1 /*
2 * Copyright (c) 1998, 2010, 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 "compiler/compileLog.hpp"
27 #include "interpreter/linkResolver.hpp"
28 #include "memory/universe.inline.hpp"
29 #include "oops/objArrayKlass.hpp"
30 #include "opto/addnode.hpp"
31 #include "opto/memnode.hpp"
32 #include "opto/parse.hpp"
33 #include "opto/rootnode.hpp"
34 #include "opto/runtime.hpp"
35 #include "opto/subnode.hpp"
36 #include "runtime/deoptimization.hpp"
37 #include "runtime/handles.inline.hpp"
38
39 //=============================================================================
40 // Helper methods for _get* and _put* bytecodes
41 //=============================================================================
42 bool Parse::static_field_ok_in_clinit(ciField *field, ciMethod *method) {
43 // Could be the field_holder's <clinit> method, or <clinit> for a subklass.
44 // Better to check now than to Deoptimize as soon as we execute
45 assert( field->is_static(), "Only check if field is static");
46 // is_being_initialized() is too generous. It allows access to statics
47 // by threads that are not running the <clinit> before the <clinit> finishes.
48 // return field->holder()->is_being_initialized();
49
50 // The following restriction is correct but conservative.
51 // It is also desirable to allow compilation of methods called from <clinit>
52 // but this generated code will need to be made safe for execution by
53 // other threads, or the transition from interpreted to compiled code would
54 // need to be guarded.
55 ciInstanceKlass *field_holder = field->holder();
56
57 bool access_OK = false;
58 if (method->holder()->is_subclass_of(field_holder)) {
59 if (method->is_static()) {
60 if (method->name() == ciSymbol::class_initializer_name()) {
61 // OK to access static fields inside initializer
62 access_OK = true;
63 }
64 } else {
65 if (method->name() == ciSymbol::object_initializer_name()) {
66 // It's also OK to access static fields inside a constructor,
67 // because any thread calling the constructor must first have
68 // synchronized on the class by executing a '_new' bytecode.
69 access_OK = true;
70 }
71 }
72 }
73
74 return access_OK;
75
76 }
77
78
79 void Parse::do_field_access(bool is_get, bool is_field) {
80 bool will_link;
81 ciField* field = iter().get_field(will_link);
82 assert(will_link, "getfield: typeflow responsibility");
83
84 ciInstanceKlass* field_holder = field->holder();
85
86 if (is_field == field->is_static()) {
87 // Interpreter will throw java_lang_IncompatibleClassChangeError
88 // Check this before allowing <clinit> methods to access static fields
89 uncommon_trap(Deoptimization::Reason_unhandled,
90 Deoptimization::Action_none);
91 return;
92 }
93
94 if (!is_field && !field_holder->is_initialized()) {
95 if (!static_field_ok_in_clinit(field, method())) {
96 uncommon_trap(Deoptimization::Reason_uninitialized,
97 Deoptimization::Action_reinterpret,
98 NULL, "!static_field_ok_in_clinit");
99 return;
100 }
101 }
102
103 assert(field->will_link(method()->holder(), bc()), "getfield: typeflow responsibility");
104
105 // Note: We do not check for an unloaded field type here any more.
106
107 // Generate code for the object pointer.
108 Node* obj;
109 if (is_field) {
110 int obj_depth = is_get ? 0 : field->type()->size();
111 obj = do_null_check(peek(obj_depth), T_OBJECT);
112 // Compile-time detect of null-exception?
113 if (stopped()) return;
114
115 const TypeInstPtr *tjp = TypeInstPtr::make(TypePtr::NotNull, iter().get_declared_field_holder());
116 assert(_gvn.type(obj)->higher_equal(tjp), "cast_up is no longer needed");
117
118 if (is_get) {
119 --_sp; // pop receiver before getting
120 do_get_xxx(tjp, obj, field, is_field);
121 } else {
122 do_put_xxx(tjp, obj, field, is_field);
123 --_sp; // pop receiver after putting
124 }
125 } else {
126 const TypeKlassPtr* tkp = TypeKlassPtr::make(field_holder);
127 obj = _gvn.makecon(tkp);
128 if (is_get) {
129 do_get_xxx(tkp, obj, field, is_field);
130 } else {
131 do_put_xxx(tkp, obj, field, is_field);
132 }
133 }
134 }
135
136
137 void Parse::do_get_xxx(const TypePtr* obj_type, Node* obj, ciField* field, bool is_field) {
138 // Does this field have a constant value? If so, just push the value.
139 if (field->is_constant()) {
140 if (field->is_static()) {
141 // final static field
142 if (push_constant(field->constant_value()))
143 return;
144 }
145 else {
146 // final non-static field of a trusted class ({java,sun}.dyn
147 // classes).
148 if (obj->is_Con()) {
149 const TypeOopPtr* oop_ptr = obj->bottom_type()->isa_oopptr();
150 ciObject* constant_oop = oop_ptr->const_oop();
151 ciConstant constant = field->constant_value_of(constant_oop);
152
153 if (push_constant(constant, true))
154 return;
155 }
156 }
157 }
158
159 ciType* field_klass = field->type();
160 bool is_vol = field->is_volatile();
161
162 // Compute address and memory type.
163 int offset = field->offset_in_bytes();
164 const TypePtr* adr_type = C->alias_type(field)->adr_type();
165 Node *adr = basic_plus_adr(obj, obj, offset);
166 BasicType bt = field->layout_type();
167
168 // Build the resultant type of the load
169 const Type *type;
170
171 bool must_assert_null = false;
172
173 if( bt == T_OBJECT ) {
174 if (!field->type()->is_loaded()) {
175 type = TypeInstPtr::BOTTOM;
176 must_assert_null = true;
177 } else if (field->is_constant() && field->is_static()) {
178 // This can happen if the constant oop is non-perm.
179 ciObject* con = field->constant_value().as_object();
180 // Do not "join" in the previous type; it doesn't add value,
181 // and may yield a vacuous result if the field is of interface type.
182 type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
183 assert(type != NULL, "field singleton type must be consistent");
184 } else {
185 type = TypeOopPtr::make_from_klass(field_klass->as_klass());
186 }
187 } else {
188 type = Type::get_const_basic_type(bt);
189 }
190 // Build the load.
191 Node* ld = make_load(NULL, adr, type, bt, adr_type, is_vol);
192
193 // Adjust Java stack
194 if (type2size[bt] == 1)
195 push(ld);
196 else
197 push_pair(ld);
198
199 if (must_assert_null) {
200 // Do not take a trap here. It's possible that the program
201 // will never load the field's class, and will happily see
202 // null values in this field forever. Don't stumble into a
203 // trap for such a program, or we might get a long series
204 // of useless recompilations. (Or, we might load a class
205 // which should not be loaded.) If we ever see a non-null
206 // value, we will then trap and recompile. (The trap will
207 // not need to mention the class index, since the class will
208 // already have been loaded if we ever see a non-null value.)
209 // uncommon_trap(iter().get_field_signature_index());
210 #ifndef PRODUCT
211 if (PrintOpto && (Verbose || WizardMode)) {
212 method()->print_name(); tty->print_cr(" asserting nullness of field at bci: %d", bci());
213 }
214 #endif
215 if (C->log() != NULL) {
216 C->log()->elem("assert_null reason='field' klass='%d'",
217 C->log()->identify(field->type()));
218 }
219 // If there is going to be a trap, put it at the next bytecode:
220 set_bci(iter().next_bci());
221 do_null_assert(peek(), T_OBJECT);
222 set_bci(iter().cur_bci()); // put it back
223 }
224
225 // If reference is volatile, prevent following memory ops from
226 // floating up past the volatile read. Also prevents commoning
227 // another volatile read.
228 if (field->is_volatile()) {
229 // Memory barrier includes bogus read of value to force load BEFORE membar
230 insert_mem_bar(Op_MemBarAcquire, ld);
231 }
232 }
233
234 void Parse::do_put_xxx(const TypePtr* obj_type, Node* obj, ciField* field, bool is_field) {
235 bool is_vol = field->is_volatile();
236 // If reference is volatile, prevent following memory ops from
237 // floating down past the volatile write. Also prevents commoning
238 // another volatile read.
239 if (is_vol) insert_mem_bar(Op_MemBarRelease);
240
241 // Compute address and memory type.
242 int offset = field->offset_in_bytes();
243 const TypePtr* adr_type = C->alias_type(field)->adr_type();
244 Node* adr = basic_plus_adr(obj, obj, offset);
245 BasicType bt = field->layout_type();
246 // Value to be stored
247 Node* val = type2size[bt] == 1 ? pop() : pop_pair();
248 // Round doubles before storing
249 if (bt == T_DOUBLE) val = dstore_rounding(val);
250
251 // Store the value.
252 Node* store;
253 if (bt == T_OBJECT) {
254 const TypeOopPtr* field_type;
255 if (!field->type()->is_loaded()) {
256 field_type = TypeInstPtr::BOTTOM;
257 } else {
258 field_type = TypeOopPtr::make_from_klass(field->type()->as_klass());
259 }
260 store = store_oop_to_object( control(), obj, adr, adr_type, val, field_type, bt);
261 } else {
262 store = store_to_memory( control(), adr, val, bt, adr_type, is_vol );
263 }
264
265 // If reference is volatile, prevent following volatiles ops from
266 // floating up before the volatile write.
267 if (is_vol) {
268 // First place the specific membar for THIS volatile index. This first
269 // membar is dependent on the store, keeping any other membars generated
270 // below from floating up past the store.
271 int adr_idx = C->get_alias_index(adr_type);
272 insert_mem_bar_volatile(Op_MemBarVolatile, adr_idx, store);
273
274 // Now place a membar for AliasIdxBot for the unknown yet-to-be-parsed
275 // volatile alias indices. Skip this if the membar is redundant.
276 if (adr_idx != Compile::AliasIdxBot) {
277 insert_mem_bar_volatile(Op_MemBarVolatile, Compile::AliasIdxBot, store);
278 }
279
280 // Finally, place alias-index-specific membars for each volatile index
281 // that isn't the adr_idx membar. Typically there's only 1 or 2.
282 for( int i = Compile::AliasIdxRaw; i < C->num_alias_types(); i++ ) {
283 if (i != adr_idx && C->alias_type(i)->is_volatile()) {
284 insert_mem_bar_volatile(Op_MemBarVolatile, i, store);
285 }
286 }
287 }
288
289 // If the field is final, the rules of Java say we are in <init> or <clinit>.
290 // Note the presence of writes to final non-static fields, so that we
291 // can insert a memory barrier later on to keep the writes from floating
292 // out of the constructor.
293 if (is_field && field->is_final()) {
294 set_wrote_final(true);
295 }
296 }
297
298
299 bool Parse::push_constant(ciConstant constant, bool require_constant) {
300 switch (constant.basic_type()) {
301 case T_BOOLEAN: push( intcon(constant.as_boolean()) ); break;
302 case T_INT: push( intcon(constant.as_int()) ); break;
303 case T_CHAR: push( intcon(constant.as_char()) ); break;
304 case T_BYTE: push( intcon(constant.as_byte()) ); break;
305 case T_SHORT: push( intcon(constant.as_short()) ); break;
306 case T_FLOAT: push( makecon(TypeF::make(constant.as_float())) ); break;
307 case T_DOUBLE: push_pair( makecon(TypeD::make(constant.as_double())) ); break;
308 case T_LONG: push_pair( longcon(constant.as_long()) ); break;
309 case T_ARRAY:
310 case T_OBJECT: {
311 // cases:
312 // can_be_constant = (oop not scavengable || ScavengeRootsInCode != 0)
313 // should_be_constant = (oop not scavengable || ScavengeRootsInCode >= 2)
314 // An oop is not scavengable if it is in the perm gen.
315 ciObject* oop_constant = constant.as_object();
316 if (oop_constant->is_null_object()) {
317 push( zerocon(T_OBJECT) );
318 break;
319 } else if (require_constant || oop_constant->should_be_constant()) {
320 push( makecon(TypeOopPtr::make_from_constant(oop_constant, require_constant)) );
321 break;
322 } else {
323 // we cannot inline the oop, but we can use it later to narrow a type
324 return false;
325 }
326 }
327 case T_ILLEGAL: {
328 // Invalid ciConstant returned due to OutOfMemoryError in the CI
329 assert(C->env()->failing(), "otherwise should not see this");
330 // These always occur because of object types; we are going to
331 // bail out anyway, so make the stack depths match up
332 push( zerocon(T_OBJECT) );
333 return false;
334 }
335 default:
336 ShouldNotReachHere();
337 return false;
338 }
339
340 // success
341 return true;
342 }
343
344
345
346 //=============================================================================
347 void Parse::do_anewarray() {
348 bool will_link;
349 ciKlass* klass = iter().get_klass(will_link);
350
351 // Uncommon Trap when class that array contains is not loaded
352 // we need the loaded class for the rest of graph; do not
353 // initialize the container class (see Java spec)!!!
354 assert(will_link, "anewarray: typeflow responsibility");
355
356 ciObjArrayKlass* array_klass = ciObjArrayKlass::make(klass);
357 // Check that array_klass object is loaded
358 if (!array_klass->is_loaded()) {
359 // Generate uncommon_trap for unloaded array_class
360 uncommon_trap(Deoptimization::Reason_unloaded,
361 Deoptimization::Action_reinterpret,
362 array_klass);
363 return;
364 }
365
366 kill_dead_locals();
367
368 const TypeKlassPtr* array_klass_type = TypeKlassPtr::make(array_klass);
369 Node* count_val = pop();
370 Node* obj = new_array(makecon(array_klass_type), count_val, 1);
371 push(obj);
372 }
373
374
375 void Parse::do_newarray(BasicType elem_type) {
376 kill_dead_locals();
377
378 Node* count_val = pop();
379 const TypeKlassPtr* array_klass = TypeKlassPtr::make(ciTypeArrayKlass::make(elem_type));
380 Node* obj = new_array(makecon(array_klass), count_val, 1);
381 // Push resultant oop onto stack
382 push(obj);
383 }
384
385 // Expand simple expressions like new int[3][5] and new Object[2][nonConLen].
386 // Also handle the degenerate 1-dimensional case of anewarray.
387 Node* Parse::expand_multianewarray(ciArrayKlass* array_klass, Node* *lengths, int ndimensions, int nargs) {
388 Node* length = lengths[0];
389 assert(length != NULL, "");
390 Node* array = new_array(makecon(TypeKlassPtr::make(array_klass)), length, nargs);
391 if (ndimensions > 1) {
392 jint length_con = find_int_con(length, -1);
393 guarantee(length_con >= 0, "non-constant multianewarray");
394 ciArrayKlass* array_klass_1 = array_klass->as_obj_array_klass()->element_klass()->as_array_klass();
395 const TypePtr* adr_type = TypeAryPtr::OOPS;
396 const TypeOopPtr* elemtype = _gvn.type(array)->is_aryptr()->elem()->make_oopptr();
397 const intptr_t header = arrayOopDesc::base_offset_in_bytes(T_OBJECT);
398 for (jint i = 0; i < length_con; i++) {
399 Node* elem = expand_multianewarray(array_klass_1, &lengths[1], ndimensions-1, nargs);
400 intptr_t offset = header + ((intptr_t)i << LogBytesPerHeapOop);
401 Node* eaddr = basic_plus_adr(array, offset);
402 store_oop_to_array(control(), array, eaddr, adr_type, elem, elemtype, T_OBJECT);
403 }
404 }
405 return array;
406 }
407
408 void Parse::do_multianewarray() {
409 int ndimensions = iter().get_dimensions();
410
411 // the m-dimensional array
412 bool will_link;
413 ciArrayKlass* array_klass = iter().get_klass(will_link)->as_array_klass();
414 assert(will_link, "multianewarray: typeflow responsibility");
415
416 // Note: Array classes are always initialized; no is_initialized check.
417
418 enum { MAX_DIMENSION = 5 };
419 if (ndimensions > MAX_DIMENSION || ndimensions <= 0) {
420 uncommon_trap(Deoptimization::Reason_unhandled,
421 Deoptimization::Action_none);
422 return;
423 }
424
425 kill_dead_locals();
426
427 // get the lengths from the stack (first dimension is on top)
428 Node* length[MAX_DIMENSION+1];
429 length[ndimensions] = NULL; // terminating null for make_runtime_call
430 int j;
431 for (j = ndimensions-1; j >= 0 ; j--) length[j] = pop();
432
433 // The original expression was of this form: new T[length0][length1]...
434 // It is often the case that the lengths are small (except the last).
435 // If that happens, use the fast 1-d creator a constant number of times.
436 const jint expand_limit = MIN2((juint)MultiArrayExpandLimit, (juint)100);
437 jint expand_count = 1; // count of allocations in the expansion
438 jint expand_fanout = 1; // running total fanout
439 for (j = 0; j < ndimensions-1; j++) {
440 jint dim_con = find_int_con(length[j], -1);
441 expand_fanout *= dim_con;
442 expand_count += expand_fanout; // count the level-J sub-arrays
443 if (dim_con <= 0
444 || dim_con > expand_limit
445 || expand_count > expand_limit) {
446 expand_count = 0;
447 break;
448 }
449 }
450
451 // Can use multianewarray instead of [a]newarray if only one dimension,
452 // or if all non-final dimensions are small constants.
453 if (ndimensions == 1 || (1 <= expand_count && expand_count <= expand_limit)) {
454 Node* obj = NULL;
455 // Set the original stack and the reexecute bit for the interpreter
456 // to reexecute the multianewarray bytecode if deoptimization happens.
457 // Do it unconditionally even for one dimension multianewarray.
458 // Note: the reexecute bit will be set in GraphKit::add_safepoint_edges()
459 // when AllocateArray node for newarray is created.
460 { PreserveReexecuteState preexecs(this);
461 _sp += ndimensions;
462 // Pass 0 as nargs since uncommon trap code does not need to restore stack.
463 obj = expand_multianewarray(array_klass, &length[0], ndimensions, 0);
464 } //original reexecute and sp are set back here
465 push(obj);
466 return;
467 }
468
469 address fun = NULL;
470 switch (ndimensions) {
471 //case 1: Actually, there is no case 1. It's handled by new_array.
472 case 2: fun = OptoRuntime::multianewarray2_Java(); break;
473 case 3: fun = OptoRuntime::multianewarray3_Java(); break;
474 case 4: fun = OptoRuntime::multianewarray4_Java(); break;
475 case 5: fun = OptoRuntime::multianewarray5_Java(); break;
476 default: ShouldNotReachHere();
477 };
478
479 Node* c = make_runtime_call(RC_NO_LEAF | RC_NO_IO,
480 OptoRuntime::multianewarray_Type(ndimensions),
481 fun, NULL, TypeRawPtr::BOTTOM,
482 makecon(TypeKlassPtr::make(array_klass)),
483 length[0], length[1], length[2],
484 length[3], length[4]);
485 Node* res = _gvn.transform(new (C, 1) ProjNode(c, TypeFunc::Parms));
486
487 const Type* type = TypeOopPtr::make_from_klass_raw(array_klass);
488
489 // Improve the type: We know it's not null, exact, and of a given length.
490 type = type->is_ptr()->cast_to_ptr_type(TypePtr::NotNull);
491 type = type->is_aryptr()->cast_to_exactness(true);
492
493 const TypeInt* ltype = _gvn.find_int_type(length[0]);
494 if (ltype != NULL)
495 type = type->is_aryptr()->cast_to_size(ltype);
496
497 // We cannot sharpen the nested sub-arrays, since the top level is mutable.
498
499 Node* cast = _gvn.transform( new (C, 2) CheckCastPPNode(control(), res, type) );
500 push(cast);
501
502 // Possible improvements:
503 // - Make a fast path for small multi-arrays. (W/ implicit init. loops.)
504 // - Issue CastII against length[*] values, to TypeInt::POS.
505 }