8339342: FieldAllocationCount is mostly unused

Reviewed-by: fparain, stuefe, matsaave

Author: coleenp

src/hotspot/share/classfile/classFileParser.cpp

@@ -1352,105 +1352,16 @@ void ClassFileParser::parse_field_attributes(const ClassFileStream* const cfs,
 }
 
 
-// Field allocation types. Used for computing field offsets.
-
-enum FieldAllocationType {
-  STATIC_OOP,           // Oops
-  STATIC_BYTE,          // Boolean, Byte, char
-  STATIC_SHORT,         // shorts
-  STATIC_WORD,          // ints
-  STATIC_DOUBLE,        // aligned long or double
-  NONSTATIC_OOP,
-  NONSTATIC_BYTE,
-  NONSTATIC_SHORT,
-  NONSTATIC_WORD,
-  NONSTATIC_DOUBLE,
-  MAX_FIELD_ALLOCATION_TYPE,
-  BAD_ALLOCATION_TYPE = -1
-};
-
-static FieldAllocationType _basic_type_to_atype[2 * (T_CONFLICT + 1)] = {
-  BAD_ALLOCATION_TYPE, // 0
-  BAD_ALLOCATION_TYPE, // 1
-  BAD_ALLOCATION_TYPE, // 2
-  BAD_ALLOCATION_TYPE, // 3
-  NONSTATIC_BYTE ,     // T_BOOLEAN     =  4,
-  NONSTATIC_SHORT,     // T_CHAR        =  5,
-  NONSTATIC_WORD,      // T_FLOAT       =  6,
-  NONSTATIC_DOUBLE,    // T_DOUBLE      =  7,
-  NONSTATIC_BYTE,      // T_BYTE        =  8,
-  NONSTATIC_SHORT,     // T_SHORT       =  9,
-  NONSTATIC_WORD,      // T_INT         = 10,
-  NONSTATIC_DOUBLE,    // T_LONG        = 11,
-  NONSTATIC_OOP,       // T_OBJECT      = 12,
-  NONSTATIC_OOP,       // T_ARRAY       = 13,
-  BAD_ALLOCATION_TYPE, // T_VOID        = 14,
-  BAD_ALLOCATION_TYPE, // T_ADDRESS     = 15,
-  BAD_ALLOCATION_TYPE, // T_NARROWOOP   = 16,
-  BAD_ALLOCATION_TYPE, // T_METADATA    = 17,
-  BAD_ALLOCATION_TYPE, // T_NARROWKLASS = 18,
-  BAD_ALLOCATION_TYPE, // T_CONFLICT    = 19,
-  BAD_ALLOCATION_TYPE, // 0
-  BAD_ALLOCATION_TYPE, // 1
-  BAD_ALLOCATION_TYPE, // 2
-  BAD_ALLOCATION_TYPE, // 3
-  STATIC_BYTE ,        // T_BOOLEAN     =  4,
-  STATIC_SHORT,        // T_CHAR        =  5,
-  STATIC_WORD,         // T_FLOAT       =  6,
-  STATIC_DOUBLE,       // T_DOUBLE      =  7,
-  STATIC_BYTE,         // T_BYTE        =  8,
-  STATIC_SHORT,        // T_SHORT       =  9,
-  STATIC_WORD,         // T_INT         = 10,
-  STATIC_DOUBLE,       // T_LONG        = 11,
-  STATIC_OOP,          // T_OBJECT      = 12,
-  STATIC_OOP,          // T_ARRAY       = 13,
-  BAD_ALLOCATION_TYPE, // T_VOID        = 14,
-  BAD_ALLOCATION_TYPE, // T_ADDRESS     = 15,
-  BAD_ALLOCATION_TYPE, // T_NARROWOOP   = 16,
-  BAD_ALLOCATION_TYPE, // T_METADATA    = 17,
-  BAD_ALLOCATION_TYPE, // T_NARROWKLASS = 18,
-  BAD_ALLOCATION_TYPE, // T_CONFLICT    = 19,
-};
-
-static FieldAllocationType basic_type_to_atype(bool is_static, BasicType type) {
-  assert(type >= T_BOOLEAN && type < T_VOID, "only allowable values");
-  FieldAllocationType result = _basic_type_to_atype[type + (is_static ? (T_CONFLICT + 1) : 0)];
-  assert(result != BAD_ALLOCATION_TYPE, "bad type");
-  return result;
-}
-
-class ClassFileParser::FieldAllocationCount : public ResourceObj {
- public:
-  u2 count[MAX_FIELD_ALLOCATION_TYPE];
-
-  FieldAllocationCount() {
-    for (int i = 0; i < MAX_FIELD_ALLOCATION_TYPE; i++) {
-      count[i] = 0;
-    }
-  }
-
-  void update(bool is_static, BasicType type) {
-    FieldAllocationType atype = basic_type_to_atype(is_static, type);
-    if (atype != BAD_ALLOCATION_TYPE) {
-      // Make sure there is no overflow with injected fields.
-      assert(count[atype] < 0xFFFF, "More than 65535 fields");
-      count[atype]++;
-    }
-  }
-};
-
 // Side-effects: populates the _fields, _fields_annotations,
 // _fields_type_annotations fields
 void ClassFileParser::parse_fields(const ClassFileStream* const cfs,
                                    bool is_interface,
-                                   FieldAllocationCount* const fac,
                                    ConstantPool* cp,
                                    const int cp_size,
                                    u2* const java_fields_count_ptr,
                                    TRAPS) {
 
   assert(cfs != nullptr, "invariant");
-  assert(fac != nullptr, "invariant");
   assert(cp != nullptr, "invariant");
   assert(java_fields_count_ptr != nullptr, "invariant");
 
@@ -1544,8 +1455,10 @@ void ClassFileParser::parse_fields(const ClassFileStream* const cfs,
 
     const BasicType type = cp->basic_type_for_signature_at(signature_index);
 
-    // Update FieldAllocationCount for this kind of field
-    fac->update(is_static, type);
+    // Update number of static oop fields.
+    if (is_static && is_reference_type(type)) {
+      _static_oop_count++;
+    }
 
     FieldInfo fi(access_flags, name_index, signature_index, constantvalue_index, fieldFlags);
     fi.set_index(n);
@@ -1590,10 +1503,6 @@ void ClassFileParser::parse_fields(const ClassFileStream* const cfs,
       FieldInfo fi(aflags, (u2)(injected[n].name_index), (u2)(injected[n].signature_index), 0, fflags);
       fi.set_index(index);
       _temp_field_info->append(fi);
-
-      // Update FieldAllocationCount for this kind of field
-      const BasicType type = Signature::basic_type(injected[n].signature());
-      fac->update(false, type);
       index++;
     }
   }
@@ -5117,8 +5026,7 @@ void ClassFileParser::fill_instance_klass(InstanceKlass* ik,
   // Not yet: supers are done below to support the new subtype-checking fields
   ik->set_nonstatic_field_size(_field_info->_nonstatic_field_size);
   ik->set_has_nonstatic_fields(_field_info->_has_nonstatic_fields);
-  assert(_fac != nullptr, "invariant");
-  ik->set_static_oop_field_count(_fac->count[STATIC_OOP]);
+  ik->set_static_oop_field_count(_static_oop_count);
 
   // this transfers ownership of a lot of arrays from
   // the parser onto the InstanceKlass*
@@ -5360,6 +5268,7 @@ ClassFileParser::ClassFileParser(ClassFileStream* stream,
   _is_hidden(cl_info->is_hidden()),
   _can_access_vm_annotations(cl_info->can_access_vm_annotations()),
   _orig_cp_size(0),
+  _static_oop_count(0),
   _super_klass(),
   _cp(nullptr),
   _fieldinfo_stream(nullptr),
@@ -5380,7 +5289,6 @@ ClassFileParser::ClassFileParser(ClassFileStream* stream,
   _klass(nullptr),
   _klass_to_deallocate(nullptr),
   _parsed_annotations(nullptr),
-  _fac(nullptr),
   _field_info(nullptr),
   _temp_field_info(nullptr),
   _method_ordering(nullptr),
@@ -5706,10 +5614,8 @@ void ClassFileParser::parse_stream(const ClassFileStream* const stream,
   assert(_local_interfaces != nullptr, "invariant");
 
   // Fields (offsets are filled in later)
-  _fac = new FieldAllocationCount();
   parse_fields(stream,
                _access_flags.is_interface(),
-               _fac,
                cp,
                cp_size,
                &_java_fields_count,
@@ -5867,7 +5773,6 @@ void ClassFileParser::post_process_parsed_stream(const ClassFileStream* const st
   _itable_size = _access_flags.is_interface() ? 0 :
     klassItable::compute_itable_size(_transitive_interfaces);
 
-  assert(_fac != nullptr, "invariant");
   assert(_parsed_annotations != nullptr, "invariant");
 
   _field_info = new FieldLayoutInfo();

src/hotspot/share/classfile/classFileParser.hpp

@@ -86,7 +86,6 @@ class ClassFileParser {
   friend class FieldLayout;
 
   class ClassAnnotationCollector;
-  class FieldAllocationCount;
   class FieldAnnotationCollector;
 
  public:
@@ -116,6 +115,7 @@ class ClassFileParser {
   const bool _is_hidden;
   const bool _can_access_vm_annotations;
   int _orig_cp_size;
+  unsigned int _static_oop_count;
 
   // Metadata created before the instance klass is created.  Must be deallocated
   // if not transferred to the InstanceKlass upon successful class loading
@@ -141,7 +141,6 @@ class ClassFileParser {
   InstanceKlass* _klass_to_deallocate; // an InstanceKlass* to be destroyed
 
   ClassAnnotationCollector* _parsed_annotations;
-  FieldAllocationCount* _fac;
   FieldLayoutInfo* _field_info;
   GrowableArray<FieldInfo>* _temp_field_info;
   const intArray* _method_ordering;
@@ -260,7 +259,6 @@ class ClassFileParser {
 
   void parse_fields(const ClassFileStream* const cfs,
                     bool is_interface,
-                    FieldAllocationCount* const fac,
                     ConstantPool* cp,
                     const int cp_size,
                     u2* const java_fields_count_ptr,