Index: combine.c
===================================================================
--- combine.c	(revision 133510)
+++ combine.c	(working copy)
@@ -976,8 +976,18 @@
                      assignments later.  */
                   if (regno >= FIRST_PSEUDO_REGISTER
                       || asm_noperands (PATTERN (use_insn)) < 0)
-                    LOG_LINKS (use_insn) =
-                      alloc_INSN_LIST (insn, LOG_LINKS (use_insn));
+		    {
+		      /* Don't add duplicate links between instructions.  */
+		      rtx links;
+		      for (links = LOG_LINKS (use_insn); links;
+			   links = XEXP (links, 1))
+		        if (insn == XEXP (links, 0))
+			  break;
+
+		      if (!links)
+			LOG_LINKS (use_insn) =
+			  alloc_INSN_LIST (insn, LOG_LINKS (use_insn));
+		    }
                 }
               next_use[regno] = NULL_RTX;
             }