Cosmetics, changed loop-costs to d^2+1.
[libfirm] / ir / be / becopyopt.c
index 667bf90..e719371 100644 (file)
 #endif
 
 #include "irprog.h"
+#include "irloop_t.h"
 
 #include "xmalloc.h"
 #include "bechordal_t.h"
 #include "becopyopt.h"
 #include "becopystat.h"
 
-#define DEBUG_LVL 0 //SET_LEVEL_1
 static firm_dbg_module_t *dbg = NULL;
 
-#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)
+#define is_curr_reg_class(irn) \
+  (arch_get_irn_reg_class(get_arch_env(co), \
+                          irn, arch_pos_make_out(0)) == co->chordal_env->cls)
 
 #define MIN(a,b) ((a<b)?(a):(b))
+#define MAX(a,b) ((a<b)?(b):(a))
+
 
 /**
- * Computes a 'max independent set' wrt. ifg-edges only (no coloring conflicts, no register constraints)
- * @return The size of such a mis
- * NOTE: Code adapted from becopyheur
- * BETTER: Here we can be sure having a chordal graph to work on, so for 'larger' opt-units we
- *         could use a special algorithm.
+ * Determines a maximum weighted independent set with respect to
+ * the interference and conflict edges of all nodes in a qnode.
+ * TODO: This runs in 2^n in worst case. Use a heuristic iff n>???
  */
-static int get_ifg_mis_size(unit_t *ou) {
-       int all_size, curr_size, i, o;
-       int *which;
-       ir_node **curr, **all = alloca(ou->node_count * sizeof(*all));
-
-       /* all contains all nodes */
-       all_size = 0;
-       for (i=0; i<ou->node_count; ++i)
-               all[all_size++] = ou->nodes[i];
-
-       /* which[i] says which element to take out of all[] and put into curr[i] */
-       which = alloca(all_size*sizeof(*which));
-       for (curr_size=0; curr_size<all_size; ++curr_size)
-               which[curr_size] = curr_size;
-
-       /* stores the currently examined set */
-       curr = alloca(all_size*sizeof(*curr));
-
-       while (1) { /* this loop will terminate because at least a single node will be a max indep. set */
-               /* build current set */
-               for (i=0; i<curr_size; ++i)
-                       curr[i] = all[which[all_size-curr_size+i]];
-
-               /* check current set */
-               for (i=0; i<curr_size; ++i)
-                       for (o=i+1; o<curr_size; ++o)
-                               if (nodes_interfere(ou->co->chordal_env, curr[i], curr[o]))
-                                       goto conflict_found;
-
-               /* We had no conflict. This is the (one) max indep. set */
-               return curr_size;
-
-conflict_found:
-               /* We had a conflict. Generate next set */
-               if (which[all_size-curr_size+1] == all_size-curr_size+1) {
-                       curr_size--;
-                       for (i=0; i<curr_size; ++i)
-                               which[all_size-curr_size+i] = i;
-               } else {
-                       int redo = 1;
-                       while (redo) {
-                               int pos = all_size;
-                               do {
-                                       pos--;
-                               } while (!(which[pos] = (which[pos]+1) % all_size));
-
-                               for (i=pos+1; i<all_size; ++i)
-                                       which[i] = MIN(which[i-1]+1, all_size-1);
-
-                               redo = 0;
-                               for (i=all_size-curr_size; i<all_size-1; ++i)
-                                       if (which[i]>=which[i+1]) {
-                                               redo = 1;
-                                               break;
-                                       }
+static int ou_max_ind_set_costs(unit_t *ou) {
+       be_chordal_env_t *chordal_env = ou->co->chordal_env;
+       ir_node **safe, **unsafe;
+       int i, o, safe_count, safe_costs, unsafe_count, *unsafe_costs;
+       bitset_t *curr;
+       int max, pos, curr_weight, best_weight = 0;
+
+       /* assign the nodes into two groups.
+        * safe: node has no interference, hence it is in every max stable set.
+        * unsafe: node has an interference
+        */
+       safe = alloca((ou->node_count-1) * sizeof(*safe));
+       safe_costs = 0;
+       safe_count = 0;
+       unsafe = alloca((ou->node_count-1) * sizeof(*unsafe));
+       unsafe_costs = alloca((ou->node_count-1) * sizeof(*unsafe_costs));
+       unsafe_count = 0;
+       for(i=1; i<ou->node_count; ++i) {
+               int is_safe = 1;
+               for(o=1; o<ou->node_count; ++o) {
+                       if (i==o)
+                               continue;
+                       if (nodes_interfere(chordal_env, ou->nodes[i], ou->nodes[o])) {
+                               unsafe_costs[unsafe_count] = ou->costs[i];
+                               unsafe[unsafe_count] = ou->nodes[i];
+                               ++unsafe_count;
+                               is_safe = 0;
+                               break;
                        }
                }
+               if (is_safe) {
+                       safe_costs += ou->costs[i];
+                       safe[safe_count++] = ou->nodes[i];
+               }
+       }
+
+
+
+       /* now brute force the best set out of the unsafe nodes*/
+       curr = bitset_alloca(unsafe_count);
+
+       bitset_set_all(curr);
+       while ((max = bitset_popcnt(curr)) != 0) {
+               /* check if curr is a stable set */
+               for (i=bitset_next_set(curr, 0); i!=-1; i=bitset_next_set(curr, i+1))
+                       for (o=bitset_next_set(curr, i+1); o!=-1; o=bitset_next_set(curr, o+1)) /* !!!!! difference to qnode_max_ind_set(): NOT (curr, i) */
+                                       if (nodes_interfere(chordal_env, unsafe[i], unsafe[o]))
+                                               goto no_stable_set;
+
+               /* if we arrive here, we have a stable set */
+               /* compute the weigth of the stable set*/
+               curr_weight = 0;
+               bitset_foreach(curr, pos)
+                       curr_weight += unsafe_costs[pos];
+
+               /* any better ? */
+               if (curr_weight > best_weight) {
+                       best_weight = curr_weight;
+               }
+
+no_stable_set:
+               bitset_minus1(curr);
        }
-       assert(0 && "How did you get here?");
+
+       return safe_costs+best_weight;
 }
 
 /**
@@ -106,6 +114,8 @@ conflict_found:
 static void co_append_unit(copy_opt_t *co, ir_node *root) {
        int i, arity;
        unit_t *unit;
+       struct list_head *tmp;
+
        DBG((dbg, LEVEL_1, "\t  Root: %n %N\n", root, root));
        /* check if we encountered this root earlier */
        if (pset_find_ptr(co->roots, root))
@@ -118,38 +128,74 @@ static void co_append_unit(copy_opt_t *co, ir_node *root) {
        arity = get_irn_arity(root);
        unit = xcalloc(1, sizeof(*unit));
        unit->co = co;
-       unit->interf = 0;
-       unit->node_count = 1;
        unit->nodes = xmalloc((arity+1) * sizeof(*unit->nodes));
+       unit->costs = xmalloc((arity+1) * sizeof(*unit->costs));
+       unit->node_count = 1;
        unit->nodes[0] = root;
        INIT_LIST_HEAD(&unit->queue);
 
        /* check all args */
-       if (is_Phi(root)) {
+       if (is_Phi(root) && mode_is_datab(get_irn_mode(root))) {
                for (i=0; i<arity; ++i) {
+                       int o, arg_pos = 0;
                        ir_node *arg = get_irn_n(root, i);
+
                        assert(is_curr_reg_class(arg) && "Argument not in same register class.");
-                       if (arg != root) {
-                               if (!nodes_interfere(co->chordal_env, root, arg)) {
-                                       DBG((dbg, LEVEL_1, "\t   Member: %n %N\n", arg, arg));
-                                       if (is_optimizable(co->chordal_env->arch_env, arg))
-                                               co_append_unit(co, arg);
-                                       unit->nodes[unit->node_count++] = arg;
-                               } else
-                                       unit->interf++;
+                       if (arg == root)
+                               continue;
+                       if (nodes_interfere(co->chordal_env, root, arg)) {
+                               unit->inevitable_costs += co->get_costs(root, arg, i);
+                               continue;
+                       }
+
+                       /* Else insert the argument of the phi to the members of this ou */
+                       DBG((dbg, LEVEL_1, "\t   Member: %n %N\n", arg, arg));
+
+                       /* Check if arg has occurred at a prior position in the arg/list */
+                       for (o=0; o<unit->node_count; ++o)
+                               if (unit->nodes[o] == arg) {
+                                       arg_pos = o;
+                                       break;
+                               }
+
+                       if (!arg_pos) { /* a new argument */
+                               /* insert node, set costs */
+                               unit->nodes[unit->node_count] = arg;
+                               unit->costs[unit->node_count] = co->get_costs(root, arg, i);
+                               unit->node_count++;
+                       } else { /* arg has occured before in same phi */
+                               /* increase costs for existing arg */
+                               unit->costs[arg_pos] += co->get_costs(root, arg, i);
                        }
                }
                unit->nodes = xrealloc(unit->nodes, unit->node_count * sizeof(*unit->nodes));
-       } else if (is_Copy(co->chordal_env->arch_env, root)) {
+               unit->costs = xrealloc(unit->costs, unit->node_count * sizeof(*unit->costs));
+       } else if (is_Copy(get_arch_env(co), root)) {
                assert(!nodes_interfere(co->chordal_env, root, get_Copy_src(root)));
-               unit->nodes[unit->node_count++] = get_Copy_src(root);
+               unit->nodes[1] = get_Copy_src(root);
+               unit->costs[1] = co->get_costs(root, unit->nodes[1], -1);
+               unit->node_count = 2;
                unit->nodes = xrealloc(unit->nodes, 2 * sizeof(*unit->nodes));
+               unit->costs = xrealloc(unit->costs, 2 * sizeof(*unit->costs));
        } else
                assert(0 && "This is not an optimizable node!");
+       /* TODO add ou's for 2-addr-code instructions */
+
+
+       /* Determine the maximum costs this unit can cause: all_nodes_cost */
+       for(i=1; i<unit->node_count; ++i) {
+               unit->sort_key = MAX(unit->sort_key, unit->costs[i]);
+               unit->all_nodes_costs += unit->costs[i];
+       }
+
+       /* Determine the minimal costs this unit will cause: min_nodes_costs */
+       unit->min_nodes_costs += unit->all_nodes_costs - ou_max_ind_set_costs(unit);
 
-       list_add_tail(&unit->units, &co->units);
-       /* Init ifg_mis_size to node_count. So get_lower_bound returns correct results. */
-       unit->ifg_mis_size = get_ifg_mis_size(unit);
+       /* Insert the new ou according to its sort_key */
+       tmp = &co->units;
+       while (tmp->next != &co->units && list_entry_units(tmp->next)->sort_key > unit->sort_key)
+               tmp = tmp->next;
+       list_add(&unit->units, tmp);
 }
 
 static void co_collect_in_block(ir_node *block, void *env) {
@@ -158,38 +204,39 @@ static void co_collect_in_block(ir_node *block, void *env) {
        border_t *curr;
 
        list_for_each_entry_reverse(border_t, curr, head, list)
-               if (curr->is_def && curr->is_real && is_optimizable(co->chordal_env->arch_env, curr->irn))
+               if (curr->is_def && curr->is_real && is_optimizable(get_arch_env(co), curr->irn))
                        co_append_unit(co, curr->irn);
 }
 
 static void co_collect_units(copy_opt_t *co) {
        DBG((dbg, LEVEL_1, "\tCollecting optimization units\n"));
        co->roots = pset_new_ptr(64);
-       dom_tree_walk_irg(co->chordal_env->irg, co_collect_in_block, NULL, co);
+       dom_tree_walk_irg(get_irg(co), co_collect_in_block, NULL, co);
        del_pset(co->roots);
 }
 
-copy_opt_t *new_copy_opt(be_chordal_env_t *chordal_env) {
+copy_opt_t *new_copy_opt(be_chordal_env_t *chordal_env, int (*get_costs)(ir_node*, ir_node*, int)) {
        const char *s1, *s2, *s3;
        int len;
-        copy_opt_t *co;
+       copy_opt_t *co;
 
        dbg = firm_dbg_register("ir.be.copyopt");
-       firm_dbg_set_mask(dbg, DEBUG_LVL);
+       firm_dbg_set_mask(dbg, DEBUG_LVL_CO);
 
        co = xcalloc(1, sizeof(*co));
        co->chordal_env = chordal_env;
+       co->get_costs = get_costs;
 
        s1 = get_irp_prog_name();
-       s2 = get_entity_name(get_irg_entity(co->chordal_env->irg));
+       s2 = get_entity_name(get_irg_entity(get_irg(co)));
        s3 = chordal_env->cls->name;
        len = strlen(s1) + strlen(s2) + strlen(s3) + 5;
        co->name = xmalloc(len);
        snprintf(co->name, len, "%s__%s__%s", s1, s2, s3);
        if (!strcmp(co->name, DEBUG_IRG))
-               firm_dbg_set_mask(dbg, DEBUG_LVL_CO);
+               firm_dbg_set_mask(dbg, DEBUG_IRG_LVL_CO);
        else
-               firm_dbg_set_mask(dbg, DEBUG_LVL);
+               firm_dbg_set_mask(dbg, DEBUG_LVL_CO);
 
        INIT_LIST_HEAD(&co->units);
        co_collect_units(co);
@@ -209,81 +256,81 @@ int is_optimizable_arg(const copy_opt_t *co, ir_node *irn) {
        int i, max;
        for(i=0, max=get_irn_n_outs(irn); i<max; ++i) {
                ir_node *n = get_irn_out(irn, i);
-               if ((is_Phi(n) || is_Perm(co->chordal_env->arch_env, n)) && (irn == n || !nodes_interfere(co->chordal_env, irn, n)))
+               if (((is_Phi(n) && mode_is_datab(get_irn_mode(n))) ||
+                        is_Perm(get_arch_env(co), n)) && (irn == n || !nodes_interfere(co->chordal_env, irn, n)))
                        return 1;
        }
        return 0;
 }
 
-int co_get_copy_count(const copy_opt_t *co) {
+int get_costs_loop_depth(ir_node *root, ir_node* arg, int pos) {
+       int cost = 0;
+       ir_loop *loop;
+       ir_node *root_block = get_nodes_block(root);
+
+       assert(pos==-1 || is_Phi(root));
+       if (pos == -1) {
+               /* a perm places the copy in the same block as it resides */
+               loop = get_irn_loop(root_block);
+       } else {
+               /* for phis the copies are placed in the corresponding pred-block */
+               loop = get_irn_loop(get_Block_cfgpred_block(root_block, pos));
+       }
+       if (loop) {
+               int d = get_loop_depth(loop);
+               cost = d*d;
+       }
+       return cost+1;
+}
+
+int get_costs_all_one(ir_node *root, ir_node* arg, int pos) {
+       return 1;
+}
+
+int co_get_max_copy_costs(const copy_opt_t *co) {
        int i, res = 0;
        unit_t *curr;
+
        list_for_each_entry(unit_t, curr, &co->units, units) {
-               int root_col = get_irn_col(co, curr->nodes[0]);
-               res += curr->interf;
-               DBG((dbg, LEVEL_1, "%n %N has %d intf\n", curr->nodes[0], curr->nodes[0], curr->interf));
+               res += curr->inevitable_costs;
                for (i=1; i<curr->node_count; ++i)
-                       if (root_col != get_irn_col(co, curr->nodes[i])) {
-                               DBG((dbg, LEVEL_1, "  %n %N\n", curr->nodes[i], curr->nodes[i]));
-                               res++;
-                       }
+                       res += curr->costs[i];
        }
        return res;
 }
 
-int co_get_lower_bound(const copy_opt_t *co) {
+int co_get_inevit_copy_costs(const copy_opt_t *co) {
        int res = 0;
        unit_t *curr;
-       list_for_each_entry(unit_t, curr, &co->units, units)
-               res += curr->interf + curr->node_count - curr->ifg_mis_size;
-       return res;
-}
 
-int co_get_interferer_count(const copy_opt_t *co) {
-       int res = 0;
-       unit_t *curr;
        list_for_each_entry(unit_t, curr, &co->units, units)
-               res += curr->interf;
+               res += curr->inevitable_costs;
        return res;
 }
 
-/**
- * Needed for result checking
- */
-static void co_collect_for_checker(ir_node *block, void *env) {
-       copy_opt_t *co = env;
-       struct list_head *head = get_block_border_head(co->chordal_env, block);
-       border_t *curr;
-
-       list_for_each_entry_reverse(border_t, curr, head, list)
-               if (curr->is_def && curr->is_real && is_curr_reg_class(curr->irn))
-                       obstack_ptr_grow(&co->ob, curr->irn);
-}
+int co_get_copy_costs(const copy_opt_t *co) {
+       int i, res = 0;
+       unit_t *curr;
 
-/**
- * This O(n^2) checker checks if
- *     two ifg-connected nodes have the same color
- *     register constraint are satisfied
- */
-void co_check_allocation(copy_opt_t *co) {
-       ir_node **nodes, *n1, *n2;
-       int i, o;
-
-       obstack_init(&co->ob);
-       dom_tree_walk_irg(co->chordal_env->irg, co_collect_for_checker, NULL, co);
-       obstack_ptr_grow(&co->ob, NULL);
-
-       nodes = (ir_node **) obstack_finish(&co->ob);
-       for (i = 0, n1 = nodes[i]; n1; n1 = nodes[++i]) {
-               assert(arch_reg_is_allocatable(co->chordal_env->arch_env, n1, arch_pos_make_out(0),
-                       arch_get_irn_register(co->chordal_env->arch_env, n1, 0)) && "Constraint does not hold");
-               for (o = i+1, n2 = nodes[o]; n2; n2 = nodes[++o])
-                       if (nodes_interfere(co->chordal_env, n1, n2)
-          && get_irn_col(co, n1) == get_irn_col(co, n2)) {
-                               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)));
-                               assert(0 && "Interfering values have the same color!");
+       list_for_each_entry(unit_t, curr, &co->units, units) {
+               int root_col = get_irn_col(co, curr->nodes[0]);
+               DBG((dbg, LEVEL_1, "  %3d costs for root %+F color %d\n", curr->inevitable_costs, curr->nodes[0], root_col));
+               res += curr->inevitable_costs;
+               for (i=1; i<curr->node_count; ++i) {
+                       int arg_col = get_irn_col(co, curr->nodes[i]);
+                       if (root_col != arg_col) {
+                               DBG((dbg, LEVEL_1, "  %3d for arg %+F color %d\n", curr->costs[i], curr->nodes[i], arg_col));
+                               res += curr->costs[i];
                        }
+               }
        }
-       obstack_free(&co->ob, NULL);
-       DBG((dbg, 2, "The checker seems to be happy!\n"));
+       return res;
+}
+
+int co_get_lower_bound(const copy_opt_t *co) {
+       int res = 0;
+       unit_t *curr;
+       list_for_each_entry(unit_t, curr, &co->units, units)
+               res += curr->inevitable_costs + curr->min_nodes_costs;
+       return res;
 }