Actual source code: baijfact13.c

  1: #define PETSCMAT_DLL

  3: /*
  4:     Factorization code for BAIJ format. 
  5: */
 6:  #include src/mat/impls/baij/seq/baij.h
 7:  #include src/inline/ilu.h

  9: /* ------------------------------------------------------------*/
 10: /*
 11:       Version for when blocks are 3 by 3
 12: */
 15: PetscErrorCode MatLUFactorNumeric_SeqBAIJ_3(Mat A,MatFactorInfo *info,Mat *B)
 16: {
 17:   Mat            C = *B;
 18:   Mat_SeqBAIJ    *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ *)C->data;
 19:   IS             isrow = b->row,isicol = b->icol;
 21:   PetscInt       *r,*ic,i,j,n = a->mbs,*bi = b->i,*bj = b->j;
 22:   PetscInt       *ajtmpold,*ajtmp,nz,row,*ai=a->i,*aj=a->j;
 23:   PetscInt       *diag_offset = b->diag,idx,*pj;
 24:   MatScalar      *pv,*v,*rtmp,*pc,*w,*x;
 25:   MatScalar      p1,p2,p3,p4,m1,m2,m3,m4,m5,m6,m7,m8,m9,x1,x2,x3,x4;
 26:   MatScalar      p5,p6,p7,p8,p9,x5,x6,x7,x8,x9;
 27:   MatScalar      *ba = b->a,*aa = a->a;

 30:   ISGetIndices(isrow,&r);
 31:   ISGetIndices(isicol,&ic);
 32:   PetscMalloc(9*(n+1)*sizeof(MatScalar),&rtmp);

 34:   for (i=0; i<n; i++) {
 35:     nz    = bi[i+1] - bi[i];
 36:     ajtmp = bj + bi[i];
 37:     for  (j=0; j<nz; j++) {
 38:       x = rtmp + 9*ajtmp[j];
 39:       x[0] = x[1] = x[2] = x[3] = x[4] = x[5] = x[6] = x[7] = x[8] = 0.0;
 40:     }
 41:     /* load in initial (unfactored row) */
 42:     idx      = r[i];
 43:     nz       = ai[idx+1] - ai[idx];
 44:     ajtmpold = aj + ai[idx];
 45:     v        = aa + 9*ai[idx];
 46:     for (j=0; j<nz; j++) {
 47:       x    = rtmp + 9*ic[ajtmpold[j]];
 48:       x[0] = v[0]; x[1] = v[1]; x[2] = v[2]; x[3] = v[3];
 49:       x[4] = v[4]; x[5] = v[5]; x[6] = v[6]; x[7] = v[7]; x[8] = v[8];
 50:       v    += 9;
 51:     }
 52:     row = *ajtmp++;
 53:     while (row < i) {
 54:       pc = rtmp + 9*row;
 55:       p1 = pc[0]; p2 = pc[1]; p3 = pc[2]; p4 = pc[3];
 56:       p5 = pc[4]; p6 = pc[5]; p7 = pc[6]; p8 = pc[7]; p9 = pc[8];
 57:       if (p1 != 0.0 || p2 != 0.0 || p3 != 0.0 || p4 != 0.0 || p5 != 0.0 ||
 58:           p6 != 0.0 || p7 != 0.0 || p8 != 0.0 || p9 != 0.0) {
 59:         pv = ba + 9*diag_offset[row];
 60:         pj = bj + diag_offset[row] + 1;
 61:         x1 = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
 62:         x5 = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
 63:         pc[0] = m1 = p1*x1 + p4*x2 + p7*x3;
 64:         pc[1] = m2 = p2*x1 + p5*x2 + p8*x3;
 65:         pc[2] = m3 = p3*x1 + p6*x2 + p9*x3;

 67:         pc[3] = m4 = p1*x4 + p4*x5 + p7*x6;
 68:         pc[4] = m5 = p2*x4 + p5*x5 + p8*x6;
 69:         pc[5] = m6 = p3*x4 + p6*x5 + p9*x6;

 71:         pc[6] = m7 = p1*x7 + p4*x8 + p7*x9;
 72:         pc[7] = m8 = p2*x7 + p5*x8 + p8*x9;
 73:         pc[8] = m9 = p3*x7 + p6*x8 + p9*x9;
 74:         nz = bi[row+1] - diag_offset[row] - 1;
 75:         pv += 9;
 76:         for (j=0; j<nz; j++) {
 77:           x1   = pv[0]; x2 = pv[1]; x3 = pv[2]; x4 = pv[3];
 78:           x5   = pv[4]; x6 = pv[5]; x7 = pv[6]; x8 = pv[7]; x9 = pv[8];
 79:           x    = rtmp + 9*pj[j];
 80:           x[0] -= m1*x1 + m4*x2 + m7*x3;
 81:           x[1] -= m2*x1 + m5*x2 + m8*x3;
 82:           x[2] -= m3*x1 + m6*x2 + m9*x3;
 83: 
 84:           x[3] -= m1*x4 + m4*x5 + m7*x6;
 85:           x[4] -= m2*x4 + m5*x5 + m8*x6;
 86:           x[5] -= m3*x4 + m6*x5 + m9*x6;

 88:           x[6] -= m1*x7 + m4*x8 + m7*x9;
 89:           x[7] -= m2*x7 + m5*x8 + m8*x9;
 90:           x[8] -= m3*x7 + m6*x8 + m9*x9;
 91:           pv   += 9;
 92:         }
 93:         PetscLogFlops(54*nz+36);
 94:       }
 95:       row = *ajtmp++;
 96:     }
 97:     /* finished row so stick it into b->a */
 98:     pv = ba + 9*bi[i];
 99:     pj = bj + bi[i];
100:     nz = bi[i+1] - bi[i];
101:     for (j=0; j<nz; j++) {
102:       x     = rtmp + 9*pj[j];
103:       pv[0] = x[0]; pv[1] = x[1]; pv[2] = x[2]; pv[3] = x[3];
104:       pv[4] = x[4]; pv[5] = x[5]; pv[6] = x[6]; pv[7] = x[7]; pv[8] = x[8];
105:       pv   += 9;
106:     }
107:     /* invert diagonal block */
108:     w = ba + 9*diag_offset[i];
109:     Kernel_A_gets_inverse_A_3(w);
110:   }

112:   PetscFree(rtmp);
113:   ISRestoreIndices(isicol,&ic);
114:   ISRestoreIndices(isrow,&r);
115:   C->factor = FACTOR_LU;
116:   C->assembled = PETSC_TRUE;
117:   PetscLogFlops(1.3333*27*b->mbs); /* from inverting diagonal blocks */
118:   return(0);
119: }