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src/hotspot/share/ci/ciObject.cpp

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  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "ci/ciObject.hpp"
 26 #include "ci/ciUtilities.inline.hpp"

 27 #include "gc/shared/collectedHeap.inline.hpp"
 28 #include "oops/oop.inline.hpp"
 29 #include "runtime/jniHandles.inline.hpp"
 30 
 31 // ciObject
 32 //
 33 // This class represents an oop in the HotSpot virtual machine.
 34 // Its subclasses are structured in a hierarchy which mirrors
 35 // an aggregate of the VM's oop and klass hierarchies (see
 36 // oopHierarchy.hpp).  Each instance of ciObject holds a handle
 37 // to a corresponding oop on the VM side and provides routines
 38 // for accessing the information in its oop.  By using the ciObject
 39 // hierarchy for accessing oops in the VM, the compiler ensures
 40 // that it is safe with respect to garbage collection; that is,
 41 // GC and compilation can proceed independently without
 42 // interference.
 43 //
 44 // Within the VM, the oop and klass hierarchies are separate.
 45 // The compiler interface does not preserve this separation --
 46 // the distinction between `Klass*' and `Klass' are not

185   return ciConstant();
186 }
187 
188 // ------------------------------------------------------------------
189 // ciObject::add_to_constant_value_cache()
190 //
191 // Add a constant value to the cache.
192 void ciObject::add_to_constant_value_cache(int off, ciConstant val) {
193   assert(val.is_valid(), "value must be valid");
194   assert(!check_constant_value_cache(off, val.basic_type()).is_valid(), "duplicate");
195   if (_constant_values == nullptr) {
196     Arena* arena = CURRENT_ENV->arena();
197     _constant_values = new (arena) GrowableArray<ConstantValue>(arena, 1, 0, ConstantValue());
198   }
199   _constant_values->append(ConstantValue(off, val));
200 }
201 
202 // ------------------------------------------------------------------
203 // ciObject::should_be_constant()
204 bool ciObject::should_be_constant() {
205   if (ScavengeRootsInCode >= 2)  return true;  // force everybody to be a constant
206   if (is_null_object()) return true;
207 



208   ciEnv* env = CURRENT_ENV;
209 
210     // We want Strings and Classes to be embeddable by default since
211     // they used to be in the perm world.  Not all Strings used to be
212     // embeddable but there's no easy way to distinguish the interned
213     // from the regulars ones so just treat them all that way.
214     if (klass() == env->String_klass() || klass() == env->Class_klass()) {
215       return true;
216     }
217   if (klass()->is_subclass_of(env->MethodHandle_klass()) ||
218       klass()->is_subclass_of(env->CallSite_klass())) {

219     // We want to treat these aggressively.
220     return true;
221   }
222 
223   return handle() == nullptr;
224 }
225 
226 // ------------------------------------------------------------------
227 // ciObject::print
228 //
229 // Print debugging output about this ciObject.
230 //
231 // Implementation note: dispatch to the virtual print_impl behavior
232 // for this ciObject.
233 void ciObject::print(outputStream* st) {
234   st->print("<%s", type_string());
235   GUARDED_VM_ENTRY(print_impl(st);)
236   st->print(" ident=%d address=" INTPTR_FORMAT ">", ident(), p2i(this));
237 }
238 

  7  * published by the Free Software Foundation.
  8  *
  9  * This code is distributed in the hope that it will be useful, but WITHOUT
 10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 12  * version 2 for more details (a copy is included in the LICENSE file that
 13  * accompanied this code).
 14  *
 15  * You should have received a copy of the GNU General Public License version
 16  * 2 along with this work; if not, write to the Free Software Foundation,
 17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 18  *
 19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 20  * or visit www.oracle.com if you need additional information or have any
 21  * questions.
 22  *
 23  */
 24 
 25 #include "ci/ciObject.hpp"
 26 #include "ci/ciUtilities.inline.hpp"
 27 #include "code/SCCache.hpp"
 28 #include "gc/shared/collectedHeap.inline.hpp"
 29 #include "oops/oop.inline.hpp"
 30 #include "runtime/jniHandles.inline.hpp"
 31 
 32 // ciObject
 33 //
 34 // This class represents an oop in the HotSpot virtual machine.
 35 // Its subclasses are structured in a hierarchy which mirrors
 36 // an aggregate of the VM's oop and klass hierarchies (see
 37 // oopHierarchy.hpp).  Each instance of ciObject holds a handle
 38 // to a corresponding oop on the VM side and provides routines
 39 // for accessing the information in its oop.  By using the ciObject
 40 // hierarchy for accessing oops in the VM, the compiler ensures
 41 // that it is safe with respect to garbage collection; that is,
 42 // GC and compilation can proceed independently without
 43 // interference.
 44 //
 45 // Within the VM, the oop and klass hierarchies are separate.
 46 // The compiler interface does not preserve this separation --
 47 // the distinction between `Klass*' and `Klass' are not

186   return ciConstant();
187 }
188 
189 // ------------------------------------------------------------------
190 // ciObject::add_to_constant_value_cache()
191 //
192 // Add a constant value to the cache.
193 void ciObject::add_to_constant_value_cache(int off, ciConstant val) {
194   assert(val.is_valid(), "value must be valid");
195   assert(!check_constant_value_cache(off, val.basic_type()).is_valid(), "duplicate");
196   if (_constant_values == nullptr) {
197     Arena* arena = CURRENT_ENV->arena();
198     _constant_values = new (arena) GrowableArray<ConstantValue>(arena, 1, 0, ConstantValue());
199   }
200   _constant_values->append(ConstantValue(off, val));
201 }
202 
203 // ------------------------------------------------------------------
204 // ciObject::should_be_constant()
205 bool ciObject::should_be_constant() {
206   if (ScavengeRootsInCode >= 2 && !(SCCache::is_on_for_write())) {
207     return true;  // force everybody to be a constant
208   }
209   if (is_null_object()) {
210     return true;
211   }
212   ciEnv* env = CURRENT_ENV;
213 
214   // We want Strings and Classes to be embeddable by default since
215   // they used to be in the perm world.  Not all Strings used to be
216   // embeddable but there's no easy way to distinguish the interned
217   // from the regulars ones so just treat them all that way.
218   if (klass() == env->String_klass() || klass() == env->Class_klass()) {
219     return true;
220   }
221   if ((klass()->is_subclass_of(env->MethodHandle_klass()) ||
222        klass()->is_subclass_of(env->CallSite_klass())) &&
223       !(SCCache::is_on_for_write())) { // For now disable it when caching startup code.
224     // We want to treat these aggressively.
225     return true;
226   }
227 
228   return handle() == nullptr;
229 }
230 
231 // ------------------------------------------------------------------
232 // ciObject::print
233 //
234 // Print debugging output about this ciObject.
235 //
236 // Implementation note: dispatch to the virtual print_impl behavior
237 // for this ciObject.
238 void ciObject::print(outputStream* st) {
239   st->print("<%s", type_string());
240   GUARDED_VM_ENTRY(print_impl(st);)
241   st->print(" ident=%d address=" INTPTR_FORMAT ">", ident(), p2i(this));
242 }
243 
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