TILE-Gx: Fix bundling when encountering consecutive barriers.

        * config/tilegx/tilegx.c (tilegx_gen_bundles): Preserve
          end-of-bundle marker for consecutive barriers.

From-SVN: r242617

gcc/ChangeLog

 2016-11-18  Walter Lee  <walt@tilera.com>
 
+	* config/tilegx/tilegx.c (tilegx_gen_bundles): Preserve
+	  end-of-bundle marker for consecutive barriers.
+
+2016-11-18  Walter Lee  <walt@tilera.com>
+
 	* config/tilegx/tilegx.md (clzsi2): Fix for big-endian.
 
 2016-11-18  Jakub Jelinek  <jakub@redhat.com>

gcc/config/tilegx/tilegx.c

@@ -4469,8 +4469,7 @@ tilegx_gen_bundles (void)
       rtx_insn *end = NEXT_INSN (BB_END (bb));
 
       prev = NULL;
-      for (insn = next_insn_to_bundle (BB_HEAD (bb), end); insn;
-	   prev = insn, insn = next)
+      for (insn = next_insn_to_bundle (BB_HEAD (bb), end); insn; insn = next)
 	{
 	  next = next_insn_to_bundle (NEXT_INSN (insn), end);
 
@@ -4506,7 +4505,11 @@ tilegx_gen_bundles (void)
 		PUT_MODE (prev, QImode);
 	      }
 	    delete_insn (insn);
+
+            // Note: prev remains the same for next iteration.
 	  }
+          else
+            prev = insn;
 	}
     }
 }