatCreateSeqAIJWithArrays()`, `MatGetInfo()`,
3968           `MatSeqAIJSetTotalPreallocation()`
3969 @*/
3970 PetscErrorCode MatSeqAIJSetPreallocation(Mat B, PetscInt nz, const PetscInt nnz[])
3971 {
3972   PetscFunctionBegin;
3973   PetscValidHeaderSpecific(B, MAT_CLASSID, 1);
3974   PetscValidType(B, 1);
3975   PetscTryMethod(B, "MatSeqAIJSetPreallocation_C", (Mat, PetscInt, const PetscInt[]), (B, nz, nnz));
3976   PetscFunctionReturn(PETSC_SUCCESS);
3977 }
3978 
3979 PetscErrorCode MatSeqAIJSetPreallocation_SeqAIJ(Mat B, PetscInt nz, const PetscInt *nnz)
3980 {
3981   Mat_SeqAIJ *b              = (Mat_SeqAIJ *)B->data;
3982   PetscBool   skipallocation = PETSC_FALSE, realalloc = PETSC_FALSE;
3983   PetscInt    i;
3984 
3985   PetscFunctionBegin;
3986   if (B->hash_active) {
3987     B->ops[0] = b->cops;
3988     PetscCall(PetscHMapIJVDestroy(&b->ht));
3989     PetscCall(PetscFree(b->dnz));
3990     B->hash_active = PETSC_FALSE;
3991   }
3992   if (nz >= 0 || nnz) realalloc = PETSC_TRUE;
3993   if (nz == MAT_SKIP_ALLOCATION) {
3994     skipallocation = PETSC_TRUE;
3995     nz             = 0;
3996   }
3997   PetscCall(PetscLayoutSetUp(B->rmap));
3998   PetscCall(PetscLayoutSetUp(B->cmap));
3999 
4000   if (nz == PETSC_DEFAULT || nz == PETSC_DECIDE) nz = 5;
4001   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nz cannot be less than 0: value %" PetscInt_FMT, nz);
4002   if (nnz) {
4003     for (i = 0; i < B->rmap->n; i++) {
4004       PetscCheck(nnz[i] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nnz cannot be less than 0: local row %" PetscInt_FMT " value %" PetscInt_FMT, i, nnz[i]);
4005       PetscCheck(nnz[i] <= B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nnz cannot be greater than row length: local row %" PetscInt_FMT " value %" PetscInt_FMT " rowlength %" PetscInt_FMT, i, nnz[i], B->cmap->n);
4006     }
4007   }
4008 
4009   B->preallocated = PETSC_TRUE;
4010   if (!skipallocation) {
4011     if (!b->imax) { PetscCall(PetscMalloc1(B->rmap->n, &b->imax)); }
4012     if (!b->ilen) {
4013       /* b->ilen will count nonzeros in each row so far. */
4014       PetscCall(PetscCalloc1(B->rmap->n, &b->ilen));
4015     } else {
4016       PetscCall(PetscMemzero(b->ilen, B->rmap->n * sizeof(PetscInt)));
4017     }
4018     if (!b->ipre) PetscCall(PetscMalloc1(B->rmap->n, &b->ipre));
4019     if (!nnz) {
4020       if (nz == PETSC_DEFAULT || nz == PETSC_DECIDE) nz = 10;
4021       else if (nz < 0) nz = 1;
4022       nz = PetscMin(nz, B->cmap->n);
4023       for (i = 0; i < B->rmap->n; i++) b->imax[i] = nz;
4024       PetscCall(PetscIntMultError(nz, B->rmap->n, &nz));
4025     } else {
4026       PetscInt64 nz64 = 0;
4027       for (i = 0; i < B->rmap->n; i++) {
4028         b->imax[i] = nnz[i];
4029         nz64 += nnz[i];
4030       }
4031       PetscCall(PetscIntCast(nz64, &nz));
4032     }
4033 
4034     /* allocate the matrix space */
4035     PetscCall(MatSeqXAIJFreeAIJ(B, &b->a, &b->j, &b->i));
4036     PetscCall(PetscShmgetAllocateArray(nz, sizeof(PetscInt), (void **)&b->j));
4037     PetscCall(PetscShmgetAllocateArray(B->rmap->n + 1, sizeof(PetscInt), (void **)&b->i));
4038     b->free_ij = PETSC_TRUE;
4039     if (B->structure_only) {
4040       b->free_a = PETSC_FALSE;
4041     } else {
4042       PetscCall(PetscShmgetAllocateArray(nz, sizeof(PetscScalar), (void **)&b->a));
4043       b->free_a = PETSC_TRUE;
4044     }
4045     b->i[0] = 0;
4046     for (i = 1; i < B->rmap->n + 1; i++) b->i[i] = b->i[i - 1] + b->imax[i - 1];
4047   } else {
4048     b->free_a  = PETSC_FALSE;
4049     b->free_ij = PETSC_FALSE;
4050   }
4051 
4052   if (b->ipre && nnz != b->ipre && b->imax) {
4053     /* reserve user-requested sparsity */
4054     PetscCall(PetscArraycpy(b->ipre, b->imax, B->rmap->n));
4055   }
4056 
4057   b->nz               = 0;
4058   b->maxnz            = nz;
4059   B->info.nz_unneeded = (double)b->maxnz;
4060   if (realalloc) PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE));
4061   B->was_assembled = PETSC_FALSE;
4062   B->assembled     = PETSC_FALSE;
4063   /* We simply deem preallocation has changed nonzero state. Updating the state
4064      will give clients (like AIJKokkos) a chance to know something has happened.
4065   */
4066   B->nonzerostate++;
4067   PetscFunctionReturn(PETSC_SUCCESS);
4068 }
4069 
4070 static PetscErrorCode MatResetPreallocation_SeqAIJ(Mat A)
4071 {
4072   Mat_SeqAIJ *a;
4073   PetscInt    i;
4074   PetscBool   skipreset;
4075 
4076   PetscFunctionBegin;
4077   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
4078 
4079   /* Check local size. If zero, then return */
4080   if (!A->rmap->n) PetscFunctionReturn(PETSC_SUCCESS);
4081 
4082   a = (Mat_SeqAIJ *)A->data;
4083   /* if no saved info, we error out */
4084   PetscCheck(a->ipre, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "No saved preallocation info ");
4085 
4086   PetscCheck(a->i && a->imax && a->ilen, PETSC_COMM_SELF, PETSC_ERR_ARG_NULL, "Memory info is incomplete, and can not reset preallocation ");
4087 
4088   PetscCall(PetscArraycmp(a->ipre, a->ilen, A->rmap->n, &skipreset));
4089   if (!skipreset) {
4090     PetscCall(PetscArraycpy(a->imax, a->ipre, A->rmap->n));
4091     PetscCall(PetscArrayzero(a->ilen, A->rmap->n));
4092     a->i[0] = 0;
4093     for (i = 1; i < A->rmap->n + 1; i++) a->i[i] = a->i[i - 1] + a->imax[i - 1];
4094     A->preallocated     = PETSC_TRUE;
4095     a->nz               = 0;
4096     a->maxnz            = a->i[A->rmap->n];
4097     A->info.nz_unneeded = (double)a->maxnz;
4098     A->was_assembled    = PETSC_FALSE;
4099     A->assembled        = PETSC_FALSE;
4100   }
4101   PetscFunctionReturn(PETSC_SUCCESS);
4102 }
4103 
4104 /*@
4105   MatSeqAIJSetPreallocationCSR - Allocates memory for a sparse sequential matrix in `MATSEQAIJ` format.
4106 
4107   Input Parameters:
4108 + B - the matrix
4109 . i - the indices into `j` for the start of each row (indices start with zero)
4110 . j - the column indices for each row (indices start with zero) these must be sorted for each row
4111 - v - optional values in the matrix, use `NULL` if not provided
4112 
4113   Level: developer
4114 
4115   Notes:
4116   The `i`,`j`,`v` values are COPIED with this routine; to avoid the copy use `MatCreateSeqAIJWithArrays()`
4117 
4118   This routine may be called multiple times with different nonzero patterns (or the same nonzero pattern). The nonzero
4119   structure will be the union of all the previous nonzero structures.
4120 
4121   Developer Notes:
4122   An optimization could be added to the implementation where it checks if the `i`, and `j` are identical to the current `i` and `j` and
4123   then just copies the `v` values directly with `PetscMemcpy()`.
4124 
4125   This routine could also take a `PetscCopyMode` argument to allow sharing the values instead of always copying them.
4126 
4127 .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatSeqAIJSetPreallocation()`, `MATSEQAIJ`, `MatResetPreallocation()`
4128 @*/
4129 PetscErrorCode MatSeqAIJSetPreallocationCSR(Mat B, const PetscInt i[], const PetscInt j[], const PetscScalar v[])
4130 {
4131   PetscFunctionBegin;
4132   PetscValidHeaderSpecific(B, MAT_CLASSID, 1);
4133   PetscValidType(B, 1);
4134   PetscTryMethod(B, "MatSeqAIJSetPreallocationCSR_C", (Mat, const PetscInt[], const PetscInt[], const PetscScalar[]), (B, i, j, v));
4135   PetscFunctionReturn(PETSC_SUCCESS);
4136 }
4137 
4138 static PetscErrorCode MatSeqAIJSetPreallocationCSR_SeqAIJ(Mat B, const PetscInt Ii[], const PetscInt J[], const PetscScalar v[])
4139 {
4140   PetscInt  i;
4141   PetscInt  m, n;
4142   PetscInt  nz;
4143   PetscInt *nnz;
4144 
4145   PetscFunctionBegin;
4146   PetscCheck(Ii[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Ii[0] must be 0 it is %" PetscInt_FMT, Ii[0]);
4147 
4148   PetscCall(PetscLayoutSetUp(B->rmap));
4149   PetscCall(PetscLayoutSetUp(B->cmap));
4150 
4151   PetscCall(MatGetSize(B, &m, &n));
4152   PetscCall(PetscMalloc1(m + 1, &nnz));
4153   for (i = 0; i < m; i++) {
4154     nz = Ii[i + 1] - Ii[i];
4155     PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local row %" PetscInt_FMT " has a negative number of columns %" PetscInt_FMT, i, nz);
4156     nnz[i] = nz;
4157   }
4158   PetscCall(MatSeqAIJSetPreallocation(B, 0, nnz));
4159   PetscCall(PetscFree(nnz));
4160 
4161   for (i = 0; i < m; i++) PetscCall(MatSetValues_SeqAIJ(B, 1, &i, Ii[i + 1] - Ii[i], J + Ii[i], PetscSafePointerPlusOffset(v, Ii[i]), INSERT_VALUES));
4162 
4163   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
4164   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
4165 
4166   PetscCall(MatSetOption(B, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
4167   PetscFunctionReturn(PETSC_SUCCESS);
4168 }
4169 
4170 /*@
4171   MatSeqAIJKron - Computes `C`, the Kronecker product of `A` and `B`.
4172 
4173   Input Parameters:
4174 + A     - left-hand side matrix
4175 . B     - right-hand side matrix
4176 - reuse - either `MAT_INITIAL_MATRIX` or `MAT_REUSE_MATRIX`
4177 
4178   Output Parameter:
4179 . C - Kronecker product of `A` and `B`
4180 
4181   Level: intermediate
4182 
4183   Note:
4184   `MAT_REUSE_MATRIX` can only be used when the nonzero structure of the product matrix has not changed from that last call to `MatSeqAIJKron()`.
4185 
4186 .seealso: [](ch_matrices), `Mat`, `MatCreateSeqAIJ()`, `MATSEQAIJ`, `MATKAIJ`, `MatReuse`
4187 @*/
4188 PetscErrorCode MatSeqAIJKron(Mat A, Mat B, MatReuse reuse, Mat *C)
4189 {
4190   PetscFunctionBegin;
4191   PetscValidHeaderSpecific(A, MAT_CLASSID, 1);
4192   PetscValidType(A, 1);
4193   PetscValidHeaderSpecific(B, MAT_CLASSID, 2);
4194   PetscValidType(B, 2);
4195   PetscAssertPointer(C, 4);
4196   if (reuse == MAT_REUSE_MATRIX) {
4197     PetscValidHeaderSpecific(*C, MAT_CLASSID, 4);
4198     PetscValidType(*C, 4);
4199   }
4200   PetscTryMethod(A, "MatSeqAIJKron_C", (Mat, Mat, MatReuse, Mat *), (A, B, reuse, C));
4201   PetscFunctionReturn(PETSC_SUCCESS);
4202 }
4203 
4204 static PetscErrorCode MatSeqAIJKron_SeqAIJ(Mat A, Mat B, MatReuse reuse, Mat *C)
4205 {
4206   Mat                newmat;
4207   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data;
4208   Mat_SeqAIJ        *b = (Mat_SeqAIJ *)B->data;
4209   PetscScalar       *v;
4210   const PetscScalar *aa, *ba;
4211   PetscInt          *i, *j, m, n, p, q, nnz = 0, am = A->rmap->n, bm = B->rmap->n, an = A->cmap->n, bn = B->cmap->n;
4212   PetscBool          flg;
4213 
4214   PetscFunctionBegin;
4215   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4216   PetscCheck(A->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4217   PetscCheck(!B->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
4218   PetscCheck(B->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for unassembled matrix");
4219   PetscCall(PetscObjectTypeCompare((PetscObject)B, MATSEQAIJ, &flg));
4220   PetscCheck(flg, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatType %s", ((PetscObject)B)->type_name);
4221   PetscCheck(reuse == MAT_INITIAL_MATRIX || reuse == MAT_REUSE_MATRIX, PETSC_COMM_SELF, PETSC_ERR_SUP, "MatReuse %d", (int)reuse);
4222   if (reuse == MAT_INITIAL_MATRIX) {
4223     PetscCall(PetscMalloc2(am * bm + 1, &i, a->i[am] * b->i[bm], &j));
4224     PetscCall(MatCreate(PETSC_COMM_SELF, &newmat));
4225     PetscCall(MatSetSizes(newmat, am * bm, an * bn, am * bm, an * bn));
4226     PetscCall(MatSetType(newmat, MATAIJ));
4227     i[0] = 0;
4228     for (m = 0; m < am; ++m) {
4229       for (p = 0; p < bm; ++p) {
4230         i[m * bm + p + 1] = i[m * bm + p] + (a->i[m + 1] - a->i[m]) * (b->i[p + 1] - b->i[p]);
4231         for (n = a->i[m]; n < a->i[m + 1]; ++n) {
4232           for (q = b->i[p]; q < b->i[p + 1]; ++q) j[nnz++] = a->j[n] * bn + b->j[q];
4233         }
4234       }
4235     }
4236     PetscCall(MatSeqAIJSetPreallocationCSR(newmat, i, j, NULL));
4237     *C = newmat;
4238     PetscCall(PetscFree2(i, j));
4239     nnz = 0;
4240   }
4241   PetscCall(MatSeqAIJGetArray(*C, &v));
4242   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
4243   PetscCall(MatSeqAIJGetArrayRead(B, &ba));
4244   for (m = 0; m < am; ++m) {
4245     for (p = 0; p < bm; ++p) {
4246       for (n = a->i[m]; n < a->i[m + 1]; ++n) {
4247         for (q = b->i[p]; q < b->i[p + 1]; ++q) v[nnz++] = aa[n] * ba[q];
4248       }
4249     }
4250   }
4251   PetscCall(MatSeqAIJRestoreArray(*C, &v));
4252   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
4253   PetscCall(MatSeqAIJRestoreArrayRead(B, &ba));
4254   PetscFunctionReturn(PETSC_SUCCESS);
4255 }
4256 
4257 #include <../src/mat/impls/dense/seq/dense.h>
4258 #include <petsc/private/kernels/petscaxpy.h>
4259 
4260 /*
4261     Computes (B'*A')' since computing B*A directly is untenable
4262 
4263                n                       p                          p
4264         [             ]       [             ]         [                 ]
4265       m [      A      ]  *  n [       B     ]   =   m [         C       ]
4266         [             ]       [             ]         [                 ]
4267 
4268 */
4269 PetscErrorCode MatMatMultNumeric_SeqDense_SeqAIJ(Mat A, Mat B, Mat C)
4270 {
4271   Mat_SeqDense      *sub_a = (Mat_SeqDense *)A->data;
4272   Mat_SeqAIJ        *sub_b = (Mat_SeqAIJ *)B->data;
4273   Mat_SeqDense      *sub_c = (Mat_SeqDense *)C->data;
4274   PetscInt           i, j, n, m, q, p;
4275   const PetscInt    *ii, *idx;
4276   const PetscScalar *b, *a, *a_q;
4277   PetscScalar       *c, *c_q;
4278   PetscInt           clda = sub_c->lda;
4279   PetscInt           alda = sub_a->lda;
4280 
4281   PetscFunctionBegin;
4282   m = A->rmap->n;
4283   n = A->cmap->n;
4284   p = B->cmap->n;
4285   a = sub_a->v;
4286   b = sub_b->a;
4287   c = sub_c->v;
4288   if (clda == m) {
4289     PetscCall(PetscArrayzero(c, m * p));
4290   } else {
4291     for (j = 0; j < p; j++)
4292       for (i = 0; i < m; i++) c[j * clda + i] = 0.0;
4293   }
4294   ii  = sub_b->i;
4295   idx = sub_b->j;
4296   for (i = 0; i < n; i++) {
4297     q = ii[i + 1] - ii[i];
4298     while (q-- > 0) {
4299       c_q = c + clda * (*idx);
4300       a_q = a + alda * i;
4301       PetscKernelAXPY(c_q, *b, a_q, m);
4302       idx++;
4303       b++;
4304     }
4305   }
4306   PetscFunctionReturn(PETSC_SUCCESS);
4307 }
4308 
4309 PetscErrorCode MatMatMultSymbolic_SeqDense_SeqAIJ(Mat A, Mat B, PetscReal fill, Mat C)
4310 {
4311   PetscInt  m = A->rmap->n, n = B->cmap->n;
4312   PetscBool cisdense;
4313 
4314   PetscFunctionBegin;
4315   PetscCheck(A->cmap->n == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "A->cmap->n %" PetscInt_FMT " != B->rmap->n %" PetscInt_FMT, A->cmap->n, B->rmap->n);
4316   PetscCall(MatSetSizes(C, m, n, m, n));
4317   PetscCall(MatSetBlockSizesFromMats(C, A, B));
4318   PetscCall(PetscObjectTypeCompareAny((PetscObject)C, &cisdense, MATSEQDENSE, MATSEQDENSECUDA, MATSEQDENSEHIP, ""));
4319   if (!cisdense) PetscCall(MatSetType(C, MATDENSE));
4320   PetscCall(MatSetUp(C));
4321 
4322   C->ops->matmultnumeric = MatMatMultNumeric_SeqDense_SeqAIJ;
4323   PetscFunctionReturn(PETSC_SUCCESS);
4324 }
4325 
4326 /*MC
4327    MATSEQAIJ - MATSEQAIJ = "seqaij" - A matrix type to be used for sequential sparse matrices,
4328    based on compressed sparse row format.
4329 
4330    Options Database Key:
4331 . -mat_type seqaij - sets the matrix type to "seqaij" during a call to MatSetFromOptions()
4332 
4333    Level: beginner
4334 
4335    Notes:
4336     `MatSetValues()` may be called for this matrix type with a `NULL` argument for the numerical values,
4337     in this case the values associated with the rows and columns one passes in are set to zero
4338     in the matrix
4339 
4340     `MatSetOptions`(,`MAT_STRUCTURE_ONLY`,`PETSC_TRUE`) may be called for this matrix type. In this no
4341     space is allocated for the nonzero entries and any entries passed with `MatSetValues()` are ignored
4342 
4343   Developer Note:
4344     It would be nice if all matrix formats supported passing `NULL` in for the numerical values
4345 
4346 .seealso: [](ch_matrices), `Mat`, `MatCreateSeqAIJ()`, `MatSetFromOptions()`, `MatSetType()`, `MatCreate()`, `MatType`, `MATSELL`, `MATSEQSELL`, `MATMPISELL`
4347 M*/
4348 
4349 /*MC
4350    MATAIJ - MATAIJ = "aij" - A matrix type to be used for sparse matrices.
4351 
4352    This matrix type is identical to `MATSEQAIJ` when constructed with a single process communicator,
4353    and `MATMPIAIJ` otherwise.  As a result, for single process communicators,
4354    `MatSeqAIJSetPreallocation()` is supported, and similarly `MatMPIAIJSetPreallocation()` is supported
4355    for communicators controlling multiple processes.  It is recommended that you call both of
4356    the above preallocation routines for simplicity.
4357 
4358    Options Database Key:
4359 . -mat_type aij - sets the matrix type to "aij" during a call to `MatSetFromOptions()`
4360 
4361   Level: beginner
4362 
4363    Note:
4364    Subclasses include `MATAIJCUSPARSE`, `MATAIJPERM`, `MATAIJSELL`, `MATAIJMKL`, `MATAIJCRL`, and also automatically switches over to use inodes when
4365    enough exist.
4366 
4367 .seealso: [](ch_matrices), `Mat`, `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MATSEQAIJ`, `MATMPIAIJ`, `MATSELL`, `MATSEQSELL`, `MATMPISELL`
4368 M*/
4369 
4370 /*MC
4371    MATAIJCRL - MATAIJCRL = "aijcrl" - A matrix type to be used for sparse matrices.
4372 
4373    Options Database Key:
4374 . -mat_type aijcrl - sets the matrix type to "aijcrl" during a call to `MatSetFromOptions()`
4375 
4376   Level: beginner
4377 
4378    Note:
4379    This matrix type is identical to `MATSEQAIJCRL` when constructed with a single process communicator,
4380    and `MATMPIAIJCRL` otherwise.  As a result, for single process communicators,
4381    `MatSeqAIJSetPreallocation()` is supported, and similarly `MatMPIAIJSetPreallocation()` is supported
4382    for communicators controlling multiple processes.  It is recommended that you call both of
4383    the above preallocation routines for simplicity.
4384 
4385 .seealso: [](ch_matrices), `Mat`, `MatCreateMPIAIJCRL`, `MATSEQAIJCRL`, `MATMPIAIJCRL`, `MATSEQAIJCRL`, `MATMPIAIJCRL`
4386 M*/
4387 
4388 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCRL(Mat, MatType, MatReuse, Mat *);
4389 #if defined(PETSC_HAVE_ELEMENTAL)
4390 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_Elemental(Mat, MatType, MatReuse, Mat *);
4391 #endif
4392 #if defined(PETSC_HAVE_SCALAPACK)
4393 PETSC_INTERN PetscErrorCode MatConvert_AIJ_ScaLAPACK(Mat, MatType, MatReuse, Mat *);
4394 #endif
4395 #if defined(PETSC_HAVE_HYPRE)
4396 PETSC_INTERN PetscErrorCode MatConvert_AIJ_HYPRE(Mat A, MatType, MatReuse, Mat *);
4397 #endif
4398 
4399 PETSC_EXTERN PetscErrorCode MatConvert_SeqAIJ_SeqSELL(Mat, MatType, MatReuse, Mat *);
4400 PETSC_INTERN PetscErrorCode MatConvert_XAIJ_IS(Mat, MatType, MatReuse, Mat *);
4401 PETSC_INTERN PetscErrorCode MatProductSetFromOptions_IS_XAIJ(Mat);
4402 
4403 /*@C
4404   MatSeqAIJGetArray - gives read/write access to the array where the data for a `MATSEQAIJ` matrix is stored
4405 
4406   Not Collective
4407 
4408   Input Parameter:
4409 . A - a `MATSEQAIJ` matrix
4410 
4411   Output Parameter:
4412 . array - pointer to the data
4413 
4414   Level: intermediate
4415 
4416   Fortran Notes:
4417   `MatSeqAIJGetArray()` Fortran binding is deprecated (since PETSc 3.19), use `MatSeqAIJGetArrayF90()`
4418 
4419 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJRestoreArray()`, `MatSeqAIJGetArrayF90()`
4420 @*/
4421 PetscErrorCode MatSeqAIJGetArray(Mat A, PetscScalar *array[])
4422 {
4423   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4424 
4425   PetscFunctionBegin;
4426   if (aij->ops->getarray) {
4427     PetscCall((*aij->ops->getarray)(A, array));
4428   } else {
4429     *array = aij->a;
4430   }
4431   PetscFunctionReturn(PETSC_SUCCESS);
4432 }
4433 
4434 /*@C
4435   MatSeqAIJRestoreArray - returns access to the array where the data for a `MATSEQAIJ` matrix is stored obtained by `MatSeqAIJGetArray()`
4436 
4437   Not Collective
4438 
4439   Input Parameters:
4440 + A     - a `MATSEQAIJ` matrix
4441 - array - pointer to the data
4442 
4443   Level: intermediate
4444 
4445   Fortran Notes:
4446   `MatSeqAIJRestoreArray()` Fortran binding is deprecated (since PETSc 3.19), use `MatSeqAIJRestoreArrayF90()`
4447 
4448 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArrayF90()`
4449 @*/
4450 PetscErrorCode MatSeqAIJRestoreArray(Mat A, PetscScalar *array[])
4451 {
4452   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4453 
4454   PetscFunctionBegin;
4455   if (aij->ops->restorearray) {
4456     PetscCall((*aij->ops->restorearray)(A, array));
4457   } else {
4458     *array = NULL;
4459   }
4460   PetscCall(MatSeqAIJInvalidateDiagonal(A));
4461   PetscCall(PetscObjectStateIncrease((PetscObject)A));
4462   PetscFunctionReturn(PETSC_SUCCESS);
4463 }
4464 
4465 /*@C
4466   MatSeqAIJGetArrayRead - gives read-only access to the array where the data for a `MATSEQAIJ` matrix is stored
4467 
4468   Not Collective; No Fortran Support
4469 
4470   Input Parameter:
4471 . A - a `MATSEQAIJ` matrix
4472 
4473   Output Parameter:
4474 . array - pointer to the data
4475 
4476   Level: intermediate
4477 
4478 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArrayRead()`
4479 @*/
4480 PetscErrorCode MatSeqAIJGetArrayRead(Mat A, const PetscScalar *array[])
4481 {
4482   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4483 
4484   PetscFunctionBegin;
4485   if (aij->ops->getarrayread) {
4486     PetscCall((*aij->ops->getarrayread)(A, array));
4487   } else {
4488     *array = aij->a;
4489   }
4490   PetscFunctionReturn(PETSC_SUCCESS);
4491 }
4492 
4493 /*@C
4494   MatSeqAIJRestoreArrayRead - restore the read-only access array obtained from `MatSeqAIJGetArrayRead()`
4495 
4496   Not Collective; No Fortran Support
4497 
4498   Input Parameter:
4499 . A - a `MATSEQAIJ` matrix
4500 
4501   Output Parameter:
4502 . array - pointer to the data
4503 
4504   Level: intermediate
4505 
4506 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJGetArray()`, `MatSeqAIJGetArrayRead()`
4507 @*/
4508 PetscErrorCode MatSeqAIJRestoreArrayRead(Mat A, const PetscScalar *array[])
4509 {
4510   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4511 
4512   PetscFunctionBegin;
4513   if (aij->ops->restorearrayread) {
4514     PetscCall((*aij->ops->restorearrayread)(A, array));
4515   } else {
4516     *array = NULL;
4517   }
4518   PetscFunctionReturn(PETSC_SUCCESS);
4519 }
4520 
4521 /*@C
4522   MatSeqAIJGetArrayWrite - gives write-only access to the array where the data for a `MATSEQAIJ` matrix is stored
4523 
4524   Not Collective; No Fortran Support
4525 
4526   Input Parameter:
4527 . A - a `MATSEQAIJ` matrix
4528 
4529   Output Parameter:
4530 . array - pointer to the data
4531 
4532   Level: intermediate
4533 
4534 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArrayRead()`
4535 @*/
4536 PetscErrorCode MatSeqAIJGetArrayWrite(Mat A, PetscScalar *array[])
4537 {
4538   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4539 
4540   PetscFunctionBegin;
4541   if (aij->ops->getarraywrite) {
4542     PetscCall((*aij->ops->getarraywrite)(A, array));
4543   } else {
4544     *array = aij->a;
4545   }
4546   PetscCall(MatSeqAIJInvalidateDiagonal(A));
4547   PetscCall(PetscObjectStateIncrease((PetscObject)A));
4548   PetscFunctionReturn(PETSC_SUCCESS);
4549 }
4550 
4551 /*@C
4552   MatSeqAIJRestoreArrayWrite - restore the read-only access array obtained from MatSeqAIJGetArrayRead
4553 
4554   Not Collective; No Fortran Support
4555 
4556   Input Parameter:
4557 . A - a MATSEQAIJ matrix
4558 
4559   Output Parameter:
4560 . array - pointer to the data
4561 
4562   Level: intermediate
4563 
4564 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJGetArray()`, `MatSeqAIJGetArrayRead()`
4565 @*/
4566 PetscErrorCode MatSeqAIJRestoreArrayWrite(Mat A, PetscScalar *array[])
4567 {
4568   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4569 
4570   PetscFunctionBegin;
4571   if (aij->ops->restorearraywrite) {
4572     PetscCall((*aij->ops->restorearraywrite)(A, array));
4573   } else {
4574     *array = NULL;
4575   }
4576   PetscFunctionReturn(PETSC_SUCCESS);
4577 }
4578 
4579 /*@C
4580   MatSeqAIJGetCSRAndMemType - Get the CSR arrays and the memory type of the `MATSEQAIJ` matrix
4581 
4582   Not Collective; No Fortran Support
4583 
4584   Input Parameter:
4585 . mat - a matrix of type `MATSEQAIJ` or its subclasses
4586 
4587   Output Parameters:
4588 + i     - row map array of the matrix
4589 . j     - column index array of the matrix
4590 . a     - data array of the matrix
4591 - mtype - memory type of the arrays
4592 
4593   Level: developer
4594 
4595   Notes:
4596   Any of the output parameters can be `NULL`, in which case the corresponding value is not returned.
4597   If mat is a device matrix, the arrays are on the device. Otherwise, they are on the host.
4598 
4599   One can call this routine on a preallocated but not assembled matrix to just get the memory of the CSR underneath the matrix.
4600   If the matrix is assembled, the data array `a` is guaranteed to have the latest values of the matrix.
4601 
4602 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJGetArray()`, `MatSeqAIJGetArrayRead()`
4603 @*/
4604 PetscErrorCode MatSeqAIJGetCSRAndMemType(Mat mat, const PetscInt *i[], const PetscInt *j[], PetscScalar *a[], PetscMemType *mtype)
4605 {
4606   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)mat->data;
4607 
4608   PetscFunctionBegin;
4609   PetscCheck(mat->preallocated, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "matrix is not preallocated");
4610   if (aij->ops->getcsrandmemtype) {
4611     PetscCall((*aij->ops->getcsrandmemtype)(mat, i, j, a, mtype));
4612   } else {
4613     if (i) *i = aij->i;
4614     if (j) *j = aij->j;
4615     if (a) *a = aij->a;
4616     if (mtype) *mtype = PETSC_MEMTYPE_HOST;
4617   }
4618   PetscFunctionReturn(PETSC_SUCCESS);
4619 }
4620 
4621 /*@
4622   MatSeqAIJGetMaxRowNonzeros - returns the maximum number of nonzeros in any row
4623 
4624   Not Collective
4625 
4626   Input Parameter:
4627 . A - a `MATSEQAIJ` matrix
4628 
4629   Output Parameter:
4630 . nz - the maximum number of nonzeros in any row
4631 
4632   Level: intermediate
4633 
4634 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJRestoreArray()`, `MatSeqAIJGetArrayF90()`
4635 @*/
4636 PetscErrorCode MatSeqAIJGetMaxRowNonzeros(Mat A, PetscInt *nz)
4637 {
4638   Mat_SeqAIJ *aij = (Mat_SeqAIJ *)A->data;
4639 
4640   PetscFunctionBegin;
4641   *nz = aij->rmax;
4642   PetscFunctionReturn(PETSC_SUCCESS);
4643 }
4644 
4645 static PetscErrorCode MatCOOStructDestroy_SeqAIJ(void **data)
4646 {
4647   MatCOOStruct_SeqAIJ *coo = (MatCOOStruct_SeqAIJ *)*data;
4648 
4649   PetscFunctionBegin;
4650   PetscCall(PetscFree(coo->perm));
4651   PetscCall(PetscFree(coo->jmap));
4652   PetscCall(PetscFree(coo));
4653   PetscFunctionReturn(PETSC_SUCCESS);
4654 }
4655 
4656 PetscErrorCode MatSetPreallocationCOO_SeqAIJ(Mat mat, PetscCount coo_n, PetscInt coo_i[], PetscInt coo_j[])
4657 {
4658   MPI_Comm             comm;
4659   PetscInt            *i, *j;
4660   PetscInt             M, N, row, iprev;
4661   PetscCount           k, p, q, nneg, nnz, start, end; /* Index the coo array, so use PetscCount as their type */
4662   PetscInt            *Ai;                             /* Change to PetscCount once we use it for row pointers */
4663   PetscInt            *Aj;
4664   PetscScalar         *Aa;
4665   Mat_SeqAIJ          *seqaij = (Mat_SeqAIJ *)mat->data;
4666   MatType              rtype;
4667   PetscCount          *perm, *jmap;
4668   MatCOOStruct_SeqAIJ *coo;
4669   PetscBool            isorted;
4670   PetscBool            hypre;
4671   const char          *name;
4672 
4673   PetscFunctionBegin;
4674   PetscCall(PetscObjectGetComm((PetscObject)mat, &comm));
4675   PetscCall(MatGetSize(mat, &M, &N));
4676   i = coo_i;
4677   j = coo_j;
4678   PetscCall(PetscMalloc1(coo_n, &perm));
4679 
4680   /* Ignore entries with negative row or col indices; at the same time, check if i[] is already sorted (e.g., MatConvert_AlJ_HYPRE results in this case) */
4681   isorted = PETSC_TRUE;
4682   iprev   = PETSC_INT_MIN;
4683   for (k = 0; k < coo_n; k++) {
4684     if (j[k] < 0) i[k] = -1;
4685     if (isorted) {
4686       if (i[k] < iprev) isorted = PETSC_FALSE;
4687       else iprev = i[k];
4688     }
4689     perm[k] = k;
4690   }
4691 
4692   /* Sort by row if not already */
4693   if (!isorted) PetscCall(PetscSortIntWithIntCountArrayPair(coo_n, i, j, perm));
4694 
4695   /* Advance k to the first row with a non-negative index */
4696   for (k = 0; k < coo_n; k++)
4697     if (i[k] >= 0) break;
4698   nneg = k;
4699   PetscCall(PetscMalloc1(coo_n - nneg + 1, &jmap)); /* +1 to make a CSR-like data structure. jmap[i] originally is the number of repeats for i-th nonzero */
4700   nnz = 0;                                          /* Total number of unique nonzeros to be counted */
4701   jmap++;                                           /* Inc jmap by 1 for convenience */
4702 
4703   PetscCall(PetscShmgetAllocateArray(M + 1, sizeof(PetscInt), (void **)&Ai)); /* CSR of A */
4704   PetscCall(PetscArrayzero(Ai, M + 1));
4705   PetscCall(PetscShmgetAllocateArray(coo_n - nneg, sizeof(PetscInt), (void **)&Aj)); /* We have at most coo_n-nneg unique nonzeros */
4706 
4707   PetscCall(PetscObjectGetName((PetscObject)mat, &name));
4708   PetscCall(PetscStrcmp("_internal_COO_mat_for_hypre", name, &hypre));
4709 
4710   /* In each row, sort by column, then unique column indices to get row length */
4711   Ai++;  /* Inc by 1 for convenience */
4712   q = 0; /* q-th unique nonzero, with q starting from 0 */
4713   while (k < coo_n) {
4714     PetscBool strictly_sorted; // this row is strictly sorted?
4715     PetscInt  jprev;
4716 
4717     /* get [start,end) indices for this row; also check if cols in this row are strictly sorted */
4718     row             = i[k];
4719     start           = k;
4720     jprev           = PETSC_INT_MIN;
4721     strictly_sorted = PETSC_TRUE;
4722     while (k < coo_n && i[k] == row) {
4723       if (strictly_sorted) {
4724         if (j[k] <= jprev) strictly_sorted = PETSC_FALSE;
4725         else jprev = j[k];
4726       }
4727       k++;
4728     }
4729     end = k;
4730 
4731     /* hack for HYPRE: swap min column to diag so that diagonal values will go first */
4732     if (hypre) {
4733       PetscInt  minj    = PETSC_INT_MAX;
4734       PetscBool hasdiag = PETSC_FALSE;
4735 
4736       if (strictly_sorted) { // fast path to swap the first and the diag
4737         PetscCount tmp;
4738         for (p = start; p < end; p++) {
4739           if (j[p] == row && p != start) {
4740             j[p]        = j[start]; // swap j[], so that the diagonal value will go first (manipulated by perm[])
4741             j[start]    = row;
4742             tmp         = perm[start];
4743             perm[start] = perm[p]; // also swap perm[] so we can save the call to PetscSortIntWithCountArray() below
4744             perm[p]     = tmp;
4745             break;
4746           }
4747         }
4748       } else {
4749         for (p = start; p < end; p++) {
4750           hasdiag = (PetscBool)(hasdiag || (j[p] == row));
4751           minj    = PetscMin(minj, j[p]);
4752         }
4753 
4754         if (hasdiag) {
4755           for (p = start; p < end; p++) {
4756             if (j[p] == minj) j[p] = row;
4757             else if (j[p] == row) j[p] = minj;
4758           }
4759         }
4760       }
4761     }
4762     // sort by columns in a row. perm[] indicates their original order
4763     if (!strictly_sorted) PetscCall(PetscSortIntWithCountArray(end - start, j + start, perm + start));
4764 
4765     if (strictly_sorted) { // fast path to set Aj[], jmap[], Ai[], nnz, q
4766       for (p = start; p < end; p++, q++) {
4767         Aj[q]   = j[p];
4768         jmap[q] = 1;
4769       }
4770       PetscCall(PetscIntCast(end - start, Ai + row));
4771       nnz += Ai[row]; // q is already advanced
4772     } else {
4773       /* Find number of unique col entries in this row */
4774       Aj[q]   = j[start]; /* Log the first nonzero in this row */
4775       jmap[q] = 1;        /* Number of repeats of this nonzero entry */
4776       Ai[row] = 1;
4777       nnz++;
4778 
4779       for (p = start + 1; p < end; p++) { /* Scan remaining nonzero in this row */
4780         if (j[p] != j[p - 1]) {           /* Meet a new nonzero */
4781           q++;
4782           jmap[q] = 1;
4783           Aj[q]   = j[p];
4784           Ai[row]++;
4785           nnz++;
4786         } else {
4787           jmap[q]++;
4788         }
4789       }
4790       q++; /* Move to next row and thus next unique nonzero */
4791     }
4792   }
4793 
4794   Ai--; /* Back to the beginning of Ai[] */
4795   for (k = 0; k < M; k++) Ai[k + 1] += Ai[k];
4796   jmap--; // Back to the beginning of jmap[]
4797   jmap[0] = 0;
4798   for (k = 0; k < nnz; k++) jmap[k + 1] += jmap[k];
4799 
4800   if (nnz < coo_n - nneg) { /* Reallocate with actual number of unique nonzeros */
4801     PetscCount *jmap_new;
4802     PetscInt   *Aj_new;
4803 
4804     PetscCall(PetscMalloc1(nnz + 1, &jmap_new));
4805     PetscCall(PetscArraycpy(jmap_new, jmap, nnz + 1));
4806     PetscCall(PetscFree(jmap));
4807     jmap = jmap_new;
4808 
4809     PetscCall(PetscShmgetAllocateArray(nnz, sizeof(PetscInt), (void **)&Aj_new));
4810     PetscCall(PetscArraycpy(Aj_new, Aj, nnz));
4811     PetscCall(PetscShmgetDeallocateArray((void **)&Aj));
4812     Aj = Aj_new;
4813   }
4814 
4815   if (nneg) { /* Discard heading entries with negative indices in perm[], as we'll access it from index 0 in MatSetValuesCOO */
4816     PetscCount *perm_new;
4817 
4818     PetscCall(PetscMalloc1(coo_n - nneg, &perm_new));
4819     PetscCall(PetscArraycpy(perm_new, perm + nneg, coo_n - nneg));
4820     PetscCall(PetscFree(perm));
4821     perm = perm_new;
4822   }
4823 
4824   PetscCall(MatGetRootType_Private(mat, &rtype));
4825   PetscCall(PetscShmgetAllocateArray(nnz, sizeof(PetscScalar), (void **)&Aa));
4826   PetscCall(PetscArrayzero(Aa, nnz));
4827   PetscCall(MatSetSeqAIJWithArrays_private(PETSC_COMM_SELF, M, N, Ai, Aj, Aa, rtype, mat));
4828 
4829   seqaij->free_a = seqaij->free_ij = PETSC_TRUE; /* Let newmat own Ai, Aj and Aa */
4830 
4831   // Put the COO struct in a container and then attach that to the matrix
4832   PetscCall(PetscMalloc1(1, &coo));
4833   PetscCall(PetscIntCast(nnz, &coo->nz));
4834   coo->n    = coo_n;
4835   coo->Atot = coo_n - nneg; // Annz is seqaij->nz, so no need to record that again
4836   coo->jmap = jmap;         // of length nnz+1
4837   coo->perm = perm;
4838   PetscCall(PetscObjectContainerCompose((PetscObject)mat, "__PETSc_MatCOOStruct_Host", coo, MatCOOStructDestroy_SeqAIJ));
4839   PetscFunctionReturn(PETSC_SUCCESS);
4840 }
4841 
4842 static PetscErrorCode MatSetValuesCOO_SeqAIJ(Mat A, const PetscScalar v[], InsertMode imode)
4843 {
4844   Mat_SeqAIJ          *aseq = (Mat_SeqAIJ *)A->data;
4845   PetscCount           i, j, Annz = aseq->nz;
4846   PetscCount          *perm, *jmap;
4847   PetscScalar         *Aa;
4848   PetscContainer       container;
4849   MatCOOStruct_SeqAIJ *coo;
4850 
4851   PetscFunctionBegin;
4852   PetscCall(PetscObjectQuery((PetscObject)A, "__PETSc_MatCOOStruct_Host", (PetscObject *)&container));
4853   PetscCheck(container, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Not found MatCOOStruct on this matrix");
4854   PetscCall(PetscContainerGetPointer(container, (void **)&coo));
4855   perm = coo->perm;
4856   jmap = coo->jmap;
4857   PetscCall(MatSeqAIJGetArray(A, &Aa));
4858   for (i = 0; i < Annz; i++) {
4859     PetscScalar sum = 0.0;
4860     for (j = jmap[i]; j < jmap[i + 1]; j++) sum += v[perm[j]];
4861     Aa[i] = (imode == INSERT_VALUES ? 0.0 : Aa[i]) + sum;
4862   }
4863   PetscCall(MatSeqAIJRestoreArray(A, &Aa));
4864   PetscFunctionReturn(PETSC_SUCCESS);
4865 }
4866 
4867 #if defined(PETSC_HAVE_CUDA)
4868 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJCUSPARSE(Mat, MatType, MatReuse, Mat *);
4869 #endif
4870 #if defined(PETSC_HAVE_HIP)
4871 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJHIPSPARSE(Mat, MatType, MatReuse, Mat *);
4872 #endif
4873 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
4874 PETSC_INTERN PetscErrorCode MatConvert_SeqAIJ_SeqAIJKokkos(Mat, MatType, MatReuse, Mat *);
4875 #endif
4876 
4877 PETSC_EXTERN PetscErrorCode MatCreate_SeqAIJ(Mat B)
4878 {
4879   Mat_SeqAIJ *b;
4880   PetscMPIInt size;
4881 
4882   PetscFunctionBegin;
4883   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)B), &size));
4884   PetscCheck(size <= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Comm must be of size 1");
4885 
4886   PetscCall(PetscNew(&b));
4887 
4888   B->data   = (void *)b;
4889   B->ops[0] = MatOps_Values;
4890   if (B->sortedfull) B->ops->setvalues = MatSetValues_SeqAIJ_SortedFull;
4891 
4892   b->row                = NULL;
4893   b->col                = NULL;
4894   b->icol               = NULL;
4895   b->reallocs           = 0;
4896   b->ignorezeroentries  = PETSC_FALSE;
4897   b->roworiented        = PETSC_TRUE;
4898   b->nonew              = 0;
4899   b->diag               = NULL;
4900   b->solve_work         = NULL;
4901   B->spptr              = NULL;
4902   b->saved_values       = NULL;
4903   b->idiag              = NULL;
4904   b->mdiag              = NULL;
4905   b->ssor_work          = NULL;
4906   b->omega              = 1.0;
4907   b->fshift             = 0.0;
4908   b->idiagvalid         = PETSC_FALSE;
4909   b->ibdiagvalid        = PETSC_FALSE;
4910   b->keepnonzeropattern = PETSC_FALSE;
4911 
4912   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJ));
4913 #if defined(PETSC_HAVE_MATLAB)
4914   PetscCall(PetscObjectComposeFunction((PetscObject)B, "PetscMatlabEnginePut_C", MatlabEnginePut_SeqAIJ));
4915   PetscCall(PetscObjectComposeFunction((PetscObject)B, "PetscMatlabEngineGet_C", MatlabEngineGet_SeqAIJ));
4916 #endif
4917   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJSetColumnIndices_C", MatSeqAIJSetColumnIndices_SeqAIJ));
4918   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatStoreValues_C", MatStoreValues_SeqAIJ));
4919   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatRetrieveValues_C", MatRetrieveValues_SeqAIJ));
4920   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqsbaij_C", MatConvert_SeqAIJ_SeqSBAIJ));
4921   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqbaij_C", MatConvert_SeqAIJ_SeqBAIJ));
4922   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijperm_C", MatConvert_SeqAIJ_SeqAIJPERM));
4923   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijsell_C", MatConvert_SeqAIJ_SeqAIJSELL));
4924 #if defined(PETSC_HAVE_MKL_SPARSE)
4925   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijmkl_C", MatConvert_SeqAIJ_SeqAIJMKL));
4926 #endif
4927 #if defined(PETSC_HAVE_CUDA)
4928   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijcusparse_C", MatConvert_SeqAIJ_SeqAIJCUSPARSE));
4929   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaijcusparse_seqaij_C", MatProductSetFromOptions_SeqAIJ));
4930   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaij_seqaijcusparse_C", MatProductSetFromOptions_SeqAIJ));
4931 #endif
4932 #if defined(PETSC_HAVE_HIP)
4933   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijhipsparse_C", MatConvert_SeqAIJ_SeqAIJHIPSPARSE));
4934   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaijhipsparse_seqaij_C", MatProductSetFromOptions_SeqAIJ));
4935   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaij_seqaijhipsparse_C", MatProductSetFromOptions_SeqAIJ));
4936 #endif
4937 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
4938   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijkokkos_C", MatConvert_SeqAIJ_SeqAIJKokkos));
4939 #endif
4940   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqaijcrl_C", MatConvert_SeqAIJ_SeqAIJCRL));
4941 #if defined(PETSC_HAVE_ELEMENTAL)
4942   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_elemental_C", MatConvert_SeqAIJ_Elemental));
4943 #endif
4944 #if defined(PETSC_HAVE_SCALAPACK)
4945   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_scalapack_C", MatConvert_AIJ_ScaLAPACK));
4946 #endif
4947 #if defined(PETSC_HAVE_HYPRE)
4948   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_hypre_C", MatConvert_AIJ_HYPRE));
4949   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_transpose_seqaij_seqaij_C", MatProductSetFromOptions_Transpose_AIJ_AIJ));
4950 #endif
4951   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqdense_C", MatConvert_SeqAIJ_SeqDense));
4952   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_seqsell_C", MatConvert_SeqAIJ_SeqSELL));
4953   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqaij_is_C", MatConvert_XAIJ_IS));
4954   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatIsTranspose_C", MatIsTranspose_SeqAIJ));
4955   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatIsHermitianTranspose_C", MatIsHermitianTranspose_SeqAIJ));
4956   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJSetPreallocation_C", MatSeqAIJSetPreallocation_SeqAIJ));
4957   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatResetPreallocation_C", MatResetPreallocation_SeqAIJ));
4958   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatResetHash_C", MatResetHash_SeqAIJ));
4959   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJSetPreallocationCSR_C", MatSeqAIJSetPreallocationCSR_SeqAIJ));
4960   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatReorderForNonzeroDiagonal_C", MatReorderForNonzeroDiagonal_SeqAIJ));
4961   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_is_seqaij_C", MatProductSetFromOptions_IS_XAIJ));
4962   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqdense_seqaij_C", MatProductSetFromOptions_SeqDense_SeqAIJ));
4963   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatProductSetFromOptions_seqaij_seqaij_C", MatProductSetFromOptions_SeqAIJ));
4964   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqAIJKron_C", MatSeqAIJKron_SeqAIJ));
4965   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSetPreallocationCOO_C", MatSetPreallocationCOO_SeqAIJ));
4966   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSetValuesCOO_C", MatSetValuesCOO_SeqAIJ));
4967   PetscCall(MatCreate_SeqAIJ_Inode(B));
4968   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQAIJ));
4969   PetscCall(MatSeqAIJSetTypeFromOptions(B)); /* this allows changing the matrix subtype to say MATSEQAIJPERM */
4970   PetscFunctionReturn(PETSC_SUCCESS);
4971 }
4972 
4973 /*
4974     Given a matrix generated with MatGetFactor() duplicates all the information in A into C
4975 */
4976 PetscErrorCode MatDuplicateNoCreate_SeqAIJ(Mat C, Mat A, MatDuplicateOption cpvalues, PetscBool mallocmatspace)
4977 {
4978   Mat_SeqAIJ *c = (Mat_SeqAIJ *)C->data, *a = (Mat_SeqAIJ *)A->data;
4979   PetscInt    m = A->rmap->n, i;
4980 
4981   PetscFunctionBegin;
4982   PetscCheck(A->assembled || cpvalues == MAT_DO_NOT_COPY_VALUES, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot duplicate unassembled matrix");
4983 
4984   C->factortype    = A->factortype;
4985   c->row           = NULL;
4986   c->col           = NULL;
4987   c->icol          = NULL;
4988   c->reallocs      = 0;
4989   c->diagonaldense = a->diagonaldense;
4990 
4991   C->assembled = A->assembled;
4992 
4993   if (A->preallocated) {
4994     PetscCall(PetscLayoutReference(A->rmap, &C->rmap));
4995     PetscCall(PetscLayoutReference(A->cmap, &C->cmap));
4996 
4997     if (!A->hash_active) {
4998       PetscCall(PetscMalloc1(m, &c->imax));
4999       PetscCall(PetscMemcpy(c->imax, a->imax, m * sizeof(PetscInt)));
5000       PetscCall(PetscMalloc1(m, &c->ilen));
5001       PetscCall(PetscMemcpy(c->ilen, a->ilen, m * sizeof(PetscInt)));
5002 
5003       /* allocate the matrix space */
5004       if (mallocmatspace) {
5005         PetscCall(PetscShmgetAllocateArray(a->i[m], sizeof(PetscScalar), (void **)&c->a));
5006         PetscCall(PetscShmgetAllocateArray(a->i[m], sizeof(PetscInt), (void **)&c->j));
5007         PetscCall(PetscShmgetAllocateArray(m + 1, sizeof(PetscInt), (void **)&c->i));
5008         PetscCall(PetscArraycpy(c->i, a->i, m + 1));
5009         c->free_a  = PETSC_TRUE;
5010         c->free_ij = PETSC_TRUE;
5011         if (m > 0) {
5012           PetscCall(PetscArraycpy(c->j, a->j, a->i[m]));
5013           if (cpvalues == MAT_COPY_VALUES) {
5014             const PetscScalar *aa;
5015 
5016             PetscCall(MatSeqAIJGetArrayRead(A, &aa));
5017             PetscCall(PetscArraycpy(c->a, aa, a->i[m]));
5018             PetscCall(MatSeqAIJGetArrayRead(A, &aa));
5019           } else {
5020             PetscCall(PetscArrayzero(c->a, a->i[m]));
5021           }
5022         }
5023       }
5024       C->preallocated = PETSC_TRUE;
5025     } else {
5026       PetscCheck(mallocmatspace, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Cannot malloc matrix memory from a non-preallocated matrix");
5027       PetscCall(MatSetUp(C));
5028     }
5029 
5030     c->ignorezeroentries = a->ignorezeroentries;
5031     c->roworiented       = a->roworiented;
5032     c->nonew             = a->nonew;
5033     if (a->diag) {
5034       PetscCall(PetscMalloc1(m + 1, &c->diag));
5035       PetscCall(PetscMemcpy(c->diag, a->diag, m * sizeof(PetscInt)));
5036     } else c->diag = NULL;
5037 
5038     c->solve_work         = NULL;
5039     c->saved_values       = NULL;
5040     c->idiag              = NULL;
5041     c->ssor_work          = NULL;
5042     c->keepnonzeropattern = a->keepnonzeropattern;
5043 
5044     c->rmax  = a->rmax;
5045     c->nz    = a->nz;
5046     c->maxnz = a->nz; /* Since we allocate exactly the right amount */
5047 
5048     c->compressedrow.use   = a->compressedrow.use;
5049     c->compressedrow.nrows = a->compressedrow.nrows;
5050     if (a->compressedrow.use) {
5051       i = a->compressedrow.nrows;
5052       PetscCall(PetscMalloc2(i + 1, &c->compressedrow.i, i, &c->compressedrow.rindex));
5053       PetscCall(PetscArraycpy(c->compressedrow.i, a->compressedrow.i, i + 1));
5054       PetscCall(PetscArraycpy(c->compressedrow.rindex, a->compressedrow.rindex, i));
5055     } else {
5056       c->compressedrow.use    = PETSC_FALSE;
5057       c->compressedrow.i      = NULL;
5058       c->compressedrow.rindex = NULL;
5059     }
5060     c->nonzerorowcnt = a->nonzerorowcnt;
5061     C->nonzerostate  = A->nonzerostate;
5062 
5063     PetscCall(MatDuplicate_SeqAIJ_Inode(A, cpvalues, &C));
5064   }
5065   PetscCall(PetscFunctionListDuplicate(((PetscObject)A)->qlist, &((PetscObject)C)->qlist));
5066   PetscFunctionReturn(PETSC_SUCCESS);
5067 }
5068 
5069 PetscErrorCode MatDuplicate_SeqAIJ(Mat A, MatDuplicateOption cpvalues, Mat *B)
5070 {
5071   PetscFunctionBegin;
5072   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
5073   PetscCall(MatSetSizes(*B, A->rmap->n, A->cmap->n, A->rmap->n, A->cmap->n));
5074   if (!(A->rmap->n % A->rmap->bs) && !(A->cmap->n % A->cmap->bs)) PetscCall(MatSetBlockSizesFromMats(*B, A, A));
5075   PetscCall(MatSetType(*B, ((PetscObject)A)->type_name));
5076   PetscCall(MatDuplicateNoCreate_SeqAIJ(*B, A, cpvalues, PETSC_TRUE));
5077   PetscFunctionReturn(PETSC_SUCCESS);
5078 }
5079 
5080 PetscErrorCode MatLoad_SeqAIJ(Mat newMat, PetscViewer viewer)
5081 {
5082   PetscBool isbinary, ishdf5;
5083 
5084   PetscFunctionBegin;
5085   PetscValidHeaderSpecific(newMat, MAT_CLASSID, 1);
5086   PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 2);
5087   /* force binary viewer to load .info file if it has not yet done so */
5088   PetscCall(PetscViewerSetUp(viewer));
5089   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
5090   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERHDF5, &ishdf5));
5091   if (isbinary) {
5092     PetscCall(MatLoad_SeqAIJ_Binary(newMat, viewer));
5093   } else if (ishdf5) {
5094 #if defined(PETSC_HAVE_HDF5)
5095     PetscCall(MatLoad_AIJ_HDF5(newMat, viewer));
5096 #else
5097     SETERRQ(PetscObjectComm((PetscObject)newMat), PETSC_ERR_SUP, "HDF5 not supported in this build.\nPlease reconfigure using --download-hdf5");
5098 #endif
5099   } else {
5100     SETERRQ(PetscObjectComm((PetscObject)newMat), PETSC_ERR_SUP, "Viewer type %s not yet supported for reading %s matrices", ((PetscObject)viewer)->type_name, ((PetscObject)newMat)->type_name);
5101   }
5102   PetscFunctionReturn(PETSC_SUCCESS);
5103 }
5104 
5105 PetscErrorCode MatLoad_SeqAIJ_Binary(Mat mat, PetscViewer viewer)
5106 {
5107   Mat_SeqAIJ *a = (Mat_SeqAIJ *)mat->data;
5108   PetscInt    header[4], *rowlens, M, N, nz, sum, rows, cols, i;
5109 
5110   PetscFunctionBegin;
5111   PetscCall(PetscViewerSetUp(viewer));
5112 
5113   /* read in matrix header */
5114   PetscCall(PetscViewerBinaryRead(viewer, header, 4, NULL, PETSC_INT));
5115   PetscCheck(header[0] == MAT_FILE_CLASSID, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Not a matrix object in file");
5116   M  = header[1];
5117   N  = header[2];
5118   nz = header[3];
5119   PetscCheck(M >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix row size (%" PetscInt_FMT ") in file is negative", M);
5120   PetscCheck(N >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix column size (%" PetscInt_FMT ") in file is negative", N);
5121   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix stored in special format on disk, cannot load as SeqAIJ");
5122 
5123   /* set block sizes from the viewer's .info file */
5124   PetscCall(MatLoad_Binary_BlockSizes(mat, viewer));
5125   /* set local and global sizes if not set already */
5126   if (mat->rmap->n < 0) mat->rmap->n = M;
5127   if (mat->cmap->n < 0) mat->cmap->n = N;
5128   if (mat->rmap->N < 0) mat->rmap->N = M;
5129   if (mat->cmap->N < 0) mat->cmap->N = N;
5130   PetscCall(PetscLayoutSetUp(mat->rmap));
5131   PetscCall(PetscLayoutSetUp(mat->cmap));
5132 
5133   /* check if the matrix sizes are correct */
5134   PetscCall(MatGetSize(mat, &rows, &cols));
5135   PetscCheck(M == rows && N == cols, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix in file of different sizes (%" PetscInt_FMT ", %" PetscInt_FMT ") than the input matrix (%" PetscInt_FMT ", %" PetscInt_FMT ")", M, N, rows, cols);
5136 
5137   /* read in row lengths */
5138   PetscCall(PetscMalloc1(M, &rowlens));
5139   PetscCall(PetscViewerBinaryRead(viewer, rowlens, M, NULL, PETSC_INT));
5140   /* check if sum(rowlens) is same as nz */
5141   sum = 0;
5142   for (i = 0; i < M; i++) sum += rowlens[i];
5143   PetscCheck(sum == nz, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Inconsistent matrix data in file: nonzeros = %" PetscInt_FMT ", sum-row-lengths = %" PetscInt_FMT, nz, sum);
5144   /* preallocate and check sizes */
5145   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(mat, 0, rowlens));
5146   PetscCall(MatGetSize(mat, &rows, &cols));
5147   PetscCheck(M == rows && N == cols, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix in file of different length (%" PetscInt_FMT ", %" PetscInt_FMT ") than the input matrix (%" PetscInt_FMT ", %" PetscInt_FMT ")", M, N, rows, cols);
5148   /* store row lengths */
5149   PetscCall(PetscArraycpy(a->ilen, rowlens, M));
5150   PetscCall(PetscFree(rowlens));
5151 
5152   /* fill in "i" row pointers */
5153   a->i[0] = 0;
5154   for (i = 0; i < M; i++) a->i[i + 1] = a->i[i] + a->ilen[i];
5155   /* read in "j" column indices */
5156   PetscCall(PetscViewerBinaryRead(viewer, a->j, nz, NULL, PETSC_INT));
5157   /* read in "a" nonzero values */
5158   PetscCall(PetscViewerBinaryRead(viewer, a->a, nz, NULL, PETSC_SCALAR));
5159 
5160   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
5161   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
5162   PetscFunctionReturn(PETSC_SUCCESS);
5163 }
5164 
5165 PetscErrorCode MatEqual_SeqAIJ(Mat A, Mat B, PetscBool *flg)
5166 {
5167   Mat_SeqAIJ        *a = (Mat_SeqAIJ *)A->data, *b = (Mat_SeqAIJ *)B->data;
5168   const PetscScalar *aa, *ba;
5169 #if defined(PETSC_USE_COMPLEX)
5170   PetscInt k;
5171 #endif
5172 
5173   PetscFunctionBegin;
5174   /* If the  matrix dimensions are not equal,or no of nonzeros */
5175   if ((A->rmap->n != B->rmap->n) || (A->cmap->n != B->cmap->n) || (a->nz != b->nz)) {
5176     *flg = PETSC_FALSE;
5177     PetscFunctionReturn(PETSC_SUCCESS);
5178   }
5179 
5180   /* if the a->i are the same */
5181   PetscCall(PetscArraycmp(a->i, b->i, A->rmap->n + 1, flg));
5182   if (!*flg) PetscFunctionReturn(PETSC_SUCCESS);
5183 
5184   /* if a->j are the same */
5185   PetscCall(PetscArraycmp(a->j, b->j, a->nz, flg));
5186   if (!*flg) PetscFunctionReturn(PETSC_SUCCESS);
5187 
5188   PetscCall(MatSeqAIJGetArrayRead(A, &aa));
5189   PetscCall(MatSeqAIJGetArrayRead(B, &ba));
5190   /* if a->a are the same */
5191 #if defined(PETSC_USE_COMPLEX)
5192   for (k = 0; k < a->nz; k++) {
5193     if (PetscRealPart(aa[k]) != PetscRealPart(ba[k]) || PetscImaginaryPart(aa[k]) != PetscImaginaryPart(ba[k])) {
5194       *flg = PETSC_FALSE;
5195       PetscFunctionReturn(PETSC_SUCCESS);
5196     }
5197   }
5198 #else
5199   PetscCall(PetscArraycmp(aa, ba, a->nz, flg));
5200 #endif
5201   PetscCall(MatSeqAIJRestoreArrayRead(A, &aa));
5202   PetscCall(MatSeqAIJRestoreArrayRead(B, &ba));
5203   PetscFunctionReturn(PETSC_SUCCESS);
5204 }
5205 
5206 /*@
5207   MatCreateSeqAIJWithArrays - Creates an sequential `MATSEQAIJ` matrix using matrix elements (in CSR format)
5208   provided by the user.
5209 
5210   Collective
5211 
5212   Input Parameters:
5213 + comm - must be an MPI communicator of size 1
5214 . m    - number of rows
5215 . n    - number of columns
5216 . i    - row indices; that is i[0] = 0, i[row] = i[row-1] + number of elements in that row of the matrix
5217 . j    - column indices
5218 - a    - matrix values
5219 
5220   Output Parameter:
5221 . mat - the matrix
5222 
5223   Level: intermediate
5224 
5225   Notes:
5226   The `i`, `j`, and `a` arrays are not copied by this routine, the user must free these arrays
5227   once the matrix is destroyed and not before
5228 
5229   You cannot set new nonzero locations into this matrix, that will generate an error.
5230 
5231   The `i` and `j` indices are 0 based
5232 
5233   The format which is used for the sparse matrix input, is equivalent to a
5234   row-major ordering.. i.e for the following matrix, the input data expected is
5235   as shown
5236 .vb
5237         1 0 0
5238         2 0 3
5239         4 5 6
5240 
5241         i =  {0,1,3,6}  [size = nrow+1  = 3+1]
5242         j =  {0,0,2,0,1,2}  [size = 6]; values must be sorted for each row
5243         v =  {1,2,3,4,5,6}  [size = 6]
5244 .ve
5245 
5246 .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MatCreateMPIAIJWithArrays()`, `MatMPIAIJSetPreallocationCSR()`
5247 @*/
5248 PetscErrorCode MatCreateSeqAIJWithArrays(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt i[], PetscInt j[], PetscScalar a[], Mat *mat)
5249 {
5250   PetscInt    ii;
5251   Mat_SeqAIJ *aij;
5252   PetscInt    jj;
5253 
5254   PetscFunctionBegin;
5255   PetscCheck(m <= 0 || i[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "i (row indices) must start with 0");
5256   PetscCall(MatCreate(comm, mat));
5257   PetscCall(MatSetSizes(*mat, m, n, m, n));
5258   /* PetscCall(MatSetBlockSizes(*mat,,)); */
5259   PetscCall(MatSetType(*mat, MATSEQAIJ));
5260   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*mat, MAT_SKIP_ALLOCATION, NULL));
5261   aij = (Mat_SeqAIJ *)(*mat)->data;
5262   PetscCall(PetscMalloc1(m, &aij->imax));
5263   PetscCall(PetscMalloc1(m, &aij->ilen));
5264 
5265   aij->i       = i;
5266   aij->j       = j;
5267   aij->a       = a;
5268   aij->nonew   = -1; /*this indicates that inserting a new value in the matrix that generates a new nonzero is an error*/
5269   aij->free_a  = PETSC_FALSE;
5270   aij->free_ij = PETSC_FALSE;
5271 
5272   for (ii = 0, aij->nonzerorowcnt = 0, aij->rmax = 0; ii < m; ii++) {
5273     aij->ilen[ii] = aij->imax[ii] = i[ii + 1] - i[ii];
5274     if (PetscDefined(USE_DEBUG)) {
5275       PetscCheck(i[ii + 1] - i[ii] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative row length in i (row indices) row = %" PetscInt_FMT " length = %" PetscInt_FMT, ii, i[ii + 1] - i[ii]);
5276       for (jj = i[ii] + 1; jj < i[ii + 1]; jj++) {
5277         PetscCheck(j[jj] >= j[jj - 1], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column entry number %" PetscInt_FMT " (actual column %" PetscInt_FMT ") in row %" PetscInt_FMT " is not sorted", jj - i[ii], j[jj], ii);
5278         PetscCheck(j[jj] != j[jj - 1], PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column entry number %" PetscInt_FMT " (actual column %" PetscInt_FMT ") in row %" PetscInt_FMT " is identical to previous entry", jj - i[ii], j[jj], ii);
5279       }
5280     }
5281   }
5282   if (PetscDefined(USE_DEBUG)) {
5283     for (ii = 0; ii < aij->i[m]; ii++) {
5284       PetscCheck(j[ii] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative column index at location = %" PetscInt_FMT " index = %" PetscInt_FMT, ii, j[ii]);
5285       PetscCheck(j[ii] <= n - 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column index to large at location = %" PetscInt_FMT " index = %" PetscInt_FMT " last column = %" PetscInt_FMT, ii, j[ii], n - 1);
5286     }
5287   }
5288 
5289   PetscCall(MatAssemblyBegin(*mat, MAT_FINAL_ASSEMBLY));
5290   PetscCall(MatAssemblyEnd(*mat, MAT_FINAL_ASSEMBLY));
5291   PetscFunctionReturn(PETSC_SUCCESS);
5292 }
5293 
5294 /*@
5295   MatCreateSeqAIJFromTriple - Creates an sequential `MATSEQAIJ` matrix using matrix elements (in COO format)
5296   provided by the user.
5297 
5298   Collective
5299 
5300   Input Parameters:
5301 + comm - must be an MPI communicator of size 1
5302 . m    - number of rows
5303 . n    - number of columns
5304 . i    - row indices
5305 . j    - column indices
5306 . a    - matrix values
5307 . nz   - number of nonzeros
5308 - idx  - if the `i` and `j` indices start with 1 use `PETSC_TRUE` otherwise use `PETSC_FALSE`
5309 
5310   Output Parameter:
5311 . mat - the matrix
5312 
5313   Level: intermediate
5314 
5315   Example:
5316   For the following matrix, the input data expected is as shown (using 0 based indexing)
5317 .vb
5318         1 0 0
5319         2 0 3
5320         4 5 6
5321 
5322         i =  {0,1,1,2,2,2}
5323         j =  {0,0,2,0,1,2}
5324         v =  {1,2,3,4,5,6}
5325 .ve
5326 
5327   Note:
5328   Instead of using this function, users should also consider `MatSetPreallocationCOO()` and `MatSetValuesCOO()`, which allow repeated or remote entries,
5329   and are particularly useful in iterative applications.
5330 
5331 .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateAIJ()`, `MatCreateSeqAIJ()`, `MatCreateSeqAIJWithArrays()`, `MatMPIAIJSetPreallocationCSR()`, `MatSetValuesCOO()`, `MatSetPreallocationCOO()`
5332 @*/
5333 PetscErrorCode MatCreateSeqAIJFromTriple(MPI_Comm comm, PetscInt m, PetscInt n, PetscInt i[], PetscInt j[], PetscScalar a[], Mat *mat, PetscInt nz, PetscBool idx)
5334 {
5335   PetscInt ii, *nnz, one = 1, row, col;
5336 
5337   PetscFunctionBegin;
5338   PetscCall(PetscCalloc1(m, &nnz));
5339   for (ii = 0; ii < nz; ii++) nnz[i[ii] - !!idx] += 1;
5340   PetscCall(MatCreate(comm, mat));
5341   PetscCall(MatSetSizes(*mat, m, n, m, n));
5342   PetscCall(MatSetType(*mat, MATSEQAIJ));
5343   PetscCall(MatSeqAIJSetPreallocation_SeqAIJ(*mat, 0, nnz));
5344   for (ii = 0; ii < nz; ii++) {
5345     if (idx) {
5346       row = i[ii] - 1;
5347       col = j[ii] - 1;
5348     } else {
5349       row = i[ii];
5350       col = j[ii];
5351     }
5352     PetscCall(MatSetValues(*mat, one, &row, one, &col, &a[ii], ADD_VALUES));
5353   }
5354   PetscCall(MatAssemblyBegin(*mat, MAT_FINAL_ASSEMBLY));
5355   PetscCall(MatAssemblyEnd(*mat, MAT_FINAL_ASSEMBLY));
5356   PetscCall(PetscFree(nnz));
5357   PetscFunctionReturn(PETSC_SUCCESS);
5358 }
5359 
5360 PetscErrorCode MatSeqAIJInvalidateDiagonal(Mat A)
5361 {
5362   Mat_SeqAIJ *a = (Mat_SeqAIJ *)A->data;
5363 
5364   PetscFunctionBegin;
5365   a->idiagvalid  = PETSC_FALSE;
5366   a->ibdiagvalid = PETSC_FALSE;
5367 
5368   PetscCall(MatSeqAIJInvalidateDiagonal_Inode(A));
5369   PetscFunctionReturn(PETSC_SUCCESS);
5370 }
5371 
5372 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_SeqAIJ(MPI_Comm comm, Mat inmat, PetscInt n, MatReuse scall, Mat *outmat)
5373 {
5374   PetscFunctionBegin;
5375   PetscCall(MatCreateMPIMatConcatenateSeqMat_MPIAIJ(comm, inmat, n, scall, outmat));
5376   PetscFunctionReturn(PETSC_SUCCESS);
5377 }
5378 
5379 /*
5380  Permute A into C's *local* index space using rowemb,colemb.
5381  The embedding are supposed to be injections and the above implies that the range of rowemb is a subset
5382  of [0,m), colemb is in [0,n).
5383  If pattern == DIFFERENT_NONZERO_PATTERN, C is preallocated according to A.
5384  */
5385 PetscErrorCode MatSetSeqMat_SeqAIJ(Mat C, IS rowemb, IS colemb, MatStructure pattern, Mat B)
5386 {
5387   /* If making this function public, change the error returned in this function away from _PLIB. */
5388   Mat_SeqAIJ     *Baij;
5389   PetscBool       seqaij;
5390   PetscInt        m, n, *nz, i, j, count;
5391   PetscScalar     v;
5392   const PetscInt *rowindices, *colindices;
5393 
5394   PetscFunctionBegin;
5395   if (!B) PetscFunctionReturn(PETSC_SUCCESS);
5396   /* Check to make sure the target matrix (and embeddings) are compatible with C and each other. */
5397   PetscCall(PetscObjectBaseTypeCompare((PetscObject)B, MATSEQAIJ, &seqaij));
5398   PetscCheck(seqaij, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Input matrix is of wrong type");
5399   if (rowemb) {
5400     PetscCall(ISGetLocalSize(rowemb, &m));
5401     PetscCheck(m == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Row IS of size %" PetscInt_FMT " is incompatible with matrix row size %" PetscInt_FMT, m, B->rmap->n);
5402   } else {
5403     PetscCheck(C->rmap->n == B->rmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Input matrix is row-incompatible with the target matrix");
5404   }
5405   if (colemb) {
5406     PetscCall(ISGetLocalSize(colemb, &n));
5407     PetscCheck(n == B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Diag col IS of size %" PetscInt_FMT " is incompatible with input matrix col size %" PetscInt_FMT, n, B->cmap->n);
5408   } else {
5409     PetscCheck(C->cmap->n == B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Input matrix is col-incompatible with the target matrix");
5410   }
5411 
5412   Baij = (Mat_SeqAIJ *)B->data;
5413   if (pattern == DIFFERENT_NONZERO_PATTERN) {
5414     PetscCall(PetscMalloc1(B->rmap->n, &nz));
5415     for (i = 0; i < B->rmap->n; i++) nz[i] = Baij->i[i + 1] - Baij->i[i];
5416     PetscCall(MatSeqAIJSetPreallocation(C, 0, nz));
5417     PetscCall(PetscFree(nz));
5418   }
5419   if (pattern == SUBSET_NONZERO_PATTERN) PetscCall(MatZeroEntries(C));
5420   count      = 0;
5421   rowindices = NULL;
5422   colindices = NULL;
5423   if (rowemb) PetscCall(ISGetIndices(rowemb, &rowindices));
5424   if (colemb) PetscCall(ISGetIndices(colemb, &colindices));
5425   for (i = 0; i < B->rmap->n; i++) {
5426     PetscInt row;
5427     row = i;
5428     if (rowindices) row = rowindices[i];
5429     for (j = Baij->i[i]; j < Baij->i[i + 1]; j++) {
5430       PetscInt col;
5431       col = Baij->j[count];
5432       if (colindices) col = colindices[col];
5433       v = Baij->a[count];
5434       PetscCall(MatSetValues(C, 1, &row, 1, &col, &v, INSERT_VALUES));
5435       ++count;
5436     }
5437   }
5438   /* FIXME: set C's nonzerostate correctly. */
5439   /* Assembly for C is necessary. */
5440   C->preallocated  = PETSC_TRUE;
5441   C->assembled     = PETSC_TRUE;
5442   C->was_assembled = PETSC_FALSE;
5443   PetscFunctionReturn(PETSC_SUCCESS);
5444 }
5445 
5446 PetscErrorCode MatEliminateZeros_SeqAIJ(Mat A, PetscBool keep)
5447 {
5448   Mat_SeqAIJ *a  = (Mat_SeqAIJ *)A->data;
5449   MatScalar  *aa = a->a;
5450   PetscInt    m = A->rmap->n, fshift = 0, fshift_prev = 0, i, k;
5451   PetscInt   *ailen = a->ilen, *imax = a->imax, *ai = a->i, *aj = a->j, rmax = 0;
5452 
5453   PetscFunctionBegin;
5454   PetscCheck(A->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot eliminate zeros for unassembled matrix");
5455   if (m) rmax = ailen[0]; /* determine row with most nonzeros */
5456   for (i = 1; i <= m; i++) {
5457     /* move each nonzero entry back by the amount of zero slots (fshift) before it*/
5458     for (k = ai[i - 1]; k < ai[i]; k++) {
5459       if (aa[k] == 0 && (aj[k] != i - 1 || !keep)) fshift++;
5460       else {
5461         if (aa[k] == 0 && aj[k] == i - 1) PetscCall(PetscInfo(A, "Keep the diagonal zero at row %" PetscInt_FMT "\n", i - 1));
5462         aa[k - fshift] = aa[k];
5463         aj[k - fshift] = aj[k];
5464       }
5465     }
5466     ai[i - 1] -= fshift_prev; // safe to update ai[i-1] now since it will not be used in the next iteration
5467     fshift_prev = fshift;
5468     /* reset ilen and imax for each row */
5469     ailen[i - 1] = imax[i - 1] = ai[i] - fshift - ai[i - 1];
5470     a->nonzerorowcnt += ((ai[i] - fshift - ai[i - 1]) > 0);
5471     rmax = PetscMax(rmax, ailen[i - 1]);
5472   }
5473   if (fshift) {
5474     if (m) {
5475       ai[m] -= fshift;
5476       a->nz = ai[m];
5477     }
5478     PetscCall(PetscInfo(A, "Matrix size: %" PetscInt_FMT " X %" PetscInt_FMT "; zeros eliminated: %" PetscInt_FMT "; nonzeros left: %" PetscInt_FMT "\n", m, A->cmap->n, fshift, a->nz));
5479     A->nonzerostate++;
5480     A->info.nz_unneeded += (PetscReal)fshift;
5481     a->rmax = rmax;
5482     if (a->inode.use && a->inode.checked) PetscCall(MatSeqAIJCheckInode(A));
5483     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
5484     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
5485   }
5486   PetscFunctionReturn(PETSC_SUCCESS);
5487 }
5488 
5489 PetscFunctionList MatSeqAIJList = NULL;
5490 
5491 /*@
5492   MatSeqAIJSetType - Converts a `MATSEQAIJ` matrix to a subtype
5493 
5494   Collective
5495 
5496   Input Parameters:
5497 + mat    - the matrix object
5498 - matype - matrix type
5499 
5500   Options Database Key:
5501 . -mat_seqaij_type  <method> - for example seqaijcrl
5502 
5503   Level: intermediate
5504 
5505 .seealso: [](ch_matrices), `Mat`, `PCSetType()`, `VecSetType()`, `MatCreate()`, `MatType`
5506 @*/
5507 PetscErrorCode MatSeqAIJSetType(Mat mat, MatType matype)
5508 {
5509   PetscBool sametype;
5510   PetscErrorCode (*r)(Mat, MatType, MatReuse, Mat *);
5511 
5512   PetscFunctionBegin;
5513   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
5514   PetscCall(PetscObjectTypeCompare((PetscObject)mat, matype, &sametype));
5515   if (sametype) PetscFunctionReturn(PETSC_SUCCESS);
5516 
5517   PetscCall(PetscFunctionListFind(MatSeqAIJList, matype, &r));
5518   PetscCheck(r, PetscObjectComm((PetscObject)mat), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown Mat type given: %s", matype);
5519   PetscCall((*r)(mat, matype, MAT_INPLACE_MATRIX, &mat));
5520   PetscFunctionReturn(PETSC_SUCCESS);
5521 }
5522 
5523 /*@C
5524   MatSeqAIJRegister -  - Adds a new sub-matrix type for sequential `MATSEQAIJ` matrices
5525 
5526   Not Collective, No Fortran Support
5527 
5528   Input Parameters:
5529 + sname    - name of a new user-defined matrix type, for example `MATSEQAIJCRL`
5530 - function - routine to convert to subtype
5531 
5532   Level: advanced
5533 
5534   Notes:
5535   `MatSeqAIJRegister()` may be called multiple times to add several user-defined solvers.
5536 
5537   Then, your matrix can be chosen with the procedural interface at runtime via the option
5538 $     -mat_seqaij_type my_mat
5539 
5540 .seealso: [](ch_matrices), `Mat`, `MatSeqAIJRegisterAll()`
5541 @*/
5542 PetscErrorCode MatSeqAIJRegister(const char sname[], PetscErrorCode (*function)(Mat, MatType, MatReuse, Mat *))
5543 {
5544   PetscFunctionBegin;
5545   PetscCall(MatInitializePackage());
5546   PetscCall(PetscFunctionListAdd(&MatSeqAIJList, sname, function));
5547   PetscFunctionReturn(PETSC_SUCCESS);
5548 }
5549 
5550 PetscBool MatSeqAIJRegisterAllCalled = PETSC_FALSE;
5551 
5552 /*@C
5553   MatSeqAIJRegisterAll - Registers all of the matrix subtypes of `MATSSEQAIJ`
5554 
5555   Not Collective
5556 
5557   Level: advanced
5558 
5559   Note:
5560   This registers the versions of `MATSEQAIJ` for GPUs
5561 
5562 .seealso: [](ch_matrices), `Mat`, `MatRegisterAll()`, `MatSeqAIJRegister()`
5563 @*/
5564 PetscErrorCode MatSeqAIJRegisterAll(void)
5565 {
5566   PetscFunctionBegin;
5567   if (MatSeqAIJRegisterAllCalled) PetscFunctionReturn(PETSC_SUCCESS);
5568   MatSeqAIJRegisterAllCalled = PETSC_TRUE;
5569 
5570   PetscCall(MatSeqAIJRegister(MATSEQAIJCRL, MatConvert_SeqAIJ_SeqAIJCRL));
5571   PetscCall(MatSeqAIJRegister(MATSEQAIJPERM, MatConvert_SeqAIJ_SeqAIJPERM));
5572   PetscCall(MatSeqAIJRegister(MATSEQAIJSELL, MatConvert_SeqAIJ_SeqAIJSELL));
5573 #if defined(PETSC_HAVE_MKL_SPARSE)
5574   PetscCall(MatSeqAIJRegister(MATSEQAIJMKL, MatConvert_SeqAIJ_SeqAIJMKL));
5575 #endif
5576 #if defined(PETSC_HAVE_CUDA)
5577   PetscCall(MatSeqAIJRegister(MATSEQAIJCUSPARSE, MatConvert_SeqAIJ_SeqAIJCUSPARSE));
5578 #endif
5579 #if defined(PETSC_HAVE_HIP)
5580   PetscCall(MatSeqAIJRegister(MATSEQAIJHIPSPARSE, MatConvert_SeqAIJ_SeqAIJHIPSPARSE));
5581 #endif
5582 #if defined(PETSC_HAVE_KOKKOS_KERNELS)
5583   PetscCall(MatSeqAIJRegister(MATSEQAIJKOKKOS, MatConvert_SeqAIJ_SeqAIJKokkos));
5584 #endif
5585 #if defined(PETSC_HAVE_VIENNACL) && defined(PETSC_HAVE_VIENNACL_NO_CUDA)
5586   PetscCall(MatSeqAIJRegister(MATMPIAIJVIENNACL, MatConvert_SeqAIJ_SeqAIJViennaCL));
5587 #endif
5588   PetscFunctionReturn(PETSC_SUCCESS);
5589 }
5590 
5591 /*
5592     Special version for direct calls from Fortran
5593 */
5594 #if defined(PETSC_HAVE_FORTRAN_CAPS)
5595   #define matsetvaluesseqaij_ MATSETVALUESSEQAIJ
5596 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
5597   #define matsetvaluesseqaij_ matsetvaluesseqaij
5598 #endif
5599 
5600 /* Change these macros so can be used in void function */
5601 
5602 /* Change these macros so can be used in void function */
5603 /* Identical to PetscCallVoid, except it assigns to *_ierr */
5604 #undef PetscCall
5605 #define PetscCall(...) \
5606   do { \
5607     PetscErrorCode ierr_msv_mpiaij = __VA_ARGS__; \
5608     if (PetscUnlikely(ierr_msv_mpiaij)) { \
5609       *_ierr = PetscError(PETSC_COMM_SELF, __LINE__, PETSC_FUNCTION_NAME, __FILE__, ierr_msv_mpiaij, PETSC_ERROR_REPEAT, " "); \
5610       return; \
5611     } \
5612   } while (0)
5613 
5614 #undef SETERRQ
5615 #define SETERRQ(comm, ierr, ...) \
5616   do { \
5617     *_ierr = PetscError(comm, __LINE__, PETSC_FUNCTION_NAME, __FILE__, ierr, PETSC_ERROR_INITIAL, __VA_ARGS__); \
5618     return; \
5619   } while (0)
5620 
5621 PETSC_EXTERN void matsetvaluesseqaij_(Mat *AA, PetscInt *mm, const PetscInt im[], PetscInt *nn, const PetscInt in[], const PetscScalar v[], InsertMode *isis, PetscErrorCode *_ierr)
5622 {
5623   Mat         A = *AA;
5624   PetscInt    m = *mm, n = *nn;
5625   InsertMode  is = *isis;
5626   Mat_SeqAIJ *a  = (Mat_SeqAIJ *)A->data;
5627   PetscInt   *rp, k, low, high, t, ii, row, nrow, i, col, l, rmax, N;
5628   PetscInt   *imax, *ai, *ailen;
5629   PetscInt   *aj, nonew = a->nonew, lastcol = -1;
5630   MatScalar  *ap, value, *aa;
5631   PetscBool   ignorezeroentries = a->ignorezeroentries;
5632   PetscBool   roworiented       = a->roworiented;
5633 
5634   PetscFunctionBegin;
5635   MatCheckPreallocated(A, 1);
5636   imax  = a->imax;
5637   ai    = a->i;
5638   ailen = a->ilen;
5639   aj    = a->j;
5640   aa    = a->a;
5641 
5642   for (k = 0; k < m; k++) { /* loop over added rows */
5643     row = im[k];
5644     if (row < 0) continue;
5645     PetscCheck(row < A->rmap->n, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Row too large");
5646     rp   = aj + ai[row];
5647     ap   = aa + ai[row];
5648     rmax = imax[row];
5649     nrow = ailen[row];
5650     low  = 0;
5651     high = nrow;
5652     for (l = 0; l < n; l++) { /* loop over added columns */
5653       if (in[l] < 0) continue;
5654       PetscCheck(in[l] < A->cmap->n, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Column too large");
5655       col = in[l];
5656       if (roworiented) value = v[l + k * n];
5657       else value = v[k + l * m];
5658 
5659       if (value == 0.0 && ignorezeroentries && (is == ADD_VALUES)) continue;
5660 
5661       if (col <= lastcol) low = 0;
5662       else high = nrow;
5663       lastcol = col;
5664       while (high - low > 5) {
5665         t = (low + high) / 2;
5666         if (rp[t] > col) high = t;
5667         else low = t;
5668       }
5669       for (i = low; i < high; i++) {
5670         if (rp[i] > col) break;
5671         if (rp[i] == col) {
5672           if (is == ADD_VALUES) ap[i] += value;
5673           else ap[i] = value;
5674           goto noinsert;
5675         }
5676       }
5677       if (value == 0.0 && ignorezeroentries) goto noinsert;
5678       if (nonew == 1) goto noinsert;
5679       PetscCheck(nonew != -1, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero in the matrix");
5680       MatSeqXAIJReallocateAIJ(A, A->rmap->n, 1, nrow, row, col, rmax, aa, ai, aj, rp, ap, imax, nonew, MatScalar);
5681       N = nrow++ - 1;
5682       a->nz++;
5683       high++;
5684       /* shift up all the later entries in this row */
5685       for (ii = N; ii >= i; ii--) {
5686         rp[ii + 1] = rp[ii];
5687         ap[ii + 1] = ap[ii];
5688       }
5689       rp[i] = col;
5690       ap[i] = value;
5691     noinsert:;
5692       low = i + 1;
5693     }
5694     ailen[row] = nrow;
5695   }
5696   PetscFunctionReturnVoid();
5697 }
5698 /* Undefining these here since they were redefined from their original definition above! No
5699  * other PETSc functions should be defined past this point, as it is impossible to recover the
5700  * original definitions */
5701 #undef PetscCall
5702 #undef SETERRQ
5703