Date: 2016-07-24T17:04:14+00:00

Actual source code: xxt.c
petsc-3.7.3 2016-07-24
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      2: /*************************************xxt.c************************************
      3: Module Name: xxt
      4: Module Info:

      6: author:  Henry M. Tufo III
      7: e-mail:  hmt@asci.uchicago.edu
      8: contact:
      9: +--------------------------------+--------------------------------+
     10: |MCS Division - Building 221     |Department of Computer Science  |
     11: |Argonne National Laboratory     |Ryerson 152                     |
     12: |9700 S. Cass Avenue             |The University of Chicago       |
     13: |Argonne, IL  60439              |Chicago, IL  60637              |
     14: |(630) 252-5354/5986 ph/fx       |(773) 702-6019/8487 ph/fx       |
     15: +--------------------------------+--------------------------------+

     17: Last Modification: 3.20.01
     18: **************************************xxt.c***********************************/
     19: #include <../src/ksp/pc/impls/tfs/tfs.h>

     21: #define LEFT  -1
     22: #define RIGHT  1
     23: #define BOTH   0

     25: typedef struct xxt_solver_info {
     26:   PetscInt    n, m, n_global, m_global;
     27:   PetscInt    nnz, max_nnz, msg_buf_sz;
     28:   PetscInt    *nsep, *lnsep, *fo, nfo, *stages;
     29:   PetscInt    *col_sz, *col_indices;
     30:   PetscScalar **col_vals, *x, *solve_uu, *solve_w;
     31:   PetscInt    nsolves;
     32:   PetscScalar tot_solve_time;
     33: } xxt_info;

     35: typedef struct matvec_info {
     36:   PetscInt     n, m, n_global, m_global;
     37:   PetscInt     *local2global;
     38:   PCTFS_gs_ADT PCTFS_gs_handle;
     39:   PetscErrorCode (*matvec)(struct matvec_info*,PetscScalar*,PetscScalar*);
     40:   void *grid_data;
     41: } mv_info;

     43: struct xxt_CDT {
     44:   PetscInt id;
     45:   PetscInt ns;
     46:   PetscInt level;
     47:   xxt_info *info;
     48:   mv_info  *mvi;
     49: };

     51: static PetscInt n_xxt        =0;
     52: static PetscInt n_xxt_handles=0;

     54: /* prototypes */
     55: static PetscErrorCode do_xxt_solve(xxt_ADT xxt_handle, PetscScalar *rhs);
     56: static PetscErrorCode check_handle(xxt_ADT xxt_handle);
     57: static PetscErrorCode det_separators(xxt_ADT xxt_handle);
     58: static PetscErrorCode do_matvec(mv_info *A, PetscScalar *v, PetscScalar *u);
     59: static PetscInt xxt_generate(xxt_ADT xxt_handle);
     60: static PetscInt do_xxt_factor(xxt_ADT xxt_handle);
     61: static mv_info *set_mvi(PetscInt *local2global, PetscInt n, PetscInt m, PetscErrorCode (*matvec)(mv_info*,PetscScalar*,PetscScalar*), void *grid_data);

     63: /**************************************xxt.c***********************************/
     64: xxt_ADT XXT_new(void)
     65: {
     66:   xxt_ADT xxt_handle;

     68:   /* rolling count on n_xxt ... pot. problem here */
     69:   n_xxt_handles++;
     70:   xxt_handle       = (xxt_ADT)malloc(sizeof(struct xxt_CDT));
     71:   xxt_handle->id   = ++n_xxt;
     72:   xxt_handle->info = NULL; xxt_handle->mvi  = NULL;

     74:   return(xxt_handle);
     75: }

     77: /**************************************xxt.c***********************************/
     78: PetscInt XXT_factor(xxt_ADT xxt_handle,     /* prev. allocated xxt  handle */
     79:                     PetscInt *local2global, /* global column mapping       */
     80:                     PetscInt n,             /* local num rows              */
     81:                     PetscInt m,             /* local num cols              */
     82:                     PetscErrorCode (*matvec)(void*,PetscScalar*,PetscScalar*), /* b_loc=A_local.x_loc         */
     83:                     void *grid_data)        /* grid data for matvec        */
     84: {
     85:   PCTFS_comm_init();
     86:   check_handle(xxt_handle);

     88:   /* only 2^k for now and all nodes participating */
     89:   if ((1<<(xxt_handle->level=PCTFS_i_log2_num_nodes))!=PCTFS_num_nodes) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"only 2^k for now and MPI_COMM_WORLD!!! %D != %D\n",1<<PCTFS_i_log2_num_nodes,PCTFS_num_nodes);

     91:   /* space for X info */
     92:   xxt_handle->info = (xxt_info*)malloc(sizeof(xxt_info));

     94:   /* set up matvec handles */
     95:   xxt_handle->mvi = set_mvi(local2global, n, m, (PetscErrorCode (*)(mv_info*,PetscScalar*,PetscScalar*))matvec, grid_data);

     97:   /* matrix is assumed to be of full rank */
     98:   /* LATER we can reset to indicate rank def. */
     99:   xxt_handle->ns=0;

    101:   /* determine separators and generate firing order - NB xxt info set here */
    102:   det_separators(xxt_handle);

    104:   return(do_xxt_factor(xxt_handle));
    105: }

    107: /**************************************xxt.c***********************************/
    108: PetscInt XXT_solve(xxt_ADT xxt_handle, PetscScalar *x, PetscScalar *b)
    109: {

    111:   PCTFS_comm_init();
    112:   check_handle(xxt_handle);

    114:   /* need to copy b into x? */
    115:   if (b) PCTFS_rvec_copy(x,b,xxt_handle->mvi->n);
    116:   do_xxt_solve(xxt_handle,x);

    118:   return(0);
    119: }

    121: /**************************************xxt.c***********************************/
    122: PetscInt XXT_free(xxt_ADT xxt_handle)
    123: {

    125:   PCTFS_comm_init();
    126:   check_handle(xxt_handle);
    127:   n_xxt_handles--;

    129:   free(xxt_handle->info->nsep);
    130:   free(xxt_handle->info->lnsep);
    131:   free(xxt_handle->info->fo);
    132:   free(xxt_handle->info->stages);
    133:   free(xxt_handle->info->solve_uu);
    134:   free(xxt_handle->info->solve_w);
    135:   free(xxt_handle->info->x);
    136:   free(xxt_handle->info->col_vals);
    137:   free(xxt_handle->info->col_sz);
    138:   free(xxt_handle->info->col_indices);
    139:   free(xxt_handle->info);
    140:   free(xxt_handle->mvi->local2global);
    141:   PCTFS_gs_free(xxt_handle->mvi->PCTFS_gs_handle);
    142:   free(xxt_handle->mvi);
    143:   free(xxt_handle);

    145:   /* if the check fails we nuke */
    146:   /* if NULL pointer passed to free we nuke */
    147:   /* if the calls to free fail that's not my problem */
    148:   return(0);
    149: }

    151: /**************************************xxt.c***********************************/
    152: PetscInt XXT_stats(xxt_ADT xxt_handle)
    153: {
    154:   PetscInt       op[]  = {NON_UNIFORM,GL_MIN,GL_MAX,GL_ADD,GL_MIN,GL_MAX,GL_ADD,GL_MIN,GL_MAX,GL_ADD};
    155:   PetscInt       fop[] = {NON_UNIFORM,GL_MIN,GL_MAX,GL_ADD};
    156:   PetscInt       vals[9],  work[9];
    157:   PetscScalar    fvals[3], fwork[3];

    160:   PCTFS_comm_init();
    161:   check_handle(xxt_handle);

    163:   /* if factorization not done there are no stats */
    164:   if (!xxt_handle->info||!xxt_handle->mvi) {
    165:     if (!PCTFS_my_id) { PetscPrintf(PETSC_COMM_WORLD,"XXT_stats() :: no stats available!\n"); }
    166:     return 1;
    167:   }

    169:   vals[0]=vals[1]=vals[2]=xxt_handle->info->nnz;
    170:   vals[3]=vals[4]=vals[5]=xxt_handle->mvi->n;
    171:   vals[6]=vals[7]=vals[8]=xxt_handle->info->msg_buf_sz;
    172:   PCTFS_giop(vals,work,sizeof(op)/sizeof(op[0])-1,op);

    174:   fvals[0]=fvals[1]=fvals[2] =xxt_handle->info->tot_solve_time/xxt_handle->info->nsolves++;
    175:   PCTFS_grop(fvals,fwork,sizeof(fop)/sizeof(fop[0])-1,fop);

    177:   if (!PCTFS_my_id) {
    178:     PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_nnz=%D\n",PCTFS_my_id,vals[0]);
    179:     PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_nnz=%D\n",PCTFS_my_id,vals[1]);
    180:     PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_nnz=%g\n",PCTFS_my_id,1.0*vals[2]/PCTFS_num_nodes);
    181:     PetscPrintf(PETSC_COMM_WORLD,"%D :: tot   xxt_nnz=%D\n",PCTFS_my_id,vals[2]);
    182:     PetscPrintf(PETSC_COMM_WORLD,"%D :: xxt   C(2d)  =%g\n",PCTFS_my_id,vals[2]/(PetscPowReal(1.0*vals[5],1.5)));
    183:     PetscPrintf(PETSC_COMM_WORLD,"%D :: xxt   C(3d)  =%g\n",PCTFS_my_id,vals[2]/(PetscPowReal(1.0*vals[5],1.6667)));
    184:     PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_n  =%D\n",PCTFS_my_id,vals[3]);
    185:     PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_n  =%D\n",PCTFS_my_id,vals[4]);
    186:     PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_n  =%g\n",PCTFS_my_id,1.0*vals[5]/PCTFS_num_nodes);
    187:     PetscPrintf(PETSC_COMM_WORLD,"%D :: tot   xxt_n  =%D\n",PCTFS_my_id,vals[5]);
    188:     PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_buf=%D\n",PCTFS_my_id,vals[6]);
    189:     PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_buf=%D\n",PCTFS_my_id,vals[7]);
    190:     PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_buf=%g\n",PCTFS_my_id,1.0*vals[8]/PCTFS_num_nodes);
    191:     PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_slv=%g\n",PCTFS_my_id,fvals[0]);
    192:     PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_slv=%g\n",PCTFS_my_id,fvals[1]);
    193:     PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_slv=%g\n",PCTFS_my_id,fvals[2]/PCTFS_num_nodes);
    194:   }

    196:   return(0);
    197: }

    199: /*************************************xxt.c************************************

    201: Description: get A_local, local portion of global coarse matrix which
    202: is a row dist. nxm matrix w/ n<m.
    203:    o my_ml holds address of ML struct associated w/A_local and coarse grid
    204:    o local2global holds global number of column i (i=0,...,m-1)
    205:    o local2global holds global number of row    i (i=0,...,n-1)
    206:    o mylocmatvec performs A_local . vec_local (note that gs is performed using
    207:    PCTFS_gs_init/gop).

    209: mylocmatvec = my_ml->Amat[grid_tag].matvec->external;
    210: mylocmatvec (void :: void *data, double *in, double *out)
    211: **************************************xxt.c***********************************/
    212: static PetscInt do_xxt_factor(xxt_ADT xxt_handle)
    213: {
    214:   return xxt_generate(xxt_handle);
    215: }

    217: /**************************************xxt.c***********************************/
    218: static PetscInt xxt_generate(xxt_ADT xxt_handle)
    219: {
    220:   PetscInt       i,j,k,idex;
    221:   PetscInt       dim, col;
    222:   PetscScalar    *u, *uu, *v, *z, *w, alpha, alpha_w;
    223:   PetscInt       *segs;
    224:   PetscInt       op[] = {GL_ADD,0};
    225:   PetscInt       off, len;
    226:   PetscScalar    *x_ptr;
    227:   PetscInt       *iptr, flag;
    228:   PetscInt       start =0, end, work;
    229:   PetscInt       op2[] = {GL_MIN,0};
    230:   PCTFS_gs_ADT   PCTFS_gs_handle;
    231:   PetscInt       *nsep, *lnsep, *fo;
    232:   PetscInt       a_n            =xxt_handle->mvi->n;
    233:   PetscInt       a_m            =xxt_handle->mvi->m;
    234:   PetscInt       *a_local2global=xxt_handle->mvi->local2global;
    235:   PetscInt       level;
    236:   PetscInt       xxt_nnz=0, xxt_max_nnz=0;
    237:   PetscInt       n, m;
    238:   PetscInt       *col_sz, *col_indices, *stages;
    239:   PetscScalar    **col_vals, *x;
    240:   PetscInt       n_global;
    241:   PetscInt       xxt_zero_nnz  =0;
    242:   PetscInt       xxt_zero_nnz_0=0;
    243:   PetscBLASInt   i1            = 1,dlen;
    244:   PetscScalar    dm1           = -1.0;

    247:   n               = xxt_handle->mvi->n;
    248:   nsep            = xxt_handle->info->nsep;
    249:   lnsep           = xxt_handle->info->lnsep;
    250:   fo              = xxt_handle->info->fo;
    251:   end             = lnsep[0];
    252:   level           = xxt_handle->level;
    253:   PCTFS_gs_handle = xxt_handle->mvi->PCTFS_gs_handle;

    255:   /* is there a null space? */
    256:   /* LATER add in ability to detect null space by checking alpha */
    257:   for (i=0, j=0; i<=level; i++) j+=nsep[i];

    259:   m = j-xxt_handle->ns;
    260:   if (m!=j) {
    261:     PetscPrintf(PETSC_COMM_WORLD,"xxt_generate() :: null space exists %D %D %D\n",m,j,xxt_handle->ns);
    262:   }

    264:   /* get and initialize storage for x local         */
    265:   /* note that x local is nxm and stored by columns */
    266:   col_sz      = (PetscInt*) malloc(m*sizeof(PetscInt));
    267:   col_indices = (PetscInt*) malloc((2*m+1)*sizeof(PetscInt));
    268:   col_vals    = (PetscScalar**) malloc(m*sizeof(PetscScalar*));
    269:   for (i=j=0; i<m; i++, j+=2) {
    270:     col_indices[j]=col_indices[j+1]=col_sz[i]=-1;
    271:     col_vals[i]   = NULL;
    272:   }
    273:   col_indices[j]=-1;

    275:   /* size of separators for each sub-hc working from bottom of tree to top */
    276:   /* this looks like nsep[]=segments */
    277:   stages = (PetscInt*) malloc((level+1)*sizeof(PetscInt));
    278:   segs   = (PetscInt*) malloc((level+1)*sizeof(PetscInt));
    279:   PCTFS_ivec_zero(stages,level+1);
    280:   PCTFS_ivec_copy(segs,nsep,level+1);
    281:   for (i=0; i<level; i++) segs[i+1] += segs[i];
    282:   stages[0] = segs[0];

    284:   /* temporary vectors  */
    285:   u  = (PetscScalar*) malloc(n*sizeof(PetscScalar));
    286:   z  = (PetscScalar*) malloc(n*sizeof(PetscScalar));
    287:   v  = (PetscScalar*) malloc(a_m*sizeof(PetscScalar));
    288:   uu = (PetscScalar*) malloc(m*sizeof(PetscScalar));
    289:   w  = (PetscScalar*) malloc(m*sizeof(PetscScalar));

    291:   /* extra nnz due to replication of vertices across separators */
    292:   for (i=1, j=0; i<=level; i++) j+=nsep[i];

    294:   /* storage for sparse x values */
    295:   n_global    = xxt_handle->info->n_global;
    296:   xxt_max_nnz = (PetscInt)(2.5*PetscPowReal(1.0*n_global,1.6667) + j*n/2)/PCTFS_num_nodes;
    297:   x           = (PetscScalar*) malloc(xxt_max_nnz*sizeof(PetscScalar));
    298:   xxt_nnz     = 0;

    300:   /* LATER - can embed next sep to fire in gs */
    301:   /* time to make the donuts - generate X factor */
    302:   for (dim=i=j=0; i<m; i++) {
    303:     /* time to move to the next level? */
    304:     while (i==segs[dim]) {
    305:       if (dim==level) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"dim about to exceed level\n");
    306:       stages[dim++]=i;
    307:       end         +=lnsep[dim];
    308:     }
    309:     stages[dim]=i;

    311:     /* which column are we firing? */
    312:     /* i.e. set v_l */
    313:     /* use new seps and do global min across hc to determine which one to fire */
    314:     (start<end) ? (col=fo[start]) : (col=INT_MAX);
    315:     PCTFS_giop_hc(&col,&work,1,op2,dim);

    317:     /* shouldn't need this */
    318:     if (col==INT_MAX) {
    319:       PetscInfo(0,"hey ... col==INT_MAX??\n");
    320:       continue;
    321:     }

    323:     /* do I own it? I should */
    324:     PCTFS_rvec_zero(v,a_m);
    325:     if (col==fo[start]) {
    326:       start++;
    327:       idex=PCTFS_ivec_linear_search(col, a_local2global, a_n);
    328:       if (idex!=-1) {
    329:         v[idex] = 1.0; j++;
    330:       } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"NOT FOUND!\n");
    331:     } else {
    332:       idex=PCTFS_ivec_linear_search(col, a_local2global, a_m);
    333:       if (idex!=-1) v[idex] = 1.0;
    334:     }

    336:     /* perform u = A.v_l */
    337:     PCTFS_rvec_zero(u,n);
    338:     do_matvec(xxt_handle->mvi,v,u);

    340:     /* uu =  X^T.u_l (local portion) */
    341:     /* technically only need to zero out first i entries */
    342:     /* later turn this into an XXT_solve call ? */
    343:     PCTFS_rvec_zero(uu,m);
    344:     x_ptr=x;
    345:     iptr = col_indices;
    346:     for (k=0; k<i; k++) {
    347:       off   = *iptr++;
    348:       len   = *iptr++;
    349:       PetscBLASIntCast(len,&dlen);
    350:       PetscStackCallBLAS("BLASdot",uu[k] = BLASdot_(&dlen,u+off,&i1,x_ptr,&i1));
    351:       x_ptr+=len;
    352:     }

    355:     /* uu = X^T.u_l (comm portion) */
    356:     PCTFS_ssgl_radd  (uu, w, dim, stages);

    358:     /* z = X.uu */
    359:     PCTFS_rvec_zero(z,n);
    360:     x_ptr=x;
    361:     iptr = col_indices;
    362:     for (k=0; k<i; k++) {
    363:       off  = *iptr++;
    364:       len  = *iptr++;
    365:       PetscBLASIntCast(len,&dlen);
    366:       PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&dlen,&uu[k],x_ptr,&i1,z+off,&i1));
    367:       x_ptr+=len;
    368:     }

    370:     /* compute v_l = v_l - z */
    371:     PCTFS_rvec_zero(v+a_n,a_m-a_n);
    372:     PetscBLASIntCast(n,&dlen);
    373:     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&dlen,&dm1,z,&i1,v,&i1));

    375:     /* compute u_l = A.v_l */
    376:     if (a_n!=a_m) PCTFS_gs_gop_hc(PCTFS_gs_handle,v,"+\0",dim);
    377:     PCTFS_rvec_zero(u,n);
    378:     do_matvec(xxt_handle->mvi,v,u);

    380:     /* compute sqrt(alpha) = sqrt(v_l^T.u_l) - local portion */
    381:     PetscBLASIntCast(n,&dlen);
    382:     PetscStackCallBLAS("BLASdot",alpha = BLASdot_(&dlen,u,&i1,v,&i1));
    383:     /* compute sqrt(alpha) = sqrt(v_l^T.u_l) - comm portion */
    384:     PCTFS_grop_hc(&alpha, &alpha_w, 1, op, dim);

    386:     alpha = (PetscScalar) PetscSqrtReal((PetscReal)alpha);

    388:     /* check for small alpha                             */
    389:     /* LATER use this to detect and determine null space */
    390:     if (PetscAbsScalar(alpha)<1.0e-14) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"bad alpha! %g\n",alpha);

    392:     /* compute v_l = v_l/sqrt(alpha) */
    393:     PCTFS_rvec_scale(v,1.0/alpha,n);

    395:     /* add newly generated column, v_l, to X */
    396:     flag = 1;
    397:     off=len=0;
    398:     for (k=0; k<n; k++) {
    399:       if (v[k]!=0.0) {
    400:         len=k;
    401:         if (flag) { off=k; flag=0; }
    402:       }
    403:     }

    405:     len -= (off-1);

    407:     if (len>0) {
    408:       if ((xxt_nnz+len)>xxt_max_nnz) {
    409:         PetscInfo(0,"increasing space for X by 2x!\n");
    410:         xxt_max_nnz *= 2;
    411:         x_ptr        = (PetscScalar*) malloc(xxt_max_nnz*sizeof(PetscScalar));
    412:         PCTFS_rvec_copy(x_ptr,x,xxt_nnz);
    413:         free(x);
    414:         x     = x_ptr;
    415:         x_ptr+=xxt_nnz;
    416:       }
    417:       xxt_nnz += len;
    418:       PCTFS_rvec_copy(x_ptr,v+off,len);

    420:       /* keep track of number of zeros */
    421:       if (dim) {
    422:         for (k=0; k<len; k++) {
    423:           if (x_ptr[k]==0.0) xxt_zero_nnz++;
    424:         }
    425:       } else {
    426:         for (k=0; k<len; k++) {
    427:           if (x_ptr[k]==0.0) xxt_zero_nnz_0++;
    428:         }
    429:       }
    430:       col_indices[2*i] = off;
    431:       col_sz[i] = col_indices[2*i+1] = len;
    432:       col_vals[i] = x_ptr;
    433:     }
    434:     else {
    435:       col_indices[2*i] = 0;
    436:       col_sz[i]        = col_indices[2*i+1] = 0;
    437:       col_vals[i]      = x_ptr;
    438:     }
    439:   }

    441:   /* close off stages for execution phase */
    442:   while (dim!=level) {
    443:     stages[dim++] = i;
    444:     PetscInfo2(0,"disconnected!!! dim(%D)!=level(%D)\n",dim,level);
    445:   }
    446:   stages[dim]=i;

    448:   xxt_handle->info->n              = xxt_handle->mvi->n;
    449:   xxt_handle->info->m              = m;
    450:   xxt_handle->info->nnz            = xxt_nnz;
    451:   xxt_handle->info->max_nnz        = xxt_max_nnz;
    452:   xxt_handle->info->msg_buf_sz     = stages[level]-stages[0];
    453:   xxt_handle->info->solve_uu       = (PetscScalar*) malloc(m*sizeof(PetscScalar));
    454:   xxt_handle->info->solve_w        = (PetscScalar*) malloc(m*sizeof(PetscScalar));
    455:   xxt_handle->info->x              = x;
    456:   xxt_handle->info->col_vals       = col_vals;
    457:   xxt_handle->info->col_sz         = col_sz;
    458:   xxt_handle->info->col_indices    = col_indices;
    459:   xxt_handle->info->stages         = stages;
    460:   xxt_handle->info->nsolves        = 0;
    461:   xxt_handle->info->tot_solve_time = 0.0;

    463:   free(segs);
    464:   free(u);
    465:   free(v);
    466:   free(uu);
    467:   free(z);
    468:   free(w);

    470:   return(0);
    471: }

    473: /**************************************xxt.c***********************************/
    474: static PetscErrorCode do_xxt_solve(xxt_ADT xxt_handle,  PetscScalar *uc)
    475: {
    476:   PetscInt       off, len, *iptr;
    477:   PetscInt       level        = xxt_handle->level;
    478:   PetscInt       n            = xxt_handle->info->n;
    479:   PetscInt       m            = xxt_handle->info->m;
    480:   PetscInt       *stages      = xxt_handle->info->stages;
    481:   PetscInt       *col_indices = xxt_handle->info->col_indices;
    482:   PetscScalar    *x_ptr, *uu_ptr;
    483:   PetscScalar    *solve_uu = xxt_handle->info->solve_uu;
    484:   PetscScalar    *solve_w  = xxt_handle->info->solve_w;
    485:   PetscScalar    *x        = xxt_handle->info->x;
    486:   PetscBLASInt   i1        = 1,dlen;

    490:   uu_ptr=solve_uu;
    491:   PCTFS_rvec_zero(uu_ptr,m);

    493:   /* x  = X.Y^T.b */
    494:   /* uu = Y^T.b */
    495:   for (x_ptr=x,iptr=col_indices; *iptr!=-1; x_ptr+=len) {
    496:     off       =*iptr++;
    497:     len       =*iptr++;
    498:     PetscBLASIntCast(len,&dlen);
    499:     PetscStackCallBLAS("BLASdot",*uu_ptr++ = BLASdot_(&dlen,uc+off,&i1,x_ptr,&i1));
    500:   }

    502:   /* comunication of beta */
    503:   uu_ptr=solve_uu;
    504:   if (level) PCTFS_ssgl_radd(uu_ptr, solve_w, level, stages);

    506:   PCTFS_rvec_zero(uc,n);

    508:   /* x = X.uu */
    509:   for (x_ptr=x,iptr=col_indices; *iptr!=-1; x_ptr+=len) {
    510:     off  =*iptr++;
    511:     len  =*iptr++;
    512:     PetscBLASIntCast(len,&dlen);
    513:     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&dlen,uu_ptr++,x_ptr,&i1,uc+off,&i1));
    514:   }
    515:   return(0);
    516: }

    518: /**************************************xxt.c***********************************/
    519: static PetscErrorCode check_handle(xxt_ADT xxt_handle)
    520: {
    521:   PetscInt vals[2], work[2], op[] = {NON_UNIFORM,GL_MIN,GL_MAX};

    524:   if (!xxt_handle) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"check_handle() :: bad handle :: NULL %D\n",xxt_handle);

    526:   vals[0]=vals[1]=xxt_handle->id;
    527:   PCTFS_giop(vals,work,sizeof(op)/sizeof(op[0])-1,op);
    528:   if ((vals[0]!=vals[1])||(xxt_handle->id<=0)) SETERRQ3(PETSC_COMM_SELF,PETSC_ERR_PLIB,"check_handle() :: bad handle :: id mismatch min/max %D/%D %D\n",vals[0],vals[1], xxt_handle->id);
    529:   return(0);
    530: }

    532: /**************************************xxt.c***********************************/
    533: static PetscErrorCode det_separators(xxt_ADT xxt_handle)
    534: {
    535:   PetscInt     i, ct, id;
    536:   PetscInt     mask, edge, *iptr;
    537:   PetscInt     *dir, *used;
    538:   PetscInt     sum[4], w[4];
    539:   PetscScalar  rsum[4], rw[4];
    540:   PetscInt     op[] = {GL_ADD,0};
    541:   PetscScalar  *lhs, *rhs;
    542:   PetscInt     *nsep, *lnsep, *fo, nfo=0;
    543:   PCTFS_gs_ADT PCTFS_gs_handle = xxt_handle->mvi->PCTFS_gs_handle;
    544:   PetscInt     *local2global   = xxt_handle->mvi->local2global;
    545:   PetscInt     n               = xxt_handle->mvi->n;
    546:   PetscInt     m               = xxt_handle->mvi->m;
    547:   PetscInt     level           = xxt_handle->level;
    548:   PetscInt     shared          = 0;

    551:   dir  = (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
    552:   nsep = (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
    553:   lnsep= (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
    554:   fo   = (PetscInt*)malloc(sizeof(PetscInt)*(n+1));
    555:   used = (PetscInt*)malloc(sizeof(PetscInt)*n);

    557:   PCTFS_ivec_zero(dir,level+1);
    558:   PCTFS_ivec_zero(nsep,level+1);
    559:   PCTFS_ivec_zero(lnsep,level+1);
    560:   PCTFS_ivec_set (fo,-1,n+1);
    561:   PCTFS_ivec_zero(used,n);

    563:   lhs = (PetscScalar*)malloc(sizeof(PetscScalar)*m);
    564:   rhs = (PetscScalar*)malloc(sizeof(PetscScalar)*m);

    566:   /* determine the # of unique dof */
    567:   PCTFS_rvec_zero(lhs,m);
    568:   PCTFS_rvec_set(lhs,1.0,n);
    569:   PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",level);
    570:   PCTFS_rvec_zero(rsum,2);
    571:   for (i=0; i<n; i++) {
    572:     if (lhs[i]!=0.0) {
    573:       rsum[0]+=1.0/lhs[i]; rsum[1]+=lhs[i];
    574:     }
    575:   }
    576:   PCTFS_grop_hc(rsum,rw,2,op,level);
    577:   rsum[0]+=0.1;
    578:   rsum[1]+=0.1;

    580:   if (PetscAbsScalar(rsum[0]-rsum[1])>EPS) shared=1;

    582:   xxt_handle->info->n_global=xxt_handle->info->m_global=(PetscInt) rsum[0];
    583:   xxt_handle->mvi->n_global =xxt_handle->mvi->m_global =(PetscInt) rsum[0];

    585:   /* determine separator sets top down */
    586:   if (shared) {
    587:     for (iptr=fo+n,id=PCTFS_my_id,mask=PCTFS_num_nodes>>1,edge=level;edge>0;edge--,mask>>=1) {

    589:       /* set rsh of hc, fire, and collect lhs responses */
    590:       (id<mask) ? PCTFS_rvec_zero(lhs,m) : PCTFS_rvec_set(lhs,1.0,m);
    591:       PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge);

    593:       /* set lsh of hc, fire, and collect rhs responses */
    594:       (id<mask) ? PCTFS_rvec_set(rhs,1.0,m) : PCTFS_rvec_zero(rhs,m);
    595:       PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge);
    596:
    597:       for (i=0;i<n;i++) {
    598:         if (id< mask) {
    599:           if (lhs[i]!=0.0) lhs[i]=1.0;
    600:         }
    601:
    602:         if (id>=mask) {
    603:           if (rhs[i]!=0.0) rhs[i]=1.0;
    604:         }
    605:       }

    607:       if (id< mask) PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge-1);
    608:       else          PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge-1);

    610:       /* count number of dofs I own that have signal and not in sep set */
    611:       PCTFS_rvec_zero(rsum,4);
    612:       for (PCTFS_ivec_zero(sum,4),ct=i=0;i<n;i++) {
    613:
    614:         if (!used[i]) {
    615:           /* number of unmarked dofs on node */
    616:           ct++;
    617:           /* number of dofs to be marked on lhs hc */
    618:           if (id< mask) {
    619:             if (lhs[i]!=0.0) { sum[0]++; rsum[0]+=1.0/lhs[i]; }
    620:           }
    621:           /* number of dofs to be marked on rhs hc */
    622:           if (id>=mask) {
    623:             if (rhs[i]!=0.0) { sum[1]++; rsum[1]+=1.0/rhs[i]; }
    624:           }
    625:         }
    626:       }

    628:       /* go for load balance - choose half with most unmarked dofs, bias LHS */
    629:       (id<mask) ? (sum[2]=ct) : (sum[3]=ct);
    630:       (id<mask) ? (rsum[2]=ct) : (rsum[3]=ct);
    631:       PCTFS_giop_hc(sum,w,4,op,edge);
    632:       PCTFS_grop_hc(rsum,rw,4,op,edge);
    633:       rsum[0]+=0.1; rsum[1]+=0.1; rsum[2]+=0.1; rsum[3]+=0.1;

    635:       if (id<mask) {
    636:         /* mark dofs I own that have signal and not in sep set */
    637:         for (ct=i=0;i<n;i++) {
    638:           if ((!used[i])&&(lhs[i]!=0.0)) {
    639:             ct++; nfo++;

    641:             if (nfo>n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"nfo about to exceed n\n");

    643:             *--iptr = local2global[i];
    644:             used[i] = edge;
    645:           }
    646:         }
    647:         if (ct>1) PCTFS_ivec_sort(iptr,ct);

    649:         lnsep[edge]=ct;
    650:         nsep[edge]=(PetscInt) rsum[0];
    651:         dir [edge]=LEFT;
    652:       }

    654:       if (id>=mask) {
    655:         /* mark dofs I own that have signal and not in sep set */
    656:         for (ct=i=0;i<n;i++) {
    657:           if ((!used[i])&&(rhs[i]!=0.0)) {
    658:             ct++; nfo++;

    660:             if (nfo>n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"nfo about to exceed n\n");

    662:             *--iptr = local2global[i];
    663:             used[i] = edge;
    664:           }
    665:         }
    666:         if (ct>1) PCTFS_ivec_sort(iptr,ct);

    668:         lnsep[edge] = ct;
    669:         nsep[edge]  = (PetscInt) rsum[1];
    670:         dir [edge]  = RIGHT;
    671:       }

    673:       /* LATER or we can recur on these to order seps at this level */
    674:       /* do we need full set of separators for this?                */

    676:       /* fold rhs hc into lower */
    677:       if (id>=mask) id-=mask;
    678:     }
    679:   } else {
    680:     for (iptr=fo+n,id=PCTFS_my_id,mask=PCTFS_num_nodes>>1,edge=level;edge>0;edge--,mask>>=1) {
    681:       /* set rsh of hc, fire, and collect lhs responses */
    682:       (id<mask) ? PCTFS_rvec_zero(lhs,m) : PCTFS_rvec_set(lhs,1.0,m);
    683:       PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge);

    685:       /* set lsh of hc, fire, and collect rhs responses */
    686:       (id<mask) ? PCTFS_rvec_set(rhs,1.0,m) : PCTFS_rvec_zero(rhs,m);
    687:       PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge);

    689:       /* count number of dofs I own that have signal and not in sep set */
    690:       for (PCTFS_ivec_zero(sum,4),ct=i=0;i<n;i++) {
    691:         if (!used[i]) {
    692:           /* number of unmarked dofs on node */
    693:           ct++;
    694:           /* number of dofs to be marked on lhs hc */
    695:           if ((id< mask)&&(lhs[i]!=0.0)) sum[0]++;
    696:           /* number of dofs to be marked on rhs hc */
    697:           if ((id>=mask)&&(rhs[i]!=0.0)) sum[1]++;
    698:         }
    699:       }

    701:       /* go for load balance - choose half with most unmarked dofs, bias LHS */
    702:       (id<mask) ? (sum[2]=ct) : (sum[3]=ct);
    703:       PCTFS_giop_hc(sum,w,4,op,edge);

    705:       /* lhs hc wins */
    706:       if (sum[2]>=sum[3]) {
    707:         if (id<mask) {
    708:           /* mark dofs I own that have signal and not in sep set */
    709:           for (ct=i=0;i<n;i++) {
    710:             if ((!used[i])&&(lhs[i]!=0.0)) {
    711:               ct++; nfo++;
    712:               *--iptr = local2global[i];
    713:               used[i]=edge;
    714:             }
    715:           }
    716:           if (ct>1) PCTFS_ivec_sort(iptr,ct);
    717:           lnsep[edge]=ct;
    718:         }
    719:         nsep[edge]=sum[0];
    720:         dir [edge]=LEFT;
    721:       } else { /* rhs hc wins */
    722:         if (id>=mask) {
    723:           /* mark dofs I own that have signal and not in sep set */
    724:           for (ct=i=0;i<n;i++) {
    725:             if ((!used[i])&&(rhs[i]!=0.0)) {
    726:               ct++; nfo++;
    727:               *--iptr = local2global[i];
    728:               used[i]=edge;
    729:             }
    730:           }
    731:           if (ct>1) PCTFS_ivec_sort(iptr,ct);
    732:           lnsep[edge]=ct;
    733:         }
    734:         nsep[edge]=sum[1];
    735:         dir [edge]=RIGHT;
    736:       }
    737:       /* LATER or we can recur on these to order seps at this level */
    738:       /* do we need full set of separators for this?                */

    740:       /* fold rhs hc into lower */
    741:       if (id>=mask) id-=mask;
    742:     }
    743:   }

    746:   /* level 0 is on processor case - so mark the remainder */
    747:   for (ct=i=0; i<n; i++) {
    748:     if (!used[i]) {
    749:       ct++; nfo++;
    750:       *--iptr = local2global[i];
    751:       used[i] = edge;
    752:     }
    753:   }
    754:   if (ct>1) PCTFS_ivec_sort(iptr,ct);
    755:   lnsep[edge]=ct;
    756:   nsep [edge]=ct;
    757:   dir  [edge]=LEFT;

    759:   xxt_handle->info->nsep  = nsep;
    760:   xxt_handle->info->lnsep = lnsep;
    761:   xxt_handle->info->fo    = fo;
    762:   xxt_handle->info->nfo   = nfo;

    764:   free(dir);
    765:   free(lhs);
    766:   free(rhs);
    767:   free(used);
    768:   return(0);
    769: }

    771: /**************************************xxt.c***********************************/
    772: static mv_info *set_mvi(PetscInt *local2global,PetscInt n,PetscInt m,PetscErrorCode (*matvec)(mv_info*,PetscScalar*,PetscScalar*),void *grid_data)
    773: {
    774:   mv_info *mvi;

    777:   mvi               = (mv_info*)malloc(sizeof(mv_info));
    778:   mvi->n            = n;
    779:   mvi->m            = m;
    780:   mvi->n_global     = -1;
    781:   mvi->m_global     = -1;
    782:   mvi->local2global = (PetscInt*)malloc((m+1)*sizeof(PetscInt));
    783:   PCTFS_ivec_copy(mvi->local2global,local2global,m);
    784:   mvi->local2global[m] = INT_MAX;
    785:   mvi->matvec          = matvec;
    786:   mvi->grid_data       = grid_data;

    788:   /* set xxt communication handle to perform restricted matvec */
    789:   mvi->PCTFS_gs_handle = PCTFS_gs_init(local2global, m, PCTFS_num_nodes);

    791:   return(mvi);
    792: }

    794: /**************************************xxt.c***********************************/
    795: static PetscErrorCode do_matvec(mv_info *A, PetscScalar *v, PetscScalar *u)
    796: {
    798:   A->matvec((mv_info*)A->grid_data,v,u);
    799:   return(0);
    800: }