xref: /petsc/src/mat/impls/baij/seq/baijsolvtrannat6.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
1 #include <../src/mat/impls/baij/seq/baij.h>
2 
3 PetscErrorCode MatSolveTranspose_SeqBAIJ_6_NaturalOrdering_inplace(Mat A,Vec bb,Vec xx)
4 {
5   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ*)A->data;
6   const PetscInt  *diag=a->diag,n=a->mbs,*vi,*ai=a->i,*aj=a->j;
7   PetscInt        i,nz,idx,idt,oidx;
8   const MatScalar *aa=a->a,*v;
9   PetscScalar     s1,s2,s3,s4,s5,s6,x1,x2,x3,x4,x5,x6,*x;
10 
11   PetscFunctionBegin;
12   PetscCall(VecCopy(bb,xx));
13   PetscCall(VecGetArray(xx,&x));
14 
15   /* forward solve the U^T */
16   idx = 0;
17   for (i=0; i<n; i++) {
18 
19     v = aa + 36*diag[i];
20     /* multiply by the inverse of the block diagonal */
21     x1 = x[idx];   x2 = x[1+idx]; x3    = x[2+idx]; x4 = x[3+idx]; x5 = x[4+idx];
22     x6 = x[5+idx];
23     s1 = v[0]*x1  +  v[1]*x2 +  v[2]*x3 +  v[3]*x4 +  v[4]*x5 +  v[5]*x6;
24     s2 = v[6]*x1  +  v[7]*x2 +  v[8]*x3 +  v[9]*x4 + v[10]*x5 + v[11]*x6;
25     s3 = v[12]*x1 + v[13]*x2 + v[14]*x3 + v[15]*x4 + v[16]*x5 + v[17]*x6;
26     s4 = v[18]*x1 + v[19]*x2 + v[20]*x3 + v[21]*x4 + v[22]*x5 + v[23]*x6;
27     s5 = v[24]*x1 + v[25]*x2 + v[26]*x3 + v[27]*x4 + v[28]*x5 + v[29]*x6;
28     s6 = v[30]*x1 + v[31]*x2 + v[32]*x3 + v[33]*x4 + v[34]*x5 + v[35]*x6;
29     v += 36;
30 
31     vi = aj + diag[i] + 1;
32     nz = ai[i+1] - diag[i] - 1;
33     while (nz--) {
34       oidx       = 6*(*vi++);
35       x[oidx]   -= v[0]*s1  +  v[1]*s2 +  v[2]*s3 +  v[3]*s4 +  v[4]*s5 +  v[5]*s6;
36       x[oidx+1] -= v[6]*s1  +  v[7]*s2 +  v[8]*s3 +  v[9]*s4 + v[10]*s5 + v[11]*s6;
37       x[oidx+2] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4 + v[16]*s5 + v[17]*s6;
38       x[oidx+3] -= v[18]*s1 + v[19]*s2 + v[20]*s3 + v[21]*s4 + v[22]*s5 + v[23]*s6;
39       x[oidx+4] -= v[24]*s1 + v[25]*s2 + v[26]*s3 + v[27]*s4 + v[28]*s5 + v[29]*s6;
40       x[oidx+5] -= v[30]*s1 + v[31]*s2 + v[32]*s3 + v[33]*s4 + v[34]*s5 + v[35]*s6;
41       v         += 36;
42     }
43     x[idx]   = s1;x[1+idx] = s2; x[2+idx] = s3;x[3+idx] = s4; x[4+idx] = s5;
44     x[5+idx] = s6;
45     idx     += 6;
46   }
47   /* backward solve the L^T */
48   for (i=n-1; i>=0; i--) {
49     v   = aa + 36*diag[i] - 36;
50     vi  = aj + diag[i] - 1;
51     nz  = diag[i] - ai[i];
52     idt = 6*i;
53     s1  = x[idt];  s2 = x[1+idt]; s3 = x[2+idt];s4 = x[3+idt]; s5 = x[4+idt];
54     s6  = x[5+idt];
55     while (nz--) {
56       idx       = 6*(*vi--);
57       x[idx]   -=  v[0]*s1 +  v[1]*s2 +  v[2]*s3 +  v[3]*s4 +  v[4]*s5 +  v[5]*s6;
58       x[idx+1] -=  v[6]*s1 +  v[7]*s2 +  v[8]*s3 +  v[9]*s4 + v[10]*s5 + v[11]*s6;
59       x[idx+2] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4 + v[16]*s5 + v[17]*s6;
60       x[idx+3] -= v[18]*s1 + v[19]*s2 + v[20]*s3 + v[21]*s4 + v[22]*s5 + v[23]*s6;
61       x[idx+4] -= v[24]*s1 + v[25]*s2 + v[26]*s3 + v[27]*s4 + v[28]*s5 + v[29]*s6;
62       x[idx+5] -= v[30]*s1 + v[31]*s2 + v[32]*s3 + v[33]*s4 + v[34]*s5 + v[35]*s6;
63       v        -= 36;
64     }
65   }
66   PetscCall(VecRestoreArray(xx,&x));
67   PetscCall(PetscLogFlops(2.0*36*(a->nz) - 6.0*A->cmap->n));
68   PetscFunctionReturn(0);
69 }
70 
71 PetscErrorCode MatSolveTranspose_SeqBAIJ_6_NaturalOrdering(Mat A,Vec bb,Vec xx)
72 {
73   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ*)A->data;
74   const PetscInt  n=a->mbs,*vi,*ai=a->i,*aj=a->j,*diag=a->diag;
75   PetscInt        nz,idx,idt,j,i,oidx;
76   const PetscInt  bs =A->rmap->bs,bs2=a->bs2;
77   const MatScalar *aa=a->a,*v;
78   PetscScalar     s1,s2,s3,s4,s5,s6,x1,x2,x3,x4,x5,x6,*x;
79 
80   PetscFunctionBegin;
81   PetscCall(VecCopy(bb,xx));
82   PetscCall(VecGetArray(xx,&x));
83 
84   /* forward solve the U^T */
85   idx = 0;
86   for (i=0; i<n; i++) {
87     v = aa + bs2*diag[i];
88     /* multiply by the inverse of the block diagonal */
89     x1 = x[idx];   x2 = x[1+idx];  x3 = x[2+idx];  x4 = x[3+idx];
90     x5 = x[4+idx]; x6 = x[5+idx];
91     s1 = v[0]*x1  +  v[1]*x2 +  v[2]*x3 +  v[3]*x4 +  v[4]*x5 +  v[5]*x6;
92     s2 = v[6]*x1  +  v[7]*x2 +  v[8]*x3 +  v[9]*x4 + v[10]*x5 + v[11]*x6;
93     s3 = v[12]*x1 + v[13]*x2 + v[14]*x3 + v[15]*x4 + v[16]*x5 + v[17]*x6;
94     s4 = v[18]*x1 + v[19]*x2 + v[20]*x3 + v[21]*x4 + v[22]*x5 + v[23]*x6;
95     s5 = v[24]*x1 + v[25]*x2 + v[26]*x3 + v[27]*x4 + v[28]*x5 + v[29]*x6;
96     s6 = v[30]*x1 + v[31]*x2 + v[32]*x3 + v[33]*x4 + v[34]*x5 + v[35]*x6;
97     v -= bs2;
98 
99     vi = aj + diag[i] - 1;
100     nz = diag[i] - diag[i+1] - 1;
101     for (j=0; j>-nz; j--) {
102       oidx       = bs*vi[j];
103       x[oidx]   -= v[0]*s1  +  v[1]*s2 +  v[2]*s3 +  v[3]*s4 +  v[4]*s5 +  v[5]*s6;
104       x[oidx+1] -= v[6]*s1  +  v[7]*s2 +  v[8]*s3 +  v[9]*s4 + v[10]*s5 + v[11]*s6;
105       x[oidx+2] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4 + v[16]*s5 + v[17]*s6;
106       x[oidx+3] -= v[18]*s1 + v[19]*s2 + v[20]*s3 + v[21]*s4 + v[22]*s5 + v[23]*s6;
107       x[oidx+4] -= v[24]*s1 + v[25]*s2 + v[26]*s3 + v[27]*s4 + v[28]*s5 + v[29]*s6;
108       x[oidx+5] -= v[30]*s1 + v[31]*s2 + v[32]*s3 + v[33]*s4 + v[34]*s5 + v[35]*s6;
109       v         -= bs2;
110     }
111     x[idx]   = s1;x[1+idx] = s2;  x[2+idx] = s3;  x[3+idx] = s4; x[4+idx] = s5;
112     x[5+idx] = s6;
113     idx     += bs;
114   }
115   /* backward solve the L^T */
116   for (i=n-1; i>=0; i--) {
117     v   = aa + bs2*ai[i];
118     vi  = aj + ai[i];
119     nz  = ai[i+1] - ai[i];
120     idt = bs*i;
121     s1  = x[idt];  s2 = x[1+idt];  s3 = x[2+idt];  s4 = x[3+idt];  s5 = x[4+idt];
122     s6  = x[5+idt];
123     for (j=0; j<nz; j++) {
124       idx       = bs*vi[j];
125       x[idx]   -= v[0]*s1  +  v[1]*s2 +  v[2]*s3 +  v[3]*s4 +  v[4]*s5 +  v[5]*s6;
126       x[idx+1] -= v[6]*s1  +  v[7]*s2 +  v[8]*s3 +  v[9]*s4 + v[10]*s5 + v[11]*s6;
127       x[idx+2] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4 + v[16]*s5 + v[17]*s6;
128       x[idx+3] -= v[18]*s1 + v[19]*s2 + v[20]*s3 + v[21]*s4 + v[22]*s5 + v[23]*s6;
129       x[idx+4] -= v[24]*s1 + v[25]*s2 + v[26]*s3 + v[27]*s4 + v[28]*s5 + v[29]*s6;
130       x[idx+5] -= v[30]*s1 + v[31]*s2 + v[32]*s3 + v[33]*s4 + v[34]*s5 + v[35]*s6;
131       v        += bs2;
132     }
133   }
134   PetscCall(VecRestoreArray(xx,&x));
135   PetscCall(PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n));
136   PetscFunctionReturn(0);
137 }
138