diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 43d9a8fb6612..4056a358e810 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2009-12-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/42244
+	* ddg.c (add_inter_loop_mem_dep): Use ANTI_DEP if from or to
+	is a DEBUG_INSN.
+
 2009-12-07  Sebastian Pop  <sebastian.pop@amd.com>
 
 	* config/i386/driver-i386.c (host_detect_local_cpu): Add -mlwp to the
diff --git a/gcc/ddg.c b/gcc/ddg.c
index 23fa6fa2aeb0..f51c5dc4e296 100644
--- a/gcc/ddg.c
+++ b/gcc/ddg.c
@@ -359,9 +359,13 @@ add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to)
   if (mem_write_insn_p (from->insn))
     {
       if (mem_read_insn_p (to->insn))
-  	create_ddg_dep_no_link (g, from, to, TRUE_DEP, MEM_DEP, 1);
+  	create_ddg_dep_no_link (g, from, to,
+				DEBUG_INSN_P (to->insn)
+				? ANTI_DEP : TRUE_DEP, MEM_DEP, 1);
       else if (from->cuid != to->cuid)
-  	create_ddg_dep_no_link (g, from, to, OUTPUT_DEP, MEM_DEP, 1);
+  	create_ddg_dep_no_link (g, from, to,
+				DEBUG_INSN_P (to->insn)
+				? ANTI_DEP : OUTPUT_DEP, MEM_DEP, 1);
     }
   else
     {
@@ -369,8 +373,11 @@ add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to)
 	return;
       else if (from->cuid != to->cuid)
 	{
-  	  create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 1);
-  	  create_ddg_dep_no_link (g, to, from, TRUE_DEP, MEM_DEP, 1);
+	  create_ddg_dep_no_link (g, from, to, ANTI_DEP, MEM_DEP, 1);
+	  if (DEBUG_INSN_P (from->insn) || DEBUG_INSN_P (to->insn))
+	    create_ddg_dep_no_link (g, to, from, ANTI_DEP, MEM_DEP, 1);
+	  else
+	    create_ddg_dep_no_link (g, to, from, TRUE_DEP, MEM_DEP, 1);
 	}
     }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index fbe13dd4fefe..7d245b73041a 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-12-07  Jakub Jelinek  <jakub@redhat.com>
+
+	PR debug/42244
+	* gcc.dg/debug/pr42244.c: New test.
+
 2009-12-07  Jakub Jelinek  <jakub@redhat.com>
 
 	* gcc.target/i386/sse-12.c: Add -mabm to dg-options, mention
diff --git a/gcc/testsuite/gcc.dg/debug/pr42244.c b/gcc/testsuite/gcc.dg/debug/pr42244.c
new file mode 100644
index 000000000000..ff2542873363
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/debug/pr42244.c
@@ -0,0 +1,13 @@
+/* PR debug/42444 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -g -fmodulo-sched -ffloat-store" } */
+
+extern int a, b;
+
+double
+foo (double x)
+{
+  for (; a > b; a--)
+    x *= (double) a;
+  return x;
+}