xref: /petsc/src/mat/impls/baij/seq/baijsolvnat7.c (revision 31d78bcd2b98084dc1368b20eb1129c8b9fb39fe)
1 #include <../src/mat/impls/baij/seq/baij.h>
2 #include <petsc/private/kernels/blockinvert.h>
3 
MatSolve_SeqBAIJ_7_NaturalOrdering_inplace(Mat A,Vec bb,Vec xx)4 PetscErrorCode MatSolve_SeqBAIJ_7_NaturalOrdering_inplace(Mat A, Vec bb, Vec xx)
5 {
6   Mat_SeqBAIJ       *a    = (Mat_SeqBAIJ *)A->data;
7   const PetscInt    *diag = a->diag, n = a->mbs, *vi, *ai = a->i, *aj = a->j;
8   PetscInt           i, nz, idx, idt, jdx;
9   const MatScalar   *aa = a->a, *v;
10   PetscScalar       *x, s1, s2, s3, s4, s5, s6, s7, x1, x2, x3, x4, x5, x6, x7;
11   const PetscScalar *b;
12 
13   PetscFunctionBegin;
14   PetscCall(VecGetArrayRead(bb, &b));
15   PetscCall(VecGetArray(xx, &x));
16   /* forward solve the lower triangular */
17   idx  = 0;
18   x[0] = b[idx];
19   x[1] = b[1 + idx];
20   x[2] = b[2 + idx];
21   x[3] = b[3 + idx];
22   x[4] = b[4 + idx];
23   x[5] = b[5 + idx];
24   x[6] = b[6 + idx];
25   for (i = 1; i < n; i++) {
26     v   = aa + 49 * ai[i];
27     vi  = aj + ai[i];
28     nz  = diag[i] - ai[i];
29     idx = 7 * i;
30     s1  = b[idx];
31     s2  = b[1 + idx];
32     s3  = b[2 + idx];
33     s4  = b[3 + idx];
34     s5  = b[4 + idx];
35     s6  = b[5 + idx];
36     s7  = b[6 + idx];
37     while (nz--) {
38       jdx = 7 * (*vi++);
39       x1  = x[jdx];
40       x2  = x[1 + jdx];
41       x3  = x[2 + jdx];
42       x4  = x[3 + jdx];
43       x5  = x[4 + jdx];
44       x6  = x[5 + jdx];
45       x7  = x[6 + jdx];
46       s1 -= v[0] * x1 + v[7] * x2 + v[14] * x3 + v[21] * x4 + v[28] * x5 + v[35] * x6 + v[42] * x7;
47       s2 -= v[1] * x1 + v[8] * x2 + v[15] * x3 + v[22] * x4 + v[29] * x5 + v[36] * x6 + v[43] * x7;
48       s3 -= v[2] * x1 + v[9] * x2 + v[16] * x3 + v[23] * x4 + v[30] * x5 + v[37] * x6 + v[44] * x7;
49       s4 -= v[3] * x1 + v[10] * x2 + v[17] * x3 + v[24] * x4 + v[31] * x5 + v[38] * x6 + v[45] * x7;
50       s5 -= v[4] * x1 + v[11] * x2 + v[18] * x3 + v[25] * x4 + v[32] * x5 + v[39] * x6 + v[46] * x7;
51       s6 -= v[5] * x1 + v[12] * x2 + v[19] * x3 + v[26] * x4 + v[33] * x5 + v[40] * x6 + v[47] * x7;
52       s7 -= v[6] * x1 + v[13] * x2 + v[20] * x3 + v[27] * x4 + v[34] * x5 + v[41] * x6 + v[48] * x7;
53       v += 49;
54     }
55     x[idx]     = s1;
56     x[1 + idx] = s2;
57     x[2 + idx] = s3;
58     x[3 + idx] = s4;
59     x[4 + idx] = s5;
60     x[5 + idx] = s6;
61     x[6 + idx] = s7;
62   }
63   /* backward solve the upper triangular */
64   for (i = n - 1; i >= 0; i--) {
65     v   = aa + 49 * diag[i] + 49;
66     vi  = aj + diag[i] + 1;
67     nz  = ai[i + 1] - diag[i] - 1;
68     idt = 7 * i;
69     s1  = x[idt];
70     s2  = x[1 + idt];
71     s3  = x[2 + idt];
72     s4  = x[3 + idt];
73     s5  = x[4 + idt];
74     s6  = x[5 + idt];
75     s7  = x[6 + idt];
76     while (nz--) {
77       idx = 7 * (*vi++);
78       x1  = x[idx];
79       x2  = x[1 + idx];
80       x3  = x[2 + idx];
81       x4  = x[3 + idx];
82       x5  = x[4 + idx];
83       x6  = x[5 + idx];
84       x7  = x[6 + idx];
85       s1 -= v[0] * x1 + v[7] * x2 + v[14] * x3 + v[21] * x4 + v[28] * x5 + v[35] * x6 + v[42] * x7;
86       s2 -= v[1] * x1 + v[8] * x2 + v[15] * x3 + v[22] * x4 + v[29] * x5 + v[36] * x6 + v[43] * x7;
87       s3 -= v[2] * x1 + v[9] * x2 + v[16] * x3 + v[23] * x4 + v[30] * x5 + v[37] * x6 + v[44] * x7;
88       s4 -= v[3] * x1 + v[10] * x2 + v[17] * x3 + v[24] * x4 + v[31] * x5 + v[38] * x6 + v[45] * x7;
89       s5 -= v[4] * x1 + v[11] * x2 + v[18] * x3 + v[25] * x4 + v[32] * x5 + v[39] * x6 + v[46] * x7;
90       s6 -= v[5] * x1 + v[12] * x2 + v[19] * x3 + v[26] * x4 + v[33] * x5 + v[40] * x6 + v[47] * x7;
91       s7 -= v[6] * x1 + v[13] * x2 + v[20] * x3 + v[27] * x4 + v[34] * x5 + v[41] * x6 + v[48] * x7;
92       v += 49;
93     }
94     v          = aa + 49 * diag[i];
95     x[idt]     = v[0] * s1 + v[7] * s2 + v[14] * s3 + v[21] * s4 + v[28] * s5 + v[35] * s6 + v[42] * s7;
96     x[1 + idt] = v[1] * s1 + v[8] * s2 + v[15] * s3 + v[22] * s4 + v[29] * s5 + v[36] * s6 + v[43] * s7;
97     x[2 + idt] = v[2] * s1 + v[9] * s2 + v[16] * s3 + v[23] * s4 + v[30] * s5 + v[37] * s6 + v[44] * s7;
98     x[3 + idt] = v[3] * s1 + v[10] * s2 + v[17] * s3 + v[24] * s4 + v[31] * s5 + v[38] * s6 + v[45] * s7;
99     x[4 + idt] = v[4] * s1 + v[11] * s2 + v[18] * s3 + v[25] * s4 + v[32] * s5 + v[39] * s6 + v[46] * s7;
100     x[5 + idt] = v[5] * s1 + v[12] * s2 + v[19] * s3 + v[26] * s4 + v[33] * s5 + v[40] * s6 + v[47] * s7;
101     x[6 + idt] = v[6] * s1 + v[13] * s2 + v[20] * s3 + v[27] * s4 + v[34] * s5 + v[41] * s6 + v[48] * s7;
102   }
103 
104   PetscCall(VecRestoreArrayRead(bb, &b));
105   PetscCall(VecRestoreArray(xx, &x));
106   PetscCall(PetscLogFlops(2.0 * 36 * (a->nz) - 6.0 * A->cmap->n));
107   PetscFunctionReturn(PETSC_SUCCESS);
108 }
109 
MatSolve_SeqBAIJ_7_NaturalOrdering(Mat A,Vec bb,Vec xx)110 PetscErrorCode MatSolve_SeqBAIJ_7_NaturalOrdering(Mat A, Vec bb, Vec xx)
111 {
112   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ *)A->data;
113   const PetscInt     n = a->mbs, *vi, *ai = a->i, *aj = a->j, *adiag = a->diag;
114   PetscInt           i, k, nz, idx, jdx, idt;
115   const PetscInt     bs = A->rmap->bs, bs2 = a->bs2;
116   const MatScalar   *aa = a->a, *v;
117   PetscScalar       *x;
118   const PetscScalar *b;
119   PetscScalar        s1, s2, s3, s4, s5, s6, s7, x1, x2, x3, x4, x5, x6, x7;
120 
121   PetscFunctionBegin;
122   PetscCall(VecGetArrayRead(bb, &b));
123   PetscCall(VecGetArray(xx, &x));
124   /* forward solve the lower triangular */
125   idx  = 0;
126   x[0] = b[idx];
127   x[1] = b[1 + idx];
128   x[2] = b[2 + idx];
129   x[3] = b[3 + idx];
130   x[4] = b[4 + idx];
131   x[5] = b[5 + idx];
132   x[6] = b[6 + idx];
133   for (i = 1; i < n; i++) {
134     v   = aa + bs2 * ai[i];
135     vi  = aj + ai[i];
136     nz  = ai[i + 1] - ai[i];
137     idx = bs * i;
138     s1  = b[idx];
139     s2  = b[1 + idx];
140     s3  = b[2 + idx];
141     s4  = b[3 + idx];
142     s5  = b[4 + idx];
143     s6  = b[5 + idx];
144     s7  = b[6 + idx];
145     for (k = 0; k < nz; k++) {
146       jdx = bs * vi[k];
147       x1  = x[jdx];
148       x2  = x[1 + jdx];
149       x3  = x[2 + jdx];
150       x4  = x[3 + jdx];
151       x5  = x[4 + jdx];
152       x6  = x[5 + jdx];
153       x7  = x[6 + jdx];
154       s1 -= v[0] * x1 + v[7] * x2 + v[14] * x3 + v[21] * x4 + v[28] * x5 + v[35] * x6 + v[42] * x7;
155       s2 -= v[1] * x1 + v[8] * x2 + v[15] * x3 + v[22] * x4 + v[29] * x5 + v[36] * x6 + v[43] * x7;
156       s3 -= v[2] * x1 + v[9] * x2 + v[16] * x3 + v[23] * x4 + v[30] * x5 + v[37] * x6 + v[44] * x7;
157       s4 -= v[3] * x1 + v[10] * x2 + v[17] * x3 + v[24] * x4 + v[31] * x5 + v[38] * x6 + v[45] * x7;
158       s5 -= v[4] * x1 + v[11] * x2 + v[18] * x3 + v[25] * x4 + v[32] * x5 + v[39] * x6 + v[46] * x7;
159       s6 -= v[5] * x1 + v[12] * x2 + v[19] * x3 + v[26] * x4 + v[33] * x5 + v[40] * x6 + v[47] * x7;
160       s7 -= v[6] * x1 + v[13] * x2 + v[20] * x3 + v[27] * x4 + v[34] * x5 + v[41] * x6 + v[48] * x7;
161       v += bs2;
162     }
163 
164     x[idx]     = s1;
165     x[1 + idx] = s2;
166     x[2 + idx] = s3;
167     x[3 + idx] = s4;
168     x[4 + idx] = s5;
169     x[5 + idx] = s6;
170     x[6 + idx] = s7;
171   }
172 
173   /* backward solve the upper triangular */
174   for (i = n - 1; i >= 0; i--) {
175     v   = aa + bs2 * (adiag[i + 1] + 1);
176     vi  = aj + adiag[i + 1] + 1;
177     nz  = adiag[i] - adiag[i + 1] - 1;
178     idt = bs * i;
179     s1  = x[idt];
180     s2  = x[1 + idt];
181     s3  = x[2 + idt];
182     s4  = x[3 + idt];
183     s5  = x[4 + idt];
184     s6  = x[5 + idt];
185     s7  = x[6 + idt];
186     for (k = 0; k < nz; k++) {
187       idx = bs * vi[k];
188       x1  = x[idx];
189       x2  = x[1 + idx];
190       x3  = x[2 + idx];
191       x4  = x[3 + idx];
192       x5  = x[4 + idx];
193       x6  = x[5 + idx];
194       x7  = x[6 + idx];
195       s1 -= v[0] * x1 + v[7] * x2 + v[14] * x3 + v[21] * x4 + v[28] * x5 + v[35] * x6 + v[42] * x7;
196       s2 -= v[1] * x1 + v[8] * x2 + v[15] * x3 + v[22] * x4 + v[29] * x5 + v[36] * x6 + v[43] * x7;
197       s3 -= v[2] * x1 + v[9] * x2 + v[16] * x3 + v[23] * x4 + v[30] * x5 + v[37] * x6 + v[44] * x7;
198       s4 -= v[3] * x1 + v[10] * x2 + v[17] * x3 + v[24] * x4 + v[31] * x5 + v[38] * x6 + v[45] * x7;
199       s5 -= v[4] * x1 + v[11] * x2 + v[18] * x3 + v[25] * x4 + v[32] * x5 + v[39] * x6 + v[46] * x7;
200       s6 -= v[5] * x1 + v[12] * x2 + v[19] * x3 + v[26] * x4 + v[33] * x5 + v[40] * x6 + v[47] * x7;
201       s7 -= v[6] * x1 + v[13] * x2 + v[20] * x3 + v[27] * x4 + v[34] * x5 + v[41] * x6 + v[48] * x7;
202       v += bs2;
203     }
204     /* x = inv_diagonal*x */
205     x[idt]     = v[0] * s1 + v[7] * s2 + v[14] * s3 + v[21] * s4 + v[28] * s5 + v[35] * s6 + v[42] * s7;
206     x[1 + idt] = v[1] * s1 + v[8] * s2 + v[15] * s3 + v[22] * s4 + v[29] * s5 + v[36] * s6 + v[43] * s7;
207     x[2 + idt] = v[2] * s1 + v[9] * s2 + v[16] * s3 + v[23] * s4 + v[30] * s5 + v[37] * s6 + v[44] * s7;
208     x[3 + idt] = v[3] * s1 + v[10] * s2 + v[17] * s3 + v[24] * s4 + v[31] * s5 + v[38] * s6 + v[45] * s7;
209     x[4 + idt] = v[4] * s1 + v[11] * s2 + v[18] * s3 + v[25] * s4 + v[32] * s5 + v[39] * s6 + v[46] * s7;
210     x[5 + idt] = v[5] * s1 + v[12] * s2 + v[19] * s3 + v[26] * s4 + v[33] * s5 + v[40] * s6 + v[47] * s7;
211     x[6 + idt] = v[6] * s1 + v[13] * s2 + v[20] * s3 + v[27] * s4 + v[34] * s5 + v[41] * s6 + v[48] * s7;
212   }
213 
214   PetscCall(VecRestoreArrayRead(bb, &b));
215   PetscCall(VecRestoreArray(xx, &x));
216   PetscCall(PetscLogFlops(2.0 * bs2 * (a->nz) - bs * A->cmap->n));
217   PetscFunctionReturn(PETSC_SUCCESS);
218 }
219