From c6407fab16d7df27e24a26864e15874e9eb43f3f Mon Sep 17 00:00:00 2001
From: rth <rth@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Thu, 10 Sep 2009 18:27:59 +0000
Subject: [PATCH] * tree-cfg.c (gimple_can_merge_blocks_p): Move label and     
    loop latch tests earlier.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@151604 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog  |  3 +++
 gcc/tree-cfg.c | 33 ++++++++++++++++++---------------
 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 9b91445..c110d53 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,8 @@
 2009-09-10  Richard Henderson  <rth@redhat.com>
 
+	* tree-cfg.c (gimple_can_merge_blocks_p): Move label and
+	loop latch tests earlier.
+
 	* gimple-iterator.c (gimple_find_edge_insert_loc): Insert
 	before GIMPLE_RETURN, not after its predecessor; insert
 	before GIMPLE_RESX.
diff --git a/gcc/tree-cfg.c b/gcc/tree-cfg.c
index 1357064..b834943 100644
--- a/gcc/tree-cfg.c
+++ b/gcc/tree-cfg.c
@@ -1354,6 +1354,24 @@ gimple_can_merge_blocks_p (basic_block a, basic_block b)
       && DECL_NONLOCAL (gimple_label_label (stmt)))
     return false;
 
+  /* Examine the labels at the beginning of B.  */
+  for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
+    {
+      tree lab;
+      stmt = gsi_stmt (gsi);
+      if (gimple_code (stmt) != GIMPLE_LABEL)
+	break;
+      lab = gimple_label_label (stmt);
+
+      /* Do not remove user labels.  */
+      if (!DECL_ARTIFICIAL (lab))
+	return false;
+    }
+
+  /* Protect the loop latches.  */
+  if (current_loops && b->loop_father->latch == b)
+    return false;
+
   /* It must be possible to eliminate all phi nodes in B.  If ssa form
      is not up-to-date, we cannot eliminate any phis; however, if only
      some symbols as whole are marked for renaming, this is not a problem,
@@ -1377,21 +1395,6 @@ gimple_can_merge_blocks_p (basic_block a, basic_block b)
 	}
     }
 
-  /* Do not remove user labels.  */
-  for (gsi = gsi_start_bb (b); !gsi_end_p (gsi); gsi_next (&gsi))
-    {
-      stmt = gsi_stmt (gsi);
-      if (gimple_code (stmt) != GIMPLE_LABEL)
-	break;
-      if (!DECL_ARTIFICIAL (gimple_label_label (stmt)))
-	return false;
-    }
-
-  /* Protect the loop latches.  */
-  if (current_loops
-      && b->loop_father->latch == b)
-    return false;
-
   return true;
 }
 
-- 
2.7.4