Fix "regression" reported by c6x testing.

	* gcc.dg/tree-ssa/ssa-dse-26.c: Make existing dg-final scan
	conditional on !c6x.  Add dg-final scan pattern for c6x.

gcc/testsuite/ChangeLog

+2020-01-30  Jeff Law  <law@redhat.com
+
+	* gcc.dg/tree-ssa/ssa-dse-26.c: Make existing dg-final scan
+	conditional on !c6x.  Add dg-final scan pattern for c6x.
+
 2020-01-30  Martin Sebor  <msebor@redhat.com>
 
 	PR middle-end/92323

gcc/testsuite/gcc.dg/tree-ssa/ssa-dse-26.c

@@ -30,6 +30,13 @@ constraint_equal (struct constraint a, struct constraint b)
     && constraint_expr_equal (a.rhs, b.rhs);
 }
 
-/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 1 "dse1" } } */
-/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 1 "dse1" } } */
+/* Most targets should be using this test.  */
+/* { dg-final { scan-tree-dump-times "Deleted dead store: x = " 1 "dse1" { target { ! tic6x-*-* } } } } */
+/* { dg-final { scan-tree-dump-times "Deleted dead store: y = " 1 "dse1" { target { ! tic6x-*-* } } } } */
+
+/* The c6x port generates significantly different gimple which
+   changes the SRA and DSE decisions.   Verify we remove all
+   dead stores.  */
+/* { dg-final { scan-tree-dump-times "Deleted dead store: \[ax\].. = " 2 "dse1" { target tic6x-*-* } } } */
+/* { dg-final { scan-tree-dump-times "Deleted dead store: \[by\].. = " 2 "dse1" { target tic6x-*-* } } } */