1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "ci/ciReplay.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/exceptionHandlerTable.hpp"
31 #include "code/nmethod.hpp"
32 #include "compiler/compileLog.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "compiler/oopMap.hpp"
35 #include "opto/addnode.hpp"
36 #include "opto/block.hpp"
37 #include "opto/c2compiler.hpp"
38 #include "opto/callGenerator.hpp"
39 #include "opto/callnode.hpp"
40 #include "opto/cfgnode.hpp"
41 #include "opto/chaitin.hpp"
42 #include "opto/compile.hpp"
43 #include "opto/connode.hpp"
44 #include "opto/divnode.hpp"
45 #include "opto/escape.hpp"
46 #include "opto/idealGraphPrinter.hpp"
47 #include "opto/loopnode.hpp"
48 #include "opto/machnode.hpp"
49 #include "opto/macro.hpp"
50 #include "opto/matcher.hpp"
51 #include "opto/mathexactnode.hpp"
52 #include "opto/memnode.hpp"
53 #include "opto/mulnode.hpp"
54 #include "opto/narrowptrnode.hpp"
55 #include "opto/node.hpp"
56 #include "opto/opcodes.hpp"
57 #include "opto/output.hpp"
58 #include "opto/parse.hpp"
59 #include "opto/phaseX.hpp"
60 #include "opto/rootnode.hpp"
61 #include "opto/runtime.hpp"
62 #include "opto/stringopts.hpp"
63 #include "opto/type.hpp"
64 #include "opto/vectornode.hpp"
65 #include "runtime/arguments.hpp"
66 #include "runtime/signature.hpp"
67 #include "runtime/stubRoutines.hpp"
68 #include "runtime/timer.hpp"
69 #include "trace/tracing.hpp"
70 #include "utilities/copy.hpp"
71
72
73 // -------------------- Compile::mach_constant_base_node -----------------------
74 // Constant table base node singleton.
75 MachConstantBaseNode* Compile::mach_constant_base_node() {
76 if (_mach_constant_base_node == NULL) {
77 _mach_constant_base_node = new MachConstantBaseNode();
78 _mach_constant_base_node->add_req(C->root());
79 }
80 return _mach_constant_base_node;
81 }
82
83
84 /// Support for intrinsics.
85
86 // Return the index at which m must be inserted (or already exists).
87 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
88 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
89 #ifdef ASSERT
90 for (int i = 1; i < _intrinsics->length(); i++) {
91 CallGenerator* cg1 = _intrinsics->at(i-1);
92 CallGenerator* cg2 = _intrinsics->at(i);
93 assert(cg1->method() != cg2->method()
94 ? cg1->method() < cg2->method()
95 : cg1->is_virtual() < cg2->is_virtual(),
96 "compiler intrinsics list must stay sorted");
97 }
98 #endif
99 // Binary search sorted list, in decreasing intervals [lo, hi].
100 int lo = 0, hi = _intrinsics->length()-1;
101 while (lo <= hi) {
102 int mid = (uint)(hi + lo) / 2;
103 ciMethod* mid_m = _intrinsics->at(mid)->method();
104 if (m < mid_m) {
105 hi = mid-1;
106 } else if (m > mid_m) {
107 lo = mid+1;
108 } else {
109 // look at minor sort key
110 bool mid_virt = _intrinsics->at(mid)->is_virtual();
111 if (is_virtual < mid_virt) {
112 hi = mid-1;
113 } else if (is_virtual > mid_virt) {
114 lo = mid+1;
115 } else {
116 return mid; // exact match
117 }
118 }
119 }
120 return lo; // inexact match
121 }
122
123 void Compile::register_intrinsic(CallGenerator* cg) {
124 if (_intrinsics == NULL) {
125 _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
126 }
127 // This code is stolen from ciObjectFactory::insert.
128 // Really, GrowableArray should have methods for
129 // insert_at, remove_at, and binary_search.
130 int len = _intrinsics->length();
131 int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
132 if (index == len) {
133 _intrinsics->append(cg);
134 } else {
135 #ifdef ASSERT
136 CallGenerator* oldcg = _intrinsics->at(index);
137 assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
138 #endif
139 _intrinsics->append(_intrinsics->at(len-1));
140 int pos;
141 for (pos = len-2; pos >= index; pos--) {
142 _intrinsics->at_put(pos+1,_intrinsics->at(pos));
143 }
144 _intrinsics->at_put(index, cg);
145 }
146 assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
147 }
148
149 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
150 assert(m->is_loaded(), "don't try this on unloaded methods");
151 if (_intrinsics != NULL) {
152 int index = intrinsic_insertion_index(m, is_virtual);
153 if (index < _intrinsics->length()
154 && _intrinsics->at(index)->method() == m
155 && _intrinsics->at(index)->is_virtual() == is_virtual) {
156 return _intrinsics->at(index);
157 }
158 }
159 // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
160 if (m->intrinsic_id() != vmIntrinsics::_none &&
161 m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
162 CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
163 if (cg != NULL) {
164 // Save it for next time:
165 register_intrinsic(cg);
166 return cg;
167 } else {
168 gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
169 }
170 }
171 return NULL;
172 }
173
174 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
175 // in library_call.cpp.
176
177
178 #ifndef PRODUCT
179 // statistics gathering...
180
181 juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
182 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
183
184 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
185 assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
186 int oflags = _intrinsic_hist_flags[id];
187 assert(flags != 0, "what happened?");
188 if (is_virtual) {
189 flags |= _intrinsic_virtual;
190 }
191 bool changed = (flags != oflags);
192 if ((flags & _intrinsic_worked) != 0) {
193 juint count = (_intrinsic_hist_count[id] += 1);
194 if (count == 1) {
195 changed = true; // first time
196 }
197 // increment the overall count also:
198 _intrinsic_hist_count[vmIntrinsics::_none] += 1;
199 }
200 if (changed) {
201 if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
202 // Something changed about the intrinsic's virtuality.
203 if ((flags & _intrinsic_virtual) != 0) {
204 // This is the first use of this intrinsic as a virtual call.
205 if (oflags != 0) {
206 // We already saw it as a non-virtual, so note both cases.
207 flags |= _intrinsic_both;
208 }
209 } else if ((oflags & _intrinsic_both) == 0) {
210 // This is the first use of this intrinsic as a non-virtual
211 flags |= _intrinsic_both;
212 }
213 }
214 _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
215 }
216 // update the overall flags also:
217 _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
218 return changed;
219 }
220
221 static char* format_flags(int flags, char* buf) {
222 buf[0] = 0;
223 if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
224 if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
225 if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
226 if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
227 if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
228 if (buf[0] == 0) strcat(buf, ",");
229 assert(buf[0] == ',', "must be");
230 return &buf[1];
231 }
232
233 void Compile::print_intrinsic_statistics() {
234 char flagsbuf[100];
235 ttyLocker ttyl;
236 if (xtty != NULL) xtty->head("statistics type='intrinsic'");
237 tty->print_cr("Compiler intrinsic usage:");
238 juint total = _intrinsic_hist_count[vmIntrinsics::_none];
239 if (total == 0) total = 1; // avoid div0 in case of no successes
240 #define PRINT_STAT_LINE(name, c, f) \
241 tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
242 for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
243 vmIntrinsics::ID id = (vmIntrinsics::ID) index;
244 int flags = _intrinsic_hist_flags[id];
245 juint count = _intrinsic_hist_count[id];
246 if ((flags | count) != 0) {
247 PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
248 }
249 }
250 PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
251 if (xtty != NULL) xtty->tail("statistics");
252 }
253
254 void Compile::print_statistics() {
255 { ttyLocker ttyl;
256 if (xtty != NULL) xtty->head("statistics type='opto'");
257 Parse::print_statistics();
258 PhaseCCP::print_statistics();
259 PhaseRegAlloc::print_statistics();
260 Scheduling::print_statistics();
261 PhasePeephole::print_statistics();
262 PhaseIdealLoop::print_statistics();
263 if (xtty != NULL) xtty->tail("statistics");
264 }
265 if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
266 // put this under its own <statistics> element.
267 print_intrinsic_statistics();
268 }
269 }
270 #endif //PRODUCT
271
272 // Support for bundling info
273 Bundle* Compile::node_bundling(const Node *n) {
274 assert(valid_bundle_info(n), "oob");
275 return &_node_bundling_base[n->_idx];
276 }
277
278 bool Compile::valid_bundle_info(const Node *n) {
279 return (_node_bundling_limit > n->_idx);
280 }
281
282
283 void Compile::gvn_replace_by(Node* n, Node* nn) {
284 for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
285 Node* use = n->last_out(i);
286 bool is_in_table = initial_gvn()->hash_delete(use);
287 uint uses_found = 0;
288 for (uint j = 0; j < use->len(); j++) {
289 if (use->in(j) == n) {
290 if (j < use->req())
291 use->set_req(j, nn);
292 else
293 use->set_prec(j, nn);
294 uses_found++;
295 }
296 }
297 if (is_in_table) {
298 // reinsert into table
299 initial_gvn()->hash_find_insert(use);
300 }
301 record_for_igvn(use);
302 i -= uses_found; // we deleted 1 or more copies of this edge
303 }
304 }
305
306
307 static inline bool not_a_node(const Node* n) {
308 if (n == NULL) return true;
309 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
310 if (*(address*)n == badAddress) return true; // kill by Node::destruct
311 return false;
312 }
313
314 // Identify all nodes that are reachable from below, useful.
315 // Use breadth-first pass that records state in a Unique_Node_List,
316 // recursive traversal is slower.
317 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
318 int estimated_worklist_size = unique();
319 useful.map( estimated_worklist_size, NULL ); // preallocate space
320
321 // Initialize worklist
322 if (root() != NULL) { useful.push(root()); }
323 // If 'top' is cached, declare it useful to preserve cached node
324 if( cached_top_node() ) { useful.push(cached_top_node()); }
325
326 // Push all useful nodes onto the list, breadthfirst
327 for( uint next = 0; next < useful.size(); ++next ) {
328 assert( next < unique(), "Unique useful nodes < total nodes");
329 Node *n = useful.at(next);
330 uint max = n->len();
331 for( uint i = 0; i < max; ++i ) {
332 Node *m = n->in(i);
333 if (not_a_node(m)) continue;
334 useful.push(m);
335 }
336 }
337 }
338
339 // Update dead_node_list with any missing dead nodes using useful
340 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
341 void Compile::update_dead_node_list(Unique_Node_List &useful) {
342 uint max_idx = unique();
343 VectorSet& useful_node_set = useful.member_set();
344
345 for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
346 // If node with index node_idx is not in useful set,
347 // mark it as dead in dead node list.
348 if (! useful_node_set.test(node_idx) ) {
349 record_dead_node(node_idx);
350 }
351 }
352 }
353
354 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
355 int shift = 0;
356 for (int i = 0; i < inlines->length(); i++) {
357 CallGenerator* cg = inlines->at(i);
358 CallNode* call = cg->call_node();
359 if (shift > 0) {
360 inlines->at_put(i-shift, cg);
361 }
362 if (!useful.member(call)) {
363 shift++;
364 }
365 }
366 inlines->trunc_to(inlines->length()-shift);
367 }
368
369 // Disconnect all useless nodes by disconnecting those at the boundary.
370 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
371 uint next = 0;
372 while (next < useful.size()) {
373 Node *n = useful.at(next++);
374 if (n->is_SafePoint()) {
375 // We're done with a parsing phase. Replaced nodes are not valid
376 // beyond that point.
377 n->as_SafePoint()->delete_replaced_nodes();
378 }
379 // Use raw traversal of out edges since this code removes out edges
380 int max = n->outcnt();
381 for (int j = 0; j < max; ++j) {
382 Node* child = n->raw_out(j);
383 if (! useful.member(child)) {
384 assert(!child->is_top() || child != top(),
385 "If top is cached in Compile object it is in useful list");
386 // Only need to remove this out-edge to the useless node
387 n->raw_del_out(j);
388 --j;
389 --max;
390 }
391 }
392 if (n->outcnt() == 1 && n->has_special_unique_user()) {
393 record_for_igvn(n->unique_out());
394 }
395 }
396 // Remove useless macro and predicate opaq nodes
397 for (int i = C->macro_count()-1; i >= 0; i--) {
398 Node* n = C->macro_node(i);
399 if (!useful.member(n)) {
400 remove_macro_node(n);
401 }
402 }
403 // Remove useless expensive node
404 for (int i = C->expensive_count()-1; i >= 0; i--) {
405 Node* n = C->expensive_node(i);
406 if (!useful.member(n)) {
407 remove_expensive_node(n);
408 }
409 }
410 // clean up the late inline lists
411 remove_useless_late_inlines(&_string_late_inlines, useful);
412 remove_useless_late_inlines(&_boxing_late_inlines, useful);
413 remove_useless_late_inlines(&_late_inlines, useful);
414 debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
415 }
416
417 //------------------------------frame_size_in_words-----------------------------
418 // frame_slots in units of words
419 int Compile::frame_size_in_words() const {
420 // shift is 0 in LP32 and 1 in LP64
421 const int shift = (LogBytesPerWord - LogBytesPerInt);
422 int words = _frame_slots >> shift;
423 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
424 return words;
425 }
426
427 // To bang the stack of this compiled method we use the stack size
428 // that the interpreter would need in case of a deoptimization. This
429 // removes the need to bang the stack in the deoptimization blob which
430 // in turn simplifies stack overflow handling.
431 int Compile::bang_size_in_bytes() const {
432 return MAX2(_interpreter_frame_size, frame_size_in_bytes());
433 }
434
435 // ============================================================================
436 //------------------------------CompileWrapper---------------------------------
437 class CompileWrapper : public StackObj {
438 Compile *const _compile;
439 public:
440 CompileWrapper(Compile* compile);
441
442 ~CompileWrapper();
443 };
444
445 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
446 // the Compile* pointer is stored in the current ciEnv:
447 ciEnv* env = compile->env();
448 assert(env == ciEnv::current(), "must already be a ciEnv active");
449 assert(env->compiler_data() == NULL, "compile already active?");
450 env->set_compiler_data(compile);
451 assert(compile == Compile::current(), "sanity");
452
453 compile->set_type_dict(NULL);
454 compile->set_type_hwm(NULL);
455 compile->set_type_last_size(0);
456 compile->set_last_tf(NULL, NULL);
457 compile->set_indexSet_arena(NULL);
458 compile->set_indexSet_free_block_list(NULL);
459 compile->init_type_arena();
460 Type::Initialize(compile);
461 _compile->set_scratch_buffer_blob(NULL);
462 _compile->begin_method();
463 }
464 CompileWrapper::~CompileWrapper() {
465 _compile->end_method();
466 if (_compile->scratch_buffer_blob() != NULL)
467 BufferBlob::free(_compile->scratch_buffer_blob());
468 _compile->env()->set_compiler_data(NULL);
469 }
470
471
472 //----------------------------print_compile_messages---------------------------
473 void Compile::print_compile_messages() {
474 #ifndef PRODUCT
475 // Check if recompiling
476 if (_subsume_loads == false && PrintOpto) {
477 // Recompiling without allowing machine instructions to subsume loads
478 tty->print_cr("*********************************************************");
479 tty->print_cr("** Bailout: Recompile without subsuming loads **");
480 tty->print_cr("*********************************************************");
481 }
482 if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
483 // Recompiling without escape analysis
484 tty->print_cr("*********************************************************");
485 tty->print_cr("** Bailout: Recompile without escape analysis **");
486 tty->print_cr("*********************************************************");
487 }
488 if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
489 // Recompiling without boxing elimination
490 tty->print_cr("*********************************************************");
491 tty->print_cr("** Bailout: Recompile without boxing elimination **");
492 tty->print_cr("*********************************************************");
493 }
494 if (env()->break_at_compile()) {
495 // Open the debugger when compiling this method.
496 tty->print("### Breaking when compiling: ");
497 method()->print_short_name();
498 tty->cr();
499 BREAKPOINT;
500 }
501
502 if( PrintOpto ) {
503 if (is_osr_compilation()) {
504 tty->print("[OSR]%3d", _compile_id);
505 } else {
506 tty->print("%3d", _compile_id);
507 }
508 }
509 #endif
510 }
511
512
513 //-----------------------init_scratch_buffer_blob------------------------------
514 // Construct a temporary BufferBlob and cache it for this compile.
515 void Compile::init_scratch_buffer_blob(int const_size) {
516 // If there is already a scratch buffer blob allocated and the
517 // constant section is big enough, use it. Otherwise free the
518 // current and allocate a new one.
519 BufferBlob* blob = scratch_buffer_blob();
520 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
521 // Use the current blob.
522 } else {
523 if (blob != NULL) {
524 BufferBlob::free(blob);
525 }
526
527 ResourceMark rm;
528 _scratch_const_size = const_size;
529 int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
530 blob = BufferBlob::create("Compile::scratch_buffer", size);
531 // Record the buffer blob for next time.
532 set_scratch_buffer_blob(blob);
533 // Have we run out of code space?
534 if (scratch_buffer_blob() == NULL) {
535 // Let CompilerBroker disable further compilations.
536 record_failure("Not enough space for scratch buffer in CodeCache");
537 return;
538 }
539 }
540
541 // Initialize the relocation buffers
542 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
543 set_scratch_locs_memory(locs_buf);
544 }
545
546
547 //-----------------------scratch_emit_size-------------------------------------
548 // Helper function that computes size by emitting code
549 uint Compile::scratch_emit_size(const Node* n) {
550 // Start scratch_emit_size section.
551 set_in_scratch_emit_size(true);
552
553 // Emit into a trash buffer and count bytes emitted.
554 // This is a pretty expensive way to compute a size,
555 // but it works well enough if seldom used.
556 // All common fixed-size instructions are given a size
557 // method by the AD file.
558 // Note that the scratch buffer blob and locs memory are
559 // allocated at the beginning of the compile task, and
560 // may be shared by several calls to scratch_emit_size.
561 // The allocation of the scratch buffer blob is particularly
562 // expensive, since it has to grab the code cache lock.
563 BufferBlob* blob = this->scratch_buffer_blob();
564 assert(blob != NULL, "Initialize BufferBlob at start");
565 assert(blob->size() > MAX_inst_size, "sanity");
566 relocInfo* locs_buf = scratch_locs_memory();
567 address blob_begin = blob->content_begin();
568 address blob_end = (address)locs_buf;
569 assert(blob->content_contains(blob_end), "sanity");
570 CodeBuffer buf(blob_begin, blob_end - blob_begin);
571 buf.initialize_consts_size(_scratch_const_size);
572 buf.initialize_stubs_size(MAX_stubs_size);
573 assert(locs_buf != NULL, "sanity");
574 int lsize = MAX_locs_size / 3;
575 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
576 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
577 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
578
579 // Do the emission.
580
581 Label fakeL; // Fake label for branch instructions.
582 Label* saveL = NULL;
583 uint save_bnum = 0;
584 bool is_branch = n->is_MachBranch();
585 if (is_branch) {
586 MacroAssembler masm(&buf);
587 masm.bind(fakeL);
588 n->as_MachBranch()->save_label(&saveL, &save_bnum);
589 n->as_MachBranch()->label_set(&fakeL, 0);
590 }
591 n->emit(buf, this->regalloc());
592 if (is_branch) // Restore label.
593 n->as_MachBranch()->label_set(saveL, save_bnum);
594
595 // End scratch_emit_size section.
596 set_in_scratch_emit_size(false);
597
598 return buf.insts_size();
599 }
600
601
602 // ============================================================================
603 //------------------------------Compile standard-------------------------------
604 debug_only( int Compile::_debug_idx = 100000; )
605
606 // Compile a method. entry_bci is -1 for normal compilations and indicates
607 // the continuation bci for on stack replacement.
608
609
610 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
611 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
612 : Phase(Compiler),
613 _env(ci_env),
614 _log(ci_env->log()),
615 _compile_id(ci_env->compile_id()),
616 _save_argument_registers(false),
617 _stub_name(NULL),
618 _stub_function(NULL),
619 _stub_entry_point(NULL),
620 _method(target),
621 _entry_bci(osr_bci),
622 _initial_gvn(NULL),
623 _for_igvn(NULL),
624 _warm_calls(NULL),
625 _subsume_loads(subsume_loads),
626 _do_escape_analysis(do_escape_analysis),
627 _eliminate_boxing(eliminate_boxing),
628 _failure_reason(NULL),
629 _code_buffer("Compile::Fill_buffer"),
630 _orig_pc_slot(0),
631 _orig_pc_slot_offset_in_bytes(0),
632 _has_method_handle_invokes(false),
633 _mach_constant_base_node(NULL),
634 _node_bundling_limit(0),
635 _node_bundling_base(NULL),
636 _java_calls(0),
637 _inner_loops(0),
638 _scratch_const_size(-1),
639 _in_scratch_emit_size(false),
640 _dead_node_list(comp_arena()),
641 _dead_node_count(0),
642 #ifndef PRODUCT
643 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
644 _in_dump_cnt(0),
645 _printer(IdealGraphPrinter::printer()),
646 #endif
647 _congraph(NULL),
648 _replay_inline_data(NULL),
649 _late_inlines(comp_arena(), 2, 0, NULL),
650 _string_late_inlines(comp_arena(), 2, 0, NULL),
651 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
652 _late_inlines_pos(0),
653 _number_of_mh_late_inlines(0),
654 _inlining_progress(false),
655 _inlining_incrementally(false),
656 _print_inlining_list(NULL),
657 _print_inlining_stream(NULL),
658 _print_inlining_idx(0),
659 _print_inlining_output(NULL),
660 _interpreter_frame_size(0) {
661 C = this;
662
663 CompileWrapper cw(this);
664 #ifndef PRODUCT
665 if (TimeCompiler2) {
666 tty->print(" ");
667 target->holder()->name()->print();
668 tty->print(".");
669 target->print_short_name();
670 tty->print(" ");
671 }
672 TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
673 TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
674 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
675 if (!print_opto_assembly) {
676 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
677 if (print_assembly && !Disassembler::can_decode()) {
678 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
679 print_opto_assembly = true;
680 }
681 }
682 set_print_assembly(print_opto_assembly);
683 set_parsed_irreducible_loop(false);
684
685 if (method()->has_option("ReplayInline")) {
686 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
687 }
688 #endif
689 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
690 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
691 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
692
693 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
694 // Make sure the method being compiled gets its own MDO,
695 // so we can at least track the decompile_count().
696 // Need MDO to record RTM code generation state.
697 method()->ensure_method_data();
698 }
699
700 Init(::AliasLevel);
701
702
703 print_compile_messages();
704
705 _ilt = InlineTree::build_inline_tree_root();
706
707 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
708 assert(num_alias_types() >= AliasIdxRaw, "");
709
710 #define MINIMUM_NODE_HASH 1023
711 // Node list that Iterative GVN will start with
712 Unique_Node_List for_igvn(comp_arena());
713 set_for_igvn(&for_igvn);
714
715 // GVN that will be run immediately on new nodes
716 uint estimated_size = method()->code_size()*4+64;
717 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
718 PhaseGVN gvn(node_arena(), estimated_size);
719 set_initial_gvn(&gvn);
720
721 print_inlining_init();
722 { // Scope for timing the parser
723 TracePhase t3("parse", &_t_parser, true);
724
725 // Put top into the hash table ASAP.
726 initial_gvn()->transform_no_reclaim(top());
727
728 // Set up tf(), start(), and find a CallGenerator.
729 CallGenerator* cg = NULL;
730 if (is_osr_compilation()) {
731 const TypeTuple *domain = StartOSRNode::osr_domain();
732 const TypeTuple *range = TypeTuple::make_range(method()->signature());
733 init_tf(TypeFunc::make(domain, range));
734 StartNode* s = new StartOSRNode(root(), domain);
735 initial_gvn()->set_type_bottom(s);
736 init_start(s);
737 cg = CallGenerator::for_osr(method(), entry_bci());
738 } else {
739 // Normal case.
740 init_tf(TypeFunc::make(method()));
741 StartNode* s = new StartNode(root(), tf()->domain());
742 initial_gvn()->set_type_bottom(s);
743 init_start(s);
744 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
745 // With java.lang.ref.reference.get() we must go through the
746 // intrinsic when G1 is enabled - even when get() is the root
747 // method of the compile - so that, if necessary, the value in
748 // the referent field of the reference object gets recorded by
749 // the pre-barrier code.
750 // Specifically, if G1 is enabled, the value in the referent
751 // field is recorded by the G1 SATB pre barrier. This will
752 // result in the referent being marked live and the reference
753 // object removed from the list of discovered references during
754 // reference processing.
755 cg = find_intrinsic(method(), false);
756 }
757 if (cg == NULL) {
758 float past_uses = method()->interpreter_invocation_count();
759 float expected_uses = past_uses;
760 cg = CallGenerator::for_inline(method(), expected_uses);
761 }
762 }
763 if (failing()) return;
764 if (cg == NULL) {
765 record_method_not_compilable_all_tiers("cannot parse method");
766 return;
767 }
768 JVMState* jvms = build_start_state(start(), tf());
769 if ((jvms = cg->generate(jvms)) == NULL) {
770 record_method_not_compilable("method parse failed");
771 return;
772 }
773 GraphKit kit(jvms);
774
775 if (!kit.stopped()) {
776 // Accept return values, and transfer control we know not where.
777 // This is done by a special, unique ReturnNode bound to root.
778 return_values(kit.jvms());
779 }
780
781 if (kit.has_exceptions()) {
782 // Any exceptions that escape from this call must be rethrown
783 // to whatever caller is dynamically above us on the stack.
784 // This is done by a special, unique RethrowNode bound to root.
785 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
786 }
787
788 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
789
790 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
791 inline_string_calls(true);
792 }
793
794 if (failing()) return;
795
796 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
797
798 // Remove clutter produced by parsing.
799 if (!failing()) {
800 ResourceMark rm;
801 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
802 }
803 }
804
805 // Note: Large methods are capped off in do_one_bytecode().
806 if (failing()) return;
807
808 // After parsing, node notes are no longer automagic.
809 // They must be propagated by register_new_node_with_optimizer(),
810 // clone(), or the like.
811 set_default_node_notes(NULL);
812
813 for (;;) {
814 int successes = Inline_Warm();
815 if (failing()) return;
816 if (successes == 0) break;
817 }
818
819 // Drain the list.
820 Finish_Warm();
821 #ifndef PRODUCT
822 if (_printer) {
823 _printer->print_inlining(this);
824 }
825 #endif
826
827 if (failing()) return;
828 NOT_PRODUCT( verify_graph_edges(); )
829
830 // Now optimize
831 Optimize();
832 if (failing()) return;
833 NOT_PRODUCT( verify_graph_edges(); )
834
835 #ifndef PRODUCT
836 if (PrintIdeal) {
837 ttyLocker ttyl; // keep the following output all in one block
838 // This output goes directly to the tty, not the compiler log.
839 // To enable tools to match it up with the compilation activity,
840 // be sure to tag this tty output with the compile ID.
841 if (xtty != NULL) {
842 xtty->head("ideal compile_id='%d'%s", compile_id(),
843 is_osr_compilation() ? " compile_kind='osr'" :
844 "");
845 }
846 root()->dump(9999);
847 if (xtty != NULL) {
848 xtty->tail("ideal");
849 }
850 }
851 #endif
852
853 NOT_PRODUCT( verify_barriers(); )
854
855 // Dump compilation data to replay it.
856 if (method()->has_option("DumpReplay")) {
857 env()->dump_replay_data(_compile_id);
858 }
859 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
860 env()->dump_inline_data(_compile_id);
861 }
862
863 // Now that we know the size of all the monitors we can add a fixed slot
864 // for the original deopt pc.
865
866 _orig_pc_slot = fixed_slots();
867 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
868 set_fixed_slots(next_slot);
869
870 // Compute when to use implicit null checks. Used by matching trap based
871 // nodes and NullCheck optimization.
872 set_allowed_deopt_reasons();
873
874 // Now generate code
875 Code_Gen();
876 if (failing()) return;
877
878 // Check if we want to skip execution of all compiled code.
879 {
880 #ifndef PRODUCT
881 if (OptoNoExecute) {
882 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
883 return;
884 }
885 TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
886 #endif
887
888 if (is_osr_compilation()) {
889 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
890 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
891 } else {
892 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
893 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
894 }
895
896 env()->register_method(_method, _entry_bci,
897 &_code_offsets,
898 _orig_pc_slot_offset_in_bytes,
899 code_buffer(),
900 frame_size_in_words(), _oop_map_set,
901 &_handler_table, &_inc_table,
902 compiler,
903 env()->comp_level(),
904 has_unsafe_access(),
905 SharedRuntime::is_wide_vector(max_vector_size()),
906 rtm_state()
907 );
908
909 if (log() != NULL) // Print code cache state into compiler log
910 log()->code_cache_state();
911 }
912 }
913
914 //------------------------------Compile----------------------------------------
915 // Compile a runtime stub
916 Compile::Compile( ciEnv* ci_env,
917 TypeFunc_generator generator,
918 address stub_function,
919 const char *stub_name,
920 int is_fancy_jump,
921 bool pass_tls,
922 bool save_arg_registers,
923 bool return_pc )
924 : Phase(Compiler),
925 _env(ci_env),
926 _log(ci_env->log()),
927 _compile_id(0),
928 _save_argument_registers(save_arg_registers),
929 _method(NULL),
930 _stub_name(stub_name),
931 _stub_function(stub_function),
932 _stub_entry_point(NULL),
933 _entry_bci(InvocationEntryBci),
934 _initial_gvn(NULL),
935 _for_igvn(NULL),
936 _warm_calls(NULL),
937 _orig_pc_slot(0),
938 _orig_pc_slot_offset_in_bytes(0),
939 _subsume_loads(true),
940 _do_escape_analysis(false),
941 _eliminate_boxing(false),
942 _failure_reason(NULL),
943 _code_buffer("Compile::Fill_buffer"),
944 _has_method_handle_invokes(false),
945 _mach_constant_base_node(NULL),
946 _node_bundling_limit(0),
947 _node_bundling_base(NULL),
948 _java_calls(0),
949 _inner_loops(0),
950 #ifndef PRODUCT
951 _trace_opto_output(TraceOptoOutput),
952 _in_dump_cnt(0),
953 _printer(NULL),
954 #endif
955 _dead_node_list(comp_arena()),
956 _dead_node_count(0),
957 _congraph(NULL),
958 _replay_inline_data(NULL),
959 _number_of_mh_late_inlines(0),
960 _inlining_progress(false),
961 _inlining_incrementally(false),
962 _print_inlining_list(NULL),
963 _print_inlining_stream(NULL),
964 _print_inlining_idx(0),
965 _print_inlining_output(NULL),
966 _allowed_reasons(0),
967 _interpreter_frame_size(0) {
968 C = this;
969
970 #ifndef PRODUCT
971 TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
972 TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
973 set_print_assembly(PrintFrameConverterAssembly);
974 set_parsed_irreducible_loop(false);
975 #endif
976 set_has_irreducible_loop(false); // no loops
977
978 CompileWrapper cw(this);
979 Init(/*AliasLevel=*/ 0);
980 init_tf((*generator)());
981
982 {
983 // The following is a dummy for the sake of GraphKit::gen_stub
984 Unique_Node_List for_igvn(comp_arena());
985 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
986 PhaseGVN gvn(Thread::current()->resource_area(),255);
987 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
988 gvn.transform_no_reclaim(top());
989
990 GraphKit kit;
991 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
992 }
993
994 NOT_PRODUCT( verify_graph_edges(); )
995 Code_Gen();
996 if (failing()) return;
997
998
999 // Entry point will be accessed using compile->stub_entry_point();
1000 if (code_buffer() == NULL) {
1001 Matcher::soft_match_failure();
1002 } else {
1003 if (PrintAssembly && (WizardMode || Verbose))
1004 tty->print_cr("### Stub::%s", stub_name);
1005
1006 if (!failing()) {
1007 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1008
1009 // Make the NMethod
1010 // For now we mark the frame as never safe for profile stackwalking
1011 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1012 code_buffer(),
1013 CodeOffsets::frame_never_safe,
1014 // _code_offsets.value(CodeOffsets::Frame_Complete),
1015 frame_size_in_words(),
1016 _oop_map_set,
1017 save_arg_registers);
1018 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1019
1020 _stub_entry_point = rs->entry_point();
1021 }
1022 }
1023 }
1024
1025 //------------------------------Init-------------------------------------------
1026 // Prepare for a single compilation
1027 void Compile::Init(int aliaslevel) {
1028 _unique = 0;
1029 _regalloc = NULL;
1030
1031 _tf = NULL; // filled in later
1032 _top = NULL; // cached later
1033 _matcher = NULL; // filled in later
1034 _cfg = NULL; // filled in later
1035
1036 set_24_bit_selection_and_mode(Use24BitFP, false);
1037
1038 _node_note_array = NULL;
1039 _default_node_notes = NULL;
1040
1041 _immutable_memory = NULL; // filled in at first inquiry
1042
1043 // Globally visible Nodes
1044 // First set TOP to NULL to give safe behavior during creation of RootNode
1045 set_cached_top_node(NULL);
1046 set_root(new RootNode());
1047 // Now that you have a Root to point to, create the real TOP
1048 set_cached_top_node( new ConNode(Type::TOP) );
1049 set_recent_alloc(NULL, NULL);
1050
1051 // Create Debug Information Recorder to record scopes, oopmaps, etc.
1052 env()->set_oop_recorder(new OopRecorder(env()->arena()));
1053 env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1054 env()->set_dependencies(new Dependencies(env()));
1055
1056 _fixed_slots = 0;
1057 set_has_split_ifs(false);
1058 set_has_loops(has_method() && method()->has_loops()); // first approximation
1059 set_has_stringbuilder(false);
1060 set_has_boxed_value(false);
1061 _trap_can_recompile = false; // no traps emitted yet
1062 _major_progress = true; // start out assuming good things will happen
1063 set_has_unsafe_access(false);
1064 set_max_vector_size(0);
1065 Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1066 set_decompile_count(0);
1067
1068 set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1069 set_num_loop_opts(LoopOptsCount);
1070 set_do_inlining(Inline);
1071 set_max_inline_size(MaxInlineSize);
1072 set_freq_inline_size(FreqInlineSize);
1073 set_do_scheduling(OptoScheduling);
1074 set_do_count_invocations(false);
1075 set_do_method_data_update(false);
1076 set_age_code(has_method() && method()->profile_aging());
1077 set_rtm_state(NoRTM); // No RTM lock eliding by default
1078 #if INCLUDE_RTM_OPT
1079 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1080 int rtm_state = method()->method_data()->rtm_state();
1081 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1082 // Don't generate RTM lock eliding code.
1083 set_rtm_state(NoRTM);
1084 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1085 // Generate RTM lock eliding code without abort ratio calculation code.
1086 set_rtm_state(UseRTM);
1087 } else if (UseRTMDeopt) {
1088 // Generate RTM lock eliding code and include abort ratio calculation
1089 // code if UseRTMDeopt is on.
1090 set_rtm_state(ProfileRTM);
1091 }
1092 }
1093 #endif
1094 if (debug_info()->recording_non_safepoints()) {
1095 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1096 (comp_arena(), 8, 0, NULL));
1097 set_default_node_notes(Node_Notes::make(this));
1098 }
1099
1100 // // -- Initialize types before each compile --
1101 // // Update cached type information
1102 // if( _method && _method->constants() )
1103 // Type::update_loaded_types(_method, _method->constants());
1104
1105 // Init alias_type map.
1106 if (!_do_escape_analysis && aliaslevel == 3)
1107 aliaslevel = 2; // No unique types without escape analysis
1108 _AliasLevel = aliaslevel;
1109 const int grow_ats = 16;
1110 _max_alias_types = grow_ats;
1111 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1112 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1113 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1114 {
1115 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1116 }
1117 // Initialize the first few types.
1118 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1119 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1120 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1121 _num_alias_types = AliasIdxRaw+1;
1122 // Zero out the alias type cache.
1123 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1124 // A NULL adr_type hits in the cache right away. Preload the right answer.
1125 probe_alias_cache(NULL)->_index = AliasIdxTop;
1126
1127 _intrinsics = NULL;
1128 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1129 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1130 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1131 register_library_intrinsics();
1132 }
1133
1134 //---------------------------init_start----------------------------------------
1135 // Install the StartNode on this compile object.
1136 void Compile::init_start(StartNode* s) {
1137 if (failing())
1138 return; // already failing
1139 assert(s == start(), "");
1140 }
1141
1142 StartNode* Compile::start() const {
1143 assert(!failing(), "");
1144 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1145 Node* start = root()->fast_out(i);
1146 if( start->is_Start() )
1147 return start->as_Start();
1148 }
1149 fatal("Did not find Start node!");
1150 return NULL;
1151 }
1152
1153 //-------------------------------immutable_memory-------------------------------------
1154 // Access immutable memory
1155 Node* Compile::immutable_memory() {
1156 if (_immutable_memory != NULL) {
1157 return _immutable_memory;
1158 }
1159 StartNode* s = start();
1160 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1161 Node *p = s->fast_out(i);
1162 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1163 _immutable_memory = p;
1164 return _immutable_memory;
1165 }
1166 }
1167 ShouldNotReachHere();
1168 return NULL;
1169 }
1170
1171 //----------------------set_cached_top_node------------------------------------
1172 // Install the cached top node, and make sure Node::is_top works correctly.
1173 void Compile::set_cached_top_node(Node* tn) {
1174 if (tn != NULL) verify_top(tn);
1175 Node* old_top = _top;
1176 _top = tn;
1177 // Calling Node::setup_is_top allows the nodes the chance to adjust
1178 // their _out arrays.
1179 if (_top != NULL) _top->setup_is_top();
1180 if (old_top != NULL) old_top->setup_is_top();
1181 assert(_top == NULL || top()->is_top(), "");
1182 }
1183
1184 #ifdef ASSERT
1185 uint Compile::count_live_nodes_by_graph_walk() {
1186 Unique_Node_List useful(comp_arena());
1187 // Get useful node list by walking the graph.
1188 identify_useful_nodes(useful);
1189 return useful.size();
1190 }
1191
1192 void Compile::print_missing_nodes() {
1193
1194 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1195 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1196 return;
1197 }
1198
1199 // This is an expensive function. It is executed only when the user
1200 // specifies VerifyIdealNodeCount option or otherwise knows the
1201 // additional work that needs to be done to identify reachable nodes
1202 // by walking the flow graph and find the missing ones using
1203 // _dead_node_list.
1204
1205 Unique_Node_List useful(comp_arena());
1206 // Get useful node list by walking the graph.
1207 identify_useful_nodes(useful);
1208
1209 uint l_nodes = C->live_nodes();
1210 uint l_nodes_by_walk = useful.size();
1211
1212 if (l_nodes != l_nodes_by_walk) {
1213 if (_log != NULL) {
1214 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1215 _log->stamp();
1216 _log->end_head();
1217 }
1218 VectorSet& useful_member_set = useful.member_set();
1219 int last_idx = l_nodes_by_walk;
1220 for (int i = 0; i < last_idx; i++) {
1221 if (useful_member_set.test(i)) {
1222 if (_dead_node_list.test(i)) {
1223 if (_log != NULL) {
1224 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1225 }
1226 if (PrintIdealNodeCount) {
1227 // Print the log message to tty
1228 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1229 useful.at(i)->dump();
1230 }
1231 }
1232 }
1233 else if (! _dead_node_list.test(i)) {
1234 if (_log != NULL) {
1235 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1236 }
1237 if (PrintIdealNodeCount) {
1238 // Print the log message to tty
1239 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1240 }
1241 }
1242 }
1243 if (_log != NULL) {
1244 _log->tail("mismatched_nodes");
1245 }
1246 }
1247 }
1248 #endif
1249
1250 #ifndef PRODUCT
1251 void Compile::verify_top(Node* tn) const {
1252 if (tn != NULL) {
1253 assert(tn->is_Con(), "top node must be a constant");
1254 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1255 assert(tn->in(0) != NULL, "must have live top node");
1256 }
1257 }
1258 #endif
1259
1260
1261 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1262
1263 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1264 guarantee(arr != NULL, "");
1265 int num_blocks = arr->length();
1266 if (grow_by < num_blocks) grow_by = num_blocks;
1267 int num_notes = grow_by * _node_notes_block_size;
1268 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1269 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1270 while (num_notes > 0) {
1271 arr->append(notes);
1272 notes += _node_notes_block_size;
1273 num_notes -= _node_notes_block_size;
1274 }
1275 assert(num_notes == 0, "exact multiple, please");
1276 }
1277
1278 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1279 if (source == NULL || dest == NULL) return false;
1280
1281 if (dest->is_Con())
1282 return false; // Do not push debug info onto constants.
1283
1284 #ifdef ASSERT
1285 // Leave a bread crumb trail pointing to the original node:
1286 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1287 dest->set_debug_orig(source);
1288 }
1289 #endif
1290
1291 if (node_note_array() == NULL)
1292 return false; // Not collecting any notes now.
1293
1294 // This is a copy onto a pre-existing node, which may already have notes.
1295 // If both nodes have notes, do not overwrite any pre-existing notes.
1296 Node_Notes* source_notes = node_notes_at(source->_idx);
1297 if (source_notes == NULL || source_notes->is_clear()) return false;
1298 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1299 if (dest_notes == NULL || dest_notes->is_clear()) {
1300 return set_node_notes_at(dest->_idx, source_notes);
1301 }
1302
1303 Node_Notes merged_notes = (*source_notes);
1304 // The order of operations here ensures that dest notes will win...
1305 merged_notes.update_from(dest_notes);
1306 return set_node_notes_at(dest->_idx, &merged_notes);
1307 }
1308
1309
1310 //--------------------------allow_range_check_smearing-------------------------
1311 // Gating condition for coalescing similar range checks.
1312 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1313 // single covering check that is at least as strong as any of them.
1314 // If the optimization succeeds, the simplified (strengthened) range check
1315 // will always succeed. If it fails, we will deopt, and then give up
1316 // on the optimization.
1317 bool Compile::allow_range_check_smearing() const {
1318 // If this method has already thrown a range-check,
1319 // assume it was because we already tried range smearing
1320 // and it failed.
1321 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1322 return !already_trapped;
1323 }
1324
1325
1326 //------------------------------flatten_alias_type-----------------------------
1327 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1328 int offset = tj->offset();
1329 TypePtr::PTR ptr = tj->ptr();
1330
1331 // Known instance (scalarizable allocation) alias only with itself.
1332 bool is_known_inst = tj->isa_oopptr() != NULL &&
1333 tj->is_oopptr()->is_known_instance();
1334
1335 // Process weird unsafe references.
1336 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1337 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1338 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1339 tj = TypeOopPtr::BOTTOM;
1340 ptr = tj->ptr();
1341 offset = tj->offset();
1342 }
1343
1344 // Array pointers need some flattening
1345 const TypeAryPtr *ta = tj->isa_aryptr();
1346 if (ta && ta->is_stable()) {
1347 // Erase stability property for alias analysis.
1348 tj = ta = ta->cast_to_stable(false);
1349 }
1350 if( ta && is_known_inst ) {
1351 if ( offset != Type::OffsetBot &&
1352 offset > arrayOopDesc::length_offset_in_bytes() ) {
1353 offset = Type::OffsetBot; // Flatten constant access into array body only
1354 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1355 }
1356 } else if( ta && _AliasLevel >= 2 ) {
1357 // For arrays indexed by constant indices, we flatten the alias
1358 // space to include all of the array body. Only the header, klass
1359 // and array length can be accessed un-aliased.
1360 if( offset != Type::OffsetBot ) {
1361 if( ta->const_oop() ) { // MethodData* or Method*
1362 offset = Type::OffsetBot; // Flatten constant access into array body
1363 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1364 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1365 // range is OK as-is.
1366 tj = ta = TypeAryPtr::RANGE;
1367 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1368 tj = TypeInstPtr::KLASS; // all klass loads look alike
1369 ta = TypeAryPtr::RANGE; // generic ignored junk
1370 ptr = TypePtr::BotPTR;
1371 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1372 tj = TypeInstPtr::MARK;
1373 ta = TypeAryPtr::RANGE; // generic ignored junk
1374 ptr = TypePtr::BotPTR;
1375 } else { // Random constant offset into array body
1376 offset = Type::OffsetBot; // Flatten constant access into array body
1377 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1378 }
1379 }
1380 // Arrays of fixed size alias with arrays of unknown size.
1381 if (ta->size() != TypeInt::POS) {
1382 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1383 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1384 }
1385 // Arrays of known objects become arrays of unknown objects.
1386 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1387 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1388 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1389 }
1390 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1391 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1392 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1393 }
1394 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1395 // cannot be distinguished by bytecode alone.
1396 if (ta->elem() == TypeInt::BOOL) {
1397 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1398 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1399 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1400 }
1401 // During the 2nd round of IterGVN, NotNull castings are removed.
1402 // Make sure the Bottom and NotNull variants alias the same.
1403 // Also, make sure exact and non-exact variants alias the same.
1404 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1405 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1406 }
1407 }
1408
1409 // Oop pointers need some flattening
1410 const TypeInstPtr *to = tj->isa_instptr();
1411 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1412 ciInstanceKlass *k = to->klass()->as_instance_klass();
1413 if( ptr == TypePtr::Constant ) {
1414 if (to->klass() != ciEnv::current()->Class_klass() ||
1415 offset < k->size_helper() * wordSize) {
1416 // No constant oop pointers (such as Strings); they alias with
1417 // unknown strings.
1418 assert(!is_known_inst, "not scalarizable allocation");
1419 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1420 }
1421 } else if( is_known_inst ) {
1422 tj = to; // Keep NotNull and klass_is_exact for instance type
1423 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1424 // During the 2nd round of IterGVN, NotNull castings are removed.
1425 // Make sure the Bottom and NotNull variants alias the same.
1426 // Also, make sure exact and non-exact variants alias the same.
1427 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1428 }
1429 if (to->speculative() != NULL) {
1430 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1431 }
1432 // Canonicalize the holder of this field
1433 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1434 // First handle header references such as a LoadKlassNode, even if the
1435 // object's klass is unloaded at compile time (4965979).
1436 if (!is_known_inst) { // Do it only for non-instance types
1437 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1438 }
1439 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1440 // Static fields are in the space above the normal instance
1441 // fields in the java.lang.Class instance.
1442 if (to->klass() != ciEnv::current()->Class_klass()) {
1443 to = NULL;
1444 tj = TypeOopPtr::BOTTOM;
1445 offset = tj->offset();
1446 }
1447 } else {
1448 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1449 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1450 if( is_known_inst ) {
1451 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1452 } else {
1453 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1454 }
1455 }
1456 }
1457 }
1458
1459 // Klass pointers to object array klasses need some flattening
1460 const TypeKlassPtr *tk = tj->isa_klassptr();
1461 if( tk ) {
1462 // If we are referencing a field within a Klass, we need
1463 // to assume the worst case of an Object. Both exact and
1464 // inexact types must flatten to the same alias class so
1465 // use NotNull as the PTR.
1466 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1467
1468 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1469 TypeKlassPtr::OBJECT->klass(),
1470 offset);
1471 }
1472
1473 ciKlass* klass = tk->klass();
1474 if( klass->is_obj_array_klass() ) {
1475 ciKlass* k = TypeAryPtr::OOPS->klass();
1476 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1477 k = TypeInstPtr::BOTTOM->klass();
1478 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1479 }
1480
1481 // Check for precise loads from the primary supertype array and force them
1482 // to the supertype cache alias index. Check for generic array loads from
1483 // the primary supertype array and also force them to the supertype cache
1484 // alias index. Since the same load can reach both, we need to merge
1485 // these 2 disparate memories into the same alias class. Since the
1486 // primary supertype array is read-only, there's no chance of confusion
1487 // where we bypass an array load and an array store.
1488 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1489 if (offset == Type::OffsetBot ||
1490 (offset >= primary_supers_offset &&
1491 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1492 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1493 offset = in_bytes(Klass::secondary_super_cache_offset());
1494 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1495 }
1496 }
1497
1498 // Flatten all Raw pointers together.
1499 if (tj->base() == Type::RawPtr)
1500 tj = TypeRawPtr::BOTTOM;
1501
1502 if (tj->base() == Type::AnyPtr)
1503 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1504
1505 // Flatten all to bottom for now
1506 switch( _AliasLevel ) {
1507 case 0:
1508 tj = TypePtr::BOTTOM;
1509 break;
1510 case 1: // Flatten to: oop, static, field or array
1511 switch (tj->base()) {
1512 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1513 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1514 case Type::AryPtr: // do not distinguish arrays at all
1515 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1516 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1517 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1518 default: ShouldNotReachHere();
1519 }
1520 break;
1521 case 2: // No collapsing at level 2; keep all splits
1522 case 3: // No collapsing at level 3; keep all splits
1523 break;
1524 default:
1525 Unimplemented();
1526 }
1527
1528 offset = tj->offset();
1529 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1530
1531 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1532 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1533 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1534 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1535 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1536 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1537 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1538 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1539 assert( tj->ptr() != TypePtr::TopPTR &&
1540 tj->ptr() != TypePtr::AnyNull &&
1541 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1542 // assert( tj->ptr() != TypePtr::Constant ||
1543 // tj->base() == Type::RawPtr ||
1544 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1545
1546 return tj;
1547 }
1548
1549 void Compile::AliasType::Init(int i, const TypePtr* at) {
1550 _index = i;
1551 _adr_type = at;
1552 _field = NULL;
1553 _element = NULL;
1554 _is_rewritable = true; // default
1555 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1556 if (atoop != NULL && atoop->is_known_instance()) {
1557 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1558 _general_index = Compile::current()->get_alias_index(gt);
1559 } else {
1560 _general_index = 0;
1561 }
1562 }
1563
1564 //---------------------------------print_on------------------------------------
1565 #ifndef PRODUCT
1566 void Compile::AliasType::print_on(outputStream* st) {
1567 if (index() < 10)
1568 st->print("@ <%d> ", index());
1569 else st->print("@ <%d>", index());
1570 st->print(is_rewritable() ? " " : " RO");
1571 int offset = adr_type()->offset();
1572 if (offset == Type::OffsetBot)
1573 st->print(" +any");
1574 else st->print(" +%-3d", offset);
1575 st->print(" in ");
1576 adr_type()->dump_on(st);
1577 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1578 if (field() != NULL && tjp) {
1579 if (tjp->klass() != field()->holder() ||
1580 tjp->offset() != field()->offset_in_bytes()) {
1581 st->print(" != ");
1582 field()->print();
1583 st->print(" ***");
1584 }
1585 }
1586 }
1587
1588 void print_alias_types() {
1589 Compile* C = Compile::current();
1590 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1591 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1592 C->alias_type(idx)->print_on(tty);
1593 tty->cr();
1594 }
1595 }
1596 #endif
1597
1598
1599 //----------------------------probe_alias_cache--------------------------------
1600 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1601 intptr_t key = (intptr_t) adr_type;
1602 key ^= key >> logAliasCacheSize;
1603 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1604 }
1605
1606
1607 //-----------------------------grow_alias_types--------------------------------
1608 void Compile::grow_alias_types() {
1609 const int old_ats = _max_alias_types; // how many before?
1610 const int new_ats = old_ats; // how many more?
1611 const int grow_ats = old_ats+new_ats; // how many now?
1612 _max_alias_types = grow_ats;
1613 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1614 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1615 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1616 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1617 }
1618
1619
1620 //--------------------------------find_alias_type------------------------------
1621 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1622 if (_AliasLevel == 0)
1623 return alias_type(AliasIdxBot);
1624
1625 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1626 if (ace->_adr_type == adr_type) {
1627 return alias_type(ace->_index);
1628 }
1629
1630 // Handle special cases.
1631 if (adr_type == NULL) return alias_type(AliasIdxTop);
1632 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1633
1634 // Do it the slow way.
1635 const TypePtr* flat = flatten_alias_type(adr_type);
1636
1637 #ifdef ASSERT
1638 assert(flat == flatten_alias_type(flat), "idempotent");
1639 assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
1640 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1641 const TypeOopPtr* foop = flat->is_oopptr();
1642 // Scalarizable allocations have exact klass always.
1643 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1644 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1645 assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1646 }
1647 assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1648 #endif
1649
1650 int idx = AliasIdxTop;
1651 for (int i = 0; i < num_alias_types(); i++) {
1652 if (alias_type(i)->adr_type() == flat) {
1653 idx = i;
1654 break;
1655 }
1656 }
1657
1658 if (idx == AliasIdxTop) {
1659 if (no_create) return NULL;
1660 // Grow the array if necessary.
1661 if (_num_alias_types == _max_alias_types) grow_alias_types();
1662 // Add a new alias type.
1663 idx = _num_alias_types++;
1664 _alias_types[idx]->Init(idx, flat);
1665 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1666 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1667 if (flat->isa_instptr()) {
1668 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1669 && flat->is_instptr()->klass() == env()->Class_klass())
1670 alias_type(idx)->set_rewritable(false);
1671 }
1672 if (flat->isa_aryptr()) {
1673 #ifdef ASSERT
1674 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1675 // (T_BYTE has the weakest alignment and size restrictions...)
1676 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1677 #endif
1678 if (flat->offset() == TypePtr::OffsetBot) {
1679 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1680 }
1681 }
1682 if (flat->isa_klassptr()) {
1683 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1684 alias_type(idx)->set_rewritable(false);
1685 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1686 alias_type(idx)->set_rewritable(false);
1687 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1688 alias_type(idx)->set_rewritable(false);
1689 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1690 alias_type(idx)->set_rewritable(false);
1691 }
1692 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1693 // but the base pointer type is not distinctive enough to identify
1694 // references into JavaThread.)
1695
1696 // Check for final fields.
1697 const TypeInstPtr* tinst = flat->isa_instptr();
1698 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1699 ciField* field;
1700 if (tinst->const_oop() != NULL &&
1701 tinst->klass() == ciEnv::current()->Class_klass() &&
1702 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1703 // static field
1704 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1705 field = k->get_field_by_offset(tinst->offset(), true);
1706 } else {
1707 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1708 field = k->get_field_by_offset(tinst->offset(), false);
1709 }
1710 assert(field == NULL ||
1711 original_field == NULL ||
1712 (field->holder() == original_field->holder() &&
1713 field->offset() == original_field->offset() &&
1714 field->is_static() == original_field->is_static()), "wrong field?");
1715 // Set field() and is_rewritable() attributes.
1716 if (field != NULL) alias_type(idx)->set_field(field);
1717 }
1718 }
1719
1720 // Fill the cache for next time.
1721 ace->_adr_type = adr_type;
1722 ace->_index = idx;
1723 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1724
1725 // Might as well try to fill the cache for the flattened version, too.
1726 AliasCacheEntry* face = probe_alias_cache(flat);
1727 if (face->_adr_type == NULL) {
1728 face->_adr_type = flat;
1729 face->_index = idx;
1730 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1731 }
1732
1733 return alias_type(idx);
1734 }
1735
1736
1737 Compile::AliasType* Compile::alias_type(ciField* field) {
1738 const TypeOopPtr* t;
1739 if (field->is_static())
1740 t = TypeInstPtr::make(field->holder()->java_mirror());
1741 else
1742 t = TypeOopPtr::make_from_klass_raw(field->holder());
1743 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1744 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1745 return atp;
1746 }
1747
1748
1749 //------------------------------have_alias_type--------------------------------
1750 bool Compile::have_alias_type(const TypePtr* adr_type) {
1751 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1752 if (ace->_adr_type == adr_type) {
1753 return true;
1754 }
1755
1756 // Handle special cases.
1757 if (adr_type == NULL) return true;
1758 if (adr_type == TypePtr::BOTTOM) return true;
1759
1760 return find_alias_type(adr_type, true, NULL) != NULL;
1761 }
1762
1763 //-----------------------------must_alias--------------------------------------
1764 // True if all values of the given address type are in the given alias category.
1765 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1766 if (alias_idx == AliasIdxBot) return true; // the universal category
1767 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1768 if (alias_idx == AliasIdxTop) return false; // the empty category
1769 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1770
1771 // the only remaining possible overlap is identity
1772 int adr_idx = get_alias_index(adr_type);
1773 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1774 assert(adr_idx == alias_idx ||
1775 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1776 && adr_type != TypeOopPtr::BOTTOM),
1777 "should not be testing for overlap with an unsafe pointer");
1778 return adr_idx == alias_idx;
1779 }
1780
1781 //------------------------------can_alias--------------------------------------
1782 // True if any values of the given address type are in the given alias category.
1783 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1784 if (alias_idx == AliasIdxTop) return false; // the empty category
1785 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1786 if (alias_idx == AliasIdxBot) return true; // the universal category
1787 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1788
1789 // the only remaining possible overlap is identity
1790 int adr_idx = get_alias_index(adr_type);
1791 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1792 return adr_idx == alias_idx;
1793 }
1794
1795
1796
1797 //---------------------------pop_warm_call-------------------------------------
1798 WarmCallInfo* Compile::pop_warm_call() {
1799 WarmCallInfo* wci = _warm_calls;
1800 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1801 return wci;
1802 }
1803
1804 //----------------------------Inline_Warm--------------------------------------
1805 int Compile::Inline_Warm() {
1806 // If there is room, try to inline some more warm call sites.
1807 // %%% Do a graph index compaction pass when we think we're out of space?
1808 if (!InlineWarmCalls) return 0;
1809
1810 int calls_made_hot = 0;
1811 int room_to_grow = NodeCountInliningCutoff - unique();
1812 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1813 int amount_grown = 0;
1814 WarmCallInfo* call;
1815 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1816 int est_size = (int)call->size();
1817 if (est_size > (room_to_grow - amount_grown)) {
1818 // This one won't fit anyway. Get rid of it.
1819 call->make_cold();
1820 continue;
1821 }
1822 call->make_hot();
1823 calls_made_hot++;
1824 amount_grown += est_size;
1825 amount_to_grow -= est_size;
1826 }
1827
1828 if (calls_made_hot > 0) set_major_progress();
1829 return calls_made_hot;
1830 }
1831
1832
1833 //----------------------------Finish_Warm--------------------------------------
1834 void Compile::Finish_Warm() {
1835 if (!InlineWarmCalls) return;
1836 if (failing()) return;
1837 if (warm_calls() == NULL) return;
1838
1839 // Clean up loose ends, if we are out of space for inlining.
1840 WarmCallInfo* call;
1841 while ((call = pop_warm_call()) != NULL) {
1842 call->make_cold();
1843 }
1844 }
1845
1846 //---------------------cleanup_loop_predicates-----------------------
1847 // Remove the opaque nodes that protect the predicates so that all unused
1848 // checks and uncommon_traps will be eliminated from the ideal graph
1849 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1850 if (predicate_count()==0) return;
1851 for (int i = predicate_count(); i > 0; i--) {
1852 Node * n = predicate_opaque1_node(i-1);
1853 assert(n->Opcode() == Op_Opaque1, "must be");
1854 igvn.replace_node(n, n->in(1));
1855 }
1856 assert(predicate_count()==0, "should be clean!");
1857 }
1858
1859 // StringOpts and late inlining of string methods
1860 void Compile::inline_string_calls(bool parse_time) {
1861 {
1862 // remove useless nodes to make the usage analysis simpler
1863 ResourceMark rm;
1864 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1865 }
1866
1867 {
1868 ResourceMark rm;
1869 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1870 PhaseStringOpts pso(initial_gvn(), for_igvn());
1871 print_method(PHASE_AFTER_STRINGOPTS, 3);
1872 }
1873
1874 // now inline anything that we skipped the first time around
1875 if (!parse_time) {
1876 _late_inlines_pos = _late_inlines.length();
1877 }
1878
1879 while (_string_late_inlines.length() > 0) {
1880 CallGenerator* cg = _string_late_inlines.pop();
1881 cg->do_late_inline();
1882 if (failing()) return;
1883 }
1884 _string_late_inlines.trunc_to(0);
1885 }
1886
1887 // Late inlining of boxing methods
1888 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1889 if (_boxing_late_inlines.length() > 0) {
1890 assert(has_boxed_value(), "inconsistent");
1891
1892 PhaseGVN* gvn = initial_gvn();
1893 set_inlining_incrementally(true);
1894
1895 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1896 for_igvn()->clear();
1897 gvn->replace_with(&igvn);
1898
1899 _late_inlines_pos = _late_inlines.length();
1900
1901 while (_boxing_late_inlines.length() > 0) {
1902 CallGenerator* cg = _boxing_late_inlines.pop();
1903 cg->do_late_inline();
1904 if (failing()) return;
1905 }
1906 _boxing_late_inlines.trunc_to(0);
1907
1908 {
1909 ResourceMark rm;
1910 PhaseRemoveUseless pru(gvn, for_igvn());
1911 }
1912
1913 igvn = PhaseIterGVN(gvn);
1914 igvn.optimize();
1915
1916 set_inlining_progress(false);
1917 set_inlining_incrementally(false);
1918 }
1919 }
1920
1921 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1922 assert(IncrementalInline, "incremental inlining should be on");
1923 PhaseGVN* gvn = initial_gvn();
1924
1925 set_inlining_progress(false);
1926 for_igvn()->clear();
1927 gvn->replace_with(&igvn);
1928
1929 int i = 0;
1930
1931 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1932 CallGenerator* cg = _late_inlines.at(i);
1933 _late_inlines_pos = i+1;
1934 cg->do_late_inline();
1935 if (failing()) return;
1936 }
1937 int j = 0;
1938 for (; i < _late_inlines.length(); i++, j++) {
1939 _late_inlines.at_put(j, _late_inlines.at(i));
1940 }
1941 _late_inlines.trunc_to(j);
1942
1943 {
1944 ResourceMark rm;
1945 PhaseRemoveUseless pru(gvn, for_igvn());
1946 }
1947
1948 igvn = PhaseIterGVN(gvn);
1949 }
1950
1951 // Perform incremental inlining until bound on number of live nodes is reached
1952 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1953 PhaseGVN* gvn = initial_gvn();
1954
1955 set_inlining_incrementally(true);
1956 set_inlining_progress(true);
1957 uint low_live_nodes = 0;
1958
1959 while(inlining_progress() && _late_inlines.length() > 0) {
1960
1961 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1962 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1963 // PhaseIdealLoop is expensive so we only try it once we are
1964 // out of live nodes and we only try it again if the previous
1965 // helped got the number of nodes down significantly
1966 PhaseIdealLoop ideal_loop( igvn, false, true );
1967 if (failing()) return;
1968 low_live_nodes = live_nodes();
1969 _major_progress = true;
1970 }
1971
1972 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1973 break;
1974 }
1975 }
1976
1977 inline_incrementally_one(igvn);
1978
1979 if (failing()) return;
1980
1981 igvn.optimize();
1982
1983 if (failing()) return;
1984 }
1985
1986 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1987
1988 if (_string_late_inlines.length() > 0) {
1989 assert(has_stringbuilder(), "inconsistent");
1990 for_igvn()->clear();
1991 initial_gvn()->replace_with(&igvn);
1992
1993 inline_string_calls(false);
1994
1995 if (failing()) return;
1996
1997 {
1998 ResourceMark rm;
1999 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2000 }
2001
2002 igvn = PhaseIterGVN(gvn);
2003
2004 igvn.optimize();
2005 }
2006
2007 set_inlining_incrementally(false);
2008 }
2009
2010
2011 //------------------------------Optimize---------------------------------------
2012 // Given a graph, optimize it.
2013 void Compile::Optimize() {
2014 TracePhase t1("optimizer", &_t_optimizer, true);
2015
2016 #ifndef PRODUCT
2017 if (env()->break_at_compile()) {
2018 BREAKPOINT;
2019 }
2020
2021 #endif
2022
2023 ResourceMark rm;
2024 int loop_opts_cnt;
2025
2026 print_inlining_reinit();
2027
2028 NOT_PRODUCT( verify_graph_edges(); )
2029
2030 print_method(PHASE_AFTER_PARSING);
2031
2032 {
2033 // Iterative Global Value Numbering, including ideal transforms
2034 // Initialize IterGVN with types and values from parse-time GVN
2035 PhaseIterGVN igvn(initial_gvn());
2036 {
2037 NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
2038 igvn.optimize();
2039 }
2040
2041 print_method(PHASE_ITER_GVN1, 2);
2042
2043 if (failing()) return;
2044
2045 {
2046 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2047 inline_incrementally(igvn);
2048 }
2049
2050 print_method(PHASE_INCREMENTAL_INLINE, 2);
2051
2052 if (failing()) return;
2053
2054 if (eliminate_boxing()) {
2055 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2056 // Inline valueOf() methods now.
2057 inline_boxing_calls(igvn);
2058
2059 if (AlwaysIncrementalInline) {
2060 inline_incrementally(igvn);
2061 }
2062
2063 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2064
2065 if (failing()) return;
2066 }
2067
2068 // Remove the speculative part of types and clean up the graph from
2069 // the extra CastPP nodes whose only purpose is to carry them. Do
2070 // that early so that optimizations are not disrupted by the extra
2071 // CastPP nodes.
2072 remove_speculative_types(igvn);
2073
2074 // No more new expensive nodes will be added to the list from here
2075 // so keep only the actual candidates for optimizations.
2076 cleanup_expensive_nodes(igvn);
2077
2078 // Perform escape analysis
2079 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2080 if (has_loops()) {
2081 // Cleanup graph (remove dead nodes).
2082 TracePhase t2("idealLoop", &_t_idealLoop, true);
2083 PhaseIdealLoop ideal_loop( igvn, false, true );
2084 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2085 if (failing()) return;
2086 }
2087 ConnectionGraph::do_analysis(this, &igvn);
2088
2089 if (failing()) return;
2090
2091 // Optimize out fields loads from scalar replaceable allocations.
2092 igvn.optimize();
2093 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2094
2095 if (failing()) return;
2096
2097 if (congraph() != NULL && macro_count() > 0) {
2098 NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2099 PhaseMacroExpand mexp(igvn);
2100 mexp.eliminate_macro_nodes();
2101 igvn.set_delay_transform(false);
2102
2103 igvn.optimize();
2104 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2105
2106 if (failing()) return;
2107 }
2108 }
2109
2110 // Loop transforms on the ideal graph. Range Check Elimination,
2111 // peeling, unrolling, etc.
2112
2113 // Set loop opts counter
2114 loop_opts_cnt = num_loop_opts();
2115 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2116 {
2117 TracePhase t2("idealLoop", &_t_idealLoop, true);
2118 PhaseIdealLoop ideal_loop( igvn, true );
2119 loop_opts_cnt--;
2120 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2121 if (failing()) return;
2122 }
2123 // Loop opts pass if partial peeling occurred in previous pass
2124 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2125 TracePhase t3("idealLoop", &_t_idealLoop, true);
2126 PhaseIdealLoop ideal_loop( igvn, false );
2127 loop_opts_cnt--;
2128 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2129 if (failing()) return;
2130 }
2131 // Loop opts pass for loop-unrolling before CCP
2132 if(major_progress() && (loop_opts_cnt > 0)) {
2133 TracePhase t4("idealLoop", &_t_idealLoop, true);
2134 PhaseIdealLoop ideal_loop( igvn, false );
2135 loop_opts_cnt--;
2136 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2137 }
2138 if (!failing()) {
2139 // Verify that last round of loop opts produced a valid graph
2140 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2141 PhaseIdealLoop::verify(igvn);
2142 }
2143 }
2144 if (failing()) return;
2145
2146 // Conditional Constant Propagation;
2147 PhaseCCP ccp( &igvn );
2148 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2149 {
2150 TracePhase t2("ccp", &_t_ccp, true);
2151 ccp.do_transform();
2152 }
2153 print_method(PHASE_CPP1, 2);
2154
2155 assert( true, "Break here to ccp.dump_old2new_map()");
2156
2157 // Iterative Global Value Numbering, including ideal transforms
2158 {
2159 NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2160 igvn = ccp;
2161 igvn.optimize();
2162 }
2163
2164 print_method(PHASE_ITER_GVN2, 2);
2165
2166 if (failing()) return;
2167
2168 // Loop transforms on the ideal graph. Range Check Elimination,
2169 // peeling, unrolling, etc.
2170 if(loop_opts_cnt > 0) {
2171 debug_only( int cnt = 0; );
2172 while(major_progress() && (loop_opts_cnt > 0)) {
2173 TracePhase t2("idealLoop", &_t_idealLoop, true);
2174 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2175 PhaseIdealLoop ideal_loop( igvn, true);
2176 loop_opts_cnt--;
2177 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2178 if (failing()) return;
2179 }
2180 }
2181
2182 {
2183 // Verify that all previous optimizations produced a valid graph
2184 // at least to this point, even if no loop optimizations were done.
2185 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2186 PhaseIdealLoop::verify(igvn);
2187 }
2188
2189 {
2190 NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2191 PhaseMacroExpand mex(igvn);
2192 if (mex.expand_macro_nodes()) {
2193 assert(failing(), "must bail out w/ explicit message");
2194 return;
2195 }
2196 }
2197
2198 } // (End scope of igvn; run destructor if necessary for asserts.)
2199
2200 process_print_inlining();
2201 // A method with only infinite loops has no edges entering loops from root
2202 {
2203 NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2204 if (final_graph_reshaping()) {
2205 assert(failing(), "must bail out w/ explicit message");
2206 return;
2207 }
2208 }
2209
2210 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2211 }
2212
2213
2214 //------------------------------Code_Gen---------------------------------------
2215 // Given a graph, generate code for it
2216 void Compile::Code_Gen() {
2217 if (failing()) {
2218 return;
2219 }
2220
2221 // Perform instruction selection. You might think we could reclaim Matcher
2222 // memory PDQ, but actually the Matcher is used in generating spill code.
2223 // Internals of the Matcher (including some VectorSets) must remain live
2224 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2225 // set a bit in reclaimed memory.
2226
2227 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2228 // nodes. Mapping is only valid at the root of each matched subtree.
2229 NOT_PRODUCT( verify_graph_edges(); )
2230
2231 Matcher matcher;
2232 _matcher = &matcher;
2233 {
2234 TracePhase t2("matcher", &_t_matcher, true);
2235 matcher.match();
2236 }
2237 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2238 // nodes. Mapping is only valid at the root of each matched subtree.
2239 NOT_PRODUCT( verify_graph_edges(); )
2240
2241 // If you have too many nodes, or if matching has failed, bail out
2242 check_node_count(0, "out of nodes matching instructions");
2243 if (failing()) {
2244 return;
2245 }
2246
2247 // Build a proper-looking CFG
2248 PhaseCFG cfg(node_arena(), root(), matcher);
2249 _cfg = &cfg;
2250 {
2251 NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2252 bool success = cfg.do_global_code_motion();
2253 if (!success) {
2254 return;
2255 }
2256
2257 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2258 NOT_PRODUCT( verify_graph_edges(); )
2259 debug_only( cfg.verify(); )
2260 }
2261
2262 PhaseChaitin regalloc(unique(), cfg, matcher);
2263 _regalloc = ®alloc;
2264 {
2265 TracePhase t2("regalloc", &_t_registerAllocation, true);
2266 // Perform register allocation. After Chaitin, use-def chains are
2267 // no longer accurate (at spill code) and so must be ignored.
2268 // Node->LRG->reg mappings are still accurate.
2269 _regalloc->Register_Allocate();
2270
2271 // Bail out if the allocator builds too many nodes
2272 if (failing()) {
2273 return;
2274 }
2275 }
2276
2277 // Prior to register allocation we kept empty basic blocks in case the
2278 // the allocator needed a place to spill. After register allocation we
2279 // are not adding any new instructions. If any basic block is empty, we
2280 // can now safely remove it.
2281 {
2282 NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2283 cfg.remove_empty_blocks();
2284 if (do_freq_based_layout()) {
2285 PhaseBlockLayout layout(cfg);
2286 } else {
2287 cfg.set_loop_alignment();
2288 }
2289 cfg.fixup_flow();
2290 }
2291
2292 // Apply peephole optimizations
2293 if( OptoPeephole ) {
2294 NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2295 PhasePeephole peep( _regalloc, cfg);
2296 peep.do_transform();
2297 }
2298
2299 // Do late expand if CPU requires this.
2300 if (Matcher::require_postalloc_expand) {
2301 NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
2302 cfg.postalloc_expand(_regalloc);
2303 }
2304
2305 // Convert Nodes to instruction bits in a buffer
2306 {
2307 // %%%% workspace merge brought two timers together for one job
2308 TracePhase t2a("output", &_t_output, true);
2309 NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2310 Output();
2311 }
2312
2313 print_method(PHASE_FINAL_CODE);
2314
2315 // He's dead, Jim.
2316 _cfg = (PhaseCFG*)0xdeadbeef;
2317 _regalloc = (PhaseChaitin*)0xdeadbeef;
2318 }
2319
2320
2321 //------------------------------dump_asm---------------------------------------
2322 // Dump formatted assembly
2323 #ifndef PRODUCT
2324 void Compile::dump_asm(int *pcs, uint pc_limit) {
2325 bool cut_short = false;
2326 tty->print_cr("#");
2327 tty->print("# "); _tf->dump(); tty->cr();
2328 tty->print_cr("#");
2329
2330 // For all blocks
2331 int pc = 0x0; // Program counter
2332 char starts_bundle = ' ';
2333 _regalloc->dump_frame();
2334
2335 Node *n = NULL;
2336 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2337 if (VMThread::should_terminate()) {
2338 cut_short = true;
2339 break;
2340 }
2341 Block* block = _cfg->get_block(i);
2342 if (block->is_connector() && !Verbose) {
2343 continue;
2344 }
2345 n = block->head();
2346 if (pcs && n->_idx < pc_limit) {
2347 tty->print("%3.3x ", pcs[n->_idx]);
2348 } else {
2349 tty->print(" ");
2350 }
2351 block->dump_head(_cfg);
2352 if (block->is_connector()) {
2353 tty->print_cr(" # Empty connector block");
2354 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2355 tty->print_cr(" # Block is sole successor of call");
2356 }
2357
2358 // For all instructions
2359 Node *delay = NULL;
2360 for (uint j = 0; j < block->number_of_nodes(); j++) {
2361 if (VMThread::should_terminate()) {
2362 cut_short = true;
2363 break;
2364 }
2365 n = block->get_node(j);
2366 if (valid_bundle_info(n)) {
2367 Bundle* bundle = node_bundling(n);
2368 if (bundle->used_in_unconditional_delay()) {
2369 delay = n;
2370 continue;
2371 }
2372 if (bundle->starts_bundle()) {
2373 starts_bundle = '+';
2374 }
2375 }
2376
2377 if (WizardMode) {
2378 n->dump();
2379 }
2380
2381 if( !n->is_Region() && // Dont print in the Assembly
2382 !n->is_Phi() && // a few noisely useless nodes
2383 !n->is_Proj() &&
2384 !n->is_MachTemp() &&
2385 !n->is_SafePointScalarObject() &&
2386 !n->is_Catch() && // Would be nice to print exception table targets
2387 !n->is_MergeMem() && // Not very interesting
2388 !n->is_top() && // Debug info table constants
2389 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2390 ) {
2391 if (pcs && n->_idx < pc_limit)
2392 tty->print("%3.3x", pcs[n->_idx]);
2393 else
2394 tty->print(" ");
2395 tty->print(" %c ", starts_bundle);
2396 starts_bundle = ' ';
2397 tty->print("\t");
2398 n->format(_regalloc, tty);
2399 tty->cr();
2400 }
2401
2402 // If we have an instruction with a delay slot, and have seen a delay,
2403 // then back up and print it
2404 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2405 assert(delay != NULL, "no unconditional delay instruction");
2406 if (WizardMode) delay->dump();
2407
2408 if (node_bundling(delay)->starts_bundle())
2409 starts_bundle = '+';
2410 if (pcs && n->_idx < pc_limit)
2411 tty->print("%3.3x", pcs[n->_idx]);
2412 else
2413 tty->print(" ");
2414 tty->print(" %c ", starts_bundle);
2415 starts_bundle = ' ';
2416 tty->print("\t");
2417 delay->format(_regalloc, tty);
2418 tty->cr();
2419 delay = NULL;
2420 }
2421
2422 // Dump the exception table as well
2423 if( n->is_Catch() && (Verbose || WizardMode) ) {
2424 // Print the exception table for this offset
2425 _handler_table.print_subtable_for(pc);
2426 }
2427 }
2428
2429 if (pcs && n->_idx < pc_limit)
2430 tty->print_cr("%3.3x", pcs[n->_idx]);
2431 else
2432 tty->cr();
2433
2434 assert(cut_short || delay == NULL, "no unconditional delay branch");
2435
2436 } // End of per-block dump
2437 tty->cr();
2438
2439 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2440 }
2441 #endif
2442
2443 //------------------------------Final_Reshape_Counts---------------------------
2444 // This class defines counters to help identify when a method
2445 // may/must be executed using hardware with only 24-bit precision.
2446 struct Final_Reshape_Counts : public StackObj {
2447 int _call_count; // count non-inlined 'common' calls
2448 int _float_count; // count float ops requiring 24-bit precision
2449 int _double_count; // count double ops requiring more precision
2450 int _java_call_count; // count non-inlined 'java' calls
2451 int _inner_loop_count; // count loops which need alignment
2452 VectorSet _visited; // Visitation flags
2453 Node_List _tests; // Set of IfNodes & PCTableNodes
2454
2455 Final_Reshape_Counts() :
2456 _call_count(0), _float_count(0), _double_count(0),
2457 _java_call_count(0), _inner_loop_count(0),
2458 _visited( Thread::current()->resource_area() ) { }
2459
2460 void inc_call_count () { _call_count ++; }
2461 void inc_float_count () { _float_count ++; }
2462 void inc_double_count() { _double_count++; }
2463 void inc_java_call_count() { _java_call_count++; }
2464 void inc_inner_loop_count() { _inner_loop_count++; }
2465
2466 int get_call_count () const { return _call_count ; }
2467 int get_float_count () const { return _float_count ; }
2468 int get_double_count() const { return _double_count; }
2469 int get_java_call_count() const { return _java_call_count; }
2470 int get_inner_loop_count() const { return _inner_loop_count; }
2471 };
2472
2473 #ifdef ASSERT
2474 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2475 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2476 // Make sure the offset goes inside the instance layout.
2477 return k->contains_field_offset(tp->offset());
2478 // Note that OffsetBot and OffsetTop are very negative.
2479 }
2480 #endif
2481
2482 // Eliminate trivially redundant StoreCMs and accumulate their
2483 // precedence edges.
2484 void Compile::eliminate_redundant_card_marks(Node* n) {
2485 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2486 if (n->in(MemNode::Address)->outcnt() > 1) {
2487 // There are multiple users of the same address so it might be
2488 // possible to eliminate some of the StoreCMs
2489 Node* mem = n->in(MemNode::Memory);
2490 Node* adr = n->in(MemNode::Address);
2491 Node* val = n->in(MemNode::ValueIn);
2492 Node* prev = n;
2493 bool done = false;
2494 // Walk the chain of StoreCMs eliminating ones that match. As
2495 // long as it's a chain of single users then the optimization is
2496 // safe. Eliminating partially redundant StoreCMs would require
2497 // cloning copies down the other paths.
2498 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2499 if (adr == mem->in(MemNode::Address) &&
2500 val == mem->in(MemNode::ValueIn)) {
2501 // redundant StoreCM
2502 if (mem->req() > MemNode::OopStore) {
2503 // Hasn't been processed by this code yet.
2504 n->add_prec(mem->in(MemNode::OopStore));
2505 } else {
2506 // Already converted to precedence edge
2507 for (uint i = mem->req(); i < mem->len(); i++) {
2508 // Accumulate any precedence edges
2509 if (mem->in(i) != NULL) {
2510 n->add_prec(mem->in(i));
2511 }
2512 }
2513 // Everything above this point has been processed.
2514 done = true;
2515 }
2516 // Eliminate the previous StoreCM
2517 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2518 assert(mem->outcnt() == 0, "should be dead");
2519 mem->disconnect_inputs(NULL, this);
2520 } else {
2521 prev = mem;
2522 }
2523 mem = prev->in(MemNode::Memory);
2524 }
2525 }
2526 }
2527
2528 //------------------------------final_graph_reshaping_impl----------------------
2529 // Implement items 1-5 from final_graph_reshaping below.
2530 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2531
2532 if ( n->outcnt() == 0 ) return; // dead node
2533 uint nop = n->Opcode();
2534
2535 // Check for 2-input instruction with "last use" on right input.
2536 // Swap to left input. Implements item (2).
2537 if( n->req() == 3 && // two-input instruction
2538 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2539 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2540 n->in(2)->outcnt() == 1 &&// right use IS a last use
2541 !n->in(2)->is_Con() ) { // right use is not a constant
2542 // Check for commutative opcode
2543 switch( nop ) {
2544 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2545 case Op_MaxI: case Op_MinI:
2546 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2547 case Op_AndL: case Op_XorL: case Op_OrL:
2548 case Op_AndI: case Op_XorI: case Op_OrI: {
2549 // Move "last use" input to left by swapping inputs
2550 n->swap_edges(1, 2);
2551 break;
2552 }
2553 default:
2554 break;
2555 }
2556 }
2557
2558 #ifdef ASSERT
2559 if( n->is_Mem() ) {
2560 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2561 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2562 // oop will be recorded in oop map if load crosses safepoint
2563 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2564 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2565 "raw memory operations should have control edge");
2566 }
2567 #endif
2568 // Count FPU ops and common calls, implements item (3)
2569 switch( nop ) {
2570 // Count all float operations that may use FPU
2571 case Op_AddF:
2572 case Op_SubF:
2573 case Op_MulF:
2574 case Op_DivF:
2575 case Op_NegF:
2576 case Op_ModF:
2577 case Op_ConvI2F:
2578 case Op_ConF:
2579 case Op_CmpF:
2580 case Op_CmpF3:
2581 // case Op_ConvL2F: // longs are split into 32-bit halves
2582 frc.inc_float_count();
2583 break;
2584
2585 case Op_ConvF2D:
2586 case Op_ConvD2F:
2587 frc.inc_float_count();
2588 frc.inc_double_count();
2589 break;
2590
2591 // Count all double operations that may use FPU
2592 case Op_AddD:
2593 case Op_SubD:
2594 case Op_MulD:
2595 case Op_DivD:
2596 case Op_NegD:
2597 case Op_ModD:
2598 case Op_ConvI2D:
2599 case Op_ConvD2I:
2600 // case Op_ConvL2D: // handled by leaf call
2601 // case Op_ConvD2L: // handled by leaf call
2602 case Op_ConD:
2603 case Op_CmpD:
2604 case Op_CmpD3:
2605 frc.inc_double_count();
2606 break;
2607 case Op_Opaque1: // Remove Opaque Nodes before matching
2608 case Op_Opaque2: // Remove Opaque Nodes before matching
2609 case Op_Opaque3:
2610 n->subsume_by(n->in(1), this);
2611 break;
2612 case Op_CallStaticJava:
2613 case Op_CallJava:
2614 case Op_CallDynamicJava:
2615 frc.inc_java_call_count(); // Count java call site;
2616 case Op_CallRuntime:
2617 case Op_CallLeaf:
2618 case Op_CallLeafNoFP: {
2619 assert( n->is_Call(), "" );
2620 CallNode *call = n->as_Call();
2621 // Count call sites where the FP mode bit would have to be flipped.
2622 // Do not count uncommon runtime calls:
2623 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2624 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2625 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2626 frc.inc_call_count(); // Count the call site
2627 } else { // See if uncommon argument is shared
2628 Node *n = call->in(TypeFunc::Parms);
2629 int nop = n->Opcode();
2630 // Clone shared simple arguments to uncommon calls, item (1).
2631 if( n->outcnt() > 1 &&
2632 !n->is_Proj() &&
2633 nop != Op_CreateEx &&
2634 nop != Op_CheckCastPP &&
2635 nop != Op_DecodeN &&
2636 nop != Op_DecodeNKlass &&
2637 !n->is_Mem() ) {
2638 Node *x = n->clone();
2639 call->set_req( TypeFunc::Parms, x );
2640 }
2641 }
2642 break;
2643 }
2644
2645 case Op_StoreD:
2646 case Op_LoadD:
2647 case Op_LoadD_unaligned:
2648 frc.inc_double_count();
2649 goto handle_mem;
2650 case Op_StoreF:
2651 case Op_LoadF:
2652 frc.inc_float_count();
2653 goto handle_mem;
2654
2655 case Op_StoreCM:
2656 {
2657 // Convert OopStore dependence into precedence edge
2658 Node* prec = n->in(MemNode::OopStore);
2659 n->del_req(MemNode::OopStore);
2660 n->add_prec(prec);
2661 eliminate_redundant_card_marks(n);
2662 }
2663
2664 // fall through
2665
2666 case Op_StoreB:
2667 case Op_StoreC:
2668 case Op_StorePConditional:
2669 case Op_StoreI:
2670 case Op_StoreL:
2671 case Op_StoreIConditional:
2672 case Op_StoreLConditional:
2673 case Op_CompareAndSwapI:
2674 case Op_CompareAndSwapL:
2675 case Op_CompareAndSwapP:
2676 case Op_CompareAndSwapN:
2677 case Op_GetAndAddI:
2678 case Op_GetAndAddL:
2679 case Op_GetAndSetI:
2680 case Op_GetAndSetL:
2681 case Op_GetAndSetP:
2682 case Op_GetAndSetN:
2683 case Op_StoreP:
2684 case Op_StoreN:
2685 case Op_StoreNKlass:
2686 case Op_LoadB:
2687 case Op_LoadUB:
2688 case Op_LoadUS:
2689 case Op_LoadI:
2690 case Op_LoadKlass:
2691 case Op_LoadNKlass:
2692 case Op_LoadL:
2693 case Op_LoadL_unaligned:
2694 case Op_LoadPLocked:
2695 case Op_LoadP:
2696 case Op_LoadN:
2697 case Op_LoadRange:
2698 case Op_LoadS: {
2699 handle_mem:
2700 #ifdef ASSERT
2701 if( VerifyOptoOopOffsets ) {
2702 assert( n->is_Mem(), "" );
2703 MemNode *mem = (MemNode*)n;
2704 // Check to see if address types have grounded out somehow.
2705 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2706 assert( !tp || oop_offset_is_sane(tp), "" );
2707 }
2708 #endif
2709 break;
2710 }
2711
2712 case Op_AddP: { // Assert sane base pointers
2713 Node *addp = n->in(AddPNode::Address);
2714 assert( !addp->is_AddP() ||
2715 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2716 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2717 "Base pointers must match" );
2718 #ifdef _LP64
2719 if ((UseCompressedOops || UseCompressedClassPointers) &&
2720 addp->Opcode() == Op_ConP &&
2721 addp == n->in(AddPNode::Base) &&
2722 n->in(AddPNode::Offset)->is_Con()) {
2723 // Use addressing with narrow klass to load with offset on x86.
2724 // On sparc loading 32-bits constant and decoding it have less
2725 // instructions (4) then load 64-bits constant (7).
2726 // Do this transformation here since IGVN will convert ConN back to ConP.
2727 const Type* t = addp->bottom_type();
2728 if (t->isa_oopptr() || t->isa_klassptr()) {
2729 Node* nn = NULL;
2730
2731 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2732
2733 // Look for existing ConN node of the same exact type.
2734 Node* r = root();
2735 uint cnt = r->outcnt();
2736 for (uint i = 0; i < cnt; i++) {
2737 Node* m = r->raw_out(i);
2738 if (m!= NULL && m->Opcode() == op &&
2739 m->bottom_type()->make_ptr() == t) {
2740 nn = m;
2741 break;
2742 }
2743 }
2744 if (nn != NULL) {
2745 // Decode a narrow oop to match address
2746 // [R12 + narrow_oop_reg<<3 + offset]
2747 if (t->isa_oopptr()) {
2748 nn = new DecodeNNode(nn, t);
2749 } else {
2750 nn = new DecodeNKlassNode(nn, t);
2751 }
2752 n->set_req(AddPNode::Base, nn);
2753 n->set_req(AddPNode::Address, nn);
2754 if (addp->outcnt() == 0) {
2755 addp->disconnect_inputs(NULL, this);
2756 }
2757 }
2758 }
2759 }
2760 #endif
2761 break;
2762 }
2763
2764 #ifdef _LP64
2765 case Op_CastPP:
2766 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2767 Node* in1 = n->in(1);
2768 const Type* t = n->bottom_type();
2769 Node* new_in1 = in1->clone();
2770 new_in1->as_DecodeN()->set_type(t);
2771
2772 if (!Matcher::narrow_oop_use_complex_address()) {
2773 //
2774 // x86, ARM and friends can handle 2 adds in addressing mode
2775 // and Matcher can fold a DecodeN node into address by using
2776 // a narrow oop directly and do implicit NULL check in address:
2777 //
2778 // [R12 + narrow_oop_reg<<3 + offset]
2779 // NullCheck narrow_oop_reg
2780 //
2781 // On other platforms (Sparc) we have to keep new DecodeN node and
2782 // use it to do implicit NULL check in address:
2783 //
2784 // decode_not_null narrow_oop_reg, base_reg
2785 // [base_reg + offset]
2786 // NullCheck base_reg
2787 //
2788 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2789 // to keep the information to which NULL check the new DecodeN node
2790 // corresponds to use it as value in implicit_null_check().
2791 //
2792 new_in1->set_req(0, n->in(0));
2793 }
2794
2795 n->subsume_by(new_in1, this);
2796 if (in1->outcnt() == 0) {
2797 in1->disconnect_inputs(NULL, this);
2798 }
2799 }
2800 break;
2801
2802 case Op_CmpP:
2803 // Do this transformation here to preserve CmpPNode::sub() and
2804 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2805 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2806 Node* in1 = n->in(1);
2807 Node* in2 = n->in(2);
2808 if (!in1->is_DecodeNarrowPtr()) {
2809 in2 = in1;
2810 in1 = n->in(2);
2811 }
2812 assert(in1->is_DecodeNarrowPtr(), "sanity");
2813
2814 Node* new_in2 = NULL;
2815 if (in2->is_DecodeNarrowPtr()) {
2816 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2817 new_in2 = in2->in(1);
2818 } else if (in2->Opcode() == Op_ConP) {
2819 const Type* t = in2->bottom_type();
2820 if (t == TypePtr::NULL_PTR) {
2821 assert(in1->is_DecodeN(), "compare klass to null?");
2822 // Don't convert CmpP null check into CmpN if compressed
2823 // oops implicit null check is not generated.
2824 // This will allow to generate normal oop implicit null check.
2825 if (Matcher::gen_narrow_oop_implicit_null_checks())
2826 new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2827 //
2828 // This transformation together with CastPP transformation above
2829 // will generated code for implicit NULL checks for compressed oops.
2830 //
2831 // The original code after Optimize()
2832 //
2833 // LoadN memory, narrow_oop_reg
2834 // decode narrow_oop_reg, base_reg
2835 // CmpP base_reg, NULL
2836 // CastPP base_reg // NotNull
2837 // Load [base_reg + offset], val_reg
2838 //
2839 // after these transformations will be
2840 //
2841 // LoadN memory, narrow_oop_reg
2842 // CmpN narrow_oop_reg, NULL
2843 // decode_not_null narrow_oop_reg, base_reg
2844 // Load [base_reg + offset], val_reg
2845 //
2846 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2847 // since narrow oops can be used in debug info now (see the code in
2848 // final_graph_reshaping_walk()).
2849 //
2850 // At the end the code will be matched to
2851 // on x86:
2852 //
2853 // Load_narrow_oop memory, narrow_oop_reg
2854 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2855 // NullCheck narrow_oop_reg
2856 //
2857 // and on sparc:
2858 //
2859 // Load_narrow_oop memory, narrow_oop_reg
2860 // decode_not_null narrow_oop_reg, base_reg
2861 // Load [base_reg + offset], val_reg
2862 // NullCheck base_reg
2863 //
2864 } else if (t->isa_oopptr()) {
2865 new_in2 = ConNode::make(this, t->make_narrowoop());
2866 } else if (t->isa_klassptr()) {
2867 new_in2 = ConNode::make(this, t->make_narrowklass());
2868 }
2869 }
2870 if (new_in2 != NULL) {
2871 Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2872 n->subsume_by(cmpN, this);
2873 if (in1->outcnt() == 0) {
2874 in1->disconnect_inputs(NULL, this);
2875 }
2876 if (in2->outcnt() == 0) {
2877 in2->disconnect_inputs(NULL, this);
2878 }
2879 }
2880 }
2881 break;
2882
2883 case Op_DecodeN:
2884 case Op_DecodeNKlass:
2885 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2886 // DecodeN could be pinned when it can't be fold into
2887 // an address expression, see the code for Op_CastPP above.
2888 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2889 break;
2890
2891 case Op_EncodeP:
2892 case Op_EncodePKlass: {
2893 Node* in1 = n->in(1);
2894 if (in1->is_DecodeNarrowPtr()) {
2895 n->subsume_by(in1->in(1), this);
2896 } else if (in1->Opcode() == Op_ConP) {
2897 const Type* t = in1->bottom_type();
2898 if (t == TypePtr::NULL_PTR) {
2899 assert(t->isa_oopptr(), "null klass?");
2900 n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2901 } else if (t->isa_oopptr()) {
2902 n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2903 } else if (t->isa_klassptr()) {
2904 n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2905 }
2906 }
2907 if (in1->outcnt() == 0) {
2908 in1->disconnect_inputs(NULL, this);
2909 }
2910 break;
2911 }
2912
2913 case Op_Proj: {
2914 if (OptimizeStringConcat) {
2915 ProjNode* p = n->as_Proj();
2916 if (p->_is_io_use) {
2917 // Separate projections were used for the exception path which
2918 // are normally removed by a late inline. If it wasn't inlined
2919 // then they will hang around and should just be replaced with
2920 // the original one.
2921 Node* proj = NULL;
2922 // Replace with just one
2923 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2924 Node *use = i.get();
2925 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2926 proj = use;
2927 break;
2928 }
2929 }
2930 assert(proj != NULL, "must be found");
2931 p->subsume_by(proj, this);
2932 }
2933 }
2934 break;
2935 }
2936
2937 case Op_Phi:
2938 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2939 // The EncodeP optimization may create Phi with the same edges
2940 // for all paths. It is not handled well by Register Allocator.
2941 Node* unique_in = n->in(1);
2942 assert(unique_in != NULL, "");
2943 uint cnt = n->req();
2944 for (uint i = 2; i < cnt; i++) {
2945 Node* m = n->in(i);
2946 assert(m != NULL, "");
2947 if (unique_in != m)
2948 unique_in = NULL;
2949 }
2950 if (unique_in != NULL) {
2951 n->subsume_by(unique_in, this);
2952 }
2953 }
2954 break;
2955
2956 #endif
2957
2958 case Op_ModI:
2959 if (UseDivMod) {
2960 // Check if a%b and a/b both exist
2961 Node* d = n->find_similar(Op_DivI);
2962 if (d) {
2963 // Replace them with a fused divmod if supported
2964 if (Matcher::has_match_rule(Op_DivModI)) {
2965 DivModINode* divmod = DivModINode::make(this, n);
2966 d->subsume_by(divmod->div_proj(), this);
2967 n->subsume_by(divmod->mod_proj(), this);
2968 } else {
2969 // replace a%b with a-((a/b)*b)
2970 Node* mult = new MulINode(d, d->in(2));
2971 Node* sub = new SubINode(d->in(1), mult);
2972 n->subsume_by(sub, this);
2973 }
2974 }
2975 }
2976 break;
2977
2978 case Op_ModL:
2979 if (UseDivMod) {
2980 // Check if a%b and a/b both exist
2981 Node* d = n->find_similar(Op_DivL);
2982 if (d) {
2983 // Replace them with a fused divmod if supported
2984 if (Matcher::has_match_rule(Op_DivModL)) {
2985 DivModLNode* divmod = DivModLNode::make(this, n);
2986 d->subsume_by(divmod->div_proj(), this);
2987 n->subsume_by(divmod->mod_proj(), this);
2988 } else {
2989 // replace a%b with a-((a/b)*b)
2990 Node* mult = new MulLNode(d, d->in(2));
2991 Node* sub = new SubLNode(d->in(1), mult);
2992 n->subsume_by(sub, this);
2993 }
2994 }
2995 }
2996 break;
2997
2998 case Op_LoadVector:
2999 case Op_StoreVector:
3000 break;
3001
3002 case Op_PackB:
3003 case Op_PackS:
3004 case Op_PackI:
3005 case Op_PackF:
3006 case Op_PackL:
3007 case Op_PackD:
3008 if (n->req()-1 > 2) {
3009 // Replace many operand PackNodes with a binary tree for matching
3010 PackNode* p = (PackNode*) n;
3011 Node* btp = p->binary_tree_pack(this, 1, n->req());
3012 n->subsume_by(btp, this);
3013 }
3014 break;
3015 case Op_Loop:
3016 case Op_CountedLoop:
3017 if (n->as_Loop()->is_inner_loop()) {
3018 frc.inc_inner_loop_count();
3019 }
3020 break;
3021 case Op_LShiftI:
3022 case Op_RShiftI:
3023 case Op_URShiftI:
3024 case Op_LShiftL:
3025 case Op_RShiftL:
3026 case Op_URShiftL:
3027 if (Matcher::need_masked_shift_count) {
3028 // The cpu's shift instructions don't restrict the count to the
3029 // lower 5/6 bits. We need to do the masking ourselves.
3030 Node* in2 = n->in(2);
3031 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3032 const TypeInt* t = in2->find_int_type();
3033 if (t != NULL && t->is_con()) {
3034 juint shift = t->get_con();
3035 if (shift > mask) { // Unsigned cmp
3036 n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
3037 }
3038 } else {
3039 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3040 Node* shift = new AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
3041 n->set_req(2, shift);
3042 }
3043 }
3044 if (in2->outcnt() == 0) { // Remove dead node
3045 in2->disconnect_inputs(NULL, this);
3046 }
3047 }
3048 break;
3049 case Op_MemBarStoreStore:
3050 case Op_MemBarRelease:
3051 // Break the link with AllocateNode: it is no longer useful and
3052 // confuses register allocation.
3053 if (n->req() > MemBarNode::Precedent) {
3054 n->set_req(MemBarNode::Precedent, top());
3055 }
3056 break;
3057 default:
3058 assert( !n->is_Call(), "" );
3059 assert( !n->is_Mem(), "" );
3060 break;
3061 }
3062
3063 // Collect CFG split points
3064 if (n->is_MultiBranch())
3065 frc._tests.push(n);
3066 }
3067
3068 //------------------------------final_graph_reshaping_walk---------------------
3069 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3070 // requires that the walk visits a node's inputs before visiting the node.
3071 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3072 ResourceArea *area = Thread::current()->resource_area();
3073 Unique_Node_List sfpt(area);
3074
3075 frc._visited.set(root->_idx); // first, mark node as visited
3076 uint cnt = root->req();
3077 Node *n = root;
3078 uint i = 0;
3079 while (true) {
3080 if (i < cnt) {
3081 // Place all non-visited non-null inputs onto stack
3082 Node* m = n->in(i);
3083 ++i;
3084 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3085 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3086 // compute worst case interpreter size in case of a deoptimization
3087 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3088
3089 sfpt.push(m);
3090 }
3091 cnt = m->req();
3092 nstack.push(n, i); // put on stack parent and next input's index
3093 n = m;
3094 i = 0;
3095 }
3096 } else {
3097 // Now do post-visit work
3098 final_graph_reshaping_impl( n, frc );
3099 if (nstack.is_empty())
3100 break; // finished
3101 n = nstack.node(); // Get node from stack
3102 cnt = n->req();
3103 i = nstack.index();
3104 nstack.pop(); // Shift to the next node on stack
3105 }
3106 }
3107
3108 // Skip next transformation if compressed oops are not used.
3109 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3110 (!UseCompressedOops && !UseCompressedClassPointers))
3111 return;
3112
3113 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3114 // It could be done for an uncommon traps or any safepoints/calls
3115 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3116 while (sfpt.size() > 0) {
3117 n = sfpt.pop();
3118 JVMState *jvms = n->as_SafePoint()->jvms();
3119 assert(jvms != NULL, "sanity");
3120 int start = jvms->debug_start();
3121 int end = n->req();
3122 bool is_uncommon = (n->is_CallStaticJava() &&
3123 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3124 for (int j = start; j < end; j++) {
3125 Node* in = n->in(j);
3126 if (in->is_DecodeNarrowPtr()) {
3127 bool safe_to_skip = true;
3128 if (!is_uncommon ) {
3129 // Is it safe to skip?
3130 for (uint i = 0; i < in->outcnt(); i++) {
3131 Node* u = in->raw_out(i);
3132 if (!u->is_SafePoint() ||
3133 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3134 safe_to_skip = false;
3135 }
3136 }
3137 }
3138 if (safe_to_skip) {
3139 n->set_req(j, in->in(1));
3140 }
3141 if (in->outcnt() == 0) {
3142 in->disconnect_inputs(NULL, this);
3143 }
3144 }
3145 }
3146 }
3147 }
3148
3149 //------------------------------final_graph_reshaping--------------------------
3150 // Final Graph Reshaping.
3151 //
3152 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3153 // and not commoned up and forced early. Must come after regular
3154 // optimizations to avoid GVN undoing the cloning. Clone constant
3155 // inputs to Loop Phis; these will be split by the allocator anyways.
3156 // Remove Opaque nodes.
3157 // (2) Move last-uses by commutative operations to the left input to encourage
3158 // Intel update-in-place two-address operations and better register usage
3159 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3160 // calls canonicalizing them back.
3161 // (3) Count the number of double-precision FP ops, single-precision FP ops
3162 // and call sites. On Intel, we can get correct rounding either by
3163 // forcing singles to memory (requires extra stores and loads after each
3164 // FP bytecode) or we can set a rounding mode bit (requires setting and
3165 // clearing the mode bit around call sites). The mode bit is only used
3166 // if the relative frequency of single FP ops to calls is low enough.
3167 // This is a key transform for SPEC mpeg_audio.
3168 // (4) Detect infinite loops; blobs of code reachable from above but not
3169 // below. Several of the Code_Gen algorithms fail on such code shapes,
3170 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3171 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3172 // Detection is by looking for IfNodes where only 1 projection is
3173 // reachable from below or CatchNodes missing some targets.
3174 // (5) Assert for insane oop offsets in debug mode.
3175
3176 bool Compile::final_graph_reshaping() {
3177 // an infinite loop may have been eliminated by the optimizer,
3178 // in which case the graph will be empty.
3179 if (root()->req() == 1) {
3180 record_method_not_compilable("trivial infinite loop");
3181 return true;
3182 }
3183
3184 // Expensive nodes have their control input set to prevent the GVN
3185 // from freely commoning them. There's no GVN beyond this point so
3186 // no need to keep the control input. We want the expensive nodes to
3187 // be freely moved to the least frequent code path by gcm.
3188 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3189 for (int i = 0; i < expensive_count(); i++) {
3190 _expensive_nodes->at(i)->set_req(0, NULL);
3191 }
3192
3193 Final_Reshape_Counts frc;
3194
3195 // Visit everybody reachable!
3196 // Allocate stack of size C->unique()/2 to avoid frequent realloc
3197 Node_Stack nstack(unique() >> 1);
3198 final_graph_reshaping_walk(nstack, root(), frc);
3199
3200 // Check for unreachable (from below) code (i.e., infinite loops).
3201 for( uint i = 0; i < frc._tests.size(); i++ ) {
3202 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3203 // Get number of CFG targets.
3204 // Note that PCTables include exception targets after calls.
3205 uint required_outcnt = n->required_outcnt();
3206 if (n->outcnt() != required_outcnt) {
3207 // Check for a few special cases. Rethrow Nodes never take the
3208 // 'fall-thru' path, so expected kids is 1 less.
3209 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3210 if (n->in(0)->in(0)->is_Call()) {
3211 CallNode *call = n->in(0)->in(0)->as_Call();
3212 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3213 required_outcnt--; // Rethrow always has 1 less kid
3214 } else if (call->req() > TypeFunc::Parms &&
3215 call->is_CallDynamicJava()) {
3216 // Check for null receiver. In such case, the optimizer has
3217 // detected that the virtual call will always result in a null
3218 // pointer exception. The fall-through projection of this CatchNode
3219 // will not be populated.
3220 Node *arg0 = call->in(TypeFunc::Parms);
3221 if (arg0->is_Type() &&
3222 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3223 required_outcnt--;
3224 }
3225 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3226 call->req() > TypeFunc::Parms+1 &&
3227 call->is_CallStaticJava()) {
3228 // Check for negative array length. In such case, the optimizer has
3229 // detected that the allocation attempt will always result in an
3230 // exception. There is no fall-through projection of this CatchNode .
3231 Node *arg1 = call->in(TypeFunc::Parms+1);
3232 if (arg1->is_Type() &&
3233 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3234 required_outcnt--;
3235 }
3236 }
3237 }
3238 }
3239 // Recheck with a better notion of 'required_outcnt'
3240 if (n->outcnt() != required_outcnt) {
3241 record_method_not_compilable("malformed control flow");
3242 return true; // Not all targets reachable!
3243 }
3244 }
3245 // Check that I actually visited all kids. Unreached kids
3246 // must be infinite loops.
3247 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3248 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3249 record_method_not_compilable("infinite loop");
3250 return true; // Found unvisited kid; must be unreach
3251 }
3252 }
3253
3254 // If original bytecodes contained a mixture of floats and doubles
3255 // check if the optimizer has made it homogenous, item (3).
3256 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3257 frc.get_float_count() > 32 &&
3258 frc.get_double_count() == 0 &&
3259 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3260 set_24_bit_selection_and_mode( false, true );
3261 }
3262
3263 set_java_calls(frc.get_java_call_count());
3264 set_inner_loops(frc.get_inner_loop_count());
3265
3266 // No infinite loops, no reason to bail out.
3267 return false;
3268 }
3269
3270 //-----------------------------too_many_traps----------------------------------
3271 // Report if there are too many traps at the current method and bci.
3272 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3273 bool Compile::too_many_traps(ciMethod* method,
3274 int bci,
3275 Deoptimization::DeoptReason reason) {
3276 ciMethodData* md = method->method_data();
3277 if (md->is_empty()) {
3278 // Assume the trap has not occurred, or that it occurred only
3279 // because of a transient condition during start-up in the interpreter.
3280 return false;
3281 }
3282 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3283 if (md->has_trap_at(bci, m, reason) != 0) {
3284 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3285 // Also, if there are multiple reasons, or if there is no per-BCI record,
3286 // assume the worst.
3287 if (log())
3288 log()->elem("observe trap='%s' count='%d'",
3289 Deoptimization::trap_reason_name(reason),
3290 md->trap_count(reason));
3291 return true;
3292 } else {
3293 // Ignore method/bci and see if there have been too many globally.
3294 return too_many_traps(reason, md);
3295 }
3296 }
3297
3298 // Less-accurate variant which does not require a method and bci.
3299 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3300 ciMethodData* logmd) {
3301 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3302 // Too many traps globally.
3303 // Note that we use cumulative trap_count, not just md->trap_count.
3304 if (log()) {
3305 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3306 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3307 Deoptimization::trap_reason_name(reason),
3308 mcount, trap_count(reason));
3309 }
3310 return true;
3311 } else {
3312 // The coast is clear.
3313 return false;
3314 }
3315 }
3316
3317 //--------------------------too_many_recompiles--------------------------------
3318 // Report if there are too many recompiles at the current method and bci.
3319 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3320 // Is not eager to return true, since this will cause the compiler to use
3321 // Action_none for a trap point, to avoid too many recompilations.
3322 bool Compile::too_many_recompiles(ciMethod* method,
3323 int bci,
3324 Deoptimization::DeoptReason reason) {
3325 ciMethodData* md = method->method_data();
3326 if (md->is_empty()) {
3327 // Assume the trap has not occurred, or that it occurred only
3328 // because of a transient condition during start-up in the interpreter.
3329 return false;
3330 }
3331 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3332 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3333 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3334 Deoptimization::DeoptReason per_bc_reason
3335 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3336 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3337 if ((per_bc_reason == Deoptimization::Reason_none
3338 || md->has_trap_at(bci, m, reason) != 0)
3339 // The trap frequency measure we care about is the recompile count:
3340 && md->trap_recompiled_at(bci, m)
3341 && md->overflow_recompile_count() >= bc_cutoff) {
3342 // Do not emit a trap here if it has already caused recompilations.
3343 // Also, if there are multiple reasons, or if there is no per-BCI record,
3344 // assume the worst.
3345 if (log())
3346 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3347 Deoptimization::trap_reason_name(reason),
3348 md->trap_count(reason),
3349 md->overflow_recompile_count());
3350 return true;
3351 } else if (trap_count(reason) != 0
3352 && decompile_count() >= m_cutoff) {
3353 // Too many recompiles globally, and we have seen this sort of trap.
3354 // Use cumulative decompile_count, not just md->decompile_count.
3355 if (log())
3356 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3357 Deoptimization::trap_reason_name(reason),
3358 md->trap_count(reason), trap_count(reason),
3359 md->decompile_count(), decompile_count());
3360 return true;
3361 } else {
3362 // The coast is clear.
3363 return false;
3364 }
3365 }
3366
3367 // Compute when not to trap. Used by matching trap based nodes and
3368 // NullCheck optimization.
3369 void Compile::set_allowed_deopt_reasons() {
3370 _allowed_reasons = 0;
3371 if (is_method_compilation()) {
3372 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3373 assert(rs < BitsPerInt, "recode bit map");
3374 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3375 _allowed_reasons |= nth_bit(rs);
3376 }
3377 }
3378 }
3379 }
3380
3381 #ifndef PRODUCT
3382 //------------------------------verify_graph_edges---------------------------
3383 // Walk the Graph and verify that there is a one-to-one correspondence
3384 // between Use-Def edges and Def-Use edges in the graph.
3385 void Compile::verify_graph_edges(bool no_dead_code) {
3386 if (VerifyGraphEdges) {
3387 ResourceArea *area = Thread::current()->resource_area();
3388 Unique_Node_List visited(area);
3389 // Call recursive graph walk to check edges
3390 _root->verify_edges(visited);
3391 if (no_dead_code) {
3392 // Now make sure that no visited node is used by an unvisited node.
3393 bool dead_nodes = false;
3394 Unique_Node_List checked(area);
3395 while (visited.size() > 0) {
3396 Node* n = visited.pop();
3397 checked.push(n);
3398 for (uint i = 0; i < n->outcnt(); i++) {
3399 Node* use = n->raw_out(i);
3400 if (checked.member(use)) continue; // already checked
3401 if (visited.member(use)) continue; // already in the graph
3402 if (use->is_Con()) continue; // a dead ConNode is OK
3403 // At this point, we have found a dead node which is DU-reachable.
3404 if (!dead_nodes) {
3405 tty->print_cr("*** Dead nodes reachable via DU edges:");
3406 dead_nodes = true;
3407 }
3408 use->dump(2);
3409 tty->print_cr("---");
3410 checked.push(use); // No repeats; pretend it is now checked.
3411 }
3412 }
3413 assert(!dead_nodes, "using nodes must be reachable from root");
3414 }
3415 }
3416 }
3417
3418 // Verify GC barriers consistency
3419 // Currently supported:
3420 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3421 void Compile::verify_barriers() {
3422 if (UseG1GC) {
3423 // Verify G1 pre-barriers
3424 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3425
3426 ResourceArea *area = Thread::current()->resource_area();
3427 Unique_Node_List visited(area);
3428 Node_List worklist(area);
3429 // We're going to walk control flow backwards starting from the Root
3430 worklist.push(_root);
3431 while (worklist.size() > 0) {
3432 Node* x = worklist.pop();
3433 if (x == NULL || x == top()) continue;
3434 if (visited.member(x)) {
3435 continue;
3436 } else {
3437 visited.push(x);
3438 }
3439
3440 if (x->is_Region()) {
3441 for (uint i = 1; i < x->req(); i++) {
3442 worklist.push(x->in(i));
3443 }
3444 } else {
3445 worklist.push(x->in(0));
3446 // We are looking for the pattern:
3447 // /->ThreadLocal
3448 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3449 // \->ConI(0)
3450 // We want to verify that the If and the LoadB have the same control
3451 // See GraphKit::g1_write_barrier_pre()
3452 if (x->is_If()) {
3453 IfNode *iff = x->as_If();
3454 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3455 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3456 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3457 && cmp->in(1)->is_Load()) {
3458 LoadNode* load = cmp->in(1)->as_Load();
3459 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3460 && load->in(2)->in(3)->is_Con()
3461 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3462
3463 Node* if_ctrl = iff->in(0);
3464 Node* load_ctrl = load->in(0);
3465
3466 if (if_ctrl != load_ctrl) {
3467 // Skip possible CProj->NeverBranch in infinite loops
3468 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3469 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3470 if_ctrl = if_ctrl->in(0)->in(0);
3471 }
3472 }
3473 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3474 }
3475 }
3476 }
3477 }
3478 }
3479 }
3480 }
3481 }
3482
3483 #endif
3484
3485 // The Compile object keeps track of failure reasons separately from the ciEnv.
3486 // This is required because there is not quite a 1-1 relation between the
3487 // ciEnv and its compilation task and the Compile object. Note that one
3488 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3489 // to backtrack and retry without subsuming loads. Other than this backtracking
3490 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3491 // by the logic in C2Compiler.
3492 void Compile::record_failure(const char* reason) {
3493 if (log() != NULL) {
3494 log()->elem("failure reason='%s' phase='compile'", reason);
3495 }
3496 if (_failure_reason == NULL) {
3497 // Record the first failure reason.
3498 _failure_reason = reason;
3499 }
3500
3501 EventCompilerFailure event;
3502 if (event.should_commit()) {
3503 event.set_compileID(Compile::compile_id());
3504 event.set_failure(reason);
3505 event.commit();
3506 }
3507
3508 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3509 C->print_method(PHASE_FAILURE);
3510 }
3511 _root = NULL; // flush the graph, too
3512 }
3513
3514 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3515 : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3516 _phase_name(name), _dolog(dolog)
3517 {
3518 if (dolog) {
3519 C = Compile::current();
3520 _log = C->log();
3521 } else {
3522 C = NULL;
3523 _log = NULL;
3524 }
3525 if (_log != NULL) {
3526 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3527 _log->stamp();
3528 _log->end_head();
3529 }
3530 }
3531
3532 Compile::TracePhase::~TracePhase() {
3533
3534 C = Compile::current();
3535 if (_dolog) {
3536 _log = C->log();
3537 } else {
3538 _log = NULL;
3539 }
3540
3541 #ifdef ASSERT
3542 if (PrintIdealNodeCount) {
3543 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3544 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3545 }
3546
3547 if (VerifyIdealNodeCount) {
3548 Compile::current()->print_missing_nodes();
3549 }
3550 #endif
3551
3552 if (_log != NULL) {
3553 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3554 }
3555 }
3556
3557 //=============================================================================
3558 // Two Constant's are equal when the type and the value are equal.
3559 bool Compile::Constant::operator==(const Constant& other) {
3560 if (type() != other.type() ) return false;
3561 if (can_be_reused() != other.can_be_reused()) return false;
3562 // For floating point values we compare the bit pattern.
3563 switch (type()) {
3564 case T_FLOAT: return (_v._value.i == other._v._value.i);
3565 case T_LONG:
3566 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3567 case T_OBJECT:
3568 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3569 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3570 case T_METADATA: return (_v._metadata == other._v._metadata);
3571 default: ShouldNotReachHere();
3572 }
3573 return false;
3574 }
3575
3576 static int type_to_size_in_bytes(BasicType t) {
3577 switch (t) {
3578 case T_LONG: return sizeof(jlong );
3579 case T_FLOAT: return sizeof(jfloat );
3580 case T_DOUBLE: return sizeof(jdouble);
3581 case T_METADATA: return sizeof(Metadata*);
3582 // We use T_VOID as marker for jump-table entries (labels) which
3583 // need an internal word relocation.
3584 case T_VOID:
3585 case T_ADDRESS:
3586 case T_OBJECT: return sizeof(jobject);
3587 }
3588
3589 ShouldNotReachHere();
3590 return -1;
3591 }
3592
3593 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3594 // sort descending
3595 if (a->freq() > b->freq()) return -1;
3596 if (a->freq() < b->freq()) return 1;
3597 return 0;
3598 }
3599
3600 void Compile::ConstantTable::calculate_offsets_and_size() {
3601 // First, sort the array by frequencies.
3602 _constants.sort(qsort_comparator);
3603
3604 #ifdef ASSERT
3605 // Make sure all jump-table entries were sorted to the end of the
3606 // array (they have a negative frequency).
3607 bool found_void = false;
3608 for (int i = 0; i < _constants.length(); i++) {
3609 Constant con = _constants.at(i);
3610 if (con.type() == T_VOID)
3611 found_void = true; // jump-tables
3612 else
3613 assert(!found_void, "wrong sorting");
3614 }
3615 #endif
3616
3617 int offset = 0;
3618 for (int i = 0; i < _constants.length(); i++) {
3619 Constant* con = _constants.adr_at(i);
3620
3621 // Align offset for type.
3622 int typesize = type_to_size_in_bytes(con->type());
3623 offset = align_size_up(offset, typesize);
3624 con->set_offset(offset); // set constant's offset
3625
3626 if (con->type() == T_VOID) {
3627 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3628 offset = offset + typesize * n->outcnt(); // expand jump-table
3629 } else {
3630 offset = offset + typesize;
3631 }
3632 }
3633
3634 // Align size up to the next section start (which is insts; see
3635 // CodeBuffer::align_at_start).
3636 assert(_size == -1, "already set?");
3637 _size = align_size_up(offset, CodeEntryAlignment);
3638 }
3639
3640 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3641 MacroAssembler _masm(&cb);
3642 for (int i = 0; i < _constants.length(); i++) {
3643 Constant con = _constants.at(i);
3644 address constant_addr;
3645 switch (con.type()) {
3646 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3647 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3648 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3649 case T_OBJECT: {
3650 jobject obj = con.get_jobject();
3651 int oop_index = _masm.oop_recorder()->find_index(obj);
3652 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3653 break;
3654 }
3655 case T_ADDRESS: {
3656 address addr = (address) con.get_jobject();
3657 constant_addr = _masm.address_constant(addr);
3658 break;
3659 }
3660 // We use T_VOID as marker for jump-table entries (labels) which
3661 // need an internal word relocation.
3662 case T_VOID: {
3663 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3664 // Fill the jump-table with a dummy word. The real value is
3665 // filled in later in fill_jump_table.
3666 address dummy = (address) n;
3667 constant_addr = _masm.address_constant(dummy);
3668 // Expand jump-table
3669 for (uint i = 1; i < n->outcnt(); i++) {
3670 address temp_addr = _masm.address_constant(dummy + i);
3671 assert(temp_addr, "consts section too small");
3672 }
3673 break;
3674 }
3675 case T_METADATA: {
3676 Metadata* obj = con.get_metadata();
3677 int metadata_index = _masm.oop_recorder()->find_index(obj);
3678 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3679 break;
3680 }
3681 default: ShouldNotReachHere();
3682 }
3683 assert(constant_addr, "consts section too small");
3684 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3685 err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3686 }
3687 }
3688
3689 int Compile::ConstantTable::find_offset(Constant& con) const {
3690 int idx = _constants.find(con);
3691 assert(idx != -1, "constant must be in constant table");
3692 int offset = _constants.at(idx).offset();
3693 assert(offset != -1, "constant table not emitted yet?");
3694 return offset;
3695 }
3696
3697 void Compile::ConstantTable::add(Constant& con) {
3698 if (con.can_be_reused()) {
3699 int idx = _constants.find(con);
3700 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3701 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3702 return;
3703 }
3704 }
3705 (void) _constants.append(con);
3706 }
3707
3708 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3709 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3710 Constant con(type, value, b->_freq);
3711 add(con);
3712 return con;
3713 }
3714
3715 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3716 Constant con(metadata);
3717 add(con);
3718 return con;
3719 }
3720
3721 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3722 jvalue value;
3723 BasicType type = oper->type()->basic_type();
3724 switch (type) {
3725 case T_LONG: value.j = oper->constantL(); break;
3726 case T_FLOAT: value.f = oper->constantF(); break;
3727 case T_DOUBLE: value.d = oper->constantD(); break;
3728 case T_OBJECT:
3729 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3730 case T_METADATA: return add((Metadata*)oper->constant()); break;
3731 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3732 }
3733 return add(n, type, value);
3734 }
3735
3736 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3737 jvalue value;
3738 // We can use the node pointer here to identify the right jump-table
3739 // as this method is called from Compile::Fill_buffer right before
3740 // the MachNodes are emitted and the jump-table is filled (means the
3741 // MachNode pointers do not change anymore).
3742 value.l = (jobject) n;
3743 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3744 add(con);
3745 return con;
3746 }
3747
3748 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3749 // If called from Compile::scratch_emit_size do nothing.
3750 if (Compile::current()->in_scratch_emit_size()) return;
3751
3752 assert(labels.is_nonempty(), "must be");
3753 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3754
3755 // Since MachConstantNode::constant_offset() also contains
3756 // table_base_offset() we need to subtract the table_base_offset()
3757 // to get the plain offset into the constant table.
3758 int offset = n->constant_offset() - table_base_offset();
3759
3760 MacroAssembler _masm(&cb);
3761 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3762
3763 for (uint i = 0; i < n->outcnt(); i++) {
3764 address* constant_addr = &jump_table_base[i];
3765 assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i)));
3766 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3767 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3768 }
3769 }
3770
3771 // The message about the current inlining is accumulated in
3772 // _print_inlining_stream and transfered into the _print_inlining_list
3773 // once we know whether inlining succeeds or not. For regular
3774 // inlining, messages are appended to the buffer pointed by
3775 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3776 // a new buffer is added after _print_inlining_idx in the list. This
3777 // way we can update the inlining message for late inlining call site
3778 // when the inlining is attempted again.
3779 void Compile::print_inlining_init() {
3780 if (print_inlining() || print_intrinsics()) {
3781 _print_inlining_stream = new stringStream();
3782 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3783 }
3784 }
3785
3786 void Compile::print_inlining_reinit() {
3787 if (print_inlining() || print_intrinsics()) {
3788 // Re allocate buffer when we change ResourceMark
3789 _print_inlining_stream = new stringStream();
3790 }
3791 }
3792
3793 void Compile::print_inlining_reset() {
3794 _print_inlining_stream->reset();
3795 }
3796
3797 void Compile::print_inlining_commit() {
3798 assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3799 // Transfer the message from _print_inlining_stream to the current
3800 // _print_inlining_list buffer and clear _print_inlining_stream.
3801 _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3802 print_inlining_reset();
3803 }
3804
3805 void Compile::print_inlining_push() {
3806 // Add new buffer to the _print_inlining_list at current position
3807 _print_inlining_idx++;
3808 _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3809 }
3810
3811 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3812 return _print_inlining_list->at(_print_inlining_idx);
3813 }
3814
3815 void Compile::print_inlining_update(CallGenerator* cg) {
3816 if (print_inlining() || print_intrinsics()) {
3817 if (!cg->is_late_inline()) {
3818 if (print_inlining_current().cg() != NULL) {
3819 print_inlining_push();
3820 }
3821 print_inlining_commit();
3822 } else {
3823 if (print_inlining_current().cg() != cg &&
3824 (print_inlining_current().cg() != NULL ||
3825 print_inlining_current().ss()->size() != 0)) {
3826 print_inlining_push();
3827 }
3828 print_inlining_commit();
3829 print_inlining_current().set_cg(cg);
3830 }
3831 }
3832 }
3833
3834 void Compile::print_inlining_move_to(CallGenerator* cg) {
3835 // We resume inlining at a late inlining call site. Locate the
3836 // corresponding inlining buffer so that we can update it.
3837 if (print_inlining()) {
3838 for (int i = 0; i < _print_inlining_list->length(); i++) {
3839 if (_print_inlining_list->adr_at(i)->cg() == cg) {
3840 _print_inlining_idx = i;
3841 return;
3842 }
3843 }
3844 ShouldNotReachHere();
3845 }
3846 }
3847
3848 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3849 if (print_inlining()) {
3850 assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3851 assert(print_inlining_current().cg() == cg, "wrong entry");
3852 // replace message with new message
3853 _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3854 print_inlining_commit();
3855 print_inlining_current().set_cg(cg);
3856 }
3857 }
3858
3859 void Compile::print_inlining_assert_ready() {
3860 assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3861 }
3862
3863 void Compile::process_print_inlining() {
3864 bool do_print_inlining = print_inlining() || print_intrinsics();
3865 if (do_print_inlining || log() != NULL) {
3866 // Print inlining message for candidates that we couldn't inline
3867 // for lack of space
3868 for (int i = 0; i < _late_inlines.length(); i++) {
3869 CallGenerator* cg = _late_inlines.at(i);
3870 if (!cg->is_mh_late_inline()) {
3871 const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3872 if (do_print_inlining) {
3873 cg->print_inlining_late(msg);
3874 }
3875 log_late_inline_failure(cg, msg);
3876 }
3877 }
3878 }
3879 if (do_print_inlining) {
3880 ResourceMark rm;
3881 stringStream ss;
3882 for (int i = 0; i < _print_inlining_list->length(); i++) {
3883 ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3884 }
3885 size_t end = ss.size();
3886 _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
3887 strncpy(_print_inlining_output, ss.base(), end+1);
3888 _print_inlining_output[end] = 0;
3889 }
3890 }
3891
3892 void Compile::dump_print_inlining() {
3893 if (_print_inlining_output != NULL) {
3894 tty->print_raw(_print_inlining_output);
3895 }
3896 }
3897
3898 void Compile::log_late_inline(CallGenerator* cg) {
3899 if (log() != NULL) {
3900 log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3901 cg->unique_id());
3902 JVMState* p = cg->call_node()->jvms();
3903 while (p != NULL) {
3904 log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
3905 p = p->caller();
3906 }
3907 log()->tail("late_inline");
3908 }
3909 }
3910
3911 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
3912 log_late_inline(cg);
3913 if (log() != NULL) {
3914 log()->inline_fail(msg);
3915 }
3916 }
3917
3918 void Compile::log_inline_id(CallGenerator* cg) {
3919 if (log() != NULL) {
3920 // The LogCompilation tool needs a unique way to identify late
3921 // inline call sites. This id must be unique for this call site in
3922 // this compilation. Try to have it unique across compilations as
3923 // well because it can be convenient when grepping through the log
3924 // file.
3925 // Distinguish OSR compilations from others in case CICountOSR is
3926 // on.
3927 jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
3928 cg->set_unique_id(id);
3929 log()->elem("inline_id id='" JLONG_FORMAT "'", id);
3930 }
3931 }
3932
3933 void Compile::log_inline_failure(const char* msg) {
3934 if (C->log() != NULL) {
3935 C->log()->inline_fail(msg);
3936 }
3937 }
3938
3939
3940 // Dump inlining replay data to the stream.
3941 // Don't change thread state and acquire any locks.
3942 void Compile::dump_inline_data(outputStream* out) {
3943 InlineTree* inl_tree = ilt();
3944 if (inl_tree != NULL) {
3945 out->print(" inline %d", inl_tree->count());
3946 inl_tree->dump_replay_data(out);
3947 }
3948 }
3949
3950 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3951 if (n1->Opcode() < n2->Opcode()) return -1;
3952 else if (n1->Opcode() > n2->Opcode()) return 1;
3953
3954 assert(n1->req() == n2->req(), err_msg_res("can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req()));
3955 for (uint i = 1; i < n1->req(); i++) {
3956 if (n1->in(i) < n2->in(i)) return -1;
3957 else if (n1->in(i) > n2->in(i)) return 1;
3958 }
3959
3960 return 0;
3961 }
3962
3963 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3964 Node* n1 = *n1p;
3965 Node* n2 = *n2p;
3966
3967 return cmp_expensive_nodes(n1, n2);
3968 }
3969
3970 void Compile::sort_expensive_nodes() {
3971 if (!expensive_nodes_sorted()) {
3972 _expensive_nodes->sort(cmp_expensive_nodes);
3973 }
3974 }
3975
3976 bool Compile::expensive_nodes_sorted() const {
3977 for (int i = 1; i < _expensive_nodes->length(); i++) {
3978 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3979 return false;
3980 }
3981 }
3982 return true;
3983 }
3984
3985 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3986 if (_expensive_nodes->length() == 0) {
3987 return false;
3988 }
3989
3990 assert(OptimizeExpensiveOps, "optimization off?");
3991
3992 // Take this opportunity to remove dead nodes from the list
3993 int j = 0;
3994 for (int i = 0; i < _expensive_nodes->length(); i++) {
3995 Node* n = _expensive_nodes->at(i);
3996 if (!n->is_unreachable(igvn)) {
3997 assert(n->is_expensive(), "should be expensive");
3998 _expensive_nodes->at_put(j, n);
3999 j++;
4000 }
4001 }
4002 _expensive_nodes->trunc_to(j);
4003
4004 // Then sort the list so that similar nodes are next to each other
4005 // and check for at least two nodes of identical kind with same data
4006 // inputs.
4007 sort_expensive_nodes();
4008
4009 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4010 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4011 return true;
4012 }
4013 }
4014
4015 return false;
4016 }
4017
4018 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4019 if (_expensive_nodes->length() == 0) {
4020 return;
4021 }
4022
4023 assert(OptimizeExpensiveOps, "optimization off?");
4024
4025 // Sort to bring similar nodes next to each other and clear the
4026 // control input of nodes for which there's only a single copy.
4027 sort_expensive_nodes();
4028
4029 int j = 0;
4030 int identical = 0;
4031 int i = 0;
4032 for (; i < _expensive_nodes->length()-1; i++) {
4033 assert(j <= i, "can't write beyond current index");
4034 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4035 identical++;
4036 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4037 continue;
4038 }
4039 if (identical > 0) {
4040 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4041 identical = 0;
4042 } else {
4043 Node* n = _expensive_nodes->at(i);
4044 igvn.hash_delete(n);
4045 n->set_req(0, NULL);
4046 igvn.hash_insert(n);
4047 }
4048 }
4049 if (identical > 0) {
4050 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4051 } else if (_expensive_nodes->length() >= 1) {
4052 Node* n = _expensive_nodes->at(i);
4053 igvn.hash_delete(n);
4054 n->set_req(0, NULL);
4055 igvn.hash_insert(n);
4056 }
4057 _expensive_nodes->trunc_to(j);
4058 }
4059
4060 void Compile::add_expensive_node(Node * n) {
4061 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4062 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4063 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4064 if (OptimizeExpensiveOps) {
4065 _expensive_nodes->append(n);
4066 } else {
4067 // Clear control input and let IGVN optimize expensive nodes if
4068 // OptimizeExpensiveOps is off.
4069 n->set_req(0, NULL);
4070 }
4071 }
4072
4073 /**
4074 * Remove the speculative part of types and clean up the graph
4075 */
4076 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4077 if (UseTypeSpeculation) {
4078 Unique_Node_List worklist;
4079 worklist.push(root());
4080 int modified = 0;
4081 // Go over all type nodes that carry a speculative type, drop the
4082 // speculative part of the type and enqueue the node for an igvn
4083 // which may optimize it out.
4084 for (uint next = 0; next < worklist.size(); ++next) {
4085 Node *n = worklist.at(next);
4086 if (n->is_Type()) {
4087 TypeNode* tn = n->as_Type();
4088 const Type* t = tn->type();
4089 const Type* t_no_spec = t->remove_speculative();
4090 if (t_no_spec != t) {
4091 bool in_hash = igvn.hash_delete(n);
4092 assert(in_hash, "node should be in igvn hash table");
4093 tn->set_type(t_no_spec);
4094 igvn.hash_insert(n);
4095 igvn._worklist.push(n); // give it a chance to go away
4096 modified++;
4097 }
4098 }
4099 uint max = n->len();
4100 for( uint i = 0; i < max; ++i ) {
4101 Node *m = n->in(i);
4102 if (not_a_node(m)) continue;
4103 worklist.push(m);
4104 }
4105 }
4106 // Drop the speculative part of all types in the igvn's type table
4107 igvn.remove_speculative_types();
4108 if (modified > 0) {
4109 igvn.optimize();
4110 }
4111 #ifdef ASSERT
4112 // Verify that after the IGVN is over no speculative type has resurfaced
4113 worklist.clear();
4114 worklist.push(root());
4115 for (uint next = 0; next < worklist.size(); ++next) {
4116 Node *n = worklist.at(next);
4117 const Type* t = igvn.type_or_null(n);
4118 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4119 if (n->is_Type()) {
4120 t = n->as_Type()->type();
4121 assert(t == t->remove_speculative(), "no more speculative types");
4122 }
4123 uint max = n->len();
4124 for( uint i = 0; i < max; ++i ) {
4125 Node *m = n->in(i);
4126 if (not_a_node(m)) continue;
4127 worklist.push(m);
4128 }
4129 }
4130 igvn.check_no_speculative_types();
4131 #endif
4132 }
4133 }
4134
4135 // Auxiliary method to support randomized stressing/fuzzing.
4136 //
4137 // This method can be called the arbitrary number of times, with current count
4138 // as the argument. The logic allows selecting a single candidate from the
4139 // running list of candidates as follows:
4140 // int count = 0;
4141 // Cand* selected = null;
4142 // while(cand = cand->next()) {
4143 // if (randomized_select(++count)) {
4144 // selected = cand;
4145 // }
4146 // }
4147 //
4148 // Including count equalizes the chances any candidate is "selected".
4149 // This is useful when we don't have the complete list of candidates to choose
4150 // from uniformly. In this case, we need to adjust the randomicity of the
4151 // selection, or else we will end up biasing the selection towards the latter
4152 // candidates.
4153 //
4154 // Quick back-envelope calculation shows that for the list of n candidates
4155 // the equal probability for the candidate to persist as "best" can be
4156 // achieved by replacing it with "next" k-th candidate with the probability
4157 // of 1/k. It can be easily shown that by the end of the run, the
4158 // probability for any candidate is converged to 1/n, thus giving the
4159 // uniform distribution among all the candidates.
4160 //
4161 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4162 #define RANDOMIZED_DOMAIN_POW 29
4163 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4164 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4165 bool Compile::randomized_select(int count) {
4166 assert(count > 0, "only positive");
4167 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4168 }