--- gcc/ddg.c	(/gcc-local/trunk)	(revision 30596)
+++ gcc/ddg.c	(/gcc-local/export-ddg)	(revision 30596)
@@ -43,6 +43,7 @@ along with GCC; see the file COPYING3.  
 #include "expr.h"
 #include "bitmap.h"
 #include "ddg.h"
+#include "tree-data-ref-export.h"
 
 /* A flag indicating that a ddg edge belongs to an SCC or not.  */
 enum edge_flag {NOT_IN_SCC = 0, IN_SCC};
@@ -333,12 +334,49 @@ build_inter_loop_deps (ddg_ptr g)
   }
 }
 
+static int
+walk_mems_2 (rtx *x, rtx mem)
+{
+  if (MEM_P (*x))
+    {
+      if (may_alias_mems_by_ddr (mem, *x, 2))
+	/* Indicate that dependence was determined and stop traversal.  */
+	return 1;
+      return -1;
+    }
+  return 0;
+}
+
+static int
+walk_mems_1 (rtx *x, rtx *pat)
+{
+  if (MEM_P (*x))
+    {
+      /* Visit all MEMs in *PAT and check indepedence.  */
+      if (for_each_rtx (pat, (rtx_function) walk_mems_2, *x))
+	/* Indicate that dependence was determined and stop traversal.  */
+	return 1;
+      return -1;
+    }
+  return 0;
+}
+
+static bool
+independent_by_exported_info (rtx insn1, rtx insn2)
+{
+  /* For each pair of MEMs in INSN1 and INSN2 check their independence.  */
+  return ! for_each_rtx (&PATTERN (insn1), (rtx_function) walk_mems_1,
+			 &PATTERN (insn2));
+}
 
 /* Given two nodes, analyze their RTL insns and add inter-loop mem deps
    to ddg G.  */
 static void
 add_inter_loop_mem_dep (ddg_ptr g, ddg_node_ptr from, ddg_node_ptr to)
 {
+  if (independent_by_exported_info (from->insn, to->insn))
+    /* Do not create edge if memory references are known to be independent.  */
+    return;
   if (mem_write_insn_p (from->insn))
     {
       if (mem_read_insn_p (to->insn))
--- gcc/modulo-sched.c	(/gcc-local/trunk)	(revision 30596)
+++ gcc/modulo-sched.c	(/gcc-local/export-ddg)	(revision 30596)
@@ -47,6 +47,7 @@ along with GCC; see the file COPYING3.  
 #include "ddg.h"
 #include "timevar.h"
 #include "tree-pass.h"
+#include "tree-data-ref-export.h"
 
 #ifdef INSN_SCHEDULING
 
@@ -2331,6 +2354,7 @@ rest_of_handle_sms (void)
   basic_block bb;
 
   /* Collect loop information to be used in SMS.  */
+  ddg_export_disambiguate_only_intra_loop_deps (true);
   cfg_layout_initialize (0);
   sms_schedule ();
 
@@ -2343,6 +2367,7 @@ rest_of_handle_sms (void)
       bb->aux = bb->next_bb;
   free_dominance_info (CDI_DOMINATORS);
   cfg_layout_finalize ();
+  ddg_export_disambiguate_only_intra_loop_deps (false);
 #endif /* INSN_SCHEDULING */
   return 0;
 }