X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fbe%2Fbeuses.c;h=f511839eb59f68ddcfee85e4b1bdddb44574366c;hb=8535fe8732b0acf822be252812a7158ce5b8134a;hp=dc7f30288cb111ac3d64ee23f2abbc01c2b708a9;hpb=48f893878b07f6e334389ff52abda5cc2adbf179;p=libfirm

diff --git a/ir/be/beuses.c b/ir/be/beuses.c
index dc7f30288..f511839eb 100644
--- a/ir/be/beuses.c
+++ b/ir/be/beuses.c
@@ -1,13 +1,16 @@
 /**
  * @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>
@@ -32,136 +35,273 @@
 #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);
 }