8291781: assert(!is_visited) failed: visit only once with -XX:+SuperWordRTDepCheck

Reviewed-by: thartmann

Author: Fei Gao

src/hotspot/share/opto/superword.cpp

@@ -1113,10 +1113,11 @@ void SuperWord::dependence_graph() {
         int cmp = p1.cmp(p2);
         if (SuperWordRTDepCheck &&
             p1.base() != p2.base() && p1.valid() && p2.valid()) {
-          // Create a runtime check to disambiguate
+          // Trace disjoint pointers
           OrderedPair pp(p1.base(), p2.base());
           _disjoint_ptrs.append_if_missing(pp);
-        } else if (!SWPointer::not_equal(cmp)) {
+        }
+        if (!SWPointer::not_equal(cmp)) {
           // Possibly same address
           _dg.make_edge(s1, s2);
           sink_dependent = false;

test/hotspot/jtreg/compiler/c2/irTests/TestVectorizeTypeConversion.java

@@ -51,7 +51,7 @@ public class TestVectorizeTypeConversion {
     private static float[] floatb = new float[SIZE];
 
     public static void main(String[] args) {
-        TestFramework.run();
+        TestFramework.runWithFlags("-XX:+SuperWordRTDepCheck");
     }
 
     @Test