1 /*
2 * Copyright (c) 1998, 2023, 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->is_loaded())) {
76 if (C->log() != nullptr) {
77 if (!will_link) {
78 C->log()->elem("assert_null reason='checkcast' klass='%d'",
79 C->log()->identify(klass));
80 }
81 if (tp && !tp->is_loaded()) {
82 // %%% Cannot happen?
83 ciKlass* klass = tp->unloaded_klass();
84 C->log()->elem("assert_null reason='checkcast source' klass='%d'",
85 C->log()->identify(klass));
86 }
87 }
88 null_assert(obj);
89 assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
90 return;
91 }
92
93 Node* res = gen_checkcast(obj, makecon(TypeKlassPtr::make(klass, Type::trust_interfaces)));
94 if (stopped()) {
95 return;
96 }
97
98 // Pop from stack AFTER gen_checkcast because it can uncommon trap and
99 // the debug info has to be correct.
100 pop();
101 push(res);
102 }
103
104
105 //------------------------------do_instanceof----------------------------------
106 void Parse::do_instanceof() {
107 if (stopped()) return;
108 // We would like to return false if class is not loaded, emitting a
109 // dependency, but Java requires instanceof to load its operand.
110
111 // Throw uncommon trap if class is not loaded
112 bool will_link;
113 ciKlass* klass = iter().get_klass(will_link);
114
115 if (!will_link) {
116 if (C->log() != nullptr) {
117 C->log()->elem("assert_null reason='instanceof' klass='%d'",
118 C->log()->identify(klass));
119 }
120 null_assert(peek());
121 assert( stopped() || _gvn.type(peek())->higher_equal(TypePtr::NULL_PTR), "what's left behind is null" );
122 if (!stopped()) {
123 // The object is now known to be null.
124 // Shortcut the effect of gen_instanceof and return "false" directly.
125 pop(); // pop the null
126 push(_gvn.intcon(0)); // push false answer
127 }
128 return;
129 }
130
131 // Push the bool result back on stack
132 Node* res = gen_instanceof(peek(), makecon(TypeKlassPtr::make(klass, Type::trust_interfaces)), true);
133
134 // Pop from stack AFTER gen_instanceof because it can uncommon trap.
135 pop();
136 push(res);
137 }
138
139 //------------------------------array_store_check------------------------------
140 // pull array from stack and check that the store is valid
141 void Parse::array_store_check() {
142
143 // Shorthand access to array store elements without popping them.
144 Node *obj = peek(0);
145 Node *idx = peek(1);
146 Node *ary = peek(2);
147
148 if (_gvn.type(obj) == TypePtr::NULL_PTR) {
149 // There's never a type check on null values.
150 // This cutout lets us avoid the uncommon_trap(Reason_array_check)
151 // below, which turns into a performance liability if the
152 // gen_checkcast folds up completely.
153 return;
154 }
155
156 // Extract the array klass type
157 int klass_offset = oopDesc::klass_offset_in_bytes();
158 Node* p = basic_plus_adr( ary, ary, klass_offset );
159 // p's type is array-of-OOPS plus klass_offset
160 Node* array_klass = _gvn.transform(LoadKlassNode::make(_gvn, nullptr, immutable_memory(), p, TypeInstPtr::KLASS));
161 // Get the array klass
162 const TypeKlassPtr *tak = _gvn.type(array_klass)->is_klassptr();
163
164 // The type of array_klass is usually INexact array-of-oop. Heroically
165 // cast array_klass to EXACT array and uncommon-trap if the cast fails.
166 // Make constant out of the inexact array klass, but use it only if the cast
167 // succeeds.
168 bool always_see_exact_class = false;
169 if (MonomorphicArrayCheck
170 && !too_many_traps(Deoptimization::Reason_array_check)
171 && !tak->klass_is_exact()
172 && tak != TypeInstKlassPtr::OBJECT) {
173 // Regarding the fourth condition in the if-statement from above:
174 //
175 // If the compiler has determined that the type of array 'ary' (represented
176 // by 'array_klass') is java/lang/Object, the compiler must not assume that
177 // the array 'ary' is monomorphic.
178 //
179 // If 'ary' were of type java/lang/Object, this arraystore would have to fail,
180 // because it is not possible to perform a arraystore into an object that is not
181 // a "proper" array.
182 //
183 // Therefore, let's obtain at runtime the type of 'ary' and check if we can still
184 // successfully perform the store.
185 //
186 // The implementation reasons for the condition are the following:
187 //
188 // java/lang/Object is the superclass of all arrays, but it is represented by the VM
189 // as an InstanceKlass. The checks generated by gen_checkcast() (see below) expect
190 // 'array_klass' to be ObjArrayKlass, which can result in invalid memory accesses.
191 //
192 // See issue JDK-8057622 for details.
193
194 always_see_exact_class = true;
195 // (If no MDO at all, hope for the best, until a trap actually occurs.)
196
197 // Make a constant out of the inexact array klass
198 const TypeKlassPtr *extak = tak->cast_to_exactness(true);
199
200 if (extak->exact_klass(true) != nullptr) {
201 Node* con = makecon(extak);
202 Node* cmp = _gvn.transform(new CmpPNode( array_klass, con ));
203 Node* bol = _gvn.transform(new BoolNode( cmp, BoolTest::eq ));
204 Node* ctrl= control();
205 { BuildCutout unless(this, bol, PROB_MAX);
206 uncommon_trap(Deoptimization::Reason_array_check,
207 Deoptimization::Action_maybe_recompile,
208 extak->exact_klass());
209 }
210 if (stopped()) { // MUST uncommon-trap?
211 set_control(ctrl); // Then Don't Do It, just fall into the normal checking
212 } else { // Cast array klass to exactness:
213 // Use the exact constant value we know it is.
214 replace_in_map(array_klass,con);
215 CompileLog* log = C->log();
216 if (log != nullptr) {
217 log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'",
218 log->identify(extak->exact_klass()));
219 }
220 array_klass = con; // Use cast value moving forward
221 }
222 }
223 }
224
225 // Come here for polymorphic array klasses
226
227 // Extract the array element class
228 int element_klass_offset = in_bytes(ObjArrayKlass::element_klass_offset());
229 Node *p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset);
230 // We are allowed to use the constant type only if cast succeeded. If always_see_exact_class is true,
231 // we must set a control edge from the IfTrue node created by the uncommon_trap above to the
232 // LoadKlassNode.
233 Node* a_e_klass = _gvn.transform(LoadKlassNode::make(_gvn, always_see_exact_class ? control() : nullptr,
234 immutable_memory(), p2, tak));
235
236 // Check (the hard way) and throw if not a subklass.
237 // Result is ignored, we just need the CFG effects.
238 gen_checkcast(obj, a_e_klass);
239 }
240
241
242 //------------------------------do_new-----------------------------------------
243 void Parse::do_new() {
244 kill_dead_locals();
245
246 bool will_link;
247 ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass();
248 assert(will_link, "_new: typeflow responsibility");
249
250 // Should throw an InstantiationError?
251 if (klass->is_abstract() || klass->is_interface() ||
252 klass->name() == ciSymbols::java_lang_Class() ||
253 iter().is_unresolved_klass()) {
254 uncommon_trap(Deoptimization::Reason_unhandled,
255 Deoptimization::Action_none,
256 klass);
257 return;
258 }
259
260 if (C->needs_clinit_barrier(klass, method())) {
261 clinit_barrier(klass, method());
262 if (stopped()) return;
263 }
264
265 Node* kls = makecon(TypeKlassPtr::make(klass));
266 Node* obj = new_instance(kls);
267
268 // Push resultant oop onto stack
269 push(obj);
270
271 // Keep track of whether opportunities exist for StringBuilder
272 // optimizations.
273 if (OptimizeStringConcat &&
274 (klass == C->env()->StringBuilder_klass() ||
275 klass == C->env()->StringBuffer_klass())) {
276 C->set_has_stringbuilder(true);
277 }
278
279 // Keep track of boxed values for EliminateAutoBox optimizations.
280 if (C->eliminate_boxing() && klass->is_box_klass()) {
281 C->set_has_boxed_value(true);
282 }
283 }
284
285 #ifndef PRODUCT
286 //------------------------------dump_map_adr_mem-------------------------------
287 // Debug dump of the mapping from address types to MergeMemNode indices.
288 void Parse::dump_map_adr_mem() const {
289 tty->print_cr("--- Mapping from address types to memory Nodes ---");
290 MergeMemNode *mem = map() == nullptr ? nullptr : (map()->memory()->is_MergeMem() ?
291 map()->memory()->as_MergeMem() : nullptr);
292 for (uint i = 0; i < (uint)C->num_alias_types(); i++) {
293 C->alias_type(i)->print_on(tty);
294 tty->print("\t");
295 // Node mapping, if any
296 if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) {
297 mem->in(i)->dump();
298 } else {
299 tty->cr();
300 }
301 }
302 }
303
304 #endif