xref: /petsc/src/mat/impls/sbaij/seq/sbaijfact7.c (revision 73fdd05bb67e49f40fd8fd311695ff6fdf0b9b8a)
1 
2 #include <../src/mat/impls/sbaij/seq/sbaij.h>
3 #include <petsc/private/kernels/blockinvert.h>
4 
5 /* Version for when blocks are 5 by 5  */
6 PetscErrorCode MatCholeskyFactorNumeric_SeqSBAIJ_5(Mat C, Mat A, const MatFactorInfo *info)
7 {
8   Mat_SeqSBAIJ   *a = (Mat_SeqSBAIJ *)A->data, *b = (Mat_SeqSBAIJ *)C->data;
9   IS              perm = b->row;
10   const PetscInt *ai, *aj, *perm_ptr, mbs = a->mbs, *bi = b->i, *bj = b->j;
11   PetscInt        i, j, *a2anew, k, k1, jmin, jmax, *jl, *il, vj, nexti, ili, ipvt[5];
12   MatScalar      *ba = b->a, *aa, *ap, *dk, *uik;
13   MatScalar      *u, *d, *rtmp, *rtmp_ptr, work[25];
14   PetscReal       shift = info->shiftamount;
15   PetscBool       allowzeropivot, zeropivotdetected;
16 
17   PetscFunctionBegin;
18   /* initialization */
19   allowzeropivot = PetscNot(A->erroriffailure);
20   PetscCall(PetscCalloc1(25 * mbs, &rtmp));
21   PetscCall(PetscMalloc2(mbs, &il, mbs, &jl));
22   il[0] = 0;
23   for (i = 0; i < mbs; i++) jl[i] = mbs;
24 
25   PetscCall(PetscMalloc2(25, &dk, 25, &uik));
26   PetscCall(ISGetIndices(perm, &perm_ptr));
27 
28   /* check permutation */
29   if (!a->permute) {
30     ai = a->i;
31     aj = a->j;
32     aa = a->a;
33   } else {
34     ai = a->inew;
35     aj = a->jnew;
36     PetscCall(PetscMalloc1(25 * ai[mbs], &aa));
37     PetscCall(PetscArraycpy(aa, a->a, 25 * ai[mbs]));
38     PetscCall(PetscMalloc1(ai[mbs], &a2anew));
39     PetscCall(PetscArraycpy(a2anew, a->a2anew, ai[mbs]));
40 
41     for (i = 0; i < mbs; i++) {
42       jmin = ai[i];
43       jmax = ai[i + 1];
44       for (j = jmin; j < jmax; j++) {
45         while (a2anew[j] != j) {
46           k         = a2anew[j];
47           a2anew[j] = a2anew[k];
48           a2anew[k] = k;
49           for (k1 = 0; k1 < 25; k1++) {
50             dk[k1]          = aa[k * 25 + k1];
51             aa[k * 25 + k1] = aa[j * 25 + k1];
52             aa[j * 25 + k1] = dk[k1];
53           }
54         }
55         /* transform columnoriented blocks that lie in the lower triangle to roworiented blocks */
56         if (i > aj[j]) {
57           /* printf("change orientation, row: %d, col: %d\n",i,aj[j]); */
58           ap = aa + j * 25;                       /* ptr to the beginning of j-th block of aa */
59           for (k = 0; k < 25; k++) dk[k] = ap[k]; /* dk <- j-th block of aa */
60           for (k = 0; k < 5; k++) {               /* j-th block of aa <- dk^T */
61             for (k1 = 0; k1 < 5; k1++) *ap++ = dk[k + 5 * k1];
62           }
63         }
64       }
65     }
66     PetscCall(PetscFree(a2anew));
67   }
68 
69   /* for each row k */
70   for (k = 0; k < mbs; k++) {
71     /*initialize k-th row with elements nonzero in row perm(k) of A */
72     jmin = ai[perm_ptr[k]];
73     jmax = ai[perm_ptr[k] + 1];
74     if (jmin < jmax) {
75       ap = aa + jmin * 25;
76       for (j = jmin; j < jmax; j++) {
77         vj       = perm_ptr[aj[j]]; /* block col. index */
78         rtmp_ptr = rtmp + vj * 25;
79         for (i = 0; i < 25; i++) *rtmp_ptr++ = *ap++;
80       }
81     }
82 
83     /* modify k-th row by adding in those rows i with U(i,k) != 0 */
84     PetscCall(PetscArraycpy(dk, rtmp + k * 25, 25));
85     i = jl[k]; /* first row to be added to k_th row  */
86 
87     while (i < mbs) {
88       nexti = jl[i]; /* next row to be added to k_th row */
89 
90       /* compute multiplier */
91       ili = il[i]; /* index of first nonzero element in U(i,k:bms-1) */
92 
93       /* uik = -inv(Di)*U_bar(i,k) */
94       d = ba + i * 25;
95       u = ba + ili * 25;
96 
97       uik[0] = -(d[0] * u[0] + d[5] * u[1] + d[10] * u[2] + d[15] * u[3] + d[20] * u[4]);
98       uik[1] = -(d[1] * u[0] + d[6] * u[1] + d[11] * u[2] + d[16] * u[3] + d[21] * u[4]);
99       uik[2] = -(d[2] * u[0] + d[7] * u[1] + d[12] * u[2] + d[17] * u[3] + d[22] * u[4]);
100       uik[3] = -(d[3] * u[0] + d[8] * u[1] + d[13] * u[2] + d[18] * u[3] + d[23] * u[4]);
101       uik[4] = -(d[4] * u[0] + d[9] * u[1] + d[14] * u[2] + d[19] * u[3] + d[24] * u[4]);
102 
103       uik[5] = -(d[0] * u[5] + d[5] * u[6] + d[10] * u[7] + d[15] * u[8] + d[20] * u[9]);
104       uik[6] = -(d[1] * u[5] + d[6] * u[6] + d[11] * u[7] + d[16] * u[8] + d[21] * u[9]);
105       uik[7] = -(d[2] * u[5] + d[7] * u[6] + d[12] * u[7] + d[17] * u[8] + d[22] * u[9]);
106       uik[8] = -(d[3] * u[5] + d[8] * u[6] + d[13] * u[7] + d[18] * u[8] + d[23] * u[9]);
107       uik[9] = -(d[4] * u[5] + d[9] * u[6] + d[14] * u[7] + d[19] * u[8] + d[24] * u[9]);
108 
109       uik[10] = -(d[0] * u[10] + d[5] * u[11] + d[10] * u[12] + d[15] * u[13] + d[20] * u[14]);
110       uik[11] = -(d[1] * u[10] + d[6] * u[11] + d[11] * u[12] + d[16] * u[13] + d[21] * u[14]);
111       uik[12] = -(d[2] * u[10] + d[7] * u[11] + d[12] * u[12] + d[17] * u[13] + d[22] * u[14]);
112       uik[13] = -(d[3] * u[10] + d[8] * u[11] + d[13] * u[12] + d[18] * u[13] + d[23] * u[14]);
113       uik[14] = -(d[4] * u[10] + d[9] * u[11] + d[14] * u[12] + d[19] * u[13] + d[24] * u[14]);
114 
115       uik[15] = -(d[0] * u[15] + d[5] * u[16] + d[10] * u[17] + d[15] * u[18] + d[20] * u[19]);
116       uik[16] = -(d[1] * u[15] + d[6] * u[16] + d[11] * u[17] + d[16] * u[18] + d[21] * u[19]);
117       uik[17] = -(d[2] * u[15] + d[7] * u[16] + d[12] * u[17] + d[17] * u[18] + d[22] * u[19]);
118       uik[18] = -(d[3] * u[15] + d[8] * u[16] + d[13] * u[17] + d[18] * u[18] + d[23] * u[19]);
119       uik[19] = -(d[4] * u[15] + d[9] * u[16] + d[14] * u[17] + d[19] * u[18] + d[24] * u[19]);
120 
121       uik[20] = -(d[0] * u[20] + d[5] * u[21] + d[10] * u[22] + d[15] * u[23] + d[20] * u[24]);
122       uik[21] = -(d[1] * u[20] + d[6] * u[21] + d[11] * u[22] + d[16] * u[23] + d[21] * u[24]);
123       uik[22] = -(d[2] * u[20] + d[7] * u[21] + d[12] * u[22] + d[17] * u[23] + d[22] * u[24]);
124       uik[23] = -(d[3] * u[20] + d[8] * u[21] + d[13] * u[22] + d[18] * u[23] + d[23] * u[24]);
125       uik[24] = -(d[4] * u[20] + d[9] * u[21] + d[14] * u[22] + d[19] * u[23] + d[24] * u[24]);
126 
127       /* update D(k) += -U(i,k)^T * U_bar(i,k) */
128       dk[0] += uik[0] * u[0] + uik[1] * u[1] + uik[2] * u[2] + uik[3] * u[3] + uik[4] * u[4];
129       dk[1] += uik[5] * u[0] + uik[6] * u[1] + uik[7] * u[2] + uik[8] * u[3] + uik[9] * u[4];
130       dk[2] += uik[10] * u[0] + uik[11] * u[1] + uik[12] * u[2] + uik[13] * u[3] + uik[14] * u[4];
131       dk[3] += uik[15] * u[0] + uik[16] * u[1] + uik[17] * u[2] + uik[18] * u[3] + uik[19] * u[4];
132       dk[4] += uik[20] * u[0] + uik[21] * u[1] + uik[22] * u[2] + uik[23] * u[3] + uik[24] * u[4];
133 
134       dk[5] += uik[0] * u[5] + uik[1] * u[6] + uik[2] * u[7] + uik[3] * u[8] + uik[4] * u[9];
135       dk[6] += uik[5] * u[5] + uik[6] * u[6] + uik[7] * u[7] + uik[8] * u[8] + uik[9] * u[9];
136       dk[7] += uik[10] * u[5] + uik[11] * u[6] + uik[12] * u[7] + uik[13] * u[8] + uik[14] * u[9];
137       dk[8] += uik[15] * u[5] + uik[16] * u[6] + uik[17] * u[7] + uik[18] * u[8] + uik[19] * u[9];
138       dk[9] += uik[20] * u[5] + uik[21] * u[6] + uik[22] * u[7] + uik[23] * u[8] + uik[24] * u[9];
139 
140       dk[10] += uik[0] * u[10] + uik[1] * u[11] + uik[2] * u[12] + uik[3] * u[13] + uik[4] * u[14];
141       dk[11] += uik[5] * u[10] + uik[6] * u[11] + uik[7] * u[12] + uik[8] * u[13] + uik[9] * u[14];
142       dk[12] += uik[10] * u[10] + uik[11] * u[11] + uik[12] * u[12] + uik[13] * u[13] + uik[14] * u[14];
143       dk[13] += uik[15] * u[10] + uik[16] * u[11] + uik[17] * u[12] + uik[18] * u[13] + uik[19] * u[14];
144       dk[14] += uik[20] * u[10] + uik[21] * u[11] + uik[22] * u[12] + uik[23] * u[13] + uik[24] * u[14];
145 
146       dk[15] += uik[0] * u[15] + uik[1] * u[16] + uik[2] * u[17] + uik[3] * u[18] + uik[4] * u[19];
147       dk[16] += uik[5] * u[15] + uik[6] * u[16] + uik[7] * u[17] + uik[8] * u[18] + uik[9] * u[19];
148       dk[17] += uik[10] * u[15] + uik[11] * u[16] + uik[12] * u[17] + uik[13] * u[18] + uik[14] * u[19];
149       dk[18] += uik[15] * u[15] + uik[16] * u[16] + uik[17] * u[17] + uik[18] * u[18] + uik[19] * u[19];
150       dk[19] += uik[20] * u[15] + uik[21] * u[16] + uik[22] * u[17] + uik[23] * u[18] + uik[24] * u[19];
151 
152       dk[20] += uik[0] * u[20] + uik[1] * u[21] + uik[2] * u[22] + uik[3] * u[23] + uik[4] * u[24];
153       dk[21] += uik[5] * u[20] + uik[6] * u[21] + uik[7] * u[22] + uik[8] * u[23] + uik[9] * u[24];
154       dk[22] += uik[10] * u[20] + uik[11] * u[21] + uik[12] * u[22] + uik[13] * u[23] + uik[14] * u[24];
155       dk[23] += uik[15] * u[20] + uik[16] * u[21] + uik[17] * u[22] + uik[18] * u[23] + uik[19] * u[24];
156       dk[24] += uik[20] * u[20] + uik[21] * u[21] + uik[22] * u[22] + uik[23] * u[23] + uik[24] * u[24];
157 
158       PetscCall(PetscLogFlops(125.0 * 4.0));
159 
160       /* update -U(i,k) */
161       PetscCall(PetscArraycpy(ba + ili * 25, uik, 25));
162 
163       /* add multiple of row i to k-th row ... */
164       jmin = ili + 1;
165       jmax = bi[i + 1];
166       if (jmin < jmax) {
167         for (j = jmin; j < jmax; j++) {
168           /* rtmp += -U(i,k)^T * U_bar(i,j) */
169           rtmp_ptr = rtmp + bj[j] * 25;
170           u        = ba + j * 25;
171           rtmp_ptr[0] += uik[0] * u[0] + uik[1] * u[1] + uik[2] * u[2] + uik[3] * u[3] + uik[4] * u[4];
172           rtmp_ptr[1] += uik[5] * u[0] + uik[6] * u[1] + uik[7] * u[2] + uik[8] * u[3] + uik[9] * u[4];
173           rtmp_ptr[2] += uik[10] * u[0] + uik[11] * u[1] + uik[12] * u[2] + uik[13] * u[3] + uik[14] * u[4];
174           rtmp_ptr[3] += uik[15] * u[0] + uik[16] * u[1] + uik[17] * u[2] + uik[18] * u[3] + uik[19] * u[4];
175           rtmp_ptr[4] += uik[20] * u[0] + uik[21] * u[1] + uik[22] * u[2] + uik[23] * u[3] + uik[24] * u[4];
176 
177           rtmp_ptr[5] += uik[0] * u[5] + uik[1] * u[6] + uik[2] * u[7] + uik[3] * u[8] + uik[4] * u[9];
178           rtmp_ptr[6] += uik[5] * u[5] + uik[6] * u[6] + uik[7] * u[7] + uik[8] * u[8] + uik[9] * u[9];
179           rtmp_ptr[7] += uik[10] * u[5] + uik[11] * u[6] + uik[12] * u[7] + uik[13] * u[8] + uik[14] * u[9];
180           rtmp_ptr[8] += uik[15] * u[5] + uik[16] * u[6] + uik[17] * u[7] + uik[18] * u[8] + uik[19] * u[9];
181           rtmp_ptr[9] += uik[20] * u[5] + uik[21] * u[6] + uik[22] * u[7] + uik[23] * u[8] + uik[24] * u[9];
182 
183           rtmp_ptr[10] += uik[0] * u[10] + uik[1] * u[11] + uik[2] * u[12] + uik[3] * u[13] + uik[4] * u[14];
184           rtmp_ptr[11] += uik[5] * u[10] + uik[6] * u[11] + uik[7] * u[12] + uik[8] * u[13] + uik[9] * u[14];
185           rtmp_ptr[12] += uik[10] * u[10] + uik[11] * u[11] + uik[12] * u[12] + uik[13] * u[13] + uik[14] * u[14];
186           rtmp_ptr[13] += uik[15] * u[10] + uik[16] * u[11] + uik[17] * u[12] + uik[18] * u[13] + uik[19] * u[14];
187           rtmp_ptr[14] += uik[20] * u[10] + uik[21] * u[11] + uik[22] * u[12] + uik[23] * u[13] + uik[24] * u[14];
188 
189           rtmp_ptr[15] += uik[0] * u[15] + uik[1] * u[16] + uik[2] * u[17] + uik[3] * u[18] + uik[4] * u[19];
190           rtmp_ptr[16] += uik[5] * u[15] + uik[6] * u[16] + uik[7] * u[17] + uik[8] * u[18] + uik[9] * u[19];
191           rtmp_ptr[17] += uik[10] * u[15] + uik[11] * u[16] + uik[12] * u[17] + uik[13] * u[18] + uik[14] * u[19];
192           rtmp_ptr[18] += uik[15] * u[15] + uik[16] * u[16] + uik[17] * u[17] + uik[18] * u[18] + uik[19] * u[19];
193           rtmp_ptr[19] += uik[20] * u[15] + uik[21] * u[16] + uik[22] * u[17] + uik[23] * u[18] + uik[24] * u[19];
194 
195           rtmp_ptr[20] += uik[0] * u[20] + uik[1] * u[21] + uik[2] * u[22] + uik[3] * u[23] + uik[4] * u[24];
196           rtmp_ptr[21] += uik[5] * u[20] + uik[6] * u[21] + uik[7] * u[22] + uik[8] * u[23] + uik[9] * u[24];
197           rtmp_ptr[22] += uik[10] * u[20] + uik[11] * u[21] + uik[12] * u[22] + uik[13] * u[23] + uik[14] * u[24];
198           rtmp_ptr[23] += uik[15] * u[20] + uik[16] * u[21] + uik[17] * u[22] + uik[18] * u[23] + uik[19] * u[24];
199           rtmp_ptr[24] += uik[20] * u[20] + uik[21] * u[21] + uik[22] * u[22] + uik[23] * u[23] + uik[24] * u[24];
200         }
201         PetscCall(PetscLogFlops(2.0 * 125.0 * (jmax - jmin)));
202 
203         /* ... add i to row list for next nonzero entry */
204         il[i] = jmin; /* update il(i) in column k+1, ... mbs-1 */
205         j     = bj[jmin];
206         jl[i] = jl[j];
207         jl[j] = i; /* update jl */
208       }
209       i = nexti;
210     }
211 
212     /* save nonzero entries in k-th row of U ... */
213 
214     /* invert diagonal block */
215     d = ba + k * 25;
216     PetscCall(PetscArraycpy(d, dk, 25));
217     PetscCall(PetscKernel_A_gets_inverse_A_5(d, ipvt, work, shift, allowzeropivot, &zeropivotdetected));
218     if (zeropivotdetected) C->factorerrortype = MAT_FACTOR_NUMERIC_ZEROPIVOT;
219 
220     jmin = bi[k];
221     jmax = bi[k + 1];
222     if (jmin < jmax) {
223       for (j = jmin; j < jmax; j++) {
224         vj       = bj[j]; /* block col. index of U */
225         u        = ba + j * 25;
226         rtmp_ptr = rtmp + vj * 25;
227         for (k1 = 0; k1 < 25; k1++) {
228           *u++        = *rtmp_ptr;
229           *rtmp_ptr++ = 0.0;
230         }
231       }
232 
233       /* ... add k to row list for first nonzero entry in k-th row */
234       il[k] = jmin;
235       i     = bj[jmin];
236       jl[k] = jl[i];
237       jl[i] = k;
238     }
239   }
240 
241   PetscCall(PetscFree(rtmp));
242   PetscCall(PetscFree2(il, jl));
243   PetscCall(PetscFree2(dk, uik));
244   if (a->permute) PetscCall(PetscFree(aa));
245 
246   PetscCall(ISRestoreIndices(perm, &perm_ptr));
247 
248   C->ops->solve          = MatSolve_SeqSBAIJ_5_inplace;
249   C->ops->solvetranspose = MatSolve_SeqSBAIJ_5_inplace;
250   C->assembled           = PETSC_TRUE;
251   C->preallocated        = PETSC_TRUE;
252 
253   PetscCall(PetscLogFlops(1.3333 * 125 * b->mbs)); /* from inverting diagonal blocks */
254   PetscFunctionReturn(PETSC_SUCCESS);
255 }
256