xref: /petsc/src/mat/impls/baij/seq/baijsolvnat14.c (revision 2c733ed45a445b0336611d812c866924feeaee2c)
1*2c733ed4SBarry Smith #include <../src/mat/impls/baij/seq/baij.h>
2*2c733ed4SBarry Smith #include <petsc/private/kernels/blockinvert.h>
3*2c733ed4SBarry Smith 
4*2c733ed4SBarry Smith /* Block operations are done by accessing one column at at time */
5*2c733ed4SBarry Smith /* Default MatSolve for block size 14 */
6*2c733ed4SBarry Smith 
7*2c733ed4SBarry Smith PetscErrorCode MatSolve_SeqBAIJ_14_NaturalOrdering(Mat A,Vec bb,Vec xx)
8*2c733ed4SBarry Smith {
9*2c733ed4SBarry Smith   Mat_SeqBAIJ       *a=(Mat_SeqBAIJ*)A->data;
10*2c733ed4SBarry Smith   PetscErrorCode    ierr;
11*2c733ed4SBarry Smith   const PetscInt    n=a->mbs,*ai=a->i,*aj=a->j,*adiag=a->diag,*vi,bs=A->rmap->bs,bs2=a->bs2;
12*2c733ed4SBarry Smith   PetscInt          i,k,nz,idx,idt,m;
13*2c733ed4SBarry Smith   const MatScalar   *aa=a->a,*v;
14*2c733ed4SBarry Smith   PetscScalar       s[14];
15*2c733ed4SBarry Smith   PetscScalar       *x,xv;
16*2c733ed4SBarry Smith   const PetscScalar *b;
17*2c733ed4SBarry Smith 
18*2c733ed4SBarry Smith   PetscFunctionBegin;
19*2c733ed4SBarry Smith   ierr = VecGetArrayRead(bb,&b);CHKERRQ(ierr);
20*2c733ed4SBarry Smith   ierr = VecGetArray(xx,&x);CHKERRQ(ierr);
21*2c733ed4SBarry Smith 
22*2c733ed4SBarry Smith   /* forward solve the lower triangular */
23*2c733ed4SBarry Smith   for (i=0; i<n; i++) {
24*2c733ed4SBarry Smith     v         = aa + bs2*ai[i];
25*2c733ed4SBarry Smith     vi        = aj + ai[i];
26*2c733ed4SBarry Smith     nz        = ai[i+1] - ai[i];
27*2c733ed4SBarry Smith     idt       = bs*i;
28*2c733ed4SBarry Smith     x[idt]    = b[idt];    x[1+idt]  = b[1+idt];  x[2+idt]  = b[2+idt];  x[3+idt]  = b[3+idt];  x[4+idt]  = b[4+idt];
29*2c733ed4SBarry Smith     x[5+idt]  = b[5+idt];  x[6+idt]  = b[6+idt];  x[7+idt]  = b[7+idt];  x[8+idt]  = b[8+idt];  x[9+idt] = b[9+idt];
30*2c733ed4SBarry Smith     x[10+idt] = b[10+idt]; x[11+idt] = b[11+idt]; x[12+idt] = b[12+idt]; x[13+idt] = b[13+idt];
31*2c733ed4SBarry Smith     for (m=0; m<nz; m++) {
32*2c733ed4SBarry Smith       idx = bs*vi[m];
33*2c733ed4SBarry Smith       for (k=0; k<bs; k++) {
34*2c733ed4SBarry Smith         xv         = x[k + idx];
35*2c733ed4SBarry Smith         x[idt]    -= v[0]*xv;
36*2c733ed4SBarry Smith         x[1+idt]  -= v[1]*xv;
37*2c733ed4SBarry Smith         x[2+idt]  -= v[2]*xv;
38*2c733ed4SBarry Smith         x[3+idt]  -= v[3]*xv;
39*2c733ed4SBarry Smith         x[4+idt]  -= v[4]*xv;
40*2c733ed4SBarry Smith         x[5+idt]  -= v[5]*xv;
41*2c733ed4SBarry Smith         x[6+idt]  -= v[6]*xv;
42*2c733ed4SBarry Smith         x[7+idt]  -= v[7]*xv;
43*2c733ed4SBarry Smith         x[8+idt]  -= v[8]*xv;
44*2c733ed4SBarry Smith         x[9+idt]  -= v[9]*xv;
45*2c733ed4SBarry Smith         x[10+idt] -= v[10]*xv;
46*2c733ed4SBarry Smith         x[11+idt] -= v[11]*xv;
47*2c733ed4SBarry Smith         x[12+idt] -= v[12]*xv;
48*2c733ed4SBarry Smith         x[13+idt] -= v[13]*xv;
49*2c733ed4SBarry Smith         v         += 14;
50*2c733ed4SBarry Smith       }
51*2c733ed4SBarry Smith     }
52*2c733ed4SBarry Smith   }
53*2c733ed4SBarry Smith   /* backward solve the upper triangular */
54*2c733ed4SBarry Smith   for (i=n-1; i>=0; i--) {
55*2c733ed4SBarry Smith     v     = aa + bs2*(adiag[i+1]+1);
56*2c733ed4SBarry Smith     vi    = aj + adiag[i+1]+1;
57*2c733ed4SBarry Smith     nz    = adiag[i] - adiag[i+1] - 1;
58*2c733ed4SBarry Smith     idt   = bs*i;
59*2c733ed4SBarry Smith     s[0]  = x[idt];    s[1]  = x[1+idt];  s[2]  = x[2+idt];  s[3]  = x[3+idt];  s[4]  = x[4+idt];
60*2c733ed4SBarry Smith     s[5]  = x[5+idt];  s[6]  = x[6+idt];  s[7]  = x[7+idt];  s[8]  = x[8+idt];  s[9]  = x[9+idt];
61*2c733ed4SBarry Smith     s[10] = x[10+idt]; s[11] = x[11+idt]; s[12] = x[12+idt]; s[13] = x[13+idt];
62*2c733ed4SBarry Smith 
63*2c733ed4SBarry Smith     for (m=0; m<nz; m++) {
64*2c733ed4SBarry Smith       idx = bs*vi[m];
65*2c733ed4SBarry Smith       for (k=0; k<bs; k++) {
66*2c733ed4SBarry Smith         xv     = x[k + idx];
67*2c733ed4SBarry Smith         s[0]  -= v[0]*xv;
68*2c733ed4SBarry Smith         s[1]  -= v[1]*xv;
69*2c733ed4SBarry Smith         s[2]  -= v[2]*xv;
70*2c733ed4SBarry Smith         s[3]  -= v[3]*xv;
71*2c733ed4SBarry Smith         s[4]  -= v[4]*xv;
72*2c733ed4SBarry Smith         s[5]  -= v[5]*xv;
73*2c733ed4SBarry Smith         s[6]  -= v[6]*xv;
74*2c733ed4SBarry Smith         s[7]  -= v[7]*xv;
75*2c733ed4SBarry Smith         s[8]  -= v[8]*xv;
76*2c733ed4SBarry Smith         s[9]  -= v[9]*xv;
77*2c733ed4SBarry Smith         s[10] -= v[10]*xv;
78*2c733ed4SBarry Smith         s[11] -= v[11]*xv;
79*2c733ed4SBarry Smith         s[12] -= v[12]*xv;
80*2c733ed4SBarry Smith         s[13] -= v[13]*xv;
81*2c733ed4SBarry Smith         v     += 14;
82*2c733ed4SBarry Smith       }
83*2c733ed4SBarry Smith     }
84*2c733ed4SBarry Smith     ierr = PetscMemzero(x+idt,bs*sizeof(MatScalar));CHKERRQ(ierr);
85*2c733ed4SBarry Smith     for (k=0; k<bs; k++) {
86*2c733ed4SBarry Smith       x[idt]    += v[0]*s[k];
87*2c733ed4SBarry Smith       x[1+idt]  += v[1]*s[k];
88*2c733ed4SBarry Smith       x[2+idt]  += v[2]*s[k];
89*2c733ed4SBarry Smith       x[3+idt]  += v[3]*s[k];
90*2c733ed4SBarry Smith       x[4+idt]  += v[4]*s[k];
91*2c733ed4SBarry Smith       x[5+idt]  += v[5]*s[k];
92*2c733ed4SBarry Smith       x[6+idt]  += v[6]*s[k];
93*2c733ed4SBarry Smith       x[7+idt]  += v[7]*s[k];
94*2c733ed4SBarry Smith       x[8+idt]  += v[8]*s[k];
95*2c733ed4SBarry Smith       x[9+idt]  += v[9]*s[k];
96*2c733ed4SBarry Smith       x[10+idt] += v[10]*s[k];
97*2c733ed4SBarry Smith       x[11+idt] += v[11]*s[k];
98*2c733ed4SBarry Smith       x[12+idt] += v[12]*s[k];
99*2c733ed4SBarry Smith       x[13+idt] += v[13]*s[k];
100*2c733ed4SBarry Smith       v         += 14;
101*2c733ed4SBarry Smith     }
102*2c733ed4SBarry Smith   }
103*2c733ed4SBarry Smith   ierr = VecRestoreArrayRead(bb,&b);CHKERRQ(ierr);
104*2c733ed4SBarry Smith   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
105*2c733ed4SBarry Smith   ierr = PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n);CHKERRQ(ierr);
106*2c733ed4SBarry Smith   PetscFunctionReturn(0);
107*2c733ed4SBarry Smith }
108*2c733ed4SBarry Smith 
109*2c733ed4SBarry Smith /* Block operations are done by accessing one column at at time */
110*2c733ed4SBarry Smith /* Default MatSolve for block size 13 */
111*2c733ed4SBarry Smith 
112*2c733ed4SBarry Smith PetscErrorCode MatSolve_SeqBAIJ_13_NaturalOrdering(Mat A,Vec bb,Vec xx)
113*2c733ed4SBarry Smith {
114*2c733ed4SBarry Smith   Mat_SeqBAIJ       *a=(Mat_SeqBAIJ*)A->data;
115*2c733ed4SBarry Smith   PetscErrorCode    ierr;
116*2c733ed4SBarry Smith   const PetscInt    n=a->mbs,*ai=a->i,*aj=a->j,*adiag=a->diag,*vi,bs=A->rmap->bs,bs2=a->bs2;
117*2c733ed4SBarry Smith   PetscInt          i,k,nz,idx,idt,m;
118*2c733ed4SBarry Smith   const MatScalar   *aa=a->a,*v;
119*2c733ed4SBarry Smith   PetscScalar       s[13];
120*2c733ed4SBarry Smith   PetscScalar       *x,xv;
121*2c733ed4SBarry Smith   const PetscScalar *b;
122*2c733ed4SBarry Smith 
123*2c733ed4SBarry Smith   PetscFunctionBegin;
124*2c733ed4SBarry Smith   ierr = VecGetArrayRead(bb,&b);CHKERRQ(ierr);
125*2c733ed4SBarry Smith   ierr = VecGetArray(xx,&x);CHKERRQ(ierr);
126*2c733ed4SBarry Smith 
127*2c733ed4SBarry Smith   /* forward solve the lower triangular */
128*2c733ed4SBarry Smith   for (i=0; i<n; i++) {
129*2c733ed4SBarry Smith     v         = aa + bs2*ai[i];
130*2c733ed4SBarry Smith     vi        = aj + ai[i];
131*2c733ed4SBarry Smith     nz        = ai[i+1] - ai[i];
132*2c733ed4SBarry Smith     idt       = bs*i;
133*2c733ed4SBarry Smith     x[idt]    = b[idt];    x[1+idt]  = b[1+idt];  x[2+idt]  = b[2+idt];  x[3+idt]  = b[3+idt];  x[4+idt]  = b[4+idt];
134*2c733ed4SBarry Smith     x[5+idt]  = b[5+idt];  x[6+idt]  = b[6+idt];  x[7+idt]  = b[7+idt];  x[8+idt]  = b[8+idt];  x[9+idt] = b[9+idt];
135*2c733ed4SBarry Smith     x[10+idt] = b[10+idt]; x[11+idt] = b[11+idt]; x[12+idt] = b[12+idt];
136*2c733ed4SBarry Smith     for (m=0; m<nz; m++) {
137*2c733ed4SBarry Smith       idx = bs*vi[m];
138*2c733ed4SBarry Smith       for (k=0; k<bs; k++) {
139*2c733ed4SBarry Smith         xv         = x[k + idx];
140*2c733ed4SBarry Smith         x[idt]    -= v[0]*xv;
141*2c733ed4SBarry Smith         x[1+idt]  -= v[1]*xv;
142*2c733ed4SBarry Smith         x[2+idt]  -= v[2]*xv;
143*2c733ed4SBarry Smith         x[3+idt]  -= v[3]*xv;
144*2c733ed4SBarry Smith         x[4+idt]  -= v[4]*xv;
145*2c733ed4SBarry Smith         x[5+idt]  -= v[5]*xv;
146*2c733ed4SBarry Smith         x[6+idt]  -= v[6]*xv;
147*2c733ed4SBarry Smith         x[7+idt]  -= v[7]*xv;
148*2c733ed4SBarry Smith         x[8+idt]  -= v[8]*xv;
149*2c733ed4SBarry Smith         x[9+idt]  -= v[9]*xv;
150*2c733ed4SBarry Smith         x[10+idt] -= v[10]*xv;
151*2c733ed4SBarry Smith         x[11+idt] -= v[11]*xv;
152*2c733ed4SBarry Smith         x[12+idt] -= v[12]*xv;
153*2c733ed4SBarry Smith         v         += 13;
154*2c733ed4SBarry Smith       }
155*2c733ed4SBarry Smith     }
156*2c733ed4SBarry Smith   }
157*2c733ed4SBarry Smith   /* backward solve the upper triangular */
158*2c733ed4SBarry Smith   for (i=n-1; i>=0; i--) {
159*2c733ed4SBarry Smith     v     = aa + bs2*(adiag[i+1]+1);
160*2c733ed4SBarry Smith     vi    = aj + adiag[i+1]+1;
161*2c733ed4SBarry Smith     nz    = adiag[i] - adiag[i+1] - 1;
162*2c733ed4SBarry Smith     idt   = bs*i;
163*2c733ed4SBarry Smith     s[0]  = x[idt];    s[1]  = x[1+idt];  s[2]  = x[2+idt];  s[3]  = x[3+idt];  s[4]  = x[4+idt];
164*2c733ed4SBarry Smith     s[5]  = x[5+idt];  s[6]  = x[6+idt];  s[7]  = x[7+idt];  s[8]  = x[8+idt];  s[9]  = x[9+idt];
165*2c733ed4SBarry Smith     s[10] = x[10+idt]; s[11] = x[11+idt]; s[12] = x[12+idt];
166*2c733ed4SBarry Smith 
167*2c733ed4SBarry Smith     for (m=0; m<nz; m++) {
168*2c733ed4SBarry Smith       idx = bs*vi[m];
169*2c733ed4SBarry Smith       for (k=0; k<bs; k++) {
170*2c733ed4SBarry Smith         xv     = x[k + idx];
171*2c733ed4SBarry Smith         s[0]  -= v[0]*xv;
172*2c733ed4SBarry Smith         s[1]  -= v[1]*xv;
173*2c733ed4SBarry Smith         s[2]  -= v[2]*xv;
174*2c733ed4SBarry Smith         s[3]  -= v[3]*xv;
175*2c733ed4SBarry Smith         s[4]  -= v[4]*xv;
176*2c733ed4SBarry Smith         s[5]  -= v[5]*xv;
177*2c733ed4SBarry Smith         s[6]  -= v[6]*xv;
178*2c733ed4SBarry Smith         s[7]  -= v[7]*xv;
179*2c733ed4SBarry Smith         s[8]  -= v[8]*xv;
180*2c733ed4SBarry Smith         s[9]  -= v[9]*xv;
181*2c733ed4SBarry Smith         s[10] -= v[10]*xv;
182*2c733ed4SBarry Smith         s[11] -= v[11]*xv;
183*2c733ed4SBarry Smith         s[12] -= v[12]*xv;
184*2c733ed4SBarry Smith         v     += 13;
185*2c733ed4SBarry Smith       }
186*2c733ed4SBarry Smith     }
187*2c733ed4SBarry Smith     ierr = PetscMemzero(x+idt,bs*sizeof(MatScalar));CHKERRQ(ierr);
188*2c733ed4SBarry Smith     for (k=0; k<bs; k++) {
189*2c733ed4SBarry Smith       x[idt]    += v[0]*s[k];
190*2c733ed4SBarry Smith       x[1+idt]  += v[1]*s[k];
191*2c733ed4SBarry Smith       x[2+idt]  += v[2]*s[k];
192*2c733ed4SBarry Smith       x[3+idt]  += v[3]*s[k];
193*2c733ed4SBarry Smith       x[4+idt]  += v[4]*s[k];
194*2c733ed4SBarry Smith       x[5+idt]  += v[5]*s[k];
195*2c733ed4SBarry Smith       x[6+idt]  += v[6]*s[k];
196*2c733ed4SBarry Smith       x[7+idt]  += v[7]*s[k];
197*2c733ed4SBarry Smith       x[8+idt]  += v[8]*s[k];
198*2c733ed4SBarry Smith       x[9+idt]  += v[9]*s[k];
199*2c733ed4SBarry Smith       x[10+idt] += v[10]*s[k];
200*2c733ed4SBarry Smith       x[11+idt] += v[11]*s[k];
201*2c733ed4SBarry Smith       x[12+idt] += v[12]*s[k];
202*2c733ed4SBarry Smith       v         += 13;
203*2c733ed4SBarry Smith     }
204*2c733ed4SBarry Smith   }
205*2c733ed4SBarry Smith   ierr = VecRestoreArrayRead(bb,&b);CHKERRQ(ierr);
206*2c733ed4SBarry Smith   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
207*2c733ed4SBarry Smith   ierr = PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n);CHKERRQ(ierr);
208*2c733ed4SBarry Smith   PetscFunctionReturn(0);
209*2c733ed4SBarry Smith }
210*2c733ed4SBarry Smith 
211*2c733ed4SBarry Smith /* Block operations are done by accessing one column at at time */
212*2c733ed4SBarry Smith /* Default MatSolve for block size 12 */
213*2c733ed4SBarry Smith 
214*2c733ed4SBarry Smith PetscErrorCode MatSolve_SeqBAIJ_12_NaturalOrdering(Mat A,Vec bb,Vec xx)
215*2c733ed4SBarry Smith {
216*2c733ed4SBarry Smith   Mat_SeqBAIJ       *a=(Mat_SeqBAIJ*)A->data;
217*2c733ed4SBarry Smith   PetscErrorCode    ierr;
218*2c733ed4SBarry Smith   const PetscInt    n=a->mbs,*ai=a->i,*aj=a->j,*adiag=a->diag,*vi,bs=A->rmap->bs,bs2=a->bs2;
219*2c733ed4SBarry Smith   PetscInt          i,k,nz,idx,idt,m;
220*2c733ed4SBarry Smith   const MatScalar   *aa=a->a,*v;
221*2c733ed4SBarry Smith   PetscScalar       s[12];
222*2c733ed4SBarry Smith   PetscScalar       *x,xv;
223*2c733ed4SBarry Smith   const PetscScalar *b;
224*2c733ed4SBarry Smith 
225*2c733ed4SBarry Smith   PetscFunctionBegin;
226*2c733ed4SBarry Smith   ierr = VecGetArrayRead(bb,&b);CHKERRQ(ierr);
227*2c733ed4SBarry Smith   ierr = VecGetArray(xx,&x);CHKERRQ(ierr);
228*2c733ed4SBarry Smith 
229*2c733ed4SBarry Smith   /* forward solve the lower triangular */
230*2c733ed4SBarry Smith   for (i=0; i<n; i++) {
231*2c733ed4SBarry Smith     v         = aa + bs2*ai[i];
232*2c733ed4SBarry Smith     vi        = aj + ai[i];
233*2c733ed4SBarry Smith     nz        = ai[i+1] - ai[i];
234*2c733ed4SBarry Smith     idt       = bs*i;
235*2c733ed4SBarry Smith     x[idt]    = b[idt];    x[1+idt]  = b[1+idt];  x[2+idt]  = b[2+idt];  x[3+idt]  = b[3+idt];  x[4+idt]  = b[4+idt];
236*2c733ed4SBarry Smith     x[5+idt]  = b[5+idt];  x[6+idt]  = b[6+idt];  x[7+idt]  = b[7+idt];  x[8+idt]  = b[8+idt];  x[9+idt] = b[9+idt];
237*2c733ed4SBarry Smith     x[10+idt] = b[10+idt]; x[11+idt] = b[11+idt];
238*2c733ed4SBarry Smith     for (m=0; m<nz; m++) {
239*2c733ed4SBarry Smith       idx = bs*vi[m];
240*2c733ed4SBarry Smith       for (k=0; k<bs; k++) {
241*2c733ed4SBarry Smith         xv         = x[k + idx];
242*2c733ed4SBarry Smith         x[idt]    -= v[0]*xv;
243*2c733ed4SBarry Smith         x[1+idt]  -= v[1]*xv;
244*2c733ed4SBarry Smith         x[2+idt]  -= v[2]*xv;
245*2c733ed4SBarry Smith         x[3+idt]  -= v[3]*xv;
246*2c733ed4SBarry Smith         x[4+idt]  -= v[4]*xv;
247*2c733ed4SBarry Smith         x[5+idt]  -= v[5]*xv;
248*2c733ed4SBarry Smith         x[6+idt]  -= v[6]*xv;
249*2c733ed4SBarry Smith         x[7+idt]  -= v[7]*xv;
250*2c733ed4SBarry Smith         x[8+idt]  -= v[8]*xv;
251*2c733ed4SBarry Smith         x[9+idt]  -= v[9]*xv;
252*2c733ed4SBarry Smith         x[10+idt] -= v[10]*xv;
253*2c733ed4SBarry Smith         x[11+idt] -= v[11]*xv;
254*2c733ed4SBarry Smith         v         += 12;
255*2c733ed4SBarry Smith       }
256*2c733ed4SBarry Smith     }
257*2c733ed4SBarry Smith   }
258*2c733ed4SBarry Smith   /* backward solve the upper triangular */
259*2c733ed4SBarry Smith   for (i=n-1; i>=0; i--) {
260*2c733ed4SBarry Smith     v     = aa + bs2*(adiag[i+1]+1);
261*2c733ed4SBarry Smith     vi    = aj + adiag[i+1]+1;
262*2c733ed4SBarry Smith     nz    = adiag[i] - adiag[i+1] - 1;
263*2c733ed4SBarry Smith     idt   = bs*i;
264*2c733ed4SBarry Smith     s[0]  = x[idt];    s[1]  = x[1+idt];  s[2]  = x[2+idt];  s[3]  = x[3+idt];  s[4]  = x[4+idt];
265*2c733ed4SBarry Smith     s[5]  = x[5+idt];  s[6]  = x[6+idt];  s[7]  = x[7+idt];  s[8]  = x[8+idt];  s[9]  = x[9+idt];
266*2c733ed4SBarry Smith     s[10] = x[10+idt]; s[11] = x[11+idt];
267*2c733ed4SBarry Smith 
268*2c733ed4SBarry Smith     for (m=0; m<nz; m++) {
269*2c733ed4SBarry Smith       idx = bs*vi[m];
270*2c733ed4SBarry Smith       for (k=0; k<bs; k++) {
271*2c733ed4SBarry Smith         xv     = x[k + idx];
272*2c733ed4SBarry Smith         s[0]  -= v[0]*xv;
273*2c733ed4SBarry Smith         s[1]  -= v[1]*xv;
274*2c733ed4SBarry Smith         s[2]  -= v[2]*xv;
275*2c733ed4SBarry Smith         s[3]  -= v[3]*xv;
276*2c733ed4SBarry Smith         s[4]  -= v[4]*xv;
277*2c733ed4SBarry Smith         s[5]  -= v[5]*xv;
278*2c733ed4SBarry Smith         s[6]  -= v[6]*xv;
279*2c733ed4SBarry Smith         s[7]  -= v[7]*xv;
280*2c733ed4SBarry Smith         s[8]  -= v[8]*xv;
281*2c733ed4SBarry Smith         s[9]  -= v[9]*xv;
282*2c733ed4SBarry Smith         s[10] -= v[10]*xv;
283*2c733ed4SBarry Smith         s[11] -= v[11]*xv;
284*2c733ed4SBarry Smith         v     += 12;
285*2c733ed4SBarry Smith       }
286*2c733ed4SBarry Smith     }
287*2c733ed4SBarry Smith     ierr = PetscMemzero(x+idt,bs*sizeof(MatScalar));CHKERRQ(ierr);
288*2c733ed4SBarry Smith     for (k=0; k<bs; k++) {
289*2c733ed4SBarry Smith       x[idt]    += v[0]*s[k];
290*2c733ed4SBarry Smith       x[1+idt]  += v[1]*s[k];
291*2c733ed4SBarry Smith       x[2+idt]  += v[2]*s[k];
292*2c733ed4SBarry Smith       x[3+idt]  += v[3]*s[k];
293*2c733ed4SBarry Smith       x[4+idt]  += v[4]*s[k];
294*2c733ed4SBarry Smith       x[5+idt]  += v[5]*s[k];
295*2c733ed4SBarry Smith       x[6+idt]  += v[6]*s[k];
296*2c733ed4SBarry Smith       x[7+idt]  += v[7]*s[k];
297*2c733ed4SBarry Smith       x[8+idt]  += v[8]*s[k];
298*2c733ed4SBarry Smith       x[9+idt]  += v[9]*s[k];
299*2c733ed4SBarry Smith       x[10+idt] += v[10]*s[k];
300*2c733ed4SBarry Smith       x[11+idt] += v[11]*s[k];
301*2c733ed4SBarry Smith       v         += 12;
302*2c733ed4SBarry Smith     }
303*2c733ed4SBarry Smith   }
304*2c733ed4SBarry Smith   ierr = VecRestoreArrayRead(bb,&b);CHKERRQ(ierr);
305*2c733ed4SBarry Smith   ierr = VecRestoreArray(xx,&x);CHKERRQ(ierr);
306*2c733ed4SBarry Smith   ierr = PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n);CHKERRQ(ierr);
307*2c733ed4SBarry Smith   PetscFunctionReturn(0);
308*2c733ed4SBarry Smith }
309