/**
* @file beuse.c
* @date 27.06.2005
- * @author Sebastian Hack
+ * @author Sebastian Hack, Matthias Braun
*
* Methods to compute when a value will be used again.
*
* Copyright (C) 2005 Universitaet Karlsruhe
* Released under the GPL
*/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
#include <limits.h>
#include <stdlib.h>
#include "beirgmod.h"
#include "bearch.h"
#include "beuses_t.h"
+#include "benodesets.h"
-#define DBG_LEVEL SET_LEVEL_0
+#define SCAN_INTERBLOCK_USES
typedef struct _be_use_t {
- const ir_node *bl;
- const ir_node *irn;
+ const ir_node *block;
+ const ir_node *node;
+ int outermost_loop;
unsigned next_use;
+ unsigned visited;
} be_use_t;
struct _be_uses_t {
- set *uses;
- ir_graph *irg;
- const be_lv_t *lv;
- const arch_env_t *arch_env;
- DEBUG_ONLY(firm_dbg_module_t *dbg;)
+ set *uses;
+ ir_graph *irg;
+ const be_lv_t *lv;
+ unsigned visited_counter;
+ DEBUG_ONLY(firm_dbg_module_t *dbg;)
};
static int cmp_use(const void *a, const void *b, size_t n)
{
- const be_use_t *p = a;
- const be_use_t *q = b;
- return !(p->bl == q->bl && p->irn == q->irn);
+ const be_use_t *p = a;
+ const be_use_t *q = b;
+ return !(p->block == q->block && p->node == q->node);
}
-static INLINE be_use_t *get_or_set_use(be_uses_t *uses,
- const ir_node *bl, const ir_node *def, unsigned next_use)
+static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
+ unsigned from_step, const ir_node *def,
+ int skip_from_uses);
+
+static const be_use_t *get_or_set_use_block(be_uses_t *env,
+ const ir_node *block,
+ const ir_node *def)
{
- unsigned hash = HASH_COMBINE(HASH_PTR(bl), HASH_PTR(def));
- be_use_t templ;
- be_use_t* result;
+ unsigned hash = HASH_COMBINE(nodeset_hash(block), nodeset_hash(def));
+ be_use_t temp;
+ be_use_t* result;
+
+ temp.block = block;
+ temp.node = def;
+ result = set_find(env->uses, &temp, sizeof(temp), hash);
+
+ if(result == NULL) {
+ // insert templ first as we might end in a loop in the get_next_use
+ // call otherwise
+ temp.next_use = USES_INFINITY;
+ temp.outermost_loop = -1;
+ temp.visited = 0;
+ result = set_insert(env->uses, &temp, sizeof(temp), hash);
+ }
- templ.bl = bl;
- templ.irn = def;
- templ.next_use = be_get_next_use(uses, sched_first(bl), 0, def, 0);
- result = set_insert(uses->uses, &templ, sizeof(templ), hash);
+ if(result->outermost_loop < 0 && result->visited < env->visited_counter) {
+ be_next_use_t next_use;
- return result;
-}
+ result->visited = env->visited_counter;
+ next_use = get_next_use(env, sched_first(block), 0, def, 0);
+ if(next_use.outermost_loop >= 0) {
+ result->next_use = next_use.time;
+ result->outermost_loop = next_use.outermost_loop;
+ DBG((env->dbg, LEVEL_5, "Setting nextuse of %+F in block %+F to %u (outermostloop %d)\n", def, block, result->next_use, result->outermost_loop));
+ }
+ }
-unsigned be_get_next_use(be_uses_t *uses, const ir_node *from,
- unsigned from_step, const ir_node *def, int skip_from_uses);
+ return result;
+}
-static unsigned get_next_use_bl(be_uses_t *uses, const ir_node *bl,
- const ir_node *def)
+static int be_is_phi_argument(const be_lv_t *lv, const ir_node *block, const ir_node *def)
{
- be_use_t *u = get_or_set_use(uses, bl, def, 0);
+ ir_node *node;
+ ir_node *succ_block = NULL;
+ const ir_edge_t *edge;
+ int arity, i;
+
+#if 0
+ if(get_irn_n_edges_kind(block, EDGE_KIND_BLOCK) > 1)
+ return 0;
+#endif
+
+ foreach_block_succ(block, edge) {
+ succ_block = get_edge_src_irn(edge);
+ break;
+ }
+
+ arity = get_Block_n_cfgpreds(succ_block);
+ if(arity <= 1)
+ return 0;
+
+ for(i = 0; i < arity; ++i) {
+ if(get_Block_cfgpred_block(succ_block, i) == block)
+ break;
+ }
+ assert(i < arity);
+
+ sched_foreach(succ_block, node) {
+ ir_node *arg;
- return u->next_use;
+ if(!is_Phi(node))
+ break;
+
+ arg = get_irn_n(node, i);
+ if(arg == def)
+ return 1;
+ }
+
+ return 0;
}
-static unsigned get_next_use(be_uses_t *uses, const ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses, unsigned long visited_nr)
+static be_next_use_t get_next_use(be_uses_t *env, ir_node *from,
+ unsigned from_step, const ir_node *def,
+ int skip_from_uses)
{
- unsigned next_use = USES_INFINITY;
- unsigned step = from_step;
- unsigned n = 0;
- ir_node *bl = get_nodes_block(from);
- const ir_node *irn;
- const ir_edge_t *succ_edge;
+ unsigned step = from_step;
+ ir_node *block = get_nodes_block(from);
+ ir_node *node;
+ const ir_edge_t *edge;
+
+ if(skip_from_uses) {
+ step++;
+ from = sched_next(from);
+ }
+
+ sched_foreach_from(from, node) {
+ int i, arity;
+
+ if(is_Phi(node)) {
+ step++;
+ continue;
+ }
- set_irn_visited(bl, visited_nr);
+ arity = get_irn_arity(node);
+ for (i = 0; i < arity; ++i) {
+ const ir_node *operand = get_irn_n(node, i);
- sched_foreach_from(from, irn) {
- int i, n;
+ if (operand == def) {
+ be_next_use_t result;
- if (! skip_from_uses) {
- for (i = 0, n = get_irn_arity(irn); i < n; ++i) {
- ir_node *operand = get_irn_n(irn, i);
+ DBG((env->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, node));
- if (operand == def) {
- DBG((uses->dbg, LEVEL_3, "found use of %+F at %+F\n", operand, irn));
- return step;
+ /**
+ * Spills/Reloads are a special case, they're not really a
+ * usage of a value, continue searching
+ */
+ if (be_is_Spill(node) || be_is_Reload(node)) {
+ return be_get_next_use(env, node, step, node, 1);
}
+
+ result.time = step;
+ result.outermost_loop = get_loop_depth(get_irn_loop(block));
+ return result;
}
}
- skip_from_uses = 0;
step++;
}
- /* FIXME: quick and dirty hack to prevent ignore nodes (like stack pointer) from being spilled */
- return be_is_live_end(uses->lv, bl, def) ? step : USES_INFINITY;
+ if(be_is_phi_argument(env->lv, block, def)) {
+ // TODO we really should continue searching the uses of the phi,
+ // as a phi isn't a real use that implies a reload (because we could
+ // easily spill the whole phi)
- next_use = USES_INFINITY;
- foreach_block_succ(bl, succ_edge) {
- const ir_node *succ_bl = succ_edge->src;
- if(get_irn_visited(succ_bl) < visited_nr && (be_is_live_in(uses->lv, succ_bl, def) || (get_irn_arity(succ_bl) > 1 && be_is_live_end(uses->lv, bl, def)))) {
- unsigned next = get_next_use_bl(uses, succ_bl, def);
+ be_next_use_t result;
+ result.time = step;
+ result.outermost_loop = get_loop_depth(get_irn_loop(block));
+ return result;
+ }
- DBG((uses->dbg, LEVEL_2, "\t\tnext use in succ %+F: %d\n", succ_bl, next));
- next_use = MIN(next_use, next);
- n++;
+#ifdef SCAN_INTERBLOCK_USES
+ {
+ unsigned next_use = USES_INFINITY;
+ int outermost_loop;
+ be_next_use_t result;
+ ir_loop *loop = get_irn_loop(block);
+ int loopdepth = get_loop_depth(loop);
+ int found_visited = 0;
+ int found_use = 0;
+ ir_graph *irg = get_irn_irg(block);
+ ir_node *startblock = get_irg_start_block(irg);
+
+ outermost_loop = loopdepth;
+ foreach_block_succ(block, edge) {
+ const be_use_t *use;
+ const ir_node *succ_block = get_edge_src_irn(edge);
+ ir_loop *succ_loop;
+ int use_dist;
+
+ if(succ_block == startblock)
+ continue;
+
+ DBG((env->dbg, LEVEL_5, "Checking succ of block %+F: %+F (for use of %+F)\n", block, succ_block, def));
+ if(!be_is_live_in(env->lv, succ_block, def)) {
+ //next_use = USES_INFINITY;
+ DBG((env->dbg, LEVEL_5, " not live in\n"));
+ continue;
}
- }
- return next_use + step;
-}
+ use = get_or_set_use_block(env, succ_block, def);
+ DBG((env->dbg, LEVEL_5, "Found %u (loopdepth %d) (we're in block %+F)\n", use->next_use,
+ use->outermost_loop, block));
+ if(USES_IS_INFINITE(use->next_use)) {
+ if(use->outermost_loop < 0) {
+ found_visited = 1;
+ }
+ continue;
+ }
-unsigned be_get_next_use(be_uses_t *uses, const ir_node *from, unsigned from_step, const ir_node *def, int skip_from_uses)
-{
- unsigned long visited_nr = get_irg_visited(uses->irg) + 1;
+ found_use = 1;
+ use_dist = use->next_use;
- set_irg_visited(uses->irg, visited_nr);
- return get_next_use(uses, from, from_step, def, skip_from_uses, visited_nr);
-}
+ succ_loop = get_irn_loop(succ_block);
+ if(get_loop_depth(succ_loop) < loopdepth) {
+ int factor = (loopdepth - get_loop_depth(succ_loop)) * 5000;
+ DBG((env->dbg, LEVEL_5, "Increase usestep because of loop out edge %d -> %d (%u)\n", factor));
+ // TODO we should use the number of nodes in the loop or so...
+ use_dist += factor;
+ }
+ if(use_dist < next_use) {
+ next_use = use_dist;
+ outermost_loop = use->outermost_loop;
+ }
+ }
-be_uses_t *be_begin_uses(ir_graph *irg, const be_lv_t *lv, const arch_env_t *arch_env, const arch_register_class_t *cls)
-{
- be_uses_t *uses = xmalloc(sizeof(uses[0]));
+ if(loopdepth < outermost_loop)
+ outermost_loop = loopdepth;
- edges_assure(irg);
+ result.time = next_use + step;
+ result.outermost_loop = outermost_loop;
- uses->arch_env = arch_env;
- uses->uses = new_set(cmp_use, 512);
- uses->irg = irg;
- uses->lv = lv;
- FIRM_DBG_REGISTER(uses->dbg, "firm.be.uses");
+ if(!found_use && found_visited) {
+ // the current result is correct for the current search, but isn't
+ // generally correct, so mark it
+ result.outermost_loop = -1;
+ }
+ DBG((env->dbg, LEVEL_5, "Result: %d (outerloop: %d)\n", result.time, result.outermost_loop));
+ return result;
+ }
+#else
+ return USES_INFINITY;
+#endif
+}
- return uses;
+be_next_use_t be_get_next_use(be_uses_t *env, ir_node *from,
+ unsigned from_step, const ir_node *def,
+ int skip_from_uses)
+{
+ env->visited_counter++;
+ return get_next_use(env, from, from_step, def, skip_from_uses);
}
-void be_end_uses(be_uses_t *uses)
+be_uses_t *be_begin_uses(ir_graph *irg, const be_lv_t *lv)
{
- del_set(uses->uses);
- free(uses);
+ be_uses_t *env = xmalloc(sizeof(env[0]));
+
+ edges_assure(irg);
+
+ env->uses = new_set(cmp_use, 512);
+ env->irg = irg;
+ env->lv = lv;
+ env->visited_counter = 0;
+ FIRM_DBG_REGISTER(env->dbg, "firm.be.uses");
+
+ return env;
}
-int loc_compare(const void *a, const void *b)
+void be_end_uses(be_uses_t *env)
{
- const loc_t *p = a;
- const loc_t *q = b;
- return p->time - q->time;
+ del_set(env->uses);
+ free(env);
}
projects / libfirm / blobdiff