Actual source code: baijsolvtrannat4.c

  1: #include <../src/mat/impls/baij/seq/baij.h>

  3: PetscErrorCode MatSolveTranspose_SeqBAIJ_4_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,x1,x2,x3,x4,*x;

 11:   VecCopy(bb,xx);
 12:   VecGetArray(xx,&x);

 14:   /* forward solve the U^T */
 15:   idx = 0;
 16:   for (i=0; i<n; i++) {

 18:     v = aa + 16*diag[i];
 19:     /* multiply by the inverse of the block diagonal */
 20:     x1 = x[idx];   x2 = x[1+idx]; x3    = x[2+idx]; x4 = x[3+idx];
 21:     s1 = v[0]*x1  +  v[1]*x2 +  v[2]*x3 +  v[3]*x4;
 22:     s2 = v[4]*x1  +  v[5]*x2 +  v[6]*x3 +  v[7]*x4;
 23:     s3 = v[8]*x1  +  v[9]*x2 + v[10]*x3 + v[11]*x4;
 24:     s4 = v[12]*x1 + v[13]*x2 + v[14]*x3 + v[15]*x4;
 25:     v += 16;

 27:     vi = aj + diag[i] + 1;
 28:     nz = ai[i+1] - diag[i] - 1;
 29:     while (nz--) {
 30:       oidx       = 4*(*vi++);
 31:       x[oidx]   -= v[0]*s1  +  v[1]*s2 +  v[2]*s3 +  v[3]*s4;
 32:       x[oidx+1] -= v[4]*s1  +  v[5]*s2 +  v[6]*s3 +  v[7]*s4;
 33:       x[oidx+2] -= v[8]*s1 + v[9]*s2 + v[10]*s3 + v[11]*s4;
 34:       x[oidx+3] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4;
 35:       v         += 16;
 36:     }
 37:     x[idx] = s1;x[1+idx] = s2; x[2+idx] = s3;x[3+idx] = s4;
 38:     idx   += 4;
 39:   }
 40:   /* backward solve the L^T */
 41:   for (i=n-1; i>=0; i--) {
 42:     v   = aa + 16*diag[i] - 16;
 43:     vi  = aj + diag[i] - 1;
 44:     nz  = diag[i] - ai[i];
 45:     idt = 4*i;
 46:     s1  = x[idt];  s2 = x[1+idt]; s3 = x[2+idt];s4 = x[3+idt];
 47:     while (nz--) {
 48:       idx       = 4*(*vi--);
 49:       x[idx]   -=  v[0]*s1 +  v[1]*s2 +  v[2]*s3 +  v[3]*s4;
 50:       x[idx+1] -=  v[4]*s1 +  v[5]*s2 +  v[6]*s3 +  v[7]*s4;
 51:       x[idx+2] -= v[8]*s1 + v[9]*s2 + v[10]*s3 + v[11]*s4;
 52:       x[idx+3] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4;
 53:       v        -= 16;
 54:     }
 55:   }
 56:   VecRestoreArray(xx,&x);
 57:   PetscLogFlops(2.0*16*(a->nz) - 4.0*A->cmap->n);
 58:   return 0;
 59: }

 61: PetscErrorCode MatSolveTranspose_SeqBAIJ_4_NaturalOrdering(Mat A,Vec bb,Vec xx)
 62: {
 63:   Mat_SeqBAIJ     *a=(Mat_SeqBAIJ*)A->data;
 64:   const PetscInt  n=a->mbs,*vi,*ai=a->i,*aj=a->j,*diag=a->diag;
 65:   PetscInt        nz,idx,idt,j,i,oidx;
 66:   const PetscInt  bs =A->rmap->bs,bs2=a->bs2;
 67:   const MatScalar *aa=a->a,*v;
 68:   PetscScalar     s1,s2,s3,s4,x1,x2,x3,x4,*x;

 70:   VecCopy(bb,xx);
 71:   VecGetArray(xx,&x);

 73:   /* forward solve the U^T */
 74:   idx = 0;
 75:   for (i=0; i<n; i++) {
 76:     v = aa + bs2*diag[i];
 77:     /* multiply by the inverse of the block diagonal */
 78:     x1 = x[idx];   x2 = x[1+idx];  x3 = x[2+idx];  x4 = x[3+idx];
 79:     s1 =  v[0]*x1  +  v[1]*x2  + v[2]*x3  + v[3]*x4;
 80:     s2 =  v[4]*x1  +  v[5]*x2  + v[6]*x3  + v[7]*x4;
 81:     s3 =  v[8]*x1  +  v[9]*x2  + v[10]*x3 + v[11]*x4;
 82:     s4 =  v[12]*x1 +  v[13]*x2 + v[14]*x3 + v[15]*x4;
 83:     v -= bs2;

 85:     vi = aj + diag[i] - 1;
 86:     nz = diag[i] - diag[i+1] - 1;
 87:     for (j=0; j>-nz; j--) {
 88:       oidx       = bs*vi[j];
 89:       x[oidx]   -=  v[0]*s1  +  v[1]*s2  + v[2]*s3  + v[3]*s4;
 90:       x[oidx+1] -=  v[4]*s1  +  v[5]*s2  + v[6]*s3  + v[7]*s4;
 91:       x[oidx+2] -=  v[8]*s1  +  v[9]*s2  + v[10]*s3 + v[11]*s4;
 92:       x[oidx+3] -=  v[12]*s1 +  v[13]*s2 + v[14]*s3 + v[15]*s4;
 93:       v         -= bs2;
 94:     }
 95:     x[idx] = s1;x[1+idx] = s2;  x[2+idx] = s3;  x[3+idx] = s4;
 96:     idx   += bs;
 97:   }
 98:   /* backward solve the L^T */
 99:   for (i=n-1; i>=0; i--) {
100:     v   = aa + bs2*ai[i];
101:     vi  = aj + ai[i];
102:     nz  = ai[i+1] - ai[i];
103:     idt = bs*i;
104:     s1  = x[idt];  s2 = x[1+idt];  s3 = x[2+idt];  s4 = x[3+idt];
105:     for (j=0; j<nz; j++) {
106:       idx       = bs*vi[j];
107:       x[idx]   -=  v[0]*s1  +  v[1]*s2  + v[2]*s3  + v[3]*s4;
108:       x[idx+1] -=  v[4]*s1  +  v[5]*s2  + v[6]*s3  + v[7]*s4;
109:       x[idx+2] -=  v[8]*s1  +  v[9]*s2  + v[10]*s3 + v[11]*s4;
110:       x[idx+3] -=  v[12]*s1 +  v[13]*s2 + v[14]*s3 + v[15]*s4;
111:       v        += bs2;
112:     }
113:   }
114:   VecRestoreArray(xx,&x);
115:   PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n);
116:   return 0;
117: }