1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "ci/ciReplay.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/exceptionHandlerTable.hpp"
31 #include "code/nmethod.hpp"
32 #include "compiler/compileLog.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "compiler/oopMap.hpp"
35 #include "opto/addnode.hpp"
36 #include "opto/block.hpp"
37 #include "opto/c2compiler.hpp"
38 #include "opto/callGenerator.hpp"
39 #include "opto/callnode.hpp"
40 #include "opto/cfgnode.hpp"
41 #include "opto/chaitin.hpp"
42 #include "opto/compile.hpp"
43 #include "opto/connode.hpp"
44 #include "opto/divnode.hpp"
45 #include "opto/escape.hpp"
46 #include "opto/idealGraphPrinter.hpp"
47 #include "opto/loopnode.hpp"
48 #include "opto/machnode.hpp"
49 #include "opto/macro.hpp"
50 #include "opto/matcher.hpp"
51 #include "opto/mathexactnode.hpp"
52 #include "opto/memnode.hpp"
53 #include "opto/mulnode.hpp"
54 #include "opto/narrowptrnode.hpp"
55 #include "opto/node.hpp"
56 #include "opto/opcodes.hpp"
57 #include "opto/output.hpp"
58 #include "opto/parse.hpp"
59 #include "opto/phaseX.hpp"
60 #include "opto/rootnode.hpp"
61 #include "opto/runtime.hpp"
62 #include "opto/stringopts.hpp"
63 #include "opto/type.hpp"
64 #include "opto/vectornode.hpp"
65 #include "runtime/arguments.hpp"
66 #include "runtime/signature.hpp"
67 #include "runtime/stubRoutines.hpp"
68 #include "runtime/timer.hpp"
69 #include "trace/tracing.hpp"
70 #include "utilities/copy.hpp"
71 #ifdef TARGET_ARCH_MODEL_x86_32
72 # include "adfiles/ad_x86_32.hpp"
73 #endif
74 #ifdef TARGET_ARCH_MODEL_x86_64
75 # include "adfiles/ad_x86_64.hpp"
76 #endif
77 #ifdef TARGET_ARCH_MODEL_sparc
78 # include "adfiles/ad_sparc.hpp"
79 #endif
80 #ifdef TARGET_ARCH_MODEL_zero
81 # include "adfiles/ad_zero.hpp"
82 #endif
83 #ifdef TARGET_ARCH_MODEL_arm
84 # include "adfiles/ad_arm.hpp"
85 #endif
86 #ifdef TARGET_ARCH_MODEL_ppc_32
87 # include "adfiles/ad_ppc_32.hpp"
88 #endif
89 #ifdef TARGET_ARCH_MODEL_ppc_64
90 # include "adfiles/ad_ppc_64.hpp"
91 #endif
92
93
94 // -------------------- Compile::mach_constant_base_node -----------------------
95 // Constant table base node singleton.
96 MachConstantBaseNode* Compile::mach_constant_base_node() {
97 if (_mach_constant_base_node == NULL) {
98 _mach_constant_base_node = new (C) MachConstantBaseNode();
99 _mach_constant_base_node->add_req(C->root());
100 }
101 return _mach_constant_base_node;
102 }
103
104
105 /// Support for intrinsics.
106
107 // Return the index at which m must be inserted (or already exists).
108 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
109 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
110 #ifdef ASSERT
111 for (int i = 1; i < _intrinsics->length(); i++) {
112 CallGenerator* cg1 = _intrinsics->at(i-1);
113 CallGenerator* cg2 = _intrinsics->at(i);
114 assert(cg1->method() != cg2->method()
115 ? cg1->method() < cg2->method()
116 : cg1->is_virtual() < cg2->is_virtual(),
117 "compiler intrinsics list must stay sorted");
118 }
119 #endif
120 // Binary search sorted list, in decreasing intervals [lo, hi].
121 int lo = 0, hi = _intrinsics->length()-1;
122 while (lo <= hi) {
123 int mid = (uint)(hi + lo) / 2;
124 ciMethod* mid_m = _intrinsics->at(mid)->method();
125 if (m < mid_m) {
126 hi = mid-1;
127 } else if (m > mid_m) {
128 lo = mid+1;
129 } else {
130 // look at minor sort key
131 bool mid_virt = _intrinsics->at(mid)->is_virtual();
132 if (is_virtual < mid_virt) {
133 hi = mid-1;
134 } else if (is_virtual > mid_virt) {
135 lo = mid+1;
136 } else {
137 return mid; // exact match
138 }
139 }
140 }
141 return lo; // inexact match
142 }
143
144 void Compile::register_intrinsic(CallGenerator* cg) {
145 if (_intrinsics == NULL) {
146 _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
147 }
148 // This code is stolen from ciObjectFactory::insert.
149 // Really, GrowableArray should have methods for
150 // insert_at, remove_at, and binary_search.
151 int len = _intrinsics->length();
152 int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
153 if (index == len) {
154 _intrinsics->append(cg);
155 } else {
156 #ifdef ASSERT
157 CallGenerator* oldcg = _intrinsics->at(index);
158 assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
159 #endif
160 _intrinsics->append(_intrinsics->at(len-1));
161 int pos;
162 for (pos = len-2; pos >= index; pos--) {
163 _intrinsics->at_put(pos+1,_intrinsics->at(pos));
164 }
165 _intrinsics->at_put(index, cg);
166 }
167 assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
168 }
169
170 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
171 assert(m->is_loaded(), "don't try this on unloaded methods");
172 if (_intrinsics != NULL) {
173 int index = intrinsic_insertion_index(m, is_virtual);
174 if (index < _intrinsics->length()
175 && _intrinsics->at(index)->method() == m
176 && _intrinsics->at(index)->is_virtual() == is_virtual) {
177 return _intrinsics->at(index);
178 }
179 }
180 // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
181 if (m->intrinsic_id() != vmIntrinsics::_none &&
182 m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
183 CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
184 if (cg != NULL) {
185 // Save it for next time:
186 register_intrinsic(cg);
187 return cg;
188 } else {
189 gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
190 }
191 }
192 return NULL;
193 }
194
195 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
196 // in library_call.cpp.
197
198
199 #ifndef PRODUCT
200 // statistics gathering...
201
202 juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
203 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
204
205 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
206 assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
207 int oflags = _intrinsic_hist_flags[id];
208 assert(flags != 0, "what happened?");
209 if (is_virtual) {
210 flags |= _intrinsic_virtual;
211 }
212 bool changed = (flags != oflags);
213 if ((flags & _intrinsic_worked) != 0) {
214 juint count = (_intrinsic_hist_count[id] += 1);
215 if (count == 1) {
216 changed = true; // first time
217 }
218 // increment the overall count also:
219 _intrinsic_hist_count[vmIntrinsics::_none] += 1;
220 }
221 if (changed) {
222 if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
223 // Something changed about the intrinsic's virtuality.
224 if ((flags & _intrinsic_virtual) != 0) {
225 // This is the first use of this intrinsic as a virtual call.
226 if (oflags != 0) {
227 // We already saw it as a non-virtual, so note both cases.
228 flags |= _intrinsic_both;
229 }
230 } else if ((oflags & _intrinsic_both) == 0) {
231 // This is the first use of this intrinsic as a non-virtual
232 flags |= _intrinsic_both;
233 }
234 }
235 _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
236 }
237 // update the overall flags also:
238 _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
239 return changed;
240 }
241
242 static char* format_flags(int flags, char* buf) {
243 buf[0] = 0;
244 if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
245 if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
246 if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
247 if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
248 if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
249 if (buf[0] == 0) strcat(buf, ",");
250 assert(buf[0] == ',', "must be");
251 return &buf[1];
252 }
253
254 void Compile::print_intrinsic_statistics() {
255 char flagsbuf[100];
256 ttyLocker ttyl;
257 if (xtty != NULL) xtty->head("statistics type='intrinsic'");
258 tty->print_cr("Compiler intrinsic usage:");
259 juint total = _intrinsic_hist_count[vmIntrinsics::_none];
260 if (total == 0) total = 1; // avoid div0 in case of no successes
261 #define PRINT_STAT_LINE(name, c, f) \
262 tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
263 for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
264 vmIntrinsics::ID id = (vmIntrinsics::ID) index;
265 int flags = _intrinsic_hist_flags[id];
266 juint count = _intrinsic_hist_count[id];
267 if ((flags | count) != 0) {
268 PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
269 }
270 }
271 PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
272 if (xtty != NULL) xtty->tail("statistics");
273 }
274
275 void Compile::print_statistics() {
276 { ttyLocker ttyl;
277 if (xtty != NULL) xtty->head("statistics type='opto'");
278 Parse::print_statistics();
279 PhaseCCP::print_statistics();
280 PhaseRegAlloc::print_statistics();
281 Scheduling::print_statistics();
282 PhasePeephole::print_statistics();
283 PhaseIdealLoop::print_statistics();
284 if (xtty != NULL) xtty->tail("statistics");
285 }
286 if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
287 // put this under its own <statistics> element.
288 print_intrinsic_statistics();
289 }
290 }
291 #endif //PRODUCT
292
293 // Support for bundling info
294 Bundle* Compile::node_bundling(const Node *n) {
295 assert(valid_bundle_info(n), "oob");
296 return &_node_bundling_base[n->_idx];
297 }
298
299 bool Compile::valid_bundle_info(const Node *n) {
300 return (_node_bundling_limit > n->_idx);
301 }
302
303
304 void Compile::gvn_replace_by(Node* n, Node* nn) {
305 for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
306 Node* use = n->last_out(i);
307 bool is_in_table = initial_gvn()->hash_delete(use);
308 uint uses_found = 0;
309 for (uint j = 0; j < use->len(); j++) {
310 if (use->in(j) == n) {
311 if (j < use->req())
312 use->set_req(j, nn);
313 else
314 use->set_prec(j, nn);
315 uses_found++;
316 }
317 }
318 if (is_in_table) {
319 // reinsert into table
320 initial_gvn()->hash_find_insert(use);
321 }
322 record_for_igvn(use);
323 i -= uses_found; // we deleted 1 or more copies of this edge
324 }
325 }
326
327
328 static inline bool not_a_node(const Node* n) {
329 if (n == NULL) return true;
330 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
331 if (*(address*)n == badAddress) return true; // kill by Node::destruct
332 return false;
333 }
334
335 // Identify all nodes that are reachable from below, useful.
336 // Use breadth-first pass that records state in a Unique_Node_List,
337 // recursive traversal is slower.
338 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
339 int estimated_worklist_size = unique();
340 useful.map( estimated_worklist_size, NULL ); // preallocate space
341
342 // Initialize worklist
343 if (root() != NULL) { useful.push(root()); }
344 // If 'top' is cached, declare it useful to preserve cached node
345 if( cached_top_node() ) { useful.push(cached_top_node()); }
346
347 // Push all useful nodes onto the list, breadthfirst
348 for( uint next = 0; next < useful.size(); ++next ) {
349 assert( next < unique(), "Unique useful nodes < total nodes");
350 Node *n = useful.at(next);
351 uint max = n->len();
352 for( uint i = 0; i < max; ++i ) {
353 Node *m = n->in(i);
354 if (not_a_node(m)) continue;
355 useful.push(m);
356 }
357 }
358 }
359
360 // Update dead_node_list with any missing dead nodes using useful
361 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
362 void Compile::update_dead_node_list(Unique_Node_List &useful) {
363 uint max_idx = unique();
364 VectorSet& useful_node_set = useful.member_set();
365
366 for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
367 // If node with index node_idx is not in useful set,
368 // mark it as dead in dead node list.
369 if (! useful_node_set.test(node_idx) ) {
370 record_dead_node(node_idx);
371 }
372 }
373 }
374
375 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
376 int shift = 0;
377 for (int i = 0; i < inlines->length(); i++) {
378 CallGenerator* cg = inlines->at(i);
379 CallNode* call = cg->call_node();
380 if (shift > 0) {
381 inlines->at_put(i-shift, cg);
382 }
383 if (!useful.member(call)) {
384 shift++;
385 }
386 }
387 inlines->trunc_to(inlines->length()-shift);
388 }
389
390 // Disconnect all useless nodes by disconnecting those at the boundary.
391 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
392 uint next = 0;
393 while (next < useful.size()) {
394 Node *n = useful.at(next++);
395 // Use raw traversal of out edges since this code removes out edges
396 int max = n->outcnt();
397 for (int j = 0; j < max; ++j) {
398 Node* child = n->raw_out(j);
399 if (! useful.member(child)) {
400 assert(!child->is_top() || child != top(),
401 "If top is cached in Compile object it is in useful list");
402 // Only need to remove this out-edge to the useless node
403 n->raw_del_out(j);
404 --j;
405 --max;
406 }
407 }
408 if (n->outcnt() == 1 && n->has_special_unique_user()) {
409 record_for_igvn(n->unique_out());
410 }
411 }
412 // Remove useless macro and predicate opaq nodes
413 for (int i = C->macro_count()-1; i >= 0; i--) {
414 Node* n = C->macro_node(i);
415 if (!useful.member(n)) {
416 remove_macro_node(n);
417 }
418 }
419 // Remove useless expensive node
420 for (int i = C->expensive_count()-1; i >= 0; i--) {
421 Node* n = C->expensive_node(i);
422 if (!useful.member(n)) {
423 remove_expensive_node(n);
424 }
425 }
426 // clean up the late inline lists
427 remove_useless_late_inlines(&_string_late_inlines, useful);
428 remove_useless_late_inlines(&_boxing_late_inlines, useful);
429 remove_useless_late_inlines(&_late_inlines, useful);
430 debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
431 }
432
433 //------------------------------frame_size_in_words-----------------------------
434 // frame_slots in units of words
435 int Compile::frame_size_in_words() const {
436 // shift is 0 in LP32 and 1 in LP64
437 const int shift = (LogBytesPerWord - LogBytesPerInt);
438 int words = _frame_slots >> shift;
439 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
440 return words;
441 }
442
443 // To bang the stack of this compiled method we use the stack size
444 // that the interpreter would need in case of a deoptimization. This
445 // removes the need to bang the stack in the deoptimization blob which
446 // in turn simplifies stack overflow handling.
447 int Compile::bang_size_in_bytes() const {
448 return MAX2(_interpreter_frame_size, frame_size_in_bytes());
449 }
450
451 // ============================================================================
452 //------------------------------CompileWrapper---------------------------------
453 class CompileWrapper : public StackObj {
454 Compile *const _compile;
455 public:
456 CompileWrapper(Compile* compile);
457
458 ~CompileWrapper();
459 };
460
461 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
462 // the Compile* pointer is stored in the current ciEnv:
463 ciEnv* env = compile->env();
464 assert(env == ciEnv::current(), "must already be a ciEnv active");
465 assert(env->compiler_data() == NULL, "compile already active?");
466 env->set_compiler_data(compile);
467 assert(compile == Compile::current(), "sanity");
468
469 compile->set_type_dict(NULL);
470 compile->set_type_hwm(NULL);
471 compile->set_type_last_size(0);
472 compile->set_last_tf(NULL, NULL);
473 compile->set_indexSet_arena(NULL);
474 compile->set_indexSet_free_block_list(NULL);
475 compile->init_type_arena();
476 Type::Initialize(compile);
477 _compile->set_scratch_buffer_blob(NULL);
478 _compile->begin_method();
479 }
480 CompileWrapper::~CompileWrapper() {
481 _compile->end_method();
482 if (_compile->scratch_buffer_blob() != NULL)
483 BufferBlob::free(_compile->scratch_buffer_blob());
484 _compile->env()->set_compiler_data(NULL);
485 }
486
487
488 //----------------------------print_compile_messages---------------------------
489 void Compile::print_compile_messages() {
490 #ifndef PRODUCT
491 // Check if recompiling
492 if (_subsume_loads == false && PrintOpto) {
493 // Recompiling without allowing machine instructions to subsume loads
494 tty->print_cr("*********************************************************");
495 tty->print_cr("** Bailout: Recompile without subsuming loads **");
496 tty->print_cr("*********************************************************");
497 }
498 if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
499 // Recompiling without escape analysis
500 tty->print_cr("*********************************************************");
501 tty->print_cr("** Bailout: Recompile without escape analysis **");
502 tty->print_cr("*********************************************************");
503 }
504 if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
505 // Recompiling without boxing elimination
506 tty->print_cr("*********************************************************");
507 tty->print_cr("** Bailout: Recompile without boxing elimination **");
508 tty->print_cr("*********************************************************");
509 }
510 if (env()->break_at_compile()) {
511 // Open the debugger when compiling this method.
512 tty->print("### Breaking when compiling: ");
513 method()->print_short_name();
514 tty->cr();
515 BREAKPOINT;
516 }
517
518 if( PrintOpto ) {
519 if (is_osr_compilation()) {
520 tty->print("[OSR]%3d", _compile_id);
521 } else {
522 tty->print("%3d", _compile_id);
523 }
524 }
525 #endif
526 }
527
528
529 //-----------------------init_scratch_buffer_blob------------------------------
530 // Construct a temporary BufferBlob and cache it for this compile.
531 void Compile::init_scratch_buffer_blob(int const_size) {
532 // If there is already a scratch buffer blob allocated and the
533 // constant section is big enough, use it. Otherwise free the
534 // current and allocate a new one.
535 BufferBlob* blob = scratch_buffer_blob();
536 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
537 // Use the current blob.
538 } else {
539 if (blob != NULL) {
540 BufferBlob::free(blob);
541 }
542
543 ResourceMark rm;
544 _scratch_const_size = const_size;
545 int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
546 blob = BufferBlob::create("Compile::scratch_buffer", size);
547 // Record the buffer blob for next time.
548 set_scratch_buffer_blob(blob);
549 // Have we run out of code space?
550 if (scratch_buffer_blob() == NULL) {
551 // Let CompilerBroker disable further compilations.
552 record_failure("Not enough space for scratch buffer in CodeCache");
553 return;
554 }
555 }
556
557 // Initialize the relocation buffers
558 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
559 set_scratch_locs_memory(locs_buf);
560 }
561
562
563 //-----------------------scratch_emit_size-------------------------------------
564 // Helper function that computes size by emitting code
565 uint Compile::scratch_emit_size(const Node* n) {
566 // Start scratch_emit_size section.
567 set_in_scratch_emit_size(true);
568
569 // Emit into a trash buffer and count bytes emitted.
570 // This is a pretty expensive way to compute a size,
571 // but it works well enough if seldom used.
572 // All common fixed-size instructions are given a size
573 // method by the AD file.
574 // Note that the scratch buffer blob and locs memory are
575 // allocated at the beginning of the compile task, and
576 // may be shared by several calls to scratch_emit_size.
577 // The allocation of the scratch buffer blob is particularly
578 // expensive, since it has to grab the code cache lock.
579 BufferBlob* blob = this->scratch_buffer_blob();
580 assert(blob != NULL, "Initialize BufferBlob at start");
581 assert(blob->size() > MAX_inst_size, "sanity");
582 relocInfo* locs_buf = scratch_locs_memory();
583 address blob_begin = blob->content_begin();
584 address blob_end = (address)locs_buf;
585 assert(blob->content_contains(blob_end), "sanity");
586 CodeBuffer buf(blob_begin, blob_end - blob_begin);
587 buf.initialize_consts_size(_scratch_const_size);
588 buf.initialize_stubs_size(MAX_stubs_size);
589 assert(locs_buf != NULL, "sanity");
590 int lsize = MAX_locs_size / 3;
591 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
592 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
593 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
594
595 // Do the emission.
596
597 Label fakeL; // Fake label for branch instructions.
598 Label* saveL = NULL;
599 uint save_bnum = 0;
600 bool is_branch = n->is_MachBranch();
601 if (is_branch) {
602 MacroAssembler masm(&buf);
603 masm.bind(fakeL);
604 n->as_MachBranch()->save_label(&saveL, &save_bnum);
605 n->as_MachBranch()->label_set(&fakeL, 0);
606 }
607 n->emit(buf, this->regalloc());
608 if (is_branch) // Restore label.
609 n->as_MachBranch()->label_set(saveL, save_bnum);
610
611 // End scratch_emit_size section.
612 set_in_scratch_emit_size(false);
613
614 return buf.insts_size();
615 }
616
617
618 // ============================================================================
619 //------------------------------Compile standard-------------------------------
620 debug_only( int Compile::_debug_idx = 100000; )
621
622 // Compile a method. entry_bci is -1 for normal compilations and indicates
623 // the continuation bci for on stack replacement.
624
625
626 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
627 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
628 : Phase(Compiler),
629 _env(ci_env),
630 _log(ci_env->log()),
631 _compile_id(ci_env->compile_id()),
632 _save_argument_registers(false),
633 _stub_name(NULL),
634 _stub_function(NULL),
635 _stub_entry_point(NULL),
636 _method(target),
637 _entry_bci(osr_bci),
638 _initial_gvn(NULL),
639 _for_igvn(NULL),
640 _warm_calls(NULL),
641 _subsume_loads(subsume_loads),
642 _do_escape_analysis(do_escape_analysis),
643 _eliminate_boxing(eliminate_boxing),
644 _failure_reason(NULL),
645 _code_buffer("Compile::Fill_buffer"),
646 _orig_pc_slot(0),
647 _orig_pc_slot_offset_in_bytes(0),
648 _has_method_handle_invokes(false),
649 _mach_constant_base_node(NULL),
650 _node_bundling_limit(0),
651 _node_bundling_base(NULL),
652 _java_calls(0),
653 _inner_loops(0),
654 _scratch_const_size(-1),
655 _in_scratch_emit_size(false),
656 _dead_node_list(comp_arena()),
657 _dead_node_count(0),
658 #ifndef PRODUCT
659 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
660 _in_dump_cnt(0),
661 _printer(IdealGraphPrinter::printer()),
662 #endif
663 _congraph(NULL),
664 _replay_inline_data(NULL),
665 _late_inlines(comp_arena(), 2, 0, NULL),
666 _string_late_inlines(comp_arena(), 2, 0, NULL),
667 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
668 _late_inlines_pos(0),
669 _number_of_mh_late_inlines(0),
670 _inlining_progress(false),
671 _inlining_incrementally(false),
672 _print_inlining_list(NULL),
673 _print_inlining_stream(NULL),
674 _print_inlining_idx(0),
675 _preserve_jvm_state(0),
676 _interpreter_frame_size(0) {
677 C = this;
678
679 CompileWrapper cw(this);
680 #ifndef PRODUCT
681 if (TimeCompiler2) {
682 tty->print(" ");
683 target->holder()->name()->print();
684 tty->print(".");
685 target->print_short_name();
686 tty->print(" ");
687 }
688 TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
689 TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
690 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
691 if (!print_opto_assembly) {
692 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
693 if (print_assembly && !Disassembler::can_decode()) {
694 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
695 print_opto_assembly = true;
696 }
697 }
698 set_print_assembly(print_opto_assembly);
699 set_parsed_irreducible_loop(false);
700
701 if (method()->has_option("ReplayInline")) {
702 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
703 }
704 #endif
705 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
706 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
707 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
708
709 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
710 // Make sure the method being compiled gets its own MDO,
711 // so we can at least track the decompile_count().
712 // Need MDO to record RTM code generation state.
713 method()->ensure_method_data();
714 }
715
716 Init(::AliasLevel);
717
718
719 print_compile_messages();
720
721 _ilt = InlineTree::build_inline_tree_root();
722
723 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
724 assert(num_alias_types() >= AliasIdxRaw, "");
725
726 #define MINIMUM_NODE_HASH 1023
727 // Node list that Iterative GVN will start with
728 Unique_Node_List for_igvn(comp_arena());
729 set_for_igvn(&for_igvn);
730
731 // GVN that will be run immediately on new nodes
732 uint estimated_size = method()->code_size()*4+64;
733 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
734 PhaseGVN gvn(node_arena(), estimated_size);
735 set_initial_gvn(&gvn);
736
737 print_inlining_init();
738 { // Scope for timing the parser
739 TracePhase t3("parse", &_t_parser, true);
740
741 // Put top into the hash table ASAP.
742 initial_gvn()->transform_no_reclaim(top());
743
744 // Set up tf(), start(), and find a CallGenerator.
745 CallGenerator* cg = NULL;
746 if (is_osr_compilation()) {
747 const TypeTuple *domain = StartOSRNode::osr_domain();
748 const TypeTuple *range = TypeTuple::make_range(method()->signature());
749 init_tf(TypeFunc::make(domain, range));
750 StartNode* s = new (this) StartOSRNode(root(), domain);
751 initial_gvn()->set_type_bottom(s);
752 init_start(s);
753 cg = CallGenerator::for_osr(method(), entry_bci());
754 } else {
755 // Normal case.
756 init_tf(TypeFunc::make(method()));
757 StartNode* s = new (this) StartNode(root(), tf()->domain());
758 initial_gvn()->set_type_bottom(s);
759 init_start(s);
760 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
761 // With java.lang.ref.reference.get() we must go through the
762 // intrinsic when G1 is enabled - even when get() is the root
763 // method of the compile - so that, if necessary, the value in
764 // the referent field of the reference object gets recorded by
765 // the pre-barrier code.
766 // Specifically, if G1 is enabled, the value in the referent
767 // field is recorded by the G1 SATB pre barrier. This will
768 // result in the referent being marked live and the reference
769 // object removed from the list of discovered references during
770 // reference processing.
771 cg = find_intrinsic(method(), false);
772 }
773 if (cg == NULL) {
774 float past_uses = method()->interpreter_invocation_count();
775 float expected_uses = past_uses;
776 cg = CallGenerator::for_inline(method(), expected_uses);
777 }
778 }
779 if (failing()) return;
780 if (cg == NULL) {
781 record_method_not_compilable_all_tiers("cannot parse method");
782 return;
783 }
784 JVMState* jvms = build_start_state(start(), tf());
785 if ((jvms = cg->generate(jvms, NULL)) == NULL) {
786 record_method_not_compilable("method parse failed");
787 return;
788 }
789 GraphKit kit(jvms);
790
791 if (!kit.stopped()) {
792 // Accept return values, and transfer control we know not where.
793 // This is done by a special, unique ReturnNode bound to root.
794 return_values(kit.jvms());
795 }
796
797 if (kit.has_exceptions()) {
798 // Any exceptions that escape from this call must be rethrown
799 // to whatever caller is dynamically above us on the stack.
800 // This is done by a special, unique RethrowNode bound to root.
801 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
802 }
803
804 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
805
806 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
807 inline_string_calls(true);
808 }
809
810 if (failing()) return;
811
812 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
813
814 // Remove clutter produced by parsing.
815 if (!failing()) {
816 ResourceMark rm;
817 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
818 }
819 }
820
821 // Note: Large methods are capped off in do_one_bytecode().
822 if (failing()) return;
823
824 // After parsing, node notes are no longer automagic.
825 // They must be propagated by register_new_node_with_optimizer(),
826 // clone(), or the like.
827 set_default_node_notes(NULL);
828
829 for (;;) {
830 int successes = Inline_Warm();
831 if (failing()) return;
832 if (successes == 0) break;
833 }
834
835 // Drain the list.
836 Finish_Warm();
837 #ifndef PRODUCT
838 if (_printer) {
839 _printer->print_inlining(this);
840 }
841 #endif
842
843 if (failing()) return;
844 NOT_PRODUCT( verify_graph_edges(); )
845
846 // Now optimize
847 Optimize();
848 if (failing()) return;
849 NOT_PRODUCT( verify_graph_edges(); )
850
851 #ifndef PRODUCT
852 if (PrintIdeal) {
853 ttyLocker ttyl; // keep the following output all in one block
854 // This output goes directly to the tty, not the compiler log.
855 // To enable tools to match it up with the compilation activity,
856 // be sure to tag this tty output with the compile ID.
857 if (xtty != NULL) {
858 xtty->head("ideal compile_id='%d'%s", compile_id(),
859 is_osr_compilation() ? " compile_kind='osr'" :
860 "");
861 }
862 root()->dump(9999);
863 if (xtty != NULL) {
864 xtty->tail("ideal");
865 }
866 }
867 #endif
868
869 NOT_PRODUCT( verify_barriers(); )
870
871 // Dump compilation data to replay it.
872 if (method()->has_option("DumpReplay")) {
873 env()->dump_replay_data(_compile_id);
874 }
875 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
876 env()->dump_inline_data(_compile_id);
877 }
878
879 // Now that we know the size of all the monitors we can add a fixed slot
880 // for the original deopt pc.
881
882 _orig_pc_slot = fixed_slots();
883 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
884 set_fixed_slots(next_slot);
885
886 // Compute when to use implicit null checks. Used by matching trap based
887 // nodes and NullCheck optimization.
888 set_allowed_deopt_reasons();
889
890 // Now generate code
891 Code_Gen();
892 if (failing()) return;
893
894 // Check if we want to skip execution of all compiled code.
895 {
896 #ifndef PRODUCT
897 if (OptoNoExecute) {
898 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
899 return;
900 }
901 TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
902 #endif
903
904 if (is_osr_compilation()) {
905 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
906 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
907 } else {
908 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
909 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
910 }
911
912 env()->register_method(_method, _entry_bci,
913 &_code_offsets,
914 _orig_pc_slot_offset_in_bytes,
915 code_buffer(),
916 frame_size_in_words(), _oop_map_set,
917 &_handler_table, &_inc_table,
918 compiler,
919 env()->comp_level(),
920 has_unsafe_access(),
921 SharedRuntime::is_wide_vector(max_vector_size()),
922 rtm_state()
923 );
924
925 if (log() != NULL) // Print code cache state into compiler log
926 log()->code_cache_state();
927 }
928 }
929
930 //------------------------------Compile----------------------------------------
931 // Compile a runtime stub
932 Compile::Compile( ciEnv* ci_env,
933 TypeFunc_generator generator,
934 address stub_function,
935 const char *stub_name,
936 int is_fancy_jump,
937 bool pass_tls,
938 bool save_arg_registers,
939 bool return_pc )
940 : Phase(Compiler),
941 _env(ci_env),
942 _log(ci_env->log()),
943 _compile_id(0),
944 _save_argument_registers(save_arg_registers),
945 _method(NULL),
946 _stub_name(stub_name),
947 _stub_function(stub_function),
948 _stub_entry_point(NULL),
949 _entry_bci(InvocationEntryBci),
950 _initial_gvn(NULL),
951 _for_igvn(NULL),
952 _warm_calls(NULL),
953 _orig_pc_slot(0),
954 _orig_pc_slot_offset_in_bytes(0),
955 _subsume_loads(true),
956 _do_escape_analysis(false),
957 _eliminate_boxing(false),
958 _failure_reason(NULL),
959 _code_buffer("Compile::Fill_buffer"),
960 _has_method_handle_invokes(false),
961 _mach_constant_base_node(NULL),
962 _node_bundling_limit(0),
963 _node_bundling_base(NULL),
964 _java_calls(0),
965 _inner_loops(0),
966 #ifndef PRODUCT
967 _trace_opto_output(TraceOptoOutput),
968 _in_dump_cnt(0),
969 _printer(NULL),
970 #endif
971 _dead_node_list(comp_arena()),
972 _dead_node_count(0),
973 _congraph(NULL),
974 _replay_inline_data(NULL),
975 _number_of_mh_late_inlines(0),
976 _inlining_progress(false),
977 _inlining_incrementally(false),
978 _print_inlining_list(NULL),
979 _print_inlining_stream(NULL),
980 _print_inlining_idx(0),
981 _preserve_jvm_state(0),
982 _allowed_reasons(0),
983 _interpreter_frame_size(0) {
984 C = this;
985
986 #ifndef PRODUCT
987 TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
988 TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
989 set_print_assembly(PrintFrameConverterAssembly);
990 set_parsed_irreducible_loop(false);
991 #endif
992 set_has_irreducible_loop(false); // no loops
993
994 CompileWrapper cw(this);
995 Init(/*AliasLevel=*/ 0);
996 init_tf((*generator)());
997
998 {
999 // The following is a dummy for the sake of GraphKit::gen_stub
1000 Unique_Node_List for_igvn(comp_arena());
1001 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
1002 PhaseGVN gvn(Thread::current()->resource_area(),255);
1003 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
1004 gvn.transform_no_reclaim(top());
1005
1006 GraphKit kit;
1007 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1008 }
1009
1010 NOT_PRODUCT( verify_graph_edges(); )
1011 Code_Gen();
1012 if (failing()) return;
1013
1014
1015 // Entry point will be accessed using compile->stub_entry_point();
1016 if (code_buffer() == NULL) {
1017 Matcher::soft_match_failure();
1018 } else {
1019 if (PrintAssembly && (WizardMode || Verbose))
1020 tty->print_cr("### Stub::%s", stub_name);
1021
1022 if (!failing()) {
1023 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1024
1025 // Make the NMethod
1026 // For now we mark the frame as never safe for profile stackwalking
1027 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1028 code_buffer(),
1029 CodeOffsets::frame_never_safe,
1030 // _code_offsets.value(CodeOffsets::Frame_Complete),
1031 frame_size_in_words(),
1032 _oop_map_set,
1033 save_arg_registers);
1034 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1035
1036 _stub_entry_point = rs->entry_point();
1037 }
1038 }
1039 }
1040
1041 //------------------------------Init-------------------------------------------
1042 // Prepare for a single compilation
1043 void Compile::Init(int aliaslevel) {
1044 _unique = 0;
1045 _regalloc = NULL;
1046
1047 _tf = NULL; // filled in later
1048 _top = NULL; // cached later
1049 _matcher = NULL; // filled in later
1050 _cfg = NULL; // filled in later
1051
1052 set_24_bit_selection_and_mode(Use24BitFP, false);
1053
1054 _node_note_array = NULL;
1055 _default_node_notes = NULL;
1056
1057 _immutable_memory = NULL; // filled in at first inquiry
1058
1059 // Globally visible Nodes
1060 // First set TOP to NULL to give safe behavior during creation of RootNode
1061 set_cached_top_node(NULL);
1062 set_root(new (this) RootNode());
1063 // Now that you have a Root to point to, create the real TOP
1064 set_cached_top_node( new (this) ConNode(Type::TOP) );
1065 set_recent_alloc(NULL, NULL);
1066
1067 // Create Debug Information Recorder to record scopes, oopmaps, etc.
1068 env()->set_oop_recorder(new OopRecorder(env()->arena()));
1069 env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1070 env()->set_dependencies(new Dependencies(env()));
1071
1072 _fixed_slots = 0;
1073 set_has_split_ifs(false);
1074 set_has_loops(has_method() && method()->has_loops()); // first approximation
1075 set_has_stringbuilder(false);
1076 set_has_boxed_value(false);
1077 _trap_can_recompile = false; // no traps emitted yet
1078 _major_progress = true; // start out assuming good things will happen
1079 set_has_unsafe_access(false);
1080 set_max_vector_size(0);
1081 Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1082 set_decompile_count(0);
1083
1084 set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1085 set_num_loop_opts(LoopOptsCount);
1086 set_do_inlining(Inline);
1087 set_max_inline_size(MaxInlineSize);
1088 set_freq_inline_size(FreqInlineSize);
1089 set_do_scheduling(OptoScheduling);
1090 set_do_count_invocations(false);
1091 set_do_method_data_update(false);
1092 set_rtm_state(NoRTM); // No RTM lock eliding by default
1093 #if INCLUDE_RTM_OPT
1094 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1095 int rtm_state = method()->method_data()->rtm_state();
1096 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1097 // Don't generate RTM lock eliding code.
1098 set_rtm_state(NoRTM);
1099 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1100 // Generate RTM lock eliding code without abort ratio calculation code.
1101 set_rtm_state(UseRTM);
1102 } else if (UseRTMDeopt) {
1103 // Generate RTM lock eliding code and include abort ratio calculation
1104 // code if UseRTMDeopt is on.
1105 set_rtm_state(ProfileRTM);
1106 }
1107 }
1108 #endif
1109 if (debug_info()->recording_non_safepoints()) {
1110 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1111 (comp_arena(), 8, 0, NULL));
1112 set_default_node_notes(Node_Notes::make(this));
1113 }
1114
1115 // // -- Initialize types before each compile --
1116 // // Update cached type information
1117 // if( _method && _method->constants() )
1118 // Type::update_loaded_types(_method, _method->constants());
1119
1120 // Init alias_type map.
1121 if (!_do_escape_analysis && aliaslevel == 3)
1122 aliaslevel = 2; // No unique types without escape analysis
1123 _AliasLevel = aliaslevel;
1124 const int grow_ats = 16;
1125 _max_alias_types = grow_ats;
1126 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1127 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1128 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1129 {
1130 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1131 }
1132 // Initialize the first few types.
1133 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1134 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1135 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1136 _num_alias_types = AliasIdxRaw+1;
1137 // Zero out the alias type cache.
1138 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1139 // A NULL adr_type hits in the cache right away. Preload the right answer.
1140 probe_alias_cache(NULL)->_index = AliasIdxTop;
1141
1142 _intrinsics = NULL;
1143 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1144 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1145 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1146 register_library_intrinsics();
1147 }
1148
1149 //---------------------------init_start----------------------------------------
1150 // Install the StartNode on this compile object.
1151 void Compile::init_start(StartNode* s) {
1152 if (failing())
1153 return; // already failing
1154 assert(s == start(), "");
1155 }
1156
1157 StartNode* Compile::start() const {
1158 assert(!failing(), "");
1159 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1160 Node* start = root()->fast_out(i);
1161 if( start->is_Start() )
1162 return start->as_Start();
1163 }
1164 fatal("Did not find Start node!");
1165 return NULL;
1166 }
1167
1168 //-------------------------------immutable_memory-------------------------------------
1169 // Access immutable memory
1170 Node* Compile::immutable_memory() {
1171 if (_immutable_memory != NULL) {
1172 return _immutable_memory;
1173 }
1174 StartNode* s = start();
1175 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1176 Node *p = s->fast_out(i);
1177 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1178 _immutable_memory = p;
1179 return _immutable_memory;
1180 }
1181 }
1182 ShouldNotReachHere();
1183 return NULL;
1184 }
1185
1186 //----------------------set_cached_top_node------------------------------------
1187 // Install the cached top node, and make sure Node::is_top works correctly.
1188 void Compile::set_cached_top_node(Node* tn) {
1189 if (tn != NULL) verify_top(tn);
1190 Node* old_top = _top;
1191 _top = tn;
1192 // Calling Node::setup_is_top allows the nodes the chance to adjust
1193 // their _out arrays.
1194 if (_top != NULL) _top->setup_is_top();
1195 if (old_top != NULL) old_top->setup_is_top();
1196 assert(_top == NULL || top()->is_top(), "");
1197 }
1198
1199 #ifdef ASSERT
1200 uint Compile::count_live_nodes_by_graph_walk() {
1201 Unique_Node_List useful(comp_arena());
1202 // Get useful node list by walking the graph.
1203 identify_useful_nodes(useful);
1204 return useful.size();
1205 }
1206
1207 void Compile::print_missing_nodes() {
1208
1209 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1210 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1211 return;
1212 }
1213
1214 // This is an expensive function. It is executed only when the user
1215 // specifies VerifyIdealNodeCount option or otherwise knows the
1216 // additional work that needs to be done to identify reachable nodes
1217 // by walking the flow graph and find the missing ones using
1218 // _dead_node_list.
1219
1220 Unique_Node_List useful(comp_arena());
1221 // Get useful node list by walking the graph.
1222 identify_useful_nodes(useful);
1223
1224 uint l_nodes = C->live_nodes();
1225 uint l_nodes_by_walk = useful.size();
1226
1227 if (l_nodes != l_nodes_by_walk) {
1228 if (_log != NULL) {
1229 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1230 _log->stamp();
1231 _log->end_head();
1232 }
1233 VectorSet& useful_member_set = useful.member_set();
1234 int last_idx = l_nodes_by_walk;
1235 for (int i = 0; i < last_idx; i++) {
1236 if (useful_member_set.test(i)) {
1237 if (_dead_node_list.test(i)) {
1238 if (_log != NULL) {
1239 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1240 }
1241 if (PrintIdealNodeCount) {
1242 // Print the log message to tty
1243 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1244 useful.at(i)->dump();
1245 }
1246 }
1247 }
1248 else if (! _dead_node_list.test(i)) {
1249 if (_log != NULL) {
1250 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1251 }
1252 if (PrintIdealNodeCount) {
1253 // Print the log message to tty
1254 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1255 }
1256 }
1257 }
1258 if (_log != NULL) {
1259 _log->tail("mismatched_nodes");
1260 }
1261 }
1262 }
1263 #endif
1264
1265 #ifndef PRODUCT
1266 void Compile::verify_top(Node* tn) const {
1267 if (tn != NULL) {
1268 assert(tn->is_Con(), "top node must be a constant");
1269 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1270 assert(tn->in(0) != NULL, "must have live top node");
1271 }
1272 }
1273 #endif
1274
1275
1276 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1277
1278 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1279 guarantee(arr != NULL, "");
1280 int num_blocks = arr->length();
1281 if (grow_by < num_blocks) grow_by = num_blocks;
1282 int num_notes = grow_by * _node_notes_block_size;
1283 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1284 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1285 while (num_notes > 0) {
1286 arr->append(notes);
1287 notes += _node_notes_block_size;
1288 num_notes -= _node_notes_block_size;
1289 }
1290 assert(num_notes == 0, "exact multiple, please");
1291 }
1292
1293 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1294 if (source == NULL || dest == NULL) return false;
1295
1296 if (dest->is_Con())
1297 return false; // Do not push debug info onto constants.
1298
1299 #ifdef ASSERT
1300 // Leave a bread crumb trail pointing to the original node:
1301 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1302 dest->set_debug_orig(source);
1303 }
1304 #endif
1305
1306 if (node_note_array() == NULL)
1307 return false; // Not collecting any notes now.
1308
1309 // This is a copy onto a pre-existing node, which may already have notes.
1310 // If both nodes have notes, do not overwrite any pre-existing notes.
1311 Node_Notes* source_notes = node_notes_at(source->_idx);
1312 if (source_notes == NULL || source_notes->is_clear()) return false;
1313 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1314 if (dest_notes == NULL || dest_notes->is_clear()) {
1315 return set_node_notes_at(dest->_idx, source_notes);
1316 }
1317
1318 Node_Notes merged_notes = (*source_notes);
1319 // The order of operations here ensures that dest notes will win...
1320 merged_notes.update_from(dest_notes);
1321 return set_node_notes_at(dest->_idx, &merged_notes);
1322 }
1323
1324
1325 //--------------------------allow_range_check_smearing-------------------------
1326 // Gating condition for coalescing similar range checks.
1327 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1328 // single covering check that is at least as strong as any of them.
1329 // If the optimization succeeds, the simplified (strengthened) range check
1330 // will always succeed. If it fails, we will deopt, and then give up
1331 // on the optimization.
1332 bool Compile::allow_range_check_smearing() const {
1333 // If this method has already thrown a range-check,
1334 // assume it was because we already tried range smearing
1335 // and it failed.
1336 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1337 return !already_trapped;
1338 }
1339
1340
1341 //------------------------------flatten_alias_type-----------------------------
1342 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1343 int offset = tj->offset();
1344 TypePtr::PTR ptr = tj->ptr();
1345
1346 // Known instance (scalarizable allocation) alias only with itself.
1347 bool is_known_inst = tj->isa_oopptr() != NULL &&
1348 tj->is_oopptr()->is_known_instance();
1349
1350 // Process weird unsafe references.
1351 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1352 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1353 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1354 tj = TypeOopPtr::BOTTOM;
1355 ptr = tj->ptr();
1356 offset = tj->offset();
1357 }
1358
1359 // Array pointers need some flattening
1360 const TypeAryPtr *ta = tj->isa_aryptr();
1361 if (ta && ta->is_stable()) {
1362 // Erase stability property for alias analysis.
1363 tj = ta = ta->cast_to_stable(false);
1364 }
1365 if( ta && is_known_inst ) {
1366 if ( offset != Type::OffsetBot &&
1367 offset > arrayOopDesc::length_offset_in_bytes() ) {
1368 offset = Type::OffsetBot; // Flatten constant access into array body only
1369 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1370 }
1371 } else if( ta && _AliasLevel >= 2 ) {
1372 // For arrays indexed by constant indices, we flatten the alias
1373 // space to include all of the array body. Only the header, klass
1374 // and array length can be accessed un-aliased.
1375 if( offset != Type::OffsetBot ) {
1376 if( ta->const_oop() ) { // MethodData* or Method*
1377 offset = Type::OffsetBot; // Flatten constant access into array body
1378 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1379 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1380 // range is OK as-is.
1381 tj = ta = TypeAryPtr::RANGE;
1382 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1383 tj = TypeInstPtr::KLASS; // all klass loads look alike
1384 ta = TypeAryPtr::RANGE; // generic ignored junk
1385 ptr = TypePtr::BotPTR;
1386 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1387 tj = TypeInstPtr::MARK;
1388 ta = TypeAryPtr::RANGE; // generic ignored junk
1389 ptr = TypePtr::BotPTR;
1390 } else { // Random constant offset into array body
1391 offset = Type::OffsetBot; // Flatten constant access into array body
1392 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1393 }
1394 }
1395 // Arrays of fixed size alias with arrays of unknown size.
1396 if (ta->size() != TypeInt::POS) {
1397 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1398 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1399 }
1400 // Arrays of known objects become arrays of unknown objects.
1401 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1402 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1403 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1404 }
1405 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1406 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1407 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1408 }
1409 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1410 // cannot be distinguished by bytecode alone.
1411 if (ta->elem() == TypeInt::BOOL) {
1412 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1413 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1414 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1415 }
1416 // During the 2nd round of IterGVN, NotNull castings are removed.
1417 // Make sure the Bottom and NotNull variants alias the same.
1418 // Also, make sure exact and non-exact variants alias the same.
1419 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1420 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1421 }
1422 }
1423
1424 // Oop pointers need some flattening
1425 const TypeInstPtr *to = tj->isa_instptr();
1426 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1427 ciInstanceKlass *k = to->klass()->as_instance_klass();
1428 if( ptr == TypePtr::Constant ) {
1429 if (to->klass() != ciEnv::current()->Class_klass() ||
1430 offset < k->size_helper() * wordSize) {
1431 // No constant oop pointers (such as Strings); they alias with
1432 // unknown strings.
1433 assert(!is_known_inst, "not scalarizable allocation");
1434 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1435 }
1436 } else if( is_known_inst ) {
1437 tj = to; // Keep NotNull and klass_is_exact for instance type
1438 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1439 // During the 2nd round of IterGVN, NotNull castings are removed.
1440 // Make sure the Bottom and NotNull variants alias the same.
1441 // Also, make sure exact and non-exact variants alias the same.
1442 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1443 }
1444 if (to->speculative() != NULL) {
1445 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1446 }
1447 // Canonicalize the holder of this field
1448 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1449 // First handle header references such as a LoadKlassNode, even if the
1450 // object's klass is unloaded at compile time (4965979).
1451 if (!is_known_inst) { // Do it only for non-instance types
1452 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1453 }
1454 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1455 // Static fields are in the space above the normal instance
1456 // fields in the java.lang.Class instance.
1457 if (to->klass() != ciEnv::current()->Class_klass()) {
1458 to = NULL;
1459 tj = TypeOopPtr::BOTTOM;
1460 offset = tj->offset();
1461 }
1462 } else {
1463 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1464 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1465 if( is_known_inst ) {
1466 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1467 } else {
1468 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1469 }
1470 }
1471 }
1472 }
1473
1474 // Klass pointers to object array klasses need some flattening
1475 const TypeKlassPtr *tk = tj->isa_klassptr();
1476 if( tk ) {
1477 // If we are referencing a field within a Klass, we need
1478 // to assume the worst case of an Object. Both exact and
1479 // inexact types must flatten to the same alias class so
1480 // use NotNull as the PTR.
1481 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1482
1483 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1484 TypeKlassPtr::OBJECT->klass(),
1485 offset);
1486 }
1487
1488 ciKlass* klass = tk->klass();
1489 if( klass->is_obj_array_klass() ) {
1490 ciKlass* k = TypeAryPtr::OOPS->klass();
1491 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1492 k = TypeInstPtr::BOTTOM->klass();
1493 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1494 }
1495
1496 // Check for precise loads from the primary supertype array and force them
1497 // to the supertype cache alias index. Check for generic array loads from
1498 // the primary supertype array and also force them to the supertype cache
1499 // alias index. Since the same load can reach both, we need to merge
1500 // these 2 disparate memories into the same alias class. Since the
1501 // primary supertype array is read-only, there's no chance of confusion
1502 // where we bypass an array load and an array store.
1503 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1504 if (offset == Type::OffsetBot ||
1505 (offset >= primary_supers_offset &&
1506 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1507 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1508 offset = in_bytes(Klass::secondary_super_cache_offset());
1509 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1510 }
1511 }
1512
1513 // Flatten all Raw pointers together.
1514 if (tj->base() == Type::RawPtr)
1515 tj = TypeRawPtr::BOTTOM;
1516
1517 if (tj->base() == Type::AnyPtr)
1518 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1519
1520 // Flatten all to bottom for now
1521 switch( _AliasLevel ) {
1522 case 0:
1523 tj = TypePtr::BOTTOM;
1524 break;
1525 case 1: // Flatten to: oop, static, field or array
1526 switch (tj->base()) {
1527 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1528 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1529 case Type::AryPtr: // do not distinguish arrays at all
1530 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1531 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1532 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1533 default: ShouldNotReachHere();
1534 }
1535 break;
1536 case 2: // No collapsing at level 2; keep all splits
1537 case 3: // No collapsing at level 3; keep all splits
1538 break;
1539 default:
1540 Unimplemented();
1541 }
1542
1543 offset = tj->offset();
1544 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1545
1546 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1547 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1548 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1549 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1550 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1551 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1552 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1553 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1554 assert( tj->ptr() != TypePtr::TopPTR &&
1555 tj->ptr() != TypePtr::AnyNull &&
1556 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1557 // assert( tj->ptr() != TypePtr::Constant ||
1558 // tj->base() == Type::RawPtr ||
1559 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1560
1561 return tj;
1562 }
1563
1564 void Compile::AliasType::Init(int i, const TypePtr* at) {
1565 _index = i;
1566 _adr_type = at;
1567 _field = NULL;
1568 _element = NULL;
1569 _is_rewritable = true; // default
1570 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1571 if (atoop != NULL && atoop->is_known_instance()) {
1572 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1573 _general_index = Compile::current()->get_alias_index(gt);
1574 } else {
1575 _general_index = 0;
1576 }
1577 }
1578
1579 //---------------------------------print_on------------------------------------
1580 #ifndef PRODUCT
1581 void Compile::AliasType::print_on(outputStream* st) {
1582 if (index() < 10)
1583 st->print("@ <%d> ", index());
1584 else st->print("@ <%d>", index());
1585 st->print(is_rewritable() ? " " : " RO");
1586 int offset = adr_type()->offset();
1587 if (offset == Type::OffsetBot)
1588 st->print(" +any");
1589 else st->print(" +%-3d", offset);
1590 st->print(" in ");
1591 adr_type()->dump_on(st);
1592 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1593 if (field() != NULL && tjp) {
1594 if (tjp->klass() != field()->holder() ||
1595 tjp->offset() != field()->offset_in_bytes()) {
1596 st->print(" != ");
1597 field()->print();
1598 st->print(" ***");
1599 }
1600 }
1601 }
1602
1603 void print_alias_types() {
1604 Compile* C = Compile::current();
1605 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1606 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1607 C->alias_type(idx)->print_on(tty);
1608 tty->cr();
1609 }
1610 }
1611 #endif
1612
1613
1614 //----------------------------probe_alias_cache--------------------------------
1615 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1616 intptr_t key = (intptr_t) adr_type;
1617 key ^= key >> logAliasCacheSize;
1618 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1619 }
1620
1621
1622 //-----------------------------grow_alias_types--------------------------------
1623 void Compile::grow_alias_types() {
1624 const int old_ats = _max_alias_types; // how many before?
1625 const int new_ats = old_ats; // how many more?
1626 const int grow_ats = old_ats+new_ats; // how many now?
1627 _max_alias_types = grow_ats;
1628 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1629 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1630 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1631 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1632 }
1633
1634
1635 //--------------------------------find_alias_type------------------------------
1636 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1637 if (_AliasLevel == 0)
1638 return alias_type(AliasIdxBot);
1639
1640 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1641 if (ace->_adr_type == adr_type) {
1642 return alias_type(ace->_index);
1643 }
1644
1645 // Handle special cases.
1646 if (adr_type == NULL) return alias_type(AliasIdxTop);
1647 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1648
1649 // Do it the slow way.
1650 const TypePtr* flat = flatten_alias_type(adr_type);
1651
1652 #ifdef ASSERT
1653 assert(flat == flatten_alias_type(flat), "idempotent");
1654 assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
1655 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1656 const TypeOopPtr* foop = flat->is_oopptr();
1657 // Scalarizable allocations have exact klass always.
1658 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1659 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1660 assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1661 }
1662 assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1663 #endif
1664
1665 int idx = AliasIdxTop;
1666 for (int i = 0; i < num_alias_types(); i++) {
1667 if (alias_type(i)->adr_type() == flat) {
1668 idx = i;
1669 break;
1670 }
1671 }
1672
1673 if (idx == AliasIdxTop) {
1674 if (no_create) return NULL;
1675 // Grow the array if necessary.
1676 if (_num_alias_types == _max_alias_types) grow_alias_types();
1677 // Add a new alias type.
1678 idx = _num_alias_types++;
1679 _alias_types[idx]->Init(idx, flat);
1680 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1681 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1682 if (flat->isa_instptr()) {
1683 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1684 && flat->is_instptr()->klass() == env()->Class_klass())
1685 alias_type(idx)->set_rewritable(false);
1686 }
1687 if (flat->isa_aryptr()) {
1688 #ifdef ASSERT
1689 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1690 // (T_BYTE has the weakest alignment and size restrictions...)
1691 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1692 #endif
1693 if (flat->offset() == TypePtr::OffsetBot) {
1694 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1695 }
1696 }
1697 if (flat->isa_klassptr()) {
1698 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1699 alias_type(idx)->set_rewritable(false);
1700 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1701 alias_type(idx)->set_rewritable(false);
1702 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1703 alias_type(idx)->set_rewritable(false);
1704 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1705 alias_type(idx)->set_rewritable(false);
1706 }
1707 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1708 // but the base pointer type is not distinctive enough to identify
1709 // references into JavaThread.)
1710
1711 // Check for final fields.
1712 const TypeInstPtr* tinst = flat->isa_instptr();
1713 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1714 ciField* field;
1715 if (tinst->const_oop() != NULL &&
1716 tinst->klass() == ciEnv::current()->Class_klass() &&
1717 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1718 // static field
1719 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1720 field = k->get_field_by_offset(tinst->offset(), true);
1721 } else {
1722 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1723 field = k->get_field_by_offset(tinst->offset(), false);
1724 }
1725 assert(field == NULL ||
1726 original_field == NULL ||
1727 (field->holder() == original_field->holder() &&
1728 field->offset() == original_field->offset() &&
1729 field->is_static() == original_field->is_static()), "wrong field?");
1730 // Set field() and is_rewritable() attributes.
1731 if (field != NULL) alias_type(idx)->set_field(field);
1732 }
1733 }
1734
1735 // Fill the cache for next time.
1736 ace->_adr_type = adr_type;
1737 ace->_index = idx;
1738 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1739
1740 // Might as well try to fill the cache for the flattened version, too.
1741 AliasCacheEntry* face = probe_alias_cache(flat);
1742 if (face->_adr_type == NULL) {
1743 face->_adr_type = flat;
1744 face->_index = idx;
1745 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1746 }
1747
1748 return alias_type(idx);
1749 }
1750
1751
1752 Compile::AliasType* Compile::alias_type(ciField* field) {
1753 const TypeOopPtr* t;
1754 if (field->is_static())
1755 t = TypeInstPtr::make(field->holder()->java_mirror());
1756 else
1757 t = TypeOopPtr::make_from_klass_raw(field->holder());
1758 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1759 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1760 return atp;
1761 }
1762
1763
1764 //------------------------------have_alias_type--------------------------------
1765 bool Compile::have_alias_type(const TypePtr* adr_type) {
1766 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1767 if (ace->_adr_type == adr_type) {
1768 return true;
1769 }
1770
1771 // Handle special cases.
1772 if (adr_type == NULL) return true;
1773 if (adr_type == TypePtr::BOTTOM) return true;
1774
1775 return find_alias_type(adr_type, true, NULL) != NULL;
1776 }
1777
1778 //-----------------------------must_alias--------------------------------------
1779 // True if all values of the given address type are in the given alias category.
1780 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1781 if (alias_idx == AliasIdxBot) return true; // the universal category
1782 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1783 if (alias_idx == AliasIdxTop) return false; // the empty category
1784 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1785
1786 // the only remaining possible overlap is identity
1787 int adr_idx = get_alias_index(adr_type);
1788 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1789 assert(adr_idx == alias_idx ||
1790 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1791 && adr_type != TypeOopPtr::BOTTOM),
1792 "should not be testing for overlap with an unsafe pointer");
1793 return adr_idx == alias_idx;
1794 }
1795
1796 //------------------------------can_alias--------------------------------------
1797 // True if any values of the given address type are in the given alias category.
1798 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1799 if (alias_idx == AliasIdxTop) return false; // the empty category
1800 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1801 if (alias_idx == AliasIdxBot) return true; // the universal category
1802 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1803
1804 // the only remaining possible overlap is identity
1805 int adr_idx = get_alias_index(adr_type);
1806 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1807 return adr_idx == alias_idx;
1808 }
1809
1810
1811
1812 //---------------------------pop_warm_call-------------------------------------
1813 WarmCallInfo* Compile::pop_warm_call() {
1814 WarmCallInfo* wci = _warm_calls;
1815 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1816 return wci;
1817 }
1818
1819 //----------------------------Inline_Warm--------------------------------------
1820 int Compile::Inline_Warm() {
1821 // If there is room, try to inline some more warm call sites.
1822 // %%% Do a graph index compaction pass when we think we're out of space?
1823 if (!InlineWarmCalls) return 0;
1824
1825 int calls_made_hot = 0;
1826 int room_to_grow = NodeCountInliningCutoff - unique();
1827 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1828 int amount_grown = 0;
1829 WarmCallInfo* call;
1830 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1831 int est_size = (int)call->size();
1832 if (est_size > (room_to_grow - amount_grown)) {
1833 // This one won't fit anyway. Get rid of it.
1834 call->make_cold();
1835 continue;
1836 }
1837 call->make_hot();
1838 calls_made_hot++;
1839 amount_grown += est_size;
1840 amount_to_grow -= est_size;
1841 }
1842
1843 if (calls_made_hot > 0) set_major_progress();
1844 return calls_made_hot;
1845 }
1846
1847
1848 //----------------------------Finish_Warm--------------------------------------
1849 void Compile::Finish_Warm() {
1850 if (!InlineWarmCalls) return;
1851 if (failing()) return;
1852 if (warm_calls() == NULL) return;
1853
1854 // Clean up loose ends, if we are out of space for inlining.
1855 WarmCallInfo* call;
1856 while ((call = pop_warm_call()) != NULL) {
1857 call->make_cold();
1858 }
1859 }
1860
1861 //---------------------cleanup_loop_predicates-----------------------
1862 // Remove the opaque nodes that protect the predicates so that all unused
1863 // checks and uncommon_traps will be eliminated from the ideal graph
1864 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1865 if (predicate_count()==0) return;
1866 for (int i = predicate_count(); i > 0; i--) {
1867 Node * n = predicate_opaque1_node(i-1);
1868 assert(n->Opcode() == Op_Opaque1, "must be");
1869 igvn.replace_node(n, n->in(1));
1870 }
1871 assert(predicate_count()==0, "should be clean!");
1872 }
1873
1874 // StringOpts and late inlining of string methods
1875 void Compile::inline_string_calls(bool parse_time) {
1876 {
1877 // remove useless nodes to make the usage analysis simpler
1878 ResourceMark rm;
1879 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1880 }
1881
1882 {
1883 ResourceMark rm;
1884 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1885 PhaseStringOpts pso(initial_gvn(), for_igvn());
1886 print_method(PHASE_AFTER_STRINGOPTS, 3);
1887 }
1888
1889 // now inline anything that we skipped the first time around
1890 if (!parse_time) {
1891 _late_inlines_pos = _late_inlines.length();
1892 }
1893
1894 while (_string_late_inlines.length() > 0) {
1895 CallGenerator* cg = _string_late_inlines.pop();
1896 cg->do_late_inline();
1897 if (failing()) return;
1898 }
1899 _string_late_inlines.trunc_to(0);
1900 }
1901
1902 // Late inlining of boxing methods
1903 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1904 if (_boxing_late_inlines.length() > 0) {
1905 assert(has_boxed_value(), "inconsistent");
1906
1907 PhaseGVN* gvn = initial_gvn();
1908 set_inlining_incrementally(true);
1909
1910 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1911 for_igvn()->clear();
1912 gvn->replace_with(&igvn);
1913
1914 while (_boxing_late_inlines.length() > 0) {
1915 CallGenerator* cg = _boxing_late_inlines.pop();
1916 cg->do_late_inline();
1917 if (failing()) return;
1918 }
1919 _boxing_late_inlines.trunc_to(0);
1920
1921 {
1922 ResourceMark rm;
1923 PhaseRemoveUseless pru(gvn, for_igvn());
1924 }
1925
1926 igvn = PhaseIterGVN(gvn);
1927 igvn.optimize();
1928
1929 set_inlining_progress(false);
1930 set_inlining_incrementally(false);
1931 }
1932 }
1933
1934 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1935 assert(IncrementalInline, "incremental inlining should be on");
1936 PhaseGVN* gvn = initial_gvn();
1937
1938 set_inlining_progress(false);
1939 for_igvn()->clear();
1940 gvn->replace_with(&igvn);
1941
1942 int i = 0;
1943
1944 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1945 CallGenerator* cg = _late_inlines.at(i);
1946 _late_inlines_pos = i+1;
1947 cg->do_late_inline();
1948 if (failing()) return;
1949 }
1950 int j = 0;
1951 for (; i < _late_inlines.length(); i++, j++) {
1952 _late_inlines.at_put(j, _late_inlines.at(i));
1953 }
1954 _late_inlines.trunc_to(j);
1955
1956 {
1957 ResourceMark rm;
1958 PhaseRemoveUseless pru(gvn, for_igvn());
1959 }
1960
1961 igvn = PhaseIterGVN(gvn);
1962 }
1963
1964 // Perform incremental inlining until bound on number of live nodes is reached
1965 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1966 PhaseGVN* gvn = initial_gvn();
1967
1968 set_inlining_incrementally(true);
1969 set_inlining_progress(true);
1970 uint low_live_nodes = 0;
1971
1972 while(inlining_progress() && _late_inlines.length() > 0) {
1973
1974 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1975 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1976 // PhaseIdealLoop is expensive so we only try it once we are
1977 // out of loop and we only try it again if the previous helped
1978 // got the number of nodes down significantly
1979 PhaseIdealLoop ideal_loop( igvn, false, true );
1980 if (failing()) return;
1981 low_live_nodes = live_nodes();
1982 _major_progress = true;
1983 }
1984
1985 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1986 break;
1987 }
1988 }
1989
1990 inline_incrementally_one(igvn);
1991
1992 if (failing()) return;
1993
1994 igvn.optimize();
1995
1996 if (failing()) return;
1997 }
1998
1999 assert( igvn._worklist.size() == 0, "should be done with igvn" );
2000
2001 if (_string_late_inlines.length() > 0) {
2002 assert(has_stringbuilder(), "inconsistent");
2003 for_igvn()->clear();
2004 initial_gvn()->replace_with(&igvn);
2005
2006 inline_string_calls(false);
2007
2008 if (failing()) return;
2009
2010 {
2011 ResourceMark rm;
2012 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2013 }
2014
2015 igvn = PhaseIterGVN(gvn);
2016
2017 igvn.optimize();
2018 }
2019
2020 set_inlining_incrementally(false);
2021 }
2022
2023
2024 //------------------------------Optimize---------------------------------------
2025 // Given a graph, optimize it.
2026 void Compile::Optimize() {
2027 TracePhase t1("optimizer", &_t_optimizer, true);
2028
2029 #ifndef PRODUCT
2030 if (env()->break_at_compile()) {
2031 BREAKPOINT;
2032 }
2033
2034 #endif
2035
2036 ResourceMark rm;
2037 int loop_opts_cnt;
2038
2039 print_inlining_reinit();
2040
2041 NOT_PRODUCT( verify_graph_edges(); )
2042
2043 print_method(PHASE_AFTER_PARSING);
2044
2045 {
2046 // Iterative Global Value Numbering, including ideal transforms
2047 // Initialize IterGVN with types and values from parse-time GVN
2048 PhaseIterGVN igvn(initial_gvn());
2049 {
2050 NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
2051 igvn.optimize();
2052 }
2053
2054 print_method(PHASE_ITER_GVN1, 2);
2055
2056 if (failing()) return;
2057
2058 {
2059 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2060 inline_incrementally(igvn);
2061 }
2062
2063 print_method(PHASE_INCREMENTAL_INLINE, 2);
2064
2065 if (failing()) return;
2066
2067 if (eliminate_boxing()) {
2068 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2069 // Inline valueOf() methods now.
2070 inline_boxing_calls(igvn);
2071
2072 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2073
2074 if (failing()) return;
2075 }
2076
2077 // Remove the speculative part of types and clean up the graph from
2078 // the extra CastPP nodes whose only purpose is to carry them. Do
2079 // that early so that optimizations are not disrupted by the extra
2080 // CastPP nodes.
2081 remove_speculative_types(igvn);
2082
2083 // No more new expensive nodes will be added to the list from here
2084 // so keep only the actual candidates for optimizations.
2085 cleanup_expensive_nodes(igvn);
2086
2087 // Perform escape analysis
2088 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2089 if (has_loops()) {
2090 // Cleanup graph (remove dead nodes).
2091 TracePhase t2("idealLoop", &_t_idealLoop, true);
2092 PhaseIdealLoop ideal_loop( igvn, false, true );
2093 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2094 if (failing()) return;
2095 }
2096 ConnectionGraph::do_analysis(this, &igvn);
2097
2098 if (failing()) return;
2099
2100 // Optimize out fields loads from scalar replaceable allocations.
2101 igvn.optimize();
2102 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2103
2104 if (failing()) return;
2105
2106 if (congraph() != NULL && macro_count() > 0) {
2107 NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2108 PhaseMacroExpand mexp(igvn);
2109 mexp.eliminate_macro_nodes();
2110 igvn.set_delay_transform(false);
2111
2112 igvn.optimize();
2113 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2114
2115 if (failing()) return;
2116 }
2117 }
2118
2119 // Loop transforms on the ideal graph. Range Check Elimination,
2120 // peeling, unrolling, etc.
2121
2122 // Set loop opts counter
2123 loop_opts_cnt = num_loop_opts();
2124 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2125 {
2126 TracePhase t2("idealLoop", &_t_idealLoop, true);
2127 PhaseIdealLoop ideal_loop( igvn, true );
2128 loop_opts_cnt--;
2129 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2130 if (failing()) return;
2131 }
2132 // Loop opts pass if partial peeling occurred in previous pass
2133 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2134 TracePhase t3("idealLoop", &_t_idealLoop, true);
2135 PhaseIdealLoop ideal_loop( igvn, false );
2136 loop_opts_cnt--;
2137 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2138 if (failing()) return;
2139 }
2140 // Loop opts pass for loop-unrolling before CCP
2141 if(major_progress() && (loop_opts_cnt > 0)) {
2142 TracePhase t4("idealLoop", &_t_idealLoop, true);
2143 PhaseIdealLoop ideal_loop( igvn, false );
2144 loop_opts_cnt--;
2145 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2146 }
2147 if (!failing()) {
2148 // Verify that last round of loop opts produced a valid graph
2149 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2150 PhaseIdealLoop::verify(igvn);
2151 }
2152 }
2153 if (failing()) return;
2154
2155 // Conditional Constant Propagation;
2156 PhaseCCP ccp( &igvn );
2157 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2158 {
2159 TracePhase t2("ccp", &_t_ccp, true);
2160 ccp.do_transform();
2161 }
2162 print_method(PHASE_CPP1, 2);
2163
2164 assert( true, "Break here to ccp.dump_old2new_map()");
2165
2166 // Iterative Global Value Numbering, including ideal transforms
2167 {
2168 NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2169 igvn = ccp;
2170 igvn.optimize();
2171 }
2172
2173 print_method(PHASE_ITER_GVN2, 2);
2174
2175 if (failing()) return;
2176
2177 // Loop transforms on the ideal graph. Range Check Elimination,
2178 // peeling, unrolling, etc.
2179 if(loop_opts_cnt > 0) {
2180 debug_only( int cnt = 0; );
2181 while(major_progress() && (loop_opts_cnt > 0)) {
2182 TracePhase t2("idealLoop", &_t_idealLoop, true);
2183 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2184 PhaseIdealLoop ideal_loop( igvn, true);
2185 loop_opts_cnt--;
2186 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2187 if (failing()) return;
2188 }
2189 }
2190
2191 {
2192 // Verify that all previous optimizations produced a valid graph
2193 // at least to this point, even if no loop optimizations were done.
2194 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2195 PhaseIdealLoop::verify(igvn);
2196 }
2197
2198 {
2199 NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2200 PhaseMacroExpand mex(igvn);
2201 if (mex.expand_macro_nodes()) {
2202 assert(failing(), "must bail out w/ explicit message");
2203 return;
2204 }
2205 }
2206
2207 } // (End scope of igvn; run destructor if necessary for asserts.)
2208
2209 dump_inlining();
2210 // A method with only infinite loops has no edges entering loops from root
2211 {
2212 NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2213 if (final_graph_reshaping()) {
2214 assert(failing(), "must bail out w/ explicit message");
2215 return;
2216 }
2217 }
2218
2219 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2220 }
2221
2222
2223 //------------------------------Code_Gen---------------------------------------
2224 // Given a graph, generate code for it
2225 void Compile::Code_Gen() {
2226 if (failing()) {
2227 return;
2228 }
2229
2230 // Perform instruction selection. You might think we could reclaim Matcher
2231 // memory PDQ, but actually the Matcher is used in generating spill code.
2232 // Internals of the Matcher (including some VectorSets) must remain live
2233 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2234 // set a bit in reclaimed memory.
2235
2236 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2237 // nodes. Mapping is only valid at the root of each matched subtree.
2238 NOT_PRODUCT( verify_graph_edges(); )
2239
2240 Matcher matcher;
2241 _matcher = &matcher;
2242 {
2243 TracePhase t2("matcher", &_t_matcher, true);
2244 matcher.match();
2245 }
2246 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2247 // nodes. Mapping is only valid at the root of each matched subtree.
2248 NOT_PRODUCT( verify_graph_edges(); )
2249
2250 // If you have too many nodes, or if matching has failed, bail out
2251 check_node_count(0, "out of nodes matching instructions");
2252 if (failing()) {
2253 return;
2254 }
2255
2256 // Build a proper-looking CFG
2257 PhaseCFG cfg(node_arena(), root(), matcher);
2258 _cfg = &cfg;
2259 {
2260 NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2261 bool success = cfg.do_global_code_motion();
2262 if (!success) {
2263 return;
2264 }
2265
2266 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2267 NOT_PRODUCT( verify_graph_edges(); )
2268 debug_only( cfg.verify(); )
2269 }
2270
2271 PhaseChaitin regalloc(unique(), cfg, matcher);
2272 _regalloc = ®alloc;
2273 {
2274 TracePhase t2("regalloc", &_t_registerAllocation, true);
2275 // Perform register allocation. After Chaitin, use-def chains are
2276 // no longer accurate (at spill code) and so must be ignored.
2277 // Node->LRG->reg mappings are still accurate.
2278 _regalloc->Register_Allocate();
2279
2280 // Bail out if the allocator builds too many nodes
2281 if (failing()) {
2282 return;
2283 }
2284 }
2285
2286 // Prior to register allocation we kept empty basic blocks in case the
2287 // the allocator needed a place to spill. After register allocation we
2288 // are not adding any new instructions. If any basic block is empty, we
2289 // can now safely remove it.
2290 {
2291 NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2292 cfg.remove_empty_blocks();
2293 if (do_freq_based_layout()) {
2294 PhaseBlockLayout layout(cfg);
2295 } else {
2296 cfg.set_loop_alignment();
2297 }
2298 cfg.fixup_flow();
2299 }
2300
2301 // Apply peephole optimizations
2302 if( OptoPeephole ) {
2303 NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2304 PhasePeephole peep( _regalloc, cfg);
2305 peep.do_transform();
2306 }
2307
2308 // Do late expand if CPU requires this.
2309 if (Matcher::require_postalloc_expand) {
2310 NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
2311 cfg.postalloc_expand(_regalloc);
2312 }
2313
2314 // Convert Nodes to instruction bits in a buffer
2315 {
2316 // %%%% workspace merge brought two timers together for one job
2317 TracePhase t2a("output", &_t_output, true);
2318 NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2319 Output();
2320 }
2321
2322 print_method(PHASE_FINAL_CODE);
2323
2324 // He's dead, Jim.
2325 _cfg = (PhaseCFG*)0xdeadbeef;
2326 _regalloc = (PhaseChaitin*)0xdeadbeef;
2327 }
2328
2329
2330 //------------------------------dump_asm---------------------------------------
2331 // Dump formatted assembly
2332 #ifndef PRODUCT
2333 void Compile::dump_asm(int *pcs, uint pc_limit) {
2334 bool cut_short = false;
2335 tty->print_cr("#");
2336 tty->print("# "); _tf->dump(); tty->cr();
2337 tty->print_cr("#");
2338
2339 // For all blocks
2340 int pc = 0x0; // Program counter
2341 char starts_bundle = ' ';
2342 _regalloc->dump_frame();
2343
2344 Node *n = NULL;
2345 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2346 if (VMThread::should_terminate()) {
2347 cut_short = true;
2348 break;
2349 }
2350 Block* block = _cfg->get_block(i);
2351 if (block->is_connector() && !Verbose) {
2352 continue;
2353 }
2354 n = block->head();
2355 if (pcs && n->_idx < pc_limit) {
2356 tty->print("%3.3x ", pcs[n->_idx]);
2357 } else {
2358 tty->print(" ");
2359 }
2360 block->dump_head(_cfg);
2361 if (block->is_connector()) {
2362 tty->print_cr(" # Empty connector block");
2363 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2364 tty->print_cr(" # Block is sole successor of call");
2365 }
2366
2367 // For all instructions
2368 Node *delay = NULL;
2369 for (uint j = 0; j < block->number_of_nodes(); j++) {
2370 if (VMThread::should_terminate()) {
2371 cut_short = true;
2372 break;
2373 }
2374 n = block->get_node(j);
2375 if (valid_bundle_info(n)) {
2376 Bundle* bundle = node_bundling(n);
2377 if (bundle->used_in_unconditional_delay()) {
2378 delay = n;
2379 continue;
2380 }
2381 if (bundle->starts_bundle()) {
2382 starts_bundle = '+';
2383 }
2384 }
2385
2386 if (WizardMode) {
2387 n->dump();
2388 }
2389
2390 if( !n->is_Region() && // Dont print in the Assembly
2391 !n->is_Phi() && // a few noisely useless nodes
2392 !n->is_Proj() &&
2393 !n->is_MachTemp() &&
2394 !n->is_SafePointScalarObject() &&
2395 !n->is_Catch() && // Would be nice to print exception table targets
2396 !n->is_MergeMem() && // Not very interesting
2397 !n->is_top() && // Debug info table constants
2398 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2399 ) {
2400 if (pcs && n->_idx < pc_limit)
2401 tty->print("%3.3x", pcs[n->_idx]);
2402 else
2403 tty->print(" ");
2404 tty->print(" %c ", starts_bundle);
2405 starts_bundle = ' ';
2406 tty->print("\t");
2407 n->format(_regalloc, tty);
2408 tty->cr();
2409 }
2410
2411 // If we have an instruction with a delay slot, and have seen a delay,
2412 // then back up and print it
2413 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2414 assert(delay != NULL, "no unconditional delay instruction");
2415 if (WizardMode) delay->dump();
2416
2417 if (node_bundling(delay)->starts_bundle())
2418 starts_bundle = '+';
2419 if (pcs && n->_idx < pc_limit)
2420 tty->print("%3.3x", pcs[n->_idx]);
2421 else
2422 tty->print(" ");
2423 tty->print(" %c ", starts_bundle);
2424 starts_bundle = ' ';
2425 tty->print("\t");
2426 delay->format(_regalloc, tty);
2427 tty->print_cr("");
2428 delay = NULL;
2429 }
2430
2431 // Dump the exception table as well
2432 if( n->is_Catch() && (Verbose || WizardMode) ) {
2433 // Print the exception table for this offset
2434 _handler_table.print_subtable_for(pc);
2435 }
2436 }
2437
2438 if (pcs && n->_idx < pc_limit)
2439 tty->print_cr("%3.3x", pcs[n->_idx]);
2440 else
2441 tty->print_cr("");
2442
2443 assert(cut_short || delay == NULL, "no unconditional delay branch");
2444
2445 } // End of per-block dump
2446 tty->print_cr("");
2447
2448 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2449 }
2450 #endif
2451
2452 //------------------------------Final_Reshape_Counts---------------------------
2453 // This class defines counters to help identify when a method
2454 // may/must be executed using hardware with only 24-bit precision.
2455 struct Final_Reshape_Counts : public StackObj {
2456 int _call_count; // count non-inlined 'common' calls
2457 int _float_count; // count float ops requiring 24-bit precision
2458 int _double_count; // count double ops requiring more precision
2459 int _java_call_count; // count non-inlined 'java' calls
2460 int _inner_loop_count; // count loops which need alignment
2461 VectorSet _visited; // Visitation flags
2462 Node_List _tests; // Set of IfNodes & PCTableNodes
2463
2464 Final_Reshape_Counts() :
2465 _call_count(0), _float_count(0), _double_count(0),
2466 _java_call_count(0), _inner_loop_count(0),
2467 _visited( Thread::current()->resource_area() ) { }
2468
2469 void inc_call_count () { _call_count ++; }
2470 void inc_float_count () { _float_count ++; }
2471 void inc_double_count() { _double_count++; }
2472 void inc_java_call_count() { _java_call_count++; }
2473 void inc_inner_loop_count() { _inner_loop_count++; }
2474
2475 int get_call_count () const { return _call_count ; }
2476 int get_float_count () const { return _float_count ; }
2477 int get_double_count() const { return _double_count; }
2478 int get_java_call_count() const { return _java_call_count; }
2479 int get_inner_loop_count() const { return _inner_loop_count; }
2480 };
2481
2482 #ifdef ASSERT
2483 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2484 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2485 // Make sure the offset goes inside the instance layout.
2486 return k->contains_field_offset(tp->offset());
2487 // Note that OffsetBot and OffsetTop are very negative.
2488 }
2489 #endif
2490
2491 // Eliminate trivially redundant StoreCMs and accumulate their
2492 // precedence edges.
2493 void Compile::eliminate_redundant_card_marks(Node* n) {
2494 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2495 if (n->in(MemNode::Address)->outcnt() > 1) {
2496 // There are multiple users of the same address so it might be
2497 // possible to eliminate some of the StoreCMs
2498 Node* mem = n->in(MemNode::Memory);
2499 Node* adr = n->in(MemNode::Address);
2500 Node* val = n->in(MemNode::ValueIn);
2501 Node* prev = n;
2502 bool done = false;
2503 // Walk the chain of StoreCMs eliminating ones that match. As
2504 // long as it's a chain of single users then the optimization is
2505 // safe. Eliminating partially redundant StoreCMs would require
2506 // cloning copies down the other paths.
2507 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2508 if (adr == mem->in(MemNode::Address) &&
2509 val == mem->in(MemNode::ValueIn)) {
2510 // redundant StoreCM
2511 if (mem->req() > MemNode::OopStore) {
2512 // Hasn't been processed by this code yet.
2513 n->add_prec(mem->in(MemNode::OopStore));
2514 } else {
2515 // Already converted to precedence edge
2516 for (uint i = mem->req(); i < mem->len(); i++) {
2517 // Accumulate any precedence edges
2518 if (mem->in(i) != NULL) {
2519 n->add_prec(mem->in(i));
2520 }
2521 }
2522 // Everything above this point has been processed.
2523 done = true;
2524 }
2525 // Eliminate the previous StoreCM
2526 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2527 assert(mem->outcnt() == 0, "should be dead");
2528 mem->disconnect_inputs(NULL, this);
2529 } else {
2530 prev = mem;
2531 }
2532 mem = prev->in(MemNode::Memory);
2533 }
2534 }
2535 }
2536
2537 //------------------------------final_graph_reshaping_impl----------------------
2538 // Implement items 1-5 from final_graph_reshaping below.
2539 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2540
2541 if ( n->outcnt() == 0 ) return; // dead node
2542 uint nop = n->Opcode();
2543
2544 // Check for 2-input instruction with "last use" on right input.
2545 // Swap to left input. Implements item (2).
2546 if( n->req() == 3 && // two-input instruction
2547 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2548 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2549 n->in(2)->outcnt() == 1 &&// right use IS a last use
2550 !n->in(2)->is_Con() ) { // right use is not a constant
2551 // Check for commutative opcode
2552 switch( nop ) {
2553 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2554 case Op_MaxI: case Op_MinI:
2555 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2556 case Op_AndL: case Op_XorL: case Op_OrL:
2557 case Op_AndI: case Op_XorI: case Op_OrI: {
2558 // Move "last use" input to left by swapping inputs
2559 n->swap_edges(1, 2);
2560 break;
2561 }
2562 default:
2563 break;
2564 }
2565 }
2566
2567 #ifdef ASSERT
2568 if( n->is_Mem() ) {
2569 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2570 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2571 // oop will be recorded in oop map if load crosses safepoint
2572 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2573 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2574 "raw memory operations should have control edge");
2575 }
2576 #endif
2577 // Count FPU ops and common calls, implements item (3)
2578 switch( nop ) {
2579 // Count all float operations that may use FPU
2580 case Op_AddF:
2581 case Op_SubF:
2582 case Op_MulF:
2583 case Op_DivF:
2584 case Op_NegF:
2585 case Op_ModF:
2586 case Op_ConvI2F:
2587 case Op_ConF:
2588 case Op_CmpF:
2589 case Op_CmpF3:
2590 // case Op_ConvL2F: // longs are split into 32-bit halves
2591 frc.inc_float_count();
2592 break;
2593
2594 case Op_ConvF2D:
2595 case Op_ConvD2F:
2596 frc.inc_float_count();
2597 frc.inc_double_count();
2598 break;
2599
2600 // Count all double operations that may use FPU
2601 case Op_AddD:
2602 case Op_SubD:
2603 case Op_MulD:
2604 case Op_DivD:
2605 case Op_NegD:
2606 case Op_ModD:
2607 case Op_ConvI2D:
2608 case Op_ConvD2I:
2609 // case Op_ConvL2D: // handled by leaf call
2610 // case Op_ConvD2L: // handled by leaf call
2611 case Op_ConD:
2612 case Op_CmpD:
2613 case Op_CmpD3:
2614 frc.inc_double_count();
2615 break;
2616 case Op_Opaque1: // Remove Opaque Nodes before matching
2617 case Op_Opaque2: // Remove Opaque Nodes before matching
2618 case Op_Opaque3:
2619 n->subsume_by(n->in(1), this);
2620 break;
2621 case Op_CallStaticJava:
2622 case Op_CallJava:
2623 case Op_CallDynamicJava:
2624 frc.inc_java_call_count(); // Count java call site;
2625 case Op_CallRuntime:
2626 case Op_CallLeaf:
2627 case Op_CallLeafNoFP: {
2628 assert( n->is_Call(), "" );
2629 CallNode *call = n->as_Call();
2630 // Count call sites where the FP mode bit would have to be flipped.
2631 // Do not count uncommon runtime calls:
2632 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2633 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2634 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2635 frc.inc_call_count(); // Count the call site
2636 } else { // See if uncommon argument is shared
2637 Node *n = call->in(TypeFunc::Parms);
2638 int nop = n->Opcode();
2639 // Clone shared simple arguments to uncommon calls, item (1).
2640 if( n->outcnt() > 1 &&
2641 !n->is_Proj() &&
2642 nop != Op_CreateEx &&
2643 nop != Op_CheckCastPP &&
2644 nop != Op_DecodeN &&
2645 nop != Op_DecodeNKlass &&
2646 !n->is_Mem() ) {
2647 Node *x = n->clone();
2648 call->set_req( TypeFunc::Parms, x );
2649 }
2650 }
2651 break;
2652 }
2653
2654 case Op_StoreD:
2655 case Op_LoadD:
2656 case Op_LoadD_unaligned:
2657 frc.inc_double_count();
2658 goto handle_mem;
2659 case Op_StoreF:
2660 case Op_LoadF:
2661 frc.inc_float_count();
2662 goto handle_mem;
2663
2664 case Op_StoreCM:
2665 {
2666 // Convert OopStore dependence into precedence edge
2667 Node* prec = n->in(MemNode::OopStore);
2668 n->del_req(MemNode::OopStore);
2669 n->add_prec(prec);
2670 eliminate_redundant_card_marks(n);
2671 }
2672
2673 // fall through
2674
2675 case Op_StoreB:
2676 case Op_StoreC:
2677 case Op_StorePConditional:
2678 case Op_StoreI:
2679 case Op_StoreL:
2680 case Op_StoreIConditional:
2681 case Op_StoreLConditional:
2682 case Op_CompareAndSwapI:
2683 case Op_CompareAndSwapL:
2684 case Op_CompareAndSwapP:
2685 case Op_CompareAndSwapN:
2686 case Op_GetAndAddI:
2687 case Op_GetAndAddL:
2688 case Op_GetAndSetI:
2689 case Op_GetAndSetL:
2690 case Op_GetAndSetP:
2691 case Op_GetAndSetN:
2692 case Op_StoreP:
2693 case Op_StoreN:
2694 case Op_StoreNKlass:
2695 case Op_LoadB:
2696 case Op_LoadUB:
2697 case Op_LoadUS:
2698 case Op_LoadI:
2699 case Op_LoadKlass:
2700 case Op_LoadNKlass:
2701 case Op_LoadL:
2702 case Op_LoadL_unaligned:
2703 case Op_LoadPLocked:
2704 case Op_LoadP:
2705 case Op_LoadN:
2706 case Op_LoadRange:
2707 case Op_LoadS: {
2708 handle_mem:
2709 #ifdef ASSERT
2710 if( VerifyOptoOopOffsets ) {
2711 assert( n->is_Mem(), "" );
2712 MemNode *mem = (MemNode*)n;
2713 // Check to see if address types have grounded out somehow.
2714 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2715 assert( !tp || oop_offset_is_sane(tp), "" );
2716 }
2717 #endif
2718 break;
2719 }
2720
2721 case Op_AddP: { // Assert sane base pointers
2722 Node *addp = n->in(AddPNode::Address);
2723 assert( !addp->is_AddP() ||
2724 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2725 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2726 "Base pointers must match" );
2727 #ifdef _LP64
2728 if ((UseCompressedOops || UseCompressedClassPointers) &&
2729 addp->Opcode() == Op_ConP &&
2730 addp == n->in(AddPNode::Base) &&
2731 n->in(AddPNode::Offset)->is_Con()) {
2732 // Use addressing with narrow klass to load with offset on x86.
2733 // On sparc loading 32-bits constant and decoding it have less
2734 // instructions (4) then load 64-bits constant (7).
2735 // Do this transformation here since IGVN will convert ConN back to ConP.
2736 const Type* t = addp->bottom_type();
2737 if (t->isa_oopptr() || t->isa_klassptr()) {
2738 Node* nn = NULL;
2739
2740 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2741
2742 // Look for existing ConN node of the same exact type.
2743 Node* r = root();
2744 uint cnt = r->outcnt();
2745 for (uint i = 0; i < cnt; i++) {
2746 Node* m = r->raw_out(i);
2747 if (m!= NULL && m->Opcode() == op &&
2748 m->bottom_type()->make_ptr() == t) {
2749 nn = m;
2750 break;
2751 }
2752 }
2753 if (nn != NULL) {
2754 // Decode a narrow oop to match address
2755 // [R12 + narrow_oop_reg<<3 + offset]
2756 if (t->isa_oopptr()) {
2757 nn = new (this) DecodeNNode(nn, t);
2758 } else {
2759 nn = new (this) DecodeNKlassNode(nn, t);
2760 }
2761 n->set_req(AddPNode::Base, nn);
2762 n->set_req(AddPNode::Address, nn);
2763 if (addp->outcnt() == 0) {
2764 addp->disconnect_inputs(NULL, this);
2765 }
2766 }
2767 }
2768 }
2769 #endif
2770 break;
2771 }
2772
2773 #ifdef _LP64
2774 case Op_CastPP:
2775 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2776 Node* in1 = n->in(1);
2777 const Type* t = n->bottom_type();
2778 Node* new_in1 = in1->clone();
2779 new_in1->as_DecodeN()->set_type(t);
2780
2781 if (!Matcher::narrow_oop_use_complex_address()) {
2782 //
2783 // x86, ARM and friends can handle 2 adds in addressing mode
2784 // and Matcher can fold a DecodeN node into address by using
2785 // a narrow oop directly and do implicit NULL check in address:
2786 //
2787 // [R12 + narrow_oop_reg<<3 + offset]
2788 // NullCheck narrow_oop_reg
2789 //
2790 // On other platforms (Sparc) we have to keep new DecodeN node and
2791 // use it to do implicit NULL check in address:
2792 //
2793 // decode_not_null narrow_oop_reg, base_reg
2794 // [base_reg + offset]
2795 // NullCheck base_reg
2796 //
2797 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2798 // to keep the information to which NULL check the new DecodeN node
2799 // corresponds to use it as value in implicit_null_check().
2800 //
2801 new_in1->set_req(0, n->in(0));
2802 }
2803
2804 n->subsume_by(new_in1, this);
2805 if (in1->outcnt() == 0) {
2806 in1->disconnect_inputs(NULL, this);
2807 }
2808 }
2809 break;
2810
2811 case Op_CmpP:
2812 // Do this transformation here to preserve CmpPNode::sub() and
2813 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2814 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2815 Node* in1 = n->in(1);
2816 Node* in2 = n->in(2);
2817 if (!in1->is_DecodeNarrowPtr()) {
2818 in2 = in1;
2819 in1 = n->in(2);
2820 }
2821 assert(in1->is_DecodeNarrowPtr(), "sanity");
2822
2823 Node* new_in2 = NULL;
2824 if (in2->is_DecodeNarrowPtr()) {
2825 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2826 new_in2 = in2->in(1);
2827 } else if (in2->Opcode() == Op_ConP) {
2828 const Type* t = in2->bottom_type();
2829 if (t == TypePtr::NULL_PTR) {
2830 assert(in1->is_DecodeN(), "compare klass to null?");
2831 // Don't convert CmpP null check into CmpN if compressed
2832 // oops implicit null check is not generated.
2833 // This will allow to generate normal oop implicit null check.
2834 if (Matcher::gen_narrow_oop_implicit_null_checks())
2835 new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2836 //
2837 // This transformation together with CastPP transformation above
2838 // will generated code for implicit NULL checks for compressed oops.
2839 //
2840 // The original code after Optimize()
2841 //
2842 // LoadN memory, narrow_oop_reg
2843 // decode narrow_oop_reg, base_reg
2844 // CmpP base_reg, NULL
2845 // CastPP base_reg // NotNull
2846 // Load [base_reg + offset], val_reg
2847 //
2848 // after these transformations will be
2849 //
2850 // LoadN memory, narrow_oop_reg
2851 // CmpN narrow_oop_reg, NULL
2852 // decode_not_null narrow_oop_reg, base_reg
2853 // Load [base_reg + offset], val_reg
2854 //
2855 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2856 // since narrow oops can be used in debug info now (see the code in
2857 // final_graph_reshaping_walk()).
2858 //
2859 // At the end the code will be matched to
2860 // on x86:
2861 //
2862 // Load_narrow_oop memory, narrow_oop_reg
2863 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2864 // NullCheck narrow_oop_reg
2865 //
2866 // and on sparc:
2867 //
2868 // Load_narrow_oop memory, narrow_oop_reg
2869 // decode_not_null narrow_oop_reg, base_reg
2870 // Load [base_reg + offset], val_reg
2871 // NullCheck base_reg
2872 //
2873 } else if (t->isa_oopptr()) {
2874 new_in2 = ConNode::make(this, t->make_narrowoop());
2875 } else if (t->isa_klassptr()) {
2876 new_in2 = ConNode::make(this, t->make_narrowklass());
2877 }
2878 }
2879 if (new_in2 != NULL) {
2880 Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2881 n->subsume_by(cmpN, this);
2882 if (in1->outcnt() == 0) {
2883 in1->disconnect_inputs(NULL, this);
2884 }
2885 if (in2->outcnt() == 0) {
2886 in2->disconnect_inputs(NULL, this);
2887 }
2888 }
2889 }
2890 break;
2891
2892 case Op_DecodeN:
2893 case Op_DecodeNKlass:
2894 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2895 // DecodeN could be pinned when it can't be fold into
2896 // an address expression, see the code for Op_CastPP above.
2897 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2898 break;
2899
2900 case Op_EncodeP:
2901 case Op_EncodePKlass: {
2902 Node* in1 = n->in(1);
2903 if (in1->is_DecodeNarrowPtr()) {
2904 n->subsume_by(in1->in(1), this);
2905 } else if (in1->Opcode() == Op_ConP) {
2906 const Type* t = in1->bottom_type();
2907 if (t == TypePtr::NULL_PTR) {
2908 assert(t->isa_oopptr(), "null klass?");
2909 n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
2910 } else if (t->isa_oopptr()) {
2911 n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
2912 } else if (t->isa_klassptr()) {
2913 n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
2914 }
2915 }
2916 if (in1->outcnt() == 0) {
2917 in1->disconnect_inputs(NULL, this);
2918 }
2919 break;
2920 }
2921
2922 case Op_Proj: {
2923 if (OptimizeStringConcat) {
2924 ProjNode* p = n->as_Proj();
2925 if (p->_is_io_use) {
2926 // Separate projections were used for the exception path which
2927 // are normally removed by a late inline. If it wasn't inlined
2928 // then they will hang around and should just be replaced with
2929 // the original one.
2930 Node* proj = NULL;
2931 // Replace with just one
2932 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2933 Node *use = i.get();
2934 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2935 proj = use;
2936 break;
2937 }
2938 }
2939 assert(proj != NULL, "must be found");
2940 p->subsume_by(proj, this);
2941 }
2942 }
2943 break;
2944 }
2945
2946 case Op_Phi:
2947 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2948 // The EncodeP optimization may create Phi with the same edges
2949 // for all paths. It is not handled well by Register Allocator.
2950 Node* unique_in = n->in(1);
2951 assert(unique_in != NULL, "");
2952 uint cnt = n->req();
2953 for (uint i = 2; i < cnt; i++) {
2954 Node* m = n->in(i);
2955 assert(m != NULL, "");
2956 if (unique_in != m)
2957 unique_in = NULL;
2958 }
2959 if (unique_in != NULL) {
2960 n->subsume_by(unique_in, this);
2961 }
2962 }
2963 break;
2964
2965 #endif
2966
2967 case Op_ModI:
2968 if (UseDivMod) {
2969 // Check if a%b and a/b both exist
2970 Node* d = n->find_similar(Op_DivI);
2971 if (d) {
2972 // Replace them with a fused divmod if supported
2973 if (Matcher::has_match_rule(Op_DivModI)) {
2974 DivModINode* divmod = DivModINode::make(this, n);
2975 d->subsume_by(divmod->div_proj(), this);
2976 n->subsume_by(divmod->mod_proj(), this);
2977 } else {
2978 // replace a%b with a-((a/b)*b)
2979 Node* mult = new (this) MulINode(d, d->in(2));
2980 Node* sub = new (this) SubINode(d->in(1), mult);
2981 n->subsume_by(sub, this);
2982 }
2983 }
2984 }
2985 break;
2986
2987 case Op_ModL:
2988 if (UseDivMod) {
2989 // Check if a%b and a/b both exist
2990 Node* d = n->find_similar(Op_DivL);
2991 if (d) {
2992 // Replace them with a fused divmod if supported
2993 if (Matcher::has_match_rule(Op_DivModL)) {
2994 DivModLNode* divmod = DivModLNode::make(this, n);
2995 d->subsume_by(divmod->div_proj(), this);
2996 n->subsume_by(divmod->mod_proj(), this);
2997 } else {
2998 // replace a%b with a-((a/b)*b)
2999 Node* mult = new (this) MulLNode(d, d->in(2));
3000 Node* sub = new (this) SubLNode(d->in(1), mult);
3001 n->subsume_by(sub, this);
3002 }
3003 }
3004 }
3005 break;
3006
3007 case Op_LoadVector:
3008 case Op_StoreVector:
3009 break;
3010
3011 case Op_PackB:
3012 case Op_PackS:
3013 case Op_PackI:
3014 case Op_PackF:
3015 case Op_PackL:
3016 case Op_PackD:
3017 if (n->req()-1 > 2) {
3018 // Replace many operand PackNodes with a binary tree for matching
3019 PackNode* p = (PackNode*) n;
3020 Node* btp = p->binary_tree_pack(this, 1, n->req());
3021 n->subsume_by(btp, this);
3022 }
3023 break;
3024 case Op_Loop:
3025 case Op_CountedLoop:
3026 if (n->as_Loop()->is_inner_loop()) {
3027 frc.inc_inner_loop_count();
3028 }
3029 break;
3030 case Op_LShiftI:
3031 case Op_RShiftI:
3032 case Op_URShiftI:
3033 case Op_LShiftL:
3034 case Op_RShiftL:
3035 case Op_URShiftL:
3036 if (Matcher::need_masked_shift_count) {
3037 // The cpu's shift instructions don't restrict the count to the
3038 // lower 5/6 bits. We need to do the masking ourselves.
3039 Node* in2 = n->in(2);
3040 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3041 const TypeInt* t = in2->find_int_type();
3042 if (t != NULL && t->is_con()) {
3043 juint shift = t->get_con();
3044 if (shift > mask) { // Unsigned cmp
3045 n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
3046 }
3047 } else {
3048 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3049 Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
3050 n->set_req(2, shift);
3051 }
3052 }
3053 if (in2->outcnt() == 0) { // Remove dead node
3054 in2->disconnect_inputs(NULL, this);
3055 }
3056 }
3057 break;
3058 case Op_MemBarStoreStore:
3059 case Op_MemBarRelease:
3060 // Break the link with AllocateNode: it is no longer useful and
3061 // confuses register allocation.
3062 if (n->req() > MemBarNode::Precedent) {
3063 n->set_req(MemBarNode::Precedent, top());
3064 }
3065 break;
3066 default:
3067 assert( !n->is_Call(), "" );
3068 assert( !n->is_Mem(), "" );
3069 break;
3070 }
3071
3072 // Collect CFG split points
3073 if (n->is_MultiBranch())
3074 frc._tests.push(n);
3075 }
3076
3077 //------------------------------final_graph_reshaping_walk---------------------
3078 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3079 // requires that the walk visits a node's inputs before visiting the node.
3080 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3081 ResourceArea *area = Thread::current()->resource_area();
3082 Unique_Node_List sfpt(area);
3083
3084 frc._visited.set(root->_idx); // first, mark node as visited
3085 uint cnt = root->req();
3086 Node *n = root;
3087 uint i = 0;
3088 while (true) {
3089 if (i < cnt) {
3090 // Place all non-visited non-null inputs onto stack
3091 Node* m = n->in(i);
3092 ++i;
3093 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3094 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3095 // compute worst case interpreter size in case of a deoptimization
3096 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3097
3098 sfpt.push(m);
3099 }
3100 cnt = m->req();
3101 nstack.push(n, i); // put on stack parent and next input's index
3102 n = m;
3103 i = 0;
3104 }
3105 } else {
3106 // Now do post-visit work
3107 final_graph_reshaping_impl( n, frc );
3108 if (nstack.is_empty())
3109 break; // finished
3110 n = nstack.node(); // Get node from stack
3111 cnt = n->req();
3112 i = nstack.index();
3113 nstack.pop(); // Shift to the next node on stack
3114 }
3115 }
3116
3117 // Skip next transformation if compressed oops are not used.
3118 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3119 (!UseCompressedOops && !UseCompressedClassPointers))
3120 return;
3121
3122 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3123 // It could be done for an uncommon traps or any safepoints/calls
3124 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3125 while (sfpt.size() > 0) {
3126 n = sfpt.pop();
3127 JVMState *jvms = n->as_SafePoint()->jvms();
3128 assert(jvms != NULL, "sanity");
3129 int start = jvms->debug_start();
3130 int end = n->req();
3131 bool is_uncommon = (n->is_CallStaticJava() &&
3132 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3133 for (int j = start; j < end; j++) {
3134 Node* in = n->in(j);
3135 if (in->is_DecodeNarrowPtr()) {
3136 bool safe_to_skip = true;
3137 if (!is_uncommon ) {
3138 // Is it safe to skip?
3139 for (uint i = 0; i < in->outcnt(); i++) {
3140 Node* u = in->raw_out(i);
3141 if (!u->is_SafePoint() ||
3142 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3143 safe_to_skip = false;
3144 }
3145 }
3146 }
3147 if (safe_to_skip) {
3148 n->set_req(j, in->in(1));
3149 }
3150 if (in->outcnt() == 0) {
3151 in->disconnect_inputs(NULL, this);
3152 }
3153 }
3154 }
3155 }
3156 }
3157
3158 //------------------------------final_graph_reshaping--------------------------
3159 // Final Graph Reshaping.
3160 //
3161 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3162 // and not commoned up and forced early. Must come after regular
3163 // optimizations to avoid GVN undoing the cloning. Clone constant
3164 // inputs to Loop Phis; these will be split by the allocator anyways.
3165 // Remove Opaque nodes.
3166 // (2) Move last-uses by commutative operations to the left input to encourage
3167 // Intel update-in-place two-address operations and better register usage
3168 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3169 // calls canonicalizing them back.
3170 // (3) Count the number of double-precision FP ops, single-precision FP ops
3171 // and call sites. On Intel, we can get correct rounding either by
3172 // forcing singles to memory (requires extra stores and loads after each
3173 // FP bytecode) or we can set a rounding mode bit (requires setting and
3174 // clearing the mode bit around call sites). The mode bit is only used
3175 // if the relative frequency of single FP ops to calls is low enough.
3176 // This is a key transform for SPEC mpeg_audio.
3177 // (4) Detect infinite loops; blobs of code reachable from above but not
3178 // below. Several of the Code_Gen algorithms fail on such code shapes,
3179 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3180 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3181 // Detection is by looking for IfNodes where only 1 projection is
3182 // reachable from below or CatchNodes missing some targets.
3183 // (5) Assert for insane oop offsets in debug mode.
3184
3185 bool Compile::final_graph_reshaping() {
3186 // an infinite loop may have been eliminated by the optimizer,
3187 // in which case the graph will be empty.
3188 if (root()->req() == 1) {
3189 record_method_not_compilable("trivial infinite loop");
3190 return true;
3191 }
3192
3193 // Expensive nodes have their control input set to prevent the GVN
3194 // from freely commoning them. There's no GVN beyond this point so
3195 // no need to keep the control input. We want the expensive nodes to
3196 // be freely moved to the least frequent code path by gcm.
3197 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3198 for (int i = 0; i < expensive_count(); i++) {
3199 _expensive_nodes->at(i)->set_req(0, NULL);
3200 }
3201
3202 Final_Reshape_Counts frc;
3203
3204 // Visit everybody reachable!
3205 // Allocate stack of size C->unique()/2 to avoid frequent realloc
3206 Node_Stack nstack(unique() >> 1);
3207 final_graph_reshaping_walk(nstack, root(), frc);
3208
3209 // Check for unreachable (from below) code (i.e., infinite loops).
3210 for( uint i = 0; i < frc._tests.size(); i++ ) {
3211 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3212 // Get number of CFG targets.
3213 // Note that PCTables include exception targets after calls.
3214 uint required_outcnt = n->required_outcnt();
3215 if (n->outcnt() != required_outcnt) {
3216 // Check for a few special cases. Rethrow Nodes never take the
3217 // 'fall-thru' path, so expected kids is 1 less.
3218 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3219 if (n->in(0)->in(0)->is_Call()) {
3220 CallNode *call = n->in(0)->in(0)->as_Call();
3221 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3222 required_outcnt--; // Rethrow always has 1 less kid
3223 } else if (call->req() > TypeFunc::Parms &&
3224 call->is_CallDynamicJava()) {
3225 // Check for null receiver. In such case, the optimizer has
3226 // detected that the virtual call will always result in a null
3227 // pointer exception. The fall-through projection of this CatchNode
3228 // will not be populated.
3229 Node *arg0 = call->in(TypeFunc::Parms);
3230 if (arg0->is_Type() &&
3231 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3232 required_outcnt--;
3233 }
3234 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3235 call->req() > TypeFunc::Parms+1 &&
3236 call->is_CallStaticJava()) {
3237 // Check for negative array length. In such case, the optimizer has
3238 // detected that the allocation attempt will always result in an
3239 // exception. There is no fall-through projection of this CatchNode .
3240 Node *arg1 = call->in(TypeFunc::Parms+1);
3241 if (arg1->is_Type() &&
3242 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3243 required_outcnt--;
3244 }
3245 }
3246 }
3247 }
3248 // Recheck with a better notion of 'required_outcnt'
3249 if (n->outcnt() != required_outcnt) {
3250 record_method_not_compilable("malformed control flow");
3251 return true; // Not all targets reachable!
3252 }
3253 }
3254 // Check that I actually visited all kids. Unreached kids
3255 // must be infinite loops.
3256 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3257 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3258 record_method_not_compilable("infinite loop");
3259 return true; // Found unvisited kid; must be unreach
3260 }
3261 }
3262
3263 // If original bytecodes contained a mixture of floats and doubles
3264 // check if the optimizer has made it homogenous, item (3).
3265 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3266 frc.get_float_count() > 32 &&
3267 frc.get_double_count() == 0 &&
3268 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3269 set_24_bit_selection_and_mode( false, true );
3270 }
3271
3272 set_java_calls(frc.get_java_call_count());
3273 set_inner_loops(frc.get_inner_loop_count());
3274
3275 // No infinite loops, no reason to bail out.
3276 return false;
3277 }
3278
3279 //-----------------------------too_many_traps----------------------------------
3280 // Report if there are too many traps at the current method and bci.
3281 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3282 bool Compile::too_many_traps(ciMethod* method,
3283 int bci,
3284 Deoptimization::DeoptReason reason) {
3285 ciMethodData* md = method->method_data();
3286 if (md->is_empty()) {
3287 // Assume the trap has not occurred, or that it occurred only
3288 // because of a transient condition during start-up in the interpreter.
3289 return false;
3290 }
3291 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3292 if (md->has_trap_at(bci, m, reason) != 0) {
3293 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3294 // Also, if there are multiple reasons, or if there is no per-BCI record,
3295 // assume the worst.
3296 if (log())
3297 log()->elem("observe trap='%s' count='%d'",
3298 Deoptimization::trap_reason_name(reason),
3299 md->trap_count(reason));
3300 return true;
3301 } else {
3302 // Ignore method/bci and see if there have been too many globally.
3303 return too_many_traps(reason, md);
3304 }
3305 }
3306
3307 // Less-accurate variant which does not require a method and bci.
3308 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3309 ciMethodData* logmd) {
3310 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3311 // Too many traps globally.
3312 // Note that we use cumulative trap_count, not just md->trap_count.
3313 if (log()) {
3314 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3315 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3316 Deoptimization::trap_reason_name(reason),
3317 mcount, trap_count(reason));
3318 }
3319 return true;
3320 } else {
3321 // The coast is clear.
3322 return false;
3323 }
3324 }
3325
3326 //--------------------------too_many_recompiles--------------------------------
3327 // Report if there are too many recompiles at the current method and bci.
3328 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3329 // Is not eager to return true, since this will cause the compiler to use
3330 // Action_none for a trap point, to avoid too many recompilations.
3331 bool Compile::too_many_recompiles(ciMethod* method,
3332 int bci,
3333 Deoptimization::DeoptReason reason) {
3334 ciMethodData* md = method->method_data();
3335 if (md->is_empty()) {
3336 // Assume the trap has not occurred, or that it occurred only
3337 // because of a transient condition during start-up in the interpreter.
3338 return false;
3339 }
3340 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3341 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3342 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3343 Deoptimization::DeoptReason per_bc_reason
3344 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3345 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3346 if ((per_bc_reason == Deoptimization::Reason_none
3347 || md->has_trap_at(bci, m, reason) != 0)
3348 // The trap frequency measure we care about is the recompile count:
3349 && md->trap_recompiled_at(bci, m)
3350 && md->overflow_recompile_count() >= bc_cutoff) {
3351 // Do not emit a trap here if it has already caused recompilations.
3352 // Also, if there are multiple reasons, or if there is no per-BCI record,
3353 // assume the worst.
3354 if (log())
3355 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3356 Deoptimization::trap_reason_name(reason),
3357 md->trap_count(reason),
3358 md->overflow_recompile_count());
3359 return true;
3360 } else if (trap_count(reason) != 0
3361 && decompile_count() >= m_cutoff) {
3362 // Too many recompiles globally, and we have seen this sort of trap.
3363 // Use cumulative decompile_count, not just md->decompile_count.
3364 if (log())
3365 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3366 Deoptimization::trap_reason_name(reason),
3367 md->trap_count(reason), trap_count(reason),
3368 md->decompile_count(), decompile_count());
3369 return true;
3370 } else {
3371 // The coast is clear.
3372 return false;
3373 }
3374 }
3375
3376 // Compute when not to trap. Used by matching trap based nodes and
3377 // NullCheck optimization.
3378 void Compile::set_allowed_deopt_reasons() {
3379 _allowed_reasons = 0;
3380 if (is_method_compilation()) {
3381 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3382 assert(rs < BitsPerInt, "recode bit map");
3383 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3384 _allowed_reasons |= nth_bit(rs);
3385 }
3386 }
3387 }
3388 }
3389
3390 #ifndef PRODUCT
3391 //------------------------------verify_graph_edges---------------------------
3392 // Walk the Graph and verify that there is a one-to-one correspondence
3393 // between Use-Def edges and Def-Use edges in the graph.
3394 void Compile::verify_graph_edges(bool no_dead_code) {
3395 if (VerifyGraphEdges) {
3396 ResourceArea *area = Thread::current()->resource_area();
3397 Unique_Node_List visited(area);
3398 // Call recursive graph walk to check edges
3399 _root->verify_edges(visited);
3400 if (no_dead_code) {
3401 // Now make sure that no visited node is used by an unvisited node.
3402 bool dead_nodes = 0;
3403 Unique_Node_List checked(area);
3404 while (visited.size() > 0) {
3405 Node* n = visited.pop();
3406 checked.push(n);
3407 for (uint i = 0; i < n->outcnt(); i++) {
3408 Node* use = n->raw_out(i);
3409 if (checked.member(use)) continue; // already checked
3410 if (visited.member(use)) continue; // already in the graph
3411 if (use->is_Con()) continue; // a dead ConNode is OK
3412 // At this point, we have found a dead node which is DU-reachable.
3413 if (dead_nodes++ == 0)
3414 tty->print_cr("*** Dead nodes reachable via DU edges:");
3415 use->dump(2);
3416 tty->print_cr("---");
3417 checked.push(use); // No repeats; pretend it is now checked.
3418 }
3419 }
3420 assert(dead_nodes == 0, "using nodes must be reachable from root");
3421 }
3422 }
3423 }
3424
3425 // Verify GC barriers consistency
3426 // Currently supported:
3427 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3428 void Compile::verify_barriers() {
3429 if (UseG1GC) {
3430 // Verify G1 pre-barriers
3431 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3432
3433 ResourceArea *area = Thread::current()->resource_area();
3434 Unique_Node_List visited(area);
3435 Node_List worklist(area);
3436 // We're going to walk control flow backwards starting from the Root
3437 worklist.push(_root);
3438 while (worklist.size() > 0) {
3439 Node* x = worklist.pop();
3440 if (x == NULL || x == top()) continue;
3441 if (visited.member(x)) {
3442 continue;
3443 } else {
3444 visited.push(x);
3445 }
3446
3447 if (x->is_Region()) {
3448 for (uint i = 1; i < x->req(); i++) {
3449 worklist.push(x->in(i));
3450 }
3451 } else {
3452 worklist.push(x->in(0));
3453 // We are looking for the pattern:
3454 // /->ThreadLocal
3455 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3456 // \->ConI(0)
3457 // We want to verify that the If and the LoadB have the same control
3458 // See GraphKit::g1_write_barrier_pre()
3459 if (x->is_If()) {
3460 IfNode *iff = x->as_If();
3461 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3462 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3463 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3464 && cmp->in(1)->is_Load()) {
3465 LoadNode* load = cmp->in(1)->as_Load();
3466 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3467 && load->in(2)->in(3)->is_Con()
3468 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3469
3470 Node* if_ctrl = iff->in(0);
3471 Node* load_ctrl = load->in(0);
3472
3473 if (if_ctrl != load_ctrl) {
3474 // Skip possible CProj->NeverBranch in infinite loops
3475 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3476 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3477 if_ctrl = if_ctrl->in(0)->in(0);
3478 }
3479 }
3480 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3481 }
3482 }
3483 }
3484 }
3485 }
3486 }
3487 }
3488 }
3489
3490 #endif
3491
3492 // The Compile object keeps track of failure reasons separately from the ciEnv.
3493 // This is required because there is not quite a 1-1 relation between the
3494 // ciEnv and its compilation task and the Compile object. Note that one
3495 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3496 // to backtrack and retry without subsuming loads. Other than this backtracking
3497 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3498 // by the logic in C2Compiler.
3499 void Compile::record_failure(const char* reason) {
3500 if (log() != NULL) {
3501 log()->elem("failure reason='%s' phase='compile'", reason);
3502 }
3503 if (_failure_reason == NULL) {
3504 // Record the first failure reason.
3505 _failure_reason = reason;
3506 }
3507
3508 EventCompilerFailure event;
3509 if (event.should_commit()) {
3510 event.set_compileID(Compile::compile_id());
3511 event.set_failure(reason);
3512 event.commit();
3513 }
3514
3515 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3516 C->print_method(PHASE_FAILURE);
3517 }
3518 _root = NULL; // flush the graph, too
3519 }
3520
3521 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3522 : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3523 _phase_name(name), _dolog(dolog)
3524 {
3525 if (dolog) {
3526 C = Compile::current();
3527 _log = C->log();
3528 } else {
3529 C = NULL;
3530 _log = NULL;
3531 }
3532 if (_log != NULL) {
3533 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3534 _log->stamp();
3535 _log->end_head();
3536 }
3537 }
3538
3539 Compile::TracePhase::~TracePhase() {
3540
3541 C = Compile::current();
3542 if (_dolog) {
3543 _log = C->log();
3544 } else {
3545 _log = NULL;
3546 }
3547
3548 #ifdef ASSERT
3549 if (PrintIdealNodeCount) {
3550 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3551 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3552 }
3553
3554 if (VerifyIdealNodeCount) {
3555 Compile::current()->print_missing_nodes();
3556 }
3557 #endif
3558
3559 if (_log != NULL) {
3560 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3561 }
3562 }
3563
3564 //=============================================================================
3565 // Two Constant's are equal when the type and the value are equal.
3566 bool Compile::Constant::operator==(const Constant& other) {
3567 if (type() != other.type() ) return false;
3568 if (can_be_reused() != other.can_be_reused()) return false;
3569 // For floating point values we compare the bit pattern.
3570 switch (type()) {
3571 case T_FLOAT: return (_v._value.i == other._v._value.i);
3572 case T_LONG:
3573 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3574 case T_OBJECT:
3575 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3576 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3577 case T_METADATA: return (_v._metadata == other._v._metadata);
3578 default: ShouldNotReachHere();
3579 }
3580 return false;
3581 }
3582
3583 static int type_to_size_in_bytes(BasicType t) {
3584 switch (t) {
3585 case T_LONG: return sizeof(jlong );
3586 case T_FLOAT: return sizeof(jfloat );
3587 case T_DOUBLE: return sizeof(jdouble);
3588 case T_METADATA: return sizeof(Metadata*);
3589 // We use T_VOID as marker for jump-table entries (labels) which
3590 // need an internal word relocation.
3591 case T_VOID:
3592 case T_ADDRESS:
3593 case T_OBJECT: return sizeof(jobject);
3594 }
3595
3596 ShouldNotReachHere();
3597 return -1;
3598 }
3599
3600 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3601 // sort descending
3602 if (a->freq() > b->freq()) return -1;
3603 if (a->freq() < b->freq()) return 1;
3604 return 0;
3605 }
3606
3607 void Compile::ConstantTable::calculate_offsets_and_size() {
3608 // First, sort the array by frequencies.
3609 _constants.sort(qsort_comparator);
3610
3611 #ifdef ASSERT
3612 // Make sure all jump-table entries were sorted to the end of the
3613 // array (they have a negative frequency).
3614 bool found_void = false;
3615 for (int i = 0; i < _constants.length(); i++) {
3616 Constant con = _constants.at(i);
3617 if (con.type() == T_VOID)
3618 found_void = true; // jump-tables
3619 else
3620 assert(!found_void, "wrong sorting");
3621 }
3622 #endif
3623
3624 int offset = 0;
3625 for (int i = 0; i < _constants.length(); i++) {
3626 Constant* con = _constants.adr_at(i);
3627
3628 // Align offset for type.
3629 int typesize = type_to_size_in_bytes(con->type());
3630 offset = align_size_up(offset, typesize);
3631 con->set_offset(offset); // set constant's offset
3632
3633 if (con->type() == T_VOID) {
3634 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3635 offset = offset + typesize * n->outcnt(); // expand jump-table
3636 } else {
3637 offset = offset + typesize;
3638 }
3639 }
3640
3641 // Align size up to the next section start (which is insts; see
3642 // CodeBuffer::align_at_start).
3643 assert(_size == -1, "already set?");
3644 _size = align_size_up(offset, CodeEntryAlignment);
3645 }
3646
3647 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3648 MacroAssembler _masm(&cb);
3649 for (int i = 0; i < _constants.length(); i++) {
3650 Constant con = _constants.at(i);
3651 address constant_addr;
3652 switch (con.type()) {
3653 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3654 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3655 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3656 case T_OBJECT: {
3657 jobject obj = con.get_jobject();
3658 int oop_index = _masm.oop_recorder()->find_index(obj);
3659 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3660 break;
3661 }
3662 case T_ADDRESS: {
3663 address addr = (address) con.get_jobject();
3664 constant_addr = _masm.address_constant(addr);
3665 break;
3666 }
3667 // We use T_VOID as marker for jump-table entries (labels) which
3668 // need an internal word relocation.
3669 case T_VOID: {
3670 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3671 // Fill the jump-table with a dummy word. The real value is
3672 // filled in later in fill_jump_table.
3673 address dummy = (address) n;
3674 constant_addr = _masm.address_constant(dummy);
3675 // Expand jump-table
3676 for (uint i = 1; i < n->outcnt(); i++) {
3677 address temp_addr = _masm.address_constant(dummy + i);
3678 assert(temp_addr, "consts section too small");
3679 }
3680 break;
3681 }
3682 case T_METADATA: {
3683 Metadata* obj = con.get_metadata();
3684 int metadata_index = _masm.oop_recorder()->find_index(obj);
3685 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3686 break;
3687 }
3688 default: ShouldNotReachHere();
3689 }
3690 assert(constant_addr, "consts section too small");
3691 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
3692 }
3693 }
3694
3695 int Compile::ConstantTable::find_offset(Constant& con) const {
3696 int idx = _constants.find(con);
3697 assert(idx != -1, "constant must be in constant table");
3698 int offset = _constants.at(idx).offset();
3699 assert(offset != -1, "constant table not emitted yet?");
3700 return offset;
3701 }
3702
3703 void Compile::ConstantTable::add(Constant& con) {
3704 if (con.can_be_reused()) {
3705 int idx = _constants.find(con);
3706 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3707 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3708 return;
3709 }
3710 }
3711 (void) _constants.append(con);
3712 }
3713
3714 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3715 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3716 Constant con(type, value, b->_freq);
3717 add(con);
3718 return con;
3719 }
3720
3721 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3722 Constant con(metadata);
3723 add(con);
3724 return con;
3725 }
3726
3727 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3728 jvalue value;
3729 BasicType type = oper->type()->basic_type();
3730 switch (type) {
3731 case T_LONG: value.j = oper->constantL(); break;
3732 case T_FLOAT: value.f = oper->constantF(); break;
3733 case T_DOUBLE: value.d = oper->constantD(); break;
3734 case T_OBJECT:
3735 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3736 case T_METADATA: return add((Metadata*)oper->constant()); break;
3737 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3738 }
3739 return add(n, type, value);
3740 }
3741
3742 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3743 jvalue value;
3744 // We can use the node pointer here to identify the right jump-table
3745 // as this method is called from Compile::Fill_buffer right before
3746 // the MachNodes are emitted and the jump-table is filled (means the
3747 // MachNode pointers do not change anymore).
3748 value.l = (jobject) n;
3749 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3750 add(con);
3751 return con;
3752 }
3753
3754 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3755 // If called from Compile::scratch_emit_size do nothing.
3756 if (Compile::current()->in_scratch_emit_size()) return;
3757
3758 assert(labels.is_nonempty(), "must be");
3759 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3760
3761 // Since MachConstantNode::constant_offset() also contains
3762 // table_base_offset() we need to subtract the table_base_offset()
3763 // to get the plain offset into the constant table.
3764 int offset = n->constant_offset() - table_base_offset();
3765
3766 MacroAssembler _masm(&cb);
3767 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3768
3769 for (uint i = 0; i < n->outcnt(); i++) {
3770 address* constant_addr = &jump_table_base[i];
3771 assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, *constant_addr, (((address) n) + i)));
3772 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3773 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3774 }
3775 }
3776
3777 // The message about the current inlining is accumulated in
3778 // _print_inlining_stream and transfered into the _print_inlining_list
3779 // once we know whether inlining succeeds or not. For regular
3780 // inlining, messages are appended to the buffer pointed by
3781 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3782 // a new buffer is added after _print_inlining_idx in the list. This
3783 // way we can update the inlining message for late inlining call site
3784 // when the inlining is attempted again.
3785 void Compile::print_inlining_init() {
3786 if (print_inlining() || print_intrinsics()) {
3787 _print_inlining_stream = new stringStream();
3788 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3789 }
3790 }
3791
3792 void Compile::print_inlining_reinit() {
3793 if (print_inlining() || print_intrinsics()) {
3794 // Re allocate buffer when we change ResourceMark
3795 _print_inlining_stream = new stringStream();
3796 }
3797 }
3798
3799 void Compile::print_inlining_reset() {
3800 _print_inlining_stream->reset();
3801 }
3802
3803 void Compile::print_inlining_commit() {
3804 assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3805 // Transfer the message from _print_inlining_stream to the current
3806 // _print_inlining_list buffer and clear _print_inlining_stream.
3807 _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3808 print_inlining_reset();
3809 }
3810
3811 void Compile::print_inlining_push() {
3812 // Add new buffer to the _print_inlining_list at current position
3813 _print_inlining_idx++;
3814 _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3815 }
3816
3817 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3818 return _print_inlining_list->at(_print_inlining_idx);
3819 }
3820
3821 void Compile::print_inlining_update(CallGenerator* cg) {
3822 if (print_inlining() || print_intrinsics()) {
3823 if (!cg->is_late_inline()) {
3824 if (print_inlining_current().cg() != NULL) {
3825 print_inlining_push();
3826 }
3827 print_inlining_commit();
3828 } else {
3829 if (print_inlining_current().cg() != cg &&
3830 (print_inlining_current().cg() != NULL ||
3831 print_inlining_current().ss()->size() != 0)) {
3832 print_inlining_push();
3833 }
3834 print_inlining_commit();
3835 print_inlining_current().set_cg(cg);
3836 }
3837 }
3838 }
3839
3840 void Compile::print_inlining_move_to(CallGenerator* cg) {
3841 // We resume inlining at a late inlining call site. Locate the
3842 // corresponding inlining buffer so that we can update it.
3843 if (print_inlining()) {
3844 for (int i = 0; i < _print_inlining_list->length(); i++) {
3845 if (_print_inlining_list->adr_at(i)->cg() == cg) {
3846 _print_inlining_idx = i;
3847 return;
3848 }
3849 }
3850 ShouldNotReachHere();
3851 }
3852 }
3853
3854 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3855 if (print_inlining()) {
3856 assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3857 assert(print_inlining_current().cg() == cg, "wrong entry");
3858 // replace message with new message
3859 _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3860 print_inlining_commit();
3861 print_inlining_current().set_cg(cg);
3862 }
3863 }
3864
3865 void Compile::print_inlining_assert_ready() {
3866 assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3867 }
3868
3869 void Compile::dump_inlining() {
3870 bool do_print_inlining = print_inlining() || print_intrinsics();
3871 if (do_print_inlining || log() != NULL) {
3872 // Print inlining message for candidates that we couldn't inline
3873 // for lack of space
3874 for (int i = 0; i < _late_inlines.length(); i++) {
3875 CallGenerator* cg = _late_inlines.at(i);
3876 if (!cg->is_mh_late_inline()) {
3877 const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3878 if (do_print_inlining) {
3879 cg->print_inlining_late(msg);
3880 }
3881 log_late_inline_failure(cg, msg);
3882 }
3883 }
3884 }
3885 if (do_print_inlining) {
3886 for (int i = 0; i < _print_inlining_list->length(); i++) {
3887 tty->print(_print_inlining_list->adr_at(i)->ss()->as_string());
3888 }
3889 }
3890 }
3891
3892 void Compile::log_late_inline(CallGenerator* cg) {
3893 if (log() != NULL) {
3894 log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3895 cg->unique_id());
3896 JVMState* p = cg->call_node()->jvms();
3897 while (p != NULL) {
3898 log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
3899 p = p->caller();
3900 }
3901 log()->tail("late_inline");
3902 }
3903 }
3904
3905 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
3906 log_late_inline(cg);
3907 if (log() != NULL) {
3908 log()->inline_fail(msg);
3909 }
3910 }
3911
3912 void Compile::log_inline_id(CallGenerator* cg) {
3913 if (log() != NULL) {
3914 // The LogCompilation tool needs a unique way to identify late
3915 // inline call sites. This id must be unique for this call site in
3916 // this compilation. Try to have it unique across compilations as
3917 // well because it can be convenient when grepping through the log
3918 // file.
3919 // Distinguish OSR compilations from others in case CICountOSR is
3920 // on.
3921 jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
3922 cg->set_unique_id(id);
3923 log()->elem("inline_id id='" JLONG_FORMAT "'", id);
3924 }
3925 }
3926
3927 void Compile::log_inline_failure(const char* msg) {
3928 if (C->log() != NULL) {
3929 C->log()->inline_fail(msg);
3930 }
3931 }
3932
3933
3934 // Dump inlining replay data to the stream.
3935 // Don't change thread state and acquire any locks.
3936 void Compile::dump_inline_data(outputStream* out) {
3937 InlineTree* inl_tree = ilt();
3938 if (inl_tree != NULL) {
3939 out->print(" inline %d", inl_tree->count());
3940 inl_tree->dump_replay_data(out);
3941 }
3942 }
3943
3944 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3945 if (n1->Opcode() < n2->Opcode()) return -1;
3946 else if (n1->Opcode() > n2->Opcode()) return 1;
3947
3948 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()));
3949 for (uint i = 1; i < n1->req(); i++) {
3950 if (n1->in(i) < n2->in(i)) return -1;
3951 else if (n1->in(i) > n2->in(i)) return 1;
3952 }
3953
3954 return 0;
3955 }
3956
3957 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3958 Node* n1 = *n1p;
3959 Node* n2 = *n2p;
3960
3961 return cmp_expensive_nodes(n1, n2);
3962 }
3963
3964 void Compile::sort_expensive_nodes() {
3965 if (!expensive_nodes_sorted()) {
3966 _expensive_nodes->sort(cmp_expensive_nodes);
3967 }
3968 }
3969
3970 bool Compile::expensive_nodes_sorted() const {
3971 for (int i = 1; i < _expensive_nodes->length(); i++) {
3972 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3973 return false;
3974 }
3975 }
3976 return true;
3977 }
3978
3979 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3980 if (_expensive_nodes->length() == 0) {
3981 return false;
3982 }
3983
3984 assert(OptimizeExpensiveOps, "optimization off?");
3985
3986 // Take this opportunity to remove dead nodes from the list
3987 int j = 0;
3988 for (int i = 0; i < _expensive_nodes->length(); i++) {
3989 Node* n = _expensive_nodes->at(i);
3990 if (!n->is_unreachable(igvn)) {
3991 assert(n->is_expensive(), "should be expensive");
3992 _expensive_nodes->at_put(j, n);
3993 j++;
3994 }
3995 }
3996 _expensive_nodes->trunc_to(j);
3997
3998 // Then sort the list so that similar nodes are next to each other
3999 // and check for at least two nodes of identical kind with same data
4000 // inputs.
4001 sort_expensive_nodes();
4002
4003 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4004 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4005 return true;
4006 }
4007 }
4008
4009 return false;
4010 }
4011
4012 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4013 if (_expensive_nodes->length() == 0) {
4014 return;
4015 }
4016
4017 assert(OptimizeExpensiveOps, "optimization off?");
4018
4019 // Sort to bring similar nodes next to each other and clear the
4020 // control input of nodes for which there's only a single copy.
4021 sort_expensive_nodes();
4022
4023 int j = 0;
4024 int identical = 0;
4025 int i = 0;
4026 for (; i < _expensive_nodes->length()-1; i++) {
4027 assert(j <= i, "can't write beyond current index");
4028 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4029 identical++;
4030 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4031 continue;
4032 }
4033 if (identical > 0) {
4034 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4035 identical = 0;
4036 } else {
4037 Node* n = _expensive_nodes->at(i);
4038 igvn.hash_delete(n);
4039 n->set_req(0, NULL);
4040 igvn.hash_insert(n);
4041 }
4042 }
4043 if (identical > 0) {
4044 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4045 } else if (_expensive_nodes->length() >= 1) {
4046 Node* n = _expensive_nodes->at(i);
4047 igvn.hash_delete(n);
4048 n->set_req(0, NULL);
4049 igvn.hash_insert(n);
4050 }
4051 _expensive_nodes->trunc_to(j);
4052 }
4053
4054 void Compile::add_expensive_node(Node * n) {
4055 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4056 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4057 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4058 if (OptimizeExpensiveOps) {
4059 _expensive_nodes->append(n);
4060 } else {
4061 // Clear control input and let IGVN optimize expensive nodes if
4062 // OptimizeExpensiveOps is off.
4063 n->set_req(0, NULL);
4064 }
4065 }
4066
4067 /**
4068 * Remove the speculative part of types and clean up the graph
4069 */
4070 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4071 if (UseTypeSpeculation) {
4072 Unique_Node_List worklist;
4073 worklist.push(root());
4074 int modified = 0;
4075 // Go over all type nodes that carry a speculative type, drop the
4076 // speculative part of the type and enqueue the node for an igvn
4077 // which may optimize it out.
4078 for (uint next = 0; next < worklist.size(); ++next) {
4079 Node *n = worklist.at(next);
4080 if (n->is_Type()) {
4081 TypeNode* tn = n->as_Type();
4082 const Type* t = tn->type();
4083 const Type* t_no_spec = t->remove_speculative();
4084 if (t_no_spec != t) {
4085 bool in_hash = igvn.hash_delete(n);
4086 assert(in_hash, "node should be in igvn hash table");
4087 tn->set_type(t_no_spec);
4088 igvn.hash_insert(n);
4089 igvn._worklist.push(n); // give it a chance to go away
4090 modified++;
4091 }
4092 }
4093 uint max = n->len();
4094 for( uint i = 0; i < max; ++i ) {
4095 Node *m = n->in(i);
4096 if (not_a_node(m)) continue;
4097 worklist.push(m);
4098 }
4099 }
4100 // Drop the speculative part of all types in the igvn's type table
4101 igvn.remove_speculative_types();
4102 if (modified > 0) {
4103 igvn.optimize();
4104 }
4105 #ifdef ASSERT
4106 // Verify that after the IGVN is over no speculative type has resurfaced
4107 worklist.clear();
4108 worklist.push(root());
4109 for (uint next = 0; next < worklist.size(); ++next) {
4110 Node *n = worklist.at(next);
4111 const Type* t = igvn.type_or_null(n);
4112 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4113 if (n->is_Type()) {
4114 t = n->as_Type()->type();
4115 assert(t == t->remove_speculative(), "no more speculative types");
4116 }
4117 uint max = n->len();
4118 for( uint i = 0; i < max; ++i ) {
4119 Node *m = n->in(i);
4120 if (not_a_node(m)) continue;
4121 worklist.push(m);
4122 }
4123 }
4124 igvn.check_no_speculative_types();
4125 #endif
4126 }
4127 }
4128
4129 // Auxiliary method to support randomized stressing/fuzzing.
4130 //
4131 // This method can be called the arbitrary number of times, with current count
4132 // as the argument. The logic allows selecting a single candidate from the
4133 // running list of candidates as follows:
4134 // int count = 0;
4135 // Cand* selected = null;
4136 // while(cand = cand->next()) {
4137 // if (randomized_select(++count)) {
4138 // selected = cand;
4139 // }
4140 // }
4141 //
4142 // Including count equalizes the chances any candidate is "selected".
4143 // This is useful when we don't have the complete list of candidates to choose
4144 // from uniformly. In this case, we need to adjust the randomicity of the
4145 // selection, or else we will end up biasing the selection towards the latter
4146 // candidates.
4147 //
4148 // Quick back-envelope calculation shows that for the list of n candidates
4149 // the equal probability for the candidate to persist as "best" can be
4150 // achieved by replacing it with "next" k-th candidate with the probability
4151 // of 1/k. It can be easily shown that by the end of the run, the
4152 // probability for any candidate is converged to 1/n, thus giving the
4153 // uniform distribution among all the candidates.
4154 //
4155 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4156 #define RANDOMIZED_DOMAIN_POW 29
4157 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4158 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4159 bool Compile::randomized_select(int count) {
4160 assert(count > 0, "only positive");
4161 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4162 }