1:  #include <../src/mat/impls/baij/seq/baij.h>
  2:  #include <petsc/private/kernels/blockinvert.h>

  4: PetscErrorCode MatSolve_SeqBAIJ_5_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:   PetscErrorCode    ierr;
 10:   const MatScalar   *aa=a->a,*v;
 11:   PetscScalar       *x,s1,s2,s3,s4,s5,x1,x2,x3,x4,x5;
 12:   const PetscScalar *b;

 15:   VecGetArrayRead(bb,&b);
 16:   VecGetArray(xx,&x);
 17:   /* forward solve the lower triangular */
 18:   idx  = 0;
 19:   x[0] = b[idx]; x[1] = b[1+idx]; x[2] = b[2+idx]; x[3] = b[3+idx];x[4] = b[4+idx];
 20:   for (i=1; i<n; i++) {
 21:     v   =  aa + 25*ai[i];
 22:     vi  =  aj + ai[i];
 23:     nz  =  diag[i] - ai[i];
 24:     idx =  5*i;
 25:     s1  =  b[idx];s2 = b[1+idx];s3 = b[2+idx];s4 = b[3+idx];s5 = b[4+idx];
 26:     while (nz--) {
 27:       jdx = 5*(*vi++);
 28:       x1  = x[jdx];x2 = x[1+jdx];x3 = x[2+jdx];x4 = x[3+jdx];x5 = x[4+jdx];
 29:       s1 -= v[0]*x1 + v[5]*x2 + v[10]*x3  + v[15]*x4 + v[20]*x5;
 30:       s2 -= v[1]*x1 + v[6]*x2 + v[11]*x3  + v[16]*x4 + v[21]*x5;
 31:       s3 -= v[2]*x1 + v[7]*x2 + v[12]*x3  + v[17]*x4 + v[22]*x5;
 32:       s4 -= v[3]*x1 + v[8]*x2 + v[13]*x3  + v[18]*x4 + v[23]*x5;
 33:       s5 -= v[4]*x1 + v[9]*x2 + v[14]*x3  + v[19]*x4 + v[24]*x5;
 34:       v  += 25;
 35:     }
 36:     x[idx]   = s1;
 37:     x[1+idx] = s2;
 38:     x[2+idx] = s3;
 39:     x[3+idx] = s4;
 40:     x[4+idx] = s5;
 41:   }
 42:   /* backward solve the upper triangular */
 43:   for (i=n-1; i>=0; i--) {
 44:     v   = aa + 25*diag[i] + 25;
 45:     vi  = aj + diag[i] + 1;
 46:     nz  = ai[i+1] - diag[i] - 1;
 47:     idt = 5*i;
 48:     s1  = x[idt];  s2 = x[1+idt];
 49:     s3  = x[2+idt];s4 = x[3+idt]; s5 = x[4+idt];
 50:     while (nz--) {
 51:       idx = 5*(*vi++);
 52:       x1  = x[idx];   x2 = x[1+idx];x3    = x[2+idx]; x4 = x[3+idx]; x5 = x[4+idx];
 53:       s1 -= v[0]*x1 + v[5]*x2 + v[10]*x3  + v[15]*x4 + v[20]*x5;
 54:       s2 -= v[1]*x1 + v[6]*x2 + v[11]*x3  + v[16]*x4 + v[21]*x5;
 55:       s3 -= v[2]*x1 + v[7]*x2 + v[12]*x3  + v[17]*x4 + v[22]*x5;
 56:       s4 -= v[3]*x1 + v[8]*x2 + v[13]*x3  + v[18]*x4 + v[23]*x5;
 57:       s5 -= v[4]*x1 + v[9]*x2 + v[14]*x3  + v[19]*x4 + v[24]*x5;
 58:       v  += 25;
 59:     }
 60:     v        = aa + 25*diag[i];
 61:     x[idt]   = v[0]*s1 + v[5]*s2 + v[10]*s3  + v[15]*s4 + v[20]*s5;
 62:     x[1+idt] = v[1]*s1 + v[6]*s2 + v[11]*s3  + v[16]*s4 + v[21]*s5;
 63:     x[2+idt] = v[2]*s1 + v[7]*s2 + v[12]*s3  + v[17]*s4 + v[22]*s5;
 64:     x[3+idt] = v[3]*s1 + v[8]*s2 + v[13]*s3  + v[18]*s4 + v[23]*s5;
 65:     x[4+idt] = v[4]*s1 + v[9]*s2 + v[14]*s3  + v[19]*s4 + v[24]*s5;
 66:   }

 68:   VecRestoreArrayRead(bb,&b);
 69:   VecRestoreArray(xx,&x);
 70:   PetscLogFlops(2.0*25*(a->nz) - 5.0*A->cmap->n);
 71:   return(0);
 72: }

 74: PetscErrorCode MatSolve_SeqBAIJ_5_NaturalOrdering(Mat A,Vec bb,Vec xx)
 75: {
 76:   Mat_SeqBAIJ       *a = (Mat_SeqBAIJ*)A->data;
 77:   const PetscInt    n  = a->mbs,*vi,*ai=a->i,*aj=a->j,*adiag=a->diag;
 78:   PetscInt          i,k,nz,idx,idt,jdx;
 79:   PetscErrorCode    ierr;
 80:   const MatScalar   *aa=a->a,*v;
 81:   PetscScalar       *x,s1,s2,s3,s4,s5,x1,x2,x3,x4,x5;
 82:   const PetscScalar *b;

 85:   VecGetArrayRead(bb,&b);
 86:   VecGetArray(xx,&x);
 87:   /* forward solve the lower triangular */
 88:   idx  = 0;
 89:   x[0] = b[idx]; x[1] = b[1+idx]; x[2] = b[2+idx]; x[3] = b[3+idx];x[4] = b[4+idx];
 90:   for (i=1; i<n; i++) {
 91:     v   = aa + 25*ai[i];
 92:     vi  = aj + ai[i];
 93:     nz  = ai[i+1] - ai[i];
 94:     idx = 5*i;
 95:     s1  = b[idx];s2 = b[1+idx];s3 = b[2+idx];s4 = b[3+idx];s5 = b[4+idx];
 96:     for (k=0; k<nz; k++) {
 97:       jdx = 5*vi[k];
 98:       x1  = x[jdx];x2 = x[1+jdx];x3 = x[2+jdx];x4 = x[3+jdx];x5 = x[4+jdx];
 99:       s1 -= v[0]*x1 + v[5]*x2 + v[10]*x3  + v[15]*x4 + v[20]*x5;
100:       s2 -= v[1]*x1 + v[6]*x2 + v[11]*x3  + v[16]*x4 + v[21]*x5;
101:       s3 -= v[2]*x1 + v[7]*x2 + v[12]*x3  + v[17]*x4 + v[22]*x5;
102:       s4 -= v[3]*x1 + v[8]*x2 + v[13]*x3  + v[18]*x4 + v[23]*x5;
103:       s5 -= v[4]*x1 + v[9]*x2 + v[14]*x3  + v[19]*x4 + v[24]*x5;
104:       v  += 25;
105:     }
106:     x[idx]   = s1;
107:     x[1+idx] = s2;
108:     x[2+idx] = s3;
109:     x[3+idx] = s4;
110:     x[4+idx] = s5;
111:   }

113:   /* backward solve the upper triangular */
114:   for (i=n-1; i>=0; i--) {
115:     v   = aa + 25*(adiag[i+1]+1);
116:     vi  = aj + adiag[i+1]+1;
117:     nz  = adiag[i] - adiag[i+1]-1;
118:     idt = 5*i;
119:     s1  = x[idt];  s2 = x[1+idt];
120:     s3  = x[2+idt];s4 = x[3+idt]; s5 = x[4+idt];
121:     for (k=0; k<nz; k++) {
122:       idx = 5*vi[k];
123:       x1  = x[idx];   x2 = x[1+idx];x3    = x[2+idx]; x4 = x[3+idx]; x5 = x[4+idx];
124:       s1 -= v[0]*x1 + v[5]*x2 + v[10]*x3  + v[15]*x4 + v[20]*x5;
125:       s2 -= v[1]*x1 + v[6]*x2 + v[11]*x3  + v[16]*x4 + v[21]*x5;
126:       s3 -= v[2]*x1 + v[7]*x2 + v[12]*x3  + v[17]*x4 + v[22]*x5;
127:       s4 -= v[3]*x1 + v[8]*x2 + v[13]*x3  + v[18]*x4 + v[23]*x5;
128:       s5 -= v[4]*x1 + v[9]*x2 + v[14]*x3  + v[19]*x4 + v[24]*x5;
129:       v  += 25;
130:     }
131:     /* x = inv_diagonal*x */
132:     x[idt]   = v[0]*s1 + v[5]*s2 + v[10]*s3  + v[15]*s4 + v[20]*s5;
133:     x[1+idt] = v[1]*s1 + v[6]*s2 + v[11]*s3  + v[16]*s4 + v[21]*s5;
134:     x[2+idt] = v[2]*s1 + v[7]*s2 + v[12]*s3  + v[17]*s4 + v[22]*s5;
135:     x[3+idt] = v[3]*s1 + v[8]*s2 + v[13]*s3  + v[18]*s4 + v[23]*s5;
136:     x[4+idt] = v[4]*s1 + v[9]*s2 + v[14]*s3  + v[19]*s4 + v[24]*s5;
137:   }

139:   VecRestoreArrayRead(bb,&b);
140:   VecRestoreArray(xx,&x);
141:   PetscLogFlops(2.0*25*(a->nz) - 5.0*A->cmap->n);
142:   return(0);
143: }