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 return;
539 }
540 }
541
542 // Initialize the relocation buffers
543 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
544 set_scratch_locs_memory(locs_buf);
545 }
546
547
548 //-----------------------scratch_emit_size-------------------------------------
549 // Helper function that computes size by emitting code
550 uint Compile::scratch_emit_size(const Node* n) {
551 // Start scratch_emit_size section.
552 set_in_scratch_emit_size(true);
553
554 // Emit into a trash buffer and count bytes emitted.
555 // This is a pretty expensive way to compute a size,
556 // but it works well enough if seldom used.
557 // All common fixed-size instructions are given a size
558 // method by the AD file.
559 // Note that the scratch buffer blob and locs memory are
560 // allocated at the beginning of the compile task, and
561 // may be shared by several calls to scratch_emit_size.
562 // The allocation of the scratch buffer blob is particularly
563 // expensive, since it has to grab the code cache lock.
564 BufferBlob* blob = this->scratch_buffer_blob();
565 assert(blob != NULL, "Initialize BufferBlob at start");
566 assert(blob->size() > MAX_inst_size, "sanity");
567 relocInfo* locs_buf = scratch_locs_memory();
568 address blob_begin = blob->content_begin();
569 address blob_end = (address)locs_buf;
570 assert(blob->content_contains(blob_end), "sanity");
571 CodeBuffer buf(blob_begin, blob_end - blob_begin);
572 buf.initialize_consts_size(_scratch_const_size);
573 buf.initialize_stubs_size(MAX_stubs_size);
574 assert(locs_buf != NULL, "sanity");
575 int lsize = MAX_locs_size / 3;
576 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
577 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
578 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
579
580 // Do the emission.
581
582 Label fakeL; // Fake label for branch instructions.
583 Label* saveL = NULL;
584 uint save_bnum = 0;
585 bool is_branch = n->is_MachBranch();
586 if (is_branch) {
587 MacroAssembler masm(&buf);
588 masm.bind(fakeL);
589 n->as_MachBranch()->save_label(&saveL, &save_bnum);
590 n->as_MachBranch()->label_set(&fakeL, 0);
591 }
592 n->emit(buf, this->regalloc());
593 if (is_branch) // Restore label.
594 n->as_MachBranch()->label_set(saveL, save_bnum);
595
596 // End scratch_emit_size section.
597 set_in_scratch_emit_size(false);
598
599 return buf.insts_size();
600 }
601
602
603 // ============================================================================
604 //------------------------------Compile standard-------------------------------
605 debug_only( int Compile::_debug_idx = 100000; )
606
607 // Compile a method. entry_bci is -1 for normal compilations and indicates
608 // the continuation bci for on stack replacement.
609
610
611 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
612 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
613 : Phase(Compiler),
614 _env(ci_env),
615 _log(ci_env->log()),
616 _compile_id(ci_env->compile_id()),
617 _save_argument_registers(false),
618 _stub_name(NULL),
619 _stub_function(NULL),
620 _stub_entry_point(NULL),
621 _method(target),
622 _entry_bci(osr_bci),
623 _initial_gvn(NULL),
624 _for_igvn(NULL),
625 _warm_calls(NULL),
626 _subsume_loads(subsume_loads),
627 _do_escape_analysis(do_escape_analysis),
628 _eliminate_boxing(eliminate_boxing),
629 _failure_reason(NULL),
630 _code_buffer("Compile::Fill_buffer"),
631 _orig_pc_slot(0),
632 _orig_pc_slot_offset_in_bytes(0),
633 _has_method_handle_invokes(false),
634 _mach_constant_base_node(NULL),
635 _node_bundling_limit(0),
636 _node_bundling_base(NULL),
637 _java_calls(0),
638 _inner_loops(0),
639 _scratch_const_size(-1),
640 _in_scratch_emit_size(false),
641 _dead_node_list(comp_arena()),
642 _dead_node_count(0),
643 #ifndef PRODUCT
644 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
645 _in_dump_cnt(0),
646 _printer(IdealGraphPrinter::printer()),
647 #endif
648 _congraph(NULL),
649 _comp_arena(mtCompiler),
650 _node_arena(mtCompiler),
651 _old_arena(mtCompiler),
652 _Compile_types(mtCompiler),
653 _replay_inline_data(NULL),
654 _late_inlines(comp_arena(), 2, 0, NULL),
655 _string_late_inlines(comp_arena(), 2, 0, NULL),
656 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
657 _late_inlines_pos(0),
658 _number_of_mh_late_inlines(0),
659 _inlining_progress(false),
660 _inlining_incrementally(false),
661 _print_inlining_list(NULL),
662 _print_inlining_stream(NULL),
663 _print_inlining_idx(0),
664 _print_inlining_output(NULL),
665 _interpreter_frame_size(0) {
666 C = this;
667
668 CompileWrapper cw(this);
669
670 if (CITimeVerbose) {
671 tty->print(" ");
672 target->holder()->name()->print();
673 tty->print(".");
674 target->print_short_name();
675 tty->print(" ");
676 }
677 TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
678 TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
679
680 #ifndef PRODUCT
681 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
682 if (!print_opto_assembly) {
683 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
684 if (print_assembly && !Disassembler::can_decode()) {
685 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
686 print_opto_assembly = true;
687 }
688 }
689 set_print_assembly(print_opto_assembly);
690 set_parsed_irreducible_loop(false);
691
692 if (method()->has_option("ReplayInline")) {
693 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
694 }
695 #endif
696 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
697 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
698 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
699
700 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
701 // Make sure the method being compiled gets its own MDO,
702 // so we can at least track the decompile_count().
703 // Need MDO to record RTM code generation state.
704 method()->ensure_method_data();
705 }
706
707 Init(::AliasLevel);
708
709
710 print_compile_messages();
711
712 _ilt = InlineTree::build_inline_tree_root();
713
714 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
715 assert(num_alias_types() >= AliasIdxRaw, "");
716
717 #define MINIMUM_NODE_HASH 1023
718 // Node list that Iterative GVN will start with
719 Unique_Node_List for_igvn(comp_arena());
720 set_for_igvn(&for_igvn);
721
722 // GVN that will be run immediately on new nodes
723 uint estimated_size = method()->code_size()*4+64;
724 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
725 PhaseGVN gvn(node_arena(), estimated_size);
726 set_initial_gvn(&gvn);
727
728 print_inlining_init();
729 { // Scope for timing the parser
730 TracePhase tp("parse", &timers[_t_parser]);
731
732 // Put top into the hash table ASAP.
733 initial_gvn()->transform_no_reclaim(top());
734
735 // Set up tf(), start(), and find a CallGenerator.
736 CallGenerator* cg = NULL;
737 if (is_osr_compilation()) {
738 const TypeTuple *domain = StartOSRNode::osr_domain();
739 const TypeTuple *range = TypeTuple::make_range(method()->signature());
740 init_tf(TypeFunc::make(domain, range));
741 StartNode* s = new StartOSRNode(root(), domain);
742 initial_gvn()->set_type_bottom(s);
743 init_start(s);
744 cg = CallGenerator::for_osr(method(), entry_bci());
745 } else {
746 // Normal case.
747 init_tf(TypeFunc::make(method()));
748 StartNode* s = new StartNode(root(), tf()->domain());
749 initial_gvn()->set_type_bottom(s);
750 init_start(s);
751 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
752 // With java.lang.ref.reference.get() we must go through the
753 // intrinsic when G1 is enabled - even when get() is the root
754 // method of the compile - so that, if necessary, the value in
755 // the referent field of the reference object gets recorded by
756 // the pre-barrier code.
757 // Specifically, if G1 is enabled, the value in the referent
758 // field is recorded by the G1 SATB pre barrier. This will
759 // result in the referent being marked live and the reference
760 // object removed from the list of discovered references during
761 // reference processing.
762 cg = find_intrinsic(method(), false);
763 }
764 if (cg == NULL) {
765 float past_uses = method()->interpreter_invocation_count();
766 float expected_uses = past_uses;
767 cg = CallGenerator::for_inline(method(), expected_uses);
768 }
769 }
770 if (failing()) return;
771 if (cg == NULL) {
772 record_method_not_compilable_all_tiers("cannot parse method");
773 return;
774 }
775 JVMState* jvms = build_start_state(start(), tf());
776 if ((jvms = cg->generate(jvms)) == NULL) {
777 record_method_not_compilable("method parse failed");
778 return;
779 }
780 GraphKit kit(jvms);
781
782 if (!kit.stopped()) {
783 // Accept return values, and transfer control we know not where.
784 // This is done by a special, unique ReturnNode bound to root.
785 return_values(kit.jvms());
786 }
787
788 if (kit.has_exceptions()) {
789 // Any exceptions that escape from this call must be rethrown
790 // to whatever caller is dynamically above us on the stack.
791 // This is done by a special, unique RethrowNode bound to root.
792 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
793 }
794
795 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
796
797 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
798 inline_string_calls(true);
799 }
800
801 if (failing()) return;
802
803 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
804
805 // Remove clutter produced by parsing.
806 if (!failing()) {
807 ResourceMark rm;
808 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
809 }
810 }
811
812 // Note: Large methods are capped off in do_one_bytecode().
813 if (failing()) return;
814
815 // After parsing, node notes are no longer automagic.
816 // They must be propagated by register_new_node_with_optimizer(),
817 // clone(), or the like.
818 set_default_node_notes(NULL);
819
820 for (;;) {
821 int successes = Inline_Warm();
822 if (failing()) return;
823 if (successes == 0) break;
824 }
825
826 // Drain the list.
827 Finish_Warm();
828 #ifndef PRODUCT
829 if (_printer && _printer->should_print(_method)) {
830 _printer->print_inlining(this);
831 }
832 #endif
833
834 if (failing()) return;
835 NOT_PRODUCT( verify_graph_edges(); )
836
837 // Now optimize
838 Optimize();
839 if (failing()) return;
840 NOT_PRODUCT( verify_graph_edges(); )
841
842 #ifndef PRODUCT
843 if (PrintIdeal) {
844 ttyLocker ttyl; // keep the following output all in one block
845 // This output goes directly to the tty, not the compiler log.
846 // To enable tools to match it up with the compilation activity,
847 // be sure to tag this tty output with the compile ID.
848 if (xtty != NULL) {
849 xtty->head("ideal compile_id='%d'%s", compile_id(),
850 is_osr_compilation() ? " compile_kind='osr'" :
851 "");
852 }
853 root()->dump(9999);
854 if (xtty != NULL) {
855 xtty->tail("ideal");
856 }
857 }
858 #endif
859
860 NOT_PRODUCT( verify_barriers(); )
861
862 // Dump compilation data to replay it.
863 if (method()->has_option("DumpReplay")) {
864 env()->dump_replay_data(_compile_id);
865 }
866 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
867 env()->dump_inline_data(_compile_id);
868 }
869
870 // Now that we know the size of all the monitors we can add a fixed slot
871 // for the original deopt pc.
872
873 _orig_pc_slot = fixed_slots();
874 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
875 set_fixed_slots(next_slot);
876
877 // Compute when to use implicit null checks. Used by matching trap based
878 // nodes and NullCheck optimization.
879 set_allowed_deopt_reasons();
880
881 // Now generate code
882 Code_Gen();
883 if (failing()) return;
884
885 // Check if we want to skip execution of all compiled code.
886 {
887 #ifndef PRODUCT
888 if (OptoNoExecute) {
889 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
890 return;
891 }
892 #endif
893 TracePhase tp("install_code", &timers[_t_registerMethod]);
894
895 if (is_osr_compilation()) {
896 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
897 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
898 } else {
899 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
900 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
901 }
902
903 env()->register_method(_method, _entry_bci,
904 &_code_offsets,
905 _orig_pc_slot_offset_in_bytes,
906 code_buffer(),
907 frame_size_in_words(), _oop_map_set,
908 &_handler_table, &_inc_table,
909 compiler,
910 env()->comp_level(),
911 has_unsafe_access(),
912 SharedRuntime::is_wide_vector(max_vector_size()),
913 rtm_state()
914 );
915
916 if (log() != NULL) // Print code cache state into compiler log
917 log()->code_cache_state();
918 }
919 }
920
921 //------------------------------Compile----------------------------------------
922 // Compile a runtime stub
923 Compile::Compile( ciEnv* ci_env,
924 TypeFunc_generator generator,
925 address stub_function,
926 const char *stub_name,
927 int is_fancy_jump,
928 bool pass_tls,
929 bool save_arg_registers,
930 bool return_pc )
931 : Phase(Compiler),
932 _env(ci_env),
933 _log(ci_env->log()),
934 _compile_id(0),
935 _save_argument_registers(save_arg_registers),
936 _method(NULL),
937 _stub_name(stub_name),
938 _stub_function(stub_function),
939 _stub_entry_point(NULL),
940 _entry_bci(InvocationEntryBci),
941 _initial_gvn(NULL),
942 _for_igvn(NULL),
943 _warm_calls(NULL),
944 _orig_pc_slot(0),
945 _orig_pc_slot_offset_in_bytes(0),
946 _subsume_loads(true),
947 _do_escape_analysis(false),
948 _eliminate_boxing(false),
949 _failure_reason(NULL),
950 _code_buffer("Compile::Fill_buffer"),
951 _has_method_handle_invokes(false),
952 _mach_constant_base_node(NULL),
953 _node_bundling_limit(0),
954 _node_bundling_base(NULL),
955 _java_calls(0),
956 _inner_loops(0),
957 #ifndef PRODUCT
958 _trace_opto_output(TraceOptoOutput),
959 _in_dump_cnt(0),
960 _printer(NULL),
961 #endif
962 _comp_arena(mtCompiler),
963 _node_arena(mtCompiler),
964 _old_arena(mtCompiler),
965 _Compile_types(mtCompiler),
966 _dead_node_list(comp_arena()),
967 _dead_node_count(0),
968 _congraph(NULL),
969 _replay_inline_data(NULL),
970 _number_of_mh_late_inlines(0),
971 _inlining_progress(false),
972 _inlining_incrementally(false),
973 _print_inlining_list(NULL),
974 _print_inlining_stream(NULL),
975 _print_inlining_idx(0),
976 _print_inlining_output(NULL),
977 _allowed_reasons(0),
978 _interpreter_frame_size(0) {
979 C = this;
980
981 TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
982 TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
983
984 #ifndef PRODUCT
985 set_print_assembly(PrintFrameConverterAssembly);
986 set_parsed_irreducible_loop(false);
987 #endif
988 set_has_irreducible_loop(false); // no loops
989
990 CompileWrapper cw(this);
991 Init(/*AliasLevel=*/ 0);
992 init_tf((*generator)());
993
994 {
995 // The following is a dummy for the sake of GraphKit::gen_stub
996 Unique_Node_List for_igvn(comp_arena());
997 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
998 PhaseGVN gvn(Thread::current()->resource_area(),255);
999 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
1000 gvn.transform_no_reclaim(top());
1001
1002 GraphKit kit;
1003 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1004 }
1005
1006 NOT_PRODUCT( verify_graph_edges(); )
1007 Code_Gen();
1008 if (failing()) return;
1009
1010
1011 // Entry point will be accessed using compile->stub_entry_point();
1012 if (code_buffer() == NULL) {
1013 Matcher::soft_match_failure();
1014 } else {
1015 if (PrintAssembly && (WizardMode || Verbose))
1016 tty->print_cr("### Stub::%s", stub_name);
1017
1018 if (!failing()) {
1019 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1020
1021 // Make the NMethod
1022 // For now we mark the frame as never safe for profile stackwalking
1023 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1024 code_buffer(),
1025 CodeOffsets::frame_never_safe,
1026 // _code_offsets.value(CodeOffsets::Frame_Complete),
1027 frame_size_in_words(),
1028 _oop_map_set,
1029 save_arg_registers);
1030 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1031
1032 _stub_entry_point = rs->entry_point();
1033 }
1034 }
1035 }
1036
1037 //------------------------------Init-------------------------------------------
1038 // Prepare for a single compilation
1039 void Compile::Init(int aliaslevel) {
1040 _unique = 0;
1041 _regalloc = NULL;
1042
1043 _tf = NULL; // filled in later
1044 _top = NULL; // cached later
1045 _matcher = NULL; // filled in later
1046 _cfg = NULL; // filled in later
1047
1048 set_24_bit_selection_and_mode(Use24BitFP, false);
1049
1050 _node_note_array = NULL;
1051 _default_node_notes = NULL;
1052 DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1053
1054 _immutable_memory = NULL; // filled in at first inquiry
1055
1056 // Globally visible Nodes
1057 // First set TOP to NULL to give safe behavior during creation of RootNode
1058 set_cached_top_node(NULL);
1059 set_root(new RootNode());
1060 // Now that you have a Root to point to, create the real TOP
1061 set_cached_top_node( new ConNode(Type::TOP) );
1062 set_recent_alloc(NULL, NULL);
1063
1064 // Create Debug Information Recorder to record scopes, oopmaps, etc.
1065 env()->set_oop_recorder(new OopRecorder(env()->arena()));
1066 env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1067 env()->set_dependencies(new Dependencies(env()));
1068
1069 _fixed_slots = 0;
1070 set_has_split_ifs(false);
1071 set_has_loops(has_method() && method()->has_loops()); // first approximation
1072 set_has_stringbuilder(false);
1073 set_has_boxed_value(false);
1074 _trap_can_recompile = false; // no traps emitted yet
1075 _major_progress = true; // start out assuming good things will happen
1076 set_has_unsafe_access(false);
1077 set_max_vector_size(0);
1078 Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1079 set_decompile_count(0);
1080
1081 set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1082 set_num_loop_opts(LoopOptsCount);
1083 set_do_inlining(Inline);
1084 set_max_inline_size(MaxInlineSize);
1085 set_freq_inline_size(FreqInlineSize);
1086 set_do_scheduling(OptoScheduling);
1087 set_do_count_invocations(false);
1088 set_do_method_data_update(false);
1089 set_age_code(has_method() && method()->profile_aging());
1090 set_rtm_state(NoRTM); // No RTM lock eliding by default
1091 #if INCLUDE_RTM_OPT
1092 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1093 int rtm_state = method()->method_data()->rtm_state();
1094 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1095 // Don't generate RTM lock eliding code.
1096 set_rtm_state(NoRTM);
1097 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1098 // Generate RTM lock eliding code without abort ratio calculation code.
1099 set_rtm_state(UseRTM);
1100 } else if (UseRTMDeopt) {
1101 // Generate RTM lock eliding code and include abort ratio calculation
1102 // code if UseRTMDeopt is on.
1103 set_rtm_state(ProfileRTM);
1104 }
1105 }
1106 #endif
1107 if (debug_info()->recording_non_safepoints()) {
1108 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1109 (comp_arena(), 8, 0, NULL));
1110 set_default_node_notes(Node_Notes::make(this));
1111 }
1112
1113 // // -- Initialize types before each compile --
1114 // // Update cached type information
1115 // if( _method && _method->constants() )
1116 // Type::update_loaded_types(_method, _method->constants());
1117
1118 // Init alias_type map.
1119 if (!_do_escape_analysis && aliaslevel == 3)
1120 aliaslevel = 2; // No unique types without escape analysis
1121 _AliasLevel = aliaslevel;
1122 const int grow_ats = 16;
1123 _max_alias_types = grow_ats;
1124 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1125 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1126 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1127 {
1128 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1129 }
1130 // Initialize the first few types.
1131 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1132 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1133 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1134 _num_alias_types = AliasIdxRaw+1;
1135 // Zero out the alias type cache.
1136 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1137 // A NULL adr_type hits in the cache right away. Preload the right answer.
1138 probe_alias_cache(NULL)->_index = AliasIdxTop;
1139
1140 _intrinsics = NULL;
1141 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1142 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1143 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1144 register_library_intrinsics();
1145 }
1146
1147 //---------------------------init_start----------------------------------------
1148 // Install the StartNode on this compile object.
1149 void Compile::init_start(StartNode* s) {
1150 if (failing())
1151 return; // already failing
1152 assert(s == start(), "");
1153 }
1154
1155 /**
1156 * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1157 * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1158 * the ideal graph.
1159 */
1160 StartNode* Compile::start() const {
1161 assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
1162 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1163 Node* start = root()->fast_out(i);
1164 if (start->is_Start()) {
1165 return start->as_Start();
1166 }
1167 }
1168 fatal("Did not find Start node!");
1169 return NULL;
1170 }
1171
1172 //-------------------------------immutable_memory-------------------------------------
1173 // Access immutable memory
1174 Node* Compile::immutable_memory() {
1175 if (_immutable_memory != NULL) {
1176 return _immutable_memory;
1177 }
1178 StartNode* s = start();
1179 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1180 Node *p = s->fast_out(i);
1181 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1182 _immutable_memory = p;
1183 return _immutable_memory;
1184 }
1185 }
1186 ShouldNotReachHere();
1187 return NULL;
1188 }
1189
1190 //----------------------set_cached_top_node------------------------------------
1191 // Install the cached top node, and make sure Node::is_top works correctly.
1192 void Compile::set_cached_top_node(Node* tn) {
1193 if (tn != NULL) verify_top(tn);
1194 Node* old_top = _top;
1195 _top = tn;
1196 // Calling Node::setup_is_top allows the nodes the chance to adjust
1197 // their _out arrays.
1198 if (_top != NULL) _top->setup_is_top();
1199 if (old_top != NULL) old_top->setup_is_top();
1200 assert(_top == NULL || top()->is_top(), "");
1201 }
1202
1203 #ifdef ASSERT
1204 uint Compile::count_live_nodes_by_graph_walk() {
1205 Unique_Node_List useful(comp_arena());
1206 // Get useful node list by walking the graph.
1207 identify_useful_nodes(useful);
1208 return useful.size();
1209 }
1210
1211 void Compile::print_missing_nodes() {
1212
1213 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1214 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1215 return;
1216 }
1217
1218 // This is an expensive function. It is executed only when the user
1219 // specifies VerifyIdealNodeCount option or otherwise knows the
1220 // additional work that needs to be done to identify reachable nodes
1221 // by walking the flow graph and find the missing ones using
1222 // _dead_node_list.
1223
1224 Unique_Node_List useful(comp_arena());
1225 // Get useful node list by walking the graph.
1226 identify_useful_nodes(useful);
1227
1228 uint l_nodes = C->live_nodes();
1229 uint l_nodes_by_walk = useful.size();
1230
1231 if (l_nodes != l_nodes_by_walk) {
1232 if (_log != NULL) {
1233 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1234 _log->stamp();
1235 _log->end_head();
1236 }
1237 VectorSet& useful_member_set = useful.member_set();
1238 int last_idx = l_nodes_by_walk;
1239 for (int i = 0; i < last_idx; i++) {
1240 if (useful_member_set.test(i)) {
1241 if (_dead_node_list.test(i)) {
1242 if (_log != NULL) {
1243 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1244 }
1245 if (PrintIdealNodeCount) {
1246 // Print the log message to tty
1247 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1248 useful.at(i)->dump();
1249 }
1250 }
1251 }
1252 else if (! _dead_node_list.test(i)) {
1253 if (_log != NULL) {
1254 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1255 }
1256 if (PrintIdealNodeCount) {
1257 // Print the log message to tty
1258 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1259 }
1260 }
1261 }
1262 if (_log != NULL) {
1263 _log->tail("mismatched_nodes");
1264 }
1265 }
1266 }
1267 void Compile::record_modified_node(Node* n) {
1268 if (_modified_nodes != NULL && !_inlining_incrementally &&
1269 n->outcnt() != 0 && !n->is_Con()) {
1270 _modified_nodes->push(n);
1271 }
1272 }
1273
1274 void Compile::remove_modified_node(Node* n) {
1275 if (_modified_nodes != NULL) {
1276 _modified_nodes->remove(n);
1277 }
1278 }
1279 #endif
1280
1281 #ifndef PRODUCT
1282 void Compile::verify_top(Node* tn) const {
1283 if (tn != NULL) {
1284 assert(tn->is_Con(), "top node must be a constant");
1285 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1286 assert(tn->in(0) != NULL, "must have live top node");
1287 }
1288 }
1289 #endif
1290
1291
1292 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1293
1294 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1295 guarantee(arr != NULL, "");
1296 int num_blocks = arr->length();
1297 if (grow_by < num_blocks) grow_by = num_blocks;
1298 int num_notes = grow_by * _node_notes_block_size;
1299 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1300 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1301 while (num_notes > 0) {
1302 arr->append(notes);
1303 notes += _node_notes_block_size;
1304 num_notes -= _node_notes_block_size;
1305 }
1306 assert(num_notes == 0, "exact multiple, please");
1307 }
1308
1309 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1310 if (source == NULL || dest == NULL) return false;
1311
1312 if (dest->is_Con())
1313 return false; // Do not push debug info onto constants.
1314
1315 #ifdef ASSERT
1316 // Leave a bread crumb trail pointing to the original node:
1317 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1318 dest->set_debug_orig(source);
1319 }
1320 #endif
1321
1322 if (node_note_array() == NULL)
1323 return false; // Not collecting any notes now.
1324
1325 // This is a copy onto a pre-existing node, which may already have notes.
1326 // If both nodes have notes, do not overwrite any pre-existing notes.
1327 Node_Notes* source_notes = node_notes_at(source->_idx);
1328 if (source_notes == NULL || source_notes->is_clear()) return false;
1329 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1330 if (dest_notes == NULL || dest_notes->is_clear()) {
1331 return set_node_notes_at(dest->_idx, source_notes);
1332 }
1333
1334 Node_Notes merged_notes = (*source_notes);
1335 // The order of operations here ensures that dest notes will win...
1336 merged_notes.update_from(dest_notes);
1337 return set_node_notes_at(dest->_idx, &merged_notes);
1338 }
1339
1340
1341 //--------------------------allow_range_check_smearing-------------------------
1342 // Gating condition for coalescing similar range checks.
1343 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1344 // single covering check that is at least as strong as any of them.
1345 // If the optimization succeeds, the simplified (strengthened) range check
1346 // will always succeed. If it fails, we will deopt, and then give up
1347 // on the optimization.
1348 bool Compile::allow_range_check_smearing() const {
1349 // If this method has already thrown a range-check,
1350 // assume it was because we already tried range smearing
1351 // and it failed.
1352 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1353 return !already_trapped;
1354 }
1355
1356
1357 //------------------------------flatten_alias_type-----------------------------
1358 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1359 int offset = tj->offset();
1360 TypePtr::PTR ptr = tj->ptr();
1361
1362 // Known instance (scalarizable allocation) alias only with itself.
1363 bool is_known_inst = tj->isa_oopptr() != NULL &&
1364 tj->is_oopptr()->is_known_instance();
1365
1366 // Process weird unsafe references.
1367 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1368 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1369 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1370 tj = TypeOopPtr::BOTTOM;
1371 ptr = tj->ptr();
1372 offset = tj->offset();
1373 }
1374
1375 // Array pointers need some flattening
1376 const TypeAryPtr *ta = tj->isa_aryptr();
1377 if (ta && ta->is_stable()) {
1378 // Erase stability property for alias analysis.
1379 tj = ta = ta->cast_to_stable(false);
1380 }
1381 if( ta && is_known_inst ) {
1382 if ( offset != Type::OffsetBot &&
1383 offset > arrayOopDesc::length_offset_in_bytes() ) {
1384 offset = Type::OffsetBot; // Flatten constant access into array body only
1385 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1386 }
1387 } else if( ta && _AliasLevel >= 2 ) {
1388 // For arrays indexed by constant indices, we flatten the alias
1389 // space to include all of the array body. Only the header, klass
1390 // and array length can be accessed un-aliased.
1391 if( offset != Type::OffsetBot ) {
1392 if( ta->const_oop() ) { // MethodData* or Method*
1393 offset = Type::OffsetBot; // Flatten constant access into array body
1394 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1395 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1396 // range is OK as-is.
1397 tj = ta = TypeAryPtr::RANGE;
1398 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1399 tj = TypeInstPtr::KLASS; // all klass loads look alike
1400 ta = TypeAryPtr::RANGE; // generic ignored junk
1401 ptr = TypePtr::BotPTR;
1402 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1403 tj = TypeInstPtr::MARK;
1404 ta = TypeAryPtr::RANGE; // generic ignored junk
1405 ptr = TypePtr::BotPTR;
1406 } else { // Random constant offset into array body
1407 offset = Type::OffsetBot; // Flatten constant access into array body
1408 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1409 }
1410 }
1411 // Arrays of fixed size alias with arrays of unknown size.
1412 if (ta->size() != TypeInt::POS) {
1413 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1414 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1415 }
1416 // Arrays of known objects become arrays of unknown objects.
1417 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1418 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1419 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1420 }
1421 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1422 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1423 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1424 }
1425 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1426 // cannot be distinguished by bytecode alone.
1427 if (ta->elem() == TypeInt::BOOL) {
1428 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1429 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1430 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1431 }
1432 // During the 2nd round of IterGVN, NotNull castings are removed.
1433 // Make sure the Bottom and NotNull variants alias the same.
1434 // Also, make sure exact and non-exact variants alias the same.
1435 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1436 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1437 }
1438 }
1439
1440 // Oop pointers need some flattening
1441 const TypeInstPtr *to = tj->isa_instptr();
1442 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1443 ciInstanceKlass *k = to->klass()->as_instance_klass();
1444 if( ptr == TypePtr::Constant ) {
1445 if (to->klass() != ciEnv::current()->Class_klass() ||
1446 offset < k->size_helper() * wordSize) {
1447 // No constant oop pointers (such as Strings); they alias with
1448 // unknown strings.
1449 assert(!is_known_inst, "not scalarizable allocation");
1450 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1451 }
1452 } else if( is_known_inst ) {
1453 tj = to; // Keep NotNull and klass_is_exact for instance type
1454 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1455 // During the 2nd round of IterGVN, NotNull castings are removed.
1456 // Make sure the Bottom and NotNull variants alias the same.
1457 // Also, make sure exact and non-exact variants alias the same.
1458 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1459 }
1460 if (to->speculative() != NULL) {
1461 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1462 }
1463 // Canonicalize the holder of this field
1464 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1465 // First handle header references such as a LoadKlassNode, even if the
1466 // object's klass is unloaded at compile time (4965979).
1467 if (!is_known_inst) { // Do it only for non-instance types
1468 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1469 }
1470 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1471 // Static fields are in the space above the normal instance
1472 // fields in the java.lang.Class instance.
1473 if (to->klass() != ciEnv::current()->Class_klass()) {
1474 to = NULL;
1475 tj = TypeOopPtr::BOTTOM;
1476 offset = tj->offset();
1477 }
1478 } else {
1479 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1480 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1481 if( is_known_inst ) {
1482 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1483 } else {
1484 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1485 }
1486 }
1487 }
1488 }
1489
1490 // Klass pointers to object array klasses need some flattening
1491 const TypeKlassPtr *tk = tj->isa_klassptr();
1492 if( tk ) {
1493 // If we are referencing a field within a Klass, we need
1494 // to assume the worst case of an Object. Both exact and
1495 // inexact types must flatten to the same alias class so
1496 // use NotNull as the PTR.
1497 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1498
1499 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1500 TypeKlassPtr::OBJECT->klass(),
1501 offset);
1502 }
1503
1504 ciKlass* klass = tk->klass();
1505 if( klass->is_obj_array_klass() ) {
1506 ciKlass* k = TypeAryPtr::OOPS->klass();
1507 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1508 k = TypeInstPtr::BOTTOM->klass();
1509 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1510 }
1511
1512 // Check for precise loads from the primary supertype array and force them
1513 // to the supertype cache alias index. Check for generic array loads from
1514 // the primary supertype array and also force them to the supertype cache
1515 // alias index. Since the same load can reach both, we need to merge
1516 // these 2 disparate memories into the same alias class. Since the
1517 // primary supertype array is read-only, there's no chance of confusion
1518 // where we bypass an array load and an array store.
1519 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1520 if (offset == Type::OffsetBot ||
1521 (offset >= primary_supers_offset &&
1522 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1523 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1524 offset = in_bytes(Klass::secondary_super_cache_offset());
1525 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1526 }
1527 }
1528
1529 // Flatten all Raw pointers together.
1530 if (tj->base() == Type::RawPtr)
1531 tj = TypeRawPtr::BOTTOM;
1532
1533 if (tj->base() == Type::AnyPtr)
1534 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1535
1536 // Flatten all to bottom for now
1537 switch( _AliasLevel ) {
1538 case 0:
1539 tj = TypePtr::BOTTOM;
1540 break;
1541 case 1: // Flatten to: oop, static, field or array
1542 switch (tj->base()) {
1543 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1544 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1545 case Type::AryPtr: // do not distinguish arrays at all
1546 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1547 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1548 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1549 default: ShouldNotReachHere();
1550 }
1551 break;
1552 case 2: // No collapsing at level 2; keep all splits
1553 case 3: // No collapsing at level 3; keep all splits
1554 break;
1555 default:
1556 Unimplemented();
1557 }
1558
1559 offset = tj->offset();
1560 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1561
1562 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1563 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1564 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1565 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1566 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1567 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1568 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1569 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1570 assert( tj->ptr() != TypePtr::TopPTR &&
1571 tj->ptr() != TypePtr::AnyNull &&
1572 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1573 // assert( tj->ptr() != TypePtr::Constant ||
1574 // tj->base() == Type::RawPtr ||
1575 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1576
1577 return tj;
1578 }
1579
1580 void Compile::AliasType::Init(int i, const TypePtr* at) {
1581 _index = i;
1582 _adr_type = at;
1583 _field = NULL;
1584 _element = NULL;
1585 _is_rewritable = true; // default
1586 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1587 if (atoop != NULL && atoop->is_known_instance()) {
1588 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1589 _general_index = Compile::current()->get_alias_index(gt);
1590 } else {
1591 _general_index = 0;
1592 }
1593 }
1594
1595 //---------------------------------print_on------------------------------------
1596 #ifndef PRODUCT
1597 void Compile::AliasType::print_on(outputStream* st) {
1598 if (index() < 10)
1599 st->print("@ <%d> ", index());
1600 else st->print("@ <%d>", index());
1601 st->print(is_rewritable() ? " " : " RO");
1602 int offset = adr_type()->offset();
1603 if (offset == Type::OffsetBot)
1604 st->print(" +any");
1605 else st->print(" +%-3d", offset);
1606 st->print(" in ");
1607 adr_type()->dump_on(st);
1608 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1609 if (field() != NULL && tjp) {
1610 if (tjp->klass() != field()->holder() ||
1611 tjp->offset() != field()->offset_in_bytes()) {
1612 st->print(" != ");
1613 field()->print();
1614 st->print(" ***");
1615 }
1616 }
1617 }
1618
1619 void print_alias_types() {
1620 Compile* C = Compile::current();
1621 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1622 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1623 C->alias_type(idx)->print_on(tty);
1624 tty->cr();
1625 }
1626 }
1627 #endif
1628
1629
1630 //----------------------------probe_alias_cache--------------------------------
1631 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1632 intptr_t key = (intptr_t) adr_type;
1633 key ^= key >> logAliasCacheSize;
1634 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1635 }
1636
1637
1638 //-----------------------------grow_alias_types--------------------------------
1639 void Compile::grow_alias_types() {
1640 const int old_ats = _max_alias_types; // how many before?
1641 const int new_ats = old_ats; // how many more?
1642 const int grow_ats = old_ats+new_ats; // how many now?
1643 _max_alias_types = grow_ats;
1644 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1645 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1646 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1647 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1648 }
1649
1650
1651 //--------------------------------find_alias_type------------------------------
1652 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1653 if (_AliasLevel == 0)
1654 return alias_type(AliasIdxBot);
1655
1656 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1657 if (ace->_adr_type == adr_type) {
1658 return alias_type(ace->_index);
1659 }
1660
1661 // Handle special cases.
1662 if (adr_type == NULL) return alias_type(AliasIdxTop);
1663 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1664
1665 // Do it the slow way.
1666 const TypePtr* flat = flatten_alias_type(adr_type);
1667
1668 #ifdef ASSERT
1669 assert(flat == flatten_alias_type(flat), "idempotent");
1670 assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
1671 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1672 const TypeOopPtr* foop = flat->is_oopptr();
1673 // Scalarizable allocations have exact klass always.
1674 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1675 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1676 assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1677 }
1678 assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1679 #endif
1680
1681 int idx = AliasIdxTop;
1682 for (int i = 0; i < num_alias_types(); i++) {
1683 if (alias_type(i)->adr_type() == flat) {
1684 idx = i;
1685 break;
1686 }
1687 }
1688
1689 if (idx == AliasIdxTop) {
1690 if (no_create) return NULL;
1691 // Grow the array if necessary.
1692 if (_num_alias_types == _max_alias_types) grow_alias_types();
1693 // Add a new alias type.
1694 idx = _num_alias_types++;
1695 _alias_types[idx]->Init(idx, flat);
1696 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1697 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1698 if (flat->isa_instptr()) {
1699 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1700 && flat->is_instptr()->klass() == env()->Class_klass())
1701 alias_type(idx)->set_rewritable(false);
1702 }
1703 if (flat->isa_aryptr()) {
1704 #ifdef ASSERT
1705 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1706 // (T_BYTE has the weakest alignment and size restrictions...)
1707 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1708 #endif
1709 if (flat->offset() == TypePtr::OffsetBot) {
1710 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1711 }
1712 }
1713 if (flat->isa_klassptr()) {
1714 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1715 alias_type(idx)->set_rewritable(false);
1716 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1717 alias_type(idx)->set_rewritable(false);
1718 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1719 alias_type(idx)->set_rewritable(false);
1720 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1721 alias_type(idx)->set_rewritable(false);
1722 }
1723 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1724 // but the base pointer type is not distinctive enough to identify
1725 // references into JavaThread.)
1726
1727 // Check for final fields.
1728 const TypeInstPtr* tinst = flat->isa_instptr();
1729 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1730 ciField* field;
1731 if (tinst->const_oop() != NULL &&
1732 tinst->klass() == ciEnv::current()->Class_klass() &&
1733 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1734 // static field
1735 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1736 field = k->get_field_by_offset(tinst->offset(), true);
1737 } else {
1738 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1739 field = k->get_field_by_offset(tinst->offset(), false);
1740 }
1741 assert(field == NULL ||
1742 original_field == NULL ||
1743 (field->holder() == original_field->holder() &&
1744 field->offset() == original_field->offset() &&
1745 field->is_static() == original_field->is_static()), "wrong field?");
1746 // Set field() and is_rewritable() attributes.
1747 if (field != NULL) alias_type(idx)->set_field(field);
1748 }
1749 }
1750
1751 // Fill the cache for next time.
1752 ace->_adr_type = adr_type;
1753 ace->_index = idx;
1754 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1755
1756 // Might as well try to fill the cache for the flattened version, too.
1757 AliasCacheEntry* face = probe_alias_cache(flat);
1758 if (face->_adr_type == NULL) {
1759 face->_adr_type = flat;
1760 face->_index = idx;
1761 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1762 }
1763
1764 return alias_type(idx);
1765 }
1766
1767
1768 Compile::AliasType* Compile::alias_type(ciField* field) {
1769 const TypeOopPtr* t;
1770 if (field->is_static())
1771 t = TypeInstPtr::make(field->holder()->java_mirror());
1772 else
1773 t = TypeOopPtr::make_from_klass_raw(field->holder());
1774 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1775 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1776 return atp;
1777 }
1778
1779
1780 //------------------------------have_alias_type--------------------------------
1781 bool Compile::have_alias_type(const TypePtr* adr_type) {
1782 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1783 if (ace->_adr_type == adr_type) {
1784 return true;
1785 }
1786
1787 // Handle special cases.
1788 if (adr_type == NULL) return true;
1789 if (adr_type == TypePtr::BOTTOM) return true;
1790
1791 return find_alias_type(adr_type, true, NULL) != NULL;
1792 }
1793
1794 //-----------------------------must_alias--------------------------------------
1795 // True if all values of the given address type are in the given alias category.
1796 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1797 if (alias_idx == AliasIdxBot) return true; // the universal category
1798 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1799 if (alias_idx == AliasIdxTop) return false; // the empty category
1800 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1801
1802 // the only remaining possible overlap is identity
1803 int adr_idx = get_alias_index(adr_type);
1804 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1805 assert(adr_idx == alias_idx ||
1806 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1807 && adr_type != TypeOopPtr::BOTTOM),
1808 "should not be testing for overlap with an unsafe pointer");
1809 return adr_idx == alias_idx;
1810 }
1811
1812 //------------------------------can_alias--------------------------------------
1813 // True if any values of the given address type are in the given alias category.
1814 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1815 if (alias_idx == AliasIdxTop) return false; // the empty category
1816 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1817 if (alias_idx == AliasIdxBot) return true; // the universal category
1818 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1819
1820 // the only remaining possible overlap is identity
1821 int adr_idx = get_alias_index(adr_type);
1822 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1823 return adr_idx == alias_idx;
1824 }
1825
1826
1827
1828 //---------------------------pop_warm_call-------------------------------------
1829 WarmCallInfo* Compile::pop_warm_call() {
1830 WarmCallInfo* wci = _warm_calls;
1831 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1832 return wci;
1833 }
1834
1835 //----------------------------Inline_Warm--------------------------------------
1836 int Compile::Inline_Warm() {
1837 // If there is room, try to inline some more warm call sites.
1838 // %%% Do a graph index compaction pass when we think we're out of space?
1839 if (!InlineWarmCalls) return 0;
1840
1841 int calls_made_hot = 0;
1842 int room_to_grow = NodeCountInliningCutoff - unique();
1843 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1844 int amount_grown = 0;
1845 WarmCallInfo* call;
1846 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1847 int est_size = (int)call->size();
1848 if (est_size > (room_to_grow - amount_grown)) {
1849 // This one won't fit anyway. Get rid of it.
1850 call->make_cold();
1851 continue;
1852 }
1853 call->make_hot();
1854 calls_made_hot++;
1855 amount_grown += est_size;
1856 amount_to_grow -= est_size;
1857 }
1858
1859 if (calls_made_hot > 0) set_major_progress();
1860 return calls_made_hot;
1861 }
1862
1863
1864 //----------------------------Finish_Warm--------------------------------------
1865 void Compile::Finish_Warm() {
1866 if (!InlineWarmCalls) return;
1867 if (failing()) return;
1868 if (warm_calls() == NULL) return;
1869
1870 // Clean up loose ends, if we are out of space for inlining.
1871 WarmCallInfo* call;
1872 while ((call = pop_warm_call()) != NULL) {
1873 call->make_cold();
1874 }
1875 }
1876
1877 //---------------------cleanup_loop_predicates-----------------------
1878 // Remove the opaque nodes that protect the predicates so that all unused
1879 // checks and uncommon_traps will be eliminated from the ideal graph
1880 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1881 if (predicate_count()==0) return;
1882 for (int i = predicate_count(); i > 0; i--) {
1883 Node * n = predicate_opaque1_node(i-1);
1884 assert(n->Opcode() == Op_Opaque1, "must be");
1885 igvn.replace_node(n, n->in(1));
1886 }
1887 assert(predicate_count()==0, "should be clean!");
1888 }
1889
1890 // StringOpts and late inlining of string methods
1891 void Compile::inline_string_calls(bool parse_time) {
1892 {
1893 // remove useless nodes to make the usage analysis simpler
1894 ResourceMark rm;
1895 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1896 }
1897
1898 {
1899 ResourceMark rm;
1900 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1901 PhaseStringOpts pso(initial_gvn(), for_igvn());
1902 print_method(PHASE_AFTER_STRINGOPTS, 3);
1903 }
1904
1905 // now inline anything that we skipped the first time around
1906 if (!parse_time) {
1907 _late_inlines_pos = _late_inlines.length();
1908 }
1909
1910 while (_string_late_inlines.length() > 0) {
1911 CallGenerator* cg = _string_late_inlines.pop();
1912 cg->do_late_inline();
1913 if (failing()) return;
1914 }
1915 _string_late_inlines.trunc_to(0);
1916 }
1917
1918 // Late inlining of boxing methods
1919 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1920 if (_boxing_late_inlines.length() > 0) {
1921 assert(has_boxed_value(), "inconsistent");
1922
1923 PhaseGVN* gvn = initial_gvn();
1924 set_inlining_incrementally(true);
1925
1926 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1927 for_igvn()->clear();
1928 gvn->replace_with(&igvn);
1929
1930 _late_inlines_pos = _late_inlines.length();
1931
1932 while (_boxing_late_inlines.length() > 0) {
1933 CallGenerator* cg = _boxing_late_inlines.pop();
1934 cg->do_late_inline();
1935 if (failing()) return;
1936 }
1937 _boxing_late_inlines.trunc_to(0);
1938
1939 {
1940 ResourceMark rm;
1941 PhaseRemoveUseless pru(gvn, for_igvn());
1942 }
1943
1944 igvn = PhaseIterGVN(gvn);
1945 igvn.optimize();
1946
1947 set_inlining_progress(false);
1948 set_inlining_incrementally(false);
1949 }
1950 }
1951
1952 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1953 assert(IncrementalInline, "incremental inlining should be on");
1954 PhaseGVN* gvn = initial_gvn();
1955
1956 set_inlining_progress(false);
1957 for_igvn()->clear();
1958 gvn->replace_with(&igvn);
1959
1960 {
1961 TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1962 int i = 0;
1963 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1964 CallGenerator* cg = _late_inlines.at(i);
1965 _late_inlines_pos = i+1;
1966 cg->do_late_inline();
1967 if (failing()) return;
1968 }
1969 int j = 0;
1970 for (; i < _late_inlines.length(); i++, j++) {
1971 _late_inlines.at_put(j, _late_inlines.at(i));
1972 }
1973 _late_inlines.trunc_to(j);
1974 }
1975
1976 {
1977 TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
1978 ResourceMark rm;
1979 PhaseRemoveUseless pru(gvn, for_igvn());
1980 }
1981
1982 {
1983 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
1984 igvn = PhaseIterGVN(gvn);
1985 }
1986 }
1987
1988 // Perform incremental inlining until bound on number of live nodes is reached
1989 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1990 TracePhase tp("incrementalInline", &timers[_t_incrInline]);
1991
1992 PhaseGVN* gvn = initial_gvn();
1993
1994 set_inlining_incrementally(true);
1995 set_inlining_progress(true);
1996 uint low_live_nodes = 0;
1997
1998 while(inlining_progress() && _late_inlines.length() > 0) {
1999
2000 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2001 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2002 TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2003 // PhaseIdealLoop is expensive so we only try it once we are
2004 // out of live nodes and we only try it again if the previous
2005 // helped got the number of nodes down significantly
2006 PhaseIdealLoop ideal_loop( igvn, false, true );
2007 if (failing()) return;
2008 low_live_nodes = live_nodes();
2009 _major_progress = true;
2010 }
2011
2012 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2013 break;
2014 }
2015 }
2016
2017 inline_incrementally_one(igvn);
2018
2019 if (failing()) return;
2020
2021 {
2022 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2023 igvn.optimize();
2024 }
2025
2026 if (failing()) return;
2027 }
2028
2029 assert( igvn._worklist.size() == 0, "should be done with igvn" );
2030
2031 if (_string_late_inlines.length() > 0) {
2032 assert(has_stringbuilder(), "inconsistent");
2033 for_igvn()->clear();
2034 initial_gvn()->replace_with(&igvn);
2035
2036 inline_string_calls(false);
2037
2038 if (failing()) return;
2039
2040 {
2041 TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2042 ResourceMark rm;
2043 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2044 }
2045
2046 {
2047 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2048 igvn = PhaseIterGVN(gvn);
2049 igvn.optimize();
2050 }
2051 }
2052
2053 set_inlining_incrementally(false);
2054 }
2055
2056
2057 //------------------------------Optimize---------------------------------------
2058 // Given a graph, optimize it.
2059 void Compile::Optimize() {
2060 TracePhase tp("optimizer", &timers[_t_optimizer]);
2061
2062 #ifndef PRODUCT
2063 if (env()->break_at_compile()) {
2064 BREAKPOINT;
2065 }
2066
2067 #endif
2068
2069 ResourceMark rm;
2070 int loop_opts_cnt;
2071
2072 print_inlining_reinit();
2073
2074 NOT_PRODUCT( verify_graph_edges(); )
2075
2076 print_method(PHASE_AFTER_PARSING);
2077
2078 {
2079 // Iterative Global Value Numbering, including ideal transforms
2080 // Initialize IterGVN with types and values from parse-time GVN
2081 PhaseIterGVN igvn(initial_gvn());
2082 #ifdef ASSERT
2083 _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2084 #endif
2085 {
2086 TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2087 igvn.optimize();
2088 }
2089
2090 print_method(PHASE_ITER_GVN1, 2);
2091
2092 if (failing()) return;
2093
2094 inline_incrementally(igvn);
2095
2096 print_method(PHASE_INCREMENTAL_INLINE, 2);
2097
2098 if (failing()) return;
2099
2100 if (eliminate_boxing()) {
2101 // Inline valueOf() methods now.
2102 inline_boxing_calls(igvn);
2103
2104 if (AlwaysIncrementalInline) {
2105 inline_incrementally(igvn);
2106 }
2107
2108 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2109
2110 if (failing()) return;
2111 }
2112
2113 // Remove the speculative part of types and clean up the graph from
2114 // the extra CastPP nodes whose only purpose is to carry them. Do
2115 // that early so that optimizations are not disrupted by the extra
2116 // CastPP nodes.
2117 remove_speculative_types(igvn);
2118
2119 // No more new expensive nodes will be added to the list from here
2120 // so keep only the actual candidates for optimizations.
2121 cleanup_expensive_nodes(igvn);
2122
2123 // Perform escape analysis
2124 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2125 if (has_loops()) {
2126 // Cleanup graph (remove dead nodes).
2127 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2128 PhaseIdealLoop ideal_loop( igvn, false, true );
2129 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2130 if (failing()) return;
2131 }
2132 ConnectionGraph::do_analysis(this, &igvn);
2133
2134 if (failing()) return;
2135
2136 // Optimize out fields loads from scalar replaceable allocations.
2137 igvn.optimize();
2138 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2139
2140 if (failing()) return;
2141
2142 if (congraph() != NULL && macro_count() > 0) {
2143 TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2144 PhaseMacroExpand mexp(igvn);
2145 mexp.eliminate_macro_nodes();
2146 igvn.set_delay_transform(false);
2147
2148 igvn.optimize();
2149 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2150
2151 if (failing()) return;
2152 }
2153 }
2154
2155 // Loop transforms on the ideal graph. Range Check Elimination,
2156 // peeling, unrolling, etc.
2157
2158 // Set loop opts counter
2159 loop_opts_cnt = num_loop_opts();
2160 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2161 {
2162 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2163 PhaseIdealLoop ideal_loop( igvn, true );
2164 loop_opts_cnt--;
2165 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2166 if (failing()) return;
2167 }
2168 // Loop opts pass if partial peeling occurred in previous pass
2169 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2170 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2171 PhaseIdealLoop ideal_loop( igvn, false );
2172 loop_opts_cnt--;
2173 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2174 if (failing()) return;
2175 }
2176 // Loop opts pass for loop-unrolling before CCP
2177 if(major_progress() && (loop_opts_cnt > 0)) {
2178 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2179 PhaseIdealLoop ideal_loop( igvn, false );
2180 loop_opts_cnt--;
2181 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2182 }
2183 if (!failing()) {
2184 // Verify that last round of loop opts produced a valid graph
2185 TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2186 PhaseIdealLoop::verify(igvn);
2187 }
2188 }
2189 if (failing()) return;
2190
2191 // Conditional Constant Propagation;
2192 PhaseCCP ccp( &igvn );
2193 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2194 {
2195 TracePhase tp("ccp", &timers[_t_ccp]);
2196 ccp.do_transform();
2197 }
2198 print_method(PHASE_CPP1, 2);
2199
2200 assert( true, "Break here to ccp.dump_old2new_map()");
2201
2202 // Iterative Global Value Numbering, including ideal transforms
2203 {
2204 TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2205 igvn = ccp;
2206 igvn.optimize();
2207 }
2208
2209 print_method(PHASE_ITER_GVN2, 2);
2210
2211 if (failing()) return;
2212
2213 // Loop transforms on the ideal graph. Range Check Elimination,
2214 // peeling, unrolling, etc.
2215 if(loop_opts_cnt > 0) {
2216 debug_only( int cnt = 0; );
2217 while(major_progress() && (loop_opts_cnt > 0)) {
2218 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2219 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2220 PhaseIdealLoop ideal_loop( igvn, true);
2221 loop_opts_cnt--;
2222 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2223 if (failing()) return;
2224 }
2225 }
2226
2227 {
2228 // Verify that all previous optimizations produced a valid graph
2229 // at least to this point, even if no loop optimizations were done.
2230 TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2231 PhaseIdealLoop::verify(igvn);
2232 }
2233
2234 {
2235 TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2236 PhaseMacroExpand mex(igvn);
2237 if (mex.expand_macro_nodes()) {
2238 assert(failing(), "must bail out w/ explicit message");
2239 return;
2240 }
2241 }
2242
2243 DEBUG_ONLY( _modified_nodes = NULL; )
2244 } // (End scope of igvn; run destructor if necessary for asserts.)
2245
2246 process_print_inlining();
2247 // A method with only infinite loops has no edges entering loops from root
2248 {
2249 TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2250 if (final_graph_reshaping()) {
2251 assert(failing(), "must bail out w/ explicit message");
2252 return;
2253 }
2254 }
2255
2256 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2257 }
2258
2259
2260 //------------------------------Code_Gen---------------------------------------
2261 // Given a graph, generate code for it
2262 void Compile::Code_Gen() {
2263 if (failing()) {
2264 return;
2265 }
2266
2267 // Perform instruction selection. You might think we could reclaim Matcher
2268 // memory PDQ, but actually the Matcher is used in generating spill code.
2269 // Internals of the Matcher (including some VectorSets) must remain live
2270 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2271 // set a bit in reclaimed memory.
2272
2273 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2274 // nodes. Mapping is only valid at the root of each matched subtree.
2275 NOT_PRODUCT( verify_graph_edges(); )
2276
2277 Matcher matcher;
2278 _matcher = &matcher;
2279 {
2280 TracePhase tp("matcher", &timers[_t_matcher]);
2281 matcher.match();
2282 }
2283 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2284 // nodes. Mapping is only valid at the root of each matched subtree.
2285 NOT_PRODUCT( verify_graph_edges(); )
2286
2287 // If you have too many nodes, or if matching has failed, bail out
2288 check_node_count(0, "out of nodes matching instructions");
2289 if (failing()) {
2290 return;
2291 }
2292
2293 // Build a proper-looking CFG
2294 PhaseCFG cfg(node_arena(), root(), matcher);
2295 _cfg = &cfg;
2296 {
2297 TracePhase tp("scheduler", &timers[_t_scheduler]);
2298 bool success = cfg.do_global_code_motion();
2299 if (!success) {
2300 return;
2301 }
2302
2303 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2304 NOT_PRODUCT( verify_graph_edges(); )
2305 debug_only( cfg.verify(); )
2306 }
2307
2308 PhaseChaitin regalloc(unique(), cfg, matcher);
2309 _regalloc = ®alloc;
2310 {
2311 TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2312 // Perform register allocation. After Chaitin, use-def chains are
2313 // no longer accurate (at spill code) and so must be ignored.
2314 // Node->LRG->reg mappings are still accurate.
2315 _regalloc->Register_Allocate();
2316
2317 // Bail out if the allocator builds too many nodes
2318 if (failing()) {
2319 return;
2320 }
2321 }
2322
2323 // Prior to register allocation we kept empty basic blocks in case the
2324 // the allocator needed a place to spill. After register allocation we
2325 // are not adding any new instructions. If any basic block is empty, we
2326 // can now safely remove it.
2327 {
2328 TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2329 cfg.remove_empty_blocks();
2330 if (do_freq_based_layout()) {
2331 PhaseBlockLayout layout(cfg);
2332 } else {
2333 cfg.set_loop_alignment();
2334 }
2335 cfg.fixup_flow();
2336 }
2337
2338 // Apply peephole optimizations
2339 if( OptoPeephole ) {
2340 TracePhase tp("peephole", &timers[_t_peephole]);
2341 PhasePeephole peep( _regalloc, cfg);
2342 peep.do_transform();
2343 }
2344
2345 // Do late expand if CPU requires this.
2346 if (Matcher::require_postalloc_expand) {
2347 TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2348 cfg.postalloc_expand(_regalloc);
2349 }
2350
2351 // Convert Nodes to instruction bits in a buffer
2352 {
2353 TraceTime tp("output", &timers[_t_output], CITime);
2354 Output();
2355 }
2356
2357 print_method(PHASE_FINAL_CODE);
2358
2359 // He's dead, Jim.
2360 _cfg = (PhaseCFG*)0xdeadbeef;
2361 _regalloc = (PhaseChaitin*)0xdeadbeef;
2362 }
2363
2364
2365 //------------------------------dump_asm---------------------------------------
2366 // Dump formatted assembly
2367 #ifndef PRODUCT
2368 void Compile::dump_asm(int *pcs, uint pc_limit) {
2369 bool cut_short = false;
2370 tty->print_cr("#");
2371 tty->print("# "); _tf->dump(); tty->cr();
2372 tty->print_cr("#");
2373
2374 // For all blocks
2375 int pc = 0x0; // Program counter
2376 char starts_bundle = ' ';
2377 _regalloc->dump_frame();
2378
2379 Node *n = NULL;
2380 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2381 if (VMThread::should_terminate()) {
2382 cut_short = true;
2383 break;
2384 }
2385 Block* block = _cfg->get_block(i);
2386 if (block->is_connector() && !Verbose) {
2387 continue;
2388 }
2389 n = block->head();
2390 if (pcs && n->_idx < pc_limit) {
2391 tty->print("%3.3x ", pcs[n->_idx]);
2392 } else {
2393 tty->print(" ");
2394 }
2395 block->dump_head(_cfg);
2396 if (block->is_connector()) {
2397 tty->print_cr(" # Empty connector block");
2398 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2399 tty->print_cr(" # Block is sole successor of call");
2400 }
2401
2402 // For all instructions
2403 Node *delay = NULL;
2404 for (uint j = 0; j < block->number_of_nodes(); j++) {
2405 if (VMThread::should_terminate()) {
2406 cut_short = true;
2407 break;
2408 }
2409 n = block->get_node(j);
2410 if (valid_bundle_info(n)) {
2411 Bundle* bundle = node_bundling(n);
2412 if (bundle->used_in_unconditional_delay()) {
2413 delay = n;
2414 continue;
2415 }
2416 if (bundle->starts_bundle()) {
2417 starts_bundle = '+';
2418 }
2419 }
2420
2421 if (WizardMode) {
2422 n->dump();
2423 }
2424
2425 if( !n->is_Region() && // Dont print in the Assembly
2426 !n->is_Phi() && // a few noisely useless nodes
2427 !n->is_Proj() &&
2428 !n->is_MachTemp() &&
2429 !n->is_SafePointScalarObject() &&
2430 !n->is_Catch() && // Would be nice to print exception table targets
2431 !n->is_MergeMem() && // Not very interesting
2432 !n->is_top() && // Debug info table constants
2433 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2434 ) {
2435 if (pcs && n->_idx < pc_limit)
2436 tty->print("%3.3x", pcs[n->_idx]);
2437 else
2438 tty->print(" ");
2439 tty->print(" %c ", starts_bundle);
2440 starts_bundle = ' ';
2441 tty->print("\t");
2442 n->format(_regalloc, tty);
2443 tty->cr();
2444 }
2445
2446 // If we have an instruction with a delay slot, and have seen a delay,
2447 // then back up and print it
2448 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2449 assert(delay != NULL, "no unconditional delay instruction");
2450 if (WizardMode) delay->dump();
2451
2452 if (node_bundling(delay)->starts_bundle())
2453 starts_bundle = '+';
2454 if (pcs && n->_idx < pc_limit)
2455 tty->print("%3.3x", pcs[n->_idx]);
2456 else
2457 tty->print(" ");
2458 tty->print(" %c ", starts_bundle);
2459 starts_bundle = ' ';
2460 tty->print("\t");
2461 delay->format(_regalloc, tty);
2462 tty->cr();
2463 delay = NULL;
2464 }
2465
2466 // Dump the exception table as well
2467 if( n->is_Catch() && (Verbose || WizardMode) ) {
2468 // Print the exception table for this offset
2469 _handler_table.print_subtable_for(pc);
2470 }
2471 }
2472
2473 if (pcs && n->_idx < pc_limit)
2474 tty->print_cr("%3.3x", pcs[n->_idx]);
2475 else
2476 tty->cr();
2477
2478 assert(cut_short || delay == NULL, "no unconditional delay branch");
2479
2480 } // End of per-block dump
2481 tty->cr();
2482
2483 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2484 }
2485 #endif
2486
2487 //------------------------------Final_Reshape_Counts---------------------------
2488 // This class defines counters to help identify when a method
2489 // may/must be executed using hardware with only 24-bit precision.
2490 struct Final_Reshape_Counts : public StackObj {
2491 int _call_count; // count non-inlined 'common' calls
2492 int _float_count; // count float ops requiring 24-bit precision
2493 int _double_count; // count double ops requiring more precision
2494 int _java_call_count; // count non-inlined 'java' calls
2495 int _inner_loop_count; // count loops which need alignment
2496 VectorSet _visited; // Visitation flags
2497 Node_List _tests; // Set of IfNodes & PCTableNodes
2498
2499 Final_Reshape_Counts() :
2500 _call_count(0), _float_count(0), _double_count(0),
2501 _java_call_count(0), _inner_loop_count(0),
2502 _visited( Thread::current()->resource_area() ) { }
2503
2504 void inc_call_count () { _call_count ++; }
2505 void inc_float_count () { _float_count ++; }
2506 void inc_double_count() { _double_count++; }
2507 void inc_java_call_count() { _java_call_count++; }
2508 void inc_inner_loop_count() { _inner_loop_count++; }
2509
2510 int get_call_count () const { return _call_count ; }
2511 int get_float_count () const { return _float_count ; }
2512 int get_double_count() const { return _double_count; }
2513 int get_java_call_count() const { return _java_call_count; }
2514 int get_inner_loop_count() const { return _inner_loop_count; }
2515 };
2516
2517 #ifdef ASSERT
2518 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2519 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2520 // Make sure the offset goes inside the instance layout.
2521 return k->contains_field_offset(tp->offset());
2522 // Note that OffsetBot and OffsetTop are very negative.
2523 }
2524 #endif
2525
2526 // Eliminate trivially redundant StoreCMs and accumulate their
2527 // precedence edges.
2528 void Compile::eliminate_redundant_card_marks(Node* n) {
2529 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2530 if (n->in(MemNode::Address)->outcnt() > 1) {
2531 // There are multiple users of the same address so it might be
2532 // possible to eliminate some of the StoreCMs
2533 Node* mem = n->in(MemNode::Memory);
2534 Node* adr = n->in(MemNode::Address);
2535 Node* val = n->in(MemNode::ValueIn);
2536 Node* prev = n;
2537 bool done = false;
2538 // Walk the chain of StoreCMs eliminating ones that match. As
2539 // long as it's a chain of single users then the optimization is
2540 // safe. Eliminating partially redundant StoreCMs would require
2541 // cloning copies down the other paths.
2542 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2543 if (adr == mem->in(MemNode::Address) &&
2544 val == mem->in(MemNode::ValueIn)) {
2545 // redundant StoreCM
2546 if (mem->req() > MemNode::OopStore) {
2547 // Hasn't been processed by this code yet.
2548 n->add_prec(mem->in(MemNode::OopStore));
2549 } else {
2550 // Already converted to precedence edge
2551 for (uint i = mem->req(); i < mem->len(); i++) {
2552 // Accumulate any precedence edges
2553 if (mem->in(i) != NULL) {
2554 n->add_prec(mem->in(i));
2555 }
2556 }
2557 // Everything above this point has been processed.
2558 done = true;
2559 }
2560 // Eliminate the previous StoreCM
2561 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2562 assert(mem->outcnt() == 0, "should be dead");
2563 mem->disconnect_inputs(NULL, this);
2564 } else {
2565 prev = mem;
2566 }
2567 mem = prev->in(MemNode::Memory);
2568 }
2569 }
2570 }
2571
2572 //------------------------------final_graph_reshaping_impl----------------------
2573 // Implement items 1-5 from final_graph_reshaping below.
2574 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2575
2576 if ( n->outcnt() == 0 ) return; // dead node
2577 uint nop = n->Opcode();
2578
2579 // Check for 2-input instruction with "last use" on right input.
2580 // Swap to left input. Implements item (2).
2581 if( n->req() == 3 && // two-input instruction
2582 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2583 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2584 n->in(2)->outcnt() == 1 &&// right use IS a last use
2585 !n->in(2)->is_Con() ) { // right use is not a constant
2586 // Check for commutative opcode
2587 switch( nop ) {
2588 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2589 case Op_MaxI: case Op_MinI:
2590 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2591 case Op_AndL: case Op_XorL: case Op_OrL:
2592 case Op_AndI: case Op_XorI: case Op_OrI: {
2593 // Move "last use" input to left by swapping inputs
2594 n->swap_edges(1, 2);
2595 break;
2596 }
2597 default:
2598 break;
2599 }
2600 }
2601
2602 #ifdef ASSERT
2603 if( n->is_Mem() ) {
2604 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2605 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2606 // oop will be recorded in oop map if load crosses safepoint
2607 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2608 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2609 "raw memory operations should have control edge");
2610 }
2611 #endif
2612 // Count FPU ops and common calls, implements item (3)
2613 switch( nop ) {
2614 // Count all float operations that may use FPU
2615 case Op_AddF:
2616 case Op_SubF:
2617 case Op_MulF:
2618 case Op_DivF:
2619 case Op_NegF:
2620 case Op_ModF:
2621 case Op_ConvI2F:
2622 case Op_ConF:
2623 case Op_CmpF:
2624 case Op_CmpF3:
2625 // case Op_ConvL2F: // longs are split into 32-bit halves
2626 frc.inc_float_count();
2627 break;
2628
2629 case Op_ConvF2D:
2630 case Op_ConvD2F:
2631 frc.inc_float_count();
2632 frc.inc_double_count();
2633 break;
2634
2635 // Count all double operations that may use FPU
2636 case Op_AddD:
2637 case Op_SubD:
2638 case Op_MulD:
2639 case Op_DivD:
2640 case Op_NegD:
2641 case Op_ModD:
2642 case Op_ConvI2D:
2643 case Op_ConvD2I:
2644 // case Op_ConvL2D: // handled by leaf call
2645 // case Op_ConvD2L: // handled by leaf call
2646 case Op_ConD:
2647 case Op_CmpD:
2648 case Op_CmpD3:
2649 frc.inc_double_count();
2650 break;
2651 case Op_Opaque1: // Remove Opaque Nodes before matching
2652 case Op_Opaque2: // Remove Opaque Nodes before matching
2653 case Op_Opaque3:
2654 n->subsume_by(n->in(1), this);
2655 break;
2656 case Op_CallStaticJava:
2657 case Op_CallJava:
2658 case Op_CallDynamicJava:
2659 frc.inc_java_call_count(); // Count java call site;
2660 case Op_CallRuntime:
2661 case Op_CallLeaf:
2662 case Op_CallLeafNoFP: {
2663 assert( n->is_Call(), "" );
2664 CallNode *call = n->as_Call();
2665 // Count call sites where the FP mode bit would have to be flipped.
2666 // Do not count uncommon runtime calls:
2667 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2668 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2669 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2670 frc.inc_call_count(); // Count the call site
2671 } else { // See if uncommon argument is shared
2672 Node *n = call->in(TypeFunc::Parms);
2673 int nop = n->Opcode();
2674 // Clone shared simple arguments to uncommon calls, item (1).
2675 if( n->outcnt() > 1 &&
2676 !n->is_Proj() &&
2677 nop != Op_CreateEx &&
2678 nop != Op_CheckCastPP &&
2679 nop != Op_DecodeN &&
2680 nop != Op_DecodeNKlass &&
2681 !n->is_Mem() ) {
2682 Node *x = n->clone();
2683 call->set_req( TypeFunc::Parms, x );
2684 }
2685 }
2686 break;
2687 }
2688
2689 case Op_StoreD:
2690 case Op_LoadD:
2691 case Op_LoadD_unaligned:
2692 frc.inc_double_count();
2693 goto handle_mem;
2694 case Op_StoreF:
2695 case Op_LoadF:
2696 frc.inc_float_count();
2697 goto handle_mem;
2698
2699 case Op_StoreCM:
2700 {
2701 // Convert OopStore dependence into precedence edge
2702 Node* prec = n->in(MemNode::OopStore);
2703 n->del_req(MemNode::OopStore);
2704 n->add_prec(prec);
2705 eliminate_redundant_card_marks(n);
2706 }
2707
2708 // fall through
2709
2710 case Op_StoreB:
2711 case Op_StoreC:
2712 case Op_StorePConditional:
2713 case Op_StoreI:
2714 case Op_StoreL:
2715 case Op_StoreIConditional:
2716 case Op_StoreLConditional:
2717 case Op_CompareAndSwapI:
2718 case Op_CompareAndSwapL:
2719 case Op_CompareAndSwapP:
2720 case Op_CompareAndSwapN:
2721 case Op_GetAndAddI:
2722 case Op_GetAndAddL:
2723 case Op_GetAndSetI:
2724 case Op_GetAndSetL:
2725 case Op_GetAndSetP:
2726 case Op_GetAndSetN:
2727 case Op_StoreP:
2728 case Op_StoreN:
2729 case Op_StoreNKlass:
2730 case Op_LoadB:
2731 case Op_LoadUB:
2732 case Op_LoadUS:
2733 case Op_LoadI:
2734 case Op_LoadKlass:
2735 case Op_LoadNKlass:
2736 case Op_LoadL:
2737 case Op_LoadL_unaligned:
2738 case Op_LoadPLocked:
2739 case Op_LoadP:
2740 case Op_LoadN:
2741 case Op_LoadRange:
2742 case Op_LoadS: {
2743 handle_mem:
2744 #ifdef ASSERT
2745 if( VerifyOptoOopOffsets ) {
2746 assert( n->is_Mem(), "" );
2747 MemNode *mem = (MemNode*)n;
2748 // Check to see if address types have grounded out somehow.
2749 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2750 assert( !tp || oop_offset_is_sane(tp), "" );
2751 }
2752 #endif
2753 break;
2754 }
2755
2756 case Op_AddP: { // Assert sane base pointers
2757 Node *addp = n->in(AddPNode::Address);
2758 assert( !addp->is_AddP() ||
2759 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2760 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2761 "Base pointers must match" );
2762 #ifdef _LP64
2763 if ((UseCompressedOops || UseCompressedClassPointers) &&
2764 addp->Opcode() == Op_ConP &&
2765 addp == n->in(AddPNode::Base) &&
2766 n->in(AddPNode::Offset)->is_Con()) {
2767 // Use addressing with narrow klass to load with offset on x86.
2768 // On sparc loading 32-bits constant and decoding it have less
2769 // instructions (4) then load 64-bits constant (7).
2770 // Do this transformation here since IGVN will convert ConN back to ConP.
2771 const Type* t = addp->bottom_type();
2772 if (t->isa_oopptr() || t->isa_klassptr()) {
2773 Node* nn = NULL;
2774
2775 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2776
2777 // Look for existing ConN node of the same exact type.
2778 Node* r = root();
2779 uint cnt = r->outcnt();
2780 for (uint i = 0; i < cnt; i++) {
2781 Node* m = r->raw_out(i);
2782 if (m!= NULL && m->Opcode() == op &&
2783 m->bottom_type()->make_ptr() == t) {
2784 nn = m;
2785 break;
2786 }
2787 }
2788 if (nn != NULL) {
2789 // Decode a narrow oop to match address
2790 // [R12 + narrow_oop_reg<<3 + offset]
2791 if (t->isa_oopptr()) {
2792 nn = new DecodeNNode(nn, t);
2793 } else {
2794 nn = new DecodeNKlassNode(nn, t);
2795 }
2796 n->set_req(AddPNode::Base, nn);
2797 n->set_req(AddPNode::Address, nn);
2798 if (addp->outcnt() == 0) {
2799 addp->disconnect_inputs(NULL, this);
2800 }
2801 }
2802 }
2803 }
2804 #endif
2805 break;
2806 }
2807
2808 #ifdef _LP64
2809 case Op_CastPP:
2810 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2811 Node* in1 = n->in(1);
2812 const Type* t = n->bottom_type();
2813 Node* new_in1 = in1->clone();
2814 new_in1->as_DecodeN()->set_type(t);
2815
2816 if (!Matcher::narrow_oop_use_complex_address()) {
2817 //
2818 // x86, ARM and friends can handle 2 adds in addressing mode
2819 // and Matcher can fold a DecodeN node into address by using
2820 // a narrow oop directly and do implicit NULL check in address:
2821 //
2822 // [R12 + narrow_oop_reg<<3 + offset]
2823 // NullCheck narrow_oop_reg
2824 //
2825 // On other platforms (Sparc) we have to keep new DecodeN node and
2826 // use it to do implicit NULL check in address:
2827 //
2828 // decode_not_null narrow_oop_reg, base_reg
2829 // [base_reg + offset]
2830 // NullCheck base_reg
2831 //
2832 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2833 // to keep the information to which NULL check the new DecodeN node
2834 // corresponds to use it as value in implicit_null_check().
2835 //
2836 new_in1->set_req(0, n->in(0));
2837 }
2838
2839 n->subsume_by(new_in1, this);
2840 if (in1->outcnt() == 0) {
2841 in1->disconnect_inputs(NULL, this);
2842 }
2843 }
2844 break;
2845
2846 case Op_CmpP:
2847 // Do this transformation here to preserve CmpPNode::sub() and
2848 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2849 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2850 Node* in1 = n->in(1);
2851 Node* in2 = n->in(2);
2852 if (!in1->is_DecodeNarrowPtr()) {
2853 in2 = in1;
2854 in1 = n->in(2);
2855 }
2856 assert(in1->is_DecodeNarrowPtr(), "sanity");
2857
2858 Node* new_in2 = NULL;
2859 if (in2->is_DecodeNarrowPtr()) {
2860 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2861 new_in2 = in2->in(1);
2862 } else if (in2->Opcode() == Op_ConP) {
2863 const Type* t = in2->bottom_type();
2864 if (t == TypePtr::NULL_PTR) {
2865 assert(in1->is_DecodeN(), "compare klass to null?");
2866 // Don't convert CmpP null check into CmpN if compressed
2867 // oops implicit null check is not generated.
2868 // This will allow to generate normal oop implicit null check.
2869 if (Matcher::gen_narrow_oop_implicit_null_checks())
2870 new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
2871 //
2872 // This transformation together with CastPP transformation above
2873 // will generated code for implicit NULL checks for compressed oops.
2874 //
2875 // The original code after Optimize()
2876 //
2877 // LoadN memory, narrow_oop_reg
2878 // decode narrow_oop_reg, base_reg
2879 // CmpP base_reg, NULL
2880 // CastPP base_reg // NotNull
2881 // Load [base_reg + offset], val_reg
2882 //
2883 // after these transformations will be
2884 //
2885 // LoadN memory, narrow_oop_reg
2886 // CmpN narrow_oop_reg, NULL
2887 // decode_not_null narrow_oop_reg, base_reg
2888 // Load [base_reg + offset], val_reg
2889 //
2890 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2891 // since narrow oops can be used in debug info now (see the code in
2892 // final_graph_reshaping_walk()).
2893 //
2894 // At the end the code will be matched to
2895 // on x86:
2896 //
2897 // Load_narrow_oop memory, narrow_oop_reg
2898 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2899 // NullCheck narrow_oop_reg
2900 //
2901 // and on sparc:
2902 //
2903 // Load_narrow_oop memory, narrow_oop_reg
2904 // decode_not_null narrow_oop_reg, base_reg
2905 // Load [base_reg + offset], val_reg
2906 // NullCheck base_reg
2907 //
2908 } else if (t->isa_oopptr()) {
2909 new_in2 = ConNode::make(t->make_narrowoop());
2910 } else if (t->isa_klassptr()) {
2911 new_in2 = ConNode::make(t->make_narrowklass());
2912 }
2913 }
2914 if (new_in2 != NULL) {
2915 Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2916 n->subsume_by(cmpN, this);
2917 if (in1->outcnt() == 0) {
2918 in1->disconnect_inputs(NULL, this);
2919 }
2920 if (in2->outcnt() == 0) {
2921 in2->disconnect_inputs(NULL, this);
2922 }
2923 }
2924 }
2925 break;
2926
2927 case Op_DecodeN:
2928 case Op_DecodeNKlass:
2929 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2930 // DecodeN could be pinned when it can't be fold into
2931 // an address expression, see the code for Op_CastPP above.
2932 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2933 break;
2934
2935 case Op_EncodeP:
2936 case Op_EncodePKlass: {
2937 Node* in1 = n->in(1);
2938 if (in1->is_DecodeNarrowPtr()) {
2939 n->subsume_by(in1->in(1), this);
2940 } else if (in1->Opcode() == Op_ConP) {
2941 const Type* t = in1->bottom_type();
2942 if (t == TypePtr::NULL_PTR) {
2943 assert(t->isa_oopptr(), "null klass?");
2944 n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
2945 } else if (t->isa_oopptr()) {
2946 n->subsume_by(ConNode::make(t->make_narrowoop()), this);
2947 } else if (t->isa_klassptr()) {
2948 n->subsume_by(ConNode::make(t->make_narrowklass()), this);
2949 }
2950 }
2951 if (in1->outcnt() == 0) {
2952 in1->disconnect_inputs(NULL, this);
2953 }
2954 break;
2955 }
2956
2957 case Op_Proj: {
2958 if (OptimizeStringConcat) {
2959 ProjNode* p = n->as_Proj();
2960 if (p->_is_io_use) {
2961 // Separate projections were used for the exception path which
2962 // are normally removed by a late inline. If it wasn't inlined
2963 // then they will hang around and should just be replaced with
2964 // the original one.
2965 Node* proj = NULL;
2966 // Replace with just one
2967 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2968 Node *use = i.get();
2969 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2970 proj = use;
2971 break;
2972 }
2973 }
2974 assert(proj != NULL, "must be found");
2975 p->subsume_by(proj, this);
2976 }
2977 }
2978 break;
2979 }
2980
2981 case Op_Phi:
2982 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2983 // The EncodeP optimization may create Phi with the same edges
2984 // for all paths. It is not handled well by Register Allocator.
2985 Node* unique_in = n->in(1);
2986 assert(unique_in != NULL, "");
2987 uint cnt = n->req();
2988 for (uint i = 2; i < cnt; i++) {
2989 Node* m = n->in(i);
2990 assert(m != NULL, "");
2991 if (unique_in != m)
2992 unique_in = NULL;
2993 }
2994 if (unique_in != NULL) {
2995 n->subsume_by(unique_in, this);
2996 }
2997 }
2998 break;
2999
3000 #endif
3001
3002 case Op_ModI:
3003 if (UseDivMod) {
3004 // Check if a%b and a/b both exist
3005 Node* d = n->find_similar(Op_DivI);
3006 if (d) {
3007 // Replace them with a fused divmod if supported
3008 if (Matcher::has_match_rule(Op_DivModI)) {
3009 DivModINode* divmod = DivModINode::make(n);
3010 d->subsume_by(divmod->div_proj(), this);
3011 n->subsume_by(divmod->mod_proj(), this);
3012 } else {
3013 // replace a%b with a-((a/b)*b)
3014 Node* mult = new MulINode(d, d->in(2));
3015 Node* sub = new SubINode(d->in(1), mult);
3016 n->subsume_by(sub, this);
3017 }
3018 }
3019 }
3020 break;
3021
3022 case Op_ModL:
3023 if (UseDivMod) {
3024 // Check if a%b and a/b both exist
3025 Node* d = n->find_similar(Op_DivL);
3026 if (d) {
3027 // Replace them with a fused divmod if supported
3028 if (Matcher::has_match_rule(Op_DivModL)) {
3029 DivModLNode* divmod = DivModLNode::make(n);
3030 d->subsume_by(divmod->div_proj(), this);
3031 n->subsume_by(divmod->mod_proj(), this);
3032 } else {
3033 // replace a%b with a-((a/b)*b)
3034 Node* mult = new MulLNode(d, d->in(2));
3035 Node* sub = new SubLNode(d->in(1), mult);
3036 n->subsume_by(sub, this);
3037 }
3038 }
3039 }
3040 break;
3041
3042 case Op_LoadVector:
3043 case Op_StoreVector:
3044 break;
3045
3046 case Op_PackB:
3047 case Op_PackS:
3048 case Op_PackI:
3049 case Op_PackF:
3050 case Op_PackL:
3051 case Op_PackD:
3052 if (n->req()-1 > 2) {
3053 // Replace many operand PackNodes with a binary tree for matching
3054 PackNode* p = (PackNode*) n;
3055 Node* btp = p->binary_tree_pack(1, n->req());
3056 n->subsume_by(btp, this);
3057 }
3058 break;
3059 case Op_Loop:
3060 case Op_CountedLoop:
3061 if (n->as_Loop()->is_inner_loop()) {
3062 frc.inc_inner_loop_count();
3063 }
3064 break;
3065 case Op_LShiftI:
3066 case Op_RShiftI:
3067 case Op_URShiftI:
3068 case Op_LShiftL:
3069 case Op_RShiftL:
3070 case Op_URShiftL:
3071 if (Matcher::need_masked_shift_count) {
3072 // The cpu's shift instructions don't restrict the count to the
3073 // lower 5/6 bits. We need to do the masking ourselves.
3074 Node* in2 = n->in(2);
3075 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3076 const TypeInt* t = in2->find_int_type();
3077 if (t != NULL && t->is_con()) {
3078 juint shift = t->get_con();
3079 if (shift > mask) { // Unsigned cmp
3080 n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3081 }
3082 } else {
3083 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3084 Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3085 n->set_req(2, shift);
3086 }
3087 }
3088 if (in2->outcnt() == 0) { // Remove dead node
3089 in2->disconnect_inputs(NULL, this);
3090 }
3091 }
3092 break;
3093 case Op_MemBarStoreStore:
3094 case Op_MemBarRelease:
3095 // Break the link with AllocateNode: it is no longer useful and
3096 // confuses register allocation.
3097 if (n->req() > MemBarNode::Precedent) {
3098 n->set_req(MemBarNode::Precedent, top());
3099 }
3100 break;
3101 default:
3102 assert( !n->is_Call(), "" );
3103 assert( !n->is_Mem(), "" );
3104 break;
3105 }
3106
3107 // Collect CFG split points
3108 if (n->is_MultiBranch())
3109 frc._tests.push(n);
3110 }
3111
3112 //------------------------------final_graph_reshaping_walk---------------------
3113 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3114 // requires that the walk visits a node's inputs before visiting the node.
3115 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3116 ResourceArea *area = Thread::current()->resource_area();
3117 Unique_Node_List sfpt(area);
3118
3119 frc._visited.set(root->_idx); // first, mark node as visited
3120 uint cnt = root->req();
3121 Node *n = root;
3122 uint i = 0;
3123 while (true) {
3124 if (i < cnt) {
3125 // Place all non-visited non-null inputs onto stack
3126 Node* m = n->in(i);
3127 ++i;
3128 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3129 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3130 // compute worst case interpreter size in case of a deoptimization
3131 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3132
3133 sfpt.push(m);
3134 }
3135 cnt = m->req();
3136 nstack.push(n, i); // put on stack parent and next input's index
3137 n = m;
3138 i = 0;
3139 }
3140 } else {
3141 // Now do post-visit work
3142 final_graph_reshaping_impl( n, frc );
3143 if (nstack.is_empty())
3144 break; // finished
3145 n = nstack.node(); // Get node from stack
3146 cnt = n->req();
3147 i = nstack.index();
3148 nstack.pop(); // Shift to the next node on stack
3149 }
3150 }
3151
3152 // Skip next transformation if compressed oops are not used.
3153 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3154 (!UseCompressedOops && !UseCompressedClassPointers))
3155 return;
3156
3157 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3158 // It could be done for an uncommon traps or any safepoints/calls
3159 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3160 while (sfpt.size() > 0) {
3161 n = sfpt.pop();
3162 JVMState *jvms = n->as_SafePoint()->jvms();
3163 assert(jvms != NULL, "sanity");
3164 int start = jvms->debug_start();
3165 int end = n->req();
3166 bool is_uncommon = (n->is_CallStaticJava() &&
3167 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3168 for (int j = start; j < end; j++) {
3169 Node* in = n->in(j);
3170 if (in->is_DecodeNarrowPtr()) {
3171 bool safe_to_skip = true;
3172 if (!is_uncommon ) {
3173 // Is it safe to skip?
3174 for (uint i = 0; i < in->outcnt(); i++) {
3175 Node* u = in->raw_out(i);
3176 if (!u->is_SafePoint() ||
3177 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3178 safe_to_skip = false;
3179 }
3180 }
3181 }
3182 if (safe_to_skip) {
3183 n->set_req(j, in->in(1));
3184 }
3185 if (in->outcnt() == 0) {
3186 in->disconnect_inputs(NULL, this);
3187 }
3188 }
3189 }
3190 }
3191 }
3192
3193 //------------------------------final_graph_reshaping--------------------------
3194 // Final Graph Reshaping.
3195 //
3196 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3197 // and not commoned up and forced early. Must come after regular
3198 // optimizations to avoid GVN undoing the cloning. Clone constant
3199 // inputs to Loop Phis; these will be split by the allocator anyways.
3200 // Remove Opaque nodes.
3201 // (2) Move last-uses by commutative operations to the left input to encourage
3202 // Intel update-in-place two-address operations and better register usage
3203 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3204 // calls canonicalizing them back.
3205 // (3) Count the number of double-precision FP ops, single-precision FP ops
3206 // and call sites. On Intel, we can get correct rounding either by
3207 // forcing singles to memory (requires extra stores and loads after each
3208 // FP bytecode) or we can set a rounding mode bit (requires setting and
3209 // clearing the mode bit around call sites). The mode bit is only used
3210 // if the relative frequency of single FP ops to calls is low enough.
3211 // This is a key transform for SPEC mpeg_audio.
3212 // (4) Detect infinite loops; blobs of code reachable from above but not
3213 // below. Several of the Code_Gen algorithms fail on such code shapes,
3214 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3215 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3216 // Detection is by looking for IfNodes where only 1 projection is
3217 // reachable from below or CatchNodes missing some targets.
3218 // (5) Assert for insane oop offsets in debug mode.
3219
3220 bool Compile::final_graph_reshaping() {
3221 // an infinite loop may have been eliminated by the optimizer,
3222 // in which case the graph will be empty.
3223 if (root()->req() == 1) {
3224 record_method_not_compilable("trivial infinite loop");
3225 return true;
3226 }
3227
3228 // Expensive nodes have their control input set to prevent the GVN
3229 // from freely commoning them. There's no GVN beyond this point so
3230 // no need to keep the control input. We want the expensive nodes to
3231 // be freely moved to the least frequent code path by gcm.
3232 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3233 for (int i = 0; i < expensive_count(); i++) {
3234 _expensive_nodes->at(i)->set_req(0, NULL);
3235 }
3236
3237 Final_Reshape_Counts frc;
3238
3239 // Visit everybody reachable!
3240 // Allocate stack of size C->unique()/2 to avoid frequent realloc
3241 Node_Stack nstack(unique() >> 1);
3242 final_graph_reshaping_walk(nstack, root(), frc);
3243
3244 // Check for unreachable (from below) code (i.e., infinite loops).
3245 for( uint i = 0; i < frc._tests.size(); i++ ) {
3246 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3247 // Get number of CFG targets.
3248 // Note that PCTables include exception targets after calls.
3249 uint required_outcnt = n->required_outcnt();
3250 if (n->outcnt() != required_outcnt) {
3251 // Check for a few special cases. Rethrow Nodes never take the
3252 // 'fall-thru' path, so expected kids is 1 less.
3253 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3254 if (n->in(0)->in(0)->is_Call()) {
3255 CallNode *call = n->in(0)->in(0)->as_Call();
3256 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3257 required_outcnt--; // Rethrow always has 1 less kid
3258 } else if (call->req() > TypeFunc::Parms &&
3259 call->is_CallDynamicJava()) {
3260 // Check for null receiver. In such case, the optimizer has
3261 // detected that the virtual call will always result in a null
3262 // pointer exception. The fall-through projection of this CatchNode
3263 // will not be populated.
3264 Node *arg0 = call->in(TypeFunc::Parms);
3265 if (arg0->is_Type() &&
3266 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3267 required_outcnt--;
3268 }
3269 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3270 call->req() > TypeFunc::Parms+1 &&
3271 call->is_CallStaticJava()) {
3272 // Check for negative array length. In such case, the optimizer has
3273 // detected that the allocation attempt will always result in an
3274 // exception. There is no fall-through projection of this CatchNode .
3275 Node *arg1 = call->in(TypeFunc::Parms+1);
3276 if (arg1->is_Type() &&
3277 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3278 required_outcnt--;
3279 }
3280 }
3281 }
3282 }
3283 // Recheck with a better notion of 'required_outcnt'
3284 if (n->outcnt() != required_outcnt) {
3285 record_method_not_compilable("malformed control flow");
3286 return true; // Not all targets reachable!
3287 }
3288 }
3289 // Check that I actually visited all kids. Unreached kids
3290 // must be infinite loops.
3291 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3292 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3293 record_method_not_compilable("infinite loop");
3294 return true; // Found unvisited kid; must be unreach
3295 }
3296 }
3297
3298 // If original bytecodes contained a mixture of floats and doubles
3299 // check if the optimizer has made it homogenous, item (3).
3300 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3301 frc.get_float_count() > 32 &&
3302 frc.get_double_count() == 0 &&
3303 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3304 set_24_bit_selection_and_mode( false, true );
3305 }
3306
3307 set_java_calls(frc.get_java_call_count());
3308 set_inner_loops(frc.get_inner_loop_count());
3309
3310 // No infinite loops, no reason to bail out.
3311 return false;
3312 }
3313
3314 //-----------------------------too_many_traps----------------------------------
3315 // Report if there are too many traps at the current method and bci.
3316 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3317 bool Compile::too_many_traps(ciMethod* method,
3318 int bci,
3319 Deoptimization::DeoptReason reason) {
3320 ciMethodData* md = method->method_data();
3321 if (md->is_empty()) {
3322 // Assume the trap has not occurred, or that it occurred only
3323 // because of a transient condition during start-up in the interpreter.
3324 return false;
3325 }
3326 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3327 if (md->has_trap_at(bci, m, reason) != 0) {
3328 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3329 // Also, if there are multiple reasons, or if there is no per-BCI record,
3330 // assume the worst.
3331 if (log())
3332 log()->elem("observe trap='%s' count='%d'",
3333 Deoptimization::trap_reason_name(reason),
3334 md->trap_count(reason));
3335 return true;
3336 } else {
3337 // Ignore method/bci and see if there have been too many globally.
3338 return too_many_traps(reason, md);
3339 }
3340 }
3341
3342 // Less-accurate variant which does not require a method and bci.
3343 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3344 ciMethodData* logmd) {
3345 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3346 // Too many traps globally.
3347 // Note that we use cumulative trap_count, not just md->trap_count.
3348 if (log()) {
3349 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3350 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3351 Deoptimization::trap_reason_name(reason),
3352 mcount, trap_count(reason));
3353 }
3354 return true;
3355 } else {
3356 // The coast is clear.
3357 return false;
3358 }
3359 }
3360
3361 //--------------------------too_many_recompiles--------------------------------
3362 // Report if there are too many recompiles at the current method and bci.
3363 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3364 // Is not eager to return true, since this will cause the compiler to use
3365 // Action_none for a trap point, to avoid too many recompilations.
3366 bool Compile::too_many_recompiles(ciMethod* method,
3367 int bci,
3368 Deoptimization::DeoptReason reason) {
3369 ciMethodData* md = method->method_data();
3370 if (md->is_empty()) {
3371 // Assume the trap has not occurred, or that it occurred only
3372 // because of a transient condition during start-up in the interpreter.
3373 return false;
3374 }
3375 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3376 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3377 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3378 Deoptimization::DeoptReason per_bc_reason
3379 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3380 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3381 if ((per_bc_reason == Deoptimization::Reason_none
3382 || md->has_trap_at(bci, m, reason) != 0)
3383 // The trap frequency measure we care about is the recompile count:
3384 && md->trap_recompiled_at(bci, m)
3385 && md->overflow_recompile_count() >= bc_cutoff) {
3386 // Do not emit a trap here if it has already caused recompilations.
3387 // Also, if there are multiple reasons, or if there is no per-BCI record,
3388 // assume the worst.
3389 if (log())
3390 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3391 Deoptimization::trap_reason_name(reason),
3392 md->trap_count(reason),
3393 md->overflow_recompile_count());
3394 return true;
3395 } else if (trap_count(reason) != 0
3396 && decompile_count() >= m_cutoff) {
3397 // Too many recompiles globally, and we have seen this sort of trap.
3398 // Use cumulative decompile_count, not just md->decompile_count.
3399 if (log())
3400 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3401 Deoptimization::trap_reason_name(reason),
3402 md->trap_count(reason), trap_count(reason),
3403 md->decompile_count(), decompile_count());
3404 return true;
3405 } else {
3406 // The coast is clear.
3407 return false;
3408 }
3409 }
3410
3411 // Compute when not to trap. Used by matching trap based nodes and
3412 // NullCheck optimization.
3413 void Compile::set_allowed_deopt_reasons() {
3414 _allowed_reasons = 0;
3415 if (is_method_compilation()) {
3416 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3417 assert(rs < BitsPerInt, "recode bit map");
3418 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3419 _allowed_reasons |= nth_bit(rs);
3420 }
3421 }
3422 }
3423 }
3424
3425 #ifndef PRODUCT
3426 //------------------------------verify_graph_edges---------------------------
3427 // Walk the Graph and verify that there is a one-to-one correspondence
3428 // between Use-Def edges and Def-Use edges in the graph.
3429 void Compile::verify_graph_edges(bool no_dead_code) {
3430 if (VerifyGraphEdges) {
3431 ResourceArea *area = Thread::current()->resource_area();
3432 Unique_Node_List visited(area);
3433 // Call recursive graph walk to check edges
3434 _root->verify_edges(visited);
3435 if (no_dead_code) {
3436 // Now make sure that no visited node is used by an unvisited node.
3437 bool dead_nodes = false;
3438 Unique_Node_List checked(area);
3439 while (visited.size() > 0) {
3440 Node* n = visited.pop();
3441 checked.push(n);
3442 for (uint i = 0; i < n->outcnt(); i++) {
3443 Node* use = n->raw_out(i);
3444 if (checked.member(use)) continue; // already checked
3445 if (visited.member(use)) continue; // already in the graph
3446 if (use->is_Con()) continue; // a dead ConNode is OK
3447 // At this point, we have found a dead node which is DU-reachable.
3448 if (!dead_nodes) {
3449 tty->print_cr("*** Dead nodes reachable via DU edges:");
3450 dead_nodes = true;
3451 }
3452 use->dump(2);
3453 tty->print_cr("---");
3454 checked.push(use); // No repeats; pretend it is now checked.
3455 }
3456 }
3457 assert(!dead_nodes, "using nodes must be reachable from root");
3458 }
3459 }
3460 }
3461
3462 // Verify GC barriers consistency
3463 // Currently supported:
3464 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3465 void Compile::verify_barriers() {
3466 if (UseG1GC) {
3467 // Verify G1 pre-barriers
3468 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3469
3470 ResourceArea *area = Thread::current()->resource_area();
3471 Unique_Node_List visited(area);
3472 Node_List worklist(area);
3473 // We're going to walk control flow backwards starting from the Root
3474 worklist.push(_root);
3475 while (worklist.size() > 0) {
3476 Node* x = worklist.pop();
3477 if (x == NULL || x == top()) continue;
3478 if (visited.member(x)) {
3479 continue;
3480 } else {
3481 visited.push(x);
3482 }
3483
3484 if (x->is_Region()) {
3485 for (uint i = 1; i < x->req(); i++) {
3486 worklist.push(x->in(i));
3487 }
3488 } else {
3489 worklist.push(x->in(0));
3490 // We are looking for the pattern:
3491 // /->ThreadLocal
3492 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3493 // \->ConI(0)
3494 // We want to verify that the If and the LoadB have the same control
3495 // See GraphKit::g1_write_barrier_pre()
3496 if (x->is_If()) {
3497 IfNode *iff = x->as_If();
3498 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3499 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3500 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3501 && cmp->in(1)->is_Load()) {
3502 LoadNode* load = cmp->in(1)->as_Load();
3503 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3504 && load->in(2)->in(3)->is_Con()
3505 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3506
3507 Node* if_ctrl = iff->in(0);
3508 Node* load_ctrl = load->in(0);
3509
3510 if (if_ctrl != load_ctrl) {
3511 // Skip possible CProj->NeverBranch in infinite loops
3512 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3513 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3514 if_ctrl = if_ctrl->in(0)->in(0);
3515 }
3516 }
3517 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3518 }
3519 }
3520 }
3521 }
3522 }
3523 }
3524 }
3525 }
3526
3527 #endif
3528
3529 // The Compile object keeps track of failure reasons separately from the ciEnv.
3530 // This is required because there is not quite a 1-1 relation between the
3531 // ciEnv and its compilation task and the Compile object. Note that one
3532 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3533 // to backtrack and retry without subsuming loads. Other than this backtracking
3534 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3535 // by the logic in C2Compiler.
3536 void Compile::record_failure(const char* reason) {
3537 if (log() != NULL) {
3538 log()->elem("failure reason='%s' phase='compile'", reason);
3539 }
3540 if (_failure_reason == NULL) {
3541 // Record the first failure reason.
3542 _failure_reason = reason;
3543 }
3544
3545 EventCompilerFailure event;
3546 if (event.should_commit()) {
3547 event.set_compileID(Compile::compile_id());
3548 event.set_failure(reason);
3549 event.commit();
3550 }
3551
3552 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3553 C->print_method(PHASE_FAILURE);
3554 }
3555 _root = NULL; // flush the graph, too
3556 }
3557
3558 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3559 : TraceTime(name, accumulator, CITime, CITimeVerbose),
3560 _phase_name(name), _dolog(CITimeVerbose)
3561 {
3562 if (_dolog) {
3563 C = Compile::current();
3564 _log = C->log();
3565 } else {
3566 C = NULL;
3567 _log = NULL;
3568 }
3569 if (_log != NULL) {
3570 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3571 _log->stamp();
3572 _log->end_head();
3573 }
3574 }
3575
3576 Compile::TracePhase::~TracePhase() {
3577
3578 C = Compile::current();
3579 if (_dolog) {
3580 _log = C->log();
3581 } else {
3582 _log = NULL;
3583 }
3584
3585 #ifdef ASSERT
3586 if (PrintIdealNodeCount) {
3587 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3588 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3589 }
3590
3591 if (VerifyIdealNodeCount) {
3592 Compile::current()->print_missing_nodes();
3593 }
3594 #endif
3595
3596 if (_log != NULL) {
3597 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3598 }
3599 }
3600
3601 //=============================================================================
3602 // Two Constant's are equal when the type and the value are equal.
3603 bool Compile::Constant::operator==(const Constant& other) {
3604 if (type() != other.type() ) return false;
3605 if (can_be_reused() != other.can_be_reused()) return false;
3606 // For floating point values we compare the bit pattern.
3607 switch (type()) {
3608 case T_FLOAT: return (_v._value.i == other._v._value.i);
3609 case T_LONG:
3610 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3611 case T_OBJECT:
3612 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3613 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3614 case T_METADATA: return (_v._metadata == other._v._metadata);
3615 default: ShouldNotReachHere();
3616 }
3617 return false;
3618 }
3619
3620 static int type_to_size_in_bytes(BasicType t) {
3621 switch (t) {
3622 case T_LONG: return sizeof(jlong );
3623 case T_FLOAT: return sizeof(jfloat );
3624 case T_DOUBLE: return sizeof(jdouble);
3625 case T_METADATA: return sizeof(Metadata*);
3626 // We use T_VOID as marker for jump-table entries (labels) which
3627 // need an internal word relocation.
3628 case T_VOID:
3629 case T_ADDRESS:
3630 case T_OBJECT: return sizeof(jobject);
3631 }
3632
3633 ShouldNotReachHere();
3634 return -1;
3635 }
3636
3637 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3638 // sort descending
3639 if (a->freq() > b->freq()) return -1;
3640 if (a->freq() < b->freq()) return 1;
3641 return 0;
3642 }
3643
3644 void Compile::ConstantTable::calculate_offsets_and_size() {
3645 // First, sort the array by frequencies.
3646 _constants.sort(qsort_comparator);
3647
3648 #ifdef ASSERT
3649 // Make sure all jump-table entries were sorted to the end of the
3650 // array (they have a negative frequency).
3651 bool found_void = false;
3652 for (int i = 0; i < _constants.length(); i++) {
3653 Constant con = _constants.at(i);
3654 if (con.type() == T_VOID)
3655 found_void = true; // jump-tables
3656 else
3657 assert(!found_void, "wrong sorting");
3658 }
3659 #endif
3660
3661 int offset = 0;
3662 for (int i = 0; i < _constants.length(); i++) {
3663 Constant* con = _constants.adr_at(i);
3664
3665 // Align offset for type.
3666 int typesize = type_to_size_in_bytes(con->type());
3667 offset = align_size_up(offset, typesize);
3668 con->set_offset(offset); // set constant's offset
3669
3670 if (con->type() == T_VOID) {
3671 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3672 offset = offset + typesize * n->outcnt(); // expand jump-table
3673 } else {
3674 offset = offset + typesize;
3675 }
3676 }
3677
3678 // Align size up to the next section start (which is insts; see
3679 // CodeBuffer::align_at_start).
3680 assert(_size == -1, "already set?");
3681 _size = align_size_up(offset, CodeEntryAlignment);
3682 }
3683
3684 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3685 MacroAssembler _masm(&cb);
3686 for (int i = 0; i < _constants.length(); i++) {
3687 Constant con = _constants.at(i);
3688 address constant_addr;
3689 switch (con.type()) {
3690 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3691 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3692 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3693 case T_OBJECT: {
3694 jobject obj = con.get_jobject();
3695 int oop_index = _masm.oop_recorder()->find_index(obj);
3696 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3697 break;
3698 }
3699 case T_ADDRESS: {
3700 address addr = (address) con.get_jobject();
3701 constant_addr = _masm.address_constant(addr);
3702 break;
3703 }
3704 // We use T_VOID as marker for jump-table entries (labels) which
3705 // need an internal word relocation.
3706 case T_VOID: {
3707 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3708 // Fill the jump-table with a dummy word. The real value is
3709 // filled in later in fill_jump_table.
3710 address dummy = (address) n;
3711 constant_addr = _masm.address_constant(dummy);
3712 // Expand jump-table
3713 for (uint i = 1; i < n->outcnt(); i++) {
3714 address temp_addr = _masm.address_constant(dummy + i);
3715 assert(temp_addr, "consts section too small");
3716 }
3717 break;
3718 }
3719 case T_METADATA: {
3720 Metadata* obj = con.get_metadata();
3721 int metadata_index = _masm.oop_recorder()->find_index(obj);
3722 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3723 break;
3724 }
3725 default: ShouldNotReachHere();
3726 }
3727 assert(constant_addr, "consts section too small");
3728 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3729 err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3730 }
3731 }
3732
3733 int Compile::ConstantTable::find_offset(Constant& con) const {
3734 int idx = _constants.find(con);
3735 assert(idx != -1, "constant must be in constant table");
3736 int offset = _constants.at(idx).offset();
3737 assert(offset != -1, "constant table not emitted yet?");
3738 return offset;
3739 }
3740
3741 void Compile::ConstantTable::add(Constant& con) {
3742 if (con.can_be_reused()) {
3743 int idx = _constants.find(con);
3744 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3745 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3746 return;
3747 }
3748 }
3749 (void) _constants.append(con);
3750 }
3751
3752 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3753 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3754 Constant con(type, value, b->_freq);
3755 add(con);
3756 return con;
3757 }
3758
3759 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3760 Constant con(metadata);
3761 add(con);
3762 return con;
3763 }
3764
3765 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3766 jvalue value;
3767 BasicType type = oper->type()->basic_type();
3768 switch (type) {
3769 case T_LONG: value.j = oper->constantL(); break;
3770 case T_FLOAT: value.f = oper->constantF(); break;
3771 case T_DOUBLE: value.d = oper->constantD(); break;
3772 case T_OBJECT:
3773 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3774 case T_METADATA: return add((Metadata*)oper->constant()); break;
3775 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3776 }
3777 return add(n, type, value);
3778 }
3779
3780 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3781 jvalue value;
3782 // We can use the node pointer here to identify the right jump-table
3783 // as this method is called from Compile::Fill_buffer right before
3784 // the MachNodes are emitted and the jump-table is filled (means the
3785 // MachNode pointers do not change anymore).
3786 value.l = (jobject) n;
3787 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3788 add(con);
3789 return con;
3790 }
3791
3792 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3793 // If called from Compile::scratch_emit_size do nothing.
3794 if (Compile::current()->in_scratch_emit_size()) return;
3795
3796 assert(labels.is_nonempty(), "must be");
3797 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3798
3799 // Since MachConstantNode::constant_offset() also contains
3800 // table_base_offset() we need to subtract the table_base_offset()
3801 // to get the plain offset into the constant table.
3802 int offset = n->constant_offset() - table_base_offset();
3803
3804 MacroAssembler _masm(&cb);
3805 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3806
3807 for (uint i = 0; i < n->outcnt(); i++) {
3808 address* constant_addr = &jump_table_base[i];
3809 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)));
3810 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3811 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3812 }
3813 }
3814
3815 //----------------------------static_subtype_check-----------------------------
3816 // Shortcut important common cases when superklass is exact:
3817 // (0) superklass is java.lang.Object (can occur in reflective code)
3818 // (1) subklass is already limited to a subtype of superklass => always ok
3819 // (2) subklass does not overlap with superklass => always fail
3820 // (3) superklass has NO subtypes and we can check with a simple compare.
3821 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
3822 if (StressReflectiveCode) {
3823 return SSC_full_test; // Let caller generate the general case.
3824 }
3825
3826 if (superk == env()->Object_klass()) {
3827 return SSC_always_true; // (0) this test cannot fail
3828 }
3829
3830 ciType* superelem = superk;
3831 if (superelem->is_array_klass())
3832 superelem = superelem->as_array_klass()->base_element_type();
3833
3834 if (!subk->is_interface()) { // cannot trust static interface types yet
3835 if (subk->is_subtype_of(superk)) {
3836 return SSC_always_true; // (1) false path dead; no dynamic test needed
3837 }
3838 if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
3839 !superk->is_subtype_of(subk)) {
3840 return SSC_always_false;
3841 }
3842 }
3843
3844 // If casting to an instance klass, it must have no subtypes
3845 if (superk->is_interface()) {
3846 // Cannot trust interfaces yet.
3847 // %%% S.B. superk->nof_implementors() == 1
3848 } else if (superelem->is_instance_klass()) {
3849 ciInstanceKlass* ik = superelem->as_instance_klass();
3850 if (!ik->has_subklass() && !ik->is_interface()) {
3851 if (!ik->is_final()) {
3852 // Add a dependency if there is a chance of a later subclass.
3853 dependencies()->assert_leaf_type(ik);
3854 }
3855 return SSC_easy_test; // (3) caller can do a simple ptr comparison
3856 }
3857 } else {
3858 // A primitive array type has no subtypes.
3859 return SSC_easy_test; // (3) caller can do a simple ptr comparison
3860 }
3861
3862 return SSC_full_test;
3863 }
3864
3865 // The message about the current inlining is accumulated in
3866 // _print_inlining_stream and transfered into the _print_inlining_list
3867 // once we know whether inlining succeeds or not. For regular
3868 // inlining, messages are appended to the buffer pointed by
3869 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3870 // a new buffer is added after _print_inlining_idx in the list. This
3871 // way we can update the inlining message for late inlining call site
3872 // when the inlining is attempted again.
3873 void Compile::print_inlining_init() {
3874 if (print_inlining() || print_intrinsics()) {
3875 _print_inlining_stream = new stringStream();
3876 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3877 }
3878 }
3879
3880 void Compile::print_inlining_reinit() {
3881 if (print_inlining() || print_intrinsics()) {
3882 // Re allocate buffer when we change ResourceMark
3883 _print_inlining_stream = new stringStream();
3884 }
3885 }
3886
3887 void Compile::print_inlining_reset() {
3888 _print_inlining_stream->reset();
3889 }
3890
3891 void Compile::print_inlining_commit() {
3892 assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3893 // Transfer the message from _print_inlining_stream to the current
3894 // _print_inlining_list buffer and clear _print_inlining_stream.
3895 _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3896 print_inlining_reset();
3897 }
3898
3899 void Compile::print_inlining_push() {
3900 // Add new buffer to the _print_inlining_list at current position
3901 _print_inlining_idx++;
3902 _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3903 }
3904
3905 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3906 return _print_inlining_list->at(_print_inlining_idx);
3907 }
3908
3909 void Compile::print_inlining_update(CallGenerator* cg) {
3910 if (print_inlining() || print_intrinsics()) {
3911 if (!cg->is_late_inline()) {
3912 if (print_inlining_current().cg() != NULL) {
3913 print_inlining_push();
3914 }
3915 print_inlining_commit();
3916 } else {
3917 if (print_inlining_current().cg() != cg &&
3918 (print_inlining_current().cg() != NULL ||
3919 print_inlining_current().ss()->size() != 0)) {
3920 print_inlining_push();
3921 }
3922 print_inlining_commit();
3923 print_inlining_current().set_cg(cg);
3924 }
3925 }
3926 }
3927
3928 void Compile::print_inlining_move_to(CallGenerator* cg) {
3929 // We resume inlining at a late inlining call site. Locate the
3930 // corresponding inlining buffer so that we can update it.
3931 if (print_inlining()) {
3932 for (int i = 0; i < _print_inlining_list->length(); i++) {
3933 if (_print_inlining_list->adr_at(i)->cg() == cg) {
3934 _print_inlining_idx = i;
3935 return;
3936 }
3937 }
3938 ShouldNotReachHere();
3939 }
3940 }
3941
3942 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3943 if (print_inlining()) {
3944 assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3945 assert(print_inlining_current().cg() == cg, "wrong entry");
3946 // replace message with new message
3947 _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3948 print_inlining_commit();
3949 print_inlining_current().set_cg(cg);
3950 }
3951 }
3952
3953 void Compile::print_inlining_assert_ready() {
3954 assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3955 }
3956
3957 void Compile::process_print_inlining() {
3958 bool do_print_inlining = print_inlining() || print_intrinsics();
3959 if (do_print_inlining || log() != NULL) {
3960 // Print inlining message for candidates that we couldn't inline
3961 // for lack of space
3962 for (int i = 0; i < _late_inlines.length(); i++) {
3963 CallGenerator* cg = _late_inlines.at(i);
3964 if (!cg->is_mh_late_inline()) {
3965 const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3966 if (do_print_inlining) {
3967 cg->print_inlining_late(msg);
3968 }
3969 log_late_inline_failure(cg, msg);
3970 }
3971 }
3972 }
3973 if (do_print_inlining) {
3974 ResourceMark rm;
3975 stringStream ss;
3976 for (int i = 0; i < _print_inlining_list->length(); i++) {
3977 ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3978 }
3979 size_t end = ss.size();
3980 _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
3981 strncpy(_print_inlining_output, ss.base(), end+1);
3982 _print_inlining_output[end] = 0;
3983 }
3984 }
3985
3986 void Compile::dump_print_inlining() {
3987 if (_print_inlining_output != NULL) {
3988 tty->print_raw(_print_inlining_output);
3989 }
3990 }
3991
3992 void Compile::log_late_inline(CallGenerator* cg) {
3993 if (log() != NULL) {
3994 log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3995 cg->unique_id());
3996 JVMState* p = cg->call_node()->jvms();
3997 while (p != NULL) {
3998 log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
3999 p = p->caller();
4000 }
4001 log()->tail("late_inline");
4002 }
4003 }
4004
4005 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4006 log_late_inline(cg);
4007 if (log() != NULL) {
4008 log()->inline_fail(msg);
4009 }
4010 }
4011
4012 void Compile::log_inline_id(CallGenerator* cg) {
4013 if (log() != NULL) {
4014 // The LogCompilation tool needs a unique way to identify late
4015 // inline call sites. This id must be unique for this call site in
4016 // this compilation. Try to have it unique across compilations as
4017 // well because it can be convenient when grepping through the log
4018 // file.
4019 // Distinguish OSR compilations from others in case CICountOSR is
4020 // on.
4021 jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4022 cg->set_unique_id(id);
4023 log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4024 }
4025 }
4026
4027 void Compile::log_inline_failure(const char* msg) {
4028 if (C->log() != NULL) {
4029 C->log()->inline_fail(msg);
4030 }
4031 }
4032
4033
4034 // Dump inlining replay data to the stream.
4035 // Don't change thread state and acquire any locks.
4036 void Compile::dump_inline_data(outputStream* out) {
4037 InlineTree* inl_tree = ilt();
4038 if (inl_tree != NULL) {
4039 out->print(" inline %d", inl_tree->count());
4040 inl_tree->dump_replay_data(out);
4041 }
4042 }
4043
4044 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4045 if (n1->Opcode() < n2->Opcode()) return -1;
4046 else if (n1->Opcode() > n2->Opcode()) return 1;
4047
4048 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()));
4049 for (uint i = 1; i < n1->req(); i++) {
4050 if (n1->in(i) < n2->in(i)) return -1;
4051 else if (n1->in(i) > n2->in(i)) return 1;
4052 }
4053
4054 return 0;
4055 }
4056
4057 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4058 Node* n1 = *n1p;
4059 Node* n2 = *n2p;
4060
4061 return cmp_expensive_nodes(n1, n2);
4062 }
4063
4064 void Compile::sort_expensive_nodes() {
4065 if (!expensive_nodes_sorted()) {
4066 _expensive_nodes->sort(cmp_expensive_nodes);
4067 }
4068 }
4069
4070 bool Compile::expensive_nodes_sorted() const {
4071 for (int i = 1; i < _expensive_nodes->length(); i++) {
4072 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4073 return false;
4074 }
4075 }
4076 return true;
4077 }
4078
4079 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4080 if (_expensive_nodes->length() == 0) {
4081 return false;
4082 }
4083
4084 assert(OptimizeExpensiveOps, "optimization off?");
4085
4086 // Take this opportunity to remove dead nodes from the list
4087 int j = 0;
4088 for (int i = 0; i < _expensive_nodes->length(); i++) {
4089 Node* n = _expensive_nodes->at(i);
4090 if (!n->is_unreachable(igvn)) {
4091 assert(n->is_expensive(), "should be expensive");
4092 _expensive_nodes->at_put(j, n);
4093 j++;
4094 }
4095 }
4096 _expensive_nodes->trunc_to(j);
4097
4098 // Then sort the list so that similar nodes are next to each other
4099 // and check for at least two nodes of identical kind with same data
4100 // inputs.
4101 sort_expensive_nodes();
4102
4103 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4104 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4105 return true;
4106 }
4107 }
4108
4109 return false;
4110 }
4111
4112 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4113 if (_expensive_nodes->length() == 0) {
4114 return;
4115 }
4116
4117 assert(OptimizeExpensiveOps, "optimization off?");
4118
4119 // Sort to bring similar nodes next to each other and clear the
4120 // control input of nodes for which there's only a single copy.
4121 sort_expensive_nodes();
4122
4123 int j = 0;
4124 int identical = 0;
4125 int i = 0;
4126 bool modified = false;
4127 for (; i < _expensive_nodes->length()-1; i++) {
4128 assert(j <= i, "can't write beyond current index");
4129 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4130 identical++;
4131 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4132 continue;
4133 }
4134 if (identical > 0) {
4135 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4136 identical = 0;
4137 } else {
4138 Node* n = _expensive_nodes->at(i);
4139 igvn.replace_input_of(n, 0, NULL);
4140 igvn.hash_insert(n);
4141 modified = true;
4142 }
4143 }
4144 if (identical > 0) {
4145 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4146 } else if (_expensive_nodes->length() >= 1) {
4147 Node* n = _expensive_nodes->at(i);
4148 igvn.replace_input_of(n, 0, NULL);
4149 igvn.hash_insert(n);
4150 modified = true;
4151 }
4152 _expensive_nodes->trunc_to(j);
4153 if (modified) {
4154 igvn.optimize();
4155 }
4156 }
4157
4158 void Compile::add_expensive_node(Node * n) {
4159 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4160 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4161 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4162 if (OptimizeExpensiveOps) {
4163 _expensive_nodes->append(n);
4164 } else {
4165 // Clear control input and let IGVN optimize expensive nodes if
4166 // OptimizeExpensiveOps is off.
4167 n->set_req(0, NULL);
4168 }
4169 }
4170
4171 /**
4172 * Remove the speculative part of types and clean up the graph
4173 */
4174 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4175 if (UseTypeSpeculation) {
4176 Unique_Node_List worklist;
4177 worklist.push(root());
4178 int modified = 0;
4179 // Go over all type nodes that carry a speculative type, drop the
4180 // speculative part of the type and enqueue the node for an igvn
4181 // which may optimize it out.
4182 for (uint next = 0; next < worklist.size(); ++next) {
4183 Node *n = worklist.at(next);
4184 if (n->is_Type()) {
4185 TypeNode* tn = n->as_Type();
4186 const Type* t = tn->type();
4187 const Type* t_no_spec = t->remove_speculative();
4188 if (t_no_spec != t) {
4189 bool in_hash = igvn.hash_delete(n);
4190 assert(in_hash, "node should be in igvn hash table");
4191 tn->set_type(t_no_spec);
4192 igvn.hash_insert(n);
4193 igvn._worklist.push(n); // give it a chance to go away
4194 modified++;
4195 }
4196 }
4197 uint max = n->len();
4198 for( uint i = 0; i < max; ++i ) {
4199 Node *m = n->in(i);
4200 if (not_a_node(m)) continue;
4201 worklist.push(m);
4202 }
4203 }
4204 // Drop the speculative part of all types in the igvn's type table
4205 igvn.remove_speculative_types();
4206 if (modified > 0) {
4207 igvn.optimize();
4208 }
4209 #ifdef ASSERT
4210 // Verify that after the IGVN is over no speculative type has resurfaced
4211 worklist.clear();
4212 worklist.push(root());
4213 for (uint next = 0; next < worklist.size(); ++next) {
4214 Node *n = worklist.at(next);
4215 const Type* t = igvn.type_or_null(n);
4216 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4217 if (n->is_Type()) {
4218 t = n->as_Type()->type();
4219 assert(t == t->remove_speculative(), "no more speculative types");
4220 }
4221 uint max = n->len();
4222 for( uint i = 0; i < max; ++i ) {
4223 Node *m = n->in(i);
4224 if (not_a_node(m)) continue;
4225 worklist.push(m);
4226 }
4227 }
4228 igvn.check_no_speculative_types();
4229 #endif
4230 }
4231 }
4232
4233 // Auxiliary method to support randomized stressing/fuzzing.
4234 //
4235 // This method can be called the arbitrary number of times, with current count
4236 // as the argument. The logic allows selecting a single candidate from the
4237 // running list of candidates as follows:
4238 // int count = 0;
4239 // Cand* selected = null;
4240 // while(cand = cand->next()) {
4241 // if (randomized_select(++count)) {
4242 // selected = cand;
4243 // }
4244 // }
4245 //
4246 // Including count equalizes the chances any candidate is "selected".
4247 // This is useful when we don't have the complete list of candidates to choose
4248 // from uniformly. In this case, we need to adjust the randomicity of the
4249 // selection, or else we will end up biasing the selection towards the latter
4250 // candidates.
4251 //
4252 // Quick back-envelope calculation shows that for the list of n candidates
4253 // the equal probability for the candidate to persist as "best" can be
4254 // achieved by replacing it with "next" k-th candidate with the probability
4255 // of 1/k. It can be easily shown that by the end of the run, the
4256 // probability for any candidate is converged to 1/n, thus giving the
4257 // uniform distribution among all the candidates.
4258 //
4259 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4260 #define RANDOMIZED_DOMAIN_POW 29
4261 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4262 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4263 bool Compile::randomized_select(int count) {
4264 assert(count > 0, "only positive");
4265 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4266 }