src/hotspot/share/c1/c1_LIRGenerator.cpp

*** 1541,1551 ****
  #endif
  
    if (x->needs_null_check() &&
        (needs_patching ||
         MacroAssembler::needs_explicit_null_check(x->offset()))) {
!     if (needs_patching && x->field()->is_q_type()) {
        // We are storing a field of type "QT;" into holder class H, but H is not yet
        // loaded. (If H had been loaded, then T must also have already been loaded
        // due to the "Q" signature, and needs_patching would be false).
        assert(!x->field()->holder()->is_loaded(), "must be");
        // We don't know the offset of this field. Let's deopt and recompile.
--- 1541,1551 ----
  #endif
  
    if (x->needs_null_check() &&
        (needs_patching ||
         MacroAssembler::needs_explicit_null_check(x->offset()))) {
!     if (needs_patching && x->field()->is_flattenable()) {
        // We are storing a field of type "QT;" into holder class H, but H is not yet
        // loaded. (If H had been loaded, then T must also have already been loaded
        // due to the "Q" signature, and needs_patching would be false).
        assert(!x->field()->holder()->is_loaded(), "must be");
        // We don't know the offset of this field. Let's deopt and recompile.
*** 1869,1879 ****
    }
  
    return _barrier_set->resolve(this, decorators, obj);
  }
  
! Value LIRGenerator::q_type_load_field_prolog(LoadField* x, CodeEmitInfo* info) {
    ciField* field = x->field();
    ciInstanceKlass* holder = field->holder();
    Value default_value = NULL;
  
    // Unloaded "QV;" klasses are represented by a ciInstanceKlass
--- 1869,1879 ----
    }
  
    return _barrier_set->resolve(this, decorators, obj);
  }
  
! Value LIRGenerator::flattenable_load_field_prolog(LoadField* x, CodeEmitInfo* info) {
    ciField* field = x->field();
    ciInstanceKlass* holder = field->holder();
    Value default_value = NULL;
  
    // Unloaded "QV;" klasses are represented by a ciInstanceKlass
*** 1882,1919 ****
    // Check for edge cases (1), (2) and (3) for getstatic and getfield
    bool deopt = false;
    bool need_default = false;
    if (field->is_static()) {
        // (1) holder is unloaded -- no problem: it will be loaded by patching, and field offset will be determined.
  
      if (field_type_unloaded) {
        // (2) field type is unloaded -- problem: we don't know what the default value is. Let's deopt.
        //                               FIXME: consider getting the default value in patching code.
        deopt = true;
      } else {
        need_default = true;
      }
  
!       // (3) field is not flattenable -- we don't care: static fields are never flattened.
    } else {
      if (!holder->is_loaded()) {
        // (1) holder is unloaded -- problem: we needed the field offset back in GraphBuilder::access_field()
        //                           FIXME: consider getting field offset in patching code (but only if the field
        //                           type was loaded at compilation time).
        deopt = true;
      } else if (field_type_unloaded) {
!       // (2) field type is unloaded -- problem: we don't whether it's flattened or not. Let's deopt
        deopt = true;
      } else if (!field->is_flattened()) {
!       // (3) field is not flattenable -- need default value in cases of uninitialized field
        need_default = true;
      }
    }
  
-   assert(!(deopt && need_default), "cannot both be true");
- 
    if (deopt) {
      assert(x->needs_patching(), "must be");
      assert(info != NULL, "must be");
      CodeStub* stub = new DeoptimizeStub(new CodeEmitInfo(info),
                                          Deoptimization::Reason_unloaded,
                                          Deoptimization::Action_make_not_entrant);
--- 1882,1920 ----
    // Check for edge cases (1), (2) and (3) for getstatic and getfield
    bool deopt = false;
    bool need_default = false;
    if (field->is_static()) {
        // (1) holder is unloaded -- no problem: it will be loaded by patching, and field offset will be determined.
+       // No check needed here.
  
      if (field_type_unloaded) {
        // (2) field type is unloaded -- problem: we don't know what the default value is. Let's deopt.
        //                               FIXME: consider getting the default value in patching code.
        deopt = true;
      } else {
        need_default = true;
      }
  
!       // (3) field is not flattened -- we don't care: static fields are never flattened.
!       // No check needed here.
    } else {
      if (!holder->is_loaded()) {
        // (1) holder is unloaded -- problem: we needed the field offset back in GraphBuilder::access_field()
        //                           FIXME: consider getting field offset in patching code (but only if the field
        //                           type was loaded at compilation time).
        deopt = true;
      } else if (field_type_unloaded) {
!       // (2) field type is unloaded -- problem: we don't know whether it's flattened or not. Let's deopt
        deopt = true;
      } else if (!field->is_flattened()) {
!       // (3) field is not flattened -- need default value in cases of uninitialized field
        need_default = true;
      }
    }
  
    if (deopt) {
+     assert(!need_default, "deopt and need_default cannot both be true");
      assert(x->needs_patching(), "must be");
      assert(info != NULL, "must be");
      CodeStub* stub = new DeoptimizeStub(new CodeEmitInfo(info),
                                          Deoptimization::Reason_unloaded,
                                          Deoptimization::Action_make_not_entrant);
*** 1972,1983 ****
                    x->is_static() ?  "static" : "field", x->printable_bci());
    }
  #endif
  
    Value default_value = NULL;
!   if (x->field()->is_q_type()) {
!     default_value = q_type_load_field_prolog(x, info);
    }
  
    bool stress_deopt = StressLoopInvariantCodeMotion && info && info->deoptimize_on_exception();
    if (x->needs_null_check() &&
        (needs_patching ||
--- 1973,1984 ----
                    x->is_static() ?  "static" : "field", x->printable_bci());
    }
  #endif
  
    Value default_value = NULL;
!   if (x->field()->is_flattenable()) {
!     default_value = flattenable_load_field_prolog(x, info);
    }
  
    bool stress_deopt = StressLoopInvariantCodeMotion && info && info->deoptimize_on_exception();
    if (x->needs_null_check() &&
        (needs_patching ||