Actual source code: baijsolvtran4.c

petsc-master 2019-08-15
Report Typos and Errors
  1:  #include <../src/mat/impls/baij/seq/baij.h>
  2:  #include <petsc/private/kernels/blockinvert.h>

  4: PetscErrorCode MatSolveTranspose_SeqBAIJ_4_inplace(Mat A,Vec bb,Vec xx)
  5: {
  6:   Mat_SeqBAIJ       *a   =(Mat_SeqBAIJ*)A->data;
  7:   IS                iscol=a->col,isrow=a->row;
  8:   PetscErrorCode    ierr;
  9:   const PetscInt    *r,*c,*rout,*cout;
 10:   const PetscInt    *diag=a->diag,n=a->mbs,*vi,*ai=a->i,*aj=a->j;
 11:   PetscInt          i,nz,idx,idt,ii,ic,ir,oidx;
 12:   const MatScalar   *aa=a->a,*v;
 13:   PetscScalar       s1,s2,s3,s4,x1,x2,x3,x4,*x,*t;
 14:   const PetscScalar *b;

 17:   VecGetArrayRead(bb,&b);
 18:   VecGetArray(xx,&x);
 19:   t    = a->solve_work;

 21:   ISGetIndices(isrow,&rout); r = rout;
 22:   ISGetIndices(iscol,&cout); c = cout;

 24:   /* copy the b into temp work space according to permutation */
 25:   ii = 0;
 26:   for (i=0; i<n; i++) {
 27:     ic      = 4*c[i];
 28:     t[ii]   = b[ic];
 29:     t[ii+1] = b[ic+1];
 30:     t[ii+2] = b[ic+2];
 31:     t[ii+3] = b[ic+3];
 32:     ii     += 4;
 33:   }

 35:   /* forward solve the U^T */
 36:   idx = 0;
 37:   for (i=0; i<n; i++) {

 39:     v = aa + 16*diag[i];
 40:     /* multiply by the inverse of the block diagonal */
 41:     x1 = t[idx];   x2 = t[1+idx]; x3    = t[2+idx]; x4 = t[3+idx];
 42:     s1 = v[0]*x1  +  v[1]*x2 +  v[2]*x3 +  v[3]*x4;
 43:     s2 = v[4]*x1  +  v[5]*x2 +  v[6]*x3 +  v[7]*x4;
 44:     s3 = v[8]*x1  +  v[9]*x2 + v[10]*x3 + v[11]*x4;
 45:     s4 = v[12]*x1 + v[13]*x2 + v[14]*x3 + v[15]*x4;
 46:     v += 16;

 48:     vi = aj + diag[i] + 1;
 49:     nz = ai[i+1] - diag[i] - 1;
 50:     while (nz--) {
 51:       oidx       = 4*(*vi++);
 52:       t[oidx]   -= v[0]*s1  +  v[1]*s2 +  v[2]*s3 +  v[3]*s4;
 53:       t[oidx+1] -= v[4]*s1  +  v[5]*s2 +  v[6]*s3 +  v[7]*s4;
 54:       t[oidx+2] -= v[8]*s1 + v[9]*s2 + v[10]*s3 + v[11]*s4;
 55:       t[oidx+3] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4;
 56:       v         += 16;
 57:     }
 58:     t[idx] = s1;t[1+idx] = s2; t[2+idx] = s3;t[3+idx] = s4;
 59:     idx   += 4;
 60:   }
 61:   /* backward solve the L^T */
 62:   for (i=n-1; i>=0; i--) {
 63:     v   = aa + 16*diag[i] - 16;
 64:     vi  = aj + diag[i] - 1;
 65:     nz  = diag[i] - ai[i];
 66:     idt = 4*i;
 67:     s1  = t[idt];  s2 = t[1+idt]; s3 = t[2+idt];s4 = t[3+idt];
 68:     while (nz--) {
 69:       idx       = 4*(*vi--);
 70:       t[idx]   -=  v[0]*s1 +  v[1]*s2 +  v[2]*s3 +  v[3]*s4;
 71:       t[idx+1] -=  v[4]*s1 +  v[5]*s2 +  v[6]*s3 +  v[7]*s4;
 72:       t[idx+2] -= v[8]*s1 + v[9]*s2 + v[10]*s3 + v[11]*s4;
 73:       t[idx+3] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4;
 74:       v        -= 16;
 75:     }
 76:   }

 78:   /* copy t into x according to permutation */
 79:   ii = 0;
 80:   for (i=0; i<n; i++) {
 81:     ir      = 4*r[i];
 82:     x[ir]   = t[ii];
 83:     x[ir+1] = t[ii+1];
 84:     x[ir+2] = t[ii+2];
 85:     x[ir+3] = t[ii+3];
 86:     ii     += 4;
 87:   }

 89:   ISRestoreIndices(isrow,&rout);
 90:   ISRestoreIndices(iscol,&cout);
 91:   VecRestoreArrayRead(bb,&b);
 92:   VecRestoreArray(xx,&x);
 93:   PetscLogFlops(2.0*16*(a->nz) - 4.0*A->cmap->n);
 94:   return(0);
 95: }

 97: PetscErrorCode MatSolveTranspose_SeqBAIJ_4(Mat A,Vec bb,Vec xx)
 98: {
 99:   Mat_SeqBAIJ       *a=(Mat_SeqBAIJ*)A->data;
100:   PetscErrorCode    ierr;
101:   IS                iscol=a->col,isrow=a->row;
102:   const PetscInt    n    =a->mbs,*vi,*ai=a->i,*aj=a->j,*diag=a->diag;
103:   const PetscInt    *r,*c,*rout,*cout;
104:   PetscInt          nz,idx,idt,j,i,oidx,ii,ic,ir;
105:   const PetscInt    bs =A->rmap->bs,bs2=a->bs2;
106:   const MatScalar   *aa=a->a,*v;
107:   PetscScalar       s1,s2,s3,s4,x1,x2,x3,x4,*x,*t;
108:   const PetscScalar *b;

111:   VecGetArrayRead(bb,&b);
112:   VecGetArray(xx,&x);
113:   t    = a->solve_work;

115:   ISGetIndices(isrow,&rout); r = rout;
116:   ISGetIndices(iscol,&cout); c = cout;

118:   /* copy b into temp work space according to permutation */
119:   for (i=0; i<n; i++) {
120:     ii    = bs*i; ic = bs*c[i];
121:     t[ii] = b[ic]; t[ii+1] = b[ic+1]; t[ii+2] = b[ic+2]; t[ii+3] = b[ic+3];
122:   }

124:   /* forward solve the U^T */
125:   idx = 0;
126:   for (i=0; i<n; i++) {
127:     v = aa + bs2*diag[i];
128:     /* multiply by the inverse of the block diagonal */
129:     x1 = t[idx];   x2 = t[1+idx]; x3    = t[2+idx];  x4 = t[3+idx];
130:     s1 = v[0]*x1  +  v[1]*x2 +  v[2]*x3 +  v[3]*x4;
131:     s2 = v[4]*x1  +  v[5]*x2 +  v[6]*x3 +  v[7]*x4;
132:     s3 = v[8]*x1  +  v[9]*x2 + v[10]*x3 + v[11]*x4;
133:     s4 = v[12]*x1 + v[13]*x2 + v[14]*x3 + v[15]*x4;
134:     v -= bs2;

136:     vi = aj + diag[i] - 1;
137:     nz = diag[i] - diag[i+1] - 1;
138:     for (j=0; j>-nz; j--) {
139:       oidx       = bs*vi[j];
140:       t[oidx]   -= v[0]*s1  +  v[1]*s2 +  v[2]*s3 +  v[3]*s4;
141:       t[oidx+1] -= v[4]*s1  +  v[5]*s2 +  v[6]*s3 +  v[7]*s4;
142:       t[oidx+2] -= v[8]*s1 + v[9]*s2 + v[10]*s3 + v[11]*s4;
143:       t[oidx+3] -= v[12]*s1 + v[13]*s2 + v[14]*s3 + v[15]*s4;
144:       v         -= bs2;
145:     }
146:     t[idx] = s1;t[1+idx] = s2;  t[2+idx] = s3;  t[3+idx] = s4;
147:     idx   += bs;
148:   }
149:   /* backward solve the L^T */
150:   for (i=n-1; i>=0; i--) {
151:     v   = aa + bs2*ai[i];
152:     vi  = aj + ai[i];
153:     nz  = ai[i+1] - ai[i];
154:     idt = bs*i;
155:     s1  = t[idt];  s2 = t[1+idt];  s3 = t[2+idt];  s4 = t[3+idt];
156:     for (j=0; j<nz; j++) {
157:       idx       = bs*vi[j];
158:       t[idx]   -=  v[0]*s1 +  v[1]*s2 +  v[2]*s3  +  v[3]*s4;
159:       t[idx+1] -=  v[4]*s1 +  v[5]*s2 +  v[6]*s3  +  v[7]*s4;
160:       t[idx+2] -=  v[8]*s1 +  v[9]*s2 +  v[10]*s3 + v[11]*s4;
161:       t[idx+3] -= v[12]*s1 +  v[13]*s2 + v[14]*s3 + v[15]*s4;
162:       v        += bs2;
163:     }
164:   }

166:   /* copy t into x according to permutation */
167:   for (i=0; i<n; i++) {
168:     ii    = bs*i;  ir = bs*r[i];
169:     x[ir] = t[ii];  x[ir+1] = t[ii+1]; x[ir+2] = t[ii+2];  x[ir+3] = t[ii+3];
170:   }

172:   ISRestoreIndices(isrow,&rout);
173:   ISRestoreIndices(iscol,&cout);
174:   VecRestoreArrayRead(bb,&b);
175:   VecRestoreArray(xx,&x);
176:   PetscLogFlops(2.0*bs2*(a->nz) - bs*A->cmap->n);
177:   return(0);
178: }