nsz Git - libfirm/blob - ir/be/becopyilp.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  */
   7 #ifdef HAVE_CONFIG_H
   8 #include "config.h"
   9 #endif
  10
  11 #ifdef HAVE_ALLOCA_H
  12 #include <alloca.h>
  13 #endif
  14 #ifdef HAVE_MALLOC_H
  15 #include <malloc.h>
  16 #endif
  17
  18 #include "irprog.h"
  19
  20 #include "lpp.h"
  21 #include "lpp_local.h"
  22 #include "lpp_remote.h"
  23 #include "xmalloc.h"
  24 #include "becopyopt.h"
  25 #include "becopystat.h"
  26
  27 #undef DUMP_MPS
  28 #define DEBUG_LVL SET_LEVEL_1
  29 static firm_dbg_module_t *dbg = NULL;
  30
  31 #define EPSILON 0.00001
  32 #define SLOTS_LIVING 32
  33
  34 typedef struct _simpl_t {
  35         struct list_head chain;
  36         if_node_t *ifn;
  37 } simpl_t;
  38
  39 typedef struct _problem_instance_t {
  40         const copy_opt_t *co;                   /** the copy_opt problem */
  41         /* problem size reduction removing simple nodes */
  42         struct list_head simplicials;   /**< holds all simpl_t's in right order to color*/
  43         pset *removed;                                  /**< holds all removed simplicial irns */
  44         /* lp problem */
  45         lpp_t *dilp;                                    /**< problem formulation directly as milp */
  46         /* overhead stuff */
  47         lpp_t *curr_lp;                                 /**< points to the problem currently used */
  48         int cst_counter, last_x_var;
  49         char buf[32];
  50         int all_simplicial;
  51 } problem_instance_t;
  52
  53 #define is_removed(irn) pset_find_ptr(pi->removed, irn)
  54
  55 #define is_color_possible(irn,color) arch_reg_is_allocatable(pi->co->chordal_env->arch_env, irn, arch_pos_make_out(0), arch_register_for_index(pi->co->chordal_env->cls, color))
  56
  57 /*
  58  * Some stuff for variable name handling.
  59  */
  60 #define mangle_cst(buf, prefix, nr) \
  61                         snprintf((buf), sizeof(buf), "%c%d", (prefix), (nr))
  62
  63 #define mangle_var(buf, prefix, node_nr, color) \
  64                         snprintf((buf), sizeof(buf), "%c%d_%d", (prefix), (node_nr), (color))
  65
  66 #define mangle_var_irn(buf, prefix, irn, color) \
  67                         mangle_var((buf), (prefix), get_irn_graph_nr(irn), (color))
  68
  69 #define split_var(var, nnr, col) \
  70                         sscanf(var, "x%d_%d", (nnr), (col))
  71
  72
  73 /**
  74  * Checks if a node is simplicial in the graph
  75  * heeding the already removed nodes.
  76  */
  77 static INLINE int pi_is_simplicial(problem_instance_t *pi, const if_node_t *ifn) {
  78         int i, o, size = 0;
  79         if_node_t **all, *curr;
  80         all = alloca(ifn_get_degree(ifn) * sizeof(*all));
  81
  82         /* get all non-removed neighbors */
  83         foreach_neighb(ifn, curr)
  84                 if (!is_removed(curr))
  85                         all[size++] = curr;
  86
  87         /* check if these form a clique */
  88         for (i=0; i<size; ++i)
  89                 for (o=i+1; o<size; ++o)
  90                         if (!ifg_has_edge(pi->co->chordal_env, all[i], all[o]))
  91                                 return 0;
  92
  93         /* all edges exist so this is a clique */
  94         return 1;
  95 }
  96
  97 /**
  98  * Iterative finds and 'removes' from the graph all nodes which are
  99  * simplicial AND not member of a equal-color-wish
 100  */
 101 static void pi_find_simplicials(problem_instance_t *pi) {
 102         set *if_nodes;
 103         if_node_t *ifn;
 104         int redo = 1;
 105
 106         DBG((dbg, LEVEL_2, "Find simlicials...\n"));
 107
 108         if_nodes = be_ra_get_ifg_nodes(pi->co->chordal_env);
 109         while (redo) {
 110                 redo = 0;
 111                 for (ifn = set_first(if_nodes); ifn; ifn = set_next(if_nodes)) {
 112                         ir_node *irn = get_irn_for_graph_nr(pi->co->chordal_env->irg, ifn->nnr);
 113                         if (!is_removed(irn) && !is_optimizable(pi->co->chordal_env->arch_env, irn) &&
 114           !is_optimizable_arg(pi->co, irn) && pi_is_simplicial(pi, ifn)) {
 115                                 simpl_t *s = xmalloc(sizeof(*s));
 116                                 s->ifn = ifn;
 117                                 list_add(&s->chain, &pi->simplicials);
 118                                 pset_insert_ptr(pi->removed, irn);
 119                                 redo = 1;
 120                                 DBG((dbg, LEVEL_2, " Removed %n %d\n", irn, get_irn_graph_nr(irn)));
 121                         }
 122                 }
 123         }
 124         if (set_count(be_ra_get_ifg_nodes(pi->co->chordal_env)) == pset_count(pi->removed))
 125                 pi->all_simplicial = 1;
 126 }
 127
 128 /**
 129  * Add coloring-force conditions
 130  * Matrix A: knapsack constraint for each node
 131  */
 132 static void pi_add_constr_A(problem_instance_t *pi) {
 133         pmap_entry *pme;
 134
 135         DBG((dbg, LEVEL_2, "Add A constraints...\n"));
 136         /* iterate over all blocks */
 137         pmap_foreach(pi->co->chordal_env->border_heads, pme) {
 138                 struct list_head *head = pme->value;
 139                 border_t *curr;
 140                 bitset_t *pos_regs = bitset_alloca(pi->co->chordal_env->cls->n_regs);
 141
 142                 list_for_each_entry_reverse(border_t, curr, head, list)
 143                         if (curr->is_def && curr->is_real && !is_removed(curr->irn)) {
 144                                 int cst_idx, nnr, col;
 145
 146                                 nnr = get_irn_graph_nr(curr->irn);
 147                                 mangle_cst(pi->buf, 'A', nnr);
 148                                 cst_idx = lpp_add_cst(pi->curr_lp, pi->buf, equal, 1);
 149
 150                                 // iterate over all possible colors in order
 151                                 bitset_clear_all(pos_regs);
 152                                 arch_get_allocatable_regs(pi->co->chordal_env->arch_env, curr->irn, arch_pos_make_out(0), pi->co->chordal_env->cls, pos_regs);
 153                                 bitset_foreach(pos_regs, col) {
 154                                         int var_idx;
 155                                         mangle_var(pi->buf, 'x', nnr, col);
 156                                         var_idx = lpp_add_var(pi->curr_lp, pi->buf, binary, 0);
 157                                         pi->last_x_var = var_idx;
 158                                         lpp_set_factor_fast(pi->curr_lp, cst_idx, var_idx, 1);
 159                                 }
 160                         }
 161         }
 162 }
 163
 164 /**
 165  * Checks if all nodes in @p living are live in in block @p block.
 166  * @return 1 if all are live in
 167  *         0 else
 168  */
 169 static INLINE int all_live_in(ir_node *block, pset *living) {
 170         ir_node *n;
 171         for (n = pset_first(living); n; n = pset_next(living))
 172                 if (!is_live_in(block, n)) {
 173                         pset_break(living);
 174                         return 0;
 175                 }
 176         return 1;
 177 }
 178
 179 /**
 180  * Finds cliques in the interference graph, considering only nodes
 181  * for which the color @p color is possible. Finds only 'maximal-cliques',
 182  * viz cliques which are not contained in another one.
 183  * Matrix B: interference constraints using cliques
 184  */
 185 static void pi_add_constr_B(problem_instance_t *pi, int color) {
 186         enum phase_t {growing, shrinking} phase = growing;
 187         border_t *b;
 188         pmap_entry *pme;
 189         pset *living = pset_new_ptr(SLOTS_LIVING);
 190
 191         DBG((dbg, LEVEL_2, "Add B constraints (col = %d)...\n", color));
 192         /* iterate over all blocks */
 193         pmap_foreach(pi->co->chordal_env->border_heads, pme) {
 194                 ir_node *block = pme->key;
 195                 struct list_head *head = pme->value;
 196
 197                 list_for_each_entry_reverse(border_t, b, head, list) {
 198                         const ir_node *irn = b->irn;
 199                         if (is_removed(irn) || !is_color_possible(irn, color))
 200                                 continue;
 201
 202                         if (b->is_def) {
 203                                 DBG((dbg, LEVEL_2, "Def %n\n", irn));
 204                                 pset_insert_ptr(living, irn);
 205                                 phase = growing;
 206                         } else { /* is_use */
 207                                 DBG((dbg, LEVEL_2, "Use %n\n", irn));
 208
 209                                 /* before shrinking the set, store the current 'maximum' clique;
 210                                  * do NOT if clique is a single node
 211                                  * do NOT if all values are live_in (in this case they were contained in a live-out clique elsewhere) */
 212                                 if (phase == growing && pset_count(living) >= 2 && !all_live_in(block, living)) {
 213                                         int cst_idx;
 214                                         ir_node *n;
 215                                         mangle_cst(pi->buf, 'B', pi->cst_counter);
 216                                         cst_idx = lpp_add_cst(pi->curr_lp, pi->buf, less, 1);
 217                                         for (n = pset_first(living); n; n = pset_next(living)) {
 218                                                 int var_idx;
 219                                                 mangle_var_irn(pi->buf, 'x', n, color);
 220                                                 var_idx = lpp_get_var_idx(pi->curr_lp, pi->buf);
 221                                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, var_idx, 1);
 222                                         }
 223                                         pi->cst_counter++;
 224                                 }
 225                                 pset_remove_ptr(living, irn);
 226                                 phase = shrinking;
 227                         }
 228                 }
 229         }
 230         assert(0 == pset_count(living));
 231         del_pset(living);
 232 }
 233
 234 /**
 235  * Generates constraints which interrelate x with y variables.
 236  * y=1 ==> x1 and x2 must have the same color.
 237  *     <== is achieved automatically by minimization.
 238  */
 239 static void pi_add_constr_E(problem_instance_t *pi) {
 240         unit_t *curr;
 241         bitset_t *root_regs, *arg_regs;
 242         int cst_counter = 0;
 243         unsigned nregs = pi->co->chordal_env->cls->n_regs;
 244         root_regs = bitset_alloca(nregs);
 245         arg_regs = bitset_alloca(nregs);
 246
 247         DBG((dbg, LEVEL_2, "Add E constraints...\n"));
 248         /* for all roots of optimization units */
 249         list_for_each_entry(unit_t, curr, &pi->co->units, units) {
 250                 ir_node *root, *arg;
 251                 int rootnr, argnr, color;
 252                 int y_idx, i;
 253                 char buf[32];
 254
 255                 root = curr->nodes[0];
 256                 rootnr = get_irn_graph_nr(root);
 257                 bitset_clear_all(root_regs);
 258                 arch_get_allocatable_regs(pi->co->chordal_env->arch_env, root, arch_pos_make_out(0), pi->co->chordal_env->cls, root_regs);
 259
 260                 /* for all arguments of root */
 261                 for (i = 1; i < curr->node_count; ++i) {
 262                         arg = curr->nodes[i];
 263                         argnr = get_irn_graph_nr(arg);
 264                         bitset_clear_all(arg_regs);
 265                         arch_get_allocatable_regs(pi->co->chordal_env->arch_env, arg, arch_pos_make_out(0), pi->co->chordal_env->cls, arg_regs);
 266
 267                         /* Introduce new variable and set factor in objective function */
 268                         mangle_var(buf, 'y', rootnr, argnr);
 269                         y_idx = lpp_add_var(pi->curr_lp, buf, continous, curr->costs[i]);
 270
 271                         /* set starting value */
 272                         //lpp_set_start_value(pi->curr_lp, y_idx, (get_irn_col(pi->co, root) != get_irn_col(pi->co, arg)));
 273
 274                         /* For all colors root and arg have in common, add 2 constraints to E */
 275                         bitset_and(arg_regs, root_regs);
 276                         bitset_foreach(arg_regs, color) {
 277                                 int root_idx, arg_idx, cst_idx;
 278                                 mangle_var(buf, 'x', rootnr, color);
 279                                 root_idx = lpp_get_var_idx(pi->curr_lp, buf);
 280                                 mangle_var(buf, 'x', argnr, color);
 281                                 arg_idx = lpp_get_var_idx(pi->curr_lp, buf);
 282
 283                                 /* add root-arg-y <= 0 */
 284                                 mangle_cst(buf, 'E', cst_counter++);
 285                                 cst_idx = lpp_add_cst(pi->curr_lp, buf, less, 0);
 286                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, 1);
 287                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, -1);
 288                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
 289
 290                                 /* add arg-root-y <= 0 */
 291                                 mangle_cst(buf, 'E', cst_counter++);
 292                                 cst_idx = lpp_add_cst(pi->curr_lp, buf, less, 0);
 293                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, root_idx, -1);
 294                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, arg_idx, 1);
 295                                 lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, -1);
 296                         }
 297                         /* TODO:
 298                          * \forall c \in p(v_i) \ p(v_j)
 299                          *              y_ij >= x_ic
 300                          * \forall c \in p(v_j) \ p(v_i)
 301                          *              y_ij >= x_jc
 302                          */
 303                 }
 304         }
 305 }
 306
 307 /**
 308  * Matrix M: maximum independent set constraints
 309  * Generates lower bound-cuts for optimization units with inner interferences.
 310  * Sum(y_{root, arg}, arg \in Args) <= max_indep_set_size - 1
 311  */
 312 static void pi_add_constr_M(problem_instance_t *pi) {
 313         unit_t *curr;
 314         int cst_counter = 0;
 315         DBG((dbg, LEVEL_2, "Add M constraints...\n"));
 316
 317         /* for all optimization units */
 318         list_for_each_entry(unit_t, curr, &pi->co->units, units) {
 319                 const ir_node *root, *arg;
 320                 int rootnr, argnr;
 321                 int cst_idx, y_idx, i;
 322                 char buf[32];
 323
 324                 if (curr->minimal_costs == 0)
 325                         continue;
 326
 327                 root = curr->nodes[0];
 328                 rootnr = get_irn_graph_nr(root);
 329                 mangle_cst(buf, 'M', cst_counter++);
 330                 cst_idx = lpp_add_cst(pi->curr_lp, buf, greater, curr->minimal_costs);
 331
 332                 /* for all arguments */
 333                 for (i = 1; i < curr->node_count; ++i) {
 334                         arg = curr->nodes[i];
 335                         argnr = get_irn_graph_nr(arg);
 336                         mangle_var(buf, 'y', rootnr, argnr);
 337                         y_idx = lpp_get_var_idx(pi->curr_lp, buf);
 338                         lpp_set_factor_fast(pi->curr_lp, cst_idx, y_idx, 1);
 339                 }
 340         }
 341 }
 342
 343 /**
 344  * Generate the initial problem matrices and vectors.
 345  */
 346 static problem_instance_t *new_pi(const copy_opt_t *co) {
 347         problem_instance_t *pi;
 348         int col;
 349
 350         DBG((dbg, LEVEL_2, "Generating new instance...\n"));
 351         pi = xcalloc(1, sizeof(*pi));
 352         pi->co = co;
 353         pi->removed = pset_new_ptr_default();
 354         INIT_LIST_HEAD(&pi->simplicials);
 355         pi->dilp = new_lpp(co->name, minimize);
 356         pi->last_x_var = -1;
 357
 358         /* problem size reduction */
 359         pi_find_simplicials(pi);
 360         //TODO If you wish to see it: dump_ifg_w/o_removed
 361         if (pi->all_simplicial)
 362                 return pi;
 363
 364         /* built objective abd constraints */
 365         pi->curr_lp = pi->dilp;
 366         pi_add_constr_A(pi);
 367         for (col = 0; col < pi->co->chordal_env->cls->n_regs; ++col)
 368                 pi_add_constr_B(pi, col);
 369         pi_add_constr_E(pi);
 370         pi_add_constr_M(pi);
 371
 372         return pi;
 373 }
 374
 375 /**
 376  * Clean the problem instance
 377  */
 378 static void free_pi(problem_instance_t *pi) {
 379         simpl_t *simpl, *tmp;
 380
 381         DBG((dbg, LEVEL_2, "Free instance...\n"));
 382         free_lpp(pi->dilp);
 383         list_for_each_entry_safe(simpl_t, simpl, tmp, &pi->simplicials, chain)
 384                 free(simpl);
 385         del_pset(pi->removed);
 386         free(pi);
 387 }
 388
 389 /**
 390  * Set starting values for the mip problem according
 391  * to the current coloring of the graph.
 392  */
 393 static void pi_set_start_sol(problem_instance_t *pi) {
 394         int i;
 395         char var_name[64];
 396         DBG((dbg, LEVEL_2, "Set start solution...\n"));
 397         for (i=1; i<=pi->last_x_var; ++i) {
 398                 int nnr, col;
 399                 double val;
 400                 /* get variable name */
 401                 lpp_get_var_name(pi->curr_lp, i, var_name, sizeof(var_name));
 402                 /* split into components */
 403                 if (split_var(var_name, &nnr, &col) == 2) {
 404                         assert(get_irn_col(pi->co, get_irn_for_graph_nr(pi->co->chordal_env->irg, nnr)) != -1);
 405                         val = (get_irn_col(pi->co, get_irn_for_graph_nr(pi->co->chordal_env->irg, nnr)) == col) ? 1 : 0;
 406                         lpp_set_start_value(pi->curr_lp, i, val);
 407                 } else {
 408                         fprintf(stderr, "Variable name is: %s\n", var_name);
 409                         assert(0 && "x vars always look like this 'x123_45'");
 410                 }
 411         }
 412 }
 413
 414 /**
 415  * Invoke a solver
 416  */
 417 static void pi_solve_ilp(problem_instance_t *pi, void (*lpp_solve)(lpp_t *)) {
 418         pi_set_start_sol(pi);
 419         lpp_solve(pi->curr_lp);
 420 }
 421
 422 /**
 423  * Set the color of all simplicial nodes removed form
 424  * the graph before transforming it to an ilp.
 425  */
 426 static void pi_set_simplicials(problem_instance_t *pi) {
 427         simpl_t *simpl, *tmp;
 428         bitset_t *used_cols = bitset_alloca(arch_register_class_n_regs(pi->co->chordal_env->cls));
 429
 430         DBG((dbg, LEVEL_2, "Set simplicials...\n"));
 431         /* color the simplicial nodes in right order */
 432         list_for_each_entry_safe(simpl_t, simpl, tmp, &pi->simplicials, chain) {
 433                 int free_col;
 434                 ir_node *other_irn, *irn;
 435                 if_node_t *other, *ifn;
 436
 437                 /* get free color by inspecting all neighbors */
 438                 ifn = simpl->ifn;
 439                 irn = get_irn_for_graph_nr(pi->co->chordal_env->irg, ifn->nnr);
 440                 bitset_clear_all(used_cols);
 441                 foreach_neighb(ifn, other) {
 442                         other_irn = get_irn_for_graph_nr(pi->co->chordal_env->irg, other->nnr);
 443                         if (!is_removed(other_irn)) /* only inspect nodes which are in graph right now */
 444                                 bitset_set(used_cols, get_irn_col(pi->co, other_irn));
 445                 }
 446
 447                 /* now all bits not set are possible colors */
 448                 free_col = bitset_next_clear(used_cols, 0);
 449                 assert(free_col != -1 && "No free color found. This can not be.");
 450                 set_irn_col(pi->co, irn, free_col);
 451                 pset_remove_ptr(pi->removed, irn); /* irn is back in graph again */
 452         }
 453 }
 454
 455 /**
 456  * Sets the colors of irns according to the values of variables
 457  * provided by the solution of the solver.
 458  */
 459 static void pi_apply_solution(problem_instance_t *pi) {
 460         int i;
 461         double *sol;
 462         sol_state_t state;
 463         DBG((dbg, LEVEL_2, "Applying solution...\n"));
 464
 465 #ifdef DO_STAT
 466         curr_vals[I_ILP_ITER] += lpp_get_iter_cnt(pi->curr_lp);
 467         curr_vals[I_ILP_TIME] += lpp_get_sol_time(pi->curr_lp);
 468 #endif
 469
 470         sol = xmalloc((pi->last_x_var+1) * sizeof(*sol));
 471         state = lpp_get_solution(pi->curr_lp, sol, 1, pi->last_x_var);
 472         if (state != optimal) {
 473                 printf("Solution state is not 'optimal': %d\n", state);
 474                 assert(state >= feasible && "The solution should at least be feasible!");
 475         }
 476         for (i=0; i<pi->last_x_var; ++i) {
 477                 int nnr, col;
 478                 char var_name[64];
 479
 480                 if (sol[i] > 1-EPSILON) { /* split varibale name into components */
 481                         lpp_get_var_name(pi->curr_lp, 1+i, var_name, sizeof(var_name));
 482                         if (split_var(var_name, &nnr, &col) == 2) {
 483                                 DBG((dbg, LEVEL_2, "Irn %n  Idx %d  Var %s  Val %f\n", get_irn_for_graph_nr(pi->co->chordal_env->irg, nnr), i, var_name, sol[i]));
 484                                 DBG((dbg, LEVEL_2, "x%d = %d\n", nnr, col));
 485                                 set_irn_col(pi->co, get_irn_for_graph_nr(pi->co->chordal_env->irg, nnr), col);
 486                         } else
 487                                 assert(0 && "This should be a x-var");
 488                 }
 489         }
 490 }
 491
 492 void co_ilp_opt(copy_opt_t *co) {
 493         problem_instance_t *pi;
 494
 495         dbg = firm_dbg_register("ir.be.copyoptilp");
 496         if (!strcmp(co->name, DEBUG_IRG))
 497                 firm_dbg_set_mask(dbg, DEBUG_LVL_ILP);
 498         else
 499                 firm_dbg_set_mask(dbg, DEBUG_LVL);
 500
 501         pi = new_pi(co);
 502         if (!pi->all_simplicial) {
 503 #ifdef DUMP_MPS
 504                 char buf[512];
 505                 snprintf(buf, sizeof(buf), "%s.mps", co->name);
 506                 lpp_dump(pi->curr_lp, buf);
 507 #endif
 508                 pi_solve_ilp(pi, lpp_solve_local);
 509                 pi_apply_solution(pi);
 510                 pi_set_simplicials(pi);
 511         }
 512         free_pi(pi);
 513 }