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