From d6600130faf0a670610f412c88dd3614be5886c0 Mon Sep 17 00:00:00 2001
From: Jakub Jelinek <jakub@redhat.com>
Date: Tue, 19 Jan 2010 13:39:42 +0100
Subject: [PATCH] re PR tree-optimization/42719 ("-fcompare-debug failure" with
 "-O2 -ftracer")

	PR tree-optimization/42719
	* tree-outof-ssa.c (trivially_conflicts_p): Don't consider debug
	stmt uses.

	* gcc.dg/pr42719.c: New test.

From-SVN: r156038
---
 gcc/ChangeLog                  |  4 ++++
 gcc/testsuite/ChangeLog        |  3 +++
 gcc/testsuite/gcc.dg/pr42719.c | 14 ++++++++++++++
 gcc/tree-outof-ssa.c           |  2 ++
 4 files changed, 23 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/pr42719.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b6ea293c4e8..18dccd607c7 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,9 @@
 2010-01-19  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/42719
+	* tree-outof-ssa.c (trivially_conflicts_p): Don't consider debug
+	stmt uses.
+
 	PR debug/42728
 	* fwprop.c (all_uses_available_at): Return false if def_set dest
 	is a REG that is used in def_insn.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f2a4f8a1984..a4aafda48b7 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2010-01-19  Jakub Jelinek  <jakub@redhat.com>
 
+	PR tree-optimization/42719
+	* gcc.dg/pr42719.c: New test.
+
 	PR debug/42728
 	* gcc.dg/pr42728.c: New test.
 
diff --git a/gcc/testsuite/gcc.dg/pr42719.c b/gcc/testsuite/gcc.dg/pr42719.c
new file mode 100644
index 00000000000..94a58e41a1a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr42719.c
@@ -0,0 +1,14 @@
+/* PR tree-optimization/42719 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -ftracer -fcompare-debug" } */
+
+int *v;
+
+void
+foo (int a)
+{
+  int i, j;
+  for (j = i = a; i != -1; j = i, i = v[i])
+    ;
+  v[j] = v[a];
+}
diff --git a/gcc/tree-outof-ssa.c b/gcc/tree-outof-ssa.c
index a82cec824fd..32aa464948b 100644
--- a/gcc/tree-outof-ssa.c
+++ b/gcc/tree-outof-ssa.c
@@ -956,6 +956,8 @@ trivially_conflicts_p (basic_block bb, tree result, tree arg)
   FOR_EACH_IMM_USE_FAST (use, imm_iter, result)
     {
       gimple use_stmt = USE_STMT (use);
+      if (is_gimple_debug (use_stmt))
+	continue;
       /* Now, if there's a use of RESULT that lies outside this basic block,
 	 then there surely is a conflict with ARG.  */
       if (gimple_bb (use_stmt) != bb)