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 /* ----------------------------------------------------------- */ 84a2ae208SSatish Balay #undef __FUNCT__ 94a2ae208SSatish Balay #define __FUNCT__ "MatLUFactorNumeric_SeqBAIJ_N" 10dfbe8321SBarry Smith PetscErrorCode MatLUFactorNumeric_SeqBAIJ_N(Mat A,Mat *B) 1183287d42SBarry Smith { 1283287d42SBarry Smith Mat C = *B; 1383287d42SBarry Smith Mat_SeqBAIJ *a = (Mat_SeqBAIJ*)A->data,*b = (Mat_SeqBAIJ *)C->data; 1483287d42SBarry Smith IS isrow = b->row,isicol = b->icol; 15*6849ba73SBarry Smith PetscErrorCode ierr; 16*6849ba73SBarry Smith int *r,*ic,i,j,n = a->mbs,*bi = b->i,*bj = b->j; 1783287d42SBarry Smith int *ajtmpold,*ajtmp,nz,row,bslog,*ai=a->i,*aj=a->j,k,flg; 1883287d42SBarry Smith int *diag_offset=b->diag,diag,bs=a->bs,bs2 = a->bs2,*v_pivots,*pj; 1983287d42SBarry Smith MatScalar *ba = b->a,*aa = a->a,*pv,*v,*rtmp,*multiplier,*v_work,*pc,*w; 2083287d42SBarry Smith 2183287d42SBarry Smith PetscFunctionBegin; 2283287d42SBarry Smith ierr = ISGetIndices(isrow,&r);CHKERRQ(ierr); 2383287d42SBarry Smith ierr = ISGetIndices(isicol,&ic);CHKERRQ(ierr); 24b0a32e0cSBarry Smith ierr = PetscMalloc(bs2*(n+1)*sizeof(MatScalar),&rtmp);CHKERRQ(ierr); 2583287d42SBarry Smith ierr = PetscMemzero(rtmp,bs2*(n+1)*sizeof(MatScalar));CHKERRQ(ierr); 2683287d42SBarry Smith /* generate work space needed by dense LU factorization */ 2782502324SSatish Balay ierr = PetscMalloc(bs*sizeof(int) + (bs+bs2)*sizeof(MatScalar),&v_work);CHKERRQ(ierr); 2883287d42SBarry Smith multiplier = v_work + bs; 2983287d42SBarry Smith v_pivots = (int*)(multiplier + bs2); 3083287d42SBarry Smith 3183287d42SBarry Smith /* flops in while loop */ 3283287d42SBarry Smith bslog = 2*bs*bs2; 3383287d42SBarry Smith 3483287d42SBarry Smith for (i=0; i<n; i++) { 3583287d42SBarry Smith nz = bi[i+1] - bi[i]; 3683287d42SBarry Smith ajtmp = bj + bi[i]; 3783287d42SBarry Smith for (j=0; j<nz; j++) { 3883287d42SBarry Smith ierr = PetscMemzero(rtmp+bs2*ajtmp[j],bs2*sizeof(MatScalar));CHKERRQ(ierr); 3983287d42SBarry Smith } 4083287d42SBarry Smith /* load in initial (unfactored row) */ 4183287d42SBarry Smith nz = ai[r[i]+1] - ai[r[i]]; 4283287d42SBarry Smith ajtmpold = aj + ai[r[i]]; 4383287d42SBarry Smith v = aa + bs2*ai[r[i]]; 4483287d42SBarry Smith for (j=0; j<nz; j++) { 4583287d42SBarry Smith ierr = PetscMemcpy(rtmp+bs2*ic[ajtmpold[j]],v+bs2*j,bs2*sizeof(MatScalar));CHKERRQ(ierr); 4683287d42SBarry Smith } 4783287d42SBarry Smith row = *ajtmp++; 4883287d42SBarry Smith while (row < i) { 4983287d42SBarry Smith pc = rtmp + bs2*row; 5083287d42SBarry Smith /* if (*pc) { */ 5183287d42SBarry Smith for (flg=0,k=0; k<bs2; k++) { if (pc[k]!=0.0) { flg = 1; break; }} 5283287d42SBarry Smith if (flg) { 5383287d42SBarry Smith pv = ba + bs2*diag_offset[row]; 5483287d42SBarry Smith pj = bj + diag_offset[row] + 1; 5583287d42SBarry Smith Kernel_A_gets_A_times_B(bs,pc,pv,multiplier); 5683287d42SBarry Smith nz = bi[row+1] - diag_offset[row] - 1; 5783287d42SBarry Smith pv += bs2; 5883287d42SBarry Smith for (j=0; j<nz; j++) { 5983287d42SBarry Smith Kernel_A_gets_A_minus_B_times_C(bs,rtmp+bs2*pj[j],pc,pv+bs2*j); 6083287d42SBarry Smith } 61b0a32e0cSBarry Smith PetscLogFlops(bslog*(nz+1)-bs); 6283287d42SBarry Smith } 6383287d42SBarry Smith row = *ajtmp++; 6483287d42SBarry Smith } 6583287d42SBarry Smith /* finished row so stick it into b->a */ 6683287d42SBarry Smith pv = ba + bs2*bi[i]; 6783287d42SBarry Smith pj = bj + bi[i]; 6883287d42SBarry Smith nz = bi[i+1] - bi[i]; 6983287d42SBarry Smith for (j=0; j<nz; j++) { 7083287d42SBarry Smith ierr = PetscMemcpy(pv+bs2*j,rtmp+bs2*pj[j],bs2*sizeof(MatScalar));CHKERRQ(ierr); 7183287d42SBarry Smith } 7283287d42SBarry Smith diag = diag_offset[i] - bi[i]; 7383287d42SBarry Smith /* invert diagonal block */ 7483287d42SBarry Smith w = pv + bs2*diag; 7583287d42SBarry Smith Kernel_A_gets_inverse_A(bs,w,v_pivots,v_work); 7683287d42SBarry Smith } 7783287d42SBarry Smith 7883287d42SBarry Smith ierr = PetscFree(rtmp);CHKERRQ(ierr); 7983287d42SBarry Smith ierr = PetscFree(v_work);CHKERRQ(ierr); 8083287d42SBarry Smith ierr = ISRestoreIndices(isicol,&ic);CHKERRQ(ierr); 8183287d42SBarry Smith ierr = ISRestoreIndices(isrow,&r);CHKERRQ(ierr); 8283287d42SBarry Smith C->factor = FACTOR_LU; 8383287d42SBarry Smith C->assembled = PETSC_TRUE; 84b0a32e0cSBarry Smith PetscLogFlops(1.3333*bs*bs2*b->mbs); /* from inverting diagonal blocks */ 8583287d42SBarry Smith PetscFunctionReturn(0); 8683287d42SBarry Smith } 87