From: Michael Beck <beck@ipd.info.uni-karlsruhe.de>
Date: Thu, 20 Sep 2007 09:02:45 +0000 (+0000)
Subject: Add a reassoc_running flag used to disable some local optimizations only while reasso... 
X-Git-Url: http://nsz.repo.hu/git/?a=commitdiff_plain;h=f210fb5c29c0d72050c8150db3b814b624389faa;p=libfirm

Add a reassoc_running flag used to disable some local optimizations only while reassoc is running (to prevent endless loops)

[r15895]
---

diff --git a/ir/ir/irflag_t.def b/ir/ir/irflag_t.def
index 80d06db0f..c64bb3b35 100644
--- a/ir/ir/irflag_t.def
+++ b/ir/ir/irflag_t.def
@@ -114,8 +114,11 @@ I_FLAG(auto_create_sync                   , 27, OFF)
 /** Enable Alias-analysis. */
 I_FLAG(alias_analysis                     , 28, ON)
 
+/** This flag is set while the reassociation optimizations are running */
+I_FLAG(reassoc_running                    , 29, OFF)
+
 /** This flag is set while architecture dependent optimizations are running */
-I_FLAG(arch_dep_running                   , 29, OFF)
+I_FLAG(arch_dep_running                   , 30, OFF)
 
 /** Closed world assumption. */
 I_FLAG(closed_world                       , 31, OFF)
diff --git a/ir/ir/iropt.c b/ir/ir/iropt.c
index b0ba8c800..a16a2b004 100644
--- a/ir/ir/iropt.c
+++ b/ir/ir/iropt.c
@@ -1943,7 +1943,7 @@ static ir_node *transform_node_Add(ir_node *n) {
 			DBG_OPT_ALGSIM0(oldn, n, FS_OPT_ADD_A_MINUS_B);
 			return n;
 		}
-		if (! get_opt_reassociation()) {
+		if (! get_opt_reassoc_running()) {
 			/* do NOT execute this code if reassociation is enabled, it does the inverse! */
 			if (is_Mul(a)) {
 				ir_node *ma = get_Mul_left(a);
@@ -2247,7 +2247,7 @@ restart:
 		}
 	}
 	/* do NOT execute this code if reassociation is enabled, it does the inverse! */
-	if (get_opt_reassociation() && is_Mul(a)) {
+	if (get_opt_reassoc_running() && is_Mul(a)) {
 		ir_node *ma = get_Mul_left(a);
 		ir_node *mb = get_Mul_right(a);
 
diff --git a/ir/opt/reassoc.c b/ir/opt/reassoc.c
index 46068786e..1890716b7 100644
--- a/ir/opt/reassoc.c
+++ b/ir/opt/reassoc.c
@@ -761,12 +761,17 @@ void optimize_reassociation(ir_graph *irg)
 	env.changes = 0;
 	env.wq      = new_waitq();
 
-	/* now we have collected enough information, optimize */
-	irg_walk_graph(irg, NULL, wq_walker, &env);
-	do_reassociation(&env);
-
-	/* reverse those rules that do not result in collapsed constants */
-	irg_walk_graph(irg, NULL, reverse_rules, &env);
+	/* disable some optimizations while reassoc is running to prevent endless loops */
+	set_opt_reassoc_running(1);
+	{
+		/* now we have collected enough information, optimize */
+		irg_walk_graph(irg, NULL, wq_walker, &env);
+		do_reassociation(&env);
+
+		/* reverse those rules that do not result in collapsed constants */
+		irg_walk_graph(irg, NULL, reverse_rules, &env);
+	}
+	set_opt_reassoc_running(0);
 
 	/* Handle graph state */
 	if (env.changes) {