xref: /petsc/src/ksp/pc/impls/tfs/xxt.c (revision 5c8f6a953e7ed1c81f507d64aebddb11080b60e9)
1 
2 /*************************************xxt.c************************************
3 Module Name: xxt
4 Module Info:
5 
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 +--------------------------------+--------------------------------+
16 
17 Last Modification: 3.20.01
18 **************************************xxt.c***********************************/
19 #include <../src/ksp/pc/impls/tfs/tfs.h>
20 
21 #define LEFT  -1
22 #define RIGHT  1
23 #define BOTH   0
24 
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;
34 
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;
42 
43 struct xxt_CDT{
44   PetscInt id;
45   PetscInt ns;
46   PetscInt level;
47   xxt_info *info;
48   mv_info  *mvi;
49 };
50 
51 static PetscInt n_xxt=0;
52 static PetscInt n_xxt_handles=0;
53 
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);
62 
63 /**************************************xxt.c***********************************/
64 xxt_ADT XXT_new(void)
65 {
66   xxt_ADT xxt_handle;
67 
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;
73 
74   return(xxt_handle);
75 }
76 
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);
87 
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);
90 
91   /* space for X info */
92   xxt_handle->info = (xxt_info*)malloc(sizeof(xxt_info));
93 
94   /* set up matvec handles */
95   xxt_handle->mvi  = set_mvi(local2global, n, m, (PetscErrorCode (*)(mv_info*,PetscScalar*,PetscScalar*))matvec, grid_data);
96 
97   /* matrix is assumed to be of full rank */
98   /* LATER we can reset to indicate rank def. */
99   xxt_handle->ns=0;
100 
101   /* determine separators and generate firing order - NB xxt info set here */
102   det_separators(xxt_handle);
103 
104   return(do_xxt_factor(xxt_handle));
105 }
106 
107 /**************************************xxt.c***********************************/
108 PetscInt XXT_solve(xxt_ADT xxt_handle, PetscScalar *x, PetscScalar *b)
109 {
110 
111   PCTFS_comm_init();
112   check_handle(xxt_handle);
113 
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);
117 
118   return(0);
119 }
120 
121 /**************************************xxt.c***********************************/
122 PetscInt XXT_free(xxt_ADT xxt_handle)
123 {
124 
125   PCTFS_comm_init();
126   check_handle(xxt_handle);
127   n_xxt_handles--;
128 
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);
144 
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 }
150 
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];
158   PetscErrorCode ierr;
159 
160   PCTFS_comm_init();
161   check_handle(xxt_handle);
162 
163   /* if factorization not done there are no stats */
164   if (!xxt_handle->info||!xxt_handle->mvi) {
165     if (!PCTFS_my_id) { ierr = PetscPrintf(PETSC_COMM_WORLD,"XXT_stats() :: no stats available!\n");CHKERRQ(ierr); }
166     return 1;
167   }
168 
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);
173 
174   fvals[0]=fvals[1]=fvals[2]
175     =xxt_handle->info->tot_solve_time/xxt_handle->info->nsolves++;
176   PCTFS_grop(fvals,fwork,sizeof(fop)/sizeof(fop[0])-1,fop);
177 
178   if (!PCTFS_my_id) {
179     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_nnz=%D\n",PCTFS_my_id,vals[0]);CHKERRQ(ierr);
180     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_nnz=%D\n",PCTFS_my_id,vals[1]);CHKERRQ(ierr);
181     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_nnz=%g\n",PCTFS_my_id,1.0*vals[2]/PCTFS_num_nodes);CHKERRQ(ierr);
182     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: tot   xxt_nnz=%D\n",PCTFS_my_id,vals[2]);CHKERRQ(ierr);
183     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: xxt   C(2d)  =%g\n",PCTFS_my_id,vals[2]/(pow(1.0*vals[5],1.5)));CHKERRQ(ierr);
184     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: xxt   C(3d)  =%g\n",PCTFS_my_id,vals[2]/(pow(1.0*vals[5],1.6667)));CHKERRQ(ierr);
185     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_n  =%D\n",PCTFS_my_id,vals[3]);CHKERRQ(ierr);
186     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_n  =%D\n",PCTFS_my_id,vals[4]);CHKERRQ(ierr);
187     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_n  =%g\n",PCTFS_my_id,1.0*vals[5]/PCTFS_num_nodes);CHKERRQ(ierr);
188     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: tot   xxt_n  =%D\n",PCTFS_my_id,vals[5]);CHKERRQ(ierr);
189     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_buf=%D\n",PCTFS_my_id,vals[6]);CHKERRQ(ierr);
190     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_buf=%D\n",PCTFS_my_id,vals[7]);CHKERRQ(ierr);
191     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_buf=%g\n",PCTFS_my_id,1.0*vals[8]/PCTFS_num_nodes);CHKERRQ(ierr);
192     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_slv=%g\n",PCTFS_my_id,fvals[0]);CHKERRQ(ierr);
193     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_slv=%g\n",PCTFS_my_id,fvals[1]);CHKERRQ(ierr);
194     ierr = PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_slv=%g\n",PCTFS_my_id,fvals[2]/PCTFS_num_nodes);CHKERRQ(ierr);
195   }
196 
197   return(0);
198 }
199 
200 /*************************************xxt.c************************************
201 
202 Description: get A_local, local portion of global coarse matrix which
203 is a row dist. nxm matrix w/ n<m.
204    o my_ml holds address of ML struct associated w/A_local and coarse grid
205    o local2global holds global number of column i (i=0,...,m-1)
206    o local2global holds global number of row    i (i=0,...,n-1)
207    o mylocmatvec performs A_local . vec_local (note that gs is performed using
208    PCTFS_gs_init/gop).
209 
210 mylocmatvec = my_ml->Amat[grid_tag].matvec->external;
211 mylocmatvec (void :: void *data, double *in, double *out)
212 **************************************xxt.c***********************************/
213 static PetscInt do_xxt_factor(xxt_ADT xxt_handle)
214 {
215   return xxt_generate(xxt_handle);
216 }
217 
218 /**************************************xxt.c***********************************/
219 static PetscInt xxt_generate(xxt_ADT xxt_handle)
220 {
221   PetscInt i,j,k,idex;
222   PetscInt dim, col;
223   PetscScalar *u, *uu, *v, *z, *w, alpha, alpha_w;
224   PetscInt *segs;
225   PetscInt op[] = {GL_ADD,0};
226   PetscInt off, len;
227   PetscScalar *x_ptr;
228   PetscInt *iptr, flag;
229   PetscInt start=0, end, work;
230   PetscInt op2[] = {GL_MIN,0};
231   PCTFS_gs_ADT PCTFS_gs_handle;
232   PetscInt *nsep, *lnsep, *fo;
233   PetscInt a_n=xxt_handle->mvi->n;
234   PetscInt a_m=xxt_handle->mvi->m;
235   PetscInt *a_local2global=xxt_handle->mvi->local2global;
236   PetscInt level;
237   PetscInt xxt_nnz=0, xxt_max_nnz=0;
238   PetscInt n, m;
239   PetscInt *col_sz, *col_indices, *stages;
240   PetscScalar **col_vals, *x;
241   PetscInt n_global;
242   PetscInt xxt_zero_nnz=0;
243   PetscInt xxt_zero_nnz_0=0;
244   PetscBLASInt i1 = 1,dlen;
245   PetscScalar dm1 = -1.0;
246   PetscErrorCode ierr;
247 
248   n=xxt_handle->mvi->n;
249   nsep=xxt_handle->info->nsep;
250   lnsep=xxt_handle->info->lnsep;
251   fo=xxt_handle->info->fo;
252   end=lnsep[0];
253   level=xxt_handle->level;
254   PCTFS_gs_handle=xxt_handle->mvi->PCTFS_gs_handle;
255 
256   /* is there a null space? */
257   /* LATER add in ability to detect null space by checking alpha */
258   for (i=0, j=0; i<=level; i++)
259     {j+=nsep[i];}
260 
261   m = j-xxt_handle->ns;
262   if (m!=j) {
263     ierr = PetscPrintf(PETSC_COMM_WORLD,"xxt_generate() :: null space exists %D %D %D\n",m,j,xxt_handle->ns);CHKERRQ(ierr);
264   }
265 
266   /* get and initialize storage for x local         */
267   /* note that x local is nxm and stored by columns */
268   col_sz = (PetscInt*) malloc(m*sizeof(PetscInt));
269   col_indices = (PetscInt*) malloc((2*m+1)*sizeof(PetscInt));
270   col_vals = (PetscScalar **) malloc(m*sizeof(PetscScalar *));
271   for (i=j=0; i<m; i++, j+=2) {
272     col_indices[j]=col_indices[j+1]=col_sz[i]=-1;
273     col_vals[i] = NULL;
274   }
275   col_indices[j]=-1;
276 
277   /* size of separators for each sub-hc working from bottom of tree to top */
278   /* this looks like nsep[]=segments */
279   stages = (PetscInt*) malloc((level+1)*sizeof(PetscInt));
280   segs   = (PetscInt*) malloc((level+1)*sizeof(PetscInt));
281   PCTFS_ivec_zero(stages,level+1);
282   PCTFS_ivec_copy(segs,nsep,level+1);
283   for (i=0; i<level; i++) { segs[i+1] += segs[i]; }
284   stages[0] = segs[0];
285 
286   /* temporary vectors  */
287   u  = (PetscScalar *) malloc(n*sizeof(PetscScalar));
288   z  = (PetscScalar *) malloc(n*sizeof(PetscScalar));
289   v  = (PetscScalar *) malloc(a_m*sizeof(PetscScalar));
290   uu = (PetscScalar *) malloc(m*sizeof(PetscScalar));
291   w  = (PetscScalar *) malloc(m*sizeof(PetscScalar));
292 
293   /* extra nnz due to replication of vertices across separators */
294   for (i=1, j=0; i<=level; i++) {j+=nsep[i];}
295 
296   /* storage for sparse x values */
297   n_global = xxt_handle->info->n_global;
298   xxt_max_nnz = (PetscInt)(2.5*pow(1.0*n_global,1.6667) + j*n/2)/PCTFS_num_nodes;
299   x = (PetscScalar *) malloc(xxt_max_nnz*sizeof(PetscScalar));
300   xxt_nnz = 0;
301 
302   /* LATER - can embed next sep to fire in gs */
303   /* time to make the donuts - generate X factor */
304   for (dim=i=j=0;i<m;i++)
305   {
306     /* time to move to the next level? */
307     while (i==segs[dim]) {
308       if (dim==level) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"dim about to exceed level\n");
309       stages[dim++]=i;
310       end+=lnsep[dim];
311     }
312     stages[dim]=i;
313 
314     /* which column are we firing? */
315     /* i.e. set v_l */
316     /* use new seps and do global min across hc to determine which one to fire */
317     (start<end) ? (col=fo[start]) : (col=INT_MAX);
318     PCTFS_giop_hc(&col,&work,1,op2,dim);
319 
320     /* shouldn't need this */
321     if (col==INT_MAX) {
322       ierr = PetscInfo(0,"hey ... col==INT_MAX??\n");CHKERRQ(ierr);
323       continue;
324     }
325 
326     /* do I own it? I should */
327     PCTFS_rvec_zero(v ,a_m);
328     if (col==fo[start]) {
329       start++;
330       idex=PCTFS_ivec_linear_search(col, a_local2global, a_n);
331       if (idex!=-1) {
332         v[idex] = 1.0; j++;
333       } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"NOT FOUND!\n");
334     } else {
335       idex=PCTFS_ivec_linear_search(col, a_local2global, a_m);
336       if (idex!=-1)
337         {v[idex] = 1.0;}
338     }
339 
340     /* perform u = A.v_l */
341     PCTFS_rvec_zero(u,n);
342     do_matvec(xxt_handle->mvi,v,u);
343 
344     /* uu =  X^T.u_l (local portion) */
345     /* technically only need to zero out first i entries */
346     /* later turn this into an XXT_solve call ? */
347     PCTFS_rvec_zero(uu,m);
348     x_ptr=x;
349     iptr = col_indices;
350     for (k=0; k<i; k++) {
351       off = *iptr++;
352       len = *iptr++;
353       dlen = PetscBLASIntCast(len);
354       uu[k] = BLASdot_(&dlen,u+off,&i1,x_ptr,&i1);
355       x_ptr+=len;
356     }
357 
358 
359     /* uu = X^T.u_l (comm portion) */
360     PCTFS_ssgl_radd  (uu, w, dim, stages);
361 
362     /* z = X.uu */
363     PCTFS_rvec_zero(z,n);
364     x_ptr=x;
365     iptr = col_indices;
366     for (k=0; k<i; k++) {
367       off = *iptr++;
368       len = *iptr++;
369       dlen = PetscBLASIntCast(len);
370       BLASaxpy_(&dlen,&uu[k],x_ptr,&i1,z+off,&i1);
371       x_ptr+=len;
372     }
373 
374     /* compute v_l = v_l - z */
375     PCTFS_rvec_zero(v+a_n,a_m-a_n);
376     dlen = PetscBLASIntCast(n);
377     BLASaxpy_(&dlen,&dm1,z,&i1,v,&i1);
378 
379     /* compute u_l = A.v_l */
380     if (a_n!=a_m) { PCTFS_gs_gop_hc(PCTFS_gs_handle,v,"+\0",dim); }
381     PCTFS_rvec_zero(u,n);
382     do_matvec(xxt_handle->mvi,v,u);
383 
384     /* compute sqrt(alpha) = sqrt(v_l^T.u_l) - local portion */
385     dlen = PetscBLASIntCast(n);
386     alpha = BLASdot_(&dlen,u,&i1,v,&i1);
387     /* compute sqrt(alpha) = sqrt(v_l^T.u_l) - comm portion */
388     PCTFS_grop_hc(&alpha, &alpha_w, 1, op, dim);
389 
390     alpha = (PetscScalar) PetscSqrtReal((PetscReal)alpha);
391 
392     /* check for small alpha                             */
393     /* LATER use this to detect and determine null space */
394     if (fabs(alpha)<1.0e-14) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"bad alpha! %g\n",alpha);
395 
396     /* compute v_l = v_l/sqrt(alpha) */
397     PCTFS_rvec_scale(v,1.0/alpha,n);
398 
399     /* add newly generated column, v_l, to X */
400     flag = 1;
401     off=len=0;
402     for (k=0; k<n; k++) {
403       if (v[k]!=0.0) {
404         len=k;
405         if (flag) { off=k; flag=0; }
406       }
407     }
408 
409     len -= (off-1);
410 
411     if (len>0) {
412       if ((xxt_nnz+len)>xxt_max_nnz) {
413         ierr = PetscInfo(0,"increasing space for X by 2x!\n");CHKERRQ(ierr);
414         xxt_max_nnz *= 2;
415         x_ptr = (PetscScalar *) malloc(xxt_max_nnz*sizeof(PetscScalar));
416         PCTFS_rvec_copy(x_ptr,x,xxt_nnz);
417         free(x);
418         x = x_ptr;
419         x_ptr+=xxt_nnz;
420       }
421       xxt_nnz += len;
422       PCTFS_rvec_copy(x_ptr,v+off,len);
423 
424       /* keep track of number of zeros */
425       if (dim) {
426         for (k=0; k<len; k++) {
427           if (x_ptr[k]==0.0) { xxt_zero_nnz++; }
428         }
429       } else {
430         for (k=0; k<len; k++) {
431           if (x_ptr[k]==0.0) {xxt_zero_nnz_0++;}
432         }
433       }
434       col_indices[2*i] = off;
435       col_sz[i] = col_indices[2*i+1] = len;
436       col_vals[i] = x_ptr;
437     }
438     else {
439       col_indices[2*i] = 0;
440       col_sz[i] = col_indices[2*i+1] = 0;
441       col_vals[i] = x_ptr;
442     }
443   }
444 
445   /* close off stages for execution phase */
446   while (dim!=level) {
447     stages[dim++]=i;
448     ierr = PetscInfo2(0,"disconnected!!! dim(%D)!=level(%D)\n",dim,level);CHKERRQ(ierr);
449   }
450   stages[dim]=i;
451 
452   xxt_handle->info->n=xxt_handle->mvi->n;
453   xxt_handle->info->m=m;
454   xxt_handle->info->nnz=xxt_nnz;
455   xxt_handle->info->max_nnz=xxt_max_nnz;
456   xxt_handle->info->msg_buf_sz=stages[level]-stages[0];
457   xxt_handle->info->solve_uu = (PetscScalar *) malloc(m*sizeof(PetscScalar));
458   xxt_handle->info->solve_w  = (PetscScalar *) malloc(m*sizeof(PetscScalar));
459   xxt_handle->info->x=x;
460   xxt_handle->info->col_vals=col_vals;
461   xxt_handle->info->col_sz=col_sz;
462   xxt_handle->info->col_indices=col_indices;
463   xxt_handle->info->stages=stages;
464   xxt_handle->info->nsolves=0;
465   xxt_handle->info->tot_solve_time=0.0;
466 
467   free(segs);
468   free(u);
469   free(v);
470   free(uu);
471   free(z);
472   free(w);
473 
474   return(0);
475 }
476 
477 /**************************************xxt.c***********************************/
478 static PetscErrorCode do_xxt_solve(xxt_ADT xxt_handle,  PetscScalar *uc)
479 {
480   PetscInt off, len, *iptr;
481   PetscInt level       =xxt_handle->level;
482   PetscInt n           =xxt_handle->info->n;
483   PetscInt m           =xxt_handle->info->m;
484   PetscInt *stages     =xxt_handle->info->stages;
485   PetscInt *col_indices=xxt_handle->info->col_indices;
486   PetscScalar *x_ptr, *uu_ptr;
487   PetscScalar *solve_uu=xxt_handle->info->solve_uu;
488   PetscScalar *solve_w =xxt_handle->info->solve_w;
489   PetscScalar *x       =xxt_handle->info->x;
490   PetscBLASInt i1 = 1,dlen;
491 
492   PetscFunctionBegin;
493   uu_ptr=solve_uu;
494   PCTFS_rvec_zero(uu_ptr,m);
495 
496   /* x  = X.Y^T.b */
497   /* uu = Y^T.b */
498   for (x_ptr=x,iptr=col_indices; *iptr!=-1; x_ptr+=len) {
499     off=*iptr++; len=*iptr++;
500     dlen = PetscBLASIntCast(len);
501     *uu_ptr++ = BLASdot_(&dlen,uc+off,&i1,x_ptr,&i1);
502   }
503 
504   /* comunication of beta */
505   uu_ptr=solve_uu;
506   if (level) { PCTFS_ssgl_radd(uu_ptr, solve_w, level, stages); }
507 
508   PCTFS_rvec_zero(uc,n);
509 
510   /* x = X.uu */
511   for (x_ptr=x,iptr=col_indices; *iptr!=-1; x_ptr+=len) {
512     off=*iptr++; len=*iptr++;
513     dlen = PetscBLASIntCast(len);
514     BLASaxpy_(&dlen,uu_ptr++,x_ptr,&i1,uc+off,&i1);
515   }
516   PetscFunctionReturn(0);
517 }
518 
519 /**************************************xxt.c***********************************/
520 static PetscErrorCode check_handle(xxt_ADT xxt_handle)
521 {
522   PetscInt vals[2], work[2], op[] = {NON_UNIFORM,GL_MIN,GL_MAX};
523 
524   PetscFunctionBegin;
525   if (!xxt_handle) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_PLIB,"check_handle() :: bad handle :: NULL %D\n",xxt_handle);
526 
527   vals[0]=vals[1]=xxt_handle->id;
528   PCTFS_giop(vals,work,sizeof(op)/sizeof(op[0])-1,op);
529   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);
530   PetscFunctionReturn(0);
531 }
532 
533 /**************************************xxt.c***********************************/
534 static  PetscErrorCode det_separators(xxt_ADT xxt_handle)
535 {
536   PetscInt i, ct, id;
537   PetscInt mask, edge, *iptr;
538   PetscInt *dir, *used;
539   PetscInt sum[4], w[4];
540   PetscScalar rsum[4], rw[4];
541   PetscInt op[] = {GL_ADD,0};
542   PetscScalar *lhs, *rhs;
543   PetscInt *nsep, *lnsep, *fo, nfo=0;
544   PCTFS_gs_ADT PCTFS_gs_handle=xxt_handle->mvi->PCTFS_gs_handle;
545   PetscInt *local2global=xxt_handle->mvi->local2global;
546   PetscInt  n=xxt_handle->mvi->n;
547   PetscInt  m=xxt_handle->mvi->m;
548   PetscInt level=xxt_handle->level;
549   PetscInt shared=0;
550 
551   PetscFunctionBegin;
552   dir  = (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
553   nsep = (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
554   lnsep= (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
555   fo   = (PetscInt*)malloc(sizeof(PetscInt)*(n+1));
556   used = (PetscInt*)malloc(sizeof(PetscInt)*n);
557 
558   PCTFS_ivec_zero(dir  ,level+1);
559   PCTFS_ivec_zero(nsep ,level+1);
560   PCTFS_ivec_zero(lnsep,level+1);
561   PCTFS_ivec_set (fo   ,-1,n+1);
562   PCTFS_ivec_zero(used,n);
563 
564   lhs  = (PetscScalar*)malloc(sizeof(PetscScalar)*m);
565   rhs  = (PetscScalar*)malloc(sizeof(PetscScalar)*m);
566 
567   /* determine the # of unique dof */
568   PCTFS_rvec_zero(lhs,m);
569   PCTFS_rvec_set(lhs,1.0,n);
570   PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",level);
571   PCTFS_rvec_zero(rsum,2);
572   for (ct=i=0;i<n;i++) {
573     if (lhs[i]!=0.0)
574       {rsum[0]+=1.0/lhs[i]; rsum[1]+=lhs[i];}
575   }
576   PCTFS_grop_hc(rsum,rw,2,op,level);
577   rsum[0]+=0.1;
578   rsum[1]+=0.1;
579 
580   if (fabs(rsum[0]-rsum[1])>EPS) { shared=1; }
581 
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];
584 
585   /* determine separator sets top down */
586   if (shared)
587   {
588     for (iptr=fo+n,id=PCTFS_my_id,mask=PCTFS_num_nodes>>1,edge=level;edge>0;edge--,mask>>=1) {
589 
590       /* set rsh of hc, fire, and collect lhs responses */
591       (id<mask) ? PCTFS_rvec_zero(lhs,m) : PCTFS_rvec_set(lhs,1.0,m);
592       PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge);
593 
594       /* set lsh of hc, fire, and collect rhs responses */
595       (id<mask) ? PCTFS_rvec_set(rhs,1.0,m) : PCTFS_rvec_zero(rhs,m);
596       PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge);
597 
598       for (i=0;i<n;i++) {
599         if (id< mask) {
600           if (lhs[i]!=0.0) { lhs[i]=1.0; }
601         }
602 
603         if (id>=mask) {
604           if (rhs[i]!=0.0) { rhs[i]=1.0; }
605         }
606       }
607 
608       if (id< mask) { PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge-1); }
609       else          { PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge-1); }
610 
611       /* count number of dofs I own that have signal and not in sep set */
612       PCTFS_rvec_zero(rsum,4);
613       for (PCTFS_ivec_zero(sum,4),ct=i=0;i<n;i++) {
614 
615         if (!used[i]) {
616           /* number of unmarked dofs on node */
617           ct++;
618           /* number of dofs to be marked on lhs hc */
619           if (id< mask) {
620             if (lhs[i]!=0.0) { sum[0]++; rsum[0]+=1.0/lhs[i]; }
621           }
622           /* number of dofs to be marked on rhs hc */
623           if (id>=mask) {
624             if (rhs[i]!=0.0) { sum[1]++; rsum[1]+=1.0/rhs[i]; }
625           }
626         }
627 
628       }
629 
630       /* go for load balance - choose half with most unmarked dofs, bias LHS */
631       (id<mask) ? (sum[2]=ct) : (sum[3]=ct);
632       (id<mask) ? (rsum[2]=ct) : (rsum[3]=ct);
633       PCTFS_giop_hc(sum,w,4,op,edge);
634       PCTFS_grop_hc(rsum,rw,4,op,edge);
635       rsum[0]+=0.1; rsum[1]+=0.1; rsum[2]+=0.1; rsum[3]+=0.1;
636 
637       if (id<mask) {
638         /* mark dofs I own that have signal and not in sep set */
639         for (ct=i=0;i<n;i++) {
640           if ((!used[i])&&(lhs[i]!=0.0)) {
641             ct++; nfo++;
642 
643             if (nfo>n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"nfo about to exceed n\n");
644 
645             *--iptr = local2global[i];
646             used[i]=edge;
647           }
648         }
649         if (ct>1) {PCTFS_ivec_sort(iptr,ct);}
650 
651         lnsep[edge]=ct;
652         nsep[edge]=(PetscInt) rsum[0];
653         dir [edge]=LEFT;
654       }
655 
656       if (id>=mask) {
657         /* mark dofs I own that have signal and not in sep set */
658         for (ct=i=0;i<n;i++) {
659           if ((!used[i])&&(rhs[i]!=0.0)) {
660             ct++; nfo++;
661 
662             if (nfo>n) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"nfo about to exceed n\n");
663 
664             *--iptr = local2global[i];
665             used[i]=edge;
666           }
667         }
668         if (ct>1) { PCTFS_ivec_sort(iptr,ct); }
669 
670         lnsep[edge]=ct;
671         nsep[edge]= (PetscInt) rsum[1];
672         dir [edge]=RIGHT;
673       }
674 
675       /* LATER or we can recur on these to order seps at this level */
676       /* do we need full set of separators for this?                */
677 
678       /* fold rhs hc into lower */
679       if (id>=mask) { id-=mask; }
680     }
681   } else {
682     for (iptr=fo+n,id=PCTFS_my_id,mask=PCTFS_num_nodes>>1,edge=level;edge>0;edge--,mask>>=1) {
683       /* set rsh of hc, fire, and collect lhs responses */
684       (id<mask) ? PCTFS_rvec_zero(lhs,m) : PCTFS_rvec_set(lhs,1.0,m);
685       PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge);
686 
687       /* set lsh of hc, fire, and collect rhs responses */
688       (id<mask) ? PCTFS_rvec_set(rhs,1.0,m) : PCTFS_rvec_zero(rhs,m);
689       PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge);
690 
691       /* count number of dofs I own that have signal and not in sep set */
692       for (PCTFS_ivec_zero(sum,4),ct=i=0;i<n;i++) {
693         if (!used[i]) {
694           /* number of unmarked dofs on node */
695           ct++;
696           /* number of dofs to be marked on lhs hc */
697           if ((id< mask)&&(lhs[i]!=0.0)) { sum[0]++; }
698           /* number of dofs to be marked on rhs hc */
699           if ((id>=mask)&&(rhs[i]!=0.0)) { sum[1]++; }
700         }
701       }
702 
703       /* go for load balance - choose half with most unmarked dofs, bias LHS */
704       (id<mask) ? (sum[2]=ct) : (sum[3]=ct);
705       PCTFS_giop_hc(sum,w,4,op,edge);
706 
707       /* lhs hc wins */
708       if (sum[2]>=sum[3]) {
709         if (id<mask) {
710           /* mark dofs I own that have signal and not in sep set */
711           for (ct=i=0;i<n;i++) {
712             if ((!used[i])&&(lhs[i]!=0.0)) {
713               ct++; nfo++;
714               *--iptr = local2global[i];
715               used[i]=edge;
716             }
717           }
718           if (ct>1) { PCTFS_ivec_sort(iptr,ct); }
719           lnsep[edge]=ct;
720         }
721         nsep[edge]=sum[0];
722         dir [edge]=LEFT;
723       } else { /* rhs hc wins */
724         if (id>=mask) {
725           /* mark dofs I own that have signal and not in sep set */
726           for (ct=i=0;i<n;i++) {
727             if ((!used[i])&&(rhs[i]!=0.0)) {
728               ct++; nfo++;
729               *--iptr = local2global[i];
730               used[i]=edge;
731             }
732           }
733           if (ct>1) {PCTFS_ivec_sort(iptr,ct);}
734           lnsep[edge]=ct;
735         }
736         nsep[edge]=sum[1];
737         dir [edge]=RIGHT;
738       }
739       /* LATER or we can recur on these to order seps at this level */
740       /* do we need full set of separators for this?                */
741 
742       /* fold rhs hc into lower */
743       if (id>=mask) { id-=mask; }
744     }
745   }
746 
747 
748   /* level 0 is on processor case - so mark the remainder */
749   for (ct=i=0;i<n;i++) {
750     if (!used[i]) {
751       ct++; nfo++;
752       *--iptr = local2global[i];
753       used[i]=edge;
754     }
755   }
756   if (ct>1) { PCTFS_ivec_sort(iptr,ct); }
757   lnsep[edge]=ct;
758   nsep [edge]=ct;
759   dir  [edge]=LEFT;
760 
761   xxt_handle->info->nsep=nsep;
762   xxt_handle->info->lnsep=lnsep;
763   xxt_handle->info->fo=fo;
764   xxt_handle->info->nfo=nfo;
765 
766   free(dir);
767   free(lhs);
768   free(rhs);
769   free(used);
770   PetscFunctionReturn(0);
771 }
772 
773 /**************************************xxt.c***********************************/
774 static mv_info *set_mvi(PetscInt *local2global,PetscInt n,PetscInt m,PetscErrorCode (*matvec)(mv_info*,PetscScalar*,PetscScalar*),void *grid_data)
775 {
776   mv_info *mvi;
777 
778 
779   mvi = (mv_info*)malloc(sizeof(mv_info));
780   mvi->n=n;
781   mvi->m=m;
782   mvi->n_global=-1;
783   mvi->m_global=-1;
784   mvi->local2global=(PetscInt*)malloc((m+1)*sizeof(PetscInt));
785   PCTFS_ivec_copy(mvi->local2global,local2global,m);
786   mvi->local2global[m] = INT_MAX;
787   mvi->matvec=matvec;
788   mvi->grid_data=grid_data;
789 
790   /* set xxt communication handle to perform restricted matvec */
791   mvi->PCTFS_gs_handle = PCTFS_gs_init(local2global, m, PCTFS_num_nodes);
792 
793   return(mvi);
794 }
795 
796 /**************************************xxt.c***********************************/
797 static PetscErrorCode do_matvec(mv_info *A, PetscScalar *v, PetscScalar *u)
798 {
799   PetscFunctionBegin;
800   A->matvec((mv_info*)A->grid_data,v,u);
801   PetscFunctionReturn(0);
802 }
803 
804 
805 
806