From 5ae717192480a725e5bd7f55acefc10ca47bbc07 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu@cs.umass.edu>
Date: Tue, 9 Nov 2004 14:59:49 +0000
Subject: [PATCH] tree-phinodes.c (phi_reverse): New.

	* tree-phinodes.c (phi_reverse): New.
	* tree-cfg.c (tree_make_forwarder_block, tree_duplicate_bb):
	Use it.
	* tree-flow.h: Add a prototype for phi_reverse.

From-SVN: r90344
---
 gcc/ChangeLog       |  7 +++++++
 gcc/tree-cfg.c      | 13 +++----------
 gcc/tree-flow.h     |  1 +
 gcc/tree-phinodes.c | 15 +++++++++++++++
 4 files changed, 26 insertions(+), 10 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5ee1a5d54ee..d9cd2213d10 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2004-11-09  Kazu Hirata  <kazu@cs.umass.edu>
+
+	* tree-phinodes.c (phi_reverse): New.
+	* tree-cfg.c (tree_make_forwarder_block, tree_duplicate_bb):
+	Use it.
+	* tree-flow.h: Add a prototype for phi_reverse.
+
 2004-11-09  Kazu Hirata  <kazu@cs.umass.edu>
 
 	* tree-ssa-loop-ivopts.c: Fix a comment typo.
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 8dfaffb13b0..8da78c8ff0d 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -3655,7 +3655,7 @@ tree_make_forwarder_block (edge fallthru)
   edge e;
   edge_iterator ei;
   basic_block dummy, bb;
-  tree phi, new_phi, var, prev, next;
+  tree phi, new_phi, var;
 
   dummy = fallthru->src;
   bb = fallthru->dest;
@@ -3675,14 +3675,7 @@ tree_make_forwarder_block (edge fallthru)
     }
 
   /* Ensure that the PHI node chain is in the same order.  */
-  prev = NULL;
-  for (phi = phi_nodes (bb); phi; phi = next)
-    {
-      next = PHI_CHAIN (phi);
-      PHI_CHAIN (phi) = prev;
-      prev = phi;
-    }
-  set_phi_nodes (bb, prev);
+  set_phi_nodes (bb, phi_reverse (phi_nodes (bb)));
 
   /* Add the arguments we have stored on edges.  */
   FOR_EACH_EDGE (e, ei, bb->preds)
@@ -4281,7 +4274,7 @@ tree_duplicate_bb (basic_block bb)
       mark_for_rewrite (PHI_RESULT (phi));
       create_phi_node (PHI_RESULT (phi), new_bb);
     }
-  set_phi_nodes (new_bb, nreverse (phi_nodes (new_bb)));
+  set_phi_nodes (new_bb, phi_reverse (phi_nodes (new_bb)));
 
   bsi_tgt = bsi_start (new_bb);
   for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi))
diff --git a/gcc/tree-flow.h b/gcc/tree-flow.h
index 829eff8ef2c..354f02c0024 100644
--- a/gcc/tree-flow.h
+++ b/gcc/tree-flow.h
@@ -516,6 +516,7 @@ extern void remove_phi_arg (tree, basic_block);
 extern void remove_phi_arg_num (tree, int);
 extern void remove_phi_node (tree, tree, basic_block);
 extern void remove_all_phi_nodes_for (bitmap);
+extern tree phi_reverse (tree);
 extern void dump_dfa_stats (FILE *);
 extern void debug_dfa_stats (void);
 extern void debug_referenced_vars (void);
diff --git a/gcc/tree-phinodes.c b/gcc/tree-phinodes.c
index 0d621b53339..a38a57273be 100644
--- a/gcc/tree-phinodes.c
+++ b/gcc/tree-phinodes.c
@@ -491,6 +491,21 @@ remove_all_phi_nodes_for (bitmap vars)
     }
 }
 
+/* Reverse the order of PHI nodes in the chain PHI.
+   Return the new head of the chain (old last PHI node).  */
+
+tree
+phi_reverse (tree phi)
+{
+  tree prev = NULL_TREE, next;
+  for (; phi; phi = next)
+    {
+      next = PHI_CHAIN (phi);
+      PHI_CHAIN (phi) = prev;
+      prev = phi;
+    }
+  return prev;
+}
 
 #include "gt-tree-phinodes.h"
 
-- 
2.30.2