1 /*
2 * Copyright (c) 2009, 2018, 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 "opto/addnode.hpp"
28 #include "opto/callGenerator.hpp"
29 #include "opto/callnode.hpp"
30 #include "opto/divnode.hpp"
31 #include "opto/graphKit.hpp"
32 #include "opto/idealKit.hpp"
33 #include "opto/rootnode.hpp"
34 #include "opto/runtime.hpp"
35 #include "opto/stringopts.hpp"
36 #include "opto/subnode.hpp"
37 #include "runtime/sharedRuntime.hpp"
38
39 #define __ kit.
40
41 class StringConcat : public ResourceObj {
42 private:
43 PhaseStringOpts* _stringopts;
44 Node* _string_alloc;
45 AllocateNode* _begin; // The allocation the begins the pattern
46 CallStaticJavaNode* _end; // The final call of the pattern. Will either be
47 // SB.toString or or String.<init>(SB.toString)
48 bool _multiple; // indicates this is a fusion of two or more
49 // separate StringBuilders
50
51 Node* _arguments; // The list of arguments to be concatenated
52 GrowableArray<int> _mode; // into a String along with a mode flag
53 // indicating how to treat the value.
54 Node_List _constructors; // List of constructors (many in case of stacked concat)
55 Node_List _control; // List of control nodes that will be deleted
56 Node_List _uncommon_traps; // Uncommon traps that needs to be rewritten
57 // to restart at the initial JVMState.
58
59 public:
60 // Mode for converting arguments to Strings
61 enum {
62 StringMode,
63 IntMode,
64 CharMode,
65 StringNullCheckMode
66 };
67
68 StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
69 _stringopts(stringopts),
70 _string_alloc(NULL),
71 _begin(NULL),
72 _end(end),
73 _multiple(false) {
74 _arguments = new Node(1);
75 _arguments->del_req(0);
76 }
77
78 bool validate_mem_flow();
79 bool validate_control_flow();
80
81 void merge_add() {
82 #if 0
83 // XXX This is place holder code for reusing an existing String
84 // allocation but the logic for checking the state safety is
85 // probably inadequate at the moment.
86 CallProjections endprojs;
87 sc->end()->extract_projections(&endprojs, false);
88 if (endprojs.resproj != NULL) {
89 for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
90 CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
91 if (use != NULL && use->method() != NULL &&
92 use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
93 use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
94 // Found useless new String(sb.toString()) so reuse the newly allocated String
95 // when creating the result instead of allocating a new one.
96 sc->set_string_alloc(use->in(TypeFunc::Parms));
97 sc->set_end(use);
98 }
99 }
100 }
101 #endif
102 }
103
104 StringConcat* merge(StringConcat* other, Node* arg);
105
106 void set_allocation(AllocateNode* alloc) {
107 _begin = alloc;
108 }
109
110 void append(Node* value, int mode) {
111 _arguments->add_req(value);
112 _mode.append(mode);
113 }
114 void push(Node* value, int mode) {
115 _arguments->ins_req(0, value);
116 _mode.insert_before(0, mode);
117 }
118
119 void push_string(Node* value) {
120 push(value, StringMode);
121 }
122 void push_string_null_check(Node* value) {
123 push(value, StringNullCheckMode);
124 }
125 void push_int(Node* value) {
126 push(value, IntMode);
127 }
128 void push_char(Node* value) {
129 push(value, CharMode);
130 }
131
132 static bool is_SB_toString(Node* call) {
133 if (call->is_CallStaticJava()) {
134 CallStaticJavaNode* csj = call->as_CallStaticJava();
135 ciMethod* m = csj->method();
136 if (m != NULL &&
137 (m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
138 m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
139 return true;
140 }
141 }
142 return false;
143 }
144
145 static Node* skip_string_null_check(Node* value) {
146 // Look for a diamond shaped Null check of toString() result
147 // (could be code from String.valueOf()):
148 // (Proj == NULL) ? "null":"CastPP(Proj)#NotNULL
149 if (value->is_Phi()) {
150 int true_path = value->as_Phi()->is_diamond_phi();
151 if (true_path != 0) {
152 // phi->region->if_proj->ifnode->bool
153 BoolNode* b = value->in(0)->in(1)->in(0)->in(1)->as_Bool();
154 Node* cmp = b->in(1);
155 Node* v1 = cmp->in(1);
156 Node* v2 = cmp->in(2);
157 // Null check of the return of toString which can simply be skipped.
158 if (b->_test._test == BoolTest::ne &&
159 v2->bottom_type() == TypePtr::NULL_PTR &&
160 value->in(true_path)->Opcode() == Op_CastPP &&
161 value->in(true_path)->in(1) == v1 &&
162 v1->is_Proj() && is_SB_toString(v1->in(0))) {
163 return v1;
164 }
165 }
166 }
167 return value;
168 }
169
170 Node* argument(int i) {
171 return _arguments->in(i);
172 }
173 Node* argument_uncast(int i) {
174 Node* arg = argument(i);
175 int amode = mode(i);
176 if (amode == StringConcat::StringMode ||
177 amode == StringConcat::StringNullCheckMode) {
178 arg = skip_string_null_check(arg);
179 }
180 return arg;
181 }
182 void set_argument(int i, Node* value) {
183 _arguments->set_req(i, value);
184 }
185 int num_arguments() {
186 return _mode.length();
187 }
188 int mode(int i) {
189 return _mode.at(i);
190 }
191 void add_control(Node* ctrl) {
192 assert(!_control.contains(ctrl), "only push once");
193 _control.push(ctrl);
194 }
195 void add_constructor(Node* init) {
196 assert(!_constructors.contains(init), "only push once");
197 _constructors.push(init);
198 }
199 CallStaticJavaNode* end() { return _end; }
200 AllocateNode* begin() { return _begin; }
201 Node* string_alloc() { return _string_alloc; }
202
203 void eliminate_unneeded_control();
204 void eliminate_initialize(InitializeNode* init);
205 void eliminate_call(CallNode* call);
206
207 void maybe_log_transform() {
208 CompileLog* log = _stringopts->C->log();
209 if (log != NULL) {
210 log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
211 num_arguments(),
212 _string_alloc != NULL,
213 _multiple);
214 JVMState* p = _begin->jvms();
215 while (p != NULL) {
216 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
217 p = p->caller();
218 }
219 log->tail("replace_string_concat");
220 }
221 }
222
223 void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
224 for (uint u = 0; u < _uncommon_traps.size(); u++) {
225 Node* uct = _uncommon_traps.at(u);
226
227 // Build a new call using the jvms state of the allocate
228 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
229 const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
230 const TypePtr* no_memory_effects = NULL;
231 Compile* C = _stringopts->C;
232 CallStaticJavaNode* call = new CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
233 jvms->bci(), no_memory_effects);
234 for (int e = 0; e < TypeFunc::Parms; e++) {
235 call->init_req(e, uct->in(e));
236 }
237 // Set the trap request to record intrinsic failure if this trap
238 // is taken too many times. Ideally we would handle then traps by
239 // doing the original bookkeeping in the MDO so that if it caused
240 // the code to be thrown out we could still recompile and use the
241 // optimization. Failing the uncommon traps doesn't really mean
242 // that the optimization is a bad idea but there's no other way to
243 // do the MDO updates currently.
244 int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
245 Deoptimization::Action_make_not_entrant);
246 call->init_req(TypeFunc::Parms, __ intcon(trap_request));
247 kit.add_safepoint_edges(call);
248
249 _stringopts->gvn()->transform(call);
250 C->gvn_replace_by(uct, call);
251 uct->disconnect_inputs(NULL, C);
252 }
253 }
254
255 void cleanup() {
256 // disconnect the hook node
257 _arguments->disconnect_inputs(NULL, _stringopts->C);
258 }
259 };
260
261
262 void StringConcat::eliminate_unneeded_control() {
263 for (uint i = 0; i < _control.size(); i++) {
264 Node* n = _control.at(i);
265 if (n->is_Allocate()) {
266 eliminate_initialize(n->as_Allocate()->initialization());
267 }
268 if (n->is_Call()) {
269 if (n != _end) {
270 eliminate_call(n->as_Call());
271 }
272 } else if (n->is_IfTrue()) {
273 Compile* C = _stringopts->C;
274 C->gvn_replace_by(n, n->in(0)->in(0));
275 // get rid of the other projection
276 C->gvn_replace_by(n->in(0)->as_If()->proj_out(false), C->top());
277 }
278 }
279 }
280
281
282 StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
283 StringConcat* result = new StringConcat(_stringopts, _end);
284 for (uint x = 0; x < _control.size(); x++) {
285 Node* n = _control.at(x);
286 if (n->is_Call()) {
287 result->_control.push(n);
288 }
289 }
290 for (uint x = 0; x < other->_control.size(); x++) {
291 Node* n = other->_control.at(x);
292 if (n->is_Call()) {
293 result->_control.push(n);
294 }
295 }
296 assert(result->_control.contains(other->_end), "what?");
297 assert(result->_control.contains(_begin), "what?");
298 for (int x = 0; x < num_arguments(); x++) {
299 Node* argx = argument_uncast(x);
300 if (argx == arg) {
301 // replace the toString result with the all the arguments that
302 // made up the other StringConcat
303 for (int y = 0; y < other->num_arguments(); y++) {
304 result->append(other->argument(y), other->mode(y));
305 }
306 } else {
307 result->append(argx, mode(x));
308 }
309 }
310 result->set_allocation(other->_begin);
311 for (uint i = 0; i < _constructors.size(); i++) {
312 result->add_constructor(_constructors.at(i));
313 }
314 for (uint i = 0; i < other->_constructors.size(); i++) {
315 result->add_constructor(other->_constructors.at(i));
316 }
317 result->_multiple = true;
318 return result;
319 }
320
321
322 void StringConcat::eliminate_call(CallNode* call) {
323 Compile* C = _stringopts->C;
324 CallProjections projs;
325 call->extract_projections(&projs, false);
326 if (projs.fallthrough_catchproj != NULL) {
327 C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
328 }
329 if (projs.fallthrough_memproj != NULL) {
330 C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
331 }
332 if (projs.catchall_memproj != NULL) {
333 C->gvn_replace_by(projs.catchall_memproj, C->top());
334 }
335 if (projs.fallthrough_ioproj != NULL) {
336 C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
337 }
338 if (projs.catchall_ioproj != NULL) {
339 C->gvn_replace_by(projs.catchall_ioproj, C->top());
340 }
341 if (projs.catchall_catchproj != NULL) {
342 // EA can't cope with the partially collapsed graph this
343 // creates so put it on the worklist to be collapsed later.
344 for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
345 Node *use = i.get();
346 int opc = use->Opcode();
347 if (opc == Op_CreateEx || opc == Op_Region) {
348 _stringopts->record_dead_node(use);
349 }
350 }
351 C->gvn_replace_by(projs.catchall_catchproj, C->top());
352 }
353 if (projs.resproj != NULL) {
354 C->gvn_replace_by(projs.resproj, C->top());
355 }
356 C->gvn_replace_by(call, C->top());
357 }
358
359 void StringConcat::eliminate_initialize(InitializeNode* init) {
360 Compile* C = _stringopts->C;
361
362 // Eliminate Initialize node.
363 assert(init->outcnt() <= 2, "only a control and memory projection expected");
364 assert(init->req() <= InitializeNode::RawStores, "no pending inits");
365 Node *ctrl_proj = init->proj_out_or_null(TypeFunc::Control);
366 if (ctrl_proj != NULL) {
367 C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
368 }
369 Node *mem_proj = init->proj_out_or_null(TypeFunc::Memory);
370 if (mem_proj != NULL) {
371 Node *mem = init->in(TypeFunc::Memory);
372 C->gvn_replace_by(mem_proj, mem);
373 }
374 C->gvn_replace_by(init, C->top());
375 init->disconnect_inputs(NULL, C);
376 }
377
378 Node_List PhaseStringOpts::collect_toString_calls() {
379 Node_List string_calls;
380 Node_List worklist;
381
382 _visited.Clear();
383
384 // Prime the worklist
385 for (uint i = 1; i < C->root()->len(); i++) {
386 Node* n = C->root()->in(i);
387 if (n != NULL && !_visited.test_set(n->_idx)) {
388 worklist.push(n);
389 }
390 }
391
392 while (worklist.size() > 0) {
393 Node* ctrl = worklist.pop();
394 if (StringConcat::is_SB_toString(ctrl)) {
395 CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
396 string_calls.push(csj);
397 }
398 if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
399 worklist.push(ctrl->in(0));
400 }
401 if (ctrl->is_Region()) {
402 for (uint i = 1; i < ctrl->len(); i++) {
403 if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
404 worklist.push(ctrl->in(i));
405 }
406 }
407 }
408 }
409 return string_calls;
410 }
411
412
413 StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
414 ciMethod* m = call->method();
415 ciSymbol* string_sig;
416 ciSymbol* int_sig;
417 ciSymbol* char_sig;
418 if (m->holder() == C->env()->StringBuilder_klass()) {
419 string_sig = ciSymbol::String_StringBuilder_signature();
420 int_sig = ciSymbol::int_StringBuilder_signature();
421 char_sig = ciSymbol::char_StringBuilder_signature();
422 } else if (m->holder() == C->env()->StringBuffer_klass()) {
423 string_sig = ciSymbol::String_StringBuffer_signature();
424 int_sig = ciSymbol::int_StringBuffer_signature();
425 char_sig = ciSymbol::char_StringBuffer_signature();
426 } else {
427 return NULL;
428 }
429 #ifndef PRODUCT
430 if (PrintOptimizeStringConcat) {
431 tty->print("considering toString call in ");
432 call->jvms()->dump_spec(tty); tty->cr();
433 }
434 #endif
435
436 StringConcat* sc = new StringConcat(this, call);
437
438 AllocateNode* alloc = NULL;
439 InitializeNode* init = NULL;
440
441 // possible opportunity for StringBuilder fusion
442 CallStaticJavaNode* cnode = call;
443 while (cnode) {
444 Node* recv = cnode->in(TypeFunc::Parms)->uncast();
445 if (recv->is_Proj()) {
446 recv = recv->in(0);
447 }
448 cnode = recv->isa_CallStaticJava();
449 if (cnode == NULL) {
450 alloc = recv->isa_Allocate();
451 if (alloc == NULL) {
452 break;
453 }
454 // Find the constructor call
455 Node* result = alloc->result_cast();
456 if (result == NULL || !result->is_CheckCastPP() || alloc->in(TypeFunc::Memory)->is_top()) {
457 // strange looking allocation
458 #ifndef PRODUCT
459 if (PrintOptimizeStringConcat) {
460 tty->print("giving up because allocation looks strange ");
461 alloc->jvms()->dump_spec(tty); tty->cr();
462 }
463 #endif
464 break;
465 }
466 Node* constructor = NULL;
467 for (SimpleDUIterator i(result); i.has_next(); i.next()) {
468 CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
469 if (use != NULL &&
470 use->method() != NULL &&
471 !use->method()->is_static() &&
472 use->method()->name() == ciSymbol::object_initializer_name() &&
473 use->method()->holder() == m->holder()) {
474 // Matched the constructor.
475 ciSymbol* sig = use->method()->signature()->as_symbol();
476 if (sig == ciSymbol::void_method_signature() ||
477 sig == ciSymbol::int_void_signature() ||
478 sig == ciSymbol::string_void_signature()) {
479 if (sig == ciSymbol::string_void_signature()) {
480 // StringBuilder(String) so pick this up as the first argument
481 assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
482 const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1));
483 if (type == TypePtr::NULL_PTR) {
484 // StringBuilder(null) throws exception.
485 #ifndef PRODUCT
486 if (PrintOptimizeStringConcat) {
487 tty->print("giving up because StringBuilder(null) throws exception");
488 alloc->jvms()->dump_spec(tty); tty->cr();
489 }
490 #endif
491 return NULL;
492 }
493 // StringBuilder(str) argument needs null check.
494 sc->push_string_null_check(use->in(TypeFunc::Parms + 1));
495 }
496 // The int variant takes an initial size for the backing
497 // array so just treat it like the void version.
498 constructor = use;
499 } else {
500 #ifndef PRODUCT
501 if (PrintOptimizeStringConcat) {
502 tty->print("unexpected constructor signature: %s", sig->as_utf8());
503 }
504 #endif
505 }
506 break;
507 }
508 }
509 if (constructor == NULL) {
510 // couldn't find constructor
511 #ifndef PRODUCT
512 if (PrintOptimizeStringConcat) {
513 tty->print("giving up because couldn't find constructor ");
514 alloc->jvms()->dump_spec(tty); tty->cr();
515 }
516 #endif
517 break;
518 }
519
520 // Walked all the way back and found the constructor call so see
521 // if this call converted into a direct string concatenation.
522 sc->add_control(call);
523 sc->add_control(constructor);
524 sc->add_control(alloc);
525 sc->set_allocation(alloc);
526 sc->add_constructor(constructor);
527 if (sc->validate_control_flow() && sc->validate_mem_flow()) {
528 return sc;
529 } else {
530 return NULL;
531 }
532 } else if (cnode->method() == NULL) {
533 break;
534 } else if (!cnode->method()->is_static() &&
535 cnode->method()->holder() == m->holder() &&
536 cnode->method()->name() == ciSymbol::append_name() &&
537 (cnode->method()->signature()->as_symbol() == string_sig ||
538 cnode->method()->signature()->as_symbol() == char_sig ||
539 cnode->method()->signature()->as_symbol() == int_sig)) {
540 sc->add_control(cnode);
541 Node* arg = cnode->in(TypeFunc::Parms + 1);
542 if (cnode->method()->signature()->as_symbol() == int_sig) {
543 sc->push_int(arg);
544 } else if (cnode->method()->signature()->as_symbol() == char_sig) {
545 sc->push_char(arg);
546 } else {
547 if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
548 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
549 if (csj->method() != NULL &&
550 csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
551 arg->outcnt() == 1) {
552 // _control is the list of StringBuilder calls nodes which
553 // will be replaced by new String code after this optimization.
554 // Integer::toString() call is not part of StringBuilder calls
555 // chain. It could be eliminated only if its result is used
556 // only by this SB calls chain.
557 // Another limitation: it should be used only once because
558 // it is unknown that it is used only by this SB calls chain
559 // until all related SB calls nodes are collected.
560 assert(arg->unique_out() == cnode, "sanity");
561 sc->add_control(csj);
562 sc->push_int(csj->in(TypeFunc::Parms));
563 continue;
564 }
565 }
566 sc->push_string(arg);
567 }
568 continue;
569 } else {
570 // some unhandled signature
571 #ifndef PRODUCT
572 if (PrintOptimizeStringConcat) {
573 tty->print("giving up because encountered unexpected signature ");
574 cnode->tf()->dump(); tty->cr();
575 cnode->in(TypeFunc::Parms + 1)->dump();
576 }
577 #endif
578 break;
579 }
580 }
581 return NULL;
582 }
583
584
585 PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
586 Phase(StringOpts),
587 _gvn(gvn),
588 _visited(Thread::current()->resource_area()) {
589
590 assert(OptimizeStringConcat, "shouldn't be here");
591
592 size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
593 ciSymbol::make("[I"), true);
594 if (size_table_field == NULL) {
595 // Something wrong so give up.
596 assert(false, "why can't we find Integer.sizeTable?");
597 return;
598 }
599
600 // Collect the types needed to talk about the various slices of memory
601 byte_adr_idx = C->get_alias_index(TypeAryPtr::BYTES);
602
603 // For each locally allocated StringBuffer see if the usages can be
604 // collapsed into a single String construction.
605
606 // Run through the list of allocation looking for SB.toString to see
607 // if it's possible to fuse the usage of the SB into a single String
608 // construction.
609 GrowableArray<StringConcat*> concats;
610 Node_List toStrings = collect_toString_calls();
611 while (toStrings.size() > 0) {
612 StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
613 if (sc != NULL) {
614 concats.push(sc);
615 }
616 }
617
618 // try to coalesce separate concats
619 restart:
620 for (int c = 0; c < concats.length(); c++) {
621 StringConcat* sc = concats.at(c);
622 for (int i = 0; i < sc->num_arguments(); i++) {
623 Node* arg = sc->argument_uncast(i);
624 if (arg->is_Proj() && StringConcat::is_SB_toString(arg->in(0))) {
625 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
626 for (int o = 0; o < concats.length(); o++) {
627 if (c == o) continue;
628 StringConcat* other = concats.at(o);
629 if (other->end() == csj) {
630 #ifndef PRODUCT
631 if (PrintOptimizeStringConcat) {
632 tty->print_cr("considering stacked concats");
633 }
634 #endif
635
636 StringConcat* merged = sc->merge(other, arg);
637 if (merged->validate_control_flow() && merged->validate_mem_flow()) {
638 #ifndef PRODUCT
639 if (PrintOptimizeStringConcat) {
640 tty->print_cr("stacking would succeed");
641 }
642 #endif
643 if (c < o) {
644 concats.remove_at(o);
645 concats.at_put(c, merged);
646 } else {
647 concats.remove_at(c);
648 concats.at_put(o, merged);
649 }
650 goto restart;
651 } else {
652 #ifndef PRODUCT
653 if (PrintOptimizeStringConcat) {
654 tty->print_cr("stacking would fail");
655 }
656 #endif
657 }
658 }
659 }
660 }
661 }
662 }
663
664
665 for (int c = 0; c < concats.length(); c++) {
666 StringConcat* sc = concats.at(c);
667 replace_string_concat(sc);
668 }
669
670 remove_dead_nodes();
671 }
672
673 void PhaseStringOpts::record_dead_node(Node* dead) {
674 dead_worklist.push(dead);
675 }
676
677 void PhaseStringOpts::remove_dead_nodes() {
678 // Delete any dead nodes to make things clean enough that escape
679 // analysis doesn't get unhappy.
680 while (dead_worklist.size() > 0) {
681 Node* use = dead_worklist.pop();
682 int opc = use->Opcode();
683 switch (opc) {
684 case Op_Region: {
685 uint i = 1;
686 for (i = 1; i < use->req(); i++) {
687 if (use->in(i) != C->top()) {
688 break;
689 }
690 }
691 if (i >= use->req()) {
692 for (SimpleDUIterator i(use); i.has_next(); i.next()) {
693 Node* m = i.get();
694 if (m->is_Phi()) {
695 dead_worklist.push(m);
696 }
697 }
698 C->gvn_replace_by(use, C->top());
699 }
700 break;
701 }
702 case Op_AddP:
703 case Op_CreateEx: {
704 // Recurisvely clean up references to CreateEx so EA doesn't
705 // get unhappy about the partially collapsed graph.
706 for (SimpleDUIterator i(use); i.has_next(); i.next()) {
707 Node* m = i.get();
708 if (m->is_AddP()) {
709 dead_worklist.push(m);
710 }
711 }
712 C->gvn_replace_by(use, C->top());
713 break;
714 }
715 case Op_Phi:
716 if (use->in(0) == C->top()) {
717 C->gvn_replace_by(use, C->top());
718 }
719 break;
720 }
721 }
722 }
723
724
725 bool StringConcat::validate_mem_flow() {
726 Compile* C = _stringopts->C;
727
728 for (uint i = 0; i < _control.size(); i++) {
729 #ifndef PRODUCT
730 Node_List path;
731 #endif
732 Node* curr = _control.at(i);
733 if (curr->is_Call() && curr != _begin) { // For all calls except the first allocation
734 // Now here's the main invariant in our case:
735 // For memory between the constructor, and appends, and toString we should only see bottom memory,
736 // produced by the previous call we know about.
737 if (!_constructors.contains(curr)) {
738 NOT_PRODUCT(path.push(curr);)
739 Node* mem = curr->in(TypeFunc::Memory);
740 assert(mem != NULL, "calls should have memory edge");
741 assert(!mem->is_Phi(), "should be handled by control flow validation");
742 NOT_PRODUCT(path.push(mem);)
743 while (mem->is_MergeMem()) {
744 for (uint i = 1; i < mem->req(); i++) {
745 if (i != Compile::AliasIdxBot && mem->in(i) != C->top()) {
746 #ifndef PRODUCT
747 if (PrintOptimizeStringConcat) {
748 tty->print("fusion has incorrect memory flow (side effects) for ");
749 _begin->jvms()->dump_spec(tty); tty->cr();
750 path.dump();
751 }
752 #endif
753 return false;
754 }
755 }
756 // skip through a potential MergeMem chain, linked through Bot
757 mem = mem->in(Compile::AliasIdxBot);
758 NOT_PRODUCT(path.push(mem);)
759 }
760 // now let it fall through, and see if we have a projection
761 if (mem->is_Proj()) {
762 // Should point to a previous known call
763 Node *prev = mem->in(0);
764 NOT_PRODUCT(path.push(prev);)
765 if (!prev->is_Call() || !_control.contains(prev)) {
766 #ifndef PRODUCT
767 if (PrintOptimizeStringConcat) {
768 tty->print("fusion has incorrect memory flow (unknown call) for ");
769 _begin->jvms()->dump_spec(tty); tty->cr();
770 path.dump();
771 }
772 #endif
773 return false;
774 }
775 } else {
776 assert(mem->is_Store() || mem->is_LoadStore(), "unexpected node type: %s", mem->Name());
777 #ifndef PRODUCT
778 if (PrintOptimizeStringConcat) {
779 tty->print("fusion has incorrect memory flow (unexpected source) for ");
780 _begin->jvms()->dump_spec(tty); tty->cr();
781 path.dump();
782 }
783 #endif
784 return false;
785 }
786 } else {
787 // For memory that feeds into constructors it's more complicated.
788 // However the advantage is that any side effect that happens between the Allocate/Initialize and
789 // the constructor will have to be control-dependent on Initialize.
790 // So we actually don't have to do anything, since it's going to be caught by the control flow
791 // analysis.
792 #ifdef ASSERT
793 // Do a quick verification of the control pattern between the constructor and the initialize node
794 assert(curr->is_Call(), "constructor should be a call");
795 // Go up the control starting from the constructor call
796 Node* ctrl = curr->in(0);
797 IfNode* iff = NULL;
798 RegionNode* copy = NULL;
799
800 while (true) {
801 // skip known check patterns
802 if (ctrl->is_Region()) {
803 if (ctrl->as_Region()->is_copy()) {
804 copy = ctrl->as_Region();
805 ctrl = copy->is_copy();
806 } else { // a cast
807 assert(ctrl->req() == 3 &&
808 ctrl->in(1) != NULL && ctrl->in(1)->is_Proj() &&
809 ctrl->in(2) != NULL && ctrl->in(2)->is_Proj() &&
810 ctrl->in(1)->in(0) == ctrl->in(2)->in(0) &&
811 ctrl->in(1)->in(0) != NULL && ctrl->in(1)->in(0)->is_If(),
812 "must be a simple diamond");
813 Node* true_proj = ctrl->in(1)->is_IfTrue() ? ctrl->in(1) : ctrl->in(2);
814 for (SimpleDUIterator i(true_proj); i.has_next(); i.next()) {
815 Node* use = i.get();
816 assert(use == ctrl || use->is_ConstraintCast(),
817 "unexpected user: %s", use->Name());
818 }
819
820 iff = ctrl->in(1)->in(0)->as_If();
821 ctrl = iff->in(0);
822 }
823 } else if (ctrl->is_IfTrue()) { // null checks, class checks
824 iff = ctrl->in(0)->as_If();
825 // Verify that the other arm is an uncommon trap
826 Node* otherproj = iff->proj_out(1 - ctrl->as_Proj()->_con);
827 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
828 assert(strcmp(call->_name, "uncommon_trap") == 0, "must be uncommon trap");
829 ctrl = iff->in(0);
830 } else {
831 break;
832 }
833 }
834
835 assert(ctrl->is_Proj(), "must be a projection");
836 assert(ctrl->in(0)->is_Initialize(), "should be initialize");
837 for (SimpleDUIterator i(ctrl); i.has_next(); i.next()) {
838 Node* use = i.get();
839 assert(use == copy || use == iff || use == curr || use->is_CheckCastPP() || use->is_Load(),
840 "unexpected user: %s", use->Name());
841 }
842 #endif // ASSERT
843 }
844 }
845 }
846
847 #ifndef PRODUCT
848 if (PrintOptimizeStringConcat) {
849 tty->print("fusion has correct memory flow for ");
850 _begin->jvms()->dump_spec(tty); tty->cr();
851 tty->cr();
852 }
853 #endif
854 return true;
855 }
856
857 bool StringConcat::validate_control_flow() {
858 // We found all the calls and arguments now lets see if it's
859 // safe to transform the graph as we would expect.
860
861 // Check to see if this resulted in too many uncommon traps previously
862 if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
863 Deoptimization::Reason_intrinsic)) {
864 return false;
865 }
866
867 // Walk backwards over the control flow from toString to the
868 // allocation and make sure all the control flow is ok. This
869 // means it's either going to be eliminated once the calls are
870 // removed or it can safely be transformed into an uncommon
871 // trap.
872
873 int null_check_count = 0;
874 Unique_Node_List ctrl_path;
875
876 assert(_control.contains(_begin), "missing");
877 assert(_control.contains(_end), "missing");
878
879 // Collect the nodes that we know about and will eliminate into ctrl_path
880 for (uint i = 0; i < _control.size(); i++) {
881 // Push the call and it's control projection
882 Node* n = _control.at(i);
883 if (n->is_Allocate()) {
884 AllocateNode* an = n->as_Allocate();
885 InitializeNode* init = an->initialization();
886 ctrl_path.push(init);
887 ctrl_path.push(init->as_Multi()->proj_out(0));
888 }
889 if (n->is_Call()) {
890 CallNode* cn = n->as_Call();
891 ctrl_path.push(cn);
892 ctrl_path.push(cn->proj_out(0));
893 ctrl_path.push(cn->proj_out(0)->unique_out());
894 Node* catchproj = cn->proj_out(0)->unique_out()->as_Catch()->proj_out_or_null(0);
895 if (catchproj != NULL) {
896 ctrl_path.push(catchproj);
897 }
898 } else {
899 ShouldNotReachHere();
900 }
901 }
902
903 // Skip backwards through the control checking for unexpected control flow
904 Node* ptr = _end;
905 bool fail = false;
906 while (ptr != _begin) {
907 if (ptr->is_Call() && ctrl_path.member(ptr)) {
908 ptr = ptr->in(0);
909 } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
910 ptr = ptr->in(0)->in(0)->in(0);
911 assert(ctrl_path.member(ptr), "should be a known piece of control");
912 } else if (ptr->is_IfTrue()) {
913 IfNode* iff = ptr->in(0)->as_If();
914 BoolNode* b = iff->in(1)->isa_Bool();
915
916 if (b == NULL) {
917 #ifndef PRODUCT
918 if (PrintOptimizeStringConcat) {
919 tty->print_cr("unexpected input to IfNode");
920 iff->in(1)->dump();
921 tty->cr();
922 }
923 #endif
924 fail = true;
925 break;
926 }
927
928 Node* cmp = b->in(1);
929 Node* v1 = cmp->in(1);
930 Node* v2 = cmp->in(2);
931 Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
932
933 // Null check of the return of append which can simply be eliminated
934 if (b->_test._test == BoolTest::ne &&
935 v2->bottom_type() == TypePtr::NULL_PTR &&
936 v1->is_Proj() && ctrl_path.member(v1->in(0))) {
937 // NULL check of the return value of the append
938 null_check_count++;
939 if (otherproj->outcnt() == 1) {
940 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
941 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
942 ctrl_path.push(call);
943 }
944 }
945 _control.push(ptr);
946 ptr = ptr->in(0)->in(0);
947 continue;
948 }
949
950 // A test which leads to an uncommon trap which should be safe.
951 // Later this trap will be converted into a trap that restarts
952 // at the beginning.
953 if (otherproj->outcnt() == 1) {
954 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
955 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
956 // control flow leads to uct so should be ok
957 _uncommon_traps.push(call);
958 ctrl_path.push(call);
959 ptr = ptr->in(0)->in(0);
960 continue;
961 }
962 }
963
964 #ifndef PRODUCT
965 // Some unexpected control flow we don't know how to handle.
966 if (PrintOptimizeStringConcat) {
967 tty->print_cr("failing with unknown test");
968 b->dump();
969 cmp->dump();
970 v1->dump();
971 v2->dump();
972 tty->cr();
973 }
974 #endif
975 fail = true;
976 break;
977 } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
978 ptr = ptr->in(0)->in(0);
979 } else if (ptr->is_Region()) {
980 Node* copy = ptr->as_Region()->is_copy();
981 if (copy != NULL) {
982 ptr = copy;
983 continue;
984 }
985 if (ptr->req() == 3 &&
986 ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
987 ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
988 ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
989 ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
990 // Simple diamond.
991 // XXX should check for possibly merging stores. simple data merges are ok.
992 // The IGVN will make this simple diamond go away when it
993 // transforms the Region. Make sure it sees it.
994 Compile::current()->record_for_igvn(ptr);
995 ptr = ptr->in(1)->in(0)->in(0);
996 continue;
997 }
998 #ifndef PRODUCT
999 if (PrintOptimizeStringConcat) {
1000 tty->print_cr("fusion would fail for region");
1001 _begin->dump();
1002 ptr->dump(2);
1003 }
1004 #endif
1005 fail = true;
1006 break;
1007 } else {
1008 // other unknown control
1009 if (!fail) {
1010 #ifndef PRODUCT
1011 if (PrintOptimizeStringConcat) {
1012 tty->print_cr("fusion would fail for");
1013 _begin->dump();
1014 }
1015 #endif
1016 fail = true;
1017 }
1018 #ifndef PRODUCT
1019 if (PrintOptimizeStringConcat) {
1020 ptr->dump();
1021 }
1022 #endif
1023 ptr = ptr->in(0);
1024 }
1025 }
1026 #ifndef PRODUCT
1027 if (PrintOptimizeStringConcat && fail) {
1028 tty->cr();
1029 }
1030 #endif
1031 if (fail) return !fail;
1032
1033 // Validate that all these results produced are contained within
1034 // this cluster of objects. First collect all the results produced
1035 // by calls in the region.
1036 _stringopts->_visited.Clear();
1037 Node_List worklist;
1038 Node* final_result = _end->proj_out_or_null(TypeFunc::Parms);
1039 for (uint i = 0; i < _control.size(); i++) {
1040 CallNode* cnode = _control.at(i)->isa_Call();
1041 if (cnode != NULL) {
1042 _stringopts->_visited.test_set(cnode->_idx);
1043 }
1044 Node* result = cnode != NULL ? cnode->proj_out_or_null(TypeFunc::Parms) : NULL;
1045 if (result != NULL && result != final_result) {
1046 worklist.push(result);
1047 }
1048 }
1049
1050 Node* last_result = NULL;
1051 while (worklist.size() > 0) {
1052 Node* result = worklist.pop();
1053 if (_stringopts->_visited.test_set(result->_idx))
1054 continue;
1055 for (SimpleDUIterator i(result); i.has_next(); i.next()) {
1056 Node *use = i.get();
1057 if (ctrl_path.member(use)) {
1058 // already checked this
1059 continue;
1060 }
1061 int opc = use->Opcode();
1062 if (opc == Op_CmpP || opc == Op_Node) {
1063 ctrl_path.push(use);
1064 continue;
1065 }
1066 if (opc == Op_CastPP || opc == Op_CheckCastPP) {
1067 for (SimpleDUIterator j(use); j.has_next(); j.next()) {
1068 worklist.push(j.get());
1069 }
1070 worklist.push(use->in(1));
1071 ctrl_path.push(use);
1072 continue;
1073 }
1074 #ifndef PRODUCT
1075 if (PrintOptimizeStringConcat) {
1076 if (result != last_result) {
1077 last_result = result;
1078 tty->print_cr("extra uses for result:");
1079 last_result->dump();
1080 }
1081 use->dump();
1082 }
1083 #endif
1084 fail = true;
1085 break;
1086 }
1087 }
1088
1089 #ifndef PRODUCT
1090 if (PrintOptimizeStringConcat && !fail) {
1091 ttyLocker ttyl;
1092 tty->cr();
1093 tty->print("fusion has correct control flow (%d %d) for ", null_check_count, _uncommon_traps.size());
1094 _begin->jvms()->dump_spec(tty); tty->cr();
1095 for (int i = 0; i < num_arguments(); i++) {
1096 argument(i)->dump();
1097 }
1098 _control.dump();
1099 tty->cr();
1100 }
1101 #endif
1102
1103 return !fail;
1104 }
1105
1106 Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
1107 const TypeInstPtr* mirror_type = TypeInstPtr::make(field->holder()->java_mirror());
1108 Node* klass_node = __ makecon(mirror_type);
1109 BasicType bt = field->layout_type();
1110 ciType* field_klass = field->type();
1111
1112 const Type *type;
1113 if( bt == T_OBJECT ) {
1114 if (!field->type()->is_loaded()) {
1115 type = TypeInstPtr::BOTTOM;
1116 } else if (field->is_static_constant()) {
1117 // This can happen if the constant oop is non-perm.
1118 ciObject* con = field->constant_value().as_object();
1119 // Do not "join" in the previous type; it doesn't add value,
1120 // and may yield a vacuous result if the field is of interface type.
1121 type = TypeOopPtr::make_from_constant(con, true)->isa_oopptr();
1122 assert(type != NULL, "field singleton type must be consistent");
1123 return __ makecon(type);
1124 } else {
1125 type = TypeOopPtr::make_from_klass(field_klass->as_klass());
1126 }
1127 } else {
1128 type = Type::get_const_basic_type(bt);
1129 }
1130
1131 return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
1132 type, T_OBJECT,
1133 C->get_alias_index(mirror_type->add_offset(field->offset_in_bytes())),
1134 MemNode::unordered);
1135 }
1136
1137 Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
1138 if (arg->is_Con()) {
1139 // Constant integer. Compute constant length using Integer.sizeTable
1140 int arg_val = arg->get_int();
1141 int count = 1;
1142 if (arg_val < 0) {
1143 arg_val = -arg_val;
1144 count++;
1145 }
1146
1147 ciArray* size_table = (ciArray*)size_table_field->constant_value().as_object();
1148 for (int i = 0; i < size_table->length(); i++) {
1149 if (arg_val <= size_table->element_value(i).as_int()) {
1150 count += i;
1151 break;
1152 }
1153 }
1154 return __ intcon(count);
1155 }
1156
1157 RegionNode *final_merge = new RegionNode(3);
1158 kit.gvn().set_type(final_merge, Type::CONTROL);
1159 Node* final_size = new PhiNode(final_merge, TypeInt::INT);
1160 kit.gvn().set_type(final_size, TypeInt::INT);
1161
1162 IfNode* iff = kit.create_and_map_if(kit.control(),
1163 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
1164 PROB_FAIR, COUNT_UNKNOWN);
1165 Node* is_min = __ IfFalse(iff);
1166 final_merge->init_req(1, is_min);
1167 final_size->init_req(1, __ intcon(11));
1168
1169 kit.set_control(__ IfTrue(iff));
1170 if (kit.stopped()) {
1171 final_merge->init_req(2, C->top());
1172 final_size->init_req(2, C->top());
1173 } else {
1174
1175 // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
1176 RegionNode *r = new RegionNode(3);
1177 kit.gvn().set_type(r, Type::CONTROL);
1178 Node *phi = new PhiNode(r, TypeInt::INT);
1179 kit.gvn().set_type(phi, TypeInt::INT);
1180 Node *size = new PhiNode(r, TypeInt::INT);
1181 kit.gvn().set_type(size, TypeInt::INT);
1182 Node* chk = __ CmpI(arg, __ intcon(0));
1183 Node* p = __ Bool(chk, BoolTest::lt);
1184 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
1185 Node* lessthan = __ IfTrue(iff);
1186 Node* greaterequal = __ IfFalse(iff);
1187 r->init_req(1, lessthan);
1188 phi->init_req(1, __ SubI(__ intcon(0), arg));
1189 size->init_req(1, __ intcon(1));
1190 r->init_req(2, greaterequal);
1191 phi->init_req(2, arg);
1192 size->init_req(2, __ intcon(0));
1193 kit.set_control(r);
1194 C->record_for_igvn(r);
1195 C->record_for_igvn(phi);
1196 C->record_for_igvn(size);
1197
1198 // for (int i=0; ; i++)
1199 // if (x <= sizeTable[i])
1200 // return i+1;
1201
1202 // Add loop predicate first.
1203 kit.add_predicate();
1204
1205 RegionNode *loop = new RegionNode(3);
1206 loop->init_req(1, kit.control());
1207 kit.gvn().set_type(loop, Type::CONTROL);
1208
1209 Node *index = new PhiNode(loop, TypeInt::INT);
1210 index->init_req(1, __ intcon(0));
1211 kit.gvn().set_type(index, TypeInt::INT);
1212 kit.set_control(loop);
1213 Node* sizeTable = fetch_static_field(kit, size_table_field);
1214
1215 sizeTable = kit.access_resolve(sizeTable, ACCESS_READ);
1216 Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
1217 C->record_for_igvn(value);
1218 Node* limit = __ CmpI(phi, value);
1219 Node* limitb = __ Bool(limit, BoolTest::le);
1220 IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
1221 Node* lessEqual = __ IfTrue(iff2);
1222 Node* greater = __ IfFalse(iff2);
1223
1224 loop->init_req(2, greater);
1225 index->init_req(2, __ AddI(index, __ intcon(1)));
1226
1227 kit.set_control(lessEqual);
1228 C->record_for_igvn(loop);
1229 C->record_for_igvn(index);
1230
1231 final_merge->init_req(2, kit.control());
1232 final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
1233 }
1234
1235 kit.set_control(final_merge);
1236 C->record_for_igvn(final_merge);
1237 C->record_for_igvn(final_size);
1238
1239 return final_size;
1240 }
1241
1242 // Simplified version of Integer.getChars
1243 void PhaseStringOpts::getChars(GraphKit& kit, Node* arg, Node* dst_array, BasicType bt, Node* end, Node* final_merge, Node* final_mem, int merge_index) {
1244 // if (i < 0) {
1245 // sign = '-';
1246 // i = -i;
1247 // }
1248 IfNode* iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
1249 PROB_FAIR, COUNT_UNKNOWN);
1250
1251 RegionNode* merge = new RegionNode(3);
1252 kit.gvn().set_type(merge, Type::CONTROL);
1253 Node* i = new PhiNode(merge, TypeInt::INT);
1254 kit.gvn().set_type(i, TypeInt::INT);
1255 Node* sign = new PhiNode(merge, TypeInt::INT);
1256 kit.gvn().set_type(sign, TypeInt::INT);
1257
1258 merge->init_req(1, __ IfTrue(iff));
1259 i->init_req(1, __ SubI(__ intcon(0), arg));
1260 sign->init_req(1, __ intcon('-'));
1261 merge->init_req(2, __ IfFalse(iff));
1262 i->init_req(2, arg);
1263 sign->init_req(2, __ intcon(0));
1264
1265 kit.set_control(merge);
1266
1267 C->record_for_igvn(merge);
1268 C->record_for_igvn(i);
1269 C->record_for_igvn(sign);
1270
1271 // for (;;) {
1272 // q = i / 10;
1273 // r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ...
1274 // buf [--charPos] = digits [r];
1275 // i = q;
1276 // if (i == 0) break;
1277 // }
1278
1279 // Add loop predicate first.
1280 kit.add_predicate();
1281
1282 RegionNode* head = new RegionNode(3);
1283 head->init_req(1, kit.control());
1284
1285 kit.gvn().set_type(head, Type::CONTROL);
1286 Node* i_phi = new PhiNode(head, TypeInt::INT);
1287 i_phi->init_req(1, i);
1288 kit.gvn().set_type(i_phi, TypeInt::INT);
1289 Node* charPos = new PhiNode(head, TypeInt::INT);
1290 charPos->init_req(1, end);
1291 kit.gvn().set_type(charPos, TypeInt::INT);
1292 Node* mem = PhiNode::make(head, kit.memory(byte_adr_idx), Type::MEMORY, TypeAryPtr::BYTES);
1293 kit.gvn().set_type(mem, Type::MEMORY);
1294
1295 kit.set_control(head);
1296 kit.set_memory(mem, byte_adr_idx);
1297
1298 Node* q = __ DivI(kit.null(), i_phi, __ intcon(10));
1299 Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
1300 __ LShiftI(q, __ intcon(1))));
1301 Node* index = __ SubI(charPos, __ intcon((bt == T_BYTE) ? 1 : 2));
1302 Node* ch = __ AddI(r, __ intcon('0'));
1303 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(dst_array, index, T_BYTE),
1304 ch, bt, byte_adr_idx, MemNode::unordered, (bt != T_BYTE) /* mismatched */);
1305
1306 iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
1307 PROB_FAIR, COUNT_UNKNOWN);
1308 Node* ne = __ IfTrue(iff);
1309 Node* eq = __ IfFalse(iff);
1310
1311 head->init_req(2, ne);
1312 mem->init_req(2, st);
1313
1314 i_phi->init_req(2, q);
1315 charPos->init_req(2, index);
1316 charPos = index;
1317
1318 kit.set_control(eq);
1319 kit.set_memory(st, byte_adr_idx);
1320
1321 C->record_for_igvn(head);
1322 C->record_for_igvn(mem);
1323 C->record_for_igvn(i_phi);
1324 C->record_for_igvn(charPos);
1325
1326 // if (sign != 0) {
1327 // buf [--charPos] = sign;
1328 // }
1329 iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
1330 PROB_FAIR, COUNT_UNKNOWN);
1331
1332 final_merge->init_req(merge_index + 2, __ IfFalse(iff));
1333 final_mem->init_req(merge_index + 2, kit.memory(byte_adr_idx));
1334
1335 kit.set_control(__ IfTrue(iff));
1336 if (kit.stopped()) {
1337 final_merge->init_req(merge_index + 1, C->top());
1338 final_mem->init_req(merge_index + 1, C->top());
1339 } else {
1340 Node* index = __ SubI(charPos, __ intcon((bt == T_BYTE) ? 1 : 2));
1341 st = __ store_to_memory(kit.control(), kit.array_element_address(dst_array, index, T_BYTE),
1342 sign, bt, byte_adr_idx, MemNode::unordered, (bt != T_BYTE) /* mismatched */);
1343
1344 final_merge->init_req(merge_index + 1, kit.control());
1345 final_mem->init_req(merge_index + 1, st);
1346 }
1347 }
1348
1349 // Copy the characters representing arg into dst_array starting at start
1350 Node* PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* dst_array, Node* dst_coder, Node* start, Node* size) {
1351 bool dcon = dst_coder->is_Con();
1352 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false;
1353 Node* end = __ AddI(start, __ LShiftI(size, dst_coder));
1354
1355 // The final_merge node has 4 entries in case the encoding is known:
1356 // (0) Control, (1) result w/ sign, (2) result w/o sign, (3) result for Integer.min_value
1357 // or 6 entries in case the encoding is not known:
1358 // (0) Control, (1) Latin1 w/ sign, (2) Latin1 w/o sign, (3) min_value, (4) UTF16 w/ sign, (5) UTF16 w/o sign
1359 RegionNode* final_merge = new RegionNode(dcon ? 4 : 6);
1360 kit.gvn().set_type(final_merge, Type::CONTROL);
1361
1362 Node* final_mem = PhiNode::make(final_merge, kit.memory(byte_adr_idx), Type::MEMORY, TypeAryPtr::BYTES);
1363 kit.gvn().set_type(final_mem, Type::MEMORY);
1364
1365 // need to handle arg == Integer.MIN_VALUE specially because negating doesn't make it positive
1366 IfNode* iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
1367 PROB_FAIR, COUNT_UNKNOWN);
1368
1369 Node* old_mem = kit.memory(byte_adr_idx);
1370
1371 kit.set_control(__ IfFalse(iff));
1372 if (kit.stopped()) {
1373 // Statically not equal to MIN_VALUE so this path is dead
1374 final_merge->init_req(3, kit.control());
1375 } else {
1376 copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
1377 dst_array, dst_coder, start);
1378 final_merge->init_req(3, kit.control());
1379 final_mem->init_req(3, kit.memory(byte_adr_idx));
1380 }
1381
1382 kit.set_control(__ IfTrue(iff));
1383 kit.set_memory(old_mem, byte_adr_idx);
1384
1385 if (!dcon) {
1386 // Check encoding of destination
1387 iff = kit.create_and_map_if(kit.control(), __ Bool(__ CmpI(dst_coder, __ intcon(0)), BoolTest::eq),
1388 PROB_FAIR, COUNT_UNKNOWN);
1389 old_mem = kit.memory(byte_adr_idx);
1390 }
1391 if (!dcon || dbyte) {
1392 // Destination is Latin1,
1393 if (!dcon) {
1394 kit.set_control(__ IfTrue(iff));
1395 }
1396 getChars(kit, arg, dst_array, T_BYTE, end, final_merge, final_mem);
1397 }
1398 if (!dcon || !dbyte) {
1399 // Destination is UTF16
1400 int merge_index = 0;
1401 if (!dcon) {
1402 kit.set_control(__ IfFalse(iff));
1403 kit.set_memory(old_mem, byte_adr_idx);
1404 merge_index = 3; // Account for Latin1 case
1405 }
1406 getChars(kit, arg, dst_array, T_CHAR, end, final_merge, final_mem, merge_index);
1407 }
1408
1409 // Final merge point for Latin1 and UTF16 case
1410 kit.set_control(final_merge);
1411 kit.set_memory(final_mem, byte_adr_idx);
1412
1413 C->record_for_igvn(final_merge);
1414 C->record_for_igvn(final_mem);
1415 return end;
1416 }
1417
1418 // Copy 'count' bytes/chars from src_array to dst_array starting at index start
1419 void PhaseStringOpts::arraycopy(GraphKit& kit, IdealKit& ideal, Node* src_array, Node* dst_array, BasicType elembt, Node* start, Node* count) {
1420 assert(elembt == T_BYTE || elembt == T_CHAR, "Invalid type for arraycopy");
1421
1422 if (elembt == T_CHAR) {
1423 // Get number of chars
1424 count = __ RShiftI(count, __ intcon(1));
1425 }
1426
1427 Node* extra = NULL;
1428 #ifdef _LP64
1429 count = __ ConvI2L(count);
1430 extra = C->top();
1431 #endif
1432
1433 Node* src_ptr = __ array_element_address(src_array, __ intcon(0), T_BYTE);
1434 Node* dst_ptr = __ array_element_address(dst_array, start, T_BYTE);
1435 // Check if destination address is aligned to HeapWordSize
1436 const TypeInt* tdst = __ gvn().type(start)->is_int();
1437 bool aligned = tdst->is_con() && ((tdst->get_con() * type2aelembytes(T_BYTE)) % HeapWordSize == 0);
1438 // Figure out which arraycopy runtime method to call (disjoint, uninitialized).
1439 const char* copyfunc_name = "arraycopy";
1440 address copyfunc_addr = StubRoutines::select_arraycopy_function(elembt, aligned, true, copyfunc_name, true);
1441 ideal.make_leaf_call_no_fp(OptoRuntime::fast_arraycopy_Type(), copyfunc_addr, copyfunc_name,
1442 TypeAryPtr::BYTES, src_ptr, dst_ptr, count, extra);
1443 }
1444
1445 #undef __
1446 #define __ ideal.
1447
1448 // Copy contents of a Latin1 encoded string from src_array to dst_array
1449 void PhaseStringOpts::copy_latin1_string(GraphKit& kit, IdealKit& ideal, Node* src_array, IdealVariable& count,
1450 Node* dst_array, Node* dst_coder, Node* start) {
1451 bool dcon = dst_coder->is_Con();
1452 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false;
1453
1454 if (!dcon) {
1455 __ if_then(dst_coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1));
1456 }
1457 if (!dcon || dbyte) {
1458 // Destination is Latin1. Simply emit a byte arraycopy.
1459 arraycopy(kit, ideal, src_array, dst_array, T_BYTE, start, __ value(count));
1460 }
1461 if (!dcon) {
1462 __ else_();
1463 }
1464 if (!dcon || !dbyte) {
1465 // Destination is UTF16. Inflate src_array into dst_array.
1466 kit.sync_kit(ideal);
1467 if (Matcher::match_rule_supported(Op_StrInflatedCopy)) {
1468 // Use fast intrinsic
1469 Node* src = kit.array_element_address(src_array, kit.intcon(0), T_BYTE);
1470 Node* dst = kit.array_element_address(dst_array, start, T_BYTE);
1471 kit.inflate_string(src, dst, TypeAryPtr::BYTES, __ value(count));
1472 } else {
1473 // No intrinsic available, use slow method
1474 kit.inflate_string_slow(src_array, dst_array, start, __ value(count));
1475 }
1476 ideal.sync_kit(&kit);
1477 // Multiply count by two since we now need two bytes per char
1478 __ set(count, __ LShiftI(__ value(count), __ ConI(1)));
1479 }
1480 if (!dcon) {
1481 __ end_if();
1482 }
1483 }
1484
1485 // Read two bytes from index and index+1 and convert them to a char
1486 static jchar readChar(ciTypeArray* array, int index) {
1487 int shift_high, shift_low;
1488 #ifdef VM_LITTLE_ENDIAN
1489 shift_high = 0;
1490 shift_low = 8;
1491 #else
1492 shift_high = 8;
1493 shift_low = 0;
1494 #endif
1495
1496 jchar b1 = ((jchar) array->byte_at(index)) & 0xff;
1497 jchar b2 = ((jchar) array->byte_at(index+1)) & 0xff;
1498 return (b1 << shift_high) | (b2 << shift_low);
1499 }
1500
1501 // Copy contents of constant src_array to dst_array by emitting individual stores
1502 void PhaseStringOpts::copy_constant_string(GraphKit& kit, IdealKit& ideal, ciTypeArray* src_array, IdealVariable& count,
1503 bool src_is_byte, Node* dst_array, Node* dst_coder, Node* start) {
1504 bool dcon = dst_coder->is_Con();
1505 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false;
1506 int length = src_array->length();
1507
1508 if (!dcon) {
1509 __ if_then(dst_coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1));
1510 }
1511 if (!dcon || dbyte) {
1512 // Destination is Latin1. Copy each byte of src_array into dst_array.
1513 Node* index = start;
1514 for (int i = 0; i < length; i++) {
1515 Node* adr = kit.array_element_address(dst_array, index, T_BYTE);
1516 Node* val = __ ConI(src_array->byte_at(i));
1517 __ store(__ ctrl(), adr, val, T_BYTE, byte_adr_idx, MemNode::unordered);
1518 index = __ AddI(index, __ ConI(1));
1519 }
1520 }
1521 if (!dcon) {
1522 __ else_();
1523 }
1524 if (!dcon || !dbyte) {
1525 // Destination is UTF16. Copy each char of src_array into dst_array.
1526 Node* index = start;
1527 for (int i = 0; i < length; i++) {
1528 Node* adr = kit.array_element_address(dst_array, index, T_BYTE);
1529 jchar val;
1530 if (src_is_byte) {
1531 val = src_array->byte_at(i) & 0xff;
1532 } else {
1533 val = readChar(src_array, i++);
1534 }
1535 __ store(__ ctrl(), adr, __ ConI(val), T_CHAR, byte_adr_idx, MemNode::unordered, true /* mismatched */);
1536 index = __ AddI(index, __ ConI(2));
1537 }
1538 if (src_is_byte) {
1539 // Multiply count by two since we now need two bytes per char
1540 __ set(count, __ ConI(2 * length));
1541 }
1542 }
1543 if (!dcon) {
1544 __ end_if();
1545 }
1546 }
1547
1548 // Compress copy contents of the byte/char String str into dst_array starting at index start.
1549 Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* dst_array, Node* dst_coder, Node* start) {
1550 Node* src_array = kit.load_String_value(str, true);
1551 src_array = kit.access_resolve(src_array, ACCESS_READ);
1552
1553 IdealKit ideal(&kit, true, true);
1554 IdealVariable count(ideal); __ declarations_done();
1555
1556 if (str->is_Con()) {
1557 // Constant source string
1558 ciTypeArray* src_array_type = get_constant_value(kit, str);
1559
1560 // Check encoding of constant string
1561 bool src_is_byte = (get_constant_coder(kit, str) == java_lang_String::CODER_LATIN1);
1562
1563 // For small constant strings just emit individual stores.
1564 // A length of 6 seems like a good space/speed tradeof.
1565 __ set(count, __ ConI(src_array_type->length()));
1566 int src_len = src_array_type->length() / (src_is_byte ? 1 : 2);
1567 if (src_len < unroll_string_copy_length) {
1568 // Small constant string
1569 copy_constant_string(kit, ideal, src_array_type, count, src_is_byte, dst_array, dst_coder, start);
1570 } else if (src_is_byte) {
1571 // Source is Latin1
1572 copy_latin1_string(kit, ideal, src_array, count, dst_array, dst_coder, start);
1573 } else {
1574 // Source is UTF16 (destination too). Simply emit a char arraycopy.
1575 arraycopy(kit, ideal, src_array, dst_array, T_CHAR, start, __ value(count));
1576 }
1577 } else {
1578 Node* size = kit.load_array_length(src_array);
1579 __ set(count, size);
1580 // Non-constant source string
1581 if (CompactStrings) {
1582 // Emit runtime check for coder
1583 Node* coder = kit.load_String_coder(str, true);
1584 __ if_then(coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1)); {
1585 // Source is Latin1
1586 copy_latin1_string(kit, ideal, src_array, count, dst_array, dst_coder, start);
1587 } __ else_();
1588 }
1589 // Source is UTF16 (destination too). Simply emit a char arraycopy.
1590 arraycopy(kit, ideal, src_array, dst_array, T_CHAR, start, __ value(count));
1591
1592 if (CompactStrings) {
1593 __ end_if();
1594 }
1595 }
1596
1597 // Finally sync IdealKit and GraphKit.
1598 kit.sync_kit(ideal);
1599 return __ AddI(start, __ value(count));
1600 }
1601
1602 // Compress copy the char into dst_array at index start.
1603 Node* PhaseStringOpts::copy_char(GraphKit& kit, Node* val, Node* dst_array, Node* dst_coder, Node* start) {
1604 bool dcon = (dst_coder != NULL) && dst_coder->is_Con();
1605 bool dbyte = dcon ? (dst_coder->get_int() == java_lang_String::CODER_LATIN1) : false;
1606
1607 IdealKit ideal(&kit, true, true);
1608 IdealVariable end(ideal); __ declarations_done();
1609 Node* adr = kit.array_element_address(dst_array, start, T_BYTE);
1610 if (!dcon){
1611 __ if_then(dst_coder, BoolTest::eq, __ ConI(java_lang_String::CODER_LATIN1));
1612 }
1613 if (!dcon || dbyte) {
1614 // Destination is Latin1. Store a byte.
1615 __ store(__ ctrl(), adr, val, T_BYTE, byte_adr_idx, MemNode::unordered);
1616 __ set(end, __ AddI(start, __ ConI(1)));
1617 }
1618 if (!dcon) {
1619 __ else_();
1620 }
1621 if (!dcon || !dbyte) {
1622 // Destination is UTF16. Store a char.
1623 __ store(__ ctrl(), adr, val, T_CHAR, byte_adr_idx, MemNode::unordered, true /* mismatched */);
1624 __ set(end, __ AddI(start, __ ConI(2)));
1625 }
1626 if (!dcon) {
1627 __ end_if();
1628 }
1629 // Finally sync IdealKit and GraphKit.
1630 kit.sync_kit(ideal);
1631 return __ value(end);
1632 }
1633
1634 #undef __
1635 #define __ kit.
1636
1637 // Allocate a byte array of specified length.
1638 Node* PhaseStringOpts::allocate_byte_array(GraphKit& kit, IdealKit* ideal, Node* length) {
1639 if (ideal != NULL) {
1640 // Sync IdealKit and graphKit.
1641 kit.sync_kit(*ideal);
1642 }
1643 Node* byte_array = NULL;
1644 {
1645 PreserveReexecuteState preexecs(&kit);
1646 // The original jvms is for an allocation of either a String or
1647 // StringBuffer so no stack adjustment is necessary for proper
1648 // reexecution. If we deoptimize in the slow path the bytecode
1649 // will be reexecuted and the char[] allocation will be thrown away.
1650 kit.jvms()->set_should_reexecute(true);
1651 byte_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_BYTE))),
1652 length, 1);
1653 }
1654
1655 // Mark the allocation so that zeroing is skipped since the code
1656 // below will overwrite the entire array
1657 AllocateArrayNode* byte_alloc = AllocateArrayNode::Ideal_array_allocation(byte_array, _gvn);
1658 byte_alloc->maybe_set_complete(_gvn);
1659
1660 if (ideal != NULL) {
1661 // Sync IdealKit and graphKit.
1662 ideal->sync_kit(&kit);
1663 }
1664 return byte_array;
1665 }
1666
1667 jbyte PhaseStringOpts::get_constant_coder(GraphKit& kit, Node* str) {
1668 assert(str->is_Con(), "String must be constant");
1669 const TypeOopPtr* str_type = kit.gvn().type(str)->isa_oopptr();
1670 ciInstance* str_instance = str_type->const_oop()->as_instance();
1671 jbyte coder = str_instance->field_value_by_offset(java_lang_String::coder_offset_in_bytes()).as_byte();
1672 assert(CompactStrings || (coder == java_lang_String::CODER_UTF16), "Strings must be UTF16 encoded");
1673 return coder;
1674 }
1675
1676 int PhaseStringOpts::get_constant_length(GraphKit& kit, Node* str) {
1677 assert(str->is_Con(), "String must be constant");
1678 return get_constant_value(kit, str)->length();
1679 }
1680
1681 ciTypeArray* PhaseStringOpts::get_constant_value(GraphKit& kit, Node* str) {
1682 assert(str->is_Con(), "String must be constant");
1683 const TypeOopPtr* str_type = kit.gvn().type(str)->isa_oopptr();
1684 ciInstance* str_instance = str_type->const_oop()->as_instance();
1685 ciObject* src_array = str_instance->field_value_by_offset(java_lang_String::value_offset_in_bytes()).as_object();
1686 return src_array->as_type_array();
1687 }
1688
1689 void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
1690 // Log a little info about the transformation
1691 sc->maybe_log_transform();
1692
1693 // pull the JVMState of the allocation into a SafePointNode to serve as
1694 // as a shim for the insertion of the new code.
1695 JVMState* jvms = sc->begin()->jvms()->clone_shallow(C);
1696 uint size = sc->begin()->req();
1697 SafePointNode* map = new SafePointNode(size, jvms);
1698
1699 // copy the control and memory state from the final call into our
1700 // new starting state. This allows any preceeding tests to feed
1701 // into the new section of code.
1702 for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
1703 map->init_req(i1, sc->end()->in(i1));
1704 }
1705 // blow away old allocation arguments
1706 for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
1707 map->init_req(i1, C->top());
1708 }
1709 // Copy the rest of the inputs for the JVMState
1710 for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
1711 map->init_req(i1, sc->begin()->in(i1));
1712 }
1713 // Make sure the memory state is a MergeMem for parsing.
1714 if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
1715 map->set_req(TypeFunc::Memory, MergeMemNode::make(map->in(TypeFunc::Memory)));
1716 }
1717
1718 jvms->set_map(map);
1719 map->ensure_stack(jvms, jvms->method()->max_stack());
1720
1721 // disconnect all the old StringBuilder calls from the graph
1722 sc->eliminate_unneeded_control();
1723
1724 // At this point all the old work has been completely removed from
1725 // the graph and the saved JVMState exists at the point where the
1726 // final toString call used to be.
1727 GraphKit kit(jvms);
1728
1729 // There may be uncommon traps which are still using the
1730 // intermediate states and these need to be rewritten to point at
1731 // the JVMState at the beginning of the transformation.
1732 sc->convert_uncommon_traps(kit, jvms);
1733
1734 // Now insert the logic to compute the size of the string followed
1735 // by all the logic to construct array and resulting string.
1736
1737 Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
1738
1739 // Create a region for the overflow checks to merge into.
1740 int args = MAX2(sc->num_arguments(), 1);
1741 RegionNode* overflow = new RegionNode(args);
1742 kit.gvn().set_type(overflow, Type::CONTROL);
1743
1744 // Create a hook node to hold onto the individual sizes since they
1745 // are need for the copying phase.
1746 Node* string_sizes = new Node(args);
1747
1748 Node* coder = __ intcon(0);
1749 Node* length = __ intcon(0);
1750 // If at least one argument is UTF16 encoded, we can fix the encoding.
1751 bool coder_fixed = false;
1752
1753 if (!CompactStrings) {
1754 // Fix encoding of result string to UTF16
1755 coder_fixed = true;
1756 coder = __ intcon(java_lang_String::CODER_UTF16);
1757 }
1758
1759 for (int argi = 0; argi < sc->num_arguments(); argi++) {
1760 Node* arg = sc->argument(argi);
1761 switch (sc->mode(argi)) {
1762 case StringConcat::IntMode: {
1763 Node* string_size = int_stringSize(kit, arg);
1764
1765 // accumulate total
1766 length = __ AddI(length, string_size);
1767
1768 // Cache this value for the use by int_toString
1769 string_sizes->init_req(argi, string_size);
1770 break;
1771 }
1772 case StringConcat::StringNullCheckMode: {
1773 const Type* type = kit.gvn().type(arg);
1774 assert(type != TypePtr::NULL_PTR, "missing check");
1775 if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
1776 // Null check with uncommon trap since
1777 // StringBuilder(null) throws exception.
1778 // Use special uncommon trap instead of
1779 // calling normal do_null_check().
1780 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
1781 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
1782 overflow->add_req(__ IfFalse(iff));
1783 Node* notnull = __ IfTrue(iff);
1784 kit.set_control(notnull); // set control for the cast_not_null
1785 arg = kit.cast_not_null(arg, false);
1786 sc->set_argument(argi, arg);
1787 }
1788 assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity");
1789 // Fallthrough to add string length.
1790 }
1791 case StringConcat::StringMode: {
1792 const Type* type = kit.gvn().type(arg);
1793 Node* count = NULL;
1794 Node* arg_coder = NULL;
1795 if (type == TypePtr::NULL_PTR) {
1796 // replace the argument with the null checked version
1797 arg = null_string;
1798 sc->set_argument(argi, arg);
1799 count = kit.load_String_length(arg, true);
1800 arg_coder = kit.load_String_coder(arg, true);
1801 } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
1802 // s = s != null ? s : "null";
1803 // length = length + (s.count - s.offset);
1804 RegionNode *r = new RegionNode(3);
1805 kit.gvn().set_type(r, Type::CONTROL);
1806 Node *phi = new PhiNode(r, type);
1807 kit.gvn().set_type(phi, phi->bottom_type());
1808 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
1809 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
1810 Node* notnull = __ IfTrue(iff);
1811 Node* isnull = __ IfFalse(iff);
1812 kit.set_control(notnull); // set control for the cast_not_null
1813 r->init_req(1, notnull);
1814 phi->init_req(1, kit.cast_not_null(arg, false));
1815 r->init_req(2, isnull);
1816 phi->init_req(2, null_string);
1817 kit.set_control(r);
1818 C->record_for_igvn(r);
1819 C->record_for_igvn(phi);
1820 // replace the argument with the null checked version
1821 arg = phi;
1822 sc->set_argument(argi, arg);
1823 count = kit.load_String_length(arg, true);
1824 arg_coder = kit.load_String_coder(arg, true);
1825 } else {
1826 // A corresponding nullcheck will be connected during IGVN MemNode::Ideal_common_DU_postCCP
1827 // kit.control might be a different test, that can be hoisted above the actual nullcheck
1828 // in case, that the control input is not null, Ideal_common_DU_postCCP will not look for a nullcheck.
1829 count = kit.load_String_length(arg, false);
1830 arg_coder = kit.load_String_coder(arg, false);
1831 }
1832 if (arg->is_Con()) {
1833 // Constant string. Get constant coder and length.
1834 jbyte const_coder = get_constant_coder(kit, arg);
1835 int const_length = get_constant_length(kit, arg);
1836 if (const_coder == java_lang_String::CODER_LATIN1) {
1837 // Can be latin1 encoded
1838 arg_coder = __ intcon(const_coder);
1839 count = __ intcon(const_length);
1840 } else {
1841 // Found UTF16 encoded string. Fix result array encoding to UTF16.
1842 coder_fixed = true;
1843 coder = __ intcon(const_coder);
1844 count = __ intcon(const_length / 2);
1845 }
1846 }
1847
1848 if (!coder_fixed) {
1849 coder = __ OrI(coder, arg_coder);
1850 }
1851 length = __ AddI(length, count);
1852 string_sizes->init_req(argi, NULL);
1853 break;
1854 }
1855 case StringConcat::CharMode: {
1856 // one character only
1857 const TypeInt* t = kit.gvn().type(arg)->is_int();
1858 if (!coder_fixed && t->is_con()) {
1859 // Constant char
1860 if (t->get_con() <= 255) {
1861 // Can be latin1 encoded
1862 coder = __ OrI(coder, __ intcon(java_lang_String::CODER_LATIN1));
1863 } else {
1864 // Must be UTF16 encoded. Fix result array encoding to UTF16.
1865 coder_fixed = true;
1866 coder = __ intcon(java_lang_String::CODER_UTF16);
1867 }
1868 } else if (!coder_fixed) {
1869 // Not constant
1870 #undef __
1871 #define __ ideal.
1872 IdealKit ideal(&kit, true, true);
1873 IdealVariable char_coder(ideal); __ declarations_done();
1874 // Check if character can be latin1 encoded
1875 __ if_then(arg, BoolTest::le, __ ConI(0xFF));
1876 __ set(char_coder, __ ConI(java_lang_String::CODER_LATIN1));
1877 __ else_();
1878 __ set(char_coder, __ ConI(java_lang_String::CODER_UTF16));
1879 __ end_if();
1880 kit.sync_kit(ideal);
1881 coder = __ OrI(coder, __ value(char_coder));
1882 #undef __
1883 #define __ kit.
1884 }
1885 length = __ AddI(length, __ intcon(1));
1886 break;
1887 }
1888 default:
1889 ShouldNotReachHere();
1890 }
1891 if (argi > 0) {
1892 // Check that the sum hasn't overflowed
1893 IfNode* iff = kit.create_and_map_if(kit.control(),
1894 __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
1895 PROB_MIN, COUNT_UNKNOWN);
1896 kit.set_control(__ IfFalse(iff));
1897 overflow->set_req(argi, __ IfTrue(iff));
1898 }
1899 }
1900
1901 {
1902 // Hook
1903 PreserveJVMState pjvms(&kit);
1904 kit.set_control(overflow);
1905 C->record_for_igvn(overflow);
1906 kit.uncommon_trap(Deoptimization::Reason_intrinsic,
1907 Deoptimization::Action_make_not_entrant);
1908 }
1909
1910 Node* result;
1911 if (!kit.stopped()) {
1912 assert(CompactStrings || (coder->is_Con() && coder->get_int() == java_lang_String::CODER_UTF16),
1913 "Result string must be UTF16 encoded if CompactStrings is disabled");
1914
1915 Node* dst_array = NULL;
1916 if (sc->num_arguments() == 1 &&
1917 (sc->mode(0) == StringConcat::StringMode ||
1918 sc->mode(0) == StringConcat::StringNullCheckMode)) {
1919 // Handle the case when there is only a single String argument.
1920 // In this case, we can just pull the value from the String itself.
1921 dst_array = kit.load_String_value(sc->argument(0), true);
1922 } else {
1923 // Allocate destination byte array according to coder
1924 dst_array = allocate_byte_array(kit, NULL, __ LShiftI(length, coder));
1925
1926 // Now copy the string representations into the final byte[]
1927 Node* start = __ intcon(0);
1928 for (int argi = 0; argi < sc->num_arguments(); argi++) {
1929 Node* arg = sc->argument(argi);
1930 switch (sc->mode(argi)) {
1931 case StringConcat::IntMode: {
1932 start = int_getChars(kit, arg, dst_array, coder, start, string_sizes->in(argi));
1933 break;
1934 }
1935 case StringConcat::StringNullCheckMode:
1936 case StringConcat::StringMode: {
1937 start = copy_string(kit, arg, dst_array, coder, start);
1938 break;
1939 }
1940 case StringConcat::CharMode: {
1941 start = copy_char(kit, arg, dst_array, coder, start);
1942 break;
1943 }
1944 default:
1945 ShouldNotReachHere();
1946 }
1947 }
1948 }
1949
1950 // If we're not reusing an existing String allocation then allocate one here.
1951 result = sc->string_alloc();
1952 if (result == NULL) {
1953 PreserveReexecuteState preexecs(&kit);
1954 // The original jvms is for an allocation of either a String or
1955 // StringBuffer so no stack adjustment is necessary for proper
1956 // reexecution.
1957 kit.jvms()->set_should_reexecute(true);
1958 result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
1959 }
1960
1961 // Initialize the string
1962 kit.store_String_value(result, dst_array);
1963 kit.store_String_coder(result, coder);
1964
1965 // The value field is final. Emit a barrier here to ensure that the effect
1966 // of the initialization is committed to memory before any code publishes
1967 // a reference to the newly constructed object (see Parse::do_exits()).
1968 assert(AllocateNode::Ideal_allocation(result, _gvn) != NULL, "should be newly allocated");
1969 kit.insert_mem_bar(Op_MemBarRelease, result);
1970 } else {
1971 result = C->top();
1972 }
1973 // hook up the outgoing control and result
1974 kit.replace_call(sc->end(), result);
1975
1976 // Unhook any hook nodes
1977 string_sizes->disconnect_inputs(NULL, C);
1978 sc->cleanup();
1979 }