src/hotspot/share/c1/c1_GraphBuilder.cpp

*** 1239,1251 ****
  
  void GraphBuilder::if_node(Value x, If::Condition cond, Value y, ValueStack* state_before) {
    BlockBegin* tsux = block_at(stream()->get_dest());
    BlockBegin* fsux = block_at(stream()->next_bci());
    bool is_bb = tsux->bci() < stream()->cur_bci() || fsux->bci() < stream()->cur_bci();
    // In case of loop invariant code motion or predicate insertion
    // before the body of a loop the state is needed
!   Instruction *i = append(new If(x, cond, false, y, tsux, fsux, (is_bb || compilation()->is_optimistic()) ? state_before : NULL, is_bb));
  
    assert(i->as_Goto() == NULL ||
           (i->as_Goto()->sux_at(0) == tsux  && i->as_Goto()->is_safepoint() == tsux->bci() < stream()->cur_bci()) ||
           (i->as_Goto()->sux_at(0) == fsux  && i->as_Goto()->is_safepoint() == fsux->bci() < stream()->cur_bci()),
           "safepoint state of Goto returned by canonicalizer incorrect");
--- 1239,1281 ----
  
  void GraphBuilder::if_node(Value x, If::Condition cond, Value y, ValueStack* state_before) {
    BlockBegin* tsux = block_at(stream()->get_dest());
    BlockBegin* fsux = block_at(stream()->next_bci());
    bool is_bb = tsux->bci() < stream()->cur_bci() || fsux->bci() < stream()->cur_bci();
+ 
+   bool subst_check = false;
+   if (EnableValhalla && ACmpOnValues == 3 &&
+       (stream()->cur_bc() == Bytecodes::_if_acmpeq || stream()->cur_bc() == Bytecodes::_if_acmpne) &&
+       method() != ciEnv::current()->ValueBootstrapMethods_klass()->find_method(ciSymbol::isSubstitutable_name(), ciSymbol::object_object_boolean_signature())) {
+     // If current method is ValueBootstrapMethods::isSubstitutable(),
+     // compile the acmp as a regular pointer comparison otherwise we
+     // could call ValueBootstrapMethods::isSubstitutable() back
+     ValueType* left_vt = x->type();
+     ValueType* right_vt = y->type();
+     if (left_vt->is_object()) {
+       assert(right_vt->is_object(), "must be");
+       ciKlass* left_klass = x->as_loaded_klass_or_null();
+       ciKlass* right_klass = y->as_loaded_klass_or_null();
+ 
+       if (left_klass == NULL || right_klass == NULL) {
+         // The klass is still unloaded, or came from a Phi node. Go slow case;
+         subst_check = true;
+       } else if (left_klass->is_java_lang_Object() || left_klass->is_interface() ||
+                  right_klass->is_java_lang_Object() || right_klass->is_interface()) {
+         // Either operand may be a value object, but we're not sure.  Go slow case;
+         subst_check = true;
+       } else if (left_klass->is_valuetype() || right_klass->is_valuetype()) {
+         subst_check = true;
+       } else {
+         // No need to do substituability check
+       }
+     }
+   }
+ 
    // In case of loop invariant code motion or predicate insertion
    // before the body of a loop the state is needed
!   Instruction *i = append(new If(x, cond, false, y, tsux, fsux, (is_bb || compilation()->is_optimistic() || subst_check) ? state_before : NULL, is_bb, subst_check));
  
    assert(i->as_Goto() == NULL ||
           (i->as_Goto()->sux_at(0) == tsux  && i->as_Goto()->is_safepoint() == tsux->bci() < stream()->cur_bci()) ||
           (i->as_Goto()->sux_at(0) == fsux  && i->as_Goto()->is_safepoint() == fsux->bci() < stream()->cur_bci()),
           "safepoint state of Goto returned by canonicalizer incorrect");