Fri, 25 May 2012 07:53:11 -0700
7170463: C2 should recognize "obj.getClass() == A.class" code pattern
Summary: optimize this code pattern obj.getClass() == A.class.
Reviewed-by: jrose, kvn
Contributed-by: Krystal Mok <sajia@taobao.com>
1 /*
2 * Copyright (c) 2009, 2012, 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 */
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"
38 #define __ kit.
40 class StringConcat : public ResourceObj {
41 private:
42 PhaseStringOpts* _stringopts;
43 Node* _string_alloc;
44 AllocateNode* _begin; // The allocation the begins the pattern
45 CallStaticJavaNode* _end; // The final call of the pattern. Will either be
46 // SB.toString or or String.<init>(SB.toString)
47 bool _multiple; // indicates this is a fusion of two or more
48 // separate StringBuilders
50 Node* _arguments; // The list of arguments to be concatenated
51 GrowableArray<int> _mode; // into a String along with a mode flag
52 // indicating how to treat the value.
54 Node_List _control; // List of control nodes that will be deleted
55 Node_List _uncommon_traps; // Uncommon traps that needs to be rewritten
56 // to restart at the initial JVMState.
57 public:
58 // Mode for converting arguments to Strings
59 enum {
60 StringMode,
61 IntMode,
62 CharMode,
63 StringNullCheckMode
64 };
66 StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
67 _end(end),
68 _begin(NULL),
69 _multiple(false),
70 _string_alloc(NULL),
71 _stringopts(stringopts) {
72 _arguments = new (_stringopts->C, 1) Node(1);
73 _arguments->del_req(0);
74 }
76 bool validate_control_flow();
78 void merge_add() {
79 #if 0
80 // XXX This is place holder code for reusing an existing String
81 // allocation but the logic for checking the state safety is
82 // probably inadequate at the moment.
83 CallProjections endprojs;
84 sc->end()->extract_projections(&endprojs, false);
85 if (endprojs.resproj != NULL) {
86 for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
87 CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
88 if (use != NULL && use->method() != NULL &&
89 use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
90 use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
91 // Found useless new String(sb.toString()) so reuse the newly allocated String
92 // when creating the result instead of allocating a new one.
93 sc->set_string_alloc(use->in(TypeFunc::Parms));
94 sc->set_end(use);
95 }
96 }
97 }
98 #endif
99 }
101 StringConcat* merge(StringConcat* other, Node* arg);
103 void set_allocation(AllocateNode* alloc) {
104 _begin = alloc;
105 }
107 void append(Node* value, int mode) {
108 _arguments->add_req(value);
109 _mode.append(mode);
110 }
111 void push(Node* value, int mode) {
112 _arguments->ins_req(0, value);
113 _mode.insert_before(0, mode);
114 }
115 void push_string(Node* value) {
116 push(value, StringMode);
117 }
118 void push_string_null_check(Node* value) {
119 push(value, StringNullCheckMode);
120 }
121 void push_int(Node* value) {
122 push(value, IntMode);
123 }
124 void push_char(Node* value) {
125 push(value, CharMode);
126 }
128 Node* argument(int i) {
129 return _arguments->in(i);
130 }
131 void set_argument(int i, Node* value) {
132 _arguments->set_req(i, value);
133 }
134 int num_arguments() {
135 return _mode.length();
136 }
137 int mode(int i) {
138 return _mode.at(i);
139 }
140 void add_control(Node* ctrl) {
141 assert(!_control.contains(ctrl), "only push once");
142 _control.push(ctrl);
143 }
144 CallStaticJavaNode* end() { return _end; }
145 AllocateNode* begin() { return _begin; }
146 Node* string_alloc() { return _string_alloc; }
148 void eliminate_unneeded_control();
149 void eliminate_initialize(InitializeNode* init);
150 void eliminate_call(CallNode* call);
152 void maybe_log_transform() {
153 CompileLog* log = _stringopts->C->log();
154 if (log != NULL) {
155 log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
156 num_arguments(),
157 _string_alloc != NULL,
158 _multiple);
159 JVMState* p = _begin->jvms();
160 while (p != NULL) {
161 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
162 p = p->caller();
163 }
164 log->tail("replace_string_concat");
165 }
166 }
168 void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
169 for (uint u = 0; u < _uncommon_traps.size(); u++) {
170 Node* uct = _uncommon_traps.at(u);
172 // Build a new call using the jvms state of the allocate
173 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
174 const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
175 int size = call_type->domain()->cnt();
176 const TypePtr* no_memory_effects = NULL;
177 Compile* C = _stringopts->C;
178 CallStaticJavaNode* call = new (C, size) CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
179 jvms->bci(), no_memory_effects);
180 for (int e = 0; e < TypeFunc::Parms; e++) {
181 call->init_req(e, uct->in(e));
182 }
183 // Set the trap request to record intrinsic failure if this trap
184 // is taken too many times. Ideally we would handle then traps by
185 // doing the original bookkeeping in the MDO so that if it caused
186 // the code to be thrown out we could still recompile and use the
187 // optimization. Failing the uncommon traps doesn't really mean
188 // that the optimization is a bad idea but there's no other way to
189 // do the MDO updates currently.
190 int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
191 Deoptimization::Action_make_not_entrant);
192 call->init_req(TypeFunc::Parms, __ intcon(trap_request));
193 kit.add_safepoint_edges(call);
195 _stringopts->gvn()->transform(call);
196 C->gvn_replace_by(uct, call);
197 uct->disconnect_inputs(NULL);
198 }
199 }
201 void cleanup() {
202 // disconnect the hook node
203 _arguments->disconnect_inputs(NULL);
204 }
205 };
208 void StringConcat::eliminate_unneeded_control() {
209 eliminate_initialize(begin()->initialization());
210 for (uint i = 0; i < _control.size(); i++) {
211 Node* n = _control.at(i);
212 if (n->is_Call()) {
213 if (n != _end) {
214 eliminate_call(n->as_Call());
215 }
216 } else if (n->is_IfTrue()) {
217 Compile* C = _stringopts->C;
218 C->gvn_replace_by(n, n->in(0)->in(0));
219 C->gvn_replace_by(n->in(0), C->top());
220 }
221 }
222 }
225 StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
226 StringConcat* result = new StringConcat(_stringopts, _end);
227 for (uint x = 0; x < _control.size(); x++) {
228 Node* n = _control.at(x);
229 if (n->is_Call()) {
230 result->_control.push(n);
231 }
232 }
233 for (uint x = 0; x < other->_control.size(); x++) {
234 Node* n = other->_control.at(x);
235 if (n->is_Call()) {
236 result->_control.push(n);
237 }
238 }
239 assert(result->_control.contains(other->_end), "what?");
240 assert(result->_control.contains(_begin), "what?");
241 for (int x = 0; x < num_arguments(); x++) {
242 if (argument(x) == arg) {
243 // replace the toString result with the all the arguments that
244 // made up the other StringConcat
245 for (int y = 0; y < other->num_arguments(); y++) {
246 result->append(other->argument(y), other->mode(y));
247 }
248 } else {
249 result->append(argument(x), mode(x));
250 }
251 }
252 result->set_allocation(other->_begin);
253 result->_multiple = true;
254 return result;
255 }
258 void StringConcat::eliminate_call(CallNode* call) {
259 Compile* C = _stringopts->C;
260 CallProjections projs;
261 call->extract_projections(&projs, false);
262 if (projs.fallthrough_catchproj != NULL) {
263 C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
264 }
265 if (projs.fallthrough_memproj != NULL) {
266 C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
267 }
268 if (projs.catchall_memproj != NULL) {
269 C->gvn_replace_by(projs.catchall_memproj, C->top());
270 }
271 if (projs.fallthrough_ioproj != NULL) {
272 C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
273 }
274 if (projs.catchall_ioproj != NULL) {
275 C->gvn_replace_by(projs.catchall_ioproj, C->top());
276 }
277 if (projs.catchall_catchproj != NULL) {
278 // EA can't cope with the partially collapsed graph this
279 // creates so put it on the worklist to be collapsed later.
280 for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
281 Node *use = i.get();
282 int opc = use->Opcode();
283 if (opc == Op_CreateEx || opc == Op_Region) {
284 _stringopts->record_dead_node(use);
285 }
286 }
287 C->gvn_replace_by(projs.catchall_catchproj, C->top());
288 }
289 if (projs.resproj != NULL) {
290 C->gvn_replace_by(projs.resproj, C->top());
291 }
292 C->gvn_replace_by(call, C->top());
293 }
295 void StringConcat::eliminate_initialize(InitializeNode* init) {
296 Compile* C = _stringopts->C;
298 // Eliminate Initialize node.
299 assert(init->outcnt() <= 2, "only a control and memory projection expected");
300 assert(init->req() <= InitializeNode::RawStores, "no pending inits");
301 Node *ctrl_proj = init->proj_out(TypeFunc::Control);
302 if (ctrl_proj != NULL) {
303 C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
304 }
305 Node *mem_proj = init->proj_out(TypeFunc::Memory);
306 if (mem_proj != NULL) {
307 Node *mem = init->in(TypeFunc::Memory);
308 C->gvn_replace_by(mem_proj, mem);
309 }
310 C->gvn_replace_by(init, C->top());
311 init->disconnect_inputs(NULL);
312 }
314 Node_List PhaseStringOpts::collect_toString_calls() {
315 Node_List string_calls;
316 Node_List worklist;
318 _visited.Clear();
320 // Prime the worklist
321 for (uint i = 1; i < C->root()->len(); i++) {
322 Node* n = C->root()->in(i);
323 if (n != NULL && !_visited.test_set(n->_idx)) {
324 worklist.push(n);
325 }
326 }
328 while (worklist.size() > 0) {
329 Node* ctrl = worklist.pop();
330 if (ctrl->is_CallStaticJava()) {
331 CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
332 ciMethod* m = csj->method();
333 if (m != NULL &&
334 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
335 m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString)) {
336 string_calls.push(csj);
337 }
338 }
339 if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
340 worklist.push(ctrl->in(0));
341 }
342 if (ctrl->is_Region()) {
343 for (uint i = 1; i < ctrl->len(); i++) {
344 if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
345 worklist.push(ctrl->in(i));
346 }
347 }
348 }
349 }
350 return string_calls;
351 }
354 StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
355 ciMethod* m = call->method();
356 ciSymbol* string_sig;
357 ciSymbol* int_sig;
358 ciSymbol* char_sig;
359 if (m->holder() == C->env()->StringBuilder_klass()) {
360 string_sig = ciSymbol::String_StringBuilder_signature();
361 int_sig = ciSymbol::int_StringBuilder_signature();
362 char_sig = ciSymbol::char_StringBuilder_signature();
363 } else if (m->holder() == C->env()->StringBuffer_klass()) {
364 string_sig = ciSymbol::String_StringBuffer_signature();
365 int_sig = ciSymbol::int_StringBuffer_signature();
366 char_sig = ciSymbol::char_StringBuffer_signature();
367 } else {
368 return NULL;
369 }
370 #ifndef PRODUCT
371 if (PrintOptimizeStringConcat) {
372 tty->print("considering toString call in ");
373 call->jvms()->dump_spec(tty); tty->cr();
374 }
375 #endif
377 StringConcat* sc = new StringConcat(this, call);
379 AllocateNode* alloc = NULL;
380 InitializeNode* init = NULL;
382 // possible opportunity for StringBuilder fusion
383 CallStaticJavaNode* cnode = call;
384 while (cnode) {
385 Node* recv = cnode->in(TypeFunc::Parms)->uncast();
386 if (recv->is_Proj()) {
387 recv = recv->in(0);
388 }
389 cnode = recv->isa_CallStaticJava();
390 if (cnode == NULL) {
391 alloc = recv->isa_Allocate();
392 if (alloc == NULL) {
393 break;
394 }
395 // Find the constructor call
396 Node* result = alloc->result_cast();
397 if (result == NULL || !result->is_CheckCastPP()) {
398 // strange looking allocation
399 #ifndef PRODUCT
400 if (PrintOptimizeStringConcat) {
401 tty->print("giving up because allocation looks strange ");
402 alloc->jvms()->dump_spec(tty); tty->cr();
403 }
404 #endif
405 break;
406 }
407 Node* constructor = NULL;
408 for (SimpleDUIterator i(result); i.has_next(); i.next()) {
409 CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
410 if (use != NULL &&
411 use->method() != NULL &&
412 !use->method()->is_static() &&
413 use->method()->name() == ciSymbol::object_initializer_name() &&
414 use->method()->holder() == m->holder()) {
415 // Matched the constructor.
416 ciSymbol* sig = use->method()->signature()->as_symbol();
417 if (sig == ciSymbol::void_method_signature() ||
418 sig == ciSymbol::int_void_signature() ||
419 sig == ciSymbol::string_void_signature()) {
420 if (sig == ciSymbol::string_void_signature()) {
421 // StringBuilder(String) so pick this up as the first argument
422 assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
423 const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1));
424 if (type == TypePtr::NULL_PTR) {
425 // StringBuilder(null) throws exception.
426 #ifndef PRODUCT
427 if (PrintOptimizeStringConcat) {
428 tty->print("giving up because StringBuilder(null) throws exception");
429 alloc->jvms()->dump_spec(tty); tty->cr();
430 }
431 #endif
432 return NULL;
433 }
434 // StringBuilder(str) argument needs null check.
435 sc->push_string_null_check(use->in(TypeFunc::Parms + 1));
436 }
437 // The int variant takes an initial size for the backing
438 // array so just treat it like the void version.
439 constructor = use;
440 } else {
441 #ifndef PRODUCT
442 if (PrintOptimizeStringConcat) {
443 tty->print("unexpected constructor signature: %s", sig->as_utf8());
444 }
445 #endif
446 }
447 break;
448 }
449 }
450 if (constructor == NULL) {
451 // couldn't find constructor
452 #ifndef PRODUCT
453 if (PrintOptimizeStringConcat) {
454 tty->print("giving up because couldn't find constructor ");
455 alloc->jvms()->dump_spec(tty); tty->cr();
456 }
457 #endif
458 break;
459 }
461 // Walked all the way back and found the constructor call so see
462 // if this call converted into a direct string concatenation.
463 sc->add_control(call);
464 sc->add_control(constructor);
465 sc->add_control(alloc);
466 sc->set_allocation(alloc);
467 if (sc->validate_control_flow()) {
468 return sc;
469 } else {
470 return NULL;
471 }
472 } else if (cnode->method() == NULL) {
473 break;
474 } else if (!cnode->method()->is_static() &&
475 cnode->method()->holder() == m->holder() &&
476 cnode->method()->name() == ciSymbol::append_name() &&
477 (cnode->method()->signature()->as_symbol() == string_sig ||
478 cnode->method()->signature()->as_symbol() == char_sig ||
479 cnode->method()->signature()->as_symbol() == int_sig)) {
480 sc->add_control(cnode);
481 Node* arg = cnode->in(TypeFunc::Parms + 1);
482 if (cnode->method()->signature()->as_symbol() == int_sig) {
483 sc->push_int(arg);
484 } else if (cnode->method()->signature()->as_symbol() == char_sig) {
485 sc->push_char(arg);
486 } else {
487 if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
488 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
489 if (csj->method() != NULL &&
490 csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString) {
491 sc->add_control(csj);
492 sc->push_int(csj->in(TypeFunc::Parms));
493 continue;
494 }
495 }
496 sc->push_string(arg);
497 }
498 continue;
499 } else {
500 // some unhandled signature
501 #ifndef PRODUCT
502 if (PrintOptimizeStringConcat) {
503 tty->print("giving up because encountered unexpected signature ");
504 cnode->tf()->dump(); tty->cr();
505 cnode->in(TypeFunc::Parms + 1)->dump();
506 }
507 #endif
508 break;
509 }
510 }
511 return NULL;
512 }
515 PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
516 Phase(StringOpts),
517 _gvn(gvn),
518 _visited(Thread::current()->resource_area()) {
520 assert(OptimizeStringConcat, "shouldn't be here");
522 size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
523 ciSymbol::make("[I"), true);
524 if (size_table_field == NULL) {
525 // Something wrong so give up.
526 assert(false, "why can't we find Integer.sizeTable?");
527 return;
528 }
530 // Collect the types needed to talk about the various slices of memory
531 char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS);
533 // For each locally allocated StringBuffer see if the usages can be
534 // collapsed into a single String construction.
536 // Run through the list of allocation looking for SB.toString to see
537 // if it's possible to fuse the usage of the SB into a single String
538 // construction.
539 GrowableArray<StringConcat*> concats;
540 Node_List toStrings = collect_toString_calls();
541 while (toStrings.size() > 0) {
542 StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
543 if (sc != NULL) {
544 concats.push(sc);
545 }
546 }
548 // try to coalesce separate concats
549 restart:
550 for (int c = 0; c < concats.length(); c++) {
551 StringConcat* sc = concats.at(c);
552 for (int i = 0; i < sc->num_arguments(); i++) {
553 Node* arg = sc->argument(i);
554 if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
555 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
556 if (csj->method() != NULL &&
557 (csj->method()->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
558 csj->method()->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
559 for (int o = 0; o < concats.length(); o++) {
560 if (c == o) continue;
561 StringConcat* other = concats.at(o);
562 if (other->end() == csj) {
563 #ifndef PRODUCT
564 if (PrintOptimizeStringConcat) {
565 tty->print_cr("considering stacked concats");
566 }
567 #endif
569 StringConcat* merged = sc->merge(other, arg);
570 if (merged->validate_control_flow()) {
571 #ifndef PRODUCT
572 if (PrintOptimizeStringConcat) {
573 tty->print_cr("stacking would succeed");
574 }
575 #endif
576 if (c < o) {
577 concats.remove_at(o);
578 concats.at_put(c, merged);
579 } else {
580 concats.remove_at(c);
581 concats.at_put(o, merged);
582 }
583 goto restart;
584 } else {
585 #ifndef PRODUCT
586 if (PrintOptimizeStringConcat) {
587 tty->print_cr("stacking would fail");
588 }
589 #endif
590 }
591 }
592 }
593 }
594 }
595 }
596 }
599 for (int c = 0; c < concats.length(); c++) {
600 StringConcat* sc = concats.at(c);
601 replace_string_concat(sc);
602 }
604 remove_dead_nodes();
605 }
607 void PhaseStringOpts::record_dead_node(Node* dead) {
608 dead_worklist.push(dead);
609 }
611 void PhaseStringOpts::remove_dead_nodes() {
612 // Delete any dead nodes to make things clean enough that escape
613 // analysis doesn't get unhappy.
614 while (dead_worklist.size() > 0) {
615 Node* use = dead_worklist.pop();
616 int opc = use->Opcode();
617 switch (opc) {
618 case Op_Region: {
619 uint i = 1;
620 for (i = 1; i < use->req(); i++) {
621 if (use->in(i) != C->top()) {
622 break;
623 }
624 }
625 if (i >= use->req()) {
626 for (SimpleDUIterator i(use); i.has_next(); i.next()) {
627 Node* m = i.get();
628 if (m->is_Phi()) {
629 dead_worklist.push(m);
630 }
631 }
632 C->gvn_replace_by(use, C->top());
633 }
634 break;
635 }
636 case Op_AddP:
637 case Op_CreateEx: {
638 // Recurisvely clean up references to CreateEx so EA doesn't
639 // get unhappy about the partially collapsed graph.
640 for (SimpleDUIterator i(use); i.has_next(); i.next()) {
641 Node* m = i.get();
642 if (m->is_AddP()) {
643 dead_worklist.push(m);
644 }
645 }
646 C->gvn_replace_by(use, C->top());
647 break;
648 }
649 case Op_Phi:
650 if (use->in(0) == C->top()) {
651 C->gvn_replace_by(use, C->top());
652 }
653 break;
654 }
655 }
656 }
659 bool StringConcat::validate_control_flow() {
660 // We found all the calls and arguments now lets see if it's
661 // safe to transform the graph as we would expect.
663 // Check to see if this resulted in too many uncommon traps previously
664 if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
665 Deoptimization::Reason_intrinsic)) {
666 return false;
667 }
669 // Walk backwards over the control flow from toString to the
670 // allocation and make sure all the control flow is ok. This
671 // means it's either going to be eliminated once the calls are
672 // removed or it can safely be transformed into an uncommon
673 // trap.
675 int null_check_count = 0;
676 Unique_Node_List ctrl_path;
678 assert(_control.contains(_begin), "missing");
679 assert(_control.contains(_end), "missing");
681 // Collect the nodes that we know about and will eliminate into ctrl_path
682 for (uint i = 0; i < _control.size(); i++) {
683 // Push the call and it's control projection
684 Node* n = _control.at(i);
685 if (n->is_Allocate()) {
686 AllocateNode* an = n->as_Allocate();
687 InitializeNode* init = an->initialization();
688 ctrl_path.push(init);
689 ctrl_path.push(init->as_Multi()->proj_out(0));
690 }
691 if (n->is_Call()) {
692 CallNode* cn = n->as_Call();
693 ctrl_path.push(cn);
694 ctrl_path.push(cn->proj_out(0));
695 ctrl_path.push(cn->proj_out(0)->unique_out());
696 ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0));
697 } else {
698 ShouldNotReachHere();
699 }
700 }
702 // Skip backwards through the control checking for unexpected contro flow
703 Node* ptr = _end;
704 bool fail = false;
705 while (ptr != _begin) {
706 if (ptr->is_Call() && ctrl_path.member(ptr)) {
707 ptr = ptr->in(0);
708 } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
709 ptr = ptr->in(0)->in(0)->in(0);
710 assert(ctrl_path.member(ptr), "should be a known piece of control");
711 } else if (ptr->is_IfTrue()) {
712 IfNode* iff = ptr->in(0)->as_If();
713 BoolNode* b = iff->in(1)->isa_Bool();
714 Node* cmp = b->in(1);
715 Node* v1 = cmp->in(1);
716 Node* v2 = cmp->in(2);
717 Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
719 // Null check of the return of append which can simply be eliminated
720 if (b->_test._test == BoolTest::ne &&
721 v2->bottom_type() == TypePtr::NULL_PTR &&
722 v1->is_Proj() && ctrl_path.member(v1->in(0))) {
723 // NULL check of the return value of the append
724 null_check_count++;
725 if (otherproj->outcnt() == 1) {
726 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
727 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
728 ctrl_path.push(call);
729 }
730 }
731 _control.push(ptr);
732 ptr = ptr->in(0)->in(0);
733 continue;
734 }
736 // A test which leads to an uncommon trap which should be safe.
737 // Later this trap will be converted into a trap that restarts
738 // at the beginning.
739 if (otherproj->outcnt() == 1) {
740 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
741 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
742 // control flow leads to uct so should be ok
743 _uncommon_traps.push(call);
744 ctrl_path.push(call);
745 ptr = ptr->in(0)->in(0);
746 continue;
747 }
748 }
750 #ifndef PRODUCT
751 // Some unexpected control flow we don't know how to handle.
752 if (PrintOptimizeStringConcat) {
753 tty->print_cr("failing with unknown test");
754 b->dump();
755 cmp->dump();
756 v1->dump();
757 v2->dump();
758 tty->cr();
759 }
760 #endif
761 fail = true;
762 break;
763 } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
764 ptr = ptr->in(0)->in(0);
765 } else if (ptr->is_Region()) {
766 Node* copy = ptr->as_Region()->is_copy();
767 if (copy != NULL) {
768 ptr = copy;
769 continue;
770 }
771 if (ptr->req() == 3 &&
772 ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
773 ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
774 ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
775 ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
776 // Simple diamond.
777 // XXX should check for possibly merging stores. simple data merges are ok.
778 ptr = ptr->in(1)->in(0)->in(0);
779 continue;
780 }
781 #ifndef PRODUCT
782 if (PrintOptimizeStringConcat) {
783 tty->print_cr("fusion would fail for region");
784 _begin->dump();
785 ptr->dump(2);
786 }
787 #endif
788 fail = true;
789 break;
790 } else {
791 // other unknown control
792 if (!fail) {
793 #ifndef PRODUCT
794 if (PrintOptimizeStringConcat) {
795 tty->print_cr("fusion would fail for");
796 _begin->dump();
797 }
798 #endif
799 fail = true;
800 }
801 #ifndef PRODUCT
802 if (PrintOptimizeStringConcat) {
803 ptr->dump();
804 }
805 #endif
806 ptr = ptr->in(0);
807 }
808 }
809 #ifndef PRODUCT
810 if (PrintOptimizeStringConcat && fail) {
811 tty->cr();
812 }
813 #endif
814 if (fail) return !fail;
816 // Validate that all these results produced are contained within
817 // this cluster of objects. First collect all the results produced
818 // by calls in the region.
819 _stringopts->_visited.Clear();
820 Node_List worklist;
821 Node* final_result = _end->proj_out(TypeFunc::Parms);
822 for (uint i = 0; i < _control.size(); i++) {
823 CallNode* cnode = _control.at(i)->isa_Call();
824 if (cnode != NULL) {
825 _stringopts->_visited.test_set(cnode->_idx);
826 }
827 Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL;
828 if (result != NULL && result != final_result) {
829 worklist.push(result);
830 }
831 }
833 Node* last_result = NULL;
834 while (worklist.size() > 0) {
835 Node* result = worklist.pop();
836 if (_stringopts->_visited.test_set(result->_idx))
837 continue;
838 for (SimpleDUIterator i(result); i.has_next(); i.next()) {
839 Node *use = i.get();
840 if (ctrl_path.member(use)) {
841 // already checked this
842 continue;
843 }
844 int opc = use->Opcode();
845 if (opc == Op_CmpP || opc == Op_Node) {
846 ctrl_path.push(use);
847 continue;
848 }
849 if (opc == Op_CastPP || opc == Op_CheckCastPP) {
850 for (SimpleDUIterator j(use); j.has_next(); j.next()) {
851 worklist.push(j.get());
852 }
853 worklist.push(use->in(1));
854 ctrl_path.push(use);
855 continue;
856 }
857 #ifndef PRODUCT
858 if (PrintOptimizeStringConcat) {
859 if (result != last_result) {
860 last_result = result;
861 tty->print_cr("extra uses for result:");
862 last_result->dump();
863 }
864 use->dump();
865 }
866 #endif
867 fail = true;
868 break;
869 }
870 }
872 #ifndef PRODUCT
873 if (PrintOptimizeStringConcat && !fail) {
874 ttyLocker ttyl;
875 tty->cr();
876 tty->print("fusion would succeed (%d %d) for ", null_check_count, _uncommon_traps.size());
877 _begin->jvms()->dump_spec(tty); tty->cr();
878 for (int i = 0; i < num_arguments(); i++) {
879 argument(i)->dump();
880 }
881 _control.dump();
882 tty->cr();
883 }
884 #endif
886 return !fail;
887 }
889 Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
890 const TypeInstPtr* mirror_type = TypeInstPtr::make(field->holder()->java_mirror());
891 Node* klass_node = __ makecon(mirror_type);
892 BasicType bt = field->layout_type();
893 ciType* field_klass = field->type();
895 const Type *type;
896 if( bt == T_OBJECT ) {
897 if (!field->type()->is_loaded()) {
898 type = TypeInstPtr::BOTTOM;
899 } else if (field->is_constant()) {
900 // This can happen if the constant oop is non-perm.
901 ciObject* con = field->constant_value().as_object();
902 // Do not "join" in the previous type; it doesn't add value,
903 // and may yield a vacuous result if the field is of interface type.
904 type = TypeOopPtr::make_from_constant(con, true)->isa_oopptr();
905 assert(type != NULL, "field singleton type must be consistent");
906 return __ makecon(type);
907 } else {
908 type = TypeOopPtr::make_from_klass(field_klass->as_klass());
909 }
910 } else {
911 type = Type::get_const_basic_type(bt);
912 }
914 return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
915 type, T_OBJECT,
916 C->get_alias_index(mirror_type->add_offset(field->offset_in_bytes())));
917 }
919 Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
920 RegionNode *final_merge = new (C, 3) RegionNode(3);
921 kit.gvn().set_type(final_merge, Type::CONTROL);
922 Node* final_size = new (C, 3) PhiNode(final_merge, TypeInt::INT);
923 kit.gvn().set_type(final_size, TypeInt::INT);
925 IfNode* iff = kit.create_and_map_if(kit.control(),
926 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
927 PROB_FAIR, COUNT_UNKNOWN);
928 Node* is_min = __ IfFalse(iff);
929 final_merge->init_req(1, is_min);
930 final_size->init_req(1, __ intcon(11));
932 kit.set_control(__ IfTrue(iff));
933 if (kit.stopped()) {
934 final_merge->init_req(2, C->top());
935 final_size->init_req(2, C->top());
936 } else {
938 // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
939 RegionNode *r = new (C, 3) RegionNode(3);
940 kit.gvn().set_type(r, Type::CONTROL);
941 Node *phi = new (C, 3) PhiNode(r, TypeInt::INT);
942 kit.gvn().set_type(phi, TypeInt::INT);
943 Node *size = new (C, 3) PhiNode(r, TypeInt::INT);
944 kit.gvn().set_type(size, TypeInt::INT);
945 Node* chk = __ CmpI(arg, __ intcon(0));
946 Node* p = __ Bool(chk, BoolTest::lt);
947 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
948 Node* lessthan = __ IfTrue(iff);
949 Node* greaterequal = __ IfFalse(iff);
950 r->init_req(1, lessthan);
951 phi->init_req(1, __ SubI(__ intcon(0), arg));
952 size->init_req(1, __ intcon(1));
953 r->init_req(2, greaterequal);
954 phi->init_req(2, arg);
955 size->init_req(2, __ intcon(0));
956 kit.set_control(r);
957 C->record_for_igvn(r);
958 C->record_for_igvn(phi);
959 C->record_for_igvn(size);
961 // for (int i=0; ; i++)
962 // if (x <= sizeTable[i])
963 // return i+1;
965 // Add loop predicate first.
966 kit.add_predicate();
968 RegionNode *loop = new (C, 3) RegionNode(3);
969 loop->init_req(1, kit.control());
970 kit.gvn().set_type(loop, Type::CONTROL);
972 Node *index = new (C, 3) PhiNode(loop, TypeInt::INT);
973 index->init_req(1, __ intcon(0));
974 kit.gvn().set_type(index, TypeInt::INT);
975 kit.set_control(loop);
976 Node* sizeTable = fetch_static_field(kit, size_table_field);
978 Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
979 C->record_for_igvn(value);
980 Node* limit = __ CmpI(phi, value);
981 Node* limitb = __ Bool(limit, BoolTest::le);
982 IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
983 Node* lessEqual = __ IfTrue(iff2);
984 Node* greater = __ IfFalse(iff2);
986 loop->init_req(2, greater);
987 index->init_req(2, __ AddI(index, __ intcon(1)));
989 kit.set_control(lessEqual);
990 C->record_for_igvn(loop);
991 C->record_for_igvn(index);
993 final_merge->init_req(2, kit.control());
994 final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
995 }
997 kit.set_control(final_merge);
998 C->record_for_igvn(final_merge);
999 C->record_for_igvn(final_size);
1001 return final_size;
1002 }
1004 void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) {
1005 RegionNode *final_merge = new (C, 4) RegionNode(4);
1006 kit.gvn().set_type(final_merge, Type::CONTROL);
1007 Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
1008 kit.gvn().set_type(final_mem, Type::MEMORY);
1010 // need to handle Integer.MIN_VALUE specially because negating doesn't make it positive
1011 {
1012 // i == MIN_VALUE
1013 IfNode* iff = kit.create_and_map_if(kit.control(),
1014 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
1015 PROB_FAIR, COUNT_UNKNOWN);
1017 Node* old_mem = kit.memory(char_adr_idx);
1019 kit.set_control(__ IfFalse(iff));
1020 if (kit.stopped()) {
1021 // Statically not equal to MIN_VALUE so this path is dead
1022 final_merge->init_req(3, kit.control());
1023 } else {
1024 copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
1025 char_array, start);
1026 final_merge->init_req(3, kit.control());
1027 final_mem->init_req(3, kit.memory(char_adr_idx));
1028 }
1030 kit.set_control(__ IfTrue(iff));
1031 kit.set_memory(old_mem, char_adr_idx);
1032 }
1035 // Simplified version of Integer.getChars
1037 // int q, r;
1038 // int charPos = index;
1039 Node* charPos = end;
1041 // char sign = 0;
1043 Node* i = arg;
1044 Node* sign = __ intcon(0);
1046 // if (i < 0) {
1047 // sign = '-';
1048 // i = -i;
1049 // }
1050 {
1051 IfNode* iff = kit.create_and_map_if(kit.control(),
1052 __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
1053 PROB_FAIR, COUNT_UNKNOWN);
1055 RegionNode *merge = new (C, 3) RegionNode(3);
1056 kit.gvn().set_type(merge, Type::CONTROL);
1057 i = new (C, 3) PhiNode(merge, TypeInt::INT);
1058 kit.gvn().set_type(i, TypeInt::INT);
1059 sign = new (C, 3) PhiNode(merge, TypeInt::INT);
1060 kit.gvn().set_type(sign, TypeInt::INT);
1062 merge->init_req(1, __ IfTrue(iff));
1063 i->init_req(1, __ SubI(__ intcon(0), arg));
1064 sign->init_req(1, __ intcon('-'));
1065 merge->init_req(2, __ IfFalse(iff));
1066 i->init_req(2, arg);
1067 sign->init_req(2, __ intcon(0));
1069 kit.set_control(merge);
1071 C->record_for_igvn(merge);
1072 C->record_for_igvn(i);
1073 C->record_for_igvn(sign);
1074 }
1076 // for (;;) {
1077 // q = i / 10;
1078 // r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ...
1079 // buf [--charPos] = digits [r];
1080 // i = q;
1081 // if (i == 0) break;
1082 // }
1084 {
1085 // Add loop predicate first.
1086 kit.add_predicate();
1088 RegionNode *head = new (C, 3) RegionNode(3);
1089 head->init_req(1, kit.control());
1090 kit.gvn().set_type(head, Type::CONTROL);
1091 Node *i_phi = new (C, 3) PhiNode(head, TypeInt::INT);
1092 i_phi->init_req(1, i);
1093 kit.gvn().set_type(i_phi, TypeInt::INT);
1094 charPos = PhiNode::make(head, charPos);
1095 kit.gvn().set_type(charPos, TypeInt::INT);
1096 Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
1097 kit.gvn().set_type(mem, Type::MEMORY);
1098 kit.set_control(head);
1099 kit.set_memory(mem, char_adr_idx);
1101 Node* q = __ DivI(NULL, i_phi, __ intcon(10));
1102 Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
1103 __ LShiftI(q, __ intcon(1))));
1104 Node* m1 = __ SubI(charPos, __ intcon(1));
1105 Node* ch = __ AddI(r, __ intcon('0'));
1107 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
1108 ch, T_CHAR, char_adr_idx);
1111 IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
1112 PROB_FAIR, COUNT_UNKNOWN);
1113 Node* ne = __ IfTrue(iff);
1114 Node* eq = __ IfFalse(iff);
1116 head->init_req(2, ne);
1117 mem->init_req(2, st);
1118 i_phi->init_req(2, q);
1119 charPos->init_req(2, m1);
1121 charPos = m1;
1123 kit.set_control(eq);
1124 kit.set_memory(st, char_adr_idx);
1126 C->record_for_igvn(head);
1127 C->record_for_igvn(mem);
1128 C->record_for_igvn(i_phi);
1129 C->record_for_igvn(charPos);
1130 }
1132 {
1133 // if (sign != 0) {
1134 // buf [--charPos] = sign;
1135 // }
1136 IfNode* iff = kit.create_and_map_if(kit.control(),
1137 __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
1138 PROB_FAIR, COUNT_UNKNOWN);
1140 final_merge->init_req(2, __ IfFalse(iff));
1141 final_mem->init_req(2, kit.memory(char_adr_idx));
1143 kit.set_control(__ IfTrue(iff));
1144 if (kit.stopped()) {
1145 final_merge->init_req(1, C->top());
1146 final_mem->init_req(1, C->top());
1147 } else {
1148 Node* m1 = __ SubI(charPos, __ intcon(1));
1149 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
1150 sign, T_CHAR, char_adr_idx);
1152 final_merge->init_req(1, kit.control());
1153 final_mem->init_req(1, st);
1154 }
1156 kit.set_control(final_merge);
1157 kit.set_memory(final_mem, char_adr_idx);
1159 C->record_for_igvn(final_merge);
1160 C->record_for_igvn(final_mem);
1161 }
1162 }
1165 Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) {
1166 Node* string = str;
1167 Node* offset = kit.load_String_offset(kit.control(), string);
1168 Node* count = kit.load_String_length(kit.control(), string);
1169 Node* value = kit.load_String_value (kit.control(), string);
1171 // copy the contents
1172 if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) {
1173 // For small constant strings just emit individual stores.
1174 // A length of 6 seems like a good space/speed tradeof.
1175 int c = count->get_int();
1176 int o = offset->get_int();
1177 const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr();
1178 ciTypeArray* value_array = t->const_oop()->as_type_array();
1179 for (int e = 0; e < c; e++) {
1180 __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
1181 __ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx);
1182 start = __ AddI(start, __ intcon(1));
1183 }
1184 } else {
1185 Node* src_ptr = kit.array_element_address(value, offset, T_CHAR);
1186 Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR);
1187 Node* c = count;
1188 Node* extra = NULL;
1189 #ifdef _LP64
1190 c = __ ConvI2L(c);
1191 extra = C->top();
1192 #endif
1193 Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP,
1194 OptoRuntime::fast_arraycopy_Type(),
1195 CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()),
1196 "jshort_disjoint_arraycopy", TypeAryPtr::CHARS,
1197 src_ptr, dst_ptr, c, extra);
1198 start = __ AddI(start, count);
1199 }
1200 return start;
1201 }
1204 void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
1205 // Log a little info about the transformation
1206 sc->maybe_log_transform();
1208 // pull the JVMState of the allocation into a SafePointNode to serve as
1209 // as a shim for the insertion of the new code.
1210 JVMState* jvms = sc->begin()->jvms()->clone_shallow(C);
1211 uint size = sc->begin()->req();
1212 SafePointNode* map = new (C, size) SafePointNode(size, jvms);
1214 // copy the control and memory state from the final call into our
1215 // new starting state. This allows any preceeding tests to feed
1216 // into the new section of code.
1217 for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
1218 map->init_req(i1, sc->end()->in(i1));
1219 }
1220 // blow away old allocation arguments
1221 for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
1222 map->init_req(i1, C->top());
1223 }
1224 // Copy the rest of the inputs for the JVMState
1225 for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
1226 map->init_req(i1, sc->begin()->in(i1));
1227 }
1228 // Make sure the memory state is a MergeMem for parsing.
1229 if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
1230 map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
1231 }
1233 jvms->set_map(map);
1234 map->ensure_stack(jvms, jvms->method()->max_stack());
1237 // disconnect all the old StringBuilder calls from the graph
1238 sc->eliminate_unneeded_control();
1240 // At this point all the old work has been completely removed from
1241 // the graph and the saved JVMState exists at the point where the
1242 // final toString call used to be.
1243 GraphKit kit(jvms);
1245 // There may be uncommon traps which are still using the
1246 // intermediate states and these need to be rewritten to point at
1247 // the JVMState at the beginning of the transformation.
1248 sc->convert_uncommon_traps(kit, jvms);
1250 // Now insert the logic to compute the size of the string followed
1251 // by all the logic to construct array and resulting string.
1253 Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
1255 // Create a region for the overflow checks to merge into.
1256 int args = MAX2(sc->num_arguments(), 1);
1257 RegionNode* overflow = new (C, args) RegionNode(args);
1258 kit.gvn().set_type(overflow, Type::CONTROL);
1260 // Create a hook node to hold onto the individual sizes since they
1261 // are need for the copying phase.
1262 Node* string_sizes = new (C, args) Node(args);
1264 Node* length = __ intcon(0);
1265 for (int argi = 0; argi < sc->num_arguments(); argi++) {
1266 Node* arg = sc->argument(argi);
1267 switch (sc->mode(argi)) {
1268 case StringConcat::IntMode: {
1269 Node* string_size = int_stringSize(kit, arg);
1271 // accumulate total
1272 length = __ AddI(length, string_size);
1274 // Cache this value for the use by int_toString
1275 string_sizes->init_req(argi, string_size);
1276 break;
1277 }
1278 case StringConcat::StringNullCheckMode: {
1279 const Type* type = kit.gvn().type(arg);
1280 assert(type != TypePtr::NULL_PTR, "missing check");
1281 if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
1282 // Null check with uncommont trap since
1283 // StringBuilder(null) throws exception.
1284 // Use special uncommon trap instead of
1285 // calling normal do_null_check().
1286 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
1287 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
1288 overflow->add_req(__ IfFalse(iff));
1289 Node* notnull = __ IfTrue(iff);
1290 kit.set_control(notnull); // set control for the cast_not_null
1291 arg = kit.cast_not_null(arg, false);
1292 sc->set_argument(argi, arg);
1293 }
1294 assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity");
1295 // Fallthrough to add string length.
1296 }
1297 case StringConcat::StringMode: {
1298 const Type* type = kit.gvn().type(arg);
1299 if (type == TypePtr::NULL_PTR) {
1300 // replace the argument with the null checked version
1301 arg = null_string;
1302 sc->set_argument(argi, arg);
1303 } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
1304 // s = s != null ? s : "null";
1305 // length = length + (s.count - s.offset);
1306 RegionNode *r = new (C, 3) RegionNode(3);
1307 kit.gvn().set_type(r, Type::CONTROL);
1308 Node *phi = new (C, 3) PhiNode(r, type);
1309 kit.gvn().set_type(phi, phi->bottom_type());
1310 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
1311 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
1312 Node* notnull = __ IfTrue(iff);
1313 Node* isnull = __ IfFalse(iff);
1314 kit.set_control(notnull); // set control for the cast_not_null
1315 r->init_req(1, notnull);
1316 phi->init_req(1, kit.cast_not_null(arg, false));
1317 r->init_req(2, isnull);
1318 phi->init_req(2, null_string);
1319 kit.set_control(r);
1320 C->record_for_igvn(r);
1321 C->record_for_igvn(phi);
1322 // replace the argument with the null checked version
1323 arg = phi;
1324 sc->set_argument(argi, arg);
1325 }
1327 Node* count = kit.load_String_length(kit.control(), arg);
1329 length = __ AddI(length, count);
1330 string_sizes->init_req(argi, NULL);
1331 break;
1332 }
1333 case StringConcat::CharMode: {
1334 // one character only
1335 length = __ AddI(length, __ intcon(1));
1336 break;
1337 }
1338 default:
1339 ShouldNotReachHere();
1340 }
1341 if (argi > 0) {
1342 // Check that the sum hasn't overflowed
1343 IfNode* iff = kit.create_and_map_if(kit.control(),
1344 __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
1345 PROB_MIN, COUNT_UNKNOWN);
1346 kit.set_control(__ IfFalse(iff));
1347 overflow->set_req(argi, __ IfTrue(iff));
1348 }
1349 }
1351 {
1352 // Hook
1353 PreserveJVMState pjvms(&kit);
1354 kit.set_control(overflow);
1355 C->record_for_igvn(overflow);
1356 kit.uncommon_trap(Deoptimization::Reason_intrinsic,
1357 Deoptimization::Action_make_not_entrant);
1358 }
1360 // length now contains the number of characters needed for the
1361 // char[] so create a new AllocateArray for the char[]
1362 Node* char_array = NULL;
1363 {
1364 PreserveReexecuteState preexecs(&kit);
1365 // The original jvms is for an allocation of either a String or
1366 // StringBuffer so no stack adjustment is necessary for proper
1367 // reexecution. If we deoptimize in the slow path the bytecode
1368 // will be reexecuted and the char[] allocation will be thrown away.
1369 kit.jvms()->set_should_reexecute(true);
1370 char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))),
1371 length, 1);
1372 }
1374 // Mark the allocation so that zeroing is skipped since the code
1375 // below will overwrite the entire array
1376 AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
1377 char_alloc->maybe_set_complete(_gvn);
1379 // Now copy the string representations into the final char[]
1380 Node* start = __ intcon(0);
1381 for (int argi = 0; argi < sc->num_arguments(); argi++) {
1382 Node* arg = sc->argument(argi);
1383 switch (sc->mode(argi)) {
1384 case StringConcat::IntMode: {
1385 Node* end = __ AddI(start, string_sizes->in(argi));
1386 // getChars words backwards so pass the ending point as well as the start
1387 int_getChars(kit, arg, char_array, start, end);
1388 start = end;
1389 break;
1390 }
1391 case StringConcat::StringNullCheckMode:
1392 case StringConcat::StringMode: {
1393 start = copy_string(kit, arg, char_array, start);
1394 break;
1395 }
1396 case StringConcat::CharMode: {
1397 __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
1398 arg, T_CHAR, char_adr_idx);
1399 start = __ AddI(start, __ intcon(1));
1400 break;
1401 }
1402 default:
1403 ShouldNotReachHere();
1404 }
1405 }
1407 // If we're not reusing an existing String allocation then allocate one here.
1408 Node* result = sc->string_alloc();
1409 if (result == NULL) {
1410 PreserveReexecuteState preexecs(&kit);
1411 // The original jvms is for an allocation of either a String or
1412 // StringBuffer so no stack adjustment is necessary for proper
1413 // reexecution.
1414 kit.jvms()->set_should_reexecute(true);
1415 result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
1416 }
1418 // Intialize the string
1419 if (java_lang_String::has_offset_field()) {
1420 kit.store_String_offset(kit.control(), result, __ intcon(0));
1421 kit.store_String_length(kit.control(), result, length);
1422 }
1423 kit.store_String_value(kit.control(), result, char_array);
1425 // hook up the outgoing control and result
1426 kit.replace_call(sc->end(), result);
1428 // Unhook any hook nodes
1429 string_sizes->disconnect_inputs(NULL);
1430 sc->cleanup();
1431 }