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src/hotspot/share/opto/subtypenode.cpp

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 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
 23  *
 24  */
 25 
 26 #include "opto/addnode.hpp"
 27 #include "opto/callnode.hpp"
 28 #include "opto/connode.hpp"
 29 #include "opto/convertnode.hpp"
 30 #include "opto/phaseX.hpp"
 31 #include "opto/rootnode.hpp"
 32 #include "opto/subnode.hpp"
 33 #include "opto/subtypenode.hpp"
 34 
 35 const Type* SubTypeCheckNode::sub(const Type* sub_t, const Type* super_t) const {
 36   const TypeKlassPtr* superk = super_t->isa_klassptr();
 37   assert(sub_t != Type::TOP && !TypePtr::NULL_PTR->higher_equal(sub_t), "should be not null");
 38   const TypeKlassPtr* subk = sub_t->isa_klassptr() ? sub_t->is_klassptr() : sub_t->is_oopptr()->as_klass_type();
 39 
 40   // Oop can't be a subtype of abstract type that has no subclass.
 41   if (sub_t->isa_oopptr() && superk->isa_instklassptr() && superk->klass_is_exact()) {
 42     ciKlass* superklass = superk->exact_klass();
 43     if (!superklass->is_interface() && superklass->is_abstract() &&
 44         !superklass->as_instance_klass()->has_subklass()) {
 45       Compile::current()->dependencies()->assert_leaf_type(superklass);
 46       return TypeInt::CC_GT;
 47     }
 48   }
 49 
 50   if (subk != nullptr) {
 51     switch (Compile::current()->static_subtype_check(superk, subk, false)) {
 52       case Compile::SSC_always_false:
 53         return TypeInt::CC_GT;
 54       case Compile::SSC_always_true:
 55         return TypeInt::CC_EQ;
 56       case Compile::SSC_easy_test:
 57       case Compile::SSC_full_test:
 58         break;
 59       default:
 60         ShouldNotReachHere();

























 61     }
 62   }
 63 












 64   return bottom_type();
 65 }
 66 
 67 Node *SubTypeCheckNode::Ideal(PhaseGVN* phase, bool can_reshape) {
 68   Node* obj_or_subklass = in(ObjOrSubKlass);
 69   Node* superklass = in(SuperKlass);
 70 
 71   if (obj_or_subklass == nullptr ||
 72       superklass == nullptr) {
 73     return nullptr;
 74   }
 75 
 76   const Type* sub_t = phase->type(obj_or_subklass);
 77   const Type* super_t = phase->type(superklass);
 78 
 79   if (!super_t->isa_klassptr() ||
 80       (!sub_t->isa_klassptr() && !sub_t->isa_oopptr())) {
 81     return nullptr;
 82   }
 83 

117 }
118 
119 #ifdef ASSERT
120 bool SubTypeCheckNode::is_oop(PhaseGVN* phase, Node* n) {
121     const Type* t = phase->type(n);
122     if (!t->isa_oopptr() && t != Type::TOP) {
123       n->dump();
124       t->dump(); tty->cr();
125       return false;
126     }
127     return true;
128 }
129 
130 static Node* record_for_cleanup(Node* n, PhaseGVN* phase) {
131   if (phase->is_IterGVN()) {
132     phase->is_IterGVN()->_worklist.push(n); // record for cleanup
133   }
134   return n;
135 }
136 bool SubTypeCheckNode::verify_helper(PhaseGVN* phase, Node* subklass, const Type* cached_t) {
137   Node* cmp = phase->transform(new CmpPNode(subklass, in(SuperKlass)));

138   record_for_cleanup(cmp, phase);
139 
140   const Type* cmp_t = phase->type(cmp);
141   const Type* t = Value(phase);
142 
143   if (t == cmp_t ||
144       t != cached_t || // previous observations don't hold anymore
145       (cmp_t != TypeInt::CC_GT && cmp_t != TypeInt::CC_EQ)) {
146     return true;
147   } else {
148     t->dump(); tty->cr();
149     this->dump(2); tty->cr();

150     cmp_t->dump(); tty->cr();
151     subklass->dump(2); tty->cr();
152     tty->print_cr("==============================");
153     phase->C->root()->dump(9999);
154     return false;
155   }
156 }
157 
158 // Verify that optimizing the subtype check to a simple code pattern when possible would not constant fold better.
159 bool SubTypeCheckNode::verify(PhaseGVN* phase) {
160   Compile* C = phase->C;
161   Node* obj_or_subklass = in(ObjOrSubKlass);
162   Node* superklass = in(SuperKlass);
163 
164   const Type* sub_t = phase->type(obj_or_subklass);
165   const Type* super_t = phase->type(superklass);
166 
167   const TypeKlassPtr* superk = super_t->isa_klassptr();
168   const TypeKlassPtr* subk = sub_t->isa_klassptr() ? sub_t->is_klassptr() : sub_t->is_oopptr()->as_klass_type();
169 
170   if (super_t->singleton() && subk != nullptr) {
171     if (obj_or_subklass->bottom_type() == Type::TOP) {
172       // The bottom type of obj_or_subklass is TOP, despite its recorded type
173       // being an OOP or a klass pointer. This can happen for example in
174       // transient scenarios where obj_or_subklass is a projection of the TOP
175       // node. In such cases, skip verification to avoid violating the contract
176       // of LoadKlassNode::make(). This does not weaken the effect of verify(),
177       // as SubTypeCheck nodes with TOP obj_or_subklass inputs are dead anyway.
178       return true;
179     }
180     const Type* cached_t = Value(phase); // cache the type to validate consistency
181     switch (C->static_subtype_check(superk, subk, false)) {
182       case Compile::SSC_easy_test: {
183         return verify_helper(phase, load_klass(phase), cached_t);
184       }
185       case Compile::SSC_full_test: {
186         Node* p1 = phase->transform(AddPNode::make_off_heap(superklass, phase->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
187         Node* chk_off = phase->transform(new LoadINode(nullptr, C->immutable_memory(), p1, phase->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
188         record_for_cleanup(chk_off, phase);
189 
190         int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
191         bool might_be_cache = (phase->find_int_con(chk_off, cacheoff_con) == cacheoff_con);
192         if (!might_be_cache) {
193           Node* subklass = load_klass(phase);
194           Node* chk_off_X = chk_off;
195 #ifdef _LP64
196           chk_off_X = phase->transform(new ConvI2LNode(chk_off_X));
197 #endif
198           Node* p2 = phase->transform(AddPNode::make_off_heap(subklass, chk_off_X));
199           Node* nkls = phase->transform(LoadKlassNode::make(*phase, C->immutable_memory(), p2, phase->type(p2)->is_ptr(), TypeInstKlassPtr::OBJECT_OR_NULL));
200 
201           return verify_helper(phase, nkls, cached_t);
202         }
203         break;
204       }
205       case Compile::SSC_always_false:
206       case Compile::SSC_always_true:
207       default: {
208         break; // nothing to do
209       }
210     }
211   }

227   return subklass;
228 }
229 #endif
230 
231 uint SubTypeCheckNode::size_of() const {
232   return sizeof(*this);
233 }
234 
235 uint SubTypeCheckNode::hash() const {
236   return NO_HASH;
237 }
238 
239 #ifndef PRODUCT
240 void SubTypeCheckNode::dump_spec(outputStream* st) const {
241   if (_method != nullptr) {
242     st->print(" profiled at:");
243     _method->print_short_name(st);
244     st->print(":%d", _bci);
245   }
246 }
247 #endif

 16  * You should have received a copy of the GNU General Public License version
 17  * 2 along with this work; if not, write to the Free Software Foundation,
 18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 19  *
 20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 21  * or visit www.oracle.com if you need additional information or have any
 22  * questions.
 23  *
 24  */
 25 
 26 #include "opto/addnode.hpp"
 27 #include "opto/callnode.hpp"
 28 #include "opto/connode.hpp"
 29 #include "opto/convertnode.hpp"
 30 #include "opto/phaseX.hpp"
 31 #include "opto/rootnode.hpp"
 32 #include "opto/subnode.hpp"
 33 #include "opto/subtypenode.hpp"
 34 
 35 const Type* SubTypeCheckNode::sub(const Type* sub_t, const Type* super_t) const {
 36   const TypeKlassPtr* super_klass_type = super_t->isa_klassptr();
 37   assert(sub_t != Type::TOP && !TypePtr::NULL_PTR->higher_equal(sub_t), "should be not null");
 38   const TypeKlassPtr* sub_klass_type = sub_t->isa_klassptr() ? sub_t->is_klassptr() : sub_t->is_oopptr()->as_klass_type();
 39 
 40   // Oop can't be a subtype of abstract type that has no subclass.
 41   if (sub_t->isa_oopptr() && super_klass_type->isa_instklassptr() && super_klass_type->klass_is_exact()) {
 42     ciKlass* superklass = super_klass_type->exact_klass();
 43     if (!superklass->is_interface() && superklass->is_abstract() &&
 44         !superklass->as_instance_klass()->has_subklass()) {
 45       Compile::current()->dependencies()->assert_leaf_type(superklass);
 46       return TypeInt::CC_GT;
 47     }
 48   }
 49 
 50   // FIXME: shouldn't this be encoded in helper methods of the type system (maybe_java_subtype_of() etc.?)
 51   // Similar to logic in CmpPNode::sub()
 52   bool unrelated_classes = false;
 53 
 54   // Handle inline type arrays
 55   //
 56   // The super klass can be an exact non-array klass constant which is known to be not flat in array (e.g. Object)
 57   // while the sub klass could very well be flat in array:
 58   //
 59   //           MyValue       <:       Object:exact
 60   //        flat in array          not flat in array
 61   //
 62   // We therefore first cast the super klass to inexact (if the class is not final itself) and recompute the flat in
 63   // array property for the super klass (all done in cast_to_exactness()) in order to check whether the sub klass is
 64   // flat in array and the super klass is not flat in array. If that's the case, the classes must be unrelated.
 65   const TypeKlassPtr* super_klass_type_for_flat_in_array = super_klass_type;
 66   if (super_klass_type->isa_instklassptr()) {
 67     // Only relevant for TypeInstKlassPtr. TypeAryKlassPtr will always be not flat in array.
 68     super_klass_type_for_flat_in_array = super_klass_type->cast_to_exactness(false);
 69   }
 70 
 71   if ((sub_klass_type->is_flat_in_array() && super_klass_type_for_flat_in_array->is_not_flat_in_array()) ||
 72       (super_klass_type_for_flat_in_array->is_flat_in_array() && sub_klass_type->is_not_flat_in_array())) {
 73     // The subtype is flat in array and the supertype is not in flat array or vice versa. Cannot subtype and thus unrelated.
 74     unrelated_classes = true;
 75   } else if (sub_klass_type->is_not_flat() && super_klass_type->is_flat()) {
 76     // The subtype is a non-flat array and the supertype is a flat array. Must be unrelated.
 77     unrelated_classes = true;
 78   } else if (sub_klass_type->is_not_null_free() && super_klass_type->is_null_free()) {
 79     // The subtype is a nullable array and the supertype is null-free array. Must be unrelated.
 80     unrelated_classes = true;
 81   }
 82   if (unrelated_classes) {
 83     TypePtr::PTR jp = sub_t->is_ptr()->join_ptr(super_t->is_ptr()->_ptr);
 84     if (jp != TypePtr::Null && jp != TypePtr::BotPTR) {
 85       return TypeInt::CC_GT;
 86     }
 87   }
 88 
 89   switch (Compile::current()->static_subtype_check(super_klass_type, sub_klass_type, false)) {
 90     case Compile::SSC_always_false:
 91       return TypeInt::CC_GT;
 92     case Compile::SSC_always_true:
 93       return TypeInt::CC_EQ;
 94     case Compile::SSC_easy_test:
 95     case Compile::SSC_full_test:
 96       break;
 97     default:
 98       ShouldNotReachHere();
 99   }
100 
101   return bottom_type();
102 }
103 
104 Node *SubTypeCheckNode::Ideal(PhaseGVN* phase, bool can_reshape) {
105   Node* obj_or_subklass = in(ObjOrSubKlass);
106   Node* superklass = in(SuperKlass);
107 
108   if (obj_or_subklass == nullptr ||
109       superklass == nullptr) {
110     return nullptr;
111   }
112 
113   const Type* sub_t = phase->type(obj_or_subklass);
114   const Type* super_t = phase->type(superklass);
115 
116   if (!super_t->isa_klassptr() ||
117       (!sub_t->isa_klassptr() && !sub_t->isa_oopptr())) {
118     return nullptr;
119   }
120 

154 }
155 
156 #ifdef ASSERT
157 bool SubTypeCheckNode::is_oop(PhaseGVN* phase, Node* n) {
158     const Type* t = phase->type(n);
159     if (!t->isa_oopptr() && t != Type::TOP) {
160       n->dump();
161       t->dump(); tty->cr();
162       return false;
163     }
164     return true;
165 }
166 
167 static Node* record_for_cleanup(Node* n, PhaseGVN* phase) {
168   if (phase->is_IterGVN()) {
169     phase->is_IterGVN()->_worklist.push(n); // record for cleanup
170   }
171   return n;
172 }
173 bool SubTypeCheckNode::verify_helper(PhaseGVN* phase, Node* subklass, const Type* cached_t) {
174   Node* cmp_orig = new CmpPNode(subklass, in(SuperKlass));
175   Node* cmp = phase->transform(cmp_orig);
176   record_for_cleanup(cmp, phase);
177 
178   const Type* cmp_t = phase->type(cmp);
179   const Type* t = Value(phase);
180 
181   if (t == cmp_t ||
182       t != cached_t || // previous observations don't hold anymore
183       (cmp_t != TypeInt::CC_GT && cmp_t != TypeInt::CC_EQ)) {
184     return true;
185   } else {
186     t->dump(); tty->cr();
187     this->dump(2); tty->cr();
188     tty->print_cr("VS.\n");
189     cmp_t->dump(); tty->cr();
190     cmp_orig->dump(2); tty->cr();
191     tty->print_cr("==============================\n");
192     phase->C->root()->dump(9999);
193     return false;
194   }
195 }
196 
197 // Verify that optimizing the subtype check to a simple code pattern when possible would not constant fold better.
198 bool SubTypeCheckNode::verify(PhaseGVN* phase) {
199   Compile* C = phase->C;
200   Node* obj_or_subklass = in(ObjOrSubKlass);
201   Node* superklass = in(SuperKlass);
202 
203   const Type* sub_t = phase->type(obj_or_subklass);
204   const Type* super_t = phase->type(superklass);
205 
206   const TypeKlassPtr* superk = super_t->isa_klassptr();
207   const TypeKlassPtr* subk = sub_t->isa_klassptr() ? sub_t->is_klassptr() : sub_t->is_oopptr()->as_klass_type();
208 
209   if (super_t->singleton() && subk != nullptr) {
210     if (obj_or_subklass->bottom_type() == Type::TOP) {
211       // The bottom type of obj_or_subklass is TOP, despite its recorded type
212       // being an OOP or a klass pointer. This can happen for example in
213       // transient scenarios where obj_or_subklass is a projection of the TOP
214       // node. In such cases, skip verification to avoid violating the contract
215       // of LoadKlassNode::make(). This does not weaken the effect of verify(),
216       // as SubTypeCheck nodes with TOP obj_or_subklass inputs are dead anyway.
217       return true;
218     }
219     const Type* cached_t = Value(phase); // cache the type to validate consistency
220     switch (C->static_subtype_check(superk, subk, false)) {
221       case Compile::SSC_easy_test: {
222         return verify_helper(phase, load_klass(phase), cached_t);
223       }
224       case Compile::SSC_full_test: {
225         Node* p1 = phase->transform(AddPNode::make_off_heap(superklass, phase->MakeConX(in_bytes(Klass::super_check_offset_offset()))));
226         Node* chk_off = phase->transform(new LoadINode(nullptr, C->immutable_memory(), p1, phase->type(p1)->is_ptr(), TypeInt::INT, MemNode::unordered));
227         record_for_cleanup(chk_off, phase);
228 
229         int cacheoff_con = in_bytes(Klass::secondary_super_cache_offset());
230         bool might_be_cache = phase->find_int_con(chk_off, cacheoff_con) == cacheoff_con;
231         if (!might_be_cache) {
232           Node* subklass = load_klass(phase);
233           Node* chk_off_X = chk_off;
234 #ifdef _LP64
235           chk_off_X = phase->transform(new ConvI2LNode(chk_off_X));
236 #endif
237           Node* p2 = phase->transform(AddPNode::make_off_heap(subklass, chk_off_X));
238           Node* nkls = phase->transform(LoadKlassNode::make(*phase, C->immutable_memory(), p2, phase->type(p2)->is_ptr(), TypeInstKlassPtr::OBJECT_OR_NULL));
239 
240           return verify_helper(phase, nkls, cached_t);
241         }
242         break;
243       }
244       case Compile::SSC_always_false:
245       case Compile::SSC_always_true:
246       default: {
247         break; // nothing to do
248       }
249     }
250   }

266   return subklass;
267 }
268 #endif
269 
270 uint SubTypeCheckNode::size_of() const {
271   return sizeof(*this);
272 }
273 
274 uint SubTypeCheckNode::hash() const {
275   return NO_HASH;
276 }
277 
278 #ifndef PRODUCT
279 void SubTypeCheckNode::dump_spec(outputStream* st) const {
280   if (_method != nullptr) {
281     st->print(" profiled at:");
282     _method->print_short_name(st);
283     st->print(":%d", _bci);
284   }
285 }
286 #endif
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