src/hotspot/share/opto/superword.cpp

@@ -92,12 +92,15 @@
  }
  
  //------------------------------transform_loop---------------------------
  void SuperWord::transform_loop(IdealLoopTree* lpt, bool do_optimization) {
    assert(UseSuperWord, "should be");
-   // Do vectors exist on this architecture?
-   if (Matcher::vector_width_in_bytes(T_BYTE) < 2) return;
+   // SuperWord only works with power of two vector sizes.
+   int vector_width = Matcher::vector_width_in_bytes(T_BYTE);
+   if (vector_width < 2 || !is_power_of_2(vector_width)) {
+     return;
+   }
  
    assert(lpt->_head->is_CountedLoop(), "must be");
    CountedLoopNode *cl = lpt->_head->as_CountedLoop();
  
    if (!cl->is_valid_counted_loop()) return; // skip malformed counted loop