Cosmetics, changed loop-costs to d^2+1.
[libfirm] / ir / be / becopyheur.c
index 55092fe..4659f8f 100644 (file)
@@ -26,8 +26,8 @@
 #include "xmalloc.h"
 #include "becopyopt.h"
 #include "becopystat.h"
+#include "bitset.h"
 
-#define DEBUG_LVL 0 //SET_LEVEL_1
 static firm_dbg_module_t *dbg = NULL;
 
 #define SLOTS_PINNED_GLOBAL 256
@@ -63,7 +63,8 @@ typedef struct _qnode_t {
        const unit_t *ou;                       /**< the opt unit this qnode belongs to */
        int color;                                      /**< target color */
        set *conflicts;                         /**< contains conflict_t's. All internal conflicts */
-       int mis_size;                           /**< number of nodes in the mis. */
+       int mis_costs;                          /**< costs of nodes/copies in the mis. */
+       int mis_size;                           /**< size of the array below */
        ir_node **mis;                          /**< the nodes of unit_t->nodes[] being part of the max independent set */
        set *changed_nodes;                     /**< contains node_stat_t's. */
 } qnode_t;
@@ -82,7 +83,7 @@ static int set_cmp_conflict_t(const void *x, const void *y, size_t size) {
  */
 static INLINE void qnode_add_conflict(const qnode_t *qn, const ir_node *n1, const ir_node *n2) {
        conflict_t c;
-       DBG((dbg, LEVEL_4, "\t      %n -- %n\n", n1, n2));
+       DBG((dbg, LEVEL_4, "\t      %+F -- %+F\n", n1, n2));
 
        if ((int)n1 < (int)n2) {
                c.n1 = n1;
@@ -207,15 +208,17 @@ static ir_node *qnode_color_irn(const qnode_t *qn, ir_node *irn, int col, const
        ir_node **confl, *cn;
        int i, irn_col;
        const be_chordal_env_t *chordal_env = qn->ou->co->chordal_env;
-       const arch_env_t *arch_env = chordal_env->arch_env;
+       const arch_env_t *arch_env = get_arch_env(qn->ou->co);
        const arch_register_class_t *cls = chordal_env->cls;
 
-       DBG((dbg, LEVEL_3, "\t      %n \tcaused col(%n) \t%2d --> %2d\n", trigger, irn, qnode_get_new_color(qn, irn), col));
+       DBG((dbg, LEVEL_3, "\t      %+F \tcaused col(%+F) \t%2d --> %2d\n", trigger, irn, qnode_get_new_color(qn, irn), col));
        obstack_init(&confl_ob);
        irn_col = qnode_get_new_color(qn, irn);
 
-       if (irn_col == col)
+       if (irn_col == col) {
+               DBG((dbg, LEVEL_4, "\t      Already same color.\n"));
                goto ret_save;
+       }
        if (pset_find_ptr(pinned_global, irn) || qnode_is_pinned_local(qn, irn)) {
                res = irn;
                goto ret_confl;
@@ -238,15 +241,17 @@ static ir_node *qnode_color_irn(const qnode_t *qn, ir_node *irn, int col, const
                {
                        ir_node *n;
                        pset *live_ins = put_live_in(irn_bl, pset_new_ptr_default());
-                       for (n = pset_first(live_ins); n; n = pset_next(live_ins))
+                       for (n = pset_first(live_ins); n; n = pset_next(live_ins)) {
+                               DBG((dbg, LEVEL_4, "Checking %+F which is live-in at the block\n", n));
                                if (arch_irn_has_reg_class(arch_env, n, arch_pos_make_out(0), cls)
-            && n != trigger && qnode_get_new_color(qn, n) == col
-            && nodes_interfere(chordal_env, irn, n)) {
+                                       && n != trigger && qnode_get_new_color(qn, n) == col
+                                       && nodes_interfere(chordal_env, irn, n)) {
 
-                                       DBG((dbg, LEVEL_4, "\t        %n\ttroubles\n", n));
+                                       DBG((dbg, LEVEL_4, "\t        %+F\ttroubles\n", n));
                                        obstack_ptr_grow(&confl_ob, n);
                                        pset_break(live_ins);
                                        break;
+                               }
                        }
             del_pset(live_ins);
                }
@@ -270,12 +275,12 @@ static ir_node *qnode_color_irn(const qnode_t *qn, ir_node *irn, int col, const
                         * the target color and interfere with the irn */
                        for (i = 0, max = get_irn_n_outs(curr_bl); i < max; ++i) {
                                ir_node *n = get_irn_out(curr_bl, i);
+                               DBG((dbg, LEVEL_4, "Checking %+F defined in same block\n", n));
                                if (arch_irn_has_reg_class(arch_env, n, arch_pos_make_out(0), cls)
-            && n != trigger && qnode_get_new_color(qn, n) == col
-            && nodes_interfere(chordal_env, irn, n)) {
-
-                                       DBG((dbg, LEVEL_4, "\t        %n\ttroubles\n", n));
-                                       obstack_ptr_grow(&confl_ob, n);
+                                       && n != trigger && qnode_get_new_color(qn, n) == col
+                                       && nodes_interfere(chordal_env, irn, n)) {
+                                               DBG((dbg, LEVEL_4, "\t        %+F\ttroubles\n", n));
+                                               obstack_ptr_grow(&confl_ob, n);
                                }
                        }
 
@@ -308,18 +313,18 @@ static ir_node *qnode_color_irn(const qnode_t *qn, ir_node *irn, int col, const
        /* if we arrive here all sub changes can be applied, so it's save to change this irn */
 
 ret_save:
-       DBG((dbg, LEVEL_3, "\t      %n save\n", irn));
+       DBG((dbg, LEVEL_3, "\t      %+F save\n", irn));
        obstack_free(&confl_ob, NULL);
        qnode_set_new_color(qn, irn, col);
        return CHANGE_SAVE;
 
 ret_imposs:
-       DBG((dbg, LEVEL_3, "\t      %n impossible\n", irn));
+       DBG((dbg, LEVEL_3, "\t      %+F impossible\n", irn));
        obstack_free(&confl_ob, NULL);
        return CHANGE_IMPOSSIBLE;
 
 ret_confl:
-       DBG((dbg, LEVEL_3, "\t      %n conflicting\n", irn));
+       DBG((dbg, LEVEL_3, "\t      %+F conflicting\n", irn));
        obstack_free(&confl_ob, NULL);
        return res;
 }
@@ -336,7 +341,7 @@ static int qnode_try_color(const qnode_t *qn) {
                ir_node *test_node, *confl_node;
 
                test_node = qn->mis[i];
-               DBG((dbg, LEVEL_3, "\t    Testing %n\n", test_node));
+               DBG((dbg, LEVEL_3, "\t    Testing %+F\n", test_node));
                confl_node = qnode_color_irn(qn, test_node, qn->color, test_node);
 
                if (confl_node == CHANGE_SAVE) {
@@ -348,8 +353,16 @@ static int qnode_try_color(const qnode_t *qn) {
                } else {
                        if (qnode_is_pinned_local(qn, confl_node)) {
                                /* changing test_node would change back a node of current ou */
-                               DBG((dbg, LEVEL_3, "\t    Conflicting local --> add conflict\n"));
-                               qnode_add_conflict(qn, confl_node, test_node);
+                               if (confl_node == qn->ou->nodes[0]) {
+                                       /* Adding a conflict edge between testnode and conflnode
+                                        * would introduce a root -- arg interference.
+                                        * So remove the arg of the qn */
+                                       DBG((dbg, LEVEL_3, "\t    Conflicting local with phi --> remove from qnode\n"));
+                                       qnode_add_conflict(qn, test_node, test_node);
+                               } else {
+                                       DBG((dbg, LEVEL_3, "\t    Conflicting local --> add conflict\n"));
+                                       qnode_add_conflict(qn, confl_node, test_node);
+                               }
                        }
                        if (pset_find_ptr(pinned_global, confl_node)) {
                                /* changing test_node would change back a node of a prior ou */
@@ -365,71 +378,84 @@ static int qnode_try_color(const qnode_t *qn) {
 }
 
 /**
- * Determines a maximum independent set with respect to the interference and
- * conflict edges of all nodes in a qnode.
+ * 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 INLINE void qnode_max_ind_set(qnode_t *qn, const unit_t *ou) {
-       int all_size, curr_size, i, o;
-       int *which;
-       ir_node **curr, **all = alloca(ou->node_count * sizeof(*all));
+       ir_node **safe, **unsafe;
+       int i, o, safe_count, safe_costs, unsafe_count, *unsafe_costs;
+       bitset_t *curr, *best;
+       int max, next, 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 (qnode_are_conflicting(qn, ou->nodes[i], ou->nodes[o])) {
+                               if (i!=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];
+               }
+       }
 
-       /* all contains all nodes not removed in this qn */
-       all_size = 0;
-       for (i=0; i<ou->node_count; ++i)
-               if (!qnode_are_conflicting(qn, ou->nodes[i], ou->nodes[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 (qnode_are_conflicting(qn, curr[i], curr[o]))
-                                       goto conflict_found;
-
-               /* We had no conflict. This is the max indep. set */
-               qn->mis_size = curr_size;
-               for (i=0; i<curr_size; ++i)
-                       qn->mis[i] = curr[i];
-               return;
 
-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;
-                                       }
-                       }
+
+       /* now brute force the best set out of the unsafe nodes*/
+       best = bitset_alloca(unsafe_count);
+       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); o!=-1; o=bitset_next_set(curr, o+1)) /* !!!!! difference to ou_max_ind_set_costs(): NOT (curr, i+1) */
+                                       if (qnode_are_conflicting(qn, 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;
+                       bitset_copy(best, curr);
                }
+
+no_stable_set:
+               bitset_minus1(curr);
        }
+
+       /* transfer the best set into the qn */
+       qn->mis_size = 1+safe_count+bitset_popcnt(best);
+       qn->mis_costs = safe_costs+best_weight;
+       qn->mis[0] = ou->nodes[0]; /* the root is alwazs in a max stable set */
+       next = 1;
+       for (i=0; i<safe_count; ++i)
+               qn->mis[next++] = safe[i];
+       bitset_foreach(best, pos)
+               qn->mis[next++] = unsafe[pos];
 }
 
 /**
@@ -470,11 +496,11 @@ static INLINE void ou_insert_qnode(unit_t *ou, qnode_t *qn) {
 
        qnode_max_ind_set(qn, ou);
        /* do the insertion */
-       DBG((dbg, LEVEL_4, "\t  Insert qnode color %d with size %d\n", qn->color, qn->mis_size));
+       DBG((dbg, LEVEL_4, "\t  Insert qnode color %d with cost %d\n", qn->color, qn->mis_costs));
        lh = &ou->queue;
        while (lh->next != &ou->queue) {
                qnode_t *curr = list_entry_queue(lh->next);
-               if (curr->mis_size <= qn->mis_size)
+               if (curr->mis_costs <= qn->mis_costs)
                        break;
                lh = lh->next;
        }
@@ -482,10 +508,10 @@ static INLINE void ou_insert_qnode(unit_t *ou, qnode_t *qn) {
 }
 
 /**
- * Tries to re-allocate colors of nodes in this opt unit, to achieve lower
- * number of copy instructions placed during SSA-destruction and lowering.
+ * Tries to re-allocate colors of nodes in this opt unit, to achieve lower
+ * costs of copy instructions placed during SSA-destruction and lowering.
  * Works only for opt units with exactly 1 root node, which is the
- * case for approximately 80% of all phi classes and all register constrained
+ * case for approximately 80% of all phi classes and 100% of register constrained
  * nodes. (All other phi classes are reduced to this case.)
  */
 static void ou_optimize(unit_t *ou) {
@@ -495,11 +521,11 @@ static void ou_optimize(unit_t *ou) {
 
        DBG((dbg, LEVEL_1, "\tOptimizing unit:\n"));
        for (i=0; i<ou->node_count; ++i)
-               DBG((dbg, LEVEL_1, "\t %n\n", ou->nodes[i]));
+               DBG((dbg, LEVEL_1, "\t %+F\n", ou->nodes[i]));
 
        /* init queue */
        INIT_LIST_HEAD(&ou->queue);
-       arch_get_allocatable_regs(ou->co->chordal_env->arch_env, ou->nodes[0], arch_pos_make_out(0), ou->co->chordal_env->cls, pos_regs);
+       arch_get_allocatable_regs(get_arch_env(ou->co), ou->nodes[0], arch_pos_make_out(0), ou->co->chordal_env->cls, pos_regs);
        bitset_foreach(pos_regs, i)
                ou_insert_qnode(ou, new_qnode(ou, i));
 
@@ -508,7 +534,7 @@ static void ou_optimize(unit_t *ou) {
                /* get head of queue */
                curr = list_entry_queue(ou->queue.next);
                list_del(&curr->queue);
-               DBG((dbg, LEVEL_2, "\t  Examine qnode color %d with size %d\n", curr->color, curr->mis_size));
+               DBG((dbg, LEVEL_2, "\t  Examine qnode color %d with cost %d\n", curr->color, curr->mis_costs));
 
                /* try */
                if (qnode_try_color(curr))
@@ -522,9 +548,8 @@ static void ou_optimize(unit_t *ou) {
        /* apply the best found qnode */
        if (curr->mis_size >= 2) {
                node_stat_t *ns;
-
-               DBG((dbg, LEVEL_1, "\t  Best color: %d  Copies: %d/%d\n", curr->color, ou->interf+ou->node_count-curr->mis_size, ou->interf+ou->node_count-1));
-               /* globally pin root and eventually others */
+               DBG((dbg, LEVEL_1, "\t  Best color: %d  Costs: %d << %d << %d\n", curr->color, ou->min_nodes_costs, ou->all_nodes_costs - curr->mis_costs, ou->all_nodes_costs));
+               /* globally pin root and all args which have the same color */
                pset_insert_ptr(pinned_global, ou->nodes[0]);
                for (i=1; i<ou->node_count; ++i) {
                        ir_node *irn = ou->nodes[i];
@@ -537,10 +562,14 @@ static void ou_optimize(unit_t *ou) {
                for (ns = set_first(curr->changed_nodes); ns; ns = set_next(curr->changed_nodes)) {
                        /* NO_COLOR is possible, if we had an undo */
                        if (ns->new_color != NO_COLOR) {
-                               DBG((dbg, LEVEL_2, "\t    color(%n) := %d\n", ns->irn, ns->new_color));
+                               DBG((dbg, LEVEL_1, "\t    color(%+F) := %d\n", ns->irn, ns->new_color));
                                set_irn_col(ou->co, ns->irn, ns->new_color);
                        }
                }
+               /*
+                * Enable for checking register allocation after each ou
+                * be_ra_chordal_check(ou->co->chordal_env);
+                */
        }
 
        /* free best qnode (curr) and queue */
@@ -552,11 +581,10 @@ static void ou_optimize(unit_t *ou) {
 void co_heur_opt(copy_opt_t *co) {
        unit_t *curr;
        dbg = firm_dbg_register("ir.be.copyoptheur");
-       firm_dbg_set_mask(dbg, DEBUG_LVL);
        if (!strcmp(co->name, DEBUG_IRG))
-               firm_dbg_set_mask(dbg, DEBUG_LVL_HEUR);
+               firm_dbg_set_mask(dbg, DEBUG_IRG_LVL_HEUR);
        else
-               firm_dbg_set_mask(dbg, DEBUG_LVL);
+               firm_dbg_set_mask(dbg, DEBUG_LVL_HEUR);
 
        pinned_global = pset_new_ptr(SLOTS_PINNED_GLOBAL);
        list_for_each_entry(unit_t, curr, &co->units, units)