1 /*
2 * Copyright (c) 1998, 2025, 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 "ci/ciSymbols.hpp"
26 #include "compiler/compileLog.hpp"
27 #include "oops/objArrayKlass.hpp"
28 #include "opto/addnode.hpp"
29 #include "opto/memnode.hpp"
30 #include "opto/mulnode.hpp"
31 #include "opto/parse.hpp"
32 #include "opto/rootnode.hpp"
33 #include "opto/runtime.hpp"
34 #include "runtime/sharedRuntime.hpp"
35
36 //------------------------------make_dtrace_method_entry_exit ----------------
37 // Dtrace -- record entry or exit of a method if compiled with dtrace support
38 void GraphKit::make_dtrace_method_entry_exit(ciMethod* method, bool is_entry) {
39 const TypeFunc *call_type = OptoRuntime::dtrace_method_entry_exit_Type();
40 address call_address = is_entry ? CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_entry) :
41 CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_method_exit);
42 const char *call_name = is_entry ? "dtrace_method_entry" : "dtrace_method_exit";
43
44 // Get base of thread-local storage area
45 Node* thread = _gvn.transform( new ThreadLocalNode() );
46
47 // Get method
48 const TypePtr* method_type = TypeMetadataPtr::make(method);
49 Node *method_node = _gvn.transform(ConNode::make(method_type));
50
51 kill_dead_locals();
52
53 // For some reason, this call reads only raw memory.
54 const TypePtr* raw_adr_type = TypeRawPtr::BOTTOM;
55 make_runtime_call(RC_LEAF | RC_NARROW_MEM,
56 call_type, call_address,
57 call_name, raw_adr_type,
58 thread, method_node);
59 }
60
61
62 //=============================================================================
63 //------------------------------do_checkcast-----------------------------------
64 void Parse::do_checkcast() {
65 bool will_link;
66 ciKlass* klass = iter().get_klass(will_link);
67
68 Node *obj = peek();
69
70 // Throw uncommon trap if class is not loaded or the value we are casting
71 // _from_ is not loaded, and value is not null. If the value _is_ null,
72 // then the checkcast does nothing.
73 const TypeOopPtr *tp = _gvn.type(obj)->isa_oopptr();
74 if (!will_link || (tp && !tp->is_loaded())) {
75 if (C->log() != nullptr) {
76 if (!will_link) {
77 C->log()->elem("assert_null reason='checkcast' klass='%d'",
78 C->log()->identify(klass));
79 }
80 if (tp && !tp->is_loaded()) {
81 // %%% Cannot happen?
82 ciKlass* klass = tp->unloaded_klass();
83 C->log()->elem("assert_null reason='checkcast source' klass='%d'",
84 C->log()->identify(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, Type::trust_interfaces)));
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() != nullptr) {
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, Type::trust_interfaces)), 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, 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 if (MonomorphicArrayCheck &&
168 !too_many_traps(Deoptimization::Reason_array_check) &&
169 !tak->klass_is_exact() &&
170 tak->isa_aryklassptr()) {
171 // Regarding the fourth condition in the if-statement from above:
172 //
173 // If the compiler has determined that the type of array 'ary' (represented
174 // by 'array_klass') is java/lang/Object, the compiler must not assume that
175 // the array 'ary' is monomorphic.
176 //
177 // If 'ary' were of type java/lang/Object, this arraystore would have to fail,
178 // because it is not possible to perform a arraystore into an object that is not
179 // a "proper" array.
180 //
181 // Therefore, let's obtain at runtime the type of 'ary' and check if we can still
182 // successfully perform the store.
183 //
184 // The implementation reasons for the condition are the following:
185 //
186 // java/lang/Object is the superclass of all arrays, but it is represented by the VM
187 // as an InstanceKlass. The checks generated by gen_checkcast() (see below) expect
188 // 'array_klass' to be ObjArrayKlass, which can result in invalid memory accesses.
189 //
190 // See issue JDK-8057622 for details.
191
192 // Make a constant out of the exact array klass
193 const TypeAryKlassPtr* extak = tak->cast_to_exactness(true)->is_aryklassptr();
194 if (extak->exact_klass(true) != nullptr) {
195 Node* con = makecon(extak);
196 Node* cmp = _gvn.transform(new CmpPNode(array_klass, con));
197 Node* bol = _gvn.transform(new BoolNode(cmp, BoolTest::eq));
198 Node* ctrl= control();
199 { BuildCutout unless(this, bol, PROB_MAX);
200 uncommon_trap(Deoptimization::Reason_array_check,
201 Deoptimization::Action_maybe_recompile,
202 extak->exact_klass());
203 }
204 if (stopped()) { // MUST uncommon-trap?
205 set_control(ctrl); // Then Don't Do It, just fall into the normal checking
206 } else { // Cast array klass to exactness:
207 // Use the exact constant value we know it is.
208 replace_in_map(array_klass, con);
209 CompileLog* log = C->log();
210 if (log != nullptr) {
211 log->elem("cast_up reason='monomorphic_array' from='%d' to='(exact)'",
212 log->identify(extak->exact_klass()));
213 }
214 array_klass = con; // Use cast value moving forward
215 }
216 }
217 }
218
219 // Come here for polymorphic array klasses
220
221 // Extract the array element class
222 int element_klass_offset = in_bytes(ObjArrayKlass::element_klass_offset());
223 Node* p2 = basic_plus_adr(array_klass, array_klass, element_klass_offset);
224 Node* a_e_klass = _gvn.transform(LoadKlassNode::make(_gvn, immutable_memory(), p2, tak));
225 assert(array_klass->is_Con() == a_e_klass->is_Con() || StressReflectiveCode, "a constant array type must come with a constant element type");
226
227 // Check (the hard way) and throw if not a subklass.
228 // Result is ignored, we just need the CFG effects.
229 gen_checkcast(obj, a_e_klass);
230 }
231
232
233 //------------------------------do_new-----------------------------------------
234 void Parse::do_new() {
235 kill_dead_locals();
236
237 bool will_link;
238 ciInstanceKlass* klass = iter().get_klass(will_link)->as_instance_klass();
239 assert(will_link, "_new: typeflow responsibility");
240
241 // Should throw an InstantiationError?
242 if (klass->is_abstract() || klass->is_interface() ||
243 klass->name() == ciSymbols::java_lang_Class() ||
244 iter().is_unresolved_klass()) {
245 uncommon_trap(Deoptimization::Reason_unhandled,
246 Deoptimization::Action_none,
247 klass);
248 return;
249 }
250
251 if (C->needs_clinit_barrier(klass, method())) {
252 clinit_barrier(klass, method());
253 if (stopped()) return;
254 }
255
256 Node* kls = makecon(TypeKlassPtr::make(klass));
257 Node* obj = new_instance(kls);
258
259 // Push resultant oop onto stack
260 push(obj);
261
262 // Keep track of whether opportunities exist for StringBuilder
263 // optimizations.
264 if (OptimizeStringConcat &&
265 (klass == C->env()->StringBuilder_klass() ||
266 klass == C->env()->StringBuffer_klass())) {
267 C->set_has_stringbuilder(true);
268 }
269
270 // Keep track of boxed values for EliminateAutoBox optimizations.
271 if (C->eliminate_boxing() && klass->is_box_klass()) {
272 C->set_has_boxed_value(true);
273 }
274 }
275
276 #ifndef PRODUCT
277 //------------------------------dump_map_adr_mem-------------------------------
278 // Debug dump of the mapping from address types to MergeMemNode indices.
279 void Parse::dump_map_adr_mem() const {
280 tty->print_cr("--- Mapping from address types to memory Nodes ---");
281 MergeMemNode *mem = map() == nullptr ? nullptr : (map()->memory()->is_MergeMem() ?
282 map()->memory()->as_MergeMem() : nullptr);
283 for (uint i = 0; i < (uint)C->num_alias_types(); i++) {
284 C->alias_type(i)->print_on(tty);
285 tty->print("\t");
286 // Node mapping, if any
287 if (mem && i < mem->req() && mem->in(i) && mem->in(i) != mem->empty_memory()) {
288 mem->in(i)->dump();
289 } else {
290 tty->cr();
291 }
292 }
293 }
294
295 #endif