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

   1 /**
   2  * Author:      Daniel Grund
   3  * Date:                12.04.2005
   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 #ifdef HAVE_ALLOCA_H
  11 #include <alloca.h>
  12 #endif
  13
  14 #include "irprog.h"
  15
  16 #include "xmalloc.h"
  17 #include "bechordal_t.h"
  18 #include "becopyopt.h"
  19 #include "becopystat.h"
  20
  21 #define DEBUG_LVL 0 //SET_LEVEL_1
  22 static firm_dbg_module_t *dbg = NULL;
  23
  24 #define is_curr_reg_class(irn) (arch_get_irn_reg_class(co->chordal_env->arch_env, irn, arch_pos_make_out(0)) == co->chordal_env->cls)
  25
  26 #define MIN(a,b) ((a<b)?(a):(b))
  27
  28 /**
  29  * Computes a 'max independent set' wrt. ifg-edges only (no coloring conflicts, no register constraints)
  30  * @return The size of such a mis
  31  * NOTE: Code adapted from becopyheur
  32  * BETTER: Here we can be sure having a chordal graph to work on, so for 'larger' opt-units we
  33  *         could use a special algorithm.
  34  */
  35 static int get_ifg_mis_size(unit_t *ou) {
  36         int all_size, curr_size, i, o;
  37         int *which;
  38         ir_node **curr, **all = alloca(ou->node_count * sizeof(*all));
  39
  40         /* all contains all nodes */
  41         all_size = 0;
  42         for (i=0; i<ou->node_count; ++i)
  43                 all[all_size++] = ou->nodes[i];
  44
  45         /* which[i] says which element to take out of all[] and put into curr[i] */
  46         which = alloca(all_size*sizeof(*which));
  47         for (curr_size=0; curr_size<all_size; ++curr_size)
  48                 which[curr_size] = curr_size;
  49
  50         /* stores the currently examined set */
  51         curr = alloca(all_size*sizeof(*curr));
  52
  53         while (1) { /* this loop will terminate because at least a single node will be a max indep. set */
  54                 /* build current set */
  55                 for (i=0; i<curr_size; ++i)
  56                         curr[i] = all[which[all_size-curr_size+i]];
  57
  58                 /* check current set */
  59                 for (i=0; i<curr_size; ++i)
  60                         for (o=i+1; o<curr_size; ++o)
  61                                 if (nodes_interfere(ou->co->chordal_env, curr[i], curr[o]))
  62                                         goto conflict_found;
  63
  64                 /* We had no conflict. This is the (one) max indep. set */
  65                 return curr_size;
  66
  67 conflict_found:
  68                 /* We had a conflict. Generate next set */
  69                 if (which[all_size-curr_size+1] == all_size-curr_size+1) {
  70                         curr_size--;
  71                         for (i=0; i<curr_size; ++i)
  72                                 which[all_size-curr_size+i] = i;
  73                 } else {
  74                         int redo = 1;
  75                         while (redo) {
  76                                 int pos = all_size;
  77                                 do {
  78                                         pos--;
  79                                 } while (!(which[pos] = (which[pos]+1) % all_size));
  80
  81                                 for (i=pos+1; i<all_size; ++i)
  82                                         which[i] = MIN(which[i-1]+1, all_size-1);
  83
  84                                 redo = 0;
  85                                 for (i=all_size-curr_size; i<all_size-1; ++i)
  86                                         if (which[i]>=which[i+1]) {
  87                                                 redo = 1;
  88                                                 break;
  89                                         }
  90                         }
  91                 }
  92         }
  93         assert(0 && "How did you get here?");
  94 }
  95
  96 /**
  97  * Builds an optimization unit for a given optimizable irn (root).
  98  * This opt-unit is inserted in the main structure co.
  99  * If an arg of root itself is optimizable process this arg before with a
 100  * recursive call. For handling this situation and loops co->root is used
 101  * to remember all roots.
 102  */
 103 static void co_append_unit(copy_opt_t *co, ir_node *root) {
 104         int i, arity;
 105         unit_t *unit;
 106         DBG((dbg, LEVEL_1, "\t  Root: %n %N\n", root, root));
 107         /* check if we encountered this root earlier */
 108         if (pset_find_ptr(co->roots, root))
 109                 return;
 110         pset_insert_ptr(co->roots, root);
 111
 112         assert(is_curr_reg_class(root) && "node is in wrong register class!");
 113
 114         /* init unit */
 115         arity = get_irn_arity(root);
 116         unit = xcalloc(1, sizeof(*unit));
 117         unit->co = co;
 118         unit->interf = 0;
 119         unit->node_count = 1;
 120         unit->nodes = xmalloc((arity+1) * sizeof(*unit->nodes));
 121         unit->nodes[0] = root;
 122         INIT_LIST_HEAD(&unit->queue);
 123
 124         /* check all args */
 125         if (is_Phi(root)) {
 126                 for (i=0; i<arity; ++i) {
 127                         ir_node *arg = get_irn_n(root, i);
 128                         assert(is_curr_reg_class(arg) && "Argument not in same register class.");
 129                         if (arg != root) {
 130                                 if (!nodes_interfere(co->chordal_env, root, arg)) {
 131                                         DBG((dbg, LEVEL_1, "\t   Member: %n %N\n", arg, arg));
 132                                         if (is_optimizable(arg))
 133                                                 co_append_unit(co, arg);
 134                                         unit->nodes[unit->node_count++] = arg;
 135                                 } else
 136                                         unit->interf++;
 137                         }
 138                 }
 139                 unit->nodes = xrealloc(unit->nodes, unit->node_count * sizeof(*unit->nodes));
 140         } else if (is_Copy(root)) {
 141                 assert(!nodes_interfere(co->chordal_env, root, get_Copy_src(root)));
 142                 unit->nodes[unit->node_count++] = get_Copy_src(root);
 143                 unit->nodes = xrealloc(unit->nodes, 2 * sizeof(*unit->nodes));
 144         } else
 145                 assert(0 && "This is not an optimizable node!");
 146
 147         list_add_tail(&unit->units, &co->units);
 148         /* Init ifg_mis_size to node_count. So get_lower_bound returns correct results. */
 149         unit->ifg_mis_size = get_ifg_mis_size(unit);
 150 }
 151
 152 static void co_collect_in_block(ir_node *block, void *env) {
 153         copy_opt_t *co = env;
 154         struct list_head *head = get_block_border_head(co->chordal_env, block);
 155         border_t *curr;
 156
 157         list_for_each_entry_reverse(border_t, curr, head, list)
 158                 if (curr->is_def && curr->is_real && is_optimizable(curr->irn))
 159                         co_append_unit(co, curr->irn);
 160 }
 161
 162 static void co_collect_units(copy_opt_t *co) {
 163         DBG((dbg, LEVEL_1, "\tCollecting optimization units\n"));
 164         co->roots = pset_new_ptr(64);
 165         dom_tree_walk_irg(co->chordal_env->irg, co_collect_in_block, NULL, co);
 166         del_pset(co->roots);
 167 }
 168
 169 copy_opt_t *new_copy_opt(be_chordal_env_t *chordal_env) {
 170         const char *s1, *s2, *s3;
 171         int len;
 172         copy_opt_t *co;
 173
 174         dbg = firm_dbg_register("ir.be.copyopt");
 175         firm_dbg_set_mask(dbg, DEBUG_LVL);
 176
 177         co = xcalloc(1, sizeof(*co));
 178         co->chordal_env = chordal_env;
 179
 180         s1 = get_irp_prog_name();
 181         s2 = get_entity_name(get_irg_entity(co->chordal_env->irg));
 182         s3 = chordal_env->cls->name;
 183         len = strlen(s1) + strlen(s2) + strlen(s3) + 5;
 184         co->name = xmalloc(len);
 185         snprintf(co->name, len, "%s__%s__%s", s1, s2, s3);
 186         if (!strcmp(co->name, DEBUG_IRG))
 187                 firm_dbg_set_mask(dbg, DEBUG_LVL_CO);
 188         else
 189                 firm_dbg_set_mask(dbg, DEBUG_LVL);
 190
 191         INIT_LIST_HEAD(&co->units);
 192         co_collect_units(co);
 193         return co;
 194 }
 195
 196 void free_copy_opt(copy_opt_t *co) {
 197         unit_t *curr, *tmp;
 198         xfree(co->name);
 199         list_for_each_entry_safe(unit_t, curr, tmp, &co->units, units) {
 200                 xfree(curr->nodes);
 201                 xfree(curr);
 202         }
 203 }
 204
 205 int is_optimizable_arg(const copy_opt_t *co, ir_node *irn) {
 206         int i, max;
 207         for(i=0, max=get_irn_n_outs(irn); i<max; ++i) {
 208                 ir_node *n = get_irn_out(irn, i);
 209                 if ((is_Phi(n) || is_Perm(n)) && (irn == n || !nodes_interfere(co->chordal_env, irn, n)))
 210                         return 1;
 211         }
 212         return 0;
 213 }
 214
 215 int co_get_copy_count(const copy_opt_t *co) {
 216         int i, res = 0;
 217         unit_t *curr;
 218         list_for_each_entry(unit_t, curr, &co->units, units) {
 219                 int root_col = get_irn_col(co, curr->nodes[0]);
 220                 res += curr->interf;
 221                 DBG((dbg, LEVEL_1, "%n %N has %d intf\n", curr->nodes[0], curr->nodes[0], curr->interf));
 222                 for (i=1; i<curr->node_count; ++i)
 223                         if (root_col != get_irn_col(co, curr->nodes[i])) {
 224                                 DBG((dbg, LEVEL_1, "  %n %N\n", curr->nodes[i], curr->nodes[i]));
 225                                 res++;
 226                         }
 227         }
 228         return res;
 229 }
 230
 231 int co_get_lower_bound(const copy_opt_t *co) {
 232         int res = 0;
 233         unit_t *curr;
 234         list_for_each_entry(unit_t, curr, &co->units, units)
 235                 res += curr->interf + curr->node_count - curr->ifg_mis_size;
 236         return res;
 237 }
 238
 239 int co_get_interferer_count(const copy_opt_t *co) {
 240         int res = 0;
 241         unit_t *curr;
 242         list_for_each_entry(unit_t, curr, &co->units, units)
 243                 res += curr->interf;
 244         return res;
 245 }
 246
 247 /**
 248  * Needed for result checking
 249  */
 250 static void co_collect_for_checker(ir_node *block, void *env) {
 251         copy_opt_t *co = env;
 252         struct list_head *head = get_block_border_head(co->chordal_env, block);
 253         border_t *curr;
 254
 255         list_for_each_entry_reverse(border_t, curr, head, list)
 256                 if (curr->is_def && curr->is_real && is_curr_reg_class(curr->irn))
 257                         obstack_ptr_grow(&co->ob, curr->irn);
 258 }
 259
 260 /**
 261  * This O(n^2) checker checks if
 262  *      two ifg-connected nodes have the same color
 263  *      register constraint are satisfied
 264  */
 265 void co_check_allocation(copy_opt_t *co) {
 266         ir_node **nodes, *n1, *n2;
 267         int i, o;
 268
 269         obstack_init(&co->ob);
 270         dom_tree_walk_irg(co->chordal_env->irg, co_collect_for_checker, NULL, co);
 271         obstack_ptr_grow(&co->ob, NULL);
 272
 273         nodes = (ir_node **) obstack_finish(&co->ob);
 274         for (i = 0, n1 = nodes[i]; n1; n1 = nodes[++i]) {
 275                 assert(arch_reg_is_allocatable(co->chordal_env->arch_env, n1, arch_pos_make_out(0),
 276                         arch_get_irn_register(co->chordal_env->arch_env, n1, 0)) && "Constraint does not hold");
 277                 for (o = i+1, n2 = nodes[o]; n2; n2 = nodes[++o])
 278                         if (nodes_interfere(co->chordal_env, n1, n2)
 279           && get_irn_col(co, n1) == get_irn_col(co, n2)) {
 280                                 DBG((dbg, 0, "Error in graph %s: %n %d  and  %n %d have the same color %d.\n", co->name, n1, get_irn_graph_nr(n1), n2, get_irn_graph_nr(n2), get_irn_col(co, n1)));
 281                                 assert(0 && "Interfering values have the same color!");
 282                         }
 283         }
 284         obstack_free(&co->ob, NULL);
 285         DBG((dbg, 2, "The checker seems to be happy!\n"));
 286 }