xref: /petsc/src/mat/impls/baij/seq/baij.c (revision 3d1372b23971def3aed7e3dc12090948688700a0)
1 /*
2     Defines the basic matrix operations for the BAIJ (compressed row)
3   matrix storage format.
4 */
5 #include <../src/mat/impls/baij/seq/baij.h> /*I   "petscmat.h"  I*/
6 #include <petscblaslapack.h>
7 #include <petsc/private/kernels/blockinvert.h>
8 #include <petsc/private/kernels/blockmatmult.h>
9 
10 /* defines MatSetValues_Seq_Hash(), MatAssemblyEnd_Seq_Hash(), MatSetUp_Seq_Hash() */
11 #define TYPE BAIJ
12 #define TYPE_BS
13 #include "../src/mat/impls/aij/seq/seqhashmatsetvalues.h"
14 #undef TYPE_BS
15 #define TYPE_BS _BS
16 #define TYPE_BS_ON
17 #include "../src/mat/impls/aij/seq/seqhashmatsetvalues.h"
18 #undef TYPE_BS
19 #include "../src/mat/impls/aij/seq/seqhashmat.h"
20 #undef TYPE
21 #undef TYPE_BS_ON
22 
23 #if defined(PETSC_HAVE_HYPRE)
24 PETSC_INTERN PetscErrorCode MatConvert_AIJ_HYPRE(Mat, MatType, MatReuse, Mat *);
25 #endif
26 
27 #if defined(PETSC_HAVE_MKL_SPARSE_OPTIMIZE)
28 PETSC_INTERN PetscErrorCode MatConvert_SeqBAIJ_SeqBAIJMKL(Mat, MatType, MatReuse, Mat *);
29 #endif
30 PETSC_INTERN PetscErrorCode MatConvert_XAIJ_IS(Mat, MatType, MatReuse, Mat *);
31 
32 MatGetDiagonalMarkers(SeqBAIJ, A->rmap->bs)
33 
34 static PetscErrorCode MatGetColumnReductions_SeqBAIJ(Mat A, PetscInt type, PetscReal *reductions)
35 {
36   Mat_SeqBAIJ *a_aij = (Mat_SeqBAIJ *)A->data;
37   PetscInt     m, n, ib, jb, bs = A->rmap->bs;
38   MatScalar   *a_val = a_aij->a;
39 
40   PetscFunctionBegin;
41   PetscCall(MatGetSize(A, &m, &n));
42   PetscCall(PetscArrayzero(reductions, n));
43   if (type == NORM_2) {
44     for (PetscInt i = a_aij->i[0]; i < a_aij->i[A->rmap->n / bs]; i++) {
45       for (jb = 0; jb < bs; jb++) {
46         for (ib = 0; ib < bs; ib++) {
47           reductions[A->cmap->rstart + a_aij->j[i] * bs + jb] += PetscAbsScalar(*a_val * *a_val);
48           a_val++;
49         }
50       }
51     }
52   } else if (type == NORM_1) {
53     for (PetscInt i = a_aij->i[0]; i < a_aij->i[A->rmap->n / bs]; i++) {
54       for (jb = 0; jb < bs; jb++) {
55         for (ib = 0; ib < bs; ib++) {
56           reductions[A->cmap->rstart + a_aij->j[i] * bs + jb] += PetscAbsScalar(*a_val);
57           a_val++;
58         }
59       }
60     }
61   } else if (type == NORM_INFINITY) {
62     for (PetscInt i = a_aij->i[0]; i < a_aij->i[A->rmap->n / bs]; i++) {
63       for (jb = 0; jb < bs; jb++) {
64         for (ib = 0; ib < bs; ib++) {
65           PetscInt col    = A->cmap->rstart + a_aij->j[i] * bs + jb;
66           reductions[col] = PetscMax(PetscAbsScalar(*a_val), reductions[col]);
67           a_val++;
68         }
69       }
70     }
71   } else if (type == REDUCTION_SUM_REALPART || type == REDUCTION_MEAN_REALPART) {
72     for (PetscInt i = a_aij->i[0]; i < a_aij->i[A->rmap->n / bs]; i++) {
73       for (jb = 0; jb < bs; jb++) {
74         for (ib = 0; ib < bs; ib++) {
75           reductions[A->cmap->rstart + a_aij->j[i] * bs + jb] += PetscRealPart(*a_val);
76           a_val++;
77         }
78       }
79     }
80   } else if (type == REDUCTION_SUM_IMAGINARYPART || type == REDUCTION_MEAN_IMAGINARYPART) {
81     for (PetscInt i = a_aij->i[0]; i < a_aij->i[A->rmap->n / bs]; i++) {
82       for (jb = 0; jb < bs; jb++) {
83         for (ib = 0; ib < bs; ib++) {
84           reductions[A->cmap->rstart + a_aij->j[i] * bs + jb] += PetscImaginaryPart(*a_val);
85           a_val++;
86         }
87       }
88     }
89   } else SETERRQ(PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Unknown reduction type");
90   if (type == NORM_2) {
91     for (PetscInt i = 0; i < n; i++) reductions[i] = PetscSqrtReal(reductions[i]);
92   } else if (type == REDUCTION_MEAN_REALPART || type == REDUCTION_MEAN_IMAGINARYPART) {
93     for (PetscInt i = 0; i < n; i++) reductions[i] /= m;
94   }
95   PetscFunctionReturn(PETSC_SUCCESS);
96 }
97 
98 static PetscErrorCode MatInvertBlockDiagonal_SeqBAIJ(Mat A, const PetscScalar **values)
99 {
100   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ *)A->data;
101   PetscInt        i, bs = A->rmap->bs, mbs = a->mbs, ipvt[5], bs2 = bs * bs, *v_pivots;
102   MatScalar      *v     = a->a, *odiag, *diag, work[25], *v_work;
103   PetscReal       shift = 0.0;
104   PetscBool       allowzeropivot, zeropivotdetected = PETSC_FALSE;
105   const PetscInt *adiag;
106 
107   PetscFunctionBegin;
108   allowzeropivot = PetscNot(A->erroriffailure);
109 
110   if (a->idiagvalid) {
111     if (values) *values = a->idiag;
112     PetscFunctionReturn(PETSC_SUCCESS);
113   }
114   PetscCall(MatGetDiagonalMarkers_SeqBAIJ(A, &adiag, NULL));
115   if (!a->idiag) PetscCall(PetscMalloc1(bs2 * mbs, &a->idiag));
116   diag = a->idiag;
117   if (values) *values = a->idiag;
118   /* factor and invert each block */
119   switch (bs) {
120   case 1:
121     for (i = 0; i < mbs; i++) {
122       odiag   = v + 1 * adiag[i];
123       diag[0] = odiag[0];
124 
125       if (PetscAbsScalar(diag[0] + shift) < PETSC_MACHINE_EPSILON) {
126         PetscCheck(allowzeropivot, PETSC_COMM_SELF, PETSC_ERR_MAT_LU_ZRPVT, "Zero pivot, row %" PetscInt_FMT " pivot value %g tolerance %g", i, (double)PetscAbsScalar(diag[0]), (double)PETSC_MACHINE_EPSILON);
127         A->factorerrortype             = MAT_FACTOR_NUMERIC_ZEROPIVOT;
128         A->factorerror_zeropivot_value = PetscAbsScalar(diag[0]);
129         A->factorerror_zeropivot_row   = i;
130         PetscCall(PetscInfo(A, "Zero pivot, row %" PetscInt_FMT "\n", i));
131       }
132 
133       diag[0] = (PetscScalar)1.0 / (diag[0] + shift);
134       diag += 1;
135     }
136     break;
137   case 2:
138     for (i = 0; i < mbs; i++) {
139       odiag   = v + 4 * adiag[i];
140       diag[0] = odiag[0];
141       diag[1] = odiag[1];
142       diag[2] = odiag[2];
143       diag[3] = odiag[3];
144       PetscCall(PetscKernel_A_gets_inverse_A_2(diag, shift, allowzeropivot, &zeropivotdetected));
145       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
146       diag += 4;
147     }
148     break;
149   case 3:
150     for (i = 0; i < mbs; i++) {
151       odiag   = v + 9 * adiag[i];
152       diag[0] = odiag[0];
153       diag[1] = odiag[1];
154       diag[2] = odiag[2];
155       diag[3] = odiag[3];
156       diag[4] = odiag[4];
157       diag[5] = odiag[5];
158       diag[6] = odiag[6];
159       diag[7] = odiag[7];
160       diag[8] = odiag[8];
161       PetscCall(PetscKernel_A_gets_inverse_A_3(diag, shift, allowzeropivot, &zeropivotdetected));
162       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
163       diag += 9;
164     }
165     break;
166   case 4:
167     for (i = 0; i < mbs; i++) {
168       odiag = v + 16 * adiag[i];
169       PetscCall(PetscArraycpy(diag, odiag, 16));
170       PetscCall(PetscKernel_A_gets_inverse_A_4(diag, shift, allowzeropivot, &zeropivotdetected));
171       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
172       diag += 16;
173     }
174     break;
175   case 5:
176     for (i = 0; i < mbs; i++) {
177       odiag = v + 25 * adiag[i];
178       PetscCall(PetscArraycpy(diag, odiag, 25));
179       PetscCall(PetscKernel_A_gets_inverse_A_5(diag, ipvt, work, shift, allowzeropivot, &zeropivotdetected));
180       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
181       diag += 25;
182     }
183     break;
184   case 6:
185     for (i = 0; i < mbs; i++) {
186       odiag = v + 36 * adiag[i];
187       PetscCall(PetscArraycpy(diag, odiag, 36));
188       PetscCall(PetscKernel_A_gets_inverse_A_6(diag, shift, allowzeropivot, &zeropivotdetected));
189       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
190       diag += 36;
191     }
192     break;
193   case 7:
194     for (i = 0; i < mbs; i++) {
195       odiag = v + 49 * adiag[i];
196       PetscCall(PetscArraycpy(diag, odiag, 49));
197       PetscCall(PetscKernel_A_gets_inverse_A_7(diag, shift, allowzeropivot, &zeropivotdetected));
198       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
199       diag += 49;
200     }
201     break;
202   default:
203     PetscCall(PetscMalloc2(bs, &v_work, bs, &v_pivots));
204     for (i = 0; i < mbs; i++) {
205       odiag = v + bs2 * adiag[i];
206       PetscCall(PetscArraycpy(diag, odiag, bs2));
207       PetscCall(PetscKernel_A_gets_inverse_A(bs, diag, v_pivots, v_work, allowzeropivot, &zeropivotdetected));
208       if (zeropivotdetected) A->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
209       diag += bs2;
210     }
211     PetscCall(PetscFree2(v_work, v_pivots));
212   }
213   a->idiagvalid = PETSC_TRUE;
214   PetscFunctionReturn(PETSC_SUCCESS);
215 }
216 
217 static PetscErrorCode MatSOR_SeqBAIJ(Mat A, Vec bb, PetscReal omega, MatSORType flag, PetscReal fshift, PetscInt its, PetscInt lits, Vec xx)
218 {
219   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ *)A->data;
220   PetscScalar       *x, *work, *w, *workt, *t;
221   const MatScalar   *v, *aa = a->a, *idiag;
222   const PetscScalar *b, *xb;
223   PetscScalar        s[7], xw[7] = {0}; /* avoid some compilers thinking xw is uninitialized */
224   PetscInt           m = a->mbs, i, i2, nz, bs = A->rmap->bs, bs2 = bs * bs, k, j, idx, it;
225   const PetscInt    *diag, *ai = a->i, *aj = a->j, *vi;
226 
227   PetscFunctionBegin;
228   its = its * lits;
229   PetscCheck(!(flag & SOR_EISENSTAT), PETSC_COMM_SELF, PETSC_ERR_SUP, "No support yet for Eisenstat");
230   PetscCheck(its > 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Relaxation requires global its %" PetscInt_FMT " and local its %" PetscInt_FMT " both positive", its, lits);
231   PetscCheck(!fshift, PETSC_COMM_SELF, PETSC_ERR_SUP, "No support for diagonal shift");
232   PetscCheck(omega == 1.0, PETSC_COMM_SELF, PETSC_ERR_SUP, "No support for non-trivial relaxation factor");
233   PetscCheck(!(flag & SOR_APPLY_UPPER) && !(flag & SOR_APPLY_LOWER), PETSC_COMM_SELF, PETSC_ERR_SUP, "No support for applying upper or lower triangular parts");
234 
235   if (!a->idiagvalid) PetscCall(MatInvertBlockDiagonal(A, NULL));
236 
237   if (!m) PetscFunctionReturn(PETSC_SUCCESS);
238   diag  = a->diag;
239   idiag = a->idiag;
240   k     = PetscMax(A->rmap->n, A->cmap->n);
241   if (!a->mult_work) PetscCall(PetscMalloc1(k + 1, &a->mult_work));
242   if (!a->sor_workt) PetscCall(PetscMalloc1(k, &a->sor_workt));
243   if (!a->sor_work) PetscCall(PetscMalloc1(bs, &a->sor_work));
244   work = a->mult_work;
245   t    = a->sor_workt;
246   w    = a->sor_work;
247 
248   PetscCall(VecGetArray(xx, &x));
249   PetscCall(VecGetArrayRead(bb, &b));
250 
251   if (flag & SOR_ZERO_INITIAL_GUESS) {
252     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
253       switch (bs) {
254       case 1:
255         PetscKernel_v_gets_A_times_w_1(x, idiag, b);
256         t[0] = b[0];
257         i2   = 1;
258         idiag += 1;
259         for (i = 1; i < m; i++) {
260           v    = aa + ai[i];
261           vi   = aj + ai[i];
262           nz   = diag[i] - ai[i];
263           s[0] = b[i2];
264           for (j = 0; j < nz; j++) {
265             xw[0] = x[vi[j]];
266             PetscKernel_v_gets_v_minus_A_times_w_1(s, (v + j), xw);
267           }
268           t[i2] = s[0];
269           PetscKernel_v_gets_A_times_w_1(xw, idiag, s);
270           x[i2] = xw[0];
271           idiag += 1;
272           i2 += 1;
273         }
274         break;
275       case 2:
276         PetscKernel_v_gets_A_times_w_2(x, idiag, b);
277         t[0] = b[0];
278         t[1] = b[1];
279         i2   = 2;
280         idiag += 4;
281         for (i = 1; i < m; i++) {
282           v    = aa + 4 * ai[i];
283           vi   = aj + ai[i];
284           nz   = diag[i] - ai[i];
285           s[0] = b[i2];
286           s[1] = b[i2 + 1];
287           for (j = 0; j < nz; j++) {
288             idx   = 2 * vi[j];
289             it    = 4 * j;
290             xw[0] = x[idx];
291             xw[1] = x[1 + idx];
292             PetscKernel_v_gets_v_minus_A_times_w_2(s, (v + it), xw);
293           }
294           t[i2]     = s[0];
295           t[i2 + 1] = s[1];
296           PetscKernel_v_gets_A_times_w_2(xw, idiag, s);
297           x[i2]     = xw[0];
298           x[i2 + 1] = xw[1];
299           idiag += 4;
300           i2 += 2;
301         }
302         break;
303       case 3:
304         PetscKernel_v_gets_A_times_w_3(x, idiag, b);
305         t[0] = b[0];
306         t[1] = b[1];
307         t[2] = b[2];
308         i2   = 3;
309         idiag += 9;
310         for (i = 1; i < m; i++) {
311           v    = aa + 9 * ai[i];
312           vi   = aj + ai[i];
313           nz   = diag[i] - ai[i];
314           s[0] = b[i2];
315           s[1] = b[i2 + 1];
316           s[2] = b[i2 + 2];
317           while (nz--) {
318             idx   = 3 * (*vi++);
319             xw[0] = x[idx];
320             xw[1] = x[1 + idx];
321             xw[2] = x[2 + idx];
322             PetscKernel_v_gets_v_minus_A_times_w_3(s, v, xw);
323             v += 9;
324           }
325           t[i2]     = s[0];
326           t[i2 + 1] = s[1];
327           t[i2 + 2] = s[2];
328           PetscKernel_v_gets_A_times_w_3(xw, idiag, s);
329           x[i2]     = xw[0];
330           x[i2 + 1] = xw[1];
331           x[i2 + 2] = xw[2];
332           idiag += 9;
333           i2 += 3;
334         }
335         break;
336       case 4:
337         PetscKernel_v_gets_A_times_w_4(x, idiag, b);
338         t[0] = b[0];
339         t[1] = b[1];
340         t[2] = b[2];
341         t[3] = b[3];
342         i2   = 4;
343         idiag += 16;
344         for (i = 1; i < m; i++) {
345           v    = aa + 16 * ai[i];
346           vi   = aj + ai[i];
347           nz   = diag[i] - ai[i];
348           s[0] = b[i2];
349           s[1] = b[i2 + 1];
350           s[2] = b[i2 + 2];
351           s[3] = b[i2 + 3];
352           while (nz--) {
353             idx   = 4 * (*vi++);
354             xw[0] = x[idx];
355             xw[1] = x[1 + idx];
356             xw[2] = x[2 + idx];
357             xw[3] = x[3 + idx];
358             PetscKernel_v_gets_v_minus_A_times_w_4(s, v, xw);
359             v += 16;
360           }
361           t[i2]     = s[0];
362           t[i2 + 1] = s[1];
363           t[i2 + 2] = s[2];
364           t[i2 + 3] = s[3];
365           PetscKernel_v_gets_A_times_w_4(xw, idiag, s);
366           x[i2]     = xw[0];
367           x[i2 + 1] = xw[1];
368           x[i2 + 2] = xw[2];
369           x[i2 + 3] = xw[3];
370           idiag += 16;
371           i2 += 4;
372         }
373         break;
374       case 5:
375         PetscKernel_v_gets_A_times_w_5(x, idiag, b);
376         t[0] = b[0];
377         t[1] = b[1];
378         t[2] = b[2];
379         t[3] = b[3];
380         t[4] = b[4];
381         i2   = 5;
382         idiag += 25;
383         for (i = 1; i < m; i++) {
384           v    = aa + 25 * ai[i];
385           vi   = aj + ai[i];
386           nz   = diag[i] - ai[i];
387           s[0] = b[i2];
388           s[1] = b[i2 + 1];
389           s[2] = b[i2 + 2];
390           s[3] = b[i2 + 3];
391           s[4] = b[i2 + 4];
392           while (nz--) {
393             idx   = 5 * (*vi++);
394             xw[0] = x[idx];
395             xw[1] = x[1 + idx];
396             xw[2] = x[2 + idx];
397             xw[3] = x[3 + idx];
398             xw[4] = x[4 + idx];
399             PetscKernel_v_gets_v_minus_A_times_w_5(s, v, xw);
400             v += 25;
401           }
402           t[i2]     = s[0];
403           t[i2 + 1] = s[1];
404           t[i2 + 2] = s[2];
405           t[i2 + 3] = s[3];
406           t[i2 + 4] = s[4];
407           PetscKernel_v_gets_A_times_w_5(xw, idiag, s);
408           x[i2]     = xw[0];
409           x[i2 + 1] = xw[1];
410           x[i2 + 2] = xw[2];
411           x[i2 + 3] = xw[3];
412           x[i2 + 4] = xw[4];
413           idiag += 25;
414           i2 += 5;
415         }
416         break;
417       case 6:
418         PetscKernel_v_gets_A_times_w_6(x, idiag, b);
419         t[0] = b[0];
420         t[1] = b[1];
421         t[2] = b[2];
422         t[3] = b[3];
423         t[4] = b[4];
424         t[5] = b[5];
425         i2   = 6;
426         idiag += 36;
427         for (i = 1; i < m; i++) {
428           v    = aa + 36 * ai[i];
429           vi   = aj + ai[i];
430           nz   = diag[i] - ai[i];
431           s[0] = b[i2];
432           s[1] = b[i2 + 1];
433           s[2] = b[i2 + 2];
434           s[3] = b[i2 + 3];
435           s[4] = b[i2 + 4];
436           s[5] = b[i2 + 5];
437           while (nz--) {
438             idx   = 6 * (*vi++);
439             xw[0] = x[idx];
440             xw[1] = x[1 + idx];
441             xw[2] = x[2 + idx];
442             xw[3] = x[3 + idx];
443             xw[4] = x[4 + idx];
444             xw[5] = x[5 + idx];
445             PetscKernel_v_gets_v_minus_A_times_w_6(s, v, xw);
446             v += 36;
447           }
448           t[i2]     = s[0];
449           t[i2 + 1] = s[1];
450           t[i2 + 2] = s[2];
451           t[i2 + 3] = s[3];
452           t[i2 + 4] = s[4];
453           t[i2 + 5] = s[5];
454           PetscKernel_v_gets_A_times_w_6(xw, idiag, s);
455           x[i2]     = xw[0];
456           x[i2 + 1] = xw[1];
457           x[i2 + 2] = xw[2];
458           x[i2 + 3] = xw[3];
459           x[i2 + 4] = xw[4];
460           x[i2 + 5] = xw[5];
461           idiag += 36;
462           i2 += 6;
463         }
464         break;
465       case 7:
466         PetscKernel_v_gets_A_times_w_7(x, idiag, b);
467         t[0] = b[0];
468         t[1] = b[1];
469         t[2] = b[2];
470         t[3] = b[3];
471         t[4] = b[4];
472         t[5] = b[5];
473         t[6] = b[6];
474         i2   = 7;
475         idiag += 49;
476         for (i = 1; i < m; i++) {
477           v    = aa + 49 * ai[i];
478           vi   = aj + ai[i];
479           nz   = diag[i] - ai[i];
480           s[0] = b[i2];
481           s[1] = b[i2 + 1];
482           s[2] = b[i2 + 2];
483           s[3] = b[i2 + 3];
484           s[4] = b[i2 + 4];
485           s[5] = b[i2 + 5];
486           s[6] = b[i2 + 6];
487           while (nz--) {
488             idx   = 7 * (*vi++);
489             xw[0] = x[idx];
490             xw[1] = x[1 + idx];
491             xw[2] = x[2 + idx];
492             xw[3] = x[3 + idx];
493             xw[4] = x[4 + idx];
494             xw[5] = x[5 + idx];
495             xw[6] = x[6 + idx];
496             PetscKernel_v_gets_v_minus_A_times_w_7(s, v, xw);
497             v += 49;
498           }
499           t[i2]     = s[0];
500           t[i2 + 1] = s[1];
501           t[i2 + 2] = s[2];
502           t[i2 + 3] = s[3];
503           t[i2 + 4] = s[4];
504           t[i2 + 5] = s[5];
505           t[i2 + 6] = s[6];
506           PetscKernel_v_gets_A_times_w_7(xw, idiag, s);
507           x[i2]     = xw[0];
508           x[i2 + 1] = xw[1];
509           x[i2 + 2] = xw[2];
510           x[i2 + 3] = xw[3];
511           x[i2 + 4] = xw[4];
512           x[i2 + 5] = xw[5];
513           x[i2 + 6] = xw[6];
514           idiag += 49;
515           i2 += 7;
516         }
517         break;
518       default:
519         PetscKernel_w_gets_Ar_times_v(bs, bs, b, idiag, x);
520         PetscCall(PetscArraycpy(t, b, bs));
521         i2 = bs;
522         idiag += bs2;
523         for (i = 1; i < m; i++) {
524           v  = aa + bs2 * ai[i];
525           vi = aj + ai[i];
526           nz = diag[i] - ai[i];
527 
528           PetscCall(PetscArraycpy(w, b + i2, bs));
529           /* copy all rows of x that are needed into contiguous space */
530           workt = work;
531           for (j = 0; j < nz; j++) {
532             PetscCall(PetscArraycpy(workt, x + bs * (*vi++), bs));
533             workt += bs;
534           }
535           PetscKernel_w_gets_w_minus_Ar_times_v(bs, bs * nz, w, v, work);
536           PetscCall(PetscArraycpy(t + i2, w, bs));
537           PetscKernel_w_gets_Ar_times_v(bs, bs, w, idiag, x + i2);
538 
539           idiag += bs2;
540           i2 += bs;
541         }
542         break;
543       }
544       /* for logging purposes assume number of nonzero in lower half is 1/2 of total */
545       PetscCall(PetscLogFlops(1.0 * bs2 * a->nz));
546       xb = t;
547     } else xb = b;
548     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {
549       idiag = a->idiag + bs2 * (a->mbs - 1);
550       i2    = bs * (m - 1);
551       switch (bs) {
552       case 1:
553         s[0] = xb[i2];
554         PetscKernel_v_gets_A_times_w_1(xw, idiag, s);
555         x[i2] = xw[0];
556         i2 -= 1;
557         for (i = m - 2; i >= 0; i--) {
558           v    = aa + (diag[i] + 1);
559           vi   = aj + diag[i] + 1;
560           nz   = ai[i + 1] - diag[i] - 1;
561           s[0] = xb[i2];
562           for (j = 0; j < nz; j++) {
563             xw[0] = x[vi[j]];
564             PetscKernel_v_gets_v_minus_A_times_w_1(s, (v + j), xw);
565           }
566           PetscKernel_v_gets_A_times_w_1(xw, idiag, s);
567           x[i2] = xw[0];
568           idiag -= 1;
569           i2 -= 1;
570         }
571         break;
572       case 2:
573         s[0] = xb[i2];
574         s[1] = xb[i2 + 1];
575         PetscKernel_v_gets_A_times_w_2(xw, idiag, s);
576         x[i2]     = xw[0];
577         x[i2 + 1] = xw[1];
578         i2 -= 2;
579         idiag -= 4;
580         for (i = m - 2; i >= 0; i--) {
581           v    = aa + 4 * (diag[i] + 1);
582           vi   = aj + diag[i] + 1;
583           nz   = ai[i + 1] - diag[i] - 1;
584           s[0] = xb[i2];
585           s[1] = xb[i2 + 1];
586           for (j = 0; j < nz; j++) {
587             idx   = 2 * vi[j];
588             it    = 4 * j;
589             xw[0] = x[idx];
590             xw[1] = x[1 + idx];
591             PetscKernel_v_gets_v_minus_A_times_w_2(s, (v + it), xw);
592           }
593           PetscKernel_v_gets_A_times_w_2(xw, idiag, s);
594           x[i2]     = xw[0];
595           x[i2 + 1] = xw[1];
596           idiag -= 4;
597           i2 -= 2;
598         }
599         break;
600       case 3:
601         s[0] = xb[i2];
602         s[1] = xb[i2 + 1];
603         s[2] = xb[i2 + 2];
604         PetscKernel_v_gets_A_times_w_3(xw, idiag, s);
605         x[i2]     = xw[0];
606         x[i2 + 1] = xw[1];
607         x[i2 + 2] = xw[2];
608         i2 -= 3;
609         idiag -= 9;
610         for (i = m - 2; i >= 0; i--) {
611           v    = aa + 9 * (diag[i] + 1);
612           vi   = aj + diag[i] + 1;
613           nz   = ai[i + 1] - diag[i] - 1;
614           s[0] = xb[i2];
615           s[1] = xb[i2 + 1];
616           s[2] = xb[i2 + 2];
617           while (nz--) {
618             idx   = 3 * (*vi++);
619             xw[0] = x[idx];
620             xw[1] = x[1 + idx];
621             xw[2] = x[2 + idx];
622             PetscKernel_v_gets_v_minus_A_times_w_3(s, v, xw);
623             v += 9;
624           }
625           PetscKernel_v_gets_A_times_w_3(xw, idiag, s);
626           x[i2]     = xw[0];
627           x[i2 + 1] = xw[1];
628           x[i2 + 2] = xw[2];
629           idiag -= 9;
630           i2 -= 3;
631         }
632         break;
633       case 4:
634         s[0] = xb[i2];
635         s[1] = xb[i2 + 1];
636         s[2] = xb[i2 + 2];
637         s[3] = xb[i2 + 3];
638         PetscKernel_v_gets_A_times_w_4(xw, idiag, s);
639         x[i2]     = xw[0];
640         x[i2 + 1] = xw[1];
641         x[i2 + 2] = xw[2];
642         x[i2 + 3] = xw[3];
643         i2 -= 4;
644         idiag -= 16;
645         for (i = m - 2; i >= 0; i--) {
646           v    = aa + 16 * (diag[i] + 1);
647           vi   = aj + diag[i] + 1;
648           nz   = ai[i + 1] - diag[i] - 1;
649           s[0] = xb[i2];
650           s[1] = xb[i2 + 1];
651           s[2] = xb[i2 + 2];
652           s[3] = xb[i2 + 3];
653           while (nz--) {
654             idx   = 4 * (*vi++);
655             xw[0] = x[idx];
656             xw[1] = x[1 + idx];
657             xw[2] = x[2 + idx];
658             xw[3] = x[3 + idx];
659             PetscKernel_v_gets_v_minus_A_times_w_4(s, v, xw);
660             v += 16;
661           }
662           PetscKernel_v_gets_A_times_w_4(xw, idiag, s);
663           x[i2]     = xw[0];
664           x[i2 + 1] = xw[1];
665           x[i2 + 2] = xw[2];
666           x[i2 + 3] = xw[3];
667           idiag -= 16;
668           i2 -= 4;
669         }
670         break;
671       case 5:
672         s[0] = xb[i2];
673         s[1] = xb[i2 + 1];
674         s[2] = xb[i2 + 2];
675         s[3] = xb[i2 + 3];
676         s[4] = xb[i2 + 4];
677         PetscKernel_v_gets_A_times_w_5(xw, idiag, s);
678         x[i2]     = xw[0];
679         x[i2 + 1] = xw[1];
680         x[i2 + 2] = xw[2];
681         x[i2 + 3] = xw[3];
682         x[i2 + 4] = xw[4];
683         i2 -= 5;
684         idiag -= 25;
685         for (i = m - 2; i >= 0; i--) {
686           v    = aa + 25 * (diag[i] + 1);
687           vi   = aj + diag[i] + 1;
688           nz   = ai[i + 1] - diag[i] - 1;
689           s[0] = xb[i2];
690           s[1] = xb[i2 + 1];
691           s[2] = xb[i2 + 2];
692           s[3] = xb[i2 + 3];
693           s[4] = xb[i2 + 4];
694           while (nz--) {
695             idx   = 5 * (*vi++);
696             xw[0] = x[idx];
697             xw[1] = x[1 + idx];
698             xw[2] = x[2 + idx];
699             xw[3] = x[3 + idx];
700             xw[4] = x[4 + idx];
701             PetscKernel_v_gets_v_minus_A_times_w_5(s, v, xw);
702             v += 25;
703           }
704           PetscKernel_v_gets_A_times_w_5(xw, idiag, s);
705           x[i2]     = xw[0];
706           x[i2 + 1] = xw[1];
707           x[i2 + 2] = xw[2];
708           x[i2 + 3] = xw[3];
709           x[i2 + 4] = xw[4];
710           idiag -= 25;
711           i2 -= 5;
712         }
713         break;
714       case 6:
715         s[0] = xb[i2];
716         s[1] = xb[i2 + 1];
717         s[2] = xb[i2 + 2];
718         s[3] = xb[i2 + 3];
719         s[4] = xb[i2 + 4];
720         s[5] = xb[i2 + 5];
721         PetscKernel_v_gets_A_times_w_6(xw, idiag, s);
722         x[i2]     = xw[0];
723         x[i2 + 1] = xw[1];
724         x[i2 + 2] = xw[2];
725         x[i2 + 3] = xw[3];
726         x[i2 + 4] = xw[4];
727         x[i2 + 5] = xw[5];
728         i2 -= 6;
729         idiag -= 36;
730         for (i = m - 2; i >= 0; i--) {
731           v    = aa + 36 * (diag[i] + 1);
732           vi   = aj + diag[i] + 1;
733           nz   = ai[i + 1] - diag[i] - 1;
734           s[0] = xb[i2];
735           s[1] = xb[i2 + 1];
736           s[2] = xb[i2 + 2];
737           s[3] = xb[i2 + 3];
738           s[4] = xb[i2 + 4];
739           s[5] = xb[i2 + 5];
740           while (nz--) {
741             idx   = 6 * (*vi++);
742             xw[0] = x[idx];
743             xw[1] = x[1 + idx];
744             xw[2] = x[2 + idx];
745             xw[3] = x[3 + idx];
746             xw[4] = x[4 + idx];
747             xw[5] = x[5 + idx];
748             PetscKernel_v_gets_v_minus_A_times_w_6(s, v, xw);
749             v += 36;
750           }
751           PetscKernel_v_gets_A_times_w_6(xw, idiag, s);
752           x[i2]     = xw[0];
753           x[i2 + 1] = xw[1];
754           x[i2 + 2] = xw[2];
755           x[i2 + 3] = xw[3];
756           x[i2 + 4] = xw[4];
757           x[i2 + 5] = xw[5];
758           idiag -= 36;
759           i2 -= 6;
760         }
761         break;
762       case 7:
763         s[0] = xb[i2];
764         s[1] = xb[i2 + 1];
765         s[2] = xb[i2 + 2];
766         s[3] = xb[i2 + 3];
767         s[4] = xb[i2 + 4];
768         s[5] = xb[i2 + 5];
769         s[6] = xb[i2 + 6];
770         PetscKernel_v_gets_A_times_w_7(x, idiag, b);
771         x[i2]     = xw[0];
772         x[i2 + 1] = xw[1];
773         x[i2 + 2] = xw[2];
774         x[i2 + 3] = xw[3];
775         x[i2 + 4] = xw[4];
776         x[i2 + 5] = xw[5];
777         x[i2 + 6] = xw[6];
778         i2 -= 7;
779         idiag -= 49;
780         for (i = m - 2; i >= 0; i--) {
781           v    = aa + 49 * (diag[i] + 1);
782           vi   = aj + diag[i] + 1;
783           nz   = ai[i + 1] - diag[i] - 1;
784           s[0] = xb[i2];
785           s[1] = xb[i2 + 1];
786           s[2] = xb[i2 + 2];
787           s[3] = xb[i2 + 3];
788           s[4] = xb[i2 + 4];
789           s[5] = xb[i2 + 5];
790           s[6] = xb[i2 + 6];
791           while (nz--) {
792             idx   = 7 * (*vi++);
793             xw[0] = x[idx];
794             xw[1] = x[1 + idx];
795             xw[2] = x[2 + idx];
796             xw[3] = x[3 + idx];
797             xw[4] = x[4 + idx];
798             xw[5] = x[5 + idx];
799             xw[6] = x[6 + idx];
800             PetscKernel_v_gets_v_minus_A_times_w_7(s, v, xw);
801             v += 49;
802           }
803           PetscKernel_v_gets_A_times_w_7(xw, idiag, s);
804           x[i2]     = xw[0];
805           x[i2 + 1] = xw[1];
806           x[i2 + 2] = xw[2];
807           x[i2 + 3] = xw[3];
808           x[i2 + 4] = xw[4];
809           x[i2 + 5] = xw[5];
810           x[i2 + 6] = xw[6];
811           idiag -= 49;
812           i2 -= 7;
813         }
814         break;
815       default:
816         PetscCall(PetscArraycpy(w, xb + i2, bs));
817         PetscKernel_w_gets_Ar_times_v(bs, bs, w, idiag, x + i2);
818         i2 -= bs;
819         idiag -= bs2;
820         for (i = m - 2; i >= 0; i--) {
821           v  = aa + bs2 * (diag[i] + 1);
822           vi = aj + diag[i] + 1;
823           nz = ai[i + 1] - diag[i] - 1;
824 
825           PetscCall(PetscArraycpy(w, xb + i2, bs));
826           /* copy all rows of x that are needed into contiguous space */
827           workt = work;
828           for (j = 0; j < nz; j++) {
829             PetscCall(PetscArraycpy(workt, x + bs * (*vi++), bs));
830             workt += bs;
831           }
832           PetscKernel_w_gets_w_minus_Ar_times_v(bs, bs * nz, w, v, work);
833           PetscKernel_w_gets_Ar_times_v(bs, bs, w, idiag, x + i2);
834 
835           idiag -= bs2;
836           i2 -= bs;
837         }
838         break;
839       }
840       PetscCall(PetscLogFlops(1.0 * bs2 * (a->nz)));
841     }
842     its--;
843   }
844   while (its--) {
845     if (flag & SOR_FORWARD_SWEEP || flag & SOR_LOCAL_FORWARD_SWEEP) {
846       idiag = a->idiag;
847       i2    = 0;
848       switch (bs) {
849       case 1:
850         for (i = 0; i < m; i++) {
851           v    = aa + ai[i];
852           vi   = aj + ai[i];
853           nz   = ai[i + 1] - ai[i];
854           s[0] = b[i2];
855           for (j = 0; j < nz; j++) {
856             xw[0] = x[vi[j]];
857             PetscKernel_v_gets_v_minus_A_times_w_1(s, (v + j), xw);
858           }
859           PetscKernel_v_gets_A_times_w_1(xw, idiag, s);
860           x[i2] += xw[0];
861           idiag += 1;
862           i2 += 1;
863         }
864         break;
865       case 2:
866         for (i = 0; i < m; i++) {
867           v    = aa + 4 * ai[i];
868           vi   = aj + ai[i];
869           nz   = ai[i + 1] - ai[i];
870           s[0] = b[i2];
871           s[1] = b[i2 + 1];
872           for (j = 0; j < nz; j++) {
873             idx   = 2 * vi[j];
874             it    = 4 * j;
875             xw[0] = x[idx];
876             xw[1] = x[1 + idx];
877             PetscKernel_v_gets_v_minus_A_times_w_2(s, (v + it), xw);
878           }
879           PetscKernel_v_gets_A_times_w_2(xw, idiag, s);
880           x[i2] += xw[0];
881           x[i2 + 1] += xw[1];
882           idiag += 4;
883           i2 += 2;
884         }
885         break;
886       case 3:
887         for (i = 0; i < m; i++) {
888           v    = aa + 9 * ai[i];
889           vi   = aj + ai[i];
890           nz   = ai[i + 1] - ai[i];
891           s[0] = b[i2];
892           s[1] = b[i2 + 1];
893           s[2] = b[i2 + 2];
894           while (nz--) {
895             idx   = 3 * (*vi++);
896             xw[0] = x[idx];
897             xw[1] = x[1 + idx];
898             xw[2] = x[2 + idx];
899             PetscKernel_v_gets_v_minus_A_times_w_3(s, v, xw);
900             v += 9;
901           }
902           PetscKernel_v_gets_A_times_w_3(xw, idiag, s);
903           x[i2] += xw[0];
904           x[i2 + 1] += xw[1];
905           x[i2 + 2] += xw[2];
906           idiag += 9;
907           i2 += 3;
908         }
909         break;
910       case 4:
911         for (i = 0; i < m; i++) {
912           v    = aa + 16 * ai[i];
913           vi   = aj + ai[i];
914           nz   = ai[i + 1] - ai[i];
915           s[0] = b[i2];
916           s[1] = b[i2 + 1];
917           s[2] = b[i2 + 2];
918           s[3] = b[i2 + 3];
919           while (nz--) {
920             idx   = 4 * (*vi++);
921             xw[0] = x[idx];
922             xw[1] = x[1 + idx];
923             xw[2] = x[2 + idx];
924             xw[3] = x[3 + idx];
925             PetscKernel_v_gets_v_minus_A_times_w_4(s, v, xw);
926             v += 16;
927           }
928           PetscKernel_v_gets_A_times_w_4(xw, idiag, s);
929           x[i2] += xw[0];
930           x[i2 + 1] += xw[1];
931           x[i2 + 2] += xw[2];
932           x[i2 + 3] += xw[3];
933           idiag += 16;
934           i2 += 4;
935         }
936         break;
937       case 5:
938         for (i = 0; i < m; i++) {
939           v    = aa + 25 * ai[i];
940           vi   = aj + ai[i];
941           nz   = ai[i + 1] - ai[i];
942           s[0] = b[i2];
943           s[1] = b[i2 + 1];
944           s[2] = b[i2 + 2];
945           s[3] = b[i2 + 3];
946           s[4] = b[i2 + 4];
947           while (nz--) {
948             idx   = 5 * (*vi++);
949             xw[0] = x[idx];
950             xw[1] = x[1 + idx];
951             xw[2] = x[2 + idx];
952             xw[3] = x[3 + idx];
953             xw[4] = x[4 + idx];
954             PetscKernel_v_gets_v_minus_A_times_w_5(s, v, xw);
955             v += 25;
956           }
957           PetscKernel_v_gets_A_times_w_5(xw, idiag, s);
958           x[i2] += xw[0];
959           x[i2 + 1] += xw[1];
960           x[i2 + 2] += xw[2];
961           x[i2 + 3] += xw[3];
962           x[i2 + 4] += xw[4];
963           idiag += 25;
964           i2 += 5;
965         }
966         break;
967       case 6:
968         for (i = 0; i < m; i++) {
969           v    = aa + 36 * ai[i];
970           vi   = aj + ai[i];
971           nz   = ai[i + 1] - ai[i];
972           s[0] = b[i2];
973           s[1] = b[i2 + 1];
974           s[2] = b[i2 + 2];
975           s[3] = b[i2 + 3];
976           s[4] = b[i2 + 4];
977           s[5] = b[i2 + 5];
978           while (nz--) {
979             idx   = 6 * (*vi++);
980             xw[0] = x[idx];
981             xw[1] = x[1 + idx];
982             xw[2] = x[2 + idx];
983             xw[3] = x[3 + idx];
984             xw[4] = x[4 + idx];
985             xw[5] = x[5 + idx];
986             PetscKernel_v_gets_v_minus_A_times_w_6(s, v, xw);
987             v += 36;
988           }
989           PetscKernel_v_gets_A_times_w_6(xw, idiag, s);
990           x[i2] += xw[0];
991           x[i2 + 1] += xw[1];
992           x[i2 + 2] += xw[2];
993           x[i2 + 3] += xw[3];
994           x[i2 + 4] += xw[4];
995           x[i2 + 5] += xw[5];
996           idiag += 36;
997           i2 += 6;
998         }
999         break;
1000       case 7:
1001         for (i = 0; i < m; i++) {
1002           v    = aa + 49 * ai[i];
1003           vi   = aj + ai[i];
1004           nz   = ai[i + 1] - ai[i];
1005           s[0] = b[i2];
1006           s[1] = b[i2 + 1];
1007           s[2] = b[i2 + 2];
1008           s[3] = b[i2 + 3];
1009           s[4] = b[i2 + 4];
1010           s[5] = b[i2 + 5];
1011           s[6] = b[i2 + 6];
1012           while (nz--) {
1013             idx   = 7 * (*vi++);
1014             xw[0] = x[idx];
1015             xw[1] = x[1 + idx];
1016             xw[2] = x[2 + idx];
1017             xw[3] = x[3 + idx];
1018             xw[4] = x[4 + idx];
1019             xw[5] = x[5 + idx];
1020             xw[6] = x[6 + idx];
1021             PetscKernel_v_gets_v_minus_A_times_w_7(s, v, xw);
1022             v += 49;
1023           }
1024           PetscKernel_v_gets_A_times_w_7(xw, idiag, s);
1025           x[i2] += xw[0];
1026           x[i2 + 1] += xw[1];
1027           x[i2 + 2] += xw[2];
1028           x[i2 + 3] += xw[3];
1029           x[i2 + 4] += xw[4];
1030           x[i2 + 5] += xw[5];
1031           x[i2 + 6] += xw[6];
1032           idiag += 49;
1033           i2 += 7;
1034         }
1035         break;
1036       default:
1037         for (i = 0; i < m; i++) {
1038           v  = aa + bs2 * ai[i];
1039           vi = aj + ai[i];
1040           nz = ai[i + 1] - ai[i];
1041 
1042           PetscCall(PetscArraycpy(w, b + i2, bs));
1043           /* copy all rows of x that are needed into contiguous space */
1044           workt = work;
1045           for (j = 0; j < nz; j++) {
1046             PetscCall(PetscArraycpy(workt, x + bs * (*vi++), bs));
1047             workt += bs;
1048           }
1049           PetscKernel_w_gets_w_minus_Ar_times_v(bs, bs * nz, w, v, work);
1050           PetscKernel_w_gets_w_plus_Ar_times_v(bs, bs, w, idiag, x + i2);
1051 
1052           idiag += bs2;
1053           i2 += bs;
1054         }
1055         break;
1056       }
1057       PetscCall(PetscLogFlops(2.0 * bs2 * a->nz));
1058     }
1059     if (flag & SOR_BACKWARD_SWEEP || flag & SOR_LOCAL_BACKWARD_SWEEP) {
1060       idiag = a->idiag + bs2 * (a->mbs - 1);
1061       i2    = bs * (m - 1);
1062       switch (bs) {
1063       case 1:
1064         for (i = m - 1; i >= 0; i--) {
1065           v    = aa + ai[i];
1066           vi   = aj + ai[i];
1067           nz   = ai[i + 1] - ai[i];
1068           s[0] = b[i2];
1069           for (j = 0; j < nz; j++) {
1070             xw[0] = x[vi[j]];
1071             PetscKernel_v_gets_v_minus_A_times_w_1(s, (v + j), xw);
1072           }
1073           PetscKernel_v_gets_A_times_w_1(xw, idiag, s);
1074           x[i2] += xw[0];
1075           idiag -= 1;
1076           i2 -= 1;
1077         }
1078         break;
1079       case 2:
1080         for (i = m - 1; i >= 0; i--) {
1081           v    = aa + 4 * ai[i];
1082           vi   = aj + ai[i];
1083           nz   = ai[i + 1] - ai[i];
1084           s[0] = b[i2];
1085           s[1] = b[i2 + 1];
1086           for (j = 0; j < nz; j++) {
1087             idx   = 2 * vi[j];
1088             it    = 4 * j;
1089             xw[0] = x[idx];
1090             xw[1] = x[1 + idx];
1091             PetscKernel_v_gets_v_minus_A_times_w_2(s, (v + it), xw);
1092           }
1093           PetscKernel_v_gets_A_times_w_2(xw, idiag, s);
1094           x[i2] += xw[0];
1095           x[i2 + 1] += xw[1];
1096           idiag -= 4;
1097           i2 -= 2;
1098         }
1099         break;
1100       case 3:
1101         for (i = m - 1; i >= 0; i--) {
1102           v    = aa + 9 * ai[i];
1103           vi   = aj + ai[i];
1104           nz   = ai[i + 1] - ai[i];
1105           s[0] = b[i2];
1106           s[1] = b[i2 + 1];
1107           s[2] = b[i2 + 2];
1108           while (nz--) {
1109             idx   = 3 * (*vi++);
1110             xw[0] = x[idx];
1111             xw[1] = x[1 + idx];
1112             xw[2] = x[2 + idx];
1113             PetscKernel_v_gets_v_minus_A_times_w_3(s, v, xw);
1114             v += 9;
1115           }
1116           PetscKernel_v_gets_A_times_w_3(xw, idiag, s);
1117           x[i2] += xw[0];
1118           x[i2 + 1] += xw[1];
1119           x[i2 + 2] += xw[2];
1120           idiag -= 9;
1121           i2 -= 3;
1122         }
1123         break;
1124       case 4:
1125         for (i = m - 1; i >= 0; i--) {
1126           v    = aa + 16 * ai[i];
1127           vi   = aj + ai[i];
1128           nz   = ai[i + 1] - ai[i];
1129           s[0] = b[i2];
1130           s[1] = b[i2 + 1];
1131           s[2] = b[i2 + 2];
1132           s[3] = b[i2 + 3];
1133           while (nz--) {
1134             idx   = 4 * (*vi++);
1135             xw[0] = x[idx];
1136             xw[1] = x[1 + idx];
1137             xw[2] = x[2 + idx];
1138             xw[3] = x[3 + idx];
1139             PetscKernel_v_gets_v_minus_A_times_w_4(s, v, xw);
1140             v += 16;
1141           }
1142           PetscKernel_v_gets_A_times_w_4(xw, idiag, s);
1143           x[i2] += xw[0];
1144           x[i2 + 1] += xw[1];
1145           x[i2 + 2] += xw[2];
1146           x[i2 + 3] += xw[3];
1147           idiag -= 16;
1148           i2 -= 4;
1149         }
1150         break;
1151       case 5:
1152         for (i = m - 1; i >= 0; i--) {
1153           v    = aa + 25 * ai[i];
1154           vi   = aj + ai[i];
1155           nz   = ai[i + 1] - ai[i];
1156           s[0] = b[i2];
1157           s[1] = b[i2 + 1];
1158           s[2] = b[i2 + 2];
1159           s[3] = b[i2 + 3];
1160           s[4] = b[i2 + 4];
1161           while (nz--) {
1162             idx   = 5 * (*vi++);
1163             xw[0] = x[idx];
1164             xw[1] = x[1 + idx];
1165             xw[2] = x[2 + idx];
1166             xw[3] = x[3 + idx];
1167             xw[4] = x[4 + idx];
1168             PetscKernel_v_gets_v_minus_A_times_w_5(s, v, xw);
1169             v += 25;
1170           }
1171           PetscKernel_v_gets_A_times_w_5(xw, idiag, s);
1172           x[i2] += xw[0];
1173           x[i2 + 1] += xw[1];
1174           x[i2 + 2] += xw[2];
1175           x[i2 + 3] += xw[3];
1176           x[i2 + 4] += xw[4];
1177           idiag -= 25;
1178           i2 -= 5;
1179         }
1180         break;
1181       case 6:
1182         for (i = m - 1; i >= 0; i--) {
1183           v    = aa + 36 * ai[i];
1184           vi   = aj + ai[i];
1185           nz   = ai[i + 1] - ai[i];
1186           s[0] = b[i2];
1187           s[1] = b[i2 + 1];
1188           s[2] = b[i2 + 2];
1189           s[3] = b[i2 + 3];
1190           s[4] = b[i2 + 4];
1191           s[5] = b[i2 + 5];
1192           while (nz--) {
1193             idx   = 6 * (*vi++);
1194             xw[0] = x[idx];
1195             xw[1] = x[1 + idx];
1196             xw[2] = x[2 + idx];
1197             xw[3] = x[3 + idx];
1198             xw[4] = x[4 + idx];
1199             xw[5] = x[5 + idx];
1200             PetscKernel_v_gets_v_minus_A_times_w_6(s, v, xw);
1201             v += 36;
1202           }
1203           PetscKernel_v_gets_A_times_w_6(xw, idiag, s);
1204           x[i2] += xw[0];
1205           x[i2 + 1] += xw[1];
1206           x[i2 + 2] += xw[2];
1207           x[i2 + 3] += xw[3];
1208           x[i2 + 4] += xw[4];
1209           x[i2 + 5] += xw[5];
1210           idiag -= 36;
1211           i2 -= 6;
1212         }
1213         break;
1214       case 7:
1215         for (i = m - 1; i >= 0; i--) {
1216           v    = aa + 49 * ai[i];
1217           vi   = aj + ai[i];
1218           nz   = ai[i + 1] - ai[i];
1219           s[0] = b[i2];
1220           s[1] = b[i2 + 1];
1221           s[2] = b[i2 + 2];
1222           s[3] = b[i2 + 3];
1223           s[4] = b[i2 + 4];
1224           s[5] = b[i2 + 5];
1225           s[6] = b[i2 + 6];
1226           while (nz--) {
1227             idx   = 7 * (*vi++);
1228             xw[0] = x[idx];
1229             xw[1] = x[1 + idx];
1230             xw[2] = x[2 + idx];
1231             xw[3] = x[3 + idx];
1232             xw[4] = x[4 + idx];
1233             xw[5] = x[5 + idx];
1234             xw[6] = x[6 + idx];
1235             PetscKernel_v_gets_v_minus_A_times_w_7(s, v, xw);
1236             v += 49;
1237           }
1238           PetscKernel_v_gets_A_times_w_7(xw, idiag, s);
1239           x[i2] += xw[0];
1240           x[i2 + 1] += xw[1];
1241           x[i2 + 2] += xw[2];
1242           x[i2 + 3] += xw[3];
1243           x[i2 + 4] += xw[4];
1244           x[i2 + 5] += xw[5];
1245           x[i2 + 6] += xw[6];
1246           idiag -= 49;
1247           i2 -= 7;
1248         }
1249         break;
1250       default:
1251         for (i = m - 1; i >= 0; i--) {
1252           v  = aa + bs2 * ai[i];
1253           vi = aj + ai[i];
1254           nz = ai[i + 1] - ai[i];
1255 
1256           PetscCall(PetscArraycpy(w, b + i2, bs));
1257           /* copy all rows of x that are needed into contiguous space */
1258           workt = work;
1259           for (j = 0; j < nz; j++) {
1260             PetscCall(PetscArraycpy(workt, x + bs * (*vi++), bs));
1261             workt += bs;
1262           }
1263           PetscKernel_w_gets_w_minus_Ar_times_v(bs, bs * nz, w, v, work);
1264           PetscKernel_w_gets_w_plus_Ar_times_v(bs, bs, w, idiag, x + i2);
1265 
1266           idiag -= bs2;
1267           i2 -= bs;
1268         }
1269         break;
1270       }
1271       PetscCall(PetscLogFlops(2.0 * bs2 * (a->nz)));
1272     }
1273   }
1274   PetscCall(VecRestoreArray(xx, &x));
1275   PetscCall(VecRestoreArrayRead(bb, &b));
1276   PetscFunctionReturn(PETSC_SUCCESS);
1277 }
1278 
1279 /*
1280     Special version for direct calls from Fortran (Used in PETSc-fun3d)
1281 */
1282 #if defined(PETSC_HAVE_FORTRAN_CAPS)
1283   #define matsetvaluesblocked4_ MATSETVALUESBLOCKED4
1284 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
1285   #define matsetvaluesblocked4_ matsetvaluesblocked4
1286 #endif
1287 
1288 PETSC_EXTERN void matsetvaluesblocked4_(Mat *AA, PetscInt *mm, const PetscInt im[], PetscInt *nn, const PetscInt in[], const PetscScalar v[])
1289 {
1290   Mat                A = *AA;
1291   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ *)A->data;
1292   PetscInt          *rp, k, low, high, t, ii, jj, row, nrow, i, col, l, N, m = *mm, n = *nn;
1293   PetscInt          *ai = a->i, *ailen = a->ilen;
1294   PetscInt          *aj = a->j, stepval, lastcol = -1;
1295   const PetscScalar *value = v;
1296   MatScalar         *ap, *aa = a->a, *bap;
1297 
1298   PetscFunctionBegin;
1299   if (A->rmap->bs != 4) SETERRABORT(PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Can only be called with a block size of 4");
1300   stepval = (n - 1) * 4;
1301   for (k = 0; k < m; k++) { /* loop over added rows */
1302     row  = im[k];
1303     rp   = aj + ai[row];
1304     ap   = aa + 16 * ai[row];
1305     nrow = ailen[row];
1306     low  = 0;
1307     high = nrow;
1308     for (l = 0; l < n; l++) { /* loop over added columns */
1309       col = in[l];
1310       if (col <= lastcol) low = 0;
1311       else high = nrow;
1312       lastcol = col;
1313       value   = v + k * (stepval + 4 + l) * 4;
1314       while (high - low > 7) {
1315         t = (low + high) / 2;
1316         if (rp[t] > col) high = t;
1317         else low = t;
1318       }
1319       for (i = low; i < high; i++) {
1320         if (rp[i] > col) break;
1321         if (rp[i] == col) {
1322           bap = ap + 16 * i;
1323           for (ii = 0; ii < 4; ii++, value += stepval) {
1324             for (jj = ii; jj < 16; jj += 4) bap[jj] += *value++;
1325           }
1326           goto noinsert2;
1327         }
1328       }
1329       N = nrow++ - 1;
1330       high++; /* added new column index thus must search to one higher than before */
1331       /* shift up all the later entries in this row */
1332       for (ii = N; ii >= i; ii--) {
1333         rp[ii + 1] = rp[ii];
1334         PetscCallVoid(PetscArraycpy(ap + 16 * (ii + 1), ap + 16 * (ii), 16));
1335       }
1336       if (N >= i) PetscCallVoid(PetscArrayzero(ap + 16 * i, 16));
1337       rp[i] = col;
1338       bap   = ap + 16 * i;
1339       for (ii = 0; ii < 4; ii++, value += stepval) {
1340         for (jj = ii; jj < 16; jj += 4) bap[jj] = *value++;
1341       }
1342     noinsert2:;
1343       low = i;
1344     }
1345     ailen[row] = nrow;
1346   }
1347   PetscFunctionReturnVoid();
1348 }
1349 
1350 #if defined(PETSC_HAVE_FORTRAN_CAPS)
1351   #define matsetvalues4_ MATSETVALUES4
1352 #elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
1353   #define matsetvalues4_ matsetvalues4
1354 #endif
1355 
1356 PETSC_EXTERN void matsetvalues4_(Mat *AA, PetscInt *mm, PetscInt *im, PetscInt *nn, PetscInt *in, PetscScalar *v)
1357 {
1358   Mat          A = *AA;
1359   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
1360   PetscInt    *rp, k, low, high, t, row, nrow, i, col, l, N, n = *nn, m = *mm;
1361   PetscInt    *ai = a->i, *ailen = a->ilen;
1362   PetscInt    *aj = a->j, brow, bcol;
1363   PetscInt     ridx, cidx, lastcol = -1;
1364   MatScalar   *ap, value, *aa      = a->a, *bap;
1365 
1366   PetscFunctionBegin;
1367   for (k = 0; k < m; k++) { /* loop over added rows */
1368     row  = im[k];
1369     brow = row / 4;
1370     rp   = aj + ai[brow];
1371     ap   = aa + 16 * ai[brow];
1372     nrow = ailen[brow];
1373     low  = 0;
1374     high = nrow;
1375     for (l = 0; l < n; l++) { /* loop over added columns */
1376       col   = in[l];
1377       bcol  = col / 4;
1378       ridx  = row % 4;
1379       cidx  = col % 4;
1380       value = v[l + k * n];
1381       if (col <= lastcol) low = 0;
1382       else high = nrow;
1383       lastcol = col;
1384       while (high - low > 7) {
1385         t = (low + high) / 2;
1386         if (rp[t] > bcol) high = t;
1387         else low = t;
1388       }
1389       for (i = low; i < high; i++) {
1390         if (rp[i] > bcol) break;
1391         if (rp[i] == bcol) {
1392           bap = ap + 16 * i + 4 * cidx + ridx;
1393           *bap += value;
1394           goto noinsert1;
1395         }
1396       }
1397       N = nrow++ - 1;
1398       high++; /* added new column thus must search to one higher than before */
1399       /* shift up all the later entries in this row */
1400       PetscCallVoid(PetscArraymove(rp + i + 1, rp + i, N - i + 1));
1401       PetscCallVoid(PetscArraymove(ap + 16 * i + 16, ap + 16 * i, 16 * (N - i + 1)));
1402       PetscCallVoid(PetscArrayzero(ap + 16 * i, 16));
1403       rp[i]                        = bcol;
1404       ap[16 * i + 4 * cidx + ridx] = value;
1405     noinsert1:;
1406       low = i;
1407     }
1408     ailen[brow] = nrow;
1409   }
1410   PetscFunctionReturnVoid();
1411 }
1412 
1413 static PetscErrorCode MatGetRowIJ_SeqBAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool blockcompressed, PetscInt *nn, const PetscInt *inia[], const PetscInt *inja[], PetscBool *done)
1414 {
1415   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
1416   PetscInt     i, j, n = a->mbs, nz = a->i[n], *tia, *tja, bs = A->rmap->bs, k, l, cnt;
1417   PetscInt   **ia = (PetscInt **)inia, **ja = (PetscInt **)inja;
1418 
1419   PetscFunctionBegin;
1420   *nn = n;
1421   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
1422   if (symmetric) {
1423     PetscCall(MatToSymmetricIJ_SeqAIJ(n, a->i, a->j, PETSC_TRUE, 0, 0, &tia, &tja));
1424     nz = tia[n];
1425   } else {
1426     tia = a->i;
1427     tja = a->j;
1428   }
1429 
1430   if (!blockcompressed && bs > 1) {
1431     (*nn) *= bs;
1432     /* malloc & create the natural set of indices */
1433     PetscCall(PetscMalloc1((n + 1) * bs, ia));
1434     if (n) {
1435       (*ia)[0] = oshift;
1436       for (j = 1; j < bs; j++) (*ia)[j] = (tia[1] - tia[0]) * bs + (*ia)[j - 1];
1437     }
1438 
1439     for (i = 1; i < n; i++) {
1440       (*ia)[i * bs] = (tia[i] - tia[i - 1]) * bs + (*ia)[i * bs - 1];
1441       for (j = 1; j < bs; j++) (*ia)[i * bs + j] = (tia[i + 1] - tia[i]) * bs + (*ia)[i * bs + j - 1];
1442     }
1443     if (n) (*ia)[n * bs] = (tia[n] - tia[n - 1]) * bs + (*ia)[n * bs - 1];
1444 
1445     if (inja) {
1446       PetscCall(PetscMalloc1(nz * bs * bs, ja));
1447       cnt = 0;
1448       for (i = 0; i < n; i++) {
1449         for (j = 0; j < bs; j++) {
1450           for (k = tia[i]; k < tia[i + 1]; k++) {
1451             for (l = 0; l < bs; l++) (*ja)[cnt++] = bs * tja[k] + l;
1452           }
1453         }
1454       }
1455     }
1456 
1457     if (symmetric) { /* deallocate memory allocated in MatToSymmetricIJ_SeqAIJ() */
1458       PetscCall(PetscFree(tia));
1459       PetscCall(PetscFree(tja));
1460     }
1461   } else if (oshift == 1) {
1462     if (symmetric) {
1463       nz = tia[A->rmap->n / bs];
1464       /*  add 1 to i and j indices */
1465       for (i = 0; i < A->rmap->n / bs + 1; i++) tia[i] = tia[i] + 1;
1466       *ia = tia;
1467       if (ja) {
1468         for (i = 0; i < nz; i++) tja[i] = tja[i] + 1;
1469         *ja = tja;
1470       }
1471     } else {
1472       nz = a->i[A->rmap->n / bs];
1473       /* malloc space and  add 1 to i and j indices */
1474       PetscCall(PetscMalloc1(A->rmap->n / bs + 1, ia));
1475       for (i = 0; i < A->rmap->n / bs + 1; i++) (*ia)[i] = a->i[i] + 1;
1476       if (ja) {
1477         PetscCall(PetscMalloc1(nz, ja));
1478         for (i = 0; i < nz; i++) (*ja)[i] = a->j[i] + 1;
1479       }
1480     }
1481   } else {
1482     *ia = tia;
1483     if (ja) *ja = tja;
1484   }
1485   PetscFunctionReturn(PETSC_SUCCESS);
1486 }
1487 
1488 static PetscErrorCode MatRestoreRowIJ_SeqBAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool blockcompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
1489 {
1490   PetscFunctionBegin;
1491   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
1492   if ((!blockcompressed && A->rmap->bs > 1) || (symmetric || oshift == 1)) {
1493     PetscCall(PetscFree(*ia));
1494     if (ja) PetscCall(PetscFree(*ja));
1495   }
1496   PetscFunctionReturn(PETSC_SUCCESS);
1497 }
1498 
1499 PetscErrorCode MatDestroy_SeqBAIJ(Mat A)
1500 {
1501   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
1502 
1503   PetscFunctionBegin;
1504   if (A->hash_active) {
1505     PetscInt bs;
1506     A->ops[0] = a->cops;
1507     PetscCall(PetscHMapIJVDestroy(&a->ht));
1508     PetscCall(MatGetBlockSize(A, &bs));
1509     if (bs > 1) PetscCall(PetscHSetIJDestroy(&a->bht));
1510     PetscCall(PetscFree(a->dnz));
1511     PetscCall(PetscFree(a->bdnz));
1512     A->hash_active = PETSC_FALSE;
1513   }
1514   PetscCall(PetscLogObjectState((PetscObject)A, "Rows=%" PetscInt_FMT ", Cols=%" PetscInt_FMT ", NZ=%" PetscInt_FMT, A->rmap->N, A->cmap->n, a->nz));
1515   PetscCall(MatSeqXAIJFreeAIJ(A, &a->a, &a->j, &a->i));
1516   PetscCall(ISDestroy(&a->row));
1517   PetscCall(ISDestroy(&a->col));
1518   PetscCall(PetscFree(a->diag));
1519   PetscCall(PetscFree(a->idiag));
1520   if (a->free_imax_ilen) PetscCall(PetscFree2(a->imax, a->ilen));
1521   PetscCall(PetscFree(a->solve_work));
1522   PetscCall(PetscFree(a->mult_work));
1523   PetscCall(PetscFree(a->sor_workt));
1524   PetscCall(PetscFree(a->sor_work));
1525   PetscCall(ISDestroy(&a->icol));
1526   PetscCall(PetscFree(a->saved_values));
1527   PetscCall(PetscFree2(a->compressedrow.i, a->compressedrow.rindex));
1528 
1529   PetscCall(MatDestroy(&a->sbaijMat));
1530   PetscCall(MatDestroy(&a->parent));
1531   PetscCall(PetscFree(A->data));
1532 
1533   PetscCall(PetscObjectChangeTypeName((PetscObject)A, NULL));
1534   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqBAIJGetArray_C", NULL));
1535   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqBAIJRestoreArray_C", NULL));
1536   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatStoreValues_C", NULL));
1537   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatRetrieveValues_C", NULL));
1538   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqBAIJSetColumnIndices_C", NULL));
1539   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqbaij_seqaij_C", NULL));
1540   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqbaij_seqsbaij_C", NULL));
1541   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqBAIJSetPreallocation_C", NULL));
1542   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatSeqBAIJSetPreallocationCSR_C", NULL));
1543   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqbaij_seqbstrm_C", NULL));
1544   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatIsTranspose_C", NULL));
1545 #if defined(PETSC_HAVE_HYPRE)
1546   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqbaij_hypre_C", NULL));
1547 #endif
1548   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatConvert_seqbaij_is_C", NULL));
1549   PetscCall(PetscObjectComposeFunction((PetscObject)A, "MatFactorGetSolverType_C", NULL));
1550   PetscFunctionReturn(PETSC_SUCCESS);
1551 }
1552 
1553 static PetscErrorCode MatSetOption_SeqBAIJ(Mat A, MatOption op, PetscBool flg)
1554 {
1555   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
1556 
1557   PetscFunctionBegin;
1558   switch (op) {
1559   case MAT_ROW_ORIENTED:
1560     a->roworiented = flg;
1561     break;
1562   case MAT_KEEP_NONZERO_PATTERN:
1563     a->keepnonzeropattern = flg;
1564     break;
1565   case MAT_NEW_NONZERO_LOCATIONS:
1566     a->nonew = (flg ? 0 : 1);
1567     break;
1568   case MAT_NEW_NONZERO_LOCATION_ERR:
1569     a->nonew = (flg ? -1 : 0);
1570     break;
1571   case MAT_NEW_NONZERO_ALLOCATION_ERR:
1572     a->nonew = (flg ? -2 : 0);
1573     break;
1574   case MAT_UNUSED_NONZERO_LOCATION_ERR:
1575     a->nounused = (flg ? -1 : 0);
1576     break;
1577   default:
1578     break;
1579   }
1580   PetscFunctionReturn(PETSC_SUCCESS);
1581 }
1582 
1583 /* used for both SeqBAIJ and SeqSBAIJ matrices */
1584 PetscErrorCode MatGetRow_SeqBAIJ_private(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v, PetscInt *ai, PetscInt *aj, PetscScalar *aa)
1585 {
1586   PetscInt     itmp, i, j, k, M, bn, bp, *idx_i, bs, bs2;
1587   MatScalar   *aa_i;
1588   PetscScalar *v_i;
1589 
1590   PetscFunctionBegin;
1591   bs  = A->rmap->bs;
1592   bs2 = bs * bs;
1593   PetscCheck(row >= 0 && row < A->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row %" PetscInt_FMT " out of range", row);
1594 
1595   bn  = row / bs; /* Block number */
1596   bp  = row % bs; /* Block Position */
1597   M   = ai[bn + 1] - ai[bn];
1598   *nz = bs * M;
1599 
1600   if (v) {
1601     *v = NULL;
1602     if (*nz) {
1603       PetscCall(PetscMalloc1(*nz, v));
1604       for (i = 0; i < M; i++) { /* for each block in the block row */
1605         v_i  = *v + i * bs;
1606         aa_i = aa + bs2 * (ai[bn] + i);
1607         for (j = bp, k = 0; j < bs2; j += bs, k++) v_i[k] = aa_i[j];
1608       }
1609     }
1610   }
1611 
1612   if (idx) {
1613     *idx = NULL;
1614     if (*nz) {
1615       PetscCall(PetscMalloc1(*nz, idx));
1616       for (i = 0; i < M; i++) { /* for each block in the block row */
1617         idx_i = *idx + i * bs;
1618         itmp  = bs * aj[ai[bn] + i];
1619         for (j = 0; j < bs; j++) idx_i[j] = itmp++;
1620       }
1621     }
1622   }
1623   PetscFunctionReturn(PETSC_SUCCESS);
1624 }
1625 
1626 PetscErrorCode MatGetRow_SeqBAIJ(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
1627 {
1628   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
1629 
1630   PetscFunctionBegin;
1631   PetscCall(MatGetRow_SeqBAIJ_private(A, row, nz, idx, v, a->i, a->j, a->a));
1632   PetscFunctionReturn(PETSC_SUCCESS);
1633 }
1634 
1635 PetscErrorCode MatRestoreRow_SeqBAIJ(Mat A, PetscInt row, PetscInt *nz, PetscInt **idx, PetscScalar **v)
1636 {
1637   PetscFunctionBegin;
1638   if (idx) PetscCall(PetscFree(*idx));
1639   if (v) PetscCall(PetscFree(*v));
1640   PetscFunctionReturn(PETSC_SUCCESS);
1641 }
1642 
1643 static PetscErrorCode MatTranspose_SeqBAIJ(Mat A, MatReuse reuse, Mat *B)
1644 {
1645   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data, *at;
1646   Mat          C;
1647   PetscInt     i, j, k, *aj = a->j, *ai = a->i, bs = A->rmap->bs, mbs = a->mbs, nbs = a->nbs, *atfill;
1648   PetscInt     bs2 = a->bs2, *ati, *atj, anzj, kr;
1649   MatScalar   *ata, *aa = a->a;
1650 
1651   PetscFunctionBegin;
1652   if (reuse == MAT_REUSE_MATRIX) PetscCall(MatTransposeCheckNonzeroState_Private(A, *B));
1653   PetscCall(PetscCalloc1(1 + nbs, &atfill));
1654   if (reuse == MAT_INITIAL_MATRIX || reuse == MAT_INPLACE_MATRIX) {
1655     for (i = 0; i < ai[mbs]; i++) atfill[aj[i]] += 1; /* count num of non-zeros in row aj[i] */
1656 
1657     PetscCall(MatCreate(PetscObjectComm((PetscObject)A), &C));
1658     PetscCall(MatSetSizes(C, A->cmap->n, A->rmap->N, A->cmap->n, A->rmap->N));
1659     PetscCall(MatSetType(C, ((PetscObject)A)->type_name));
1660     PetscCall(MatSeqBAIJSetPreallocation(C, bs, 0, atfill));
1661 
1662     at  = (Mat_SeqBAIJ *)C->data;
1663     ati = at->i;
1664     for (i = 0; i < nbs; i++) at->ilen[i] = at->imax[i] = ati[i + 1] - ati[i];
1665   } else {
1666     C   = *B;
1667     at  = (Mat_SeqBAIJ *)C->data;
1668     ati = at->i;
1669   }
1670 
1671   atj = at->j;
1672   ata = at->a;
1673 
1674   /* Copy ati into atfill so we have locations of the next free space in atj */
1675   PetscCall(PetscArraycpy(atfill, ati, nbs));
1676 
1677   /* Walk through A row-wise and mark nonzero entries of A^T. */
1678   for (i = 0; i < mbs; i++) {
1679     anzj = ai[i + 1] - ai[i];
1680     for (j = 0; j < anzj; j++) {
1681       atj[atfill[*aj]] = i;
1682       for (kr = 0; kr < bs; kr++) {
1683         for (k = 0; k < bs; k++) ata[bs2 * atfill[*aj] + k * bs + kr] = *aa++;
1684       }
1685       atfill[*aj++] += 1;
1686     }
1687   }
1688   PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
1689   PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
1690 
1691   /* Clean up temporary space and complete requests. */
1692   PetscCall(PetscFree(atfill));
1693 
1694   if (reuse == MAT_INITIAL_MATRIX || reuse == MAT_REUSE_MATRIX) {
1695     PetscCall(MatSetBlockSizes(C, A->cmap->bs, A->rmap->bs));
1696     *B = C;
1697   } else {
1698     PetscCall(MatHeaderMerge(A, &C));
1699   }
1700   PetscFunctionReturn(PETSC_SUCCESS);
1701 }
1702 
1703 static PetscErrorCode MatCompare_SeqBAIJ_Private(Mat A, Mat B, PetscReal tol, PetscBool *flg)
1704 {
1705   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data, *b = (Mat_SeqBAIJ *)B->data;
1706 
1707   PetscFunctionBegin;
1708   /* If the matrix/block dimensions are not equal, or no of nonzeros or shift */
1709   if (A->rmap->N != B->rmap->N || A->cmap->n != B->cmap->n || A->rmap->bs != B->rmap->bs || a->nz != b->nz) {
1710     *flg = PETSC_FALSE;
1711     PetscFunctionReturn(PETSC_SUCCESS);
1712   }
1713 
1714   /* if the a->i are the same */
1715   PetscCall(PetscArraycmp(a->i, b->i, a->mbs + 1, flg));
1716   if (!*flg) PetscFunctionReturn(PETSC_SUCCESS);
1717 
1718   /* if a->j are the same */
1719   PetscCall(PetscArraycmp(a->j, b->j, a->nz, flg));
1720   if (!*flg) PetscFunctionReturn(PETSC_SUCCESS);
1721 
1722   if (tol == 0.0) PetscCall(PetscArraycmp(a->a, b->a, a->nz * A->rmap->bs * A->rmap->bs, flg)); /* if a->a are the same */
1723   else {
1724     *flg = PETSC_TRUE;
1725     for (PetscInt i = 0; (i < a->nz * A->rmap->bs * A->rmap->bs) && *flg; ++i)
1726       if (PetscAbsScalar(a->a[i] - b->a[i]) > tol) *flg = PETSC_FALSE;
1727   }
1728   PetscFunctionReturn(PETSC_SUCCESS);
1729 }
1730 
1731 static PetscErrorCode MatIsTranspose_SeqBAIJ(Mat A, Mat B, PetscReal tol, PetscBool *f)
1732 {
1733   Mat Btrans;
1734 
1735   PetscFunctionBegin;
1736   PetscCall(MatTranspose(A, MAT_INITIAL_MATRIX, &Btrans));
1737   PetscCall(MatCompare_SeqBAIJ_Private(A, Btrans, tol, f));
1738   PetscCall(MatDestroy(&Btrans));
1739   PetscFunctionReturn(PETSC_SUCCESS);
1740 }
1741 
1742 static PetscErrorCode MatEqual_SeqBAIJ(Mat A, Mat B, PetscBool *flg)
1743 {
1744   PetscFunctionBegin;
1745   PetscCall(MatCompare_SeqBAIJ_Private(A, B, 0.0, flg));
1746   PetscFunctionReturn(PETSC_SUCCESS);
1747 }
1748 
1749 /* Used for both SeqBAIJ and SeqSBAIJ matrices */
1750 PetscErrorCode MatView_SeqBAIJ_Binary(Mat mat, PetscViewer viewer)
1751 {
1752   Mat_SeqBAIJ *A = (Mat_SeqBAIJ *)mat->data;
1753   PetscInt     header[4], M, N, m, bs, nz, cnt, i, j, k, l;
1754   PetscInt    *rowlens, *colidxs;
1755   PetscScalar *matvals;
1756 
1757   PetscFunctionBegin;
1758   PetscCall(PetscViewerSetUp(viewer));
1759 
1760   M  = mat->rmap->N;
1761   N  = mat->cmap->N;
1762   m  = mat->rmap->n;
1763   bs = mat->rmap->bs;
1764   nz = bs * bs * A->nz;
1765 
1766   /* write matrix header */
1767   header[0] = MAT_FILE_CLASSID;
1768   header[1] = M;
1769   header[2] = N;
1770   header[3] = nz;
1771   PetscCall(PetscViewerBinaryWrite(viewer, header, 4, PETSC_INT));
1772 
1773   /* store row lengths */
1774   PetscCall(PetscMalloc1(m, &rowlens));
1775   for (cnt = 0, i = 0; i < A->mbs; i++)
1776     for (j = 0; j < bs; j++) rowlens[cnt++] = bs * (A->i[i + 1] - A->i[i]);
1777   PetscCall(PetscViewerBinaryWrite(viewer, rowlens, m, PETSC_INT));
1778   PetscCall(PetscFree(rowlens));
1779 
1780   /* store column indices  */
1781   PetscCall(PetscMalloc1(nz, &colidxs));
1782   for (cnt = 0, i = 0; i < A->mbs; i++)
1783     for (k = 0; k < bs; k++)
1784       for (j = A->i[i]; j < A->i[i + 1]; j++)
1785         for (l = 0; l < bs; l++) colidxs[cnt++] = bs * A->j[j] + l;
1786   PetscCheck(cnt == nz, PETSC_COMM_SELF, PETSC_ERR_LIB, "Internal PETSc error: cnt = %" PetscInt_FMT " nz = %" PetscInt_FMT, cnt, nz);
1787   PetscCall(PetscViewerBinaryWrite(viewer, colidxs, nz, PETSC_INT));
1788   PetscCall(PetscFree(colidxs));
1789 
1790   /* store nonzero values */
1791   PetscCall(PetscMalloc1(nz, &matvals));
1792   for (cnt = 0, i = 0; i < A->mbs; i++)
1793     for (k = 0; k < bs; k++)
1794       for (j = A->i[i]; j < A->i[i + 1]; j++)
1795         for (l = 0; l < bs; l++) matvals[cnt++] = A->a[bs * (bs * j + l) + k];
1796   PetscCheck(cnt == nz, PETSC_COMM_SELF, PETSC_ERR_LIB, "Internal PETSc error: cnt = %" PetscInt_FMT " nz = %" PetscInt_FMT, cnt, nz);
1797   PetscCall(PetscViewerBinaryWrite(viewer, matvals, nz, PETSC_SCALAR));
1798   PetscCall(PetscFree(matvals));
1799 
1800   /* write block size option to the viewer's .info file */
1801   PetscCall(MatView_Binary_BlockSizes(mat, viewer));
1802   PetscFunctionReturn(PETSC_SUCCESS);
1803 }
1804 
1805 static PetscErrorCode MatView_SeqBAIJ_ASCII_structonly(Mat A, PetscViewer viewer)
1806 {
1807   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
1808   PetscInt     i, bs = A->rmap->bs, k;
1809 
1810   PetscFunctionBegin;
1811   PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
1812   for (i = 0; i < a->mbs; i++) {
1813     PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT "-%" PetscInt_FMT ":", i * bs, i * bs + bs - 1));
1814     for (k = a->i[i]; k < a->i[i + 1]; k++) PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT "-%" PetscInt_FMT ") ", bs * a->j[k], bs * a->j[k] + bs - 1));
1815     PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
1816   }
1817   PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
1818   PetscFunctionReturn(PETSC_SUCCESS);
1819 }
1820 
1821 static PetscErrorCode MatView_SeqBAIJ_ASCII(Mat A, PetscViewer viewer)
1822 {
1823   Mat_SeqBAIJ      *a = (Mat_SeqBAIJ *)A->data;
1824   PetscInt          i, j, bs = A->rmap->bs, k, l, bs2 = a->bs2;
1825   PetscViewerFormat format;
1826 
1827   PetscFunctionBegin;
1828   if (A->structure_only) {
1829     PetscCall(MatView_SeqBAIJ_ASCII_structonly(A, viewer));
1830     PetscFunctionReturn(PETSC_SUCCESS);
1831   }
1832 
1833   PetscCall(PetscViewerGetFormat(viewer, &format));
1834   if (format == PETSC_VIEWER_ASCII_INFO || format == PETSC_VIEWER_ASCII_INFO_DETAIL) {
1835   } else if (format == PETSC_VIEWER_ASCII_MATLAB) {
1836     const char *matname;
1837     Mat         aij;
1838     PetscCall(MatConvert(A, MATSEQAIJ, MAT_INITIAL_MATRIX, &aij));
1839     PetscCall(PetscObjectGetName((PetscObject)A, &matname));
1840     PetscCall(PetscObjectSetName((PetscObject)aij, matname));
1841     PetscCall(MatView(aij, viewer));
1842     PetscCall(MatDestroy(&aij));
1843   } else if (format == PETSC_VIEWER_ASCII_FACTOR_INFO) {
1844     PetscFunctionReturn(PETSC_SUCCESS);
1845   } else if (format == PETSC_VIEWER_ASCII_COMMON) {
1846     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
1847     for (i = 0; i < a->mbs; i++) {
1848       for (j = 0; j < bs; j++) {
1849         PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i * bs + j));
1850         for (k = a->i[i]; k < a->i[i + 1]; k++) {
1851           for (l = 0; l < bs; l++) {
1852 #if defined(PETSC_USE_COMPLEX)
1853             if (PetscImaginaryPart(a->a[bs2 * k + l * bs + j]) > 0.0 && PetscRealPart(a->a[bs2 * k + l * bs + j]) != 0.0) {
1854               PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %gi) ", bs * a->j[k] + l, (double)PetscRealPart(a->a[bs2 * k + l * bs + j]), (double)PetscImaginaryPart(a->a[bs2 * k + l * bs + j])));
1855             } else if (PetscImaginaryPart(a->a[bs2 * k + l * bs + j]) < 0.0 && PetscRealPart(a->a[bs2 * k + l * bs + j]) != 0.0) {
1856               PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %gi) ", bs * a->j[k] + l, (double)PetscRealPart(a->a[bs2 * k + l * bs + j]), -(double)PetscImaginaryPart(a->a[bs2 * k + l * bs + j])));
1857             } else if (PetscRealPart(a->a[bs2 * k + l * bs + j]) != 0.0) {
1858               PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", bs * a->j[k] + l, (double)PetscRealPart(a->a[bs2 * k + l * bs + j])));
1859             }
1860 #else
1861             if (a->a[bs2 * k + l * bs + j] != 0.0) PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", bs * a->j[k] + l, (double)a->a[bs2 * k + l * bs + j]));
1862 #endif
1863           }
1864         }
1865         PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
1866       }
1867     }
1868     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
1869   } else {
1870     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_FALSE));
1871     for (i = 0; i < a->mbs; i++) {
1872       for (j = 0; j < bs; j++) {
1873         PetscCall(PetscViewerASCIIPrintf(viewer, "row %" PetscInt_FMT ":", i * bs + j));
1874         for (k = a->i[i]; k < a->i[i + 1]; k++) {
1875           for (l = 0; l < bs; l++) {
1876 #if defined(PETSC_USE_COMPLEX)
1877             if (PetscImaginaryPart(a->a[bs2 * k + l * bs + j]) > 0.0) {
1878               PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g + %g i) ", bs * a->j[k] + l, (double)PetscRealPart(a->a[bs2 * k + l * bs + j]), (double)PetscImaginaryPart(a->a[bs2 * k + l * bs + j])));
1879             } else if (PetscImaginaryPart(a->a[bs2 * k + l * bs + j]) < 0.0) {
1880               PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g - %g i) ", bs * a->j[k] + l, (double)PetscRealPart(a->a[bs2 * k + l * bs + j]), -(double)PetscImaginaryPart(a->a[bs2 * k + l * bs + j])));
1881             } else {
1882               PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", bs * a->j[k] + l, (double)PetscRealPart(a->a[bs2 * k + l * bs + j])));
1883             }
1884 #else
1885             PetscCall(PetscViewerASCIIPrintf(viewer, " (%" PetscInt_FMT ", %g) ", bs * a->j[k] + l, (double)a->a[bs2 * k + l * bs + j]));
1886 #endif
1887           }
1888         }
1889         PetscCall(PetscViewerASCIIPrintf(viewer, "\n"));
1890       }
1891     }
1892     PetscCall(PetscViewerASCIIUseTabs(viewer, PETSC_TRUE));
1893   }
1894   PetscCall(PetscViewerFlush(viewer));
1895   PetscFunctionReturn(PETSC_SUCCESS);
1896 }
1897 
1898 #include <petscdraw.h>
1899 static PetscErrorCode MatView_SeqBAIJ_Draw_Zoom(PetscDraw draw, void *Aa)
1900 {
1901   Mat               A = (Mat)Aa;
1902   Mat_SeqBAIJ      *a = (Mat_SeqBAIJ *)A->data;
1903   PetscInt          row, i, j, k, l, mbs = a->mbs, bs = A->rmap->bs, bs2 = a->bs2;
1904   PetscReal         xl, yl, xr, yr, x_l, x_r, y_l, y_r;
1905   MatScalar        *aa;
1906   PetscViewer       viewer;
1907   PetscViewerFormat format;
1908   int               color;
1909 
1910   PetscFunctionBegin;
1911   PetscCall(PetscObjectQuery((PetscObject)A, "Zoomviewer", (PetscObject *)&viewer));
1912   PetscCall(PetscViewerGetFormat(viewer, &format));
1913   PetscCall(PetscDrawGetCoordinates(draw, &xl, &yl, &xr, &yr));
1914 
1915   /* loop over matrix elements drawing boxes */
1916 
1917   if (format != PETSC_VIEWER_DRAW_CONTOUR) {
1918     PetscDrawCollectiveBegin(draw);
1919     /* Blue for negative, Cyan for zero and  Red for positive */
1920     color = PETSC_DRAW_BLUE;
1921     for (i = 0, row = 0; i < mbs; i++, row += bs) {
1922       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1923         y_l = A->rmap->N - row - 1.0;
1924         y_r = y_l + 1.0;
1925         x_l = a->j[j] * bs;
1926         x_r = x_l + 1.0;
1927         aa  = a->a + j * bs2;
1928         for (k = 0; k < bs; k++) {
1929           for (l = 0; l < bs; l++) {
1930             if (PetscRealPart(*aa++) >= 0.) continue;
1931             PetscCall(PetscDrawRectangle(draw, x_l + k, y_l - l, x_r + k, y_r - l, color, color, color, color));
1932           }
1933         }
1934       }
1935     }
1936     color = PETSC_DRAW_CYAN;
1937     for (i = 0, row = 0; i < mbs; i++, row += bs) {
1938       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1939         y_l = A->rmap->N - row - 1.0;
1940         y_r = y_l + 1.0;
1941         x_l = a->j[j] * bs;
1942         x_r = x_l + 1.0;
1943         aa  = a->a + j * bs2;
1944         for (k = 0; k < bs; k++) {
1945           for (l = 0; l < bs; l++) {
1946             if (PetscRealPart(*aa++) != 0.) continue;
1947             PetscCall(PetscDrawRectangle(draw, x_l + k, y_l - l, x_r + k, y_r - l, color, color, color, color));
1948           }
1949         }
1950       }
1951     }
1952     color = PETSC_DRAW_RED;
1953     for (i = 0, row = 0; i < mbs; i++, row += bs) {
1954       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1955         y_l = A->rmap->N - row - 1.0;
1956         y_r = y_l + 1.0;
1957         x_l = a->j[j] * bs;
1958         x_r = x_l + 1.0;
1959         aa  = a->a + j * bs2;
1960         for (k = 0; k < bs; k++) {
1961           for (l = 0; l < bs; l++) {
1962             if (PetscRealPart(*aa++) <= 0.) continue;
1963             PetscCall(PetscDrawRectangle(draw, x_l + k, y_l - l, x_r + k, y_r - l, color, color, color, color));
1964           }
1965         }
1966       }
1967     }
1968     PetscDrawCollectiveEnd(draw);
1969   } else {
1970     /* use contour shading to indicate magnitude of values */
1971     /* first determine max of all nonzero values */
1972     PetscReal minv = 0.0, maxv = 0.0;
1973     PetscDraw popup;
1974 
1975     for (i = 0; i < a->nz * a->bs2; i++) {
1976       if (PetscAbsScalar(a->a[i]) > maxv) maxv = PetscAbsScalar(a->a[i]);
1977     }
1978     if (minv >= maxv) maxv = minv + PETSC_SMALL;
1979     PetscCall(PetscDrawGetPopup(draw, &popup));
1980     PetscCall(PetscDrawScalePopup(popup, 0.0, maxv));
1981 
1982     PetscDrawCollectiveBegin(draw);
1983     for (i = 0, row = 0; i < mbs; i++, row += bs) {
1984       for (j = a->i[i]; j < a->i[i + 1]; j++) {
1985         y_l = A->rmap->N - row - 1.0;
1986         y_r = y_l + 1.0;
1987         x_l = a->j[j] * bs;
1988         x_r = x_l + 1.0;
1989         aa  = a->a + j * bs2;
1990         for (k = 0; k < bs; k++) {
1991           for (l = 0; l < bs; l++) {
1992             MatScalar v = *aa++;
1993             color       = PetscDrawRealToColor(PetscAbsScalar(v), minv, maxv);
1994             PetscCall(PetscDrawRectangle(draw, x_l + k, y_l - l, x_r + k, y_r - l, color, color, color, color));
1995           }
1996         }
1997       }
1998     }
1999     PetscDrawCollectiveEnd(draw);
2000   }
2001   PetscFunctionReturn(PETSC_SUCCESS);
2002 }
2003 
2004 static PetscErrorCode MatView_SeqBAIJ_Draw(Mat A, PetscViewer viewer)
2005 {
2006   PetscReal xl, yl, xr, yr, w, h;
2007   PetscDraw draw;
2008   PetscBool isnull;
2009 
2010   PetscFunctionBegin;
2011   PetscCall(PetscViewerDrawGetDraw(viewer, 0, &draw));
2012   PetscCall(PetscDrawIsNull(draw, &isnull));
2013   if (isnull) PetscFunctionReturn(PETSC_SUCCESS);
2014 
2015   xr = A->cmap->n;
2016   yr = A->rmap->N;
2017   h  = yr / 10.0;
2018   w  = xr / 10.0;
2019   xr += w;
2020   yr += h;
2021   xl = -w;
2022   yl = -h;
2023   PetscCall(PetscDrawSetCoordinates(draw, xl, yl, xr, yr));
2024   PetscCall(PetscObjectCompose((PetscObject)A, "Zoomviewer", (PetscObject)viewer));
2025   PetscCall(PetscDrawZoom(draw, MatView_SeqBAIJ_Draw_Zoom, A));
2026   PetscCall(PetscObjectCompose((PetscObject)A, "Zoomviewer", NULL));
2027   PetscCall(PetscDrawSave(draw));
2028   PetscFunctionReturn(PETSC_SUCCESS);
2029 }
2030 
2031 PetscErrorCode MatView_SeqBAIJ(Mat A, PetscViewer viewer)
2032 {
2033   PetscBool isascii, isbinary, isdraw;
2034 
2035   PetscFunctionBegin;
2036   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
2037   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
2038   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
2039   if (isascii) {
2040     PetscCall(MatView_SeqBAIJ_ASCII(A, viewer));
2041   } else if (isbinary) {
2042     PetscCall(MatView_SeqBAIJ_Binary(A, viewer));
2043   } else if (isdraw) {
2044     PetscCall(MatView_SeqBAIJ_Draw(A, viewer));
2045   } else {
2046     Mat B;
2047     PetscCall(MatConvert(A, MATSEQAIJ, MAT_INITIAL_MATRIX, &B));
2048     PetscCall(MatView(B, viewer));
2049     PetscCall(MatDestroy(&B));
2050   }
2051   PetscFunctionReturn(PETSC_SUCCESS);
2052 }
2053 
2054 PetscErrorCode MatGetValues_SeqBAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], PetscScalar v[])
2055 {
2056   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2057   PetscInt    *rp, k, low, high, t, row, nrow, i, col, l, *aj = a->j;
2058   PetscInt    *ai = a->i, *ailen = a->ilen;
2059   PetscInt     brow, bcol, ridx, cidx, bs = A->rmap->bs, bs2 = a->bs2;
2060   MatScalar   *ap, *aa = a->a;
2061 
2062   PetscFunctionBegin;
2063   for (k = 0; k < m; k++) { /* loop over rows */
2064     row  = im[k];
2065     brow = row / bs;
2066     if (row < 0) {
2067       v += n;
2068       continue;
2069     } /* negative row */
2070     PetscCheck(row < A->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Row %" PetscInt_FMT " too large", row);
2071     rp   = PetscSafePointerPlusOffset(aj, ai[brow]);
2072     ap   = PetscSafePointerPlusOffset(aa, bs2 * ai[brow]);
2073     nrow = ailen[brow];
2074     for (l = 0; l < n; l++) { /* loop over columns */
2075       if (in[l] < 0) {
2076         v++;
2077         continue;
2078       } /* negative column */
2079       PetscCheck(in[l] < A->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column %" PetscInt_FMT " too large", in[l]);
2080       col  = in[l];
2081       bcol = col / bs;
2082       cidx = col % bs;
2083       ridx = row % bs;
2084       high = nrow;
2085       low  = 0; /* assume unsorted */
2086       while (high - low > 5) {
2087         t = (low + high) / 2;
2088         if (rp[t] > bcol) high = t;
2089         else low = t;
2090       }
2091       for (i = low; i < high; i++) {
2092         if (rp[i] > bcol) break;
2093         if (rp[i] == bcol) {
2094           *v++ = ap[bs2 * i + bs * cidx + ridx];
2095           goto finished;
2096         }
2097       }
2098       *v++ = 0.0;
2099     finished:;
2100     }
2101   }
2102   PetscFunctionReturn(PETSC_SUCCESS);
2103 }
2104 
2105 PetscErrorCode MatSetValuesBlocked_SeqBAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
2106 {
2107   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ *)A->data;
2108   PetscInt          *rp, k, low, high, t, ii, jj, row, nrow, i, col, l, rmax, N, lastcol = -1;
2109   PetscInt          *imax = a->imax, *ai = a->i, *ailen = a->ilen;
2110   PetscInt          *aj = a->j, nonew = a->nonew, bs2 = a->bs2, bs = A->rmap->bs, stepval;
2111   PetscBool          roworiented = a->roworiented;
2112   const PetscScalar *value       = v;
2113   MatScalar         *ap = NULL, *aa = a->a, *bap;
2114 
2115   PetscFunctionBegin;
2116   if (roworiented) {
2117     stepval = (n - 1) * bs;
2118   } else {
2119     stepval = (m - 1) * bs;
2120   }
2121   for (k = 0; k < m; k++) { /* loop over added rows */
2122     row = im[k];
2123     if (row < 0) continue;
2124     PetscCheck(row < a->mbs, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Block row index too large %" PetscInt_FMT " max %" PetscInt_FMT, row, a->mbs - 1);
2125     rp = aj + ai[row];
2126     if (!A->structure_only) ap = aa + bs2 * ai[row];
2127     rmax = imax[row];
2128     nrow = ailen[row];
2129     low  = 0;
2130     high = nrow;
2131     for (l = 0; l < n; l++) { /* loop over added columns */
2132       if (in[l] < 0) continue;
2133       PetscCheck(in[l] < a->nbs, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Block column index too large %" PetscInt_FMT " max %" PetscInt_FMT, in[l], a->nbs - 1);
2134       col = in[l];
2135       if (!A->structure_only) {
2136         if (roworiented) {
2137           value = v + (k * (stepval + bs) + l) * bs;
2138         } else {
2139           value = v + (l * (stepval + bs) + k) * bs;
2140         }
2141       }
2142       if (col <= lastcol) low = 0;
2143       else high = nrow;
2144       lastcol = col;
2145       while (high - low > 7) {
2146         t = (low + high) / 2;
2147         if (rp[t] > col) high = t;
2148         else low = t;
2149       }
2150       for (i = low; i < high; i++) {
2151         if (rp[i] > col) break;
2152         if (rp[i] == col) {
2153           if (A->structure_only) goto noinsert2;
2154           bap = ap + bs2 * i;
2155           if (roworiented) {
2156             if (is == ADD_VALUES) {
2157               for (ii = 0; ii < bs; ii++, value += stepval) {
2158                 for (jj = ii; jj < bs2; jj += bs) bap[jj] += *value++;
2159               }
2160             } else {
2161               for (ii = 0; ii < bs; ii++, value += stepval) {
2162                 for (jj = ii; jj < bs2; jj += bs) bap[jj] = *value++;
2163               }
2164             }
2165           } else {
2166             if (is == ADD_VALUES) {
2167               for (ii = 0; ii < bs; ii++, value += bs + stepval) {
2168                 for (jj = 0; jj < bs; jj++) bap[jj] += value[jj];
2169                 bap += bs;
2170               }
2171             } else {
2172               for (ii = 0; ii < bs; ii++, value += bs + stepval) {
2173                 for (jj = 0; jj < bs; jj++) bap[jj] = value[jj];
2174                 bap += bs;
2175               }
2176             }
2177           }
2178           goto noinsert2;
2179         }
2180       }
2181       if (nonew == 1) goto noinsert2;
2182       PetscCheck(nonew != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new blocked index new nonzero block (%" PetscInt_FMT ", %" PetscInt_FMT ") in the matrix", row, col);
2183       if (A->structure_only) {
2184         MatSeqXAIJReallocateAIJ_structure_only(A, a->mbs, bs2, nrow, row, col, rmax, ai, aj, rp, imax, nonew, MatScalar);
2185       } else {
2186         MatSeqXAIJReallocateAIJ(A, a->mbs, bs2, nrow, row, col, rmax, aa, ai, aj, rp, ap, imax, nonew, MatScalar);
2187       }
2188       N = nrow++ - 1;
2189       high++;
2190       /* shift up all the later entries in this row */
2191       PetscCall(PetscArraymove(rp + i + 1, rp + i, N - i + 1));
2192       rp[i] = col;
2193       if (!A->structure_only) {
2194         PetscCall(PetscArraymove(ap + bs2 * (i + 1), ap + bs2 * i, bs2 * (N - i + 1)));
2195         bap = ap + bs2 * i;
2196         if (roworiented) {
2197           for (ii = 0; ii < bs; ii++, value += stepval) {
2198             for (jj = ii; jj < bs2; jj += bs) bap[jj] = *value++;
2199           }
2200         } else {
2201           for (ii = 0; ii < bs; ii++, value += stepval) {
2202             for (jj = 0; jj < bs; jj++) *bap++ = *value++;
2203           }
2204         }
2205       }
2206     noinsert2:;
2207       low = i;
2208     }
2209     ailen[row] = nrow;
2210   }
2211   PetscFunctionReturn(PETSC_SUCCESS);
2212 }
2213 
2214 PetscErrorCode MatAssemblyEnd_SeqBAIJ(Mat A, MatAssemblyType mode)
2215 {
2216   Mat_SeqBAIJ *a      = (Mat_SeqBAIJ *)A->data;
2217   PetscInt     fshift = 0, i, *ai = a->i, *aj = a->j, *imax = a->imax;
2218   PetscInt     m = A->rmap->N, *ip, N, *ailen = a->ilen;
2219   PetscInt     mbs = a->mbs, bs2 = a->bs2, rmax = 0;
2220   MatScalar   *aa    = a->a, *ap;
2221   PetscReal    ratio = 0.6;
2222 
2223   PetscFunctionBegin;
2224   if (mode == MAT_FLUSH_ASSEMBLY || (A->was_assembled && A->ass_nonzerostate == A->nonzerostate)) PetscFunctionReturn(PETSC_SUCCESS);
2225 
2226   if (m) rmax = ailen[0];
2227   for (i = 1; i < mbs; i++) {
2228     /* move each row back by the amount of empty slots (fshift) before it*/
2229     fshift += imax[i - 1] - ailen[i - 1];
2230     rmax = PetscMax(rmax, ailen[i]);
2231     if (fshift) {
2232       ip = aj + ai[i];
2233       ap = aa + bs2 * ai[i];
2234       N  = ailen[i];
2235       PetscCall(PetscArraymove(ip - fshift, ip, N));
2236       if (!A->structure_only) PetscCall(PetscArraymove(ap - bs2 * fshift, ap, bs2 * N));
2237     }
2238     ai[i] = ai[i - 1] + ailen[i - 1];
2239   }
2240   if (mbs) {
2241     fshift += imax[mbs - 1] - ailen[mbs - 1];
2242     ai[mbs] = ai[mbs - 1] + ailen[mbs - 1];
2243   }
2244 
2245   /* reset ilen and imax for each row */
2246   a->nonzerorowcnt = 0;
2247   if (A->structure_only) {
2248     PetscCall(PetscFree2(a->imax, a->ilen));
2249   } else { /* !A->structure_only */
2250     for (i = 0; i < mbs; i++) {
2251       ailen[i] = imax[i] = ai[i + 1] - ai[i];
2252       a->nonzerorowcnt += ((ai[i + 1] - ai[i]) > 0);
2253     }
2254   }
2255   a->nz = ai[mbs];
2256 
2257   /* diagonals may have moved, so kill the diagonal pointers */
2258   a->idiagvalid = PETSC_FALSE;
2259   if (fshift) PetscCheck(a->nounused != -1, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unused space detected in matrix: %" PetscInt_FMT " X %" PetscInt_FMT " block size %" PetscInt_FMT ", %" PetscInt_FMT " unneeded", m, A->cmap->n, A->rmap->bs, fshift * bs2);
2260   PetscCall(PetscInfo(A, "Matrix size: %" PetscInt_FMT " X %" PetscInt_FMT ", block size %" PetscInt_FMT "; storage space: %" PetscInt_FMT " unneeded, %" PetscInt_FMT " used\n", m, A->cmap->n, A->rmap->bs, fshift * bs2, a->nz * bs2));
2261   PetscCall(PetscInfo(A, "Number of mallocs during MatSetValues is %" PetscInt_FMT "\n", a->reallocs));
2262   PetscCall(PetscInfo(A, "Most nonzeros blocks in any row is %" PetscInt_FMT "\n", rmax));
2263 
2264   A->info.mallocs += a->reallocs;
2265   a->reallocs         = 0;
2266   A->info.nz_unneeded = (PetscReal)fshift * bs2;
2267   a->rmax             = rmax;
2268 
2269   if (!A->structure_only) PetscCall(MatCheckCompressedRow(A, a->nonzerorowcnt, &a->compressedrow, a->i, mbs, ratio));
2270   PetscFunctionReturn(PETSC_SUCCESS);
2271 }
2272 
2273 /*
2274    This function returns an array of flags which indicate the locations of contiguous
2275    blocks that should be zeroed. for eg: if bs = 3  and is = [0,1,2,3,5,6,7,8,9]
2276    then the resulting sizes = [3,1,1,3,1] corresponding to sets [(0,1,2),(3),(5),(6,7,8),(9)]
2277    Assume: sizes should be long enough to hold all the values.
2278 */
2279 static PetscErrorCode MatZeroRows_SeqBAIJ_Check_Blocks(PetscInt idx[], PetscInt n, PetscInt bs, PetscInt sizes[], PetscInt *bs_max)
2280 {
2281   PetscInt j = 0;
2282 
2283   PetscFunctionBegin;
2284   for (PetscInt i = 0; i < n; j++) {
2285     PetscInt row = idx[i];
2286     if (row % bs != 0) { /* Not the beginning of a block */
2287       sizes[j] = 1;
2288       i++;
2289     } else if (i + bs > n) { /* complete block doesn't exist (at idx end) */
2290       sizes[j] = 1;          /* Also makes sure at least 'bs' values exist for next else */
2291       i++;
2292     } else { /* Beginning of the block, so check if the complete block exists */
2293       PetscBool flg = PETSC_TRUE;
2294       for (PetscInt k = 1; k < bs; k++) {
2295         if (row + k != idx[i + k]) { /* break in the block */
2296           flg = PETSC_FALSE;
2297           break;
2298         }
2299       }
2300       if (flg) { /* No break in the bs */
2301         sizes[j] = bs;
2302         i += bs;
2303       } else {
2304         sizes[j] = 1;
2305         i++;
2306       }
2307     }
2308   }
2309   *bs_max = j;
2310   PetscFunctionReturn(PETSC_SUCCESS);
2311 }
2312 
2313 PetscErrorCode MatZeroRows_SeqBAIJ(Mat A, PetscInt is_n, const PetscInt is_idx[], PetscScalar diag, Vec x, Vec b)
2314 {
2315   Mat_SeqBAIJ       *baij = (Mat_SeqBAIJ *)A->data;
2316   PetscInt           i, j, k, count, *rows;
2317   PetscInt           bs = A->rmap->bs, bs2 = baij->bs2, *sizes, row, bs_max;
2318   PetscScalar        zero = 0.0;
2319   MatScalar         *aa;
2320   const PetscScalar *xx;
2321   PetscScalar       *bb;
2322 
2323   PetscFunctionBegin;
2324   /* fix right-hand side if needed */
2325   if (x && b) {
2326     PetscCall(VecGetArrayRead(x, &xx));
2327     PetscCall(VecGetArray(b, &bb));
2328     for (i = 0; i < is_n; i++) bb[is_idx[i]] = diag * xx[is_idx[i]];
2329     PetscCall(VecRestoreArrayRead(x, &xx));
2330     PetscCall(VecRestoreArray(b, &bb));
2331   }
2332 
2333   /* Make a copy of the IS and  sort it */
2334   /* allocate memory for rows,sizes */
2335   PetscCall(PetscMalloc2(is_n, &rows, 2 * is_n, &sizes));
2336 
2337   /* copy IS values to rows, and sort them */
2338   for (i = 0; i < is_n; i++) rows[i] = is_idx[i];
2339   PetscCall(PetscSortInt(is_n, rows));
2340 
2341   if (baij->keepnonzeropattern) {
2342     for (i = 0; i < is_n; i++) sizes[i] = 1;
2343     bs_max = is_n;
2344   } else {
2345     PetscCall(MatZeroRows_SeqBAIJ_Check_Blocks(rows, is_n, bs, sizes, &bs_max));
2346     A->nonzerostate++;
2347   }
2348 
2349   for (i = 0, j = 0; i < bs_max; j += sizes[i], i++) {
2350     row = rows[j];
2351     PetscCheck(row >= 0 && row <= A->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", row);
2352     count = (baij->i[row / bs + 1] - baij->i[row / bs]) * bs;
2353     aa    = baij->a + baij->i[row / bs] * bs2 + (row % bs);
2354     if (sizes[i] == bs && !baij->keepnonzeropattern) {
2355       if (diag != (PetscScalar)0.0) {
2356         if (baij->ilen[row / bs] > 0) {
2357           baij->ilen[row / bs]       = 1;
2358           baij->j[baij->i[row / bs]] = row / bs;
2359 
2360           PetscCall(PetscArrayzero(aa, count * bs));
2361         }
2362         /* Now insert all the diagonal values for this bs */
2363         for (k = 0; k < bs; k++) PetscUseTypeMethod(A, setvalues, 1, rows + j + k, 1, rows + j + k, &diag, INSERT_VALUES);
2364       } else { /* (diag == 0.0) */
2365         baij->ilen[row / bs] = 0;
2366       } /* end (diag == 0.0) */
2367     } else { /* (sizes[i] != bs) */
2368       PetscAssert(sizes[i] == 1, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Internal Error. Value should be 1");
2369       for (k = 0; k < count; k++) {
2370         aa[0] = zero;
2371         aa += bs;
2372       }
2373       if (diag != (PetscScalar)0.0) PetscUseTypeMethod(A, setvalues, 1, rows + j, 1, rows + j, &diag, INSERT_VALUES);
2374     }
2375   }
2376 
2377   PetscCall(PetscFree2(rows, sizes));
2378   PetscCall(MatAssemblyEnd_SeqBAIJ(A, MAT_FINAL_ASSEMBLY));
2379   PetscFunctionReturn(PETSC_SUCCESS);
2380 }
2381 
2382 static PetscErrorCode MatZeroRowsColumns_SeqBAIJ(Mat A, PetscInt is_n, const PetscInt is_idx[], PetscScalar diag, Vec x, Vec b)
2383 {
2384   Mat_SeqBAIJ       *baij = (Mat_SeqBAIJ *)A->data;
2385   PetscInt           i, j, k, count;
2386   PetscInt           bs = A->rmap->bs, bs2 = baij->bs2, row, col;
2387   PetscScalar        zero = 0.0;
2388   MatScalar         *aa;
2389   const PetscScalar *xx;
2390   PetscScalar       *bb;
2391   PetscBool         *zeroed, vecs = PETSC_FALSE;
2392 
2393   PetscFunctionBegin;
2394   /* fix right-hand side if needed */
2395   if (x && b) {
2396     PetscCall(VecGetArrayRead(x, &xx));
2397     PetscCall(VecGetArray(b, &bb));
2398     vecs = PETSC_TRUE;
2399   }
2400 
2401   /* zero the columns */
2402   PetscCall(PetscCalloc1(A->rmap->n, &zeroed));
2403   for (i = 0; i < is_n; i++) {
2404     PetscCheck(is_idx[i] >= 0 && is_idx[i] < A->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "row %" PetscInt_FMT " out of range", is_idx[i]);
2405     zeroed[is_idx[i]] = PETSC_TRUE;
2406   }
2407   for (i = 0; i < A->rmap->N; i++) {
2408     if (!zeroed[i]) {
2409       row = i / bs;
2410       for (j = baij->i[row]; j < baij->i[row + 1]; j++) {
2411         for (k = 0; k < bs; k++) {
2412           col = bs * baij->j[j] + k;
2413           if (zeroed[col]) {
2414             aa = baij->a + j * bs2 + (i % bs) + bs * k;
2415             if (vecs) bb[i] -= aa[0] * xx[col];
2416             aa[0] = 0.0;
2417           }
2418         }
2419       }
2420     } else if (vecs) bb[i] = diag * xx[i];
2421   }
2422   PetscCall(PetscFree(zeroed));
2423   if (vecs) {
2424     PetscCall(VecRestoreArrayRead(x, &xx));
2425     PetscCall(VecRestoreArray(b, &bb));
2426   }
2427 
2428   /* zero the rows */
2429   for (i = 0; i < is_n; i++) {
2430     row   = is_idx[i];
2431     count = (baij->i[row / bs + 1] - baij->i[row / bs]) * bs;
2432     aa    = baij->a + baij->i[row / bs] * bs2 + (row % bs);
2433     for (k = 0; k < count; k++) {
2434       aa[0] = zero;
2435       aa += bs;
2436     }
2437     if (diag != (PetscScalar)0.0) PetscUseTypeMethod(A, setvalues, 1, &row, 1, &row, &diag, INSERT_VALUES);
2438   }
2439   PetscCall(MatAssemblyEnd_SeqBAIJ(A, MAT_FINAL_ASSEMBLY));
2440   PetscFunctionReturn(PETSC_SUCCESS);
2441 }
2442 
2443 PetscErrorCode MatSetValues_SeqBAIJ(Mat A, PetscInt m, const PetscInt im[], PetscInt n, const PetscInt in[], const PetscScalar v[], InsertMode is)
2444 {
2445   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2446   PetscInt    *rp, k, low, high, t, ii, row, nrow, i, col, l, rmax, N, lastcol = -1;
2447   PetscInt    *imax = a->imax, *ai = a->i, *ailen = a->ilen;
2448   PetscInt    *aj = a->j, nonew = a->nonew, bs = A->rmap->bs, brow, bcol;
2449   PetscInt     ridx, cidx, bs2                 = a->bs2;
2450   PetscBool    roworiented = a->roworiented;
2451   MatScalar   *ap = NULL, value = 0.0, *aa = a->a, *bap;
2452 
2453   PetscFunctionBegin;
2454   for (k = 0; k < m; k++) { /* loop over added rows */
2455     row  = im[k];
2456     brow = row / bs;
2457     if (row < 0) continue;
2458     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);
2459     rp = PetscSafePointerPlusOffset(aj, ai[brow]);
2460     if (!A->structure_only) ap = PetscSafePointerPlusOffset(aa, bs2 * ai[brow]);
2461     rmax = imax[brow];
2462     nrow = ailen[brow];
2463     low  = 0;
2464     high = nrow;
2465     for (l = 0; l < n; l++) { /* loop over added columns */
2466       if (in[l] < 0) continue;
2467       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);
2468       col  = in[l];
2469       bcol = col / bs;
2470       ridx = row % bs;
2471       cidx = col % bs;
2472       if (!A->structure_only) {
2473         if (roworiented) {
2474           value = v[l + k * n];
2475         } else {
2476           value = v[k + l * m];
2477         }
2478       }
2479       if (col <= lastcol) low = 0;
2480       else high = nrow;
2481       lastcol = col;
2482       while (high - low > 7) {
2483         t = (low + high) / 2;
2484         if (rp[t] > bcol) high = t;
2485         else low = t;
2486       }
2487       for (i = low; i < high; i++) {
2488         if (rp[i] > bcol) break;
2489         if (rp[i] == bcol) {
2490           bap = PetscSafePointerPlusOffset(ap, bs2 * i + bs * cidx + ridx);
2491           if (!A->structure_only) {
2492             if (is == ADD_VALUES) *bap += value;
2493             else *bap = value;
2494           }
2495           goto noinsert1;
2496         }
2497       }
2498       if (nonew == 1) goto noinsert1;
2499       PetscCheck(nonew != -1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Inserting a new nonzero (%" PetscInt_FMT ", %" PetscInt_FMT ") in the matrix", row, col);
2500       if (A->structure_only) {
2501         MatSeqXAIJReallocateAIJ_structure_only(A, a->mbs, bs2, nrow, brow, bcol, rmax, ai, aj, rp, imax, nonew, MatScalar);
2502       } else {
2503         MatSeqXAIJReallocateAIJ(A, a->mbs, bs2, nrow, brow, bcol, rmax, aa, ai, aj, rp, ap, imax, nonew, MatScalar);
2504       }
2505       N = nrow++ - 1;
2506       high++;
2507       /* shift up all the later entries in this row */
2508       PetscCall(PetscArraymove(rp + i + 1, rp + i, N - i + 1));
2509       rp[i] = bcol;
2510       if (!A->structure_only) {
2511         PetscCall(PetscArraymove(ap + bs2 * (i + 1), ap + bs2 * i, bs2 * (N - i + 1)));
2512         PetscCall(PetscArrayzero(ap + bs2 * i, bs2));
2513         ap[bs2 * i + bs * cidx + ridx] = value;
2514       }
2515       a->nz++;
2516     noinsert1:;
2517       low = i;
2518     }
2519     ailen[brow] = nrow;
2520   }
2521   PetscFunctionReturn(PETSC_SUCCESS);
2522 }
2523 
2524 static PetscErrorCode MatILUFactor_SeqBAIJ(Mat inA, IS row, IS col, const MatFactorInfo *info)
2525 {
2526   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)inA->data;
2527   Mat          outA;
2528   PetscBool    row_identity, col_identity;
2529 
2530   PetscFunctionBegin;
2531   PetscCheck(info->levels == 0, PETSC_COMM_SELF, PETSC_ERR_SUP, "Only levels = 0 supported for in-place ILU");
2532   PetscCall(ISIdentity(row, &row_identity));
2533   PetscCall(ISIdentity(col, &col_identity));
2534   PetscCheck(row_identity && col_identity, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Row and column permutations must be identity for in-place ILU");
2535 
2536   outA            = inA;
2537   inA->factortype = MAT_FACTOR_LU;
2538   PetscCall(PetscFree(inA->solvertype));
2539   PetscCall(PetscStrallocpy(MATSOLVERPETSC, &inA->solvertype));
2540 
2541   PetscCall(PetscObjectReference((PetscObject)row));
2542   PetscCall(ISDestroy(&a->row));
2543   a->row = row;
2544   PetscCall(PetscObjectReference((PetscObject)col));
2545   PetscCall(ISDestroy(&a->col));
2546   a->col = col;
2547 
2548   /* Create the invert permutation so that it can be used in MatLUFactorNumeric() */
2549   PetscCall(ISDestroy(&a->icol));
2550   PetscCall(ISInvertPermutation(col, PETSC_DECIDE, &a->icol));
2551 
2552   PetscCall(MatSeqBAIJSetNumericFactorization_inplace(inA, (PetscBool)(row_identity && col_identity)));
2553   if (!a->solve_work) PetscCall(PetscMalloc1(inA->rmap->N + inA->rmap->bs, &a->solve_work));
2554   PetscCall(MatLUFactorNumeric(outA, inA, info));
2555   PetscFunctionReturn(PETSC_SUCCESS);
2556 }
2557 
2558 static PetscErrorCode MatSeqBAIJSetColumnIndices_SeqBAIJ(Mat mat, const PetscInt *indices)
2559 {
2560   Mat_SeqBAIJ *baij = (Mat_SeqBAIJ *)mat->data;
2561 
2562   PetscFunctionBegin;
2563   baij->nz = baij->maxnz;
2564   PetscCall(PetscArraycpy(baij->j, indices, baij->nz));
2565   PetscCall(PetscArraycpy(baij->ilen, baij->imax, baij->mbs));
2566   PetscFunctionReturn(PETSC_SUCCESS);
2567 }
2568 
2569 /*@
2570   MatSeqBAIJSetColumnIndices - Set the column indices for all the block rows in the matrix.
2571 
2572   Input Parameters:
2573 + mat     - the `MATSEQBAIJ` matrix
2574 - indices - the block column indices
2575 
2576   Level: advanced
2577 
2578   Notes:
2579   This can be called if you have precomputed the nonzero structure of the
2580   matrix and want to provide it to the matrix object to improve the performance
2581   of the `MatSetValues()` operation.
2582 
2583   You MUST have set the correct numbers of nonzeros per row in the call to
2584   `MatCreateSeqBAIJ()`, and the columns indices MUST be sorted.
2585 
2586   MUST be called before any calls to `MatSetValues()`
2587 
2588 .seealso: [](ch_matrices), `Mat`, `MATSEQBAIJ`, `MatSetValues()`
2589 @*/
2590 PetscErrorCode MatSeqBAIJSetColumnIndices(Mat mat, PetscInt *indices)
2591 {
2592   PetscFunctionBegin;
2593   PetscValidHeaderSpecific(mat, MAT_CLASSID, 1);
2594   PetscAssertPointer(indices, 2);
2595   PetscUseMethod(mat, "MatSeqBAIJSetColumnIndices_C", (Mat, const PetscInt *), (mat, (const PetscInt *)indices));
2596   PetscFunctionReturn(PETSC_SUCCESS);
2597 }
2598 
2599 static PetscErrorCode MatGetRowMaxAbs_SeqBAIJ(Mat A, Vec v, PetscInt idx[])
2600 {
2601   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2602   PetscInt     i, j, n, row, bs, *ai, *aj, mbs;
2603   PetscReal    atmp;
2604   PetscScalar *x, zero = 0.0;
2605   MatScalar   *aa;
2606   PetscInt     ncols, brow, krow, kcol;
2607 
2608   PetscFunctionBegin;
2609   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2610   bs  = A->rmap->bs;
2611   aa  = a->a;
2612   ai  = a->i;
2613   aj  = a->j;
2614   mbs = a->mbs;
2615 
2616   PetscCall(VecSet(v, zero));
2617   PetscCall(VecGetArray(v, &x));
2618   PetscCall(VecGetLocalSize(v, &n));
2619   PetscCheck(n == A->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
2620   for (i = 0; i < mbs; i++) {
2621     ncols = ai[1] - ai[0];
2622     ai++;
2623     brow = bs * i;
2624     for (j = 0; j < ncols; j++) {
2625       for (kcol = 0; kcol < bs; kcol++) {
2626         for (krow = 0; krow < bs; krow++) {
2627           atmp = PetscAbsScalar(*aa);
2628           aa++;
2629           row = brow + krow; /* row index */
2630           if (PetscAbsScalar(x[row]) < atmp) {
2631             x[row] = atmp;
2632             if (idx) idx[row] = bs * (*aj) + kcol;
2633           }
2634         }
2635       }
2636       aj++;
2637     }
2638   }
2639   PetscCall(VecRestoreArray(v, &x));
2640   PetscFunctionReturn(PETSC_SUCCESS);
2641 }
2642 
2643 static PetscErrorCode MatGetRowSumAbs_SeqBAIJ(Mat A, Vec v)
2644 {
2645   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2646   PetscInt     i, j, n, row, bs, *ai, mbs;
2647   PetscReal    atmp;
2648   PetscScalar *x, zero = 0.0;
2649   MatScalar   *aa;
2650   PetscInt     ncols, brow, krow, kcol;
2651 
2652   PetscFunctionBegin;
2653   PetscCheck(!A->factortype, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Not for factored matrix");
2654   bs  = A->rmap->bs;
2655   aa  = a->a;
2656   ai  = a->i;
2657   mbs = a->mbs;
2658 
2659   PetscCall(VecSet(v, zero));
2660   PetscCall(VecGetArrayWrite(v, &x));
2661   PetscCall(VecGetLocalSize(v, &n));
2662   PetscCheck(n == A->rmap->N, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Nonconforming matrix and vector");
2663   for (i = 0; i < mbs; i++) {
2664     ncols = ai[1] - ai[0];
2665     ai++;
2666     brow = bs * i;
2667     for (j = 0; j < ncols; j++) {
2668       for (kcol = 0; kcol < bs; kcol++) {
2669         for (krow = 0; krow < bs; krow++) {
2670           atmp = PetscAbsScalar(*aa);
2671           aa++;
2672           row = brow + krow; /* row index */
2673           x[row] += atmp;
2674         }
2675       }
2676     }
2677   }
2678   PetscCall(VecRestoreArrayWrite(v, &x));
2679   PetscFunctionReturn(PETSC_SUCCESS);
2680 }
2681 
2682 static PetscErrorCode MatCopy_SeqBAIJ(Mat A, Mat B, MatStructure str)
2683 {
2684   PetscFunctionBegin;
2685   /* If the two matrices have the same copy implementation, use fast copy. */
2686   if (str == SAME_NONZERO_PATTERN && (A->ops->copy == B->ops->copy)) {
2687     Mat_SeqBAIJ *a    = (Mat_SeqBAIJ *)A->data;
2688     Mat_SeqBAIJ *b    = (Mat_SeqBAIJ *)B->data;
2689     PetscInt     ambs = a->mbs, bmbs = b->mbs, abs = A->rmap->bs, bbs = B->rmap->bs, bs2 = abs * abs;
2690 
2691     PetscCheck(a->i[ambs] == b->i[bmbs], PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Number of nonzero blocks in matrices A %" PetscInt_FMT " and B %" PetscInt_FMT " are different", a->i[ambs], b->i[bmbs]);
2692     PetscCheck(abs == bbs, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Block size A %" PetscInt_FMT " and B %" PetscInt_FMT " are different", abs, bbs);
2693     PetscCall(PetscArraycpy(b->a, a->a, bs2 * a->i[ambs]));
2694     PetscCall(PetscObjectStateIncrease((PetscObject)B));
2695   } else {
2696     PetscCall(MatCopy_Basic(A, B, str));
2697   }
2698   PetscFunctionReturn(PETSC_SUCCESS);
2699 }
2700 
2701 static PetscErrorCode MatSeqBAIJGetArray_SeqBAIJ(Mat A, PetscScalar *array[])
2702 {
2703   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2704 
2705   PetscFunctionBegin;
2706   *array = a->a;
2707   PetscFunctionReturn(PETSC_SUCCESS);
2708 }
2709 
2710 static PetscErrorCode MatSeqBAIJRestoreArray_SeqBAIJ(Mat A, PetscScalar *array[])
2711 {
2712   PetscFunctionBegin;
2713   *array = NULL;
2714   PetscFunctionReturn(PETSC_SUCCESS);
2715 }
2716 
2717 PetscErrorCode MatAXPYGetPreallocation_SeqBAIJ(Mat Y, Mat X, PetscInt *nnz)
2718 {
2719   PetscInt     bs = Y->rmap->bs, mbs = Y->rmap->N / bs;
2720   Mat_SeqBAIJ *x = (Mat_SeqBAIJ *)X->data;
2721   Mat_SeqBAIJ *y = (Mat_SeqBAIJ *)Y->data;
2722 
2723   PetscFunctionBegin;
2724   /* Set the number of nonzeros in the new matrix */
2725   PetscCall(MatAXPYGetPreallocation_SeqX_private(mbs, x->i, x->j, y->i, y->j, nnz));
2726   PetscFunctionReturn(PETSC_SUCCESS);
2727 }
2728 
2729 PetscErrorCode MatAXPY_SeqBAIJ(Mat Y, PetscScalar a, Mat X, MatStructure str)
2730 {
2731   Mat_SeqBAIJ *x = (Mat_SeqBAIJ *)X->data, *y = (Mat_SeqBAIJ *)Y->data;
2732   PetscInt     bs = Y->rmap->bs, bs2 = bs * bs;
2733   PetscBLASInt one = 1;
2734 
2735   PetscFunctionBegin;
2736   if (str == UNKNOWN_NONZERO_PATTERN || (PetscDefined(USE_DEBUG) && str == SAME_NONZERO_PATTERN)) {
2737     PetscBool e = x->nz == y->nz && x->mbs == y->mbs && bs == X->rmap->bs ? PETSC_TRUE : PETSC_FALSE;
2738     if (e) {
2739       PetscCall(PetscArraycmp(x->i, y->i, x->mbs + 1, &e));
2740       if (e) {
2741         PetscCall(PetscArraycmp(x->j, y->j, x->i[x->mbs], &e));
2742         if (e) str = SAME_NONZERO_PATTERN;
2743       }
2744     }
2745     if (!e) PetscCheck(str != SAME_NONZERO_PATTERN, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "MatStructure is not SAME_NONZERO_PATTERN");
2746   }
2747   if (str == SAME_NONZERO_PATTERN) {
2748     PetscScalar  alpha = a;
2749     PetscBLASInt bnz;
2750     PetscCall(PetscBLASIntCast(x->nz * bs2, &bnz));
2751     PetscCallBLAS("BLASaxpy", BLASaxpy_(&bnz, &alpha, x->a, &one, y->a, &one));
2752     PetscCall(PetscObjectStateIncrease((PetscObject)Y));
2753   } else if (str == SUBSET_NONZERO_PATTERN) { /* nonzeros of X is a subset of Y's */
2754     PetscCall(MatAXPY_Basic(Y, a, X, str));
2755   } else {
2756     Mat       B;
2757     PetscInt *nnz;
2758     PetscCheck(bs == X->rmap->bs, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Matrices must have same block size");
2759     PetscCall(PetscMalloc1(Y->rmap->N, &nnz));
2760     PetscCall(MatCreate(PetscObjectComm((PetscObject)Y), &B));
2761     PetscCall(PetscObjectSetName((PetscObject)B, ((PetscObject)Y)->name));
2762     PetscCall(MatSetSizes(B, Y->rmap->n, Y->cmap->n, Y->rmap->N, Y->cmap->N));
2763     PetscCall(MatSetBlockSizesFromMats(B, Y, Y));
2764     PetscCall(MatSetType(B, (MatType)((PetscObject)Y)->type_name));
2765     PetscCall(MatAXPYGetPreallocation_SeqBAIJ(Y, X, nnz));
2766     PetscCall(MatSeqBAIJSetPreallocation(B, bs, 0, nnz));
2767     PetscCall(MatAXPY_BasicWithPreallocation(B, Y, a, X, str));
2768     PetscCall(MatHeaderMerge(Y, &B));
2769     PetscCall(PetscFree(nnz));
2770   }
2771   PetscFunctionReturn(PETSC_SUCCESS);
2772 }
2773 
2774 PETSC_INTERN PetscErrorCode MatConjugate_SeqBAIJ(Mat A)
2775 {
2776 #if PetscDefined(USE_COMPLEX)
2777   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2778   PetscInt     i, nz = a->bs2 * a->i[a->mbs];
2779   MatScalar   *aa = a->a;
2780 
2781   PetscFunctionBegin;
2782   for (i = 0; i < nz; i++) aa[i] = PetscConj(aa[i]);
2783   PetscFunctionReturn(PETSC_SUCCESS);
2784 #else
2785   (void)A;
2786   return PETSC_SUCCESS;
2787 #endif
2788 }
2789 
2790 static PetscErrorCode MatRealPart_SeqBAIJ(Mat A)
2791 {
2792 #if PetscDefined(USE_COMPLEX)
2793   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2794   PetscInt     i, nz = a->bs2 * a->i[a->mbs];
2795   MatScalar   *aa = a->a;
2796 
2797   PetscFunctionBegin;
2798   for (i = 0; i < nz; i++) aa[i] = PetscRealPart(aa[i]);
2799   PetscFunctionReturn(PETSC_SUCCESS);
2800 #else
2801   (void)A;
2802   return PETSC_SUCCESS;
2803 #endif
2804 }
2805 
2806 static PetscErrorCode MatImaginaryPart_SeqBAIJ(Mat A)
2807 {
2808 #if PetscDefined(USE_COMPLEX)
2809   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2810   PetscInt     i, nz = a->bs2 * a->i[a->mbs];
2811   MatScalar   *aa = a->a;
2812 
2813   PetscFunctionBegin;
2814   for (i = 0; i < nz; i++) aa[i] = PetscImaginaryPart(aa[i]);
2815   PetscFunctionReturn(PETSC_SUCCESS);
2816 #else
2817   (void)A;
2818   return PETSC_SUCCESS;
2819 #endif
2820 }
2821 
2822 /*
2823     Code almost identical to MatGetColumnIJ_SeqAIJ() should share common code
2824 */
2825 static PetscErrorCode MatGetColumnIJ_SeqBAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
2826 {
2827   Mat_SeqBAIJ *a  = (Mat_SeqBAIJ *)A->data;
2828   PetscInt     bs = A->rmap->bs, i, *collengths, *cia, *cja, n = A->cmap->n / bs, m = A->rmap->n / bs;
2829   PetscInt     nz = a->i[m], row, *jj, mr, col;
2830 
2831   PetscFunctionBegin;
2832   *nn = n;
2833   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
2834   PetscCheck(!symmetric, PETSC_COMM_SELF, PETSC_ERR_SUP, "Not for BAIJ matrices");
2835   PetscCall(PetscCalloc1(n, &collengths));
2836   PetscCall(PetscMalloc1(n + 1, &cia));
2837   PetscCall(PetscMalloc1(nz, &cja));
2838   jj = a->j;
2839   for (i = 0; i < nz; i++) collengths[jj[i]]++;
2840   cia[0] = oshift;
2841   for (i = 0; i < n; i++) cia[i + 1] = cia[i] + collengths[i];
2842   PetscCall(PetscArrayzero(collengths, n));
2843   jj = a->j;
2844   for (row = 0; row < m; row++) {
2845     mr = a->i[row + 1] - a->i[row];
2846     for (i = 0; i < mr; i++) {
2847       col = *jj++;
2848 
2849       cja[cia[col] + collengths[col]++ - oshift] = row + oshift;
2850     }
2851   }
2852   PetscCall(PetscFree(collengths));
2853   *ia = cia;
2854   *ja = cja;
2855   PetscFunctionReturn(PETSC_SUCCESS);
2856 }
2857 
2858 static PetscErrorCode MatRestoreColumnIJ_SeqBAIJ(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscBool *done)
2859 {
2860   PetscFunctionBegin;
2861   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
2862   PetscCall(PetscFree(*ia));
2863   PetscCall(PetscFree(*ja));
2864   PetscFunctionReturn(PETSC_SUCCESS);
2865 }
2866 
2867 /*
2868  MatGetColumnIJ_SeqBAIJ_Color() and MatRestoreColumnIJ_SeqBAIJ_Color() are customized from
2869  MatGetColumnIJ_SeqBAIJ() and MatRestoreColumnIJ_SeqBAIJ() by adding an output
2870  spidx[], index of a->a, to be used in MatTransposeColoringCreate() and MatFDColoringCreate()
2871  */
2872 PetscErrorCode MatGetColumnIJ_SeqBAIJ_Color(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *nn, const PetscInt *ia[], const PetscInt *ja[], PetscInt *spidx[], PetscBool *done)
2873 {
2874   Mat_SeqBAIJ *a = (Mat_SeqBAIJ *)A->data;
2875   PetscInt     i, *collengths, *cia, *cja, n = a->nbs, m = a->mbs;
2876   PetscInt     nz = a->i[m], row, *jj, mr, col;
2877   PetscInt    *cspidx;
2878 
2879   PetscFunctionBegin;
2880   *nn = n;
2881   if (!ia) PetscFunctionReturn(PETSC_SUCCESS);
2882 
2883   PetscCall(PetscCalloc1(n, &collengths));
2884   PetscCall(PetscMalloc1(n + 1, &cia));
2885   PetscCall(PetscMalloc1(nz, &cja));
2886   PetscCall(PetscMalloc1(nz, &cspidx));
2887   jj = a->j;
2888   for (i = 0; i < nz; i++) collengths[jj[i]]++;
2889   cia[0] = oshift;
2890   for (i = 0; i < n; i++) cia[i + 1] = cia[i] + collengths[i];
2891   PetscCall(PetscArrayzero(collengths, n));
2892   jj = a->j;
2893   for (row = 0; row < m; row++) {
2894     mr = a->i[row + 1] - a->i[row];
2895     for (i = 0; i < mr; i++) {
2896       col                                         = *jj++;
2897       cspidx[cia[col] + collengths[col] - oshift] = a->i[row] + i; /* index of a->j */
2898       cja[cia[col] + collengths[col]++ - oshift]  = row + oshift;
2899     }
2900   }
2901   PetscCall(PetscFree(collengths));
2902   *ia    = cia;
2903   *ja    = cja;
2904   *spidx = cspidx;
2905   PetscFunctionReturn(PETSC_SUCCESS);
2906 }
2907 
2908 PetscErrorCode MatRestoreColumnIJ_SeqBAIJ_Color(Mat A, PetscInt oshift, PetscBool symmetric, PetscBool inodecompressed, PetscInt *n, const PetscInt *ia[], const PetscInt *ja[], PetscInt *spidx[], PetscBool *done)
2909 {
2910   PetscFunctionBegin;
2911   PetscCall(MatRestoreColumnIJ_SeqBAIJ(A, oshift, symmetric, inodecompressed, n, ia, ja, done));
2912   PetscCall(PetscFree(*spidx));
2913   PetscFunctionReturn(PETSC_SUCCESS);
2914 }
2915 
2916 static PetscErrorCode MatShift_SeqBAIJ(Mat Y, PetscScalar a)
2917 {
2918   Mat_SeqBAIJ *aij = (Mat_SeqBAIJ *)Y->data;
2919 
2920   PetscFunctionBegin;
2921   if (!Y->preallocated || !aij->nz) PetscCall(MatSeqBAIJSetPreallocation(Y, Y->rmap->bs, 1, NULL));
2922   PetscCall(MatShift_Basic(Y, a));
2923   PetscFunctionReturn(PETSC_SUCCESS);
2924 }
2925 
2926 PetscErrorCode MatEliminateZeros_SeqBAIJ(Mat A, PetscBool keep)
2927 {
2928   Mat_SeqBAIJ *a      = (Mat_SeqBAIJ *)A->data;
2929   PetscInt     fshift = 0, fshift_prev = 0, i, *ai = a->i, *aj = a->j, *imax = a->imax, j, k;
2930   PetscInt     m = A->rmap->N, *ailen = a->ilen;
2931   PetscInt     mbs = a->mbs, bs2 = a->bs2, rmax = 0;
2932   MatScalar   *aa = a->a, *ap;
2933   PetscBool    zero;
2934 
2935   PetscFunctionBegin;
2936   PetscCheck(A->assembled, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Cannot eliminate zeros for unassembled matrix");
2937   if (m) rmax = ailen[0];
2938   for (i = 1; i <= mbs; i++) {
2939     for (k = ai[i - 1]; k < ai[i]; k++) {
2940       zero = PETSC_TRUE;
2941       ap   = aa + bs2 * k;
2942       for (j = 0; j < bs2 && zero; j++) {
2943         if (ap[j] != 0.0) zero = PETSC_FALSE;
2944       }
2945       if (zero && (aj[k] != i - 1 || !keep)) fshift++;
2946       else {
2947         if (zero && aj[k] == i - 1) PetscCall(PetscInfo(A, "Keep the diagonal block at row %" PetscInt_FMT "\n", i - 1));
2948         aj[k - fshift] = aj[k];
2949         PetscCall(PetscArraymove(ap - bs2 * fshift, ap, bs2));
2950       }
2951     }
2952     ai[i - 1] -= fshift_prev;
2953     fshift_prev  = fshift;
2954     ailen[i - 1] = imax[i - 1] = ai[i] - fshift - ai[i - 1];
2955     a->nonzerorowcnt += ((ai[i] - fshift - ai[i - 1]) > 0);
2956     rmax = PetscMax(rmax, ailen[i - 1]);
2957   }
2958   if (fshift) {
2959     if (mbs) {
2960       ai[mbs] -= fshift;
2961       a->nz = ai[mbs];
2962     }
2963     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));
2964     A->nonzerostate++;
2965     A->info.nz_unneeded += (PetscReal)fshift;
2966     a->rmax = rmax;
2967     PetscCall(MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY));
2968     PetscCall(MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY));
2969   }
2970   PetscFunctionReturn(PETSC_SUCCESS);
2971 }
2972 
2973 static struct _MatOps MatOps_Values = {MatSetValues_SeqBAIJ,
2974                                        MatGetRow_SeqBAIJ,
2975                                        MatRestoreRow_SeqBAIJ,
2976                                        MatMult_SeqBAIJ_N,
2977                                        /* 4*/ MatMultAdd_SeqBAIJ_N,
2978                                        MatMultTranspose_SeqBAIJ,
2979                                        MatMultTransposeAdd_SeqBAIJ,
2980                                        NULL,
2981                                        NULL,
2982                                        NULL,
2983                                        /* 10*/ NULL,
2984                                        MatLUFactor_SeqBAIJ,
2985                                        NULL,
2986                                        NULL,
2987                                        MatTranspose_SeqBAIJ,
2988                                        /* 15*/ MatGetInfo_SeqBAIJ,
2989                                        MatEqual_SeqBAIJ,
2990                                        MatGetDiagonal_SeqBAIJ,
2991                                        MatDiagonalScale_SeqBAIJ,
2992                                        MatNorm_SeqBAIJ,
2993                                        /* 20*/ NULL,
2994                                        MatAssemblyEnd_SeqBAIJ,
2995                                        MatSetOption_SeqBAIJ,
2996                                        MatZeroEntries_SeqBAIJ,
2997                                        /* 24*/ MatZeroRows_SeqBAIJ,
2998                                        NULL,
2999                                        NULL,
3000                                        NULL,
3001                                        NULL,
3002                                        /* 29*/ MatSetUp_Seq_Hash,
3003                                        NULL,
3004                                        NULL,
3005                                        NULL,
3006                                        NULL,
3007                                        /* 34*/ MatDuplicate_SeqBAIJ,
3008                                        NULL,
3009                                        NULL,
3010                                        MatILUFactor_SeqBAIJ,
3011                                        NULL,
3012                                        /* 39*/ MatAXPY_SeqBAIJ,
3013                                        MatCreateSubMatrices_SeqBAIJ,
3014                                        MatIncreaseOverlap_SeqBAIJ,
3015                                        MatGetValues_SeqBAIJ,
3016                                        MatCopy_SeqBAIJ,
3017                                        /* 44*/ NULL,
3018                                        MatScale_SeqBAIJ,
3019                                        MatShift_SeqBAIJ,
3020                                        NULL,
3021                                        MatZeroRowsColumns_SeqBAIJ,
3022                                        /* 49*/ NULL,
3023                                        MatGetRowIJ_SeqBAIJ,
3024                                        MatRestoreRowIJ_SeqBAIJ,
3025                                        MatGetColumnIJ_SeqBAIJ,
3026                                        MatRestoreColumnIJ_SeqBAIJ,
3027                                        /* 54*/ MatFDColoringCreate_SeqXAIJ,
3028                                        NULL,
3029                                        NULL,
3030                                        NULL,
3031                                        MatSetValuesBlocked_SeqBAIJ,
3032                                        /* 59*/ MatCreateSubMatrix_SeqBAIJ,
3033                                        MatDestroy_SeqBAIJ,
3034                                        MatView_SeqBAIJ,
3035                                        NULL,
3036                                        NULL,
3037                                        /* 64*/ NULL,
3038                                        NULL,
3039                                        NULL,
3040                                        NULL,
3041                                        MatGetRowMaxAbs_SeqBAIJ,
3042                                        /* 69*/ NULL,
3043                                        MatConvert_Basic,
3044                                        NULL,
3045                                        MatFDColoringApply_BAIJ,
3046                                        NULL,
3047                                        /* 74*/ NULL,
3048                                        NULL,
3049                                        NULL,
3050                                        NULL,
3051                                        MatLoad_SeqBAIJ,
3052                                        /* 79*/ NULL,
3053                                        NULL,
3054                                        NULL,
3055                                        NULL,
3056                                        NULL,
3057                                        /* 84*/ NULL,
3058                                        NULL,
3059                                        NULL,
3060                                        NULL,
3061                                        NULL,
3062                                        /* 89*/ NULL,
3063                                        NULL,
3064                                        NULL,
3065                                        NULL,
3066                                        MatConjugate_SeqBAIJ,
3067                                        /* 94*/ NULL,
3068                                        NULL,
3069                                        MatRealPart_SeqBAIJ,
3070                                        MatImaginaryPart_SeqBAIJ,
3071                                        NULL,
3072                                        /* 99*/ NULL,
3073                                        NULL,
3074                                        NULL,
3075                                        NULL,
3076                                        NULL,
3077                                        /*104*/ NULL,
3078                                        NULL,
3079                                        NULL,
3080                                        NULL,
3081                                        NULL,
3082                                        /*109*/ NULL,
3083                                        NULL,
3084                                        MatMultHermitianTranspose_SeqBAIJ,
3085                                        MatMultHermitianTransposeAdd_SeqBAIJ,
3086                                        NULL,
3087                                        /*114*/ NULL,
3088                                        MatGetColumnReductions_SeqBAIJ,
3089                                        MatInvertBlockDiagonal_SeqBAIJ,
3090                                        NULL,
3091                                        NULL,
3092                                        /*119*/ NULL,
3093                                        NULL,
3094                                        NULL,
3095                                        NULL,
3096                                        NULL,
3097                                        /*124*/ NULL,
3098                                        NULL,
3099                                        MatSetBlockSizes_Default,
3100                                        NULL,
3101                                        MatFDColoringSetUp_SeqXAIJ,
3102                                        /*129*/ NULL,
3103                                        MatCreateMPIMatConcatenateSeqMat_SeqBAIJ,
3104                                        MatDestroySubMatrices_SeqBAIJ,
3105                                        NULL,
3106                                        NULL,
3107                                        /*134*/ NULL,
3108                                        NULL,
3109                                        MatEliminateZeros_SeqBAIJ,
3110                                        MatGetRowSumAbs_SeqBAIJ,
3111                                        NULL,
3112                                        /*139*/ NULL,
3113                                        NULL,
3114                                        MatCopyHashToXAIJ_Seq_Hash,
3115                                        NULL,
3116                                        NULL};
3117 
3118 static PetscErrorCode MatStoreValues_SeqBAIJ(Mat mat)
3119 {
3120   Mat_SeqBAIJ *aij = (Mat_SeqBAIJ *)mat->data;
3121   PetscInt     nz  = aij->i[aij->mbs] * aij->bs2;
3122 
3123   PetscFunctionBegin;
3124   PetscCheck(aij->nonew == 1, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatSetOption(A,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);first");
3125 
3126   /* allocate space for values if not already there */
3127   if (!aij->saved_values) PetscCall(PetscMalloc1(nz + 1, &aij->saved_values));
3128 
3129   /* copy values over */
3130   PetscCall(PetscArraycpy(aij->saved_values, aij->a, nz));
3131   PetscFunctionReturn(PETSC_SUCCESS);
3132 }
3133 
3134 static PetscErrorCode MatRetrieveValues_SeqBAIJ(Mat mat)
3135 {
3136   Mat_SeqBAIJ *aij = (Mat_SeqBAIJ *)mat->data;
3137   PetscInt     nz  = aij->i[aij->mbs] * aij->bs2;
3138 
3139   PetscFunctionBegin;
3140   PetscCheck(aij->nonew == 1, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatSetOption(A,MAT_NEW_NONZERO_LOCATIONS,PETSC_FALSE);first");
3141   PetscCheck(aij->saved_values, PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call MatStoreValues(A);first");
3142 
3143   /* copy values over */
3144   PetscCall(PetscArraycpy(aij->a, aij->saved_values, nz));
3145   PetscFunctionReturn(PETSC_SUCCESS);
3146 }
3147 
3148 PETSC_INTERN PetscErrorCode MatConvert_SeqBAIJ_SeqAIJ(Mat, MatType, MatReuse, Mat *);
3149 PETSC_INTERN PetscErrorCode MatConvert_SeqBAIJ_SeqSBAIJ(Mat, MatType, MatReuse, Mat *);
3150 
3151 PetscErrorCode MatSeqBAIJSetPreallocation_SeqBAIJ(Mat B, PetscInt bs, PetscInt nz, const PetscInt nnz[])
3152 {
3153   Mat_SeqBAIJ *b = (Mat_SeqBAIJ *)B->data;
3154   PetscInt     i, mbs, nbs, bs2;
3155   PetscBool    flg = PETSC_FALSE, skipallocation = PETSC_FALSE, realalloc = PETSC_FALSE;
3156 
3157   PetscFunctionBegin;
3158   if (B->hash_active) {
3159     PetscInt bs;
3160     B->ops[0] = b->cops;
3161     PetscCall(PetscHMapIJVDestroy(&b->ht));
3162     PetscCall(MatGetBlockSize(B, &bs));
3163     if (bs > 1) PetscCall(PetscHSetIJDestroy(&b->bht));
3164     PetscCall(PetscFree(b->dnz));
3165     PetscCall(PetscFree(b->bdnz));
3166     B->hash_active = PETSC_FALSE;
3167   }
3168   if (nz >= 0 || nnz) realalloc = PETSC_TRUE;
3169   if (nz == MAT_SKIP_ALLOCATION) {
3170     skipallocation = PETSC_TRUE;
3171     nz             = 0;
3172   }
3173 
3174   PetscCall(MatSetBlockSize(B, bs));
3175   PetscCall(PetscLayoutSetUp(B->rmap));
3176   PetscCall(PetscLayoutSetUp(B->cmap));
3177   PetscCall(PetscLayoutGetBlockSize(B->rmap, &bs));
3178 
3179   B->preallocated = PETSC_TRUE;
3180 
3181   mbs = B->rmap->n / bs;
3182   nbs = B->cmap->n / bs;
3183   bs2 = bs * bs;
3184 
3185   PetscCheck(mbs * bs == B->rmap->n && nbs * bs == B->cmap->n, PETSC_COMM_SELF, PETSC_ERR_ARG_SIZ, "Number rows %" PetscInt_FMT ", cols %" PetscInt_FMT " must be divisible by blocksize %" PetscInt_FMT, B->rmap->N, B->cmap->n, bs);
3186 
3187   if (nz == PETSC_DEFAULT || nz == PETSC_DECIDE) nz = 5;
3188   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nz cannot be less than 0: value %" PetscInt_FMT, nz);
3189   if (nnz) {
3190     for (i = 0; i < mbs; i++) {
3191       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]);
3192       PetscCheck(nnz[i] <= nbs, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "nnz cannot be greater than block row length: local row %" PetscInt_FMT " value %" PetscInt_FMT " rowlength %" PetscInt_FMT, i, nnz[i], nbs);
3193     }
3194   }
3195 
3196   PetscOptionsBegin(PetscObjectComm((PetscObject)B), NULL, "Optimize options for SEQBAIJ matrix 2 ", "Mat");
3197   PetscCall(PetscOptionsBool("-mat_no_unroll", "Do not optimize for block size (slow)", NULL, flg, &flg, NULL));
3198   PetscOptionsEnd();
3199 
3200   if (!flg) {
3201     switch (bs) {
3202     case 1:
3203       B->ops->mult    = MatMult_SeqBAIJ_1;
3204       B->ops->multadd = MatMultAdd_SeqBAIJ_1;
3205       break;
3206     case 2:
3207       B->ops->mult    = MatMult_SeqBAIJ_2;
3208       B->ops->multadd = MatMultAdd_SeqBAIJ_2;
3209       break;
3210     case 3:
3211       B->ops->mult    = MatMult_SeqBAIJ_3;
3212       B->ops->multadd = MatMultAdd_SeqBAIJ_3;
3213       break;
3214     case 4:
3215       B->ops->mult    = MatMult_SeqBAIJ_4;
3216       B->ops->multadd = MatMultAdd_SeqBAIJ_4;
3217       break;
3218     case 5:
3219       B->ops->mult    = MatMult_SeqBAIJ_5;
3220       B->ops->multadd = MatMultAdd_SeqBAIJ_5;
3221       break;
3222     case 6:
3223       B->ops->mult    = MatMult_SeqBAIJ_6;
3224       B->ops->multadd = MatMultAdd_SeqBAIJ_6;
3225       break;
3226     case 7:
3227       B->ops->mult    = MatMult_SeqBAIJ_7;
3228       B->ops->multadd = MatMultAdd_SeqBAIJ_7;
3229       break;
3230     case 9: {
3231       PetscInt version = 1;
3232       PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)B)->prefix, "-mat_baij_mult_version", &version, NULL));
3233       switch (version) {
3234 #if defined(PETSC_HAVE_IMMINTRIN_H) && defined(__AVX2__) && defined(__FMA__) && defined(PETSC_USE_REAL_DOUBLE) && !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_64BIT_INDICES)
3235       case 1:
3236         B->ops->mult    = MatMult_SeqBAIJ_9_AVX2;
3237         B->ops->multadd = MatMultAdd_SeqBAIJ_9_AVX2;
3238         PetscCall(PetscInfo(B, "Using AVX2 for MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", bs));
3239         break;
3240 #endif
3241       default:
3242         B->ops->mult    = MatMult_SeqBAIJ_N;
3243         B->ops->multadd = MatMultAdd_SeqBAIJ_N;
3244         PetscCall(PetscInfo(B, "Using BLAS for MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", bs));
3245         break;
3246       }
3247       break;
3248     }
3249     case 11:
3250       B->ops->mult    = MatMult_SeqBAIJ_11;
3251       B->ops->multadd = MatMultAdd_SeqBAIJ_11;
3252       break;
3253     case 12: {
3254       PetscInt version = 1;
3255       PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)B)->prefix, "-mat_baij_mult_version", &version, NULL));
3256       switch (version) {
3257       case 1:
3258         B->ops->mult    = MatMult_SeqBAIJ_12_ver1;
3259         B->ops->multadd = MatMultAdd_SeqBAIJ_12_ver1;
3260         PetscCall(PetscInfo(B, "Using version %" PetscInt_FMT " of MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", version, bs));
3261         break;
3262       case 2:
3263         B->ops->mult    = MatMult_SeqBAIJ_12_ver2;
3264         B->ops->multadd = MatMultAdd_SeqBAIJ_12_ver2;
3265         PetscCall(PetscInfo(B, "Using version %" PetscInt_FMT " of MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", version, bs));
3266         break;
3267 #if defined(PETSC_HAVE_IMMINTRIN_H) && defined(__AVX2__) && defined(__FMA__) && defined(PETSC_USE_REAL_DOUBLE) && !defined(PETSC_USE_COMPLEX) && !defined(PETSC_USE_64BIT_INDICES)
3268       case 3:
3269         B->ops->mult    = MatMult_SeqBAIJ_12_AVX2;
3270         B->ops->multadd = MatMultAdd_SeqBAIJ_12_ver1;
3271         PetscCall(PetscInfo(B, "Using AVX2 for MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", bs));
3272         break;
3273 #endif
3274       default:
3275         B->ops->mult    = MatMult_SeqBAIJ_N;
3276         B->ops->multadd = MatMultAdd_SeqBAIJ_N;
3277         PetscCall(PetscInfo(B, "Using BLAS for MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", bs));
3278         break;
3279       }
3280       break;
3281     }
3282     case 15: {
3283       PetscInt version = 1;
3284       PetscCall(PetscOptionsGetInt(NULL, ((PetscObject)B)->prefix, "-mat_baij_mult_version", &version, NULL));
3285       switch (version) {
3286       case 1:
3287         B->ops->mult = MatMult_SeqBAIJ_15_ver1;
3288         PetscCall(PetscInfo(B, "Using version %" PetscInt_FMT " of MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", version, bs));
3289         break;
3290       case 2:
3291         B->ops->mult = MatMult_SeqBAIJ_15_ver2;
3292         PetscCall(PetscInfo(B, "Using version %" PetscInt_FMT " of MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", version, bs));
3293         break;
3294       case 3:
3295         B->ops->mult = MatMult_SeqBAIJ_15_ver3;
3296         PetscCall(PetscInfo(B, "Using version %" PetscInt_FMT " of MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", version, bs));
3297         break;
3298       case 4:
3299         B->ops->mult = MatMult_SeqBAIJ_15_ver4;
3300         PetscCall(PetscInfo(B, "Using version %" PetscInt_FMT " of MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", version, bs));
3301         break;
3302       default:
3303         B->ops->mult = MatMult_SeqBAIJ_N;
3304         PetscCall(PetscInfo(B, "Using BLAS for MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", bs));
3305         break;
3306       }
3307       B->ops->multadd = MatMultAdd_SeqBAIJ_N;
3308       break;
3309     }
3310     default:
3311       B->ops->mult    = MatMult_SeqBAIJ_N;
3312       B->ops->multadd = MatMultAdd_SeqBAIJ_N;
3313       PetscCall(PetscInfo(B, "Using BLAS for MatMult for BAIJ for blocksize %" PetscInt_FMT "\n", bs));
3314       break;
3315     }
3316   }
3317   B->ops->sor = MatSOR_SeqBAIJ;
3318   b->mbs      = mbs;
3319   b->nbs      = nbs;
3320   if (!skipallocation) {
3321     if (!b->imax) {
3322       PetscCall(PetscMalloc2(mbs, &b->imax, mbs, &b->ilen));
3323 
3324       b->free_imax_ilen = PETSC_TRUE;
3325     }
3326     /* b->ilen will count nonzeros in each block row so far. */
3327     for (i = 0; i < mbs; i++) b->ilen[i] = 0;
3328     if (!nnz) {
3329       if (nz == PETSC_DEFAULT || nz == PETSC_DECIDE) nz = 5;
3330       else if (nz < 0) nz = 1;
3331       nz = PetscMin(nz, nbs);
3332       for (i = 0; i < mbs; i++) b->imax[i] = nz;
3333       PetscCall(PetscIntMultError(nz, mbs, &nz));
3334     } else {
3335       PetscInt64 nz64 = 0;
3336       for (i = 0; i < mbs; i++) {
3337         b->imax[i] = nnz[i];
3338         nz64 += nnz[i];
3339       }
3340       PetscCall(PetscIntCast(nz64, &nz));
3341     }
3342 
3343     /* allocate the matrix space */
3344     PetscCall(MatSeqXAIJFreeAIJ(B, &b->a, &b->j, &b->i));
3345     PetscCall(PetscShmgetAllocateArray(nz, sizeof(PetscInt), (void **)&b->j));
3346     PetscCall(PetscShmgetAllocateArray(B->rmap->N + 1, sizeof(PetscInt), (void **)&b->i));
3347     if (B->structure_only) {
3348       b->free_a = PETSC_FALSE;
3349     } else {
3350       PetscInt nzbs2 = 0;
3351       PetscCall(PetscIntMultError(nz, bs2, &nzbs2));
3352       PetscCall(PetscShmgetAllocateArray(nzbs2, sizeof(PetscScalar), (void **)&b->a));
3353       b->free_a = PETSC_TRUE;
3354       PetscCall(PetscArrayzero(b->a, nzbs2));
3355     }
3356     b->free_ij = PETSC_TRUE;
3357     PetscCall(PetscArrayzero(b->j, nz));
3358 
3359     b->i[0] = 0;
3360     for (i = 1; i < mbs + 1; i++) b->i[i] = b->i[i - 1] + b->imax[i - 1];
3361   } else {
3362     b->free_a  = PETSC_FALSE;
3363     b->free_ij = PETSC_FALSE;
3364   }
3365 
3366   b->bs2              = bs2;
3367   b->mbs              = mbs;
3368   b->nz               = 0;
3369   b->maxnz            = nz;
3370   B->info.nz_unneeded = (PetscReal)b->maxnz * bs2;
3371   B->was_assembled    = PETSC_FALSE;
3372   B->assembled        = PETSC_FALSE;
3373   if (realalloc) PetscCall(MatSetOption(B, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_TRUE));
3374   PetscFunctionReturn(PETSC_SUCCESS);
3375 }
3376 
3377 static PetscErrorCode MatSeqBAIJSetPreallocationCSR_SeqBAIJ(Mat B, PetscInt bs, const PetscInt ii[], const PetscInt jj[], const PetscScalar V[])
3378 {
3379   PetscInt     i, m, nz, nz_max = 0, *nnz;
3380   PetscScalar *values      = NULL;
3381   PetscBool    roworiented = ((Mat_SeqBAIJ *)B->data)->roworiented;
3382 
3383   PetscFunctionBegin;
3384   PetscCheck(bs >= 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Invalid block size specified, must be positive but it is %" PetscInt_FMT, bs);
3385   PetscCall(PetscLayoutSetBlockSize(B->rmap, bs));
3386   PetscCall(PetscLayoutSetBlockSize(B->cmap, bs));
3387   PetscCall(PetscLayoutSetUp(B->rmap));
3388   PetscCall(PetscLayoutSetUp(B->cmap));
3389   PetscCall(PetscLayoutGetBlockSize(B->rmap, &bs));
3390   m = B->rmap->n / bs;
3391 
3392   PetscCheck(ii[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "ii[0] must be 0 but it is %" PetscInt_FMT, ii[0]);
3393   PetscCall(PetscMalloc1(m + 1, &nnz));
3394   for (i = 0; i < m; i++) {
3395     nz = ii[i + 1] - ii[i];
3396     PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Local row %" PetscInt_FMT " has a negative number of columns %" PetscInt_FMT, i, nz);
3397     nz_max = PetscMax(nz_max, nz);
3398     nnz[i] = nz;
3399   }
3400   PetscCall(MatSeqBAIJSetPreallocation(B, bs, 0, nnz));
3401   PetscCall(PetscFree(nnz));
3402 
3403   values = (PetscScalar *)V;
3404   if (!values) PetscCall(PetscCalloc1(bs * bs * (nz_max + 1), &values));
3405   for (i = 0; i < m; i++) {
3406     PetscInt        ncols = ii[i + 1] - ii[i];
3407     const PetscInt *icols = jj + ii[i];
3408     if (bs == 1 || !roworiented) {
3409       const PetscScalar *svals = values + (V ? (bs * bs * ii[i]) : 0);
3410       PetscCall(MatSetValuesBlocked_SeqBAIJ(B, 1, &i, ncols, icols, svals, INSERT_VALUES));
3411     } else {
3412       PetscInt j;
3413       for (j = 0; j < ncols; j++) {
3414         const PetscScalar *svals = values + (V ? (bs * bs * (ii[i] + j)) : 0);
3415         PetscCall(MatSetValuesBlocked_SeqBAIJ(B, 1, &i, 1, &icols[j], svals, INSERT_VALUES));
3416       }
3417     }
3418   }
3419   if (!V) PetscCall(PetscFree(values));
3420   PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
3421   PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
3422   PetscCall(MatSetOption(B, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
3423   PetscFunctionReturn(PETSC_SUCCESS);
3424 }
3425 
3426 /*@C
3427   MatSeqBAIJGetArray - gives read/write access to the array where the data for a `MATSEQBAIJ` matrix is stored
3428 
3429   Not Collective
3430 
3431   Input Parameter:
3432 . A - a `MATSEQBAIJ` matrix
3433 
3434   Output Parameter:
3435 . array - pointer to the data
3436 
3437   Level: intermediate
3438 
3439 .seealso: [](ch_matrices), `Mat`, `MATSEQBAIJ`, `MatSeqBAIJRestoreArray()`, `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArray()`
3440 @*/
3441 PetscErrorCode MatSeqBAIJGetArray(Mat A, PetscScalar *array[])
3442 {
3443   PetscFunctionBegin;
3444   PetscUseMethod(A, "MatSeqBAIJGetArray_C", (Mat, PetscScalar **), (A, array));
3445   PetscFunctionReturn(PETSC_SUCCESS);
3446 }
3447 
3448 /*@C
3449   MatSeqBAIJRestoreArray - returns access to the array where the data for a `MATSEQBAIJ` matrix is stored obtained by `MatSeqBAIJGetArray()`
3450 
3451   Not Collective
3452 
3453   Input Parameters:
3454 + A     - a `MATSEQBAIJ` matrix
3455 - array - pointer to the data
3456 
3457   Level: intermediate
3458 
3459 .seealso: [](ch_matrices), `Mat`, `MatSeqBAIJGetArray()`, `MatSeqAIJGetArray()`, `MatSeqAIJRestoreArray()`
3460 @*/
3461 PetscErrorCode MatSeqBAIJRestoreArray(Mat A, PetscScalar *array[])
3462 {
3463   PetscFunctionBegin;
3464   PetscUseMethod(A, "MatSeqBAIJRestoreArray_C", (Mat, PetscScalar **), (A, array));
3465   PetscFunctionReturn(PETSC_SUCCESS);
3466 }
3467 
3468 /*MC
3469    MATSEQBAIJ - MATSEQBAIJ = "seqbaij" - A matrix type to be used for sequential block sparse matrices, based on
3470    block sparse compressed row format.
3471 
3472    Options Database Keys:
3473 + -mat_type seqbaij - sets the matrix type to `MATSEQBAIJ` during a call to `MatSetFromOptions()`
3474 - -mat_baij_mult_version version - indicate the version of the matrix-vector product to use (0 often indicates using BLAS)
3475 
3476    Level: beginner
3477 
3478    Notes:
3479    `MatSetOptions`(,`MAT_STRUCTURE_ONLY`,`PETSC_TRUE`) may be called for this matrix type. In this no
3480    space is allocated for the nonzero entries and any entries passed with `MatSetValues()` are ignored
3481 
3482    Run with `-info` to see what version of the matrix-vector product is being used
3483 
3484 .seealso: [](ch_matrices), `Mat`, `MatCreateSeqBAIJ()`
3485 M*/
3486 
3487 PETSC_INTERN PetscErrorCode MatConvert_SeqBAIJ_SeqBSTRM(Mat, MatType, MatReuse, Mat *);
3488 
3489 PETSC_EXTERN PetscErrorCode MatCreate_SeqBAIJ(Mat B)
3490 {
3491   PetscMPIInt  size;
3492   Mat_SeqBAIJ *b;
3493 
3494   PetscFunctionBegin;
3495   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)B), &size));
3496   PetscCheck(size == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Comm must be of size 1");
3497 
3498   PetscCall(PetscNew(&b));
3499   B->data   = (void *)b;
3500   B->ops[0] = MatOps_Values;
3501 
3502   b->row          = NULL;
3503   b->col          = NULL;
3504   b->icol         = NULL;
3505   b->reallocs     = 0;
3506   b->saved_values = NULL;
3507 
3508   b->roworiented        = PETSC_TRUE;
3509   b->nonew              = 0;
3510   b->diag               = NULL;
3511   B->spptr              = NULL;
3512   B->info.nz_unneeded   = (PetscReal)b->maxnz * b->bs2;
3513   b->keepnonzeropattern = PETSC_FALSE;
3514 
3515   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqBAIJGetArray_C", MatSeqBAIJGetArray_SeqBAIJ));
3516   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqBAIJRestoreArray_C", MatSeqBAIJRestoreArray_SeqBAIJ));
3517   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatStoreValues_C", MatStoreValues_SeqBAIJ));
3518   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatRetrieveValues_C", MatRetrieveValues_SeqBAIJ));
3519   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqBAIJSetColumnIndices_C", MatSeqBAIJSetColumnIndices_SeqBAIJ));
3520   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqbaij_seqaij_C", MatConvert_SeqBAIJ_SeqAIJ));
3521   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqbaij_seqsbaij_C", MatConvert_SeqBAIJ_SeqSBAIJ));
3522   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqBAIJSetPreallocation_C", MatSeqBAIJSetPreallocation_SeqBAIJ));
3523   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatSeqBAIJSetPreallocationCSR_C", MatSeqBAIJSetPreallocationCSR_SeqBAIJ));
3524   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatIsTranspose_C", MatIsTranspose_SeqBAIJ));
3525 #if defined(PETSC_HAVE_HYPRE)
3526   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqbaij_hypre_C", MatConvert_AIJ_HYPRE));
3527 #endif
3528   PetscCall(PetscObjectComposeFunction((PetscObject)B, "MatConvert_seqbaij_is_C", MatConvert_XAIJ_IS));
3529   PetscCall(PetscObjectChangeTypeName((PetscObject)B, MATSEQBAIJ));
3530   PetscFunctionReturn(PETSC_SUCCESS);
3531 }
3532 
3533 PETSC_INTERN PetscErrorCode MatDuplicateNoCreate_SeqBAIJ(Mat C, Mat A, MatDuplicateOption cpvalues, PetscBool mallocmatspace)
3534 {
3535   Mat_SeqBAIJ *c = (Mat_SeqBAIJ *)C->data, *a = (Mat_SeqBAIJ *)A->data;
3536   PetscInt     i, mbs = a->mbs, nz = a->nz, bs2 = a->bs2;
3537 
3538   PetscFunctionBegin;
3539   PetscCheck(A->assembled, PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONGSTATE, "Cannot duplicate unassembled matrix");
3540   PetscCheck(a->i[mbs] == nz, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Corrupt matrix");
3541 
3542   if (cpvalues == MAT_SHARE_NONZERO_PATTERN) {
3543     c->imax           = a->imax;
3544     c->ilen           = a->ilen;
3545     c->free_imax_ilen = PETSC_FALSE;
3546   } else {
3547     PetscCall(PetscMalloc2(mbs, &c->imax, mbs, &c->ilen));
3548     for (i = 0; i < mbs; i++) {
3549       c->imax[i] = a->imax[i];
3550       c->ilen[i] = a->ilen[i];
3551     }
3552     c->free_imax_ilen = PETSC_TRUE;
3553   }
3554 
3555   /* allocate the matrix space */
3556   if (mallocmatspace) {
3557     if (cpvalues == MAT_SHARE_NONZERO_PATTERN) {
3558       PetscCall(PetscShmgetAllocateArray(bs2 * nz, sizeof(PetscScalar), (void **)&c->a));
3559       PetscCall(PetscArrayzero(c->a, bs2 * nz));
3560       c->free_a       = PETSC_TRUE;
3561       c->i            = a->i;
3562       c->j            = a->j;
3563       c->free_ij      = PETSC_FALSE;
3564       c->parent       = A;
3565       C->preallocated = PETSC_TRUE;
3566       C->assembled    = PETSC_TRUE;
3567 
3568       PetscCall(PetscObjectReference((PetscObject)A));
3569       PetscCall(MatSetOption(A, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
3570       PetscCall(MatSetOption(C, MAT_NEW_NONZERO_LOCATION_ERR, PETSC_TRUE));
3571     } else {
3572       PetscCall(PetscShmgetAllocateArray(bs2 * nz, sizeof(PetscScalar), (void **)&c->a));
3573       PetscCall(PetscShmgetAllocateArray(nz, sizeof(PetscInt), (void **)&c->j));
3574       PetscCall(PetscShmgetAllocateArray(mbs + 1, sizeof(PetscInt), (void **)&c->i));
3575       c->free_a  = PETSC_TRUE;
3576       c->free_ij = PETSC_TRUE;
3577 
3578       PetscCall(PetscArraycpy(c->i, a->i, mbs + 1));
3579       if (mbs > 0) {
3580         PetscCall(PetscArraycpy(c->j, a->j, nz));
3581         if (cpvalues == MAT_COPY_VALUES) {
3582           PetscCall(PetscArraycpy(c->a, a->a, bs2 * nz));
3583         } else {
3584           PetscCall(PetscArrayzero(c->a, bs2 * nz));
3585         }
3586       }
3587       C->preallocated = PETSC_TRUE;
3588       C->assembled    = PETSC_TRUE;
3589     }
3590   }
3591 
3592   c->roworiented = a->roworiented;
3593   c->nonew       = a->nonew;
3594 
3595   PetscCall(PetscLayoutReference(A->rmap, &C->rmap));
3596   PetscCall(PetscLayoutReference(A->cmap, &C->cmap));
3597 
3598   c->bs2        = a->bs2;
3599   c->mbs        = a->mbs;
3600   c->nbs        = a->nbs;
3601   c->nz         = a->nz;
3602   c->maxnz      = a->nz; /* Since we allocate exactly the right amount */
3603   c->solve_work = NULL;
3604   c->mult_work  = NULL;
3605   c->sor_workt  = NULL;
3606   c->sor_work   = NULL;
3607 
3608   c->compressedrow.use   = a->compressedrow.use;
3609   c->compressedrow.nrows = a->compressedrow.nrows;
3610   if (a->compressedrow.use) {
3611     i = a->compressedrow.nrows;
3612     PetscCall(PetscMalloc2(i + 1, &c->compressedrow.i, i + 1, &c->compressedrow.rindex));
3613     PetscCall(PetscArraycpy(c->compressedrow.i, a->compressedrow.i, i + 1));
3614     PetscCall(PetscArraycpy(c->compressedrow.rindex, a->compressedrow.rindex, i));
3615   } else {
3616     c->compressedrow.use    = PETSC_FALSE;
3617     c->compressedrow.i      = NULL;
3618     c->compressedrow.rindex = NULL;
3619   }
3620   c->nonzerorowcnt = a->nonzerorowcnt;
3621   C->nonzerostate  = A->nonzerostate;
3622 
3623   PetscCall(PetscFunctionListDuplicate(((PetscObject)A)->qlist, &((PetscObject)C)->qlist));
3624   PetscFunctionReturn(PETSC_SUCCESS);
3625 }
3626 
3627 PetscErrorCode MatDuplicate_SeqBAIJ(Mat A, MatDuplicateOption cpvalues, Mat *B)
3628 {
3629   PetscFunctionBegin;
3630   PetscCall(MatCreate(PetscObjectComm((PetscObject)A), B));
3631   PetscCall(MatSetSizes(*B, A->rmap->N, A->cmap->n, A->rmap->N, A->cmap->n));
3632   PetscCall(MatSetType(*B, MATSEQBAIJ));
3633   PetscCall(MatDuplicateNoCreate_SeqBAIJ(*B, A, cpvalues, PETSC_TRUE));
3634   PetscFunctionReturn(PETSC_SUCCESS);
3635 }
3636 
3637 /* Used for both SeqBAIJ and SeqSBAIJ matrices */
3638 PetscErrorCode MatLoad_SeqBAIJ_Binary(Mat mat, PetscViewer viewer)
3639 {
3640   PetscInt     header[4], M, N, nz, bs, m, n, mbs, nbs, rows, cols, sum, i, j, k;
3641   PetscInt    *rowidxs, *colidxs;
3642   PetscScalar *matvals;
3643 
3644   PetscFunctionBegin;
3645   PetscCall(PetscViewerSetUp(viewer));
3646 
3647   /* read matrix header */
3648   PetscCall(PetscViewerBinaryRead(viewer, header, 4, NULL, PETSC_INT));
3649   PetscCheck(header[0] == MAT_FILE_CLASSID, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Not a matrix object in file");
3650   M  = header[1];
3651   N  = header[2];
3652   nz = header[3];
3653   PetscCheck(M >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix row size (%" PetscInt_FMT ") in file is negative", M);
3654   PetscCheck(N >= 0, PetscObjectComm((PetscObject)viewer), PETSC_ERR_FILE_UNEXPECTED, "Matrix column size (%" PetscInt_FMT ") in file is negative", N);
3655   PetscCheck(nz >= 0, PETSC_COMM_SELF, PETSC_ERR_FILE_UNEXPECTED, "Matrix stored in special format on disk, cannot load as SeqBAIJ");
3656 
3657   /* set block sizes from the viewer's .info file */
3658   PetscCall(MatLoad_Binary_BlockSizes(mat, viewer));
3659   /* set local and global sizes if not set already */
3660   if (mat->rmap->n < 0) mat->rmap->n = M;
3661   if (mat->cmap->n < 0) mat->cmap->n = N;
3662   if (mat->rmap->N < 0) mat->rmap->N = M;
3663   if (mat->cmap->N < 0) mat->cmap->N = N;
3664   PetscCall(PetscLayoutSetUp(mat->rmap));
3665   PetscCall(PetscLayoutSetUp(mat->cmap));
3666 
3667   /* check if the matrix sizes are correct */
3668   PetscCall(MatGetSize(mat, &rows, &cols));
3669   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);
3670   PetscCall(MatGetBlockSize(mat, &bs));
3671   PetscCall(MatGetLocalSize(mat, &m, &n));
3672   mbs = m / bs;
3673   nbs = n / bs;
3674 
3675   /* read in row lengths, column indices and nonzero values */
3676   PetscCall(PetscMalloc1(m + 1, &rowidxs));
3677   PetscCall(PetscViewerBinaryRead(viewer, rowidxs + 1, m, NULL, PETSC_INT));
3678   rowidxs[0] = 0;
3679   for (i = 0; i < m; i++) rowidxs[i + 1] += rowidxs[i];
3680   sum = rowidxs[m];
3681   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);
3682 
3683   /* read in column indices and nonzero values */
3684   PetscCall(PetscMalloc2(rowidxs[m], &colidxs, nz, &matvals));
3685   PetscCall(PetscViewerBinaryRead(viewer, colidxs, rowidxs[m], NULL, PETSC_INT));
3686   PetscCall(PetscViewerBinaryRead(viewer, matvals, rowidxs[m], NULL, PETSC_SCALAR));
3687 
3688   {               /* preallocate matrix storage */
3689     PetscBT   bt; /* helper bit set to count nonzeros */
3690     PetscInt *nnz;
3691     PetscBool sbaij;
3692 
3693     PetscCall(PetscBTCreate(nbs, &bt));
3694     PetscCall(PetscCalloc1(mbs, &nnz));
3695     PetscCall(PetscObjectTypeCompare((PetscObject)mat, MATSEQSBAIJ, &sbaij));
3696     for (i = 0; i < mbs; i++) {
3697       PetscCall(PetscBTMemzero(nbs, bt));
3698       for (k = 0; k < bs; k++) {
3699         PetscInt row = bs * i + k;
3700         for (j = rowidxs[row]; j < rowidxs[row + 1]; j++) {
3701           PetscInt col = colidxs[j];
3702           if (!sbaij || col >= row)
3703             if (!PetscBTLookupSet(bt, col / bs)) nnz[i]++;
3704         }
3705       }
3706     }
3707     PetscCall(PetscBTDestroy(&bt));
3708     PetscCall(MatSeqBAIJSetPreallocation(mat, bs, 0, nnz));
3709     PetscCall(MatSeqSBAIJSetPreallocation(mat, bs, 0, nnz));
3710     PetscCall(PetscFree(nnz));
3711   }
3712 
3713   /* store matrix values */
3714   for (i = 0; i < m; i++) {
3715     PetscInt row = i, s = rowidxs[i], e = rowidxs[i + 1];
3716     PetscUseTypeMethod(mat, setvalues, 1, &row, e - s, colidxs + s, matvals + s, INSERT_VALUES);
3717   }
3718 
3719   PetscCall(PetscFree(rowidxs));
3720   PetscCall(PetscFree2(colidxs, matvals));
3721   PetscCall(MatAssemblyBegin(mat, MAT_FINAL_ASSEMBLY));
3722   PetscCall(MatAssemblyEnd(mat, MAT_FINAL_ASSEMBLY));
3723   PetscFunctionReturn(PETSC_SUCCESS);
3724 }
3725 
3726 PetscErrorCode MatLoad_SeqBAIJ(Mat mat, PetscViewer viewer)
3727 {
3728   PetscBool isbinary;
3729 
3730   PetscFunctionBegin;
3731   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERBINARY, &isbinary));
3732   PetscCheck(isbinary, PetscObjectComm((PetscObject)viewer), PETSC_ERR_SUP, "Viewer type %s not yet supported for reading %s matrices", ((PetscObject)viewer)->type_name, ((PetscObject)mat)->type_name);
3733   PetscCall(MatLoad_SeqBAIJ_Binary(mat, viewer));
3734   PetscFunctionReturn(PETSC_SUCCESS);
3735 }
3736 
3737 /*@
3738   MatCreateSeqBAIJ - Creates a sparse matrix in `MATSEQAIJ` (block
3739   compressed row) format.  For good matrix assembly performance the
3740   user should preallocate the matrix storage by setting the parameter `nz`
3741   (or the array `nnz`).
3742 
3743   Collective
3744 
3745   Input Parameters:
3746 + comm - MPI communicator, set to `PETSC_COMM_SELF`
3747 . bs   - size of block, the blocks are ALWAYS square. One can use `MatSetBlockSizes()` to set a different row and column blocksize but the row
3748          blocksize always defines the size of the blocks. The column blocksize sets the blocksize of the vectors obtained with `MatCreateVecs()`
3749 . m    - number of rows
3750 . n    - number of columns
3751 . nz   - number of nonzero blocks  per block row (same for all rows)
3752 - nnz  - array containing the number of nonzero blocks in the various block rows
3753          (possibly different for each block row) or `NULL`
3754 
3755   Output Parameter:
3756 . A - the matrix
3757 
3758   Options Database Keys:
3759 + -mat_no_unroll  - uses code that does not unroll the loops in the block calculations (much slower)
3760 - -mat_block_size - size of the blocks to use
3761 
3762   Level: intermediate
3763 
3764   Notes:
3765   It is recommended that one use `MatCreateFromOptions()` or the `MatCreate()`, `MatSetType()` and/or `MatSetFromOptions()`,
3766   MatXXXXSetPreallocation() paradigm instead of this routine directly.
3767   [MatXXXXSetPreallocation() is, for example, `MatSeqAIJSetPreallocation()`]
3768 
3769   The number of rows and columns must be divisible by blocksize.
3770 
3771   If the `nnz` parameter is given then the `nz` parameter is ignored
3772 
3773   A nonzero block is any block that as 1 or more nonzeros in it
3774 
3775   The `MATSEQBAIJ` format is fully compatible with standard Fortran
3776   storage.  That is, the stored row and column indices can begin at
3777   either one (as in Fortran) or zero.
3778 
3779   Specify the preallocated storage with either `nz` or `nnz` (not both).
3780   Set `nz` = `PETSC_DEFAULT` and `nnz` = `NULL` for PETSc to control dynamic memory
3781   allocation.  See [Sparse Matrices](sec_matsparse) for details.
3782   matrices.
3783 
3784 .seealso: [](ch_matrices), `Mat`, [Sparse Matrices](sec_matsparse), `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatCreateBAIJ()`
3785 @*/
3786 PetscErrorCode MatCreateSeqBAIJ(MPI_Comm comm, PetscInt bs, PetscInt m, PetscInt n, PetscInt nz, const PetscInt nnz[], Mat *A)
3787 {
3788   PetscFunctionBegin;
3789   PetscCall(MatCreate(comm, A));
3790   PetscCall(MatSetSizes(*A, m, n, m, n));
3791   PetscCall(MatSetType(*A, MATSEQBAIJ));
3792   PetscCall(MatSeqBAIJSetPreallocation(*A, bs, nz, (PetscInt *)nnz));
3793   PetscFunctionReturn(PETSC_SUCCESS);
3794 }
3795 
3796 /*@
3797   MatSeqBAIJSetPreallocation - Sets the block size and expected nonzeros
3798   per row in the matrix. For good matrix assembly performance the
3799   user should preallocate the matrix storage by setting the parameter `nz`
3800   (or the array `nnz`).
3801 
3802   Collective
3803 
3804   Input Parameters:
3805 + B   - the matrix
3806 . bs  - size of block, the blocks are ALWAYS square. One can use `MatSetBlockSizes()` to set a different row and column blocksize but the row
3807         blocksize always defines the size of the blocks. The column blocksize sets the blocksize of the vectors obtained with `MatCreateVecs()`
3808 . nz  - number of block nonzeros per block row (same for all rows)
3809 - nnz - array containing the number of block nonzeros in the various block rows
3810         (possibly different for each block row) or `NULL`
3811 
3812   Options Database Keys:
3813 + -mat_no_unroll  - uses code that does not unroll the loops in the block calculations (much slower)
3814 - -mat_block_size - size of the blocks to use
3815 
3816   Level: intermediate
3817 
3818   Notes:
3819   If the `nnz` parameter is given then the `nz` parameter is ignored
3820 
3821   You can call `MatGetInfo()` to get information on how effective the preallocation was;
3822   for example the fields mallocs,nz_allocated,nz_used,nz_unneeded;
3823   You can also run with the option `-info` and look for messages with the string
3824   malloc in them to see if additional memory allocation was needed.
3825 
3826   The `MATSEQBAIJ` format is fully compatible with standard Fortran
3827   storage.  That is, the stored row and column indices can begin at
3828   either one (as in Fortran) or zero.
3829 
3830   Specify the preallocated storage with either `nz` or `nnz` (not both).
3831   Set `nz` = `PETSC_DEFAULT` and `nnz` = `NULL` for PETSc to control dynamic memory
3832   allocation.  See [Sparse Matrices](sec_matsparse) for details.
3833 
3834 .seealso: [](ch_matrices), `Mat`, [Sparse Matrices](sec_matsparse), `MatCreate()`, `MatCreateSeqAIJ()`, `MatSetValues()`, `MatCreateBAIJ()`, `MatGetInfo()`
3835 @*/
3836 PetscErrorCode MatSeqBAIJSetPreallocation(Mat B, PetscInt bs, PetscInt nz, const PetscInt nnz[])
3837 {
3838   PetscFunctionBegin;
3839   PetscValidHeaderSpecific(B, MAT_CLASSID, 1);
3840   PetscValidType(B, 1);
3841   PetscValidLogicalCollectiveInt(B, bs, 2);
3842   PetscTryMethod(B, "MatSeqBAIJSetPreallocation_C", (Mat, PetscInt, PetscInt, const PetscInt[]), (B, bs, nz, nnz));
3843   PetscFunctionReturn(PETSC_SUCCESS);
3844 }
3845 
3846 /*@C
3847   MatSeqBAIJSetPreallocationCSR - Creates a sparse sequential matrix in `MATSEQBAIJ` format using the given nonzero structure and (optional) numerical values
3848 
3849   Collective
3850 
3851   Input Parameters:
3852 + B  - the matrix
3853 . bs - the blocksize
3854 . i  - the indices into `j` for the start of each local row (indices start with zero)
3855 . j  - the column indices for each local row (indices start with zero) these must be sorted for each row
3856 - v  - optional values in the matrix, use `NULL` if not provided
3857 
3858   Level: advanced
3859 
3860   Notes:
3861   The `i`,`j`,`v` values are COPIED with this routine; to avoid the copy use `MatCreateSeqBAIJWithArrays()`
3862 
3863   The order of the entries in values is specified by the `MatOption` `MAT_ROW_ORIENTED`.  For example, C programs
3864   may want to use the default `MAT_ROW_ORIENTED` of `PETSC_TRUE` and use an array v[nnz][bs][bs] where the second index is
3865   over rows within a block and the last index is over columns within a block row.  Fortran programs will likely set
3866   `MAT_ROW_ORIENTED` of `PETSC_FALSE` and use a Fortran array v(bs,bs,nnz) in which the first index is over rows within a
3867   block column and the second index is over columns within a block.
3868 
3869   Though this routine has Preallocation() in the name it also sets the exact nonzero locations of the matrix entries and usually the numerical values as well
3870 
3871 .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateSeqBAIJ()`, `MatSetValues()`, `MatSeqBAIJSetPreallocation()`, `MATSEQBAIJ`
3872 @*/
3873 PetscErrorCode MatSeqBAIJSetPreallocationCSR(Mat B, PetscInt bs, const PetscInt i[], const PetscInt j[], const PetscScalar v[])
3874 {
3875   PetscFunctionBegin;
3876   PetscValidHeaderSpecific(B, MAT_CLASSID, 1);
3877   PetscValidType(B, 1);
3878   PetscValidLogicalCollectiveInt(B, bs, 2);
3879   PetscTryMethod(B, "MatSeqBAIJSetPreallocationCSR_C", (Mat, PetscInt, const PetscInt[], const PetscInt[], const PetscScalar[]), (B, bs, i, j, v));
3880   PetscFunctionReturn(PETSC_SUCCESS);
3881 }
3882 
3883 /*@
3884   MatCreateSeqBAIJWithArrays - Creates a `MATSEQBAIJ` matrix using matrix elements provided by the user.
3885 
3886   Collective
3887 
3888   Input Parameters:
3889 + comm - must be an MPI communicator of size 1
3890 . bs   - size of block
3891 . m    - number of rows
3892 . n    - number of columns
3893 . i    - row indices; that is i[0] = 0, i[row] = i[row-1] + number of elements in that row block row of the matrix
3894 . j    - column indices
3895 - a    - matrix values
3896 
3897   Output Parameter:
3898 . mat - the matrix
3899 
3900   Level: advanced
3901 
3902   Notes:
3903   The `i`, `j`, and `a` arrays are not copied by this routine, the user must free these arrays
3904   once the matrix is destroyed
3905 
3906   You cannot set new nonzero locations into this matrix, that will generate an error.
3907 
3908   The `i` and `j` indices are 0 based
3909 
3910   When block size is greater than 1 the matrix values must be stored using the `MATSEQBAIJ` storage format
3911 
3912   The order of the entries in values is the same as the block compressed sparse row storage format; that is, it is
3913   the same as a three dimensional array in Fortran values(bs,bs,nnz) that contains the first column of the first
3914   block, followed by the second column of the first block etc etc.  That is, the blocks are contiguous in memory
3915   with column-major ordering within blocks.
3916 
3917 .seealso: [](ch_matrices), `Mat`, `MatCreate()`, `MatCreateBAIJ()`, `MatCreateSeqBAIJ()`
3918 @*/
3919 PetscErrorCode MatCreateSeqBAIJWithArrays(MPI_Comm comm, PetscInt bs, PetscInt m, PetscInt n, PetscInt i[], PetscInt j[], PetscScalar a[], Mat *mat)
3920 {
3921   Mat_SeqBAIJ *baij;
3922 
3923   PetscFunctionBegin;
3924   PetscCheck(bs == 1, PETSC_COMM_SELF, PETSC_ERR_SUP, "block size %" PetscInt_FMT " > 1 is not supported yet", bs);
3925   if (m > 0) PetscCheck(i[0] == 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "i (row indices) must start with 0");
3926 
3927   PetscCall(MatCreate(comm, mat));
3928   PetscCall(MatSetSizes(*mat, m, n, m, n));
3929   PetscCall(MatSetType(*mat, MATSEQBAIJ));
3930   PetscCall(MatSeqBAIJSetPreallocation(*mat, bs, MAT_SKIP_ALLOCATION, NULL));
3931   baij = (Mat_SeqBAIJ *)(*mat)->data;
3932   PetscCall(PetscMalloc2(m, &baij->imax, m, &baij->ilen));
3933 
3934   baij->i = i;
3935   baij->j = j;
3936   baij->a = a;
3937 
3938   baij->nonew          = -1; /*this indicates that inserting a new value in the matrix that generates a new nonzero is an error*/
3939   baij->free_a         = PETSC_FALSE;
3940   baij->free_ij        = PETSC_FALSE;
3941   baij->free_imax_ilen = PETSC_TRUE;
3942 
3943   for (PetscInt ii = 0; ii < m; ii++) {
3944     const PetscInt row_len = i[ii + 1] - i[ii];
3945 
3946     baij->ilen[ii] = baij->imax[ii] = row_len;
3947     PetscCheck(row_len >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative row length in i (row indices) row = %" PetscInt_FMT " length = %" PetscInt_FMT, ii, row_len);
3948   }
3949   if (PetscDefined(USE_DEBUG)) {
3950     for (PetscInt ii = 0; ii < baij->i[m]; ii++) {
3951       PetscCheck(j[ii] >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Negative column index at location = %" PetscInt_FMT " index = %" PetscInt_FMT, ii, j[ii]);
3952       PetscCheck(j[ii] <= n - 1, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Column index to large at location = %" PetscInt_FMT " index = %" PetscInt_FMT, ii, j[ii]);
3953     }
3954   }
3955 
3956   PetscCall(MatAssemblyBegin(*mat, MAT_FINAL_ASSEMBLY));
3957   PetscCall(MatAssemblyEnd(*mat, MAT_FINAL_ASSEMBLY));
3958   PetscFunctionReturn(PETSC_SUCCESS);
3959 }
3960 
3961 PetscErrorCode MatCreateMPIMatConcatenateSeqMat_SeqBAIJ(MPI_Comm comm, Mat inmat, PetscInt n, MatReuse scall, Mat *outmat)
3962 {
3963   PetscFunctionBegin;
3964   PetscCall(MatCreateMPIMatConcatenateSeqMat_MPIBAIJ(comm, inmat, n, scall, outmat));
3965   PetscFunctionReturn(PETSC_SUCCESS);
3966 }
3967