From: Christoph Mallon <christoph.mallon@gmx.de>
Date: Wed, 30 Jul 2008 09:55:44 +0000 (+0000)
Subject: Reduce worst time complexity of mem parallelisation from O(2**n) to O(n**2).
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=9bf7cffd000f23a53c12242b5ecdc797bcdf1840;p=libfirm

Reduce worst time complexity of mem parallelisation from O(2**n) to O(n**2).

[r20791]
---

diff --git a/ir/opt/ldst2.c b/ir/opt/ldst2.c
index abe200500..deed71c6e 100644
--- a/ir/opt/ldst2.c
+++ b/ir/opt/ldst2.c
@@ -628,6 +628,10 @@ typedef struct parallelise_info
 
 static void parallelise_load(parallelise_info *pi, ir_node *irn)
 {
+	/* There is no point in investigating the same subgraph twice */
+	if (ir_nodeset_contains(&pi->user_mem, irn))
+		return;
+
 	//ir_fprintf(stderr, "considering %+F\n", irn);
 	if (get_nodes_block(irn) == pi->origin_block) {
 		if (is_Proj(irn)) {
@@ -673,6 +677,10 @@ static void parallelise_load(parallelise_info *pi, ir_node *irn)
 
 static void parallelise_store(parallelise_info *pi, ir_node *irn)
 {
+	/* There is no point in investigating the same subgraph twice */
+	if (ir_nodeset_contains(&pi->user_mem, irn))
+		return;
+
 	//ir_fprintf(stderr, "considering %+F\n", irn);
 	if (get_nodes_block(irn) == pi->origin_block) {
 		if (is_Proj(irn)) {