xref: /petsc/src/mat/impls/baij/seq/baijsolvnat7.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
1 #include <../src/mat/impls/baij/seq/baij.h>
2 #include <petsc/private/kernels/blockinvert.h>
3 
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];   x[1] = b[1+idx]; x[2] = b[2+idx];
19   x[3] = b[3+idx]; x[4] = b[4+idx]; x[5] = b[5+idx];
20   x[6] = b[6+idx];
21   for (i=1; i<n; i++) {
22     v   =  aa + 49*ai[i];
23     vi  =  aj + ai[i];
24     nz  =  diag[i] - ai[i];
25     idx =  7*i;
26     s1  =  b[idx];   s2 = b[1+idx]; s3 = b[2+idx];
27     s4  =  b[3+idx]; s5 = b[4+idx]; s6 = b[5+idx];
28     s7  =  b[6+idx];
29     while (nz--) {
30       jdx = 7*(*vi++);
31       x1  = x[jdx];   x2 = x[1+jdx]; x3 = x[2+jdx];
32       x4  = x[3+jdx]; x5 = x[4+jdx]; x6 = x[5+jdx];
33       x7  = x[6+jdx];
34       s1 -= v[0]*x1 + v[7]*x2  + v[14]*x3 + v[21]*x4 + v[28]*x5 + v[35]*x6 + v[42]*x7;
35       s2 -= v[1]*x1 + v[8]*x2  + v[15]*x3 + v[22]*x4 + v[29]*x5 + v[36]*x6 + v[43]*x7;
36       s3 -= v[2]*x1 + v[9]*x2  + v[16]*x3 + v[23]*x4 + v[30]*x5 + v[37]*x6 + v[44]*x7;
37       s4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4 + v[31]*x5 + v[38]*x6 + v[45]*x7;
38       s5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4 + v[32]*x5 + v[39]*x6 + v[46]*x7;
39       s6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4 + v[33]*x5 + v[40]*x6 + v[47]*x7;
40       s7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4 + v[34]*x5 + v[41]*x6 + v[48]*x7;
41       v  += 49;
42     }
43     x[idx]   = s1;
44     x[1+idx] = s2;
45     x[2+idx] = s3;
46     x[3+idx] = s4;
47     x[4+idx] = s5;
48     x[5+idx] = s6;
49     x[6+idx] = s7;
50   }
51   /* backward solve the upper triangular */
52   for (i=n-1; i>=0; i--) {
53     v   = aa + 49*diag[i] + 49;
54     vi  = aj + diag[i] + 1;
55     nz  = ai[i+1] - diag[i] - 1;
56     idt = 7*i;
57     s1  = x[idt];   s2 = x[1+idt];
58     s3  = x[2+idt]; s4 = x[3+idt];
59     s5  = x[4+idt]; s6 = x[5+idt];
60     s7  = x[6+idt];
61     while (nz--) {
62       idx = 7*(*vi++);
63       x1  = x[idx];   x2 = x[1+idx]; x3 = x[2+idx];
64       x4  = x[3+idx]; x5 = x[4+idx]; x6 = x[5+idx];
65       x7  = x[6+idx];
66       s1 -= v[0]*x1 + v[7]*x2  + v[14]*x3 + v[21]*x4 + v[28]*x5 + v[35]*x6 + v[42]*x7;
67       s2 -= v[1]*x1 + v[8]*x2  + v[15]*x3 + v[22]*x4 + v[29]*x5 + v[36]*x6 + v[43]*x7;
68       s3 -= v[2]*x1 + v[9]*x2  + v[16]*x3 + v[23]*x4 + v[30]*x5 + v[37]*x6 + v[44]*x7;
69       s4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4 + v[31]*x5 + v[38]*x6 + v[45]*x7;
70       s5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4 + v[32]*x5 + v[39]*x6 + v[46]*x7;
71       s6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4 + v[33]*x5 + v[40]*x6 + v[47]*x7;
72       s7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4 + v[34]*x5 + v[41]*x6 + v[48]*x7;
73       v  += 49;
74     }
75     v      = aa + 49*diag[i];
76     x[idt] = v[0]*s1 + v[7]*s2  + v[14]*s3 + v[21]*s4
77              + v[28]*s5 + v[35]*s6 + v[42]*s7;
78     x[1+idt] = v[1]*s1 + v[8]*s2  + v[15]*s3 + v[22]*s4
79                + v[29]*s5 + v[36]*s6 + v[43]*s7;
80     x[2+idt] = v[2]*s1 + v[9]*s2  + v[16]*s3 + v[23]*s4
81                + v[30]*s5 + v[37]*s6 + v[44]*s7;
82     x[3+idt] = v[3]*s1 + v[10]*s2  + v[17]*s3 + v[24]*s4
83                + v[31]*s5 + v[38]*s6 + v[45]*s7;
84     x[4+idt] = v[4]*s1 + v[11]*s2  + v[18]*s3 + v[25]*s4
85                + v[32]*s5 + v[39]*s6 + v[46]*s7;
86     x[5+idt] = v[5]*s1 + v[12]*s2  + v[19]*s3 + v[26]*s4
87                + v[33]*s5 + v[40]*s6 + v[47]*s7;
88     x[6+idt] = v[6]*s1 + v[13]*s2  + v[20]*s3 + v[27]*s4
89                + v[34]*s5 + v[41]*s6 + v[48]*s7;
90   }
91 
92   PetscCall(VecRestoreArrayRead(bb,&b));
93   PetscCall(VecRestoreArray(xx,&x));
94   PetscCall(PetscLogFlops(2.0*36*(a->nz) - 6.0*A->cmap->n));
95   PetscFunctionReturn(0);
96 }
97 
98 PetscErrorCode MatSolve_SeqBAIJ_7_NaturalOrdering(Mat A,Vec bb,Vec xx)
99 {
100   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ*)A->data;
101   const PetscInt    n  =a->mbs,*vi,*ai=a->i,*aj=a->j,*adiag=a->diag;
102   PetscInt          i,k,nz,idx,jdx,idt;
103   const PetscInt    bs = A->rmap->bs,bs2 = a->bs2;
104   const MatScalar   *aa=a->a,*v;
105   PetscScalar       *x;
106   const PetscScalar *b;
107   PetscScalar       s1,s2,s3,s4,s5,s6,s7,x1,x2,x3,x4,x5,x6,x7;
108 
109   PetscFunctionBegin;
110   PetscCall(VecGetArrayRead(bb,&b));
111   PetscCall(VecGetArray(xx,&x));
112   /* forward solve the lower triangular */
113   idx  = 0;
114   x[0] = b[idx]; x[1] = b[1+idx];x[2] = b[2+idx];x[3] = b[3+idx];
115   x[4] = b[4+idx];x[5] = b[5+idx];x[6] = b[6+idx];
116   for (i=1; i<n; i++) {
117     v   = aa + bs2*ai[i];
118     vi  = aj + ai[i];
119     nz  = ai[i+1] - ai[i];
120     idx = bs*i;
121     s1  = b[idx];s2 = b[1+idx];s3 = b[2+idx];s4 = b[3+idx];
122     s5  = b[4+idx];s6 = b[5+idx];s7 = b[6+idx];
123     for (k=0; k<nz; k++) {
124       jdx = bs*vi[k];
125       x1  = x[jdx];x2 = x[1+jdx]; x3 =x[2+jdx];x4 =x[3+jdx];
126       x5  = x[4+jdx]; x6 = x[5+jdx];x7 = x[6+jdx];
127       s1 -= v[0]*x1 + v[7]*x2 + v[14]*x3 + v[21]*x4  + v[28]*x5 + v[35]*x6 + v[42]*x7;
128       s2 -= v[1]*x1 + v[8]*x2 + v[15]*x3 + v[22]*x4  + v[29]*x5 + v[36]*x6 + v[43]*x7;
129       s3 -= v[2]*x1 + v[9]*x2 + v[16]*x3 + v[23]*x4  + v[30]*x5 + v[37]*x6 + v[44]*x7;
130       s4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4  + v[31]*x5 + v[38]*x6 + v[45]*x7;
131       s5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4  + v[32]*x5 + v[39]*x6 + v[46]*x7;
132       s6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4  + v[33]*x5 + v[40]*x6 + v[47]*x7;
133       s7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4  + v[34]*x5 + v[41]*x6 + v[48]*x7;
134       v  +=  bs2;
135     }
136 
137     x[idx]   = s1;
138     x[1+idx] = s2;
139     x[2+idx] = s3;
140     x[3+idx] = s4;
141     x[4+idx] = s5;
142     x[5+idx] = s6;
143     x[6+idx] = s7;
144   }
145 
146   /* backward solve the upper triangular */
147   for (i=n-1; i>=0; i--) {
148     v   = aa + bs2*(adiag[i+1]+1);
149     vi  = aj + adiag[i+1]+1;
150     nz  = adiag[i] - adiag[i+1]-1;
151     idt = bs*i;
152     s1  = x[idt];  s2 = x[1+idt];s3 = x[2+idt];s4 = x[3+idt];
153     s5  = x[4+idt];s6 = x[5+idt];s7 = x[6+idt];
154     for (k=0; k<nz; k++) {
155       idx = bs*vi[k];
156       x1  = x[idx];   x2 = x[1+idx]; x3 = x[2+idx];x4 = x[3+idx];
157       x5  = x[4+idx];x6 = x[5+idx];x7 = x[6+idx];
158       s1 -= v[0]*x1 + v[7]*x2 + v[14]*x3 + v[21]*x4  + v[28]*x5 + v[35]*x6 + v[42]*x7;
159       s2 -= v[1]*x1 + v[8]*x2 + v[15]*x3 + v[22]*x4  + v[29]*x5 + v[36]*x6 + v[43]*x7;
160       s3 -= v[2]*x1 + v[9]*x2 + v[16]*x3 + v[23]*x4  + v[30]*x5 + v[37]*x6 + v[44]*x7;
161       s4 -= v[3]*x1 + v[10]*x2 + v[17]*x3 + v[24]*x4  + v[31]*x5 + v[38]*x6 + v[45]*x7;
162       s5 -= v[4]*x1 + v[11]*x2 + v[18]*x3 + v[25]*x4  + v[32]*x5 + v[39]*x6 + v[46]*x7;
163       s6 -= v[5]*x1 + v[12]*x2 + v[19]*x3 + v[26]*x4  + v[33]*x5 + v[40]*x6 + v[47]*x7;
164       s7 -= v[6]*x1 + v[13]*x2 + v[20]*x3 + v[27]*x4  + v[34]*x5 + v[41]*x6 + v[48]*x7;
165       v  +=  bs2;
166     }
167     /* x = inv_diagonal*x */
168     x[idt]   = v[0]*s1 + v[7]*s2 + v[14]*s3 + v[21]*s4  + v[28]*s5 + v[35]*s6 + v[42]*s7;
169     x[1+idt] = v[1]*s1 + v[8]*s2 + v[15]*s3 + v[22]*s4  + v[29]*s5 + v[36]*s6 + v[43]*s7;
170     x[2+idt] = v[2]*s1 + v[9]*s2 + v[16]*s3 + v[23]*s4  + v[30]*s5 + v[37]*s6 + v[44]*s7;
171     x[3+idt] = v[3]*s1 + v[10]*s2 + v[17]*s3 + v[24]*s4  + v[31]*s5 + v[38]*s6 + v[45]*s7;
172     x[4+idt] = v[4]*s1 + v[11]*s2 + v[18]*s3 + v[25]*s4  + v[32]*s5 + v[39]*s6 + v[46]*s7;
173     x[5+idt] = v[5]*s1 + v[12]*s2 + v[19]*s3 + v[26]*s4  + v[33]*s5 + v[40]*s6 + v[47]*s7;
174     x[6+idt] = v[6]*s1 + v[13]*s2 + v[20]*s3 + v[27]*s4  + v[34]*s5 + v[41]*s6 + v[48]*s7;
175   }
176 
177   PetscCall(VecRestoreArrayRead(bb,&b));
178   PetscCall(VecRestoreArray(xx,&x));
179   PetscCall(PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n));
180   PetscFunctionReturn(0);
181 }
182