xref: /petsc/src/ksp/pc/impls/tfs/xxt.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
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 PetscErrorCode xxt_generate(xxt_ADT xxt_handle);
60 static PetscErrorCode 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 PetscErrorCode 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   PetscCheckFalse((1<<(xxt_handle->level=PCTFS_i_log2_num_nodes))!=PCTFS_num_nodes,PETSC_COMM_SELF,PETSC_ERR_PLIB,"only 2^k for now and MPI_COMM_WORLD!!! %D != %D",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 PetscErrorCode 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   return do_xxt_solve(xxt_handle,x);
117 }
118 
119 /**************************************xxt.c***********************************/
120 PetscInt XXT_free(xxt_ADT xxt_handle)
121 {
122 
123   PCTFS_comm_init();
124   check_handle(xxt_handle);
125   n_xxt_handles--;
126 
127   free(xxt_handle->info->nsep);
128   free(xxt_handle->info->lnsep);
129   free(xxt_handle->info->fo);
130   free(xxt_handle->info->stages);
131   free(xxt_handle->info->solve_uu);
132   free(xxt_handle->info->solve_w);
133   free(xxt_handle->info->x);
134   free(xxt_handle->info->col_vals);
135   free(xxt_handle->info->col_sz);
136   free(xxt_handle->info->col_indices);
137   free(xxt_handle->info);
138   free(xxt_handle->mvi->local2global);
139   PCTFS_gs_free(xxt_handle->mvi->PCTFS_gs_handle);
140   free(xxt_handle->mvi);
141   free(xxt_handle);
142 
143   /* if the check fails we nuke */
144   /* if NULL pointer passed to free we nuke */
145   /* if the calls to free fail that's not my problem */
146   return(0);
147 }
148 
149 /**************************************xxt.c***********************************/
150 PetscErrorCode XXT_stats(xxt_ADT xxt_handle)
151 {
152   PetscInt       op[]  = {NON_UNIFORM,GL_MIN,GL_MAX,GL_ADD,GL_MIN,GL_MAX,GL_ADD,GL_MIN,GL_MAX,GL_ADD};
153   PetscInt       fop[] = {NON_UNIFORM,GL_MIN,GL_MAX,GL_ADD};
154   PetscInt       vals[9],  work[9];
155   PetscScalar    fvals[3], fwork[3];
156 
157   PCTFS_comm_init();
158   check_handle(xxt_handle);
159 
160   /* if factorization not done there are no stats */
161   if (!xxt_handle->info||!xxt_handle->mvi) {
162     if (!PCTFS_my_id) PetscCall(PetscPrintf(PETSC_COMM_WORLD,"XXT_stats() :: no stats available!\n"));
163     return 1;
164   }
165 
166   vals[0]=vals[1]=vals[2]=xxt_handle->info->nnz;
167   vals[3]=vals[4]=vals[5]=xxt_handle->mvi->n;
168   vals[6]=vals[7]=vals[8]=xxt_handle->info->msg_buf_sz;
169   PCTFS_giop(vals,work,sizeof(op)/sizeof(op[0])-1,op);
170 
171   fvals[0]=fvals[1]=fvals[2] =xxt_handle->info->tot_solve_time/xxt_handle->info->nsolves++;
172   PCTFS_grop(fvals,fwork,sizeof(fop)/sizeof(fop[0])-1,fop);
173 
174   if (!PCTFS_my_id) {
175     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_nnz=%D\n",PCTFS_my_id,vals[0]));
176     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_nnz=%D\n",PCTFS_my_id,vals[1]));
177     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_nnz=%g\n",PCTFS_my_id,1.0*vals[2]/PCTFS_num_nodes));
178     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: tot   xxt_nnz=%D\n",PCTFS_my_id,vals[2]));
179     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: xxt   C(2d)  =%g\n",PCTFS_my_id,vals[2]/(PetscPowReal(1.0*vals[5],1.5))));
180     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: xxt   C(3d)  =%g\n",PCTFS_my_id,vals[2]/(PetscPowReal(1.0*vals[5],1.6667))));
181     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_n  =%D\n",PCTFS_my_id,vals[3]));
182     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_n  =%D\n",PCTFS_my_id,vals[4]));
183     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_n  =%g\n",PCTFS_my_id,1.0*vals[5]/PCTFS_num_nodes));
184     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: tot   xxt_n  =%D\n",PCTFS_my_id,vals[5]));
185     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_buf=%D\n",PCTFS_my_id,vals[6]));
186     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_buf=%D\n",PCTFS_my_id,vals[7]));
187     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_buf=%g\n",PCTFS_my_id,1.0*vals[8]/PCTFS_num_nodes));
188     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: min   xxt_slv=%g\n",PCTFS_my_id,fvals[0]));
189     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: max   xxt_slv=%g\n",PCTFS_my_id,fvals[1]));
190     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"%D :: avg   xxt_slv=%g\n",PCTFS_my_id,fvals[2]/PCTFS_num_nodes));
191   }
192 
193   return(0);
194 }
195 
196 /*************************************xxt.c************************************
197 
198 Description: get A_local, local portion of global coarse matrix which
199 is a row dist. nxm matrix w/ n<m.
200    o my_ml holds address of ML struct associated w/A_local and coarse grid
201    o local2global holds global number of column i (i=0,...,m-1)
202    o local2global holds global number of row    i (i=0,...,n-1)
203    o mylocmatvec performs A_local . vec_local (note that gs is performed using
204    PCTFS_gs_init/gop).
205 
206 mylocmatvec = my_ml->Amat[grid_tag].matvec->external;
207 mylocmatvec (void :: void *data, double *in, double *out)
208 **************************************xxt.c***********************************/
209 static PetscErrorCode do_xxt_factor(xxt_ADT xxt_handle)
210 {
211   return xxt_generate(xxt_handle);
212 }
213 
214 /**************************************xxt.c***********************************/
215 static PetscErrorCode xxt_generate(xxt_ADT xxt_handle)
216 {
217   PetscInt       i,j,k,idex;
218   PetscInt       dim, col;
219   PetscScalar    *u, *uu, *v, *z, *w, alpha, alpha_w;
220   PetscInt       *segs;
221   PetscInt       op[] = {GL_ADD,0};
222   PetscInt       off, len;
223   PetscScalar    *x_ptr;
224   PetscInt       *iptr, flag;
225   PetscInt       start =0, end, work;
226   PetscInt       op2[] = {GL_MIN,0};
227   PCTFS_gs_ADT   PCTFS_gs_handle;
228   PetscInt       *nsep, *lnsep, *fo;
229   PetscInt       a_n            =xxt_handle->mvi->n;
230   PetscInt       a_m            =xxt_handle->mvi->m;
231   PetscInt       *a_local2global=xxt_handle->mvi->local2global;
232   PetscInt       level;
233   PetscInt       xxt_nnz=0, xxt_max_nnz=0;
234   PetscInt       n, m;
235   PetscInt       *col_sz, *col_indices, *stages;
236   PetscScalar    **col_vals, *x;
237   PetscInt       n_global;
238   PetscInt       xxt_zero_nnz  =0;
239   PetscInt       xxt_zero_nnz_0=0;
240   PetscBLASInt   i1            = 1,dlen;
241   PetscScalar    dm1           = -1.0;
242 
243   n               = xxt_handle->mvi->n;
244   nsep            = xxt_handle->info->nsep;
245   lnsep           = xxt_handle->info->lnsep;
246   fo              = xxt_handle->info->fo;
247   end             = lnsep[0];
248   level           = xxt_handle->level;
249   PCTFS_gs_handle = xxt_handle->mvi->PCTFS_gs_handle;
250 
251   /* is there a null space? */
252   /* LATER add in ability to detect null space by checking alpha */
253   for (i=0, j=0; i<=level; i++) j+=nsep[i];
254 
255   m = j-xxt_handle->ns;
256   if (m!=j) {
257     PetscCall(PetscPrintf(PETSC_COMM_WORLD,"xxt_generate() :: null space exists %D %D %D\n",m,j,xxt_handle->ns));
258   }
259 
260   /* get and initialize storage for x local         */
261   /* note that x local is nxm and stored by columns */
262   col_sz      = (PetscInt*) malloc(m*sizeof(PetscInt));
263   col_indices = (PetscInt*) malloc((2*m+1)*sizeof(PetscInt));
264   col_vals    = (PetscScalar**) malloc(m*sizeof(PetscScalar*));
265   for (i=j=0; i<m; i++, j+=2) {
266     col_indices[j]=col_indices[j+1]=col_sz[i]=-1;
267     col_vals[i]   = NULL;
268   }
269   col_indices[j]=-1;
270 
271   /* size of separators for each sub-hc working from bottom of tree to top */
272   /* this looks like nsep[]=segments */
273   stages = (PetscInt*) malloc((level+1)*sizeof(PetscInt));
274   segs   = (PetscInt*) malloc((level+1)*sizeof(PetscInt));
275   PCTFS_ivec_zero(stages,level+1);
276   PCTFS_ivec_copy(segs,nsep,level+1);
277   for (i=0; i<level; i++) segs[i+1] += segs[i];
278   stages[0] = segs[0];
279 
280   /* temporary vectors  */
281   u  = (PetscScalar*) malloc(n*sizeof(PetscScalar));
282   z  = (PetscScalar*) malloc(n*sizeof(PetscScalar));
283   v  = (PetscScalar*) malloc(a_m*sizeof(PetscScalar));
284   uu = (PetscScalar*) malloc(m*sizeof(PetscScalar));
285   w  = (PetscScalar*) malloc(m*sizeof(PetscScalar));
286 
287   /* extra nnz due to replication of vertices across separators */
288   for (i=1, j=0; i<=level; i++) j+=nsep[i];
289 
290   /* storage for sparse x values */
291   n_global    = xxt_handle->info->n_global;
292   xxt_max_nnz = (PetscInt)(2.5*PetscPowReal(1.0*n_global,1.6667) + j*n/2)/PCTFS_num_nodes;
293   x           = (PetscScalar*) malloc(xxt_max_nnz*sizeof(PetscScalar));
294   xxt_nnz     = 0;
295 
296   /* LATER - can embed next sep to fire in gs */
297   /* time to make the donuts - generate X factor */
298   for (dim=i=j=0; i<m; i++) {
299     /* time to move to the next level? */
300     while (i==segs[dim]) {
301       PetscCheckFalse(dim==level,PETSC_COMM_SELF,PETSC_ERR_PLIB,"dim about to exceed level");
302       stages[dim++]=i;
303       end         +=lnsep[dim];
304     }
305     stages[dim]=i;
306 
307     /* which column are we firing? */
308     /* i.e. set v_l */
309     /* use new seps and do global min across hc to determine which one to fire */
310     (start<end) ? (col=fo[start]) : (col=INT_MAX);
311     PCTFS_giop_hc(&col,&work,1,op2,dim);
312 
313     /* shouldn't need this */
314     if (col==INT_MAX) {
315       PetscCall(PetscInfo(0,"hey ... col==INT_MAX??\n"));
316       continue;
317     }
318 
319     /* do I own it? I should */
320     PCTFS_rvec_zero(v,a_m);
321     if (col==fo[start]) {
322       start++;
323       idex=PCTFS_ivec_linear_search(col, a_local2global, a_n);
324       if (idex!=-1) {
325         v[idex] = 1.0; j++;
326       } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"NOT FOUND!");
327     } else {
328       idex=PCTFS_ivec_linear_search(col, a_local2global, a_m);
329       if (idex!=-1) v[idex] = 1.0;
330     }
331 
332     /* perform u = A.v_l */
333     PCTFS_rvec_zero(u,n);
334     do_matvec(xxt_handle->mvi,v,u);
335 
336     /* uu =  X^T.u_l (local portion) */
337     /* technically only need to zero out first i entries */
338     /* later turn this into an XXT_solve call ? */
339     PCTFS_rvec_zero(uu,m);
340     x_ptr=x;
341     iptr = col_indices;
342     for (k=0; k<i; k++) {
343       off   = *iptr++;
344       len   = *iptr++;
345       PetscCall(PetscBLASIntCast(len,&dlen));
346       PetscStackCallBLAS("BLASdot",uu[k] = BLASdot_(&dlen,u+off,&i1,x_ptr,&i1));
347       x_ptr+=len;
348     }
349 
350     /* uu = X^T.u_l (comm portion) */
351     PetscCall(PCTFS_ssgl_radd  (uu, w, dim, stages));
352 
353     /* z = X.uu */
354     PCTFS_rvec_zero(z,n);
355     x_ptr=x;
356     iptr = col_indices;
357     for (k=0; k<i; k++) {
358       off  = *iptr++;
359       len  = *iptr++;
360       PetscCall(PetscBLASIntCast(len,&dlen));
361       PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&dlen,&uu[k],x_ptr,&i1,z+off,&i1));
362       x_ptr+=len;
363     }
364 
365     /* compute v_l = v_l - z */
366     PCTFS_rvec_zero(v+a_n,a_m-a_n);
367     PetscCall(PetscBLASIntCast(n,&dlen));
368     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&dlen,&dm1,z,&i1,v,&i1));
369 
370     /* compute u_l = A.v_l */
371     if (a_n!=a_m) PCTFS_gs_gop_hc(PCTFS_gs_handle,v,"+\0",dim);
372     PCTFS_rvec_zero(u,n);
373     do_matvec(xxt_handle->mvi,v,u);
374 
375     /* compute sqrt(alpha) = sqrt(v_l^T.u_l) - local portion */
376     PetscCall(PetscBLASIntCast(n,&dlen));
377     PetscStackCallBLAS("BLASdot",alpha = BLASdot_(&dlen,u,&i1,v,&i1));
378     /* compute sqrt(alpha) = sqrt(v_l^T.u_l) - comm portion */
379     PCTFS_grop_hc(&alpha, &alpha_w, 1, op, dim);
380 
381     alpha = (PetscScalar) PetscSqrtReal((PetscReal)alpha);
382 
383     /* check for small alpha                             */
384     /* LATER use this to detect and determine null space */
385     PetscCheckFalse(PetscAbsScalar(alpha)<1.0e-14,PETSC_COMM_SELF,PETSC_ERR_PLIB,"bad alpha! %g",alpha);
386 
387     /* compute v_l = v_l/sqrt(alpha) */
388     PCTFS_rvec_scale(v,1.0/alpha,n);
389 
390     /* add newly generated column, v_l, to X */
391     flag = 1;
392     off=len=0;
393     for (k=0; k<n; k++) {
394       if (v[k]!=0.0) {
395         len=k;
396         if (flag) { off=k; flag=0; }
397       }
398     }
399 
400     len -= (off-1);
401 
402     if (len>0) {
403       if ((xxt_nnz+len)>xxt_max_nnz) {
404         PetscCall(PetscInfo(0,"increasing space for X by 2x!\n"));
405         xxt_max_nnz *= 2;
406         x_ptr        = (PetscScalar*) malloc(xxt_max_nnz*sizeof(PetscScalar));
407         PCTFS_rvec_copy(x_ptr,x,xxt_nnz);
408         free(x);
409         x     = x_ptr;
410         x_ptr+=xxt_nnz;
411       }
412       xxt_nnz += len;
413       PCTFS_rvec_copy(x_ptr,v+off,len);
414 
415       /* keep track of number of zeros */
416       if (dim) {
417         for (k=0; k<len; k++) {
418           if (x_ptr[k]==0.0) xxt_zero_nnz++;
419         }
420       } else {
421         for (k=0; k<len; k++) {
422           if (x_ptr[k]==0.0) xxt_zero_nnz_0++;
423         }
424       }
425       col_indices[2*i] = off;
426       col_sz[i] = col_indices[2*i+1] = len;
427       col_vals[i] = x_ptr;
428     }
429     else {
430       col_indices[2*i] = 0;
431       col_sz[i]        = col_indices[2*i+1] = 0;
432       col_vals[i]      = x_ptr;
433     }
434   }
435 
436   /* close off stages for execution phase */
437   while (dim!=level) {
438     stages[dim++] = i;
439     PetscCall(PetscInfo(0,"disconnected!!! dim(%D)!=level(%D)\n",dim,level));
440   }
441   stages[dim]=i;
442 
443   xxt_handle->info->n              = xxt_handle->mvi->n;
444   xxt_handle->info->m              = m;
445   xxt_handle->info->nnz            = xxt_nnz;
446   xxt_handle->info->max_nnz        = xxt_max_nnz;
447   xxt_handle->info->msg_buf_sz     = stages[level]-stages[0];
448   xxt_handle->info->solve_uu       = (PetscScalar*) malloc(m*sizeof(PetscScalar));
449   xxt_handle->info->solve_w        = (PetscScalar*) malloc(m*sizeof(PetscScalar));
450   xxt_handle->info->x              = x;
451   xxt_handle->info->col_vals       = col_vals;
452   xxt_handle->info->col_sz         = col_sz;
453   xxt_handle->info->col_indices    = col_indices;
454   xxt_handle->info->stages         = stages;
455   xxt_handle->info->nsolves        = 0;
456   xxt_handle->info->tot_solve_time = 0.0;
457 
458   free(segs);
459   free(u);
460   free(v);
461   free(uu);
462   free(z);
463   free(w);
464 
465   return(0);
466 }
467 
468 /**************************************xxt.c***********************************/
469 static PetscErrorCode do_xxt_solve(xxt_ADT xxt_handle,  PetscScalar *uc)
470 {
471   PetscInt       off, len, *iptr;
472   PetscInt       level        = xxt_handle->level;
473   PetscInt       n            = xxt_handle->info->n;
474   PetscInt       m            = xxt_handle->info->m;
475   PetscInt       *stages      = xxt_handle->info->stages;
476   PetscInt       *col_indices = xxt_handle->info->col_indices;
477   PetscScalar    *x_ptr, *uu_ptr;
478   PetscScalar    *solve_uu = xxt_handle->info->solve_uu;
479   PetscScalar    *solve_w  = xxt_handle->info->solve_w;
480   PetscScalar    *x        = xxt_handle->info->x;
481   PetscBLASInt   i1        = 1,dlen;
482 
483   PetscFunctionBegin;
484   uu_ptr=solve_uu;
485   PCTFS_rvec_zero(uu_ptr,m);
486 
487   /* x  = X.Y^T.b */
488   /* uu = Y^T.b */
489   for (x_ptr=x,iptr=col_indices; *iptr!=-1; x_ptr+=len) {
490     off       =*iptr++;
491     len       =*iptr++;
492     PetscCall(PetscBLASIntCast(len,&dlen));
493     PetscStackCallBLAS("BLASdot",*uu_ptr++ = BLASdot_(&dlen,uc+off,&i1,x_ptr,&i1));
494   }
495 
496   /* comunication of beta */
497   uu_ptr=solve_uu;
498   if (level) PetscCall(PCTFS_ssgl_radd(uu_ptr, solve_w, level, stages));
499 
500   PCTFS_rvec_zero(uc,n);
501 
502   /* x = X.uu */
503   for (x_ptr=x,iptr=col_indices; *iptr!=-1; x_ptr+=len) {
504     off  =*iptr++;
505     len  =*iptr++;
506     PetscCall(PetscBLASIntCast(len,&dlen));
507     PetscStackCallBLAS("BLASaxpy",BLASaxpy_(&dlen,uu_ptr++,x_ptr,&i1,uc+off,&i1));
508   }
509   PetscFunctionReturn(0);
510 }
511 
512 /**************************************xxt.c***********************************/
513 static PetscErrorCode check_handle(xxt_ADT xxt_handle)
514 {
515   PetscInt vals[2], work[2], op[] = {NON_UNIFORM,GL_MIN,GL_MAX};
516 
517   PetscFunctionBegin;
518   PetscCheck(xxt_handle,PETSC_COMM_SELF,PETSC_ERR_PLIB,"check_handle() :: bad handle :: NULL %D",xxt_handle);
519 
520   vals[0]=vals[1]=xxt_handle->id;
521   PCTFS_giop(vals,work,sizeof(op)/sizeof(op[0])-1,op);
522   PetscCheckFalse((vals[0]!=vals[1])||(xxt_handle->id<=0),PETSC_COMM_SELF,PETSC_ERR_PLIB,"check_handle() :: bad handle :: id mismatch min/max %D/%D %D",vals[0],vals[1], xxt_handle->id);
523   PetscFunctionReturn(0);
524 }
525 
526 /**************************************xxt.c***********************************/
527 static PetscErrorCode det_separators(xxt_ADT xxt_handle)
528 {
529   PetscInt     i, ct, id;
530   PetscInt     mask, edge, *iptr;
531   PetscInt     *dir, *used;
532   PetscInt     sum[4], w[4];
533   PetscScalar  rsum[4], rw[4];
534   PetscInt     op[] = {GL_ADD,0};
535   PetscScalar  *lhs, *rhs;
536   PetscInt     *nsep, *lnsep, *fo, nfo=0;
537   PCTFS_gs_ADT PCTFS_gs_handle = xxt_handle->mvi->PCTFS_gs_handle;
538   PetscInt     *local2global   = xxt_handle->mvi->local2global;
539   PetscInt     n               = xxt_handle->mvi->n;
540   PetscInt     m               = xxt_handle->mvi->m;
541   PetscInt     level           = xxt_handle->level;
542   PetscInt     shared          = 0;
543 
544   PetscFunctionBegin;
545   dir  = (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
546   nsep = (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
547   lnsep= (PetscInt*)malloc(sizeof(PetscInt)*(level+1));
548   fo   = (PetscInt*)malloc(sizeof(PetscInt)*(n+1));
549   used = (PetscInt*)malloc(sizeof(PetscInt)*n);
550 
551   PCTFS_ivec_zero(dir,level+1);
552   PCTFS_ivec_zero(nsep,level+1);
553   PCTFS_ivec_zero(lnsep,level+1);
554   PCTFS_ivec_set (fo,-1,n+1);
555   PCTFS_ivec_zero(used,n);
556 
557   lhs = (PetscScalar*)malloc(sizeof(PetscScalar)*m);
558   rhs = (PetscScalar*)malloc(sizeof(PetscScalar)*m);
559 
560   /* determine the # of unique dof */
561   PCTFS_rvec_zero(lhs,m);
562   PCTFS_rvec_set(lhs,1.0,n);
563   PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",level);
564   PCTFS_rvec_zero(rsum,2);
565   for (i=0; i<n; i++) {
566     if (lhs[i]!=0.0) {
567       rsum[0]+=1.0/lhs[i]; rsum[1]+=lhs[i];
568     }
569   }
570   PCTFS_grop_hc(rsum,rw,2,op,level);
571   rsum[0]+=0.1;
572   rsum[1]+=0.1;
573 
574   if (PetscAbsScalar(rsum[0]-rsum[1])>EPS) shared=1;
575 
576   xxt_handle->info->n_global=xxt_handle->info->m_global=(PetscInt) rsum[0];
577   xxt_handle->mvi->n_global =xxt_handle->mvi->m_global =(PetscInt) rsum[0];
578 
579   /* determine separator sets top down */
580   if (shared) {
581     for (iptr=fo+n,id=PCTFS_my_id,mask=PCTFS_num_nodes>>1,edge=level;edge>0;edge--,mask>>=1) {
582 
583       /* set rsh of hc, fire, and collect lhs responses */
584       (id<mask) ? PCTFS_rvec_zero(lhs,m) : PCTFS_rvec_set(lhs,1.0,m);
585       PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge);
586 
587       /* set lsh of hc, fire, and collect rhs responses */
588       (id<mask) ? PCTFS_rvec_set(rhs,1.0,m) : PCTFS_rvec_zero(rhs,m);
589       PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge);
590 
591       for (i=0;i<n;i++) {
592         if (id< mask) {
593           if (lhs[i]!=0.0) lhs[i]=1.0;
594         }
595         if (id>=mask) {
596           if (rhs[i]!=0.0) rhs[i]=1.0;
597         }
598       }
599 
600       if (id< mask) PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge-1);
601       else          PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge-1);
602 
603       /* count number of dofs I own that have signal and not in sep set */
604       PCTFS_rvec_zero(rsum,4);
605       for (PCTFS_ivec_zero(sum,4),ct=i=0;i<n;i++) {
606         if (!used[i]) {
607           /* number of unmarked dofs on node */
608           ct++;
609           /* number of dofs to be marked on lhs hc */
610           if (id< mask) {
611             if (lhs[i]!=0.0) { sum[0]++; rsum[0]+=1.0/lhs[i]; }
612           }
613           /* number of dofs to be marked on rhs hc */
614           if (id>=mask) {
615             if (rhs[i]!=0.0) { sum[1]++; rsum[1]+=1.0/rhs[i]; }
616           }
617         }
618       }
619 
620       /* go for load balance - choose half with most unmarked dofs, bias LHS */
621       (id<mask) ? (sum[2]=ct) : (sum[3]=ct);
622       (id<mask) ? (rsum[2]=ct) : (rsum[3]=ct);
623       PCTFS_giop_hc(sum,w,4,op,edge);
624       PCTFS_grop_hc(rsum,rw,4,op,edge);
625       rsum[0]+=0.1; rsum[1]+=0.1; rsum[2]+=0.1; rsum[3]+=0.1;
626 
627       if (id<mask) {
628         /* mark dofs I own that have signal and not in sep set */
629         for (ct=i=0;i<n;i++) {
630           if ((!used[i])&&(lhs[i]!=0.0)) {
631             ct++; nfo++;
632 
633             PetscCheckFalse(nfo>n,PETSC_COMM_SELF,PETSC_ERR_PLIB,"nfo about to exceed n");
634 
635             *--iptr = local2global[i];
636             used[i] = edge;
637           }
638         }
639         if (ct>1) PCTFS_ivec_sort(iptr,ct);
640 
641         lnsep[edge]=ct;
642         nsep[edge]=(PetscInt) rsum[0];
643         dir [edge]=LEFT;
644       }
645 
646       if (id>=mask) {
647         /* mark dofs I own that have signal and not in sep set */
648         for (ct=i=0;i<n;i++) {
649           if ((!used[i])&&(rhs[i]!=0.0)) {
650             ct++; nfo++;
651 
652             PetscCheckFalse(nfo>n,PETSC_COMM_SELF,PETSC_ERR_PLIB,"nfo about to exceed n");
653 
654             *--iptr = local2global[i];
655             used[i] = edge;
656           }
657         }
658         if (ct>1) PCTFS_ivec_sort(iptr,ct);
659 
660         lnsep[edge] = ct;
661         nsep[edge]  = (PetscInt) rsum[1];
662         dir [edge]  = RIGHT;
663       }
664 
665       /* LATER or we can recur on these to order seps at this level */
666       /* do we need full set of separators for this?                */
667 
668       /* fold rhs hc into lower */
669       if (id>=mask) id-=mask;
670     }
671   } else {
672     for (iptr=fo+n,id=PCTFS_my_id,mask=PCTFS_num_nodes>>1,edge=level;edge>0;edge--,mask>>=1) {
673       /* set rsh of hc, fire, and collect lhs responses */
674       (id<mask) ? PCTFS_rvec_zero(lhs,m) : PCTFS_rvec_set(lhs,1.0,m);
675       PCTFS_gs_gop_hc(PCTFS_gs_handle,lhs,"+\0",edge);
676 
677       /* set lsh of hc, fire, and collect rhs responses */
678       (id<mask) ? PCTFS_rvec_set(rhs,1.0,m) : PCTFS_rvec_zero(rhs,m);
679       PCTFS_gs_gop_hc(PCTFS_gs_handle,rhs,"+\0",edge);
680 
681       /* count number of dofs I own that have signal and not in sep set */
682       for (PCTFS_ivec_zero(sum,4),ct=i=0;i<n;i++) {
683         if (!used[i]) {
684           /* number of unmarked dofs on node */
685           ct++;
686           /* number of dofs to be marked on lhs hc */
687           if ((id< mask)&&(lhs[i]!=0.0)) sum[0]++;
688           /* number of dofs to be marked on rhs hc */
689           if ((id>=mask)&&(rhs[i]!=0.0)) sum[1]++;
690         }
691       }
692 
693       /* go for load balance - choose half with most unmarked dofs, bias LHS */
694       (id<mask) ? (sum[2]=ct) : (sum[3]=ct);
695       PCTFS_giop_hc(sum,w,4,op,edge);
696 
697       /* lhs hc wins */
698       if (sum[2]>=sum[3]) {
699         if (id<mask) {
700           /* mark dofs I own that have signal and not in sep set */
701           for (ct=i=0;i<n;i++) {
702             if ((!used[i])&&(lhs[i]!=0.0)) {
703               ct++; nfo++;
704               *--iptr = local2global[i];
705               used[i]=edge;
706             }
707           }
708           if (ct>1) PCTFS_ivec_sort(iptr,ct);
709           lnsep[edge]=ct;
710         }
711         nsep[edge]=sum[0];
712         dir [edge]=LEFT;
713       } else { /* rhs hc wins */
714         if (id>=mask) {
715           /* mark dofs I own that have signal and not in sep set */
716           for (ct=i=0;i<n;i++) {
717             if ((!used[i])&&(rhs[i]!=0.0)) {
718               ct++; nfo++;
719               *--iptr = local2global[i];
720               used[i]=edge;
721             }
722           }
723           if (ct>1) PCTFS_ivec_sort(iptr,ct);
724           lnsep[edge]=ct;
725         }
726         nsep[edge]=sum[1];
727         dir [edge]=RIGHT;
728       }
729       /* LATER or we can recur on these to order seps at this level */
730       /* do we need full set of separators for this?                */
731 
732       /* fold rhs hc into lower */
733       if (id>=mask) id-=mask;
734     }
735   }
736 
737   /* level 0 is on processor case - so mark the remainder */
738   for (ct=i=0; i<n; i++) {
739     if (!used[i]) {
740       ct++; nfo++;
741       *--iptr = local2global[i];
742       used[i] = edge;
743     }
744   }
745   if (ct>1) PCTFS_ivec_sort(iptr,ct);
746   lnsep[edge]=ct;
747   nsep [edge]=ct;
748   dir  [edge]=LEFT;
749 
750   xxt_handle->info->nsep  = nsep;
751   xxt_handle->info->lnsep = lnsep;
752   xxt_handle->info->fo    = fo;
753   xxt_handle->info->nfo   = nfo;
754 
755   free(dir);
756   free(lhs);
757   free(rhs);
758   free(used);
759   PetscFunctionReturn(0);
760 }
761 
762 /**************************************xxt.c***********************************/
763 static mv_info *set_mvi(PetscInt *local2global,PetscInt n,PetscInt m,PetscErrorCode (*matvec)(mv_info*,PetscScalar*,PetscScalar*),void *grid_data)
764 {
765   mv_info *mvi;
766 
767   mvi               = (mv_info*)malloc(sizeof(mv_info));
768   mvi->n            = n;
769   mvi->m            = m;
770   mvi->n_global     = -1;
771   mvi->m_global     = -1;
772   mvi->local2global = (PetscInt*)malloc((m+1)*sizeof(PetscInt));
773   PCTFS_ivec_copy(mvi->local2global,local2global,m);
774   mvi->local2global[m] = INT_MAX;
775   mvi->matvec          = matvec;
776   mvi->grid_data       = grid_data;
777 
778   /* set xxt communication handle to perform restricted matvec */
779   mvi->PCTFS_gs_handle = PCTFS_gs_init(local2global, m, PCTFS_num_nodes);
780 
781   return(mvi);
782 }
783 
784 /**************************************xxt.c***********************************/
785 static PetscErrorCode do_matvec(mv_info *A, PetscScalar *v, PetscScalar *u)
786 {
787   PetscFunctionBegin;
788   A->matvec((mv_info*)A->grid_data,v,u);
789   PetscFunctionReturn(0);
790 }
791