xref: /petsc/src/mat/impls/baij/seq/baijfact13.c (revision 6849ba73f22fecb8f92ef896a42e4e8bd4cd6965)
183287d42SBarry Smith /*
283287d42SBarry Smith     Factorization code for BAIJ format.
383287d42SBarry Smith */
483287d42SBarry Smith #include "src/mat/impls/baij/seq/baij.h"
583287d42SBarry Smith #include "src/inline/ilu.h"
683287d42SBarry Smith 
783287d42SBarry Smith /* ------------------------------------------------------------*/
883287d42SBarry Smith /*
983287d42SBarry Smith       Version for when blocks are 3 by 3
1083287d42SBarry Smith */
114a2ae208SSatish Balay #undef __FUNCT__
124a2ae208SSatish Balay #define __FUNCT__ "MatLUFactorNumeric_SeqBAIJ_3"
13dfbe8321SBarry Smith PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3(Mat A,Mat *B)
1483287d42SBarry Smith {
1583287d42SBarry Smith   Mat         C = *B;
1683287d42SBarry Smith   Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ *)C->data;
1783287d42SBarry Smith   IS          isrow = b->row,isicol = b->icol;
18*6849ba73SBarry Smith   PetscErrorCode ierr;
19*6849ba73SBarry Smith   int         *r,*ic,i,j,n = a->mbs,*bi = b->i,*bj = b->j;
2083287d42SBarry Smith   int         *ajtmpold,*ajtmp,nz,row,*ai=a->i,*aj=a->j;
2183287d42SBarry Smith   int         *diag_offset = b->diag,idx,*pj;
2283287d42SBarry Smith   MatScalar   *pv,*v,*rtmp,*pc,*w,*x;
2383287d42SBarry Smith   MatScalar   p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
2483287d42SBarry Smith   MatScalar   p5,p6,p7,p8,p9,x5,x6,x7,x8,x9;
2583287d42SBarry Smith   MatScalar   *ba = b->a,*aa = a->a;
2683287d42SBarry Smith 
2783287d42SBarry Smith   PetscFunctionBegin;
2883287d42SBarry Smith   ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr);
2983287d42SBarry Smith   ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr);
30b0a32e0cSBarry Smith   ierr = PetscMalloc(9*(n+1)*sizeof(MatScalar),&rtmp);CHKERRQ(ierr);
3183287d42SBarry Smith 
3283287d42SBarry Smith   for (i=0; i<n; i++) {
3383287d42SBarry Smith     nz    = bi[i+1] - bi[i];
3483287d42SBarry Smith     ajtmp = bj + bi[i];
3583287d42SBarry Smith     for  (j=0; j<nz; j++) {
3683287d42SBarry Smith       x = rtmp + 9*ajtmp[j];
3783287d42SBarry Smith       x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = x[6] = x[7] = x[8] = 0.0;
3883287d42SBarry Smith     }
3983287d42SBarry Smith     /* load in initial (unfactored row) */
4083287d42SBarry Smith     idx      = r[i];
4183287d42SBarry Smith     nz       = ai[idx+1] - ai[idx];
4283287d42SBarry Smith     ajtmpold = aj + ai[idx];
4383287d42SBarry Smith     v        = aa + 9*ai[idx];
4483287d42SBarry Smith     for (j=0; j<nz; j++) {
4583287d42SBarry Smith       x    = rtmp + 9*ic[ajtmpold[j]];
4683287d42SBarry Smith       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
4783287d42SBarry Smith       x[4] = v[4]; x[5] = v[5]; x[6] = v[6]; x[7] = v[7]; x[8] = v[8];
4883287d42SBarry Smith       v    += 9;
4983287d42SBarry Smith     }
5083287d42SBarry Smith     row = *ajtmp++;
5183287d42SBarry Smith     while (row < i) {
5283287d42SBarry Smith       pc = rtmp + 9*row;
5383287d42SBarry Smith       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
5483287d42SBarry Smith       p5 = pc[4]; p6 = pc[5]; p7 = pc[6]; p8 = pc[7]; p9 = pc[8];
5583287d42SBarry Smith       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
5683287d42SBarry Smith           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0) {
5783287d42SBarry Smith         pv = ba + 9*diag_offset[row];
5883287d42SBarry Smith         pj = bj + diag_offset[row] + 1;
5983287d42SBarry Smith         x1 = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
6083287d42SBarry Smith         x5 = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
6183287d42SBarry Smith         pc[0] = m1 = p1*x1 + p4*x2 + p7*x3;
6283287d42SBarry Smith         pc[1] = m2 = p2*x1 + p5*x2 + p8*x3;
6383287d42SBarry Smith         pc[2] = m3 = p3*x1 + p6*x2 + p9*x3;
6483287d42SBarry Smith 
6583287d42SBarry Smith         pc[3] = m4 = p1*x4 + p4*x5 + p7*x6;
6683287d42SBarry Smith         pc[4] = m5 = p2*x4 + p5*x5 + p8*x6;
6783287d42SBarry Smith         pc[5] = m6 = p3*x4 + p6*x5 + p9*x6;
6883287d42SBarry Smith 
6983287d42SBarry Smith         pc[6] = m7 = p1*x7 + p4*x8 + p7*x9;
7083287d42SBarry Smith         pc[7] = m8 = p2*x7 + p5*x8 + p8*x9;
7183287d42SBarry Smith         pc[8] = m9 = p3*x7 + p6*x8 + p9*x9;
7283287d42SBarry Smith         nz = bi[row+1] - diag_offset[row] - 1;
7383287d42SBarry Smith         pv += 9;
7483287d42SBarry Smith         for (j=0; j<nz; j++) {
7583287d42SBarry Smith           x1   = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
7683287d42SBarry Smith           x5   = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
7783287d42SBarry Smith           x    = rtmp + 9*pj[j];
7883287d42SBarry Smith           x[0] -= m1*x1 + m4*x2 + m7*x3;
7983287d42SBarry Smith           x[1] -= m2*x1 + m5*x2 + m8*x3;
8083287d42SBarry Smith           x[2] -= m3*x1 + m6*x2 + m9*x3;
8183287d42SBarry Smith 
8283287d42SBarry Smith           x[3] -= m1*x4 + m4*x5 + m7*x6;
8383287d42SBarry Smith           x[4] -= m2*x4 + m5*x5 + m8*x6;
8483287d42SBarry Smith           x[5] -= m3*x4 + m6*x5 + m9*x6;
8583287d42SBarry Smith 
8683287d42SBarry Smith           x[6] -= m1*x7 + m4*x8 + m7*x9;
8783287d42SBarry Smith           x[7] -= m2*x7 + m5*x8 + m8*x9;
8883287d42SBarry Smith           x[8] -= m3*x7 + m6*x8 + m9*x9;
8983287d42SBarry Smith           pv   += 9;
9083287d42SBarry Smith         }
91b0a32e0cSBarry Smith         PetscLogFlops(54*nz+36);
9283287d42SBarry Smith       }
9383287d42SBarry Smith       row = *ajtmp++;
9483287d42SBarry Smith     }
9583287d42SBarry Smith     /* finished row so stick it into b->a */
9683287d42SBarry Smith     pv = ba + 9*bi[i];
9783287d42SBarry Smith     pj = bj + bi[i];
9883287d42SBarry Smith     nz = bi[i+1] - bi[i];
9983287d42SBarry Smith     for (j=0; j<nz; j++) {
10083287d42SBarry Smith       x     = rtmp + 9*pj[j];
10183287d42SBarry Smith       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
10283287d42SBarry Smith       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
10383287d42SBarry Smith       pv   += 9;
10483287d42SBarry Smith     }
10583287d42SBarry Smith     /* invert diagonal block */
10683287d42SBarry Smith     w = ba + 9*diag_offset[i];
10783287d42SBarry Smith     ierr = Kernel_A_gets_inverse_A_3(w);CHKERRQ(ierr);
10883287d42SBarry Smith   }
10983287d42SBarry Smith 
11083287d42SBarry Smith   ierr = PetscFree(rtmp);CHKERRQ(ierr);
11183287d42SBarry Smith   ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr);
11283287d42SBarry Smith   ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr);
11383287d42SBarry Smith   C->factor = FACTOR_LU;
11483287d42SBarry Smith   C->assembled = PETSC_TRUE;
115b0a32e0cSBarry Smith   PetscLogFlops(1.3333*27*b->mbs); /* from inverting diagonal blocks */
11683287d42SBarry Smith   PetscFunctionReturn(0);
11783287d42SBarry Smith }
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