1 /*
2 * Copyright (c) 1999, 2007, Oracle and/or its affiliates. All rights reserved.
3 * Copyright 2009 Red Hat, Inc.
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This code is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 only, as
8 * published by the Free Software Foundation.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 #include "incls/_precompiled.incl"
27 #include "incls/_sharkInliner.cpp.incl"
28
29 using namespace llvm;
30
31 class SharkInlineBlock : public SharkBlock {
32 public:
33 SharkInlineBlock(ciMethod* target, SharkState* state)
34 : SharkBlock(state, target),
35 _outer_state(state),
36 _entry_state(new SharkState(this)) {
37 for (int i = target->max_locals() - 1; i >= 0; i--) {
38 SharkValue *value = NULL;
39 if (i < target->arg_size())
40 value = outer_state()->pop();
41 entry_state()->set_local(i, value);
42 }
43 }
44
45 private:
46 SharkState* _outer_state;
47 SharkState* _entry_state;
48
49 private:
50 SharkState* outer_state() {
51 return _outer_state;
52 }
53 SharkState* entry_state() {
54 return _entry_state;
55 }
56
57 public:
58 void emit_IR() {
59 parse_bytecode(0, target()->code_size());
60 }
61
62 private:
63 void do_return(BasicType type) {
64 if (type != T_VOID) {
65 SharkValue *result = pop_result(type);
66 outer_state()->push(result);
67 if (result->is_two_word())
68 outer_state()->push(NULL);
69 }
70 }
71 };
72
73 class SharkInlinerHelper : public StackObj {
74 public:
75 SharkInlinerHelper(ciMethod* target, SharkState* entry_state)
76 : _target(target),
77 _entry_state(entry_state),
78 _iter(target) {}
79
80 private:
81 ciBytecodeStream _iter;
82 SharkState* _entry_state;
83 ciMethod* _target;
84
85 public:
86 ciBytecodeStream* iter() {
87 return &_iter;
88 }
89 SharkState* entry_state() const {
90 return _entry_state;
91 }
92 ciMethod* target() const {
93 return _target;
94 }
95
96 public:
97 Bytecodes::Code bc() {
98 return iter()->cur_bc();
99 }
100 int max_locals() const {
101 return target()->max_locals();
102 }
103 int max_stack() const {
104 return target()->max_stack();
105 }
106
107 // Inlinability check
108 public:
109 bool is_inlinable();
110
111 private:
112 void initialize_for_check();
113
114 bool do_getstatic() {
115 return do_field_access(true, false);
116 }
117 bool do_getfield() {
118 return do_field_access(true, true);
119 }
120 bool do_putfield() {
121 return do_field_access(false, true);
122 }
123 bool do_field_access(bool is_get, bool is_field);
124
125 // Local variables for inlinability check
126 private:
127 bool* _locals;
128
129 public:
130 bool* local_addr(int index) const {
131 assert(index >= 0 && index < max_locals(), "bad local variable index");
132 return &_locals[index];
133 }
134 bool local(int index) const {
135 return *local_addr(index);
136 }
137 void set_local(int index, bool value) {
138 *local_addr(index) = value;
139 }
140
141 // Expression stack for inlinability check
142 private:
143 bool* _stack;
144 bool* _sp;
145
146 public:
147 int stack_depth() const {
148 return _sp - _stack;
149 }
150 bool* stack_addr(int slot) const {
151 assert(slot >= 0 && slot < stack_depth(), "bad stack slot");
152 return &_sp[-(slot + 1)];
153 }
154 void push(bool value) {
155 assert(stack_depth() < max_stack(), "stack overrun");
156 *(_sp++) = value;
157 }
158 bool pop() {
159 assert(stack_depth() > 0, "stack underrun");
160 return *(--_sp);
161 }
162
163 // Methods for two-word locals
164 public:
165 void push_pair_local(int index) {
166 push(local(index));
167 push(local(index + 1));
168 }
169 void pop_pair_local(int index) {
170 set_local(index + 1, pop());
171 set_local(index, pop());
172 }
173
174 // Code generation
175 public:
176 void do_inline() {
177 (new SharkInlineBlock(target(), entry_state()))->emit_IR();
178 }
179 };
180
181 // Quick checks so we can bail out before doing too much
182 bool SharkInliner::may_be_inlinable(ciMethod *target) {
183 // We can't inline native methods
184 if (target->is_native())
185 return false;
186
187 // Not much point inlining abstract ones, and in any
188 // case we'd need a stack frame to throw the exception
189 if (target->is_abstract())
190 return false;
191
192 // Don't inline anything huge
193 if (target->code_size() > SharkMaxInlineSize)
194 return false;
195
196 // Monitors aren't allowed without a frame to put them in
197 if (target->is_synchronized() || target->has_monitor_bytecodes())
198 return false;
199
200 // We don't do control flow
201 if (target->has_exception_handlers() || target->has_jsrs())
202 return false;
203
204 // Don't try to inline constructors, as they must
205 // eventually call Object.<init> which we can't inline.
206 // Note that this catches <clinit> too, but why would
207 // we be compiling that?
208 if (target->is_initializer())
209 return false;
210
211 // Mustn't inline Object.<init>
212 // Should be caught by the above, but just in case...
213 if (target->intrinsic_id() == vmIntrinsics::_Object_init)
214 return false;
215
216 return true;
217 }
218
219 // Full-on detailed check, for methods that pass the quick checks
220 // Inlined methods have no stack frame, so we can't do anything
221 // that would require one. This means no safepoints (and hence
222 // no loops) and no VM calls. No VM calls means, amongst other
223 // things, that no exceptions can be created, which means no null
224 // checks or divide-by-zero checks are allowed. The lack of null
225 // checks in particular would eliminate practically everything,
226 // but we can get around that restriction by relying on the zero-
227 // check eliminator to strip the checks. To do that, we need to
228 // walk through the method, tracking which values are and are not
229 // zero-checked.
230 bool SharkInlinerHelper::is_inlinable() {
231 ResourceMark rm;
232 initialize_for_check();
233
234 SharkConstant *sc;
235 bool a, b, c, d;
236
237 iter()->reset_to_bci(0);
238 while (iter()->next() != ciBytecodeStream::EOBC()) {
239 switch (bc()) {
240 case Bytecodes::_nop:
241 break;
242
243 case Bytecodes::_aconst_null:
244 push(false);
245 break;
246
247 case Bytecodes::_iconst_0:
248 push(false);
249 break;
250 case Bytecodes::_iconst_m1:
251 case Bytecodes::_iconst_1:
252 case Bytecodes::_iconst_2:
253 case Bytecodes::_iconst_3:
254 case Bytecodes::_iconst_4:
255 case Bytecodes::_iconst_5:
256 push(true);
257 break;
258
259 case Bytecodes::_lconst_0:
260 push(false);
261 push(false);
262 break;
263 case Bytecodes::_lconst_1:
264 push(true);
265 push(false);
266 break;
267
268 case Bytecodes::_fconst_0:
269 case Bytecodes::_fconst_1:
270 case Bytecodes::_fconst_2:
271 push(false);
272 break;
273
274 case Bytecodes::_dconst_0:
275 case Bytecodes::_dconst_1:
276 push(false);
277 push(false);
278 break;
279
280 case Bytecodes::_bipush:
281 push(iter()->get_constant_u1() != 0);
282 break;
283 case Bytecodes::_sipush:
284 push(iter()->get_constant_u2() != 0);
285 break;
286
287 case Bytecodes::_ldc:
288 case Bytecodes::_ldc_w:
289 case Bytecodes::_ldc2_w:
290 sc = SharkConstant::for_ldc(iter());
291 if (!sc->is_loaded())
292 return false;
293 push(sc->is_nonzero());
294 if (sc->is_two_word())
295 push(false);
296 break;
297
298 case Bytecodes::_iload_0:
299 case Bytecodes::_fload_0:
300 case Bytecodes::_aload_0:
301 push(local(0));
302 break;
303 case Bytecodes::_lload_0:
304 case Bytecodes::_dload_0:
305 push_pair_local(0);
306 break;
307
308 case Bytecodes::_iload_1:
309 case Bytecodes::_fload_1:
310 case Bytecodes::_aload_1:
311 push(local(1));
312 break;
313 case Bytecodes::_lload_1:
314 case Bytecodes::_dload_1:
315 push_pair_local(1);
316 break;
317
318 case Bytecodes::_iload_2:
319 case Bytecodes::_fload_2:
320 case Bytecodes::_aload_2:
321 push(local(2));
322 break;
323 case Bytecodes::_lload_2:
324 case Bytecodes::_dload_2:
325 push_pair_local(2);
326 break;
327
328 case Bytecodes::_iload_3:
329 case Bytecodes::_fload_3:
330 case Bytecodes::_aload_3:
331 push(local(3));
332 break;
333 case Bytecodes::_lload_3:
334 case Bytecodes::_dload_3:
335 push_pair_local(3);
336 break;
337
338 case Bytecodes::_iload:
339 case Bytecodes::_fload:
340 case Bytecodes::_aload:
341 push(local(iter()->get_index()));
342 break;
343 case Bytecodes::_lload:
344 case Bytecodes::_dload:
345 push_pair_local(iter()->get_index());
346 break;
347
348 case Bytecodes::_istore_0:
349 case Bytecodes::_fstore_0:
350 case Bytecodes::_astore_0:
351 set_local(0, pop());
352 break;
353 case Bytecodes::_lstore_0:
354 case Bytecodes::_dstore_0:
355 pop_pair_local(0);
356 break;
357
358 case Bytecodes::_istore_1:
359 case Bytecodes::_fstore_1:
360 case Bytecodes::_astore_1:
361 set_local(1, pop());
362 break;
363 case Bytecodes::_lstore_1:
364 case Bytecodes::_dstore_1:
365 pop_pair_local(1);
366 break;
367
368 case Bytecodes::_istore_2:
369 case Bytecodes::_fstore_2:
370 case Bytecodes::_astore_2:
371 set_local(2, pop());
372 break;
373 case Bytecodes::_lstore_2:
374 case Bytecodes::_dstore_2:
375 pop_pair_local(2);
376 break;
377
378 case Bytecodes::_istore_3:
379 case Bytecodes::_fstore_3:
380 case Bytecodes::_astore_3:
381 set_local(3, pop());
382 break;
383 case Bytecodes::_lstore_3:
384 case Bytecodes::_dstore_3:
385 pop_pair_local(3);
386 break;
387
388 case Bytecodes::_istore:
389 case Bytecodes::_fstore:
390 case Bytecodes::_astore:
391 set_local(iter()->get_index(), pop());
392 break;
393 case Bytecodes::_lstore:
394 case Bytecodes::_dstore:
395 pop_pair_local(iter()->get_index());
396 break;
397
398 case Bytecodes::_pop:
399 pop();
400 break;
401 case Bytecodes::_pop2:
402 pop();
403 pop();
404 break;
405 case Bytecodes::_swap:
406 a = pop();
407 b = pop();
408 push(a);
409 push(b);
410 break;
411 case Bytecodes::_dup:
412 a = pop();
413 push(a);
414 push(a);
415 break;
416 case Bytecodes::_dup_x1:
417 a = pop();
418 b = pop();
419 push(a);
420 push(b);
421 push(a);
422 break;
423 case Bytecodes::_dup_x2:
424 a = pop();
425 b = pop();
426 c = pop();
427 push(a);
428 push(c);
429 push(b);
430 push(a);
431 break;
432 case Bytecodes::_dup2:
433 a = pop();
434 b = pop();
435 push(b);
436 push(a);
437 push(b);
438 push(a);
439 break;
440 case Bytecodes::_dup2_x1:
441 a = pop();
442 b = pop();
443 c = pop();
444 push(b);
445 push(a);
446 push(c);
447 push(b);
448 push(a);
449 break;
450 case Bytecodes::_dup2_x2:
451 a = pop();
452 b = pop();
453 c = pop();
454 d = pop();
455 push(b);
456 push(a);
457 push(d);
458 push(c);
459 push(b);
460 push(a);
461 break;
462
463 case Bytecodes::_getfield:
464 if (!do_getfield())
465 return false;
466 break;
467 case Bytecodes::_getstatic:
468 if (!do_getstatic())
469 return false;
470 break;
471 case Bytecodes::_putfield:
472 if (!do_putfield())
473 return false;
474 break;
475
476 case Bytecodes::_iadd:
477 case Bytecodes::_isub:
478 case Bytecodes::_imul:
479 case Bytecodes::_iand:
480 case Bytecodes::_ixor:
481 case Bytecodes::_ishl:
482 case Bytecodes::_ishr:
483 case Bytecodes::_iushr:
484 pop();
485 pop();
486 push(false);
487 break;
488 case Bytecodes::_ior:
489 a = pop();
490 b = pop();
491 push(a && b);
492 break;
493 case Bytecodes::_idiv:
494 case Bytecodes::_irem:
495 if (!pop())
496 return false;
497 pop();
498 push(false);
499 break;
500 case Bytecodes::_ineg:
501 break;
502
503 case Bytecodes::_ladd:
504 case Bytecodes::_lsub:
505 case Bytecodes::_lmul:
506 case Bytecodes::_land:
507 case Bytecodes::_lxor:
508 pop();
509 pop();
510 pop();
511 pop();
512 push(false);
513 push(false);
514 break;
515 case Bytecodes::_lor:
516 a = pop();
517 b = pop();
518 push(a && b);
519 break;
520 case Bytecodes::_ldiv:
521 case Bytecodes::_lrem:
522 pop();
523 if (!pop())
524 return false;
525 pop();
526 pop();
527 push(false);
528 push(false);
529 break;
530 case Bytecodes::_lneg:
531 break;
532 case Bytecodes::_lshl:
533 case Bytecodes::_lshr:
534 case Bytecodes::_lushr:
535 pop();
536 pop();
537 pop();
538 push(false);
539 push(false);
540 break;
541
542 case Bytecodes::_fadd:
543 case Bytecodes::_fsub:
544 case Bytecodes::_fmul:
545 case Bytecodes::_fdiv:
546 case Bytecodes::_frem:
547 pop();
548 pop();
549 push(false);
550 break;
551 case Bytecodes::_fneg:
552 break;
553
554 case Bytecodes::_dadd:
555 case Bytecodes::_dsub:
556 case Bytecodes::_dmul:
557 case Bytecodes::_ddiv:
558 case Bytecodes::_drem:
559 pop();
560 pop();
561 pop();
562 pop();
563 push(false);
564 push(false);
565 break;
566 case Bytecodes::_dneg:
567 break;
568
569 case Bytecodes::_iinc:
570 set_local(iter()->get_index(), false);
571 break;
572
573 case Bytecodes::_lcmp:
574 pop();
575 pop();
576 pop();
577 pop();
578 push(false);
579 break;
580
581 case Bytecodes::_fcmpl:
582 case Bytecodes::_fcmpg:
583 pop();
584 pop();
585 push(false);
586 break;
587
588 case Bytecodes::_dcmpl:
589 case Bytecodes::_dcmpg:
590 pop();
591 pop();
592 pop();
593 pop();
594 push(false);
595 break;
596
597 case Bytecodes::_i2l:
598 push(false);
599 break;
600 case Bytecodes::_i2f:
601 pop();
602 push(false);
603 break;
604 case Bytecodes::_i2d:
605 pop();
606 push(false);
607 push(false);
608 break;
609
610 case Bytecodes::_l2i:
611 case Bytecodes::_l2f:
612 pop();
613 pop();
614 push(false);
615 break;
616 case Bytecodes::_l2d:
617 pop();
618 pop();
619 push(false);
620 push(false);
621 break;
622
623 case Bytecodes::_f2i:
624 pop();
625 push(false);
626 break;
627 case Bytecodes::_f2l:
628 case Bytecodes::_f2d:
629 pop();
630 push(false);
631 push(false);
632 break;
633
634 case Bytecodes::_d2i:
635 case Bytecodes::_d2f:
636 pop();
637 pop();
638 push(false);
639 break;
640 case Bytecodes::_d2l:
641 pop();
642 pop();
643 push(false);
644 push(false);
645 break;
646
647 case Bytecodes::_i2b:
648 case Bytecodes::_i2c:
649 case Bytecodes::_i2s:
650 pop();
651 push(false);
652 break;
653
654 case Bytecodes::_return:
655 case Bytecodes::_ireturn:
656 case Bytecodes::_lreturn:
657 case Bytecodes::_freturn:
658 case Bytecodes::_dreturn:
659 case Bytecodes::_areturn:
660 break;
661
662 default:
663 return false;
664 }
665 }
666
667 return true;
668 }
669
670 void SharkInlinerHelper::initialize_for_check() {
671 _locals = NEW_RESOURCE_ARRAY(bool, max_locals());
672 _stack = NEW_RESOURCE_ARRAY(bool, max_stack());
673
674 memset(_locals, 0, max_locals() * sizeof(bool));
675 for (int i = 0; i < target()->arg_size(); i++) {
676 SharkValue *arg = entry_state()->stack(target()->arg_size() - 1 - i);
677 if (arg && arg->zero_checked())
678 set_local(i, true);
679 }
680
681 _sp = _stack;
682 }
683
684 bool SharkInlinerHelper::do_field_access(bool is_get, bool is_field) {
685 assert(is_get || is_field, "can't inline putstatic");
686
687 // If the holder isn't linked then there isn't a lot we can do
688 if (!target()->holder()->is_linked())
689 return false;
690
691 // Get the field
692 bool will_link;
693 ciField *field = iter()->get_field(will_link);
694 if (!will_link)
695 return false;
696
697 // If the field is mismatched then an exception needs throwing
698 if (is_field == field->is_static())
699 return false;
700
701 // Pop the value off the stack if necessary
702 if (!is_get) {
703 pop();
704 if (field->type()->is_two_word())
705 pop();
706 }
707
708 // Pop and null-check the receiver if necessary
709 if (is_field) {
710 if (!pop())
711 return false;
712 }
713
714 // Push the result if necessary
715 if (is_get) {
716 bool result_pushed = false;
717 if (field->is_constant()) {
718 SharkConstant *sc = SharkConstant::for_field(iter());
719 if (sc->is_loaded()) {
720 push(sc->is_nonzero());
721 result_pushed = true;
722 }
723 }
724
725 if (!result_pushed)
726 push(false);
727
728 if (field->type()->is_two_word())
729 push(false);
730 }
731
732 return true;
733 }
734
735 bool SharkInliner::attempt_inline(ciMethod *target, SharkState *state) {
736 if (SharkIntrinsics::is_intrinsic(target)) {
737 SharkIntrinsics::inline_intrinsic(target, state);
738 return true;
739 }
740
741 if (may_be_inlinable(target)) {
742 SharkInlinerHelper inliner(target, state);
743 if (inliner.is_inlinable()) {
744 inliner.do_inline();
745 return true;
746 }
747 }
748 return false;
749 }