xref: /petsc/src/ksp/pc/impls/tfs/xyt.c (revision d7547e516efde0cd36ffdeebcfafd4768debadcc)
1 
2 /*
3 Module Name: xyt
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 */
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 xyt_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     *xcol_sz, *xcol_indices;
30   PetscScalar **xcol_vals, *x, *solve_uu, *solve_w;
31   PetscInt     *ycol_sz, *ycol_indices;
32   PetscScalar **ycol_vals, *y;
33   PetscInt      nsolves;
34   PetscScalar   tot_solve_time;
35 } xyt_info;
36 
37 typedef struct matvec_info {
38   PetscInt     n, m, n_global, m_global;
39   PetscInt    *local2global;
40   PCTFS_gs_ADT PCTFS_gs_handle;
41   PetscErrorCode (*matvec)(struct matvec_info *, PetscScalar *, PetscScalar *);
42   void *grid_data;
43 } mv_info;
44 
45 struct xyt_CDT {
46   PetscInt  id;
47   PetscInt  ns;
48   PetscInt  level;
49   xyt_info *info;
50   mv_info  *mvi;
51 };
52 
53 static PetscInt n_xyt         = 0;
54 static PetscInt n_xyt_handles = 0;
55 
56 /* prototypes */
57 static PetscErrorCode do_xyt_solve(xyt_ADT xyt_handle, PetscScalar *rhs);
58 static PetscErrorCode check_handle(xyt_ADT xyt_handle);
59 static PetscErrorCode det_separators(xyt_ADT xyt_handle);
60 static PetscErrorCode do_matvec(mv_info *A, PetscScalar *v, PetscScalar *u);
61 static PetscErrorCode xyt_generate(xyt_ADT xyt_handle);
62 static PetscErrorCode do_xyt_factor(xyt_ADT xyt_handle);
63 static mv_info       *set_mvi(PetscInt *local2global, PetscInt n, PetscInt m, PetscErrorCode (*matvec)(mv_info *, PetscScalar *, PetscScalar *), void *grid_data);
64 
65 xyt_ADT XYT_new(void)
66 {
67   xyt_ADT xyt_handle;
68 
69   /* rolling count on n_xyt ... pot. problem here */
70   n_xyt_handles++;
71   xyt_handle       = (xyt_ADT)malloc(sizeof(struct xyt_CDT));
72   xyt_handle->id   = ++n_xyt;
73   xyt_handle->info = NULL;
74   xyt_handle->mvi  = NULL;
75 
76   return (xyt_handle);
77 }
78 
79 PetscErrorCode XYT_factor(xyt_ADT   xyt_handle,                                           /* prev. allocated xyt  handle */
80                           PetscInt *local2global,                                         /* global column mapping       */
81                           PetscInt  n,                                                    /* local num rows              */
82                           PetscInt  m,                                                    /* local num cols              */
83                           PetscErrorCode (*matvec)(void *, PetscScalar *, PetscScalar *), /* b_loc=A_local.x_loc         */
84                           void *grid_data)                                                /* grid data for matvec        */
85 {
86   PCTFS_comm_init();
87   check_handle(xyt_handle);
88 
89   /* only 2^k for now and all nodes participating */
90   PetscCheck((1 << (xyt_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);
91 
92   /* space for X info */
93   xyt_handle->info = (xyt_info *)malloc(sizeof(xyt_info));
94 
95   /* set up matvec handles */
96   xyt_handle->mvi = set_mvi(local2global, n, m, (PetscErrorCode(*)(mv_info *, PetscScalar *, PetscScalar *))matvec, grid_data);
97 
98   /* matrix is assumed to be of full rank */
99   /* LATER we can reset to indicate rank def. */
100   xyt_handle->ns = 0;
101 
102   /* determine separators and generate firing order - NB xyt info set here */
103   det_separators(xyt_handle);
104 
105   return (do_xyt_factor(xyt_handle));
106 }
107 
108 PetscErrorCode XYT_solve(xyt_ADT xyt_handle, PetscScalar *x, PetscScalar *b)
109 {
110   PCTFS_comm_init();
111   check_handle(xyt_handle);
112 
113   /* need to copy b into x? */
114   if (b) PCTFS_rvec_copy(x, b, xyt_handle->mvi->n);
115   return do_xyt_solve(xyt_handle, x);
116 }
117 
118 PetscErrorCode XYT_free(xyt_ADT xyt_handle)
119 {
120   PCTFS_comm_init();
121   check_handle(xyt_handle);
122   n_xyt_handles--;
123 
124   free(xyt_handle->info->nsep);
125   free(xyt_handle->info->lnsep);
126   free(xyt_handle->info->fo);
127   free(xyt_handle->info->stages);
128   free(xyt_handle->info->solve_uu);
129   free(xyt_handle->info->solve_w);
130   free(xyt_handle->info->x);
131   free(xyt_handle->info->xcol_vals);
132   free(xyt_handle->info->xcol_sz);
133   free(xyt_handle->info->xcol_indices);
134   free(xyt_handle->info->y);
135   free(xyt_handle->info->ycol_vals);
136   free(xyt_handle->info->ycol_sz);
137   free(xyt_handle->info->ycol_indices);
138   free(xyt_handle->info);
139   free(xyt_handle->mvi->local2global);
140   PCTFS_gs_free(xyt_handle->mvi->PCTFS_gs_handle);
141   free(xyt_handle->mvi);
142   free(xyt_handle);
143 
144   /* if the check fails we nuke */
145   /* if NULL pointer passed to free we nuke */
146   /* if the calls to free fail that's not my problem */
147   return (0);
148 }
149 
150 /* This function is currently not used */
151 PetscErrorCode XYT_stats(xyt_ADT xyt_handle)
152 {
153   PetscInt    op[]  = {NON_UNIFORM, GL_MIN, GL_MAX, GL_ADD, GL_MIN, GL_MAX, GL_ADD, GL_MIN, GL_MAX, GL_ADD};
154   PetscInt    fop[] = {NON_UNIFORM, GL_MIN, GL_MAX, GL_ADD};
155   PetscInt    vals[9], work[9];
156   PetscScalar fvals[3], fwork[3];
157 
158   PetscFunctionBegin;
159   PetscCall(PCTFS_comm_init());
160   PetscCall(check_handle(xyt_handle));
161 
162   /* if factorization not done there are no stats */
163   if (!xyt_handle->info || !xyt_handle->mvi) {
164     if (!PCTFS_my_id) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "XYT_stats() :: no stats available!\n"));
165     PetscFunctionReturn(0);
166   }
167 
168   vals[0] = vals[1] = vals[2] = xyt_handle->info->nnz;
169   vals[3] = vals[4] = vals[5] = xyt_handle->mvi->n;
170   vals[6] = vals[7] = vals[8] = xyt_handle->info->msg_buf_sz;
171   PetscCall(PCTFS_giop(vals, work, PETSC_STATIC_ARRAY_LENGTH(op) - 1, op));
172 
173   fvals[0] = fvals[1] = fvals[2] = xyt_handle->info->tot_solve_time / xyt_handle->info->nsolves++;
174   PetscCall(PCTFS_grop(fvals, fwork, PETSC_STATIC_ARRAY_LENGTH(fop) - 1, fop));
175 
176   if (!PCTFS_my_id) {
177     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: min   xyt_nnz=%" PetscInt_FMT "\n", PCTFS_my_id, vals[0]));
178     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: max   xyt_nnz=%" PetscInt_FMT "\n", PCTFS_my_id, vals[1]));
179     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: avg   xyt_nnz=%g\n", PCTFS_my_id, (double)(1.0 * vals[2] / PCTFS_num_nodes)));
180     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: tot   xyt_nnz=%" PetscInt_FMT "\n", PCTFS_my_id, vals[2]));
181     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: xyt   C(2d)  =%g\n", PCTFS_my_id, (double)(vals[2] / (PetscPowReal(1.0 * vals[5], 1.5)))));
182     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: xyt   C(3d)  =%g\n", PCTFS_my_id, (double)(vals[2] / (PetscPowReal(1.0 * vals[5], 1.6667)))));
183     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: min   xyt_n  =%" PetscInt_FMT "\n", PCTFS_my_id, vals[3]));
184     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: max   xyt_n  =%" PetscInt_FMT "\n", PCTFS_my_id, vals[4]));
185     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: avg   xyt_n  =%g\n", PCTFS_my_id, (double)(1.0 * vals[5] / PCTFS_num_nodes)));
186     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: tot   xyt_n  =%" PetscInt_FMT "\n", PCTFS_my_id, vals[5]));
187     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: min   xyt_buf=%" PetscInt_FMT "\n", PCTFS_my_id, vals[6]));
188     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: max   xyt_buf=%" PetscInt_FMT "\n", PCTFS_my_id, vals[7]));
189     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: avg   xyt_buf=%g\n", PCTFS_my_id, (double)(1.0 * vals[8] / PCTFS_num_nodes)));
190     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: min   xyt_slv=%g\n", PCTFS_my_id, (double)PetscRealPart(fvals[0])));
191     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: max   xyt_slv=%g\n", PCTFS_my_id, (double)PetscRealPart(fvals[1])));
192     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%d :: avg   xyt_slv=%g\n", PCTFS_my_id, (double)PetscRealPart(fvals[2] / PCTFS_num_nodes)));
193   }
194   PetscFunctionReturn(0);
195 }
196 
197 /*
198 
199 Description: get A_local, local portion of global coarse matrix which
200 is a row dist. nxm matrix w/ n<m.
201    o my_ml holds address of ML struct associated w/A_local and coarse grid
202    o local2global holds global number of column i (i=0,...,m-1)
203    o local2global holds global number of row    i (i=0,...,n-1)
204    o mylocmatvec performs A_local . vec_local (note that gs is performed using
205    PCTFS_gs_init/gop).
206 
207 mylocmatvec = my_ml->Amat[grid_tag].matvec->external;
208 mylocmatvec (void :: void *data, double *in, double *out)
209 */
210 static PetscErrorCode do_xyt_factor(xyt_ADT xyt_handle)
211 {
212   return xyt_generate(xyt_handle);
213 }
214 
215 static PetscErrorCode xyt_generate(xyt_ADT xyt_handle)
216 {
217   PetscInt      i, j, k, idx;
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, *y_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            = xyt_handle->mvi->n;
230   PetscInt      a_m            = xyt_handle->mvi->m;
231   PetscInt     *a_local2global = xyt_handle->mvi->local2global;
232   PetscInt      level;
233   PetscInt      n, m;
234   PetscInt     *xcol_sz, *xcol_indices, *stages;
235   PetscScalar **xcol_vals, *x;
236   PetscInt     *ycol_sz, *ycol_indices;
237   PetscScalar **ycol_vals, *y;
238   PetscInt      n_global;
239   PetscInt      xt_nnz = 0, xt_max_nnz = 0;
240   PetscInt      yt_nnz = 0, yt_max_nnz = 0;
241   PetscBLASInt  i1  = 1, dlen;
242   PetscScalar   dm1 = -1.0;
243 
244   n               = xyt_handle->mvi->n;
245   nsep            = xyt_handle->info->nsep;
246   lnsep           = xyt_handle->info->lnsep;
247   fo              = xyt_handle->info->fo;
248   end             = lnsep[0];
249   level           = xyt_handle->level;
250   PCTFS_gs_handle = xyt_handle->mvi->PCTFS_gs_handle;
251 
252   /* is there a null space? */
253   /* LATER add in ability to detect null space by checking alpha */
254   for (i = 0, j = 0; i <= level; i++) j += nsep[i];
255 
256   m = j - xyt_handle->ns;
257   if (m != j) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "xyt_generate() :: null space exists %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", m, j, xyt_handle->ns));
258 
259   PetscCall(PetscInfo(0, "xyt_generate() :: X(%" PetscInt_FMT ",%" PetscInt_FMT ")\n", n, m));
260 
261   /* get and initialize storage for x local         */
262   /* note that x local is nxm and stored by columns */
263   xcol_sz      = (PetscInt *)malloc(m * sizeof(PetscInt));
264   xcol_indices = (PetscInt *)malloc((2 * m + 1) * sizeof(PetscInt));
265   xcol_vals    = (PetscScalar **)malloc(m * sizeof(PetscScalar *));
266   for (i = j = 0; i < m; i++, j += 2) {
267     xcol_indices[j] = xcol_indices[j + 1] = xcol_sz[i] = -1;
268     xcol_vals[i]                                       = NULL;
269   }
270   xcol_indices[j] = -1;
271 
272   /* get and initialize storage for y local         */
273   /* note that y local is nxm and stored by columns */
274   ycol_sz      = (PetscInt *)malloc(m * sizeof(PetscInt));
275   ycol_indices = (PetscInt *)malloc((2 * m + 1) * sizeof(PetscInt));
276   ycol_vals    = (PetscScalar **)malloc(m * sizeof(PetscScalar *));
277   for (i = j = 0; i < m; i++, j += 2) {
278     ycol_indices[j] = ycol_indices[j + 1] = ycol_sz[i] = -1;
279     ycol_vals[i]                                       = NULL;
280   }
281   ycol_indices[j] = -1;
282 
283   /* size of separators for each sub-hc working from bottom of tree to top */
284   /* this looks like nsep[]=segments */
285   stages = (PetscInt *)malloc((level + 1) * sizeof(PetscInt));
286   segs   = (PetscInt *)malloc((level + 1) * sizeof(PetscInt));
287   PCTFS_ivec_zero(stages, level + 1);
288   PCTFS_ivec_copy(segs, nsep, level + 1);
289   for (i = 0; i < level; i++) segs[i + 1] += segs[i];
290   stages[0] = segs[0];
291 
292   /* temporary vectors  */
293   u  = (PetscScalar *)malloc(n * sizeof(PetscScalar));
294   z  = (PetscScalar *)malloc(n * sizeof(PetscScalar));
295   v  = (PetscScalar *)malloc(a_m * sizeof(PetscScalar));
296   uu = (PetscScalar *)malloc(m * sizeof(PetscScalar));
297   w  = (PetscScalar *)malloc(m * sizeof(PetscScalar));
298 
299   /* extra nnz due to replication of vertices across separators */
300   for (i = 1, j = 0; i <= level; i++) j += nsep[i];
301 
302   /* storage for sparse x values */
303   n_global   = xyt_handle->info->n_global;
304   xt_max_nnz = yt_max_nnz = (PetscInt)(2.5 * PetscPowReal(1.0 * n_global, 1.6667) + j * n / 2) / PCTFS_num_nodes;
305   x                       = (PetscScalar *)malloc(xt_max_nnz * sizeof(PetscScalar));
306   y                       = (PetscScalar *)malloc(yt_max_nnz * sizeof(PetscScalar));
307 
308   /* LATER - can embed next sep to fire in gs */
309   /* time to make the donuts - generate X factor */
310   for (dim = i = j = 0; i < m; i++) {
311     /* time to move to the next level? */
312     while (i == segs[dim]) {
313       PetscCheck(dim != level, PETSC_COMM_SELF, PETSC_ERR_PLIB, "dim about to exceed level");
314       stages[dim++] = i;
315       end += lnsep[dim];
316     }
317     stages[dim] = i;
318 
319     /* which column are we firing? */
320     /* i.e. set v_l */
321     /* use new seps and do global min across hc to determine which one to fire */
322     (start < end) ? (col = fo[start]) : (col = INT_MAX);
323     PCTFS_giop_hc(&col, &work, 1, op2, dim);
324 
325     /* shouldn't need this */
326     if (col == INT_MAX) {
327       PetscCall(PetscInfo(0, "hey ... col==INT_MAX??\n"));
328       continue;
329     }
330 
331     /* do I own it? I should */
332     PCTFS_rvec_zero(v, a_m);
333     if (col == fo[start]) {
334       start++;
335       idx = PCTFS_ivec_linear_search(col, a_local2global, a_n);
336       if (idx != -1) {
337         v[idx] = 1.0;
338         j++;
339       } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "NOT FOUND!");
340     } else {
341       idx = PCTFS_ivec_linear_search(col, a_local2global, a_m);
342       if (idx != -1) v[idx] = 1.0;
343     }
344 
345     /* perform u = A.v_l */
346     PCTFS_rvec_zero(u, n);
347     do_matvec(xyt_handle->mvi, v, u);
348 
349     /* uu =  X^T.u_l (local portion) */
350     /* technically only need to zero out first i entries */
351     /* later turn this into an XYT_solve call ? */
352     PCTFS_rvec_zero(uu, m);
353     y_ptr = y;
354     iptr  = ycol_indices;
355     for (k = 0; k < i; k++) {
356       off = *iptr++;
357       len = *iptr++;
358       PetscCall(PetscBLASIntCast(len, &dlen));
359       PetscCallBLAS("BLASdot", uu[k] = BLASdot_(&dlen, u + off, &i1, y_ptr, &i1));
360       y_ptr += len;
361     }
362 
363     /* uu = X^T.u_l (comm portion) */
364     PetscCall(PCTFS_ssgl_radd(uu, w, dim, stages));
365 
366     /* z = X.uu */
367     PCTFS_rvec_zero(z, n);
368     x_ptr = x;
369     iptr  = xcol_indices;
370     for (k = 0; k < i; k++) {
371       off = *iptr++;
372       len = *iptr++;
373       PetscCall(PetscBLASIntCast(len, &dlen));
374       PetscCallBLAS("BLASaxpy", BLASaxpy_(&dlen, &uu[k], x_ptr, &i1, z + off, &i1));
375       x_ptr += len;
376     }
377 
378     /* compute v_l = v_l - z */
379     PCTFS_rvec_zero(v + a_n, a_m - a_n);
380     PetscCall(PetscBLASIntCast(n, &dlen));
381     PetscCallBLAS("BLASaxpy", BLASaxpy_(&dlen, &dm1, z, &i1, v, &i1));
382 
383     /* compute u_l = A.v_l */
384     if (a_n != a_m) PCTFS_gs_gop_hc(PCTFS_gs_handle, v, "+\0", dim);
385     PCTFS_rvec_zero(u, n);
386     do_matvec(xyt_handle->mvi, v, u);
387 
388     /* compute sqrt(alpha) = sqrt(u_l^T.u_l) - local portion */
389     PetscCall(PetscBLASIntCast(n, &dlen));
390     PetscCallBLAS("BLASdot", alpha = BLASdot_(&dlen, u, &i1, u, &i1));
391     /* compute sqrt(alpha) = sqrt(u_l^T.u_l) - comm portion */
392     PCTFS_grop_hc(&alpha, &alpha_w, 1, op, dim);
393 
394     alpha = (PetscScalar)PetscSqrtReal((PetscReal)alpha);
395 
396     /* check for small alpha                             */
397     /* LATER use this to detect and determine null space */
398     PetscCheck(PetscAbsScalar(alpha) >= 1.0e-14, PETSC_COMM_SELF, PETSC_ERR_PLIB, "bad alpha! %g", (double)PetscAbsScalar(alpha));
399 
400     /* compute v_l = v_l/sqrt(alpha) */
401     PCTFS_rvec_scale(v, 1.0 / alpha, n);
402     PCTFS_rvec_scale(u, 1.0 / alpha, n);
403 
404     /* add newly generated column, v_l, to X */
405     flag = 1;
406     off = len = 0;
407     for (k = 0; k < n; k++) {
408       if (v[k] != 0.0) {
409         len = k;
410         if (flag) {
411           off  = k;
412           flag = 0;
413         }
414       }
415     }
416 
417     len -= (off - 1);
418 
419     if (len > 0) {
420       if ((xt_nnz + len) > xt_max_nnz) {
421         PetscCall(PetscInfo(0, "increasing space for X by 2x!\n"));
422         xt_max_nnz *= 2;
423         x_ptr = (PetscScalar *)malloc(xt_max_nnz * sizeof(PetscScalar));
424         PCTFS_rvec_copy(x_ptr, x, xt_nnz);
425         free(x);
426         x = x_ptr;
427         x_ptr += xt_nnz;
428       }
429       xt_nnz += len;
430       PCTFS_rvec_copy(x_ptr, v + off, len);
431 
432       xcol_indices[2 * i] = off;
433       xcol_sz[i] = xcol_indices[2 * i + 1] = len;
434       xcol_vals[i]                         = x_ptr;
435     } else {
436       xcol_indices[2 * i] = 0;
437       xcol_sz[i] = xcol_indices[2 * i + 1] = 0;
438       xcol_vals[i]                         = x_ptr;
439     }
440 
441     /* add newly generated column, u_l, to Y */
442     flag = 1;
443     off = len = 0;
444     for (k = 0; k < n; k++) {
445       if (u[k] != 0.0) {
446         len = k;
447         if (flag) {
448           off  = k;
449           flag = 0;
450         }
451       }
452     }
453 
454     len -= (off - 1);
455 
456     if (len > 0) {
457       if ((yt_nnz + len) > yt_max_nnz) {
458         PetscCall(PetscInfo(0, "increasing space for Y by 2x!\n"));
459         yt_max_nnz *= 2;
460         y_ptr = (PetscScalar *)malloc(yt_max_nnz * sizeof(PetscScalar));
461         PCTFS_rvec_copy(y_ptr, y, yt_nnz);
462         free(y);
463         y = y_ptr;
464         y_ptr += yt_nnz;
465       }
466       yt_nnz += len;
467       PCTFS_rvec_copy(y_ptr, u + off, len);
468 
469       ycol_indices[2 * i] = off;
470       ycol_sz[i] = ycol_indices[2 * i + 1] = len;
471       ycol_vals[i]                         = y_ptr;
472     } else {
473       ycol_indices[2 * i] = 0;
474       ycol_sz[i] = ycol_indices[2 * i + 1] = 0;
475       ycol_vals[i]                         = y_ptr;
476     }
477   }
478 
479   /* close off stages for execution phase */
480   while (dim != level) {
481     stages[dim++] = i;
482     PetscCall(PetscInfo(0, "disconnected!!! dim(%" PetscInt_FMT ")!=level(%" PetscInt_FMT ")\n", dim, level));
483   }
484   stages[dim] = i;
485 
486   xyt_handle->info->n            = xyt_handle->mvi->n;
487   xyt_handle->info->m            = m;
488   xyt_handle->info->nnz          = xt_nnz + yt_nnz;
489   xyt_handle->info->max_nnz      = xt_max_nnz + yt_max_nnz;
490   xyt_handle->info->msg_buf_sz   = stages[level] - stages[0];
491   xyt_handle->info->solve_uu     = (PetscScalar *)malloc(m * sizeof(PetscScalar));
492   xyt_handle->info->solve_w      = (PetscScalar *)malloc(m * sizeof(PetscScalar));
493   xyt_handle->info->x            = x;
494   xyt_handle->info->xcol_vals    = xcol_vals;
495   xyt_handle->info->xcol_sz      = xcol_sz;
496   xyt_handle->info->xcol_indices = xcol_indices;
497   xyt_handle->info->stages       = stages;
498   xyt_handle->info->y            = y;
499   xyt_handle->info->ycol_vals    = ycol_vals;
500   xyt_handle->info->ycol_sz      = ycol_sz;
501   xyt_handle->info->ycol_indices = ycol_indices;
502 
503   free(segs);
504   free(u);
505   free(v);
506   free(uu);
507   free(z);
508   free(w);
509 
510   return (0);
511 }
512 
513 static PetscErrorCode do_xyt_solve(xyt_ADT xyt_handle, PetscScalar *uc)
514 {
515   PetscInt     off, len, *iptr;
516   PetscInt     level        = xyt_handle->level;
517   PetscInt     n            = xyt_handle->info->n;
518   PetscInt     m            = xyt_handle->info->m;
519   PetscInt    *stages       = xyt_handle->info->stages;
520   PetscInt    *xcol_indices = xyt_handle->info->xcol_indices;
521   PetscInt    *ycol_indices = xyt_handle->info->ycol_indices;
522   PetscScalar *x_ptr, *y_ptr, *uu_ptr;
523   PetscScalar *solve_uu = xyt_handle->info->solve_uu;
524   PetscScalar *solve_w  = xyt_handle->info->solve_w;
525   PetscScalar *x        = xyt_handle->info->x;
526   PetscScalar *y        = xyt_handle->info->y;
527   PetscBLASInt i1       = 1, dlen;
528 
529   PetscFunctionBegin;
530   uu_ptr = solve_uu;
531   PCTFS_rvec_zero(uu_ptr, m);
532 
533   /* x  = X.Y^T.b */
534   /* uu = Y^T.b */
535   for (y_ptr = y, iptr = ycol_indices; *iptr != -1; y_ptr += len) {
536     off = *iptr++;
537     len = *iptr++;
538     PetscCall(PetscBLASIntCast(len, &dlen));
539     PetscCallBLAS("BLASdot", *uu_ptr++ = BLASdot_(&dlen, uc + off, &i1, y_ptr, &i1));
540   }
541 
542   /* communication of beta */
543   uu_ptr = solve_uu;
544   if (level) PetscCall(PCTFS_ssgl_radd(uu_ptr, solve_w, level, stages));
545   PCTFS_rvec_zero(uc, n);
546 
547   /* x = X.uu */
548   for (x_ptr = x, iptr = xcol_indices; *iptr != -1; x_ptr += len) {
549     off = *iptr++;
550     len = *iptr++;
551     PetscCall(PetscBLASIntCast(len, &dlen));
552     PetscCallBLAS("BLASaxpy", BLASaxpy_(&dlen, uu_ptr++, x_ptr, &i1, uc + off, &i1));
553   }
554   PetscFunctionReturn(0);
555 }
556 
557 static PetscErrorCode check_handle(xyt_ADT xyt_handle)
558 {
559   PetscInt vals[2], work[2], op[] = {NON_UNIFORM, GL_MIN, GL_MAX};
560 
561   PetscFunctionBegin;
562   PetscCheck(xyt_handle, PETSC_COMM_SELF, PETSC_ERR_PLIB, "check_handle() :: bad handle :: NULL %p", (void *)xyt_handle);
563 
564   vals[0] = vals[1] = xyt_handle->id;
565   PCTFS_giop(vals, work, PETSC_STATIC_ARRAY_LENGTH(op) - 1, op);
566   PetscCheck(!(vals[0] != vals[1]) && !(xyt_handle->id <= 0), PETSC_COMM_SELF, PETSC_ERR_PLIB, "check_handle() :: bad handle :: id mismatch min/max %" PetscInt_FMT "/%" PetscInt_FMT " %" PetscInt_FMT, vals[0], vals[1], xyt_handle->id);
567   PetscFunctionReturn(0);
568 }
569 
570 static PetscErrorCode det_separators(xyt_ADT xyt_handle)
571 {
572   PetscInt     i, ct, id;
573   PetscInt     mask, edge, *iptr;
574   PetscInt    *dir, *used;
575   PetscInt     sum[4], w[4];
576   PetscScalar  rsum[4], rw[4];
577   PetscInt     op[] = {GL_ADD, 0};
578   PetscScalar *lhs, *rhs;
579   PetscInt    *nsep, *lnsep, *fo, nfo = 0;
580   PCTFS_gs_ADT PCTFS_gs_handle = xyt_handle->mvi->PCTFS_gs_handle;
581   PetscInt    *local2global    = xyt_handle->mvi->local2global;
582   PetscInt     n               = xyt_handle->mvi->n;
583   PetscInt     m               = xyt_handle->mvi->m;
584   PetscInt     level           = xyt_handle->level;
585   PetscInt     shared          = 0;
586 
587   PetscFunctionBegin;
588   dir   = (PetscInt *)malloc(sizeof(PetscInt) * (level + 1));
589   nsep  = (PetscInt *)malloc(sizeof(PetscInt) * (level + 1));
590   lnsep = (PetscInt *)malloc(sizeof(PetscInt) * (level + 1));
591   fo    = (PetscInt *)malloc(sizeof(PetscInt) * (n + 1));
592   used  = (PetscInt *)malloc(sizeof(PetscInt) * n);
593 
594   PCTFS_ivec_zero(dir, level + 1);
595   PCTFS_ivec_zero(nsep, level + 1);
596   PCTFS_ivec_zero(lnsep, level + 1);
597   PCTFS_ivec_set(fo, -1, n + 1);
598   PCTFS_ivec_zero(used, n);
599 
600   lhs = (PetscScalar *)malloc(sizeof(PetscScalar) * m);
601   rhs = (PetscScalar *)malloc(sizeof(PetscScalar) * m);
602 
603   /* determine the # of unique dof */
604   PCTFS_rvec_zero(lhs, m);
605   PCTFS_rvec_set(lhs, 1.0, n);
606   PCTFS_gs_gop_hc(PCTFS_gs_handle, lhs, "+\0", level);
607   PetscCall(PetscInfo(0, "done first PCTFS_gs_gop_hc\n"));
608   PCTFS_rvec_zero(rsum, 2);
609   for (i = 0; i < n; i++) {
610     if (lhs[i] != 0.0) {
611       rsum[0] += 1.0 / lhs[i];
612       rsum[1] += lhs[i];
613     }
614     if (lhs[i] != 1.0) shared = 1;
615   }
616 
617   PCTFS_grop_hc(rsum, rw, 2, op, level);
618   rsum[0] += 0.1;
619   rsum[1] += 0.1;
620 
621   xyt_handle->info->n_global = xyt_handle->info->m_global = (PetscInt)rsum[0];
622   xyt_handle->mvi->n_global = xyt_handle->mvi->m_global = (PetscInt)rsum[0];
623 
624   /* determine separator sets top down */
625   if (shared) {
626     /* solution is to do as in the symmetric shared case but then */
627     /* pick the sub-hc with the most free dofs and do a mat-vec   */
628     /* and pick up the responses on the other sub-hc from the     */
629     /* initial separator set obtained from the symm. shared case  */
630     SETERRQ(PETSC_COMM_SELF, PETSC_ERR_PLIB, "shared dof separator determination not ready ... see hmt!!!");
631     /* [dead code deleted since it is unlikely to be completed] */
632   } else {
633     for (iptr = fo + n, id = PCTFS_my_id, mask = PCTFS_num_nodes >> 1, edge = level; edge > 0; edge--, mask >>= 1) {
634       /* set rsh of hc, fire, and collect lhs responses */
635       (id < mask) ? PCTFS_rvec_zero(lhs, m) : PCTFS_rvec_set(lhs, 1.0, m);
636       PCTFS_gs_gop_hc(PCTFS_gs_handle, lhs, "+\0", edge);
637 
638       /* set lsh of hc, fire, and collect rhs responses */
639       (id < mask) ? PCTFS_rvec_set(rhs, 1.0, m) : PCTFS_rvec_zero(rhs, m);
640       PCTFS_gs_gop_hc(PCTFS_gs_handle, rhs, "+\0", edge);
641 
642       /* count number of dofs I own that have signal and not in sep set */
643       for (PCTFS_ivec_zero(sum, 4), ct = i = 0; i < n; i++) {
644         if (!used[i]) {
645           /* number of unmarked dofs on node */
646           ct++;
647           /* number of dofs to be marked on lhs hc */
648           if ((id < mask) && (lhs[i] != 0.0)) sum[0]++;
649           /* number of dofs to be marked on rhs hc */
650           if ((id >= mask) && (rhs[i] != 0.0)) sum[1]++;
651         }
652       }
653 
654       /* for the non-symmetric case we need separators of width 2 */
655       /* so take both sides */
656       (id < mask) ? (sum[2] = ct) : (sum[3] = ct);
657       PCTFS_giop_hc(sum, w, 4, op, edge);
658 
659       ct = 0;
660       if (id < mask) {
661         /* mark dofs I own that have signal and not in sep set */
662         for (i = 0; i < n; i++) {
663           if ((!used[i]) && (lhs[i] != 0.0)) {
664             ct++;
665             nfo++;
666             *--iptr = local2global[i];
667             used[i] = edge;
668           }
669         }
670         /* LSH hc summation of ct should be sum[0] */
671       } else {
672         /* mark dofs I own that have signal and not in sep set */
673         for (i = 0; i < n; i++) {
674           if ((!used[i]) && (rhs[i] != 0.0)) {
675             ct++;
676             nfo++;
677             *--iptr = local2global[i];
678             used[i] = edge;
679           }
680         }
681         /* RSH hc summation of ct should be sum[1] */
682       }
683 
684       if (ct > 1) PCTFS_ivec_sort(iptr, ct);
685       lnsep[edge] = ct;
686       nsep[edge]  = sum[0] + sum[1];
687       dir[edge]   = BOTH;
688 
689       /* LATER or we can recur on these to order seps at this level */
690       /* do we need full set of separators for this?                */
691 
692       /* fold rhs hc into lower */
693       if (id >= mask) id -= mask;
694     }
695   }
696 
697   /* level 0 is on processor case - so mark the remainder */
698   for (ct = i = 0; i < n; i++) {
699     if (!used[i]) {
700       ct++;
701       nfo++;
702       *--iptr = local2global[i];
703       used[i] = edge;
704     }
705   }
706   if (ct > 1) PCTFS_ivec_sort(iptr, ct);
707   lnsep[edge] = ct;
708   nsep[edge]  = ct;
709   dir[edge]   = BOTH;
710 
711   xyt_handle->info->nsep  = nsep;
712   xyt_handle->info->lnsep = lnsep;
713   xyt_handle->info->fo    = fo;
714   xyt_handle->info->nfo   = nfo;
715 
716   free(dir);
717   free(lhs);
718   free(rhs);
719   free(used);
720   PetscFunctionReturn(0);
721 }
722 
723 static mv_info *set_mvi(PetscInt *local2global, PetscInt n, PetscInt m, PetscErrorCode (*matvec)(mv_info *, PetscScalar *, PetscScalar *), void *grid_data)
724 {
725   mv_info *mvi;
726 
727   mvi               = (mv_info *)malloc(sizeof(mv_info));
728   mvi->n            = n;
729   mvi->m            = m;
730   mvi->n_global     = -1;
731   mvi->m_global     = -1;
732   mvi->local2global = (PetscInt *)malloc((m + 1) * sizeof(PetscInt));
733 
734   PCTFS_ivec_copy(mvi->local2global, local2global, m);
735   mvi->local2global[m] = INT_MAX;
736   mvi->matvec          = matvec;
737   mvi->grid_data       = grid_data;
738 
739   /* set xyt communication handle to perform restricted matvec */
740   mvi->PCTFS_gs_handle = PCTFS_gs_init(local2global, m, PCTFS_num_nodes);
741 
742   return (mvi);
743 }
744 
745 static PetscErrorCode do_matvec(mv_info *A, PetscScalar *v, PetscScalar *u)
746 {
747   PetscFunctionBegin;
748   A->matvec((mv_info *)A->grid_data, v, u);
749   PetscFunctionReturn(0);
750 }
751