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/compileBroker.hpp"
33 #include "compiler/compileLog.hpp"
34 #include "compiler/disassembler.hpp"
35 #include "compiler/oopMap.hpp"
36 #include "opto/addnode.hpp"
37 #include "opto/block.hpp"
38 #include "opto/c2compiler.hpp"
39 #include "opto/callGenerator.hpp"
40 #include "opto/callnode.hpp"
41 #include "opto/cfgnode.hpp"
42 #include "opto/chaitin.hpp"
43 #include "opto/compile.hpp"
44 #include "opto/connode.hpp"
45 #include "opto/divnode.hpp"
46 #include "opto/escape.hpp"
47 #include "opto/idealGraphPrinter.hpp"
48 #include "opto/loopnode.hpp"
49 #include "opto/machnode.hpp"
50 #include "opto/macro.hpp"
51 #include "opto/matcher.hpp"
52 #include "opto/mathexactnode.hpp"
53 #include "opto/memnode.hpp"
54 #include "opto/mulnode.hpp"
55 #include "opto/narrowptrnode.hpp"
56 #include "opto/node.hpp"
57 #include "opto/opcodes.hpp"
58 #include "opto/output.hpp"
59 #include "opto/parse.hpp"
60 #include "opto/phaseX.hpp"
61 #include "opto/rootnode.hpp"
62 #include "opto/runtime.hpp"
63 #include "opto/stringopts.hpp"
64 #include "opto/type.hpp"
65 #include "opto/vectornode.hpp"
66 #include "runtime/arguments.hpp"
67 #include "runtime/signature.hpp"
68 #include "runtime/stubRoutines.hpp"
69 #include "runtime/timer.hpp"
70 #include "trace/tracing.hpp"
71 #include "utilities/copy.hpp"
72
73
74 // -------------------- Compile::mach_constant_base_node -----------------------
75 // Constant table base node singleton.
76 MachConstantBaseNode* Compile::mach_constant_base_node() {
77 if (_mach_constant_base_node == NULL) {
78 _mach_constant_base_node = new MachConstantBaseNode();
79 _mach_constant_base_node->add_req(C->root());
80 }
81 return _mach_constant_base_node;
82 }
83
84
85 /// Support for intrinsics.
86
87 // Return the index at which m must be inserted (or already exists).
88 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
89 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
90 #ifdef ASSERT
91 for (int i = 1; i < _intrinsics->length(); i++) {
92 CallGenerator* cg1 = _intrinsics->at(i-1);
93 CallGenerator* cg2 = _intrinsics->at(i);
94 assert(cg1->method() != cg2->method()
95 ? cg1->method() < cg2->method()
96 : cg1->is_virtual() < cg2->is_virtual(),
97 "compiler intrinsics list must stay sorted");
98 }
99 #endif
100 // Binary search sorted list, in decreasing intervals [lo, hi].
101 int lo = 0, hi = _intrinsics->length()-1;
102 while (lo <= hi) {
103 int mid = (uint)(hi + lo) / 2;
104 ciMethod* mid_m = _intrinsics->at(mid)->method();
105 if (m < mid_m) {
106 hi = mid-1;
107 } else if (m > mid_m) {
108 lo = mid+1;
109 } else {
110 // look at minor sort key
111 bool mid_virt = _intrinsics->at(mid)->is_virtual();
112 if (is_virtual < mid_virt) {
113 hi = mid-1;
114 } else if (is_virtual > mid_virt) {
115 lo = mid+1;
116 } else {
117 return mid; // exact match
118 }
119 }
120 }
121 return lo; // inexact match
122 }
123
124 void Compile::register_intrinsic(CallGenerator* cg) {
125 if (_intrinsics == NULL) {
126 _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
127 }
128 // This code is stolen from ciObjectFactory::insert.
129 // Really, GrowableArray should have methods for
130 // insert_at, remove_at, and binary_search.
131 int len = _intrinsics->length();
132 int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
133 if (index == len) {
134 _intrinsics->append(cg);
135 } else {
136 #ifdef ASSERT
137 CallGenerator* oldcg = _intrinsics->at(index);
138 assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
139 #endif
140 _intrinsics->append(_intrinsics->at(len-1));
141 int pos;
142 for (pos = len-2; pos >= index; pos--) {
143 _intrinsics->at_put(pos+1,_intrinsics->at(pos));
144 }
145 _intrinsics->at_put(index, cg);
146 }
147 assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
148 }
149
150 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
151 assert(m->is_loaded(), "don't try this on unloaded methods");
152 if (_intrinsics != NULL) {
153 int index = intrinsic_insertion_index(m, is_virtual);
154 if (index < _intrinsics->length()
155 && _intrinsics->at(index)->method() == m
156 && _intrinsics->at(index)->is_virtual() == is_virtual) {
157 return _intrinsics->at(index);
158 }
159 }
160 // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
161 if (m->intrinsic_id() != vmIntrinsics::_none &&
162 m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
163 CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
164 if (cg != NULL) {
165 // Save it for next time:
166 register_intrinsic(cg);
167 return cg;
168 } else {
169 gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
170 }
171 }
172 return NULL;
173 }
174
175 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
176 // in library_call.cpp.
177
178
179 #ifndef PRODUCT
180 // statistics gathering...
181
182 juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
183 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
184
185 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
186 assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
187 int oflags = _intrinsic_hist_flags[id];
188 assert(flags != 0, "what happened?");
189 if (is_virtual) {
190 flags |= _intrinsic_virtual;
191 }
192 bool changed = (flags != oflags);
193 if ((flags & _intrinsic_worked) != 0) {
194 juint count = (_intrinsic_hist_count[id] += 1);
195 if (count == 1) {
196 changed = true; // first time
197 }
198 // increment the overall count also:
199 _intrinsic_hist_count[vmIntrinsics::_none] += 1;
200 }
201 if (changed) {
202 if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
203 // Something changed about the intrinsic's virtuality.
204 if ((flags & _intrinsic_virtual) != 0) {
205 // This is the first use of this intrinsic as a virtual call.
206 if (oflags != 0) {
207 // We already saw it as a non-virtual, so note both cases.
208 flags |= _intrinsic_both;
209 }
210 } else if ((oflags & _intrinsic_both) == 0) {
211 // This is the first use of this intrinsic as a non-virtual
212 flags |= _intrinsic_both;
213 }
214 }
215 _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
216 }
217 // update the overall flags also:
218 _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
219 return changed;
220 }
221
222 static char* format_flags(int flags, char* buf) {
223 buf[0] = 0;
224 if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
225 if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
226 if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
227 if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
228 if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
229 if (buf[0] == 0) strcat(buf, ",");
230 assert(buf[0] == ',', "must be");
231 return &buf[1];
232 }
233
234 void Compile::print_intrinsic_statistics() {
235 char flagsbuf[100];
236 ttyLocker ttyl;
237 if (xtty != NULL) xtty->head("statistics type='intrinsic'");
238 tty->print_cr("Compiler intrinsic usage:");
239 juint total = _intrinsic_hist_count[vmIntrinsics::_none];
240 if (total == 0) total = 1; // avoid div0 in case of no successes
241 #define PRINT_STAT_LINE(name, c, f) \
242 tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
243 for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
244 vmIntrinsics::ID id = (vmIntrinsics::ID) index;
245 int flags = _intrinsic_hist_flags[id];
246 juint count = _intrinsic_hist_count[id];
247 if ((flags | count) != 0) {
248 PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
249 }
250 }
251 PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
252 if (xtty != NULL) xtty->tail("statistics");
253 }
254
255 void Compile::print_statistics() {
256 { ttyLocker ttyl;
257 if (xtty != NULL) xtty->head("statistics type='opto'");
258 Parse::print_statistics();
259 PhaseCCP::print_statistics();
260 PhaseRegAlloc::print_statistics();
261 Scheduling::print_statistics();
262 PhasePeephole::print_statistics();
263 PhaseIdealLoop::print_statistics();
264 if (xtty != NULL) xtty->tail("statistics");
265 }
266 if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
267 // put this under its own <statistics> element.
268 print_intrinsic_statistics();
269 }
270 }
271 #endif //PRODUCT
272
273 // Support for bundling info
274 Bundle* Compile::node_bundling(const Node *n) {
275 assert(valid_bundle_info(n), "oob");
276 return &_node_bundling_base[n->_idx];
277 }
278
279 bool Compile::valid_bundle_info(const Node *n) {
280 return (_node_bundling_limit > n->_idx);
281 }
282
283
284 void Compile::gvn_replace_by(Node* n, Node* nn) {
285 for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
286 Node* use = n->last_out(i);
287 bool is_in_table = initial_gvn()->hash_delete(use);
288 uint uses_found = 0;
289 for (uint j = 0; j < use->len(); j++) {
290 if (use->in(j) == n) {
291 if (j < use->req())
292 use->set_req(j, nn);
293 else
294 use->set_prec(j, nn);
295 uses_found++;
296 }
297 }
298 if (is_in_table) {
299 // reinsert into table
300 initial_gvn()->hash_find_insert(use);
301 }
302 record_for_igvn(use);
303 i -= uses_found; // we deleted 1 or more copies of this edge
304 }
305 }
306
307
308 static inline bool not_a_node(const Node* n) {
309 if (n == NULL) return true;
310 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
311 if (*(address*)n == badAddress) return true; // kill by Node::destruct
312 return false;
313 }
314
315 // Identify all nodes that are reachable from below, useful.
316 // Use breadth-first pass that records state in a Unique_Node_List,
317 // recursive traversal is slower.
318 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
319 int estimated_worklist_size = unique();
320 useful.map( estimated_worklist_size, NULL ); // preallocate space
321
322 // Initialize worklist
323 if (root() != NULL) { useful.push(root()); }
324 // If 'top' is cached, declare it useful to preserve cached node
325 if( cached_top_node() ) { useful.push(cached_top_node()); }
326
327 // Push all useful nodes onto the list, breadthfirst
328 for( uint next = 0; next < useful.size(); ++next ) {
329 assert( next < unique(), "Unique useful nodes < total nodes");
330 Node *n = useful.at(next);
331 uint max = n->len();
332 for( uint i = 0; i < max; ++i ) {
333 Node *m = n->in(i);
334 if (not_a_node(m)) continue;
335 useful.push(m);
336 }
337 }
338 }
339
340 // Update dead_node_list with any missing dead nodes using useful
341 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
342 void Compile::update_dead_node_list(Unique_Node_List &useful) {
343 uint max_idx = unique();
344 VectorSet& useful_node_set = useful.member_set();
345
346 for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
347 // If node with index node_idx is not in useful set,
348 // mark it as dead in dead node list.
349 if (! useful_node_set.test(node_idx) ) {
350 record_dead_node(node_idx);
351 }
352 }
353 }
354
355 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
356 int shift = 0;
357 for (int i = 0; i < inlines->length(); i++) {
358 CallGenerator* cg = inlines->at(i);
359 CallNode* call = cg->call_node();
360 if (shift > 0) {
361 inlines->at_put(i-shift, cg);
362 }
363 if (!useful.member(call)) {
364 shift++;
365 }
366 }
367 inlines->trunc_to(inlines->length()-shift);
368 }
369
370 // Disconnect all useless nodes by disconnecting those at the boundary.
371 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
372 uint next = 0;
373 while (next < useful.size()) {
374 Node *n = useful.at(next++);
375 if (n->is_SafePoint()) {
376 // We're done with a parsing phase. Replaced nodes are not valid
377 // beyond that point.
378 n->as_SafePoint()->delete_replaced_nodes();
379 }
380 // Use raw traversal of out edges since this code removes out edges
381 int max = n->outcnt();
382 for (int j = 0; j < max; ++j) {
383 Node* child = n->raw_out(j);
384 if (! useful.member(child)) {
385 assert(!child->is_top() || child != top(),
386 "If top is cached in Compile object it is in useful list");
387 // Only need to remove this out-edge to the useless node
388 n->raw_del_out(j);
389 --j;
390 --max;
391 }
392 }
393 if (n->outcnt() == 1 && n->has_special_unique_user()) {
394 record_for_igvn(n->unique_out());
395 }
396 }
397 // Remove useless macro and predicate opaq nodes
398 for (int i = C->macro_count()-1; i >= 0; i--) {
399 Node* n = C->macro_node(i);
400 if (!useful.member(n)) {
401 remove_macro_node(n);
402 }
403 }
404 // Remove useless expensive node
405 for (int i = C->expensive_count()-1; i >= 0; i--) {
406 Node* n = C->expensive_node(i);
407 if (!useful.member(n)) {
408 remove_expensive_node(n);
409 }
410 }
411 // clean up the late inline lists
412 remove_useless_late_inlines(&_string_late_inlines, useful);
413 remove_useless_late_inlines(&_boxing_late_inlines, useful);
414 remove_useless_late_inlines(&_late_inlines, useful);
415 debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
416 }
417
418 //------------------------------frame_size_in_words-----------------------------
419 // frame_slots in units of words
420 int Compile::frame_size_in_words() const {
421 // shift is 0 in LP32 and 1 in LP64
422 const int shift = (LogBytesPerWord - LogBytesPerInt);
423 int words = _frame_slots >> shift;
424 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
425 return words;
426 }
427
428 // To bang the stack of this compiled method we use the stack size
429 // that the interpreter would need in case of a deoptimization. This
430 // removes the need to bang the stack in the deoptimization blob which
431 // in turn simplifies stack overflow handling.
432 int Compile::bang_size_in_bytes() const {
433 return MAX2(_interpreter_frame_size, frame_size_in_bytes());
434 }
435
436 // ============================================================================
437 //------------------------------CompileWrapper---------------------------------
438 class CompileWrapper : public StackObj {
439 Compile *const _compile;
440 public:
441 CompileWrapper(Compile* compile);
442
443 ~CompileWrapper();
444 };
445
446 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
447 // the Compile* pointer is stored in the current ciEnv:
448 ciEnv* env = compile->env();
449 assert(env == ciEnv::current(), "must already be a ciEnv active");
450 assert(env->compiler_data() == NULL, "compile already active?");
451 env->set_compiler_data(compile);
452 assert(compile == Compile::current(), "sanity");
453
454 compile->set_type_dict(NULL);
455 compile->set_type_hwm(NULL);
456 compile->set_type_last_size(0);
457 compile->set_last_tf(NULL, NULL);
458 compile->set_indexSet_arena(NULL);
459 compile->set_indexSet_free_block_list(NULL);
460 compile->init_type_arena();
461 Type::Initialize(compile);
462 _compile->set_scratch_buffer_blob(NULL);
463 _compile->begin_method();
464 }
465 CompileWrapper::~CompileWrapper() {
466 _compile->end_method();
467 if (_compile->scratch_buffer_blob() != NULL)
468 BufferBlob::free(_compile->scratch_buffer_blob());
469 _compile->env()->set_compiler_data(NULL);
470 }
471
472
473 //----------------------------print_compile_messages---------------------------
474 void Compile::print_compile_messages() {
475 #ifndef PRODUCT
476 // Check if recompiling
477 if (_subsume_loads == false && PrintOpto) {
478 // Recompiling without allowing machine instructions to subsume loads
479 tty->print_cr("*********************************************************");
480 tty->print_cr("** Bailout: Recompile without subsuming loads **");
481 tty->print_cr("*********************************************************");
482 }
483 if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
484 // Recompiling without escape analysis
485 tty->print_cr("*********************************************************");
486 tty->print_cr("** Bailout: Recompile without escape analysis **");
487 tty->print_cr("*********************************************************");
488 }
489 if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
490 // Recompiling without boxing elimination
491 tty->print_cr("*********************************************************");
492 tty->print_cr("** Bailout: Recompile without boxing elimination **");
493 tty->print_cr("*********************************************************");
494 }
495 if (env()->break_at_compile()) {
496 // Open the debugger when compiling this method.
497 tty->print("### Breaking when compiling: ");
498 method()->print_short_name();
499 tty->cr();
500 BREAKPOINT;
501 }
502
503 if( PrintOpto ) {
504 if (is_osr_compilation()) {
505 tty->print("[OSR]%3d", _compile_id);
506 } else {
507 tty->print("%3d", _compile_id);
508 }
509 }
510 #endif
511 }
512
513
514 //-----------------------init_scratch_buffer_blob------------------------------
515 // Construct a temporary BufferBlob and cache it for this compile.
516 void Compile::init_scratch_buffer_blob(int const_size) {
517 // If there is already a scratch buffer blob allocated and the
518 // constant section is big enough, use it. Otherwise free the
519 // current and allocate a new one.
520 BufferBlob* blob = scratch_buffer_blob();
521 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
522 // Use the current blob.
523 } else {
524 if (blob != NULL) {
525 BufferBlob::free(blob);
526 }
527
528 ResourceMark rm;
529 _scratch_const_size = const_size;
530 int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
531 blob = BufferBlob::create("Compile::scratch_buffer", size);
532 // Record the buffer blob for next time.
533 set_scratch_buffer_blob(blob);
534 // Have we run out of code space?
535 if (scratch_buffer_blob() == NULL) {
536 // Let CompilerBroker disable further compilations.
537 record_failure("Not enough space for scratch buffer in CodeCache");
538 CompileBroker::handle_full_code_cache();
539 return;
540 }
541 }
542
543 // Initialize the relocation buffers
544 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
545 set_scratch_locs_memory(locs_buf);
546 }
547
548
549 //-----------------------scratch_emit_size-------------------------------------
550 // Helper function that computes size by emitting code
551 uint Compile::scratch_emit_size(const Node* n) {
552 // Start scratch_emit_size section.
553 set_in_scratch_emit_size(true);
554
555 // Emit into a trash buffer and count bytes emitted.
556 // This is a pretty expensive way to compute a size,
557 // but it works well enough if seldom used.
558 // All common fixed-size instructions are given a size
559 // method by the AD file.
560 // Note that the scratch buffer blob and locs memory are
561 // allocated at the beginning of the compile task, and
562 // may be shared by several calls to scratch_emit_size.
563 // The allocation of the scratch buffer blob is particularly
564 // expensive, since it has to grab the code cache lock.
565 BufferBlob* blob = this->scratch_buffer_blob();
566 assert(blob != NULL, "Initialize BufferBlob at start");
567 assert(blob->size() > MAX_inst_size, "sanity");
568 relocInfo* locs_buf = scratch_locs_memory();
569 address blob_begin = blob->content_begin();
570 address blob_end = (address)locs_buf;
571 assert(blob->content_contains(blob_end), "sanity");
572 CodeBuffer buf(blob_begin, blob_end - blob_begin);
573 buf.initialize_consts_size(_scratch_const_size);
574 buf.initialize_stubs_size(MAX_stubs_size);
575 assert(locs_buf != NULL, "sanity");
576 int lsize = MAX_locs_size / 3;
577 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
578 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
579 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
580
581 // Do the emission.
582
583 Label fakeL; // Fake label for branch instructions.
584 Label* saveL = NULL;
585 uint save_bnum = 0;
586 bool is_branch = n->is_MachBranch();
587 if (is_branch) {
588 MacroAssembler masm(&buf);
589 masm.bind(fakeL);
590 n->as_MachBranch()->save_label(&saveL, &save_bnum);
591 n->as_MachBranch()->label_set(&fakeL, 0);
592 }
593 n->emit(buf, this->regalloc());
594 if (is_branch) // Restore label.
595 n->as_MachBranch()->label_set(saveL, save_bnum);
596
597 // End scratch_emit_size section.
598 set_in_scratch_emit_size(false);
599
600 return buf.insts_size();
601 }
602
603
604 // ============================================================================
605 //------------------------------Compile standard-------------------------------
606 debug_only( int Compile::_debug_idx = 100000; )
607
608 // Compile a method. entry_bci is -1 for normal compilations and indicates
609 // the continuation bci for on stack replacement.
610
611
612 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
613 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
614 : Phase(Compiler),
615 _env(ci_env),
616 _log(ci_env->log()),
617 _compile_id(ci_env->compile_id()),
618 _save_argument_registers(false),
619 _stub_name(NULL),
620 _stub_function(NULL),
621 _stub_entry_point(NULL),
622 _method(target),
623 _entry_bci(osr_bci),
624 _initial_gvn(NULL),
625 _for_igvn(NULL),
626 _warm_calls(NULL),
627 _subsume_loads(subsume_loads),
628 _do_escape_analysis(do_escape_analysis),
629 _eliminate_boxing(eliminate_boxing),
630 _failure_reason(NULL),
631 _code_buffer("Compile::Fill_buffer"),
632 _orig_pc_slot(0),
633 _orig_pc_slot_offset_in_bytes(0),
634 _has_method_handle_invokes(false),
635 _mach_constant_base_node(NULL),
636 _node_bundling_limit(0),
637 _node_bundling_base(NULL),
638 _java_calls(0),
639 _inner_loops(0),
640 _scratch_const_size(-1),
641 _in_scratch_emit_size(false),
642 _dead_node_list(comp_arena()),
643 _dead_node_count(0),
644 #ifndef PRODUCT
645 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
646 _in_dump_cnt(0),
647 _printer(IdealGraphPrinter::printer()),
648 #endif
649 _congraph(NULL),
650 _replay_inline_data(NULL),
651 _late_inlines(comp_arena(), 2, 0, NULL),
652 _string_late_inlines(comp_arena(), 2, 0, NULL),
653 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
654 _late_inlines_pos(0),
655 _number_of_mh_late_inlines(0),
656 _inlining_progress(false),
657 _inlining_incrementally(false),
658 _print_inlining_list(NULL),
659 _print_inlining_stream(NULL),
660 _print_inlining_idx(0),
661 _print_inlining_output(NULL),
662 _interpreter_frame_size(0) {
663 C = this;
664
665 CompileWrapper cw(this);
666 #ifndef PRODUCT
667 if (TimeCompiler2) {
668 tty->print(" ");
669 target->holder()->name()->print();
670 tty->print(".");
671 target->print_short_name();
672 tty->print(" ");
673 }
674 TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
675 TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
676 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
677 if (!print_opto_assembly) {
678 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
679 if (print_assembly && !Disassembler::can_decode()) {
680 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
681 print_opto_assembly = true;
682 }
683 }
684 set_print_assembly(print_opto_assembly);
685 set_parsed_irreducible_loop(false);
686
687 if (method()->has_option("ReplayInline")) {
688 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
689 }
690 #endif
691 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
692 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
693 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
694
695 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
696 // Make sure the method being compiled gets its own MDO,
697 // so we can at least track the decompile_count().
698 // Need MDO to record RTM code generation state.
699 method()->ensure_method_data();
700 }
701
702 Init(::AliasLevel);
703
704
705 print_compile_messages();
706
707 _ilt = InlineTree::build_inline_tree_root();
708
709 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
710 assert(num_alias_types() >= AliasIdxRaw, "");
711
712 #define MINIMUM_NODE_HASH 1023
713 // Node list that Iterative GVN will start with
714 Unique_Node_List for_igvn(comp_arena());
715 set_for_igvn(&for_igvn);
716
717 // GVN that will be run immediately on new nodes
718 uint estimated_size = method()->code_size()*4+64;
719 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
720 PhaseGVN gvn(node_arena(), estimated_size);
721 set_initial_gvn(&gvn);
722
723 print_inlining_init();
724 { // Scope for timing the parser
725 TracePhase t3("parse", &_t_parser, true);
726
727 // Put top into the hash table ASAP.
728 initial_gvn()->transform_no_reclaim(top());
729
730 // Set up tf(), start(), and find a CallGenerator.
731 CallGenerator* cg = NULL;
732 if (is_osr_compilation()) {
733 const TypeTuple *domain = StartOSRNode::osr_domain();
734 const TypeTuple *range = TypeTuple::make_range(method()->signature());
735 init_tf(TypeFunc::make(domain, range));
736 StartNode* s = new StartOSRNode(root(), domain);
737 initial_gvn()->set_type_bottom(s);
738 init_start(s);
739 cg = CallGenerator::for_osr(method(), entry_bci());
740 } else {
741 // Normal case.
742 init_tf(TypeFunc::make(method()));
743 StartNode* s = new StartNode(root(), tf()->domain());
744 initial_gvn()->set_type_bottom(s);
745 init_start(s);
746 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
747 // With java.lang.ref.reference.get() we must go through the
748 // intrinsic when G1 is enabled - even when get() is the root
749 // method of the compile - so that, if necessary, the value in
750 // the referent field of the reference object gets recorded by
751 // the pre-barrier code.
752 // Specifically, if G1 is enabled, the value in the referent
753 // field is recorded by the G1 SATB pre barrier. This will
754 // result in the referent being marked live and the reference
755 // object removed from the list of discovered references during
756 // reference processing.
757 cg = find_intrinsic(method(), false);
758 }
759 if (cg == NULL) {
760 float past_uses = method()->interpreter_invocation_count();
761 float expected_uses = past_uses;
762 cg = CallGenerator::for_inline(method(), expected_uses);
763 }
764 }
765 if (failing()) return;
766 if (cg == NULL) {
767 record_method_not_compilable_all_tiers("cannot parse method");
768 return;
769 }
770 JVMState* jvms = build_start_state(start(), tf());
771 if ((jvms = cg->generate(jvms)) == NULL) {
772 record_method_not_compilable("method parse failed");
773 return;
774 }
775 GraphKit kit(jvms);
776
777 if (!kit.stopped()) {
778 // Accept return values, and transfer control we know not where.
779 // This is done by a special, unique ReturnNode bound to root.
780 return_values(kit.jvms());
781 }
782
783 if (kit.has_exceptions()) {
784 // Any exceptions that escape from this call must be rethrown
785 // to whatever caller is dynamically above us on the stack.
786 // This is done by a special, unique RethrowNode bound to root.
787 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
788 }
789
790 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
791
792 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
793 inline_string_calls(true);
794 }
795
796 if (failing()) return;
797
798 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
799
800 // Remove clutter produced by parsing.
801 if (!failing()) {
802 ResourceMark rm;
803 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
804 }
805 }
806
807 // Note: Large methods are capped off in do_one_bytecode().
808 if (failing()) return;
809
810 // After parsing, node notes are no longer automagic.
811 // They must be propagated by register_new_node_with_optimizer(),
812 // clone(), or the like.
813 set_default_node_notes(NULL);
814
815 for (;;) {
816 int successes = Inline_Warm();
817 if (failing()) return;
818 if (successes == 0) break;
819 }
820
821 // Drain the list.
822 Finish_Warm();
823 #ifndef PRODUCT
824 if (_printer) {
825 _printer->print_inlining(this);
826 }
827 #endif
828
829 if (failing()) return;
830 NOT_PRODUCT( verify_graph_edges(); )
831
832 // Now optimize
833 Optimize();
834 if (failing()) return;
835 NOT_PRODUCT( verify_graph_edges(); )
836
837 #ifndef PRODUCT
838 if (PrintIdeal) {
839 ttyLocker ttyl; // keep the following output all in one block
840 // This output goes directly to the tty, not the compiler log.
841 // To enable tools to match it up with the compilation activity,
842 // be sure to tag this tty output with the compile ID.
843 if (xtty != NULL) {
844 xtty->head("ideal compile_id='%d'%s", compile_id(),
845 is_osr_compilation() ? " compile_kind='osr'" :
846 "");
847 }
848 root()->dump(9999);
849 if (xtty != NULL) {
850 xtty->tail("ideal");
851 }
852 }
853 #endif
854
855 NOT_PRODUCT( verify_barriers(); )
856
857 // Dump compilation data to replay it.
858 if (method()->has_option("DumpReplay")) {
859 env()->dump_replay_data(_compile_id);
860 }
861 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
862 env()->dump_inline_data(_compile_id);
863 }
864
865 // Now that we know the size of all the monitors we can add a fixed slot
866 // for the original deopt pc.
867
868 _orig_pc_slot = fixed_slots();
869 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
870 set_fixed_slots(next_slot);
871
872 // Compute when to use implicit null checks. Used by matching trap based
873 // nodes and NullCheck optimization.
874 set_allowed_deopt_reasons();
875
876 // Now generate code
877 Code_Gen();
878 if (failing()) return;
879
880 // Check if we want to skip execution of all compiled code.
881 {
882 #ifndef PRODUCT
883 if (OptoNoExecute) {
884 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
885 return;
886 }
887 TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
888 #endif
889
890 if (is_osr_compilation()) {
891 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
892 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
893 } else {
894 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
895 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
896 }
897
898 env()->register_method(_method, _entry_bci,
899 &_code_offsets,
900 _orig_pc_slot_offset_in_bytes,
901 code_buffer(),
902 frame_size_in_words(), _oop_map_set,
903 &_handler_table, &_inc_table,
904 compiler,
905 env()->comp_level(),
906 has_unsafe_access(),
907 SharedRuntime::is_wide_vector(max_vector_size()),
908 rtm_state()
909 );
910
911 if (log() != NULL) // Print code cache state into compiler log
912 log()->code_cache_state();
913 }
914 }
915
916 //------------------------------Compile----------------------------------------
917 // Compile a runtime stub
918 Compile::Compile( ciEnv* ci_env,
919 TypeFunc_generator generator,
920 address stub_function,
921 const char *stub_name,
922 int is_fancy_jump,
923 bool pass_tls,
924 bool save_arg_registers,
925 bool return_pc )
926 : Phase(Compiler),
927 _env(ci_env),
928 _log(ci_env->log()),
929 _compile_id(0),
930 _save_argument_registers(save_arg_registers),
931 _method(NULL),
932 _stub_name(stub_name),
933 _stub_function(stub_function),
934 _stub_entry_point(NULL),
935 _entry_bci(InvocationEntryBci),
936 _initial_gvn(NULL),
937 _for_igvn(NULL),
938 _warm_calls(NULL),
939 _orig_pc_slot(0),
940 _orig_pc_slot_offset_in_bytes(0),
941 _subsume_loads(true),
942 _do_escape_analysis(false),
943 _eliminate_boxing(false),
944 _failure_reason(NULL),
945 _code_buffer("Compile::Fill_buffer"),
946 _has_method_handle_invokes(false),
947 _mach_constant_base_node(NULL),
948 _node_bundling_limit(0),
949 _node_bundling_base(NULL),
950 _java_calls(0),
951 _inner_loops(0),
952 #ifndef PRODUCT
953 _trace_opto_output(TraceOptoOutput),
954 _in_dump_cnt(0),
955 _printer(NULL),
956 #endif
957 _dead_node_list(comp_arena()),
958 _dead_node_count(0),
959 _congraph(NULL),
960 _replay_inline_data(NULL),
961 _number_of_mh_late_inlines(0),
962 _inlining_progress(false),
963 _inlining_incrementally(false),
964 _print_inlining_list(NULL),
965 _print_inlining_stream(NULL),
966 _print_inlining_idx(0),
967 _print_inlining_output(NULL),
968 _allowed_reasons(0),
969 _interpreter_frame_size(0) {
970 C = this;
971
972 #ifndef PRODUCT
973 TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
974 TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
975 set_print_assembly(PrintFrameConverterAssembly);
976 set_parsed_irreducible_loop(false);
977 #endif
978 set_has_irreducible_loop(false); // no loops
979
980 CompileWrapper cw(this);
981 Init(/*AliasLevel=*/ 0);
982 init_tf((*generator)());
983
984 {
985 // The following is a dummy for the sake of GraphKit::gen_stub
986 Unique_Node_List for_igvn(comp_arena());
987 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
988 PhaseGVN gvn(Thread::current()->resource_area(),255);
989 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
990 gvn.transform_no_reclaim(top());
991
992 GraphKit kit;
993 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
994 }
995
996 NOT_PRODUCT( verify_graph_edges(); )
997 Code_Gen();
998 if (failing()) return;
999
1000
1001 // Entry point will be accessed using compile->stub_entry_point();
1002 if (code_buffer() == NULL) {
1003 Matcher::soft_match_failure();
1004 } else {
1005 if (PrintAssembly && (WizardMode || Verbose))
1006 tty->print_cr("### Stub::%s", stub_name);
1007
1008 if (!failing()) {
1009 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1010
1011 // Make the NMethod
1012 // For now we mark the frame as never safe for profile stackwalking
1013 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1014 code_buffer(),
1015 CodeOffsets::frame_never_safe,
1016 // _code_offsets.value(CodeOffsets::Frame_Complete),
1017 frame_size_in_words(),
1018 _oop_map_set,
1019 save_arg_registers);
1020 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1021
1022 _stub_entry_point = rs->entry_point();
1023 }
1024 }
1025 }
1026
1027 //------------------------------Init-------------------------------------------
1028 // Prepare for a single compilation
1029 void Compile::Init(int aliaslevel) {
1030 _unique = 0;
1031 _regalloc = NULL;
1032
1033 _tf = NULL; // filled in later
1034 _top = NULL; // cached later
1035 _matcher = NULL; // filled in later
1036 _cfg = NULL; // filled in later
1037
1038 set_24_bit_selection_and_mode(Use24BitFP, false);
1039
1040 _node_note_array = NULL;
1041 _default_node_notes = NULL;
1042
1043 _immutable_memory = NULL; // filled in at first inquiry
1044
1045 // Globally visible Nodes
1046 // First set TOP to NULL to give safe behavior during creation of RootNode
1047 set_cached_top_node(NULL);
1048 set_root(new RootNode());
1049 // Now that you have a Root to point to, create the real TOP
1050 set_cached_top_node( new ConNode(Type::TOP) );
1051 set_recent_alloc(NULL, NULL);
1052
1053 // Create Debug Information Recorder to record scopes, oopmaps, etc.
1054 env()->set_oop_recorder(new OopRecorder(env()->arena()));
1055 env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1056 env()->set_dependencies(new Dependencies(env()));
1057
1058 _fixed_slots = 0;
1059 set_has_split_ifs(false);
1060 set_has_loops(has_method() && method()->has_loops()); // first approximation
1061 set_has_stringbuilder(false);
1062 set_has_boxed_value(false);
1063 _trap_can_recompile = false; // no traps emitted yet
1064 _major_progress = true; // start out assuming good things will happen
1065 set_has_unsafe_access(false);
1066 set_max_vector_size(0);
1067 Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1068 set_decompile_count(0);
1069
1070 set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1071 set_num_loop_opts(LoopOptsCount);
1072 set_do_inlining(Inline);
1073 set_max_inline_size(MaxInlineSize);
1074 set_freq_inline_size(FreqInlineSize);
1075 set_do_scheduling(OptoScheduling);
1076 set_do_count_invocations(false);
1077 set_do_method_data_update(false);
1078 set_age_code(has_method() && method()->profile_aging());
1079 set_rtm_state(NoRTM); // No RTM lock eliding by default
1080 #if INCLUDE_RTM_OPT
1081 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1082 int rtm_state = method()->method_data()->rtm_state();
1083 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1084 // Don't generate RTM lock eliding code.
1085 set_rtm_state(NoRTM);
1086 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1087 // Generate RTM lock eliding code without abort ratio calculation code.
1088 set_rtm_state(UseRTM);
1089 } else if (UseRTMDeopt) {
1090 // Generate RTM lock eliding code and include abort ratio calculation
1091 // code if UseRTMDeopt is on.
1092 set_rtm_state(ProfileRTM);
1093 }
1094 }
1095 #endif
1096 if (debug_info()->recording_non_safepoints()) {
1097 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1098 (comp_arena(), 8, 0, NULL));
1099 set_default_node_notes(Node_Notes::make(this));
1100 }
1101
1102 // // -- Initialize types before each compile --
1103 // // Update cached type information
1104 // if( _method && _method->constants() )
1105 // Type::update_loaded_types(_method, _method->constants());
1106
1107 // Init alias_type map.
1108 if (!_do_escape_analysis && aliaslevel == 3)
1109 aliaslevel = 2; // No unique types without escape analysis
1110 _AliasLevel = aliaslevel;
1111 const int grow_ats = 16;
1112 _max_alias_types = grow_ats;
1113 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1114 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1115 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1116 {
1117 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1118 }
1119 // Initialize the first few types.
1120 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1121 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1122 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1123 _num_alias_types = AliasIdxRaw+1;
1124 // Zero out the alias type cache.
1125 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1126 // A NULL adr_type hits in the cache right away. Preload the right answer.
1127 probe_alias_cache(NULL)->_index = AliasIdxTop;
1128
1129 _intrinsics = NULL;
1130 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1131 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1132 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1133 register_library_intrinsics();
1134 }
1135
1136 //---------------------------init_start----------------------------------------
1137 // Install the StartNode on this compile object.
1138 void Compile::init_start(StartNode* s) {
1139 if (failing())
1140 return; // already failing
1141 assert(s == start(), "");
1142 }
1143
1144 StartNode* Compile::start() const {
1145 assert(!failing(), "");
1146 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1147 Node* start = root()->fast_out(i);
1148 if( start->is_Start() )
1149 return start->as_Start();
1150 }
1151 fatal("Did not find Start node!");
1152 return NULL;
1153 }
1154
1155 //-------------------------------immutable_memory-------------------------------------
1156 // Access immutable memory
1157 Node* Compile::immutable_memory() {
1158 if (_immutable_memory != NULL) {
1159 return _immutable_memory;
1160 }
1161 StartNode* s = start();
1162 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1163 Node *p = s->fast_out(i);
1164 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1165 _immutable_memory = p;
1166 return _immutable_memory;
1167 }
1168 }
1169 ShouldNotReachHere();
1170 return NULL;
1171 }
1172
1173 //----------------------set_cached_top_node------------------------------------
1174 // Install the cached top node, and make sure Node::is_top works correctly.
1175 void Compile::set_cached_top_node(Node* tn) {
1176 if (tn != NULL) verify_top(tn);
1177 Node* old_top = _top;
1178 _top = tn;
1179 // Calling Node::setup_is_top allows the nodes the chance to adjust
1180 // their _out arrays.
1181 if (_top != NULL) _top->setup_is_top();
1182 if (old_top != NULL) old_top->setup_is_top();
1183 assert(_top == NULL || top()->is_top(), "");
1184 }
1185
1186 #ifdef ASSERT
1187 uint Compile::count_live_nodes_by_graph_walk() {
1188 Unique_Node_List useful(comp_arena());
1189 // Get useful node list by walking the graph.
1190 identify_useful_nodes(useful);
1191 return useful.size();
1192 }
1193
1194 void Compile::print_missing_nodes() {
1195
1196 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1197 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1198 return;
1199 }
1200
1201 // This is an expensive function. It is executed only when the user
1202 // specifies VerifyIdealNodeCount option or otherwise knows the
1203 // additional work that needs to be done to identify reachable nodes
1204 // by walking the flow graph and find the missing ones using
1205 // _dead_node_list.
1206
1207 Unique_Node_List useful(comp_arena());
1208 // Get useful node list by walking the graph.
1209 identify_useful_nodes(useful);
1210
1211 uint l_nodes = C->live_nodes();
1212 uint l_nodes_by_walk = useful.size();
1213
1214 if (l_nodes != l_nodes_by_walk) {
1215 if (_log != NULL) {
1216 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1217 _log->stamp();
1218 _log->end_head();
1219 }
1220 VectorSet& useful_member_set = useful.member_set();
1221 int last_idx = l_nodes_by_walk;
1222 for (int i = 0; i < last_idx; i++) {
1223 if (useful_member_set.test(i)) {
1224 if (_dead_node_list.test(i)) {
1225 if (_log != NULL) {
1226 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1227 }
1228 if (PrintIdealNodeCount) {
1229 // Print the log message to tty
1230 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1231 useful.at(i)->dump();
1232 }
1233 }
1234 }
1235 else if (! _dead_node_list.test(i)) {
1236 if (_log != NULL) {
1237 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1238 }
1239 if (PrintIdealNodeCount) {
1240 // Print the log message to tty
1241 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1242 }
1243 }
1244 }
1245 if (_log != NULL) {
1246 _log->tail("mismatched_nodes");
1247 }
1248 }
1249 }
1250 #endif
1251
1252 #ifndef PRODUCT
1253 void Compile::verify_top(Node* tn) const {
1254 if (tn != NULL) {
1255 assert(tn->is_Con(), "top node must be a constant");
1256 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1257 assert(tn->in(0) != NULL, "must have live top node");
1258 }
1259 }
1260 #endif
1261
1262
1263 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1264
1265 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1266 guarantee(arr != NULL, "");
1267 int num_blocks = arr->length();
1268 if (grow_by < num_blocks) grow_by = num_blocks;
1269 int num_notes = grow_by * _node_notes_block_size;
1270 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1271 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1272 while (num_notes > 0) {
1273 arr->append(notes);
1274 notes += _node_notes_block_size;
1275 num_notes -= _node_notes_block_size;
1276 }
1277 assert(num_notes == 0, "exact multiple, please");
1278 }
1279
1280 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1281 if (source == NULL || dest == NULL) return false;
1282
1283 if (dest->is_Con())
1284 return false; // Do not push debug info onto constants.
1285
1286 #ifdef ASSERT
1287 // Leave a bread crumb trail pointing to the original node:
1288 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1289 dest->set_debug_orig(source);
1290 }
1291 #endif
1292
1293 if (node_note_array() == NULL)
1294 return false; // Not collecting any notes now.
1295
1296 // This is a copy onto a pre-existing node, which may already have notes.
1297 // If both nodes have notes, do not overwrite any pre-existing notes.
1298 Node_Notes* source_notes = node_notes_at(source->_idx);
1299 if (source_notes == NULL || source_notes->is_clear()) return false;
1300 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1301 if (dest_notes == NULL || dest_notes->is_clear()) {
1302 return set_node_notes_at(dest->_idx, source_notes);
1303 }
1304
1305 Node_Notes merged_notes = (*source_notes);
1306 // The order of operations here ensures that dest notes will win...
1307 merged_notes.update_from(dest_notes);
1308 return set_node_notes_at(dest->_idx, &merged_notes);
1309 }
1310
1311
1312 //--------------------------allow_range_check_smearing-------------------------
1313 // Gating condition for coalescing similar range checks.
1314 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1315 // single covering check that is at least as strong as any of them.
1316 // If the optimization succeeds, the simplified (strengthened) range check
1317 // will always succeed. If it fails, we will deopt, and then give up
1318 // on the optimization.
1319 bool Compile::allow_range_check_smearing() const {
1320 // If this method has already thrown a range-check,
1321 // assume it was because we already tried range smearing
1322 // and it failed.
1323 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1324 return !already_trapped;
1325 }
1326
1327
1328 //------------------------------flatten_alias_type-----------------------------
1329 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1330 int offset = tj->offset();
1331 TypePtr::PTR ptr = tj->ptr();
1332
1333 // Known instance (scalarizable allocation) alias only with itself.
1334 bool is_known_inst = tj->isa_oopptr() != NULL &&
1335 tj->is_oopptr()->is_known_instance();
1336
1337 // Process weird unsafe references.
1338 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1339 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1340 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1341 tj = TypeOopPtr::BOTTOM;
1342 ptr = tj->ptr();
1343 offset = tj->offset();
1344 }
1345
1346 // Array pointers need some flattening
1347 const TypeAryPtr *ta = tj->isa_aryptr();
1348 if (ta && ta->is_stable()) {
1349 // Erase stability property for alias analysis.
1350 tj = ta = ta->cast_to_stable(false);
1351 }
1352 if( ta && is_known_inst ) {
1353 if ( offset != Type::OffsetBot &&
1354 offset > arrayOopDesc::length_offset_in_bytes() ) {
1355 offset = Type::OffsetBot; // Flatten constant access into array body only
1356 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1357 }
1358 } else if( ta && _AliasLevel >= 2 ) {
1359 // For arrays indexed by constant indices, we flatten the alias
1360 // space to include all of the array body. Only the header, klass
1361 // and array length can be accessed un-aliased.
1362 if( offset != Type::OffsetBot ) {
1363 if( ta->const_oop() ) { // MethodData* or Method*
1364 offset = Type::OffsetBot; // Flatten constant access into array body
1365 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1366 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1367 // range is OK as-is.
1368 tj = ta = TypeAryPtr::RANGE;
1369 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1370 tj = TypeInstPtr::KLASS; // all klass loads look alike
1371 ta = TypeAryPtr::RANGE; // generic ignored junk
1372 ptr = TypePtr::BotPTR;
1373 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1374 tj = TypeInstPtr::MARK;
1375 ta = TypeAryPtr::RANGE; // generic ignored junk
1376 ptr = TypePtr::BotPTR;
1377 } else { // Random constant offset into array body
1378 offset = Type::OffsetBot; // Flatten constant access into array body
1379 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1380 }
1381 }
1382 // Arrays of fixed size alias with arrays of unknown size.
1383 if (ta->size() != TypeInt::POS) {
1384 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1385 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1386 }
1387 // Arrays of known objects become arrays of unknown objects.
1388 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1389 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1390 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1391 }
1392 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1393 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1394 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1395 }
1396 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1397 // cannot be distinguished by bytecode alone.
1398 if (ta->elem() == TypeInt::BOOL) {
1399 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1400 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1401 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1402 }
1403 // During the 2nd round of IterGVN, NotNull castings are removed.
1404 // Make sure the Bottom and NotNull variants alias the same.
1405 // Also, make sure exact and non-exact variants alias the same.
1406 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1407 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1408 }
1409 }
1410
1411 // Oop pointers need some flattening
1412 const TypeInstPtr *to = tj->isa_instptr();
1413 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1414 ciInstanceKlass *k = to->klass()->as_instance_klass();
1415 if( ptr == TypePtr::Constant ) {
1416 if (to->klass() != ciEnv::current()->Class_klass() ||
1417 offset < k->size_helper() * wordSize) {
1418 // No constant oop pointers (such as Strings); they alias with
1419 // unknown strings.
1420 assert(!is_known_inst, "not scalarizable allocation");
1421 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1422 }
1423 } else if( is_known_inst ) {
1424 tj = to; // Keep NotNull and klass_is_exact for instance type
1425 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1426 // During the 2nd round of IterGVN, NotNull castings are removed.
1427 // Make sure the Bottom and NotNull variants alias the same.
1428 // Also, make sure exact and non-exact variants alias the same.
1429 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1430 }
1431 if (to->speculative() != NULL) {
1432 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1433 }
1434 // Canonicalize the holder of this field
1435 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1436 // First handle header references such as a LoadKlassNode, even if the
1437 // object's klass is unloaded at compile time (4965979).
1438 if (!is_known_inst) { // Do it only for non-instance types
1439 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1440 }
1441 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1442 // Static fields are in the space above the normal instance
1443 // fields in the java.lang.Class instance.
1444 if (to->klass() != ciEnv::current()->Class_klass()) {
1445 to = NULL;
1446 tj = TypeOopPtr::BOTTOM;
1447 offset = tj->offset();
1448 }
1449 } else {
1450 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1451 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1452 if( is_known_inst ) {
1453 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1454 } else {
1455 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1456 }
1457 }
1458 }
1459 }
1460
1461 // Klass pointers to object array klasses need some flattening
1462 const TypeKlassPtr *tk = tj->isa_klassptr();
1463 if( tk ) {
1464 // If we are referencing a field within a Klass, we need
1465 // to assume the worst case of an Object. Both exact and
1466 // inexact types must flatten to the same alias class so
1467 // use NotNull as the PTR.
1468 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1469
1470 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1471 TypeKlassPtr::OBJECT->klass(),
1472 offset);
1473 }
1474
1475 ciKlass* klass = tk->klass();
1476 if( klass->is_obj_array_klass() ) {
1477 ciKlass* k = TypeAryPtr::OOPS->klass();
1478 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1479 k = TypeInstPtr::BOTTOM->klass();
1480 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1481 }
1482
1483 // Check for precise loads from the primary supertype array and force them
1484 // to the supertype cache alias index. Check for generic array loads from
1485 // the primary supertype array and also force them to the supertype cache
1486 // alias index. Since the same load can reach both, we need to merge
1487 // these 2 disparate memories into the same alias class. Since the
1488 // primary supertype array is read-only, there's no chance of confusion
1489 // where we bypass an array load and an array store.
1490 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1491 if (offset == Type::OffsetBot ||
1492 (offset >= primary_supers_offset &&
1493 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1494 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1495 offset = in_bytes(Klass::secondary_super_cache_offset());
1496 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1497 }
1498 }
1499
1500 // Flatten all Raw pointers together.
1501 if (tj->base() == Type::RawPtr)
1502 tj = TypeRawPtr::BOTTOM;
1503
1504 if (tj->base() == Type::AnyPtr)
1505 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1506
1507 // Flatten all to bottom for now
1508 switch( _AliasLevel ) {
1509 case 0:
1510 tj = TypePtr::BOTTOM;
1511 break;
1512 case 1: // Flatten to: oop, static, field or array
1513 switch (tj->base()) {
1514 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1515 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1516 case Type::AryPtr: // do not distinguish arrays at all
1517 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1518 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1519 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1520 default: ShouldNotReachHere();
1521 }
1522 break;
1523 case 2: // No collapsing at level 2; keep all splits
1524 case 3: // No collapsing at level 3; keep all splits
1525 break;
1526 default:
1527 Unimplemented();
1528 }
1529
1530 offset = tj->offset();
1531 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1532
1533 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1534 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1535 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1536 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1537 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1538 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1539 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1540 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1541 assert( tj->ptr() != TypePtr::TopPTR &&
1542 tj->ptr() != TypePtr::AnyNull &&
1543 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1544 // assert( tj->ptr() != TypePtr::Constant ||
1545 // tj->base() == Type::RawPtr ||
1546 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1547
1548 return tj;
1549 }
1550
1551 void Compile::AliasType::Init(int i, const TypePtr* at) {
1552 _index = i;
1553 _adr_type = at;
1554 _field = NULL;
1555 _element = NULL;
1556 _is_rewritable = true; // default
1557 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1558 if (atoop != NULL && atoop->is_known_instance()) {
1559 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1560 _general_index = Compile::current()->get_alias_index(gt);
1561 } else {
1562 _general_index = 0;
1563 }
1564 }
1565
1566 //---------------------------------print_on------------------------------------
1567 #ifndef PRODUCT
1568 void Compile::AliasType::print_on(outputStream* st) {
1569 if (index() < 10)
1570 st->print("@ <%d> ", index());
1571 else st->print("@ <%d>", index());
1572 st->print(is_rewritable() ? " " : " RO");
1573 int offset = adr_type()->offset();
1574 if (offset == Type::OffsetBot)
1575 st->print(" +any");
1576 else st->print(" +%-3d", offset);
1577 st->print(" in ");
1578 adr_type()->dump_on(st);
1579 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1580 if (field() != NULL && tjp) {
1581 if (tjp->klass() != field()->holder() ||
1582 tjp->offset() != field()->offset_in_bytes()) {
1583 st->print(" != ");
1584 field()->print();
1585 st->print(" ***");
1586 }
1587 }
1588 }
1589
1590 void print_alias_types() {
1591 Compile* C = Compile::current();
1592 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1593 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1594 C->alias_type(idx)->print_on(tty);
1595 tty->cr();
1596 }
1597 }
1598 #endif
1599
1600
1601 //----------------------------probe_alias_cache--------------------------------
1602 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1603 intptr_t key = (intptr_t) adr_type;
1604 key ^= key >> logAliasCacheSize;
1605 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1606 }
1607
1608
1609 //-----------------------------grow_alias_types--------------------------------
1610 void Compile::grow_alias_types() {
1611 const int old_ats = _max_alias_types; // how many before?
1612 const int new_ats = old_ats; // how many more?
1613 const int grow_ats = old_ats+new_ats; // how many now?
1614 _max_alias_types = grow_ats;
1615 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1616 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1617 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1618 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1619 }
1620
1621
1622 //--------------------------------find_alias_type------------------------------
1623 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1624 if (_AliasLevel == 0)
1625 return alias_type(AliasIdxBot);
1626
1627 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1628 if (ace->_adr_type == adr_type) {
1629 return alias_type(ace->_index);
1630 }
1631
1632 // Handle special cases.
1633 if (adr_type == NULL) return alias_type(AliasIdxTop);
1634 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1635
1636 // Do it the slow way.
1637 const TypePtr* flat = flatten_alias_type(adr_type);
1638
1639 #ifdef ASSERT
1640 assert(flat == flatten_alias_type(flat), "idempotent");
1641 assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
1642 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1643 const TypeOopPtr* foop = flat->is_oopptr();
1644 // Scalarizable allocations have exact klass always.
1645 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1646 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1647 assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1648 }
1649 assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1650 #endif
1651
1652 int idx = AliasIdxTop;
1653 for (int i = 0; i < num_alias_types(); i++) {
1654 if (alias_type(i)->adr_type() == flat) {
1655 idx = i;
1656 break;
1657 }
1658 }
1659
1660 if (idx == AliasIdxTop) {
1661 if (no_create) return NULL;
1662 // Grow the array if necessary.
1663 if (_num_alias_types == _max_alias_types) grow_alias_types();
1664 // Add a new alias type.
1665 idx = _num_alias_types++;
1666 _alias_types[idx]->Init(idx, flat);
1667 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1668 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1669 if (flat->isa_instptr()) {
1670 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1671 && flat->is_instptr()->klass() == env()->Class_klass())
1672 alias_type(idx)->set_rewritable(false);
1673 }
1674 if (flat->isa_aryptr()) {
1675 #ifdef ASSERT
1676 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1677 // (T_BYTE has the weakest alignment and size restrictions...)
1678 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1679 #endif
1680 if (flat->offset() == TypePtr::OffsetBot) {
1681 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1682 }
1683 }
1684 if (flat->isa_klassptr()) {
1685 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1686 alias_type(idx)->set_rewritable(false);
1687 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1688 alias_type(idx)->set_rewritable(false);
1689 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1690 alias_type(idx)->set_rewritable(false);
1691 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1692 alias_type(idx)->set_rewritable(false);
1693 }
1694 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1695 // but the base pointer type is not distinctive enough to identify
1696 // references into JavaThread.)
1697
1698 // Check for final fields.
1699 const TypeInstPtr* tinst = flat->isa_instptr();
1700 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1701 ciField* field;
1702 if (tinst->const_oop() != NULL &&
1703 tinst->klass() == ciEnv::current()->Class_klass() &&
1704 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1705 // static field
1706 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1707 field = k->get_field_by_offset(tinst->offset(), true);
1708 } else {
1709 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1710 field = k->get_field_by_offset(tinst->offset(), false);
1711 }
1712 assert(field == NULL ||
1713 original_field == NULL ||
1714 (field->holder() == original_field->holder() &&
1715 field->offset() == original_field->offset() &&
1716 field->is_static() == original_field->is_static()), "wrong field?");
1717 // Set field() and is_rewritable() attributes.
1718 if (field != NULL) alias_type(idx)->set_field(field);
1719 }
1720 }
1721
1722 // Fill the cache for next time.
1723 ace->_adr_type = adr_type;
1724 ace->_index = idx;
1725 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1726
1727 // Might as well try to fill the cache for the flattened version, too.
1728 AliasCacheEntry* face = probe_alias_cache(flat);
1729 if (face->_adr_type == NULL) {
1730 face->_adr_type = flat;
1731 face->_index = idx;
1732 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1733 }
1734
1735 return alias_type(idx);
1736 }
1737
1738
1739 Compile::AliasType* Compile::alias_type(ciField* field) {
1740 const TypeOopPtr* t;
1741 if (field->is_static())
1742 t = TypeInstPtr::make(field->holder()->java_mirror());
1743 else
1744 t = TypeOopPtr::make_from_klass_raw(field->holder());
1745 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1746 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1747 return atp;
1748 }
1749
1750
1751 //------------------------------have_alias_type--------------------------------
1752 bool Compile::have_alias_type(const TypePtr* adr_type) {
1753 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1754 if (ace->_adr_type == adr_type) {
1755 return true;
1756 }
1757
1758 // Handle special cases.
1759 if (adr_type == NULL) return true;
1760 if (adr_type == TypePtr::BOTTOM) return true;
1761
1762 return find_alias_type(adr_type, true, NULL) != NULL;
1763 }
1764
1765 //-----------------------------must_alias--------------------------------------
1766 // True if all values of the given address type are in the given alias category.
1767 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1768 if (alias_idx == AliasIdxBot) return true; // the universal category
1769 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1770 if (alias_idx == AliasIdxTop) return false; // the empty category
1771 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1772
1773 // the only remaining possible overlap is identity
1774 int adr_idx = get_alias_index(adr_type);
1775 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1776 assert(adr_idx == alias_idx ||
1777 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1778 && adr_type != TypeOopPtr::BOTTOM),
1779 "should not be testing for overlap with an unsafe pointer");
1780 return adr_idx == alias_idx;
1781 }
1782
1783 //------------------------------can_alias--------------------------------------
1784 // True if any values of the given address type are in the given alias category.
1785 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1786 if (alias_idx == AliasIdxTop) return false; // the empty category
1787 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1788 if (alias_idx == AliasIdxBot) return true; // the universal category
1789 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1790
1791 // the only remaining possible overlap is identity
1792 int adr_idx = get_alias_index(adr_type);
1793 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1794 return adr_idx == alias_idx;
1795 }
1796
1797
1798
1799 //---------------------------pop_warm_call-------------------------------------
1800 WarmCallInfo* Compile::pop_warm_call() {
1801 WarmCallInfo* wci = _warm_calls;
1802 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1803 return wci;
1804 }
1805
1806 //----------------------------Inline_Warm--------------------------------------
1807 int Compile::Inline_Warm() {
1808 // If there is room, try to inline some more warm call sites.
1809 // %%% Do a graph index compaction pass when we think we're out of space?
1810 if (!InlineWarmCalls) return 0;
1811
1812 int calls_made_hot = 0;
1813 int room_to_grow = NodeCountInliningCutoff - unique();
1814 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1815 int amount_grown = 0;
1816 WarmCallInfo* call;
1817 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1818 int est_size = (int)call->size();
1819 if (est_size > (room_to_grow - amount_grown)) {
1820 // This one won't fit anyway. Get rid of it.
1821 call->make_cold();
1822 continue;
1823 }
1824 call->make_hot();
1825 calls_made_hot++;
1826 amount_grown += est_size;
1827 amount_to_grow -= est_size;
1828 }
1829
1830 if (calls_made_hot > 0) set_major_progress();
1831 return calls_made_hot;
1832 }
1833
1834
1835 //----------------------------Finish_Warm--------------------------------------
1836 void Compile::Finish_Warm() {
1837 if (!InlineWarmCalls) return;
1838 if (failing()) return;
1839 if (warm_calls() == NULL) return;
1840
1841 // Clean up loose ends, if we are out of space for inlining.
1842 WarmCallInfo* call;
1843 while ((call = pop_warm_call()) != NULL) {
1844 call->make_cold();
1845 }
1846 }
1847
1848 //---------------------cleanup_loop_predicates-----------------------
1849 // Remove the opaque nodes that protect the predicates so that all unused
1850 // checks and uncommon_traps will be eliminated from the ideal graph
1851 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1852 if (predicate_count()==0) return;
1853 for (int i = predicate_count(); i > 0; i--) {
1854 Node * n = predicate_opaque1_node(i-1);
1855 assert(n->Opcode() == Op_Opaque1, "must be");
1856 igvn.replace_node(n, n->in(1));
1857 }
1858 assert(predicate_count()==0, "should be clean!");
1859 }
1860
1861 // StringOpts and late inlining of string methods
1862 void Compile::inline_string_calls(bool parse_time) {
1863 {
1864 // remove useless nodes to make the usage analysis simpler
1865 ResourceMark rm;
1866 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1867 }
1868
1869 {
1870 ResourceMark rm;
1871 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1872 PhaseStringOpts pso(initial_gvn(), for_igvn());
1873 print_method(PHASE_AFTER_STRINGOPTS, 3);
1874 }
1875
1876 // now inline anything that we skipped the first time around
1877 if (!parse_time) {
1878 _late_inlines_pos = _late_inlines.length();
1879 }
1880
1881 while (_string_late_inlines.length() > 0) {
1882 CallGenerator* cg = _string_late_inlines.pop();
1883 cg->do_late_inline();
1884 if (failing()) return;
1885 }
1886 _string_late_inlines.trunc_to(0);
1887 }
1888
1889 // Late inlining of boxing methods
1890 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1891 if (_boxing_late_inlines.length() > 0) {
1892 assert(has_boxed_value(), "inconsistent");
1893
1894 PhaseGVN* gvn = initial_gvn();
1895 set_inlining_incrementally(true);
1896
1897 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1898 for_igvn()->clear();
1899 gvn->replace_with(&igvn);
1900
1901 _late_inlines_pos = _late_inlines.length();
1902
1903 while (_boxing_late_inlines.length() > 0) {
1904 CallGenerator* cg = _boxing_late_inlines.pop();
1905 cg->do_late_inline();
1906 if (failing()) return;
1907 }
1908 _boxing_late_inlines.trunc_to(0);
1909
1910 {
1911 ResourceMark rm;
1912 PhaseRemoveUseless pru(gvn, for_igvn());
1913 }
1914
1915 igvn = PhaseIterGVN(gvn);
1916 igvn.optimize();
1917
1918 set_inlining_progress(false);
1919 set_inlining_incrementally(false);
1920 }
1921 }
1922
1923 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1924 assert(IncrementalInline, "incremental inlining should be on");
1925 PhaseGVN* gvn = initial_gvn();
1926
1927 set_inlining_progress(false);
1928 for_igvn()->clear();
1929 gvn->replace_with(&igvn);
1930
1931 int i = 0;
1932
1933 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1934 CallGenerator* cg = _late_inlines.at(i);
1935 _late_inlines_pos = i+1;
1936 cg->do_late_inline();
1937 if (failing()) return;
1938 }
1939 int j = 0;
1940 for (; i < _late_inlines.length(); i++, j++) {
1941 _late_inlines.at_put(j, _late_inlines.at(i));
1942 }
1943 _late_inlines.trunc_to(j);
1944
1945 {
1946 ResourceMark rm;
1947 PhaseRemoveUseless pru(gvn, for_igvn());
1948 }
1949
1950 igvn = PhaseIterGVN(gvn);
1951 }
1952
1953 // Perform incremental inlining until bound on number of live nodes is reached
1954 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1955 PhaseGVN* gvn = initial_gvn();
1956
1957 set_inlining_incrementally(true);
1958 set_inlining_progress(true);
1959 uint low_live_nodes = 0;
1960
1961 while(inlining_progress() && _late_inlines.length() > 0) {
1962
1963 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1964 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1965 // PhaseIdealLoop is expensive so we only try it once we are
1966 // out of live nodes and we only try it again if the previous
1967 // helped got the number of nodes down significantly
1968 PhaseIdealLoop ideal_loop( igvn, false, true );
1969 if (failing()) return;
1970 low_live_nodes = live_nodes();
1971 _major_progress = true;
1972 }
1973
1974 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1975 break;
1976 }
1977 }
1978
1979 inline_incrementally_one(igvn);
1980
1981 if (failing()) return;
1982
1983 igvn.optimize();
1984
1985 if (failing()) return;
1986 }
1987
1988 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1989
1990 if (_string_late_inlines.length() > 0) {
1991 assert(has_stringbuilder(), "inconsistent");
1992 for_igvn()->clear();
1993 initial_gvn()->replace_with(&igvn);
1994
1995 inline_string_calls(false);
1996
1997 if (failing()) return;
1998
1999 {
2000 ResourceMark rm;
2001 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2002 }
2003
2004 igvn = PhaseIterGVN(gvn);
2005
2006 igvn.optimize();
2007 }
2008
2009 set_inlining_incrementally(false);
2010 }
2011
2012
2013 //------------------------------Optimize---------------------------------------
2014 // Given a graph, optimize it.
2015 void Compile::Optimize() {
2016 TracePhase t1("optimizer", &_t_optimizer, true);
2017
2018 #ifndef PRODUCT
2019 if (env()->break_at_compile()) {
2020 BREAKPOINT;
2021 }
2022
2023 #endif
2024
2025 ResourceMark rm;
2026 int loop_opts_cnt;
2027
2028 print_inlining_reinit();
2029
2030 NOT_PRODUCT( verify_graph_edges(); )
2031
2032 print_method(PHASE_AFTER_PARSING);
2033
2034 {
2035 // Iterative Global Value Numbering, including ideal transforms
2036 // Initialize IterGVN with types and values from parse-time GVN
2037 PhaseIterGVN igvn(initial_gvn());
2038 {
2039 NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
2040 igvn.optimize();
2041 }
2042
2043 print_method(PHASE_ITER_GVN1, 2);
2044
2045 if (failing()) return;
2046
2047 {
2048 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2049 inline_incrementally(igvn);
2050 }
2051
2052 print_method(PHASE_INCREMENTAL_INLINE, 2);
2053
2054 if (failing()) return;
2055
2056 if (eliminate_boxing()) {
2057 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2058 // Inline valueOf() methods now.
2059 inline_boxing_calls(igvn);
2060
2061 if (AlwaysIncrementalInline) {
2062 inline_incrementally(igvn);
2063 }
2064
2065 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2066
2067 if (failing()) return;
2068 }
2069
2070 // Remove the speculative part of types and clean up the graph from
2071 // the extra CastPP nodes whose only purpose is to carry them. Do
2072 // that early so that optimizations are not disrupted by the extra
2073 // CastPP nodes.
2074 remove_speculative_types(igvn);
2075
2076 // No more new expensive nodes will be added to the list from here
2077 // so keep only the actual candidates for optimizations.
2078 cleanup_expensive_nodes(igvn);
2079
2080 // Perform escape analysis
2081 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2082 if (has_loops()) {
2083 // Cleanup graph (remove dead nodes).
2084 TracePhase t2("idealLoop", &_t_idealLoop, true);
2085 PhaseIdealLoop ideal_loop( igvn, false, true );
2086 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2087 if (failing()) return;
2088 }
2089 ConnectionGraph::do_analysis(this, &igvn);
2090
2091 if (failing()) return;
2092
2093 // Optimize out fields loads from scalar replaceable allocations.
2094 igvn.optimize();
2095 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2096
2097 if (failing()) return;
2098
2099 if (congraph() != NULL && macro_count() > 0) {
2100 NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2101 PhaseMacroExpand mexp(igvn);
2102 mexp.eliminate_macro_nodes();
2103 igvn.set_delay_transform(false);
2104
2105 igvn.optimize();
2106 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2107
2108 if (failing()) return;
2109 }
2110 }
2111
2112 // Loop transforms on the ideal graph. Range Check Elimination,
2113 // peeling, unrolling, etc.
2114
2115 // Set loop opts counter
2116 loop_opts_cnt = num_loop_opts();
2117 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2118 {
2119 TracePhase t2("idealLoop", &_t_idealLoop, true);
2120 PhaseIdealLoop ideal_loop( igvn, true );
2121 loop_opts_cnt--;
2122 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2123 if (failing()) return;
2124 }
2125 // Loop opts pass if partial peeling occurred in previous pass
2126 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2127 TracePhase t3("idealLoop", &_t_idealLoop, true);
2128 PhaseIdealLoop ideal_loop( igvn, false );
2129 loop_opts_cnt--;
2130 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2131 if (failing()) return;
2132 }
2133 // Loop opts pass for loop-unrolling before CCP
2134 if(major_progress() && (loop_opts_cnt > 0)) {
2135 TracePhase t4("idealLoop", &_t_idealLoop, true);
2136 PhaseIdealLoop ideal_loop( igvn, false );
2137 loop_opts_cnt--;
2138 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2139 }
2140 if (!failing()) {
2141 // Verify that last round of loop opts produced a valid graph
2142 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2143 PhaseIdealLoop::verify(igvn);
2144 }
2145 }
2146 if (failing()) return;
2147
2148 // Conditional Constant Propagation;
2149 PhaseCCP ccp( &igvn );
2150 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2151 {
2152 TracePhase t2("ccp", &_t_ccp, true);
2153 ccp.do_transform();
2154 }
2155 print_method(PHASE_CPP1, 2);
2156
2157 assert( true, "Break here to ccp.dump_old2new_map()");
2158
2159 // Iterative Global Value Numbering, including ideal transforms
2160 {
2161 NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2162 igvn = ccp;
2163 igvn.optimize();
2164 }
2165
2166 print_method(PHASE_ITER_GVN2, 2);
2167
2168 if (failing()) return;
2169
2170 // Loop transforms on the ideal graph. Range Check Elimination,
2171 // peeling, unrolling, etc.
2172 if(loop_opts_cnt > 0) {
2173 debug_only( int cnt = 0; );
2174 while(major_progress() && (loop_opts_cnt > 0)) {
2175 TracePhase t2("idealLoop", &_t_idealLoop, true);
2176 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2177 PhaseIdealLoop ideal_loop( igvn, true);
2178 loop_opts_cnt--;
2179 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2180 if (failing()) return;
2181 }
2182 }
2183
2184 {
2185 // Verify that all previous optimizations produced a valid graph
2186 // at least to this point, even if no loop optimizations were done.
2187 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2188 PhaseIdealLoop::verify(igvn);
2189 }
2190
2191 {
2192 NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2193 PhaseMacroExpand mex(igvn);
2194 if (mex.expand_macro_nodes()) {
2195 assert(failing(), "must bail out w/ explicit message");
2196 return;
2197 }
2198 }
2199
2200 } // (End scope of igvn; run destructor if necessary for asserts.)
2201
2202 process_print_inlining();
2203 // A method with only infinite loops has no edges entering loops from root
2204 {
2205 NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2206 if (final_graph_reshaping()) {
2207 assert(failing(), "must bail out w/ explicit message");
2208 return;
2209 }
2210 }
2211
2212 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2213 }
2214
2215
2216 //------------------------------Code_Gen---------------------------------------
2217 // Given a graph, generate code for it
2218 void Compile::Code_Gen() {
2219 if (failing()) {
2220 return;
2221 }
2222
2223 // Perform instruction selection. You might think we could reclaim Matcher
2224 // memory PDQ, but actually the Matcher is used in generating spill code.
2225 // Internals of the Matcher (including some VectorSets) must remain live
2226 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2227 // set a bit in reclaimed memory.
2228
2229 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2230 // nodes. Mapping is only valid at the root of each matched subtree.
2231 NOT_PRODUCT( verify_graph_edges(); )
2232
2233 Matcher matcher;
2234 _matcher = &matcher;
2235 {
2236 TracePhase t2("matcher", &_t_matcher, true);
2237 matcher.match();
2238 }
2239 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2240 // nodes. Mapping is only valid at the root of each matched subtree.
2241 NOT_PRODUCT( verify_graph_edges(); )
2242
2243 // If you have too many nodes, or if matching has failed, bail out
2244 check_node_count(0, "out of nodes matching instructions");
2245 if (failing()) {
2246 return;
2247 }
2248
2249 // Build a proper-looking CFG
2250 PhaseCFG cfg(node_arena(), root(), matcher);
2251 _cfg = &cfg;
2252 {
2253 NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2254 bool success = cfg.do_global_code_motion();
2255 if (!success) {
2256 return;
2257 }
2258
2259 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2260 NOT_PRODUCT( verify_graph_edges(); )
2261 debug_only( cfg.verify(); )
2262 }
2263
2264 PhaseChaitin regalloc(unique(), cfg, matcher);
2265 _regalloc = ®alloc;
2266 {
2267 TracePhase t2("regalloc", &_t_registerAllocation, true);
2268 // Perform register allocation. After Chaitin, use-def chains are
2269 // no longer accurate (at spill code) and so must be ignored.
2270 // Node->LRG->reg mappings are still accurate.
2271 _regalloc->Register_Allocate();
2272
2273 // Bail out if the allocator builds too many nodes
2274 if (failing()) {
2275 return;
2276 }
2277 }
2278
2279 // Prior to register allocation we kept empty basic blocks in case the
2280 // the allocator needed a place to spill. After register allocation we
2281 // are not adding any new instructions. If any basic block is empty, we
2282 // can now safely remove it.
2283 {
2284 NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2285 cfg.remove_empty_blocks();
2286 if (do_freq_based_layout()) {
2287 PhaseBlockLayout layout(cfg);
2288 } else {
2289 cfg.set_loop_alignment();
2290 }
2291 cfg.fixup_flow();
2292 }
2293
2294 // Apply peephole optimizations
2295 if( OptoPeephole ) {
2296 NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2297 PhasePeephole peep( _regalloc, cfg);
2298 peep.do_transform();
2299 }
2300
2301 // Do late expand if CPU requires this.
2302 if (Matcher::require_postalloc_expand) {
2303 NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
2304 cfg.postalloc_expand(_regalloc);
2305 }
2306
2307 // Convert Nodes to instruction bits in a buffer
2308 {
2309 // %%%% workspace merge brought two timers together for one job
2310 TracePhase t2a("output", &_t_output, true);
2311 NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2312 Output();
2313 }
2314
2315 print_method(PHASE_FINAL_CODE);
2316
2317 // He's dead, Jim.
2318 _cfg = (PhaseCFG*)0xdeadbeef;
2319 _regalloc = (PhaseChaitin*)0xdeadbeef;
2320 }
2321
2322
2323 //------------------------------dump_asm---------------------------------------
2324 // Dump formatted assembly
2325 #ifndef PRODUCT
2326 void Compile::dump_asm(int *pcs, uint pc_limit) {
2327 bool cut_short = false;
2328 tty->print_cr("#");
2329 tty->print("# "); _tf->dump(); tty->cr();
2330 tty->print_cr("#");
2331
2332 // For all blocks
2333 int pc = 0x0; // Program counter
2334 char starts_bundle = ' ';
2335 _regalloc->dump_frame();
2336
2337 Node *n = NULL;
2338 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2339 if (VMThread::should_terminate()) {
2340 cut_short = true;
2341 break;
2342 }
2343 Block* block = _cfg->get_block(i);
2344 if (block->is_connector() && !Verbose) {
2345 continue;
2346 }
2347 n = block->head();
2348 if (pcs && n->_idx < pc_limit) {
2349 tty->print("%3.3x ", pcs[n->_idx]);
2350 } else {
2351 tty->print(" ");
2352 }
2353 block->dump_head(_cfg);
2354 if (block->is_connector()) {
2355 tty->print_cr(" # Empty connector block");
2356 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2357 tty->print_cr(" # Block is sole successor of call");
2358 }
2359
2360 // For all instructions
2361 Node *delay = NULL;
2362 for (uint j = 0; j < block->number_of_nodes(); j++) {
2363 if (VMThread::should_terminate()) {
2364 cut_short = true;
2365 break;
2366 }
2367 n = block->get_node(j);
2368 if (valid_bundle_info(n)) {
2369 Bundle* bundle = node_bundling(n);
2370 if (bundle->used_in_unconditional_delay()) {
2371 delay = n;
2372 continue;
2373 }
2374 if (bundle->starts_bundle()) {
2375 starts_bundle = '+';
2376 }
2377 }
2378
2379 if (WizardMode) {
2380 n->dump();
2381 }
2382
2383 if( !n->is_Region() && // Dont print in the Assembly
2384 !n->is_Phi() && // a few noisely useless nodes
2385 !n->is_Proj() &&
2386 !n->is_MachTemp() &&
2387 !n->is_SafePointScalarObject() &&
2388 !n->is_Catch() && // Would be nice to print exception table targets
2389 !n->is_MergeMem() && // Not very interesting
2390 !n->is_top() && // Debug info table constants
2391 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2392 ) {
2393 if (pcs && n->_idx < pc_limit)
2394 tty->print("%3.3x", pcs[n->_idx]);
2395 else
2396 tty->print(" ");
2397 tty->print(" %c ", starts_bundle);
2398 starts_bundle = ' ';
2399 tty->print("\t");
2400 n->format(_regalloc, tty);
2401 tty->cr();
2402 }
2403
2404 // If we have an instruction with a delay slot, and have seen a delay,
2405 // then back up and print it
2406 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2407 assert(delay != NULL, "no unconditional delay instruction");
2408 if (WizardMode) delay->dump();
2409
2410 if (node_bundling(delay)->starts_bundle())
2411 starts_bundle = '+';
2412 if (pcs && n->_idx < pc_limit)
2413 tty->print("%3.3x", pcs[n->_idx]);
2414 else
2415 tty->print(" ");
2416 tty->print(" %c ", starts_bundle);
2417 starts_bundle = ' ';
2418 tty->print("\t");
2419 delay->format(_regalloc, tty);
2420 tty->cr();
2421 delay = NULL;
2422 }
2423
2424 // Dump the exception table as well
2425 if( n->is_Catch() && (Verbose || WizardMode) ) {
2426 // Print the exception table for this offset
2427 _handler_table.print_subtable_for(pc);
2428 }
2429 }
2430
2431 if (pcs && n->_idx < pc_limit)
2432 tty->print_cr("%3.3x", pcs[n->_idx]);
2433 else
2434 tty->cr();
2435
2436 assert(cut_short || delay == NULL, "no unconditional delay branch");
2437
2438 } // End of per-block dump
2439 tty->cr();
2440
2441 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2442 }
2443 #endif
2444
2445 //------------------------------Final_Reshape_Counts---------------------------
2446 // This class defines counters to help identify when a method
2447 // may/must be executed using hardware with only 24-bit precision.
2448 struct Final_Reshape_Counts : public StackObj {
2449 int _call_count; // count non-inlined 'common' calls
2450 int _float_count; // count float ops requiring 24-bit precision
2451 int _double_count; // count double ops requiring more precision
2452 int _java_call_count; // count non-inlined 'java' calls
2453 int _inner_loop_count; // count loops which need alignment
2454 VectorSet _visited; // Visitation flags
2455 Node_List _tests; // Set of IfNodes & PCTableNodes
2456
2457 Final_Reshape_Counts() :
2458 _call_count(0), _float_count(0), _double_count(0),
2459 _java_call_count(0), _inner_loop_count(0),
2460 _visited( Thread::current()->resource_area() ) { }
2461
2462 void inc_call_count () { _call_count ++; }
2463 void inc_float_count () { _float_count ++; }
2464 void inc_double_count() { _double_count++; }
2465 void inc_java_call_count() { _java_call_count++; }
2466 void inc_inner_loop_count() { _inner_loop_count++; }
2467
2468 int get_call_count () const { return _call_count ; }
2469 int get_float_count () const { return _float_count ; }
2470 int get_double_count() const { return _double_count; }
2471 int get_java_call_count() const { return _java_call_count; }
2472 int get_inner_loop_count() const { return _inner_loop_count; }
2473 };
2474
2475 #ifdef ASSERT
2476 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2477 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2478 // Make sure the offset goes inside the instance layout.
2479 return k->contains_field_offset(tp->offset());
2480 // Note that OffsetBot and OffsetTop are very negative.
2481 }
2482 #endif
2483
2484 // Eliminate trivially redundant StoreCMs and accumulate their
2485 // precedence edges.
2486 void Compile::eliminate_redundant_card_marks(Node* n) {
2487 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2488 if (n->in(MemNode::Address)->outcnt() > 1) {
2489 // There are multiple users of the same address so it might be
2490 // possible to eliminate some of the StoreCMs
2491 Node* mem = n->in(MemNode::Memory);
2492 Node* adr = n->in(MemNode::Address);
2493 Node* val = n->in(MemNode::ValueIn);
2494 Node* prev = n;
2495 bool done = false;
2496 // Walk the chain of StoreCMs eliminating ones that match. As
2497 // long as it's a chain of single users then the optimization is
2498 // safe. Eliminating partially redundant StoreCMs would require
2499 // cloning copies down the other paths.
2500 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2501 if (adr == mem->in(MemNode::Address) &&
2502 val == mem->in(MemNode::ValueIn)) {
2503 // redundant StoreCM
2504 if (mem->req() > MemNode::OopStore) {
2505 // Hasn't been processed by this code yet.
2506 n->add_prec(mem->in(MemNode::OopStore));
2507 } else {
2508 // Already converted to precedence edge
2509 for (uint i = mem->req(); i < mem->len(); i++) {
2510 // Accumulate any precedence edges
2511 if (mem->in(i) != NULL) {
2512 n->add_prec(mem->in(i));
2513 }
2514 }
2515 // Everything above this point has been processed.
2516 done = true;
2517 }
2518 // Eliminate the previous StoreCM
2519 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2520 assert(mem->outcnt() == 0, "should be dead");
2521 mem->disconnect_inputs(NULL, this);
2522 } else {
2523 prev = mem;
2524 }
2525 mem = prev->in(MemNode::Memory);
2526 }
2527 }
2528 }
2529
2530 //------------------------------final_graph_reshaping_impl----------------------
2531 // Implement items 1-5 from final_graph_reshaping below.
2532 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2533
2534 if ( n->outcnt() == 0 ) return; // dead node
2535 uint nop = n->Opcode();
2536
2537 // Check for 2-input instruction with "last use" on right input.
2538 // Swap to left input. Implements item (2).
2539 if( n->req() == 3 && // two-input instruction
2540 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2541 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2542 n->in(2)->outcnt() == 1 &&// right use IS a last use
2543 !n->in(2)->is_Con() ) { // right use is not a constant
2544 // Check for commutative opcode
2545 switch( nop ) {
2546 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2547 case Op_MaxI: case Op_MinI:
2548 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2549 case Op_AndL: case Op_XorL: case Op_OrL:
2550 case Op_AndI: case Op_XorI: case Op_OrI: {
2551 // Move "last use" input to left by swapping inputs
2552 n->swap_edges(1, 2);
2553 break;
2554 }
2555 default:
2556 break;
2557 }
2558 }
2559
2560 #ifdef ASSERT
2561 if( n->is_Mem() ) {
2562 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2563 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2564 // oop will be recorded in oop map if load crosses safepoint
2565 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2566 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2567 "raw memory operations should have control edge");
2568 }
2569 #endif
2570 // Count FPU ops and common calls, implements item (3)
2571 switch( nop ) {
2572 // Count all float operations that may use FPU
2573 case Op_AddF:
2574 case Op_SubF:
2575 case Op_MulF:
2576 case Op_DivF:
2577 case Op_NegF:
2578 case Op_ModF:
2579 case Op_ConvI2F:
2580 case Op_ConF:
2581 case Op_CmpF:
2582 case Op_CmpF3:
2583 // case Op_ConvL2F: // longs are split into 32-bit halves
2584 frc.inc_float_count();
2585 break;
2586
2587 case Op_ConvF2D:
2588 case Op_ConvD2F:
2589 frc.inc_float_count();
2590 frc.inc_double_count();
2591 break;
2592
2593 // Count all double operations that may use FPU
2594 case Op_AddD:
2595 case Op_SubD:
2596 case Op_MulD:
2597 case Op_DivD:
2598 case Op_NegD:
2599 case Op_ModD:
2600 case Op_ConvI2D:
2601 case Op_ConvD2I:
2602 // case Op_ConvL2D: // handled by leaf call
2603 // case Op_ConvD2L: // handled by leaf call
2604 case Op_ConD:
2605 case Op_CmpD:
2606 case Op_CmpD3:
2607 frc.inc_double_count();
2608 break;
2609 case Op_Opaque1: // Remove Opaque Nodes before matching
2610 case Op_Opaque2: // Remove Opaque Nodes before matching
2611 case Op_Opaque3:
2612 n->subsume_by(n->in(1), this);
2613 break;
2614 case Op_CallStaticJava:
2615 case Op_CallJava:
2616 case Op_CallDynamicJava:
2617 frc.inc_java_call_count(); // Count java call site;
2618 case Op_CallRuntime:
2619 case Op_CallLeaf:
2620 case Op_CallLeafNoFP: {
2621 assert( n->is_Call(), "" );
2622 CallNode *call = n->as_Call();
2623 // Count call sites where the FP mode bit would have to be flipped.
2624 // Do not count uncommon runtime calls:
2625 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2626 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2627 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2628 frc.inc_call_count(); // Count the call site
2629 } else { // See if uncommon argument is shared
2630 Node *n = call->in(TypeFunc::Parms);
2631 int nop = n->Opcode();
2632 // Clone shared simple arguments to uncommon calls, item (1).
2633 if( n->outcnt() > 1 &&
2634 !n->is_Proj() &&
2635 nop != Op_CreateEx &&
2636 nop != Op_CheckCastPP &&
2637 nop != Op_DecodeN &&
2638 nop != Op_DecodeNKlass &&
2639 !n->is_Mem() ) {
2640 Node *x = n->clone();
2641 call->set_req( TypeFunc::Parms, x );
2642 }
2643 }
2644 break;
2645 }
2646
2647 case Op_StoreD:
2648 case Op_LoadD:
2649 case Op_LoadD_unaligned:
2650 frc.inc_double_count();
2651 goto handle_mem;
2652 case Op_StoreF:
2653 case Op_LoadF:
2654 frc.inc_float_count();
2655 goto handle_mem;
2656
2657 case Op_StoreCM:
2658 {
2659 // Convert OopStore dependence into precedence edge
2660 Node* prec = n->in(MemNode::OopStore);
2661 n->del_req(MemNode::OopStore);
2662 n->add_prec(prec);
2663 eliminate_redundant_card_marks(n);
2664 }
2665
2666 // fall through
2667
2668 case Op_StoreB:
2669 case Op_StoreC:
2670 case Op_StorePConditional:
2671 case Op_StoreI:
2672 case Op_StoreL:
2673 case Op_StoreIConditional:
2674 case Op_StoreLConditional:
2675 case Op_CompareAndSwapI:
2676 case Op_CompareAndSwapL:
2677 case Op_CompareAndSwapP:
2678 case Op_CompareAndSwapN:
2679 case Op_GetAndAddI:
2680 case Op_GetAndAddL:
2681 case Op_GetAndSetI:
2682 case Op_GetAndSetL:
2683 case Op_GetAndSetP:
2684 case Op_GetAndSetN:
2685 case Op_StoreP:
2686 case Op_StoreN:
2687 case Op_StoreNKlass:
2688 case Op_LoadB:
2689 case Op_LoadUB:
2690 case Op_LoadUS:
2691 case Op_LoadI:
2692 case Op_LoadKlass:
2693 case Op_LoadNKlass:
2694 case Op_LoadL:
2695 case Op_LoadL_unaligned:
2696 case Op_LoadPLocked:
2697 case Op_LoadP:
2698 case Op_LoadN:
2699 case Op_LoadRange:
2700 case Op_LoadS: {
2701 handle_mem:
2702 #ifdef ASSERT
2703 if( VerifyOptoOopOffsets ) {
2704 assert( n->is_Mem(), "" );
2705 MemNode *mem = (MemNode*)n;
2706 // Check to see if address types have grounded out somehow.
2707 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2708 assert( !tp || oop_offset_is_sane(tp), "" );
2709 }
2710 #endif
2711 break;
2712 }
2713
2714 case Op_AddP: { // Assert sane base pointers
2715 Node *addp = n->in(AddPNode::Address);
2716 assert( !addp->is_AddP() ||
2717 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2718 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2719 "Base pointers must match" );
2720 #ifdef _LP64
2721 if ((UseCompressedOops || UseCompressedClassPointers) &&
2722 addp->Opcode() == Op_ConP &&
2723 addp == n->in(AddPNode::Base) &&
2724 n->in(AddPNode::Offset)->is_Con()) {
2725 // Use addressing with narrow klass to load with offset on x86.
2726 // On sparc loading 32-bits constant and decoding it have less
2727 // instructions (4) then load 64-bits constant (7).
2728 // Do this transformation here since IGVN will convert ConN back to ConP.
2729 const Type* t = addp->bottom_type();
2730 if (t->isa_oopptr() || t->isa_klassptr()) {
2731 Node* nn = NULL;
2732
2733 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2734
2735 // Look for existing ConN node of the same exact type.
2736 Node* r = root();
2737 uint cnt = r->outcnt();
2738 for (uint i = 0; i < cnt; i++) {
2739 Node* m = r->raw_out(i);
2740 if (m!= NULL && m->Opcode() == op &&
2741 m->bottom_type()->make_ptr() == t) {
2742 nn = m;
2743 break;
2744 }
2745 }
2746 if (nn != NULL) {
2747 // Decode a narrow oop to match address
2748 // [R12 + narrow_oop_reg<<3 + offset]
2749 if (t->isa_oopptr()) {
2750 nn = new DecodeNNode(nn, t);
2751 } else {
2752 nn = new DecodeNKlassNode(nn, t);
2753 }
2754 n->set_req(AddPNode::Base, nn);
2755 n->set_req(AddPNode::Address, nn);
2756 if (addp->outcnt() == 0) {
2757 addp->disconnect_inputs(NULL, this);
2758 }
2759 }
2760 }
2761 }
2762 #endif
2763 break;
2764 }
2765
2766 #ifdef _LP64
2767 case Op_CastPP:
2768 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2769 Node* in1 = n->in(1);
2770 const Type* t = n->bottom_type();
2771 Node* new_in1 = in1->clone();
2772 new_in1->as_DecodeN()->set_type(t);
2773
2774 if (!Matcher::narrow_oop_use_complex_address()) {
2775 //
2776 // x86, ARM and friends can handle 2 adds in addressing mode
2777 // and Matcher can fold a DecodeN node into address by using
2778 // a narrow oop directly and do implicit NULL check in address:
2779 //
2780 // [R12 + narrow_oop_reg<<3 + offset]
2781 // NullCheck narrow_oop_reg
2782 //
2783 // On other platforms (Sparc) we have to keep new DecodeN node and
2784 // use it to do implicit NULL check in address:
2785 //
2786 // decode_not_null narrow_oop_reg, base_reg
2787 // [base_reg + offset]
2788 // NullCheck base_reg
2789 //
2790 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2791 // to keep the information to which NULL check the new DecodeN node
2792 // corresponds to use it as value in implicit_null_check().
2793 //
2794 new_in1->set_req(0, n->in(0));
2795 }
2796
2797 n->subsume_by(new_in1, this);
2798 if (in1->outcnt() == 0) {
2799 in1->disconnect_inputs(NULL, this);
2800 }
2801 }
2802 break;
2803
2804 case Op_CmpP:
2805 // Do this transformation here to preserve CmpPNode::sub() and
2806 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2807 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2808 Node* in1 = n->in(1);
2809 Node* in2 = n->in(2);
2810 if (!in1->is_DecodeNarrowPtr()) {
2811 in2 = in1;
2812 in1 = n->in(2);
2813 }
2814 assert(in1->is_DecodeNarrowPtr(), "sanity");
2815
2816 Node* new_in2 = NULL;
2817 if (in2->is_DecodeNarrowPtr()) {
2818 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2819 new_in2 = in2->in(1);
2820 } else if (in2->Opcode() == Op_ConP) {
2821 const Type* t = in2->bottom_type();
2822 if (t == TypePtr::NULL_PTR) {
2823 assert(in1->is_DecodeN(), "compare klass to null?");
2824 // Don't convert CmpP null check into CmpN if compressed
2825 // oops implicit null check is not generated.
2826 // This will allow to generate normal oop implicit null check.
2827 if (Matcher::gen_narrow_oop_implicit_null_checks())
2828 new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2829 //
2830 // This transformation together with CastPP transformation above
2831 // will generated code for implicit NULL checks for compressed oops.
2832 //
2833 // The original code after Optimize()
2834 //
2835 // LoadN memory, narrow_oop_reg
2836 // decode narrow_oop_reg, base_reg
2837 // CmpP base_reg, NULL
2838 // CastPP base_reg // NotNull
2839 // Load [base_reg + offset], val_reg
2840 //
2841 // after these transformations will be
2842 //
2843 // LoadN memory, narrow_oop_reg
2844 // CmpN narrow_oop_reg, NULL
2845 // decode_not_null narrow_oop_reg, base_reg
2846 // Load [base_reg + offset], val_reg
2847 //
2848 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2849 // since narrow oops can be used in debug info now (see the code in
2850 // final_graph_reshaping_walk()).
2851 //
2852 // At the end the code will be matched to
2853 // on x86:
2854 //
2855 // Load_narrow_oop memory, narrow_oop_reg
2856 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2857 // NullCheck narrow_oop_reg
2858 //
2859 // and on sparc:
2860 //
2861 // Load_narrow_oop memory, narrow_oop_reg
2862 // decode_not_null narrow_oop_reg, base_reg
2863 // Load [base_reg + offset], val_reg
2864 // NullCheck base_reg
2865 //
2866 } else if (t->isa_oopptr()) {
2867 new_in2 = ConNode::make(this, t->make_narrowoop());
2868 } else if (t->isa_klassptr()) {
2869 new_in2 = ConNode::make(this, t->make_narrowklass());
2870 }
2871 }
2872 if (new_in2 != NULL) {
2873 Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2874 n->subsume_by(cmpN, this);
2875 if (in1->outcnt() == 0) {
2876 in1->disconnect_inputs(NULL, this);
2877 }
2878 if (in2->outcnt() == 0) {
2879 in2->disconnect_inputs(NULL, this);
2880 }
2881 }
2882 }
2883 break;
2884
2885 case Op_DecodeN:
2886 case Op_DecodeNKlass:
2887 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2888 // DecodeN could be pinned when it can't be fold into
2889 // an address expression, see the code for Op_CastPP above.
2890 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2891 break;
2892
2893 case Op_EncodeP:
2894 case Op_EncodePKlass: {
2895 Node* in1 = n->in(1);
2896 if (in1->is_DecodeNarrowPtr()) {
2897 n->subsume_by(in1->in(1), this);
2898 } else if (in1->Opcode() == Op_ConP) {
2899 const Type* t = in1->bottom_type();
2900 if (t == TypePtr::NULL_PTR) {
2901 assert(t->isa_oopptr(), "null klass?");
2902 n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2903 } else if (t->isa_oopptr()) {
2904 n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2905 } else if (t->isa_klassptr()) {
2906 n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2907 }
2908 }
2909 if (in1->outcnt() == 0) {
2910 in1->disconnect_inputs(NULL, this);
2911 }
2912 break;
2913 }
2914
2915 case Op_Proj: {
2916 if (OptimizeStringConcat) {
2917 ProjNode* p = n->as_Proj();
2918 if (p->_is_io_use) {
2919 // Separate projections were used for the exception path which
2920 // are normally removed by a late inline. If it wasn't inlined
2921 // then they will hang around and should just be replaced with
2922 // the original one.
2923 Node* proj = NULL;
2924 // Replace with just one
2925 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2926 Node *use = i.get();
2927 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2928 proj = use;
2929 break;
2930 }
2931 }
2932 assert(proj != NULL, "must be found");
2933 p->subsume_by(proj, this);
2934 }
2935 }
2936 break;
2937 }
2938
2939 case Op_Phi:
2940 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2941 // The EncodeP optimization may create Phi with the same edges
2942 // for all paths. It is not handled well by Register Allocator.
2943 Node* unique_in = n->in(1);
2944 assert(unique_in != NULL, "");
2945 uint cnt = n->req();
2946 for (uint i = 2; i < cnt; i++) {
2947 Node* m = n->in(i);
2948 assert(m != NULL, "");
2949 if (unique_in != m)
2950 unique_in = NULL;
2951 }
2952 if (unique_in != NULL) {
2953 n->subsume_by(unique_in, this);
2954 }
2955 }
2956 break;
2957
2958 #endif
2959
2960 case Op_ModI:
2961 if (UseDivMod) {
2962 // Check if a%b and a/b both exist
2963 Node* d = n->find_similar(Op_DivI);
2964 if (d) {
2965 // Replace them with a fused divmod if supported
2966 if (Matcher::has_match_rule(Op_DivModI)) {
2967 DivModINode* divmod = DivModINode::make(this, n);
2968 d->subsume_by(divmod->div_proj(), this);
2969 n->subsume_by(divmod->mod_proj(), this);
2970 } else {
2971 // replace a%b with a-((a/b)*b)
2972 Node* mult = new MulINode(d, d->in(2));
2973 Node* sub = new SubINode(d->in(1), mult);
2974 n->subsume_by(sub, this);
2975 }
2976 }
2977 }
2978 break;
2979
2980 case Op_ModL:
2981 if (UseDivMod) {
2982 // Check if a%b and a/b both exist
2983 Node* d = n->find_similar(Op_DivL);
2984 if (d) {
2985 // Replace them with a fused divmod if supported
2986 if (Matcher::has_match_rule(Op_DivModL)) {
2987 DivModLNode* divmod = DivModLNode::make(this, n);
2988 d->subsume_by(divmod->div_proj(), this);
2989 n->subsume_by(divmod->mod_proj(), this);
2990 } else {
2991 // replace a%b with a-((a/b)*b)
2992 Node* mult = new MulLNode(d, d->in(2));
2993 Node* sub = new SubLNode(d->in(1), mult);
2994 n->subsume_by(sub, this);
2995 }
2996 }
2997 }
2998 break;
2999
3000 case Op_LoadVector:
3001 case Op_StoreVector:
3002 break;
3003
3004 case Op_PackB:
3005 case Op_PackS:
3006 case Op_PackI:
3007 case Op_PackF:
3008 case Op_PackL:
3009 case Op_PackD:
3010 if (n->req()-1 > 2) {
3011 // Replace many operand PackNodes with a binary tree for matching
3012 PackNode* p = (PackNode*) n;
3013 Node* btp = p->binary_tree_pack(this, 1, n->req());
3014 n->subsume_by(btp, this);
3015 }
3016 break;
3017 case Op_Loop:
3018 case Op_CountedLoop:
3019 if (n->as_Loop()->is_inner_loop()) {
3020 frc.inc_inner_loop_count();
3021 }
3022 break;
3023 case Op_LShiftI:
3024 case Op_RShiftI:
3025 case Op_URShiftI:
3026 case Op_LShiftL:
3027 case Op_RShiftL:
3028 case Op_URShiftL:
3029 if (Matcher::need_masked_shift_count) {
3030 // The cpu's shift instructions don't restrict the count to the
3031 // lower 5/6 bits. We need to do the masking ourselves.
3032 Node* in2 = n->in(2);
3033 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3034 const TypeInt* t = in2->find_int_type();
3035 if (t != NULL && t->is_con()) {
3036 juint shift = t->get_con();
3037 if (shift > mask) { // Unsigned cmp
3038 n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
3039 }
3040 } else {
3041 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3042 Node* shift = new AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
3043 n->set_req(2, shift);
3044 }
3045 }
3046 if (in2->outcnt() == 0) { // Remove dead node
3047 in2->disconnect_inputs(NULL, this);
3048 }
3049 }
3050 break;
3051 case Op_MemBarStoreStore:
3052 case Op_MemBarRelease:
3053 // Break the link with AllocateNode: it is no longer useful and
3054 // confuses register allocation.
3055 if (n->req() > MemBarNode::Precedent) {
3056 n->set_req(MemBarNode::Precedent, top());
3057 }
3058 break;
3059 default:
3060 assert( !n->is_Call(), "" );
3061 assert( !n->is_Mem(), "" );
3062 break;
3063 }
3064
3065 // Collect CFG split points
3066 if (n->is_MultiBranch())
3067 frc._tests.push(n);
3068 }
3069
3070 //------------------------------final_graph_reshaping_walk---------------------
3071 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3072 // requires that the walk visits a node's inputs before visiting the node.
3073 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3074 ResourceArea *area = Thread::current()->resource_area();
3075 Unique_Node_List sfpt(area);
3076
3077 frc._visited.set(root->_idx); // first, mark node as visited
3078 uint cnt = root->req();
3079 Node *n = root;
3080 uint i = 0;
3081 while (true) {
3082 if (i < cnt) {
3083 // Place all non-visited non-null inputs onto stack
3084 Node* m = n->in(i);
3085 ++i;
3086 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3087 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3088 // compute worst case interpreter size in case of a deoptimization
3089 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3090
3091 sfpt.push(m);
3092 }
3093 cnt = m->req();
3094 nstack.push(n, i); // put on stack parent and next input's index
3095 n = m;
3096 i = 0;
3097 }
3098 } else {
3099 // Now do post-visit work
3100 final_graph_reshaping_impl( n, frc );
3101 if (nstack.is_empty())
3102 break; // finished
3103 n = nstack.node(); // Get node from stack
3104 cnt = n->req();
3105 i = nstack.index();
3106 nstack.pop(); // Shift to the next node on stack
3107 }
3108 }
3109
3110 // Skip next transformation if compressed oops are not used.
3111 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3112 (!UseCompressedOops && !UseCompressedClassPointers))
3113 return;
3114
3115 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3116 // It could be done for an uncommon traps or any safepoints/calls
3117 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3118 while (sfpt.size() > 0) {
3119 n = sfpt.pop();
3120 JVMState *jvms = n->as_SafePoint()->jvms();
3121 assert(jvms != NULL, "sanity");
3122 int start = jvms->debug_start();
3123 int end = n->req();
3124 bool is_uncommon = (n->is_CallStaticJava() &&
3125 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3126 for (int j = start; j < end; j++) {
3127 Node* in = n->in(j);
3128 if (in->is_DecodeNarrowPtr()) {
3129 bool safe_to_skip = true;
3130 if (!is_uncommon ) {
3131 // Is it safe to skip?
3132 for (uint i = 0; i < in->outcnt(); i++) {
3133 Node* u = in->raw_out(i);
3134 if (!u->is_SafePoint() ||
3135 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3136 safe_to_skip = false;
3137 }
3138 }
3139 }
3140 if (safe_to_skip) {
3141 n->set_req(j, in->in(1));
3142 }
3143 if (in->outcnt() == 0) {
3144 in->disconnect_inputs(NULL, this);
3145 }
3146 }
3147 }
3148 }
3149 }
3150
3151 //------------------------------final_graph_reshaping--------------------------
3152 // Final Graph Reshaping.
3153 //
3154 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3155 // and not commoned up and forced early. Must come after regular
3156 // optimizations to avoid GVN undoing the cloning. Clone constant
3157 // inputs to Loop Phis; these will be split by the allocator anyways.
3158 // Remove Opaque nodes.
3159 // (2) Move last-uses by commutative operations to the left input to encourage
3160 // Intel update-in-place two-address operations and better register usage
3161 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3162 // calls canonicalizing them back.
3163 // (3) Count the number of double-precision FP ops, single-precision FP ops
3164 // and call sites. On Intel, we can get correct rounding either by
3165 // forcing singles to memory (requires extra stores and loads after each
3166 // FP bytecode) or we can set a rounding mode bit (requires setting and
3167 // clearing the mode bit around call sites). The mode bit is only used
3168 // if the relative frequency of single FP ops to calls is low enough.
3169 // This is a key transform for SPEC mpeg_audio.
3170 // (4) Detect infinite loops; blobs of code reachable from above but not
3171 // below. Several of the Code_Gen algorithms fail on such code shapes,
3172 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3173 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3174 // Detection is by looking for IfNodes where only 1 projection is
3175 // reachable from below or CatchNodes missing some targets.
3176 // (5) Assert for insane oop offsets in debug mode.
3177
3178 bool Compile::final_graph_reshaping() {
3179 // an infinite loop may have been eliminated by the optimizer,
3180 // in which case the graph will be empty.
3181 if (root()->req() == 1) {
3182 record_method_not_compilable("trivial infinite loop");
3183 return true;
3184 }
3185
3186 // Expensive nodes have their control input set to prevent the GVN
3187 // from freely commoning them. There's no GVN beyond this point so
3188 // no need to keep the control input. We want the expensive nodes to
3189 // be freely moved to the least frequent code path by gcm.
3190 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3191 for (int i = 0; i < expensive_count(); i++) {
3192 _expensive_nodes->at(i)->set_req(0, NULL);
3193 }
3194
3195 Final_Reshape_Counts frc;
3196
3197 // Visit everybody reachable!
3198 // Allocate stack of size C->unique()/2 to avoid frequent realloc
3199 Node_Stack nstack(unique() >> 1);
3200 final_graph_reshaping_walk(nstack, root(), frc);
3201
3202 // Check for unreachable (from below) code (i.e., infinite loops).
3203 for( uint i = 0; i < frc._tests.size(); i++ ) {
3204 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3205 // Get number of CFG targets.
3206 // Note that PCTables include exception targets after calls.
3207 uint required_outcnt = n->required_outcnt();
3208 if (n->outcnt() != required_outcnt) {
3209 // Check for a few special cases. Rethrow Nodes never take the
3210 // 'fall-thru' path, so expected kids is 1 less.
3211 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3212 if (n->in(0)->in(0)->is_Call()) {
3213 CallNode *call = n->in(0)->in(0)->as_Call();
3214 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3215 required_outcnt--; // Rethrow always has 1 less kid
3216 } else if (call->req() > TypeFunc::Parms &&
3217 call->is_CallDynamicJava()) {
3218 // Check for null receiver. In such case, the optimizer has
3219 // detected that the virtual call will always result in a null
3220 // pointer exception. The fall-through projection of this CatchNode
3221 // will not be populated.
3222 Node *arg0 = call->in(TypeFunc::Parms);
3223 if (arg0->is_Type() &&
3224 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3225 required_outcnt--;
3226 }
3227 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3228 call->req() > TypeFunc::Parms+1 &&
3229 call->is_CallStaticJava()) {
3230 // Check for negative array length. In such case, the optimizer has
3231 // detected that the allocation attempt will always result in an
3232 // exception. There is no fall-through projection of this CatchNode .
3233 Node *arg1 = call->in(TypeFunc::Parms+1);
3234 if (arg1->is_Type() &&
3235 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3236 required_outcnt--;
3237 }
3238 }
3239 }
3240 }
3241 // Recheck with a better notion of 'required_outcnt'
3242 if (n->outcnt() != required_outcnt) {
3243 record_method_not_compilable("malformed control flow");
3244 return true; // Not all targets reachable!
3245 }
3246 }
3247 // Check that I actually visited all kids. Unreached kids
3248 // must be infinite loops.
3249 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3250 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3251 record_method_not_compilable("infinite loop");
3252 return true; // Found unvisited kid; must be unreach
3253 }
3254 }
3255
3256 // If original bytecodes contained a mixture of floats and doubles
3257 // check if the optimizer has made it homogenous, item (3).
3258 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3259 frc.get_float_count() > 32 &&
3260 frc.get_double_count() == 0 &&
3261 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3262 set_24_bit_selection_and_mode( false, true );
3263 }
3264
3265 set_java_calls(frc.get_java_call_count());
3266 set_inner_loops(frc.get_inner_loop_count());
3267
3268 // No infinite loops, no reason to bail out.
3269 return false;
3270 }
3271
3272 //-----------------------------too_many_traps----------------------------------
3273 // Report if there are too many traps at the current method and bci.
3274 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3275 bool Compile::too_many_traps(ciMethod* method,
3276 int bci,
3277 Deoptimization::DeoptReason reason) {
3278 ciMethodData* md = method->method_data();
3279 if (md->is_empty()) {
3280 // Assume the trap has not occurred, or that it occurred only
3281 // because of a transient condition during start-up in the interpreter.
3282 return false;
3283 }
3284 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3285 if (md->has_trap_at(bci, m, reason) != 0) {
3286 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3287 // Also, if there are multiple reasons, or if there is no per-BCI record,
3288 // assume the worst.
3289 if (log())
3290 log()->elem("observe trap='%s' count='%d'",
3291 Deoptimization::trap_reason_name(reason),
3292 md->trap_count(reason));
3293 return true;
3294 } else {
3295 // Ignore method/bci and see if there have been too many globally.
3296 return too_many_traps(reason, md);
3297 }
3298 }
3299
3300 // Less-accurate variant which does not require a method and bci.
3301 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3302 ciMethodData* logmd) {
3303 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3304 // Too many traps globally.
3305 // Note that we use cumulative trap_count, not just md->trap_count.
3306 if (log()) {
3307 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3308 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3309 Deoptimization::trap_reason_name(reason),
3310 mcount, trap_count(reason));
3311 }
3312 return true;
3313 } else {
3314 // The coast is clear.
3315 return false;
3316 }
3317 }
3318
3319 //--------------------------too_many_recompiles--------------------------------
3320 // Report if there are too many recompiles at the current method and bci.
3321 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3322 // Is not eager to return true, since this will cause the compiler to use
3323 // Action_none for a trap point, to avoid too many recompilations.
3324 bool Compile::too_many_recompiles(ciMethod* method,
3325 int bci,
3326 Deoptimization::DeoptReason reason) {
3327 ciMethodData* md = method->method_data();
3328 if (md->is_empty()) {
3329 // Assume the trap has not occurred, or that it occurred only
3330 // because of a transient condition during start-up in the interpreter.
3331 return false;
3332 }
3333 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3334 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3335 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3336 Deoptimization::DeoptReason per_bc_reason
3337 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3338 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3339 if ((per_bc_reason == Deoptimization::Reason_none
3340 || md->has_trap_at(bci, m, reason) != 0)
3341 // The trap frequency measure we care about is the recompile count:
3342 && md->trap_recompiled_at(bci, m)
3343 && md->overflow_recompile_count() >= bc_cutoff) {
3344 // Do not emit a trap here if it has already caused recompilations.
3345 // Also, if there are multiple reasons, or if there is no per-BCI record,
3346 // assume the worst.
3347 if (log())
3348 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3349 Deoptimization::trap_reason_name(reason),
3350 md->trap_count(reason),
3351 md->overflow_recompile_count());
3352 return true;
3353 } else if (trap_count(reason) != 0
3354 && decompile_count() >= m_cutoff) {
3355 // Too many recompiles globally, and we have seen this sort of trap.
3356 // Use cumulative decompile_count, not just md->decompile_count.
3357 if (log())
3358 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3359 Deoptimization::trap_reason_name(reason),
3360 md->trap_count(reason), trap_count(reason),
3361 md->decompile_count(), decompile_count());
3362 return true;
3363 } else {
3364 // The coast is clear.
3365 return false;
3366 }
3367 }
3368
3369 // Compute when not to trap. Used by matching trap based nodes and
3370 // NullCheck optimization.
3371 void Compile::set_allowed_deopt_reasons() {
3372 _allowed_reasons = 0;
3373 if (is_method_compilation()) {
3374 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3375 assert(rs < BitsPerInt, "recode bit map");
3376 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3377 _allowed_reasons |= nth_bit(rs);
3378 }
3379 }
3380 }
3381 }
3382
3383 #ifndef PRODUCT
3384 //------------------------------verify_graph_edges---------------------------
3385 // Walk the Graph and verify that there is a one-to-one correspondence
3386 // between Use-Def edges and Def-Use edges in the graph.
3387 void Compile::verify_graph_edges(bool no_dead_code) {
3388 if (VerifyGraphEdges) {
3389 ResourceArea *area = Thread::current()->resource_area();
3390 Unique_Node_List visited(area);
3391 // Call recursive graph walk to check edges
3392 _root->verify_edges(visited);
3393 if (no_dead_code) {
3394 // Now make sure that no visited node is used by an unvisited node.
3395 bool dead_nodes = false;
3396 Unique_Node_List checked(area);
3397 while (visited.size() > 0) {
3398 Node* n = visited.pop();
3399 checked.push(n);
3400 for (uint i = 0; i < n->outcnt(); i++) {
3401 Node* use = n->raw_out(i);
3402 if (checked.member(use)) continue; // already checked
3403 if (visited.member(use)) continue; // already in the graph
3404 if (use->is_Con()) continue; // a dead ConNode is OK
3405 // At this point, we have found a dead node which is DU-reachable.
3406 if (!dead_nodes) {
3407 tty->print_cr("*** Dead nodes reachable via DU edges:");
3408 dead_nodes = true;
3409 }
3410 use->dump(2);
3411 tty->print_cr("---");
3412 checked.push(use); // No repeats; pretend it is now checked.
3413 }
3414 }
3415 assert(!dead_nodes, "using nodes must be reachable from root");
3416 }
3417 }
3418 }
3419
3420 // Verify GC barriers consistency
3421 // Currently supported:
3422 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3423 void Compile::verify_barriers() {
3424 if (UseG1GC) {
3425 // Verify G1 pre-barriers
3426 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3427
3428 ResourceArea *area = Thread::current()->resource_area();
3429 Unique_Node_List visited(area);
3430 Node_List worklist(area);
3431 // We're going to walk control flow backwards starting from the Root
3432 worklist.push(_root);
3433 while (worklist.size() > 0) {
3434 Node* x = worklist.pop();
3435 if (x == NULL || x == top()) continue;
3436 if (visited.member(x)) {
3437 continue;
3438 } else {
3439 visited.push(x);
3440 }
3441
3442 if (x->is_Region()) {
3443 for (uint i = 1; i < x->req(); i++) {
3444 worklist.push(x->in(i));
3445 }
3446 } else {
3447 worklist.push(x->in(0));
3448 // We are looking for the pattern:
3449 // /->ThreadLocal
3450 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3451 // \->ConI(0)
3452 // We want to verify that the If and the LoadB have the same control
3453 // See GraphKit::g1_write_barrier_pre()
3454 if (x->is_If()) {
3455 IfNode *iff = x->as_If();
3456 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3457 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3458 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3459 && cmp->in(1)->is_Load()) {
3460 LoadNode* load = cmp->in(1)->as_Load();
3461 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3462 && load->in(2)->in(3)->is_Con()
3463 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3464
3465 Node* if_ctrl = iff->in(0);
3466 Node* load_ctrl = load->in(0);
3467
3468 if (if_ctrl != load_ctrl) {
3469 // Skip possible CProj->NeverBranch in infinite loops
3470 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3471 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3472 if_ctrl = if_ctrl->in(0)->in(0);
3473 }
3474 }
3475 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3476 }
3477 }
3478 }
3479 }
3480 }
3481 }
3482 }
3483 }
3484
3485 #endif
3486
3487 // The Compile object keeps track of failure reasons separately from the ciEnv.
3488 // This is required because there is not quite a 1-1 relation between the
3489 // ciEnv and its compilation task and the Compile object. Note that one
3490 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3491 // to backtrack and retry without subsuming loads. Other than this backtracking
3492 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3493 // by the logic in C2Compiler.
3494 void Compile::record_failure(const char* reason) {
3495 if (log() != NULL) {
3496 log()->elem("failure reason='%s' phase='compile'", reason);
3497 }
3498 if (_failure_reason == NULL) {
3499 // Record the first failure reason.
3500 _failure_reason = reason;
3501 }
3502
3503 EventCompilerFailure event;
3504 if (event.should_commit()) {
3505 event.set_compileID(Compile::compile_id());
3506 event.set_failure(reason);
3507 event.commit();
3508 }
3509
3510 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3511 C->print_method(PHASE_FAILURE);
3512 }
3513 _root = NULL; // flush the graph, too
3514 }
3515
3516 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3517 : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3518 _phase_name(name), _dolog(dolog)
3519 {
3520 if (dolog) {
3521 C = Compile::current();
3522 _log = C->log();
3523 } else {
3524 C = NULL;
3525 _log = NULL;
3526 }
3527 if (_log != NULL) {
3528 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3529 _log->stamp();
3530 _log->end_head();
3531 }
3532 }
3533
3534 Compile::TracePhase::~TracePhase() {
3535
3536 C = Compile::current();
3537 if (_dolog) {
3538 _log = C->log();
3539 } else {
3540 _log = NULL;
3541 }
3542
3543 #ifdef ASSERT
3544 if (PrintIdealNodeCount) {
3545 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3546 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3547 }
3548
3549 if (VerifyIdealNodeCount) {
3550 Compile::current()->print_missing_nodes();
3551 }
3552 #endif
3553
3554 if (_log != NULL) {
3555 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3556 }
3557 }
3558
3559 //=============================================================================
3560 // Two Constant's are equal when the type and the value are equal.
3561 bool Compile::Constant::operator==(const Constant& other) {
3562 if (type() != other.type() ) return false;
3563 if (can_be_reused() != other.can_be_reused()) return false;
3564 // For floating point values we compare the bit pattern.
3565 switch (type()) {
3566 case T_FLOAT: return (_v._value.i == other._v._value.i);
3567 case T_LONG:
3568 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3569 case T_OBJECT:
3570 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3571 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3572 case T_METADATA: return (_v._metadata == other._v._metadata);
3573 default: ShouldNotReachHere();
3574 }
3575 return false;
3576 }
3577
3578 static int type_to_size_in_bytes(BasicType t) {
3579 switch (t) {
3580 case T_LONG: return sizeof(jlong );
3581 case T_FLOAT: return sizeof(jfloat );
3582 case T_DOUBLE: return sizeof(jdouble);
3583 case T_METADATA: return sizeof(Metadata*);
3584 // We use T_VOID as marker for jump-table entries (labels) which
3585 // need an internal word relocation.
3586 case T_VOID:
3587 case T_ADDRESS:
3588 case T_OBJECT: return sizeof(jobject);
3589 }
3590
3591 ShouldNotReachHere();
3592 return -1;
3593 }
3594
3595 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3596 // sort descending
3597 if (a->freq() > b->freq()) return -1;
3598 if (a->freq() < b->freq()) return 1;
3599 return 0;
3600 }
3601
3602 void Compile::ConstantTable::calculate_offsets_and_size() {
3603 // First, sort the array by frequencies.
3604 _constants.sort(qsort_comparator);
3605
3606 #ifdef ASSERT
3607 // Make sure all jump-table entries were sorted to the end of the
3608 // array (they have a negative frequency).
3609 bool found_void = false;
3610 for (int i = 0; i < _constants.length(); i++) {
3611 Constant con = _constants.at(i);
3612 if (con.type() == T_VOID)
3613 found_void = true; // jump-tables
3614 else
3615 assert(!found_void, "wrong sorting");
3616 }
3617 #endif
3618
3619 int offset = 0;
3620 for (int i = 0; i < _constants.length(); i++) {
3621 Constant* con = _constants.adr_at(i);
3622
3623 // Align offset for type.
3624 int typesize = type_to_size_in_bytes(con->type());
3625 offset = align_size_up(offset, typesize);
3626 con->set_offset(offset); // set constant's offset
3627
3628 if (con->type() == T_VOID) {
3629 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3630 offset = offset + typesize * n->outcnt(); // expand jump-table
3631 } else {
3632 offset = offset + typesize;
3633 }
3634 }
3635
3636 // Align size up to the next section start (which is insts; see
3637 // CodeBuffer::align_at_start).
3638 assert(_size == -1, "already set?");
3639 _size = align_size_up(offset, CodeEntryAlignment);
3640 }
3641
3642 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3643 MacroAssembler _masm(&cb);
3644 for (int i = 0; i < _constants.length(); i++) {
3645 Constant con = _constants.at(i);
3646 address constant_addr;
3647 switch (con.type()) {
3648 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3649 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3650 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3651 case T_OBJECT: {
3652 jobject obj = con.get_jobject();
3653 int oop_index = _masm.oop_recorder()->find_index(obj);
3654 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3655 break;
3656 }
3657 case T_ADDRESS: {
3658 address addr = (address) con.get_jobject();
3659 constant_addr = _masm.address_constant(addr);
3660 break;
3661 }
3662 // We use T_VOID as marker for jump-table entries (labels) which
3663 // need an internal word relocation.
3664 case T_VOID: {
3665 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3666 // Fill the jump-table with a dummy word. The real value is
3667 // filled in later in fill_jump_table.
3668 address dummy = (address) n;
3669 constant_addr = _masm.address_constant(dummy);
3670 // Expand jump-table
3671 for (uint i = 1; i < n->outcnt(); i++) {
3672 address temp_addr = _masm.address_constant(dummy + i);
3673 assert(temp_addr, "consts section too small");
3674 }
3675 break;
3676 }
3677 case T_METADATA: {
3678 Metadata* obj = con.get_metadata();
3679 int metadata_index = _masm.oop_recorder()->find_index(obj);
3680 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3681 break;
3682 }
3683 default: ShouldNotReachHere();
3684 }
3685 assert(constant_addr, "consts section too small");
3686 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3687 err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3688 }
3689 }
3690
3691 int Compile::ConstantTable::find_offset(Constant& con) const {
3692 int idx = _constants.find(con);
3693 assert(idx != -1, "constant must be in constant table");
3694 int offset = _constants.at(idx).offset();
3695 assert(offset != -1, "constant table not emitted yet?");
3696 return offset;
3697 }
3698
3699 void Compile::ConstantTable::add(Constant& con) {
3700 if (con.can_be_reused()) {
3701 int idx = _constants.find(con);
3702 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3703 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3704 return;
3705 }
3706 }
3707 (void) _constants.append(con);
3708 }
3709
3710 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3711 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3712 Constant con(type, value, b->_freq);
3713 add(con);
3714 return con;
3715 }
3716
3717 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3718 Constant con(metadata);
3719 add(con);
3720 return con;
3721 }
3722
3723 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3724 jvalue value;
3725 BasicType type = oper->type()->basic_type();
3726 switch (type) {
3727 case T_LONG: value.j = oper->constantL(); break;
3728 case T_FLOAT: value.f = oper->constantF(); break;
3729 case T_DOUBLE: value.d = oper->constantD(); break;
3730 case T_OBJECT:
3731 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3732 case T_METADATA: return add((Metadata*)oper->constant()); break;
3733 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3734 }
3735 return add(n, type, value);
3736 }
3737
3738 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3739 jvalue value;
3740 // We can use the node pointer here to identify the right jump-table
3741 // as this method is called from Compile::Fill_buffer right before
3742 // the MachNodes are emitted and the jump-table is filled (means the
3743 // MachNode pointers do not change anymore).
3744 value.l = (jobject) n;
3745 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3746 add(con);
3747 return con;
3748 }
3749
3750 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3751 // If called from Compile::scratch_emit_size do nothing.
3752 if (Compile::current()->in_scratch_emit_size()) return;
3753
3754 assert(labels.is_nonempty(), "must be");
3755 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3756
3757 // Since MachConstantNode::constant_offset() also contains
3758 // table_base_offset() we need to subtract the table_base_offset()
3759 // to get the plain offset into the constant table.
3760 int offset = n->constant_offset() - table_base_offset();
3761
3762 MacroAssembler _masm(&cb);
3763 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3764
3765 for (uint i = 0; i < n->outcnt(); i++) {
3766 address* constant_addr = &jump_table_base[i];
3767 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)));
3768 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3769 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3770 }
3771 }
3772
3773 // The message about the current inlining is accumulated in
3774 // _print_inlining_stream and transfered into the _print_inlining_list
3775 // once we know whether inlining succeeds or not. For regular
3776 // inlining, messages are appended to the buffer pointed by
3777 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3778 // a new buffer is added after _print_inlining_idx in the list. This
3779 // way we can update the inlining message for late inlining call site
3780 // when the inlining is attempted again.
3781 void Compile::print_inlining_init() {
3782 if (print_inlining() || print_intrinsics()) {
3783 _print_inlining_stream = new stringStream();
3784 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3785 }
3786 }
3787
3788 void Compile::print_inlining_reinit() {
3789 if (print_inlining() || print_intrinsics()) {
3790 // Re allocate buffer when we change ResourceMark
3791 _print_inlining_stream = new stringStream();
3792 }
3793 }
3794
3795 void Compile::print_inlining_reset() {
3796 _print_inlining_stream->reset();
3797 }
3798
3799 void Compile::print_inlining_commit() {
3800 assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3801 // Transfer the message from _print_inlining_stream to the current
3802 // _print_inlining_list buffer and clear _print_inlining_stream.
3803 _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3804 print_inlining_reset();
3805 }
3806
3807 void Compile::print_inlining_push() {
3808 // Add new buffer to the _print_inlining_list at current position
3809 _print_inlining_idx++;
3810 _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3811 }
3812
3813 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3814 return _print_inlining_list->at(_print_inlining_idx);
3815 }
3816
3817 void Compile::print_inlining_update(CallGenerator* cg) {
3818 if (print_inlining() || print_intrinsics()) {
3819 if (!cg->is_late_inline()) {
3820 if (print_inlining_current().cg() != NULL) {
3821 print_inlining_push();
3822 }
3823 print_inlining_commit();
3824 } else {
3825 if (print_inlining_current().cg() != cg &&
3826 (print_inlining_current().cg() != NULL ||
3827 print_inlining_current().ss()->size() != 0)) {
3828 print_inlining_push();
3829 }
3830 print_inlining_commit();
3831 print_inlining_current().set_cg(cg);
3832 }
3833 }
3834 }
3835
3836 void Compile::print_inlining_move_to(CallGenerator* cg) {
3837 // We resume inlining at a late inlining call site. Locate the
3838 // corresponding inlining buffer so that we can update it.
3839 if (print_inlining()) {
3840 for (int i = 0; i < _print_inlining_list->length(); i++) {
3841 if (_print_inlining_list->adr_at(i)->cg() == cg) {
3842 _print_inlining_idx = i;
3843 return;
3844 }
3845 }
3846 ShouldNotReachHere();
3847 }
3848 }
3849
3850 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3851 if (print_inlining()) {
3852 assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3853 assert(print_inlining_current().cg() == cg, "wrong entry");
3854 // replace message with new message
3855 _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3856 print_inlining_commit();
3857 print_inlining_current().set_cg(cg);
3858 }
3859 }
3860
3861 void Compile::print_inlining_assert_ready() {
3862 assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3863 }
3864
3865 void Compile::process_print_inlining() {
3866 bool do_print_inlining = print_inlining() || print_intrinsics();
3867 if (do_print_inlining || log() != NULL) {
3868 // Print inlining message for candidates that we couldn't inline
3869 // for lack of space
3870 for (int i = 0; i < _late_inlines.length(); i++) {
3871 CallGenerator* cg = _late_inlines.at(i);
3872 if (!cg->is_mh_late_inline()) {
3873 const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3874 if (do_print_inlining) {
3875 cg->print_inlining_late(msg);
3876 }
3877 log_late_inline_failure(cg, msg);
3878 }
3879 }
3880 }
3881 if (do_print_inlining) {
3882 ResourceMark rm;
3883 stringStream ss;
3884 for (int i = 0; i < _print_inlining_list->length(); i++) {
3885 ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3886 }
3887 size_t end = ss.size();
3888 _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
3889 strncpy(_print_inlining_output, ss.base(), end+1);
3890 _print_inlining_output[end] = 0;
3891 }
3892 }
3893
3894 void Compile::dump_print_inlining() {
3895 if (_print_inlining_output != NULL) {
3896 tty->print_raw(_print_inlining_output);
3897 }
3898 }
3899
3900 void Compile::log_late_inline(CallGenerator* cg) {
3901 if (log() != NULL) {
3902 log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3903 cg->unique_id());
3904 JVMState* p = cg->call_node()->jvms();
3905 while (p != NULL) {
3906 log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
3907 p = p->caller();
3908 }
3909 log()->tail("late_inline");
3910 }
3911 }
3912
3913 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
3914 log_late_inline(cg);
3915 if (log() != NULL) {
3916 log()->inline_fail(msg);
3917 }
3918 }
3919
3920 void Compile::log_inline_id(CallGenerator* cg) {
3921 if (log() != NULL) {
3922 // The LogCompilation tool needs a unique way to identify late
3923 // inline call sites. This id must be unique for this call site in
3924 // this compilation. Try to have it unique across compilations as
3925 // well because it can be convenient when grepping through the log
3926 // file.
3927 // Distinguish OSR compilations from others in case CICountOSR is
3928 // on.
3929 jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
3930 cg->set_unique_id(id);
3931 log()->elem("inline_id id='" JLONG_FORMAT "'", id);
3932 }
3933 }
3934
3935 void Compile::log_inline_failure(const char* msg) {
3936 if (C->log() != NULL) {
3937 C->log()->inline_fail(msg);
3938 }
3939 }
3940
3941
3942 // Dump inlining replay data to the stream.
3943 // Don't change thread state and acquire any locks.
3944 void Compile::dump_inline_data(outputStream* out) {
3945 InlineTree* inl_tree = ilt();
3946 if (inl_tree != NULL) {
3947 out->print(" inline %d", inl_tree->count());
3948 inl_tree->dump_replay_data(out);
3949 }
3950 }
3951
3952 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3953 if (n1->Opcode() < n2->Opcode()) return -1;
3954 else if (n1->Opcode() > n2->Opcode()) return 1;
3955
3956 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()));
3957 for (uint i = 1; i < n1->req(); i++) {
3958 if (n1->in(i) < n2->in(i)) return -1;
3959 else if (n1->in(i) > n2->in(i)) return 1;
3960 }
3961
3962 return 0;
3963 }
3964
3965 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3966 Node* n1 = *n1p;
3967 Node* n2 = *n2p;
3968
3969 return cmp_expensive_nodes(n1, n2);
3970 }
3971
3972 void Compile::sort_expensive_nodes() {
3973 if (!expensive_nodes_sorted()) {
3974 _expensive_nodes->sort(cmp_expensive_nodes);
3975 }
3976 }
3977
3978 bool Compile::expensive_nodes_sorted() const {
3979 for (int i = 1; i < _expensive_nodes->length(); i++) {
3980 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3981 return false;
3982 }
3983 }
3984 return true;
3985 }
3986
3987 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3988 if (_expensive_nodes->length() == 0) {
3989 return false;
3990 }
3991
3992 assert(OptimizeExpensiveOps, "optimization off?");
3993
3994 // Take this opportunity to remove dead nodes from the list
3995 int j = 0;
3996 for (int i = 0; i < _expensive_nodes->length(); i++) {
3997 Node* n = _expensive_nodes->at(i);
3998 if (!n->is_unreachable(igvn)) {
3999 assert(n->is_expensive(), "should be expensive");
4000 _expensive_nodes->at_put(j, n);
4001 j++;
4002 }
4003 }
4004 _expensive_nodes->trunc_to(j);
4005
4006 // Then sort the list so that similar nodes are next to each other
4007 // and check for at least two nodes of identical kind with same data
4008 // inputs.
4009 sort_expensive_nodes();
4010
4011 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4012 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4013 return true;
4014 }
4015 }
4016
4017 return false;
4018 }
4019
4020 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4021 if (_expensive_nodes->length() == 0) {
4022 return;
4023 }
4024
4025 assert(OptimizeExpensiveOps, "optimization off?");
4026
4027 // Sort to bring similar nodes next to each other and clear the
4028 // control input of nodes for which there's only a single copy.
4029 sort_expensive_nodes();
4030
4031 int j = 0;
4032 int identical = 0;
4033 int i = 0;
4034 for (; i < _expensive_nodes->length()-1; i++) {
4035 assert(j <= i, "can't write beyond current index");
4036 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4037 identical++;
4038 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4039 continue;
4040 }
4041 if (identical > 0) {
4042 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4043 identical = 0;
4044 } else {
4045 Node* n = _expensive_nodes->at(i);
4046 igvn.hash_delete(n);
4047 n->set_req(0, NULL);
4048 igvn.hash_insert(n);
4049 }
4050 }
4051 if (identical > 0) {
4052 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4053 } else if (_expensive_nodes->length() >= 1) {
4054 Node* n = _expensive_nodes->at(i);
4055 igvn.hash_delete(n);
4056 n->set_req(0, NULL);
4057 igvn.hash_insert(n);
4058 }
4059 _expensive_nodes->trunc_to(j);
4060 }
4061
4062 void Compile::add_expensive_node(Node * n) {
4063 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4064 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4065 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4066 if (OptimizeExpensiveOps) {
4067 _expensive_nodes->append(n);
4068 } else {
4069 // Clear control input and let IGVN optimize expensive nodes if
4070 // OptimizeExpensiveOps is off.
4071 n->set_req(0, NULL);
4072 }
4073 }
4074
4075 /**
4076 * Remove the speculative part of types and clean up the graph
4077 */
4078 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4079 if (UseTypeSpeculation) {
4080 Unique_Node_List worklist;
4081 worklist.push(root());
4082 int modified = 0;
4083 // Go over all type nodes that carry a speculative type, drop the
4084 // speculative part of the type and enqueue the node for an igvn
4085 // which may optimize it out.
4086 for (uint next = 0; next < worklist.size(); ++next) {
4087 Node *n = worklist.at(next);
4088 if (n->is_Type()) {
4089 TypeNode* tn = n->as_Type();
4090 const Type* t = tn->type();
4091 const Type* t_no_spec = t->remove_speculative();
4092 if (t_no_spec != t) {
4093 bool in_hash = igvn.hash_delete(n);
4094 assert(in_hash, "node should be in igvn hash table");
4095 tn->set_type(t_no_spec);
4096 igvn.hash_insert(n);
4097 igvn._worklist.push(n); // give it a chance to go away
4098 modified++;
4099 }
4100 }
4101 uint max = n->len();
4102 for( uint i = 0; i < max; ++i ) {
4103 Node *m = n->in(i);
4104 if (not_a_node(m)) continue;
4105 worklist.push(m);
4106 }
4107 }
4108 // Drop the speculative part of all types in the igvn's type table
4109 igvn.remove_speculative_types();
4110 if (modified > 0) {
4111 igvn.optimize();
4112 }
4113 #ifdef ASSERT
4114 // Verify that after the IGVN is over no speculative type has resurfaced
4115 worklist.clear();
4116 worklist.push(root());
4117 for (uint next = 0; next < worklist.size(); ++next) {
4118 Node *n = worklist.at(next);
4119 const Type* t = igvn.type_or_null(n);
4120 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4121 if (n->is_Type()) {
4122 t = n->as_Type()->type();
4123 assert(t == t->remove_speculative(), "no more speculative types");
4124 }
4125 uint max = n->len();
4126 for( uint i = 0; i < max; ++i ) {
4127 Node *m = n->in(i);
4128 if (not_a_node(m)) continue;
4129 worklist.push(m);
4130 }
4131 }
4132 igvn.check_no_speculative_types();
4133 #endif
4134 }
4135 }
4136
4137 // Auxiliary method to support randomized stressing/fuzzing.
4138 //
4139 // This method can be called the arbitrary number of times, with current count
4140 // as the argument. The logic allows selecting a single candidate from the
4141 // running list of candidates as follows:
4142 // int count = 0;
4143 // Cand* selected = null;
4144 // while(cand = cand->next()) {
4145 // if (randomized_select(++count)) {
4146 // selected = cand;
4147 // }
4148 // }
4149 //
4150 // Including count equalizes the chances any candidate is "selected".
4151 // This is useful when we don't have the complete list of candidates to choose
4152 // from uniformly. In this case, we need to adjust the randomicity of the
4153 // selection, or else we will end up biasing the selection towards the latter
4154 // candidates.
4155 //
4156 // Quick back-envelope calculation shows that for the list of n candidates
4157 // the equal probability for the candidate to persist as "best" can be
4158 // achieved by replacing it with "next" k-th candidate with the probability
4159 // of 1/k. It can be easily shown that by the end of the run, the
4160 // probability for any candidate is converged to 1/n, thus giving the
4161 // uniform distribution among all the candidates.
4162 //
4163 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4164 #define RANDOMIZED_DOMAIN_POW 29
4165 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4166 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4167 bool Compile::randomized_select(int count) {
4168 assert(count > 0, "only positive");
4169 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4170 }