Upstream-Status: Inappropriate [Backport]
From af3385141f9bfe32ab89165bfc98a7ea2ff19278 Mon Sep 17 00:00:00 2001
From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Sat, 26 Mar 2011 09:19:36 +0000
Subject: [PATCH 002/200] 	Backport from mainline
 	2011-03-17  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/48141
	* dse.c (record_store): If no positions are needed in an insn
	that cannot be deleted, at least unchain it from active_local_stores.

	* gcc.dg/pr48141.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@171545 138bc75d-0d04-0410-961f-82ee72b054a4

index 8e9b645..e43ab72 100644
--- a/gcc/dse.c
+++ b/gcc/dse.c
@@ -1,5 +1,5 @@
 /* RTL dead store elimination.
-   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2011
    Free Software Foundation, Inc.
 
    Contributed by Richard Sandiford <rsandifor@codesourcery.com>
@@ -1530,8 +1530,7 @@ record_store (rtx body, bb_info_t bb_info)
 
       /* An insn can be deleted if every position of every one of
 	 its s_infos is zero.  */
-      if (any_positions_needed_p (s_info)
-	  || ptr->cannot_delete)
+      if (any_positions_needed_p (s_info))
 	del = false;
 
       if (del)
@@ -1543,7 +1542,8 @@ record_store (rtx body, bb_info_t bb_info)
 	  else
 	    active_local_stores = ptr->next_local_store;
 
-	  delete_dead_store_insn (insn_to_delete);
+	  if (!insn_to_delete->cannot_delete)
+	    delete_dead_store_insn (insn_to_delete);
 	}
       else
 	last = ptr;
new file mode 100644
index 0000000..006f5cb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr48141.c
@@ -0,0 +1,17 @@
+/* PR rtl-optimization/48141 */
+/* { dg-do compile } */
+/* { dg-options "-O" } */
+
+#define A i = 0;
+#define B A A A A A A A A A A
+#define C B B B B B B B B B B
+#define D C C C C C C C C C C
+#define E D D D D D D D D D D
+
+int
+foo (void)
+{
+  volatile int i = 0;
+  E E E E E E E E E E E
+  return 0;
+}
-- 
1.7.0.4