nsz Git - libfirm/blob - ir/be/becopyilp1.c

   1 /**
   2  * Author:      Daniel Grund
   3  * Date:                17.05.2005
   4  * Copyright:   (c) Universitaet Karlsruhe
   5  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
   6  * CVS-ID:      $Id$
   7  *
   8  * ILP formalization using:
   9  *  - 2 classes of vars: Nodes- and optimality variables.
  10  *  - Clique constraints
  11  *  - Path constraints
  12  *  - Clique path constraints
  13  */
  14
  15 #include "becopyilp_t.h"
  16 #include "benumb_t.h"
  17 #include "belive_t.h"
  18 #include "irdom_t.h"
  19 #include "irgwalk.h"
  20
  21 #define PATH_CONSTRAINTS_FOR_CLASSES
  22 #undef PRECOLOR_MAX_CLIQUE
  23 #undef NO_NULL_COLORS
  24 #undef NO_NULL_COLORS_EXTRA_CSTS
  25 #undef NO_NULL_COLORS_WITH_COSTS
  26 #if (defined(NO_NULL_COLORS_EXTRA_CSTS) || defined(NO_NULL_COLORS_WITH_COSTS)) && !defined(NO_NULL_COLORS)
  27 #error Chose your weapon!
  28 #endif
  29
  30 #undef DUMP_MPS
  31 static firm_dbg_module_t *dbg = NULL;
  32 #define SLOTS_LIVING 32
  33
  34
  35
  36 typedef struct _simpl_t {
  37         struct list_head chain;
  38         ir_node *irn;
  39 } simpl_t;
  40
  41 typedef struct _problem_instance_t {
  42         const copy_opt_t *co;                   /** the copy_opt problem */
  43         /* problem size reduction removing simple nodes */
  44         struct list_head simplicials;   /**< holds all simpl_t's in right order to color*/
  45         pset *removed;                                  /**< holds all removed simplicial irns */
  46         /* lp problem */
  47         lpp_t *curr_lp;                                 /**< points to the problem currently used */
  48         lpp_t *dilp;                                    /**< problem formulation directly as milp */
  49 #ifdef NO_NULL_COLORS_EXTRA_CSTS
  50         int first_nnc_cst_idx;                  /**< the first index of a constraint belonging to no-null-colors stuff*/
  51 #endif
  52         int first_nnc_var_idx;                  /**< the first index of a constraint belonging to no-null-colors stuff*/
  53
  54         int cst_counter, first_x_var, last_x_var;
  55         char buf[32];
  56         int all_simplicial;
  57         pset *done;
  58 } problem_instance_t;
  59
  60 #define is_removed(irn) pset_find_ptr(pi->removed, irn)
  61
  62 #define is_color_possible(irn,color) arch_reg_is_allocatable(pi->co->aenv, irn, -1, arch_register_for_index(pi->co->cls, color))
  63
  64 /*
  65  * Some stuff for variable name handling.
  66  */
  67 #define mangle_cst(buf, prefix, nr) \
  68                         snprintf((buf), sizeof(buf), "%c%d", (prefix), (nr))
  69
  70 #define mangle_var1(buf, prefix, color) \
  71                         snprintf((buf), sizeof(buf), "%c%d", (prefix), (color))
  72
  73 #define mangle_var2(buf, prefix, node_nr, color) \
  74                         snprintf((buf), sizeof(buf), "%c%d_%d", (prefix), (node_nr), (color))
  75
  76 #define mangle_var3(buf, prefix, n1, n2, col) \
  77                         snprintf((buf), sizeof(buf), "%c%d_%d_%d", (prefix), (n1), (n2), (col))
  78
  79 #define mangle_var_irn(buf, prefix, irn, color) \
  80                         mangle_var2((buf), (prefix), get_irn_graph_nr(irn), (color))
  81
  82 #define split_var(var, nnr, col) \
  83                         sscanf(var, "x%d_%d", (nnr), (col))
  84
  85
  86 /**
  87  * Checks if a node is simplicial in the graph
  88  * heeding the already removed nodes.
  89  */
  90 static INLINE int pi_is_simplicial(problem_instance_t *pi, const ir_node *ifn) {
  91         int i, o, size = 0;
  92         ir_node **all, *curr;
  93         be_ifg_t *ifg = pi->co->cenv->ifg;
  94         void *iter = be_ifg_neighbours_iter_alloca(ifg);
  95
  96         all = alloca(be_ifg_degree(ifg, ifn) * sizeof(*all));
  97
  98         /* get all non-removed neighbors */
  99         be_ifg_foreach_neighbour(ifg, iter, ifn, curr)
 100                 if (!is_removed(curr))
 101                         all[size++] = curr;
 102
 103         /* check if these form a clique */
 104         for (i=0; i<size; ++i)
 105                 for (o=i+1; o<size; ++o)
 106                         if (!be_ifg_connected(ifg, all[i], all[o]))
 107                                 return 0;
 108
 109         /* all edges exist so this is a clique */
 110         return 1;
 111 }
 112
 113 static int irn_cmp(const void *a, const void *b, size_t n)
 114 {
 115         return a != b;
 116 }
 117
 118 /**
 119  * Iterative finds and 'removes' from the graph all nodes which are
 120  * simplicial AND not member of a equal-color-wish
 121  */
 122 static void pi_find_simplicials(problem_instance_t *pi) {
 123         ir_node *irn;
 124         int redo = 1;
 125         int n_nodes = 0;
 126         const be_ifg_t *ifg = pi->co->cenv->ifg;
 127         void *iter = be_ifg_neighbours_iter_alloca(ifg);
 128
 129         DBG((dbg, LEVEL_2, "Find simlicials...\n"));
 130
 131         while (redo) {
 132                 arch_register_req_t req;
 133                 redo = 0;
 134                 be_ifg_foreach_node(ifg, iter, irn) {
 135                         if (!is_removed(irn) && !co_is_optimizable(pi->co->aenv, irn, &req) && !co_is_optimizable_arg(pi->co, irn)) {
 136                         if (pi_is_simplicial(pi, irn)) {
 137                                         simpl_t *s = xmalloc(sizeof(*s));
 138                                         s->irn = irn;
 139                                         list_add(&s->chain, &pi->simplicials);
 140                                         pset_insert_ptr(pi->removed, irn);
 141                                         redo = 1;
 142                                         DBG((dbg, LEVEL_2, " Removed %+F\n", irn));
 143                         }
 144                         }
 145                 }
 146         }
 147
 148         /* TODO: Count inside the last look */
 149         be_ifg_foreach_node(ifg, iter, irn) {
 150                 n_nodes++;
 151         }
 152
 153         if (n_nodes == pset_count(pi->removed))
 154                 pi->all_simplicial = 1;
 155 }
 156
 157 #ifdef NO_NULL_COLORS
 158 static void pi_add_constr_no_null_colors(problem_instance_t *pi) {
 159         int cst_counter=0, col, var_idx, cst_idx;
 160         int n_colors = pi->co->chordal_env->cls->n_regs;
 161         char buf[40];
 162
 163         for (col = 0; col < n_colors; ++col) {
 164                 mangle_var1(buf, 'u', col);
 165 #ifdef NO_NULL_COLORS_WITH_COSTS
 166                 var_idx = lpp_add_var(pi->curr_lp, buf, lpp_binary, 1.0 / (double) (1 << (col+1)) );
 167 #else
 168                 var_idx = lpp_add_var(pi->curr_lp, buf, lpp_binary, 1.0 / (2.0 * n_colors) );
 169 #endif
 170                 if (!pi->first_nnc_var_idx)
 171                         pi->first_nnc_var_idx = var_idx;
 172         }
 173
 174 #ifdef NO_NULL_COLORS_EXTRA_CSTS
 175         for (col = 0; col < n_colors; ++col) {
 176                 mangle_cst(buf, 'U', cst_counter++);
 177                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_greater, 0);
 178                 if (!pi->first_nnc_cst_idx)
 179                         pi->first_nnc_cst_idx = cst_idx;
 180                 lpp_set_factor_fast(pi->curr_lp, cst_idx, pi->first_nnc_var_idx+col, -1);
 181         }
 182 #endif
 183
 184 #ifndef NO_NULL_COLORS_WITH_COSTS
 185         for (col = 0; col < n_colors - 1; ++col) {
 186                 mangle_cst(buf, 'U', cst_counter++);
 187                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_greater, 0);
 188                 lpp_set_factor_fast(pi->curr_lp, cst_idx, pi->first_nnc_var_idx+col  ,  1);
 189                 lpp_set_factor_fast(pi->curr_lp, cst_idx, pi->first_nnc_var_idx+col+1, -1);
 190         }
 191 #endif
 192
 193 }
 194 #endif
 195
 196 /**
 197  * Add coloring-force conditions
 198  * Matrix A: knapsack constraint for each node
 199  */
 200 static void pi_add_constr_A(problem_instance_t *pi) {
 201         pmap_entry *pme;
 202
 203         DBG((dbg, LEVEL_2, "Add A constraints...\n"));
 204         /* iterate over all blocks */
 205         pmap_foreach(pi->co->cenv->border_heads, pme) {
 206                 struct list_head *head = pme->value;
 207                 border_t *curr;
 208                 bitset_t *pos_regs = bitset_alloca(pi->co->cenv->cls->n_regs);
 209
 210                 list_for_each_entry_reverse(border_t, curr, head, list)
 211                         if (curr->is_def && curr->is_real && !is_removed(curr->irn)) {
 212                                 int cst_idx, nnr, col;
 213
 214                                 nnr = get_irn_graph_nr(curr->irn);
 215                                 mangle_cst(pi->buf, 'A', nnr);
 216                                 cst_idx = lpp_add_cst(pi->curr_lp, pi->buf, lpp_equal, 1);
 217
 218                                 /* iterate over all possible colors in order */
 219                                 bitset_clear_all(pos_regs);
 220                                 arch_get_allocatable_regs(pi->co->aenv, curr->irn, -1, pos_regs);
 221                                 bitset_foreach(pos_regs, col) {
 222                                         int var_idx;
 223                                         mangle_var2(pi->buf, 'x', nnr, col);
 224                                         var_idx = lpp_add_var(pi->curr_lp, pi->buf, lpp_binary, 0);
 225                                         if (!pi->first_x_var)
 226                                                 pi->first_x_var = var_idx;
 227                                         pi->last_x_var = var_idx;
 228                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, var_idx, 1);
 229 #ifdef NO_NULL_COLORS_EXTRA_CSTS
 230                                         lpp_set_factor_fast(pi->curr_lp, pi->first_nnc_cst_idx+col, var_idx, 1);
 231 #endif
 232                                 }
 233                         }
 234         }
 235 }
 236
 237 /**
 238  * Checks if all nodes in @p living are live in in block @p block.
 239  * @return 1 if all are live in
 240  *         0 else
 241  */
 242 static INLINE int all_live_in(ir_node *block, pset *living) {
 243         ir_node *n;
 244         for (n = pset_first(living); n; n = pset_next(living))
 245                 if (!is_live_in(block, n)) {
 246                         pset_break(living);
 247                         return 0;
 248                 }
 249         return 1;
 250 }
 251
 252 /**
 253  * Finds cliques in the interference graph, considering only nodes
 254  * for which the color @p color is possible. Finds only 'maximal-cliques',
 255  * viz cliques which are not contained in another one.
 256  * Matrix B: interference constraints using cliques
 257  */
 258 static void pi_add_constr_B(problem_instance_t *pi, int color) {
 259         enum phase_t {growing, shrinking} phase = growing;
 260         border_t *b;
 261         pmap_entry *pme;
 262         pset *living = pset_new_ptr(SLOTS_LIVING);
 263
 264         DBG((dbg, LEVEL_2, "Add B constraints (col = %d)...\n", color));
 265         /* iterate over all blocks */
 266         pmap_foreach(pi->co->cenv->border_heads, pme) {
 267                 ir_node *block = pme->key;
 268                 struct list_head *head = pme->value;
 269
 270                 list_for_each_entry_reverse(border_t, b, head, list) {
 271                         const ir_node *irn = b->irn;
 272                         if (is_removed(irn) || !is_color_possible(irn, color))
 273                                 continue;
 274
 275                         if (b->is_def) {
 276                                 DBG((dbg, LEVEL_2, "Def %n\n", irn));
 277                                 pset_insert_ptr(living, irn);
 278                                 phase = growing;
 279                         } else { /* is_use */
 280                                 DBG((dbg, LEVEL_2, "Use %n\n", irn));
 281
 282                                 /* before shrinking the set, store the current 'maximum' clique;
 283                                  * do NOT if clique is a single node
 284                                  * do NOT if all values are live_in (in this case they were contained in a live-out clique elsewhere) */
 285                                 if (phase == growing && pset_count(living) >= 2 && !all_live_in(block, living)) {
 286                                         int cst_idx;
 287                                         ir_node *n;
 288                                         mangle_cst(pi->buf, 'B', pi->cst_counter);
 289 #ifdef NO_NULL_COLORS
 290                                         cst_idx = lpp_add_cst(pi->curr_lp, pi->buf, lpp_less, 0);
 291 #else
 292                                         cst_idx = lpp_add_cst(pi->curr_lp, pi->buf, lpp_less, 1);
 293 #endif
 294                                         for (n = pset_first(living); n; n = pset_next(living)) {
 295                                                 int var_idx;
 296                                                 mangle_var_irn(pi->buf, 'x', n, color);
 297                                                 var_idx = lpp_get_var_idx(pi->curr_lp, pi->buf);
 298                                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, var_idx, 1);
 299                                         }
 300 #ifdef NO_NULL_COLORS
 301                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, pi->first_nnc_var_idx+color, -1.0);
 302 #endif
 303                                         pi->cst_counter++;
 304                                 }
 305                                 pset_remove_ptr(living, irn);
 306                                 phase = shrinking;
 307                         }
 308                 }
 309         }
 310         assert(0 == pset_count(living));
 311         del_pset(living);
 312 }
 313
 314 /**
 315  * Generates constraints which interrelate x with y variables.
 316  * x1 and x2 have the different colors ==> y_12 = 1
 317  */
 318 static void pi_add_constr_E(problem_instance_t *pi) {
 319         unit_t *curr;
 320         bitset_t *root_regs, *arg_regs, *work_regs;
 321         int cst_counter = 0;
 322         unsigned nregs = pi->co->cenv->cls->n_regs;
 323         root_regs = bitset_alloca(nregs);
 324         arg_regs = bitset_alloca(nregs);
 325         work_regs = bitset_alloca(nregs);
 326
 327         DBG((dbg, LEVEL_2, "Add E constraints...\n"));
 328         /* for all roots of optimization units */
 329         list_for_each_entry(unit_t, curr, &pi->co->units, units) {
 330                 ir_node *root, *arg;
 331                 int rootnr, argnr, color;
 332                 int y_idx, i;
 333                 char buf[32];
 334
 335                 root = curr->nodes[0];
 336                 rootnr = get_irn_graph_nr(root);
 337                 bitset_clear_all(root_regs);
 338                 arch_get_allocatable_regs(pi->co->aenv, root, -1, root_regs);
 339
 340                 /* for all arguments of root */
 341                 for (i = 1; i < curr->node_count; ++i) {
 342                         arg = curr->nodes[i];
 343                         argnr = get_irn_graph_nr(arg);
 344                         bitset_clear_all(arg_regs);
 345                         arch_get_allocatable_regs(pi->co->aenv, arg, -1, arg_regs);
 346
 347                         /* Introduce new variable and set factor in objective function */
 348                         mangle_var2(buf, 'y', rootnr, argnr);
 349                         y_idx = lpp_add_var(pi->curr_lp, buf, lpp_binary, curr->costs[i]);
 350
 351                         /* set starting value */
 352                         lpp_set_start_value(pi->curr_lp, y_idx, (get_irn_col(pi->co, root) != get_irn_col(pi->co, arg)));
 353
 354                         /* For all colors root and arg have in common, add 2 constraints to E */
 355                         bitset_copy(work_regs, root_regs);
 356                         bitset_and(work_regs, arg_regs);
 357                         bitset_foreach(work_regs, color) {
 358                                 int root_idx, arg_idx, cst_idx;
 359                                 mangle_var2(buf, 'x', rootnr, color);
 360                                 root_idx = lpp_get_var_idx(pi->curr_lp, buf);
 361                                 mangle_var2(buf, 'x', argnr, color);
 362                                 arg_idx = lpp_get_var_idx(pi->curr_lp, buf);
 363
 364                                 /* add root-arg-y <= 0 */
 365                                 mangle_cst(buf, 'E', cst_counter++);
 366                                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_less, 0);
 367                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, 1);
 368                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, -1);
 369                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
 370
 371                                 /* add arg-root-y <= 0 */
 372                                 mangle_cst(buf, 'E', cst_counter++);
 373                                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_less, 0);
 374                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, -1);
 375                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, 1);
 376                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
 377                         }
 378                         /* For all colors root and arg have "disjunct", add 1 constraints to E.
 379                          * If root gets a color the arg is not possible to get then they will
 380                          * definetly get different colors. So y has to be 1.
 381                          * Vice versa for arg.
 382                          */
 383                         bitset_copy(work_regs, root_regs);
 384                         bitset_xor(work_regs, arg_regs);
 385                         bitset_foreach(work_regs, color) {
 386                                 int root_idx, arg_idx, cst_idx;
 387                                 mangle_var2(buf, 'x', rootnr, color);
 388                                 root_idx = lpp_get_var_idx(pi->curr_lp, buf);
 389                                 mangle_var2(buf, 'x', argnr, color);
 390                                 arg_idx = lpp_get_var_idx(pi->curr_lp, buf);
 391
 392                                 mangle_cst(buf, 'E', cst_counter++);
 393                                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_less, 0);
 394                                 if (bitset_is_set(root_regs, color)) {
 395                                         /* add root-y <= 0 */
 396                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, 1);
 397                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
 398                                 } else {
 399                                         assert(bitset_is_set(arg_regs, color) && "bitset_xor is buggy");
 400                                         /* add arg-y <= 0 */
 401                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, 1);
 402                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
 403                                 }
 404                         }
 405                 }
 406         }
 407 }
 408
 409 static INLINE int get_costs(problem_instance_t *pi, ir_node *phi, ir_node *irn) {
 410         int i;
 411         unit_t *curr;
 412         /* search optimization unit for phi */
 413         list_for_each_entry(unit_t, curr, &pi->co->units, units)
 414                 if (curr->nodes[0] == phi) {
 415                         for (i=1; i<curr->node_count; ++i)
 416                                 if (curr->nodes[i] == irn)
 417                                         return curr->costs[i];
 418                         assert(0 && "irn must occur in this ou");
 419                 }
 420         assert(0 && "phi must be found in a ou");
 421         return 0;
 422 }
 423
 424 static void clique_path_walker(ir_node *block, void *env) {
 425         problem_instance_t *pi = env;
 426         int count, arity, row, col, other_row, *costs;
 427         ir_node **phis, *phi, *irn, **phi_matrix;
 428         pset *done;
 429         bitset_t *candidates;
 430
 431         /* Count all phi nodes of this block */
 432         for (count=0, irn = sched_first(block); is_Phi(irn); irn = sched_next(irn))
 433                 count++;
 434
 435         /* We at least 2 phi nodes for this class of inequalities */
 436         if (count < 2)
 437                 return;
 438
 439         /* Build the \Phi-Matrix */
 440         arity = get_irn_arity(sched_first(block));
 441         phis = alloca(count * sizeof(*phis));
 442         costs = alloca(count * sizeof(costs));
 443         phi_matrix = alloca(count*arity * sizeof(*phi_matrix));
 444         candidates = bitset_alloca(count);
 445
 446         phi = sched_first(block);
 447         for (row=0; row<count; ++row) {
 448                 phis[row] = phi;
 449                 for (col=0; col<arity; ++col) {
 450                         ir_node *arg = get_irn_n(phi, col);
 451                         /* Sort out all arguments interfering with its phi */
 452                         if (nodes_interfere(pi->co->cenv, phi, arg)) {
 453                                 phi_matrix[row*arity + col] =  NULL;
 454                         } else
 455                                 phi_matrix[row*arity + col] =  arg;
 456                 }
 457                 phi = sched_next(phi);
 458         }
 459
 460         /* Now find the interesting patterns in the matrix:
 461          * All nodes which are used at least twice in a column. */
 462         /* columnwise ... */
 463         for (col=0; col<arity; ++col) {
 464                 done = pset_new_ptr_default();
 465                 for (row=0; row<count; ++row) {
 466                         irn = phi_matrix[row*arity + col];
 467                         /*
 468                          * is this an interfering arg (NULL)
 469                          * or has the irn already been processed in this col?
 470                          */
 471                         if (!irn || pset_find_ptr(done, irn))
 472                                 continue;
 473                         else
 474                                 pset_insert_ptr(done, irn);
 475
 476                         /* insert irn in candidates */
 477                         bitset_clear_all(candidates);
 478                         bitset_set(candidates, row);
 479                         /* search the irn in the rows below */
 480                         for (other_row = row+1; other_row<count; ++other_row)
 481                                 if (irn == phi_matrix[other_row*arity + col]) {
 482                                         /* found the irn in the same col in another row */
 483                                         bitset_set(candidates, other_row);
 484                                 }
 485
 486                         /* now we know all occurences of irn in this col */
 487                         if (bitset_popcnt(candidates) < 2)
 488                                 continue;
 489
 490                         /* generate an unequation finally.
 491                          * phis are indexed in the bitset,
 492                          * shared argument is irn
 493                          * rhs is phi_count - 1 */
 494                         {
 495                                 char buf[32];
 496                                 ir_node *root;
 497                                 int pos, irnnr, rootnr, cst_idx, y_idx, cst_counter = 0;
 498                                 int minimal_unequal_count = bitset_popcnt(candidates)-1;
 499
 500                                 irnnr = get_irn_graph_nr(irn);
 501                                 mangle_cst(buf, 'M', cst_counter++);
 502                                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_greater, minimal_unequal_count);
 503
 504                                 /* for all phis */
 505                                 bitset_foreach(candidates, pos) {
 506                                         root = phis[pos];
 507                                         rootnr = get_irn_graph_nr(root);
 508                                         mangle_var2(buf, 'y', rootnr, irnnr);
 509                                         y_idx = lpp_get_var_idx(pi->curr_lp, buf);
 510                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, 1);
 511                                 }
 512                         }
 513                 }
 514                 del_pset(done); /* clear set for next row */
 515         } /*next col*/
 516 }
 517
 518 /**
 519  * Matrix M: Multi-Arg-Use. Interrelates different \phi-functions
 520  * in the same block, iff they use the same arg at the same pos.
 521  * Only one of the phis can get the arg.
 522  */
 523 static void pi_add_clique_path_cstr(problem_instance_t *pi) {
 524         DBG((dbg, LEVEL_2, "Adding clique path constraints...\n"));
 525         dom_tree_walk_irg(pi->co->irg, clique_path_walker, NULL, pi);
 526 }
 527
 528 #ifndef PATH_CONSTRAINTS_FOR_CLASSES
 529 /**
 530  * Matrix P: Path contraints.
 531  * If 2 nodes interfere and there is a path of equal-color-edges
 532  * connecting them, then at least one of those equal-color-edges
 533  * will break and cause some costs.
 534  */
 535 static void pi_add_path_cstr(problem_instance_t *pi) {
 536         unit_t *curr;
 537         int cst_counter = 0;
 538         DBG((dbg, LEVEL_2, "Adding path constraints...\n"));
 539
 540         /* for all optimization units (only phis) */
 541         list_for_each_entry(unit_t, curr, &pi->co->units, units) {
 542                 int i, o, rootnr;
 543
 544                 if (curr->min_nodes_costs == 0)
 545                         continue;
 546
 547                 rootnr = get_irn_graph_nr(curr->nodes[0]);
 548                 /* check all argument pairs for interference */
 549                 for (i=1; i<curr->node_count; ++i) {
 550                         const ir_node *arg1 = curr->nodes[i];
 551                         int arg1nr = get_irn_graph_nr(arg1);
 552                         for (o=i+1; o<curr->node_count; ++o) {
 553                                 const ir_node *arg2 = curr->nodes[o];
 554                                 int arg2nr = get_irn_graph_nr(arg2);
 555                                 if (nodes_interfere(pi->co->cenv, arg1, arg2)) {
 556                                         int cst_idx, y_idx;
 557                                         char buf[32];
 558
 559                                         mangle_cst(buf, 'P', cst_counter++);
 560                                         cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_greater, 1);
 561
 562                                         mangle_var2(buf, 'y', rootnr, arg1nr);
 563                                         y_idx = lpp_get_var_idx(pi->curr_lp, buf);
 564                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, 1);
 565
 566                                         mangle_var2(buf, 'y', rootnr, arg2nr);
 567                                         y_idx = lpp_get_var_idx(pi->curr_lp, buf);
 568                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, 1);
 569                                 }
 570                         }
 571                 }
 572         }
 573 }
 574 #endif
 575
 576 #ifdef PATH_CONSTRAINTS_FOR_CLASSES
 577 static INLINE int get_y_var_idx(problem_instance_t *pi, int nnr1, int nnr2) {
 578         int res;
 579         char buf[30];
 580
 581         mangle_var2(buf, 'y', nnr1, nnr2);
 582         if ((res = lpp_get_var_idx(pi->curr_lp, buf)) != -1)
 583                 return res;
 584
 585         mangle_var2(buf, 'y', nnr2, nnr1);
 586         if ((res = lpp_get_var_idx(pi->curr_lp, buf)) != -1)
 587                 return res;
 588
 589         assert(0 && "One of them must work");
 590   return -1;
 591 }
 592
 593 static void check_ecc_and_add_cut(problem_instance_t *pi, ir_node **path, int length, pset *remain, ir_node *tgt) {
 594         if (path[length-1] == tgt) { /* we found a path */
 595                 int cst_idx, var_idx, i, nnr1, nnr2;
 596                 char buf[30];
 597
 598                 /* add cut to ilp */
 599                 mangle_cst(buf, 'Q', pi->cst_counter++);
 600                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_greater, 1);
 601
 602                 /* add all vars along the path */
 603                 nnr2 = get_irn_graph_nr(path[0]);
 604                 for (i=1; i<length; ++i) {
 605                         nnr1 = nnr2;
 606                         nnr2 = get_irn_graph_nr(path[i]);
 607                         var_idx = get_y_var_idx(pi, nnr1, nnr2);
 608                         lpp_set_factor_fast(pi->curr_lp, cst_idx, var_idx, 1);
 609                 }
 610         } else { /* try to extend the path */
 611                 be_chordal_env_t *cenv = pi->co->cenv;
 612                 const ir_edge_t *edge;
 613                 ir_node *end = path[length-1];
 614                 ir_node **next = alloca(pset_count(remain) * sizeof(*next));
 615                 int i, o, max, next_pos = 0;
 616                 pset *done = pset_new_ptr_default();
 617
 618                 /* find all potential next nodes on path */
 619                 /*  args of phis */
 620                 if (is_Phi(end))
 621                         for(i=0, max=get_irn_arity(end); i<max; ++i) {
 622                                 ir_node *arg = get_irn_n(end, i);
 623                                 if (!pset_find_ptr(done, arg) && pset_find_ptr(remain, arg)) {
 624                                         next[next_pos++] = arg;
 625                                         pset_insert_ptr(done, arg);
 626                                 }
 627                         }
 628                 /*  outs of phis and other nodes */
 629                 foreach_out_edge(end, edge) {
 630                         ir_node *user = edge->src;
 631                         if (is_Phi(user) && !pset_find_ptr(done, user) && pset_find_ptr(remain, user)) {
 632                                 next[next_pos++] = user;
 633                                 pset_insert_ptr(done, user);
 634                         }
 635                 }
 636                 del_pset(done);
 637
 638
 639                 /* delete all potential nodes with interferences to other nodes in the path */
 640                 for (i=0; i<next_pos; ++i) {
 641                         ir_node *nn = next[i];
 642
 643                         /* if next is the tgt, it may interfere with path[0],
 644                          * so skip the first check */
 645                         o = (nn == tgt && length > 1) ? 1 : 0;
 646
 647                         for(; o<length; ++o)
 648                                 if (nodes_interfere(cenv, nn, path[o])) {
 649                                         next[i] = NULL;
 650                                         break;
 651                                 }
 652                 }
 653                 /* now we have all possible nodes in next; impossibles are NULL */
 654
 655                 /* try to finish path with all possible nodes */
 656                 for (i=0; i<next_pos; ++i) {
 657                         if (!next[i]) /* this was an impossible node */
 658                                 continue;
 659
 660                         path[length] = next[i];
 661                         pset_remove_ptr(remain, next[i]);
 662                         check_ecc_and_add_cut(pi, path, length+1, remain, tgt);
 663                         pset_insert_ptr(remain, next[i]);
 664                 }
 665         }
 666 }
 667
 668 static void path_cstr_for_classes_walker(ir_node *irn, void *env) {
 669         problem_instance_t *pi = env;
 670         be_chordal_env_t *cenv;
 671         int i, o, max;
 672         ir_node *m, **cls;
 673         pset *class = get_phi_class(irn);
 674         if (!class || pset_find_ptr(pi->done, class))
 675                 return;
 676
 677         pset_insert_ptr(pi->done, class);
 678
 679         /* pset to array */
 680         max = pset_count(class);
 681         cls = alloca(max * sizeof(*cls));
 682         for(i=0, m = pset_first(class); m; i++, m = pset_next(class)) {
 683                 DBG((dbg, LEVEL_1, " class member: %+F\n", m));
 684                 cls[i] = m;
 685         }
 686
 687         cenv = pi->co->cenv;
 688         for(i=0; i<max; ++i) {
 689                 ir_node **path = alloca(max * sizeof(*path));
 690                 pset *remain = pset_new_ptr(8);
 691                 pset_insert_pset_ptr(remain, class);
 692
 693                 /* add cls[i] to path and remove it from remainder */
 694                 path[0] = cls[i];
 695                 pset_remove_ptr(remain, cls[i]);
 696
 697                 for(o=i+1; o<max; ++o)
 698                         if (nodes_interfere(cenv, cls[i], cls[o]))
 699                                 check_ecc_and_add_cut(pi, path, 1, remain, cls[o]);
 700
 701                 /* insert back into remainder */
 702                 pset_insert_ptr(remain, cls[i]);
 703         }
 704 }
 705
 706
 707 /**
 708  * Matrix P: Path contraints.
 709  * If 2 nodes interfere and there is a path of equal-color-edges
 710  * connecting them, then at least one of those equal-color-edges
 711  * will break and cause some costs.
 712  */
 713 static void pi_add_path_cstr_for_classes(problem_instance_t *pi) {
 714         DBG((dbg, LEVEL_2, "Adding path constraints for phi classes...\n"));
 715         pi->cst_counter = 0;
 716         pi->done = pset_new_ptr_default();
 717         irg_walk_graph(pi->co->irg, path_cstr_for_classes_walker, NULL, pi);
 718         del_pset(pi->done);
 719 }
 720 #endif
 721
 722 #ifdef PRECOLOR_MAX_CLIQUE
 723 struct pre_col {
 724         problem_instance_t *pi;
 725         pset **clique;
 726 };
 727
 728 static void preColoringWalker(ir_node *bl, void *env) {
 729         struct pre_col *e = env;
 730         pset **clique = e->clique;
 731         pset *max_clique = clique ? *clique : NULL;
 732         int max = max_clique ? pset_count(max_clique) : 0;
 733         problem_instance_t *pi = e->pi;
 734
 735         int i, n;
 736         pset *live       = pset_new_ptr_default();
 737         ir_node *irn;
 738         irn_live_t *li;
 739
 740         /* as always, bring the live end nodes to life here */
 741         live_foreach(bl, li) {
 742           if(live_is_end(li) && has_reg_class(pi, li->irn)) {
 743             pset_insert_ptr(live, irn);
 744           }
 745         }
 746
 747         sched_foreach_reverse(bl, irn) {
 748                 int pres = pset_count(live);
 749
 750                 if(pres > max) {
 751                         max = pres;
 752                         if(max_clique)
 753                                 del_pset(max_clique);
 754
 755                         max_clique = pset_new_ptr_default();
 756                         pset_insert_pset_ptr(max_clique, live);
 757                 }
 758
 759
 760
 761                 if(has_reg_class(pi, irn))
 762                         pset_remove_ptr(live, irn);
 763
 764                 for(i = 0, n = get_irn_arity(irn); i < n; ++i) {
 765                         ir_node *op = get_irn_n(irn, i);
 766                         if(has_reg_class(pi, op) && !is_Phi(irn))
 767                                 pset_insert_ptr(live, op);
 768                 }
 769         }
 770
 771   del_pset(live);
 772   *clique = max_clique;
 773 }
 774
 775 static void pi_add_constr_preColoring(problem_instance_t *pi) {
 776         ir_node *irn;
 777         int cst_counter, color;
 778         struct pre_col pre_col;
 779
 780         pre_col.clique = NULL;
 781         pre_col.pi = pi;
 782
 783         dom_tree_walk_irg(get_irg(pi->co), preColoringWalker, NULL, &pre_col);
 784
 785         color = 0;
 786         for (irn = pset_first(*pre_col.clique); irn; irn = pset_next(*pre_col.clique)) {
 787                 int cst_idx, var_idx, nnr = get_irn_graph_nr(irn);
 788                 char buf[100];
 789
 790                 mangle_cst(buf, 'K', cst_counter++);
 791                 cst_idx = lpp_add_cst(pi->curr_lp, buf, lpp_equal, 1);
 792
 793                 mangle_var2(buf, 'x', nnr, color++);
 794                 var_idx = lpp_get_var_idx(pi->curr_lp, buf);
 795                 lpp_set_factor_fast(pi->curr_lp, cst_idx, var_idx, 1);
 796         }
 797 }
 798 #endif
 799
 800 /**
 801  * Generate the initial problem matrices and vectors.
 802  */
 803 static problem_instance_t *new_pi(const copy_opt_t *co) {
 804         problem_instance_t *pi;
 805         int col;
 806
 807         DBG((dbg, LEVEL_2, "Generating new instance...\n"));
 808         pi = xcalloc(1, sizeof(*pi));
 809         pi->co = co;
 810         pi->removed = pset_new_ptr_default();
 811         INIT_LIST_HEAD(&pi->simplicials);
 812         pi->dilp     = new_lpp(co->name, lpp_minimize);
 813
 814         /* problem size reduction */
 815         pi_find_simplicials(pi);
 816         if (pi->all_simplicial)
 817                 return pi;
 818
 819         /* built objective and constraints */
 820         pi->curr_lp = pi->dilp;
 821 #ifdef NO_NULL_COLORS
 822         pi_add_constr_no_null_colors(pi);
 823 #endif
 824         pi_add_constr_A(pi);
 825         for (col = 0; col < pi->co->cls->n_regs; ++col)
 826                 pi_add_constr_B(pi, col);
 827         pi_add_constr_E(pi);
 828
 829 #ifdef PATH_CONSTRAINTS_FOR_CLASSES
 830         pi_add_path_cstr_for_classes(pi);
 831 #else
 832         pi_add_path_cstr(pi);
 833 #endif
 834         pi_add_clique_path_cstr(pi);
 835 #ifdef PRECOLOR_MAX_CLIQUE
 836         pi_add_constr_preColoring(pi);
 837 #endif
 838
 839         return pi;
 840 }
 841
 842 /**
 843  * Clean the problem instance
 844  */
 845 static void free_pi(problem_instance_t *pi) {
 846         simpl_t *simpl, *tmp;
 847
 848         DBG((dbg, LEVEL_2, "Free instance...\n"));
 849         free_lpp(pi->dilp);
 850         list_for_each_entry_safe(simpl_t, simpl, tmp, &pi->simplicials, chain)
 851                 free(simpl);
 852         del_pset(pi->removed);
 853         free(pi);
 854 }
 855
 856 /**
 857  * Set starting values for the mip problem according
 858  * to the current coloring of the graph.
 859  */
 860 static void pi_set_start_sol(problem_instance_t *pi) {
 861         int i;
 862         char var_name[64];
 863         DBG((dbg, LEVEL_2, "Set start solution...\n"));
 864         for (i=pi->first_x_var; i<=pi->last_x_var; ++i) {
 865                 int nnr, col;
 866                 double val;
 867                 /* get variable name */
 868                 lpp_get_var_name(pi->curr_lp, i, var_name, sizeof(var_name));
 869                 /* split into components */
 870                 if (split_var(var_name, &nnr, &col) == 2) {
 871                         assert(get_irn_col(pi->co, get_irn_for_graph_nr(pi->co->irg, nnr)) != -1);
 872                         val = (get_irn_col(pi->co, get_irn_for_graph_nr(pi->co->irg, nnr)) == col) ? 1 : 0;
 873                         lpp_set_start_value(pi->curr_lp, i, val);
 874                 } else {
 875                         fprintf(stderr, "Variable name is: %s\n", var_name);
 876                         assert(0 && "x vars always look like this 'x123_45'");
 877                 }
 878         }
 879 }
 880
 881 /**
 882  * Invoke a solver
 883  */
 884 static void pi_solve_ilp(problem_instance_t *pi) {
 885   double lower_bound;
 886
 887         pi_set_start_sol(pi);
 888         lower_bound = co_get_lower_bound(pi->co) - co_get_inevit_copy_costs(pi->co);
 889         lpp_set_bound(pi->curr_lp, lower_bound);
 890         lpp_solve_net(pi->curr_lp, LPP_HOST, LPP_SOLVER);
 891 //      lpp_solve_cplex(pi->curr_lp);
 892         DBG((dbg, LEVEL_1, "Solution time: %.2f\n", pi->curr_lp->sol_time));
 893 }
 894
 895 /**
 896  * Set the color of all simplicial nodes removed form
 897  * the graph before transforming it to an ilp.
 898  */
 899 static void pi_set_simplicials(problem_instance_t *pi) {
 900         simpl_t *simpl, *tmp;
 901         be_ifg_t *ifg        = pi->co->cenv->ifg;
 902         bitset_t *used_cols  = bitset_alloca(arch_register_class_n_regs(pi->co->cls));
 903         void *iter           = be_ifg_neighbours_iter_alloca(ifg);
 904
 905         DBG((dbg, LEVEL_2, "Set simplicials...\n"));
 906         /* color the simplicial nodes in right order */
 907         list_for_each_entry_safe(simpl_t, simpl, tmp, &pi->simplicials, chain) {
 908                 int free_col;
 909                 ir_node *other, *irn;
 910
 911                 /* get free color by inspecting all neighbors */
 912                 irn = simpl->irn;
 913                 bitset_clear_all(used_cols);
 914
 915                 be_ifg_foreach_neighbour(ifg, iter, irn, other) {
 916                         if (!is_removed(other)) /* only inspect nodes which are in graph right now */
 917                                 bitset_set(used_cols, get_irn_col(pi->co, other));
 918                 }
 919
 920                 /* now all bits not set are possible colors */
 921                 free_col = bitset_next_clear(used_cols, 0);
 922                 assert(free_col != -1 && "No free color found. This can not be.");
 923                 set_irn_col(pi->co, irn, free_col);
 924                 pset_remove_ptr(pi->removed, irn); /* irn is back in graph again */
 925         }
 926 }
 927
 928 /**
 929  * Sets the colors of irns according to the values of variables
 930  * provided by the solution of the solver.
 931  */
 932 static int pi_apply_solution(problem_instance_t *pi) {
 933         int res = 1, i;
 934         double *sol;
 935         lpp_sol_state_t state;
 936         DBG((dbg, LEVEL_2, "Applying solution...\n"));
 937
 938 #ifdef DO_STAT
 939         copystat_add_ilp_time((int)(1000.0*lpp_get_sol_time(pi->curr_lp)));  //now we have ms
 940         copystat_add_ilp_vars(lpp_get_var_count(pi->curr_lp));
 941         copystat_add_ilp_csts(lpp_get_cst_count(pi->curr_lp));
 942         copystat_add_ilp_iter(lpp_get_iter_cnt(pi->curr_lp));
 943 #endif
 944
 945         sol = xmalloc((pi->last_x_var - pi->first_x_var + 1) * sizeof(*sol));
 946         state = lpp_get_solution(pi->curr_lp, sol, pi->first_x_var, pi->last_x_var);
 947         if (state != lpp_optimal) {
 948                 printf("WARNING %s: Solution state is not 'optimal': %d\n", pi->co->name, state);
 949                 assert(state >= lpp_feasible && "The solution should at least be feasible!");
 950                 res = 0;
 951         }
 952         for (i=0; i<pi->last_x_var - pi->first_x_var + 1; ++i) {
 953                 int nnr, col;
 954                 char var_name[64];
 955
 956                 if (sol[i] > 1-EPSILON) { /* split varibale name into components */
 957                         lpp_get_var_name(pi->curr_lp, pi->first_x_var+i, var_name, sizeof(var_name));
 958                         if (split_var(var_name, &nnr, &col) == 2) {
 959                                 DBG((dbg, LEVEL_2, "Irn %n  Idx %d  Var %s  Val %f\n", get_irn_for_graph_nr(pi->co->irg, nnr), i, var_name, sol[i]));
 960                                 DBG((dbg, LEVEL_2, "x%d = %d\n", nnr, col));
 961                                 set_irn_col(pi->co, get_irn_for_graph_nr(pi->co->irg, nnr), col);
 962                         } else
 963                                 assert(0 && "This should be a x-var");
 964                 }
 965         }
 966         return res;
 967 }
 968
 969 int co_solve_ilp1(copy_opt_t *co, double time_limit) {
 970         int res = 1;
 971         problem_instance_t *pi;
 972
 973         dbg = firm_dbg_register("ir.be.copyoptilp");
 974
 975         pi = new_pi(co);
 976         if (!pi->all_simplicial) {
 977 #ifdef DUMP_MPS
 978                 char buf[512];
 979                 snprintf(buf, sizeof(buf), "%s.mps", co->name);
 980                 lpp_dump(pi->curr_lp, buf);
 981 #endif
 982                 lpp_set_time_limit(pi->curr_lp, time_limit);
 983                 pi_solve_ilp(pi);
 984                 res = pi_apply_solution(pi);
 985                 pi_set_simplicials(pi);
 986         }
 987         free_pi(pi);
 988         return res;
 989 }