1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "ci/ciReplay.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/exceptionHandlerTable.hpp"
31 #include "code/nmethod.hpp"
32 #include "compiler/compileBroker.hpp"
33 #include "compiler/compileLog.hpp"
34 #include "compiler/disassembler.hpp"
35 #include "compiler/oopMap.hpp"
36 #include "opto/addnode.hpp"
37 #include "opto/block.hpp"
38 #include "opto/c2compiler.hpp"
39 #include "opto/callGenerator.hpp"
40 #include "opto/callnode.hpp"
41 #include "opto/cfgnode.hpp"
42 #include "opto/chaitin.hpp"
43 #include "opto/compile.hpp"
44 #include "opto/connode.hpp"
45 #include "opto/divnode.hpp"
46 #include "opto/escape.hpp"
47 #include "opto/idealGraphPrinter.hpp"
48 #include "opto/loopnode.hpp"
49 #include "opto/machnode.hpp"
50 #include "opto/macro.hpp"
51 #include "opto/matcher.hpp"
52 #include "opto/mathexactnode.hpp"
53 #include "opto/memnode.hpp"
54 #include "opto/mulnode.hpp"
55 #include "opto/narrowptrnode.hpp"
56 #include "opto/node.hpp"
57 #include "opto/opcodes.hpp"
58 #include "opto/output.hpp"
59 #include "opto/parse.hpp"
60 #include "opto/phaseX.hpp"
61 #include "opto/rootnode.hpp"
62 #include "opto/runtime.hpp"
63 #include "opto/stringopts.hpp"
64 #include "opto/type.hpp"
65 #include "opto/vectornode.hpp"
66 #include "runtime/arguments.hpp"
67 #include "runtime/signature.hpp"
68 #include "runtime/stubRoutines.hpp"
69 #include "runtime/timer.hpp"
70 #include "trace/tracing.hpp"
71 #include "utilities/copy.hpp"
72
73
74 // -------------------- Compile::mach_constant_base_node -----------------------
75 // Constant table base node singleton.
76 MachConstantBaseNode* Compile::mach_constant_base_node() {
77 if (_mach_constant_base_node == NULL) {
78 _mach_constant_base_node = new MachConstantBaseNode();
79 _mach_constant_base_node->add_req(C->root());
80 }
81 return _mach_constant_base_node;
82 }
83
84
85 /// Support for intrinsics.
86
87 // Return the index at which m must be inserted (or already exists).
88 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
89 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
90 #ifdef ASSERT
91 for (int i = 1; i < _intrinsics->length(); i++) {
92 CallGenerator* cg1 = _intrinsics->at(i-1);
93 CallGenerator* cg2 = _intrinsics->at(i);
94 assert(cg1->method() != cg2->method()
95 ? cg1->method() < cg2->method()
96 : cg1->is_virtual() < cg2->is_virtual(),
97 "compiler intrinsics list must stay sorted");
98 }
99 #endif
100 // Binary search sorted list, in decreasing intervals [lo, hi].
101 int lo = 0, hi = _intrinsics->length()-1;
102 while (lo <= hi) {
103 int mid = (uint)(hi + lo) / 2;
104 ciMethod* mid_m = _intrinsics->at(mid)->method();
105 if (m < mid_m) {
106 hi = mid-1;
107 } else if (m > mid_m) {
108 lo = mid+1;
109 } else {
110 // look at minor sort key
111 bool mid_virt = _intrinsics->at(mid)->is_virtual();
112 if (is_virtual < mid_virt) {
113 hi = mid-1;
114 } else if (is_virtual > mid_virt) {
115 lo = mid+1;
116 } else {
117 return mid; // exact match
118 }
119 }
120 }
121 return lo; // inexact match
122 }
123
124 void Compile::register_intrinsic(CallGenerator* cg) {
125 if (_intrinsics == NULL) {
126 _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
127 }
128 // This code is stolen from ciObjectFactory::insert.
129 // Really, GrowableArray should have methods for
130 // insert_at, remove_at, and binary_search.
131 int len = _intrinsics->length();
132 int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
133 if (index == len) {
134 _intrinsics->append(cg);
135 } else {
136 #ifdef ASSERT
137 CallGenerator* oldcg = _intrinsics->at(index);
138 assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
139 #endif
140 _intrinsics->append(_intrinsics->at(len-1));
141 int pos;
142 for (pos = len-2; pos >= index; pos--) {
143 _intrinsics->at_put(pos+1,_intrinsics->at(pos));
144 }
145 _intrinsics->at_put(index, cg);
146 }
147 assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
148 }
149
150 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
151 assert(m->is_loaded(), "don't try this on unloaded methods");
152 if (_intrinsics != NULL) {
153 int index = intrinsic_insertion_index(m, is_virtual);
154 if (index < _intrinsics->length()
155 && _intrinsics->at(index)->method() == m
156 && _intrinsics->at(index)->is_virtual() == is_virtual) {
157 return _intrinsics->at(index);
158 }
159 }
160 // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
161 if (m->intrinsic_id() != vmIntrinsics::_none &&
162 m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
163 CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
164 if (cg != NULL) {
165 // Save it for next time:
166 register_intrinsic(cg);
167 return cg;
168 } else {
169 gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
170 }
171 }
172 return NULL;
173 }
174
175 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
176 // in library_call.cpp.
177
178
179 #ifndef PRODUCT
180 // statistics gathering...
181
182 juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
183 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
184
185 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
186 assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
187 int oflags = _intrinsic_hist_flags[id];
188 assert(flags != 0, "what happened?");
189 if (is_virtual) {
190 flags |= _intrinsic_virtual;
191 }
192 bool changed = (flags != oflags);
193 if ((flags & _intrinsic_worked) != 0) {
194 juint count = (_intrinsic_hist_count[id] += 1);
195 if (count == 1) {
196 changed = true; // first time
197 }
198 // increment the overall count also:
199 _intrinsic_hist_count[vmIntrinsics::_none] += 1;
200 }
201 if (changed) {
202 if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
203 // Something changed about the intrinsic's virtuality.
204 if ((flags & _intrinsic_virtual) != 0) {
205 // This is the first use of this intrinsic as a virtual call.
206 if (oflags != 0) {
207 // We already saw it as a non-virtual, so note both cases.
208 flags |= _intrinsic_both;
209 }
210 } else if ((oflags & _intrinsic_both) == 0) {
211 // This is the first use of this intrinsic as a non-virtual
212 flags |= _intrinsic_both;
213 }
214 }
215 _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
216 }
217 // update the overall flags also:
218 _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
219 return changed;
220 }
221
222 static char* format_flags(int flags, char* buf) {
223 buf[0] = 0;
224 if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
225 if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
226 if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
227 if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
228 if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
229 if (buf[0] == 0) strcat(buf, ",");
230 assert(buf[0] == ',', "must be");
231 return &buf[1];
232 }
233
234 void Compile::print_intrinsic_statistics() {
235 char flagsbuf[100];
236 ttyLocker ttyl;
237 if (xtty != NULL) xtty->head("statistics type='intrinsic'");
238 tty->print_cr("Compiler intrinsic usage:");
239 juint total = _intrinsic_hist_count[vmIntrinsics::_none];
240 if (total == 0) total = 1; // avoid div0 in case of no successes
241 #define PRINT_STAT_LINE(name, c, f) \
242 tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
243 for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
244 vmIntrinsics::ID id = (vmIntrinsics::ID) index;
245 int flags = _intrinsic_hist_flags[id];
246 juint count = _intrinsic_hist_count[id];
247 if ((flags | count) != 0) {
248 PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
249 }
250 }
251 PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
252 if (xtty != NULL) xtty->tail("statistics");
253 }
254
255 void Compile::print_statistics() {
256 { ttyLocker ttyl;
257 if (xtty != NULL) xtty->head("statistics type='opto'");
258 Parse::print_statistics();
259 PhaseCCP::print_statistics();
260 PhaseRegAlloc::print_statistics();
261 Scheduling::print_statistics();
262 PhasePeephole::print_statistics();
263 PhaseIdealLoop::print_statistics();
264 if (xtty != NULL) xtty->tail("statistics");
265 }
266 if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
267 // put this under its own <statistics> element.
268 print_intrinsic_statistics();
269 }
270 }
271 #endif //PRODUCT
272
273 // Support for bundling info
274 Bundle* Compile::node_bundling(const Node *n) {
275 assert(valid_bundle_info(n), "oob");
276 return &_node_bundling_base[n->_idx];
277 }
278
279 bool Compile::valid_bundle_info(const Node *n) {
280 return (_node_bundling_limit > n->_idx);
281 }
282
283
284 void Compile::gvn_replace_by(Node* n, Node* nn) {
285 for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
286 Node* use = n->last_out(i);
287 bool is_in_table = initial_gvn()->hash_delete(use);
288 uint uses_found = 0;
289 for (uint j = 0; j < use->len(); j++) {
290 if (use->in(j) == n) {
291 if (j < use->req())
292 use->set_req(j, nn);
293 else
294 use->set_prec(j, nn);
295 uses_found++;
296 }
297 }
298 if (is_in_table) {
299 // reinsert into table
300 initial_gvn()->hash_find_insert(use);
301 }
302 record_for_igvn(use);
303 i -= uses_found; // we deleted 1 or more copies of this edge
304 }
305 }
306
307
308 static inline bool not_a_node(const Node* n) {
309 if (n == NULL) return true;
310 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
311 if (*(address*)n == badAddress) return true; // kill by Node::destruct
312 return false;
313 }
314
315 // Identify all nodes that are reachable from below, useful.
316 // Use breadth-first pass that records state in a Unique_Node_List,
317 // recursive traversal is slower.
318 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
319 int estimated_worklist_size = unique();
320 useful.map( estimated_worklist_size, NULL ); // preallocate space
321
322 // Initialize worklist
323 if (root() != NULL) { useful.push(root()); }
324 // If 'top' is cached, declare it useful to preserve cached node
325 if( cached_top_node() ) { useful.push(cached_top_node()); }
326
327 // Push all useful nodes onto the list, breadthfirst
328 for( uint next = 0; next < useful.size(); ++next ) {
329 assert( next < unique(), "Unique useful nodes < total nodes");
330 Node *n = useful.at(next);
331 uint max = n->len();
332 for( uint i = 0; i < max; ++i ) {
333 Node *m = n->in(i);
334 if (not_a_node(m)) continue;
335 useful.push(m);
336 }
337 }
338 }
339
340 // Update dead_node_list with any missing dead nodes using useful
341 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
342 void Compile::update_dead_node_list(Unique_Node_List &useful) {
343 uint max_idx = unique();
344 VectorSet& useful_node_set = useful.member_set();
345
346 for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
347 // If node with index node_idx is not in useful set,
348 // mark it as dead in dead node list.
349 if (! useful_node_set.test(node_idx) ) {
350 record_dead_node(node_idx);
351 }
352 }
353 }
354
355 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
356 int shift = 0;
357 for (int i = 0; i < inlines->length(); i++) {
358 CallGenerator* cg = inlines->at(i);
359 CallNode* call = cg->call_node();
360 if (shift > 0) {
361 inlines->at_put(i-shift, cg);
362 }
363 if (!useful.member(call)) {
364 shift++;
365 }
366 }
367 inlines->trunc_to(inlines->length()-shift);
368 }
369
370 // Disconnect all useless nodes by disconnecting those at the boundary.
371 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
372 uint next = 0;
373 while (next < useful.size()) {
374 Node *n = useful.at(next++);
375 if (n->is_SafePoint()) {
376 // We're done with a parsing phase. Replaced nodes are not valid
377 // beyond that point.
378 n->as_SafePoint()->delete_replaced_nodes();
379 }
380 // Use raw traversal of out edges since this code removes out edges
381 int max = n->outcnt();
382 for (int j = 0; j < max; ++j) {
383 Node* child = n->raw_out(j);
384 if (! useful.member(child)) {
385 assert(!child->is_top() || child != top(),
386 "If top is cached in Compile object it is in useful list");
387 // Only need to remove this out-edge to the useless node
388 n->raw_del_out(j);
389 --j;
390 --max;
391 }
392 }
393 if (n->outcnt() == 1 && n->has_special_unique_user()) {
394 record_for_igvn(n->unique_out());
395 }
396 }
397 // Remove useless macro and predicate opaq nodes
398 for (int i = C->macro_count()-1; i >= 0; i--) {
399 Node* n = C->macro_node(i);
400 if (!useful.member(n)) {
401 remove_macro_node(n);
402 }
403 }
404 // Remove useless expensive node
405 for (int i = C->expensive_count()-1; i >= 0; i--) {
406 Node* n = C->expensive_node(i);
407 if (!useful.member(n)) {
408 remove_expensive_node(n);
409 }
410 }
411 // clean up the late inline lists
412 remove_useless_late_inlines(&_string_late_inlines, useful);
413 remove_useless_late_inlines(&_boxing_late_inlines, useful);
414 remove_useless_late_inlines(&_late_inlines, useful);
415 debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
416 }
417
418 //------------------------------frame_size_in_words-----------------------------
419 // frame_slots in units of words
420 int Compile::frame_size_in_words() const {
421 // shift is 0 in LP32 and 1 in LP64
422 const int shift = (LogBytesPerWord - LogBytesPerInt);
423 int words = _frame_slots >> shift;
424 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
425 return words;
426 }
427
428 // To bang the stack of this compiled method we use the stack size
429 // that the interpreter would need in case of a deoptimization. This
430 // removes the need to bang the stack in the deoptimization blob which
431 // in turn simplifies stack overflow handling.
432 int Compile::bang_size_in_bytes() const {
433 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
434 }
435
436 // ============================================================================
437 //------------------------------CompileWrapper---------------------------------
438 class CompileWrapper : public StackObj {
439 Compile *const _compile;
440 public:
441 CompileWrapper(Compile* compile);
442
443 ~CompileWrapper();
444 };
445
446 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
447 // the Compile* pointer is stored in the current ciEnv:
448 ciEnv* env = compile->env();
449 assert(env == ciEnv::current(), "must already be a ciEnv active");
450 assert(env->compiler_data() == NULL, "compile already active?");
451 env->set_compiler_data(compile);
452 assert(compile == Compile::current(), "sanity");
453
454 compile->set_type_dict(NULL);
455 compile->set_type_hwm(NULL);
456 compile->set_type_last_size(0);
457 compile->set_last_tf(NULL, NULL);
458 compile->set_indexSet_arena(NULL);
459 compile->set_indexSet_free_block_list(NULL);
460 compile->init_type_arena();
461 Type::Initialize(compile);
462 _compile->set_scratch_buffer_blob(NULL);
463 _compile->begin_method();
464 }
465 CompileWrapper::~CompileWrapper() {
466 _compile->end_method();
467 if (_compile->scratch_buffer_blob() != NULL)
468 BufferBlob::free(_compile->scratch_buffer_blob());
469 _compile->env()->set_compiler_data(NULL);
470 }
471
472
473 //----------------------------print_compile_messages---------------------------
474 void Compile::print_compile_messages() {
475 #ifndef PRODUCT
476 // Check if recompiling
477 if (_subsume_loads == false && PrintOpto) {
478 // Recompiling without allowing machine instructions to subsume loads
479 tty->print_cr("*********************************************************");
480 tty->print_cr("** Bailout: Recompile without subsuming loads **");
481 tty->print_cr("*********************************************************");
482 }
483 if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
484 // Recompiling without escape analysis
485 tty->print_cr("*********************************************************");
486 tty->print_cr("** Bailout: Recompile without escape analysis **");
487 tty->print_cr("*********************************************************");
488 }
489 if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
490 // Recompiling without boxing elimination
491 tty->print_cr("*********************************************************");
492 tty->print_cr("** Bailout: Recompile without boxing elimination **");
493 tty->print_cr("*********************************************************");
494 }
495 if (env()->break_at_compile()) {
496 // Open the debugger when compiling this method.
497 tty->print("### Breaking when compiling: ");
498 method()->print_short_name();
499 tty->cr();
500 BREAKPOINT;
501 }
502
503 if( PrintOpto ) {
504 if (is_osr_compilation()) {
505 tty->print("[OSR]%3d", _compile_id);
506 } else {
507 tty->print("%3d", _compile_id);
508 }
509 }
510 #endif
511 }
512
513
514 //-----------------------init_scratch_buffer_blob------------------------------
515 // Construct a temporary BufferBlob and cache it for this compile.
516 void Compile::init_scratch_buffer_blob(int const_size) {
517 // If there is already a scratch buffer blob allocated and the
518 // constant section is big enough, use it. Otherwise free the
519 // current and allocate a new one.
520 BufferBlob* blob = scratch_buffer_blob();
521 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
522 // Use the current blob.
523 } else {
524 if (blob != NULL) {
525 BufferBlob::free(blob);
526 }
527
528 ResourceMark rm;
529 _scratch_const_size = const_size;
530 int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
531 blob = BufferBlob::create("Compile::scratch_buffer", size);
532 // Record the buffer blob for next time.
533 set_scratch_buffer_blob(blob);
534 // Have we run out of code space?
535 if (scratch_buffer_blob() == NULL) {
536 // Let CompilerBroker disable further compilations.
537 record_failure("Not enough space for scratch buffer in CodeCache");
538 CompileBroker::handle_full_code_cache(CodeBlobType::NonNMethod);
539 return;
540 }
541 }
542
543 // Initialize the relocation buffers
544 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
545 set_scratch_locs_memory(locs_buf);
546 }
547
548
549 //-----------------------scratch_emit_size-------------------------------------
550 // Helper function that computes size by emitting code
551 uint Compile::scratch_emit_size(const Node* n) {
552 // Start scratch_emit_size section.
553 set_in_scratch_emit_size(true);
554
555 // Emit into a trash buffer and count bytes emitted.
556 // This is a pretty expensive way to compute a size,
557 // but it works well enough if seldom used.
558 // All common fixed-size instructions are given a size
559 // method by the AD file.
560 // Note that the scratch buffer blob and locs memory are
561 // allocated at the beginning of the compile task, and
562 // may be shared by several calls to scratch_emit_size.
563 // The allocation of the scratch buffer blob is particularly
564 // expensive, since it has to grab the code cache lock.
565 BufferBlob* blob = this->scratch_buffer_blob();
566 assert(blob != NULL, "Initialize BufferBlob at start");
567 assert(blob->size() > MAX_inst_size, "sanity");
568 relocInfo* locs_buf = scratch_locs_memory();
569 address blob_begin = blob->content_begin();
570 address blob_end = (address)locs_buf;
571 assert(blob->content_contains(blob_end), "sanity");
572 CodeBuffer buf(blob_begin, blob_end - blob_begin);
573 buf.initialize_consts_size(_scratch_const_size);
574 buf.initialize_stubs_size(MAX_stubs_size);
575 assert(locs_buf != NULL, "sanity");
576 int lsize = MAX_locs_size / 3;
577 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
578 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
579 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
580
581 // Do the emission.
582
583 Label fakeL; // Fake label for branch instructions.
584 Label* saveL = NULL;
585 uint save_bnum = 0;
586 bool is_branch = n->is_MachBranch();
587 if (is_branch) {
588 MacroAssembler masm(&buf);
589 masm.bind(fakeL);
590 n->as_MachBranch()->save_label(&saveL, &save_bnum);
591 n->as_MachBranch()->label_set(&fakeL, 0);
592 }
593 n->emit(buf, this->regalloc());
594 if (is_branch) // Restore label.
595 n->as_MachBranch()->label_set(saveL, save_bnum);
596
597 // End scratch_emit_size section.
598 set_in_scratch_emit_size(false);
599
600 return buf.insts_size();
601 }
602
603
604 // ============================================================================
605 //------------------------------Compile standard-------------------------------
606 debug_only( int Compile::_debug_idx = 100000; )
607
608 // Compile a method. entry_bci is -1 for normal compilations and indicates
609 // the continuation bci for on stack replacement.
610
611
612 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
613 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
614 : Phase(Compiler),
615 _env(ci_env),
616 _log(ci_env->log()),
617 _compile_id(ci_env->compile_id()),
618 _save_argument_registers(false),
619 _stub_name(NULL),
620 _stub_function(NULL),
621 _stub_entry_point(NULL),
622 _method(target),
623 _entry_bci(osr_bci),
624 _initial_gvn(NULL),
625 _for_igvn(NULL),
626 _warm_calls(NULL),
627 _subsume_loads(subsume_loads),
628 _do_escape_analysis(do_escape_analysis),
629 _eliminate_boxing(eliminate_boxing),
630 _failure_reason(NULL),
631 _code_buffer("Compile::Fill_buffer"),
632 _orig_pc_slot(0),
633 _orig_pc_slot_offset_in_bytes(0),
634 _has_method_handle_invokes(false),
635 _mach_constant_base_node(NULL),
636 _node_bundling_limit(0),
637 _node_bundling_base(NULL),
638 _java_calls(0),
639 _inner_loops(0),
640 _scratch_const_size(-1),
641 _in_scratch_emit_size(false),
642 _dead_node_list(comp_arena()),
643 _dead_node_count(0),
644 #ifndef PRODUCT
645 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
646 _in_dump_cnt(0),
647 _printer(IdealGraphPrinter::printer()),
648 #endif
649 _congraph(NULL),
650 _comp_arena(mtCompiler),
651 _node_arena(mtCompiler),
652 _old_arena(mtCompiler),
653 _Compile_types(mtCompiler),
654 _replay_inline_data(NULL),
655 _late_inlines(comp_arena(), 2, 0, NULL),
656 _string_late_inlines(comp_arena(), 2, 0, NULL),
657 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
658 _late_inlines_pos(0),
659 _number_of_mh_late_inlines(0),
660 _inlining_progress(false),
661 _inlining_incrementally(false),
662 _print_inlining_list(NULL),
663 _print_inlining_stream(NULL),
664 _print_inlining_idx(0),
665 _print_inlining_output(NULL),
666 _interpreter_frame_size(0),
667 _max_node_limit(MaxNodeLimit) {
668 C = this;
669
670 CompileWrapper cw(this);
671
672 if (CITimeVerbose) {
673 tty->print(" ");
674 target->holder()->name()->print();
675 tty->print(".");
676 target->print_short_name();
677 tty->print(" ");
678 }
679 TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
680 TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
681
682 #ifndef PRODUCT
683 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
684 if (!print_opto_assembly) {
685 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
686 if (print_assembly && !Disassembler::can_decode()) {
687 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
688 print_opto_assembly = true;
689 }
690 }
691 set_print_assembly(print_opto_assembly);
692 set_parsed_irreducible_loop(false);
693
694 if (method()->has_option("ReplayInline")) {
695 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
696 }
697 #endif
698 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
699 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
700 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
701
702 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
703 // Make sure the method being compiled gets its own MDO,
704 // so we can at least track the decompile_count().
705 // Need MDO to record RTM code generation state.
706 method()->ensure_method_data();
707 }
708
709 Init(::AliasLevel);
710
711
712 print_compile_messages();
713
714 _ilt = InlineTree::build_inline_tree_root();
715
716 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
717 assert(num_alias_types() >= AliasIdxRaw, "");
718
719 #define MINIMUM_NODE_HASH 1023
720 // Node list that Iterative GVN will start with
721 Unique_Node_List for_igvn(comp_arena());
722 set_for_igvn(&for_igvn);
723
724 // GVN that will be run immediately on new nodes
725 uint estimated_size = method()->code_size()*4+64;
726 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
727 PhaseGVN gvn(node_arena(), estimated_size);
728 set_initial_gvn(&gvn);
729
730 print_inlining_init();
731 { // Scope for timing the parser
732 TracePhase tp("parse", &timers[_t_parser]);
733
734 // Put top into the hash table ASAP.
735 initial_gvn()->transform_no_reclaim(top());
736
737 // Set up tf(), start(), and find a CallGenerator.
738 CallGenerator* cg = NULL;
739 if (is_osr_compilation()) {
740 const TypeTuple *domain = StartOSRNode::osr_domain();
741 const TypeTuple *range = TypeTuple::make_range(method()->signature());
742 init_tf(TypeFunc::make(domain, range));
743 StartNode* s = new StartOSRNode(root(), domain);
744 initial_gvn()->set_type_bottom(s);
745 init_start(s);
746 cg = CallGenerator::for_osr(method(), entry_bci());
747 } else {
748 // Normal case.
749 init_tf(TypeFunc::make(method()));
750 StartNode* s = new StartNode(root(), tf()->domain());
751 initial_gvn()->set_type_bottom(s);
752 init_start(s);
753 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
754 // With java.lang.ref.reference.get() we must go through the
755 // intrinsic when G1 is enabled - even when get() is the root
756 // method of the compile - so that, if necessary, the value in
757 // the referent field of the reference object gets recorded by
758 // the pre-barrier code.
759 // Specifically, if G1 is enabled, the value in the referent
760 // field is recorded by the G1 SATB pre barrier. This will
761 // result in the referent being marked live and the reference
762 // object removed from the list of discovered references during
763 // reference processing.
764 cg = find_intrinsic(method(), false);
765 }
766 if (cg == NULL) {
767 float past_uses = method()->interpreter_invocation_count();
768 float expected_uses = past_uses;
769 cg = CallGenerator::for_inline(method(), expected_uses);
770 }
771 }
772 if (failing()) return;
773 if (cg == NULL) {
774 record_method_not_compilable_all_tiers("cannot parse method");
775 return;
776 }
777 JVMState* jvms = build_start_state(start(), tf());
778 if ((jvms = cg->generate(jvms)) == NULL) {
779 record_method_not_compilable("method parse failed");
780 return;
781 }
782 GraphKit kit(jvms);
783
784 if (!kit.stopped()) {
785 // Accept return values, and transfer control we know not where.
786 // This is done by a special, unique ReturnNode bound to root.
787 return_values(kit.jvms());
788 }
789
790 if (kit.has_exceptions()) {
791 // Any exceptions that escape from this call must be rethrown
792 // to whatever caller is dynamically above us on the stack.
793 // This is done by a special, unique RethrowNode bound to root.
794 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
795 }
796
797 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
798
799 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
800 inline_string_calls(true);
801 }
802
803 if (failing()) return;
804
805 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
806
807 // Remove clutter produced by parsing.
808 if (!failing()) {
809 ResourceMark rm;
810 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
811 }
812 }
813
814 // Note: Large methods are capped off in do_one_bytecode().
815 if (failing()) return;
816
817 // After parsing, node notes are no longer automagic.
818 // They must be propagated by register_new_node_with_optimizer(),
819 // clone(), or the like.
820 set_default_node_notes(NULL);
821
822 for (;;) {
823 int successes = Inline_Warm();
824 if (failing()) return;
825 if (successes == 0) break;
826 }
827
828 // Drain the list.
829 Finish_Warm();
830 #ifndef PRODUCT
831 if (_printer && _printer->should_print(_method)) {
832 _printer->print_inlining(this);
833 }
834 #endif
835
836 if (failing()) return;
837 NOT_PRODUCT( verify_graph_edges(); )
838
839 // Now optimize
840 Optimize();
841 if (failing()) return;
842 NOT_PRODUCT( verify_graph_edges(); )
843
844 #ifndef PRODUCT
845 if (PrintIdeal) {
846 ttyLocker ttyl; // keep the following output all in one block
847 // This output goes directly to the tty, not the compiler log.
848 // To enable tools to match it up with the compilation activity,
849 // be sure to tag this tty output with the compile ID.
850 if (xtty != NULL) {
851 xtty->head("ideal compile_id='%d'%s", compile_id(),
852 is_osr_compilation() ? " compile_kind='osr'" :
853 "");
854 }
855 root()->dump(9999);
856 if (xtty != NULL) {
857 xtty->tail("ideal");
858 }
859 }
860 #endif
861
862 NOT_PRODUCT( verify_barriers(); )
863
864 // Dump compilation data to replay it.
865 if (method()->has_option("DumpReplay")) {
866 env()->dump_replay_data(_compile_id);
867 }
868 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
869 env()->dump_inline_data(_compile_id);
870 }
871
872 // Now that we know the size of all the monitors we can add a fixed slot
873 // for the original deopt pc.
874
875 _orig_pc_slot = fixed_slots();
876 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
877 set_fixed_slots(next_slot);
878
879 // Compute when to use implicit null checks. Used by matching trap based
880 // nodes and NullCheck optimization.
881 set_allowed_deopt_reasons();
882
883 // Now generate code
884 Code_Gen();
885 if (failing()) return;
886
887 // Check if we want to skip execution of all compiled code.
888 {
889 #ifndef PRODUCT
890 if (OptoNoExecute) {
891 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
892 return;
893 }
894 #endif
895 TracePhase tp("install_code", &timers[_t_registerMethod]);
896
897 if (is_osr_compilation()) {
898 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
899 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
900 } else {
901 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
902 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
903 }
904
905 env()->register_method(_method, _entry_bci,
906 &_code_offsets,
907 _orig_pc_slot_offset_in_bytes,
908 code_buffer(),
909 frame_size_in_words(), _oop_map_set,
910 &_handler_table, &_inc_table,
911 compiler,
912 env()->comp_level(),
913 has_unsafe_access(),
914 SharedRuntime::is_wide_vector(max_vector_size()),
915 rtm_state()
916 );
917
918 if (log() != NULL) // Print code cache state into compiler log
919 log()->code_cache_state();
920 }
921 }
922
923 //------------------------------Compile----------------------------------------
924 // Compile a runtime stub
925 Compile::Compile( ciEnv* ci_env,
926 TypeFunc_generator generator,
927 address stub_function,
928 const char *stub_name,
929 int is_fancy_jump,
930 bool pass_tls,
931 bool save_arg_registers,
932 bool return_pc )
933 : Phase(Compiler),
934 _env(ci_env),
935 _log(ci_env->log()),
936 _compile_id(0),
937 _save_argument_registers(save_arg_registers),
938 _method(NULL),
939 _stub_name(stub_name),
940 _stub_function(stub_function),
941 _stub_entry_point(NULL),
942 _entry_bci(InvocationEntryBci),
943 _initial_gvn(NULL),
944 _for_igvn(NULL),
945 _warm_calls(NULL),
946 _orig_pc_slot(0),
947 _orig_pc_slot_offset_in_bytes(0),
948 _subsume_loads(true),
949 _do_escape_analysis(false),
950 _eliminate_boxing(false),
951 _failure_reason(NULL),
952 _code_buffer("Compile::Fill_buffer"),
953 _has_method_handle_invokes(false),
954 _mach_constant_base_node(NULL),
955 _node_bundling_limit(0),
956 _node_bundling_base(NULL),
957 _java_calls(0),
958 _inner_loops(0),
959 #ifndef PRODUCT
960 _trace_opto_output(TraceOptoOutput),
961 _in_dump_cnt(0),
962 _printer(NULL),
963 #endif
964 _comp_arena(mtCompiler),
965 _node_arena(mtCompiler),
966 _old_arena(mtCompiler),
967 _Compile_types(mtCompiler),
968 _dead_node_list(comp_arena()),
969 _dead_node_count(0),
970 _congraph(NULL),
971 _replay_inline_data(NULL),
972 _number_of_mh_late_inlines(0),
973 _inlining_progress(false),
974 _inlining_incrementally(false),
975 _print_inlining_list(NULL),
976 _print_inlining_stream(NULL),
977 _print_inlining_idx(0),
978 _print_inlining_output(NULL),
979 _allowed_reasons(0),
980 _interpreter_frame_size(0),
981 _max_node_limit(MaxNodeLimit) {
982 C = this;
983
984 TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
985 TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
986
987 #ifndef PRODUCT
988 set_print_assembly(PrintFrameConverterAssembly);
989 set_parsed_irreducible_loop(false);
990 #endif
991 set_has_irreducible_loop(false); // no loops
992
993 CompileWrapper cw(this);
994 Init(/*AliasLevel=*/ 0);
995 init_tf((*generator)());
996
997 {
998 // The following is a dummy for the sake of GraphKit::gen_stub
999 Unique_Node_List for_igvn(comp_arena());
1000 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
1001 PhaseGVN gvn(Thread::current()->resource_area(),255);
1002 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
1003 gvn.transform_no_reclaim(top());
1004
1005 GraphKit kit;
1006 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1007 }
1008
1009 NOT_PRODUCT( verify_graph_edges(); )
1010 Code_Gen();
1011 if (failing()) return;
1012
1013
1014 // Entry point will be accessed using compile->stub_entry_point();
1015 if (code_buffer() == NULL) {
1016 Matcher::soft_match_failure();
1017 } else {
1018 if (PrintAssembly && (WizardMode || Verbose))
1019 tty->print_cr("### Stub::%s", stub_name);
1020
1021 if (!failing()) {
1022 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1023
1024 // Make the NMethod
1025 // For now we mark the frame as never safe for profile stackwalking
1026 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1027 code_buffer(),
1028 CodeOffsets::frame_never_safe,
1029 // _code_offsets.value(CodeOffsets::Frame_Complete),
1030 frame_size_in_words(),
1031 _oop_map_set,
1032 save_arg_registers);
1033 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1034
1035 _stub_entry_point = rs->entry_point();
1036 }
1037 }
1038 }
1039
1040 //------------------------------Init-------------------------------------------
1041 // Prepare for a single compilation
1042 void Compile::Init(int aliaslevel) {
1043 _unique = 0;
1044 _regalloc = NULL;
1045
1046 _tf = NULL; // filled in later
1047 _top = NULL; // cached later
1048 _matcher = NULL; // filled in later
1049 _cfg = NULL; // filled in later
1050
1051 set_24_bit_selection_and_mode(Use24BitFP, false);
1052
1053 _node_note_array = NULL;
1054 _default_node_notes = NULL;
1055 DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
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 RootNode());
1063 // Now that you have a Root to point to, create the real TOP
1064 set_cached_top_node( new 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_age_code(has_method() && method()->profile_aging());
1093 set_rtm_state(NoRTM); // No RTM lock eliding by default
1094 method_has_option_value("MaxNodeLimit", _max_node_limit);
1095 #if INCLUDE_RTM_OPT
1096 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1097 int rtm_state = method()->method_data()->rtm_state();
1098 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1099 // Don't generate RTM lock eliding code.
1100 set_rtm_state(NoRTM);
1101 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1102 // Generate RTM lock eliding code without abort ratio calculation code.
1103 set_rtm_state(UseRTM);
1104 } else if (UseRTMDeopt) {
1105 // Generate RTM lock eliding code and include abort ratio calculation
1106 // code if UseRTMDeopt is on.
1107 set_rtm_state(ProfileRTM);
1108 }
1109 }
1110 #endif
1111 if (debug_info()->recording_non_safepoints()) {
1112 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1113 (comp_arena(), 8, 0, NULL));
1114 set_default_node_notes(Node_Notes::make(this));
1115 }
1116
1117 // // -- Initialize types before each compile --
1118 // // Update cached type information
1119 // if( _method && _method->constants() )
1120 // Type::update_loaded_types(_method, _method->constants());
1121
1122 // Init alias_type map.
1123 if (!_do_escape_analysis && aliaslevel == 3)
1124 aliaslevel = 2; // No unique types without escape analysis
1125 _AliasLevel = aliaslevel;
1126 const int grow_ats = 16;
1127 _max_alias_types = grow_ats;
1128 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1129 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1130 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1131 {
1132 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1133 }
1134 // Initialize the first few types.
1135 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1136 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1137 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1138 _num_alias_types = AliasIdxRaw+1;
1139 // Zero out the alias type cache.
1140 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1141 // A NULL adr_type hits in the cache right away. Preload the right answer.
1142 probe_alias_cache(NULL)->_index = AliasIdxTop;
1143
1144 _intrinsics = NULL;
1145 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1146 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1147 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1148 register_library_intrinsics();
1149 }
1150
1151 //---------------------------init_start----------------------------------------
1152 // Install the StartNode on this compile object.
1153 void Compile::init_start(StartNode* s) {
1154 if (failing())
1155 return; // already failing
1156 assert(s == start(), "");
1157 }
1158
1159 /**
1160 * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1161 * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1162 * the ideal graph.
1163 */
1164 StartNode* Compile::start() const {
1165 assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
1166 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1167 Node* start = root()->fast_out(i);
1168 if (start->is_Start()) {
1169 return start->as_Start();
1170 }
1171 }
1172 fatal("Did not find Start node!");
1173 return NULL;
1174 }
1175
1176 //-------------------------------immutable_memory-------------------------------------
1177 // Access immutable memory
1178 Node* Compile::immutable_memory() {
1179 if (_immutable_memory != NULL) {
1180 return _immutable_memory;
1181 }
1182 StartNode* s = start();
1183 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1184 Node *p = s->fast_out(i);
1185 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1186 _immutable_memory = p;
1187 return _immutable_memory;
1188 }
1189 }
1190 ShouldNotReachHere();
1191 return NULL;
1192 }
1193
1194 //----------------------set_cached_top_node------------------------------------
1195 // Install the cached top node, and make sure Node::is_top works correctly.
1196 void Compile::set_cached_top_node(Node* tn) {
1197 if (tn != NULL) verify_top(tn);
1198 Node* old_top = _top;
1199 _top = tn;
1200 // Calling Node::setup_is_top allows the nodes the chance to adjust
1201 // their _out arrays.
1202 if (_top != NULL) _top->setup_is_top();
1203 if (old_top != NULL) old_top->setup_is_top();
1204 assert(_top == NULL || top()->is_top(), "");
1205 }
1206
1207 #ifdef ASSERT
1208 uint Compile::count_live_nodes_by_graph_walk() {
1209 Unique_Node_List useful(comp_arena());
1210 // Get useful node list by walking the graph.
1211 identify_useful_nodes(useful);
1212 return useful.size();
1213 }
1214
1215 void Compile::print_missing_nodes() {
1216
1217 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1218 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1219 return;
1220 }
1221
1222 // This is an expensive function. It is executed only when the user
1223 // specifies VerifyIdealNodeCount option or otherwise knows the
1224 // additional work that needs to be done to identify reachable nodes
1225 // by walking the flow graph and find the missing ones using
1226 // _dead_node_list.
1227
1228 Unique_Node_List useful(comp_arena());
1229 // Get useful node list by walking the graph.
1230 identify_useful_nodes(useful);
1231
1232 uint l_nodes = C->live_nodes();
1233 uint l_nodes_by_walk = useful.size();
1234
1235 if (l_nodes != l_nodes_by_walk) {
1236 if (_log != NULL) {
1237 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1238 _log->stamp();
1239 _log->end_head();
1240 }
1241 VectorSet& useful_member_set = useful.member_set();
1242 int last_idx = l_nodes_by_walk;
1243 for (int i = 0; i < last_idx; i++) {
1244 if (useful_member_set.test(i)) {
1245 if (_dead_node_list.test(i)) {
1246 if (_log != NULL) {
1247 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1248 }
1249 if (PrintIdealNodeCount) {
1250 // Print the log message to tty
1251 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1252 useful.at(i)->dump();
1253 }
1254 }
1255 }
1256 else if (! _dead_node_list.test(i)) {
1257 if (_log != NULL) {
1258 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1259 }
1260 if (PrintIdealNodeCount) {
1261 // Print the log message to tty
1262 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1263 }
1264 }
1265 }
1266 if (_log != NULL) {
1267 _log->tail("mismatched_nodes");
1268 }
1269 }
1270 }
1271 void Compile::record_modified_node(Node* n) {
1272 if (_modified_nodes != NULL && !_inlining_incrementally &&
1273 n->outcnt() != 0 && !n->is_Con()) {
1274 _modified_nodes->push(n);
1275 }
1276 }
1277
1278 void Compile::remove_modified_node(Node* n) {
1279 if (_modified_nodes != NULL) {
1280 _modified_nodes->remove(n);
1281 }
1282 }
1283 #endif
1284
1285 #ifndef PRODUCT
1286 void Compile::verify_top(Node* tn) const {
1287 if (tn != NULL) {
1288 assert(tn->is_Con(), "top node must be a constant");
1289 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1290 assert(tn->in(0) != NULL, "must have live top node");
1291 }
1292 }
1293 #endif
1294
1295
1296 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1297
1298 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1299 guarantee(arr != NULL, "");
1300 int num_blocks = arr->length();
1301 if (grow_by < num_blocks) grow_by = num_blocks;
1302 int num_notes = grow_by * _node_notes_block_size;
1303 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1304 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1305 while (num_notes > 0) {
1306 arr->append(notes);
1307 notes += _node_notes_block_size;
1308 num_notes -= _node_notes_block_size;
1309 }
1310 assert(num_notes == 0, "exact multiple, please");
1311 }
1312
1313 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1314 if (source == NULL || dest == NULL) return false;
1315
1316 if (dest->is_Con())
1317 return false; // Do not push debug info onto constants.
1318
1319 #ifdef ASSERT
1320 // Leave a bread crumb trail pointing to the original node:
1321 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1322 dest->set_debug_orig(source);
1323 }
1324 #endif
1325
1326 if (node_note_array() == NULL)
1327 return false; // Not collecting any notes now.
1328
1329 // This is a copy onto a pre-existing node, which may already have notes.
1330 // If both nodes have notes, do not overwrite any pre-existing notes.
1331 Node_Notes* source_notes = node_notes_at(source->_idx);
1332 if (source_notes == NULL || source_notes->is_clear()) return false;
1333 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1334 if (dest_notes == NULL || dest_notes->is_clear()) {
1335 return set_node_notes_at(dest->_idx, source_notes);
1336 }
1337
1338 Node_Notes merged_notes = (*source_notes);
1339 // The order of operations here ensures that dest notes will win...
1340 merged_notes.update_from(dest_notes);
1341 return set_node_notes_at(dest->_idx, &merged_notes);
1342 }
1343
1344
1345 //--------------------------allow_range_check_smearing-------------------------
1346 // Gating condition for coalescing similar range checks.
1347 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1348 // single covering check that is at least as strong as any of them.
1349 // If the optimization succeeds, the simplified (strengthened) range check
1350 // will always succeed. If it fails, we will deopt, and then give up
1351 // on the optimization.
1352 bool Compile::allow_range_check_smearing() const {
1353 // If this method has already thrown a range-check,
1354 // assume it was because we already tried range smearing
1355 // and it failed.
1356 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1357 return !already_trapped;
1358 }
1359
1360
1361 //------------------------------flatten_alias_type-----------------------------
1362 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1363 int offset = tj->offset();
1364 TypePtr::PTR ptr = tj->ptr();
1365
1366 // Known instance (scalarizable allocation) alias only with itself.
1367 bool is_known_inst = tj->isa_oopptr() != NULL &&
1368 tj->is_oopptr()->is_known_instance();
1369
1370 // Process weird unsafe references.
1371 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1372 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1373 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1374 tj = TypeOopPtr::BOTTOM;
1375 ptr = tj->ptr();
1376 offset = tj->offset();
1377 }
1378
1379 // Array pointers need some flattening
1380 const TypeAryPtr *ta = tj->isa_aryptr();
1381 if (ta && ta->is_stable()) {
1382 // Erase stability property for alias analysis.
1383 tj = ta = ta->cast_to_stable(false);
1384 }
1385 if( ta && is_known_inst ) {
1386 if ( offset != Type::OffsetBot &&
1387 offset > arrayOopDesc::length_offset_in_bytes() ) {
1388 offset = Type::OffsetBot; // Flatten constant access into array body only
1389 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1390 }
1391 } else if( ta && _AliasLevel >= 2 ) {
1392 // For arrays indexed by constant indices, we flatten the alias
1393 // space to include all of the array body. Only the header, klass
1394 // and array length can be accessed un-aliased.
1395 if( offset != Type::OffsetBot ) {
1396 if( ta->const_oop() ) { // MethodData* or Method*
1397 offset = Type::OffsetBot; // Flatten constant access into array body
1398 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1399 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1400 // range is OK as-is.
1401 tj = ta = TypeAryPtr::RANGE;
1402 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1403 tj = TypeInstPtr::KLASS; // all klass loads look alike
1404 ta = TypeAryPtr::RANGE; // generic ignored junk
1405 ptr = TypePtr::BotPTR;
1406 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1407 tj = TypeInstPtr::MARK;
1408 ta = TypeAryPtr::RANGE; // generic ignored junk
1409 ptr = TypePtr::BotPTR;
1410 } else { // Random constant offset into array body
1411 offset = Type::OffsetBot; // Flatten constant access into array body
1412 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1413 }
1414 }
1415 // Arrays of fixed size alias with arrays of unknown size.
1416 if (ta->size() != TypeInt::POS) {
1417 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1418 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1419 }
1420 // Arrays of known objects become arrays of unknown objects.
1421 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1422 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1423 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1424 }
1425 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1426 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1427 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1428 }
1429 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1430 // cannot be distinguished by bytecode alone.
1431 if (ta->elem() == TypeInt::BOOL) {
1432 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1433 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1434 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1435 }
1436 // During the 2nd round of IterGVN, NotNull castings are removed.
1437 // Make sure the Bottom and NotNull variants alias the same.
1438 // Also, make sure exact and non-exact variants alias the same.
1439 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1440 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1441 }
1442 }
1443
1444 // Oop pointers need some flattening
1445 const TypeInstPtr *to = tj->isa_instptr();
1446 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1447 ciInstanceKlass *k = to->klass()->as_instance_klass();
1448 if( ptr == TypePtr::Constant ) {
1449 if (to->klass() != ciEnv::current()->Class_klass() ||
1450 offset < k->size_helper() * wordSize) {
1451 // No constant oop pointers (such as Strings); they alias with
1452 // unknown strings.
1453 assert(!is_known_inst, "not scalarizable allocation");
1454 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1455 }
1456 } else if( is_known_inst ) {
1457 tj = to; // Keep NotNull and klass_is_exact for instance type
1458 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1459 // During the 2nd round of IterGVN, NotNull castings are removed.
1460 // Make sure the Bottom and NotNull variants alias the same.
1461 // Also, make sure exact and non-exact variants alias the same.
1462 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1463 }
1464 if (to->speculative() != NULL) {
1465 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1466 }
1467 // Canonicalize the holder of this field
1468 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1469 // First handle header references such as a LoadKlassNode, even if the
1470 // object's klass is unloaded at compile time (4965979).
1471 if (!is_known_inst) { // Do it only for non-instance types
1472 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1473 }
1474 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1475 // Static fields are in the space above the normal instance
1476 // fields in the java.lang.Class instance.
1477 if (to->klass() != ciEnv::current()->Class_klass()) {
1478 to = NULL;
1479 tj = TypeOopPtr::BOTTOM;
1480 offset = tj->offset();
1481 }
1482 } else {
1483 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1484 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1485 if( is_known_inst ) {
1486 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1487 } else {
1488 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1489 }
1490 }
1491 }
1492 }
1493
1494 // Klass pointers to object array klasses need some flattening
1495 const TypeKlassPtr *tk = tj->isa_klassptr();
1496 if( tk ) {
1497 // If we are referencing a field within a Klass, we need
1498 // to assume the worst case of an Object. Both exact and
1499 // inexact types must flatten to the same alias class so
1500 // use NotNull as the PTR.
1501 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1502
1503 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1504 TypeKlassPtr::OBJECT->klass(),
1505 offset);
1506 }
1507
1508 ciKlass* klass = tk->klass();
1509 if( klass->is_obj_array_klass() ) {
1510 ciKlass* k = TypeAryPtr::OOPS->klass();
1511 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1512 k = TypeInstPtr::BOTTOM->klass();
1513 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1514 }
1515
1516 // Check for precise loads from the primary supertype array and force them
1517 // to the supertype cache alias index. Check for generic array loads from
1518 // the primary supertype array and also force them to the supertype cache
1519 // alias index. Since the same load can reach both, we need to merge
1520 // these 2 disparate memories into the same alias class. Since the
1521 // primary supertype array is read-only, there's no chance of confusion
1522 // where we bypass an array load and an array store.
1523 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1524 if (offset == Type::OffsetBot ||
1525 (offset >= primary_supers_offset &&
1526 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1527 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1528 offset = in_bytes(Klass::secondary_super_cache_offset());
1529 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1530 }
1531 }
1532
1533 // Flatten all Raw pointers together.
1534 if (tj->base() == Type::RawPtr)
1535 tj = TypeRawPtr::BOTTOM;
1536
1537 if (tj->base() == Type::AnyPtr)
1538 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1539
1540 // Flatten all to bottom for now
1541 switch( _AliasLevel ) {
1542 case 0:
1543 tj = TypePtr::BOTTOM;
1544 break;
1545 case 1: // Flatten to: oop, static, field or array
1546 switch (tj->base()) {
1547 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1548 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1549 case Type::AryPtr: // do not distinguish arrays at all
1550 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1551 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1552 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1553 default: ShouldNotReachHere();
1554 }
1555 break;
1556 case 2: // No collapsing at level 2; keep all splits
1557 case 3: // No collapsing at level 3; keep all splits
1558 break;
1559 default:
1560 Unimplemented();
1561 }
1562
1563 offset = tj->offset();
1564 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1565
1566 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1567 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1568 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1569 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1570 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1571 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1572 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1573 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1574 assert( tj->ptr() != TypePtr::TopPTR &&
1575 tj->ptr() != TypePtr::AnyNull &&
1576 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1577 // assert( tj->ptr() != TypePtr::Constant ||
1578 // tj->base() == Type::RawPtr ||
1579 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1580
1581 return tj;
1582 }
1583
1584 void Compile::AliasType::Init(int i, const TypePtr* at) {
1585 _index = i;
1586 _adr_type = at;
1587 _field = NULL;
1588 _element = NULL;
1589 _is_rewritable = true; // default
1590 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1591 if (atoop != NULL && atoop->is_known_instance()) {
1592 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1593 _general_index = Compile::current()->get_alias_index(gt);
1594 } else {
1595 _general_index = 0;
1596 }
1597 }
1598
1599 //---------------------------------print_on------------------------------------
1600 #ifndef PRODUCT
1601 void Compile::AliasType::print_on(outputStream* st) {
1602 if (index() < 10)
1603 st->print("@ <%d> ", index());
1604 else st->print("@ <%d>", index());
1605 st->print(is_rewritable() ? " " : " RO");
1606 int offset = adr_type()->offset();
1607 if (offset == Type::OffsetBot)
1608 st->print(" +any");
1609 else st->print(" +%-3d", offset);
1610 st->print(" in ");
1611 adr_type()->dump_on(st);
1612 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1613 if (field() != NULL && tjp) {
1614 if (tjp->klass() != field()->holder() ||
1615 tjp->offset() != field()->offset_in_bytes()) {
1616 st->print(" != ");
1617 field()->print();
1618 st->print(" ***");
1619 }
1620 }
1621 }
1622
1623 void print_alias_types() {
1624 Compile* C = Compile::current();
1625 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1626 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1627 C->alias_type(idx)->print_on(tty);
1628 tty->cr();
1629 }
1630 }
1631 #endif
1632
1633
1634 //----------------------------probe_alias_cache--------------------------------
1635 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1636 intptr_t key = (intptr_t) adr_type;
1637 key ^= key >> logAliasCacheSize;
1638 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1639 }
1640
1641
1642 //-----------------------------grow_alias_types--------------------------------
1643 void Compile::grow_alias_types() {
1644 const int old_ats = _max_alias_types; // how many before?
1645 const int new_ats = old_ats; // how many more?
1646 const int grow_ats = old_ats+new_ats; // how many now?
1647 _max_alias_types = grow_ats;
1648 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1649 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1650 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1651 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1652 }
1653
1654
1655 //--------------------------------find_alias_type------------------------------
1656 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1657 if (_AliasLevel == 0)
1658 return alias_type(AliasIdxBot);
1659
1660 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1661 if (ace->_adr_type == adr_type) {
1662 return alias_type(ace->_index);
1663 }
1664
1665 // Handle special cases.
1666 if (adr_type == NULL) return alias_type(AliasIdxTop);
1667 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1668
1669 // Do it the slow way.
1670 const TypePtr* flat = flatten_alias_type(adr_type);
1671
1672 #ifdef ASSERT
1673 assert(flat == flatten_alias_type(flat), "idempotent");
1674 assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
1675 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1676 const TypeOopPtr* foop = flat->is_oopptr();
1677 // Scalarizable allocations have exact klass always.
1678 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1679 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1680 assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1681 }
1682 assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1683 #endif
1684
1685 int idx = AliasIdxTop;
1686 for (int i = 0; i < num_alias_types(); i++) {
1687 if (alias_type(i)->adr_type() == flat) {
1688 idx = i;
1689 break;
1690 }
1691 }
1692
1693 if (idx == AliasIdxTop) {
1694 if (no_create) return NULL;
1695 // Grow the array if necessary.
1696 if (_num_alias_types == _max_alias_types) grow_alias_types();
1697 // Add a new alias type.
1698 idx = _num_alias_types++;
1699 _alias_types[idx]->Init(idx, flat);
1700 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1701 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1702 if (flat->isa_instptr()) {
1703 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1704 && flat->is_instptr()->klass() == env()->Class_klass())
1705 alias_type(idx)->set_rewritable(false);
1706 }
1707 if (flat->isa_aryptr()) {
1708 #ifdef ASSERT
1709 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1710 // (T_BYTE has the weakest alignment and size restrictions...)
1711 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1712 #endif
1713 if (flat->offset() == TypePtr::OffsetBot) {
1714 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1715 }
1716 }
1717 if (flat->isa_klassptr()) {
1718 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1719 alias_type(idx)->set_rewritable(false);
1720 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1721 alias_type(idx)->set_rewritable(false);
1722 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1723 alias_type(idx)->set_rewritable(false);
1724 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1725 alias_type(idx)->set_rewritable(false);
1726 }
1727 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1728 // but the base pointer type is not distinctive enough to identify
1729 // references into JavaThread.)
1730
1731 // Check for final fields.
1732 const TypeInstPtr* tinst = flat->isa_instptr();
1733 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1734 ciField* field;
1735 if (tinst->const_oop() != NULL &&
1736 tinst->klass() == ciEnv::current()->Class_klass() &&
1737 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1738 // static field
1739 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1740 field = k->get_field_by_offset(tinst->offset(), true);
1741 } else {
1742 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1743 field = k->get_field_by_offset(tinst->offset(), false);
1744 }
1745 assert(field == NULL ||
1746 original_field == NULL ||
1747 (field->holder() == original_field->holder() &&
1748 field->offset() == original_field->offset() &&
1749 field->is_static() == original_field->is_static()), "wrong field?");
1750 // Set field() and is_rewritable() attributes.
1751 if (field != NULL) alias_type(idx)->set_field(field);
1752 }
1753 }
1754
1755 // Fill the cache for next time.
1756 ace->_adr_type = adr_type;
1757 ace->_index = idx;
1758 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1759
1760 // Might as well try to fill the cache for the flattened version, too.
1761 AliasCacheEntry* face = probe_alias_cache(flat);
1762 if (face->_adr_type == NULL) {
1763 face->_adr_type = flat;
1764 face->_index = idx;
1765 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1766 }
1767
1768 return alias_type(idx);
1769 }
1770
1771
1772 Compile::AliasType* Compile::alias_type(ciField* field) {
1773 const TypeOopPtr* t;
1774 if (field->is_static())
1775 t = TypeInstPtr::make(field->holder()->java_mirror());
1776 else
1777 t = TypeOopPtr::make_from_klass_raw(field->holder());
1778 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1779 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1780 return atp;
1781 }
1782
1783
1784 //------------------------------have_alias_type--------------------------------
1785 bool Compile::have_alias_type(const TypePtr* adr_type) {
1786 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1787 if (ace->_adr_type == adr_type) {
1788 return true;
1789 }
1790
1791 // Handle special cases.
1792 if (adr_type == NULL) return true;
1793 if (adr_type == TypePtr::BOTTOM) return true;
1794
1795 return find_alias_type(adr_type, true, NULL) != NULL;
1796 }
1797
1798 //-----------------------------must_alias--------------------------------------
1799 // True if all values of the given address type are in the given alias category.
1800 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1801 if (alias_idx == AliasIdxBot) return true; // the universal category
1802 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1803 if (alias_idx == AliasIdxTop) return false; // the empty category
1804 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1805
1806 // the only remaining possible overlap is identity
1807 int adr_idx = get_alias_index(adr_type);
1808 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1809 assert(adr_idx == alias_idx ||
1810 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1811 && adr_type != TypeOopPtr::BOTTOM),
1812 "should not be testing for overlap with an unsafe pointer");
1813 return adr_idx == alias_idx;
1814 }
1815
1816 //------------------------------can_alias--------------------------------------
1817 // True if any values of the given address type are in the given alias category.
1818 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1819 if (alias_idx == AliasIdxTop) return false; // the empty category
1820 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1821 if (alias_idx == AliasIdxBot) return true; // the universal category
1822 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1823
1824 // the only remaining possible overlap is identity
1825 int adr_idx = get_alias_index(adr_type);
1826 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1827 return adr_idx == alias_idx;
1828 }
1829
1830
1831
1832 //---------------------------pop_warm_call-------------------------------------
1833 WarmCallInfo* Compile::pop_warm_call() {
1834 WarmCallInfo* wci = _warm_calls;
1835 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1836 return wci;
1837 }
1838
1839 //----------------------------Inline_Warm--------------------------------------
1840 int Compile::Inline_Warm() {
1841 // If there is room, try to inline some more warm call sites.
1842 // %%% Do a graph index compaction pass when we think we're out of space?
1843 if (!InlineWarmCalls) return 0;
1844
1845 int calls_made_hot = 0;
1846 int room_to_grow = NodeCountInliningCutoff - unique();
1847 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1848 int amount_grown = 0;
1849 WarmCallInfo* call;
1850 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1851 int est_size = (int)call->size();
1852 if (est_size > (room_to_grow - amount_grown)) {
1853 // This one won't fit anyway. Get rid of it.
1854 call->make_cold();
1855 continue;
1856 }
1857 call->make_hot();
1858 calls_made_hot++;
1859 amount_grown += est_size;
1860 amount_to_grow -= est_size;
1861 }
1862
1863 if (calls_made_hot > 0) set_major_progress();
1864 return calls_made_hot;
1865 }
1866
1867
1868 //----------------------------Finish_Warm--------------------------------------
1869 void Compile::Finish_Warm() {
1870 if (!InlineWarmCalls) return;
1871 if (failing()) return;
1872 if (warm_calls() == NULL) return;
1873
1874 // Clean up loose ends, if we are out of space for inlining.
1875 WarmCallInfo* call;
1876 while ((call = pop_warm_call()) != NULL) {
1877 call->make_cold();
1878 }
1879 }
1880
1881 //---------------------cleanup_loop_predicates-----------------------
1882 // Remove the opaque nodes that protect the predicates so that all unused
1883 // checks and uncommon_traps will be eliminated from the ideal graph
1884 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1885 if (predicate_count()==0) return;
1886 for (int i = predicate_count(); i > 0; i--) {
1887 Node * n = predicate_opaque1_node(i-1);
1888 assert(n->Opcode() == Op_Opaque1, "must be");
1889 igvn.replace_node(n, n->in(1));
1890 }
1891 assert(predicate_count()==0, "should be clean!");
1892 }
1893
1894 // StringOpts and late inlining of string methods
1895 void Compile::inline_string_calls(bool parse_time) {
1896 {
1897 // remove useless nodes to make the usage analysis simpler
1898 ResourceMark rm;
1899 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1900 }
1901
1902 {
1903 ResourceMark rm;
1904 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1905 PhaseStringOpts pso(initial_gvn(), for_igvn());
1906 print_method(PHASE_AFTER_STRINGOPTS, 3);
1907 }
1908
1909 // now inline anything that we skipped the first time around
1910 if (!parse_time) {
1911 _late_inlines_pos = _late_inlines.length();
1912 }
1913
1914 while (_string_late_inlines.length() > 0) {
1915 CallGenerator* cg = _string_late_inlines.pop();
1916 cg->do_late_inline();
1917 if (failing()) return;
1918 }
1919 _string_late_inlines.trunc_to(0);
1920 }
1921
1922 // Late inlining of boxing methods
1923 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1924 if (_boxing_late_inlines.length() > 0) {
1925 assert(has_boxed_value(), "inconsistent");
1926
1927 PhaseGVN* gvn = initial_gvn();
1928 set_inlining_incrementally(true);
1929
1930 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1931 for_igvn()->clear();
1932 gvn->replace_with(&igvn);
1933
1934 _late_inlines_pos = _late_inlines.length();
1935
1936 while (_boxing_late_inlines.length() > 0) {
1937 CallGenerator* cg = _boxing_late_inlines.pop();
1938 cg->do_late_inline();
1939 if (failing()) return;
1940 }
1941 _boxing_late_inlines.trunc_to(0);
1942
1943 {
1944 ResourceMark rm;
1945 PhaseRemoveUseless pru(gvn, for_igvn());
1946 }
1947
1948 igvn = PhaseIterGVN(gvn);
1949 igvn.optimize();
1950
1951 set_inlining_progress(false);
1952 set_inlining_incrementally(false);
1953 }
1954 }
1955
1956 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1957 assert(IncrementalInline, "incremental inlining should be on");
1958 PhaseGVN* gvn = initial_gvn();
1959
1960 set_inlining_progress(false);
1961 for_igvn()->clear();
1962 gvn->replace_with(&igvn);
1963
1964 {
1965 TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1966 int i = 0;
1967 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1968 CallGenerator* cg = _late_inlines.at(i);
1969 _late_inlines_pos = i+1;
1970 cg->do_late_inline();
1971 if (failing()) return;
1972 }
1973 int j = 0;
1974 for (; i < _late_inlines.length(); i++, j++) {
1975 _late_inlines.at_put(j, _late_inlines.at(i));
1976 }
1977 _late_inlines.trunc_to(j);
1978 }
1979
1980 {
1981 TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
1982 ResourceMark rm;
1983 PhaseRemoveUseless pru(gvn, for_igvn());
1984 }
1985
1986 {
1987 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
1988 igvn = PhaseIterGVN(gvn);
1989 }
1990 }
1991
1992 // Perform incremental inlining until bound on number of live nodes is reached
1993 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1994 TracePhase tp("incrementalInline", &timers[_t_incrInline]);
1995
1996 PhaseGVN* gvn = initial_gvn();
1997
1998 set_inlining_incrementally(true);
1999 set_inlining_progress(true);
2000 uint low_live_nodes = 0;
2001
2002 while(inlining_progress() && _late_inlines.length() > 0) {
2003
2004 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2005 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2006 TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2007 // PhaseIdealLoop is expensive so we only try it once we are
2008 // out of live nodes and we only try it again if the previous
2009 // helped got the number of nodes down significantly
2010 PhaseIdealLoop ideal_loop( igvn, false, true );
2011 if (failing()) return;
2012 low_live_nodes = live_nodes();
2013 _major_progress = true;
2014 }
2015
2016 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2017 break;
2018 }
2019 }
2020
2021 inline_incrementally_one(igvn);
2022
2023 if (failing()) return;
2024
2025 {
2026 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2027 igvn.optimize();
2028 }
2029
2030 if (failing()) return;
2031 }
2032
2033 assert( igvn._worklist.size() == 0, "should be done with igvn" );
2034
2035 if (_string_late_inlines.length() > 0) {
2036 assert(has_stringbuilder(), "inconsistent");
2037 for_igvn()->clear();
2038 initial_gvn()->replace_with(&igvn);
2039
2040 inline_string_calls(false);
2041
2042 if (failing()) return;
2043
2044 {
2045 TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2046 ResourceMark rm;
2047 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2048 }
2049
2050 {
2051 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2052 igvn = PhaseIterGVN(gvn);
2053 igvn.optimize();
2054 }
2055 }
2056
2057 set_inlining_incrementally(false);
2058 }
2059
2060
2061 //------------------------------Optimize---------------------------------------
2062 // Given a graph, optimize it.
2063 void Compile::Optimize() {
2064 TracePhase tp("optimizer", &timers[_t_optimizer]);
2065
2066 #ifndef PRODUCT
2067 if (env()->break_at_compile()) {
2068 BREAKPOINT;
2069 }
2070
2071 #endif
2072
2073 ResourceMark rm;
2074 int loop_opts_cnt;
2075
2076 print_inlining_reinit();
2077
2078 NOT_PRODUCT( verify_graph_edges(); )
2079
2080 print_method(PHASE_AFTER_PARSING);
2081
2082 {
2083 // Iterative Global Value Numbering, including ideal transforms
2084 // Initialize IterGVN with types and values from parse-time GVN
2085 PhaseIterGVN igvn(initial_gvn());
2086 #ifdef ASSERT
2087 _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2088 #endif
2089 {
2090 TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2091 igvn.optimize();
2092 }
2093
2094 print_method(PHASE_ITER_GVN1, 2);
2095
2096 if (failing()) return;
2097
2098 inline_incrementally(igvn);
2099
2100 print_method(PHASE_INCREMENTAL_INLINE, 2);
2101
2102 if (failing()) return;
2103
2104 if (eliminate_boxing()) {
2105 // Inline valueOf() methods now.
2106 inline_boxing_calls(igvn);
2107
2108 if (AlwaysIncrementalInline) {
2109 inline_incrementally(igvn);
2110 }
2111
2112 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2113
2114 if (failing()) return;
2115 }
2116
2117 // Remove the speculative part of types and clean up the graph from
2118 // the extra CastPP nodes whose only purpose is to carry them. Do
2119 // that early so that optimizations are not disrupted by the extra
2120 // CastPP nodes.
2121 remove_speculative_types(igvn);
2122
2123 // No more new expensive nodes will be added to the list from here
2124 // so keep only the actual candidates for optimizations.
2125 cleanup_expensive_nodes(igvn);
2126
2127 // Perform escape analysis
2128 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2129 if (has_loops()) {
2130 // Cleanup graph (remove dead nodes).
2131 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2132 PhaseIdealLoop ideal_loop( igvn, false, true );
2133 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2134 if (failing()) return;
2135 }
2136 ConnectionGraph::do_analysis(this, &igvn);
2137
2138 if (failing()) return;
2139
2140 // Optimize out fields loads from scalar replaceable allocations.
2141 igvn.optimize();
2142 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2143
2144 if (failing()) return;
2145
2146 if (congraph() != NULL && macro_count() > 0) {
2147 TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2148 PhaseMacroExpand mexp(igvn);
2149 mexp.eliminate_macro_nodes();
2150 igvn.set_delay_transform(false);
2151
2152 igvn.optimize();
2153 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2154
2155 if (failing()) return;
2156 }
2157 }
2158
2159 // Loop transforms on the ideal graph. Range Check Elimination,
2160 // peeling, unrolling, etc.
2161
2162 // Set loop opts counter
2163 loop_opts_cnt = num_loop_opts();
2164 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2165 {
2166 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2167 PhaseIdealLoop ideal_loop( igvn, true );
2168 loop_opts_cnt--;
2169 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2170 if (failing()) return;
2171 }
2172 // Loop opts pass if partial peeling occurred in previous pass
2173 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2174 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2175 PhaseIdealLoop ideal_loop( igvn, false );
2176 loop_opts_cnt--;
2177 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2178 if (failing()) return;
2179 }
2180 // Loop opts pass for loop-unrolling before CCP
2181 if(major_progress() && (loop_opts_cnt > 0)) {
2182 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2183 PhaseIdealLoop ideal_loop( igvn, false );
2184 loop_opts_cnt--;
2185 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2186 }
2187 if (!failing()) {
2188 // Verify that last round of loop opts produced a valid graph
2189 TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2190 PhaseIdealLoop::verify(igvn);
2191 }
2192 }
2193 if (failing()) return;
2194
2195 // Conditional Constant Propagation;
2196 PhaseCCP ccp( &igvn );
2197 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2198 {
2199 TracePhase tp("ccp", &timers[_t_ccp]);
2200 ccp.do_transform();
2201 }
2202 print_method(PHASE_CPP1, 2);
2203
2204 assert( true, "Break here to ccp.dump_old2new_map()");
2205
2206 // Iterative Global Value Numbering, including ideal transforms
2207 {
2208 TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2209 igvn = ccp;
2210 igvn.optimize();
2211 }
2212
2213 print_method(PHASE_ITER_GVN2, 2);
2214
2215 if (failing()) return;
2216
2217 // Loop transforms on the ideal graph. Range Check Elimination,
2218 // peeling, unrolling, etc.
2219 if(loop_opts_cnt > 0) {
2220 debug_only( int cnt = 0; );
2221 while(major_progress() && (loop_opts_cnt > 0)) {
2222 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2223 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2224 PhaseIdealLoop ideal_loop( igvn, true);
2225 loop_opts_cnt--;
2226 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2227 if (failing()) return;
2228 }
2229 }
2230
2231 {
2232 // Verify that all previous optimizations produced a valid graph
2233 // at least to this point, even if no loop optimizations were done.
2234 TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2235 PhaseIdealLoop::verify(igvn);
2236 }
2237
2238 {
2239 TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2240 PhaseMacroExpand mex(igvn);
2241 if (mex.expand_macro_nodes()) {
2242 assert(failing(), "must bail out w/ explicit message");
2243 return;
2244 }
2245 }
2246
2247 DEBUG_ONLY( _modified_nodes = NULL; )
2248 } // (End scope of igvn; run destructor if necessary for asserts.)
2249
2250 process_print_inlining();
2251 // A method with only infinite loops has no edges entering loops from root
2252 {
2253 TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2254 if (final_graph_reshaping()) {
2255 assert(failing(), "must bail out w/ explicit message");
2256 return;
2257 }
2258 }
2259
2260 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2261 }
2262
2263
2264 //------------------------------Code_Gen---------------------------------------
2265 // Given a graph, generate code for it
2266 void Compile::Code_Gen() {
2267 if (failing()) {
2268 return;
2269 }
2270
2271 // Perform instruction selection. You might think we could reclaim Matcher
2272 // memory PDQ, but actually the Matcher is used in generating spill code.
2273 // Internals of the Matcher (including some VectorSets) must remain live
2274 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2275 // set a bit in reclaimed memory.
2276
2277 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2278 // nodes. Mapping is only valid at the root of each matched subtree.
2279 NOT_PRODUCT( verify_graph_edges(); )
2280
2281 Matcher matcher;
2282 _matcher = &matcher;
2283 {
2284 TracePhase tp("matcher", &timers[_t_matcher]);
2285 matcher.match();
2286 }
2287 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2288 // nodes. Mapping is only valid at the root of each matched subtree.
2289 NOT_PRODUCT( verify_graph_edges(); )
2290
2291 // If you have too many nodes, or if matching has failed, bail out
2292 check_node_count(0, "out of nodes matching instructions");
2293 if (failing()) {
2294 return;
2295 }
2296
2297 // Build a proper-looking CFG
2298 PhaseCFG cfg(node_arena(), root(), matcher);
2299 _cfg = &cfg;
2300 {
2301 TracePhase tp("scheduler", &timers[_t_scheduler]);
2302 bool success = cfg.do_global_code_motion();
2303 if (!success) {
2304 return;
2305 }
2306
2307 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2308 NOT_PRODUCT( verify_graph_edges(); )
2309 debug_only( cfg.verify(); )
2310 }
2311
2312 PhaseChaitin regalloc(unique(), cfg, matcher);
2313 _regalloc = ®alloc;
2314 {
2315 TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2316 // Perform register allocation. After Chaitin, use-def chains are
2317 // no longer accurate (at spill code) and so must be ignored.
2318 // Node->LRG->reg mappings are still accurate.
2319 _regalloc->Register_Allocate();
2320
2321 // Bail out if the allocator builds too many nodes
2322 if (failing()) {
2323 return;
2324 }
2325 }
2326
2327 // Prior to register allocation we kept empty basic blocks in case the
2328 // the allocator needed a place to spill. After register allocation we
2329 // are not adding any new instructions. If any basic block is empty, we
2330 // can now safely remove it.
2331 {
2332 TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2333 cfg.remove_empty_blocks();
2334 if (do_freq_based_layout()) {
2335 PhaseBlockLayout layout(cfg);
2336 } else {
2337 cfg.set_loop_alignment();
2338 }
2339 cfg.fixup_flow();
2340 }
2341
2342 // Apply peephole optimizations
2343 if( OptoPeephole ) {
2344 TracePhase tp("peephole", &timers[_t_peephole]);
2345 PhasePeephole peep( _regalloc, cfg);
2346 peep.do_transform();
2347 }
2348
2349 // Do late expand if CPU requires this.
2350 if (Matcher::require_postalloc_expand) {
2351 TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2352 cfg.postalloc_expand(_regalloc);
2353 }
2354
2355 // Convert Nodes to instruction bits in a buffer
2356 {
2357 TraceTime tp("output", &timers[_t_output], CITime);
2358 Output();
2359 }
2360
2361 print_method(PHASE_FINAL_CODE);
2362
2363 // He's dead, Jim.
2364 _cfg = (PhaseCFG*)0xdeadbeef;
2365 _regalloc = (PhaseChaitin*)0xdeadbeef;
2366 }
2367
2368
2369 //------------------------------dump_asm---------------------------------------
2370 // Dump formatted assembly
2371 #ifndef PRODUCT
2372 void Compile::dump_asm(int *pcs, uint pc_limit) {
2373 bool cut_short = false;
2374 tty->print_cr("#");
2375 tty->print("# "); _tf->dump(); tty->cr();
2376 tty->print_cr("#");
2377
2378 // For all blocks
2379 int pc = 0x0; // Program counter
2380 char starts_bundle = ' ';
2381 _regalloc->dump_frame();
2382
2383 Node *n = NULL;
2384 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2385 if (VMThread::should_terminate()) {
2386 cut_short = true;
2387 break;
2388 }
2389 Block* block = _cfg->get_block(i);
2390 if (block->is_connector() && !Verbose) {
2391 continue;
2392 }
2393 n = block->head();
2394 if (pcs && n->_idx < pc_limit) {
2395 tty->print("%3.3x ", pcs[n->_idx]);
2396 } else {
2397 tty->print(" ");
2398 }
2399 block->dump_head(_cfg);
2400 if (block->is_connector()) {
2401 tty->print_cr(" # Empty connector block");
2402 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2403 tty->print_cr(" # Block is sole successor of call");
2404 }
2405
2406 // For all instructions
2407 Node *delay = NULL;
2408 for (uint j = 0; j < block->number_of_nodes(); j++) {
2409 if (VMThread::should_terminate()) {
2410 cut_short = true;
2411 break;
2412 }
2413 n = block->get_node(j);
2414 if (valid_bundle_info(n)) {
2415 Bundle* bundle = node_bundling(n);
2416 if (bundle->used_in_unconditional_delay()) {
2417 delay = n;
2418 continue;
2419 }
2420 if (bundle->starts_bundle()) {
2421 starts_bundle = '+';
2422 }
2423 }
2424
2425 if (WizardMode) {
2426 n->dump();
2427 }
2428
2429 if( !n->is_Region() && // Dont print in the Assembly
2430 !n->is_Phi() && // a few noisely useless nodes
2431 !n->is_Proj() &&
2432 !n->is_MachTemp() &&
2433 !n->is_SafePointScalarObject() &&
2434 !n->is_Catch() && // Would be nice to print exception table targets
2435 !n->is_MergeMem() && // Not very interesting
2436 !n->is_top() && // Debug info table constants
2437 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2438 ) {
2439 if (pcs && n->_idx < pc_limit)
2440 tty->print("%3.3x", pcs[n->_idx]);
2441 else
2442 tty->print(" ");
2443 tty->print(" %c ", starts_bundle);
2444 starts_bundle = ' ';
2445 tty->print("\t");
2446 n->format(_regalloc, tty);
2447 tty->cr();
2448 }
2449
2450 // If we have an instruction with a delay slot, and have seen a delay,
2451 // then back up and print it
2452 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2453 assert(delay != NULL, "no unconditional delay instruction");
2454 if (WizardMode) delay->dump();
2455
2456 if (node_bundling(delay)->starts_bundle())
2457 starts_bundle = '+';
2458 if (pcs && n->_idx < pc_limit)
2459 tty->print("%3.3x", pcs[n->_idx]);
2460 else
2461 tty->print(" ");
2462 tty->print(" %c ", starts_bundle);
2463 starts_bundle = ' ';
2464 tty->print("\t");
2465 delay->format(_regalloc, tty);
2466 tty->cr();
2467 delay = NULL;
2468 }
2469
2470 // Dump the exception table as well
2471 if( n->is_Catch() && (Verbose || WizardMode) ) {
2472 // Print the exception table for this offset
2473 _handler_table.print_subtable_for(pc);
2474 }
2475 }
2476
2477 if (pcs && n->_idx < pc_limit)
2478 tty->print_cr("%3.3x", pcs[n->_idx]);
2479 else
2480 tty->cr();
2481
2482 assert(cut_short || delay == NULL, "no unconditional delay branch");
2483
2484 } // End of per-block dump
2485 tty->cr();
2486
2487 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2488 }
2489 #endif
2490
2491 //------------------------------Final_Reshape_Counts---------------------------
2492 // This class defines counters to help identify when a method
2493 // may/must be executed using hardware with only 24-bit precision.
2494 struct Final_Reshape_Counts : public StackObj {
2495 int _call_count; // count non-inlined 'common' calls
2496 int _float_count; // count float ops requiring 24-bit precision
2497 int _double_count; // count double ops requiring more precision
2498 int _java_call_count; // count non-inlined 'java' calls
2499 int _inner_loop_count; // count loops which need alignment
2500 VectorSet _visited; // Visitation flags
2501 Node_List _tests; // Set of IfNodes & PCTableNodes
2502
2503 Final_Reshape_Counts() :
2504 _call_count(0), _float_count(0), _double_count(0),
2505 _java_call_count(0), _inner_loop_count(0),
2506 _visited( Thread::current()->resource_area() ) { }
2507
2508 void inc_call_count () { _call_count ++; }
2509 void inc_float_count () { _float_count ++; }
2510 void inc_double_count() { _double_count++; }
2511 void inc_java_call_count() { _java_call_count++; }
2512 void inc_inner_loop_count() { _inner_loop_count++; }
2513
2514 int get_call_count () const { return _call_count ; }
2515 int get_float_count () const { return _float_count ; }
2516 int get_double_count() const { return _double_count; }
2517 int get_java_call_count() const { return _java_call_count; }
2518 int get_inner_loop_count() const { return _inner_loop_count; }
2519 };
2520
2521 #ifdef ASSERT
2522 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2523 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2524 // Make sure the offset goes inside the instance layout.
2525 return k->contains_field_offset(tp->offset());
2526 // Note that OffsetBot and OffsetTop are very negative.
2527 }
2528 #endif
2529
2530 // Eliminate trivially redundant StoreCMs and accumulate their
2531 // precedence edges.
2532 void Compile::eliminate_redundant_card_marks(Node* n) {
2533 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2534 if (n->in(MemNode::Address)->outcnt() > 1) {
2535 // There are multiple users of the same address so it might be
2536 // possible to eliminate some of the StoreCMs
2537 Node* mem = n->in(MemNode::Memory);
2538 Node* adr = n->in(MemNode::Address);
2539 Node* val = n->in(MemNode::ValueIn);
2540 Node* prev = n;
2541 bool done = false;
2542 // Walk the chain of StoreCMs eliminating ones that match. As
2543 // long as it's a chain of single users then the optimization is
2544 // safe. Eliminating partially redundant StoreCMs would require
2545 // cloning copies down the other paths.
2546 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2547 if (adr == mem->in(MemNode::Address) &&
2548 val == mem->in(MemNode::ValueIn)) {
2549 // redundant StoreCM
2550 if (mem->req() > MemNode::OopStore) {
2551 // Hasn't been processed by this code yet.
2552 n->add_prec(mem->in(MemNode::OopStore));
2553 } else {
2554 // Already converted to precedence edge
2555 for (uint i = mem->req(); i < mem->len(); i++) {
2556 // Accumulate any precedence edges
2557 if (mem->in(i) != NULL) {
2558 n->add_prec(mem->in(i));
2559 }
2560 }
2561 // Everything above this point has been processed.
2562 done = true;
2563 }
2564 // Eliminate the previous StoreCM
2565 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2566 assert(mem->outcnt() == 0, "should be dead");
2567 mem->disconnect_inputs(NULL, this);
2568 } else {
2569 prev = mem;
2570 }
2571 mem = prev->in(MemNode::Memory);
2572 }
2573 }
2574 }
2575
2576 //------------------------------final_graph_reshaping_impl----------------------
2577 // Implement items 1-5 from final_graph_reshaping below.
2578 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2579
2580 if ( n->outcnt() == 0 ) return; // dead node
2581 uint nop = n->Opcode();
2582
2583 // Check for 2-input instruction with "last use" on right input.
2584 // Swap to left input. Implements item (2).
2585 if( n->req() == 3 && // two-input instruction
2586 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2587 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2588 n->in(2)->outcnt() == 1 &&// right use IS a last use
2589 !n->in(2)->is_Con() ) { // right use is not a constant
2590 // Check for commutative opcode
2591 switch( nop ) {
2592 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2593 case Op_MaxI: case Op_MinI:
2594 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2595 case Op_AndL: case Op_XorL: case Op_OrL:
2596 case Op_AndI: case Op_XorI: case Op_OrI: {
2597 // Move "last use" input to left by swapping inputs
2598 n->swap_edges(1, 2);
2599 break;
2600 }
2601 default:
2602 break;
2603 }
2604 }
2605
2606 #ifdef ASSERT
2607 if( n->is_Mem() ) {
2608 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2609 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2610 // oop will be recorded in oop map if load crosses safepoint
2611 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2612 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2613 "raw memory operations should have control edge");
2614 }
2615 #endif
2616 // Count FPU ops and common calls, implements item (3)
2617 switch( nop ) {
2618 // Count all float operations that may use FPU
2619 case Op_AddF:
2620 case Op_SubF:
2621 case Op_MulF:
2622 case Op_DivF:
2623 case Op_NegF:
2624 case Op_ModF:
2625 case Op_ConvI2F:
2626 case Op_ConF:
2627 case Op_CmpF:
2628 case Op_CmpF3:
2629 // case Op_ConvL2F: // longs are split into 32-bit halves
2630 frc.inc_float_count();
2631 break;
2632
2633 case Op_ConvF2D:
2634 case Op_ConvD2F:
2635 frc.inc_float_count();
2636 frc.inc_double_count();
2637 break;
2638
2639 // Count all double operations that may use FPU
2640 case Op_AddD:
2641 case Op_SubD:
2642 case Op_MulD:
2643 case Op_DivD:
2644 case Op_NegD:
2645 case Op_ModD:
2646 case Op_ConvI2D:
2647 case Op_ConvD2I:
2648 // case Op_ConvL2D: // handled by leaf call
2649 // case Op_ConvD2L: // handled by leaf call
2650 case Op_ConD:
2651 case Op_CmpD:
2652 case Op_CmpD3:
2653 frc.inc_double_count();
2654 break;
2655 case Op_Opaque1: // Remove Opaque Nodes before matching
2656 case Op_Opaque2: // Remove Opaque Nodes before matching
2657 case Op_Opaque3:
2658 n->subsume_by(n->in(1), this);
2659 break;
2660 case Op_CallStaticJava:
2661 case Op_CallJava:
2662 case Op_CallDynamicJava:
2663 frc.inc_java_call_count(); // Count java call site;
2664 case Op_CallRuntime:
2665 case Op_CallLeaf:
2666 case Op_CallLeafNoFP: {
2667 assert( n->is_Call(), "" );
2668 CallNode *call = n->as_Call();
2669 // Count call sites where the FP mode bit would have to be flipped.
2670 // Do not count uncommon runtime calls:
2671 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2672 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2673 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2674 frc.inc_call_count(); // Count the call site
2675 } else { // See if uncommon argument is shared
2676 Node *n = call->in(TypeFunc::Parms);
2677 int nop = n->Opcode();
2678 // Clone shared simple arguments to uncommon calls, item (1).
2679 if( n->outcnt() > 1 &&
2680 !n->is_Proj() &&
2681 nop != Op_CreateEx &&
2682 nop != Op_CheckCastPP &&
2683 nop != Op_DecodeN &&
2684 nop != Op_DecodeNKlass &&
2685 !n->is_Mem() ) {
2686 Node *x = n->clone();
2687 call->set_req( TypeFunc::Parms, x );
2688 }
2689 }
2690 break;
2691 }
2692
2693 case Op_StoreD:
2694 case Op_LoadD:
2695 case Op_LoadD_unaligned:
2696 frc.inc_double_count();
2697 goto handle_mem;
2698 case Op_StoreF:
2699 case Op_LoadF:
2700 frc.inc_float_count();
2701 goto handle_mem;
2702
2703 case Op_StoreCM:
2704 {
2705 // Convert OopStore dependence into precedence edge
2706 Node* prec = n->in(MemNode::OopStore);
2707 n->del_req(MemNode::OopStore);
2708 n->add_prec(prec);
2709 eliminate_redundant_card_marks(n);
2710 }
2711
2712 // fall through
2713
2714 case Op_StoreB:
2715 case Op_StoreC:
2716 case Op_StorePConditional:
2717 case Op_StoreI:
2718 case Op_StoreL:
2719 case Op_StoreIConditional:
2720 case Op_StoreLConditional:
2721 case Op_CompareAndSwapI:
2722 case Op_CompareAndSwapL:
2723 case Op_CompareAndSwapP:
2724 case Op_CompareAndSwapN:
2725 case Op_GetAndAddI:
2726 case Op_GetAndAddL:
2727 case Op_GetAndSetI:
2728 case Op_GetAndSetL:
2729 case Op_GetAndSetP:
2730 case Op_GetAndSetN:
2731 case Op_StoreP:
2732 case Op_StoreN:
2733 case Op_StoreNKlass:
2734 case Op_LoadB:
2735 case Op_LoadUB:
2736 case Op_LoadUS:
2737 case Op_LoadI:
2738 case Op_LoadKlass:
2739 case Op_LoadNKlass:
2740 case Op_LoadL:
2741 case Op_LoadL_unaligned:
2742 case Op_LoadPLocked:
2743 case Op_LoadP:
2744 case Op_LoadN:
2745 case Op_LoadRange:
2746 case Op_LoadS: {
2747 handle_mem:
2748 #ifdef ASSERT
2749 if( VerifyOptoOopOffsets ) {
2750 assert( n->is_Mem(), "" );
2751 MemNode *mem = (MemNode*)n;
2752 // Check to see if address types have grounded out somehow.
2753 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2754 assert( !tp || oop_offset_is_sane(tp), "" );
2755 }
2756 #endif
2757 break;
2758 }
2759
2760 case Op_AddP: { // Assert sane base pointers
2761 Node *addp = n->in(AddPNode::Address);
2762 assert( !addp->is_AddP() ||
2763 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2764 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2765 "Base pointers must match" );
2766 #ifdef _LP64
2767 if ((UseCompressedOops || UseCompressedClassPointers) &&
2768 addp->Opcode() == Op_ConP &&
2769 addp == n->in(AddPNode::Base) &&
2770 n->in(AddPNode::Offset)->is_Con()) {
2771 // Use addressing with narrow klass to load with offset on x86.
2772 // On sparc loading 32-bits constant and decoding it have less
2773 // instructions (4) then load 64-bits constant (7).
2774 // Do this transformation here since IGVN will convert ConN back to ConP.
2775 const Type* t = addp->bottom_type();
2776 if (t->isa_oopptr() || t->isa_klassptr()) {
2777 Node* nn = NULL;
2778
2779 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2780
2781 // Look for existing ConN node of the same exact type.
2782 Node* r = root();
2783 uint cnt = r->outcnt();
2784 for (uint i = 0; i < cnt; i++) {
2785 Node* m = r->raw_out(i);
2786 if (m!= NULL && m->Opcode() == op &&
2787 m->bottom_type()->make_ptr() == t) {
2788 nn = m;
2789 break;
2790 }
2791 }
2792 if (nn != NULL) {
2793 // Decode a narrow oop to match address
2794 // [R12 + narrow_oop_reg<<3 + offset]
2795 if (t->isa_oopptr()) {
2796 nn = new DecodeNNode(nn, t);
2797 } else {
2798 nn = new DecodeNKlassNode(nn, t);
2799 }
2800 n->set_req(AddPNode::Base, nn);
2801 n->set_req(AddPNode::Address, nn);
2802 if (addp->outcnt() == 0) {
2803 addp->disconnect_inputs(NULL, this);
2804 }
2805 }
2806 }
2807 }
2808 #endif
2809 break;
2810 }
2811
2812 #ifdef _LP64
2813 case Op_CastPP:
2814 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2815 Node* in1 = n->in(1);
2816 const Type* t = n->bottom_type();
2817 Node* new_in1 = in1->clone();
2818 new_in1->as_DecodeN()->set_type(t);
2819
2820 if (!Matcher::narrow_oop_use_complex_address()) {
2821 //
2822 // x86, ARM and friends can handle 2 adds in addressing mode
2823 // and Matcher can fold a DecodeN node into address by using
2824 // a narrow oop directly and do implicit NULL check in address:
2825 //
2826 // [R12 + narrow_oop_reg<<3 + offset]
2827 // NullCheck narrow_oop_reg
2828 //
2829 // On other platforms (Sparc) we have to keep new DecodeN node and
2830 // use it to do implicit NULL check in address:
2831 //
2832 // decode_not_null narrow_oop_reg, base_reg
2833 // [base_reg + offset]
2834 // NullCheck base_reg
2835 //
2836 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2837 // to keep the information to which NULL check the new DecodeN node
2838 // corresponds to use it as value in implicit_null_check().
2839 //
2840 new_in1->set_req(0, n->in(0));
2841 }
2842
2843 n->subsume_by(new_in1, this);
2844 if (in1->outcnt() == 0) {
2845 in1->disconnect_inputs(NULL, this);
2846 }
2847 }
2848 break;
2849
2850 case Op_CmpP:
2851 // Do this transformation here to preserve CmpPNode::sub() and
2852 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2853 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2854 Node* in1 = n->in(1);
2855 Node* in2 = n->in(2);
2856 if (!in1->is_DecodeNarrowPtr()) {
2857 in2 = in1;
2858 in1 = n->in(2);
2859 }
2860 assert(in1->is_DecodeNarrowPtr(), "sanity");
2861
2862 Node* new_in2 = NULL;
2863 if (in2->is_DecodeNarrowPtr()) {
2864 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2865 new_in2 = in2->in(1);
2866 } else if (in2->Opcode() == Op_ConP) {
2867 const Type* t = in2->bottom_type();
2868 if (t == TypePtr::NULL_PTR) {
2869 assert(in1->is_DecodeN(), "compare klass to null?");
2870 // Don't convert CmpP null check into CmpN if compressed
2871 // oops implicit null check is not generated.
2872 // This will allow to generate normal oop implicit null check.
2873 if (Matcher::gen_narrow_oop_implicit_null_checks())
2874 new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
2875 //
2876 // This transformation together with CastPP transformation above
2877 // will generated code for implicit NULL checks for compressed oops.
2878 //
2879 // The original code after Optimize()
2880 //
2881 // LoadN memory, narrow_oop_reg
2882 // decode narrow_oop_reg, base_reg
2883 // CmpP base_reg, NULL
2884 // CastPP base_reg // NotNull
2885 // Load [base_reg + offset], val_reg
2886 //
2887 // after these transformations will be
2888 //
2889 // LoadN memory, narrow_oop_reg
2890 // CmpN narrow_oop_reg, NULL
2891 // decode_not_null narrow_oop_reg, base_reg
2892 // Load [base_reg + offset], val_reg
2893 //
2894 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2895 // since narrow oops can be used in debug info now (see the code in
2896 // final_graph_reshaping_walk()).
2897 //
2898 // At the end the code will be matched to
2899 // on x86:
2900 //
2901 // Load_narrow_oop memory, narrow_oop_reg
2902 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2903 // NullCheck narrow_oop_reg
2904 //
2905 // and on sparc:
2906 //
2907 // Load_narrow_oop memory, narrow_oop_reg
2908 // decode_not_null narrow_oop_reg, base_reg
2909 // Load [base_reg + offset], val_reg
2910 // NullCheck base_reg
2911 //
2912 } else if (t->isa_oopptr()) {
2913 new_in2 = ConNode::make(t->make_narrowoop());
2914 } else if (t->isa_klassptr()) {
2915 new_in2 = ConNode::make(t->make_narrowklass());
2916 }
2917 }
2918 if (new_in2 != NULL) {
2919 Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2920 n->subsume_by(cmpN, this);
2921 if (in1->outcnt() == 0) {
2922 in1->disconnect_inputs(NULL, this);
2923 }
2924 if (in2->outcnt() == 0) {
2925 in2->disconnect_inputs(NULL, this);
2926 }
2927 }
2928 }
2929 break;
2930
2931 case Op_DecodeN:
2932 case Op_DecodeNKlass:
2933 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2934 // DecodeN could be pinned when it can't be fold into
2935 // an address expression, see the code for Op_CastPP above.
2936 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2937 break;
2938
2939 case Op_EncodeP:
2940 case Op_EncodePKlass: {
2941 Node* in1 = n->in(1);
2942 if (in1->is_DecodeNarrowPtr()) {
2943 n->subsume_by(in1->in(1), this);
2944 } else if (in1->Opcode() == Op_ConP) {
2945 const Type* t = in1->bottom_type();
2946 if (t == TypePtr::NULL_PTR) {
2947 assert(t->isa_oopptr(), "null klass?");
2948 n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
2949 } else if (t->isa_oopptr()) {
2950 n->subsume_by(ConNode::make(t->make_narrowoop()), this);
2951 } else if (t->isa_klassptr()) {
2952 n->subsume_by(ConNode::make(t->make_narrowklass()), this);
2953 }
2954 }
2955 if (in1->outcnt() == 0) {
2956 in1->disconnect_inputs(NULL, this);
2957 }
2958 break;
2959 }
2960
2961 case Op_Proj: {
2962 if (OptimizeStringConcat) {
2963 ProjNode* p = n->as_Proj();
2964 if (p->_is_io_use) {
2965 // Separate projections were used for the exception path which
2966 // are normally removed by a late inline. If it wasn't inlined
2967 // then they will hang around and should just be replaced with
2968 // the original one.
2969 Node* proj = NULL;
2970 // Replace with just one
2971 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2972 Node *use = i.get();
2973 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2974 proj = use;
2975 break;
2976 }
2977 }
2978 assert(proj != NULL, "must be found");
2979 p->subsume_by(proj, this);
2980 }
2981 }
2982 break;
2983 }
2984
2985 case Op_Phi:
2986 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2987 // The EncodeP optimization may create Phi with the same edges
2988 // for all paths. It is not handled well by Register Allocator.
2989 Node* unique_in = n->in(1);
2990 assert(unique_in != NULL, "");
2991 uint cnt = n->req();
2992 for (uint i = 2; i < cnt; i++) {
2993 Node* m = n->in(i);
2994 assert(m != NULL, "");
2995 if (unique_in != m)
2996 unique_in = NULL;
2997 }
2998 if (unique_in != NULL) {
2999 n->subsume_by(unique_in, this);
3000 }
3001 }
3002 break;
3003
3004 #endif
3005
3006 case Op_ModI:
3007 if (UseDivMod) {
3008 // Check if a%b and a/b both exist
3009 Node* d = n->find_similar(Op_DivI);
3010 if (d) {
3011 // Replace them with a fused divmod if supported
3012 if (Matcher::has_match_rule(Op_DivModI)) {
3013 DivModINode* divmod = DivModINode::make(n);
3014 d->subsume_by(divmod->div_proj(), this);
3015 n->subsume_by(divmod->mod_proj(), this);
3016 } else {
3017 // replace a%b with a-((a/b)*b)
3018 Node* mult = new MulINode(d, d->in(2));
3019 Node* sub = new SubINode(d->in(1), mult);
3020 n->subsume_by(sub, this);
3021 }
3022 }
3023 }
3024 break;
3025
3026 case Op_ModL:
3027 if (UseDivMod) {
3028 // Check if a%b and a/b both exist
3029 Node* d = n->find_similar(Op_DivL);
3030 if (d) {
3031 // Replace them with a fused divmod if supported
3032 if (Matcher::has_match_rule(Op_DivModL)) {
3033 DivModLNode* divmod = DivModLNode::make(n);
3034 d->subsume_by(divmod->div_proj(), this);
3035 n->subsume_by(divmod->mod_proj(), this);
3036 } else {
3037 // replace a%b with a-((a/b)*b)
3038 Node* mult = new MulLNode(d, d->in(2));
3039 Node* sub = new SubLNode(d->in(1), mult);
3040 n->subsume_by(sub, this);
3041 }
3042 }
3043 }
3044 break;
3045
3046 case Op_LoadVector:
3047 case Op_StoreVector:
3048 break;
3049
3050 case Op_PackB:
3051 case Op_PackS:
3052 case Op_PackI:
3053 case Op_PackF:
3054 case Op_PackL:
3055 case Op_PackD:
3056 if (n->req()-1 > 2) {
3057 // Replace many operand PackNodes with a binary tree for matching
3058 PackNode* p = (PackNode*) n;
3059 Node* btp = p->binary_tree_pack(1, n->req());
3060 n->subsume_by(btp, this);
3061 }
3062 break;
3063 case Op_Loop:
3064 case Op_CountedLoop:
3065 if (n->as_Loop()->is_inner_loop()) {
3066 frc.inc_inner_loop_count();
3067 }
3068 break;
3069 case Op_LShiftI:
3070 case Op_RShiftI:
3071 case Op_URShiftI:
3072 case Op_LShiftL:
3073 case Op_RShiftL:
3074 case Op_URShiftL:
3075 if (Matcher::need_masked_shift_count) {
3076 // The cpu's shift instructions don't restrict the count to the
3077 // lower 5/6 bits. We need to do the masking ourselves.
3078 Node* in2 = n->in(2);
3079 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3080 const TypeInt* t = in2->find_int_type();
3081 if (t != NULL && t->is_con()) {
3082 juint shift = t->get_con();
3083 if (shift > mask) { // Unsigned cmp
3084 n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3085 }
3086 } else {
3087 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3088 Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3089 n->set_req(2, shift);
3090 }
3091 }
3092 if (in2->outcnt() == 0) { // Remove dead node
3093 in2->disconnect_inputs(NULL, this);
3094 }
3095 }
3096 break;
3097 case Op_MemBarStoreStore:
3098 case Op_MemBarRelease:
3099 // Break the link with AllocateNode: it is no longer useful and
3100 // confuses register allocation.
3101 if (n->req() > MemBarNode::Precedent) {
3102 n->set_req(MemBarNode::Precedent, top());
3103 }
3104 break;
3105 default:
3106 assert( !n->is_Call(), "" );
3107 assert( !n->is_Mem(), "" );
3108 break;
3109 }
3110
3111 // Collect CFG split points
3112 if (n->is_MultiBranch())
3113 frc._tests.push(n);
3114 }
3115
3116 //------------------------------final_graph_reshaping_walk---------------------
3117 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3118 // requires that the walk visits a node's inputs before visiting the node.
3119 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3120 ResourceArea *area = Thread::current()->resource_area();
3121 Unique_Node_List sfpt(area);
3122
3123 frc._visited.set(root->_idx); // first, mark node as visited
3124 uint cnt = root->req();
3125 Node *n = root;
3126 uint i = 0;
3127 while (true) {
3128 if (i < cnt) {
3129 // Place all non-visited non-null inputs onto stack
3130 Node* m = n->in(i);
3131 ++i;
3132 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3133 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3134 // compute worst case interpreter size in case of a deoptimization
3135 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3136
3137 sfpt.push(m);
3138 }
3139 cnt = m->req();
3140 nstack.push(n, i); // put on stack parent and next input's index
3141 n = m;
3142 i = 0;
3143 }
3144 } else {
3145 // Now do post-visit work
3146 final_graph_reshaping_impl( n, frc );
3147 if (nstack.is_empty())
3148 break; // finished
3149 n = nstack.node(); // Get node from stack
3150 cnt = n->req();
3151 i = nstack.index();
3152 nstack.pop(); // Shift to the next node on stack
3153 }
3154 }
3155
3156 // Skip next transformation if compressed oops are not used.
3157 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3158 (!UseCompressedOops && !UseCompressedClassPointers))
3159 return;
3160
3161 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3162 // It could be done for an uncommon traps or any safepoints/calls
3163 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3164 while (sfpt.size() > 0) {
3165 n = sfpt.pop();
3166 JVMState *jvms = n->as_SafePoint()->jvms();
3167 assert(jvms != NULL, "sanity");
3168 int start = jvms->debug_start();
3169 int end = n->req();
3170 bool is_uncommon = (n->is_CallStaticJava() &&
3171 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3172 for (int j = start; j < end; j++) {
3173 Node* in = n->in(j);
3174 if (in->is_DecodeNarrowPtr()) {
3175 bool safe_to_skip = true;
3176 if (!is_uncommon ) {
3177 // Is it safe to skip?
3178 for (uint i = 0; i < in->outcnt(); i++) {
3179 Node* u = in->raw_out(i);
3180 if (!u->is_SafePoint() ||
3181 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3182 safe_to_skip = false;
3183 }
3184 }
3185 }
3186 if (safe_to_skip) {
3187 n->set_req(j, in->in(1));
3188 }
3189 if (in->outcnt() == 0) {
3190 in->disconnect_inputs(NULL, this);
3191 }
3192 }
3193 }
3194 }
3195 }
3196
3197 //------------------------------final_graph_reshaping--------------------------
3198 // Final Graph Reshaping.
3199 //
3200 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3201 // and not commoned up and forced early. Must come after regular
3202 // optimizations to avoid GVN undoing the cloning. Clone constant
3203 // inputs to Loop Phis; these will be split by the allocator anyways.
3204 // Remove Opaque nodes.
3205 // (2) Move last-uses by commutative operations to the left input to encourage
3206 // Intel update-in-place two-address operations and better register usage
3207 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3208 // calls canonicalizing them back.
3209 // (3) Count the number of double-precision FP ops, single-precision FP ops
3210 // and call sites. On Intel, we can get correct rounding either by
3211 // forcing singles to memory (requires extra stores and loads after each
3212 // FP bytecode) or we can set a rounding mode bit (requires setting and
3213 // clearing the mode bit around call sites). The mode bit is only used
3214 // if the relative frequency of single FP ops to calls is low enough.
3215 // This is a key transform for SPEC mpeg_audio.
3216 // (4) Detect infinite loops; blobs of code reachable from above but not
3217 // below. Several of the Code_Gen algorithms fail on such code shapes,
3218 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3219 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3220 // Detection is by looking for IfNodes where only 1 projection is
3221 // reachable from below or CatchNodes missing some targets.
3222 // (5) Assert for insane oop offsets in debug mode.
3223
3224 bool Compile::final_graph_reshaping() {
3225 // an infinite loop may have been eliminated by the optimizer,
3226 // in which case the graph will be empty.
3227 if (root()->req() == 1) {
3228 record_method_not_compilable("trivial infinite loop");
3229 return true;
3230 }
3231
3232 // Expensive nodes have their control input set to prevent the GVN
3233 // from freely commoning them. There's no GVN beyond this point so
3234 // no need to keep the control input. We want the expensive nodes to
3235 // be freely moved to the least frequent code path by gcm.
3236 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3237 for (int i = 0; i < expensive_count(); i++) {
3238 _expensive_nodes->at(i)->set_req(0, NULL);
3239 }
3240
3241 Final_Reshape_Counts frc;
3242
3243 // Visit everybody reachable!
3244 // Allocate stack of size C->unique()/2 to avoid frequent realloc
3245 Node_Stack nstack(unique() >> 1);
3246 final_graph_reshaping_walk(nstack, root(), frc);
3247
3248 // Check for unreachable (from below) code (i.e., infinite loops).
3249 for( uint i = 0; i < frc._tests.size(); i++ ) {
3250 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3251 // Get number of CFG targets.
3252 // Note that PCTables include exception targets after calls.
3253 uint required_outcnt = n->required_outcnt();
3254 if (n->outcnt() != required_outcnt) {
3255 // Check for a few special cases. Rethrow Nodes never take the
3256 // 'fall-thru' path, so expected kids is 1 less.
3257 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3258 if (n->in(0)->in(0)->is_Call()) {
3259 CallNode *call = n->in(0)->in(0)->as_Call();
3260 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3261 required_outcnt--; // Rethrow always has 1 less kid
3262 } else if (call->req() > TypeFunc::Parms &&
3263 call->is_CallDynamicJava()) {
3264 // Check for null receiver. In such case, the optimizer has
3265 // detected that the virtual call will always result in a null
3266 // pointer exception. The fall-through projection of this CatchNode
3267 // will not be populated.
3268 Node *arg0 = call->in(TypeFunc::Parms);
3269 if (arg0->is_Type() &&
3270 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3271 required_outcnt--;
3272 }
3273 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3274 call->req() > TypeFunc::Parms+1 &&
3275 call->is_CallStaticJava()) {
3276 // Check for negative array length. In such case, the optimizer has
3277 // detected that the allocation attempt will always result in an
3278 // exception. There is no fall-through projection of this CatchNode .
3279 Node *arg1 = call->in(TypeFunc::Parms+1);
3280 if (arg1->is_Type() &&
3281 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3282 required_outcnt--;
3283 }
3284 }
3285 }
3286 }
3287 // Recheck with a better notion of 'required_outcnt'
3288 if (n->outcnt() != required_outcnt) {
3289 record_method_not_compilable("malformed control flow");
3290 return true; // Not all targets reachable!
3291 }
3292 }
3293 // Check that I actually visited all kids. Unreached kids
3294 // must be infinite loops.
3295 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3296 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3297 record_method_not_compilable("infinite loop");
3298 return true; // Found unvisited kid; must be unreach
3299 }
3300 }
3301
3302 // If original bytecodes contained a mixture of floats and doubles
3303 // check if the optimizer has made it homogenous, item (3).
3304 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3305 frc.get_float_count() > 32 &&
3306 frc.get_double_count() == 0 &&
3307 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3308 set_24_bit_selection_and_mode( false, true );
3309 }
3310
3311 set_java_calls(frc.get_java_call_count());
3312 set_inner_loops(frc.get_inner_loop_count());
3313
3314 // No infinite loops, no reason to bail out.
3315 return false;
3316 }
3317
3318 //-----------------------------too_many_traps----------------------------------
3319 // Report if there are too many traps at the current method and bci.
3320 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3321 bool Compile::too_many_traps(ciMethod* method,
3322 int bci,
3323 Deoptimization::DeoptReason reason) {
3324 ciMethodData* md = method->method_data();
3325 if (md->is_empty()) {
3326 // Assume the trap has not occurred, or that it occurred only
3327 // because of a transient condition during start-up in the interpreter.
3328 return false;
3329 }
3330 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3331 if (md->has_trap_at(bci, m, reason) != 0) {
3332 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3333 // Also, if there are multiple reasons, or if there is no per-BCI record,
3334 // assume the worst.
3335 if (log())
3336 log()->elem("observe trap='%s' count='%d'",
3337 Deoptimization::trap_reason_name(reason),
3338 md->trap_count(reason));
3339 return true;
3340 } else {
3341 // Ignore method/bci and see if there have been too many globally.
3342 return too_many_traps(reason, md);
3343 }
3344 }
3345
3346 // Less-accurate variant which does not require a method and bci.
3347 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3348 ciMethodData* logmd) {
3349 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3350 // Too many traps globally.
3351 // Note that we use cumulative trap_count, not just md->trap_count.
3352 if (log()) {
3353 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3354 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3355 Deoptimization::trap_reason_name(reason),
3356 mcount, trap_count(reason));
3357 }
3358 return true;
3359 } else {
3360 // The coast is clear.
3361 return false;
3362 }
3363 }
3364
3365 //--------------------------too_many_recompiles--------------------------------
3366 // Report if there are too many recompiles at the current method and bci.
3367 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3368 // Is not eager to return true, since this will cause the compiler to use
3369 // Action_none for a trap point, to avoid too many recompilations.
3370 bool Compile::too_many_recompiles(ciMethod* method,
3371 int bci,
3372 Deoptimization::DeoptReason reason) {
3373 ciMethodData* md = method->method_data();
3374 if (md->is_empty()) {
3375 // Assume the trap has not occurred, or that it occurred only
3376 // because of a transient condition during start-up in the interpreter.
3377 return false;
3378 }
3379 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3380 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3381 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3382 Deoptimization::DeoptReason per_bc_reason
3383 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3384 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3385 if ((per_bc_reason == Deoptimization::Reason_none
3386 || md->has_trap_at(bci, m, reason) != 0)
3387 // The trap frequency measure we care about is the recompile count:
3388 && md->trap_recompiled_at(bci, m)
3389 && md->overflow_recompile_count() >= bc_cutoff) {
3390 // Do not emit a trap here if it has already caused recompilations.
3391 // Also, if there are multiple reasons, or if there is no per-BCI record,
3392 // assume the worst.
3393 if (log())
3394 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3395 Deoptimization::trap_reason_name(reason),
3396 md->trap_count(reason),
3397 md->overflow_recompile_count());
3398 return true;
3399 } else if (trap_count(reason) != 0
3400 && decompile_count() >= m_cutoff) {
3401 // Too many recompiles globally, and we have seen this sort of trap.
3402 // Use cumulative decompile_count, not just md->decompile_count.
3403 if (log())
3404 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3405 Deoptimization::trap_reason_name(reason),
3406 md->trap_count(reason), trap_count(reason),
3407 md->decompile_count(), decompile_count());
3408 return true;
3409 } else {
3410 // The coast is clear.
3411 return false;
3412 }
3413 }
3414
3415 // Compute when not to trap. Used by matching trap based nodes and
3416 // NullCheck optimization.
3417 void Compile::set_allowed_deopt_reasons() {
3418 _allowed_reasons = 0;
3419 if (is_method_compilation()) {
3420 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3421 assert(rs < BitsPerInt, "recode bit map");
3422 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3423 _allowed_reasons |= nth_bit(rs);
3424 }
3425 }
3426 }
3427 }
3428
3429 #ifndef PRODUCT
3430 //------------------------------verify_graph_edges---------------------------
3431 // Walk the Graph and verify that there is a one-to-one correspondence
3432 // between Use-Def edges and Def-Use edges in the graph.
3433 void Compile::verify_graph_edges(bool no_dead_code) {
3434 if (VerifyGraphEdges) {
3435 ResourceArea *area = Thread::current()->resource_area();
3436 Unique_Node_List visited(area);
3437 // Call recursive graph walk to check edges
3438 _root->verify_edges(visited);
3439 if (no_dead_code) {
3440 // Now make sure that no visited node is used by an unvisited node.
3441 bool dead_nodes = false;
3442 Unique_Node_List checked(area);
3443 while (visited.size() > 0) {
3444 Node* n = visited.pop();
3445 checked.push(n);
3446 for (uint i = 0; i < n->outcnt(); i++) {
3447 Node* use = n->raw_out(i);
3448 if (checked.member(use)) continue; // already checked
3449 if (visited.member(use)) continue; // already in the graph
3450 if (use->is_Con()) continue; // a dead ConNode is OK
3451 // At this point, we have found a dead node which is DU-reachable.
3452 if (!dead_nodes) {
3453 tty->print_cr("*** Dead nodes reachable via DU edges:");
3454 dead_nodes = true;
3455 }
3456 use->dump(2);
3457 tty->print_cr("---");
3458 checked.push(use); // No repeats; pretend it is now checked.
3459 }
3460 }
3461 assert(!dead_nodes, "using nodes must be reachable from root");
3462 }
3463 }
3464 }
3465
3466 // Verify GC barriers consistency
3467 // Currently supported:
3468 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3469 void Compile::verify_barriers() {
3470 if (UseG1GC) {
3471 // Verify G1 pre-barriers
3472 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3473
3474 ResourceArea *area = Thread::current()->resource_area();
3475 Unique_Node_List visited(area);
3476 Node_List worklist(area);
3477 // We're going to walk control flow backwards starting from the Root
3478 worklist.push(_root);
3479 while (worklist.size() > 0) {
3480 Node* x = worklist.pop();
3481 if (x == NULL || x == top()) continue;
3482 if (visited.member(x)) {
3483 continue;
3484 } else {
3485 visited.push(x);
3486 }
3487
3488 if (x->is_Region()) {
3489 for (uint i = 1; i < x->req(); i++) {
3490 worklist.push(x->in(i));
3491 }
3492 } else {
3493 worklist.push(x->in(0));
3494 // We are looking for the pattern:
3495 // /->ThreadLocal
3496 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3497 // \->ConI(0)
3498 // We want to verify that the If and the LoadB have the same control
3499 // See GraphKit::g1_write_barrier_pre()
3500 if (x->is_If()) {
3501 IfNode *iff = x->as_If();
3502 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3503 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3504 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3505 && cmp->in(1)->is_Load()) {
3506 LoadNode* load = cmp->in(1)->as_Load();
3507 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3508 && load->in(2)->in(3)->is_Con()
3509 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3510
3511 Node* if_ctrl = iff->in(0);
3512 Node* load_ctrl = load->in(0);
3513
3514 if (if_ctrl != load_ctrl) {
3515 // Skip possible CProj->NeverBranch in infinite loops
3516 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3517 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3518 if_ctrl = if_ctrl->in(0)->in(0);
3519 }
3520 }
3521 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3522 }
3523 }
3524 }
3525 }
3526 }
3527 }
3528 }
3529 }
3530
3531 #endif
3532
3533 // The Compile object keeps track of failure reasons separately from the ciEnv.
3534 // This is required because there is not quite a 1-1 relation between the
3535 // ciEnv and its compilation task and the Compile object. Note that one
3536 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3537 // to backtrack and retry without subsuming loads. Other than this backtracking
3538 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3539 // by the logic in C2Compiler.
3540 void Compile::record_failure(const char* reason) {
3541 if (log() != NULL) {
3542 log()->elem("failure reason='%s' phase='compile'", reason);
3543 }
3544 if (_failure_reason == NULL) {
3545 // Record the first failure reason.
3546 _failure_reason = reason;
3547 }
3548
3549 EventCompilerFailure event;
3550 if (event.should_commit()) {
3551 event.set_compileID(Compile::compile_id());
3552 event.set_failure(reason);
3553 event.commit();
3554 }
3555
3556 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3557 C->print_method(PHASE_FAILURE);
3558 }
3559 _root = NULL; // flush the graph, too
3560 }
3561
3562 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3563 : TraceTime(name, accumulator, CITime, CITimeVerbose),
3564 _phase_name(name), _dolog(CITimeVerbose)
3565 {
3566 if (_dolog) {
3567 C = Compile::current();
3568 _log = C->log();
3569 } else {
3570 C = NULL;
3571 _log = NULL;
3572 }
3573 if (_log != NULL) {
3574 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3575 _log->stamp();
3576 _log->end_head();
3577 }
3578 }
3579
3580 Compile::TracePhase::~TracePhase() {
3581
3582 C = Compile::current();
3583 if (_dolog) {
3584 _log = C->log();
3585 } else {
3586 _log = NULL;
3587 }
3588
3589 #ifdef ASSERT
3590 if (PrintIdealNodeCount) {
3591 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3592 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3593 }
3594
3595 if (VerifyIdealNodeCount) {
3596 Compile::current()->print_missing_nodes();
3597 }
3598 #endif
3599
3600 if (_log != NULL) {
3601 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3602 }
3603 }
3604
3605 //=============================================================================
3606 // Two Constant's are equal when the type and the value are equal.
3607 bool Compile::Constant::operator==(const Constant& other) {
3608 if (type() != other.type() ) return false;
3609 if (can_be_reused() != other.can_be_reused()) return false;
3610 // For floating point values we compare the bit pattern.
3611 switch (type()) {
3612 case T_FLOAT: return (_v._value.i == other._v._value.i);
3613 case T_LONG:
3614 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3615 case T_OBJECT:
3616 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3617 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3618 case T_METADATA: return (_v._metadata == other._v._metadata);
3619 default: ShouldNotReachHere();
3620 }
3621 return false;
3622 }
3623
3624 static int type_to_size_in_bytes(BasicType t) {
3625 switch (t) {
3626 case T_LONG: return sizeof(jlong );
3627 case T_FLOAT: return sizeof(jfloat );
3628 case T_DOUBLE: return sizeof(jdouble);
3629 case T_METADATA: return sizeof(Metadata*);
3630 // We use T_VOID as marker for jump-table entries (labels) which
3631 // need an internal word relocation.
3632 case T_VOID:
3633 case T_ADDRESS:
3634 case T_OBJECT: return sizeof(jobject);
3635 }
3636
3637 ShouldNotReachHere();
3638 return -1;
3639 }
3640
3641 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3642 // sort descending
3643 if (a->freq() > b->freq()) return -1;
3644 if (a->freq() < b->freq()) return 1;
3645 return 0;
3646 }
3647
3648 void Compile::ConstantTable::calculate_offsets_and_size() {
3649 // First, sort the array by frequencies.
3650 _constants.sort(qsort_comparator);
3651
3652 #ifdef ASSERT
3653 // Make sure all jump-table entries were sorted to the end of the
3654 // array (they have a negative frequency).
3655 bool found_void = false;
3656 for (int i = 0; i < _constants.length(); i++) {
3657 Constant con = _constants.at(i);
3658 if (con.type() == T_VOID)
3659 found_void = true; // jump-tables
3660 else
3661 assert(!found_void, "wrong sorting");
3662 }
3663 #endif
3664
3665 int offset = 0;
3666 for (int i = 0; i < _constants.length(); i++) {
3667 Constant* con = _constants.adr_at(i);
3668
3669 // Align offset for type.
3670 int typesize = type_to_size_in_bytes(con->type());
3671 offset = align_size_up(offset, typesize);
3672 con->set_offset(offset); // set constant's offset
3673
3674 if (con->type() == T_VOID) {
3675 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3676 offset = offset + typesize * n->outcnt(); // expand jump-table
3677 } else {
3678 offset = offset + typesize;
3679 }
3680 }
3681
3682 // Align size up to the next section start (which is insts; see
3683 // CodeBuffer::align_at_start).
3684 assert(_size == -1, "already set?");
3685 _size = align_size_up(offset, CodeEntryAlignment);
3686 }
3687
3688 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3689 MacroAssembler _masm(&cb);
3690 for (int i = 0; i < _constants.length(); i++) {
3691 Constant con = _constants.at(i);
3692 address constant_addr;
3693 switch (con.type()) {
3694 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3695 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3696 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3697 case T_OBJECT: {
3698 jobject obj = con.get_jobject();
3699 int oop_index = _masm.oop_recorder()->find_index(obj);
3700 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3701 break;
3702 }
3703 case T_ADDRESS: {
3704 address addr = (address) con.get_jobject();
3705 constant_addr = _masm.address_constant(addr);
3706 break;
3707 }
3708 // We use T_VOID as marker for jump-table entries (labels) which
3709 // need an internal word relocation.
3710 case T_VOID: {
3711 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3712 // Fill the jump-table with a dummy word. The real value is
3713 // filled in later in fill_jump_table.
3714 address dummy = (address) n;
3715 constant_addr = _masm.address_constant(dummy);
3716 // Expand jump-table
3717 for (uint i = 1; i < n->outcnt(); i++) {
3718 address temp_addr = _masm.address_constant(dummy + i);
3719 assert(temp_addr, "consts section too small");
3720 }
3721 break;
3722 }
3723 case T_METADATA: {
3724 Metadata* obj = con.get_metadata();
3725 int metadata_index = _masm.oop_recorder()->find_index(obj);
3726 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3727 break;
3728 }
3729 default: ShouldNotReachHere();
3730 }
3731 assert(constant_addr, "consts section too small");
3732 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3733 err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3734 }
3735 }
3736
3737 int Compile::ConstantTable::find_offset(Constant& con) const {
3738 int idx = _constants.find(con);
3739 assert(idx != -1, "constant must be in constant table");
3740 int offset = _constants.at(idx).offset();
3741 assert(offset != -1, "constant table not emitted yet?");
3742 return offset;
3743 }
3744
3745 void Compile::ConstantTable::add(Constant& con) {
3746 if (con.can_be_reused()) {
3747 int idx = _constants.find(con);
3748 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3749 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3750 return;
3751 }
3752 }
3753 (void) _constants.append(con);
3754 }
3755
3756 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3757 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3758 Constant con(type, value, b->_freq);
3759 add(con);
3760 return con;
3761 }
3762
3763 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3764 Constant con(metadata);
3765 add(con);
3766 return con;
3767 }
3768
3769 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3770 jvalue value;
3771 BasicType type = oper->type()->basic_type();
3772 switch (type) {
3773 case T_LONG: value.j = oper->constantL(); break;
3774 case T_FLOAT: value.f = oper->constantF(); break;
3775 case T_DOUBLE: value.d = oper->constantD(); break;
3776 case T_OBJECT:
3777 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3778 case T_METADATA: return add((Metadata*)oper->constant()); break;
3779 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3780 }
3781 return add(n, type, value);
3782 }
3783
3784 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3785 jvalue value;
3786 // We can use the node pointer here to identify the right jump-table
3787 // as this method is called from Compile::Fill_buffer right before
3788 // the MachNodes are emitted and the jump-table is filled (means the
3789 // MachNode pointers do not change anymore).
3790 value.l = (jobject) n;
3791 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3792 add(con);
3793 return con;
3794 }
3795
3796 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3797 // If called from Compile::scratch_emit_size do nothing.
3798 if (Compile::current()->in_scratch_emit_size()) return;
3799
3800 assert(labels.is_nonempty(), "must be");
3801 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3802
3803 // Since MachConstantNode::constant_offset() also contains
3804 // table_base_offset() we need to subtract the table_base_offset()
3805 // to get the plain offset into the constant table.
3806 int offset = n->constant_offset() - table_base_offset();
3807
3808 MacroAssembler _masm(&cb);
3809 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3810
3811 for (uint i = 0; i < n->outcnt(); i++) {
3812 address* constant_addr = &jump_table_base[i];
3813 assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i)));
3814 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3815 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3816 }
3817 }
3818
3819 //----------------------------static_subtype_check-----------------------------
3820 // Shortcut important common cases when superklass is exact:
3821 // (0) superklass is java.lang.Object (can occur in reflective code)
3822 // (1) subklass is already limited to a subtype of superklass => always ok
3823 // (2) subklass does not overlap with superklass => always fail
3824 // (3) superklass has NO subtypes and we can check with a simple compare.
3825 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
3826 if (StressReflectiveCode) {
3827 return SSC_full_test; // Let caller generate the general case.
3828 }
3829
3830 if (superk == env()->Object_klass()) {
3831 return SSC_always_true; // (0) this test cannot fail
3832 }
3833
3834 ciType* superelem = superk;
3835 if (superelem->is_array_klass())
3836 superelem = superelem->as_array_klass()->base_element_type();
3837
3838 if (!subk->is_interface()) { // cannot trust static interface types yet
3839 if (subk->is_subtype_of(superk)) {
3840 return SSC_always_true; // (1) false path dead; no dynamic test needed
3841 }
3842 if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
3843 !superk->is_subtype_of(subk)) {
3844 return SSC_always_false;
3845 }
3846 }
3847
3848 // If casting to an instance klass, it must have no subtypes
3849 if (superk->is_interface()) {
3850 // Cannot trust interfaces yet.
3851 // %%% S.B. superk->nof_implementors() == 1
3852 } else if (superelem->is_instance_klass()) {
3853 ciInstanceKlass* ik = superelem->as_instance_klass();
3854 if (!ik->has_subklass() && !ik->is_interface()) {
3855 if (!ik->is_final()) {
3856 // Add a dependency if there is a chance of a later subclass.
3857 dependencies()->assert_leaf_type(ik);
3858 }
3859 return SSC_easy_test; // (3) caller can do a simple ptr comparison
3860 }
3861 } else {
3862 // A primitive array type has no subtypes.
3863 return SSC_easy_test; // (3) caller can do a simple ptr comparison
3864 }
3865
3866 return SSC_full_test;
3867 }
3868
3869 // The message about the current inlining is accumulated in
3870 // _print_inlining_stream and transfered into the _print_inlining_list
3871 // once we know whether inlining succeeds or not. For regular
3872 // inlining, messages are appended to the buffer pointed by
3873 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3874 // a new buffer is added after _print_inlining_idx in the list. This
3875 // way we can update the inlining message for late inlining call site
3876 // when the inlining is attempted again.
3877 void Compile::print_inlining_init() {
3878 if (print_inlining() || print_intrinsics()) {
3879 _print_inlining_stream = new stringStream();
3880 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3881 }
3882 }
3883
3884 void Compile::print_inlining_reinit() {
3885 if (print_inlining() || print_intrinsics()) {
3886 // Re allocate buffer when we change ResourceMark
3887 _print_inlining_stream = new stringStream();
3888 }
3889 }
3890
3891 void Compile::print_inlining_reset() {
3892 _print_inlining_stream->reset();
3893 }
3894
3895 void Compile::print_inlining_commit() {
3896 assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3897 // Transfer the message from _print_inlining_stream to the current
3898 // _print_inlining_list buffer and clear _print_inlining_stream.
3899 _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3900 print_inlining_reset();
3901 }
3902
3903 void Compile::print_inlining_push() {
3904 // Add new buffer to the _print_inlining_list at current position
3905 _print_inlining_idx++;
3906 _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3907 }
3908
3909 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3910 return _print_inlining_list->at(_print_inlining_idx);
3911 }
3912
3913 void Compile::print_inlining_update(CallGenerator* cg) {
3914 if (print_inlining() || print_intrinsics()) {
3915 if (!cg->is_late_inline()) {
3916 if (print_inlining_current().cg() != NULL) {
3917 print_inlining_push();
3918 }
3919 print_inlining_commit();
3920 } else {
3921 if (print_inlining_current().cg() != cg &&
3922 (print_inlining_current().cg() != NULL ||
3923 print_inlining_current().ss()->size() != 0)) {
3924 print_inlining_push();
3925 }
3926 print_inlining_commit();
3927 print_inlining_current().set_cg(cg);
3928 }
3929 }
3930 }
3931
3932 void Compile::print_inlining_move_to(CallGenerator* cg) {
3933 // We resume inlining at a late inlining call site. Locate the
3934 // corresponding inlining buffer so that we can update it.
3935 if (print_inlining()) {
3936 for (int i = 0; i < _print_inlining_list->length(); i++) {
3937 if (_print_inlining_list->adr_at(i)->cg() == cg) {
3938 _print_inlining_idx = i;
3939 return;
3940 }
3941 }
3942 ShouldNotReachHere();
3943 }
3944 }
3945
3946 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3947 if (print_inlining()) {
3948 assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3949 assert(print_inlining_current().cg() == cg, "wrong entry");
3950 // replace message with new message
3951 _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3952 print_inlining_commit();
3953 print_inlining_current().set_cg(cg);
3954 }
3955 }
3956
3957 void Compile::print_inlining_assert_ready() {
3958 assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3959 }
3960
3961 void Compile::process_print_inlining() {
3962 bool do_print_inlining = print_inlining() || print_intrinsics();
3963 if (do_print_inlining || log() != NULL) {
3964 // Print inlining message for candidates that we couldn't inline
3965 // for lack of space
3966 for (int i = 0; i < _late_inlines.length(); i++) {
3967 CallGenerator* cg = _late_inlines.at(i);
3968 if (!cg->is_mh_late_inline()) {
3969 const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3970 if (do_print_inlining) {
3971 cg->print_inlining_late(msg);
3972 }
3973 log_late_inline_failure(cg, msg);
3974 }
3975 }
3976 }
3977 if (do_print_inlining) {
3978 ResourceMark rm;
3979 stringStream ss;
3980 for (int i = 0; i < _print_inlining_list->length(); i++) {
3981 ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3982 }
3983 size_t end = ss.size();
3984 _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
3985 strncpy(_print_inlining_output, ss.base(), end+1);
3986 _print_inlining_output[end] = 0;
3987 }
3988 }
3989
3990 void Compile::dump_print_inlining() {
3991 if (_print_inlining_output != NULL) {
3992 tty->print_raw(_print_inlining_output);
3993 }
3994 }
3995
3996 void Compile::log_late_inline(CallGenerator* cg) {
3997 if (log() != NULL) {
3998 log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3999 cg->unique_id());
4000 JVMState* p = cg->call_node()->jvms();
4001 while (p != NULL) {
4002 log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4003 p = p->caller();
4004 }
4005 log()->tail("late_inline");
4006 }
4007 }
4008
4009 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4010 log_late_inline(cg);
4011 if (log() != NULL) {
4012 log()->inline_fail(msg);
4013 }
4014 }
4015
4016 void Compile::log_inline_id(CallGenerator* cg) {
4017 if (log() != NULL) {
4018 // The LogCompilation tool needs a unique way to identify late
4019 // inline call sites. This id must be unique for this call site in
4020 // this compilation. Try to have it unique across compilations as
4021 // well because it can be convenient when grepping through the log
4022 // file.
4023 // Distinguish OSR compilations from others in case CICountOSR is
4024 // on.
4025 jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4026 cg->set_unique_id(id);
4027 log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4028 }
4029 }
4030
4031 void Compile::log_inline_failure(const char* msg) {
4032 if (C->log() != NULL) {
4033 C->log()->inline_fail(msg);
4034 }
4035 }
4036
4037
4038 // Dump inlining replay data to the stream.
4039 // Don't change thread state and acquire any locks.
4040 void Compile::dump_inline_data(outputStream* out) {
4041 InlineTree* inl_tree = ilt();
4042 if (inl_tree != NULL) {
4043 out->print(" inline %d", inl_tree->count());
4044 inl_tree->dump_replay_data(out);
4045 }
4046 }
4047
4048 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4049 if (n1->Opcode() < n2->Opcode()) return -1;
4050 else if (n1->Opcode() > n2->Opcode()) return 1;
4051
4052 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()));
4053 for (uint i = 1; i < n1->req(); i++) {
4054 if (n1->in(i) < n2->in(i)) return -1;
4055 else if (n1->in(i) > n2->in(i)) return 1;
4056 }
4057
4058 return 0;
4059 }
4060
4061 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4062 Node* n1 = *n1p;
4063 Node* n2 = *n2p;
4064
4065 return cmp_expensive_nodes(n1, n2);
4066 }
4067
4068 void Compile::sort_expensive_nodes() {
4069 if (!expensive_nodes_sorted()) {
4070 _expensive_nodes->sort(cmp_expensive_nodes);
4071 }
4072 }
4073
4074 bool Compile::expensive_nodes_sorted() const {
4075 for (int i = 1; i < _expensive_nodes->length(); i++) {
4076 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4077 return false;
4078 }
4079 }
4080 return true;
4081 }
4082
4083 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4084 if (_expensive_nodes->length() == 0) {
4085 return false;
4086 }
4087
4088 assert(OptimizeExpensiveOps, "optimization off?");
4089
4090 // Take this opportunity to remove dead nodes from the list
4091 int j = 0;
4092 for (int i = 0; i < _expensive_nodes->length(); i++) {
4093 Node* n = _expensive_nodes->at(i);
4094 if (!n->is_unreachable(igvn)) {
4095 assert(n->is_expensive(), "should be expensive");
4096 _expensive_nodes->at_put(j, n);
4097 j++;
4098 }
4099 }
4100 _expensive_nodes->trunc_to(j);
4101
4102 // Then sort the list so that similar nodes are next to each other
4103 // and check for at least two nodes of identical kind with same data
4104 // inputs.
4105 sort_expensive_nodes();
4106
4107 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4108 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4109 return true;
4110 }
4111 }
4112
4113 return false;
4114 }
4115
4116 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4117 if (_expensive_nodes->length() == 0) {
4118 return;
4119 }
4120
4121 assert(OptimizeExpensiveOps, "optimization off?");
4122
4123 // Sort to bring similar nodes next to each other and clear the
4124 // control input of nodes for which there's only a single copy.
4125 sort_expensive_nodes();
4126
4127 int j = 0;
4128 int identical = 0;
4129 int i = 0;
4130 bool modified = false;
4131 for (; i < _expensive_nodes->length()-1; i++) {
4132 assert(j <= i, "can't write beyond current index");
4133 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4134 identical++;
4135 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4136 continue;
4137 }
4138 if (identical > 0) {
4139 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4140 identical = 0;
4141 } else {
4142 Node* n = _expensive_nodes->at(i);
4143 igvn.replace_input_of(n, 0, NULL);
4144 igvn.hash_insert(n);
4145 modified = true;
4146 }
4147 }
4148 if (identical > 0) {
4149 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4150 } else if (_expensive_nodes->length() >= 1) {
4151 Node* n = _expensive_nodes->at(i);
4152 igvn.replace_input_of(n, 0, NULL);
4153 igvn.hash_insert(n);
4154 modified = true;
4155 }
4156 _expensive_nodes->trunc_to(j);
4157 if (modified) {
4158 igvn.optimize();
4159 }
4160 }
4161
4162 void Compile::add_expensive_node(Node * n) {
4163 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4164 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4165 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4166 if (OptimizeExpensiveOps) {
4167 _expensive_nodes->append(n);
4168 } else {
4169 // Clear control input and let IGVN optimize expensive nodes if
4170 // OptimizeExpensiveOps is off.
4171 n->set_req(0, NULL);
4172 }
4173 }
4174
4175 /**
4176 * Remove the speculative part of types and clean up the graph
4177 */
4178 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4179 if (UseTypeSpeculation) {
4180 Unique_Node_List worklist;
4181 worklist.push(root());
4182 int modified = 0;
4183 // Go over all type nodes that carry a speculative type, drop the
4184 // speculative part of the type and enqueue the node for an igvn
4185 // which may optimize it out.
4186 for (uint next = 0; next < worklist.size(); ++next) {
4187 Node *n = worklist.at(next);
4188 if (n->is_Type()) {
4189 TypeNode* tn = n->as_Type();
4190 const Type* t = tn->type();
4191 const Type* t_no_spec = t->remove_speculative();
4192 if (t_no_spec != t) {
4193 bool in_hash = igvn.hash_delete(n);
4194 assert(in_hash, "node should be in igvn hash table");
4195 tn->set_type(t_no_spec);
4196 igvn.hash_insert(n);
4197 igvn._worklist.push(n); // give it a chance to go away
4198 modified++;
4199 }
4200 }
4201 uint max = n->len();
4202 for( uint i = 0; i < max; ++i ) {
4203 Node *m = n->in(i);
4204 if (not_a_node(m)) continue;
4205 worklist.push(m);
4206 }
4207 }
4208 // Drop the speculative part of all types in the igvn's type table
4209 igvn.remove_speculative_types();
4210 if (modified > 0) {
4211 igvn.optimize();
4212 }
4213 #ifdef ASSERT
4214 // Verify that after the IGVN is over no speculative type has resurfaced
4215 worklist.clear();
4216 worklist.push(root());
4217 for (uint next = 0; next < worklist.size(); ++next) {
4218 Node *n = worklist.at(next);
4219 const Type* t = igvn.type_or_null(n);
4220 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4221 if (n->is_Type()) {
4222 t = n->as_Type()->type();
4223 assert(t == t->remove_speculative(), "no more speculative types");
4224 }
4225 uint max = n->len();
4226 for( uint i = 0; i < max; ++i ) {
4227 Node *m = n->in(i);
4228 if (not_a_node(m)) continue;
4229 worklist.push(m);
4230 }
4231 }
4232 igvn.check_no_speculative_types();
4233 #endif
4234 }
4235 }
4236
4237 // Auxiliary method to support randomized stressing/fuzzing.
4238 //
4239 // This method can be called the arbitrary number of times, with current count
4240 // as the argument. The logic allows selecting a single candidate from the
4241 // running list of candidates as follows:
4242 // int count = 0;
4243 // Cand* selected = null;
4244 // while(cand = cand->next()) {
4245 // if (randomized_select(++count)) {
4246 // selected = cand;
4247 // }
4248 // }
4249 //
4250 // Including count equalizes the chances any candidate is "selected".
4251 // This is useful when we don't have the complete list of candidates to choose
4252 // from uniformly. In this case, we need to adjust the randomicity of the
4253 // selection, or else we will end up biasing the selection towards the latter
4254 // candidates.
4255 //
4256 // Quick back-envelope calculation shows that for the list of n candidates
4257 // the equal probability for the candidate to persist as "best" can be
4258 // achieved by replacing it with "next" k-th candidate with the probability
4259 // of 1/k. It can be easily shown that by the end of the run, the
4260 // probability for any candidate is converged to 1/n, thus giving the
4261 // uniform distribution among all the candidates.
4262 //
4263 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4264 #define RANDOMIZED_DOMAIN_POW 29
4265 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4266 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4267 bool Compile::randomized_select(int count) {
4268 assert(count > 0, "only positive");
4269 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4270 }