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/ciInlineKlass.hpp"
 27 #include "ci/ciSymbols.hpp"
 28 #include "compiler/compileLog.hpp"
 29 #include "oops/flatArrayKlass.hpp"
 30 #include "oops/objArrayKlass.hpp"
 31 #include "opto/addnode.hpp"
 32 #include "opto/castnode.hpp"
 33 #include "opto/inlinetypenode.hpp"
 34 #include "opto/memnode.hpp"
 35 #include "opto/mulnode.hpp"
 36 #include "opto/parse.hpp"
 37 #include "opto/rootnode.hpp"
 38 #include "opto/runtime.hpp"
 39 #include "runtime/sharedRuntime.hpp"
 40 
 41 //------------------------------make_dtrace_method_entry_exit ----------------
 42 // Dtrace -- record entry or exit of a method if compiled with dtrace support
 43 void GraphKit::make_dtrace_method_entry_exit(ciMethod* method, bool is_entry) {
 44   const TypeFunc *call_type    = OptoRuntime::dtrace_method_entry_exit_Type();
 45   address         call_address = is_entry ? CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry) :
 46                                             CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit);
 47   const char     *call_name    = is_entry ? "dtrace_method_entry" : "dtrace_method_exit";
 48 
 49   // Get base of thread-local storage area
 50   Node* thread = _gvn.transform( new ThreadLocalNode() );
 51 
 52   // Get method
 53   const TypePtr* method_type = TypeMetadataPtr::make(method);
 54   Node *method_node = _gvn.transform(ConNode::make(method_type));
 55 
 56   kill_dead_locals();
 57 
 58   // For some reason, this call reads only raw memory.
 59   const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
 60   make_runtime_call(RC_LEAF | RC_NARROW_MEM,
 61                     call_type, call_address,
 62                     call_name, raw_adr_type,
 63                     thread, method_node);
 64 }
 65 
 66 
 67 //=============================================================================
 68 //------------------------------do_checkcast-----------------------------------
 69 void Parse::do_checkcast() {
 70   bool will_link;
 71   ciKlass* klass = iter().get_klass(will_link);
 72   bool null_free = iter().has_Q_signature();
 73   Node *obj = peek();
 74 
 75   // Throw uncommon trap if class is not loaded or the value we are casting
 76   // _from_ is not loaded, and value is not null.  If the value _is_ NULL,
 77   // then the checkcast does nothing.
 78   const TypeOopPtr *tp = _gvn.type(obj)->isa_oopptr();
 79   if (!will_link || (tp && !tp->is_loaded())) {
 80     assert(!null_free, "Inline type should be loaded");
 81     if (C->log() != NULL) {
 82       if (!will_link) {
 83         C->log()->elem("assert_null reason='checkcast' klass='%d'",
 84                        C->log()->identify(klass));
 85       }
 86       if (tp && !tp->is_loaded()) {
 87         // %%% Cannot happen?
 88         ciKlass* klass = tp->unloaded_klass();
 89         C->log()->elem("assert_null reason='checkcast source' klass='%d'",
 90                        C->log()->identify(klass));
 91       }
 92     }
 93     null_assert(obj);
 94     assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
 95     return;
 96   }
 97 
 98   Node* res = gen_checkcast(obj, makecon(TypeKlassPtr::make(klass)), NULL, null_free);
 99   if (stopped()) {
100     return;
101   }
102 
103   // Pop from stack AFTER gen_checkcast because it can uncommon trap and
104   // the debug info has to be correct.
105   pop();
106   push(res);
107 }
108 
109 
110 //------------------------------do_instanceof----------------------------------
111 void Parse::do_instanceof() {
112   if (stopped())  return;
113   // We would like to return false if class is not loaded, emitting a
114   // dependency, but Java requires instanceof to load its operand.
115 
116   // Throw uncommon trap if class is not loaded
117   bool will_link;
118   ciKlass* klass = iter().get_klass(will_link);
119 
120   if (!will_link) {
121     if (C->log() != NULL) {
122       C->log()->elem("assert_null reason='instanceof' klass='%d'",
123                      C->log()->identify(klass));
124     }
125     null_assert(peek());
126     assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
127     if (!stopped()) {
128       // The object is now known to be null.
129       // Shortcut the effect of gen_instanceof and return "false" directly.
130       pop();                   // pop the null
131       push(_gvn.intcon(0));    // push false answer
132     }
133     return;
134   }
135 
136   // Push the bool result back on stack
137   Node* res = gen_instanceof(peek(), makecon(TypeKlassPtr::make(klass)), true);
138 
139   // Pop from stack AFTER gen_instanceof because it can uncommon trap.
140   pop();
141   push(res);
142 }
143 
144 //------------------------------array_store_check------------------------------
145 // pull array from stack and check that the store is valid
146 Node* Parse::array_store_check(Node*& adr, const Type*& elemtype) {
147   // Shorthand access to array store elements without popping them.
148   Node *obj = peek(0);
149   Node *idx = peek(1);
150   Node *ary = peek(2);
151 
152   if (_gvn.type(obj) == TypePtr::NULL_PTR) {
153     // There's never a type check on null values.
154     // This cutout lets us avoid the uncommon_trap(Reason_array_check)
155     // below, which turns into a performance liability if the
156     // gen_checkcast folds up completely.
157     if (_gvn.type(ary)->is_aryptr()->is_null_free()) {
158       null_check(obj);
159     }
160     return obj;
161   }
162 
163   // Extract the array klass type
164   Node* array_klass = load_object_klass(ary);
165   // Get the array klass
166   const TypeKlassPtr* tak = _gvn.type(array_klass)->is_klassptr();
167 
168   // The type of array_klass is usually INexact array-of-oop.  Heroically
169   // cast array_klass to EXACT array and uncommon-trap if the cast fails.
170   // Make constant out of the inexact array klass, but use it only if the cast
171   // succeeds.
172   bool always_see_exact_class = false;
173   if (MonomorphicArrayCheck && !tak->klass_is_exact()) {
174     // Make a constant out of the inexact array klass
175     const TypeKlassPtr* extak = NULL;
176     const TypeOopPtr* ary_t = _gvn.type(ary)->is_oopptr();
177     ciKlass* ary_spec = ary_t->speculative_type();
178     Deoptimization::DeoptReason reason = Deoptimization::Reason_none;
179     // Try to cast the array to an exact type from profile data. First
180     // check the speculative type.
181     if (ary_spec != NULL && !too_many_traps(Deoptimization::Reason_speculate_class_check)) {
182       extak = TypeKlassPtr::make(ary_spec);
183       reason = Deoptimization::Reason_speculate_class_check;
184     } else if (UseArrayLoadStoreProfile) {
185       // No speculative type: check profile data at this bci.
186       reason = Deoptimization::Reason_class_check;
187       if (!too_many_traps(reason)) {
188         ciKlass* array_type = NULL;
189         ciKlass* element_type = NULL;
190         ProfilePtrKind element_ptr = ProfileMaybeNull;
191         bool flat_array = true;
192         bool null_free_array = true;
193         method()->array_access_profiled_type(bci(), array_type, element_type, element_ptr, flat_array, null_free_array);
194         if (array_type != NULL) {
195           extak = TypeKlassPtr::make(array_type);
196         }
197       }
198     } else if (!too_many_traps(Deoptimization::Reason_array_check) && tak != TypeInstKlassPtr::OBJECT) {
199       // If the compiler has determined that the type of array 'ary' (represented
200       // by 'array_klass') is java/lang/Object, the compiler must not assume that
201       // the array 'ary' is monomorphic.
202       //
203       // If 'ary' were of type java/lang/Object, this arraystore would have to fail,
204       // because it is not possible to perform a arraystore into an object that is not
205       // a "proper" array.
206       //
207       // Therefore, let's obtain at runtime the type of 'ary' and check if we can still
208       // successfully perform the store.
209       //
210       // The implementation reasons for the condition are the following:
211       //
212       // java/lang/Object is the superclass of all arrays, but it is represented by the VM
213       // as an InstanceKlass. The checks generated by gen_checkcast() (see below) expect
214       // 'array_klass' to be ObjArrayKlass, which can result in invalid memory accesses.
215       //
216       // See issue JDK-8057622 for details.
217       extak = tak->cast_to_exactness(true);
218       reason = Deoptimization::Reason_array_check;
219     }
220     if (extak != NULL && extak->exact_klass(true) != NULL) {
221       Node* con = makecon(extak);
222       Node* cmp = _gvn.transform(new CmpPNode(array_klass, con));
223       Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::eq));
224       // Only do it if the check does not always pass/fail
225       if (!bol->is_Con()) {
226         always_see_exact_class = true;
227         { BuildCutout unless(this, bol, PROB_MAX);
228           uncommon_trap(reason,
229                         Deoptimization::Action_maybe_recompile,
230                         extak->exact_klass());
231         }
232         // Cast array klass to exactness
233         replace_in_map(array_klass, con);
234         array_klass = con;
235         Node* cast = _gvn.transform(new CheckCastPPNode(control(), ary, extak->as_instance_type()));
236         replace_in_map(ary, cast);
237         ary = cast;
238 
239         // Recompute element type and address
240         const TypeAryPtr* arytype = _gvn.type(ary)->is_aryptr();
241         elemtype = arytype->elem();
242         adr = array_element_address(ary, idx, T_OBJECT, arytype->size(), control());
243 
244         CompileLog* log = C->log();
245         if (log != NULL) {
246           log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'",
247                     log->identify(extak->exact_klass()));
248         }
249       }
250     }
251   }
252 
253   // Come here for polymorphic array klasses
254 
255   // Extract the array element class
256   int element_klass_offset = in_bytes(ArrayKlass::element_klass_offset());
257 
258   Node *p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset);
259   // We are allowed to use the constant type only if cast succeeded. If always_see_exact_class is true,
260   // we must set a control edge from the IfTrue node created by the uncommon_trap above to the
261   // LoadKlassNode.
262   Node* a_e_klass = _gvn.transform(LoadKlassNode::make(_gvn, always_see_exact_class ? control() : NULL,
263                                                        immutable_memory(), p2, tak));
264 
265   // If we statically know that this is an inline type array, use precise element klass for checkcast
266   if (!elemtype->isa_inlinetype()) {
267     elemtype = elemtype->make_oopptr();
268   }
269   bool null_free = false;
270   if (elemtype->isa_inlinetype() != NULL || elemtype->is_inlinetypeptr()) {
271     // We statically know that this is an inline type array, use precise klass ptr
272     null_free = elemtype->isa_inlinetype() || !elemtype->maybe_null();
273     a_e_klass = makecon(TypeKlassPtr::make(elemtype->inline_klass()));
274   }
275 
276   // Check (the hard way) and throw if not a subklass.
277   return gen_checkcast(obj, a_e_klass, NULL, null_free);
278 }
279 
280 
281 //------------------------------do_new-----------------------------------------
282 void Parse::do_new() {
283   kill_dead_locals();
284 
285   bool will_link;
286   ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass();
287   assert(will_link, "_new: typeflow responsibility");
288   assert(!klass->is_inlinetype(), "unexpected inline type");
289 
290   // Should throw an InstantiationError?
291   if (klass->is_abstract() || klass->is_interface() ||
292       klass->name() == ciSymbols::java_lang_Class() ||
293       iter().is_unresolved_klass()) {
294     uncommon_trap(Deoptimization::Reason_unhandled,
295                   Deoptimization::Action_none,
296                   klass);
297     return;
298   }
299 
300   if (C->needs_clinit_barrier(klass, method())) {
301     clinit_barrier(klass, method());
302     if (stopped())  return;
303   }
304 
305   Node* kls = makecon(TypeKlassPtr::make(klass));
306   Node* obj = new_instance(kls);
307 
308   // Push resultant oop onto stack
309   push(obj);
310 
311   // Keep track of whether opportunities exist for StringBuilder
312   // optimizations.
313   if (OptimizeStringConcat &&
314       (klass == C->env()->StringBuilder_klass() ||
315        klass == C->env()->StringBuffer_klass())) {
316     C->set_has_stringbuilder(true);
317   }
318 
319   // Keep track of boxed values for EliminateAutoBox optimizations.
320   if (C->eliminate_boxing() && klass->is_box_klass()) {
321     C->set_has_boxed_value(true);
322   }
323 }
324 
325 //------------------------------do_aconst_init---------------------------------
326 void Parse::do_aconst_init() {
327   bool will_link;
328   ciInlineKlass* vk = iter().get_klass(will_link)->as_inline_klass();
329   assert(will_link && !iter().is_unresolved_klass(), "aconst_init: typeflow responsibility");
330 
331   if (C->needs_clinit_barrier(vk, method())) {
332     clinit_barrier(vk, method());
333     if (stopped())  return;
334   }
335 
336   push(InlineTypeNode::make_default(_gvn, vk));
337 }
338 
339 //------------------------------do_withfield------------------------------------
340 void Parse::do_withfield() {
341   bool will_link;
342   ciField* field = iter().get_field(will_link);
343   assert(will_link, "withfield: typeflow responsibility");
344   int holder_depth = field->type()->size();
345   null_check(peek(holder_depth));
346   if (stopped()) {
347     return;
348   }
349   Node* val = pop_node(field->layout_type());
350   Node* holder = pop();
351 
352   if (!val->is_InlineType() && field->type()->is_inlinetype()) {
353     // Scalarize inline type field value
354     assert(!field->is_null_free() || !gvn().type(val)->maybe_null(), "Null store to null-free field");
355     val = InlineTypeNode::make_from_oop(this, val, field->type()->as_inline_klass(), field->is_null_free());
356   } else if (val->is_InlineType() && !field->is_null_free()) {
357     // Field value needs to be allocated because it can be merged with an oop.
358     // Re-execute withfield if buffering triggers deoptimization.
359     PreserveReexecuteState preexecs(this);
360     jvms()->set_should_reexecute(true);
361     int nargs = 1 + field->type()->size();
362     inc_sp(nargs);
363     val = val->as_InlineType()->buffer(this);
364   }
365 
366   // Clone the inline type node and set the new field value
367   InlineTypeNode* new_vt = InlineTypeNode::make_uninitialized(gvn(), gvn().type(holder)->inline_klass());
368   for (uint i = 2; i < holder->req(); ++i) {
369     new_vt->set_req(i, holder->in(i));
370   }
371   new_vt->set_field_value_by_offset(field->offset(), val);
372   push(_gvn.transform(new_vt));
373 }
374 
375 #ifndef PRODUCT
376 //------------------------------dump_map_adr_mem-------------------------------
377 // Debug dump of the mapping from address types to MergeMemNode indices.
378 void Parse::dump_map_adr_mem() const {
379   tty->print_cr("--- Mapping from address types to memory Nodes ---");
380   MergeMemNode *mem = map() == NULL ? NULL : (map()->memory()->is_MergeMem() ?
381                                       map()->memory()->as_MergeMem() : NULL);
382   for (uint i = 0; i < (uint)C->num_alias_types(); i++) {
383     C->alias_type(i)->print_on(tty);
384     tty->print("\t");
385     // Node mapping, if any
386     if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) {
387       mem->in(i)->dump();
388     } else {
389       tty->cr();
390     }
391   }
392 }
393 
394 #endif