* Heuristic for minimizing copies using a queue which holds 'qnodes' not yet
* examined. A qnode has a 'target color', nodes out of the opt unit and
- * a 'conflict graph'. A 'max indep set' is determined form these. We try to
- * color this mis using a color-exchanging mechanism. Occuring conflicts are
- * modeled with 'conflict edges' and the qnode is reinserted in the queue. The
- * first qnode colored without conflicts is the best one.
+ * a 'conflict graph'. 'Conflict graph' = "Interference graph' + 'conflict edges'
+ * A 'max indep set' is determined form these. We try to color this mis using a
+ * color-exchanging mechanism. Occuring conflicts are modeled with 'conflict edges'
+ * and the qnode is reinserted in the queue. The first qnode colored without
+ * conflicts is the best one.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#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;
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;
struct obstack confl_ob;
ir_node **confl, *cn;
int i, irn_col;
- const arch_env_t *arch_env = qn->ou->co->env;
- const be_chordal_env_t *chordal_env = qn->ou->co->chordal_env;
+ const be_chordal_env_t *chordal_env = qn->ou->co->chordal_env;
+ const arch_env_t *arch_env = chordal_env->arch_env;
+ 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));
obstack_init(&confl_ob);
if (!arch_reg_is_allocatable(arch_env,
irn,
arch_pos_make_out(0),
- arch_register_for_index(qn->ou->co->cls, col)))
+ arch_register_for_index(cls, col)))
goto ret_imposs;
/* get all nodes which would conflict with this change */
/* first check for a conflicting node which is 'living in' the irns block */
{
ir_node *n;
- pset *live_ins = get_live_in(irn_bl);
+ pset *live_ins = put_live_in(irn_bl, pset_new_ptr_default());
for (n = pset_first(live_ins); n; n = pset_next(live_ins))
- if (arch_irn_has_reg_class(arch_env, n, arch_pos_make_out(0), qn->ou->co->cls)
+ 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)) {
obstack_ptr_grow(&confl_ob, n);
pset_break(live_ins);
break;
- }
+ }
+ del_pset(live_ins);
}
/* setup the queue of blocks. */
* 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);
- if (arch_irn_has_reg_class(arch_env, n, arch_pos_make_out(0), qn->ou->co->cls)
+ 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)) {
} 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 */
}
/**
- * 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.
*/
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 **irns;
+ int max, next, pos, curr_weight, best_weight = 0;
+ bitset_t *best, *curr;
+
+ irns = alloca((ou->node_count-1) * sizeof(*irns));
+ best = bitset_alloca(ou->node_count-1);
+ curr = bitset_alloca(ou->node_count-1);
+
+ /* brute force the best set */
+ bitset_set_all(curr);
+ while ((max = bitset_popcnt(curr)) != 0) {
+ /* check if curr is a stable set */
+ int i, o, is_stable_set = 1;
+
+ /* copy the irns */
+ i = 0;
+ bitset_foreach(curr, pos)
+ irns[i++] = ou->nodes[1+pos];
+ assert(i==max);
+
+ for(i=0; i<max; ++i)
+ for(o=i; o<max; ++o) /* !!!!! difference to ou_max_ind_set_costs(): NOT o=i+1 */
+ if (qnode_are_conflicting(qn, irns[i], irns[o])) {
+ is_stable_set = 0;
+ break;
+ }
- /* 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;
+ if (is_stable_set) {
+ /* calc current weigth */
+ curr_weight = 0;
+ bitset_foreach(curr, pos)
+ curr_weight += ou->costs[1+pos];
-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;
- }
+ /* any better ? */
+ if (curr_weight > best_weight) {
+ best_weight = curr_weight;
+ bitset_copy(best, curr);
}
}
+
+ bitset_minus1(curr);
}
+
+ /* transfer the best set into the qn */
+ qn->mis_size = bitset_popcnt(best);
+ qn->mis_costs = best_weight;
+ next = 0;
+ bitset_foreach(best, pos)
+ qn->mis[next++] = ou->nodes[1+pos];
}
/**
}
qnode_max_ind_set(qn, ou);
-
- /* set ou->mis_size for lower bound compution */
- if (ou->mis_size < qn->mis_size)
- ou->mis_size = qn->mis_size;
-
/* 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;
}
}
/**
- * Tries to re-allocate colors of nodes in this opt unit, to achieve a 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) {
int i;
qnode_t *curr, *tmp;
- bitset_t *pos_regs = bitset_alloca(ou->co->cls->n_regs);
+ bitset_t *pos_regs = bitset_alloca(ou->co->chordal_env->cls->n_regs);
DBG((dbg, LEVEL_1, "\tOptimizing unit:\n"));
for (i=0; i<ou->node_count; ++i)
/* init queue */
INIT_LIST_HEAD(&ou->queue);
- arch_get_allocatable_regs(ou->co->env, ou->nodes[0], arch_pos_make_out(0), ou->co->cls, pos_regs);
+ 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);
bitset_foreach(pos_regs, i)
ou_insert_qnode(ou, new_qnode(ou, i));
/* 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))
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));
+ DBG((dbg, LEVEL_1, "\t Best color: %d Costs: %d/%d\n", curr->color, ou->complete_costs - curr->mis_costs, ou->complete_costs));
/* globally pin root and eventually others */
pset_insert_ptr(pinned_global, ou->nodes[0]);
for (i=1; i<ou->node_count; ++i) {
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, -1);
+ firm_dbg_set_mask(dbg, DEBUG_LVL_HEUR);
+ else
+ firm_dbg_set_mask(dbg, DEBUG_LVL);
pinned_global = pset_new_ptr(SLOTS_PINNED_GLOBAL);
list_for_each_entry(unit_t, curr, &co->units, units)
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