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 "utilities/copy.hpp"
71
72
73 // -------------------- Compile::mach_constant_base_node -----------------------
74 // Constant table base node singleton.
75 MachConstantBaseNode* Compile::mach_constant_base_node() {
76 if (_mach_constant_base_node == NULL) {
77 _mach_constant_base_node = new MachConstantBaseNode();
78 _mach_constant_base_node->add_req(C->root());
79 }
80 return _mach_constant_base_node;
81 }
82
83
84 /// Support for intrinsics.
85
86 // Return the index at which m must be inserted (or already exists).
87 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
88 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
89 #ifdef ASSERT
90 for (int i = 1; i < _intrinsics->length(); i++) {
91 CallGenerator* cg1 = _intrinsics->at(i-1);
92 CallGenerator* cg2 = _intrinsics->at(i);
93 assert(cg1->method() != cg2->method()
94 ? cg1->method() < cg2->method()
95 : cg1->is_virtual() < cg2->is_virtual(),
96 "compiler intrinsics list must stay sorted");
97 }
98 #endif
99 // Binary search sorted list, in decreasing intervals [lo, hi].
100 int lo = 0, hi = _intrinsics->length()-1;
101 while (lo <= hi) {
102 int mid = (uint)(hi + lo) / 2;
103 ciMethod* mid_m = _intrinsics->at(mid)->method();
104 if (m < mid_m) {
105 hi = mid-1;
106 } else if (m > mid_m) {
107 lo = mid+1;
108 } else {
109 // look at minor sort key
110 bool mid_virt = _intrinsics->at(mid)->is_virtual();
111 if (is_virtual < mid_virt) {
112 hi = mid-1;
113 } else if (is_virtual > mid_virt) {
114 lo = mid+1;
115 } else {
116 return mid; // exact match
117 }
118 }
119 }
120 return lo; // inexact match
121 }
122
123 void Compile::register_intrinsic(CallGenerator* cg) {
124 if (_intrinsics == NULL) {
125 _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
126 }
127 // This code is stolen from ciObjectFactory::insert.
128 // Really, GrowableArray should have methods for
129 // insert_at, remove_at, and binary_search.
130 int len = _intrinsics->length();
131 int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
132 if (index == len) {
133 _intrinsics->append(cg);
134 } else {
135 #ifdef ASSERT
136 CallGenerator* oldcg = _intrinsics->at(index);
137 assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
138 #endif
139 _intrinsics->append(_intrinsics->at(len-1));
140 int pos;
141 for (pos = len-2; pos >= index; pos--) {
142 _intrinsics->at_put(pos+1,_intrinsics->at(pos));
143 }
144 _intrinsics->at_put(index, cg);
145 }
146 assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
147 }
148
149 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
150 assert(m->is_loaded(), "don't try this on unloaded methods");
151 if (_intrinsics != NULL) {
152 int index = intrinsic_insertion_index(m, is_virtual);
153 if (index < _intrinsics->length()
154 && _intrinsics->at(index)->method() == m
155 && _intrinsics->at(index)->is_virtual() == is_virtual) {
156 return _intrinsics->at(index);
157 }
158 }
159 // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
160 if (m->intrinsic_id() != vmIntrinsics::_none &&
161 m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
162 CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
163 if (cg != NULL) {
164 // Save it for next time:
165 register_intrinsic(cg);
166 return cg;
167 } else {
168 gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
169 }
170 }
171 return NULL;
172 }
173
174 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
175 // in library_call.cpp.
176
177
178 #ifndef PRODUCT
179 // statistics gathering...
180
181 juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
182 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
183
184 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
185 assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
186 int oflags = _intrinsic_hist_flags[id];
187 assert(flags != 0, "what happened?");
188 if (is_virtual) {
189 flags |= _intrinsic_virtual;
190 }
191 bool changed = (flags != oflags);
192 if ((flags & _intrinsic_worked) != 0) {
193 juint count = (_intrinsic_hist_count[id] += 1);
194 if (count == 1) {
195 changed = true; // first time
196 }
197 // increment the overall count also:
198 _intrinsic_hist_count[vmIntrinsics::_none] += 1;
199 }
200 if (changed) {
201 if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
202 // Something changed about the intrinsic's virtuality.
203 if ((flags & _intrinsic_virtual) != 0) {
204 // This is the first use of this intrinsic as a virtual call.
205 if (oflags != 0) {
206 // We already saw it as a non-virtual, so note both cases.
207 flags |= _intrinsic_both;
208 }
209 } else if ((oflags & _intrinsic_both) == 0) {
210 // This is the first use of this intrinsic as a non-virtual
211 flags |= _intrinsic_both;
212 }
213 }
214 _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
215 }
216 // update the overall flags also:
217 _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
218 return changed;
219 }
220
221 static char* format_flags(int flags, char* buf) {
222 buf[0] = 0;
223 if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
224 if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
225 if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
226 if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
227 if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
228 if (buf[0] == 0) strcat(buf, ",");
229 assert(buf[0] == ',', "must be");
230 return &buf[1];
231 }
232
233 void Compile::print_intrinsic_statistics() {
234 char flagsbuf[100];
235 ttyLocker ttyl;
236 if (xtty != NULL) xtty->head("statistics type='intrinsic'");
237 tty->print_cr("Compiler intrinsic usage:");
238 juint total = _intrinsic_hist_count[vmIntrinsics::_none];
239 if (total == 0) total = 1; // avoid div0 in case of no successes
240 #define PRINT_STAT_LINE(name, c, f) \
241 tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
242 for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
243 vmIntrinsics::ID id = (vmIntrinsics::ID) index;
244 int flags = _intrinsic_hist_flags[id];
245 juint count = _intrinsic_hist_count[id];
246 if ((flags | count) != 0) {
247 PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
248 }
249 }
250 PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
251 if (xtty != NULL) xtty->tail("statistics");
252 }
253
254 void Compile::print_statistics() {
255 { ttyLocker ttyl;
256 if (xtty != NULL) xtty->head("statistics type='opto'");
257 Parse::print_statistics();
258 PhaseCCP::print_statistics();
259 PhaseRegAlloc::print_statistics();
260 Scheduling::print_statistics();
261 PhasePeephole::print_statistics();
262 PhaseIdealLoop::print_statistics();
263 if (xtty != NULL) xtty->tail("statistics");
264 }
265 if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
266 // put this under its own <statistics> element.
267 print_intrinsic_statistics();
268 }
269 }
270 #endif //PRODUCT
271
272 // Support for bundling info
273 Bundle* Compile::node_bundling(const Node *n) {
274 assert(valid_bundle_info(n), "oob");
275 return &_node_bundling_base[n->_idx];
276 }
277
278 bool Compile::valid_bundle_info(const Node *n) {
279 return (_node_bundling_limit > n->_idx);
280 }
281
282
283 void Compile::gvn_replace_by(Node* n, Node* nn) {
284 for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
285 Node* use = n->last_out(i);
286 bool is_in_table = initial_gvn()->hash_delete(use);
287 uint uses_found = 0;
288 for (uint j = 0; j < use->len(); j++) {
289 if (use->in(j) == n) {
290 if (j < use->req())
291 use->set_req(j, nn);
292 else
293 use->set_prec(j, nn);
294 uses_found++;
295 }
296 }
297 if (is_in_table) {
298 // reinsert into table
299 initial_gvn()->hash_find_insert(use);
300 }
301 record_for_igvn(use);
302 i -= uses_found; // we deleted 1 or more copies of this edge
303 }
304 }
305
306
307 static inline bool not_a_node(const Node* n) {
308 if (n == NULL) return true;
309 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
310 if (*(address*)n == badAddress) return true; // kill by Node::destruct
311 return false;
312 }
313
314 // Identify all nodes that are reachable from below, useful.
315 // Use breadth-first pass that records state in a Unique_Node_List,
316 // recursive traversal is slower.
317 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
318 int estimated_worklist_size = unique();
319 useful.map( estimated_worklist_size, NULL ); // preallocate space
320
321 // Initialize worklist
322 if (root() != NULL) { useful.push(root()); }
323 // If 'top' is cached, declare it useful to preserve cached node
324 if( cached_top_node() ) { useful.push(cached_top_node()); }
325
326 // Push all useful nodes onto the list, breadthfirst
327 for( uint next = 0; next < useful.size(); ++next ) {
328 assert( next < unique(), "Unique useful nodes < total nodes");
329 Node *n = useful.at(next);
330 uint max = n->len();
331 for( uint i = 0; i < max; ++i ) {
332 Node *m = n->in(i);
333 if (not_a_node(m)) continue;
334 useful.push(m);
335 }
336 }
337 }
338
339 // Update dead_node_list with any missing dead nodes using useful
340 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
341 void Compile::update_dead_node_list(Unique_Node_List &useful) {
342 uint max_idx = unique();
343 VectorSet& useful_node_set = useful.member_set();
344
345 for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
346 // If node with index node_idx is not in useful set,
347 // mark it as dead in dead node list.
348 if (! useful_node_set.test(node_idx) ) {
349 record_dead_node(node_idx);
350 }
351 }
352 }
353
354 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
355 int shift = 0;
356 for (int i = 0; i < inlines->length(); i++) {
357 CallGenerator* cg = inlines->at(i);
358 CallNode* call = cg->call_node();
359 if (shift > 0) {
360 inlines->at_put(i-shift, cg);
361 }
362 if (!useful.member(call)) {
363 shift++;
364 }
365 }
366 inlines->trunc_to(inlines->length()-shift);
367 }
368
369 // Disconnect all useless nodes by disconnecting those at the boundary.
370 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
371 uint next = 0;
372 while (next < useful.size()) {
373 Node *n = useful.at(next++);
374 if (n->is_SafePoint()) {
375 // We're done with a parsing phase. Replaced nodes are not valid
376 // beyond that point.
377 n->as_SafePoint()->delete_replaced_nodes();
378 }
379 // Use raw traversal of out edges since this code removes out edges
380 int max = n->outcnt();
381 for (int j = 0; j < max; ++j) {
382 Node* child = n->raw_out(j);
383 if (! useful.member(child)) {
384 assert(!child->is_top() || child != top(),
385 "If top is cached in Compile object it is in useful list");
386 // Only need to remove this out-edge to the useless node
387 n->raw_del_out(j);
388 --j;
389 --max;
390 }
391 }
392 if (n->outcnt() == 1 && n->has_special_unique_user()) {
393 record_for_igvn(n->unique_out());
394 }
395 }
396 // Remove useless macro and predicate opaq nodes
397 for (int i = C->macro_count()-1; i >= 0; i--) {
398 Node* n = C->macro_node(i);
399 if (!useful.member(n)) {
400 remove_macro_node(n);
401 }
402 }
403 // Remove useless expensive node
404 for (int i = C->expensive_count()-1; i >= 0; i--) {
405 Node* n = C->expensive_node(i);
406 if (!useful.member(n)) {
407 remove_expensive_node(n);
408 }
409 }
410 // clean up the late inline lists
411 remove_useless_late_inlines(&_string_late_inlines, useful);
412 remove_useless_late_inlines(&_boxing_late_inlines, useful);
413 remove_useless_late_inlines(&_late_inlines, useful);
414 debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
415 }
416
417 //------------------------------frame_size_in_words-----------------------------
418 // frame_slots in units of words
419 int Compile::frame_size_in_words() const {
420 // shift is 0 in LP32 and 1 in LP64
421 const int shift = (LogBytesPerWord - LogBytesPerInt);
422 int words = _frame_slots >> shift;
423 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
424 return words;
425 }
426
427 // To bang the stack of this compiled method we use the stack size
428 // that the interpreter would need in case of a deoptimization. This
429 // removes the need to bang the stack in the deoptimization blob which
430 // in turn simplifies stack overflow handling.
431 int Compile::bang_size_in_bytes() const {
432 return MAX2(frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _interpreter_frame_size);
433 }
434
435 // ============================================================================
436 //------------------------------CompileWrapper---------------------------------
437 class CompileWrapper : public StackObj {
438 Compile *const _compile;
439 public:
440 CompileWrapper(Compile* compile);
441
442 ~CompileWrapper();
443 };
444
445 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
446 // the Compile* pointer is stored in the current ciEnv:
447 ciEnv* env = compile->env();
448 assert(env == ciEnv::current(), "must already be a ciEnv active");
449 assert(env->compiler_data() == NULL, "compile already active?");
450 env->set_compiler_data(compile);
451 assert(compile == Compile::current(), "sanity");
452
453 compile->set_type_dict(NULL);
454 compile->set_type_hwm(NULL);
455 compile->set_type_last_size(0);
456 compile->set_last_tf(NULL, NULL);
457 compile->set_indexSet_arena(NULL);
458 compile->set_indexSet_free_block_list(NULL);
459 compile->init_type_arena();
460 Type::Initialize(compile);
461 _compile->set_scratch_buffer_blob(NULL);
462 _compile->begin_method();
463 }
464 CompileWrapper::~CompileWrapper() {
465 _compile->end_method();
466 if (_compile->scratch_buffer_blob() != NULL)
467 BufferBlob::free(_compile->scratch_buffer_blob());
468 _compile->env()->set_compiler_data(NULL);
469 }
470
471
472 //----------------------------print_compile_messages---------------------------
473 void Compile::print_compile_messages() {
474 #ifndef PRODUCT
475 // Check if recompiling
476 if (_subsume_loads == false && PrintOpto) {
477 // Recompiling without allowing machine instructions to subsume loads
478 tty->print_cr("*********************************************************");
479 tty->print_cr("** Bailout: Recompile without subsuming loads **");
480 tty->print_cr("*********************************************************");
481 }
482 if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
483 // Recompiling without escape analysis
484 tty->print_cr("*********************************************************");
485 tty->print_cr("** Bailout: Recompile without escape analysis **");
486 tty->print_cr("*********************************************************");
487 }
488 if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
489 // Recompiling without boxing elimination
490 tty->print_cr("*********************************************************");
491 tty->print_cr("** Bailout: Recompile without boxing elimination **");
492 tty->print_cr("*********************************************************");
493 }
494 if (env()->break_at_compile()) {
495 // Open the debugger when compiling this method.
496 tty->print("### Breaking when compiling: ");
497 method()->print_short_name();
498 tty->cr();
499 BREAKPOINT;
500 }
501
502 if( PrintOpto ) {
503 if (is_osr_compilation()) {
504 tty->print("[OSR]%3d", _compile_id);
505 } else {
506 tty->print("%3d", _compile_id);
507 }
508 }
509 #endif
510 }
511
512
513 //-----------------------init_scratch_buffer_blob------------------------------
514 // Construct a temporary BufferBlob and cache it for this compile.
515 void Compile::init_scratch_buffer_blob(int const_size) {
516 // If there is already a scratch buffer blob allocated and the
517 // constant section is big enough, use it. Otherwise free the
518 // current and allocate a new one.
519 BufferBlob* blob = scratch_buffer_blob();
520 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
521 // Use the current blob.
522 } else {
523 if (blob != NULL) {
524 BufferBlob::free(blob);
525 }
526
527 ResourceMark rm;
528 _scratch_const_size = const_size;
529 int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
530 blob = BufferBlob::create("Compile::scratch_buffer", size);
531 // Record the buffer blob for next time.
532 set_scratch_buffer_blob(blob);
533 // Have we run out of code space?
534 if (scratch_buffer_blob() == NULL) {
535 // Let CompilerBroker disable further compilations.
536 record_failure("Not enough space for scratch buffer in CodeCache");
537 return;
538 }
539 }
540
541 // Initialize the relocation buffers
542 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
543 set_scratch_locs_memory(locs_buf);
544 }
545
546
547 //-----------------------scratch_emit_size-------------------------------------
548 // Helper function that computes size by emitting code
549 uint Compile::scratch_emit_size(const Node* n) {
550 // Start scratch_emit_size section.
551 set_in_scratch_emit_size(true);
552
553 // Emit into a trash buffer and count bytes emitted.
554 // This is a pretty expensive way to compute a size,
555 // but it works well enough if seldom used.
556 // All common fixed-size instructions are given a size
557 // method by the AD file.
558 // Note that the scratch buffer blob and locs memory are
559 // allocated at the beginning of the compile task, and
560 // may be shared by several calls to scratch_emit_size.
561 // The allocation of the scratch buffer blob is particularly
562 // expensive, since it has to grab the code cache lock.
563 BufferBlob* blob = this->scratch_buffer_blob();
564 assert(blob != NULL, "Initialize BufferBlob at start");
565 assert(blob->size() > MAX_inst_size, "sanity");
566 relocInfo* locs_buf = scratch_locs_memory();
567 address blob_begin = blob->content_begin();
568 address blob_end = (address)locs_buf;
569 assert(blob->content_contains(blob_end), "sanity");
570 CodeBuffer buf(blob_begin, blob_end - blob_begin);
571 buf.initialize_consts_size(_scratch_const_size);
572 buf.initialize_stubs_size(MAX_stubs_size);
573 assert(locs_buf != NULL, "sanity");
574 int lsize = MAX_locs_size / 3;
575 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
576 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
577 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
578
579 // Do the emission.
580
581 Label fakeL; // Fake label for branch instructions.
582 Label* saveL = NULL;
583 uint save_bnum = 0;
584 bool is_branch = n->is_MachBranch();
585 if (is_branch) {
586 MacroAssembler masm(&buf);
587 masm.bind(fakeL);
588 n->as_MachBranch()->save_label(&saveL, &save_bnum);
589 n->as_MachBranch()->label_set(&fakeL, 0);
590 }
591 n->emit(buf, this->regalloc());
592 if (is_branch) // Restore label.
593 n->as_MachBranch()->label_set(saveL, save_bnum);
594
595 // End scratch_emit_size section.
596 set_in_scratch_emit_size(false);
597
598 return buf.insts_size();
599 }
600
601
602 // ============================================================================
603 //------------------------------Compile standard-------------------------------
604 debug_only( int Compile::_debug_idx = 100000; )
605
606 // Compile a method. entry_bci is -1 for normal compilations and indicates
607 // the continuation bci for on stack replacement.
608
609
610 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
611 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
612 : Phase(Compiler),
613 _env(ci_env),
614 _log(ci_env->log()),
615 _compile_id(ci_env->compile_id()),
616 _save_argument_registers(false),
617 _stub_name(NULL),
618 _stub_function(NULL),
619 _stub_entry_point(NULL),
620 _method(target),
621 _entry_bci(osr_bci),
622 _initial_gvn(NULL),
623 _for_igvn(NULL),
624 _warm_calls(NULL),
625 _subsume_loads(subsume_loads),
626 _do_escape_analysis(do_escape_analysis),
627 _eliminate_boxing(eliminate_boxing),
628 _failure_reason(NULL),
629 _code_buffer("Compile::Fill_buffer"),
630 _orig_pc_slot(0),
631 _orig_pc_slot_offset_in_bytes(0),
632 _has_method_handle_invokes(false),
633 _mach_constant_base_node(NULL),
634 _node_bundling_limit(0),
635 _node_bundling_base(NULL),
636 _java_calls(0),
637 _inner_loops(0),
638 _scratch_const_size(-1),
639 _in_scratch_emit_size(false),
640 _dead_node_list(comp_arena()),
641 _dead_node_count(0),
642 #ifndef PRODUCT
643 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
644 _in_dump_cnt(0),
645 _printer(IdealGraphPrinter::printer()),
646 #endif
647 _congraph(NULL),
648 _comp_arena(mtCompiler),
649 _node_arena(mtCompiler),
650 _old_arena(mtCompiler),
651 _Compile_types(mtCompiler),
652 _replay_inline_data(NULL),
653 _late_inlines(comp_arena(), 2, 0, NULL),
654 _string_late_inlines(comp_arena(), 2, 0, NULL),
655 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
656 _late_inlines_pos(0),
657 _number_of_mh_late_inlines(0),
658 _inlining_progress(false),
659 _inlining_incrementally(false),
660 _print_inlining_list(NULL),
661 _print_inlining_stream(NULL),
662 _print_inlining_idx(0),
663 _print_inlining_output(NULL),
664 _interpreter_frame_size(0) {
665 C = this;
666
667 CompileWrapper cw(this);
668
669 if (CITimeVerbose) {
670 tty->print(" ");
671 target->holder()->name()->print();
672 tty->print(".");
673 target->print_short_name();
674 tty->print(" ");
675 }
676 TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
677 TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
678
679 #ifndef PRODUCT
680 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
681 if (!print_opto_assembly) {
682 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
683 if (print_assembly && !Disassembler::can_decode()) {
684 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
685 print_opto_assembly = true;
686 }
687 }
688 set_print_assembly(print_opto_assembly);
689 set_parsed_irreducible_loop(false);
690
691 if (method()->has_option("ReplayInline")) {
692 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
693 }
694 #endif
695 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
696 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
697 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
698
699 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
700 // Make sure the method being compiled gets its own MDO,
701 // so we can at least track the decompile_count().
702 // Need MDO to record RTM code generation state.
703 method()->ensure_method_data();
704 }
705
706 Init(::AliasLevel);
707
708
709 print_compile_messages();
710
711 _ilt = InlineTree::build_inline_tree_root();
712
713 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
714 assert(num_alias_types() >= AliasIdxRaw, "");
715
716 #define MINIMUM_NODE_HASH 1023
717 // Node list that Iterative GVN will start with
718 Unique_Node_List for_igvn(comp_arena());
719 set_for_igvn(&for_igvn);
720
721 // GVN that will be run immediately on new nodes
722 uint estimated_size = method()->code_size()*4+64;
723 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
724 PhaseGVN gvn(node_arena(), estimated_size);
725 set_initial_gvn(&gvn);
726
727 print_inlining_init();
728 { // Scope for timing the parser
729 TracePhase tp("parse", &timers[_t_parser]);
730
731 // Put top into the hash table ASAP.
732 initial_gvn()->transform_no_reclaim(top());
733
734 // Set up tf(), start(), and find a CallGenerator.
735 CallGenerator* cg = NULL;
736 if (is_osr_compilation()) {
737 const TypeTuple *domain = StartOSRNode::osr_domain();
738 const TypeTuple *range = TypeTuple::make_range(method()->signature());
739 init_tf(TypeFunc::make(domain, range));
740 StartNode* s = new StartOSRNode(root(), domain);
741 initial_gvn()->set_type_bottom(s);
742 init_start(s);
743 cg = CallGenerator::for_osr(method(), entry_bci());
744 } else {
745 // Normal case.
746 init_tf(TypeFunc::make(method()));
747 StartNode* s = new StartNode(root(), tf()->domain());
748 initial_gvn()->set_type_bottom(s);
749 init_start(s);
750 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
751 // With java.lang.ref.reference.get() we must go through the
752 // intrinsic when G1 is enabled - even when get() is the root
753 // method of the compile - so that, if necessary, the value in
754 // the referent field of the reference object gets recorded by
755 // the pre-barrier code.
756 // Specifically, if G1 is enabled, the value in the referent
757 // field is recorded by the G1 SATB pre barrier. This will
758 // result in the referent being marked live and the reference
759 // object removed from the list of discovered references during
760 // reference processing.
761 cg = find_intrinsic(method(), false);
762 }
763 if (cg == NULL) {
764 float past_uses = method()->interpreter_invocation_count();
765 float expected_uses = past_uses;
766 cg = CallGenerator::for_inline(method(), expected_uses);
767 }
768 }
769 if (failing()) return;
770 if (cg == NULL) {
771 record_method_not_compilable_all_tiers("cannot parse method");
772 return;
773 }
774 JVMState* jvms = build_start_state(start(), tf());
775 if ((jvms = cg->generate(jvms)) == NULL) {
776 record_method_not_compilable("method parse failed");
777 return;
778 }
779 GraphKit kit(jvms);
780
781 if (!kit.stopped()) {
782 // Accept return values, and transfer control we know not where.
783 // This is done by a special, unique ReturnNode bound to root.
784 return_values(kit.jvms());
785 }
786
787 if (kit.has_exceptions()) {
788 // Any exceptions that escape from this call must be rethrown
789 // to whatever caller is dynamically above us on the stack.
790 // This is done by a special, unique RethrowNode bound to root.
791 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
792 }
793
794 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
795
796 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
797 inline_string_calls(true);
798 }
799
800 if (failing()) return;
801
802 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
803
804 // Remove clutter produced by parsing.
805 if (!failing()) {
806 ResourceMark rm;
807 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
808 }
809 }
810
811 // Note: Large methods are capped off in do_one_bytecode().
812 if (failing()) return;
813
814 // After parsing, node notes are no longer automagic.
815 // They must be propagated by register_new_node_with_optimizer(),
816 // clone(), or the like.
817 set_default_node_notes(NULL);
818
819 for (;;) {
820 int successes = Inline_Warm();
821 if (failing()) return;
822 if (successes == 0) break;
823 }
824
825 // Drain the list.
826 Finish_Warm();
827 #ifndef PRODUCT
828 if (_printer && _printer->should_print(_method)) {
829 _printer->print_inlining(this);
830 }
831 #endif
832
833 if (failing()) return;
834 NOT_PRODUCT( verify_graph_edges(); )
835
836 // Now optimize
837 Optimize();
838 if (failing()) return;
839 NOT_PRODUCT( verify_graph_edges(); )
840
841 #ifndef PRODUCT
842 if (PrintIdeal) {
843 ttyLocker ttyl; // keep the following output all in one block
844 // This output goes directly to the tty, not the compiler log.
845 // To enable tools to match it up with the compilation activity,
846 // be sure to tag this tty output with the compile ID.
847 if (xtty != NULL) {
848 xtty->head("ideal compile_id='%d'%s", compile_id(),
849 is_osr_compilation() ? " compile_kind='osr'" :
850 "");
851 }
852 root()->dump(9999);
853 if (xtty != NULL) {
854 xtty->tail("ideal");
855 }
856 }
857 #endif
858
859 NOT_PRODUCT( verify_barriers(); )
860
861 // Dump compilation data to replay it.
862 if (method()->has_option("DumpReplay")) {
863 env()->dump_replay_data(_compile_id);
864 }
865 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
866 env()->dump_inline_data(_compile_id);
867 }
868
869 // Now that we know the size of all the monitors we can add a fixed slot
870 // for the original deopt pc.
871
872 _orig_pc_slot = fixed_slots();
873 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
874 set_fixed_slots(next_slot);
875
876 // Compute when to use implicit null checks. Used by matching trap based
877 // nodes and NullCheck optimization.
878 set_allowed_deopt_reasons();
879
880 // Now generate code
881 Code_Gen();
882 if (failing()) return;
883
884 // Check if we want to skip execution of all compiled code.
885 {
886 #ifndef PRODUCT
887 if (OptoNoExecute) {
888 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
889 return;
890 }
891 #endif
892 TracePhase tp("install_code", &timers[_t_registerMethod]);
893
894 if (is_osr_compilation()) {
895 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
896 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
897 } else {
898 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
899 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
900 }
901
902 env()->register_method(_method, _entry_bci,
903 &_code_offsets,
904 _orig_pc_slot_offset_in_bytes,
905 code_buffer(),
906 frame_size_in_words(), _oop_map_set,
907 &_handler_table, &_inc_table,
908 compiler,
909 env()->comp_level(),
910 has_unsafe_access(),
911 SharedRuntime::is_wide_vector(max_vector_size()),
912 rtm_state()
913 );
914
915 if (log() != NULL) // Print code cache state into compiler log
916 log()->code_cache_state();
917 }
918 }
919
920 //------------------------------Compile----------------------------------------
921 // Compile a runtime stub
922 Compile::Compile( ciEnv* ci_env,
923 TypeFunc_generator generator,
924 address stub_function,
925 const char *stub_name,
926 int is_fancy_jump,
927 bool pass_tls,
928 bool save_arg_registers,
929 bool return_pc )
930 : Phase(Compiler),
931 _env(ci_env),
932 _log(ci_env->log()),
933 _compile_id(0),
934 _save_argument_registers(save_arg_registers),
935 _method(NULL),
936 _stub_name(stub_name),
937 _stub_function(stub_function),
938 _stub_entry_point(NULL),
939 _entry_bci(InvocationEntryBci),
940 _initial_gvn(NULL),
941 _for_igvn(NULL),
942 _warm_calls(NULL),
943 _orig_pc_slot(0),
944 _orig_pc_slot_offset_in_bytes(0),
945 _subsume_loads(true),
946 _do_escape_analysis(false),
947 _eliminate_boxing(false),
948 _failure_reason(NULL),
949 _code_buffer("Compile::Fill_buffer"),
950 _has_method_handle_invokes(false),
951 _mach_constant_base_node(NULL),
952 _node_bundling_limit(0),
953 _node_bundling_base(NULL),
954 _java_calls(0),
955 _inner_loops(0),
956 #ifndef PRODUCT
957 _trace_opto_output(TraceOptoOutput),
958 _in_dump_cnt(0),
959 _printer(NULL),
960 #endif
961 _comp_arena(mtCompiler),
962 _node_arena(mtCompiler),
963 _old_arena(mtCompiler),
964 _Compile_types(mtCompiler),
965 _dead_node_list(comp_arena()),
966 _dead_node_count(0),
967 _congraph(NULL),
968 _replay_inline_data(NULL),
969 _number_of_mh_late_inlines(0),
970 _inlining_progress(false),
971 _inlining_incrementally(false),
972 _print_inlining_list(NULL),
973 _print_inlining_stream(NULL),
974 _print_inlining_idx(0),
975 _print_inlining_output(NULL),
976 _allowed_reasons(0),
977 _interpreter_frame_size(0) {
978 C = this;
979
980 TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
981 TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
982
983 #ifndef PRODUCT
984 set_print_assembly(PrintFrameConverterAssembly);
985 set_parsed_irreducible_loop(false);
986 #endif
987 set_has_irreducible_loop(false); // no loops
988
989 CompileWrapper cw(this);
990 Init(/*AliasLevel=*/ 0);
991 init_tf((*generator)());
992
993 {
994 // The following is a dummy for the sake of GraphKit::gen_stub
995 Unique_Node_List for_igvn(comp_arena());
996 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
997 PhaseGVN gvn(Thread::current()->resource_area(),255);
998 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
999 gvn.transform_no_reclaim(top());
1000
1001 GraphKit kit;
1002 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1003 }
1004
1005 NOT_PRODUCT( verify_graph_edges(); )
1006 Code_Gen();
1007 if (failing()) return;
1008
1009
1010 // Entry point will be accessed using compile->stub_entry_point();
1011 if (code_buffer() == NULL) {
1012 Matcher::soft_match_failure();
1013 } else {
1014 if (PrintAssembly && (WizardMode || Verbose))
1015 tty->print_cr("### Stub::%s", stub_name);
1016
1017 if (!failing()) {
1018 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1019
1020 // Make the NMethod
1021 // For now we mark the frame as never safe for profile stackwalking
1022 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1023 code_buffer(),
1024 CodeOffsets::frame_never_safe,
1025 // _code_offsets.value(CodeOffsets::Frame_Complete),
1026 frame_size_in_words(),
1027 _oop_map_set,
1028 save_arg_registers);
1029 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1030
1031 _stub_entry_point = rs->entry_point();
1032 }
1033 }
1034 }
1035
1036 //------------------------------Init-------------------------------------------
1037 // Prepare for a single compilation
1038 void Compile::Init(int aliaslevel) {
1039 _unique = 0;
1040 _regalloc = NULL;
1041
1042 _tf = NULL; // filled in later
1043 _top = NULL; // cached later
1044 _matcher = NULL; // filled in later
1045 _cfg = NULL; // filled in later
1046
1047 set_24_bit_selection_and_mode(Use24BitFP, false);
1048
1049 _node_note_array = NULL;
1050 _default_node_notes = NULL;
1051 DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
1052
1053 _immutable_memory = NULL; // filled in at first inquiry
1054
1055 // Globally visible Nodes
1056 // First set TOP to NULL to give safe behavior during creation of RootNode
1057 set_cached_top_node(NULL);
1058 set_root(new RootNode());
1059 // Now that you have a Root to point to, create the real TOP
1060 set_cached_top_node( new ConNode(Type::TOP) );
1061 set_recent_alloc(NULL, NULL);
1062
1063 // Create Debug Information Recorder to record scopes, oopmaps, etc.
1064 env()->set_oop_recorder(new OopRecorder(env()->arena()));
1065 env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1066 env()->set_dependencies(new Dependencies(env()));
1067
1068 _fixed_slots = 0;
1069 set_has_split_ifs(false);
1070 set_has_loops(has_method() && method()->has_loops()); // first approximation
1071 set_has_stringbuilder(false);
1072 set_has_boxed_value(false);
1073 _trap_can_recompile = false; // no traps emitted yet
1074 _major_progress = true; // start out assuming good things will happen
1075 set_has_unsafe_access(false);
1076 set_max_vector_size(0);
1077 Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1078 set_decompile_count(0);
1079
1080 set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1081 set_num_loop_opts(LoopOptsCount);
1082 set_do_inlining(Inline);
1083 set_max_inline_size(MaxInlineSize);
1084 set_freq_inline_size(FreqInlineSize);
1085 set_do_scheduling(OptoScheduling);
1086 set_do_count_invocations(false);
1087 set_do_method_data_update(false);
1088 set_age_code(has_method() && method()->profile_aging());
1089 set_rtm_state(NoRTM); // No RTM lock eliding by default
1090 #if INCLUDE_RTM_OPT
1091 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1092 int rtm_state = method()->method_data()->rtm_state();
1093 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1094 // Don't generate RTM lock eliding code.
1095 set_rtm_state(NoRTM);
1096 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1097 // Generate RTM lock eliding code without abort ratio calculation code.
1098 set_rtm_state(UseRTM);
1099 } else if (UseRTMDeopt) {
1100 // Generate RTM lock eliding code and include abort ratio calculation
1101 // code if UseRTMDeopt is on.
1102 set_rtm_state(ProfileRTM);
1103 }
1104 }
1105 #endif
1106 if (debug_info()->recording_non_safepoints()) {
1107 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1108 (comp_arena(), 8, 0, NULL));
1109 set_default_node_notes(Node_Notes::make(this));
1110 }
1111
1112 // // -- Initialize types before each compile --
1113 // // Update cached type information
1114 // if( _method && _method->constants() )
1115 // Type::update_loaded_types(_method, _method->constants());
1116
1117 // Init alias_type map.
1118 if (!_do_escape_analysis && aliaslevel == 3)
1119 aliaslevel = 2; // No unique types without escape analysis
1120 _AliasLevel = aliaslevel;
1121 const int grow_ats = 16;
1122 _max_alias_types = grow_ats;
1123 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1124 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1125 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1126 {
1127 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1128 }
1129 // Initialize the first few types.
1130 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1131 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1132 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1133 _num_alias_types = AliasIdxRaw+1;
1134 // Zero out the alias type cache.
1135 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1136 // A NULL adr_type hits in the cache right away. Preload the right answer.
1137 probe_alias_cache(NULL)->_index = AliasIdxTop;
1138
1139 _intrinsics = NULL;
1140 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1141 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1142 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1143 register_library_intrinsics();
1144 }
1145
1146 //---------------------------init_start----------------------------------------
1147 // Install the StartNode on this compile object.
1148 void Compile::init_start(StartNode* s) {
1149 if (failing())
1150 return; // already failing
1151 assert(s == start(), "");
1152 }
1153
1154 /**
1155 * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1156 * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1157 * the ideal graph.
1158 */
1159 StartNode* Compile::start() const {
1160 assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
1161 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1162 Node* start = root()->fast_out(i);
1163 if (start->is_Start()) {
1164 return start->as_Start();
1165 }
1166 }
1167 fatal("Did not find Start node!");
1168 return NULL;
1169 }
1170
1171 //-------------------------------immutable_memory-------------------------------------
1172 // Access immutable memory
1173 Node* Compile::immutable_memory() {
1174 if (_immutable_memory != NULL) {
1175 return _immutable_memory;
1176 }
1177 StartNode* s = start();
1178 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1179 Node *p = s->fast_out(i);
1180 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1181 _immutable_memory = p;
1182 return _immutable_memory;
1183 }
1184 }
1185 ShouldNotReachHere();
1186 return NULL;
1187 }
1188
1189 //----------------------set_cached_top_node------------------------------------
1190 // Install the cached top node, and make sure Node::is_top works correctly.
1191 void Compile::set_cached_top_node(Node* tn) {
1192 if (tn != NULL) verify_top(tn);
1193 Node* old_top = _top;
1194 _top = tn;
1195 // Calling Node::setup_is_top allows the nodes the chance to adjust
1196 // their _out arrays.
1197 if (_top != NULL) _top->setup_is_top();
1198 if (old_top != NULL) old_top->setup_is_top();
1199 assert(_top == NULL || top()->is_top(), "");
1200 }
1201
1202 #ifdef ASSERT
1203 uint Compile::count_live_nodes_by_graph_walk() {
1204 Unique_Node_List useful(comp_arena());
1205 // Get useful node list by walking the graph.
1206 identify_useful_nodes(useful);
1207 return useful.size();
1208 }
1209
1210 void Compile::print_missing_nodes() {
1211
1212 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1213 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1214 return;
1215 }
1216
1217 // This is an expensive function. It is executed only when the user
1218 // specifies VerifyIdealNodeCount option or otherwise knows the
1219 // additional work that needs to be done to identify reachable nodes
1220 // by walking the flow graph and find the missing ones using
1221 // _dead_node_list.
1222
1223 Unique_Node_List useful(comp_arena());
1224 // Get useful node list by walking the graph.
1225 identify_useful_nodes(useful);
1226
1227 uint l_nodes = C->live_nodes();
1228 uint l_nodes_by_walk = useful.size();
1229
1230 if (l_nodes != l_nodes_by_walk) {
1231 if (_log != NULL) {
1232 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1233 _log->stamp();
1234 _log->end_head();
1235 }
1236 VectorSet& useful_member_set = useful.member_set();
1237 int last_idx = l_nodes_by_walk;
1238 for (int i = 0; i < last_idx; i++) {
1239 if (useful_member_set.test(i)) {
1240 if (_dead_node_list.test(i)) {
1241 if (_log != NULL) {
1242 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1243 }
1244 if (PrintIdealNodeCount) {
1245 // Print the log message to tty
1246 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1247 useful.at(i)->dump();
1248 }
1249 }
1250 }
1251 else if (! _dead_node_list.test(i)) {
1252 if (_log != NULL) {
1253 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1254 }
1255 if (PrintIdealNodeCount) {
1256 // Print the log message to tty
1257 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1258 }
1259 }
1260 }
1261 if (_log != NULL) {
1262 _log->tail("mismatched_nodes");
1263 }
1264 }
1265 }
1266 void Compile::record_modified_node(Node* n) {
1267 if (_modified_nodes != NULL && !_inlining_incrementally &&
1268 n->outcnt() != 0 && !n->is_Con()) {
1269 _modified_nodes->push(n);
1270 }
1271 }
1272
1273 void Compile::remove_modified_node(Node* n) {
1274 if (_modified_nodes != NULL) {
1275 _modified_nodes->remove(n);
1276 }
1277 }
1278 #endif
1279
1280 #ifndef PRODUCT
1281 void Compile::verify_top(Node* tn) const {
1282 if (tn != NULL) {
1283 assert(tn->is_Con(), "top node must be a constant");
1284 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1285 assert(tn->in(0) != NULL, "must have live top node");
1286 }
1287 }
1288 #endif
1289
1290
1291 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1292
1293 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1294 guarantee(arr != NULL, "");
1295 int num_blocks = arr->length();
1296 if (grow_by < num_blocks) grow_by = num_blocks;
1297 int num_notes = grow_by * _node_notes_block_size;
1298 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1299 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1300 while (num_notes > 0) {
1301 arr->append(notes);
1302 notes += _node_notes_block_size;
1303 num_notes -= _node_notes_block_size;
1304 }
1305 assert(num_notes == 0, "exact multiple, please");
1306 }
1307
1308 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1309 if (source == NULL || dest == NULL) return false;
1310
1311 if (dest->is_Con())
1312 return false; // Do not push debug info onto constants.
1313
1314 #ifdef ASSERT
1315 // Leave a bread crumb trail pointing to the original node:
1316 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1317 dest->set_debug_orig(source);
1318 }
1319 #endif
1320
1321 if (node_note_array() == NULL)
1322 return false; // Not collecting any notes now.
1323
1324 // This is a copy onto a pre-existing node, which may already have notes.
1325 // If both nodes have notes, do not overwrite any pre-existing notes.
1326 Node_Notes* source_notes = node_notes_at(source->_idx);
1327 if (source_notes == NULL || source_notes->is_clear()) return false;
1328 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1329 if (dest_notes == NULL || dest_notes->is_clear()) {
1330 return set_node_notes_at(dest->_idx, source_notes);
1331 }
1332
1333 Node_Notes merged_notes = (*source_notes);
1334 // The order of operations here ensures that dest notes will win...
1335 merged_notes.update_from(dest_notes);
1336 return set_node_notes_at(dest->_idx, &merged_notes);
1337 }
1338
1339
1340 //--------------------------allow_range_check_smearing-------------------------
1341 // Gating condition for coalescing similar range checks.
1342 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1343 // single covering check that is at least as strong as any of them.
1344 // If the optimization succeeds, the simplified (strengthened) range check
1345 // will always succeed. If it fails, we will deopt, and then give up
1346 // on the optimization.
1347 bool Compile::allow_range_check_smearing() const {
1348 // If this method has already thrown a range-check,
1349 // assume it was because we already tried range smearing
1350 // and it failed.
1351 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1352 return !already_trapped;
1353 }
1354
1355
1356 //------------------------------flatten_alias_type-----------------------------
1357 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1358 int offset = tj->offset();
1359 TypePtr::PTR ptr = tj->ptr();
1360
1361 // Known instance (scalarizable allocation) alias only with itself.
1362 bool is_known_inst = tj->isa_oopptr() != NULL &&
1363 tj->is_oopptr()->is_known_instance();
1364
1365 // Process weird unsafe references.
1366 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1367 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1368 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1369 tj = TypeOopPtr::BOTTOM;
1370 ptr = tj->ptr();
1371 offset = tj->offset();
1372 }
1373
1374 // Array pointers need some flattening
1375 const TypeAryPtr *ta = tj->isa_aryptr();
1376 if (ta && ta->is_stable()) {
1377 // Erase stability property for alias analysis.
1378 tj = ta = ta->cast_to_stable(false);
1379 }
1380 if( ta && is_known_inst ) {
1381 if ( offset != Type::OffsetBot &&
1382 offset > arrayOopDesc::length_offset_in_bytes() ) {
1383 offset = Type::OffsetBot; // Flatten constant access into array body only
1384 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1385 }
1386 } else if( ta && _AliasLevel >= 2 ) {
1387 // For arrays indexed by constant indices, we flatten the alias
1388 // space to include all of the array body. Only the header, klass
1389 // and array length can be accessed un-aliased.
1390 if( offset != Type::OffsetBot ) {
1391 if( ta->const_oop() ) { // MethodData* or Method*
1392 offset = Type::OffsetBot; // Flatten constant access into array body
1393 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1394 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1395 // range is OK as-is.
1396 tj = ta = TypeAryPtr::RANGE;
1397 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1398 tj = TypeInstPtr::KLASS; // all klass loads look alike
1399 ta = TypeAryPtr::RANGE; // generic ignored junk
1400 ptr = TypePtr::BotPTR;
1401 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1402 tj = TypeInstPtr::MARK;
1403 ta = TypeAryPtr::RANGE; // generic ignored junk
1404 ptr = TypePtr::BotPTR;
1405 } else { // Random constant offset into array body
1406 offset = Type::OffsetBot; // Flatten constant access into array body
1407 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1408 }
1409 }
1410 // Arrays of fixed size alias with arrays of unknown size.
1411 if (ta->size() != TypeInt::POS) {
1412 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1413 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1414 }
1415 // Arrays of known objects become arrays of unknown objects.
1416 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1417 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1418 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1419 }
1420 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1421 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1422 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1423 }
1424 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1425 // cannot be distinguished by bytecode alone.
1426 if (ta->elem() == TypeInt::BOOL) {
1427 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1428 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1429 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1430 }
1431 // During the 2nd round of IterGVN, NotNull castings are removed.
1432 // Make sure the Bottom and NotNull variants alias the same.
1433 // Also, make sure exact and non-exact variants alias the same.
1434 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1435 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1436 }
1437 }
1438
1439 // Oop pointers need some flattening
1440 const TypeInstPtr *to = tj->isa_instptr();
1441 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1442 ciInstanceKlass *k = to->klass()->as_instance_klass();
1443 if( ptr == TypePtr::Constant ) {
1444 if (to->klass() != ciEnv::current()->Class_klass() ||
1445 offset < k->size_helper() * wordSize) {
1446 // No constant oop pointers (such as Strings); they alias with
1447 // unknown strings.
1448 assert(!is_known_inst, "not scalarizable allocation");
1449 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1450 }
1451 } else if( is_known_inst ) {
1452 tj = to; // Keep NotNull and klass_is_exact for instance type
1453 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1454 // During the 2nd round of IterGVN, NotNull castings are removed.
1455 // Make sure the Bottom and NotNull variants alias the same.
1456 // Also, make sure exact and non-exact variants alias the same.
1457 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1458 }
1459 if (to->speculative() != NULL) {
1460 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1461 }
1462 // Canonicalize the holder of this field
1463 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1464 // First handle header references such as a LoadKlassNode, even if the
1465 // object's klass is unloaded at compile time (4965979).
1466 if (!is_known_inst) { // Do it only for non-instance types
1467 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1468 }
1469 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1470 // Static fields are in the space above the normal instance
1471 // fields in the java.lang.Class instance.
1472 if (to->klass() != ciEnv::current()->Class_klass()) {
1473 to = NULL;
1474 tj = TypeOopPtr::BOTTOM;
1475 offset = tj->offset();
1476 }
1477 } else {
1478 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1479 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1480 if( is_known_inst ) {
1481 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1482 } else {
1483 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1484 }
1485 }
1486 }
1487 }
1488
1489 // Klass pointers to object array klasses need some flattening
1490 const TypeKlassPtr *tk = tj->isa_klassptr();
1491 if( tk ) {
1492 // If we are referencing a field within a Klass, we need
1493 // to assume the worst case of an Object. Both exact and
1494 // inexact types must flatten to the same alias class so
1495 // use NotNull as the PTR.
1496 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1497
1498 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1499 TypeKlassPtr::OBJECT->klass(),
1500 offset);
1501 }
1502
1503 ciKlass* klass = tk->klass();
1504 if( klass->is_obj_array_klass() ) {
1505 ciKlass* k = TypeAryPtr::OOPS->klass();
1506 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1507 k = TypeInstPtr::BOTTOM->klass();
1508 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1509 }
1510
1511 // Check for precise loads from the primary supertype array and force them
1512 // to the supertype cache alias index. Check for generic array loads from
1513 // the primary supertype array and also force them to the supertype cache
1514 // alias index. Since the same load can reach both, we need to merge
1515 // these 2 disparate memories into the same alias class. Since the
1516 // primary supertype array is read-only, there's no chance of confusion
1517 // where we bypass an array load and an array store.
1518 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1519 if (offset == Type::OffsetBot ||
1520 (offset >= primary_supers_offset &&
1521 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1522 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1523 offset = in_bytes(Klass::secondary_super_cache_offset());
1524 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1525 }
1526 }
1527
1528 // Flatten all Raw pointers together.
1529 if (tj->base() == Type::RawPtr)
1530 tj = TypeRawPtr::BOTTOM;
1531
1532 if (tj->base() == Type::AnyPtr)
1533 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1534
1535 // Flatten all to bottom for now
1536 switch( _AliasLevel ) {
1537 case 0:
1538 tj = TypePtr::BOTTOM;
1539 break;
1540 case 1: // Flatten to: oop, static, field or array
1541 switch (tj->base()) {
1542 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1543 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1544 case Type::AryPtr: // do not distinguish arrays at all
1545 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1546 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1547 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1548 default: ShouldNotReachHere();
1549 }
1550 break;
1551 case 2: // No collapsing at level 2; keep all splits
1552 case 3: // No collapsing at level 3; keep all splits
1553 break;
1554 default:
1555 Unimplemented();
1556 }
1557
1558 offset = tj->offset();
1559 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1560
1561 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1562 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1563 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1564 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1565 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1566 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1567 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1568 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1569 assert( tj->ptr() != TypePtr::TopPTR &&
1570 tj->ptr() != TypePtr::AnyNull &&
1571 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1572 // assert( tj->ptr() != TypePtr::Constant ||
1573 // tj->base() == Type::RawPtr ||
1574 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1575
1576 return tj;
1577 }
1578
1579 void Compile::AliasType::Init(int i, const TypePtr* at) {
1580 _index = i;
1581 _adr_type = at;
1582 _field = NULL;
1583 _element = NULL;
1584 _is_rewritable = true; // default
1585 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1586 if (atoop != NULL && atoop->is_known_instance()) {
1587 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1588 _general_index = Compile::current()->get_alias_index(gt);
1589 } else {
1590 _general_index = 0;
1591 }
1592 }
1593
1594 //---------------------------------print_on------------------------------------
1595 #ifndef PRODUCT
1596 void Compile::AliasType::print_on(outputStream* st) {
1597 if (index() < 10)
1598 st->print("@ <%d> ", index());
1599 else st->print("@ <%d>", index());
1600 st->print(is_rewritable() ? " " : " RO");
1601 int offset = adr_type()->offset();
1602 if (offset == Type::OffsetBot)
1603 st->print(" +any");
1604 else st->print(" +%-3d", offset);
1605 st->print(" in ");
1606 adr_type()->dump_on(st);
1607 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1608 if (field() != NULL && tjp) {
1609 if (tjp->klass() != field()->holder() ||
1610 tjp->offset() != field()->offset_in_bytes()) {
1611 st->print(" != ");
1612 field()->print();
1613 st->print(" ***");
1614 }
1615 }
1616 }
1617
1618 void print_alias_types() {
1619 Compile* C = Compile::current();
1620 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1621 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1622 C->alias_type(idx)->print_on(tty);
1623 tty->cr();
1624 }
1625 }
1626 #endif
1627
1628
1629 //----------------------------probe_alias_cache--------------------------------
1630 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1631 intptr_t key = (intptr_t) adr_type;
1632 key ^= key >> logAliasCacheSize;
1633 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1634 }
1635
1636
1637 //-----------------------------grow_alias_types--------------------------------
1638 void Compile::grow_alias_types() {
1639 const int old_ats = _max_alias_types; // how many before?
1640 const int new_ats = old_ats; // how many more?
1641 const int grow_ats = old_ats+new_ats; // how many now?
1642 _max_alias_types = grow_ats;
1643 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1644 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1645 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1646 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1647 }
1648
1649
1650 //--------------------------------find_alias_type------------------------------
1651 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1652 if (_AliasLevel == 0)
1653 return alias_type(AliasIdxBot);
1654
1655 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1656 if (ace->_adr_type == adr_type) {
1657 return alias_type(ace->_index);
1658 }
1659
1660 // Handle special cases.
1661 if (adr_type == NULL) return alias_type(AliasIdxTop);
1662 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1663
1664 // Do it the slow way.
1665 const TypePtr* flat = flatten_alias_type(adr_type);
1666
1667 #ifdef ASSERT
1668 assert(flat == flatten_alias_type(flat), "idempotent");
1669 assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr");
1670 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1671 const TypeOopPtr* foop = flat->is_oopptr();
1672 // Scalarizable allocations have exact klass always.
1673 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1674 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1675 assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
1676 }
1677 assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
1678 #endif
1679
1680 int idx = AliasIdxTop;
1681 for (int i = 0; i < num_alias_types(); i++) {
1682 if (alias_type(i)->adr_type() == flat) {
1683 idx = i;
1684 break;
1685 }
1686 }
1687
1688 if (idx == AliasIdxTop) {
1689 if (no_create) return NULL;
1690 // Grow the array if necessary.
1691 if (_num_alias_types == _max_alias_types) grow_alias_types();
1692 // Add a new alias type.
1693 idx = _num_alias_types++;
1694 _alias_types[idx]->Init(idx, flat);
1695 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1696 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1697 if (flat->isa_instptr()) {
1698 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1699 && flat->is_instptr()->klass() == env()->Class_klass())
1700 alias_type(idx)->set_rewritable(false);
1701 }
1702 if (flat->isa_aryptr()) {
1703 #ifdef ASSERT
1704 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1705 // (T_BYTE has the weakest alignment and size restrictions...)
1706 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1707 #endif
1708 if (flat->offset() == TypePtr::OffsetBot) {
1709 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1710 }
1711 }
1712 if (flat->isa_klassptr()) {
1713 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1714 alias_type(idx)->set_rewritable(false);
1715 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1716 alias_type(idx)->set_rewritable(false);
1717 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1718 alias_type(idx)->set_rewritable(false);
1719 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1720 alias_type(idx)->set_rewritable(false);
1721 }
1722 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1723 // but the base pointer type is not distinctive enough to identify
1724 // references into JavaThread.)
1725
1726 // Check for final fields.
1727 const TypeInstPtr* tinst = flat->isa_instptr();
1728 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1729 ciField* field;
1730 if (tinst->const_oop() != NULL &&
1731 tinst->klass() == ciEnv::current()->Class_klass() &&
1732 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1733 // static field
1734 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1735 field = k->get_field_by_offset(tinst->offset(), true);
1736 } else {
1737 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1738 field = k->get_field_by_offset(tinst->offset(), false);
1739 }
1740 assert(field == NULL ||
1741 original_field == NULL ||
1742 (field->holder() == original_field->holder() &&
1743 field->offset() == original_field->offset() &&
1744 field->is_static() == original_field->is_static()), "wrong field?");
1745 // Set field() and is_rewritable() attributes.
1746 if (field != NULL) alias_type(idx)->set_field(field);
1747 }
1748 }
1749
1750 // Fill the cache for next time.
1751 ace->_adr_type = adr_type;
1752 ace->_index = idx;
1753 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1754
1755 // Might as well try to fill the cache for the flattened version, too.
1756 AliasCacheEntry* face = probe_alias_cache(flat);
1757 if (face->_adr_type == NULL) {
1758 face->_adr_type = flat;
1759 face->_index = idx;
1760 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1761 }
1762
1763 return alias_type(idx);
1764 }
1765
1766
1767 Compile::AliasType* Compile::alias_type(ciField* field) {
1768 const TypeOopPtr* t;
1769 if (field->is_static())
1770 t = TypeInstPtr::make(field->holder()->java_mirror());
1771 else
1772 t = TypeOopPtr::make_from_klass_raw(field->holder());
1773 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1774 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1775 return atp;
1776 }
1777
1778
1779 //------------------------------have_alias_type--------------------------------
1780 bool Compile::have_alias_type(const TypePtr* adr_type) {
1781 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1782 if (ace->_adr_type == adr_type) {
1783 return true;
1784 }
1785
1786 // Handle special cases.
1787 if (adr_type == NULL) return true;
1788 if (adr_type == TypePtr::BOTTOM) return true;
1789
1790 return find_alias_type(adr_type, true, NULL) != NULL;
1791 }
1792
1793 //-----------------------------must_alias--------------------------------------
1794 // True if all values of the given address type are in the given alias category.
1795 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1796 if (alias_idx == AliasIdxBot) return true; // the universal category
1797 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1798 if (alias_idx == AliasIdxTop) return false; // the empty category
1799 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1800
1801 // the only remaining possible overlap is identity
1802 int adr_idx = get_alias_index(adr_type);
1803 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1804 assert(adr_idx == alias_idx ||
1805 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1806 && adr_type != TypeOopPtr::BOTTOM),
1807 "should not be testing for overlap with an unsafe pointer");
1808 return adr_idx == alias_idx;
1809 }
1810
1811 //------------------------------can_alias--------------------------------------
1812 // True if any values of the given address type are in the given alias category.
1813 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1814 if (alias_idx == AliasIdxTop) return false; // the empty category
1815 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1816 if (alias_idx == AliasIdxBot) return true; // the universal category
1817 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1818
1819 // the only remaining possible overlap is identity
1820 int adr_idx = get_alias_index(adr_type);
1821 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1822 return adr_idx == alias_idx;
1823 }
1824
1825
1826
1827 //---------------------------pop_warm_call-------------------------------------
1828 WarmCallInfo* Compile::pop_warm_call() {
1829 WarmCallInfo* wci = _warm_calls;
1830 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1831 return wci;
1832 }
1833
1834 //----------------------------Inline_Warm--------------------------------------
1835 int Compile::Inline_Warm() {
1836 // If there is room, try to inline some more warm call sites.
1837 // %%% Do a graph index compaction pass when we think we're out of space?
1838 if (!InlineWarmCalls) return 0;
1839
1840 int calls_made_hot = 0;
1841 int room_to_grow = NodeCountInliningCutoff - unique();
1842 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1843 int amount_grown = 0;
1844 WarmCallInfo* call;
1845 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1846 int est_size = (int)call->size();
1847 if (est_size > (room_to_grow - amount_grown)) {
1848 // This one won't fit anyway. Get rid of it.
1849 call->make_cold();
1850 continue;
1851 }
1852 call->make_hot();
1853 calls_made_hot++;
1854 amount_grown += est_size;
1855 amount_to_grow -= est_size;
1856 }
1857
1858 if (calls_made_hot > 0) set_major_progress();
1859 return calls_made_hot;
1860 }
1861
1862
1863 //----------------------------Finish_Warm--------------------------------------
1864 void Compile::Finish_Warm() {
1865 if (!InlineWarmCalls) return;
1866 if (failing()) return;
1867 if (warm_calls() == NULL) return;
1868
1869 // Clean up loose ends, if we are out of space for inlining.
1870 WarmCallInfo* call;
1871 while ((call = pop_warm_call()) != NULL) {
1872 call->make_cold();
1873 }
1874 }
1875
1876 //---------------------cleanup_loop_predicates-----------------------
1877 // Remove the opaque nodes that protect the predicates so that all unused
1878 // checks and uncommon_traps will be eliminated from the ideal graph
1879 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1880 if (predicate_count()==0) return;
1881 for (int i = predicate_count(); i > 0; i--) {
1882 Node * n = predicate_opaque1_node(i-1);
1883 assert(n->Opcode() == Op_Opaque1, "must be");
1884 igvn.replace_node(n, n->in(1));
1885 }
1886 assert(predicate_count()==0, "should be clean!");
1887 }
1888
1889 // StringOpts and late inlining of string methods
1890 void Compile::inline_string_calls(bool parse_time) {
1891 {
1892 // remove useless nodes to make the usage analysis simpler
1893 ResourceMark rm;
1894 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1895 }
1896
1897 {
1898 ResourceMark rm;
1899 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1900 PhaseStringOpts pso(initial_gvn(), for_igvn());
1901 print_method(PHASE_AFTER_STRINGOPTS, 3);
1902 }
1903
1904 // now inline anything that we skipped the first time around
1905 if (!parse_time) {
1906 _late_inlines_pos = _late_inlines.length();
1907 }
1908
1909 while (_string_late_inlines.length() > 0) {
1910 CallGenerator* cg = _string_late_inlines.pop();
1911 cg->do_late_inline();
1912 if (failing()) return;
1913 }
1914 _string_late_inlines.trunc_to(0);
1915 }
1916
1917 // Late inlining of boxing methods
1918 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1919 if (_boxing_late_inlines.length() > 0) {
1920 assert(has_boxed_value(), "inconsistent");
1921
1922 PhaseGVN* gvn = initial_gvn();
1923 set_inlining_incrementally(true);
1924
1925 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1926 for_igvn()->clear();
1927 gvn->replace_with(&igvn);
1928
1929 _late_inlines_pos = _late_inlines.length();
1930
1931 while (_boxing_late_inlines.length() > 0) {
1932 CallGenerator* cg = _boxing_late_inlines.pop();
1933 cg->do_late_inline();
1934 if (failing()) return;
1935 }
1936 _boxing_late_inlines.trunc_to(0);
1937
1938 {
1939 ResourceMark rm;
1940 PhaseRemoveUseless pru(gvn, for_igvn());
1941 }
1942
1943 igvn = PhaseIterGVN(gvn);
1944 igvn.optimize();
1945
1946 set_inlining_progress(false);
1947 set_inlining_incrementally(false);
1948 }
1949 }
1950
1951 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1952 assert(IncrementalInline, "incremental inlining should be on");
1953 PhaseGVN* gvn = initial_gvn();
1954
1955 set_inlining_progress(false);
1956 for_igvn()->clear();
1957 gvn->replace_with(&igvn);
1958
1959 {
1960 TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1961 int i = 0;
1962 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
1963 CallGenerator* cg = _late_inlines.at(i);
1964 _late_inlines_pos = i+1;
1965 cg->do_late_inline();
1966 if (failing()) return;
1967 }
1968 int j = 0;
1969 for (; i < _late_inlines.length(); i++, j++) {
1970 _late_inlines.at_put(j, _late_inlines.at(i));
1971 }
1972 _late_inlines.trunc_to(j);
1973 }
1974
1975 {
1976 TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
1977 ResourceMark rm;
1978 PhaseRemoveUseless pru(gvn, for_igvn());
1979 }
1980
1981 {
1982 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
1983 igvn = PhaseIterGVN(gvn);
1984 }
1985 }
1986
1987 // Perform incremental inlining until bound on number of live nodes is reached
1988 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1989 TracePhase tp("incrementalInline", &timers[_t_incrInline]);
1990
1991 PhaseGVN* gvn = initial_gvn();
1992
1993 set_inlining_incrementally(true);
1994 set_inlining_progress(true);
1995 uint low_live_nodes = 0;
1996
1997 while(inlining_progress() && _late_inlines.length() > 0) {
1998
1999 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2000 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2001 TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
2002 // PhaseIdealLoop is expensive so we only try it once we are
2003 // out of live nodes and we only try it again if the previous
2004 // helped got the number of nodes down significantly
2005 PhaseIdealLoop ideal_loop( igvn, false, true );
2006 if (failing()) return;
2007 low_live_nodes = live_nodes();
2008 _major_progress = true;
2009 }
2010
2011 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2012 break;
2013 }
2014 }
2015
2016 inline_incrementally_one(igvn);
2017
2018 if (failing()) return;
2019
2020 {
2021 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2022 igvn.optimize();
2023 }
2024
2025 if (failing()) return;
2026 }
2027
2028 assert( igvn._worklist.size() == 0, "should be done with igvn" );
2029
2030 if (_string_late_inlines.length() > 0) {
2031 assert(has_stringbuilder(), "inconsistent");
2032 for_igvn()->clear();
2033 initial_gvn()->replace_with(&igvn);
2034
2035 inline_string_calls(false);
2036
2037 if (failing()) return;
2038
2039 {
2040 TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
2041 ResourceMark rm;
2042 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2043 }
2044
2045 {
2046 TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
2047 igvn = PhaseIterGVN(gvn);
2048 igvn.optimize();
2049 }
2050 }
2051
2052 set_inlining_incrementally(false);
2053 }
2054
2055
2056 //------------------------------Optimize---------------------------------------
2057 // Given a graph, optimize it.
2058 void Compile::Optimize() {
2059 TracePhase tp("optimizer", &timers[_t_optimizer]);
2060
2061 #ifndef PRODUCT
2062 if (env()->break_at_compile()) {
2063 BREAKPOINT;
2064 }
2065
2066 #endif
2067
2068 ResourceMark rm;
2069 int loop_opts_cnt;
2070
2071 print_inlining_reinit();
2072
2073 NOT_PRODUCT( verify_graph_edges(); )
2074
2075 print_method(PHASE_AFTER_PARSING);
2076
2077 {
2078 // Iterative Global Value Numbering, including ideal transforms
2079 // Initialize IterGVN with types and values from parse-time GVN
2080 PhaseIterGVN igvn(initial_gvn());
2081 #ifdef ASSERT
2082 _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2083 #endif
2084 {
2085 TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2086 igvn.optimize();
2087 }
2088
2089 print_method(PHASE_ITER_GVN1, 2);
2090
2091 if (failing()) return;
2092
2093 inline_incrementally(igvn);
2094
2095 print_method(PHASE_INCREMENTAL_INLINE, 2);
2096
2097 if (failing()) return;
2098
2099 if (eliminate_boxing()) {
2100 // Inline valueOf() methods now.
2101 inline_boxing_calls(igvn);
2102
2103 if (AlwaysIncrementalInline) {
2104 inline_incrementally(igvn);
2105 }
2106
2107 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2108
2109 if (failing()) return;
2110 }
2111
2112 // Remove the speculative part of types and clean up the graph from
2113 // the extra CastPP nodes whose only purpose is to carry them. Do
2114 // that early so that optimizations are not disrupted by the extra
2115 // CastPP nodes.
2116 remove_speculative_types(igvn);
2117
2118 // No more new expensive nodes will be added to the list from here
2119 // so keep only the actual candidates for optimizations.
2120 cleanup_expensive_nodes(igvn);
2121
2122 // Perform escape analysis
2123 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2124 if (has_loops()) {
2125 // Cleanup graph (remove dead nodes).
2126 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2127 PhaseIdealLoop ideal_loop( igvn, false, true );
2128 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2129 if (failing()) return;
2130 }
2131 ConnectionGraph::do_analysis(this, &igvn);
2132
2133 if (failing()) return;
2134
2135 // Optimize out fields loads from scalar replaceable allocations.
2136 igvn.optimize();
2137 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2138
2139 if (failing()) return;
2140
2141 if (congraph() != NULL && macro_count() > 0) {
2142 TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2143 PhaseMacroExpand mexp(igvn);
2144 mexp.eliminate_macro_nodes();
2145 igvn.set_delay_transform(false);
2146
2147 igvn.optimize();
2148 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2149
2150 if (failing()) return;
2151 }
2152 }
2153
2154 // Loop transforms on the ideal graph. Range Check Elimination,
2155 // peeling, unrolling, etc.
2156
2157 // Set loop opts counter
2158 loop_opts_cnt = num_loop_opts();
2159 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2160 {
2161 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2162 PhaseIdealLoop ideal_loop( igvn, true );
2163 loop_opts_cnt--;
2164 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2165 if (failing()) return;
2166 }
2167 // Loop opts pass if partial peeling occurred in previous pass
2168 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2169 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2170 PhaseIdealLoop ideal_loop( igvn, false );
2171 loop_opts_cnt--;
2172 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2173 if (failing()) return;
2174 }
2175 // Loop opts pass for loop-unrolling before CCP
2176 if(major_progress() && (loop_opts_cnt > 0)) {
2177 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2178 PhaseIdealLoop ideal_loop( igvn, false );
2179 loop_opts_cnt--;
2180 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2181 }
2182 if (!failing()) {
2183 // Verify that last round of loop opts produced a valid graph
2184 TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2185 PhaseIdealLoop::verify(igvn);
2186 }
2187 }
2188 if (failing()) return;
2189
2190 // Conditional Constant Propagation;
2191 PhaseCCP ccp( &igvn );
2192 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2193 {
2194 TracePhase tp("ccp", &timers[_t_ccp]);
2195 ccp.do_transform();
2196 }
2197 print_method(PHASE_CPP1, 2);
2198
2199 assert( true, "Break here to ccp.dump_old2new_map()");
2200
2201 // Iterative Global Value Numbering, including ideal transforms
2202 {
2203 TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2204 igvn = ccp;
2205 igvn.optimize();
2206 }
2207
2208 print_method(PHASE_ITER_GVN2, 2);
2209
2210 if (failing()) return;
2211
2212 // Loop transforms on the ideal graph. Range Check Elimination,
2213 // peeling, unrolling, etc.
2214 if(loop_opts_cnt > 0) {
2215 debug_only( int cnt = 0; );
2216 while(major_progress() && (loop_opts_cnt > 0)) {
2217 TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2218 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2219 PhaseIdealLoop ideal_loop( igvn, true);
2220 loop_opts_cnt--;
2221 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2222 if (failing()) return;
2223 }
2224 }
2225
2226 {
2227 // Verify that all previous optimizations produced a valid graph
2228 // at least to this point, even if no loop optimizations were done.
2229 TracePhase tp("idealLoopVerify", &timers[_t_idealLoopVerify]);
2230 PhaseIdealLoop::verify(igvn);
2231 }
2232
2233 {
2234 TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2235 PhaseMacroExpand mex(igvn);
2236 if (mex.expand_macro_nodes()) {
2237 assert(failing(), "must bail out w/ explicit message");
2238 return;
2239 }
2240 }
2241
2242 DEBUG_ONLY( _modified_nodes = NULL; )
2243 } // (End scope of igvn; run destructor if necessary for asserts.)
2244
2245 process_print_inlining();
2246 // A method with only infinite loops has no edges entering loops from root
2247 {
2248 TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2249 if (final_graph_reshaping()) {
2250 assert(failing(), "must bail out w/ explicit message");
2251 return;
2252 }
2253 }
2254
2255 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2256 }
2257
2258
2259 //------------------------------Code_Gen---------------------------------------
2260 // Given a graph, generate code for it
2261 void Compile::Code_Gen() {
2262 if (failing()) {
2263 return;
2264 }
2265
2266 // Perform instruction selection. You might think we could reclaim Matcher
2267 // memory PDQ, but actually the Matcher is used in generating spill code.
2268 // Internals of the Matcher (including some VectorSets) must remain live
2269 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2270 // set a bit in reclaimed memory.
2271
2272 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2273 // nodes. Mapping is only valid at the root of each matched subtree.
2274 NOT_PRODUCT( verify_graph_edges(); )
2275
2276 Matcher matcher;
2277 _matcher = &matcher;
2278 {
2279 TracePhase tp("matcher", &timers[_t_matcher]);
2280 matcher.match();
2281 }
2282 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2283 // nodes. Mapping is only valid at the root of each matched subtree.
2284 NOT_PRODUCT( verify_graph_edges(); )
2285
2286 // If you have too many nodes, or if matching has failed, bail out
2287 check_node_count(0, "out of nodes matching instructions");
2288 if (failing()) {
2289 return;
2290 }
2291
2292 // Build a proper-looking CFG
2293 PhaseCFG cfg(node_arena(), root(), matcher);
2294 _cfg = &cfg;
2295 {
2296 TracePhase tp("scheduler", &timers[_t_scheduler]);
2297 bool success = cfg.do_global_code_motion();
2298 if (!success) {
2299 return;
2300 }
2301
2302 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2303 NOT_PRODUCT( verify_graph_edges(); )
2304 debug_only( cfg.verify(); )
2305 }
2306
2307 PhaseChaitin regalloc(unique(), cfg, matcher);
2308 _regalloc = ®alloc;
2309 {
2310 TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2311 // Perform register allocation. After Chaitin, use-def chains are
2312 // no longer accurate (at spill code) and so must be ignored.
2313 // Node->LRG->reg mappings are still accurate.
2314 _regalloc->Register_Allocate();
2315
2316 // Bail out if the allocator builds too many nodes
2317 if (failing()) {
2318 return;
2319 }
2320 }
2321
2322 // Prior to register allocation we kept empty basic blocks in case the
2323 // the allocator needed a place to spill. After register allocation we
2324 // are not adding any new instructions. If any basic block is empty, we
2325 // can now safely remove it.
2326 {
2327 TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2328 cfg.remove_empty_blocks();
2329 if (do_freq_based_layout()) {
2330 PhaseBlockLayout layout(cfg);
2331 } else {
2332 cfg.set_loop_alignment();
2333 }
2334 cfg.fixup_flow();
2335 }
2336
2337 // Apply peephole optimizations
2338 if( OptoPeephole ) {
2339 TracePhase tp("peephole", &timers[_t_peephole]);
2340 PhasePeephole peep( _regalloc, cfg);
2341 peep.do_transform();
2342 }
2343
2344 // Do late expand if CPU requires this.
2345 if (Matcher::require_postalloc_expand) {
2346 TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2347 cfg.postalloc_expand(_regalloc);
2348 }
2349
2350 // Convert Nodes to instruction bits in a buffer
2351 {
2352 TraceTime tp("output", &timers[_t_output], CITime);
2353 Output();
2354 }
2355
2356 print_method(PHASE_FINAL_CODE);
2357
2358 // He's dead, Jim.
2359 _cfg = (PhaseCFG*)0xdeadbeef;
2360 _regalloc = (PhaseChaitin*)0xdeadbeef;
2361 }
2362
2363
2364 //------------------------------dump_asm---------------------------------------
2365 // Dump formatted assembly
2366 #ifndef PRODUCT
2367 void Compile::dump_asm(int *pcs, uint pc_limit) {
2368 bool cut_short = false;
2369 tty->print_cr("#");
2370 tty->print("# "); _tf->dump(); tty->cr();
2371 tty->print_cr("#");
2372
2373 // For all blocks
2374 int pc = 0x0; // Program counter
2375 char starts_bundle = ' ';
2376 _regalloc->dump_frame();
2377
2378 Node *n = NULL;
2379 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2380 if (VMThread::should_terminate()) {
2381 cut_short = true;
2382 break;
2383 }
2384 Block* block = _cfg->get_block(i);
2385 if (block->is_connector() && !Verbose) {
2386 continue;
2387 }
2388 n = block->head();
2389 if (pcs && n->_idx < pc_limit) {
2390 tty->print("%3.3x ", pcs[n->_idx]);
2391 } else {
2392 tty->print(" ");
2393 }
2394 block->dump_head(_cfg);
2395 if (block->is_connector()) {
2396 tty->print_cr(" # Empty connector block");
2397 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2398 tty->print_cr(" # Block is sole successor of call");
2399 }
2400
2401 // For all instructions
2402 Node *delay = NULL;
2403 for (uint j = 0; j < block->number_of_nodes(); j++) {
2404 if (VMThread::should_terminate()) {
2405 cut_short = true;
2406 break;
2407 }
2408 n = block->get_node(j);
2409 if (valid_bundle_info(n)) {
2410 Bundle* bundle = node_bundling(n);
2411 if (bundle->used_in_unconditional_delay()) {
2412 delay = n;
2413 continue;
2414 }
2415 if (bundle->starts_bundle()) {
2416 starts_bundle = '+';
2417 }
2418 }
2419
2420 if (WizardMode) {
2421 n->dump();
2422 }
2423
2424 if( !n->is_Region() && // Dont print in the Assembly
2425 !n->is_Phi() && // a few noisely useless nodes
2426 !n->is_Proj() &&
2427 !n->is_MachTemp() &&
2428 !n->is_SafePointScalarObject() &&
2429 !n->is_Catch() && // Would be nice to print exception table targets
2430 !n->is_MergeMem() && // Not very interesting
2431 !n->is_top() && // Debug info table constants
2432 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2433 ) {
2434 if (pcs && n->_idx < pc_limit)
2435 tty->print("%3.3x", pcs[n->_idx]);
2436 else
2437 tty->print(" ");
2438 tty->print(" %c ", starts_bundle);
2439 starts_bundle = ' ';
2440 tty->print("\t");
2441 n->format(_regalloc, tty);
2442 tty->cr();
2443 }
2444
2445 // If we have an instruction with a delay slot, and have seen a delay,
2446 // then back up and print it
2447 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2448 assert(delay != NULL, "no unconditional delay instruction");
2449 if (WizardMode) delay->dump();
2450
2451 if (node_bundling(delay)->starts_bundle())
2452 starts_bundle = '+';
2453 if (pcs && n->_idx < pc_limit)
2454 tty->print("%3.3x", pcs[n->_idx]);
2455 else
2456 tty->print(" ");
2457 tty->print(" %c ", starts_bundle);
2458 starts_bundle = ' ';
2459 tty->print("\t");
2460 delay->format(_regalloc, tty);
2461 tty->cr();
2462 delay = NULL;
2463 }
2464
2465 // Dump the exception table as well
2466 if( n->is_Catch() && (Verbose || WizardMode) ) {
2467 // Print the exception table for this offset
2468 _handler_table.print_subtable_for(pc);
2469 }
2470 }
2471
2472 if (pcs && n->_idx < pc_limit)
2473 tty->print_cr("%3.3x", pcs[n->_idx]);
2474 else
2475 tty->cr();
2476
2477 assert(cut_short || delay == NULL, "no unconditional delay branch");
2478
2479 } // End of per-block dump
2480 tty->cr();
2481
2482 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2483 }
2484 #endif
2485
2486 //------------------------------Final_Reshape_Counts---------------------------
2487 // This class defines counters to help identify when a method
2488 // may/must be executed using hardware with only 24-bit precision.
2489 struct Final_Reshape_Counts : public StackObj {
2490 int _call_count; // count non-inlined 'common' calls
2491 int _float_count; // count float ops requiring 24-bit precision
2492 int _double_count; // count double ops requiring more precision
2493 int _java_call_count; // count non-inlined 'java' calls
2494 int _inner_loop_count; // count loops which need alignment
2495 VectorSet _visited; // Visitation flags
2496 Node_List _tests; // Set of IfNodes & PCTableNodes
2497
2498 Final_Reshape_Counts() :
2499 _call_count(0), _float_count(0), _double_count(0),
2500 _java_call_count(0), _inner_loop_count(0),
2501 _visited( Thread::current()->resource_area() ) { }
2502
2503 void inc_call_count () { _call_count ++; }
2504 void inc_float_count () { _float_count ++; }
2505 void inc_double_count() { _double_count++; }
2506 void inc_java_call_count() { _java_call_count++; }
2507 void inc_inner_loop_count() { _inner_loop_count++; }
2508
2509 int get_call_count () const { return _call_count ; }
2510 int get_float_count () const { return _float_count ; }
2511 int get_double_count() const { return _double_count; }
2512 int get_java_call_count() const { return _java_call_count; }
2513 int get_inner_loop_count() const { return _inner_loop_count; }
2514 };
2515
2516 #ifdef ASSERT
2517 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2518 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2519 // Make sure the offset goes inside the instance layout.
2520 return k->contains_field_offset(tp->offset());
2521 // Note that OffsetBot and OffsetTop are very negative.
2522 }
2523 #endif
2524
2525 // Eliminate trivially redundant StoreCMs and accumulate their
2526 // precedence edges.
2527 void Compile::eliminate_redundant_card_marks(Node* n) {
2528 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2529 if (n->in(MemNode::Address)->outcnt() > 1) {
2530 // There are multiple users of the same address so it might be
2531 // possible to eliminate some of the StoreCMs
2532 Node* mem = n->in(MemNode::Memory);
2533 Node* adr = n->in(MemNode::Address);
2534 Node* val = n->in(MemNode::ValueIn);
2535 Node* prev = n;
2536 bool done = false;
2537 // Walk the chain of StoreCMs eliminating ones that match. As
2538 // long as it's a chain of single users then the optimization is
2539 // safe. Eliminating partially redundant StoreCMs would require
2540 // cloning copies down the other paths.
2541 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2542 if (adr == mem->in(MemNode::Address) &&
2543 val == mem->in(MemNode::ValueIn)) {
2544 // redundant StoreCM
2545 if (mem->req() > MemNode::OopStore) {
2546 // Hasn't been processed by this code yet.
2547 n->add_prec(mem->in(MemNode::OopStore));
2548 } else {
2549 // Already converted to precedence edge
2550 for (uint i = mem->req(); i < mem->len(); i++) {
2551 // Accumulate any precedence edges
2552 if (mem->in(i) != NULL) {
2553 n->add_prec(mem->in(i));
2554 }
2555 }
2556 // Everything above this point has been processed.
2557 done = true;
2558 }
2559 // Eliminate the previous StoreCM
2560 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2561 assert(mem->outcnt() == 0, "should be dead");
2562 mem->disconnect_inputs(NULL, this);
2563 } else {
2564 prev = mem;
2565 }
2566 mem = prev->in(MemNode::Memory);
2567 }
2568 }
2569 }
2570
2571 //------------------------------final_graph_reshaping_impl----------------------
2572 // Implement items 1-5 from final_graph_reshaping below.
2573 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2574
2575 if ( n->outcnt() == 0 ) return; // dead node
2576 uint nop = n->Opcode();
2577
2578 // Check for 2-input instruction with "last use" on right input.
2579 // Swap to left input. Implements item (2).
2580 if( n->req() == 3 && // two-input instruction
2581 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2582 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2583 n->in(2)->outcnt() == 1 &&// right use IS a last use
2584 !n->in(2)->is_Con() ) { // right use is not a constant
2585 // Check for commutative opcode
2586 switch( nop ) {
2587 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2588 case Op_MaxI: case Op_MinI:
2589 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2590 case Op_AndL: case Op_XorL: case Op_OrL:
2591 case Op_AndI: case Op_XorI: case Op_OrI: {
2592 // Move "last use" input to left by swapping inputs
2593 n->swap_edges(1, 2);
2594 break;
2595 }
2596 default:
2597 break;
2598 }
2599 }
2600
2601 #ifdef ASSERT
2602 if( n->is_Mem() ) {
2603 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2604 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2605 // oop will be recorded in oop map if load crosses safepoint
2606 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2607 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2608 "raw memory operations should have control edge");
2609 }
2610 #endif
2611 // Count FPU ops and common calls, implements item (3)
2612 switch( nop ) {
2613 // Count all float operations that may use FPU
2614 case Op_AddF:
2615 case Op_SubF:
2616 case Op_MulF:
2617 case Op_DivF:
2618 case Op_NegF:
2619 case Op_ModF:
2620 case Op_ConvI2F:
2621 case Op_ConF:
2622 case Op_CmpF:
2623 case Op_CmpF3:
2624 // case Op_ConvL2F: // longs are split into 32-bit halves
2625 frc.inc_float_count();
2626 break;
2627
2628 case Op_ConvF2D:
2629 case Op_ConvD2F:
2630 frc.inc_float_count();
2631 frc.inc_double_count();
2632 break;
2633
2634 // Count all double operations that may use FPU
2635 case Op_AddD:
2636 case Op_SubD:
2637 case Op_MulD:
2638 case Op_DivD:
2639 case Op_NegD:
2640 case Op_ModD:
2641 case Op_ConvI2D:
2642 case Op_ConvD2I:
2643 // case Op_ConvL2D: // handled by leaf call
2644 // case Op_ConvD2L: // handled by leaf call
2645 case Op_ConD:
2646 case Op_CmpD:
2647 case Op_CmpD3:
2648 frc.inc_double_count();
2649 break;
2650 case Op_Opaque1: // Remove Opaque Nodes before matching
2651 case Op_Opaque2: // Remove Opaque Nodes before matching
2652 case Op_Opaque3:
2653 n->subsume_by(n->in(1), this);
2654 break;
2655 case Op_CallStaticJava:
2656 case Op_CallJava:
2657 case Op_CallDynamicJava:
2658 frc.inc_java_call_count(); // Count java call site;
2659 case Op_CallRuntime:
2660 case Op_CallLeaf:
2661 case Op_CallLeafNoFP: {
2662 assert( n->is_Call(), "" );
2663 CallNode *call = n->as_Call();
2664 // Count call sites where the FP mode bit would have to be flipped.
2665 // Do not count uncommon runtime calls:
2666 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2667 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2668 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2669 frc.inc_call_count(); // Count the call site
2670 } else { // See if uncommon argument is shared
2671 Node *n = call->in(TypeFunc::Parms);
2672 int nop = n->Opcode();
2673 // Clone shared simple arguments to uncommon calls, item (1).
2674 if( n->outcnt() > 1 &&
2675 !n->is_Proj() &&
2676 nop != Op_CreateEx &&
2677 nop != Op_CheckCastPP &&
2678 nop != Op_DecodeN &&
2679 nop != Op_DecodeNKlass &&
2680 !n->is_Mem() ) {
2681 Node *x = n->clone();
2682 call->set_req( TypeFunc::Parms, x );
2683 }
2684 }
2685 break;
2686 }
2687
2688 case Op_StoreD:
2689 case Op_LoadD:
2690 case Op_LoadD_unaligned:
2691 frc.inc_double_count();
2692 goto handle_mem;
2693 case Op_StoreF:
2694 case Op_LoadF:
2695 frc.inc_float_count();
2696 goto handle_mem;
2697
2698 case Op_StoreCM:
2699 {
2700 // Convert OopStore dependence into precedence edge
2701 Node* prec = n->in(MemNode::OopStore);
2702 n->del_req(MemNode::OopStore);
2703 n->add_prec(prec);
2704 eliminate_redundant_card_marks(n);
2705 }
2706
2707 // fall through
2708
2709 case Op_StoreB:
2710 case Op_StoreC:
2711 case Op_StorePConditional:
2712 case Op_StoreI:
2713 case Op_StoreL:
2714 case Op_StoreIConditional:
2715 case Op_StoreLConditional:
2716 case Op_CompareAndSwapI:
2717 case Op_CompareAndSwapL:
2718 case Op_CompareAndSwapP:
2719 case Op_CompareAndSwapN:
2720 case Op_GetAndAddI:
2721 case Op_GetAndAddL:
2722 case Op_GetAndSetI:
2723 case Op_GetAndSetL:
2724 case Op_GetAndSetP:
2725 case Op_GetAndSetN:
2726 case Op_StoreP:
2727 case Op_StoreN:
2728 case Op_StoreNKlass:
2729 case Op_LoadB:
2730 case Op_LoadUB:
2731 case Op_LoadUS:
2732 case Op_LoadI:
2733 case Op_LoadKlass:
2734 case Op_LoadNKlass:
2735 case Op_LoadL:
2736 case Op_LoadL_unaligned:
2737 case Op_LoadPLocked:
2738 case Op_LoadP:
2739 case Op_LoadN:
2740 case Op_LoadRange:
2741 case Op_LoadS: {
2742 handle_mem:
2743 #ifdef ASSERT
2744 if( VerifyOptoOopOffsets ) {
2745 assert( n->is_Mem(), "" );
2746 MemNode *mem = (MemNode*)n;
2747 // Check to see if address types have grounded out somehow.
2748 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2749 assert( !tp || oop_offset_is_sane(tp), "" );
2750 }
2751 #endif
2752 break;
2753 }
2754
2755 case Op_AddP: { // Assert sane base pointers
2756 Node *addp = n->in(AddPNode::Address);
2757 assert( !addp->is_AddP() ||
2758 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2759 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2760 "Base pointers must match" );
2761 #ifdef _LP64
2762 if ((UseCompressedOops || UseCompressedClassPointers) &&
2763 addp->Opcode() == Op_ConP &&
2764 addp == n->in(AddPNode::Base) &&
2765 n->in(AddPNode::Offset)->is_Con()) {
2766 // Use addressing with narrow klass to load with offset on x86.
2767 // On sparc loading 32-bits constant and decoding it have less
2768 // instructions (4) then load 64-bits constant (7).
2769 // Do this transformation here since IGVN will convert ConN back to ConP.
2770 const Type* t = addp->bottom_type();
2771 if (t->isa_oopptr() || t->isa_klassptr()) {
2772 Node* nn = NULL;
2773
2774 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2775
2776 // Look for existing ConN node of the same exact type.
2777 Node* r = root();
2778 uint cnt = r->outcnt();
2779 for (uint i = 0; i < cnt; i++) {
2780 Node* m = r->raw_out(i);
2781 if (m!= NULL && m->Opcode() == op &&
2782 m->bottom_type()->make_ptr() == t) {
2783 nn = m;
2784 break;
2785 }
2786 }
2787 if (nn != NULL) {
2788 // Decode a narrow oop to match address
2789 // [R12 + narrow_oop_reg<<3 + offset]
2790 if (t->isa_oopptr()) {
2791 nn = new DecodeNNode(nn, t);
2792 } else {
2793 nn = new DecodeNKlassNode(nn, t);
2794 }
2795 n->set_req(AddPNode::Base, nn);
2796 n->set_req(AddPNode::Address, nn);
2797 if (addp->outcnt() == 0) {
2798 addp->disconnect_inputs(NULL, this);
2799 }
2800 }
2801 }
2802 }
2803 #endif
2804 break;
2805 }
2806
2807 #ifdef _LP64
2808 case Op_CastPP:
2809 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2810 Node* in1 = n->in(1);
2811 const Type* t = n->bottom_type();
2812 Node* new_in1 = in1->clone();
2813 new_in1->as_DecodeN()->set_type(t);
2814
2815 if (!Matcher::narrow_oop_use_complex_address()) {
2816 //
2817 // x86, ARM and friends can handle 2 adds in addressing mode
2818 // and Matcher can fold a DecodeN node into address by using
2819 // a narrow oop directly and do implicit NULL check in address:
2820 //
2821 // [R12 + narrow_oop_reg<<3 + offset]
2822 // NullCheck narrow_oop_reg
2823 //
2824 // On other platforms (Sparc) we have to keep new DecodeN node and
2825 // use it to do implicit NULL check in address:
2826 //
2827 // decode_not_null narrow_oop_reg, base_reg
2828 // [base_reg + offset]
2829 // NullCheck base_reg
2830 //
2831 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2832 // to keep the information to which NULL check the new DecodeN node
2833 // corresponds to use it as value in implicit_null_check().
2834 //
2835 new_in1->set_req(0, n->in(0));
2836 }
2837
2838 n->subsume_by(new_in1, this);
2839 if (in1->outcnt() == 0) {
2840 in1->disconnect_inputs(NULL, this);
2841 }
2842 }
2843 break;
2844
2845 case Op_CmpP:
2846 // Do this transformation here to preserve CmpPNode::sub() and
2847 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2848 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2849 Node* in1 = n->in(1);
2850 Node* in2 = n->in(2);
2851 if (!in1->is_DecodeNarrowPtr()) {
2852 in2 = in1;
2853 in1 = n->in(2);
2854 }
2855 assert(in1->is_DecodeNarrowPtr(), "sanity");
2856
2857 Node* new_in2 = NULL;
2858 if (in2->is_DecodeNarrowPtr()) {
2859 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2860 new_in2 = in2->in(1);
2861 } else if (in2->Opcode() == Op_ConP) {
2862 const Type* t = in2->bottom_type();
2863 if (t == TypePtr::NULL_PTR) {
2864 assert(in1->is_DecodeN(), "compare klass to null?");
2865 // Don't convert CmpP null check into CmpN if compressed
2866 // oops implicit null check is not generated.
2867 // This will allow to generate normal oop implicit null check.
2868 if (Matcher::gen_narrow_oop_implicit_null_checks())
2869 new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
2870 //
2871 // This transformation together with CastPP transformation above
2872 // will generated code for implicit NULL checks for compressed oops.
2873 //
2874 // The original code after Optimize()
2875 //
2876 // LoadN memory, narrow_oop_reg
2877 // decode narrow_oop_reg, base_reg
2878 // CmpP base_reg, NULL
2879 // CastPP base_reg // NotNull
2880 // Load [base_reg + offset], val_reg
2881 //
2882 // after these transformations will be
2883 //
2884 // LoadN memory, narrow_oop_reg
2885 // CmpN narrow_oop_reg, NULL
2886 // decode_not_null narrow_oop_reg, base_reg
2887 // Load [base_reg + offset], val_reg
2888 //
2889 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2890 // since narrow oops can be used in debug info now (see the code in
2891 // final_graph_reshaping_walk()).
2892 //
2893 // At the end the code will be matched to
2894 // on x86:
2895 //
2896 // Load_narrow_oop memory, narrow_oop_reg
2897 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2898 // NullCheck narrow_oop_reg
2899 //
2900 // and on sparc:
2901 //
2902 // Load_narrow_oop memory, narrow_oop_reg
2903 // decode_not_null narrow_oop_reg, base_reg
2904 // Load [base_reg + offset], val_reg
2905 // NullCheck base_reg
2906 //
2907 } else if (t->isa_oopptr()) {
2908 new_in2 = ConNode::make(t->make_narrowoop());
2909 } else if (t->isa_klassptr()) {
2910 new_in2 = ConNode::make(t->make_narrowklass());
2911 }
2912 }
2913 if (new_in2 != NULL) {
2914 Node* cmpN = new CmpNNode(in1->in(1), new_in2);
2915 n->subsume_by(cmpN, this);
2916 if (in1->outcnt() == 0) {
2917 in1->disconnect_inputs(NULL, this);
2918 }
2919 if (in2->outcnt() == 0) {
2920 in2->disconnect_inputs(NULL, this);
2921 }
2922 }
2923 }
2924 break;
2925
2926 case Op_DecodeN:
2927 case Op_DecodeNKlass:
2928 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2929 // DecodeN could be pinned when it can't be fold into
2930 // an address expression, see the code for Op_CastPP above.
2931 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2932 break;
2933
2934 case Op_EncodeP:
2935 case Op_EncodePKlass: {
2936 Node* in1 = n->in(1);
2937 if (in1->is_DecodeNarrowPtr()) {
2938 n->subsume_by(in1->in(1), this);
2939 } else if (in1->Opcode() == Op_ConP) {
2940 const Type* t = in1->bottom_type();
2941 if (t == TypePtr::NULL_PTR) {
2942 assert(t->isa_oopptr(), "null klass?");
2943 n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
2944 } else if (t->isa_oopptr()) {
2945 n->subsume_by(ConNode::make(t->make_narrowoop()), this);
2946 } else if (t->isa_klassptr()) {
2947 n->subsume_by(ConNode::make(t->make_narrowklass()), this);
2948 }
2949 }
2950 if (in1->outcnt() == 0) {
2951 in1->disconnect_inputs(NULL, this);
2952 }
2953 break;
2954 }
2955
2956 case Op_Proj: {
2957 if (OptimizeStringConcat) {
2958 ProjNode* p = n->as_Proj();
2959 if (p->_is_io_use) {
2960 // Separate projections were used for the exception path which
2961 // are normally removed by a late inline. If it wasn't inlined
2962 // then they will hang around and should just be replaced with
2963 // the original one.
2964 Node* proj = NULL;
2965 // Replace with just one
2966 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
2967 Node *use = i.get();
2968 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
2969 proj = use;
2970 break;
2971 }
2972 }
2973 assert(proj != NULL, "must be found");
2974 p->subsume_by(proj, this);
2975 }
2976 }
2977 break;
2978 }
2979
2980 case Op_Phi:
2981 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
2982 // The EncodeP optimization may create Phi with the same edges
2983 // for all paths. It is not handled well by Register Allocator.
2984 Node* unique_in = n->in(1);
2985 assert(unique_in != NULL, "");
2986 uint cnt = n->req();
2987 for (uint i = 2; i < cnt; i++) {
2988 Node* m = n->in(i);
2989 assert(m != NULL, "");
2990 if (unique_in != m)
2991 unique_in = NULL;
2992 }
2993 if (unique_in != NULL) {
2994 n->subsume_by(unique_in, this);
2995 }
2996 }
2997 break;
2998
2999 #endif
3000
3001 case Op_ModI:
3002 if (UseDivMod) {
3003 // Check if a%b and a/b both exist
3004 Node* d = n->find_similar(Op_DivI);
3005 if (d) {
3006 // Replace them with a fused divmod if supported
3007 if (Matcher::has_match_rule(Op_DivModI)) {
3008 DivModINode* divmod = DivModINode::make(n);
3009 d->subsume_by(divmod->div_proj(), this);
3010 n->subsume_by(divmod->mod_proj(), this);
3011 } else {
3012 // replace a%b with a-((a/b)*b)
3013 Node* mult = new MulINode(d, d->in(2));
3014 Node* sub = new SubINode(d->in(1), mult);
3015 n->subsume_by(sub, this);
3016 }
3017 }
3018 }
3019 break;
3020
3021 case Op_ModL:
3022 if (UseDivMod) {
3023 // Check if a%b and a/b both exist
3024 Node* d = n->find_similar(Op_DivL);
3025 if (d) {
3026 // Replace them with a fused divmod if supported
3027 if (Matcher::has_match_rule(Op_DivModL)) {
3028 DivModLNode* divmod = DivModLNode::make(n);
3029 d->subsume_by(divmod->div_proj(), this);
3030 n->subsume_by(divmod->mod_proj(), this);
3031 } else {
3032 // replace a%b with a-((a/b)*b)
3033 Node* mult = new MulLNode(d, d->in(2));
3034 Node* sub = new SubLNode(d->in(1), mult);
3035 n->subsume_by(sub, this);
3036 }
3037 }
3038 }
3039 break;
3040
3041 case Op_LoadVector:
3042 case Op_StoreVector:
3043 break;
3044
3045 case Op_PackB:
3046 case Op_PackS:
3047 case Op_PackI:
3048 case Op_PackF:
3049 case Op_PackL:
3050 case Op_PackD:
3051 if (n->req()-1 > 2) {
3052 // Replace many operand PackNodes with a binary tree for matching
3053 PackNode* p = (PackNode*) n;
3054 Node* btp = p->binary_tree_pack(1, n->req());
3055 n->subsume_by(btp, this);
3056 }
3057 break;
3058 case Op_Loop:
3059 case Op_CountedLoop:
3060 if (n->as_Loop()->is_inner_loop()) {
3061 frc.inc_inner_loop_count();
3062 }
3063 break;
3064 case Op_LShiftI:
3065 case Op_RShiftI:
3066 case Op_URShiftI:
3067 case Op_LShiftL:
3068 case Op_RShiftL:
3069 case Op_URShiftL:
3070 if (Matcher::need_masked_shift_count) {
3071 // The cpu's shift instructions don't restrict the count to the
3072 // lower 5/6 bits. We need to do the masking ourselves.
3073 Node* in2 = n->in(2);
3074 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3075 const TypeInt* t = in2->find_int_type();
3076 if (t != NULL && t->is_con()) {
3077 juint shift = t->get_con();
3078 if (shift > mask) { // Unsigned cmp
3079 n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3080 }
3081 } else {
3082 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3083 Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3084 n->set_req(2, shift);
3085 }
3086 }
3087 if (in2->outcnt() == 0) { // Remove dead node
3088 in2->disconnect_inputs(NULL, this);
3089 }
3090 }
3091 break;
3092 case Op_MemBarStoreStore:
3093 case Op_MemBarRelease:
3094 // Break the link with AllocateNode: it is no longer useful and
3095 // confuses register allocation.
3096 if (n->req() > MemBarNode::Precedent) {
3097 n->set_req(MemBarNode::Precedent, top());
3098 }
3099 break;
3100 default:
3101 assert( !n->is_Call(), "" );
3102 assert( !n->is_Mem(), "" );
3103 break;
3104 }
3105
3106 // Collect CFG split points
3107 if (n->is_MultiBranch())
3108 frc._tests.push(n);
3109 }
3110
3111 //------------------------------final_graph_reshaping_walk---------------------
3112 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3113 // requires that the walk visits a node's inputs before visiting the node.
3114 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3115 ResourceArea *area = Thread::current()->resource_area();
3116 Unique_Node_List sfpt(area);
3117
3118 frc._visited.set(root->_idx); // first, mark node as visited
3119 uint cnt = root->req();
3120 Node *n = root;
3121 uint i = 0;
3122 while (true) {
3123 if (i < cnt) {
3124 // Place all non-visited non-null inputs onto stack
3125 Node* m = n->in(i);
3126 ++i;
3127 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3128 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3129 // compute worst case interpreter size in case of a deoptimization
3130 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3131
3132 sfpt.push(m);
3133 }
3134 cnt = m->req();
3135 nstack.push(n, i); // put on stack parent and next input's index
3136 n = m;
3137 i = 0;
3138 }
3139 } else {
3140 // Now do post-visit work
3141 final_graph_reshaping_impl( n, frc );
3142 if (nstack.is_empty())
3143 break; // finished
3144 n = nstack.node(); // Get node from stack
3145 cnt = n->req();
3146 i = nstack.index();
3147 nstack.pop(); // Shift to the next node on stack
3148 }
3149 }
3150
3151 // Skip next transformation if compressed oops are not used.
3152 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3153 (!UseCompressedOops && !UseCompressedClassPointers))
3154 return;
3155
3156 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3157 // It could be done for an uncommon traps or any safepoints/calls
3158 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3159 while (sfpt.size() > 0) {
3160 n = sfpt.pop();
3161 JVMState *jvms = n->as_SafePoint()->jvms();
3162 assert(jvms != NULL, "sanity");
3163 int start = jvms->debug_start();
3164 int end = n->req();
3165 bool is_uncommon = (n->is_CallStaticJava() &&
3166 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3167 for (int j = start; j < end; j++) {
3168 Node* in = n->in(j);
3169 if (in->is_DecodeNarrowPtr()) {
3170 bool safe_to_skip = true;
3171 if (!is_uncommon ) {
3172 // Is it safe to skip?
3173 for (uint i = 0; i < in->outcnt(); i++) {
3174 Node* u = in->raw_out(i);
3175 if (!u->is_SafePoint() ||
3176 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3177 safe_to_skip = false;
3178 }
3179 }
3180 }
3181 if (safe_to_skip) {
3182 n->set_req(j, in->in(1));
3183 }
3184 if (in->outcnt() == 0) {
3185 in->disconnect_inputs(NULL, this);
3186 }
3187 }
3188 }
3189 }
3190 }
3191
3192 //------------------------------final_graph_reshaping--------------------------
3193 // Final Graph Reshaping.
3194 //
3195 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3196 // and not commoned up and forced early. Must come after regular
3197 // optimizations to avoid GVN undoing the cloning. Clone constant
3198 // inputs to Loop Phis; these will be split by the allocator anyways.
3199 // Remove Opaque nodes.
3200 // (2) Move last-uses by commutative operations to the left input to encourage
3201 // Intel update-in-place two-address operations and better register usage
3202 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3203 // calls canonicalizing them back.
3204 // (3) Count the number of double-precision FP ops, single-precision FP ops
3205 // and call sites. On Intel, we can get correct rounding either by
3206 // forcing singles to memory (requires extra stores and loads after each
3207 // FP bytecode) or we can set a rounding mode bit (requires setting and
3208 // clearing the mode bit around call sites). The mode bit is only used
3209 // if the relative frequency of single FP ops to calls is low enough.
3210 // This is a key transform for SPEC mpeg_audio.
3211 // (4) Detect infinite loops; blobs of code reachable from above but not
3212 // below. Several of the Code_Gen algorithms fail on such code shapes,
3213 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3214 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3215 // Detection is by looking for IfNodes where only 1 projection is
3216 // reachable from below or CatchNodes missing some targets.
3217 // (5) Assert for insane oop offsets in debug mode.
3218
3219 bool Compile::final_graph_reshaping() {
3220 // an infinite loop may have been eliminated by the optimizer,
3221 // in which case the graph will be empty.
3222 if (root()->req() == 1) {
3223 record_method_not_compilable("trivial infinite loop");
3224 return true;
3225 }
3226
3227 // Expensive nodes have their control input set to prevent the GVN
3228 // from freely commoning them. There's no GVN beyond this point so
3229 // no need to keep the control input. We want the expensive nodes to
3230 // be freely moved to the least frequent code path by gcm.
3231 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3232 for (int i = 0; i < expensive_count(); i++) {
3233 _expensive_nodes->at(i)->set_req(0, NULL);
3234 }
3235
3236 Final_Reshape_Counts frc;
3237
3238 // Visit everybody reachable!
3239 // Allocate stack of size C->unique()/2 to avoid frequent realloc
3240 Node_Stack nstack(unique() >> 1);
3241 final_graph_reshaping_walk(nstack, root(), frc);
3242
3243 // Check for unreachable (from below) code (i.e., infinite loops).
3244 for( uint i = 0; i < frc._tests.size(); i++ ) {
3245 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3246 // Get number of CFG targets.
3247 // Note that PCTables include exception targets after calls.
3248 uint required_outcnt = n->required_outcnt();
3249 if (n->outcnt() != required_outcnt) {
3250 // Check for a few special cases. Rethrow Nodes never take the
3251 // 'fall-thru' path, so expected kids is 1 less.
3252 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3253 if (n->in(0)->in(0)->is_Call()) {
3254 CallNode *call = n->in(0)->in(0)->as_Call();
3255 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3256 required_outcnt--; // Rethrow always has 1 less kid
3257 } else if (call->req() > TypeFunc::Parms &&
3258 call->is_CallDynamicJava()) {
3259 // Check for null receiver. In such case, the optimizer has
3260 // detected that the virtual call will always result in a null
3261 // pointer exception. The fall-through projection of this CatchNode
3262 // will not be populated.
3263 Node *arg0 = call->in(TypeFunc::Parms);
3264 if (arg0->is_Type() &&
3265 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3266 required_outcnt--;
3267 }
3268 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3269 call->req() > TypeFunc::Parms+1 &&
3270 call->is_CallStaticJava()) {
3271 // Check for negative array length. In such case, the optimizer has
3272 // detected that the allocation attempt will always result in an
3273 // exception. There is no fall-through projection of this CatchNode .
3274 Node *arg1 = call->in(TypeFunc::Parms+1);
3275 if (arg1->is_Type() &&
3276 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3277 required_outcnt--;
3278 }
3279 }
3280 }
3281 }
3282 // Recheck with a better notion of 'required_outcnt'
3283 if (n->outcnt() != required_outcnt) {
3284 record_method_not_compilable("malformed control flow");
3285 return true; // Not all targets reachable!
3286 }
3287 }
3288 // Check that I actually visited all kids. Unreached kids
3289 // must be infinite loops.
3290 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3291 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3292 record_method_not_compilable("infinite loop");
3293 return true; // Found unvisited kid; must be unreach
3294 }
3295 }
3296
3297 // If original bytecodes contained a mixture of floats and doubles
3298 // check if the optimizer has made it homogenous, item (3).
3299 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3300 frc.get_float_count() > 32 &&
3301 frc.get_double_count() == 0 &&
3302 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3303 set_24_bit_selection_and_mode( false, true );
3304 }
3305
3306 set_java_calls(frc.get_java_call_count());
3307 set_inner_loops(frc.get_inner_loop_count());
3308
3309 // No infinite loops, no reason to bail out.
3310 return false;
3311 }
3312
3313 //-----------------------------too_many_traps----------------------------------
3314 // Report if there are too many traps at the current method and bci.
3315 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3316 bool Compile::too_many_traps(ciMethod* method,
3317 int bci,
3318 Deoptimization::DeoptReason reason) {
3319 ciMethodData* md = method->method_data();
3320 if (md->is_empty()) {
3321 // Assume the trap has not occurred, or that it occurred only
3322 // because of a transient condition during start-up in the interpreter.
3323 return false;
3324 }
3325 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3326 if (md->has_trap_at(bci, m, reason) != 0) {
3327 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3328 // Also, if there are multiple reasons, or if there is no per-BCI record,
3329 // assume the worst.
3330 if (log())
3331 log()->elem("observe trap='%s' count='%d'",
3332 Deoptimization::trap_reason_name(reason),
3333 md->trap_count(reason));
3334 return true;
3335 } else {
3336 // Ignore method/bci and see if there have been too many globally.
3337 return too_many_traps(reason, md);
3338 }
3339 }
3340
3341 // Less-accurate variant which does not require a method and bci.
3342 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3343 ciMethodData* logmd) {
3344 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3345 // Too many traps globally.
3346 // Note that we use cumulative trap_count, not just md->trap_count.
3347 if (log()) {
3348 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3349 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3350 Deoptimization::trap_reason_name(reason),
3351 mcount, trap_count(reason));
3352 }
3353 return true;
3354 } else {
3355 // The coast is clear.
3356 return false;
3357 }
3358 }
3359
3360 //--------------------------too_many_recompiles--------------------------------
3361 // Report if there are too many recompiles at the current method and bci.
3362 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3363 // Is not eager to return true, since this will cause the compiler to use
3364 // Action_none for a trap point, to avoid too many recompilations.
3365 bool Compile::too_many_recompiles(ciMethod* method,
3366 int bci,
3367 Deoptimization::DeoptReason reason) {
3368 ciMethodData* md = method->method_data();
3369 if (md->is_empty()) {
3370 // Assume the trap has not occurred, or that it occurred only
3371 // because of a transient condition during start-up in the interpreter.
3372 return false;
3373 }
3374 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3375 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3376 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3377 Deoptimization::DeoptReason per_bc_reason
3378 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3379 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3380 if ((per_bc_reason == Deoptimization::Reason_none
3381 || md->has_trap_at(bci, m, reason) != 0)
3382 // The trap frequency measure we care about is the recompile count:
3383 && md->trap_recompiled_at(bci, m)
3384 && md->overflow_recompile_count() >= bc_cutoff) {
3385 // Do not emit a trap here if it has already caused recompilations.
3386 // Also, if there are multiple reasons, or if there is no per-BCI record,
3387 // assume the worst.
3388 if (log())
3389 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3390 Deoptimization::trap_reason_name(reason),
3391 md->trap_count(reason),
3392 md->overflow_recompile_count());
3393 return true;
3394 } else if (trap_count(reason) != 0
3395 && decompile_count() >= m_cutoff) {
3396 // Too many recompiles globally, and we have seen this sort of trap.
3397 // Use cumulative decompile_count, not just md->decompile_count.
3398 if (log())
3399 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3400 Deoptimization::trap_reason_name(reason),
3401 md->trap_count(reason), trap_count(reason),
3402 md->decompile_count(), decompile_count());
3403 return true;
3404 } else {
3405 // The coast is clear.
3406 return false;
3407 }
3408 }
3409
3410 // Compute when not to trap. Used by matching trap based nodes and
3411 // NullCheck optimization.
3412 void Compile::set_allowed_deopt_reasons() {
3413 _allowed_reasons = 0;
3414 if (is_method_compilation()) {
3415 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3416 assert(rs < BitsPerInt, "recode bit map");
3417 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3418 _allowed_reasons |= nth_bit(rs);
3419 }
3420 }
3421 }
3422 }
3423
3424 #ifndef PRODUCT
3425 //------------------------------verify_graph_edges---------------------------
3426 // Walk the Graph and verify that there is a one-to-one correspondence
3427 // between Use-Def edges and Def-Use edges in the graph.
3428 void Compile::verify_graph_edges(bool no_dead_code) {
3429 if (VerifyGraphEdges) {
3430 ResourceArea *area = Thread::current()->resource_area();
3431 Unique_Node_List visited(area);
3432 // Call recursive graph walk to check edges
3433 _root->verify_edges(visited);
3434 if (no_dead_code) {
3435 // Now make sure that no visited node is used by an unvisited node.
3436 bool dead_nodes = false;
3437 Unique_Node_List checked(area);
3438 while (visited.size() > 0) {
3439 Node* n = visited.pop();
3440 checked.push(n);
3441 for (uint i = 0; i < n->outcnt(); i++) {
3442 Node* use = n->raw_out(i);
3443 if (checked.member(use)) continue; // already checked
3444 if (visited.member(use)) continue; // already in the graph
3445 if (use->is_Con()) continue; // a dead ConNode is OK
3446 // At this point, we have found a dead node which is DU-reachable.
3447 if (!dead_nodes) {
3448 tty->print_cr("*** Dead nodes reachable via DU edges:");
3449 dead_nodes = true;
3450 }
3451 use->dump(2);
3452 tty->print_cr("---");
3453 checked.push(use); // No repeats; pretend it is now checked.
3454 }
3455 }
3456 assert(!dead_nodes, "using nodes must be reachable from root");
3457 }
3458 }
3459 }
3460
3461 // Verify GC barriers consistency
3462 // Currently supported:
3463 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3464 void Compile::verify_barriers() {
3465 if (UseG1GC) {
3466 // Verify G1 pre-barriers
3467 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3468
3469 ResourceArea *area = Thread::current()->resource_area();
3470 Unique_Node_List visited(area);
3471 Node_List worklist(area);
3472 // We're going to walk control flow backwards starting from the Root
3473 worklist.push(_root);
3474 while (worklist.size() > 0) {
3475 Node* x = worklist.pop();
3476 if (x == NULL || x == top()) continue;
3477 if (visited.member(x)) {
3478 continue;
3479 } else {
3480 visited.push(x);
3481 }
3482
3483 if (x->is_Region()) {
3484 for (uint i = 1; i < x->req(); i++) {
3485 worklist.push(x->in(i));
3486 }
3487 } else {
3488 worklist.push(x->in(0));
3489 // We are looking for the pattern:
3490 // /->ThreadLocal
3491 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3492 // \->ConI(0)
3493 // We want to verify that the If and the LoadB have the same control
3494 // See GraphKit::g1_write_barrier_pre()
3495 if (x->is_If()) {
3496 IfNode *iff = x->as_If();
3497 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3498 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3499 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3500 && cmp->in(1)->is_Load()) {
3501 LoadNode* load = cmp->in(1)->as_Load();
3502 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3503 && load->in(2)->in(3)->is_Con()
3504 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3505
3506 Node* if_ctrl = iff->in(0);
3507 Node* load_ctrl = load->in(0);
3508
3509 if (if_ctrl != load_ctrl) {
3510 // Skip possible CProj->NeverBranch in infinite loops
3511 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3512 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3513 if_ctrl = if_ctrl->in(0)->in(0);
3514 }
3515 }
3516 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3517 }
3518 }
3519 }
3520 }
3521 }
3522 }
3523 }
3524 }
3525
3526 #endif
3527
3528 // The Compile object keeps track of failure reasons separately from the ciEnv.
3529 // This is required because there is not quite a 1-1 relation between the
3530 // ciEnv and its compilation task and the Compile object. Note that one
3531 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3532 // to backtrack and retry without subsuming loads. Other than this backtracking
3533 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3534 // by the logic in C2Compiler.
3535 void Compile::record_failure(const char* reason) {
3536 if (log() != NULL) {
3537 log()->elem("failure reason='%s' phase='compile'", reason);
3538 }
3539 if (_failure_reason == NULL) {
3540 // Record the first failure reason.
3541 _failure_reason = reason;
3542 }
3543
3544 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3545 C->print_method(PHASE_FAILURE);
3546 }
3547 _root = NULL; // flush the graph, too
3548 }
3549
3550 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
3551 : TraceTime(name, accumulator, CITime, CITimeVerbose),
3552 _phase_name(name), _dolog(CITimeVerbose)
3553 {
3554 if (_dolog) {
3555 C = Compile::current();
3556 _log = C->log();
3557 } else {
3558 C = NULL;
3559 _log = NULL;
3560 }
3561 if (_log != NULL) {
3562 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3563 _log->stamp();
3564 _log->end_head();
3565 }
3566 }
3567
3568 Compile::TracePhase::~TracePhase() {
3569
3570 C = Compile::current();
3571 if (_dolog) {
3572 _log = C->log();
3573 } else {
3574 _log = NULL;
3575 }
3576
3577 #ifdef ASSERT
3578 if (PrintIdealNodeCount) {
3579 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3580 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3581 }
3582
3583 if (VerifyIdealNodeCount) {
3584 Compile::current()->print_missing_nodes();
3585 }
3586 #endif
3587
3588 if (_log != NULL) {
3589 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3590 }
3591 }
3592
3593 //=============================================================================
3594 // Two Constant's are equal when the type and the value are equal.
3595 bool Compile::Constant::operator==(const Constant& other) {
3596 if (type() != other.type() ) return false;
3597 if (can_be_reused() != other.can_be_reused()) return false;
3598 // For floating point values we compare the bit pattern.
3599 switch (type()) {
3600 case T_FLOAT: return (_v._value.i == other._v._value.i);
3601 case T_LONG:
3602 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3603 case T_OBJECT:
3604 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3605 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3606 case T_METADATA: return (_v._metadata == other._v._metadata);
3607 default: ShouldNotReachHere();
3608 }
3609 return false;
3610 }
3611
3612 static int type_to_size_in_bytes(BasicType t) {
3613 switch (t) {
3614 case T_LONG: return sizeof(jlong );
3615 case T_FLOAT: return sizeof(jfloat );
3616 case T_DOUBLE: return sizeof(jdouble);
3617 case T_METADATA: return sizeof(Metadata*);
3618 // We use T_VOID as marker for jump-table entries (labels) which
3619 // need an internal word relocation.
3620 case T_VOID:
3621 case T_ADDRESS:
3622 case T_OBJECT: return sizeof(jobject);
3623 }
3624
3625 ShouldNotReachHere();
3626 return -1;
3627 }
3628
3629 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3630 // sort descending
3631 if (a->freq() > b->freq()) return -1;
3632 if (a->freq() < b->freq()) return 1;
3633 return 0;
3634 }
3635
3636 void Compile::ConstantTable::calculate_offsets_and_size() {
3637 // First, sort the array by frequencies.
3638 _constants.sort(qsort_comparator);
3639
3640 #ifdef ASSERT
3641 // Make sure all jump-table entries were sorted to the end of the
3642 // array (they have a negative frequency).
3643 bool found_void = false;
3644 for (int i = 0; i < _constants.length(); i++) {
3645 Constant con = _constants.at(i);
3646 if (con.type() == T_VOID)
3647 found_void = true; // jump-tables
3648 else
3649 assert(!found_void, "wrong sorting");
3650 }
3651 #endif
3652
3653 int offset = 0;
3654 for (int i = 0; i < _constants.length(); i++) {
3655 Constant* con = _constants.adr_at(i);
3656
3657 // Align offset for type.
3658 int typesize = type_to_size_in_bytes(con->type());
3659 offset = align_size_up(offset, typesize);
3660 con->set_offset(offset); // set constant's offset
3661
3662 if (con->type() == T_VOID) {
3663 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3664 offset = offset + typesize * n->outcnt(); // expand jump-table
3665 } else {
3666 offset = offset + typesize;
3667 }
3668 }
3669
3670 // Align size up to the next section start (which is insts; see
3671 // CodeBuffer::align_at_start).
3672 assert(_size == -1, "already set?");
3673 _size = align_size_up(offset, CodeEntryAlignment);
3674 }
3675
3676 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3677 MacroAssembler _masm(&cb);
3678 for (int i = 0; i < _constants.length(); i++) {
3679 Constant con = _constants.at(i);
3680 address constant_addr;
3681 switch (con.type()) {
3682 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3683 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3684 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3685 case T_OBJECT: {
3686 jobject obj = con.get_jobject();
3687 int oop_index = _masm.oop_recorder()->find_index(obj);
3688 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3689 break;
3690 }
3691 case T_ADDRESS: {
3692 address addr = (address) con.get_jobject();
3693 constant_addr = _masm.address_constant(addr);
3694 break;
3695 }
3696 // We use T_VOID as marker for jump-table entries (labels) which
3697 // need an internal word relocation.
3698 case T_VOID: {
3699 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3700 // Fill the jump-table with a dummy word. The real value is
3701 // filled in later in fill_jump_table.
3702 address dummy = (address) n;
3703 constant_addr = _masm.address_constant(dummy);
3704 // Expand jump-table
3705 for (uint i = 1; i < n->outcnt(); i++) {
3706 address temp_addr = _masm.address_constant(dummy + i);
3707 assert(temp_addr, "consts section too small");
3708 }
3709 break;
3710 }
3711 case T_METADATA: {
3712 Metadata* obj = con.get_metadata();
3713 int metadata_index = _masm.oop_recorder()->find_index(obj);
3714 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3715 break;
3716 }
3717 default: ShouldNotReachHere();
3718 }
3719 assert(constant_addr, "consts section too small");
3720 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3721 err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3722 }
3723 }
3724
3725 int Compile::ConstantTable::find_offset(Constant& con) const {
3726 int idx = _constants.find(con);
3727 assert(idx != -1, "constant must be in constant table");
3728 int offset = _constants.at(idx).offset();
3729 assert(offset != -1, "constant table not emitted yet?");
3730 return offset;
3731 }
3732
3733 void Compile::ConstantTable::add(Constant& con) {
3734 if (con.can_be_reused()) {
3735 int idx = _constants.find(con);
3736 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3737 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3738 return;
3739 }
3740 }
3741 (void) _constants.append(con);
3742 }
3743
3744 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3745 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3746 Constant con(type, value, b->_freq);
3747 add(con);
3748 return con;
3749 }
3750
3751 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3752 Constant con(metadata);
3753 add(con);
3754 return con;
3755 }
3756
3757 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3758 jvalue value;
3759 BasicType type = oper->type()->basic_type();
3760 switch (type) {
3761 case T_LONG: value.j = oper->constantL(); break;
3762 case T_FLOAT: value.f = oper->constantF(); break;
3763 case T_DOUBLE: value.d = oper->constantD(); break;
3764 case T_OBJECT:
3765 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3766 case T_METADATA: return add((Metadata*)oper->constant()); break;
3767 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3768 }
3769 return add(n, type, value);
3770 }
3771
3772 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3773 jvalue value;
3774 // We can use the node pointer here to identify the right jump-table
3775 // as this method is called from Compile::Fill_buffer right before
3776 // the MachNodes are emitted and the jump-table is filled (means the
3777 // MachNode pointers do not change anymore).
3778 value.l = (jobject) n;
3779 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3780 add(con);
3781 return con;
3782 }
3783
3784 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3785 // If called from Compile::scratch_emit_size do nothing.
3786 if (Compile::current()->in_scratch_emit_size()) return;
3787
3788 assert(labels.is_nonempty(), "must be");
3789 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3790
3791 // Since MachConstantNode::constant_offset() also contains
3792 // table_base_offset() we need to subtract the table_base_offset()
3793 // to get the plain offset into the constant table.
3794 int offset = n->constant_offset() - table_base_offset();
3795
3796 MacroAssembler _masm(&cb);
3797 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3798
3799 for (uint i = 0; i < n->outcnt(); i++) {
3800 address* constant_addr = &jump_table_base[i];
3801 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)));
3802 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3803 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3804 }
3805 }
3806
3807 //----------------------------static_subtype_check-----------------------------
3808 // Shortcut important common cases when superklass is exact:
3809 // (0) superklass is java.lang.Object (can occur in reflective code)
3810 // (1) subklass is already limited to a subtype of superklass => always ok
3811 // (2) subklass does not overlap with superklass => always fail
3812 // (3) superklass has NO subtypes and we can check with a simple compare.
3813 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
3814 if (StressReflectiveCode) {
3815 return SSC_full_test; // Let caller generate the general case.
3816 }
3817
3818 if (superk == env()->Object_klass()) {
3819 return SSC_always_true; // (0) this test cannot fail
3820 }
3821
3822 ciType* superelem = superk;
3823 if (superelem->is_array_klass())
3824 superelem = superelem->as_array_klass()->base_element_type();
3825
3826 if (!subk->is_interface()) { // cannot trust static interface types yet
3827 if (subk->is_subtype_of(superk)) {
3828 return SSC_always_true; // (1) false path dead; no dynamic test needed
3829 }
3830 if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
3831 !superk->is_subtype_of(subk)) {
3832 return SSC_always_false;
3833 }
3834 }
3835
3836 // If casting to an instance klass, it must have no subtypes
3837 if (superk->is_interface()) {
3838 // Cannot trust interfaces yet.
3839 // %%% S.B. superk->nof_implementors() == 1
3840 } else if (superelem->is_instance_klass()) {
3841 ciInstanceKlass* ik = superelem->as_instance_klass();
3842 if (!ik->has_subklass() && !ik->is_interface()) {
3843 if (!ik->is_final()) {
3844 // Add a dependency if there is a chance of a later subclass.
3845 dependencies()->assert_leaf_type(ik);
3846 }
3847 return SSC_easy_test; // (3) caller can do a simple ptr comparison
3848 }
3849 } else {
3850 // A primitive array type has no subtypes.
3851 return SSC_easy_test; // (3) caller can do a simple ptr comparison
3852 }
3853
3854 return SSC_full_test;
3855 }
3856
3857 // The message about the current inlining is accumulated in
3858 // _print_inlining_stream and transfered into the _print_inlining_list
3859 // once we know whether inlining succeeds or not. For regular
3860 // inlining, messages are appended to the buffer pointed by
3861 // _print_inlining_idx in the _print_inlining_list. For late inlining,
3862 // a new buffer is added after _print_inlining_idx in the list. This
3863 // way we can update the inlining message for late inlining call site
3864 // when the inlining is attempted again.
3865 void Compile::print_inlining_init() {
3866 if (print_inlining() || print_intrinsics()) {
3867 _print_inlining_stream = new stringStream();
3868 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
3869 }
3870 }
3871
3872 void Compile::print_inlining_reinit() {
3873 if (print_inlining() || print_intrinsics()) {
3874 // Re allocate buffer when we change ResourceMark
3875 _print_inlining_stream = new stringStream();
3876 }
3877 }
3878
3879 void Compile::print_inlining_reset() {
3880 _print_inlining_stream->reset();
3881 }
3882
3883 void Compile::print_inlining_commit() {
3884 assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
3885 // Transfer the message from _print_inlining_stream to the current
3886 // _print_inlining_list buffer and clear _print_inlining_stream.
3887 _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->as_string(), _print_inlining_stream->size());
3888 print_inlining_reset();
3889 }
3890
3891 void Compile::print_inlining_push() {
3892 // Add new buffer to the _print_inlining_list at current position
3893 _print_inlining_idx++;
3894 _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
3895 }
3896
3897 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
3898 return _print_inlining_list->at(_print_inlining_idx);
3899 }
3900
3901 void Compile::print_inlining_update(CallGenerator* cg) {
3902 if (print_inlining() || print_intrinsics()) {
3903 if (!cg->is_late_inline()) {
3904 if (print_inlining_current().cg() != NULL) {
3905 print_inlining_push();
3906 }
3907 print_inlining_commit();
3908 } else {
3909 if (print_inlining_current().cg() != cg &&
3910 (print_inlining_current().cg() != NULL ||
3911 print_inlining_current().ss()->size() != 0)) {
3912 print_inlining_push();
3913 }
3914 print_inlining_commit();
3915 print_inlining_current().set_cg(cg);
3916 }
3917 }
3918 }
3919
3920 void Compile::print_inlining_move_to(CallGenerator* cg) {
3921 // We resume inlining at a late inlining call site. Locate the
3922 // corresponding inlining buffer so that we can update it.
3923 if (print_inlining()) {
3924 for (int i = 0; i < _print_inlining_list->length(); i++) {
3925 if (_print_inlining_list->adr_at(i)->cg() == cg) {
3926 _print_inlining_idx = i;
3927 return;
3928 }
3929 }
3930 ShouldNotReachHere();
3931 }
3932 }
3933
3934 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
3935 if (print_inlining()) {
3936 assert(_print_inlining_stream->size() > 0, "missing inlining msg");
3937 assert(print_inlining_current().cg() == cg, "wrong entry");
3938 // replace message with new message
3939 _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
3940 print_inlining_commit();
3941 print_inlining_current().set_cg(cg);
3942 }
3943 }
3944
3945 void Compile::print_inlining_assert_ready() {
3946 assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
3947 }
3948
3949 void Compile::process_print_inlining() {
3950 bool do_print_inlining = print_inlining() || print_intrinsics();
3951 if (do_print_inlining || log() != NULL) {
3952 // Print inlining message for candidates that we couldn't inline
3953 // for lack of space
3954 for (int i = 0; i < _late_inlines.length(); i++) {
3955 CallGenerator* cg = _late_inlines.at(i);
3956 if (!cg->is_mh_late_inline()) {
3957 const char* msg = "live nodes > LiveNodeCountInliningCutoff";
3958 if (do_print_inlining) {
3959 cg->print_inlining_late(msg);
3960 }
3961 log_late_inline_failure(cg, msg);
3962 }
3963 }
3964 }
3965 if (do_print_inlining) {
3966 ResourceMark rm;
3967 stringStream ss;
3968 for (int i = 0; i < _print_inlining_list->length(); i++) {
3969 ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3970 }
3971 size_t end = ss.size();
3972 _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
3973 strncpy(_print_inlining_output, ss.base(), end+1);
3974 _print_inlining_output[end] = 0;
3975 }
3976 }
3977
3978 void Compile::dump_print_inlining() {
3979 if (_print_inlining_output != NULL) {
3980 tty->print_raw(_print_inlining_output);
3981 }
3982 }
3983
3984 void Compile::log_late_inline(CallGenerator* cg) {
3985 if (log() != NULL) {
3986 log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
3987 cg->unique_id());
3988 JVMState* p = cg->call_node()->jvms();
3989 while (p != NULL) {
3990 log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
3991 p = p->caller();
3992 }
3993 log()->tail("late_inline");
3994 }
3995 }
3996
3997 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
3998 log_late_inline(cg);
3999 if (log() != NULL) {
4000 log()->inline_fail(msg);
4001 }
4002 }
4003
4004 void Compile::log_inline_id(CallGenerator* cg) {
4005 if (log() != NULL) {
4006 // The LogCompilation tool needs a unique way to identify late
4007 // inline call sites. This id must be unique for this call site in
4008 // this compilation. Try to have it unique across compilations as
4009 // well because it can be convenient when grepping through the log
4010 // file.
4011 // Distinguish OSR compilations from others in case CICountOSR is
4012 // on.
4013 jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4014 cg->set_unique_id(id);
4015 log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4016 }
4017 }
4018
4019 void Compile::log_inline_failure(const char* msg) {
4020 if (C->log() != NULL) {
4021 C->log()->inline_fail(msg);
4022 }
4023 }
4024
4025
4026 // Dump inlining replay data to the stream.
4027 // Don't change thread state and acquire any locks.
4028 void Compile::dump_inline_data(outputStream* out) {
4029 InlineTree* inl_tree = ilt();
4030 if (inl_tree != NULL) {
4031 out->print(" inline %d", inl_tree->count());
4032 inl_tree->dump_replay_data(out);
4033 }
4034 }
4035
4036 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4037 if (n1->Opcode() < n2->Opcode()) return -1;
4038 else if (n1->Opcode() > n2->Opcode()) return 1;
4039
4040 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()));
4041 for (uint i = 1; i < n1->req(); i++) {
4042 if (n1->in(i) < n2->in(i)) return -1;
4043 else if (n1->in(i) > n2->in(i)) return 1;
4044 }
4045
4046 return 0;
4047 }
4048
4049 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4050 Node* n1 = *n1p;
4051 Node* n2 = *n2p;
4052
4053 return cmp_expensive_nodes(n1, n2);
4054 }
4055
4056 void Compile::sort_expensive_nodes() {
4057 if (!expensive_nodes_sorted()) {
4058 _expensive_nodes->sort(cmp_expensive_nodes);
4059 }
4060 }
4061
4062 bool Compile::expensive_nodes_sorted() const {
4063 for (int i = 1; i < _expensive_nodes->length(); i++) {
4064 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
4065 return false;
4066 }
4067 }
4068 return true;
4069 }
4070
4071 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4072 if (_expensive_nodes->length() == 0) {
4073 return false;
4074 }
4075
4076 assert(OptimizeExpensiveOps, "optimization off?");
4077
4078 // Take this opportunity to remove dead nodes from the list
4079 int j = 0;
4080 for (int i = 0; i < _expensive_nodes->length(); i++) {
4081 Node* n = _expensive_nodes->at(i);
4082 if (!n->is_unreachable(igvn)) {
4083 assert(n->is_expensive(), "should be expensive");
4084 _expensive_nodes->at_put(j, n);
4085 j++;
4086 }
4087 }
4088 _expensive_nodes->trunc_to(j);
4089
4090 // Then sort the list so that similar nodes are next to each other
4091 // and check for at least two nodes of identical kind with same data
4092 // inputs.
4093 sort_expensive_nodes();
4094
4095 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
4096 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
4097 return true;
4098 }
4099 }
4100
4101 return false;
4102 }
4103
4104 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4105 if (_expensive_nodes->length() == 0) {
4106 return;
4107 }
4108
4109 assert(OptimizeExpensiveOps, "optimization off?");
4110
4111 // Sort to bring similar nodes next to each other and clear the
4112 // control input of nodes for which there's only a single copy.
4113 sort_expensive_nodes();
4114
4115 int j = 0;
4116 int identical = 0;
4117 int i = 0;
4118 bool modified = false;
4119 for (; i < _expensive_nodes->length()-1; i++) {
4120 assert(j <= i, "can't write beyond current index");
4121 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4122 identical++;
4123 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4124 continue;
4125 }
4126 if (identical > 0) {
4127 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4128 identical = 0;
4129 } else {
4130 Node* n = _expensive_nodes->at(i);
4131 igvn.replace_input_of(n, 0, NULL);
4132 igvn.hash_insert(n);
4133 modified = true;
4134 }
4135 }
4136 if (identical > 0) {
4137 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4138 } else if (_expensive_nodes->length() >= 1) {
4139 Node* n = _expensive_nodes->at(i);
4140 igvn.replace_input_of(n, 0, NULL);
4141 igvn.hash_insert(n);
4142 modified = true;
4143 }
4144 _expensive_nodes->trunc_to(j);
4145 if (modified) {
4146 igvn.optimize();
4147 }
4148 }
4149
4150 void Compile::add_expensive_node(Node * n) {
4151 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4152 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4153 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4154 if (OptimizeExpensiveOps) {
4155 _expensive_nodes->append(n);
4156 } else {
4157 // Clear control input and let IGVN optimize expensive nodes if
4158 // OptimizeExpensiveOps is off.
4159 n->set_req(0, NULL);
4160 }
4161 }
4162
4163 /**
4164 * Remove the speculative part of types and clean up the graph
4165 */
4166 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4167 if (UseTypeSpeculation) {
4168 Unique_Node_List worklist;
4169 worklist.push(root());
4170 int modified = 0;
4171 // Go over all type nodes that carry a speculative type, drop the
4172 // speculative part of the type and enqueue the node for an igvn
4173 // which may optimize it out.
4174 for (uint next = 0; next < worklist.size(); ++next) {
4175 Node *n = worklist.at(next);
4176 if (n->is_Type()) {
4177 TypeNode* tn = n->as_Type();
4178 const Type* t = tn->type();
4179 const Type* t_no_spec = t->remove_speculative();
4180 if (t_no_spec != t) {
4181 bool in_hash = igvn.hash_delete(n);
4182 assert(in_hash, "node should be in igvn hash table");
4183 tn->set_type(t_no_spec);
4184 igvn.hash_insert(n);
4185 igvn._worklist.push(n); // give it a chance to go away
4186 modified++;
4187 }
4188 }
4189 uint max = n->len();
4190 for( uint i = 0; i < max; ++i ) {
4191 Node *m = n->in(i);
4192 if (not_a_node(m)) continue;
4193 worklist.push(m);
4194 }
4195 }
4196 // Drop the speculative part of all types in the igvn's type table
4197 igvn.remove_speculative_types();
4198 if (modified > 0) {
4199 igvn.optimize();
4200 }
4201 #ifdef ASSERT
4202 // Verify that after the IGVN is over no speculative type has resurfaced
4203 worklist.clear();
4204 worklist.push(root());
4205 for (uint next = 0; next < worklist.size(); ++next) {
4206 Node *n = worklist.at(next);
4207 const Type* t = igvn.type_or_null(n);
4208 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4209 if (n->is_Type()) {
4210 t = n->as_Type()->type();
4211 assert(t == t->remove_speculative(), "no more speculative types");
4212 }
4213 uint max = n->len();
4214 for( uint i = 0; i < max; ++i ) {
4215 Node *m = n->in(i);
4216 if (not_a_node(m)) continue;
4217 worklist.push(m);
4218 }
4219 }
4220 igvn.check_no_speculative_types();
4221 #endif
4222 }
4223 }
4224
4225 // Auxiliary method to support randomized stressing/fuzzing.
4226 //
4227 // This method can be called the arbitrary number of times, with current count
4228 // as the argument. The logic allows selecting a single candidate from the
4229 // running list of candidates as follows:
4230 // int count = 0;
4231 // Cand* selected = null;
4232 // while(cand = cand->next()) {
4233 // if (randomized_select(++count)) {
4234 // selected = cand;
4235 // }
4236 // }
4237 //
4238 // Including count equalizes the chances any candidate is "selected".
4239 // This is useful when we don't have the complete list of candidates to choose
4240 // from uniformly. In this case, we need to adjust the randomicity of the
4241 // selection, or else we will end up biasing the selection towards the latter
4242 // candidates.
4243 //
4244 // Quick back-envelope calculation shows that for the list of n candidates
4245 // the equal probability for the candidate to persist as "best" can be
4246 // achieved by replacing it with "next" k-th candidate with the probability
4247 // of 1/k. It can be easily shown that by the end of the run, the
4248 // probability for any candidate is converged to 1/n, thus giving the
4249 // uniform distribution among all the candidates.
4250 //
4251 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4252 #define RANDOMIZED_DOMAIN_POW 29
4253 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4254 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4255 bool Compile::randomized_select(int count) {
4256 assert(count > 0, "only positive");
4257 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4258 }