Fri, 03 Dec 2010 01:34:31 -0800
6961690: load oops from constant table on SPARC
Summary: oops should be loaded from the constant table of an nmethod instead of materializing them with a long code sequence.
Reviewed-by: never, kvn
1 /*
2 * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
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 };
65 StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
66 _end(end),
67 _begin(NULL),
68 _multiple(false),
69 _string_alloc(NULL),
70 _stringopts(stringopts) {
71 _arguments = new (_stringopts->C, 1) Node(1);
72 _arguments->del_req(0);
73 }
75 bool validate_control_flow();
77 void merge_add() {
78 #if 0
79 // XXX This is place holder code for reusing an existing String
80 // allocation but the logic for checking the state safety is
81 // probably inadequate at the moment.
82 CallProjections endprojs;
83 sc->end()->extract_projections(&endprojs, false);
84 if (endprojs.resproj != NULL) {
85 for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
86 CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
87 if (use != NULL && use->method() != NULL &&
88 use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
89 use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
90 // Found useless new String(sb.toString()) so reuse the newly allocated String
91 // when creating the result instead of allocating a new one.
92 sc->set_string_alloc(use->in(TypeFunc::Parms));
93 sc->set_end(use);
94 }
95 }
96 }
97 #endif
98 }
100 StringConcat* merge(StringConcat* other, Node* arg);
102 void set_allocation(AllocateNode* alloc) {
103 _begin = alloc;
104 }
106 void append(Node* value, int mode) {
107 _arguments->add_req(value);
108 _mode.append(mode);
109 }
110 void push(Node* value, int mode) {
111 _arguments->ins_req(0, value);
112 _mode.insert_before(0, mode);
113 }
114 void push_string(Node* value) {
115 push(value, StringMode);
116 }
117 void push_int(Node* value) {
118 push(value, IntMode);
119 }
120 void push_char(Node* value) {
121 push(value, CharMode);
122 }
124 Node* argument(int i) {
125 return _arguments->in(i);
126 }
127 void set_argument(int i, Node* value) {
128 _arguments->set_req(i, value);
129 }
130 int num_arguments() {
131 return _mode.length();
132 }
133 int mode(int i) {
134 return _mode.at(i);
135 }
136 void add_control(Node* ctrl) {
137 assert(!_control.contains(ctrl), "only push once");
138 _control.push(ctrl);
139 }
140 CallStaticJavaNode* end() { return _end; }
141 AllocateNode* begin() { return _begin; }
142 Node* string_alloc() { return _string_alloc; }
144 void eliminate_unneeded_control();
145 void eliminate_initialize(InitializeNode* init);
146 void eliminate_call(CallNode* call);
148 void maybe_log_transform() {
149 CompileLog* log = _stringopts->C->log();
150 if (log != NULL) {
151 log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
152 num_arguments(),
153 _string_alloc != NULL,
154 _multiple);
155 JVMState* p = _begin->jvms();
156 while (p != NULL) {
157 log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
158 p = p->caller();
159 }
160 log->tail("replace_string_concat");
161 }
162 }
164 void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
165 for (uint u = 0; u < _uncommon_traps.size(); u++) {
166 Node* uct = _uncommon_traps.at(u);
168 // Build a new call using the jvms state of the allocate
169 address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
170 const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
171 int size = call_type->domain()->cnt();
172 const TypePtr* no_memory_effects = NULL;
173 Compile* C = _stringopts->C;
174 CallStaticJavaNode* call = new (C, size) CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
175 jvms->bci(), no_memory_effects);
176 for (int e = 0; e < TypeFunc::Parms; e++) {
177 call->init_req(e, uct->in(e));
178 }
179 // Set the trap request to record intrinsic failure if this trap
180 // is taken too many times. Ideally we would handle then traps by
181 // doing the original bookkeeping in the MDO so that if it caused
182 // the code to be thrown out we could still recompile and use the
183 // optimization. Failing the uncommon traps doesn't really mean
184 // that the optimization is a bad idea but there's no other way to
185 // do the MDO updates currently.
186 int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
187 Deoptimization::Action_make_not_entrant);
188 call->init_req(TypeFunc::Parms, __ intcon(trap_request));
189 kit.add_safepoint_edges(call);
191 _stringopts->gvn()->transform(call);
192 C->gvn_replace_by(uct, call);
193 uct->disconnect_inputs(NULL);
194 }
195 }
197 void cleanup() {
198 // disconnect the hook node
199 _arguments->disconnect_inputs(NULL);
200 }
201 };
204 void StringConcat::eliminate_unneeded_control() {
205 eliminate_initialize(begin()->initialization());
206 for (uint i = 0; i < _control.size(); i++) {
207 Node* n = _control.at(i);
208 if (n->is_Call()) {
209 if (n != _end) {
210 eliminate_call(n->as_Call());
211 }
212 } else if (n->is_IfTrue()) {
213 Compile* C = _stringopts->C;
214 C->gvn_replace_by(n, n->in(0)->in(0));
215 C->gvn_replace_by(n->in(0), C->top());
216 }
217 }
218 }
221 StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
222 StringConcat* result = new StringConcat(_stringopts, _end);
223 for (uint x = 0; x < _control.size(); x++) {
224 Node* n = _control.at(x);
225 if (n->is_Call()) {
226 result->_control.push(n);
227 }
228 }
229 for (uint x = 0; x < other->_control.size(); x++) {
230 Node* n = other->_control.at(x);
231 if (n->is_Call()) {
232 result->_control.push(n);
233 }
234 }
235 assert(result->_control.contains(other->_end), "what?");
236 assert(result->_control.contains(_begin), "what?");
237 for (int x = 0; x < num_arguments(); x++) {
238 if (argument(x) == arg) {
239 // replace the toString result with the all the arguments that
240 // made up the other StringConcat
241 for (int y = 0; y < other->num_arguments(); y++) {
242 result->append(other->argument(y), other->mode(y));
243 }
244 } else {
245 result->append(argument(x), mode(x));
246 }
247 }
248 result->set_allocation(other->_begin);
249 result->_multiple = true;
250 return result;
251 }
254 void StringConcat::eliminate_call(CallNode* call) {
255 Compile* C = _stringopts->C;
256 CallProjections projs;
257 call->extract_projections(&projs, false);
258 if (projs.fallthrough_catchproj != NULL) {
259 C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
260 }
261 if (projs.fallthrough_memproj != NULL) {
262 C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
263 }
264 if (projs.catchall_memproj != NULL) {
265 C->gvn_replace_by(projs.catchall_memproj, C->top());
266 }
267 if (projs.fallthrough_ioproj != NULL) {
268 C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
269 }
270 if (projs.catchall_ioproj != NULL) {
271 C->gvn_replace_by(projs.catchall_ioproj, C->top());
272 }
273 if (projs.catchall_catchproj != NULL) {
274 // EA can't cope with the partially collapsed graph this
275 // creates so put it on the worklist to be collapsed later.
276 for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
277 Node *use = i.get();
278 int opc = use->Opcode();
279 if (opc == Op_CreateEx || opc == Op_Region) {
280 _stringopts->record_dead_node(use);
281 }
282 }
283 C->gvn_replace_by(projs.catchall_catchproj, C->top());
284 }
285 if (projs.resproj != NULL) {
286 C->gvn_replace_by(projs.resproj, C->top());
287 }
288 C->gvn_replace_by(call, C->top());
289 }
291 void StringConcat::eliminate_initialize(InitializeNode* init) {
292 Compile* C = _stringopts->C;
294 // Eliminate Initialize node.
295 assert(init->outcnt() <= 2, "only a control and memory projection expected");
296 assert(init->req() <= InitializeNode::RawStores, "no pending inits");
297 Node *ctrl_proj = init->proj_out(TypeFunc::Control);
298 if (ctrl_proj != NULL) {
299 C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
300 }
301 Node *mem_proj = init->proj_out(TypeFunc::Memory);
302 if (mem_proj != NULL) {
303 Node *mem = init->in(TypeFunc::Memory);
304 C->gvn_replace_by(mem_proj, mem);
305 }
306 C->gvn_replace_by(init, C->top());
307 init->disconnect_inputs(NULL);
308 }
310 Node_List PhaseStringOpts::collect_toString_calls() {
311 Node_List string_calls;
312 Node_List worklist;
314 _visited.Clear();
316 // Prime the worklist
317 for (uint i = 1; i < C->root()->len(); i++) {
318 Node* n = C->root()->in(i);
319 if (n != NULL && !_visited.test_set(n->_idx)) {
320 worklist.push(n);
321 }
322 }
324 while (worklist.size() > 0) {
325 Node* ctrl = worklist.pop();
326 if (ctrl->is_CallStaticJava()) {
327 CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
328 ciMethod* m = csj->method();
329 if (m != NULL &&
330 (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
331 m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString)) {
332 string_calls.push(csj);
333 }
334 }
335 if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
336 worklist.push(ctrl->in(0));
337 }
338 if (ctrl->is_Region()) {
339 for (uint i = 1; i < ctrl->len(); i++) {
340 if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
341 worklist.push(ctrl->in(i));
342 }
343 }
344 }
345 }
346 return string_calls;
347 }
350 StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
351 ciMethod* m = call->method();
352 ciSymbol* string_sig;
353 ciSymbol* int_sig;
354 ciSymbol* char_sig;
355 if (m->holder() == C->env()->StringBuilder_klass()) {
356 string_sig = ciSymbol::String_StringBuilder_signature();
357 int_sig = ciSymbol::int_StringBuilder_signature();
358 char_sig = ciSymbol::char_StringBuilder_signature();
359 } else if (m->holder() == C->env()->StringBuffer_klass()) {
360 string_sig = ciSymbol::String_StringBuffer_signature();
361 int_sig = ciSymbol::int_StringBuffer_signature();
362 char_sig = ciSymbol::char_StringBuffer_signature();
363 } else {
364 return NULL;
365 }
366 #ifndef PRODUCT
367 if (PrintOptimizeStringConcat) {
368 tty->print("considering toString call in ");
369 call->jvms()->dump_spec(tty); tty->cr();
370 }
371 #endif
373 StringConcat* sc = new StringConcat(this, call);
375 AllocateNode* alloc = NULL;
376 InitializeNode* init = NULL;
378 // possible opportunity for StringBuilder fusion
379 CallStaticJavaNode* cnode = call;
380 while (cnode) {
381 Node* recv = cnode->in(TypeFunc::Parms)->uncast();
382 if (recv->is_Proj()) {
383 recv = recv->in(0);
384 }
385 cnode = recv->isa_CallStaticJava();
386 if (cnode == NULL) {
387 alloc = recv->isa_Allocate();
388 if (alloc == NULL) {
389 break;
390 }
391 // Find the constructor call
392 Node* result = alloc->result_cast();
393 if (result == NULL || !result->is_CheckCastPP()) {
394 // strange looking allocation
395 #ifndef PRODUCT
396 if (PrintOptimizeStringConcat) {
397 tty->print("giving up because allocation looks strange ");
398 alloc->jvms()->dump_spec(tty); tty->cr();
399 }
400 #endif
401 break;
402 }
403 Node* constructor = NULL;
404 for (SimpleDUIterator i(result); i.has_next(); i.next()) {
405 CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
406 if (use != NULL &&
407 use->method() != NULL &&
408 !use->method()->is_static() &&
409 use->method()->name() == ciSymbol::object_initializer_name() &&
410 use->method()->holder() == m->holder()) {
411 // Matched the constructor.
412 ciSymbol* sig = use->method()->signature()->as_symbol();
413 if (sig == ciSymbol::void_method_signature() ||
414 sig == ciSymbol::int_void_signature() ||
415 sig == ciSymbol::string_void_signature()) {
416 if (sig == ciSymbol::string_void_signature()) {
417 // StringBuilder(String) so pick this up as the first argument
418 assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
419 sc->push_string(use->in(TypeFunc::Parms + 1));
420 }
421 // The int variant takes an initial size for the backing
422 // array so just treat it like the void version.
423 constructor = use;
424 } else {
425 #ifndef PRODUCT
426 if (PrintOptimizeStringConcat) {
427 tty->print("unexpected constructor signature: %s", sig->as_utf8());
428 }
429 #endif
430 }
431 break;
432 }
433 }
434 if (constructor == NULL) {
435 // couldn't find constructor
436 #ifndef PRODUCT
437 if (PrintOptimizeStringConcat) {
438 tty->print("giving up because couldn't find constructor ");
439 alloc->jvms()->dump_spec(tty);
440 }
441 #endif
442 break;
443 }
445 // Walked all the way back and found the constructor call so see
446 // if this call converted into a direct string concatenation.
447 sc->add_control(call);
448 sc->add_control(constructor);
449 sc->add_control(alloc);
450 sc->set_allocation(alloc);
451 if (sc->validate_control_flow()) {
452 return sc;
453 } else {
454 return NULL;
455 }
456 } else if (cnode->method() == NULL) {
457 break;
458 } else if (!cnode->method()->is_static() &&
459 cnode->method()->holder() == m->holder() &&
460 cnode->method()->name() == ciSymbol::append_name() &&
461 (cnode->method()->signature()->as_symbol() == string_sig ||
462 cnode->method()->signature()->as_symbol() == char_sig ||
463 cnode->method()->signature()->as_symbol() == int_sig)) {
464 sc->add_control(cnode);
465 Node* arg = cnode->in(TypeFunc::Parms + 1);
466 if (cnode->method()->signature()->as_symbol() == int_sig) {
467 sc->push_int(arg);
468 } else if (cnode->method()->signature()->as_symbol() == char_sig) {
469 sc->push_char(arg);
470 } else {
471 if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
472 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
473 if (csj->method() != NULL &&
474 csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString) {
475 sc->add_control(csj);
476 sc->push_int(csj->in(TypeFunc::Parms));
477 continue;
478 }
479 }
480 sc->push_string(arg);
481 }
482 continue;
483 } else {
484 // some unhandled signature
485 #ifndef PRODUCT
486 if (PrintOptimizeStringConcat) {
487 tty->print("giving up because encountered unexpected signature ");
488 cnode->tf()->dump(); tty->cr();
489 cnode->in(TypeFunc::Parms + 1)->dump();
490 }
491 #endif
492 break;
493 }
494 }
495 return NULL;
496 }
499 PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
500 Phase(StringOpts),
501 _gvn(gvn),
502 _visited(Thread::current()->resource_area()) {
504 assert(OptimizeStringConcat, "shouldn't be here");
506 size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
507 ciSymbol::make("[I"), true);
508 if (size_table_field == NULL) {
509 // Something wrong so give up.
510 assert(false, "why can't we find Integer.sizeTable?");
511 return;
512 }
514 // Collect the types needed to talk about the various slices of memory
515 const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
516 false, NULL, 0);
518 const TypePtr* value_field_type = string_type->add_offset(java_lang_String::value_offset_in_bytes());
519 const TypePtr* offset_field_type = string_type->add_offset(java_lang_String::offset_offset_in_bytes());
520 const TypePtr* count_field_type = string_type->add_offset(java_lang_String::count_offset_in_bytes());
522 value_field_idx = C->get_alias_index(value_field_type);
523 count_field_idx = C->get_alias_index(count_field_type);
524 offset_field_idx = C->get_alias_index(offset_field_type);
525 char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS);
527 // For each locally allocated StringBuffer see if the usages can be
528 // collapsed into a single String construction.
530 // Run through the list of allocation looking for SB.toString to see
531 // if it's possible to fuse the usage of the SB into a single String
532 // construction.
533 GrowableArray<StringConcat*> concats;
534 Node_List toStrings = collect_toString_calls();
535 while (toStrings.size() > 0) {
536 StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
537 if (sc != NULL) {
538 concats.push(sc);
539 }
540 }
542 // try to coalesce separate concats
543 restart:
544 for (int c = 0; c < concats.length(); c++) {
545 StringConcat* sc = concats.at(c);
546 for (int i = 0; i < sc->num_arguments(); i++) {
547 Node* arg = sc->argument(i);
548 if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
549 CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
550 if (csj->method() != NULL &&
551 (csj->method()->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
552 csj->method()->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
553 for (int o = 0; o < concats.length(); o++) {
554 if (c == o) continue;
555 StringConcat* other = concats.at(o);
556 if (other->end() == csj) {
557 #ifndef PRODUCT
558 if (PrintOptimizeStringConcat) {
559 tty->print_cr("considering stacked concats");
560 }
561 #endif
563 StringConcat* merged = sc->merge(other, arg);
564 if (merged->validate_control_flow()) {
565 #ifndef PRODUCT
566 if (PrintOptimizeStringConcat) {
567 tty->print_cr("stacking would succeed");
568 }
569 #endif
570 if (c < o) {
571 concats.remove_at(o);
572 concats.at_put(c, merged);
573 } else {
574 concats.remove_at(c);
575 concats.at_put(o, merged);
576 }
577 goto restart;
578 } else {
579 #ifndef PRODUCT
580 if (PrintOptimizeStringConcat) {
581 tty->print_cr("stacking would fail");
582 }
583 #endif
584 }
585 }
586 }
587 }
588 }
589 }
590 }
593 for (int c = 0; c < concats.length(); c++) {
594 StringConcat* sc = concats.at(c);
595 replace_string_concat(sc);
596 }
598 remove_dead_nodes();
599 }
601 void PhaseStringOpts::record_dead_node(Node* dead) {
602 dead_worklist.push(dead);
603 }
605 void PhaseStringOpts::remove_dead_nodes() {
606 // Delete any dead nodes to make things clean enough that escape
607 // analysis doesn't get unhappy.
608 while (dead_worklist.size() > 0) {
609 Node* use = dead_worklist.pop();
610 int opc = use->Opcode();
611 switch (opc) {
612 case Op_Region: {
613 uint i = 1;
614 for (i = 1; i < use->req(); i++) {
615 if (use->in(i) != C->top()) {
616 break;
617 }
618 }
619 if (i >= use->req()) {
620 for (SimpleDUIterator i(use); i.has_next(); i.next()) {
621 Node* m = i.get();
622 if (m->is_Phi()) {
623 dead_worklist.push(m);
624 }
625 }
626 C->gvn_replace_by(use, C->top());
627 }
628 break;
629 }
630 case Op_AddP:
631 case Op_CreateEx: {
632 // Recurisvely clean up references to CreateEx so EA doesn't
633 // get unhappy about the partially collapsed graph.
634 for (SimpleDUIterator i(use); i.has_next(); i.next()) {
635 Node* m = i.get();
636 if (m->is_AddP()) {
637 dead_worklist.push(m);
638 }
639 }
640 C->gvn_replace_by(use, C->top());
641 break;
642 }
643 case Op_Phi:
644 if (use->in(0) == C->top()) {
645 C->gvn_replace_by(use, C->top());
646 }
647 break;
648 }
649 }
650 }
653 bool StringConcat::validate_control_flow() {
654 // We found all the calls and arguments now lets see if it's
655 // safe to transform the graph as we would expect.
657 // Check to see if this resulted in too many uncommon traps previously
658 if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
659 Deoptimization::Reason_intrinsic)) {
660 return false;
661 }
663 // Walk backwards over the control flow from toString to the
664 // allocation and make sure all the control flow is ok. This
665 // means it's either going to be eliminated once the calls are
666 // removed or it can safely be transformed into an uncommon
667 // trap.
669 int null_check_count = 0;
670 Unique_Node_List ctrl_path;
672 assert(_control.contains(_begin), "missing");
673 assert(_control.contains(_end), "missing");
675 // Collect the nodes that we know about and will eliminate into ctrl_path
676 for (uint i = 0; i < _control.size(); i++) {
677 // Push the call and it's control projection
678 Node* n = _control.at(i);
679 if (n->is_Allocate()) {
680 AllocateNode* an = n->as_Allocate();
681 InitializeNode* init = an->initialization();
682 ctrl_path.push(init);
683 ctrl_path.push(init->as_Multi()->proj_out(0));
684 }
685 if (n->is_Call()) {
686 CallNode* cn = n->as_Call();
687 ctrl_path.push(cn);
688 ctrl_path.push(cn->proj_out(0));
689 ctrl_path.push(cn->proj_out(0)->unique_out());
690 ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0));
691 } else {
692 ShouldNotReachHere();
693 }
694 }
696 // Skip backwards through the control checking for unexpected contro flow
697 Node* ptr = _end;
698 bool fail = false;
699 while (ptr != _begin) {
700 if (ptr->is_Call() && ctrl_path.member(ptr)) {
701 ptr = ptr->in(0);
702 } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
703 ptr = ptr->in(0)->in(0)->in(0);
704 assert(ctrl_path.member(ptr), "should be a known piece of control");
705 } else if (ptr->is_IfTrue()) {
706 IfNode* iff = ptr->in(0)->as_If();
707 BoolNode* b = iff->in(1)->isa_Bool();
708 Node* cmp = b->in(1);
709 Node* v1 = cmp->in(1);
710 Node* v2 = cmp->in(2);
711 Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
713 // Null check of the return of append which can simply be eliminated
714 if (b->_test._test == BoolTest::ne &&
715 v2->bottom_type() == TypePtr::NULL_PTR &&
716 v1->is_Proj() && ctrl_path.member(v1->in(0))) {
717 // NULL check of the return value of the append
718 null_check_count++;
719 if (otherproj->outcnt() == 1) {
720 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
721 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
722 ctrl_path.push(call);
723 }
724 }
725 _control.push(ptr);
726 ptr = ptr->in(0)->in(0);
727 continue;
728 }
730 // A test which leads to an uncommon trap which should be safe.
731 // Later this trap will be converted into a trap that restarts
732 // at the beginning.
733 if (otherproj->outcnt() == 1) {
734 CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
735 if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
736 // control flow leads to uct so should be ok
737 _uncommon_traps.push(call);
738 ctrl_path.push(call);
739 ptr = ptr->in(0)->in(0);
740 continue;
741 }
742 }
744 #ifndef PRODUCT
745 // Some unexpected control flow we don't know how to handle.
746 if (PrintOptimizeStringConcat) {
747 tty->print_cr("failing with unknown test");
748 b->dump();
749 cmp->dump();
750 v1->dump();
751 v2->dump();
752 tty->cr();
753 }
754 #endif
755 break;
756 } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
757 ptr = ptr->in(0)->in(0);
758 } else if (ptr->is_Region()) {
759 Node* copy = ptr->as_Region()->is_copy();
760 if (copy != NULL) {
761 ptr = copy;
762 continue;
763 }
764 if (ptr->req() == 3 &&
765 ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
766 ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
767 ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
768 ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
769 // Simple diamond.
770 // XXX should check for possibly merging stores. simple data merges are ok.
771 ptr = ptr->in(1)->in(0)->in(0);
772 continue;
773 }
774 #ifndef PRODUCT
775 if (PrintOptimizeStringConcat) {
776 tty->print_cr("fusion would fail for region");
777 _begin->dump();
778 ptr->dump(2);
779 }
780 #endif
781 fail = true;
782 break;
783 } else {
784 // other unknown control
785 if (!fail) {
786 #ifndef PRODUCT
787 if (PrintOptimizeStringConcat) {
788 tty->print_cr("fusion would fail for");
789 _begin->dump();
790 }
791 #endif
792 fail = true;
793 }
794 #ifndef PRODUCT
795 if (PrintOptimizeStringConcat) {
796 ptr->dump();
797 }
798 #endif
799 ptr = ptr->in(0);
800 }
801 }
802 #ifndef PRODUCT
803 if (PrintOptimizeStringConcat && fail) {
804 tty->cr();
805 }
806 #endif
807 if (fail) return !fail;
809 // Validate that all these results produced are contained within
810 // this cluster of objects. First collect all the results produced
811 // by calls in the region.
812 _stringopts->_visited.Clear();
813 Node_List worklist;
814 Node* final_result = _end->proj_out(TypeFunc::Parms);
815 for (uint i = 0; i < _control.size(); i++) {
816 CallNode* cnode = _control.at(i)->isa_Call();
817 if (cnode != NULL) {
818 _stringopts->_visited.test_set(cnode->_idx);
819 }
820 Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL;
821 if (result != NULL && result != final_result) {
822 worklist.push(result);
823 }
824 }
826 Node* last_result = NULL;
827 while (worklist.size() > 0) {
828 Node* result = worklist.pop();
829 if (_stringopts->_visited.test_set(result->_idx))
830 continue;
831 for (SimpleDUIterator i(result); i.has_next(); i.next()) {
832 Node *use = i.get();
833 if (ctrl_path.member(use)) {
834 // already checked this
835 continue;
836 }
837 int opc = use->Opcode();
838 if (opc == Op_CmpP || opc == Op_Node) {
839 ctrl_path.push(use);
840 continue;
841 }
842 if (opc == Op_CastPP || opc == Op_CheckCastPP) {
843 for (SimpleDUIterator j(use); j.has_next(); j.next()) {
844 worklist.push(j.get());
845 }
846 worklist.push(use->in(1));
847 ctrl_path.push(use);
848 continue;
849 }
850 #ifndef PRODUCT
851 if (PrintOptimizeStringConcat) {
852 if (result != last_result) {
853 last_result = result;
854 tty->print_cr("extra uses for result:");
855 last_result->dump();
856 }
857 use->dump();
858 }
859 #endif
860 fail = true;
861 break;
862 }
863 }
865 #ifndef PRODUCT
866 if (PrintOptimizeStringConcat && !fail) {
867 ttyLocker ttyl;
868 tty->cr();
869 tty->print("fusion would succeed (%d %d) for ", null_check_count, _uncommon_traps.size());
870 _begin->jvms()->dump_spec(tty); tty->cr();
871 for (int i = 0; i < num_arguments(); i++) {
872 argument(i)->dump();
873 }
874 _control.dump();
875 tty->cr();
876 }
877 #endif
879 return !fail;
880 }
882 Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
883 const TypeKlassPtr* klass_type = TypeKlassPtr::make(field->holder());
884 Node* klass_node = __ makecon(klass_type);
885 BasicType bt = field->layout_type();
886 ciType* field_klass = field->type();
888 const Type *type;
889 if( bt == T_OBJECT ) {
890 if (!field->type()->is_loaded()) {
891 type = TypeInstPtr::BOTTOM;
892 } else if (field->is_constant()) {
893 // This can happen if the constant oop is non-perm.
894 ciObject* con = field->constant_value().as_object();
895 // Do not "join" in the previous type; it doesn't add value,
896 // and may yield a vacuous result if the field is of interface type.
897 type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
898 assert(type != NULL, "field singleton type must be consistent");
899 } else {
900 type = TypeOopPtr::make_from_klass(field_klass->as_klass());
901 }
902 } else {
903 type = Type::get_const_basic_type(bt);
904 }
906 return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
907 type, T_OBJECT,
908 C->get_alias_index(klass_type->add_offset(field->offset_in_bytes())));
909 }
911 Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
912 RegionNode *final_merge = new (C, 3) RegionNode(3);
913 kit.gvn().set_type(final_merge, Type::CONTROL);
914 Node* final_size = new (C, 3) PhiNode(final_merge, TypeInt::INT);
915 kit.gvn().set_type(final_size, TypeInt::INT);
917 IfNode* iff = kit.create_and_map_if(kit.control(),
918 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
919 PROB_FAIR, COUNT_UNKNOWN);
920 Node* is_min = __ IfFalse(iff);
921 final_merge->init_req(1, is_min);
922 final_size->init_req(1, __ intcon(11));
924 kit.set_control(__ IfTrue(iff));
925 if (kit.stopped()) {
926 final_merge->init_req(2, C->top());
927 final_size->init_req(2, C->top());
928 } else {
930 // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
931 RegionNode *r = new (C, 3) RegionNode(3);
932 kit.gvn().set_type(r, Type::CONTROL);
933 Node *phi = new (C, 3) PhiNode(r, TypeInt::INT);
934 kit.gvn().set_type(phi, TypeInt::INT);
935 Node *size = new (C, 3) PhiNode(r, TypeInt::INT);
936 kit.gvn().set_type(size, TypeInt::INT);
937 Node* chk = __ CmpI(arg, __ intcon(0));
938 Node* p = __ Bool(chk, BoolTest::lt);
939 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
940 Node* lessthan = __ IfTrue(iff);
941 Node* greaterequal = __ IfFalse(iff);
942 r->init_req(1, lessthan);
943 phi->init_req(1, __ SubI(__ intcon(0), arg));
944 size->init_req(1, __ intcon(1));
945 r->init_req(2, greaterequal);
946 phi->init_req(2, arg);
947 size->init_req(2, __ intcon(0));
948 kit.set_control(r);
949 C->record_for_igvn(r);
950 C->record_for_igvn(phi);
951 C->record_for_igvn(size);
953 // for (int i=0; ; i++)
954 // if (x <= sizeTable[i])
955 // return i+1;
956 RegionNode *loop = new (C, 3) RegionNode(3);
957 loop->init_req(1, kit.control());
958 kit.gvn().set_type(loop, Type::CONTROL);
960 Node *index = new (C, 3) PhiNode(loop, TypeInt::INT);
961 index->init_req(1, __ intcon(0));
962 kit.gvn().set_type(index, TypeInt::INT);
963 kit.set_control(loop);
964 Node* sizeTable = fetch_static_field(kit, size_table_field);
966 Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
967 C->record_for_igvn(value);
968 Node* limit = __ CmpI(phi, value);
969 Node* limitb = __ Bool(limit, BoolTest::le);
970 IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
971 Node* lessEqual = __ IfTrue(iff2);
972 Node* greater = __ IfFalse(iff2);
974 loop->init_req(2, greater);
975 index->init_req(2, __ AddI(index, __ intcon(1)));
977 kit.set_control(lessEqual);
978 C->record_for_igvn(loop);
979 C->record_for_igvn(index);
981 final_merge->init_req(2, kit.control());
982 final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
983 }
985 kit.set_control(final_merge);
986 C->record_for_igvn(final_merge);
987 C->record_for_igvn(final_size);
989 return final_size;
990 }
992 void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) {
993 RegionNode *final_merge = new (C, 4) RegionNode(4);
994 kit.gvn().set_type(final_merge, Type::CONTROL);
995 Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
996 kit.gvn().set_type(final_mem, Type::MEMORY);
998 // need to handle Integer.MIN_VALUE specially because negating doesn't make it positive
999 {
1000 // i == MIN_VALUE
1001 IfNode* iff = kit.create_and_map_if(kit.control(),
1002 __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
1003 PROB_FAIR, COUNT_UNKNOWN);
1005 Node* old_mem = kit.memory(char_adr_idx);
1007 kit.set_control(__ IfFalse(iff));
1008 if (kit.stopped()) {
1009 // Statically not equal to MIN_VALUE so this path is dead
1010 final_merge->init_req(3, kit.control());
1011 } else {
1012 copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
1013 char_array, start);
1014 final_merge->init_req(3, kit.control());
1015 final_mem->init_req(3, kit.memory(char_adr_idx));
1016 }
1018 kit.set_control(__ IfTrue(iff));
1019 kit.set_memory(old_mem, char_adr_idx);
1020 }
1023 // Simplified version of Integer.getChars
1025 // int q, r;
1026 // int charPos = index;
1027 Node* charPos = end;
1029 // char sign = 0;
1031 Node* i = arg;
1032 Node* sign = __ intcon(0);
1034 // if (i < 0) {
1035 // sign = '-';
1036 // i = -i;
1037 // }
1038 {
1039 IfNode* iff = kit.create_and_map_if(kit.control(),
1040 __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
1041 PROB_FAIR, COUNT_UNKNOWN);
1043 RegionNode *merge = new (C, 3) RegionNode(3);
1044 kit.gvn().set_type(merge, Type::CONTROL);
1045 i = new (C, 3) PhiNode(merge, TypeInt::INT);
1046 kit.gvn().set_type(i, TypeInt::INT);
1047 sign = new (C, 3) PhiNode(merge, TypeInt::INT);
1048 kit.gvn().set_type(sign, TypeInt::INT);
1050 merge->init_req(1, __ IfTrue(iff));
1051 i->init_req(1, __ SubI(__ intcon(0), arg));
1052 sign->init_req(1, __ intcon('-'));
1053 merge->init_req(2, __ IfFalse(iff));
1054 i->init_req(2, arg);
1055 sign->init_req(2, __ intcon(0));
1057 kit.set_control(merge);
1059 C->record_for_igvn(merge);
1060 C->record_for_igvn(i);
1061 C->record_for_igvn(sign);
1062 }
1064 // for (;;) {
1065 // q = i / 10;
1066 // r = i - ((q << 3) + (q << 1)); // r = i-(q*10) ...
1067 // buf [--charPos] = digits [r];
1068 // i = q;
1069 // if (i == 0) break;
1070 // }
1072 {
1073 RegionNode *head = new (C, 3) RegionNode(3);
1074 head->init_req(1, kit.control());
1075 kit.gvn().set_type(head, Type::CONTROL);
1076 Node *i_phi = new (C, 3) PhiNode(head, TypeInt::INT);
1077 i_phi->init_req(1, i);
1078 kit.gvn().set_type(i_phi, TypeInt::INT);
1079 charPos = PhiNode::make(head, charPos);
1080 kit.gvn().set_type(charPos, TypeInt::INT);
1081 Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
1082 kit.gvn().set_type(mem, Type::MEMORY);
1083 kit.set_control(head);
1084 kit.set_memory(mem, char_adr_idx);
1086 Node* q = __ DivI(NULL, i_phi, __ intcon(10));
1087 Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
1088 __ LShiftI(q, __ intcon(1))));
1089 Node* m1 = __ SubI(charPos, __ intcon(1));
1090 Node* ch = __ AddI(r, __ intcon('0'));
1092 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
1093 ch, T_CHAR, char_adr_idx);
1096 IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
1097 PROB_FAIR, COUNT_UNKNOWN);
1098 Node* ne = __ IfTrue(iff);
1099 Node* eq = __ IfFalse(iff);
1101 head->init_req(2, ne);
1102 mem->init_req(2, st);
1103 i_phi->init_req(2, q);
1104 charPos->init_req(2, m1);
1106 charPos = m1;
1108 kit.set_control(eq);
1109 kit.set_memory(st, char_adr_idx);
1111 C->record_for_igvn(head);
1112 C->record_for_igvn(mem);
1113 C->record_for_igvn(i_phi);
1114 C->record_for_igvn(charPos);
1115 }
1117 {
1118 // if (sign != 0) {
1119 // buf [--charPos] = sign;
1120 // }
1121 IfNode* iff = kit.create_and_map_if(kit.control(),
1122 __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
1123 PROB_FAIR, COUNT_UNKNOWN);
1125 final_merge->init_req(2, __ IfFalse(iff));
1126 final_mem->init_req(2, kit.memory(char_adr_idx));
1128 kit.set_control(__ IfTrue(iff));
1129 if (kit.stopped()) {
1130 final_merge->init_req(1, C->top());
1131 final_mem->init_req(1, C->top());
1132 } else {
1133 Node* m1 = __ SubI(charPos, __ intcon(1));
1134 Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
1135 sign, T_CHAR, char_adr_idx);
1137 final_merge->init_req(1, kit.control());
1138 final_mem->init_req(1, st);
1139 }
1141 kit.set_control(final_merge);
1142 kit.set_memory(final_mem, char_adr_idx);
1144 C->record_for_igvn(final_merge);
1145 C->record_for_igvn(final_mem);
1146 }
1147 }
1150 Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) {
1151 Node* string = str;
1152 Node* offset = kit.make_load(NULL,
1153 kit.basic_plus_adr(string, string, java_lang_String::offset_offset_in_bytes()),
1154 TypeInt::INT, T_INT, offset_field_idx);
1155 Node* count = kit.make_load(NULL,
1156 kit.basic_plus_adr(string, string, java_lang_String::count_offset_in_bytes()),
1157 TypeInt::INT, T_INT, count_field_idx);
1158 const TypeAryPtr* value_type = TypeAryPtr::make(TypePtr::NotNull,
1159 TypeAry::make(TypeInt::CHAR,TypeInt::POS),
1160 ciTypeArrayKlass::make(T_CHAR), true, 0);
1161 Node* value = kit.make_load(NULL,
1162 kit.basic_plus_adr(string, string, java_lang_String::value_offset_in_bytes()),
1163 value_type, T_OBJECT, value_field_idx);
1165 // copy the contents
1166 if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) {
1167 // For small constant strings just emit individual stores.
1168 // A length of 6 seems like a good space/speed tradeof.
1169 int c = count->get_int();
1170 int o = offset->get_int();
1171 const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr();
1172 ciTypeArray* value_array = t->const_oop()->as_type_array();
1173 for (int e = 0; e < c; e++) {
1174 __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
1175 __ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx);
1176 start = __ AddI(start, __ intcon(1));
1177 }
1178 } else {
1179 Node* src_ptr = kit.array_element_address(value, offset, T_CHAR);
1180 Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR);
1181 Node* c = count;
1182 Node* extra = NULL;
1183 #ifdef _LP64
1184 c = __ ConvI2L(c);
1185 extra = C->top();
1186 #endif
1187 Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP,
1188 OptoRuntime::fast_arraycopy_Type(),
1189 CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()),
1190 "jshort_disjoint_arraycopy", TypeAryPtr::CHARS,
1191 src_ptr, dst_ptr, c, extra);
1192 start = __ AddI(start, count);
1193 }
1194 return start;
1195 }
1198 void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
1199 // Log a little info about the transformation
1200 sc->maybe_log_transform();
1202 // pull the JVMState of the allocation into a SafePointNode to serve as
1203 // as a shim for the insertion of the new code.
1204 JVMState* jvms = sc->begin()->jvms()->clone_shallow(C);
1205 uint size = sc->begin()->req();
1206 SafePointNode* map = new (C, size) SafePointNode(size, jvms);
1208 // copy the control and memory state from the final call into our
1209 // new starting state. This allows any preceeding tests to feed
1210 // into the new section of code.
1211 for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
1212 map->init_req(i1, sc->end()->in(i1));
1213 }
1214 // blow away old allocation arguments
1215 for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
1216 map->init_req(i1, C->top());
1217 }
1218 // Copy the rest of the inputs for the JVMState
1219 for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
1220 map->init_req(i1, sc->begin()->in(i1));
1221 }
1222 // Make sure the memory state is a MergeMem for parsing.
1223 if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
1224 map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
1225 }
1227 jvms->set_map(map);
1228 map->ensure_stack(jvms, jvms->method()->max_stack());
1231 // disconnect all the old StringBuilder calls from the graph
1232 sc->eliminate_unneeded_control();
1234 // At this point all the old work has been completely removed from
1235 // the graph and the saved JVMState exists at the point where the
1236 // final toString call used to be.
1237 GraphKit kit(jvms);
1239 // There may be uncommon traps which are still using the
1240 // intermediate states and these need to be rewritten to point at
1241 // the JVMState at the beginning of the transformation.
1242 sc->convert_uncommon_traps(kit, jvms);
1244 // Now insert the logic to compute the size of the string followed
1245 // by all the logic to construct array and resulting string.
1247 Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
1249 // Create a region for the overflow checks to merge into.
1250 int args = MAX2(sc->num_arguments(), 1);
1251 RegionNode* overflow = new (C, args) RegionNode(args);
1252 kit.gvn().set_type(overflow, Type::CONTROL);
1254 // Create a hook node to hold onto the individual sizes since they
1255 // are need for the copying phase.
1256 Node* string_sizes = new (C, args) Node(args);
1258 Node* length = __ intcon(0);
1259 for (int argi = 0; argi < sc->num_arguments(); argi++) {
1260 Node* arg = sc->argument(argi);
1261 switch (sc->mode(argi)) {
1262 case StringConcat::IntMode: {
1263 Node* string_size = int_stringSize(kit, arg);
1265 // accumulate total
1266 length = __ AddI(length, string_size);
1268 // Cache this value for the use by int_toString
1269 string_sizes->init_req(argi, string_size);
1270 break;
1271 }
1272 case StringConcat::StringMode: {
1273 const Type* type = kit.gvn().type(arg);
1274 if (type == TypePtr::NULL_PTR) {
1275 // replace the argument with the null checked version
1276 arg = null_string;
1277 sc->set_argument(argi, arg);
1278 } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
1279 // s = s != null ? s : "null";
1280 // length = length + (s.count - s.offset);
1281 RegionNode *r = new (C, 3) RegionNode(3);
1282 kit.gvn().set_type(r, Type::CONTROL);
1283 Node *phi = new (C, 3) PhiNode(r, type);
1284 kit.gvn().set_type(phi, phi->bottom_type());
1285 Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
1286 IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
1287 Node* notnull = __ IfTrue(iff);
1288 Node* isnull = __ IfFalse(iff);
1289 kit.set_control(notnull); // set control for the cast_not_null
1290 r->init_req(1, notnull);
1291 phi->init_req(1, kit.cast_not_null(arg, false));
1292 r->init_req(2, isnull);
1293 phi->init_req(2, null_string);
1294 kit.set_control(r);
1295 C->record_for_igvn(r);
1296 C->record_for_igvn(phi);
1297 // replace the argument with the null checked version
1298 arg = phi;
1299 sc->set_argument(argi, arg);
1300 }
1301 // Node* offset = kit.make_load(NULL, kit.basic_plus_adr(arg, arg, offset_offset),
1302 // TypeInt::INT, T_INT, offset_field_idx);
1303 Node* count = kit.make_load(NULL, kit.basic_plus_adr(arg, arg, java_lang_String::count_offset_in_bytes()),
1304 TypeInt::INT, T_INT, count_field_idx);
1305 length = __ AddI(length, count);
1306 string_sizes->init_req(argi, NULL);
1307 break;
1308 }
1309 case StringConcat::CharMode: {
1310 // one character only
1311 length = __ AddI(length, __ intcon(1));
1312 break;
1313 }
1314 default:
1315 ShouldNotReachHere();
1316 }
1317 if (argi > 0) {
1318 // Check that the sum hasn't overflowed
1319 IfNode* iff = kit.create_and_map_if(kit.control(),
1320 __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
1321 PROB_MIN, COUNT_UNKNOWN);
1322 kit.set_control(__ IfFalse(iff));
1323 overflow->set_req(argi, __ IfTrue(iff));
1324 }
1325 }
1327 {
1328 // Hook
1329 PreserveJVMState pjvms(&kit);
1330 kit.set_control(overflow);
1331 kit.uncommon_trap(Deoptimization::Reason_intrinsic,
1332 Deoptimization::Action_make_not_entrant);
1333 }
1335 // length now contains the number of characters needed for the
1336 // char[] so create a new AllocateArray for the char[]
1337 Node* char_array = NULL;
1338 {
1339 PreserveReexecuteState preexecs(&kit);
1340 // The original jvms is for an allocation of either a String or
1341 // StringBuffer so no stack adjustment is necessary for proper
1342 // reexecution. If we deoptimize in the slow path the bytecode
1343 // will be reexecuted and the char[] allocation will be thrown away.
1344 kit.jvms()->set_should_reexecute(true);
1345 char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))),
1346 length, 1);
1347 }
1349 // Mark the allocation so that zeroing is skipped since the code
1350 // below will overwrite the entire array
1351 AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
1352 char_alloc->maybe_set_complete(_gvn);
1354 // Now copy the string representations into the final char[]
1355 Node* start = __ intcon(0);
1356 for (int argi = 0; argi < sc->num_arguments(); argi++) {
1357 Node* arg = sc->argument(argi);
1358 switch (sc->mode(argi)) {
1359 case StringConcat::IntMode: {
1360 Node* end = __ AddI(start, string_sizes->in(argi));
1361 // getChars words backwards so pass the ending point as well as the start
1362 int_getChars(kit, arg, char_array, start, end);
1363 start = end;
1364 break;
1365 }
1366 case StringConcat::StringMode: {
1367 start = copy_string(kit, arg, char_array, start);
1368 break;
1369 }
1370 case StringConcat::CharMode: {
1371 __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
1372 arg, T_CHAR, char_adr_idx);
1373 start = __ AddI(start, __ intcon(1));
1374 break;
1375 }
1376 default:
1377 ShouldNotReachHere();
1378 }
1379 }
1381 // If we're not reusing an existing String allocation then allocate one here.
1382 Node* result = sc->string_alloc();
1383 if (result == NULL) {
1384 PreserveReexecuteState preexecs(&kit);
1385 // The original jvms is for an allocation of either a String or
1386 // StringBuffer so no stack adjustment is necessary for proper
1387 // reexecution.
1388 kit.jvms()->set_should_reexecute(true);
1389 result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
1390 }
1392 // Intialize the string
1393 kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::offset_offset_in_bytes()),
1394 __ intcon(0), T_INT, offset_field_idx);
1395 kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::count_offset_in_bytes()),
1396 length, T_INT, count_field_idx);
1397 kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::value_offset_in_bytes()),
1398 char_array, T_OBJECT, value_field_idx);
1400 // hook up the outgoing control and result
1401 kit.replace_call(sc->end(), result);
1403 // Unhook any hook nodes
1404 string_sizes->disconnect_inputs(NULL);
1405 sc->cleanup();
1406 }