1 /*
2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "ci/ciReplay.hpp"
29 #include "classfile/systemDictionary.hpp"
30 #include "code/exceptionHandlerTable.hpp"
31 #include "code/nmethod.hpp"
32 #include "compiler/compileLog.hpp"
33 #include "compiler/disassembler.hpp"
34 #include "compiler/oopMap.hpp"
35 #include "jfr/jfrEvents.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/node.hpp"
56 #include "opto/opcodes.hpp"
57 #include "opto/output.hpp"
58 #include "opto/parse.hpp"
59 #include "opto/phaseX.hpp"
60 #include "opto/rootnode.hpp"
61 #include "opto/runtime.hpp"
62 #include "opto/stringopts.hpp"
63 #include "opto/type.hpp"
64 #include "opto/vectornode.hpp"
65 #include "runtime/arguments.hpp"
66 #include "runtime/signature.hpp"
67 #include "runtime/stubRoutines.hpp"
68 #include "runtime/timer.hpp"
69 #include "utilities/copy.hpp"
70 #if defined AD_MD_HPP
71 # include AD_MD_HPP
72 #elif defined TARGET_ARCH_MODEL_x86_32
73 # include "adfiles/ad_x86_32.hpp"
74 #elif defined TARGET_ARCH_MODEL_x86_64
75 # include "adfiles/ad_x86_64.hpp"
76 #elif defined TARGET_ARCH_MODEL_sparc
77 # include "adfiles/ad_sparc.hpp"
78 #elif defined TARGET_ARCH_MODEL_zero
79 # include "adfiles/ad_zero.hpp"
80 #elif defined TARGET_ARCH_MODEL_ppc_64
81 # include "adfiles/ad_ppc_64.hpp"
82 #endif
83
84 // -------------------- Compile::mach_constant_base_node -----------------------
85 // Constant table base node singleton.
86 MachConstantBaseNode* Compile::mach_constant_base_node() {
87 if (_mach_constant_base_node == NULL) {
88 _mach_constant_base_node = new (C) MachConstantBaseNode();
89 _mach_constant_base_node->add_req(C->root());
90 }
91 return _mach_constant_base_node;
92 }
93
94
95 /// Support for intrinsics.
96
97 // Return the index at which m must be inserted (or already exists).
98 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
99 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
100 #ifdef ASSERT
101 for (int i = 1; i < _intrinsics->length(); i++) {
102 CallGenerator* cg1 = _intrinsics->at(i-1);
103 CallGenerator* cg2 = _intrinsics->at(i);
104 assert(cg1->method() != cg2->method()
105 ? cg1->method() < cg2->method()
106 : cg1->is_virtual() < cg2->is_virtual(),
107 "compiler intrinsics list must stay sorted");
108 }
109 #endif
110 // Binary search sorted list, in decreasing intervals [lo, hi].
111 int lo = 0, hi = _intrinsics->length()-1;
112 while (lo <= hi) {
113 int mid = (uint)(hi + lo) / 2;
114 ciMethod* mid_m = _intrinsics->at(mid)->method();
115 if (m < mid_m) {
116 hi = mid-1;
117 } else if (m > mid_m) {
118 lo = mid+1;
119 } else {
120 // look at minor sort key
121 bool mid_virt = _intrinsics->at(mid)->is_virtual();
122 if (is_virtual < mid_virt) {
123 hi = mid-1;
124 } else if (is_virtual > mid_virt) {
125 lo = mid+1;
126 } else {
127 return mid; // exact match
128 }
129 }
130 }
131 return lo; // inexact match
132 }
133
134 void Compile::register_intrinsic(CallGenerator* cg) {
135 if (_intrinsics == NULL) {
136 _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
137 }
138 // This code is stolen from ciObjectFactory::insert.
139 // Really, GrowableArray should have methods for
140 // insert_at, remove_at, and binary_search.
141 int len = _intrinsics->length();
142 int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
143 if (index == len) {
144 _intrinsics->append(cg);
145 } else {
146 #ifdef ASSERT
147 CallGenerator* oldcg = _intrinsics->at(index);
148 assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
149 #endif
150 _intrinsics->append(_intrinsics->at(len-1));
151 int pos;
152 for (pos = len-2; pos >= index; pos--) {
153 _intrinsics->at_put(pos+1,_intrinsics->at(pos));
154 }
155 _intrinsics->at_put(index, cg);
156 }
157 assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
158 }
159
160 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
161 assert(m->is_loaded(), "don't try this on unloaded methods");
162 if (_intrinsics != NULL) {
163 int index = intrinsic_insertion_index(m, is_virtual);
164 if (index < _intrinsics->length()
165 && _intrinsics->at(index)->method() == m
166 && _intrinsics->at(index)->is_virtual() == is_virtual) {
167 return _intrinsics->at(index);
168 }
169 }
170 // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
171 if (m->intrinsic_id() != vmIntrinsics::_none &&
172 m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
173 CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
174 if (cg != NULL) {
175 // Save it for next time:
176 register_intrinsic(cg);
177 return cg;
178 } else {
179 gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
180 }
181 }
182 return NULL;
183 }
184
185 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
186 // in library_call.cpp.
187
188
189 #ifndef PRODUCT
190 // statistics gathering...
191
192 juint Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
193 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
194
195 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
196 assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
197 int oflags = _intrinsic_hist_flags[id];
198 assert(flags != 0, "what happened?");
199 if (is_virtual) {
200 flags |= _intrinsic_virtual;
201 }
202 bool changed = (flags != oflags);
203 if ((flags & _intrinsic_worked) != 0) {
204 juint count = (_intrinsic_hist_count[id] += 1);
205 if (count == 1) {
206 changed = true; // first time
207 }
208 // increment the overall count also:
209 _intrinsic_hist_count[vmIntrinsics::_none] += 1;
210 }
211 if (changed) {
212 if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
213 // Something changed about the intrinsic's virtuality.
214 if ((flags & _intrinsic_virtual) != 0) {
215 // This is the first use of this intrinsic as a virtual call.
216 if (oflags != 0) {
217 // We already saw it as a non-virtual, so note both cases.
218 flags |= _intrinsic_both;
219 }
220 } else if ((oflags & _intrinsic_both) == 0) {
221 // This is the first use of this intrinsic as a non-virtual
222 flags |= _intrinsic_both;
223 }
224 }
225 _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
226 }
227 // update the overall flags also:
228 _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
229 return changed;
230 }
231
232 static char* format_flags(int flags, char* buf) {
233 buf[0] = 0;
234 if ((flags & Compile::_intrinsic_worked) != 0) strcat(buf, ",worked");
235 if ((flags & Compile::_intrinsic_failed) != 0) strcat(buf, ",failed");
236 if ((flags & Compile::_intrinsic_disabled) != 0) strcat(buf, ",disabled");
237 if ((flags & Compile::_intrinsic_virtual) != 0) strcat(buf, ",virtual");
238 if ((flags & Compile::_intrinsic_both) != 0) strcat(buf, ",nonvirtual");
239 if (buf[0] == 0) strcat(buf, ",");
240 assert(buf[0] == ',', "must be");
241 return &buf[1];
242 }
243
244 void Compile::print_intrinsic_statistics() {
245 char flagsbuf[100];
246 ttyLocker ttyl;
247 if (xtty != NULL) xtty->head("statistics type='intrinsic'");
248 tty->print_cr("Compiler intrinsic usage:");
249 juint total = _intrinsic_hist_count[vmIntrinsics::_none];
250 if (total == 0) total = 1; // avoid div0 in case of no successes
251 #define PRINT_STAT_LINE(name, c, f) \
252 tty->print_cr(" %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
253 for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
254 vmIntrinsics::ID id = (vmIntrinsics::ID) index;
255 int flags = _intrinsic_hist_flags[id];
256 juint count = _intrinsic_hist_count[id];
257 if ((flags | count) != 0) {
258 PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
259 }
260 }
261 PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
262 if (xtty != NULL) xtty->tail("statistics");
263 }
264
265 void Compile::print_statistics() {
266 { ttyLocker ttyl;
267 if (xtty != NULL) xtty->head("statistics type='opto'");
268 Parse::print_statistics();
269 PhaseCCP::print_statistics();
270 PhaseRegAlloc::print_statistics();
271 Scheduling::print_statistics();
272 PhasePeephole::print_statistics();
273 PhaseIdealLoop::print_statistics();
274 if (xtty != NULL) xtty->tail("statistics");
275 }
276 if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
277 // put this under its own <statistics> element.
278 print_intrinsic_statistics();
279 }
280 }
281 #endif //PRODUCT
282
283 // Support for bundling info
284 Bundle* Compile::node_bundling(const Node *n) {
285 assert(valid_bundle_info(n), "oob");
286 return &_node_bundling_base[n->_idx];
287 }
288
289 bool Compile::valid_bundle_info(const Node *n) {
290 return (_node_bundling_limit > n->_idx);
291 }
292
293
294 void Compile::gvn_replace_by(Node* n, Node* nn) {
295 for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
296 Node* use = n->last_out(i);
297 bool is_in_table = initial_gvn()->hash_delete(use);
298 uint uses_found = 0;
299 for (uint j = 0; j < use->len(); j++) {
300 if (use->in(j) == n) {
301 if (j < use->req())
302 use->set_req(j, nn);
303 else
304 use->set_prec(j, nn);
305 uses_found++;
306 }
307 }
308 if (is_in_table) {
309 // reinsert into table
310 initial_gvn()->hash_find_insert(use);
311 }
312 record_for_igvn(use);
313 i -= uses_found; // we deleted 1 or more copies of this edge
314 }
315 }
316
317
318 static inline bool not_a_node(const Node* n) {
319 if (n == NULL) return true;
320 if (((intptr_t)n & 1) != 0) return true; // uninitialized, etc.
321 if (*(address*)n == badAddress) return true; // kill by Node::destruct
322 return false;
323 }
324
325 // Identify all nodes that are reachable from below, useful.
326 // Use breadth-first pass that records state in a Unique_Node_List,
327 // recursive traversal is slower.
328 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
329 int estimated_worklist_size = live_nodes();
330 useful.map( estimated_worklist_size, NULL ); // preallocate space
331
332 // Initialize worklist
333 if (root() != NULL) { useful.push(root()); }
334 // If 'top' is cached, declare it useful to preserve cached node
335 if( cached_top_node() ) { useful.push(cached_top_node()); }
336
337 // Push all useful nodes onto the list, breadthfirst
338 for( uint next = 0; next < useful.size(); ++next ) {
339 assert( next < unique(), "Unique useful nodes < total nodes");
340 Node *n = useful.at(next);
341 uint max = n->len();
342 for( uint i = 0; i < max; ++i ) {
343 Node *m = n->in(i);
344 if (not_a_node(m)) continue;
345 useful.push(m);
346 }
347 }
348 }
349
350 // Update dead_node_list with any missing dead nodes using useful
351 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
352 void Compile::update_dead_node_list(Unique_Node_List &useful) {
353 uint max_idx = unique();
354 VectorSet& useful_node_set = useful.member_set();
355
356 for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
357 // If node with index node_idx is not in useful set,
358 // mark it as dead in dead node list.
359 if (! useful_node_set.test(node_idx) ) {
360 record_dead_node(node_idx);
361 }
362 }
363 }
364
365 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
366 int shift = 0;
367 for (int i = 0; i < inlines->length(); i++) {
368 CallGenerator* cg = inlines->at(i);
369 CallNode* call = cg->call_node();
370 if (shift > 0) {
371 inlines->at_put(i-shift, cg);
372 }
373 if (!useful.member(call)) {
374 shift++;
375 }
376 }
377 inlines->trunc_to(inlines->length()-shift);
378 }
379
380 // Disconnect all useless nodes by disconnecting those at the boundary.
381 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
382 uint next = 0;
383 while (next < useful.size()) {
384 Node *n = useful.at(next++);
385 if (n->is_SafePoint()) {
386 // We're done with a parsing phase. Replaced nodes are not valid
387 // beyond that point.
388 n->as_SafePoint()->delete_replaced_nodes();
389 }
390 // Use raw traversal of out edges since this code removes out edges
391 int max = n->outcnt();
392 for (int j = 0; j < max; ++j) {
393 Node* child = n->raw_out(j);
394 if (! useful.member(child)) {
395 assert(!child->is_top() || child != top(),
396 "If top is cached in Compile object it is in useful list");
397 // Only need to remove this out-edge to the useless node
398 n->raw_del_out(j);
399 --j;
400 --max;
401 }
402 }
403 if (n->outcnt() == 1 && n->has_special_unique_user()) {
404 record_for_igvn(n->unique_out());
405 }
406 }
407 // Remove useless macro and predicate opaq nodes
408 for (int i = C->macro_count()-1; i >= 0; i--) {
409 Node* n = C->macro_node(i);
410 if (!useful.member(n)) {
411 remove_macro_node(n);
412 }
413 }
414 // Remove useless CastII nodes with range check dependency
415 for (int i = range_check_cast_count() - 1; i >= 0; i--) {
416 Node* cast = range_check_cast_node(i);
417 if (!useful.member(cast)) {
418 remove_range_check_cast(cast);
419 }
420 }
421 // Remove useless expensive node
422 for (int i = C->expensive_count()-1; i >= 0; i--) {
423 Node* n = C->expensive_node(i);
424 if (!useful.member(n)) {
425 remove_expensive_node(n);
426 }
427 }
428 // clean up the late inline lists
429 remove_useless_late_inlines(&_string_late_inlines, useful);
430 remove_useless_late_inlines(&_boxing_late_inlines, useful);
431 remove_useless_late_inlines(&_late_inlines, useful);
432 debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
433 }
434
435 //------------------------------frame_size_in_words-----------------------------
436 // frame_slots in units of words
437 int Compile::frame_size_in_words() const {
438 // shift is 0 in LP32 and 1 in LP64
439 const int shift = (LogBytesPerWord - LogBytesPerInt);
440 int words = _frame_slots >> shift;
441 assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
442 return words;
443 }
444
445 // To bang the stack of this compiled method we use the stack size
446 // that the interpreter would need in case of a deoptimization. This
447 // removes the need to bang the stack in the deoptimization blob which
448 // in turn simplifies stack overflow handling.
449 int Compile::bang_size_in_bytes() const {
450 return MAX2(_interpreter_frame_size, frame_size_in_bytes());
451 }
452
453 // ============================================================================
454 //------------------------------CompileWrapper---------------------------------
455 class CompileWrapper : public StackObj {
456 Compile *const _compile;
457 public:
458 CompileWrapper(Compile* compile);
459
460 ~CompileWrapper();
461 };
462
463 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
464 // the Compile* pointer is stored in the current ciEnv:
465 ciEnv* env = compile->env();
466 assert(env == ciEnv::current(), "must already be a ciEnv active");
467 assert(env->compiler_data() == NULL, "compile already active?");
468 env->set_compiler_data(compile);
469 assert(compile == Compile::current(), "sanity");
470
471 compile->set_type_dict(NULL);
472 compile->set_type_hwm(NULL);
473 compile->set_type_last_size(0);
474 compile->set_last_tf(NULL, NULL);
475 compile->set_indexSet_arena(NULL);
476 compile->set_indexSet_free_block_list(NULL);
477 compile->init_type_arena();
478 Type::Initialize(compile);
479 _compile->set_scratch_buffer_blob(NULL);
480 _compile->begin_method();
481 }
482 CompileWrapper::~CompileWrapper() {
483 _compile->end_method();
484 if (_compile->scratch_buffer_blob() != NULL)
485 BufferBlob::free(_compile->scratch_buffer_blob());
486 _compile->env()->set_compiler_data(NULL);
487 }
488
489
490 //----------------------------print_compile_messages---------------------------
491 void Compile::print_compile_messages() {
492 #ifndef PRODUCT
493 // Check if recompiling
494 if (_subsume_loads == false && PrintOpto) {
495 // Recompiling without allowing machine instructions to subsume loads
496 tty->print_cr("*********************************************************");
497 tty->print_cr("** Bailout: Recompile without subsuming loads **");
498 tty->print_cr("*********************************************************");
499 }
500 if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
501 // Recompiling without escape analysis
502 tty->print_cr("*********************************************************");
503 tty->print_cr("** Bailout: Recompile without escape analysis **");
504 tty->print_cr("*********************************************************");
505 }
506 if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
507 // Recompiling without boxing elimination
508 tty->print_cr("*********************************************************");
509 tty->print_cr("** Bailout: Recompile without boxing elimination **");
510 tty->print_cr("*********************************************************");
511 }
512 if (env()->break_at_compile()) {
513 // Open the debugger when compiling this method.
514 tty->print("### Breaking when compiling: ");
515 method()->print_short_name();
516 tty->cr();
517 BREAKPOINT;
518 }
519
520 if( PrintOpto ) {
521 if (is_osr_compilation()) {
522 tty->print("[OSR]%3d", _compile_id);
523 } else {
524 tty->print("%3d", _compile_id);
525 }
526 }
527 #endif
528 }
529
530
531 //-----------------------init_scratch_buffer_blob------------------------------
532 // Construct a temporary BufferBlob and cache it for this compile.
533 void Compile::init_scratch_buffer_blob(int const_size) {
534 // If there is already a scratch buffer blob allocated and the
535 // constant section is big enough, use it. Otherwise free the
536 // current and allocate a new one.
537 BufferBlob* blob = scratch_buffer_blob();
538 if ((blob != NULL) && (const_size <= _scratch_const_size)) {
539 // Use the current blob.
540 } else {
541 if (blob != NULL) {
542 BufferBlob::free(blob);
543 }
544
545 ResourceMark rm;
546 _scratch_const_size = const_size;
547 int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
548 blob = BufferBlob::create("Compile::scratch_buffer", size);
549 // Record the buffer blob for next time.
550 set_scratch_buffer_blob(blob);
551 // Have we run out of code space?
552 if (scratch_buffer_blob() == NULL) {
553 // Let CompilerBroker disable further compilations.
554 record_failure("Not enough space for scratch buffer in CodeCache");
555 return;
556 }
557 }
558
559 // Initialize the relocation buffers
560 relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
561 set_scratch_locs_memory(locs_buf);
562 }
563
564
565 //-----------------------scratch_emit_size-------------------------------------
566 // Helper function that computes size by emitting code
567 uint Compile::scratch_emit_size(const Node* n) {
568 // Start scratch_emit_size section.
569 set_in_scratch_emit_size(true);
570
571 // Emit into a trash buffer and count bytes emitted.
572 // This is a pretty expensive way to compute a size,
573 // but it works well enough if seldom used.
574 // All common fixed-size instructions are given a size
575 // method by the AD file.
576 // Note that the scratch buffer blob and locs memory are
577 // allocated at the beginning of the compile task, and
578 // may be shared by several calls to scratch_emit_size.
579 // The allocation of the scratch buffer blob is particularly
580 // expensive, since it has to grab the code cache lock.
581 BufferBlob* blob = this->scratch_buffer_blob();
582 assert(blob != NULL, "Initialize BufferBlob at start");
583 assert(blob->size() > MAX_inst_size, "sanity");
584 relocInfo* locs_buf = scratch_locs_memory();
585 address blob_begin = blob->content_begin();
586 address blob_end = (address)locs_buf;
587 assert(blob->content_contains(blob_end), "sanity");
588 CodeBuffer buf(blob_begin, blob_end - blob_begin);
589 buf.initialize_consts_size(_scratch_const_size);
590 buf.initialize_stubs_size(MAX_stubs_size);
591 assert(locs_buf != NULL, "sanity");
592 int lsize = MAX_locs_size / 3;
593 buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
594 buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
595 buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
596
597 // Do the emission.
598
599 Label fakeL; // Fake label for branch instructions.
600 Label* saveL = NULL;
601 uint save_bnum = 0;
602 bool is_branch = n->is_MachBranch();
603 if (is_branch) {
604 MacroAssembler masm(&buf);
605 masm.bind(fakeL);
606 n->as_MachBranch()->save_label(&saveL, &save_bnum);
607 n->as_MachBranch()->label_set(&fakeL, 0);
608 }
609 n->emit(buf, this->regalloc());
610
611 // Emitting into the scratch buffer should not fail
612 assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
613
614 if (is_branch) // Restore label.
615 n->as_MachBranch()->label_set(saveL, save_bnum);
616
617 // End scratch_emit_size section.
618 set_in_scratch_emit_size(false);
619
620 return buf.insts_size();
621 }
622
623
624 // ============================================================================
625 //------------------------------Compile standard-------------------------------
626 debug_only( int Compile::_debug_idx = 100000; )
627
628 // Compile a method. entry_bci is -1 for normal compilations and indicates
629 // the continuation bci for on stack replacement.
630
631
632 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
633 bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
634 : Phase(Compiler),
635 _env(ci_env),
636 _log(ci_env->log()),
637 _compile_id(ci_env->compile_id()),
638 _save_argument_registers(false),
639 _stub_name(NULL),
640 _stub_function(NULL),
641 _stub_entry_point(NULL),
642 _method(target),
643 _entry_bci(osr_bci),
644 _initial_gvn(NULL),
645 _for_igvn(NULL),
646 _warm_calls(NULL),
647 _subsume_loads(subsume_loads),
648 _do_escape_analysis(do_escape_analysis),
649 _eliminate_boxing(eliminate_boxing),
650 _failure_reason(NULL),
651 _code_buffer("Compile::Fill_buffer"),
652 _orig_pc_slot(0),
653 _orig_pc_slot_offset_in_bytes(0),
654 _has_method_handle_invokes(false),
655 _mach_constant_base_node(NULL),
656 _node_bundling_limit(0),
657 _node_bundling_base(NULL),
658 _java_calls(0),
659 _inner_loops(0),
660 _scratch_const_size(-1),
661 _in_scratch_emit_size(false),
662 _dead_node_list(comp_arena()),
663 _dead_node_count(0),
664 #ifndef PRODUCT
665 _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
666 _in_dump_cnt(0),
667 _printer(IdealGraphPrinter::printer()),
668 #endif
669 _congraph(NULL),
670 _comp_arena(mtCompiler),
671 _node_arena(mtCompiler),
672 _old_arena(mtCompiler),
673 _Compile_types(mtCompiler),
674 _replay_inline_data(NULL),
675 _late_inlines(comp_arena(), 2, 0, NULL),
676 _string_late_inlines(comp_arena(), 2, 0, NULL),
677 _boxing_late_inlines(comp_arena(), 2, 0, NULL),
678 _late_inlines_pos(0),
679 _number_of_mh_late_inlines(0),
680 _inlining_progress(false),
681 _inlining_incrementally(false),
682 _print_inlining_list(NULL),
683 _print_inlining_idx(0),
684 _interpreter_frame_size(0),
685 _max_node_limit(MaxNodeLimit) {
686 C = this;
687
688 CompileWrapper cw(this);
689 #ifndef PRODUCT
690 if (TimeCompiler2) {
691 tty->print(" ");
692 target->holder()->name()->print();
693 tty->print(".");
694 target->print_short_name();
695 tty->print(" ");
696 }
697 TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
698 TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
699 bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
700 if (!print_opto_assembly) {
701 bool print_assembly = (PrintAssembly || _method->should_print_assembly());
702 if (print_assembly && !Disassembler::can_decode()) {
703 tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
704 print_opto_assembly = true;
705 }
706 }
707 set_print_assembly(print_opto_assembly);
708 set_parsed_irreducible_loop(false);
709
710 if (method()->has_option("ReplayInline")) {
711 _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
712 }
713 #endif
714 set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
715 set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
716 set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
717
718 if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
719 // Make sure the method being compiled gets its own MDO,
720 // so we can at least track the decompile_count().
721 // Need MDO to record RTM code generation state.
722 method()->ensure_method_data();
723 }
724
725 Init(::AliasLevel);
726
727
728 print_compile_messages();
729
730 _ilt = InlineTree::build_inline_tree_root();
731
732 // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
733 assert(num_alias_types() >= AliasIdxRaw, "");
734
735 #define MINIMUM_NODE_HASH 1023
736 // Node list that Iterative GVN will start with
737 Unique_Node_List for_igvn(comp_arena());
738 set_for_igvn(&for_igvn);
739
740 // GVN that will be run immediately on new nodes
741 uint estimated_size = method()->code_size()*4+64;
742 estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
743 PhaseGVN gvn(node_arena(), estimated_size);
744 set_initial_gvn(&gvn);
745
746 if (print_inlining() || print_intrinsics()) {
747 _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
748 }
749 { // Scope for timing the parser
750 TracePhase t3("parse", &_t_parser, true);
751
752 // Put top into the hash table ASAP.
753 initial_gvn()->transform_no_reclaim(top());
754
755 // Set up tf(), start(), and find a CallGenerator.
756 CallGenerator* cg = NULL;
757 if (is_osr_compilation()) {
758 const TypeTuple *domain = StartOSRNode::osr_domain();
759 const TypeTuple *range = TypeTuple::make_range(method()->signature());
760 init_tf(TypeFunc::make(domain, range));
761 StartNode* s = new (this) StartOSRNode(root(), domain);
762 initial_gvn()->set_type_bottom(s);
763 init_start(s);
764 cg = CallGenerator::for_osr(method(), entry_bci());
765 } else {
766 // Normal case.
767 init_tf(TypeFunc::make(method()));
768 StartNode* s = new (this) StartNode(root(), tf()->domain());
769 initial_gvn()->set_type_bottom(s);
770 init_start(s);
771 if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
772 // With java.lang.ref.reference.get() we must go through the
773 // intrinsic when G1 is enabled - even when get() is the root
774 // method of the compile - so that, if necessary, the value in
775 // the referent field of the reference object gets recorded by
776 // the pre-barrier code.
777 // Specifically, if G1 is enabled, the value in the referent
778 // field is recorded by the G1 SATB pre barrier. This will
779 // result in the referent being marked live and the reference
780 // object removed from the list of discovered references during
781 // reference processing.
782 cg = find_intrinsic(method(), false);
783 }
784 if (cg == NULL) {
785 float past_uses = method()->interpreter_invocation_count();
786 float expected_uses = past_uses;
787 cg = CallGenerator::for_inline(method(), expected_uses);
788 }
789 }
790 if (failing()) return;
791 if (cg == NULL) {
792 record_method_not_compilable_all_tiers("cannot parse method");
793 return;
794 }
795 JVMState* jvms = build_start_state(start(), tf());
796 if ((jvms = cg->generate(jvms)) == NULL) {
797 if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
798 record_method_not_compilable("method parse failed");
799 }
800 return;
801 }
802 GraphKit kit(jvms);
803
804 if (!kit.stopped()) {
805 // Accept return values, and transfer control we know not where.
806 // This is done by a special, unique ReturnNode bound to root.
807 return_values(kit.jvms());
808 }
809
810 if (kit.has_exceptions()) {
811 // Any exceptions that escape from this call must be rethrown
812 // to whatever caller is dynamically above us on the stack.
813 // This is done by a special, unique RethrowNode bound to root.
814 rethrow_exceptions(kit.transfer_exceptions_into_jvms());
815 }
816
817 assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
818
819 if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
820 inline_string_calls(true);
821 }
822
823 if (failing()) return;
824
825 print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
826
827 // Remove clutter produced by parsing.
828 if (!failing()) {
829 ResourceMark rm;
830 PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
831 }
832 }
833
834 // Note: Large methods are capped off in do_one_bytecode().
835 if (failing()) return;
836
837 // After parsing, node notes are no longer automagic.
838 // They must be propagated by register_new_node_with_optimizer(),
839 // clone(), or the like.
840 set_default_node_notes(NULL);
841
842 for (;;) {
843 int successes = Inline_Warm();
844 if (failing()) return;
845 if (successes == 0) break;
846 }
847
848 // Drain the list.
849 Finish_Warm();
850 #ifndef PRODUCT
851 if (_printer) {
852 _printer->print_inlining(this);
853 }
854 #endif
855
856 if (failing()) return;
857 NOT_PRODUCT( verify_graph_edges(); )
858
859 // Now optimize
860 Optimize();
861 if (failing()) return;
862 NOT_PRODUCT( verify_graph_edges(); )
863
864 #ifndef PRODUCT
865 if (PrintIdeal) {
866 ttyLocker ttyl; // keep the following output all in one block
867 // This output goes directly to the tty, not the compiler log.
868 // To enable tools to match it up with the compilation activity,
869 // be sure to tag this tty output with the compile ID.
870 if (xtty != NULL) {
871 xtty->head("ideal compile_id='%d'%s", compile_id(),
872 is_osr_compilation() ? " compile_kind='osr'" :
873 "");
874 }
875 root()->dump(9999);
876 if (xtty != NULL) {
877 xtty->tail("ideal");
878 }
879 }
880 #endif
881
882 NOT_PRODUCT( verify_barriers(); )
883
884 // Dump compilation data to replay it.
885 if (method()->has_option("DumpReplay")) {
886 env()->dump_replay_data(_compile_id);
887 }
888 if (method()->has_option("DumpInline") && (ilt() != NULL)) {
889 env()->dump_inline_data(_compile_id);
890 }
891
892 // Now that we know the size of all the monitors we can add a fixed slot
893 // for the original deopt pc.
894
895 _orig_pc_slot = fixed_slots();
896 int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
897 set_fixed_slots(next_slot);
898
899 // Compute when to use implicit null checks. Used by matching trap based
900 // nodes and NullCheck optimization.
901 set_allowed_deopt_reasons();
902
903 // Now generate code
904 Code_Gen();
905 if (failing()) return;
906
907 // Check if we want to skip execution of all compiled code.
908 {
909 #ifndef PRODUCT
910 if (OptoNoExecute) {
911 record_method_not_compilable("+OptoNoExecute"); // Flag as failed
912 return;
913 }
914 TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
915 #endif
916
917 if (is_osr_compilation()) {
918 _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
919 _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
920 } else {
921 _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
922 _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
923 }
924
925 env()->register_method(_method, _entry_bci,
926 &_code_offsets,
927 _orig_pc_slot_offset_in_bytes,
928 code_buffer(),
929 frame_size_in_words(), _oop_map_set,
930 &_handler_table, &_inc_table,
931 compiler,
932 env()->comp_level(),
933 has_unsafe_access(),
934 SharedRuntime::is_wide_vector(max_vector_size()),
935 rtm_state()
936 );
937
938 if (log() != NULL) // Print code cache state into compiler log
939 log()->code_cache_state();
940 }
941 }
942
943 //------------------------------Compile----------------------------------------
944 // Compile a runtime stub
945 Compile::Compile( ciEnv* ci_env,
946 TypeFunc_generator generator,
947 address stub_function,
948 const char *stub_name,
949 int is_fancy_jump,
950 bool pass_tls,
951 bool save_arg_registers,
952 bool return_pc )
953 : Phase(Compiler),
954 _env(ci_env),
955 _log(ci_env->log()),
956 _compile_id(0),
957 _save_argument_registers(save_arg_registers),
958 _method(NULL),
959 _stub_name(stub_name),
960 _stub_function(stub_function),
961 _stub_entry_point(NULL),
962 _entry_bci(InvocationEntryBci),
963 _initial_gvn(NULL),
964 _for_igvn(NULL),
965 _warm_calls(NULL),
966 _orig_pc_slot(0),
967 _orig_pc_slot_offset_in_bytes(0),
968 _subsume_loads(true),
969 _do_escape_analysis(false),
970 _eliminate_boxing(false),
971 _failure_reason(NULL),
972 _code_buffer("Compile::Fill_buffer"),
973 _has_method_handle_invokes(false),
974 _mach_constant_base_node(NULL),
975 _node_bundling_limit(0),
976 _node_bundling_base(NULL),
977 _java_calls(0),
978 _inner_loops(0),
979 #ifndef PRODUCT
980 _trace_opto_output(TraceOptoOutput),
981 _in_dump_cnt(0),
982 _printer(NULL),
983 #endif
984 _comp_arena(mtCompiler),
985 _node_arena(mtCompiler),
986 _old_arena(mtCompiler),
987 _Compile_types(mtCompiler),
988 _dead_node_list(comp_arena()),
989 _dead_node_count(0),
990 _congraph(NULL),
991 _replay_inline_data(NULL),
992 _number_of_mh_late_inlines(0),
993 _inlining_progress(false),
994 _inlining_incrementally(false),
995 _print_inlining_list(NULL),
996 _print_inlining_idx(0),
997 _allowed_reasons(0),
998 _interpreter_frame_size(0),
999 _max_node_limit(MaxNodeLimit) {
1000 C = this;
1001
1002 #ifndef PRODUCT
1003 TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
1004 TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
1005 set_print_assembly(PrintFrameConverterAssembly);
1006 set_parsed_irreducible_loop(false);
1007 #endif
1008 set_has_irreducible_loop(false); // no loops
1009
1010 CompileWrapper cw(this);
1011 Init(/*AliasLevel=*/ 0);
1012 init_tf((*generator)());
1013
1014 {
1015 // The following is a dummy for the sake of GraphKit::gen_stub
1016 Unique_Node_List for_igvn(comp_arena());
1017 set_for_igvn(&for_igvn); // not used, but some GraphKit guys push on this
1018 PhaseGVN gvn(Thread::current()->resource_area(),255);
1019 set_initial_gvn(&gvn); // not significant, but GraphKit guys use it pervasively
1020 gvn.transform_no_reclaim(top());
1021
1022 GraphKit kit;
1023 kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1024 }
1025
1026 NOT_PRODUCT( verify_graph_edges(); )
1027 Code_Gen();
1028 if (failing()) return;
1029
1030
1031 // Entry point will be accessed using compile->stub_entry_point();
1032 if (code_buffer() == NULL) {
1033 Matcher::soft_match_failure();
1034 } else {
1035 if (PrintAssembly && (WizardMode || Verbose))
1036 tty->print_cr("### Stub::%s", stub_name);
1037
1038 if (!failing()) {
1039 assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
1040
1041 // Make the NMethod
1042 // For now we mark the frame as never safe for profile stackwalking
1043 RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
1044 code_buffer(),
1045 CodeOffsets::frame_never_safe,
1046 // _code_offsets.value(CodeOffsets::Frame_Complete),
1047 frame_size_in_words(),
1048 _oop_map_set,
1049 save_arg_registers);
1050 assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
1051
1052 _stub_entry_point = rs->entry_point();
1053 }
1054 }
1055 }
1056
1057 //------------------------------Init-------------------------------------------
1058 // Prepare for a single compilation
1059 void Compile::Init(int aliaslevel) {
1060 _unique = 0;
1061 _regalloc = NULL;
1062
1063 _tf = NULL; // filled in later
1064 _top = NULL; // cached later
1065 _matcher = NULL; // filled in later
1066 _cfg = NULL; // filled in later
1067
1068 set_24_bit_selection_and_mode(Use24BitFP, false);
1069
1070 _node_note_array = NULL;
1071 _default_node_notes = NULL;
1072
1073 _immutable_memory = NULL; // filled in at first inquiry
1074
1075 // Globally visible Nodes
1076 // First set TOP to NULL to give safe behavior during creation of RootNode
1077 set_cached_top_node(NULL);
1078 set_root(new (this) RootNode());
1079 // Now that you have a Root to point to, create the real TOP
1080 set_cached_top_node( new (this) ConNode(Type::TOP) );
1081 set_recent_alloc(NULL, NULL);
1082
1083 // Create Debug Information Recorder to record scopes, oopmaps, etc.
1084 env()->set_oop_recorder(new OopRecorder(env()->arena()));
1085 env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1086 env()->set_dependencies(new Dependencies(env()));
1087
1088 _fixed_slots = 0;
1089 set_has_split_ifs(false);
1090 set_has_loops(has_method() && method()->has_loops()); // first approximation
1091 set_has_stringbuilder(false);
1092 set_has_boxed_value(false);
1093 _trap_can_recompile = false; // no traps emitted yet
1094 _major_progress = true; // start out assuming good things will happen
1095 set_has_unsafe_access(false);
1096 set_max_vector_size(0);
1097 Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1098 set_decompile_count(0);
1099
1100 set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
1101 set_num_loop_opts(LoopOptsCount);
1102 set_do_inlining(Inline);
1103 set_max_inline_size(MaxInlineSize);
1104 set_freq_inline_size(FreqInlineSize);
1105 set_do_scheduling(OptoScheduling);
1106 set_do_count_invocations(false);
1107 set_do_method_data_update(false);
1108 set_rtm_state(NoRTM); // No RTM lock eliding by default
1109 method_has_option_value("MaxNodeLimit", _max_node_limit);
1110 #if INCLUDE_RTM_OPT
1111 if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1112 int rtm_state = method()->method_data()->rtm_state();
1113 if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
1114 // Don't generate RTM lock eliding code.
1115 set_rtm_state(NoRTM);
1116 } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1117 // Generate RTM lock eliding code without abort ratio calculation code.
1118 set_rtm_state(UseRTM);
1119 } else if (UseRTMDeopt) {
1120 // Generate RTM lock eliding code and include abort ratio calculation
1121 // code if UseRTMDeopt is on.
1122 set_rtm_state(ProfileRTM);
1123 }
1124 }
1125 #endif
1126 if (debug_info()->recording_non_safepoints()) {
1127 set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1128 (comp_arena(), 8, 0, NULL));
1129 set_default_node_notes(Node_Notes::make(this));
1130 }
1131
1132 // // -- Initialize types before each compile --
1133 // // Update cached type information
1134 // if( _method && _method->constants() )
1135 // Type::update_loaded_types(_method, _method->constants());
1136
1137 // Init alias_type map.
1138 if (!_do_escape_analysis && aliaslevel == 3)
1139 aliaslevel = 2; // No unique types without escape analysis
1140 _AliasLevel = aliaslevel;
1141 const int grow_ats = 16;
1142 _max_alias_types = grow_ats;
1143 _alias_types = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1144 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, grow_ats);
1145 Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1146 {
1147 for (int i = 0; i < grow_ats; i++) _alias_types[i] = &ats[i];
1148 }
1149 // Initialize the first few types.
1150 _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1151 _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1152 _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1153 _num_alias_types = AliasIdxRaw+1;
1154 // Zero out the alias type cache.
1155 Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1156 // A NULL adr_type hits in the cache right away. Preload the right answer.
1157 probe_alias_cache(NULL)->_index = AliasIdxTop;
1158
1159 _intrinsics = NULL;
1160 _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1161 _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1162 _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1163 _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8, 0, NULL);
1164 register_library_intrinsics();
1165 #ifdef ASSERT
1166 _type_verify_symmetry = true;
1167 #endif
1168 }
1169
1170 //---------------------------init_start----------------------------------------
1171 // Install the StartNode on this compile object.
1172 void Compile::init_start(StartNode* s) {
1173 if (failing())
1174 return; // already failing
1175 assert(s == start(), "");
1176 }
1177
1178 StartNode* Compile::start() const {
1179 assert(!failing(), "");
1180 for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1181 Node* start = root()->fast_out(i);
1182 if( start->is_Start() )
1183 return start->as_Start();
1184 }
1185 fatal("Did not find Start node!");
1186 return NULL;
1187 }
1188
1189 //-------------------------------immutable_memory-------------------------------------
1190 // Access immutable memory
1191 Node* Compile::immutable_memory() {
1192 if (_immutable_memory != NULL) {
1193 return _immutable_memory;
1194 }
1195 StartNode* s = start();
1196 for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1197 Node *p = s->fast_out(i);
1198 if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1199 _immutable_memory = p;
1200 return _immutable_memory;
1201 }
1202 }
1203 ShouldNotReachHere();
1204 return NULL;
1205 }
1206
1207 //----------------------set_cached_top_node------------------------------------
1208 // Install the cached top node, and make sure Node::is_top works correctly.
1209 void Compile::set_cached_top_node(Node* tn) {
1210 if (tn != NULL) verify_top(tn);
1211 Node* old_top = _top;
1212 _top = tn;
1213 // Calling Node::setup_is_top allows the nodes the chance to adjust
1214 // their _out arrays.
1215 if (_top != NULL) _top->setup_is_top();
1216 if (old_top != NULL) old_top->setup_is_top();
1217 assert(_top == NULL || top()->is_top(), "");
1218 }
1219
1220 #ifdef ASSERT
1221 uint Compile::count_live_nodes_by_graph_walk() {
1222 Unique_Node_List useful(comp_arena());
1223 // Get useful node list by walking the graph.
1224 identify_useful_nodes(useful);
1225 return useful.size();
1226 }
1227
1228 void Compile::print_missing_nodes() {
1229
1230 // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1231 if ((_log == NULL) && (! PrintIdealNodeCount)) {
1232 return;
1233 }
1234
1235 // This is an expensive function. It is executed only when the user
1236 // specifies VerifyIdealNodeCount option or otherwise knows the
1237 // additional work that needs to be done to identify reachable nodes
1238 // by walking the flow graph and find the missing ones using
1239 // _dead_node_list.
1240
1241 Unique_Node_List useful(comp_arena());
1242 // Get useful node list by walking the graph.
1243 identify_useful_nodes(useful);
1244
1245 uint l_nodes = C->live_nodes();
1246 uint l_nodes_by_walk = useful.size();
1247
1248 if (l_nodes != l_nodes_by_walk) {
1249 if (_log != NULL) {
1250 _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1251 _log->stamp();
1252 _log->end_head();
1253 }
1254 VectorSet& useful_member_set = useful.member_set();
1255 int last_idx = l_nodes_by_walk;
1256 for (int i = 0; i < last_idx; i++) {
1257 if (useful_member_set.test(i)) {
1258 if (_dead_node_list.test(i)) {
1259 if (_log != NULL) {
1260 _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1261 }
1262 if (PrintIdealNodeCount) {
1263 // Print the log message to tty
1264 tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1265 useful.at(i)->dump();
1266 }
1267 }
1268 }
1269 else if (! _dead_node_list.test(i)) {
1270 if (_log != NULL) {
1271 _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1272 }
1273 if (PrintIdealNodeCount) {
1274 // Print the log message to tty
1275 tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1276 }
1277 }
1278 }
1279 if (_log != NULL) {
1280 _log->tail("mismatched_nodes");
1281 }
1282 }
1283 }
1284 #endif
1285
1286 #ifndef PRODUCT
1287 void Compile::verify_top(Node* tn) const {
1288 if (tn != NULL) {
1289 assert(tn->is_Con(), "top node must be a constant");
1290 assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1291 assert(tn->in(0) != NULL, "must have live top node");
1292 }
1293 }
1294 #endif
1295
1296
1297 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1298
1299 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1300 guarantee(arr != NULL, "");
1301 int num_blocks = arr->length();
1302 if (grow_by < num_blocks) grow_by = num_blocks;
1303 int num_notes = grow_by * _node_notes_block_size;
1304 Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1305 Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1306 while (num_notes > 0) {
1307 arr->append(notes);
1308 notes += _node_notes_block_size;
1309 num_notes -= _node_notes_block_size;
1310 }
1311 assert(num_notes == 0, "exact multiple, please");
1312 }
1313
1314 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1315 if (source == NULL || dest == NULL) return false;
1316
1317 if (dest->is_Con())
1318 return false; // Do not push debug info onto constants.
1319
1320 #ifdef ASSERT
1321 // Leave a bread crumb trail pointing to the original node:
1322 if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1323 dest->set_debug_orig(source);
1324 }
1325 #endif
1326
1327 if (node_note_array() == NULL)
1328 return false; // Not collecting any notes now.
1329
1330 // This is a copy onto a pre-existing node, which may already have notes.
1331 // If both nodes have notes, do not overwrite any pre-existing notes.
1332 Node_Notes* source_notes = node_notes_at(source->_idx);
1333 if (source_notes == NULL || source_notes->is_clear()) return false;
1334 Node_Notes* dest_notes = node_notes_at(dest->_idx);
1335 if (dest_notes == NULL || dest_notes->is_clear()) {
1336 return set_node_notes_at(dest->_idx, source_notes);
1337 }
1338
1339 Node_Notes merged_notes = (*source_notes);
1340 // The order of operations here ensures that dest notes will win...
1341 merged_notes.update_from(dest_notes);
1342 return set_node_notes_at(dest->_idx, &merged_notes);
1343 }
1344
1345
1346 //--------------------------allow_range_check_smearing-------------------------
1347 // Gating condition for coalescing similar range checks.
1348 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1349 // single covering check that is at least as strong as any of them.
1350 // If the optimization succeeds, the simplified (strengthened) range check
1351 // will always succeed. If it fails, we will deopt, and then give up
1352 // on the optimization.
1353 bool Compile::allow_range_check_smearing() const {
1354 // If this method has already thrown a range-check,
1355 // assume it was because we already tried range smearing
1356 // and it failed.
1357 uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1358 return !already_trapped;
1359 }
1360
1361
1362 //------------------------------flatten_alias_type-----------------------------
1363 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1364 int offset = tj->offset();
1365 TypePtr::PTR ptr = tj->ptr();
1366
1367 // Known instance (scalarizable allocation) alias only with itself.
1368 bool is_known_inst = tj->isa_oopptr() != NULL &&
1369 tj->is_oopptr()->is_known_instance();
1370
1371 // Process weird unsafe references.
1372 if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1373 assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1374 assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1375 tj = TypeOopPtr::BOTTOM;
1376 ptr = tj->ptr();
1377 offset = tj->offset();
1378 }
1379
1380 // Array pointers need some flattening
1381 const TypeAryPtr *ta = tj->isa_aryptr();
1382 if (ta && ta->is_stable()) {
1383 // Erase stability property for alias analysis.
1384 tj = ta = ta->cast_to_stable(false);
1385 }
1386 if( ta && is_known_inst ) {
1387 if ( offset != Type::OffsetBot &&
1388 offset > arrayOopDesc::length_offset_in_bytes() ) {
1389 offset = Type::OffsetBot; // Flatten constant access into array body only
1390 tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1391 }
1392 } else if( ta && _AliasLevel >= 2 ) {
1393 // For arrays indexed by constant indices, we flatten the alias
1394 // space to include all of the array body. Only the header, klass
1395 // and array length can be accessed un-aliased.
1396 if( offset != Type::OffsetBot ) {
1397 if( ta->const_oop() ) { // MethodData* or Method*
1398 offset = Type::OffsetBot; // Flatten constant access into array body
1399 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1400 } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1401 // range is OK as-is.
1402 tj = ta = TypeAryPtr::RANGE;
1403 } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1404 tj = TypeInstPtr::KLASS; // all klass loads look alike
1405 ta = TypeAryPtr::RANGE; // generic ignored junk
1406 ptr = TypePtr::BotPTR;
1407 } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1408 tj = TypeInstPtr::MARK;
1409 ta = TypeAryPtr::RANGE; // generic ignored junk
1410 ptr = TypePtr::BotPTR;
1411 } else { // Random constant offset into array body
1412 offset = Type::OffsetBot; // Flatten constant access into array body
1413 tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1414 }
1415 }
1416 // Arrays of fixed size alias with arrays of unknown size.
1417 if (ta->size() != TypeInt::POS) {
1418 const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1419 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1420 }
1421 // Arrays of known objects become arrays of unknown objects.
1422 if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1423 const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1424 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1425 }
1426 if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1427 const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1428 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1429 }
1430 // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1431 // cannot be distinguished by bytecode alone.
1432 if (ta->elem() == TypeInt::BOOL) {
1433 const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1434 ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1435 tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1436 }
1437 // During the 2nd round of IterGVN, NotNull castings are removed.
1438 // Make sure the Bottom and NotNull variants alias the same.
1439 // Also, make sure exact and non-exact variants alias the same.
1440 if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1441 tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1442 }
1443 }
1444
1445 // Oop pointers need some flattening
1446 const TypeInstPtr *to = tj->isa_instptr();
1447 if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1448 ciInstanceKlass *k = to->klass()->as_instance_klass();
1449 if( ptr == TypePtr::Constant ) {
1450 if (to->klass() != ciEnv::current()->Class_klass() ||
1451 offset < k->size_helper() * wordSize) {
1452 // No constant oop pointers (such as Strings); they alias with
1453 // unknown strings.
1454 assert(!is_known_inst, "not scalarizable allocation");
1455 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1456 }
1457 } else if( is_known_inst ) {
1458 tj = to; // Keep NotNull and klass_is_exact for instance type
1459 } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1460 // During the 2nd round of IterGVN, NotNull castings are removed.
1461 // Make sure the Bottom and NotNull variants alias the same.
1462 // Also, make sure exact and non-exact variants alias the same.
1463 tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1464 }
1465 if (to->speculative() != NULL) {
1466 tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1467 }
1468 // Canonicalize the holder of this field
1469 if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1470 // First handle header references such as a LoadKlassNode, even if the
1471 // object's klass is unloaded at compile time (4965979).
1472 if (!is_known_inst) { // Do it only for non-instance types
1473 tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1474 }
1475 } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1476 // Static fields are in the space above the normal instance
1477 // fields in the java.lang.Class instance.
1478 if (to->klass() != ciEnv::current()->Class_klass()) {
1479 to = NULL;
1480 tj = TypeOopPtr::BOTTOM;
1481 offset = tj->offset();
1482 }
1483 } else {
1484 ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1485 if (!k->equals(canonical_holder) || tj->offset() != offset) {
1486 if( is_known_inst ) {
1487 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1488 } else {
1489 tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1490 }
1491 }
1492 }
1493 }
1494
1495 // Klass pointers to object array klasses need some flattening
1496 const TypeKlassPtr *tk = tj->isa_klassptr();
1497 if( tk ) {
1498 // If we are referencing a field within a Klass, we need
1499 // to assume the worst case of an Object. Both exact and
1500 // inexact types must flatten to the same alias class so
1501 // use NotNull as the PTR.
1502 if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1503
1504 tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1505 TypeKlassPtr::OBJECT->klass(),
1506 offset);
1507 }
1508
1509 ciKlass* klass = tk->klass();
1510 if( klass->is_obj_array_klass() ) {
1511 ciKlass* k = TypeAryPtr::OOPS->klass();
1512 if( !k || !k->is_loaded() ) // Only fails for some -Xcomp runs
1513 k = TypeInstPtr::BOTTOM->klass();
1514 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1515 }
1516
1517 // Check for precise loads from the primary supertype array and force them
1518 // to the supertype cache alias index. Check for generic array loads from
1519 // the primary supertype array and also force them to the supertype cache
1520 // alias index. Since the same load can reach both, we need to merge
1521 // these 2 disparate memories into the same alias class. Since the
1522 // primary supertype array is read-only, there's no chance of confusion
1523 // where we bypass an array load and an array store.
1524 int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1525 if (offset == Type::OffsetBot ||
1526 (offset >= primary_supers_offset &&
1527 offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1528 offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1529 offset = in_bytes(Klass::secondary_super_cache_offset());
1530 tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1531 }
1532 }
1533
1534 // Flatten all Raw pointers together.
1535 if (tj->base() == Type::RawPtr)
1536 tj = TypeRawPtr::BOTTOM;
1537
1538 if (tj->base() == Type::AnyPtr)
1539 tj = TypePtr::BOTTOM; // An error, which the caller must check for.
1540
1541 // Flatten all to bottom for now
1542 switch( _AliasLevel ) {
1543 case 0:
1544 tj = TypePtr::BOTTOM;
1545 break;
1546 case 1: // Flatten to: oop, static, field or array
1547 switch (tj->base()) {
1548 //case Type::AryPtr: tj = TypeAryPtr::RANGE; break;
1549 case Type::RawPtr: tj = TypeRawPtr::BOTTOM; break;
1550 case Type::AryPtr: // do not distinguish arrays at all
1551 case Type::InstPtr: tj = TypeInstPtr::BOTTOM; break;
1552 case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1553 case Type::AnyPtr: tj = TypePtr::BOTTOM; break; // caller checks it
1554 default: ShouldNotReachHere();
1555 }
1556 break;
1557 case 2: // No collapsing at level 2; keep all splits
1558 case 3: // No collapsing at level 3; keep all splits
1559 break;
1560 default:
1561 Unimplemented();
1562 }
1563
1564 offset = tj->offset();
1565 assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1566
1567 assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1568 (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1569 (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1570 (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1571 (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1572 (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1573 (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr) ,
1574 "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1575 assert( tj->ptr() != TypePtr::TopPTR &&
1576 tj->ptr() != TypePtr::AnyNull &&
1577 tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1578 // assert( tj->ptr() != TypePtr::Constant ||
1579 // tj->base() == Type::RawPtr ||
1580 // tj->base() == Type::KlassPtr, "No constant oop addresses" );
1581
1582 return tj;
1583 }
1584
1585 void Compile::AliasType::Init(int i, const TypePtr* at) {
1586 _index = i;
1587 _adr_type = at;
1588 _field = NULL;
1589 _element = NULL;
1590 _is_rewritable = true; // default
1591 const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1592 if (atoop != NULL && atoop->is_known_instance()) {
1593 const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1594 _general_index = Compile::current()->get_alias_index(gt);
1595 } else {
1596 _general_index = 0;
1597 }
1598 }
1599
1600 BasicType Compile::AliasType::basic_type() const {
1601 if (element() != NULL) {
1602 const Type* element = adr_type()->is_aryptr()->elem();
1603 return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1604 } if (field() != NULL) {
1605 return field()->layout_type();
1606 } else {
1607 return T_ILLEGAL; // unknown
1608 }
1609 }
1610
1611 //---------------------------------print_on------------------------------------
1612 #ifndef PRODUCT
1613 void Compile::AliasType::print_on(outputStream* st) {
1614 if (index() < 10)
1615 st->print("@ <%d> ", index());
1616 else st->print("@ <%d>", index());
1617 st->print(is_rewritable() ? " " : " RO");
1618 int offset = adr_type()->offset();
1619 if (offset == Type::OffsetBot)
1620 st->print(" +any");
1621 else st->print(" +%-3d", offset);
1622 st->print(" in ");
1623 adr_type()->dump_on(st);
1624 const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1625 if (field() != NULL && tjp) {
1626 if (tjp->klass() != field()->holder() ||
1627 tjp->offset() != field()->offset_in_bytes()) {
1628 st->print(" != ");
1629 field()->print();
1630 st->print(" ***");
1631 }
1632 }
1633 }
1634
1635 void print_alias_types() {
1636 Compile* C = Compile::current();
1637 tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1638 for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1639 C->alias_type(idx)->print_on(tty);
1640 tty->cr();
1641 }
1642 }
1643 #endif
1644
1645
1646 //----------------------------probe_alias_cache--------------------------------
1647 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1648 intptr_t key = (intptr_t) adr_type;
1649 key ^= key >> logAliasCacheSize;
1650 return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1651 }
1652
1653
1654 //-----------------------------grow_alias_types--------------------------------
1655 void Compile::grow_alias_types() {
1656 const int old_ats = _max_alias_types; // how many before?
1657 const int new_ats = old_ats; // how many more?
1658 const int grow_ats = old_ats+new_ats; // how many now?
1659 _max_alias_types = grow_ats;
1660 _alias_types = REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1661 AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1662 Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1663 for (int i = 0; i < new_ats; i++) _alias_types[old_ats+i] = &ats[i];
1664 }
1665
1666
1667 //--------------------------------find_alias_type------------------------------
1668 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1669 if (_AliasLevel == 0)
1670 return alias_type(AliasIdxBot);
1671
1672 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1673 if (ace->_adr_type == adr_type) {
1674 return alias_type(ace->_index);
1675 }
1676
1677 // Handle special cases.
1678 if (adr_type == NULL) return alias_type(AliasIdxTop);
1679 if (adr_type == TypePtr::BOTTOM) return alias_type(AliasIdxBot);
1680
1681 // Do it the slow way.
1682 const TypePtr* flat = flatten_alias_type(adr_type);
1683
1684 #ifdef ASSERT
1685 {
1686 ResourceMark rm;
1687 assert(flat == flatten_alias_type(flat),
1688 err_msg("not idempotent: adr_type = %s; flat = %s => %s", Type::str(adr_type),
1689 Type::str(flat), Type::str(flatten_alias_type(flat))));
1690 assert(flat != TypePtr::BOTTOM,
1691 err_msg("cannot alias-analyze an untyped ptr: adr_type = %s", Type::str(adr_type)));
1692 if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1693 const TypeOopPtr* foop = flat->is_oopptr();
1694 // Scalarizable allocations have exact klass always.
1695 bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1696 const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1697 assert(foop == flatten_alias_type(xoop),
1698 err_msg("exactness must not affect alias type: foop = %s; xoop = %s",
1699 Type::str(foop), Type::str(xoop)));
1700 }
1701 }
1702 #endif
1703
1704 int idx = AliasIdxTop;
1705 for (int i = 0; i < num_alias_types(); i++) {
1706 if (alias_type(i)->adr_type() == flat) {
1707 idx = i;
1708 break;
1709 }
1710 }
1711
1712 if (idx == AliasIdxTop) {
1713 if (no_create) return NULL;
1714 // Grow the array if necessary.
1715 if (_num_alias_types == _max_alias_types) grow_alias_types();
1716 // Add a new alias type.
1717 idx = _num_alias_types++;
1718 _alias_types[idx]->Init(idx, flat);
1719 if (flat == TypeInstPtr::KLASS) alias_type(idx)->set_rewritable(false);
1720 if (flat == TypeAryPtr::RANGE) alias_type(idx)->set_rewritable(false);
1721 if (flat->isa_instptr()) {
1722 if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
1723 && flat->is_instptr()->klass() == env()->Class_klass())
1724 alias_type(idx)->set_rewritable(false);
1725 }
1726 if (flat->isa_aryptr()) {
1727 #ifdef ASSERT
1728 const int header_size_min = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1729 // (T_BYTE has the weakest alignment and size restrictions...)
1730 assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1731 #endif
1732 if (flat->offset() == TypePtr::OffsetBot) {
1733 alias_type(idx)->set_element(flat->is_aryptr()->elem());
1734 }
1735 }
1736 if (flat->isa_klassptr()) {
1737 if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1738 alias_type(idx)->set_rewritable(false);
1739 if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1740 alias_type(idx)->set_rewritable(false);
1741 if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1742 alias_type(idx)->set_rewritable(false);
1743 if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1744 alias_type(idx)->set_rewritable(false);
1745 }
1746 // %%% (We would like to finalize JavaThread::threadObj_offset(),
1747 // but the base pointer type is not distinctive enough to identify
1748 // references into JavaThread.)
1749
1750 // Check for final fields.
1751 const TypeInstPtr* tinst = flat->isa_instptr();
1752 if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1753 ciField* field;
1754 if (tinst->const_oop() != NULL &&
1755 tinst->klass() == ciEnv::current()->Class_klass() &&
1756 tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1757 // static field
1758 ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1759 field = k->get_field_by_offset(tinst->offset(), true);
1760 } else {
1761 ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1762 field = k->get_field_by_offset(tinst->offset(), false);
1763 }
1764 assert(field == NULL ||
1765 original_field == NULL ||
1766 (field->holder() == original_field->holder() &&
1767 field->offset() == original_field->offset() &&
1768 field->is_static() == original_field->is_static()), "wrong field?");
1769 // Set field() and is_rewritable() attributes.
1770 if (field != NULL) alias_type(idx)->set_field(field);
1771 }
1772 }
1773
1774 // Fill the cache for next time.
1775 ace->_adr_type = adr_type;
1776 ace->_index = idx;
1777 assert(alias_type(adr_type) == alias_type(idx), "type must be installed");
1778
1779 // Might as well try to fill the cache for the flattened version, too.
1780 AliasCacheEntry* face = probe_alias_cache(flat);
1781 if (face->_adr_type == NULL) {
1782 face->_adr_type = flat;
1783 face->_index = idx;
1784 assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1785 }
1786
1787 return alias_type(idx);
1788 }
1789
1790
1791 Compile::AliasType* Compile::alias_type(ciField* field) {
1792 const TypeOopPtr* t;
1793 if (field->is_static())
1794 t = TypeInstPtr::make(field->holder()->java_mirror());
1795 else
1796 t = TypeOopPtr::make_from_klass_raw(field->holder());
1797 AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1798 assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1799 return atp;
1800 }
1801
1802
1803 //------------------------------have_alias_type--------------------------------
1804 bool Compile::have_alias_type(const TypePtr* adr_type) {
1805 AliasCacheEntry* ace = probe_alias_cache(adr_type);
1806 if (ace->_adr_type == adr_type) {
1807 return true;
1808 }
1809
1810 // Handle special cases.
1811 if (adr_type == NULL) return true;
1812 if (adr_type == TypePtr::BOTTOM) return true;
1813
1814 return find_alias_type(adr_type, true, NULL) != NULL;
1815 }
1816
1817 //-----------------------------must_alias--------------------------------------
1818 // True if all values of the given address type are in the given alias category.
1819 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1820 if (alias_idx == AliasIdxBot) return true; // the universal category
1821 if (adr_type == NULL) return true; // NULL serves as TypePtr::TOP
1822 if (alias_idx == AliasIdxTop) return false; // the empty category
1823 if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1824
1825 // the only remaining possible overlap is identity
1826 int adr_idx = get_alias_index(adr_type);
1827 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1828 assert(adr_idx == alias_idx ||
1829 (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1830 && adr_type != TypeOopPtr::BOTTOM),
1831 "should not be testing for overlap with an unsafe pointer");
1832 return adr_idx == alias_idx;
1833 }
1834
1835 //------------------------------can_alias--------------------------------------
1836 // True if any values of the given address type are in the given alias category.
1837 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1838 if (alias_idx == AliasIdxTop) return false; // the empty category
1839 if (adr_type == NULL) return false; // NULL serves as TypePtr::TOP
1840 if (alias_idx == AliasIdxBot) return true; // the universal category
1841 if (adr_type->base() == Type::AnyPtr) return true; // TypePtr::BOTTOM or its twins
1842
1843 // the only remaining possible overlap is identity
1844 int adr_idx = get_alias_index(adr_type);
1845 assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1846 return adr_idx == alias_idx;
1847 }
1848
1849
1850
1851 //---------------------------pop_warm_call-------------------------------------
1852 WarmCallInfo* Compile::pop_warm_call() {
1853 WarmCallInfo* wci = _warm_calls;
1854 if (wci != NULL) _warm_calls = wci->remove_from(wci);
1855 return wci;
1856 }
1857
1858 //----------------------------Inline_Warm--------------------------------------
1859 int Compile::Inline_Warm() {
1860 // If there is room, try to inline some more warm call sites.
1861 // %%% Do a graph index compaction pass when we think we're out of space?
1862 if (!InlineWarmCalls) return 0;
1863
1864 int calls_made_hot = 0;
1865 int room_to_grow = NodeCountInliningCutoff - unique();
1866 int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1867 int amount_grown = 0;
1868 WarmCallInfo* call;
1869 while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1870 int est_size = (int)call->size();
1871 if (est_size > (room_to_grow - amount_grown)) {
1872 // This one won't fit anyway. Get rid of it.
1873 call->make_cold();
1874 continue;
1875 }
1876 call->make_hot();
1877 calls_made_hot++;
1878 amount_grown += est_size;
1879 amount_to_grow -= est_size;
1880 }
1881
1882 if (calls_made_hot > 0) set_major_progress();
1883 return calls_made_hot;
1884 }
1885
1886
1887 //----------------------------Finish_Warm--------------------------------------
1888 void Compile::Finish_Warm() {
1889 if (!InlineWarmCalls) return;
1890 if (failing()) return;
1891 if (warm_calls() == NULL) return;
1892
1893 // Clean up loose ends, if we are out of space for inlining.
1894 WarmCallInfo* call;
1895 while ((call = pop_warm_call()) != NULL) {
1896 call->make_cold();
1897 }
1898 }
1899
1900 //---------------------cleanup_loop_predicates-----------------------
1901 // Remove the opaque nodes that protect the predicates so that all unused
1902 // checks and uncommon_traps will be eliminated from the ideal graph
1903 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1904 if (predicate_count()==0) return;
1905 for (int i = predicate_count(); i > 0; i--) {
1906 Node * n = predicate_opaque1_node(i-1);
1907 assert(n->Opcode() == Op_Opaque1, "must be");
1908 igvn.replace_node(n, n->in(1));
1909 }
1910 assert(predicate_count()==0, "should be clean!");
1911 }
1912
1913 void Compile::add_range_check_cast(Node* n) {
1914 assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1915 assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
1916 _range_check_casts->append(n);
1917 }
1918
1919 // Remove all range check dependent CastIINodes.
1920 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
1921 for (int i = range_check_cast_count(); i > 0; i--) {
1922 Node* cast = range_check_cast_node(i-1);
1923 assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
1924 igvn.replace_node(cast, cast->in(1));
1925 }
1926 assert(range_check_cast_count() == 0, "should be empty");
1927 }
1928
1929 // StringOpts and late inlining of string methods
1930 void Compile::inline_string_calls(bool parse_time) {
1931 {
1932 // remove useless nodes to make the usage analysis simpler
1933 ResourceMark rm;
1934 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1935 }
1936
1937 {
1938 ResourceMark rm;
1939 print_method(PHASE_BEFORE_STRINGOPTS, 3);
1940 PhaseStringOpts pso(initial_gvn(), for_igvn());
1941 print_method(PHASE_AFTER_STRINGOPTS, 3);
1942 }
1943
1944 // now inline anything that we skipped the first time around
1945 if (!parse_time) {
1946 _late_inlines_pos = _late_inlines.length();
1947 }
1948
1949 while (_string_late_inlines.length() > 0) {
1950 CallGenerator* cg = _string_late_inlines.pop();
1951 cg->do_late_inline();
1952 if (failing()) return;
1953 }
1954 _string_late_inlines.trunc_to(0);
1955 }
1956
1957 // Late inlining of boxing methods
1958 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1959 if (_boxing_late_inlines.length() > 0) {
1960 assert(has_boxed_value(), "inconsistent");
1961
1962 PhaseGVN* gvn = initial_gvn();
1963 set_inlining_incrementally(true);
1964
1965 assert( igvn._worklist.size() == 0, "should be done with igvn" );
1966 for_igvn()->clear();
1967 gvn->replace_with(&igvn);
1968
1969 _late_inlines_pos = _late_inlines.length();
1970
1971 while (_boxing_late_inlines.length() > 0) {
1972 CallGenerator* cg = _boxing_late_inlines.pop();
1973 cg->do_late_inline();
1974 if (failing()) return;
1975 }
1976 _boxing_late_inlines.trunc_to(0);
1977
1978 {
1979 ResourceMark rm;
1980 PhaseRemoveUseless pru(gvn, for_igvn());
1981 }
1982
1983 igvn = PhaseIterGVN(gvn);
1984 igvn.optimize();
1985
1986 set_inlining_progress(false);
1987 set_inlining_incrementally(false);
1988 }
1989 }
1990
1991 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
1992 assert(IncrementalInline, "incremental inlining should be on");
1993 PhaseGVN* gvn = initial_gvn();
1994
1995 set_inlining_progress(false);
1996 for_igvn()->clear();
1997 gvn->replace_with(&igvn);
1998
1999 int i = 0;
2000
2001 for (; i <_late_inlines.length() && !inlining_progress(); i++) {
2002 CallGenerator* cg = _late_inlines.at(i);
2003 _late_inlines_pos = i+1;
2004 cg->do_late_inline();
2005 if (failing()) return;
2006 }
2007 int j = 0;
2008 for (; i < _late_inlines.length(); i++, j++) {
2009 _late_inlines.at_put(j, _late_inlines.at(i));
2010 }
2011 _late_inlines.trunc_to(j);
2012
2013 {
2014 ResourceMark rm;
2015 PhaseRemoveUseless pru(gvn, for_igvn());
2016 }
2017
2018 igvn = PhaseIterGVN(gvn);
2019 }
2020
2021 // Perform incremental inlining until bound on number of live nodes is reached
2022 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2023 PhaseGVN* gvn = initial_gvn();
2024
2025 set_inlining_incrementally(true);
2026 set_inlining_progress(true);
2027 uint low_live_nodes = 0;
2028
2029 while(inlining_progress() && _late_inlines.length() > 0) {
2030
2031 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2032 if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
2033 // PhaseIdealLoop is expensive so we only try it once we are
2034 // out of live nodes and we only try it again if the previous
2035 // helped got the number of nodes down significantly
2036 PhaseIdealLoop ideal_loop( igvn, false, true );
2037 if (failing()) return;
2038 low_live_nodes = live_nodes();
2039 _major_progress = true;
2040 }
2041
2042 if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
2043 break;
2044 }
2045 }
2046
2047 inline_incrementally_one(igvn);
2048
2049 if (failing()) return;
2050
2051 igvn.optimize();
2052
2053 if (failing()) return;
2054 }
2055
2056 assert( igvn._worklist.size() == 0, "should be done with igvn" );
2057
2058 if (_string_late_inlines.length() > 0) {
2059 assert(has_stringbuilder(), "inconsistent");
2060 for_igvn()->clear();
2061 initial_gvn()->replace_with(&igvn);
2062
2063 inline_string_calls(false);
2064
2065 if (failing()) return;
2066
2067 {
2068 ResourceMark rm;
2069 PhaseRemoveUseless pru(initial_gvn(), for_igvn());
2070 }
2071
2072 igvn = PhaseIterGVN(gvn);
2073
2074 igvn.optimize();
2075 }
2076
2077 set_inlining_incrementally(false);
2078 }
2079
2080
2081 // Remove edges from "root" to each SafePoint at a backward branch.
2082 // They were inserted during parsing (see add_safepoint()) to make
2083 // infinite loops without calls or exceptions visible to root, i.e.,
2084 // useful.
2085 void Compile::remove_root_to_sfpts_edges() {
2086 Node *r = root();
2087 if (r != NULL) {
2088 for (uint i = r->req(); i < r->len(); ++i) {
2089 Node *n = r->in(i);
2090 if (n != NULL && n->is_SafePoint()) {
2091 r->rm_prec(i);
2092 --i;
2093 }
2094 }
2095 }
2096 }
2097
2098 //------------------------------Optimize---------------------------------------
2099 // Given a graph, optimize it.
2100 void Compile::Optimize() {
2101 TracePhase t1("optimizer", &_t_optimizer, true);
2102
2103 #ifndef PRODUCT
2104 if (env()->break_at_compile()) {
2105 BREAKPOINT;
2106 }
2107
2108 #endif
2109
2110 ResourceMark rm;
2111 int loop_opts_cnt;
2112
2113 NOT_PRODUCT( verify_graph_edges(); )
2114
2115 print_method(PHASE_AFTER_PARSING);
2116
2117 {
2118 // Iterative Global Value Numbering, including ideal transforms
2119 // Initialize IterGVN with types and values from parse-time GVN
2120 PhaseIterGVN igvn(initial_gvn());
2121 {
2122 NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
2123 igvn.optimize();
2124 }
2125
2126 print_method(PHASE_ITER_GVN1, 2);
2127
2128 if (failing()) return;
2129
2130 {
2131 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2132 inline_incrementally(igvn);
2133 }
2134
2135 print_method(PHASE_INCREMENTAL_INLINE, 2);
2136
2137 if (failing()) return;
2138
2139 if (eliminate_boxing()) {
2140 NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
2141 // Inline valueOf() methods now.
2142 inline_boxing_calls(igvn);
2143
2144 if (AlwaysIncrementalInline) {
2145 inline_incrementally(igvn);
2146 }
2147
2148 print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2149
2150 if (failing()) return;
2151 }
2152
2153 // Now that all inlining is over, cut edge from root to loop
2154 // safepoints
2155 remove_root_to_sfpts_edges();
2156
2157 // Remove the speculative part of types and clean up the graph from
2158 // the extra CastPP nodes whose only purpose is to carry them. Do
2159 // that early so that optimizations are not disrupted by the extra
2160 // CastPP nodes.
2161 remove_speculative_types(igvn);
2162
2163 // No more new expensive nodes will be added to the list from here
2164 // so keep only the actual candidates for optimizations.
2165 cleanup_expensive_nodes(igvn);
2166
2167 if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2168 NOT_PRODUCT(Compile::TracePhase t2("", &_t_renumberLive, TimeCompiler);)
2169 initial_gvn()->replace_with(&igvn);
2170 for_igvn()->clear();
2171 Unique_Node_List new_worklist(C->comp_arena());
2172 {
2173 ResourceMark rm;
2174 PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2175 }
2176 set_for_igvn(&new_worklist);
2177 igvn = PhaseIterGVN(initial_gvn());
2178 igvn.optimize();
2179 }
2180
2181 // Perform escape analysis
2182 if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2183 if (has_loops()) {
2184 // Cleanup graph (remove dead nodes).
2185 TracePhase t2("idealLoop", &_t_idealLoop, true);
2186 PhaseIdealLoop ideal_loop( igvn, false, true );
2187 if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2188 if (failing()) return;
2189 }
2190 ConnectionGraph::do_analysis(this, &igvn);
2191
2192 if (failing()) return;
2193
2194 // Optimize out fields loads from scalar replaceable allocations.
2195 igvn.optimize();
2196 print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2197
2198 if (failing()) return;
2199
2200 if (congraph() != NULL && macro_count() > 0) {
2201 NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
2202 PhaseMacroExpand mexp(igvn);
2203 mexp.eliminate_macro_nodes();
2204 igvn.set_delay_transform(false);
2205
2206 igvn.optimize();
2207 print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2208
2209 if (failing()) return;
2210 }
2211 }
2212
2213 // Loop transforms on the ideal graph. Range Check Elimination,
2214 // peeling, unrolling, etc.
2215
2216 // Set loop opts counter
2217 loop_opts_cnt = num_loop_opts();
2218 if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2219 {
2220 TracePhase t2("idealLoop", &_t_idealLoop, true);
2221 PhaseIdealLoop ideal_loop( igvn, true );
2222 loop_opts_cnt--;
2223 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2224 if (failing()) return;
2225 }
2226 // Loop opts pass if partial peeling occurred in previous pass
2227 if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
2228 TracePhase t3("idealLoop", &_t_idealLoop, true);
2229 PhaseIdealLoop ideal_loop( igvn, false );
2230 loop_opts_cnt--;
2231 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2232 if (failing()) return;
2233 }
2234 // Loop opts pass for loop-unrolling before CCP
2235 if(major_progress() && (loop_opts_cnt > 0)) {
2236 TracePhase t4("idealLoop", &_t_idealLoop, true);
2237 PhaseIdealLoop ideal_loop( igvn, false );
2238 loop_opts_cnt--;
2239 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2240 }
2241 if (!failing()) {
2242 // Verify that last round of loop opts produced a valid graph
2243 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2244 PhaseIdealLoop::verify(igvn);
2245 }
2246 }
2247 if (failing()) return;
2248
2249 // Conditional Constant Propagation;
2250 PhaseCCP ccp( &igvn );
2251 assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2252 {
2253 TracePhase t2("ccp", &_t_ccp, true);
2254 ccp.do_transform();
2255 }
2256 print_method(PHASE_CPP1, 2);
2257
2258 assert( true, "Break here to ccp.dump_old2new_map()");
2259
2260 // Iterative Global Value Numbering, including ideal transforms
2261 {
2262 NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
2263 igvn = ccp;
2264 igvn.optimize();
2265 }
2266
2267 print_method(PHASE_ITER_GVN2, 2);
2268
2269 if (failing()) return;
2270
2271 // Loop transforms on the ideal graph. Range Check Elimination,
2272 // peeling, unrolling, etc.
2273 if(loop_opts_cnt > 0) {
2274 debug_only( int cnt = 0; );
2275 while(major_progress() && (loop_opts_cnt > 0)) {
2276 TracePhase t2("idealLoop", &_t_idealLoop, true);
2277 assert( cnt++ < 40, "infinite cycle in loop optimization" );
2278 PhaseIdealLoop ideal_loop( igvn, true);
2279 loop_opts_cnt--;
2280 if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2281 if (failing()) return;
2282 }
2283 }
2284
2285 {
2286 // Verify that all previous optimizations produced a valid graph
2287 // at least to this point, even if no loop optimizations were done.
2288 NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
2289 PhaseIdealLoop::verify(igvn);
2290 }
2291
2292 if (range_check_cast_count() > 0) {
2293 // No more loop optimizations. Remove all range check dependent CastIINodes.
2294 C->remove_range_check_casts(igvn);
2295 igvn.optimize();
2296 }
2297
2298 {
2299 NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
2300 PhaseMacroExpand mex(igvn);
2301 if (mex.expand_macro_nodes()) {
2302 assert(failing(), "must bail out w/ explicit message");
2303 return;
2304 }
2305 }
2306
2307 } // (End scope of igvn; run destructor if necessary for asserts.)
2308
2309 dump_inlining();
2310 // A method with only infinite loops has no edges entering loops from root
2311 {
2312 NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
2313 if (final_graph_reshaping()) {
2314 assert(failing(), "must bail out w/ explicit message");
2315 return;
2316 }
2317 }
2318
2319 print_method(PHASE_OPTIMIZE_FINISHED, 2);
2320 }
2321
2322
2323 //------------------------------Code_Gen---------------------------------------
2324 // Given a graph, generate code for it
2325 void Compile::Code_Gen() {
2326 if (failing()) {
2327 return;
2328 }
2329
2330 // Perform instruction selection. You might think we could reclaim Matcher
2331 // memory PDQ, but actually the Matcher is used in generating spill code.
2332 // Internals of the Matcher (including some VectorSets) must remain live
2333 // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2334 // set a bit in reclaimed memory.
2335
2336 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2337 // nodes. Mapping is only valid at the root of each matched subtree.
2338 NOT_PRODUCT( verify_graph_edges(); )
2339
2340 Matcher matcher;
2341 _matcher = &matcher;
2342 {
2343 TracePhase t2("matcher", &_t_matcher, true);
2344 matcher.match();
2345 }
2346 // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2347 // nodes. Mapping is only valid at the root of each matched subtree.
2348 NOT_PRODUCT( verify_graph_edges(); )
2349
2350 // If you have too many nodes, or if matching has failed, bail out
2351 check_node_count(0, "out of nodes matching instructions");
2352 if (failing()) {
2353 return;
2354 }
2355
2356 // Build a proper-looking CFG
2357 PhaseCFG cfg(node_arena(), root(), matcher);
2358 _cfg = &cfg;
2359 {
2360 NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
2361 bool success = cfg.do_global_code_motion();
2362 if (!success) {
2363 return;
2364 }
2365
2366 print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2367 NOT_PRODUCT( verify_graph_edges(); )
2368 debug_only( cfg.verify(); )
2369 }
2370
2371 PhaseChaitin regalloc(unique(), cfg, matcher);
2372 _regalloc = ®alloc;
2373 {
2374 TracePhase t2("regalloc", &_t_registerAllocation, true);
2375 // Perform register allocation. After Chaitin, use-def chains are
2376 // no longer accurate (at spill code) and so must be ignored.
2377 // Node->LRG->reg mappings are still accurate.
2378 _regalloc->Register_Allocate();
2379
2380 // Bail out if the allocator builds too many nodes
2381 if (failing()) {
2382 return;
2383 }
2384 }
2385
2386 // Prior to register allocation we kept empty basic blocks in case the
2387 // the allocator needed a place to spill. After register allocation we
2388 // are not adding any new instructions. If any basic block is empty, we
2389 // can now safely remove it.
2390 {
2391 NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
2392 cfg.remove_empty_blocks();
2393 if (do_freq_based_layout()) {
2394 PhaseBlockLayout layout(cfg);
2395 } else {
2396 cfg.set_loop_alignment();
2397 }
2398 cfg.fixup_flow();
2399 }
2400
2401 // Apply peephole optimizations
2402 if( OptoPeephole ) {
2403 NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
2404 PhasePeephole peep( _regalloc, cfg);
2405 peep.do_transform();
2406 }
2407
2408 // Do late expand if CPU requires this.
2409 if (Matcher::require_postalloc_expand) {
2410 NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
2411 cfg.postalloc_expand(_regalloc);
2412 }
2413
2414 // Convert Nodes to instruction bits in a buffer
2415 {
2416 // %%%% workspace merge brought two timers together for one job
2417 TracePhase t2a("output", &_t_output, true);
2418 NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
2419 Output();
2420 }
2421
2422 print_method(PHASE_FINAL_CODE);
2423
2424 // He's dead, Jim.
2425 _cfg = (PhaseCFG*)((intptr_t)0xdeadbeef);
2426 _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2427 }
2428
2429
2430 //------------------------------dump_asm---------------------------------------
2431 // Dump formatted assembly
2432 #ifndef PRODUCT
2433 void Compile::dump_asm(int *pcs, uint pc_limit) {
2434 bool cut_short = false;
2435 tty->print_cr("#");
2436 tty->print("# "); _tf->dump(); tty->cr();
2437 tty->print_cr("#");
2438
2439 // For all blocks
2440 int pc = 0x0; // Program counter
2441 char starts_bundle = ' ';
2442 _regalloc->dump_frame();
2443
2444 Node *n = NULL;
2445 for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
2446 if (VMThread::should_terminate()) {
2447 cut_short = true;
2448 break;
2449 }
2450 Block* block = _cfg->get_block(i);
2451 if (block->is_connector() && !Verbose) {
2452 continue;
2453 }
2454 n = block->head();
2455 if (pcs && n->_idx < pc_limit) {
2456 tty->print("%3.3x ", pcs[n->_idx]);
2457 } else {
2458 tty->print(" ");
2459 }
2460 block->dump_head(_cfg);
2461 if (block->is_connector()) {
2462 tty->print_cr(" # Empty connector block");
2463 } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
2464 tty->print_cr(" # Block is sole successor of call");
2465 }
2466
2467 // For all instructions
2468 Node *delay = NULL;
2469 for (uint j = 0; j < block->number_of_nodes(); j++) {
2470 if (VMThread::should_terminate()) {
2471 cut_short = true;
2472 break;
2473 }
2474 n = block->get_node(j);
2475 if (valid_bundle_info(n)) {
2476 Bundle* bundle = node_bundling(n);
2477 if (bundle->used_in_unconditional_delay()) {
2478 delay = n;
2479 continue;
2480 }
2481 if (bundle->starts_bundle()) {
2482 starts_bundle = '+';
2483 }
2484 }
2485
2486 if (WizardMode) {
2487 n->dump();
2488 }
2489
2490 if( !n->is_Region() && // Dont print in the Assembly
2491 !n->is_Phi() && // a few noisely useless nodes
2492 !n->is_Proj() &&
2493 !n->is_MachTemp() &&
2494 !n->is_SafePointScalarObject() &&
2495 !n->is_Catch() && // Would be nice to print exception table targets
2496 !n->is_MergeMem() && // Not very interesting
2497 !n->is_top() && // Debug info table constants
2498 !(n->is_Con() && !n->is_Mach())// Debug info table constants
2499 ) {
2500 if (pcs && n->_idx < pc_limit)
2501 tty->print("%3.3x", pcs[n->_idx]);
2502 else
2503 tty->print(" ");
2504 tty->print(" %c ", starts_bundle);
2505 starts_bundle = ' ';
2506 tty->print("\t");
2507 n->format(_regalloc, tty);
2508 tty->cr();
2509 }
2510
2511 // If we have an instruction with a delay slot, and have seen a delay,
2512 // then back up and print it
2513 if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
2514 assert(delay != NULL, "no unconditional delay instruction");
2515 if (WizardMode) delay->dump();
2516
2517 if (node_bundling(delay)->starts_bundle())
2518 starts_bundle = '+';
2519 if (pcs && n->_idx < pc_limit)
2520 tty->print("%3.3x", pcs[n->_idx]);
2521 else
2522 tty->print(" ");
2523 tty->print(" %c ", starts_bundle);
2524 starts_bundle = ' ';
2525 tty->print("\t");
2526 delay->format(_regalloc, tty);
2527 tty->cr();
2528 delay = NULL;
2529 }
2530
2531 // Dump the exception table as well
2532 if( n->is_Catch() && (Verbose || WizardMode) ) {
2533 // Print the exception table for this offset
2534 _handler_table.print_subtable_for(pc);
2535 }
2536 }
2537
2538 if (pcs && n->_idx < pc_limit)
2539 tty->print_cr("%3.3x", pcs[n->_idx]);
2540 else
2541 tty->cr();
2542
2543 assert(cut_short || delay == NULL, "no unconditional delay branch");
2544
2545 } // End of per-block dump
2546 tty->cr();
2547
2548 if (cut_short) tty->print_cr("*** disassembly is cut short ***");
2549 }
2550 #endif
2551
2552 //------------------------------Final_Reshape_Counts---------------------------
2553 // This class defines counters to help identify when a method
2554 // may/must be executed using hardware with only 24-bit precision.
2555 struct Final_Reshape_Counts : public StackObj {
2556 int _call_count; // count non-inlined 'common' calls
2557 int _float_count; // count float ops requiring 24-bit precision
2558 int _double_count; // count double ops requiring more precision
2559 int _java_call_count; // count non-inlined 'java' calls
2560 int _inner_loop_count; // count loops which need alignment
2561 VectorSet _visited; // Visitation flags
2562 Node_List _tests; // Set of IfNodes & PCTableNodes
2563
2564 Final_Reshape_Counts() :
2565 _call_count(0), _float_count(0), _double_count(0),
2566 _java_call_count(0), _inner_loop_count(0),
2567 _visited( Thread::current()->resource_area() ) { }
2568
2569 void inc_call_count () { _call_count ++; }
2570 void inc_float_count () { _float_count ++; }
2571 void inc_double_count() { _double_count++; }
2572 void inc_java_call_count() { _java_call_count++; }
2573 void inc_inner_loop_count() { _inner_loop_count++; }
2574
2575 int get_call_count () const { return _call_count ; }
2576 int get_float_count () const { return _float_count ; }
2577 int get_double_count() const { return _double_count; }
2578 int get_java_call_count() const { return _java_call_count; }
2579 int get_inner_loop_count() const { return _inner_loop_count; }
2580 };
2581
2582 #ifdef ASSERT
2583 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
2584 ciInstanceKlass *k = tp->klass()->as_instance_klass();
2585 // Make sure the offset goes inside the instance layout.
2586 return k->contains_field_offset(tp->offset());
2587 // Note that OffsetBot and OffsetTop are very negative.
2588 }
2589 #endif
2590
2591 // Eliminate trivially redundant StoreCMs and accumulate their
2592 // precedence edges.
2593 void Compile::eliminate_redundant_card_marks(Node* n) {
2594 assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2595 if (n->in(MemNode::Address)->outcnt() > 1) {
2596 // There are multiple users of the same address so it might be
2597 // possible to eliminate some of the StoreCMs
2598 Node* mem = n->in(MemNode::Memory);
2599 Node* adr = n->in(MemNode::Address);
2600 Node* val = n->in(MemNode::ValueIn);
2601 Node* prev = n;
2602 bool done = false;
2603 // Walk the chain of StoreCMs eliminating ones that match. As
2604 // long as it's a chain of single users then the optimization is
2605 // safe. Eliminating partially redundant StoreCMs would require
2606 // cloning copies down the other paths.
2607 while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2608 if (adr == mem->in(MemNode::Address) &&
2609 val == mem->in(MemNode::ValueIn)) {
2610 // redundant StoreCM
2611 if (mem->req() > MemNode::OopStore) {
2612 // Hasn't been processed by this code yet.
2613 n->add_prec(mem->in(MemNode::OopStore));
2614 } else {
2615 // Already converted to precedence edge
2616 for (uint i = mem->req(); i < mem->len(); i++) {
2617 // Accumulate any precedence edges
2618 if (mem->in(i) != NULL) {
2619 n->add_prec(mem->in(i));
2620 }
2621 }
2622 // Everything above this point has been processed.
2623 done = true;
2624 }
2625 // Eliminate the previous StoreCM
2626 prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2627 assert(mem->outcnt() == 0, "should be dead");
2628 mem->disconnect_inputs(NULL, this);
2629 } else {
2630 prev = mem;
2631 }
2632 mem = prev->in(MemNode::Memory);
2633 }
2634 }
2635 }
2636
2637 //------------------------------final_graph_reshaping_impl----------------------
2638 // Implement items 1-5 from final_graph_reshaping below.
2639 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2640
2641 if ( n->outcnt() == 0 ) return; // dead node
2642 uint nop = n->Opcode();
2643
2644 // Check for 2-input instruction with "last use" on right input.
2645 // Swap to left input. Implements item (2).
2646 if( n->req() == 3 && // two-input instruction
2647 n->in(1)->outcnt() > 1 && // left use is NOT a last use
2648 (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2649 n->in(2)->outcnt() == 1 &&// right use IS a last use
2650 !n->in(2)->is_Con() ) { // right use is not a constant
2651 // Check for commutative opcode
2652 switch( nop ) {
2653 case Op_AddI: case Op_AddF: case Op_AddD: case Op_AddL:
2654 case Op_MaxI: case Op_MinI:
2655 case Op_MulI: case Op_MulF: case Op_MulD: case Op_MulL:
2656 case Op_AndL: case Op_XorL: case Op_OrL:
2657 case Op_AndI: case Op_XorI: case Op_OrI: {
2658 // Move "last use" input to left by swapping inputs
2659 n->swap_edges(1, 2);
2660 break;
2661 }
2662 default:
2663 break;
2664 }
2665 }
2666
2667 #ifdef ASSERT
2668 if( n->is_Mem() ) {
2669 int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2670 assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2671 // oop will be recorded in oop map if load crosses safepoint
2672 n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2673 LoadNode::is_immutable_value(n->in(MemNode::Address))),
2674 "raw memory operations should have control edge");
2675 }
2676 #endif
2677 // Count FPU ops and common calls, implements item (3)
2678 switch( nop ) {
2679 // Count all float operations that may use FPU
2680 case Op_AddF:
2681 case Op_SubF:
2682 case Op_MulF:
2683 case Op_DivF:
2684 case Op_NegF:
2685 case Op_ModF:
2686 case Op_ConvI2F:
2687 case Op_ConF:
2688 case Op_CmpF:
2689 case Op_CmpF3:
2690 // case Op_ConvL2F: // longs are split into 32-bit halves
2691 frc.inc_float_count();
2692 break;
2693
2694 case Op_ConvF2D:
2695 case Op_ConvD2F:
2696 frc.inc_float_count();
2697 frc.inc_double_count();
2698 break;
2699
2700 // Count all double operations that may use FPU
2701 case Op_AddD:
2702 case Op_SubD:
2703 case Op_MulD:
2704 case Op_DivD:
2705 case Op_NegD:
2706 case Op_ModD:
2707 case Op_ConvI2D:
2708 case Op_ConvD2I:
2709 // case Op_ConvL2D: // handled by leaf call
2710 // case Op_ConvD2L: // handled by leaf call
2711 case Op_ConD:
2712 case Op_CmpD:
2713 case Op_CmpD3:
2714 frc.inc_double_count();
2715 break;
2716 case Op_Opaque1: // Remove Opaque Nodes before matching
2717 case Op_Opaque2: // Remove Opaque Nodes before matching
2718 case Op_Opaque3:
2719 n->subsume_by(n->in(1), this);
2720 break;
2721 case Op_CallStaticJava:
2722 case Op_CallJava:
2723 case Op_CallDynamicJava:
2724 frc.inc_java_call_count(); // Count java call site;
2725 case Op_CallRuntime:
2726 case Op_CallLeaf:
2727 case Op_CallLeafNoFP: {
2728 assert( n->is_Call(), "" );
2729 CallNode *call = n->as_Call();
2730 // Count call sites where the FP mode bit would have to be flipped.
2731 // Do not count uncommon runtime calls:
2732 // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
2733 // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
2734 if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
2735 frc.inc_call_count(); // Count the call site
2736 } else { // See if uncommon argument is shared
2737 Node *n = call->in(TypeFunc::Parms);
2738 int nop = n->Opcode();
2739 // Clone shared simple arguments to uncommon calls, item (1).
2740 if( n->outcnt() > 1 &&
2741 !n->is_Proj() &&
2742 nop != Op_CreateEx &&
2743 nop != Op_CheckCastPP &&
2744 nop != Op_DecodeN &&
2745 nop != Op_DecodeNKlass &&
2746 !n->is_Mem() ) {
2747 Node *x = n->clone();
2748 call->set_req( TypeFunc::Parms, x );
2749 }
2750 }
2751 break;
2752 }
2753
2754 case Op_StoreD:
2755 case Op_LoadD:
2756 case Op_LoadD_unaligned:
2757 frc.inc_double_count();
2758 goto handle_mem;
2759 case Op_StoreF:
2760 case Op_LoadF:
2761 frc.inc_float_count();
2762 goto handle_mem;
2763
2764 case Op_StoreCM:
2765 {
2766 // Convert OopStore dependence into precedence edge
2767 Node* prec = n->in(MemNode::OopStore);
2768 n->del_req(MemNode::OopStore);
2769 n->add_prec(prec);
2770 eliminate_redundant_card_marks(n);
2771 }
2772
2773 // fall through
2774
2775 case Op_StoreB:
2776 case Op_StoreC:
2777 case Op_StorePConditional:
2778 case Op_StoreI:
2779 case Op_StoreL:
2780 case Op_StoreIConditional:
2781 case Op_StoreLConditional:
2782 case Op_CompareAndSwapI:
2783 case Op_CompareAndSwapL:
2784 case Op_CompareAndSwapP:
2785 case Op_CompareAndSwapN:
2786 case Op_GetAndAddI:
2787 case Op_GetAndAddL:
2788 case Op_GetAndSetI:
2789 case Op_GetAndSetL:
2790 case Op_GetAndSetP:
2791 case Op_GetAndSetN:
2792 case Op_StoreP:
2793 case Op_StoreN:
2794 case Op_StoreNKlass:
2795 case Op_LoadB:
2796 case Op_LoadUB:
2797 case Op_LoadUS:
2798 case Op_LoadI:
2799 case Op_LoadKlass:
2800 case Op_LoadNKlass:
2801 case Op_LoadL:
2802 case Op_LoadL_unaligned:
2803 case Op_LoadPLocked:
2804 case Op_LoadP:
2805 case Op_LoadN:
2806 case Op_LoadRange:
2807 case Op_LoadS: {
2808 handle_mem:
2809 #ifdef ASSERT
2810 if( VerifyOptoOopOffsets ) {
2811 assert( n->is_Mem(), "" );
2812 MemNode *mem = (MemNode*)n;
2813 // Check to see if address types have grounded out somehow.
2814 const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
2815 assert( !tp || oop_offset_is_sane(tp), "" );
2816 }
2817 #endif
2818 break;
2819 }
2820
2821 case Op_AddP: { // Assert sane base pointers
2822 Node *addp = n->in(AddPNode::Address);
2823 assert( !addp->is_AddP() ||
2824 addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
2825 addp->in(AddPNode::Base) == n->in(AddPNode::Base),
2826 "Base pointers must match" );
2827 #ifdef _LP64
2828 if ((UseCompressedOops || UseCompressedClassPointers) &&
2829 addp->Opcode() == Op_ConP &&
2830 addp == n->in(AddPNode::Base) &&
2831 n->in(AddPNode::Offset)->is_Con()) {
2832 // Use addressing with narrow klass to load with offset on x86.
2833 // On sparc loading 32-bits constant and decoding it have less
2834 // instructions (4) then load 64-bits constant (7).
2835 // Do this transformation here since IGVN will convert ConN back to ConP.
2836 const Type* t = addp->bottom_type();
2837 if (t->isa_oopptr() || t->isa_klassptr()) {
2838 Node* nn = NULL;
2839
2840 int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
2841
2842 // Look for existing ConN node of the same exact type.
2843 Node* r = root();
2844 uint cnt = r->outcnt();
2845 for (uint i = 0; i < cnt; i++) {
2846 Node* m = r->raw_out(i);
2847 if (m!= NULL && m->Opcode() == op &&
2848 m->bottom_type()->make_ptr() == t) {
2849 nn = m;
2850 break;
2851 }
2852 }
2853 if (nn != NULL) {
2854 // Decode a narrow oop to match address
2855 // [R12 + narrow_oop_reg<<3 + offset]
2856 if (t->isa_oopptr()) {
2857 nn = new (this) DecodeNNode(nn, t);
2858 } else {
2859 nn = new (this) DecodeNKlassNode(nn, t);
2860 }
2861 n->set_req(AddPNode::Base, nn);
2862 n->set_req(AddPNode::Address, nn);
2863 if (addp->outcnt() == 0) {
2864 addp->disconnect_inputs(NULL, this);
2865 }
2866 }
2867 }
2868 }
2869 #endif
2870 break;
2871 }
2872
2873 #ifdef _LP64
2874 case Op_CastPP:
2875 if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
2876 Node* in1 = n->in(1);
2877 const Type* t = n->bottom_type();
2878 Node* new_in1 = in1->clone();
2879 new_in1->as_DecodeN()->set_type(t);
2880
2881 if (!Matcher::narrow_oop_use_complex_address()) {
2882 //
2883 // x86, ARM and friends can handle 2 adds in addressing mode
2884 // and Matcher can fold a DecodeN node into address by using
2885 // a narrow oop directly and do implicit NULL check in address:
2886 //
2887 // [R12 + narrow_oop_reg<<3 + offset]
2888 // NullCheck narrow_oop_reg
2889 //
2890 // On other platforms (Sparc) we have to keep new DecodeN node and
2891 // use it to do implicit NULL check in address:
2892 //
2893 // decode_not_null narrow_oop_reg, base_reg
2894 // [base_reg + offset]
2895 // NullCheck base_reg
2896 //
2897 // Pin the new DecodeN node to non-null path on these platform (Sparc)
2898 // to keep the information to which NULL check the new DecodeN node
2899 // corresponds to use it as value in implicit_null_check().
2900 //
2901 new_in1->set_req(0, n->in(0));
2902 }
2903
2904 n->subsume_by(new_in1, this);
2905 if (in1->outcnt() == 0) {
2906 in1->disconnect_inputs(NULL, this);
2907 }
2908 }
2909 break;
2910
2911 case Op_CmpP:
2912 // Do this transformation here to preserve CmpPNode::sub() and
2913 // other TypePtr related Ideal optimizations (for example, ptr nullness).
2914 if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
2915 Node* in1 = n->in(1);
2916 Node* in2 = n->in(2);
2917 if (!in1->is_DecodeNarrowPtr()) {
2918 in2 = in1;
2919 in1 = n->in(2);
2920 }
2921 assert(in1->is_DecodeNarrowPtr(), "sanity");
2922
2923 Node* new_in2 = NULL;
2924 if (in2->is_DecodeNarrowPtr()) {
2925 assert(in2->Opcode() == in1->Opcode(), "must be same node type");
2926 new_in2 = in2->in(1);
2927 } else if (in2->Opcode() == Op_ConP) {
2928 const Type* t = in2->bottom_type();
2929 if (t == TypePtr::NULL_PTR) {
2930 assert(in1->is_DecodeN(), "compare klass to null?");
2931 // Don't convert CmpP null check into CmpN if compressed
2932 // oops implicit null check is not generated.
2933 // This will allow to generate normal oop implicit null check.
2934 if (Matcher::gen_narrow_oop_implicit_null_checks())
2935 new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
2936 //
2937 // This transformation together with CastPP transformation above
2938 // will generated code for implicit NULL checks for compressed oops.
2939 //
2940 // The original code after Optimize()
2941 //
2942 // LoadN memory, narrow_oop_reg
2943 // decode narrow_oop_reg, base_reg
2944 // CmpP base_reg, NULL
2945 // CastPP base_reg // NotNull
2946 // Load [base_reg + offset], val_reg
2947 //
2948 // after these transformations will be
2949 //
2950 // LoadN memory, narrow_oop_reg
2951 // CmpN narrow_oop_reg, NULL
2952 // decode_not_null narrow_oop_reg, base_reg
2953 // Load [base_reg + offset], val_reg
2954 //
2955 // and the uncommon path (== NULL) will use narrow_oop_reg directly
2956 // since narrow oops can be used in debug info now (see the code in
2957 // final_graph_reshaping_walk()).
2958 //
2959 // At the end the code will be matched to
2960 // on x86:
2961 //
2962 // Load_narrow_oop memory, narrow_oop_reg
2963 // Load [R12 + narrow_oop_reg<<3 + offset], val_reg
2964 // NullCheck narrow_oop_reg
2965 //
2966 // and on sparc:
2967 //
2968 // Load_narrow_oop memory, narrow_oop_reg
2969 // decode_not_null narrow_oop_reg, base_reg
2970 // Load [base_reg + offset], val_reg
2971 // NullCheck base_reg
2972 //
2973 } else if (t->isa_oopptr()) {
2974 new_in2 = ConNode::make(this, t->make_narrowoop());
2975 } else if (t->isa_klassptr()) {
2976 new_in2 = ConNode::make(this, t->make_narrowklass());
2977 }
2978 }
2979 if (new_in2 != NULL) {
2980 Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
2981 n->subsume_by(cmpN, this);
2982 if (in1->outcnt() == 0) {
2983 in1->disconnect_inputs(NULL, this);
2984 }
2985 if (in2->outcnt() == 0) {
2986 in2->disconnect_inputs(NULL, this);
2987 }
2988 }
2989 }
2990 break;
2991
2992 case Op_DecodeN:
2993 case Op_DecodeNKlass:
2994 assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
2995 // DecodeN could be pinned when it can't be fold into
2996 // an address expression, see the code for Op_CastPP above.
2997 assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
2998 break;
2999
3000 case Op_EncodeP:
3001 case Op_EncodePKlass: {
3002 Node* in1 = n->in(1);
3003 if (in1->is_DecodeNarrowPtr()) {
3004 n->subsume_by(in1->in(1), this);
3005 } else if (in1->Opcode() == Op_ConP) {
3006 const Type* t = in1->bottom_type();
3007 if (t == TypePtr::NULL_PTR) {
3008 assert(t->isa_oopptr(), "null klass?");
3009 n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
3010 } else if (t->isa_oopptr()) {
3011 n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
3012 } else if (t->isa_klassptr()) {
3013 n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
3014 }
3015 }
3016 if (in1->outcnt() == 0) {
3017 in1->disconnect_inputs(NULL, this);
3018 }
3019 break;
3020 }
3021
3022 case Op_Proj: {
3023 if (OptimizeStringConcat) {
3024 ProjNode* p = n->as_Proj();
3025 if (p->_is_io_use) {
3026 // Separate projections were used for the exception path which
3027 // are normally removed by a late inline. If it wasn't inlined
3028 // then they will hang around and should just be replaced with
3029 // the original one.
3030 Node* proj = NULL;
3031 // Replace with just one
3032 for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
3033 Node *use = i.get();
3034 if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
3035 proj = use;
3036 break;
3037 }
3038 }
3039 assert(proj != NULL || p->_con == TypeFunc::I_O, "io may be dropped at an infinite loop");
3040 if (proj != NULL) {
3041 p->subsume_by(proj, this);
3042 }
3043 }
3044 }
3045 break;
3046 }
3047
3048 case Op_Phi:
3049 if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3050 // The EncodeP optimization may create Phi with the same edges
3051 // for all paths. It is not handled well by Register Allocator.
3052 Node* unique_in = n->in(1);
3053 assert(unique_in != NULL, "");
3054 uint cnt = n->req();
3055 for (uint i = 2; i < cnt; i++) {
3056 Node* m = n->in(i);
3057 assert(m != NULL, "");
3058 if (unique_in != m)
3059 unique_in = NULL;
3060 }
3061 if (unique_in != NULL) {
3062 n->subsume_by(unique_in, this);
3063 }
3064 }
3065 break;
3066
3067 #endif
3068
3069 #ifdef ASSERT
3070 case Op_CastII:
3071 // Verify that all range check dependent CastII nodes were removed.
3072 if (n->isa_CastII()->has_range_check()) {
3073 n->dump(3);
3074 assert(false, "Range check dependent CastII node was not removed");
3075 }
3076 break;
3077 #endif
3078
3079 case Op_ModI:
3080 if (UseDivMod) {
3081 // Check if a%b and a/b both exist
3082 Node* d = n->find_similar(Op_DivI);
3083 if (d) {
3084 // Replace them with a fused divmod if supported
3085 if (Matcher::has_match_rule(Op_DivModI)) {
3086 DivModINode* divmod = DivModINode::make(this, n);
3087 d->subsume_by(divmod->div_proj(), this);
3088 n->subsume_by(divmod->mod_proj(), this);
3089 } else {
3090 // replace a%b with a-((a/b)*b)
3091 Node* mult = new (this) MulINode(d, d->in(2));
3092 Node* sub = new (this) SubINode(d->in(1), mult);
3093 n->subsume_by(sub, this);
3094 }
3095 }
3096 }
3097 break;
3098
3099 case Op_ModL:
3100 if (UseDivMod) {
3101 // Check if a%b and a/b both exist
3102 Node* d = n->find_similar(Op_DivL);
3103 if (d) {
3104 // Replace them with a fused divmod if supported
3105 if (Matcher::has_match_rule(Op_DivModL)) {
3106 DivModLNode* divmod = DivModLNode::make(this, n);
3107 d->subsume_by(divmod->div_proj(), this);
3108 n->subsume_by(divmod->mod_proj(), this);
3109 } else {
3110 // replace a%b with a-((a/b)*b)
3111 Node* mult = new (this) MulLNode(d, d->in(2));
3112 Node* sub = new (this) SubLNode(d->in(1), mult);
3113 n->subsume_by(sub, this);
3114 }
3115 }
3116 }
3117 break;
3118
3119 case Op_LoadVector:
3120 case Op_StoreVector:
3121 break;
3122
3123 case Op_PackB:
3124 case Op_PackS:
3125 case Op_PackI:
3126 case Op_PackF:
3127 case Op_PackL:
3128 case Op_PackD:
3129 if (n->req()-1 > 2) {
3130 // Replace many operand PackNodes with a binary tree for matching
3131 PackNode* p = (PackNode*) n;
3132 Node* btp = p->binary_tree_pack(this, 1, n->req());
3133 n->subsume_by(btp, this);
3134 }
3135 break;
3136 case Op_Loop:
3137 case Op_CountedLoop:
3138 if (n->as_Loop()->is_inner_loop()) {
3139 frc.inc_inner_loop_count();
3140 }
3141 break;
3142 case Op_LShiftI:
3143 case Op_RShiftI:
3144 case Op_URShiftI:
3145 case Op_LShiftL:
3146 case Op_RShiftL:
3147 case Op_URShiftL:
3148 if (Matcher::need_masked_shift_count) {
3149 // The cpu's shift instructions don't restrict the count to the
3150 // lower 5/6 bits. We need to do the masking ourselves.
3151 Node* in2 = n->in(2);
3152 juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3153 const TypeInt* t = in2->find_int_type();
3154 if (t != NULL && t->is_con()) {
3155 juint shift = t->get_con();
3156 if (shift > mask) { // Unsigned cmp
3157 n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
3158 }
3159 } else {
3160 if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3161 Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
3162 n->set_req(2, shift);
3163 }
3164 }
3165 if (in2->outcnt() == 0) { // Remove dead node
3166 in2->disconnect_inputs(NULL, this);
3167 }
3168 }
3169 break;
3170 case Op_MemBarStoreStore:
3171 case Op_MemBarRelease:
3172 // Break the link with AllocateNode: it is no longer useful and
3173 // confuses register allocation.
3174 if (n->req() > MemBarNode::Precedent) {
3175 n->set_req(MemBarNode::Precedent, top());
3176 }
3177 break;
3178 default:
3179 assert( !n->is_Call(), "" );
3180 assert( !n->is_Mem(), "" );
3181 assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3182 break;
3183 }
3184
3185 // Collect CFG split points
3186 if (n->is_MultiBranch())
3187 frc._tests.push(n);
3188 }
3189
3190 //------------------------------final_graph_reshaping_walk---------------------
3191 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3192 // requires that the walk visits a node's inputs before visiting the node.
3193 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3194 ResourceArea *area = Thread::current()->resource_area();
3195 Unique_Node_List sfpt(area);
3196
3197 frc._visited.set(root->_idx); // first, mark node as visited
3198 uint cnt = root->req();
3199 Node *n = root;
3200 uint i = 0;
3201 while (true) {
3202 if (i < cnt) {
3203 // Place all non-visited non-null inputs onto stack
3204 Node* m = n->in(i);
3205 ++i;
3206 if (m != NULL && !frc._visited.test_set(m->_idx)) {
3207 if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3208 // compute worst case interpreter size in case of a deoptimization
3209 update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3210
3211 sfpt.push(m);
3212 }
3213 cnt = m->req();
3214 nstack.push(n, i); // put on stack parent and next input's index
3215 n = m;
3216 i = 0;
3217 }
3218 } else {
3219 // Now do post-visit work
3220 final_graph_reshaping_impl( n, frc );
3221 if (nstack.is_empty())
3222 break; // finished
3223 n = nstack.node(); // Get node from stack
3224 cnt = n->req();
3225 i = nstack.index();
3226 nstack.pop(); // Shift to the next node on stack
3227 }
3228 }
3229
3230 // Skip next transformation if compressed oops are not used.
3231 if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3232 (!UseCompressedOops && !UseCompressedClassPointers))
3233 return;
3234
3235 // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3236 // It could be done for an uncommon traps or any safepoints/calls
3237 // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3238 while (sfpt.size() > 0) {
3239 n = sfpt.pop();
3240 JVMState *jvms = n->as_SafePoint()->jvms();
3241 assert(jvms != NULL, "sanity");
3242 int start = jvms->debug_start();
3243 int end = n->req();
3244 bool is_uncommon = (n->is_CallStaticJava() &&
3245 n->as_CallStaticJava()->uncommon_trap_request() != 0);
3246 for (int j = start; j < end; j++) {
3247 Node* in = n->in(j);
3248 if (in->is_DecodeNarrowPtr()) {
3249 bool safe_to_skip = true;
3250 if (!is_uncommon ) {
3251 // Is it safe to skip?
3252 for (uint i = 0; i < in->outcnt(); i++) {
3253 Node* u = in->raw_out(i);
3254 if (!u->is_SafePoint() ||
3255 u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
3256 safe_to_skip = false;
3257 }
3258 }
3259 }
3260 if (safe_to_skip) {
3261 n->set_req(j, in->in(1));
3262 }
3263 if (in->outcnt() == 0) {
3264 in->disconnect_inputs(NULL, this);
3265 }
3266 }
3267 }
3268 }
3269 }
3270
3271 //------------------------------final_graph_reshaping--------------------------
3272 // Final Graph Reshaping.
3273 //
3274 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3275 // and not commoned up and forced early. Must come after regular
3276 // optimizations to avoid GVN undoing the cloning. Clone constant
3277 // inputs to Loop Phis; these will be split by the allocator anyways.
3278 // Remove Opaque nodes.
3279 // (2) Move last-uses by commutative operations to the left input to encourage
3280 // Intel update-in-place two-address operations and better register usage
3281 // on RISCs. Must come after regular optimizations to avoid GVN Ideal
3282 // calls canonicalizing them back.
3283 // (3) Count the number of double-precision FP ops, single-precision FP ops
3284 // and call sites. On Intel, we can get correct rounding either by
3285 // forcing singles to memory (requires extra stores and loads after each
3286 // FP bytecode) or we can set a rounding mode bit (requires setting and
3287 // clearing the mode bit around call sites). The mode bit is only used
3288 // if the relative frequency of single FP ops to calls is low enough.
3289 // This is a key transform for SPEC mpeg_audio.
3290 // (4) Detect infinite loops; blobs of code reachable from above but not
3291 // below. Several of the Code_Gen algorithms fail on such code shapes,
3292 // so we simply bail out. Happens a lot in ZKM.jar, but also happens
3293 // from time to time in other codes (such as -Xcomp finalizer loops, etc).
3294 // Detection is by looking for IfNodes where only 1 projection is
3295 // reachable from below or CatchNodes missing some targets.
3296 // (5) Assert for insane oop offsets in debug mode.
3297
3298 bool Compile::final_graph_reshaping() {
3299 // an infinite loop may have been eliminated by the optimizer,
3300 // in which case the graph will be empty.
3301 if (root()->req() == 1) {
3302 record_method_not_compilable("trivial infinite loop");
3303 return true;
3304 }
3305
3306 // Expensive nodes have their control input set to prevent the GVN
3307 // from freely commoning them. There's no GVN beyond this point so
3308 // no need to keep the control input. We want the expensive nodes to
3309 // be freely moved to the least frequent code path by gcm.
3310 assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3311 for (int i = 0; i < expensive_count(); i++) {
3312 _expensive_nodes->at(i)->set_req(0, NULL);
3313 }
3314
3315 Final_Reshape_Counts frc;
3316
3317 // Visit everybody reachable!
3318 // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3319 Node_Stack nstack(live_nodes() >> 1);
3320 final_graph_reshaping_walk(nstack, root(), frc);
3321
3322 // Check for unreachable (from below) code (i.e., infinite loops).
3323 for( uint i = 0; i < frc._tests.size(); i++ ) {
3324 MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3325 // Get number of CFG targets.
3326 // Note that PCTables include exception targets after calls.
3327 uint required_outcnt = n->required_outcnt();
3328 if (n->outcnt() != required_outcnt) {
3329 // Check for a few special cases. Rethrow Nodes never take the
3330 // 'fall-thru' path, so expected kids is 1 less.
3331 if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3332 if (n->in(0)->in(0)->is_Call()) {
3333 CallNode *call = n->in(0)->in(0)->as_Call();
3334 if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3335 required_outcnt--; // Rethrow always has 1 less kid
3336 } else if (call->req() > TypeFunc::Parms &&
3337 call->is_CallDynamicJava()) {
3338 // Check for null receiver. In such case, the optimizer has
3339 // detected that the virtual call will always result in a null
3340 // pointer exception. The fall-through projection of this CatchNode
3341 // will not be populated.
3342 Node *arg0 = call->in(TypeFunc::Parms);
3343 if (arg0->is_Type() &&
3344 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3345 required_outcnt--;
3346 }
3347 } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3348 call->req() > TypeFunc::Parms+1 &&
3349 call->is_CallStaticJava()) {
3350 // Check for negative array length. In such case, the optimizer has
3351 // detected that the allocation attempt will always result in an
3352 // exception. There is no fall-through projection of this CatchNode .
3353 Node *arg1 = call->in(TypeFunc::Parms+1);
3354 if (arg1->is_Type() &&
3355 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3356 required_outcnt--;
3357 }
3358 }
3359 }
3360 }
3361 // Recheck with a better notion of 'required_outcnt'
3362 if (n->outcnt() != required_outcnt) {
3363 record_method_not_compilable("malformed control flow");
3364 return true; // Not all targets reachable!
3365 }
3366 }
3367 // Check that I actually visited all kids. Unreached kids
3368 // must be infinite loops.
3369 for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3370 if (!frc._visited.test(n->fast_out(j)->_idx)) {
3371 record_method_not_compilable("infinite loop");
3372 return true; // Found unvisited kid; must be unreach
3373 }
3374 }
3375
3376 // If original bytecodes contained a mixture of floats and doubles
3377 // check if the optimizer has made it homogenous, item (3).
3378 if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
3379 frc.get_float_count() > 32 &&
3380 frc.get_double_count() == 0 &&
3381 (10 * frc.get_call_count() < frc.get_float_count()) ) {
3382 set_24_bit_selection_and_mode( false, true );
3383 }
3384
3385 set_java_calls(frc.get_java_call_count());
3386 set_inner_loops(frc.get_inner_loop_count());
3387
3388 // No infinite loops, no reason to bail out.
3389 return false;
3390 }
3391
3392 //-----------------------------too_many_traps----------------------------------
3393 // Report if there are too many traps at the current method and bci.
3394 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
3395 bool Compile::too_many_traps(ciMethod* method,
3396 int bci,
3397 Deoptimization::DeoptReason reason) {
3398 ciMethodData* md = method->method_data();
3399 if (md->is_empty()) {
3400 // Assume the trap has not occurred, or that it occurred only
3401 // because of a transient condition during start-up in the interpreter.
3402 return false;
3403 }
3404 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3405 if (md->has_trap_at(bci, m, reason) != 0) {
3406 // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3407 // Also, if there are multiple reasons, or if there is no per-BCI record,
3408 // assume the worst.
3409 if (log())
3410 log()->elem("observe trap='%s' count='%d'",
3411 Deoptimization::trap_reason_name(reason),
3412 md->trap_count(reason));
3413 return true;
3414 } else {
3415 // Ignore method/bci and see if there have been too many globally.
3416 return too_many_traps(reason, md);
3417 }
3418 }
3419
3420 // Less-accurate variant which does not require a method and bci.
3421 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3422 ciMethodData* logmd) {
3423 if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3424 // Too many traps globally.
3425 // Note that we use cumulative trap_count, not just md->trap_count.
3426 if (log()) {
3427 int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3428 log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3429 Deoptimization::trap_reason_name(reason),
3430 mcount, trap_count(reason));
3431 }
3432 return true;
3433 } else {
3434 // The coast is clear.
3435 return false;
3436 }
3437 }
3438
3439 //--------------------------too_many_recompiles--------------------------------
3440 // Report if there are too many recompiles at the current method and bci.
3441 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3442 // Is not eager to return true, since this will cause the compiler to use
3443 // Action_none for a trap point, to avoid too many recompilations.
3444 bool Compile::too_many_recompiles(ciMethod* method,
3445 int bci,
3446 Deoptimization::DeoptReason reason) {
3447 ciMethodData* md = method->method_data();
3448 if (md->is_empty()) {
3449 // Assume the trap has not occurred, or that it occurred only
3450 // because of a transient condition during start-up in the interpreter.
3451 return false;
3452 }
3453 // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3454 uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3455 uint m_cutoff = (uint) PerMethodRecompilationCutoff / 2 + 1; // not zero
3456 Deoptimization::DeoptReason per_bc_reason
3457 = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3458 ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3459 if ((per_bc_reason == Deoptimization::Reason_none
3460 || md->has_trap_at(bci, m, reason) != 0)
3461 // The trap frequency measure we care about is the recompile count:
3462 && md->trap_recompiled_at(bci, m)
3463 && md->overflow_recompile_count() >= bc_cutoff) {
3464 // Do not emit a trap here if it has already caused recompilations.
3465 // Also, if there are multiple reasons, or if there is no per-BCI record,
3466 // assume the worst.
3467 if (log())
3468 log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3469 Deoptimization::trap_reason_name(reason),
3470 md->trap_count(reason),
3471 md->overflow_recompile_count());
3472 return true;
3473 } else if (trap_count(reason) != 0
3474 && decompile_count() >= m_cutoff) {
3475 // Too many recompiles globally, and we have seen this sort of trap.
3476 // Use cumulative decompile_count, not just md->decompile_count.
3477 if (log())
3478 log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3479 Deoptimization::trap_reason_name(reason),
3480 md->trap_count(reason), trap_count(reason),
3481 md->decompile_count(), decompile_count());
3482 return true;
3483 } else {
3484 // The coast is clear.
3485 return false;
3486 }
3487 }
3488
3489 // Compute when not to trap. Used by matching trap based nodes and
3490 // NullCheck optimization.
3491 void Compile::set_allowed_deopt_reasons() {
3492 _allowed_reasons = 0;
3493 if (is_method_compilation()) {
3494 for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3495 assert(rs < BitsPerInt, "recode bit map");
3496 if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3497 _allowed_reasons |= nth_bit(rs);
3498 }
3499 }
3500 }
3501 }
3502
3503 #ifndef PRODUCT
3504 //------------------------------verify_graph_edges---------------------------
3505 // Walk the Graph and verify that there is a one-to-one correspondence
3506 // between Use-Def edges and Def-Use edges in the graph.
3507 void Compile::verify_graph_edges(bool no_dead_code) {
3508 if (VerifyGraphEdges) {
3509 ResourceArea *area = Thread::current()->resource_area();
3510 Unique_Node_List visited(area);
3511 // Call recursive graph walk to check edges
3512 _root->verify_edges(visited);
3513 if (no_dead_code) {
3514 // Now make sure that no visited node is used by an unvisited node.
3515 bool dead_nodes = false;
3516 Unique_Node_List checked(area);
3517 while (visited.size() > 0) {
3518 Node* n = visited.pop();
3519 checked.push(n);
3520 for (uint i = 0; i < n->outcnt(); i++) {
3521 Node* use = n->raw_out(i);
3522 if (checked.member(use)) continue; // already checked
3523 if (visited.member(use)) continue; // already in the graph
3524 if (use->is_Con()) continue; // a dead ConNode is OK
3525 // At this point, we have found a dead node which is DU-reachable.
3526 if (!dead_nodes) {
3527 tty->print_cr("*** Dead nodes reachable via DU edges:");
3528 dead_nodes = true;
3529 }
3530 use->dump(2);
3531 tty->print_cr("---");
3532 checked.push(use); // No repeats; pretend it is now checked.
3533 }
3534 }
3535 assert(!dead_nodes, "using nodes must be reachable from root");
3536 }
3537 }
3538 }
3539
3540 // Verify GC barriers consistency
3541 // Currently supported:
3542 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
3543 void Compile::verify_barriers() {
3544 if (UseG1GC) {
3545 // Verify G1 pre-barriers
3546 const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
3547
3548 ResourceArea *area = Thread::current()->resource_area();
3549 Unique_Node_List visited(area);
3550 Node_List worklist(area);
3551 // We're going to walk control flow backwards starting from the Root
3552 worklist.push(_root);
3553 while (worklist.size() > 0) {
3554 Node* x = worklist.pop();
3555 if (x == NULL || x == top()) continue;
3556 if (visited.member(x)) {
3557 continue;
3558 } else {
3559 visited.push(x);
3560 }
3561
3562 if (x->is_Region()) {
3563 for (uint i = 1; i < x->req(); i++) {
3564 worklist.push(x->in(i));
3565 }
3566 } else {
3567 worklist.push(x->in(0));
3568 // We are looking for the pattern:
3569 // /->ThreadLocal
3570 // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
3571 // \->ConI(0)
3572 // We want to verify that the If and the LoadB have the same control
3573 // See GraphKit::g1_write_barrier_pre()
3574 if (x->is_If()) {
3575 IfNode *iff = x->as_If();
3576 if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
3577 CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
3578 if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
3579 && cmp->in(1)->is_Load()) {
3580 LoadNode* load = cmp->in(1)->as_Load();
3581 if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
3582 && load->in(2)->in(3)->is_Con()
3583 && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
3584
3585 Node* if_ctrl = iff->in(0);
3586 Node* load_ctrl = load->in(0);
3587
3588 if (if_ctrl != load_ctrl) {
3589 // Skip possible CProj->NeverBranch in infinite loops
3590 if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
3591 && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
3592 if_ctrl = if_ctrl->in(0)->in(0);
3593 }
3594 }
3595 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
3596 }
3597 }
3598 }
3599 }
3600 }
3601 }
3602 }
3603 }
3604
3605 #endif
3606
3607 // The Compile object keeps track of failure reasons separately from the ciEnv.
3608 // This is required because there is not quite a 1-1 relation between the
3609 // ciEnv and its compilation task and the Compile object. Note that one
3610 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
3611 // to backtrack and retry without subsuming loads. Other than this backtracking
3612 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
3613 // by the logic in C2Compiler.
3614 void Compile::record_failure(const char* reason) {
3615 if (log() != NULL) {
3616 log()->elem("failure reason='%s' phase='compile'", reason);
3617 }
3618 if (_failure_reason == NULL) {
3619 // Record the first failure reason.
3620 _failure_reason = reason;
3621 }
3622
3623 if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
3624 C->print_method(PHASE_FAILURE);
3625 }
3626 _root = NULL; // flush the graph, too
3627 }
3628
3629 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
3630 : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
3631 _phase_name(name), _dolog(dolog)
3632 {
3633 if (dolog) {
3634 C = Compile::current();
3635 _log = C->log();
3636 } else {
3637 C = NULL;
3638 _log = NULL;
3639 }
3640 if (_log != NULL) {
3641 _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3642 _log->stamp();
3643 _log->end_head();
3644 }
3645 }
3646
3647 Compile::TracePhase::~TracePhase() {
3648
3649 C = Compile::current();
3650 if (_dolog) {
3651 _log = C->log();
3652 } else {
3653 _log = NULL;
3654 }
3655
3656 #ifdef ASSERT
3657 if (PrintIdealNodeCount) {
3658 tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
3659 _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
3660 }
3661
3662 if (VerifyIdealNodeCount) {
3663 Compile::current()->print_missing_nodes();
3664 }
3665 #endif
3666
3667 if (_log != NULL) {
3668 _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
3669 }
3670 }
3671
3672 //=============================================================================
3673 // Two Constant's are equal when the type and the value are equal.
3674 bool Compile::Constant::operator==(const Constant& other) {
3675 if (type() != other.type() ) return false;
3676 if (can_be_reused() != other.can_be_reused()) return false;
3677 // For floating point values we compare the bit pattern.
3678 switch (type()) {
3679 case T_FLOAT: return (_v._value.i == other._v._value.i);
3680 case T_LONG:
3681 case T_DOUBLE: return (_v._value.j == other._v._value.j);
3682 case T_OBJECT:
3683 case T_ADDRESS: return (_v._value.l == other._v._value.l);
3684 case T_VOID: return (_v._value.l == other._v._value.l); // jump-table entries
3685 case T_METADATA: return (_v._metadata == other._v._metadata);
3686 default: ShouldNotReachHere();
3687 }
3688 return false;
3689 }
3690
3691 static int type_to_size_in_bytes(BasicType t) {
3692 switch (t) {
3693 case T_LONG: return sizeof(jlong );
3694 case T_FLOAT: return sizeof(jfloat );
3695 case T_DOUBLE: return sizeof(jdouble);
3696 case T_METADATA: return sizeof(Metadata*);
3697 // We use T_VOID as marker for jump-table entries (labels) which
3698 // need an internal word relocation.
3699 case T_VOID:
3700 case T_ADDRESS:
3701 case T_OBJECT: return sizeof(jobject);
3702 }
3703
3704 ShouldNotReachHere();
3705 return -1;
3706 }
3707
3708 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
3709 // sort descending
3710 if (a->freq() > b->freq()) return -1;
3711 if (a->freq() < b->freq()) return 1;
3712 return 0;
3713 }
3714
3715 void Compile::ConstantTable::calculate_offsets_and_size() {
3716 // First, sort the array by frequencies.
3717 _constants.sort(qsort_comparator);
3718
3719 #ifdef ASSERT
3720 // Make sure all jump-table entries were sorted to the end of the
3721 // array (they have a negative frequency).
3722 bool found_void = false;
3723 for (int i = 0; i < _constants.length(); i++) {
3724 Constant con = _constants.at(i);
3725 if (con.type() == T_VOID)
3726 found_void = true; // jump-tables
3727 else
3728 assert(!found_void, "wrong sorting");
3729 }
3730 #endif
3731
3732 int offset = 0;
3733 for (int i = 0; i < _constants.length(); i++) {
3734 Constant* con = _constants.adr_at(i);
3735
3736 // Align offset for type.
3737 int typesize = type_to_size_in_bytes(con->type());
3738 offset = align_size_up(offset, typesize);
3739 con->set_offset(offset); // set constant's offset
3740
3741 if (con->type() == T_VOID) {
3742 MachConstantNode* n = (MachConstantNode*) con->get_jobject();
3743 offset = offset + typesize * n->outcnt(); // expand jump-table
3744 } else {
3745 offset = offset + typesize;
3746 }
3747 }
3748
3749 // Align size up to the next section start (which is insts; see
3750 // CodeBuffer::align_at_start).
3751 assert(_size == -1, "already set?");
3752 _size = align_size_up(offset, CodeEntryAlignment);
3753 }
3754
3755 void Compile::ConstantTable::emit(CodeBuffer& cb) {
3756 MacroAssembler _masm(&cb);
3757 for (int i = 0; i < _constants.length(); i++) {
3758 Constant con = _constants.at(i);
3759 address constant_addr = NULL;
3760 switch (con.type()) {
3761 case T_LONG: constant_addr = _masm.long_constant( con.get_jlong() ); break;
3762 case T_FLOAT: constant_addr = _masm.float_constant( con.get_jfloat() ); break;
3763 case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
3764 case T_OBJECT: {
3765 jobject obj = con.get_jobject();
3766 int oop_index = _masm.oop_recorder()->find_index(obj);
3767 constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
3768 break;
3769 }
3770 case T_ADDRESS: {
3771 address addr = (address) con.get_jobject();
3772 constant_addr = _masm.address_constant(addr);
3773 break;
3774 }
3775 // We use T_VOID as marker for jump-table entries (labels) which
3776 // need an internal word relocation.
3777 case T_VOID: {
3778 MachConstantNode* n = (MachConstantNode*) con.get_jobject();
3779 // Fill the jump-table with a dummy word. The real value is
3780 // filled in later in fill_jump_table.
3781 address dummy = (address) n;
3782 constant_addr = _masm.address_constant(dummy);
3783 // Expand jump-table
3784 for (uint i = 1; i < n->outcnt(); i++) {
3785 address temp_addr = _masm.address_constant(dummy + i);
3786 assert(temp_addr, "consts section too small");
3787 }
3788 break;
3789 }
3790 case T_METADATA: {
3791 Metadata* obj = con.get_metadata();
3792 int metadata_index = _masm.oop_recorder()->find_index(obj);
3793 constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
3794 break;
3795 }
3796 default: ShouldNotReachHere();
3797 }
3798 assert(constant_addr, "consts section too small");
3799 assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
3800 err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
3801 }
3802 }
3803
3804 int Compile::ConstantTable::find_offset(Constant& con) const {
3805 int idx = _constants.find(con);
3806 assert(idx != -1, "constant must be in constant table");
3807 int offset = _constants.at(idx).offset();
3808 assert(offset != -1, "constant table not emitted yet?");
3809 return offset;
3810 }
3811
3812 void Compile::ConstantTable::add(Constant& con) {
3813 if (con.can_be_reused()) {
3814 int idx = _constants.find(con);
3815 if (idx != -1 && _constants.at(idx).can_be_reused()) {
3816 _constants.adr_at(idx)->inc_freq(con.freq()); // increase the frequency by the current value
3817 return;
3818 }
3819 }
3820 (void) _constants.append(con);
3821 }
3822
3823 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
3824 Block* b = Compile::current()->cfg()->get_block_for_node(n);
3825 Constant con(type, value, b->_freq);
3826 add(con);
3827 return con;
3828 }
3829
3830 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
3831 Constant con(metadata);
3832 add(con);
3833 return con;
3834 }
3835
3836 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
3837 jvalue value;
3838 BasicType type = oper->type()->basic_type();
3839 switch (type) {
3840 case T_LONG: value.j = oper->constantL(); break;
3841 case T_FLOAT: value.f = oper->constantF(); break;
3842 case T_DOUBLE: value.d = oper->constantD(); break;
3843 case T_OBJECT:
3844 case T_ADDRESS: value.l = (jobject) oper->constant(); break;
3845 case T_METADATA: return add((Metadata*)oper->constant()); break;
3846 default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
3847 }
3848 return add(n, type, value);
3849 }
3850
3851 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
3852 jvalue value;
3853 // We can use the node pointer here to identify the right jump-table
3854 // as this method is called from Compile::Fill_buffer right before
3855 // the MachNodes are emitted and the jump-table is filled (means the
3856 // MachNode pointers do not change anymore).
3857 value.l = (jobject) n;
3858 Constant con(T_VOID, value, next_jump_table_freq(), false); // Labels of a jump-table cannot be reused.
3859 add(con);
3860 return con;
3861 }
3862
3863 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
3864 // If called from Compile::scratch_emit_size do nothing.
3865 if (Compile::current()->in_scratch_emit_size()) return;
3866
3867 assert(labels.is_nonempty(), "must be");
3868 assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
3869
3870 // Since MachConstantNode::constant_offset() also contains
3871 // table_base_offset() we need to subtract the table_base_offset()
3872 // to get the plain offset into the constant table.
3873 int offset = n->constant_offset() - table_base_offset();
3874
3875 MacroAssembler _masm(&cb);
3876 address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
3877
3878 for (uint i = 0; i < n->outcnt(); i++) {
3879 address* constant_addr = &jump_table_base[i];
3880 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)));
3881 *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
3882 cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
3883 }
3884 }
3885
3886 void Compile::dump_inlining() {
3887 if (print_inlining() || print_intrinsics()) {
3888 // Print inlining message for candidates that we couldn't inline
3889 // for lack of space or non constant receiver
3890 for (int i = 0; i < _late_inlines.length(); i++) {
3891 CallGenerator* cg = _late_inlines.at(i);
3892 cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
3893 }
3894 Unique_Node_List useful;
3895 useful.push(root());
3896 for (uint next = 0; next < useful.size(); ++next) {
3897 Node* n = useful.at(next);
3898 if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
3899 CallNode* call = n->as_Call();
3900 CallGenerator* cg = call->generator();
3901 cg->print_inlining_late("receiver not constant");
3902 }
3903 uint max = n->len();
3904 for ( uint i = 0; i < max; ++i ) {
3905 Node *m = n->in(i);
3906 if ( m == NULL ) continue;
3907 useful.push(m);
3908 }
3909 }
3910 for (int i = 0; i < _print_inlining_list->length(); i++) {
3911 tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
3912 }
3913 }
3914 }
3915
3916 // Dump inlining replay data to the stream.
3917 // Don't change thread state and acquire any locks.
3918 void Compile::dump_inline_data(outputStream* out) {
3919 InlineTree* inl_tree = ilt();
3920 if (inl_tree != NULL) {
3921 out->print(" inline %d", inl_tree->count());
3922 inl_tree->dump_replay_data(out);
3923 }
3924 }
3925
3926 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
3927 if (n1->Opcode() < n2->Opcode()) return -1;
3928 else if (n1->Opcode() > n2->Opcode()) return 1;
3929
3930 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()));
3931 for (uint i = 1; i < n1->req(); i++) {
3932 if (n1->in(i) < n2->in(i)) return -1;
3933 else if (n1->in(i) > n2->in(i)) return 1;
3934 }
3935
3936 return 0;
3937 }
3938
3939 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
3940 Node* n1 = *n1p;
3941 Node* n2 = *n2p;
3942
3943 return cmp_expensive_nodes(n1, n2);
3944 }
3945
3946 void Compile::sort_expensive_nodes() {
3947 if (!expensive_nodes_sorted()) {
3948 _expensive_nodes->sort(cmp_expensive_nodes);
3949 }
3950 }
3951
3952 bool Compile::expensive_nodes_sorted() const {
3953 for (int i = 1; i < _expensive_nodes->length(); i++) {
3954 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
3955 return false;
3956 }
3957 }
3958 return true;
3959 }
3960
3961 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
3962 if (_expensive_nodes->length() == 0) {
3963 return false;
3964 }
3965
3966 assert(OptimizeExpensiveOps, "optimization off?");
3967
3968 // Take this opportunity to remove dead nodes from the list
3969 int j = 0;
3970 for (int i = 0; i < _expensive_nodes->length(); i++) {
3971 Node* n = _expensive_nodes->at(i);
3972 if (!n->is_unreachable(igvn)) {
3973 assert(n->is_expensive(), "should be expensive");
3974 _expensive_nodes->at_put(j, n);
3975 j++;
3976 }
3977 }
3978 _expensive_nodes->trunc_to(j);
3979
3980 // Then sort the list so that similar nodes are next to each other
3981 // and check for at least two nodes of identical kind with same data
3982 // inputs.
3983 sort_expensive_nodes();
3984
3985 for (int i = 0; i < _expensive_nodes->length()-1; i++) {
3986 if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
3987 return true;
3988 }
3989 }
3990
3991 return false;
3992 }
3993
3994 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
3995 if (_expensive_nodes->length() == 0) {
3996 return;
3997 }
3998
3999 assert(OptimizeExpensiveOps, "optimization off?");
4000
4001 // Sort to bring similar nodes next to each other and clear the
4002 // control input of nodes for which there's only a single copy.
4003 sort_expensive_nodes();
4004
4005 int j = 0;
4006 int identical = 0;
4007 int i = 0;
4008 for (; i < _expensive_nodes->length()-1; i++) {
4009 assert(j <= i, "can't write beyond current index");
4010 if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
4011 identical++;
4012 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4013 continue;
4014 }
4015 if (identical > 0) {
4016 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4017 identical = 0;
4018 } else {
4019 Node* n = _expensive_nodes->at(i);
4020 igvn.hash_delete(n);
4021 n->set_req(0, NULL);
4022 igvn.hash_insert(n);
4023 }
4024 }
4025 if (identical > 0) {
4026 _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
4027 } else if (_expensive_nodes->length() >= 1) {
4028 Node* n = _expensive_nodes->at(i);
4029 igvn.hash_delete(n);
4030 n->set_req(0, NULL);
4031 igvn.hash_insert(n);
4032 }
4033 _expensive_nodes->trunc_to(j);
4034 }
4035
4036 void Compile::add_expensive_node(Node * n) {
4037 assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
4038 assert(n->is_expensive(), "expensive nodes with non-null control here only");
4039 assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4040 if (OptimizeExpensiveOps) {
4041 _expensive_nodes->append(n);
4042 } else {
4043 // Clear control input and let IGVN optimize expensive nodes if
4044 // OptimizeExpensiveOps is off.
4045 n->set_req(0, NULL);
4046 }
4047 }
4048
4049 /**
4050 * Remove the speculative part of types and clean up the graph
4051 */
4052 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4053 if (UseTypeSpeculation) {
4054 Unique_Node_List worklist;
4055 worklist.push(root());
4056 int modified = 0;
4057 // Go over all type nodes that carry a speculative type, drop the
4058 // speculative part of the type and enqueue the node for an igvn
4059 // which may optimize it out.
4060 for (uint next = 0; next < worklist.size(); ++next) {
4061 Node *n = worklist.at(next);
4062 if (n->is_Type()) {
4063 TypeNode* tn = n->as_Type();
4064 const Type* t = tn->type();
4065 const Type* t_no_spec = t->remove_speculative();
4066 if (t_no_spec != t) {
4067 bool in_hash = igvn.hash_delete(n);
4068 assert(in_hash, "node should be in igvn hash table");
4069 tn->set_type(t_no_spec);
4070 igvn.hash_insert(n);
4071 igvn._worklist.push(n); // give it a chance to go away
4072 modified++;
4073 }
4074 }
4075 uint max = n->len();
4076 for( uint i = 0; i < max; ++i ) {
4077 Node *m = n->in(i);
4078 if (not_a_node(m)) continue;
4079 worklist.push(m);
4080 }
4081 }
4082 // Drop the speculative part of all types in the igvn's type table
4083 igvn.remove_speculative_types();
4084 if (modified > 0) {
4085 igvn.optimize();
4086 }
4087 #ifdef ASSERT
4088 // Verify that after the IGVN is over no speculative type has resurfaced
4089 worklist.clear();
4090 worklist.push(root());
4091 for (uint next = 0; next < worklist.size(); ++next) {
4092 Node *n = worklist.at(next);
4093 const Type* t = igvn.type_or_null(n);
4094 assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4095 if (n->is_Type()) {
4096 t = n->as_Type()->type();
4097 assert(t == t->remove_speculative(), "no more speculative types");
4098 }
4099 uint max = n->len();
4100 for( uint i = 0; i < max; ++i ) {
4101 Node *m = n->in(i);
4102 if (not_a_node(m)) continue;
4103 worklist.push(m);
4104 }
4105 }
4106 igvn.check_no_speculative_types();
4107 #endif
4108 }
4109 }
4110
4111 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4112 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4113 if (ctrl != NULL) {
4114 // Express control dependency by a CastII node with a narrow type.
4115 value = new (phase->C) CastIINode(value, itype, false, true /* range check dependency */);
4116 // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4117 // node from floating above the range check during loop optimizations. Otherwise, the
4118 // ConvI2L node may be eliminated independently of the range check, causing the data path
4119 // to become TOP while the control path is still there (although it's unreachable).
4120 value->set_req(0, ctrl);
4121 // Save CastII node to remove it after loop optimizations.
4122 phase->C->add_range_check_cast(value);
4123 value = phase->transform(value);
4124 }
4125 const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4126 return phase->transform(new (phase->C) ConvI2LNode(value, ltype));
4127 }
4128
4129 // Auxiliary method to support randomized stressing/fuzzing.
4130 //
4131 // This method can be called the arbitrary number of times, with current count
4132 // as the argument. The logic allows selecting a single candidate from the
4133 // running list of candidates as follows:
4134 // int count = 0;
4135 // Cand* selected = null;
4136 // while(cand = cand->next()) {
4137 // if (randomized_select(++count)) {
4138 // selected = cand;
4139 // }
4140 // }
4141 //
4142 // Including count equalizes the chances any candidate is "selected".
4143 // This is useful when we don't have the complete list of candidates to choose
4144 // from uniformly. In this case, we need to adjust the randomicity of the
4145 // selection, or else we will end up biasing the selection towards the latter
4146 // candidates.
4147 //
4148 // Quick back-envelope calculation shows that for the list of n candidates
4149 // the equal probability for the candidate to persist as "best" can be
4150 // achieved by replacing it with "next" k-th candidate with the probability
4151 // of 1/k. It can be easily shown that by the end of the run, the
4152 // probability for any candidate is converged to 1/n, thus giving the
4153 // uniform distribution among all the candidates.
4154 //
4155 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4156 #define RANDOMIZED_DOMAIN_POW 29
4157 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4158 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
4159 bool Compile::randomized_select(int count) {
4160 assert(count > 0, "only positive");
4161 return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4162 }