More refactoring

src/hotspot/share/c1/c1_Runtime1.cpp

@@ -378,8 +378,7 @@ static void allocate_instance(JavaThread* current, Klass* klass, TRAPS) {
   // make sure klass is initialized
   h->initialize(CHECK);
   oop obj = nullptr;
-  // TODO is this correct? C2 uses ciInlineKlass::is_empty instead
-  if (h->is_inline_klass() &&  InlineKlass::cast(h)->is_empty_inline_type()) {
+  if (h->is_inline_klass() && InlineKlass::cast(h)->is_empty_inline_type()) {
     obj = InlineKlass::cast(h)->default_value();
     assert(obj != nullptr, "default value must exist");
   } else {

src/hotspot/share/ci/ciInlineKlass.cpp

@@ -97,9 +97,7 @@ bool ciInlineKlass::is_empty() {
   // Do not use InlineKlass::is_empty_inline_type here because it does
   // consider the container empty even if fields of empty inline types
   // are not flat
-  // TODO double check, I think we can also consider it empty if it only contains null-free flat fields of empty inline klasses
   return nof_declared_nonstatic_fields() == 0;
-  //return nof_nonstatic_fields() == 0;
 }
 
 // When passing an inline type's fields as arguments, count the number

src/hotspot/share/ci/ciInstanceKlass.cpp

@@ -536,7 +536,6 @@ GrowableArray<ciField*>* ciInstanceKlass::compute_nonstatic_fields_impl(Growable
   }
 
   // allocate the array:
-  // TODO why do we need this?
   if (flen == 0 && !is_inlinetype()) {
     return nullptr;  // return nothing if none are locally declared
   }

src/hotspot/share/ci/ciReplay.cpp

@@ -1150,11 +1150,6 @@ class CompileReplay : public StackObj {
             Klass* actual_array_klass = parse_klass(CHECK_(true));
             Klass* kelem = ObjArrayKlass::cast(actual_array_klass)->element_klass();
             value = oopFactory::new_objArray(kelem, length, CHECK_(true));
-          } else if (field_signature[0] == JVM_SIGNATURE_ARRAY) {
-            // TODO this is dead, right?
-            Klass* kelem = resolve_klass(field_signature + 1, CHECK_(true));
-            parse_klass(CHECK_(true)); // eat up the array class name
-            value = oopFactory::new_valueArray(kelem, length, CHECK_(true));
           } else {
             report_error("unhandled array staticfield");
           }

src/hotspot/share/code/nmethod.cpp

@@ -3812,11 +3812,9 @@ void nmethod::print_nmethod_labels(outputStream* stream, address block_begin, bo
       }
       if (!did_name)
         stream->print("%s", type2name(t));
-      if ((*sig)._offset == -1) {
-        // TODO it's also -1 if it's not from a flat field
-        //stream->print(" IS INIT");
-      } else  if ((*sig)._sort_offset != (*sig)._offset) {
-        stream->print(" NULL MARKER");
+      // If the entry has a non-default sort_offset, it must be a null marker
+      if ((*sig)._sort_offset != (*sig)._offset) {
+        stream->print(" (null marker)");
       }
     }
     if (at_old_sp) {

src/hotspot/share/oops/fieldStreams.hpp

@@ -301,6 +301,10 @@ class HierarchicalFieldStream : public StackObj  {
   bool is_null_free_inline_type() {
     return _current_stream.is_null_free_inline_type();
   }
+
+  int null_marker_offset() {
+    return _current_stream.null_marker_offset();
+  }
 };
 
 #endif // SHARE_OOPS_FIELDSTREAMS_HPP

src/hotspot/share/oops/inlineKlass.cpp

@@ -306,9 +306,7 @@ int InlineKlass::collect_fields(GrowableArray<SigEntry>* sig, float& max_offset,
       // Resolve klass of flat field and recursively collect fields
       int field_null_marker_offset = -1;
       if (!fs.is_null_free_inline_type()) {
-        // TODO can we use null_marker_offset() instead?
-        InlineLayoutInfo* li = inline_layout_info_adr(fs.index());
-        field_null_marker_offset = base_off + li->null_marker_offset() - (base_off > 0 ? first_field_offset() : 0);
+        field_null_marker_offset = base_off + fs.null_marker_offset() - (base_off > 0 ? first_field_offset() : 0);
       }
       Klass* vk = get_inline_type_field_klass(fs.index());
       count += InlineKlass::cast(vk)->collect_fields(sig, max_offset, offset, field_null_marker_offset);

src/hotspot/share/runtime/sharedRuntime.cpp

@@ -2868,8 +2868,9 @@ void CompiledEntrySignature::compute_calling_conventions(bool init) {
             _sig_cc_ro->appendAll(vk->extended_sig());
             if (bt == T_OBJECT) {
               // Nullable inline type argument, insert InlineTypeNode::IsInit field right after T_METADATA delimiter
-              _sig_cc->insert_before(last+1, SigEntry(T_BOOLEAN));
-              _sig_cc_ro->insert_before(last_ro+1, SigEntry(T_BOOLEAN));
+              // Set the sort_offset so that the field is detected as null marker by nmethod::print_nmethod_labels.
+              _sig_cc->insert_before(last+1, SigEntry(T_BOOLEAN, -1, 0));
+              _sig_cc_ro->insert_before(last_ro+1, SigEntry(T_BOOLEAN, -1, 0));
             }
           }
         } else {

src/hotspot/share/runtime/signature.hpp

@@ -577,11 +577,10 @@ typedef GrowableArrayFilterIterator<SigEntry, SigEntryFilter> ExtendedSignature;
 // specially. See comment for InlineKlass::collect_fields().
 class SigEntry {
  public:
-  // TODO improve these comments
-  BasicType _bt;
-  int _offset;      // Offset of the corresponding field in it's value class holder for scalarized arguments (-1 otherwise). Used for packing and unpacking
+  BasicType _bt;      // Basic type of the argument
+  int _offset;        // Offset of the field in its value class holder for scalarized arguments (-1 otherwise). Used for packing and unpacking.
   float _sort_offset; // Offset used for sorting
-  Symbol* _symbol;  // For printing
+  Symbol* _symbol;    // Symbol for printing
 
   SigEntry()
     : _bt(T_ILLEGAL), _offset(-1), _sort_offset(-1), _symbol(NULL) {}