1 /*
  2  * Copyright (c) 1998, 2021, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  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 "precompiled.hpp"

 26 #include "ci/ciSymbols.hpp"
 27 #include "compiler/compileLog.hpp"

 28 #include "oops/objArrayKlass.hpp"
 29 #include "opto/addnode.hpp"


 30 #include "opto/memnode.hpp"
 31 #include "opto/mulnode.hpp"
 32 #include "opto/parse.hpp"
 33 #include "opto/rootnode.hpp"
 34 #include "opto/runtime.hpp"
 35 #include "runtime/sharedRuntime.hpp"
 36 
 37 //------------------------------make_dtrace_method_entry_exit ----------------
 38 // Dtrace -- record entry or exit of a method if compiled with dtrace support
 39 void GraphKit::make_dtrace_method_entry_exit(ciMethod* method, bool is_entry) {
 40   const TypeFunc *call_type    = OptoRuntime::dtrace_method_entry_exit_Type();
 41   address         call_address = is_entry ? CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry) :
 42                                             CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit);
 43   const char     *call_name    = is_entry ? "dtrace_method_entry" : "dtrace_method_exit";
 44 
 45   // Get base of thread-local storage area
 46   Node* thread = _gvn.transform( new ThreadLocalNode() );
 47 
 48   // Get method
 49   const TypePtr* method_type = TypeMetadataPtr::make(method);
 50   Node *method_node = _gvn.transform(ConNode::make(method_type));
 51 
 52   kill_dead_locals();
 53 
 54   // For some reason, this call reads only raw memory.
 55   const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
 56   make_runtime_call(RC_LEAF | RC_NARROW_MEM,
 57                     call_type, call_address,
 58                     call_name, raw_adr_type,
 59                     thread, method_node);
 60 }
 61 
 62 
 63 //=============================================================================
 64 //------------------------------do_checkcast-----------------------------------
 65 void Parse::do_checkcast() {
 66   bool will_link;
 67   ciKlass* klass = iter().get_klass(will_link);
 68 
 69   Node *obj = peek();
 70 
 71   // Throw uncommon trap if class is not loaded or the value we are casting
 72   // _from_ is not loaded, and value is not null.  If the value _is_ NULL,
 73   // then the checkcast does nothing.
 74   const TypeOopPtr *tp = _gvn.type(obj)->isa_oopptr();
 75   if (!will_link || (tp && tp->klass() && !tp->klass()->is_loaded())) {

 76     if (C->log() != NULL) {
 77       if (!will_link) {
 78         C->log()->elem("assert_null reason='checkcast' klass='%d'",
 79                        C->log()->identify(klass));
 80       }
 81       if (tp && tp->klass() && !tp->klass()->is_loaded()) {
 82         // %%% Cannot happen?
 83         C->log()->elem("assert_null reason='checkcast source' klass='%d'",
 84                        C->log()->identify(tp->klass()));
 85       }
 86     }
 87     null_assert(obj);
 88     assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
 89     return;
 90   }
 91 
 92   Node* res = gen_checkcast(obj, makecon(TypeKlassPtr::make(klass)));
 93   if (stopped()) {
 94     return;
 95   }
 96 
 97   // Pop from stack AFTER gen_checkcast because it can uncommon trap and
 98   // the debug info has to be correct.
 99   pop();
100   push(res);
101 }
102 
103 
104 //------------------------------do_instanceof----------------------------------
105 void Parse::do_instanceof() {
106   if (stopped())  return;
107   // We would like to return false if class is not loaded, emitting a
108   // dependency, but Java requires instanceof to load its operand.
109 
110   // Throw uncommon trap if class is not loaded
111   bool will_link;
112   ciKlass* klass = iter().get_klass(will_link);
113 
114   if (!will_link) {
115     if (C->log() != NULL) {
116       C->log()->elem("assert_null reason='instanceof' klass='%d'",
117                      C->log()->identify(klass));
118     }
119     null_assert(peek());
120     assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
121     if (!stopped()) {
122       // The object is now known to be null.
123       // Shortcut the effect of gen_instanceof and return "false" directly.
124       pop();                   // pop the null
125       push(_gvn.intcon(0));    // push false answer
126     }
127     return;
128   }
129 
130   // Push the bool result back on stack
131   Node* res = gen_instanceof(peek(), makecon(TypeKlassPtr::make(klass)), true);
132 
133   // Pop from stack AFTER gen_instanceof because it can uncommon trap.
134   pop();
135   push(res);
136 }
137 
138 //------------------------------array_store_check------------------------------
139 // pull array from stack and check that the store is valid
140 void Parse::array_store_check() {
141 
142   // Shorthand access to array store elements without popping them.
143   Node *obj = peek(0);
144   Node *idx = peek(1);
145   Node *ary = peek(2);
146 
147   if (_gvn.type(obj) == TypePtr::NULL_PTR) {
148     // There's never a type check on null values.
149     // This cutout lets us avoid the uncommon_trap(Reason_array_check)
150     // below, which turns into a performance liability if the
151     // gen_checkcast folds up completely.
152     return;



153   }
154 
155   // Extract the array klass type
156   int klass_offset = oopDesc::klass_offset_in_bytes();
157   Node* p = basic_plus_adr( ary, ary, klass_offset );
158   // p's type is array-of-OOPS plus klass_offset
159   Node* array_klass = _gvn.transform(LoadKlassNode::make(_gvn, NULL, immutable_memory(), p, TypeInstPtr::KLASS));
160   // Get the array klass
161   const TypeKlassPtr *tak = _gvn.type(array_klass)->is_klassptr();
162 
163   // The type of array_klass is usually INexact array-of-oop.  Heroically
164   // cast array_klass to EXACT array and uncommon-trap if the cast fails.
165   // Make constant out of the inexact array klass, but use it only if the cast
166   // succeeds.
167   bool always_see_exact_class = false;
168   if (MonomorphicArrayCheck
169       && !too_many_traps(Deoptimization::Reason_array_check)
170       && !tak->klass_is_exact()
171       && tak != TypeInstKlassPtr::OBJECT) {
172       // Regarding the fourth condition in the if-statement from above:
173       //




















174       // If the compiler has determined that the type of array 'ary' (represented
175       // by 'array_klass') is java/lang/Object, the compiler must not assume that
176       // the array 'ary' is monomorphic.
177       //
178       // If 'ary' were of type java/lang/Object, this arraystore would have to fail,
179       // because it is not possible to perform a arraystore into an object that is not
180       // a "proper" array.
181       //
182       // Therefore, let's obtain at runtime the type of 'ary' and check if we can still
183       // successfully perform the store.
184       //
185       // The implementation reasons for the condition are the following:
186       //
187       // java/lang/Object is the superclass of all arrays, but it is represented by the VM
188       // as an InstanceKlass. The checks generated by gen_checkcast() (see below) expect
189       // 'array_klass' to be ObjArrayKlass, which can result in invalid memory accesses.
190       //
191       // See issue JDK-8057622 for details.
192 
193     always_see_exact_class = true;
194     // (If no MDO at all, hope for the best, until a trap actually occurs.)
195 
196     // Make a constant out of the inexact array klass
197     const TypeKlassPtr *extak = tak->cast_to_exactness(true)->is_klassptr();
198     Node* con = makecon(extak);
199     Node* cmp = _gvn.transform(new CmpPNode( array_klass, con ));
200     Node* bol = _gvn.transform(new BoolNode( cmp, BoolTest::eq ));
201     Node* ctrl= control();
202     { BuildCutout unless(this, bol, PROB_MAX);
203       uncommon_trap(Deoptimization::Reason_array_check,
204                     Deoptimization::Action_maybe_recompile,
205                     tak->klass());
206     }
207     if (stopped()) {          // MUST uncommon-trap?
208       set_control(ctrl);      // Then Don't Do It, just fall into the normal checking
209     } else {                  // Cast array klass to exactness:
210       // Use the exact constant value we know it is.
211       replace_in_map(array_klass,con);
212       CompileLog* log = C->log();
213       if (log != NULL) {
214         log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'",
215                   log->identify(tak->klass()));




















216       }
217       array_klass = con;      // Use cast value moving forward
218     }
219   }
220 
221   // Come here for polymorphic array klasses
222 
223   // Extract the array element class
224   int element_klass_offset = in_bytes(ObjArrayKlass::element_klass_offset());

225   Node *p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset);
226   // We are allowed to use the constant type only if cast succeeded. If always_see_exact_class is true,
227   // we must set a control edge from the IfTrue node created by the uncommon_trap above to the
228   // LoadKlassNode.
229   Node* a_e_klass = _gvn.transform(LoadKlassNode::make(_gvn, always_see_exact_class ? control() : NULL,
230                                                        immutable_memory(), p2, tak));
231 











232   // Check (the hard way) and throw if not a subklass.
233   // Result is ignored, we just need the CFG effects.
234   gen_checkcast(obj, a_e_klass);
235 }
236 
237 
238 //------------------------------do_new-----------------------------------------
239 void Parse::do_new() {
240   kill_dead_locals();
241 
242   bool will_link;
243   ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass();
244   assert(will_link, "_new: typeflow responsibility");

245 
246   // Should throw an InstantiationError?
247   if (klass->is_abstract() || klass->is_interface() ||
248       klass->name() == ciSymbols::java_lang_Class() ||
249       iter().is_unresolved_klass()) {
250     uncommon_trap(Deoptimization::Reason_unhandled,
251                   Deoptimization::Action_none,
252                   klass);
253     return;
254   }
255 
256   if (C->needs_clinit_barrier(klass, method())) {
257     clinit_barrier(klass, method());
258     if (stopped())  return;
259   }
260 
261   Node* kls = makecon(TypeKlassPtr::make(klass));
262   Node* obj = new_instance(kls);
263 
264   // Push resultant oop onto stack
265   push(obj);
266 
267   // Keep track of whether opportunities exist for StringBuilder
268   // optimizations.
269   if (OptimizeStringConcat &&
270       (klass == C->env()->StringBuilder_klass() ||
271        klass == C->env()->StringBuffer_klass())) {
272     C->set_has_stringbuilder(true);
273   }
274 
275   // Keep track of boxed values for EliminateAutoBox optimizations.
276   if (C->eliminate_boxing() && klass->is_box_klass()) {
277     C->set_has_boxed_value(true);
278   }
279 }
280 




















































281 #ifndef PRODUCT
282 //------------------------------dump_map_adr_mem-------------------------------
283 // Debug dump of the mapping from address types to MergeMemNode indices.
284 void Parse::dump_map_adr_mem() const {
285   tty->print_cr("--- Mapping from address types to memory Nodes ---");
286   MergeMemNode *mem = map() == NULL ? NULL : (map()->memory()->is_MergeMem() ?
287                                       map()->memory()->as_MergeMem() : NULL);
288   for (uint i = 0; i < (uint)C->num_alias_types(); i++) {
289     C->alias_type(i)->print_on(tty);
290     tty->print("\t");
291     // Node mapping, if any
292     if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) {
293       mem->in(i)->dump();
294     } else {
295       tty->cr();
296     }
297   }
298 }
299 
300 #endif
301 
--- EOF ---