1 /*
2  * Copyright (c) 1997, 2020, 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
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24 
25 #include "precompiled.hpp"
26 #include "asm/macroAssembler.hpp"
27 #include "asm/macroAssembler.inline.hpp"
28 #include "ci/ciReplay.hpp"
29 #include "classfile/javaClasses.hpp"
30 #include "code/exceptionHandlerTable.hpp"
31 #include "code/nmethod.hpp"
32 #include "compiler/compileBroker.hpp"
33 #include "compiler/compileLog.hpp"
34 #include "compiler/disassembler.hpp"
35 #include "compiler/oopMap.hpp"
36 #include "gc/shared/barrierSet.hpp"
37 #include "gc/shared/c2/barrierSetC2.hpp"
38 #include "jfr/jfrEvents.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "opto/addnode.hpp"
41 #include "opto/block.hpp"
42 #include "opto/c2compiler.hpp"
43 #include "opto/callGenerator.hpp"
44 #include "opto/callnode.hpp"
45 #include "opto/castnode.hpp"
46 #include "opto/cfgnode.hpp"
47 #include "opto/chaitin.hpp"
48 #include "opto/compile.hpp"
49 #include "opto/connode.hpp"
50 #include "opto/convertnode.hpp"
51 #include "opto/divnode.hpp"
52 #include "opto/escape.hpp"
53 #include "opto/idealGraphPrinter.hpp"
54 #include "opto/loopnode.hpp"
55 #include "opto/machnode.hpp"
56 #include "opto/macro.hpp"
57 #include "opto/matcher.hpp"
58 #include "opto/mathexactnode.hpp"
59 #include "opto/memnode.hpp"
60 #include "opto/mulnode.hpp"
61 #include "opto/narrowptrnode.hpp"
62 #include "opto/node.hpp"
63 #include "opto/opcodes.hpp"
64 #include "opto/output.hpp"
65 #include "opto/parse.hpp"
66 #include "opto/phaseX.hpp"
67 #include "opto/rootnode.hpp"
68 #include "opto/runtime.hpp"
69 #include "opto/stringopts.hpp"
70 #include "opto/type.hpp"
71 #include "opto/vector.hpp"
72 #include "opto/vectornode.hpp"
73 #include "runtime/arguments.hpp"
74 #include "runtime/globals_extension.hpp"
75 #include "runtime/sharedRuntime.hpp"
76 #include "runtime/signature.hpp"
77 #include "runtime/stubRoutines.hpp"
78 #include "runtime/timer.hpp"
79 #include "utilities/align.hpp"
80 #include "utilities/copy.hpp"
81 #include "utilities/macros.hpp"
82 #include "utilities/resourceHash.hpp"
83 
84 
85 // -------------------- Compile::mach_constant_base_node -----------------------
86 // Constant table base node singleton.
mach_constant_base_node()87 MachConstantBaseNode* Compile::mach_constant_base_node() {
88   if (_mach_constant_base_node == NULL) {
89     _mach_constant_base_node = new MachConstantBaseNode();
90     _mach_constant_base_node->add_req(C->root());
91   }
92   return _mach_constant_base_node;
93 }
94 
95 
96 /// Support for intrinsics.
97 
98 // Return the index at which m must be inserted (or already exists).
99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
100 class IntrinsicDescPair {
101  private:
102   ciMethod* _m;
103   bool _is_virtual;
104  public:
IntrinsicDescPair(ciMethod * m,bool is_virtual)105   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
compare(IntrinsicDescPair * const & key,CallGenerator * const & elt)106   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
107     ciMethod* m= elt->method();
108     ciMethod* key_m = key->_m;
109     if (key_m < m)      return -1;
110     else if (key_m > m) return 1;
111     else {
112       bool is_virtual = elt->is_virtual();
113       bool key_virtual = key->_is_virtual;
114       if (key_virtual < is_virtual)      return -1;
115       else if (key_virtual > is_virtual) return 1;
116       else                               return 0;
117     }
118   }
119 };
intrinsic_insertion_index(ciMethod * m,bool is_virtual,bool & found)120 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
121 #ifdef ASSERT
122   for (int i = 1; i < _intrinsics.length(); i++) {
123     CallGenerator* cg1 = _intrinsics.at(i-1);
124     CallGenerator* cg2 = _intrinsics.at(i);
125     assert(cg1->method() != cg2->method()
126            ? cg1->method()     < cg2->method()
127            : cg1->is_virtual() < cg2->is_virtual(),
128            "compiler intrinsics list must stay sorted");
129   }
130 #endif
131   IntrinsicDescPair pair(m, is_virtual);
132   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
133 }
134 
register_intrinsic(CallGenerator * cg)135 void Compile::register_intrinsic(CallGenerator* cg) {
136   bool found = false;
137   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
138   assert(!found, "registering twice");
139   _intrinsics.insert_before(index, cg);
140   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
141 }
142 
find_intrinsic(ciMethod * m,bool is_virtual)143 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
144   assert(m->is_loaded(), "don't try this on unloaded methods");
145   if (_intrinsics.length() > 0) {
146     bool found = false;
147     int index = intrinsic_insertion_index(m, is_virtual, found);
148      if (found) {
149       return _intrinsics.at(index);
150     }
151   }
152   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
153   if (m->intrinsic_id() != vmIntrinsics::_none &&
154       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
155     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
156     if (cg != NULL) {
157       // Save it for next time:
158       register_intrinsic(cg);
159       return cg;
160     } else {
161       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
162     }
163   }
164   return NULL;
165 }
166 
167 // Compile::make_vm_intrinsic is defined in library_call.cpp.
168 
169 #ifndef PRODUCT
170 // statistics gathering...
171 
172 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
173 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
174 
as_int(vmIntrinsics::ID id)175 inline int as_int(vmIntrinsics::ID id) {
176   return vmIntrinsics::as_int(id);
177 }
178 
gather_intrinsic_statistics(vmIntrinsics::ID id,bool is_virtual,int flags)179 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
180   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
181   int oflags = _intrinsic_hist_flags[as_int(id)];
182   assert(flags != 0, "what happened?");
183   if (is_virtual) {
184     flags |= _intrinsic_virtual;
185   }
186   bool changed = (flags != oflags);
187   if ((flags & _intrinsic_worked) != 0) {
188     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
189     if (count == 1) {
190       changed = true;           // first time
191     }
192     // increment the overall count also:
193     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
194   }
195   if (changed) {
196     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
197       // Something changed about the intrinsic's virtuality.
198       if ((flags & _intrinsic_virtual) != 0) {
199         // This is the first use of this intrinsic as a virtual call.
200         if (oflags != 0) {
201           // We already saw it as a non-virtual, so note both cases.
202           flags |= _intrinsic_both;
203         }
204       } else if ((oflags & _intrinsic_both) == 0) {
205         // This is the first use of this intrinsic as a non-virtual
206         flags |= _intrinsic_both;
207       }
208     }
209     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
210   }
211   // update the overall flags also:
212   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
213   return changed;
214 }
215 
format_flags(int flags,char * buf)216 static char* format_flags(int flags, char* buf) {
217   buf[0] = 0;
218   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
219   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
220   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
221   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
222   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
223   if (buf[0] == 0)  strcat(buf, ",");
224   assert(buf[0] == ',', "must be");
225   return &buf[1];
226 }
227 
print_intrinsic_statistics()228 void Compile::print_intrinsic_statistics() {
229   char flagsbuf[100];
230   ttyLocker ttyl;
231   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
232   tty->print_cr("Compiler intrinsic usage:");
233   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
234   if (total == 0)  total = 1;  // avoid div0 in case of no successes
235   #define PRINT_STAT_LINE(name, c, f) \
236     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
237   for (vmIntrinsicsIterator it = vmIntrinsicsRange.begin(); it != vmIntrinsicsRange.end(); ++it) {
238     vmIntrinsicID id = *it;
239     int   flags = _intrinsic_hist_flags[as_int(id)];
240     juint count = _intrinsic_hist_count[as_int(id)];
241     if ((flags | count) != 0) {
242       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
243     }
244   }
245   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
246   if (xtty != NULL)  xtty->tail("statistics");
247 }
248 
print_statistics()249 void Compile::print_statistics() {
250   { ttyLocker ttyl;
251     if (xtty != NULL)  xtty->head("statistics type='opto'");
252     Parse::print_statistics();
253     PhaseCCP::print_statistics();
254     PhaseRegAlloc::print_statistics();
255     PhaseOutput::print_statistics();
256     PhasePeephole::print_statistics();
257     PhaseIdealLoop::print_statistics();
258     if (xtty != NULL)  xtty->tail("statistics");
259   }
260   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
261     // put this under its own <statistics> element.
262     print_intrinsic_statistics();
263   }
264 }
265 #endif //PRODUCT
266 
gvn_replace_by(Node * n,Node * nn)267 void Compile::gvn_replace_by(Node* n, Node* nn) {
268   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
269     Node* use = n->last_out(i);
270     bool is_in_table = initial_gvn()->hash_delete(use);
271     uint uses_found = 0;
272     for (uint j = 0; j < use->len(); j++) {
273       if (use->in(j) == n) {
274         if (j < use->req())
275           use->set_req(j, nn);
276         else
277           use->set_prec(j, nn);
278         uses_found++;
279       }
280     }
281     if (is_in_table) {
282       // reinsert into table
283       initial_gvn()->hash_find_insert(use);
284     }
285     record_for_igvn(use);
286     i -= uses_found;    // we deleted 1 or more copies of this edge
287   }
288 }
289 
290 
not_a_node(const Node * n)291 static inline bool not_a_node(const Node* n) {
292   if (n == NULL)                   return true;
293   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
294   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
295   return false;
296 }
297 
298 // Identify all nodes that are reachable from below, useful.
299 // Use breadth-first pass that records state in a Unique_Node_List,
300 // recursive traversal is slower.
identify_useful_nodes(Unique_Node_List & useful)301 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
302   int estimated_worklist_size = live_nodes();
303   useful.map( estimated_worklist_size, NULL );  // preallocate space
304 
305   // Initialize worklist
306   if (root() != NULL)     { useful.push(root()); }
307   // If 'top' is cached, declare it useful to preserve cached node
308   if( cached_top_node() ) { useful.push(cached_top_node()); }
309 
310   // Push all useful nodes onto the list, breadthfirst
311   for( uint next = 0; next < useful.size(); ++next ) {
312     assert( next < unique(), "Unique useful nodes < total nodes");
313     Node *n  = useful.at(next);
314     uint max = n->len();
315     for( uint i = 0; i < max; ++i ) {
316       Node *m = n->in(i);
317       if (not_a_node(m))  continue;
318       useful.push(m);
319     }
320   }
321 }
322 
323 // Update dead_node_list with any missing dead nodes using useful
324 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
update_dead_node_list(Unique_Node_List & useful)325 void Compile::update_dead_node_list(Unique_Node_List &useful) {
326   uint max_idx = unique();
327   VectorSet& useful_node_set = useful.member_set();
328 
329   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
330     // If node with index node_idx is not in useful set,
331     // mark it as dead in dead node list.
332     if (!useful_node_set.test(node_idx)) {
333       record_dead_node(node_idx);
334     }
335   }
336 }
337 
remove_useless_late_inlines(GrowableArray<CallGenerator * > * inlines,Unique_Node_List & useful)338 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
339   int shift = 0;
340   for (int i = 0; i < inlines->length(); i++) {
341     CallGenerator* cg = inlines->at(i);
342     if (useful.member(cg->call_node())) {
343       if (shift > 0) {
344         inlines->at_put(i - shift, cg);
345       }
346     } else {
347       shift++; // skip over the dead element
348     }
349   }
350   if (shift > 0) {
351     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
352   }
353 }
354 
remove_useless_late_inlines(GrowableArray<CallGenerator * > * inlines,Node * dead)355 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
356   assert(dead != NULL && dead->is_Call(), "sanity");
357   int found = 0;
358   for (int i = 0; i < inlines->length(); i++) {
359     if (inlines->at(i)->call_node() == dead) {
360       inlines->remove_at(i);
361       found++;
362       NOT_DEBUG( break; ) // elements are unique, so exit early
363     }
364   }
365   assert(found <= 1, "not unique");
366 }
367 
remove_useless_nodes(GrowableArray<Node * > & node_list,Unique_Node_List & useful)368 void Compile::remove_useless_nodes(GrowableArray<Node*>& node_list, Unique_Node_List& useful) {
369   for (int i = node_list.length() - 1; i >= 0; i--) {
370     Node* n = node_list.at(i);
371     if (!useful.member(n)) {
372       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
373     }
374   }
375 }
376 
remove_useless_node(Node * dead)377 void Compile::remove_useless_node(Node* dead) {
378   remove_modified_node(dead);
379 
380   // Constant node that has no out-edges and has only one in-edge from
381   // root is usually dead. However, sometimes reshaping walk makes
382   // it reachable by adding use edges. So, we will NOT count Con nodes
383   // as dead to be conservative about the dead node count at any
384   // given time.
385   if (!dead->is_Con()) {
386     record_dead_node(dead->_idx);
387   }
388   if (dead->is_macro()) {
389     remove_macro_node(dead);
390   }
391   if (dead->is_expensive()) {
392     remove_expensive_node(dead);
393   }
394   if (dead->for_post_loop_opts_igvn()) {
395     remove_from_post_loop_opts_igvn(dead);
396   }
397   if (dead->is_Call()) {
398     remove_useless_late_inlines(                &_late_inlines, dead);
399     remove_useless_late_inlines(         &_string_late_inlines, dead);
400     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
401     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
402   }
403   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
404   bs->unregister_potential_barrier_node(dead);
405 }
406 
407 // Disconnect all useless nodes by disconnecting those at the boundary.
remove_useless_nodes(Unique_Node_List & useful)408 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
409   uint next = 0;
410   while (next < useful.size()) {
411     Node *n = useful.at(next++);
412     if (n->is_SafePoint()) {
413       // We're done with a parsing phase. Replaced nodes are not valid
414       // beyond that point.
415       n->as_SafePoint()->delete_replaced_nodes();
416     }
417     // Use raw traversal of out edges since this code removes out edges
418     int max = n->outcnt();
419     for (int j = 0; j < max; ++j) {
420       Node* child = n->raw_out(j);
421       if (!useful.member(child)) {
422         assert(!child->is_top() || child != top(),
423                "If top is cached in Compile object it is in useful list");
424         // Only need to remove this out-edge to the useless node
425         n->raw_del_out(j);
426         --j;
427         --max;
428       }
429     }
430     if (n->outcnt() == 1 && n->has_special_unique_user()) {
431       record_for_igvn(n->unique_out());
432     }
433   }
434 
435   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro and predicate opaq nodes
436   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
437   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
438 
439   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
440   bs->eliminate_useless_gc_barriers(useful, this);
441   // clean up the late inline lists
442   remove_useless_late_inlines(                &_late_inlines, useful);
443   remove_useless_late_inlines(         &_string_late_inlines, useful);
444   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
445   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
446   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
447 }
448 
449 // ============================================================================
450 //------------------------------CompileWrapper---------------------------------
451 class CompileWrapper : public StackObj {
452   Compile *const _compile;
453  public:
454   CompileWrapper(Compile* compile);
455 
456   ~CompileWrapper();
457 };
458 
CompileWrapper(Compile * compile)459 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
460   // the Compile* pointer is stored in the current ciEnv:
461   ciEnv* env = compile->env();
462   assert(env == ciEnv::current(), "must already be a ciEnv active");
463   assert(env->compiler_data() == NULL, "compile already active?");
464   env->set_compiler_data(compile);
465   assert(compile == Compile::current(), "sanity");
466 
467   compile->set_type_dict(NULL);
468   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
469   compile->clone_map().set_clone_idx(0);
470   compile->set_type_last_size(0);
471   compile->set_last_tf(NULL, NULL);
472   compile->set_indexSet_arena(NULL);
473   compile->set_indexSet_free_block_list(NULL);
474   compile->init_type_arena();
475   Type::Initialize(compile);
476   _compile->begin_method();
477   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
478 }
~CompileWrapper()479 CompileWrapper::~CompileWrapper() {
480   _compile->end_method();
481   _compile->env()->set_compiler_data(NULL);
482 }
483 
484 
485 //----------------------------print_compile_messages---------------------------
print_compile_messages()486 void Compile::print_compile_messages() {
487 #ifndef PRODUCT
488   // Check if recompiling
489   if (_subsume_loads == false && PrintOpto) {
490     // Recompiling without allowing machine instructions to subsume loads
491     tty->print_cr("*********************************************************");
492     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
493     tty->print_cr("*********************************************************");
494   }
495   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
496     // Recompiling without escape analysis
497     tty->print_cr("*********************************************************");
498     tty->print_cr("** Bailout: Recompile without escape analysis          **");
499     tty->print_cr("*********************************************************");
500   }
501   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
502     // Recompiling without boxing elimination
503     tty->print_cr("*********************************************************");
504     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
505     tty->print_cr("*********************************************************");
506   }
507   if (C->directive()->BreakAtCompileOption) {
508     // Open the debugger when compiling this method.
509     tty->print("### Breaking when compiling: ");
510     method()->print_short_name();
511     tty->cr();
512     BREAKPOINT;
513   }
514 
515   if( PrintOpto ) {
516     if (is_osr_compilation()) {
517       tty->print("[OSR]%3d", _compile_id);
518     } else {
519       tty->print("%3d", _compile_id);
520     }
521   }
522 #endif
523 }
524 
525 // ============================================================================
526 //------------------------------Compile standard-------------------------------
debug_only(int Compile::_debug_idx=100000;)527 debug_only( int Compile::_debug_idx = 100000; )
528 
529 // Compile a method.  entry_bci is -1 for normal compilations and indicates
530 // the continuation bci for on stack replacement.
531 
532 
533 Compile::Compile( ciEnv* ci_env, ciMethod* target, int osr_bci,
534                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing, bool install_code, DirectiveSet* directive)
535                 : Phase(Compiler),
536                   _compile_id(ci_env->compile_id()),
537                   _save_argument_registers(false),
538                   _subsume_loads(subsume_loads),
539                   _do_escape_analysis(do_escape_analysis),
540                   _install_code(install_code),
541                   _eliminate_boxing(eliminate_boxing),
542                   _method(target),
543                   _entry_bci(osr_bci),
544                   _stub_function(NULL),
545                   _stub_name(NULL),
546                   _stub_entry_point(NULL),
547                   _max_node_limit(MaxNodeLimit),
548                   _post_loop_opts_phase(false),
549                   _inlining_progress(false),
550                   _inlining_incrementally(false),
551                   _do_cleanup(false),
552                   _has_reserved_stack_access(target->has_reserved_stack_access()),
553 #ifndef PRODUCT
554                   _trace_opto_output(directive->TraceOptoOutputOption),
555                   _print_ideal(directive->PrintIdealOption),
556 #endif
557                   _has_method_handle_invokes(false),
558                   _clinit_barrier_on_entry(false),
559                   _stress_seed(0),
560                   _comp_arena(mtCompiler),
561                   _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
562                   _env(ci_env),
563                   _directive(directive),
564                   _log(ci_env->log()),
565                   _failure_reason(NULL),
566                   _intrinsics        (comp_arena(), 0, 0, NULL),
567                   _macro_nodes       (comp_arena(), 8, 0, NULL),
568                   _predicate_opaqs   (comp_arena(), 8, 0, NULL),
569                   _expensive_nodes   (comp_arena(), 8, 0, NULL),
570                   _for_post_loop_igvn(comp_arena(), 8, 0, NULL),
571                   _congraph(NULL),
572                   NOT_PRODUCT(_printer(NULL) COMMA)
573                   _dead_node_list(comp_arena()),
574                   _dead_node_count(0),
575                   _node_arena(mtCompiler),
576                   _old_arena(mtCompiler),
577                   _mach_constant_base_node(NULL),
578                   _Compile_types(mtCompiler),
579                   _initial_gvn(NULL),
580                   _for_igvn(NULL),
581                   _warm_calls(NULL),
582                   _late_inlines(comp_arena(), 2, 0, NULL),
583                   _string_late_inlines(comp_arena(), 2, 0, NULL),
584                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
585                   _vector_reboxing_late_inlines(comp_arena(), 2, 0, NULL),
586                   _late_inlines_pos(0),
587                   _number_of_mh_late_inlines(0),
588                   _native_invokers(comp_arena(), 1, 0, NULL),
589                   _print_inlining_stream(NULL),
590                   _print_inlining_list(NULL),
591                   _print_inlining_idx(0),
592                   _print_inlining_output(NULL),
593                   _replay_inline_data(NULL),
594                   _java_calls(0),
595                   _inner_loops(0),
596                   _interpreter_frame_size(0)
597 #ifndef PRODUCT
598                   , _in_dump_cnt(0)
599 #endif
600 {
601   C = this;
602   CompileWrapper cw(this);
603 
604   if (CITimeVerbose) {
605     tty->print(" ");
606     target->holder()->name()->print();
607     tty->print(".");
608     target->print_short_name();
609     tty->print("  ");
610   }
611   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
612   TraceTime t2(NULL, &_t_methodCompilation, CITime, false);
613 
614 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
615   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
616   // We can always print a disassembly, either abstract (hex dump) or
617   // with the help of a suitable hsdis library. Thus, we should not
618   // couple print_assembly and print_opto_assembly controls.
619   // But: always print opto and regular assembly on compile command 'print'.
620   bool print_assembly = directive->PrintAssemblyOption;
621   set_print_assembly(print_opto_assembly || print_assembly);
622 #else
623   set_print_assembly(false); // must initialize.
624 #endif
625 
626 #ifndef PRODUCT
627   set_parsed_irreducible_loop(false);
628 
629   if (directive->ReplayInlineOption) {
630     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
631   }
632 #endif
633   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
634   set_print_intrinsics(directive->PrintIntrinsicsOption);
635   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
636 
637   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
638     // Make sure the method being compiled gets its own MDO,
639     // so we can at least track the decompile_count().
640     // Need MDO to record RTM code generation state.
641     method()->ensure_method_data();
642   }
643 
644   Init(::AliasLevel);
645 
646 
647   print_compile_messages();
648 
649   _ilt = InlineTree::build_inline_tree_root();
650 
651   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
652   assert(num_alias_types() >= AliasIdxRaw, "");
653 
654 #define MINIMUM_NODE_HASH  1023
655   // Node list that Iterative GVN will start with
656   Unique_Node_List for_igvn(comp_arena());
657   set_for_igvn(&for_igvn);
658 
659   // GVN that will be run immediately on new nodes
660   uint estimated_size = method()->code_size()*4+64;
661   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
662   PhaseGVN gvn(node_arena(), estimated_size);
663   set_initial_gvn(&gvn);
664 
665   print_inlining_init();
666   { // Scope for timing the parser
667     TracePhase tp("parse", &timers[_t_parser]);
668 
669     // Put top into the hash table ASAP.
670     initial_gvn()->transform_no_reclaim(top());
671 
672     // Set up tf(), start(), and find a CallGenerator.
673     CallGenerator* cg = NULL;
674     if (is_osr_compilation()) {
675       const TypeTuple *domain = StartOSRNode::osr_domain();
676       const TypeTuple *range = TypeTuple::make_range(method()->signature());
677       init_tf(TypeFunc::make(domain, range));
678       StartNode* s = new StartOSRNode(root(), domain);
679       initial_gvn()->set_type_bottom(s);
680       init_start(s);
681       cg = CallGenerator::for_osr(method(), entry_bci());
682     } else {
683       // Normal case.
684       init_tf(TypeFunc::make(method()));
685       StartNode* s = new StartNode(root(), tf()->domain());
686       initial_gvn()->set_type_bottom(s);
687       init_start(s);
688       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get) {
689         // With java.lang.ref.reference.get() we must go through the
690         // intrinsic - even when get() is the root
691         // method of the compile - so that, if necessary, the value in
692         // the referent field of the reference object gets recorded by
693         // the pre-barrier code.
694         cg = find_intrinsic(method(), false);
695       }
696       if (cg == NULL) {
697         float past_uses = method()->interpreter_invocation_count();
698         float expected_uses = past_uses;
699         cg = CallGenerator::for_inline(method(), expected_uses);
700       }
701     }
702     if (failing())  return;
703     if (cg == NULL) {
704       record_method_not_compilable("cannot parse method");
705       return;
706     }
707     JVMState* jvms = build_start_state(start(), tf());
708     if ((jvms = cg->generate(jvms)) == NULL) {
709       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
710         record_method_not_compilable("method parse failed");
711       }
712       return;
713     }
714     GraphKit kit(jvms);
715 
716     if (!kit.stopped()) {
717       // Accept return values, and transfer control we know not where.
718       // This is done by a special, unique ReturnNode bound to root.
719       return_values(kit.jvms());
720     }
721 
722     if (kit.has_exceptions()) {
723       // Any exceptions that escape from this call must be rethrown
724       // to whatever caller is dynamically above us on the stack.
725       // This is done by a special, unique RethrowNode bound to root.
726       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
727     }
728 
729     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
730 
731     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
732       inline_string_calls(true);
733     }
734 
735     if (failing())  return;
736 
737     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
738 
739     // Remove clutter produced by parsing.
740     if (!failing()) {
741       ResourceMark rm;
742       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
743     }
744   }
745 
746   // Note:  Large methods are capped off in do_one_bytecode().
747   if (failing())  return;
748 
749   // After parsing, node notes are no longer automagic.
750   // They must be propagated by register_new_node_with_optimizer(),
751   // clone(), or the like.
752   set_default_node_notes(NULL);
753 
754   for (;;) {
755     int successes = Inline_Warm();
756     if (failing())  return;
757     if (successes == 0)  break;
758   }
759 
760   // Drain the list.
761   Finish_Warm();
762 #ifndef PRODUCT
763   if (should_print(1)) {
764     _printer->print_inlining();
765   }
766 #endif
767 
768   if (failing())  return;
769   NOT_PRODUCT( verify_graph_edges(); )
770 
771   // If LCM, GCM, or IGVN are randomized for stress testing, seed
772   // random number generation and log the seed for repeatability.
773   if (StressLCM || StressGCM || StressIGVN) {
774     _stress_seed = FLAG_IS_DEFAULT(StressSeed) ?
775       static_cast<uint>(Ticks::now().nanoseconds()) : StressSeed;
776     if (_log != NULL) {
777       _log->elem("stress_test seed='%u'", _stress_seed);
778     } else if (FLAG_IS_DEFAULT(StressSeed)) {
779       tty->print_cr("Warning:  set +LogCompilation to log the seed.");
780     }
781   }
782 
783   // Now optimize
784   Optimize();
785   if (failing())  return;
786   NOT_PRODUCT( verify_graph_edges(); )
787 
788 #ifndef PRODUCT
789   if (print_ideal()) {
790     ttyLocker ttyl;  // keep the following output all in one block
791     // This output goes directly to the tty, not the compiler log.
792     // To enable tools to match it up with the compilation activity,
793     // be sure to tag this tty output with the compile ID.
794     if (xtty != NULL) {
795       xtty->head("ideal compile_id='%d'%s", compile_id(),
796                  is_osr_compilation()    ? " compile_kind='osr'" :
797                  "");
798     }
799     root()->dump(9999);
800     if (xtty != NULL) {
801       xtty->tail("ideal");
802     }
803   }
804 #endif
805 
806 #ifdef ASSERT
807   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
808   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
809 #endif
810 
811   // Dump compilation data to replay it.
812   if (directive->DumpReplayOption) {
813     env()->dump_replay_data(_compile_id);
814   }
815   if (directive->DumpInlineOption && (ilt() != NULL)) {
816     env()->dump_inline_data(_compile_id);
817   }
818 
819   // Now that we know the size of all the monitors we can add a fixed slot
820   // for the original deopt pc.
821   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
822   set_fixed_slots(next_slot);
823 
824   // Compute when to use implicit null checks. Used by matching trap based
825   // nodes and NullCheck optimization.
826   set_allowed_deopt_reasons();
827 
828   // Now generate code
829   Code_Gen();
830 }
831 
832 //------------------------------Compile----------------------------------------
833 // Compile a runtime stub
Compile(ciEnv * ci_env,TypeFunc_generator generator,address stub_function,const char * stub_name,int is_fancy_jump,bool pass_tls,bool save_arg_registers,bool return_pc,DirectiveSet * directive)834 Compile::Compile( ciEnv* ci_env,
835                   TypeFunc_generator generator,
836                   address stub_function,
837                   const char *stub_name,
838                   int is_fancy_jump,
839                   bool pass_tls,
840                   bool save_arg_registers,
841                   bool return_pc,
842                   DirectiveSet* directive)
843   : Phase(Compiler),
844     _compile_id(0),
845     _save_argument_registers(save_arg_registers),
846     _subsume_loads(true),
847     _do_escape_analysis(false),
848     _install_code(true),
849     _eliminate_boxing(false),
850     _method(NULL),
851     _entry_bci(InvocationEntryBci),
852     _stub_function(stub_function),
853     _stub_name(stub_name),
854     _stub_entry_point(NULL),
855     _max_node_limit(MaxNodeLimit),
856     _post_loop_opts_phase(false),
857     _inlining_progress(false),
858     _inlining_incrementally(false),
859     _has_reserved_stack_access(false),
860 #ifndef PRODUCT
861     _trace_opto_output(directive->TraceOptoOutputOption),
862     _print_ideal(directive->PrintIdealOption),
863 #endif
864     _has_method_handle_invokes(false),
865     _clinit_barrier_on_entry(false),
866     _stress_seed(0),
867     _comp_arena(mtCompiler),
868     _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
869     _env(ci_env),
870     _directive(directive),
871     _log(ci_env->log()),
872     _failure_reason(NULL),
873     _congraph(NULL),
874     NOT_PRODUCT(_printer(NULL) COMMA)
875     _dead_node_list(comp_arena()),
876     _dead_node_count(0),
877     _node_arena(mtCompiler),
878     _old_arena(mtCompiler),
879     _mach_constant_base_node(NULL),
880     _Compile_types(mtCompiler),
881     _initial_gvn(NULL),
882     _for_igvn(NULL),
883     _warm_calls(NULL),
884     _number_of_mh_late_inlines(0),
885     _native_invokers(),
886     _print_inlining_stream(NULL),
887     _print_inlining_list(NULL),
888     _print_inlining_idx(0),
889     _print_inlining_output(NULL),
890     _replay_inline_data(NULL),
891     _java_calls(0),
892     _inner_loops(0),
893     _interpreter_frame_size(0),
894 #ifndef PRODUCT
895     _in_dump_cnt(0),
896 #endif
897     _allowed_reasons(0) {
898   C = this;
899 
900   TraceTime t1(NULL, &_t_totalCompilation, CITime, false);
901   TraceTime t2(NULL, &_t_stubCompilation, CITime, false);
902 
903 #ifndef PRODUCT
904   set_print_assembly(PrintFrameConverterAssembly);
905   set_parsed_irreducible_loop(false);
906 #else
907   set_print_assembly(false); // Must initialize.
908 #endif
909   set_has_irreducible_loop(false); // no loops
910 
911   CompileWrapper cw(this);
912   Init(/*AliasLevel=*/ 0);
913   init_tf((*generator)());
914 
915   {
916     // The following is a dummy for the sake of GraphKit::gen_stub
917     Unique_Node_List for_igvn(comp_arena());
918     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
919     PhaseGVN gvn(Thread::current()->resource_area(),255);
920     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
921     gvn.transform_no_reclaim(top());
922 
923     GraphKit kit;
924     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
925   }
926 
927   NOT_PRODUCT( verify_graph_edges(); )
928 
929   Code_Gen();
930 }
931 
932 //------------------------------Init-------------------------------------------
933 // Prepare for a single compilation
Init(int aliaslevel)934 void Compile::Init(int aliaslevel) {
935   _unique  = 0;
936   _regalloc = NULL;
937 
938   _tf      = NULL;  // filled in later
939   _top     = NULL;  // cached later
940   _matcher = NULL;  // filled in later
941   _cfg     = NULL;  // filled in later
942 
943   IA32_ONLY( set_24_bit_selection_and_mode(true, false); )
944 
945   _node_note_array = NULL;
946   _default_node_notes = NULL;
947   DEBUG_ONLY( _modified_nodes = NULL; ) // Used in Optimize()
948 
949   _immutable_memory = NULL; // filled in at first inquiry
950 
951   // Globally visible Nodes
952   // First set TOP to NULL to give safe behavior during creation of RootNode
953   set_cached_top_node(NULL);
954   set_root(new RootNode());
955   // Now that you have a Root to point to, create the real TOP
956   set_cached_top_node( new ConNode(Type::TOP) );
957   set_recent_alloc(NULL, NULL);
958 
959   // Create Debug Information Recorder to record scopes, oopmaps, etc.
960   env()->set_oop_recorder(new OopRecorder(env()->arena()));
961   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
962   env()->set_dependencies(new Dependencies(env()));
963 
964   _fixed_slots = 0;
965   set_has_split_ifs(false);
966   set_has_loops(false); // first approximation
967   set_has_stringbuilder(false);
968   set_has_boxed_value(false);
969   _trap_can_recompile = false;  // no traps emitted yet
970   _major_progress = true; // start out assuming good things will happen
971   set_has_unsafe_access(false);
972   set_max_vector_size(0);
973   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
974   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
975   set_decompile_count(0);
976 
977   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
978   _loop_opts_cnt = LoopOptsCount;
979   set_do_inlining(Inline);
980   set_max_inline_size(MaxInlineSize);
981   set_freq_inline_size(FreqInlineSize);
982   set_do_scheduling(OptoScheduling);
983 
984   set_do_vector_loop(false);
985 
986   if (AllowVectorizeOnDemand) {
987     if (has_method() && (_directive->VectorizeOption || _directive->VectorizeDebugOption)) {
988       set_do_vector_loop(true);
989       NOT_PRODUCT(if (do_vector_loop() && Verbose) {tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());})
990     } else if (has_method() && method()->name() != 0 &&
991                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
992       set_do_vector_loop(true);
993     }
994   }
995   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
996   NOT_PRODUCT(if (use_cmove() && Verbose && has_method()) {tty->print("Compile::Init: use CMove without profitability tests for method %s\n",  method()->name()->as_quoted_ascii());})
997 
998   set_age_code(has_method() && method()->profile_aging());
999   set_rtm_state(NoRTM); // No RTM lock eliding by default
1000   _max_node_limit = _directive->MaxNodeLimitOption;
1001 
1002 #if INCLUDE_RTM_OPT
1003   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
1004     int rtm_state = method()->method_data()->rtm_state();
1005     if (method_has_option(CompileCommand::NoRTMLockEliding) || ((rtm_state & NoRTM) != 0)) {
1006       // Don't generate RTM lock eliding code.
1007       set_rtm_state(NoRTM);
1008     } else if (method_has_option(CompileCommand::UseRTMLockEliding) || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
1009       // Generate RTM lock eliding code without abort ratio calculation code.
1010       set_rtm_state(UseRTM);
1011     } else if (UseRTMDeopt) {
1012       // Generate RTM lock eliding code and include abort ratio calculation
1013       // code if UseRTMDeopt is on.
1014       set_rtm_state(ProfileRTM);
1015     }
1016   }
1017 #endif
1018   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1019     set_clinit_barrier_on_entry(true);
1020   }
1021   if (debug_info()->recording_non_safepoints()) {
1022     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1023                         (comp_arena(), 8, 0, NULL));
1024     set_default_node_notes(Node_Notes::make(this));
1025   }
1026 
1027   // // -- Initialize types before each compile --
1028   // // Update cached type information
1029   // if( _method && _method->constants() )
1030   //   Type::update_loaded_types(_method, _method->constants());
1031 
1032   // Init alias_type map.
1033   if (!_do_escape_analysis && aliaslevel == 3)
1034     aliaslevel = 2;  // No unique types without escape analysis
1035   _AliasLevel = aliaslevel;
1036   const int grow_ats = 16;
1037   _max_alias_types = grow_ats;
1038   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1039   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1040   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1041   {
1042     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1043   }
1044   // Initialize the first few types.
1045   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
1046   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1047   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1048   _num_alias_types = AliasIdxRaw+1;
1049   // Zero out the alias type cache.
1050   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1051   // A NULL adr_type hits in the cache right away.  Preload the right answer.
1052   probe_alias_cache(NULL)->_index = AliasIdxTop;
1053 
1054 #ifdef ASSERT
1055   _type_verify_symmetry = true;
1056   _phase_optimize_finished = false;
1057   _exception_backedge = false;
1058 #endif
1059 }
1060 
1061 //---------------------------init_start----------------------------------------
1062 // Install the StartNode on this compile object.
init_start(StartNode * s)1063 void Compile::init_start(StartNode* s) {
1064   if (failing())
1065     return; // already failing
1066   assert(s == start(), "");
1067 }
1068 
1069 /**
1070  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1071  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1072  * the ideal graph.
1073  */
start() const1074 StartNode* Compile::start() const {
1075   assert (!failing(), "Must not have pending failure. Reason is: %s", failure_reason());
1076   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1077     Node* start = root()->fast_out(i);
1078     if (start->is_Start()) {
1079       return start->as_Start();
1080     }
1081   }
1082   fatal("Did not find Start node!");
1083   return NULL;
1084 }
1085 
1086 //-------------------------------immutable_memory-------------------------------------
1087 // Access immutable memory
immutable_memory()1088 Node* Compile::immutable_memory() {
1089   if (_immutable_memory != NULL) {
1090     return _immutable_memory;
1091   }
1092   StartNode* s = start();
1093   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1094     Node *p = s->fast_out(i);
1095     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1096       _immutable_memory = p;
1097       return _immutable_memory;
1098     }
1099   }
1100   ShouldNotReachHere();
1101   return NULL;
1102 }
1103 
1104 //----------------------set_cached_top_node------------------------------------
1105 // Install the cached top node, and make sure Node::is_top works correctly.
set_cached_top_node(Node * tn)1106 void Compile::set_cached_top_node(Node* tn) {
1107   if (tn != NULL)  verify_top(tn);
1108   Node* old_top = _top;
1109   _top = tn;
1110   // Calling Node::setup_is_top allows the nodes the chance to adjust
1111   // their _out arrays.
1112   if (_top != NULL)     _top->setup_is_top();
1113   if (old_top != NULL)  old_top->setup_is_top();
1114   assert(_top == NULL || top()->is_top(), "");
1115 }
1116 
1117 #ifdef ASSERT
count_live_nodes_by_graph_walk()1118 uint Compile::count_live_nodes_by_graph_walk() {
1119   Unique_Node_List useful(comp_arena());
1120   // Get useful node list by walking the graph.
1121   identify_useful_nodes(useful);
1122   return useful.size();
1123 }
1124 
print_missing_nodes()1125 void Compile::print_missing_nodes() {
1126 
1127   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
1128   if ((_log == NULL) && (! PrintIdealNodeCount)) {
1129     return;
1130   }
1131 
1132   // This is an expensive function. It is executed only when the user
1133   // specifies VerifyIdealNodeCount option or otherwise knows the
1134   // additional work that needs to be done to identify reachable nodes
1135   // by walking the flow graph and find the missing ones using
1136   // _dead_node_list.
1137 
1138   Unique_Node_List useful(comp_arena());
1139   // Get useful node list by walking the graph.
1140   identify_useful_nodes(useful);
1141 
1142   uint l_nodes = C->live_nodes();
1143   uint l_nodes_by_walk = useful.size();
1144 
1145   if (l_nodes != l_nodes_by_walk) {
1146     if (_log != NULL) {
1147       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1148       _log->stamp();
1149       _log->end_head();
1150     }
1151     VectorSet& useful_member_set = useful.member_set();
1152     int last_idx = l_nodes_by_walk;
1153     for (int i = 0; i < last_idx; i++) {
1154       if (useful_member_set.test(i)) {
1155         if (_dead_node_list.test(i)) {
1156           if (_log != NULL) {
1157             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1158           }
1159           if (PrintIdealNodeCount) {
1160             // Print the log message to tty
1161               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1162               useful.at(i)->dump();
1163           }
1164         }
1165       }
1166       else if (! _dead_node_list.test(i)) {
1167         if (_log != NULL) {
1168           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1169         }
1170         if (PrintIdealNodeCount) {
1171           // Print the log message to tty
1172           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1173         }
1174       }
1175     }
1176     if (_log != NULL) {
1177       _log->tail("mismatched_nodes");
1178     }
1179   }
1180 }
record_modified_node(Node * n)1181 void Compile::record_modified_node(Node* n) {
1182   if (_modified_nodes != NULL && !_inlining_incrementally && !n->is_Con()) {
1183     _modified_nodes->push(n);
1184   }
1185 }
1186 
remove_modified_node(Node * n)1187 void Compile::remove_modified_node(Node* n) {
1188   if (_modified_nodes != NULL) {
1189     _modified_nodes->remove(n);
1190   }
1191 }
1192 #endif
1193 
1194 #ifndef PRODUCT
verify_top(Node * tn) const1195 void Compile::verify_top(Node* tn) const {
1196   if (tn != NULL) {
1197     assert(tn->is_Con(), "top node must be a constant");
1198     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1199     assert(tn->in(0) != NULL, "must have live top node");
1200   }
1201 }
1202 #endif
1203 
1204 
1205 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1206 
grow_node_notes(GrowableArray<Node_Notes * > * arr,int grow_by)1207 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1208   guarantee(arr != NULL, "");
1209   int num_blocks = arr->length();
1210   if (grow_by < num_blocks)  grow_by = num_blocks;
1211   int num_notes = grow_by * _node_notes_block_size;
1212   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1213   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1214   while (num_notes > 0) {
1215     arr->append(notes);
1216     notes     += _node_notes_block_size;
1217     num_notes -= _node_notes_block_size;
1218   }
1219   assert(num_notes == 0, "exact multiple, please");
1220 }
1221 
copy_node_notes_to(Node * dest,Node * source)1222 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1223   if (source == NULL || dest == NULL)  return false;
1224 
1225   if (dest->is_Con())
1226     return false;               // Do not push debug info onto constants.
1227 
1228 #ifdef ASSERT
1229   // Leave a bread crumb trail pointing to the original node:
1230   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
1231     dest->set_debug_orig(source);
1232   }
1233 #endif
1234 
1235   if (node_note_array() == NULL)
1236     return false;               // Not collecting any notes now.
1237 
1238   // This is a copy onto a pre-existing node, which may already have notes.
1239   // If both nodes have notes, do not overwrite any pre-existing notes.
1240   Node_Notes* source_notes = node_notes_at(source->_idx);
1241   if (source_notes == NULL || source_notes->is_clear())  return false;
1242   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1243   if (dest_notes == NULL || dest_notes->is_clear()) {
1244     return set_node_notes_at(dest->_idx, source_notes);
1245   }
1246 
1247   Node_Notes merged_notes = (*source_notes);
1248   // The order of operations here ensures that dest notes will win...
1249   merged_notes.update_from(dest_notes);
1250   return set_node_notes_at(dest->_idx, &merged_notes);
1251 }
1252 
1253 
1254 //--------------------------allow_range_check_smearing-------------------------
1255 // Gating condition for coalescing similar range checks.
1256 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1257 // single covering check that is at least as strong as any of them.
1258 // If the optimization succeeds, the simplified (strengthened) range check
1259 // will always succeed.  If it fails, we will deopt, and then give up
1260 // on the optimization.
allow_range_check_smearing() const1261 bool Compile::allow_range_check_smearing() const {
1262   // If this method has already thrown a range-check,
1263   // assume it was because we already tried range smearing
1264   // and it failed.
1265   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1266   return !already_trapped;
1267 }
1268 
1269 
1270 //------------------------------flatten_alias_type-----------------------------
flatten_alias_type(const TypePtr * tj) const1271 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1272   int offset = tj->offset();
1273   TypePtr::PTR ptr = tj->ptr();
1274 
1275   // Known instance (scalarizable allocation) alias only with itself.
1276   bool is_known_inst = tj->isa_oopptr() != NULL &&
1277                        tj->is_oopptr()->is_known_instance();
1278 
1279   // Process weird unsafe references.
1280   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1281     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
1282     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1283     tj = TypeOopPtr::BOTTOM;
1284     ptr = tj->ptr();
1285     offset = tj->offset();
1286   }
1287 
1288   // Array pointers need some flattening
1289   const TypeAryPtr *ta = tj->isa_aryptr();
1290   if (ta && ta->is_stable()) {
1291     // Erase stability property for alias analysis.
1292     tj = ta = ta->cast_to_stable(false);
1293   }
1294   if( ta && is_known_inst ) {
1295     if ( offset != Type::OffsetBot &&
1296          offset > arrayOopDesc::length_offset_in_bytes() ) {
1297       offset = Type::OffsetBot; // Flatten constant access into array body only
1298       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
1299     }
1300   } else if( ta && _AliasLevel >= 2 ) {
1301     // For arrays indexed by constant indices, we flatten the alias
1302     // space to include all of the array body.  Only the header, klass
1303     // and array length can be accessed un-aliased.
1304     if( offset != Type::OffsetBot ) {
1305       if( ta->const_oop() ) { // MethodData* or Method*
1306         offset = Type::OffsetBot;   // Flatten constant access into array body
1307         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
1308       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
1309         // range is OK as-is.
1310         tj = ta = TypeAryPtr::RANGE;
1311       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
1312         tj = TypeInstPtr::KLASS; // all klass loads look alike
1313         ta = TypeAryPtr::RANGE; // generic ignored junk
1314         ptr = TypePtr::BotPTR;
1315       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
1316         tj = TypeInstPtr::MARK;
1317         ta = TypeAryPtr::RANGE; // generic ignored junk
1318         ptr = TypePtr::BotPTR;
1319       } else {                  // Random constant offset into array body
1320         offset = Type::OffsetBot;   // Flatten constant access into array body
1321         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
1322       }
1323     }
1324     // Arrays of fixed size alias with arrays of unknown size.
1325     if (ta->size() != TypeInt::POS) {
1326       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
1327       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
1328     }
1329     // Arrays of known objects become arrays of unknown objects.
1330     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
1331       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
1332       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1333     }
1334     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
1335       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
1336       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
1337     }
1338     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1339     // cannot be distinguished by bytecode alone.
1340     if (ta->elem() == TypeInt::BOOL) {
1341       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
1342       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
1343       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
1344     }
1345     // During the 2nd round of IterGVN, NotNull castings are removed.
1346     // Make sure the Bottom and NotNull variants alias the same.
1347     // Also, make sure exact and non-exact variants alias the same.
1348     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
1349       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
1350     }
1351   }
1352 
1353   // Oop pointers need some flattening
1354   const TypeInstPtr *to = tj->isa_instptr();
1355   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
1356     ciInstanceKlass *k = to->klass()->as_instance_klass();
1357     if( ptr == TypePtr::Constant ) {
1358       if (to->klass() != ciEnv::current()->Class_klass() ||
1359           offset < k->size_helper() * wordSize) {
1360         // No constant oop pointers (such as Strings); they alias with
1361         // unknown strings.
1362         assert(!is_known_inst, "not scalarizable allocation");
1363         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1364       }
1365     } else if( is_known_inst ) {
1366       tj = to; // Keep NotNull and klass_is_exact for instance type
1367     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1368       // During the 2nd round of IterGVN, NotNull castings are removed.
1369       // Make sure the Bottom and NotNull variants alias the same.
1370       // Also, make sure exact and non-exact variants alias the same.
1371       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
1372     }
1373     if (to->speculative() != NULL) {
1374       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
1375     }
1376     // Canonicalize the holder of this field
1377     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1378       // First handle header references such as a LoadKlassNode, even if the
1379       // object's klass is unloaded at compile time (4965979).
1380       if (!is_known_inst) { // Do it only for non-instance types
1381         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
1382       }
1383     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
1384       // Static fields are in the space above the normal instance
1385       // fields in the java.lang.Class instance.
1386       if (to->klass() != ciEnv::current()->Class_klass()) {
1387         to = NULL;
1388         tj = TypeOopPtr::BOTTOM;
1389         offset = tj->offset();
1390       }
1391     } else {
1392       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
1393       if (!k->equals(canonical_holder) || tj->offset() != offset) {
1394         if( is_known_inst ) {
1395           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
1396         } else {
1397           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
1398         }
1399       }
1400     }
1401   }
1402 
1403   // Klass pointers to object array klasses need some flattening
1404   const TypeKlassPtr *tk = tj->isa_klassptr();
1405   if( tk ) {
1406     // If we are referencing a field within a Klass, we need
1407     // to assume the worst case of an Object.  Both exact and
1408     // inexact types must flatten to the same alias class so
1409     // use NotNull as the PTR.
1410     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1411 
1412       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
1413                                    TypeKlassPtr::OBJECT->klass(),
1414                                    offset);
1415     }
1416 
1417     ciKlass* klass = tk->klass();
1418     if( klass->is_obj_array_klass() ) {
1419       ciKlass* k = TypeAryPtr::OOPS->klass();
1420       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
1421         k = TypeInstPtr::BOTTOM->klass();
1422       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
1423     }
1424 
1425     // Check for precise loads from the primary supertype array and force them
1426     // to the supertype cache alias index.  Check for generic array loads from
1427     // the primary supertype array and also force them to the supertype cache
1428     // alias index.  Since the same load can reach both, we need to merge
1429     // these 2 disparate memories into the same alias class.  Since the
1430     // primary supertype array is read-only, there's no chance of confusion
1431     // where we bypass an array load and an array store.
1432     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1433     if (offset == Type::OffsetBot ||
1434         (offset >= primary_supers_offset &&
1435          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1436         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1437       offset = in_bytes(Klass::secondary_super_cache_offset());
1438       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
1439     }
1440   }
1441 
1442   // Flatten all Raw pointers together.
1443   if (tj->base() == Type::RawPtr)
1444     tj = TypeRawPtr::BOTTOM;
1445 
1446   if (tj->base() == Type::AnyPtr)
1447     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1448 
1449   // Flatten all to bottom for now
1450   switch( _AliasLevel ) {
1451   case 0:
1452     tj = TypePtr::BOTTOM;
1453     break;
1454   case 1:                       // Flatten to: oop, static, field or array
1455     switch (tj->base()) {
1456     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
1457     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
1458     case Type::AryPtr:   // do not distinguish arrays at all
1459     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
1460     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
1461     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
1462     default: ShouldNotReachHere();
1463     }
1464     break;
1465   case 2:                       // No collapsing at level 2; keep all splits
1466   case 3:                       // No collapsing at level 3; keep all splits
1467     break;
1468   default:
1469     Unimplemented();
1470   }
1471 
1472   offset = tj->offset();
1473   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1474 
1475   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1476           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1477           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1478           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1479           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1480           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1481           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1482           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1483   assert( tj->ptr() != TypePtr::TopPTR &&
1484           tj->ptr() != TypePtr::AnyNull &&
1485           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1486 //    assert( tj->ptr() != TypePtr::Constant ||
1487 //            tj->base() == Type::RawPtr ||
1488 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1489 
1490   return tj;
1491 }
1492 
Init(int i,const TypePtr * at)1493 void Compile::AliasType::Init(int i, const TypePtr* at) {
1494   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1495   _index = i;
1496   _adr_type = at;
1497   _field = NULL;
1498   _element = NULL;
1499   _is_rewritable = true; // default
1500   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
1501   if (atoop != NULL && atoop->is_known_instance()) {
1502     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1503     _general_index = Compile::current()->get_alias_index(gt);
1504   } else {
1505     _general_index = 0;
1506   }
1507 }
1508 
basic_type() const1509 BasicType Compile::AliasType::basic_type() const {
1510   if (element() != NULL) {
1511     const Type* element = adr_type()->is_aryptr()->elem();
1512     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1513   } if (field() != NULL) {
1514     return field()->layout_type();
1515   } else {
1516     return T_ILLEGAL; // unknown
1517   }
1518 }
1519 
1520 //---------------------------------print_on------------------------------------
1521 #ifndef PRODUCT
print_on(outputStream * st)1522 void Compile::AliasType::print_on(outputStream* st) {
1523   if (index() < 10)
1524         st->print("@ <%d> ", index());
1525   else  st->print("@ <%d>",  index());
1526   st->print(is_rewritable() ? "   " : " RO");
1527   int offset = adr_type()->offset();
1528   if (offset == Type::OffsetBot)
1529         st->print(" +any");
1530   else  st->print(" +%-3d", offset);
1531   st->print(" in ");
1532   adr_type()->dump_on(st);
1533   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1534   if (field() != NULL && tjp) {
1535     if (tjp->klass()  != field()->holder() ||
1536         tjp->offset() != field()->offset_in_bytes()) {
1537       st->print(" != ");
1538       field()->print();
1539       st->print(" ***");
1540     }
1541   }
1542 }
1543 
print_alias_types()1544 void print_alias_types() {
1545   Compile* C = Compile::current();
1546   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1547   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1548     C->alias_type(idx)->print_on(tty);
1549     tty->cr();
1550   }
1551 }
1552 #endif
1553 
1554 
1555 //----------------------------probe_alias_cache--------------------------------
probe_alias_cache(const TypePtr * adr_type)1556 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1557   intptr_t key = (intptr_t) adr_type;
1558   key ^= key >> logAliasCacheSize;
1559   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1560 }
1561 
1562 
1563 //-----------------------------grow_alias_types--------------------------------
grow_alias_types()1564 void Compile::grow_alias_types() {
1565   const int old_ats  = _max_alias_types; // how many before?
1566   const int new_ats  = old_ats;          // how many more?
1567   const int grow_ats = old_ats+new_ats;  // how many now?
1568   _max_alias_types = grow_ats;
1569   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
1570   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1571   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1572   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1573 }
1574 
1575 
1576 //--------------------------------find_alias_type------------------------------
find_alias_type(const TypePtr * adr_type,bool no_create,ciField * original_field)1577 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1578   if (_AliasLevel == 0)
1579     return alias_type(AliasIdxBot);
1580 
1581   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1582   if (ace->_adr_type == adr_type) {
1583     return alias_type(ace->_index);
1584   }
1585 
1586   // Handle special cases.
1587   if (adr_type == NULL)             return alias_type(AliasIdxTop);
1588   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1589 
1590   // Do it the slow way.
1591   const TypePtr* flat = flatten_alias_type(adr_type);
1592 
1593 #ifdef ASSERT
1594   {
1595     ResourceMark rm;
1596     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1597            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1598     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1599            Type::str(adr_type));
1600     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1601       const TypeOopPtr* foop = flat->is_oopptr();
1602       // Scalarizable allocations have exact klass always.
1603       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1604       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1605       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1606              Type::str(foop), Type::str(xoop));
1607     }
1608   }
1609 #endif
1610 
1611   int idx = AliasIdxTop;
1612   for (int i = 0; i < num_alias_types(); i++) {
1613     if (alias_type(i)->adr_type() == flat) {
1614       idx = i;
1615       break;
1616     }
1617   }
1618 
1619   if (idx == AliasIdxTop) {
1620     if (no_create)  return NULL;
1621     // Grow the array if necessary.
1622     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1623     // Add a new alias type.
1624     idx = _num_alias_types++;
1625     _alias_types[idx]->Init(idx, flat);
1626     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1627     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1628     if (flat->isa_instptr()) {
1629       if (flat->offset() == java_lang_Class::klass_offset()
1630           && flat->is_instptr()->klass() == env()->Class_klass())
1631         alias_type(idx)->set_rewritable(false);
1632     }
1633     if (flat->isa_aryptr()) {
1634 #ifdef ASSERT
1635       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1636       // (T_BYTE has the weakest alignment and size restrictions...)
1637       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1638 #endif
1639       if (flat->offset() == TypePtr::OffsetBot) {
1640         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1641       }
1642     }
1643     if (flat->isa_klassptr()) {
1644       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1645         alias_type(idx)->set_rewritable(false);
1646       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
1647         alias_type(idx)->set_rewritable(false);
1648       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
1649         alias_type(idx)->set_rewritable(false);
1650       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1651         alias_type(idx)->set_rewritable(false);
1652       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1653         alias_type(idx)->set_rewritable(false);
1654     }
1655     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1656     // but the base pointer type is not distinctive enough to identify
1657     // references into JavaThread.)
1658 
1659     // Check for final fields.
1660     const TypeInstPtr* tinst = flat->isa_instptr();
1661     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1662       ciField* field;
1663       if (tinst->const_oop() != NULL &&
1664           tinst->klass() == ciEnv::current()->Class_klass() &&
1665           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
1666         // static field
1667         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1668         field = k->get_field_by_offset(tinst->offset(), true);
1669       } else {
1670         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
1671         field = k->get_field_by_offset(tinst->offset(), false);
1672       }
1673       assert(field == NULL ||
1674              original_field == NULL ||
1675              (field->holder() == original_field->holder() &&
1676               field->offset() == original_field->offset() &&
1677               field->is_static() == original_field->is_static()), "wrong field?");
1678       // Set field() and is_rewritable() attributes.
1679       if (field != NULL)  alias_type(idx)->set_field(field);
1680     }
1681   }
1682 
1683   // Fill the cache for next time.
1684   ace->_adr_type = adr_type;
1685   ace->_index    = idx;
1686   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1687 
1688   // Might as well try to fill the cache for the flattened version, too.
1689   AliasCacheEntry* face = probe_alias_cache(flat);
1690   if (face->_adr_type == NULL) {
1691     face->_adr_type = flat;
1692     face->_index    = idx;
1693     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1694   }
1695 
1696   return alias_type(idx);
1697 }
1698 
1699 
alias_type(ciField * field)1700 Compile::AliasType* Compile::alias_type(ciField* field) {
1701   const TypeOopPtr* t;
1702   if (field->is_static())
1703     t = TypeInstPtr::make(field->holder()->java_mirror());
1704   else
1705     t = TypeOopPtr::make_from_klass_raw(field->holder());
1706   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1707   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1708   return atp;
1709 }
1710 
1711 
1712 //------------------------------have_alias_type--------------------------------
have_alias_type(const TypePtr * adr_type)1713 bool Compile::have_alias_type(const TypePtr* adr_type) {
1714   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1715   if (ace->_adr_type == adr_type) {
1716     return true;
1717   }
1718 
1719   // Handle special cases.
1720   if (adr_type == NULL)             return true;
1721   if (adr_type == TypePtr::BOTTOM)  return true;
1722 
1723   return find_alias_type(adr_type, true, NULL) != NULL;
1724 }
1725 
1726 //-----------------------------must_alias--------------------------------------
1727 // True if all values of the given address type are in the given alias category.
must_alias(const TypePtr * adr_type,int alias_idx)1728 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1729   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1730   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
1731   if (alias_idx == AliasIdxTop)         return false; // the empty category
1732   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1733 
1734   // the only remaining possible overlap is identity
1735   int adr_idx = get_alias_index(adr_type);
1736   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1737   assert(adr_idx == alias_idx ||
1738          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1739           && adr_type                       != TypeOopPtr::BOTTOM),
1740          "should not be testing for overlap with an unsafe pointer");
1741   return adr_idx == alias_idx;
1742 }
1743 
1744 //------------------------------can_alias--------------------------------------
1745 // True if any values of the given address type are in the given alias category.
can_alias(const TypePtr * adr_type,int alias_idx)1746 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1747   if (alias_idx == AliasIdxTop)         return false; // the empty category
1748   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
1749   // Known instance doesn't alias with bottom memory
1750   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1751   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1752 
1753   // the only remaining possible overlap is identity
1754   int adr_idx = get_alias_index(adr_type);
1755   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1756   return adr_idx == alias_idx;
1757 }
1758 
1759 
1760 
1761 //---------------------------pop_warm_call-------------------------------------
pop_warm_call()1762 WarmCallInfo* Compile::pop_warm_call() {
1763   WarmCallInfo* wci = _warm_calls;
1764   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
1765   return wci;
1766 }
1767 
1768 //----------------------------Inline_Warm--------------------------------------
Inline_Warm()1769 int Compile::Inline_Warm() {
1770   // If there is room, try to inline some more warm call sites.
1771   // %%% Do a graph index compaction pass when we think we're out of space?
1772   if (!InlineWarmCalls)  return 0;
1773 
1774   int calls_made_hot = 0;
1775   int room_to_grow   = NodeCountInliningCutoff - unique();
1776   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
1777   int amount_grown   = 0;
1778   WarmCallInfo* call;
1779   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
1780     int est_size = (int)call->size();
1781     if (est_size > (room_to_grow - amount_grown)) {
1782       // This one won't fit anyway.  Get rid of it.
1783       call->make_cold();
1784       continue;
1785     }
1786     call->make_hot();
1787     calls_made_hot++;
1788     amount_grown   += est_size;
1789     amount_to_grow -= est_size;
1790   }
1791 
1792   if (calls_made_hot > 0)  set_major_progress();
1793   return calls_made_hot;
1794 }
1795 
1796 
1797 //----------------------------Finish_Warm--------------------------------------
Finish_Warm()1798 void Compile::Finish_Warm() {
1799   if (!InlineWarmCalls)  return;
1800   if (failing())  return;
1801   if (warm_calls() == NULL)  return;
1802 
1803   // Clean up loose ends, if we are out of space for inlining.
1804   WarmCallInfo* call;
1805   while ((call = pop_warm_call()) != NULL) {
1806     call->make_cold();
1807   }
1808 }
1809 
1810 //---------------------cleanup_loop_predicates-----------------------
1811 // Remove the opaque nodes that protect the predicates so that all unused
1812 // checks and uncommon_traps will be eliminated from the ideal graph
cleanup_loop_predicates(PhaseIterGVN & igvn)1813 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
1814   if (predicate_count()==0) return;
1815   for (int i = predicate_count(); i > 0; i--) {
1816     Node * n = predicate_opaque1_node(i-1);
1817     assert(n->Opcode() == Op_Opaque1, "must be");
1818     igvn.replace_node(n, n->in(1));
1819   }
1820   assert(predicate_count()==0, "should be clean!");
1821 }
1822 
record_for_post_loop_opts_igvn(Node * n)1823 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1824   if (!n->for_post_loop_opts_igvn()) {
1825     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1826     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1827     _for_post_loop_igvn.append(n);
1828   }
1829 }
1830 
remove_from_post_loop_opts_igvn(Node * n)1831 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1832   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1833   _for_post_loop_igvn.remove(n);
1834 }
1835 
process_for_post_loop_opts_igvn(PhaseIterGVN & igvn)1836 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1837   // Verify that all previous optimizations produced a valid graph
1838   // at least to this point, even if no loop optimizations were done.
1839   PhaseIdealLoop::verify(igvn);
1840 
1841   C->set_post_loop_opts_phase(); // no more loop opts allowed
1842 
1843   assert(!C->major_progress(), "not cleared");
1844 
1845   if (_for_post_loop_igvn.length() > 0) {
1846     while (_for_post_loop_igvn.length() > 0) {
1847       Node* n = _for_post_loop_igvn.pop();
1848       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1849       igvn._worklist.push(n);
1850     }
1851     igvn.optimize();
1852     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1853 
1854     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1855     if (C->major_progress()) {
1856       C->clear_major_progress(); // ensure that major progress is now clear
1857     }
1858   }
1859 }
1860 
1861 // StringOpts and late inlining of string methods
inline_string_calls(bool parse_time)1862 void Compile::inline_string_calls(bool parse_time) {
1863   {
1864     // remove useless nodes to make the usage analysis simpler
1865     ResourceMark rm;
1866     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1867   }
1868 
1869   {
1870     ResourceMark rm;
1871     print_method(PHASE_BEFORE_STRINGOPTS, 3);
1872     PhaseStringOpts pso(initial_gvn(), for_igvn());
1873     print_method(PHASE_AFTER_STRINGOPTS, 3);
1874   }
1875 
1876   // now inline anything that we skipped the first time around
1877   if (!parse_time) {
1878     _late_inlines_pos = _late_inlines.length();
1879   }
1880 
1881   while (_string_late_inlines.length() > 0) {
1882     CallGenerator* cg = _string_late_inlines.pop();
1883     cg->do_late_inline();
1884     if (failing())  return;
1885   }
1886   _string_late_inlines.trunc_to(0);
1887 }
1888 
1889 // Late inlining of boxing methods
inline_boxing_calls(PhaseIterGVN & igvn)1890 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
1891   if (_boxing_late_inlines.length() > 0) {
1892     assert(has_boxed_value(), "inconsistent");
1893 
1894     PhaseGVN* gvn = initial_gvn();
1895     set_inlining_incrementally(true);
1896 
1897     assert( igvn._worklist.size() == 0, "should be done with igvn" );
1898     for_igvn()->clear();
1899     gvn->replace_with(&igvn);
1900 
1901     _late_inlines_pos = _late_inlines.length();
1902 
1903     while (_boxing_late_inlines.length() > 0) {
1904       CallGenerator* cg = _boxing_late_inlines.pop();
1905       cg->do_late_inline();
1906       if (failing())  return;
1907     }
1908     _boxing_late_inlines.trunc_to(0);
1909 
1910     inline_incrementally_cleanup(igvn);
1911 
1912     set_inlining_incrementally(false);
1913   }
1914 }
1915 
inline_incrementally_one()1916 bool Compile::inline_incrementally_one() {
1917   assert(IncrementalInline, "incremental inlining should be on");
1918 
1919   TracePhase tp("incrementalInline_inline", &timers[_t_incrInline_inline]);
1920 
1921   set_inlining_progress(false);
1922   set_do_cleanup(false);
1923 
1924   for (int i = 0; i < _late_inlines.length(); i++) {
1925     _late_inlines_pos = i+1;
1926     CallGenerator* cg = _late_inlines.at(i);
1927     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
1928     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
1929       cg->do_late_inline();
1930       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
1931       if (failing()) {
1932         return false;
1933       } else if (inlining_progress()) {
1934         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
1935         print_method(PHASE_INCREMENTAL_INLINE_STEP, cg->call_node(), 3);
1936         break; // process one call site at a time
1937       }
1938     } else {
1939       // Ignore late inline direct calls when inlining is not allowed.
1940       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
1941     }
1942   }
1943   // Remove processed elements.
1944   _late_inlines.remove_till(_late_inlines_pos);
1945   _late_inlines_pos = 0;
1946 
1947   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
1948 
1949   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
1950 
1951   set_inlining_progress(false);
1952   set_do_cleanup(false);
1953 
1954   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
1955   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
1956 }
1957 
inline_incrementally_cleanup(PhaseIterGVN & igvn)1958 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
1959   {
1960     TracePhase tp("incrementalInline_pru", &timers[_t_incrInline_pru]);
1961     ResourceMark rm;
1962     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
1963   }
1964   {
1965     TracePhase tp("incrementalInline_igvn", &timers[_t_incrInline_igvn]);
1966     igvn = PhaseIterGVN(initial_gvn());
1967     igvn.optimize();
1968   }
1969   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
1970 }
1971 
1972 // Perform incremental inlining until bound on number of live nodes is reached
inline_incrementally(PhaseIterGVN & igvn)1973 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
1974   TracePhase tp("incrementalInline", &timers[_t_incrInline]);
1975 
1976   set_inlining_incrementally(true);
1977   uint low_live_nodes = 0;
1978 
1979   while (_late_inlines.length() > 0) {
1980     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1981       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
1982         TracePhase tp("incrementalInline_ideal", &timers[_t_incrInline_ideal]);
1983         // PhaseIdealLoop is expensive so we only try it once we are
1984         // out of live nodes and we only try it again if the previous
1985         // helped got the number of nodes down significantly
1986         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
1987         if (failing())  return;
1988         low_live_nodes = live_nodes();
1989         _major_progress = true;
1990       }
1991 
1992       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
1993         bool do_print_inlining = print_inlining() || print_intrinsics();
1994         if (do_print_inlining || log() != NULL) {
1995           // Print inlining message for candidates that we couldn't inline for lack of space.
1996           for (int i = 0; i < _late_inlines.length(); i++) {
1997             CallGenerator* cg = _late_inlines.at(i);
1998             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
1999             if (do_print_inlining) {
2000               cg->print_inlining_late(msg);
2001             }
2002             log_late_inline_failure(cg, msg);
2003           }
2004         }
2005         break; // finish
2006       }
2007     }
2008 
2009     for_igvn()->clear();
2010     initial_gvn()->replace_with(&igvn);
2011 
2012     while (inline_incrementally_one()) {
2013       assert(!failing(), "inconsistent");
2014     }
2015     if (failing())  return;
2016 
2017     inline_incrementally_cleanup(igvn);
2018 
2019     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2020 
2021     if (failing())  return;
2022 
2023     if (_late_inlines.length() == 0) {
2024       break; // no more progress
2025     }
2026   }
2027   assert( igvn._worklist.size() == 0, "should be done with igvn" );
2028 
2029   if (_string_late_inlines.length() > 0) {
2030     assert(has_stringbuilder(), "inconsistent");
2031     for_igvn()->clear();
2032     initial_gvn()->replace_with(&igvn);
2033 
2034     inline_string_calls(false);
2035 
2036     if (failing())  return;
2037 
2038     inline_incrementally_cleanup(igvn);
2039   }
2040 
2041   set_inlining_incrementally(false);
2042 }
2043 
process_late_inline_calls_no_inline(PhaseIterGVN & igvn)2044 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2045   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2046   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2047   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == NULL"
2048   // as if "inlining_incrementally() == true" were set.
2049   assert(inlining_incrementally() == false, "not allowed");
2050   assert(_modified_nodes == NULL, "not allowed");
2051   assert(_late_inlines.length() > 0, "sanity");
2052 
2053   while (_late_inlines.length() > 0) {
2054     for_igvn()->clear();
2055     initial_gvn()->replace_with(&igvn);
2056 
2057     while (inline_incrementally_one()) {
2058       assert(!failing(), "inconsistent");
2059     }
2060     if (failing())  return;
2061 
2062     inline_incrementally_cleanup(igvn);
2063   }
2064 }
2065 
optimize_loops(PhaseIterGVN & igvn,LoopOptsMode mode)2066 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2067   if (_loop_opts_cnt > 0) {
2068     debug_only( int cnt = 0; );
2069     while (major_progress() && (_loop_opts_cnt > 0)) {
2070       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2071       assert( cnt++ < 40, "infinite cycle in loop optimization" );
2072       PhaseIdealLoop::optimize(igvn, mode);
2073       _loop_opts_cnt--;
2074       if (failing())  return false;
2075       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2076     }
2077   }
2078   return true;
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.
remove_root_to_sfpts_edges(PhaseIterGVN & igvn)2085 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
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         if (n->outcnt() == 0) {
2093           igvn.remove_dead_node(n);
2094         }
2095         --i;
2096       }
2097     }
2098     // Parsing may have added top inputs to the root node (Path
2099     // leading to the Halt node proven dead). Make sure we get a
2100     // chance to clean them up.
2101     igvn._worklist.push(r);
2102     igvn.optimize();
2103   }
2104 }
2105 
2106 //------------------------------Optimize---------------------------------------
2107 // Given a graph, optimize it.
Optimize()2108 void Compile::Optimize() {
2109   TracePhase tp("optimizer", &timers[_t_optimizer]);
2110 
2111 #ifndef PRODUCT
2112   if (_directive->BreakAtCompileOption) {
2113     BREAKPOINT;
2114   }
2115 
2116 #endif
2117 
2118   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2119 #ifdef ASSERT
2120   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2121 #endif
2122 
2123   ResourceMark rm;
2124 
2125   print_inlining_reinit();
2126 
2127   NOT_PRODUCT( verify_graph_edges(); )
2128 
2129   print_method(PHASE_AFTER_PARSING);
2130 
2131  {
2132   // Iterative Global Value Numbering, including ideal transforms
2133   // Initialize IterGVN with types and values from parse-time GVN
2134   PhaseIterGVN igvn(initial_gvn());
2135 #ifdef ASSERT
2136   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2137 #endif
2138   {
2139     TracePhase tp("iterGVN", &timers[_t_iterGVN]);
2140     igvn.optimize();
2141   }
2142 
2143   if (failing())  return;
2144 
2145   print_method(PHASE_ITER_GVN1, 2);
2146 
2147   inline_incrementally(igvn);
2148 
2149   print_method(PHASE_INCREMENTAL_INLINE, 2);
2150 
2151   if (failing())  return;
2152 
2153   if (eliminate_boxing()) {
2154     // Inline valueOf() methods now.
2155     inline_boxing_calls(igvn);
2156 
2157     if (AlwaysIncrementalInline) {
2158       inline_incrementally(igvn);
2159     }
2160 
2161     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2162 
2163     if (failing())  return;
2164   }
2165 
2166   // Now that all inlining is over, cut edge from root to loop
2167   // safepoints
2168   remove_root_to_sfpts_edges(igvn);
2169 
2170   // Remove the speculative part of types and clean up the graph from
2171   // the extra CastPP nodes whose only purpose is to carry them. Do
2172   // that early so that optimizations are not disrupted by the extra
2173   // CastPP nodes.
2174   remove_speculative_types(igvn);
2175 
2176   // No more new expensive nodes will be added to the list from here
2177   // so keep only the actual candidates for optimizations.
2178   cleanup_expensive_nodes(igvn);
2179 
2180   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2181   if (EnableVectorSupport && has_vbox_nodes()) {
2182     TracePhase tp("", &timers[_t_vector]);
2183     PhaseVector pv(igvn);
2184     pv.optimize_vector_boxes();
2185 
2186     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2187   }
2188   assert(!has_vbox_nodes(), "sanity");
2189 
2190   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2191     Compile::TracePhase tp("", &timers[_t_renumberLive]);
2192     initial_gvn()->replace_with(&igvn);
2193     for_igvn()->clear();
2194     Unique_Node_List new_worklist(C->comp_arena());
2195     {
2196       ResourceMark rm;
2197       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
2198     }
2199     Unique_Node_List* save_for_igvn = for_igvn();
2200     set_for_igvn(&new_worklist);
2201     igvn = PhaseIterGVN(initial_gvn());
2202     igvn.optimize();
2203     set_for_igvn(save_for_igvn);
2204   }
2205 
2206   // Perform escape analysis
2207   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
2208     if (has_loops()) {
2209       // Cleanup graph (remove dead nodes).
2210       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2211       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2212       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2213       if (failing())  return;
2214     }
2215     ConnectionGraph::do_analysis(this, &igvn);
2216 
2217     if (failing())  return;
2218 
2219     // Optimize out fields loads from scalar replaceable allocations.
2220     igvn.optimize();
2221     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2222 
2223     if (failing())  return;
2224 
2225     if (congraph() != NULL && macro_count() > 0) {
2226       TracePhase tp("macroEliminate", &timers[_t_macroEliminate]);
2227       PhaseMacroExpand mexp(igvn);
2228       mexp.eliminate_macro_nodes();
2229       igvn.set_delay_transform(false);
2230 
2231       igvn.optimize();
2232       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2233 
2234       if (failing())  return;
2235     }
2236   }
2237 
2238   // Loop transforms on the ideal graph.  Range Check Elimination,
2239   // peeling, unrolling, etc.
2240 
2241   // Set loop opts counter
2242   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2243     {
2244       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2245       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2246       _loop_opts_cnt--;
2247       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2248       if (failing())  return;
2249     }
2250     // Loop opts pass if partial peeling occurred in previous pass
2251     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2252       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2253       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2254       _loop_opts_cnt--;
2255       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2256       if (failing())  return;
2257     }
2258     // Loop opts pass for loop-unrolling before CCP
2259     if(major_progress() && (_loop_opts_cnt > 0)) {
2260       TracePhase tp("idealLoop", &timers[_t_idealLoop]);
2261       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2262       _loop_opts_cnt--;
2263       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2264     }
2265     if (!failing()) {
2266       // Verify that last round of loop opts produced a valid graph
2267       PhaseIdealLoop::verify(igvn);
2268     }
2269   }
2270   if (failing())  return;
2271 
2272   // Conditional Constant Propagation;
2273   PhaseCCP ccp( &igvn );
2274   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2275   {
2276     TracePhase tp("ccp", &timers[_t_ccp]);
2277     ccp.do_transform();
2278   }
2279   print_method(PHASE_CPP1, 2);
2280 
2281   assert( true, "Break here to ccp.dump_old2new_map()");
2282 
2283   // Iterative Global Value Numbering, including ideal transforms
2284   {
2285     TracePhase tp("iterGVN2", &timers[_t_iterGVN2]);
2286     igvn = ccp;
2287     igvn.optimize();
2288   }
2289   print_method(PHASE_ITER_GVN2, 2);
2290 
2291   if (failing())  return;
2292 
2293   // Loop transforms on the ideal graph.  Range Check Elimination,
2294   // peeling, unrolling, etc.
2295   if (!optimize_loops(igvn, LoopOptsDefault)) {
2296     return;
2297   }
2298 
2299   if (failing())  return;
2300 
2301   C->clear_major_progress(); // ensure that major progress is now clear
2302 
2303   process_for_post_loop_opts_igvn(igvn);
2304 
2305 #ifdef ASSERT
2306   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2307 #endif
2308 
2309   {
2310     TracePhase tp("macroExpand", &timers[_t_macroExpand]);
2311     PhaseMacroExpand  mex(igvn);
2312     if (mex.expand_macro_nodes()) {
2313       assert(failing(), "must bail out w/ explicit message");
2314       return;
2315     }
2316     print_method(PHASE_MACRO_EXPANSION, 2);
2317   }
2318 
2319   {
2320     TracePhase tp("barrierExpand", &timers[_t_barrierExpand]);
2321     if (bs->expand_barriers(this, igvn)) {
2322       assert(failing(), "must bail out w/ explicit message");
2323       return;
2324     }
2325     print_method(PHASE_BARRIER_EXPANSION, 2);
2326   }
2327 
2328   if (C->max_vector_size() > 0) {
2329     C->optimize_logic_cones(igvn);
2330     igvn.optimize();
2331   }
2332 
2333   DEBUG_ONLY( _modified_nodes = NULL; )
2334 
2335   assert(igvn._worklist.size() == 0, "not empty");
2336 
2337   assert(_late_inlines.length() == 0 || IncrementalInlineMH || IncrementalInlineVirtual, "not empty");
2338 
2339   if (_late_inlines.length() > 0) {
2340     // More opportunities to optimize virtual and MH calls.
2341     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2342     process_late_inline_calls_no_inline(igvn);
2343   }
2344  } // (End scope of igvn; run destructor if necessary for asserts.)
2345 
2346  process_print_inlining();
2347 
2348  // A method with only infinite loops has no edges entering loops from root
2349  {
2350    TracePhase tp("graphReshape", &timers[_t_graphReshaping]);
2351    if (final_graph_reshaping()) {
2352      assert(failing(), "must bail out w/ explicit message");
2353      return;
2354    }
2355  }
2356 
2357  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2358  DEBUG_ONLY(set_phase_optimize_finished();)
2359 }
2360 
inline_vector_reboxing_calls()2361 void Compile::inline_vector_reboxing_calls() {
2362   if (C->_vector_reboxing_late_inlines.length() > 0) {
2363     _late_inlines_pos = C->_late_inlines.length();
2364     while (_vector_reboxing_late_inlines.length() > 0) {
2365       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2366       cg->do_late_inline();
2367       if (failing())  return;
2368       print_method(PHASE_INLINE_VECTOR_REBOX, cg->call_node());
2369     }
2370     _vector_reboxing_late_inlines.trunc_to(0);
2371   }
2372 }
2373 
has_vbox_nodes()2374 bool Compile::has_vbox_nodes() {
2375   if (C->_vector_reboxing_late_inlines.length() > 0) {
2376     return true;
2377   }
2378   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2379     Node * n = C->macro_node(macro_idx);
2380     assert(n->is_macro(), "only macro nodes expected here");
2381     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2382       return true;
2383     }
2384   }
2385   return false;
2386 }
2387 
2388 //---------------------------- Bitwise operation packing optimization ---------------------------
2389 
is_vector_unary_bitwise_op(Node * n)2390 static bool is_vector_unary_bitwise_op(Node* n) {
2391   return n->Opcode() == Op_XorV &&
2392          VectorNode::is_vector_bitwise_not_pattern(n);
2393 }
2394 
is_vector_binary_bitwise_op(Node * n)2395 static bool is_vector_binary_bitwise_op(Node* n) {
2396   switch (n->Opcode()) {
2397     case Op_AndV:
2398     case Op_OrV:
2399       return true;
2400 
2401     case Op_XorV:
2402       return !is_vector_unary_bitwise_op(n);
2403 
2404     default:
2405       return false;
2406   }
2407 }
2408 
is_vector_ternary_bitwise_op(Node * n)2409 static bool is_vector_ternary_bitwise_op(Node* n) {
2410   return n->Opcode() == Op_MacroLogicV;
2411 }
2412 
is_vector_bitwise_op(Node * n)2413 static bool is_vector_bitwise_op(Node* n) {
2414   return is_vector_unary_bitwise_op(n)  ||
2415          is_vector_binary_bitwise_op(n) ||
2416          is_vector_ternary_bitwise_op(n);
2417 }
2418 
is_vector_bitwise_cone_root(Node * n)2419 static bool is_vector_bitwise_cone_root(Node* n) {
2420   if (!is_vector_bitwise_op(n)) {
2421     return false;
2422   }
2423   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2424     if (is_vector_bitwise_op(n->fast_out(i))) {
2425       return false;
2426     }
2427   }
2428   return true;
2429 }
2430 
collect_unique_inputs(Node * n,Unique_Node_List & partition,Unique_Node_List & inputs)2431 static uint collect_unique_inputs(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2432   uint cnt = 0;
2433   if (is_vector_bitwise_op(n)) {
2434     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2435       for (uint i = 1; i < n->req(); i++) {
2436         Node* in = n->in(i);
2437         bool skip = VectorNode::is_all_ones_vector(in);
2438         if (!skip && !inputs.member(in)) {
2439           inputs.push(in);
2440           cnt++;
2441         }
2442       }
2443       assert(cnt <= 1, "not unary");
2444     } else {
2445       uint last_req = n->req();
2446       if (is_vector_ternary_bitwise_op(n)) {
2447         last_req = n->req() - 1; // skip last input
2448       }
2449       for (uint i = 1; i < last_req; i++) {
2450         Node* def = n->in(i);
2451         if (!inputs.member(def)) {
2452           inputs.push(def);
2453           cnt++;
2454         }
2455       }
2456     }
2457     partition.push(n);
2458   } else { // not a bitwise operations
2459     if (!inputs.member(n)) {
2460       inputs.push(n);
2461       cnt++;
2462     }
2463   }
2464   return cnt;
2465 }
2466 
collect_logic_cone_roots(Unique_Node_List & list)2467 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2468   Unique_Node_List useful_nodes;
2469   C->identify_useful_nodes(useful_nodes);
2470 
2471   for (uint i = 0; i < useful_nodes.size(); i++) {
2472     Node* n = useful_nodes.at(i);
2473     if (is_vector_bitwise_cone_root(n)) {
2474       list.push(n);
2475     }
2476   }
2477 }
2478 
xform_to_MacroLogicV(PhaseIterGVN & igvn,const TypeVect * vt,Unique_Node_List & partition,Unique_Node_List & inputs)2479 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2480                                     const TypeVect* vt,
2481                                     Unique_Node_List& partition,
2482                                     Unique_Node_List& inputs) {
2483   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2484   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2485   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2486 
2487   Node* in1 = inputs.at(0);
2488   Node* in2 = inputs.at(1);
2489   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2490 
2491   uint func = compute_truth_table(partition, inputs);
2492   return igvn.transform(MacroLogicVNode::make(igvn, in3, in2, in1, func, vt));
2493 }
2494 
extract_bit(uint func,uint pos)2495 static uint extract_bit(uint func, uint pos) {
2496   return (func & (1 << pos)) >> pos;
2497 }
2498 
2499 //
2500 //  A macro logic node represents a truth table. It has 4 inputs,
2501 //  First three inputs corresponds to 3 columns of a truth table
2502 //  and fourth input captures the logic function.
2503 //
2504 //  eg.  fn = (in1 AND in2) OR in3;
2505 //
2506 //      MacroNode(in1,in2,in3,fn)
2507 //
2508 //  -----------------
2509 //  in1 in2 in3  fn
2510 //  -----------------
2511 //  0    0   0    0
2512 //  0    0   1    1
2513 //  0    1   0    0
2514 //  0    1   1    1
2515 //  1    0   0    0
2516 //  1    0   1    1
2517 //  1    1   0    1
2518 //  1    1   1    1
2519 //
2520 
eval_macro_logic_op(uint func,uint in1,uint in2,uint in3)2521 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2522   int res = 0;
2523   for (int i = 0; i < 8; i++) {
2524     int bit1 = extract_bit(in1, i);
2525     int bit2 = extract_bit(in2, i);
2526     int bit3 = extract_bit(in3, i);
2527 
2528     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2529     int func_bit = extract_bit(func, func_bit_pos);
2530 
2531     res |= func_bit << i;
2532   }
2533   return res;
2534 }
2535 
eval_operand(Node * n,ResourceHashtable<Node *,uint> & eval_map)2536 static uint eval_operand(Node* n, ResourceHashtable<Node*,uint>& eval_map) {
2537   assert(n != NULL, "");
2538   assert(eval_map.contains(n), "absent");
2539   return *(eval_map.get(n));
2540 }
2541 
eval_operands(Node * n,uint & func1,uint & func2,uint & func3,ResourceHashtable<Node *,uint> & eval_map)2542 static void eval_operands(Node* n,
2543                           uint& func1, uint& func2, uint& func3,
2544                           ResourceHashtable<Node*,uint>& eval_map) {
2545   assert(is_vector_bitwise_op(n), "");
2546 
2547   if (is_vector_unary_bitwise_op(n)) {
2548     Node* opnd = n->in(1);
2549     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2550       opnd = n->in(2);
2551     }
2552     func1 = eval_operand(opnd, eval_map);
2553   } else if (is_vector_binary_bitwise_op(n)) {
2554     func1 = eval_operand(n->in(1), eval_map);
2555     func2 = eval_operand(n->in(2), eval_map);
2556   } else {
2557     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2558     func1 = eval_operand(n->in(1), eval_map);
2559     func2 = eval_operand(n->in(2), eval_map);
2560     func3 = eval_operand(n->in(3), eval_map);
2561   }
2562 }
2563 
compute_truth_table(Unique_Node_List & partition,Unique_Node_List & inputs)2564 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2565   assert(inputs.size() <= 3, "sanity");
2566   ResourceMark rm;
2567   uint res = 0;
2568   ResourceHashtable<Node*,uint> eval_map;
2569 
2570   // Populate precomputed functions for inputs.
2571   // Each input corresponds to one column of 3 input truth-table.
2572   uint input_funcs[] = { 0xAA,   // (_, _, a) -> a
2573                          0xCC,   // (_, b, _) -> b
2574                          0xF0 }; // (c, _, _) -> c
2575   for (uint i = 0; i < inputs.size(); i++) {
2576     eval_map.put(inputs.at(i), input_funcs[i]);
2577   }
2578 
2579   for (uint i = 0; i < partition.size(); i++) {
2580     Node* n = partition.at(i);
2581 
2582     uint func1 = 0, func2 = 0, func3 = 0;
2583     eval_operands(n, func1, func2, func3, eval_map);
2584 
2585     switch (n->Opcode()) {
2586       case Op_OrV:
2587         assert(func3 == 0, "not binary");
2588         res = func1 | func2;
2589         break;
2590       case Op_AndV:
2591         assert(func3 == 0, "not binary");
2592         res = func1 & func2;
2593         break;
2594       case Op_XorV:
2595         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2596           assert(func2 == 0 && func3 == 0, "not unary");
2597           res = (~func1) & 0xFF;
2598         } else {
2599           assert(func3 == 0, "not binary");
2600           res = func1 ^ func2;
2601         }
2602         break;
2603       case Op_MacroLogicV:
2604         // Ordering of inputs may change during evaluation of sub-tree
2605         // containing MacroLogic node as a child node, thus a re-evaluation
2606         // makes sure that function is evaluated in context of current
2607         // inputs.
2608         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2609         break;
2610 
2611       default: assert(false, "not supported: %s", n->Name());
2612     }
2613     assert(res <= 0xFF, "invalid");
2614     eval_map.put(n, res);
2615   }
2616   return res;
2617 }
2618 
compute_logic_cone(Node * n,Unique_Node_List & partition,Unique_Node_List & inputs)2619 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2620   assert(partition.size() == 0, "not empty");
2621   assert(inputs.size() == 0, "not empty");
2622   if (is_vector_ternary_bitwise_op(n)) {
2623     return false;
2624   }
2625 
2626   bool is_unary_op = is_vector_unary_bitwise_op(n);
2627   if (is_unary_op) {
2628     assert(collect_unique_inputs(n, partition, inputs) == 1, "not unary");
2629     return false; // too few inputs
2630   }
2631 
2632   assert(is_vector_binary_bitwise_op(n), "not binary");
2633   Node* in1 = n->in(1);
2634   Node* in2 = n->in(2);
2635 
2636   int in1_unique_inputs_cnt = collect_unique_inputs(in1, partition, inputs);
2637   int in2_unique_inputs_cnt = collect_unique_inputs(in2, partition, inputs);
2638   partition.push(n);
2639 
2640   // Too many inputs?
2641   if (inputs.size() > 3) {
2642     partition.clear();
2643     inputs.clear();
2644     { // Recompute in2 inputs
2645       Unique_Node_List not_used;
2646       in2_unique_inputs_cnt = collect_unique_inputs(in2, not_used, not_used);
2647     }
2648     // Pick the node with minimum number of inputs.
2649     if (in1_unique_inputs_cnt >= 3 && in2_unique_inputs_cnt >= 3) {
2650       return false; // still too many inputs
2651     }
2652     // Recompute partition & inputs.
2653     Node* child       = (in1_unique_inputs_cnt < in2_unique_inputs_cnt ? in1 : in2);
2654     collect_unique_inputs(child, partition, inputs);
2655 
2656     Node* other_input = (in1_unique_inputs_cnt < in2_unique_inputs_cnt ? in2 : in1);
2657     inputs.push(other_input);
2658 
2659     partition.push(n);
2660   }
2661 
2662   return (partition.size() == 2 || partition.size() == 3) &&
2663          (inputs.size()    == 2 || inputs.size()    == 3);
2664 }
2665 
2666 
process_logic_cone_root(PhaseIterGVN & igvn,Node * n,VectorSet & visited)2667 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2668   assert(is_vector_bitwise_op(n), "not a root");
2669 
2670   visited.set(n->_idx);
2671 
2672   // 1) Do a DFS walk over the logic cone.
2673   for (uint i = 1; i < n->req(); i++) {
2674     Node* in = n->in(i);
2675     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2676       process_logic_cone_root(igvn, in, visited);
2677     }
2678   }
2679 
2680   // 2) Bottom up traversal: Merge node[s] with
2681   // the parent to form macro logic node.
2682   Unique_Node_List partition;
2683   Unique_Node_List inputs;
2684   if (compute_logic_cone(n, partition, inputs)) {
2685     const TypeVect* vt = n->bottom_type()->is_vect();
2686     Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
2687     igvn.replace_node(n, macro_logic);
2688   }
2689 }
2690 
optimize_logic_cones(PhaseIterGVN & igvn)2691 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
2692   ResourceMark rm;
2693   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
2694     Unique_Node_List list;
2695     collect_logic_cone_roots(list);
2696 
2697     while (list.size() > 0) {
2698       Node* n = list.pop();
2699       const TypeVect* vt = n->bottom_type()->is_vect();
2700       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
2701       if (supported) {
2702         VectorSet visited(comp_arena());
2703         process_logic_cone_root(igvn, n, visited);
2704       }
2705     }
2706   }
2707 }
2708 
2709 //------------------------------Code_Gen---------------------------------------
2710 // Given a graph, generate code for it
Code_Gen()2711 void Compile::Code_Gen() {
2712   if (failing()) {
2713     return;
2714   }
2715 
2716   // Perform instruction selection.  You might think we could reclaim Matcher
2717   // memory PDQ, but actually the Matcher is used in generating spill code.
2718   // Internals of the Matcher (including some VectorSets) must remain live
2719   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
2720   // set a bit in reclaimed memory.
2721 
2722   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2723   // nodes.  Mapping is only valid at the root of each matched subtree.
2724   NOT_PRODUCT( verify_graph_edges(); )
2725 
2726   Matcher matcher;
2727   _matcher = &matcher;
2728   {
2729     TracePhase tp("matcher", &timers[_t_matcher]);
2730     matcher.match();
2731     if (failing()) {
2732       return;
2733     }
2734     print_method(PHASE_AFTER_MATCHING, 3);
2735   }
2736   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
2737   // nodes.  Mapping is only valid at the root of each matched subtree.
2738   NOT_PRODUCT( verify_graph_edges(); )
2739 
2740   // If you have too many nodes, or if matching has failed, bail out
2741   check_node_count(0, "out of nodes matching instructions");
2742   if (failing()) {
2743     return;
2744   }
2745 
2746   print_method(PHASE_MATCHING, 2);
2747 
2748   // Build a proper-looking CFG
2749   PhaseCFG cfg(node_arena(), root(), matcher);
2750   _cfg = &cfg;
2751   {
2752     TracePhase tp("scheduler", &timers[_t_scheduler]);
2753     bool success = cfg.do_global_code_motion();
2754     if (!success) {
2755       return;
2756     }
2757 
2758     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
2759     NOT_PRODUCT( verify_graph_edges(); )
2760     debug_only( cfg.verify(); )
2761   }
2762 
2763   PhaseChaitin regalloc(unique(), cfg, matcher, false);
2764   _regalloc = &regalloc;
2765   {
2766     TracePhase tp("regalloc", &timers[_t_registerAllocation]);
2767     // Perform register allocation.  After Chaitin, use-def chains are
2768     // no longer accurate (at spill code) and so must be ignored.
2769     // Node->LRG->reg mappings are still accurate.
2770     _regalloc->Register_Allocate();
2771 
2772     // Bail out if the allocator builds too many nodes
2773     if (failing()) {
2774       return;
2775     }
2776   }
2777 
2778   // Prior to register allocation we kept empty basic blocks in case the
2779   // the allocator needed a place to spill.  After register allocation we
2780   // are not adding any new instructions.  If any basic block is empty, we
2781   // can now safely remove it.
2782   {
2783     TracePhase tp("blockOrdering", &timers[_t_blockOrdering]);
2784     cfg.remove_empty_blocks();
2785     if (do_freq_based_layout()) {
2786       PhaseBlockLayout layout(cfg);
2787     } else {
2788       cfg.set_loop_alignment();
2789     }
2790     cfg.fixup_flow();
2791   }
2792 
2793   // Apply peephole optimizations
2794   if( OptoPeephole ) {
2795     TracePhase tp("peephole", &timers[_t_peephole]);
2796     PhasePeephole peep( _regalloc, cfg);
2797     peep.do_transform();
2798   }
2799 
2800   // Do late expand if CPU requires this.
2801   if (Matcher::require_postalloc_expand) {
2802     TracePhase tp("postalloc_expand", &timers[_t_postalloc_expand]);
2803     cfg.postalloc_expand(_regalloc);
2804   }
2805 
2806   // Convert Nodes to instruction bits in a buffer
2807   {
2808     TracePhase tp("output", &timers[_t_output]);
2809     PhaseOutput output;
2810     output.Output();
2811     if (failing())  return;
2812     output.install();
2813   }
2814 
2815   print_method(PHASE_FINAL_CODE);
2816 
2817   // He's dead, Jim.
2818   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
2819   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
2820 }
2821 
2822 //------------------------------Final_Reshape_Counts---------------------------
2823 // This class defines counters to help identify when a method
2824 // may/must be executed using hardware with only 24-bit precision.
2825 struct Final_Reshape_Counts : public StackObj {
2826   int  _call_count;             // count non-inlined 'common' calls
2827   int  _float_count;            // count float ops requiring 24-bit precision
2828   int  _double_count;           // count double ops requiring more precision
2829   int  _java_call_count;        // count non-inlined 'java' calls
2830   int  _inner_loop_count;       // count loops which need alignment
2831   VectorSet _visited;           // Visitation flags
2832   Node_List _tests;             // Set of IfNodes & PCTableNodes
2833 
Final_Reshape_CountsFinal_Reshape_Counts2834   Final_Reshape_Counts() :
2835     _call_count(0), _float_count(0), _double_count(0),
2836     _java_call_count(0), _inner_loop_count(0) { }
2837 
inc_call_countFinal_Reshape_Counts2838   void inc_call_count  () { _call_count  ++; }
inc_float_countFinal_Reshape_Counts2839   void inc_float_count () { _float_count ++; }
inc_double_countFinal_Reshape_Counts2840   void inc_double_count() { _double_count++; }
inc_java_call_countFinal_Reshape_Counts2841   void inc_java_call_count() { _java_call_count++; }
inc_inner_loop_countFinal_Reshape_Counts2842   void inc_inner_loop_count() { _inner_loop_count++; }
2843 
get_call_countFinal_Reshape_Counts2844   int  get_call_count  () const { return _call_count  ; }
get_float_countFinal_Reshape_Counts2845   int  get_float_count () const { return _float_count ; }
get_double_countFinal_Reshape_Counts2846   int  get_double_count() const { return _double_count; }
get_java_call_countFinal_Reshape_Counts2847   int  get_java_call_count() const { return _java_call_count; }
get_inner_loop_countFinal_Reshape_Counts2848   int  get_inner_loop_count() const { return _inner_loop_count; }
2849 };
2850 
2851 // Eliminate trivially redundant StoreCMs and accumulate their
2852 // precedence edges.
eliminate_redundant_card_marks(Node * n)2853 void Compile::eliminate_redundant_card_marks(Node* n) {
2854   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
2855   if (n->in(MemNode::Address)->outcnt() > 1) {
2856     // There are multiple users of the same address so it might be
2857     // possible to eliminate some of the StoreCMs
2858     Node* mem = n->in(MemNode::Memory);
2859     Node* adr = n->in(MemNode::Address);
2860     Node* val = n->in(MemNode::ValueIn);
2861     Node* prev = n;
2862     bool done = false;
2863     // Walk the chain of StoreCMs eliminating ones that match.  As
2864     // long as it's a chain of single users then the optimization is
2865     // safe.  Eliminating partially redundant StoreCMs would require
2866     // cloning copies down the other paths.
2867     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
2868       if (adr == mem->in(MemNode::Address) &&
2869           val == mem->in(MemNode::ValueIn)) {
2870         // redundant StoreCM
2871         if (mem->req() > MemNode::OopStore) {
2872           // Hasn't been processed by this code yet.
2873           n->add_prec(mem->in(MemNode::OopStore));
2874         } else {
2875           // Already converted to precedence edge
2876           for (uint i = mem->req(); i < mem->len(); i++) {
2877             // Accumulate any precedence edges
2878             if (mem->in(i) != NULL) {
2879               n->add_prec(mem->in(i));
2880             }
2881           }
2882           // Everything above this point has been processed.
2883           done = true;
2884         }
2885         // Eliminate the previous StoreCM
2886         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
2887         assert(mem->outcnt() == 0, "should be dead");
2888         mem->disconnect_inputs(this);
2889       } else {
2890         prev = mem;
2891       }
2892       mem = prev->in(MemNode::Memory);
2893     }
2894   }
2895 }
2896 
2897 //------------------------------final_graph_reshaping_impl----------------------
2898 // Implement items 1-5 from final_graph_reshaping below.
final_graph_reshaping_impl(Node * n,Final_Reshape_Counts & frc)2899 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
2900 
2901   if ( n->outcnt() == 0 ) return; // dead node
2902   uint nop = n->Opcode();
2903 
2904   // Check for 2-input instruction with "last use" on right input.
2905   // Swap to left input.  Implements item (2).
2906   if( n->req() == 3 &&          // two-input instruction
2907       n->in(1)->outcnt() > 1 && // left use is NOT a last use
2908       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
2909       n->in(2)->outcnt() == 1 &&// right use IS a last use
2910       !n->in(2)->is_Con() ) {   // right use is not a constant
2911     // Check for commutative opcode
2912     switch( nop ) {
2913     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
2914     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
2915     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
2916     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
2917     case Op_AndL:  case Op_XorL:  case Op_OrL:
2918     case Op_AndI:  case Op_XorI:  case Op_OrI: {
2919       // Move "last use" input to left by swapping inputs
2920       n->swap_edges(1, 2);
2921       break;
2922     }
2923     default:
2924       break;
2925     }
2926   }
2927 
2928 #ifdef ASSERT
2929   if( n->is_Mem() ) {
2930     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
2931     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
2932             // oop will be recorded in oop map if load crosses safepoint
2933             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
2934                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
2935             "raw memory operations should have control edge");
2936   }
2937   if (n->is_MemBar()) {
2938     MemBarNode* mb = n->as_MemBar();
2939     if (mb->trailing_store() || mb->trailing_load_store()) {
2940       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
2941       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
2942       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
2943              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
2944     } else if (mb->leading()) {
2945       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
2946     }
2947   }
2948 #endif
2949   // Count FPU ops and common calls, implements item (3)
2950   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop);
2951   if (!gc_handled) {
2952     final_graph_reshaping_main_switch(n, frc, nop);
2953   }
2954 
2955   // Collect CFG split points
2956   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
2957     frc._tests.push(n);
2958   }
2959 }
2960 
final_graph_reshaping_main_switch(Node * n,Final_Reshape_Counts & frc,uint nop)2961 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop) {
2962   switch( nop ) {
2963   // Count all float operations that may use FPU
2964   case Op_AddF:
2965   case Op_SubF:
2966   case Op_MulF:
2967   case Op_DivF:
2968   case Op_NegF:
2969   case Op_ModF:
2970   case Op_ConvI2F:
2971   case Op_ConF:
2972   case Op_CmpF:
2973   case Op_CmpF3:
2974   case Op_StoreF:
2975   case Op_LoadF:
2976   // case Op_ConvL2F: // longs are split into 32-bit halves
2977     frc.inc_float_count();
2978     break;
2979 
2980   case Op_ConvF2D:
2981   case Op_ConvD2F:
2982     frc.inc_float_count();
2983     frc.inc_double_count();
2984     break;
2985 
2986   // Count all double operations that may use FPU
2987   case Op_AddD:
2988   case Op_SubD:
2989   case Op_MulD:
2990   case Op_DivD:
2991   case Op_NegD:
2992   case Op_ModD:
2993   case Op_ConvI2D:
2994   case Op_ConvD2I:
2995   // case Op_ConvL2D: // handled by leaf call
2996   // case Op_ConvD2L: // handled by leaf call
2997   case Op_ConD:
2998   case Op_CmpD:
2999   case Op_CmpD3:
3000   case Op_StoreD:
3001   case Op_LoadD:
3002   case Op_LoadD_unaligned:
3003     frc.inc_double_count();
3004     break;
3005   case Op_Opaque1:              // Remove Opaque Nodes before matching
3006   case Op_Opaque2:              // Remove Opaque Nodes before matching
3007   case Op_Opaque3:
3008     n->subsume_by(n->in(1), this);
3009     break;
3010   case Op_CallStaticJava:
3011   case Op_CallJava:
3012   case Op_CallDynamicJava:
3013     frc.inc_java_call_count(); // Count java call site;
3014   case Op_CallRuntime:
3015   case Op_CallLeaf:
3016   case Op_CallNative:
3017   case Op_CallLeafNoFP: {
3018     assert (n->is_Call(), "");
3019     CallNode *call = n->as_Call();
3020     // Count call sites where the FP mode bit would have to be flipped.
3021     // Do not count uncommon runtime calls:
3022     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3023     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3024     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3025       frc.inc_call_count();   // Count the call site
3026     } else {                  // See if uncommon argument is shared
3027       Node *n = call->in(TypeFunc::Parms);
3028       int nop = n->Opcode();
3029       // Clone shared simple arguments to uncommon calls, item (1).
3030       if (n->outcnt() > 1 &&
3031           !n->is_Proj() &&
3032           nop != Op_CreateEx &&
3033           nop != Op_CheckCastPP &&
3034           nop != Op_DecodeN &&
3035           nop != Op_DecodeNKlass &&
3036           !n->is_Mem() &&
3037           !n->is_Phi()) {
3038         Node *x = n->clone();
3039         call->set_req(TypeFunc::Parms, x);
3040       }
3041     }
3042     break;
3043   }
3044 
3045   case Op_StoreCM:
3046     {
3047       // Convert OopStore dependence into precedence edge
3048       Node* prec = n->in(MemNode::OopStore);
3049       n->del_req(MemNode::OopStore);
3050       n->add_prec(prec);
3051       eliminate_redundant_card_marks(n);
3052     }
3053 
3054     // fall through
3055 
3056   case Op_StoreB:
3057   case Op_StoreC:
3058   case Op_StorePConditional:
3059   case Op_StoreI:
3060   case Op_StoreL:
3061   case Op_StoreIConditional:
3062   case Op_StoreLConditional:
3063   case Op_CompareAndSwapB:
3064   case Op_CompareAndSwapS:
3065   case Op_CompareAndSwapI:
3066   case Op_CompareAndSwapL:
3067   case Op_CompareAndSwapP:
3068   case Op_CompareAndSwapN:
3069   case Op_WeakCompareAndSwapB:
3070   case Op_WeakCompareAndSwapS:
3071   case Op_WeakCompareAndSwapI:
3072   case Op_WeakCompareAndSwapL:
3073   case Op_WeakCompareAndSwapP:
3074   case Op_WeakCompareAndSwapN:
3075   case Op_CompareAndExchangeB:
3076   case Op_CompareAndExchangeS:
3077   case Op_CompareAndExchangeI:
3078   case Op_CompareAndExchangeL:
3079   case Op_CompareAndExchangeP:
3080   case Op_CompareAndExchangeN:
3081   case Op_GetAndAddS:
3082   case Op_GetAndAddB:
3083   case Op_GetAndAddI:
3084   case Op_GetAndAddL:
3085   case Op_GetAndSetS:
3086   case Op_GetAndSetB:
3087   case Op_GetAndSetI:
3088   case Op_GetAndSetL:
3089   case Op_GetAndSetP:
3090   case Op_GetAndSetN:
3091   case Op_StoreP:
3092   case Op_StoreN:
3093   case Op_StoreNKlass:
3094   case Op_LoadB:
3095   case Op_LoadUB:
3096   case Op_LoadUS:
3097   case Op_LoadI:
3098   case Op_LoadKlass:
3099   case Op_LoadNKlass:
3100   case Op_LoadL:
3101   case Op_LoadL_unaligned:
3102   case Op_LoadPLocked:
3103   case Op_LoadP:
3104   case Op_LoadN:
3105   case Op_LoadRange:
3106   case Op_LoadS:
3107     break;
3108 
3109   case Op_AddP: {               // Assert sane base pointers
3110     Node *addp = n->in(AddPNode::Address);
3111     assert( !addp->is_AddP() ||
3112             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
3113             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
3114             "Base pointers must match (addp %u)", addp->_idx );
3115 #ifdef _LP64
3116     if ((UseCompressedOops || UseCompressedClassPointers) &&
3117         addp->Opcode() == Op_ConP &&
3118         addp == n->in(AddPNode::Base) &&
3119         n->in(AddPNode::Offset)->is_Con()) {
3120       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3121       // on the platform and on the compressed oops mode.
3122       // Use addressing with narrow klass to load with offset on x86.
3123       // Some platforms can use the constant pool to load ConP.
3124       // Do this transformation here since IGVN will convert ConN back to ConP.
3125       const Type* t = addp->bottom_type();
3126       bool is_oop   = t->isa_oopptr() != NULL;
3127       bool is_klass = t->isa_klassptr() != NULL;
3128 
3129       if ((is_oop   && Matcher::const_oop_prefer_decode()  ) ||
3130           (is_klass && Matcher::const_klass_prefer_decode())) {
3131         Node* nn = NULL;
3132 
3133         int op = is_oop ? Op_ConN : Op_ConNKlass;
3134 
3135         // Look for existing ConN node of the same exact type.
3136         Node* r  = root();
3137         uint cnt = r->outcnt();
3138         for (uint i = 0; i < cnt; i++) {
3139           Node* m = r->raw_out(i);
3140           if (m!= NULL && m->Opcode() == op &&
3141               m->bottom_type()->make_ptr() == t) {
3142             nn = m;
3143             break;
3144           }
3145         }
3146         if (nn != NULL) {
3147           // Decode a narrow oop to match address
3148           // [R12 + narrow_oop_reg<<3 + offset]
3149           if (is_oop) {
3150             nn = new DecodeNNode(nn, t);
3151           } else {
3152             nn = new DecodeNKlassNode(nn, t);
3153           }
3154           // Check for succeeding AddP which uses the same Base.
3155           // Otherwise we will run into the assertion above when visiting that guy.
3156           for (uint i = 0; i < n->outcnt(); ++i) {
3157             Node *out_i = n->raw_out(i);
3158             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3159               out_i->set_req(AddPNode::Base, nn);
3160 #ifdef ASSERT
3161               for (uint j = 0; j < out_i->outcnt(); ++j) {
3162                 Node *out_j = out_i->raw_out(j);
3163                 assert(out_j == NULL || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3164                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3165               }
3166 #endif
3167             }
3168           }
3169           n->set_req(AddPNode::Base, nn);
3170           n->set_req(AddPNode::Address, nn);
3171           if (addp->outcnt() == 0) {
3172             addp->disconnect_inputs(this);
3173           }
3174         }
3175       }
3176     }
3177 #endif
3178     // platform dependent reshaping of the address expression
3179     reshape_address(n->as_AddP());
3180     break;
3181   }
3182 
3183   case Op_CastPP: {
3184     // Remove CastPP nodes to gain more freedom during scheduling but
3185     // keep the dependency they encode as control or precedence edges
3186     // (if control is set already) on memory operations. Some CastPP
3187     // nodes don't have a control (don't carry a dependency): skip
3188     // those.
3189     if (n->in(0) != NULL) {
3190       ResourceMark rm;
3191       Unique_Node_List wq;
3192       wq.push(n);
3193       for (uint next = 0; next < wq.size(); ++next) {
3194         Node *m = wq.at(next);
3195         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3196           Node* use = m->fast_out(i);
3197           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3198             use->ensure_control_or_add_prec(n->in(0));
3199           } else {
3200             switch(use->Opcode()) {
3201             case Op_AddP:
3202             case Op_DecodeN:
3203             case Op_DecodeNKlass:
3204             case Op_CheckCastPP:
3205             case Op_CastPP:
3206               wq.push(use);
3207               break;
3208             }
3209           }
3210         }
3211       }
3212     }
3213     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3214     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3215       Node* in1 = n->in(1);
3216       const Type* t = n->bottom_type();
3217       Node* new_in1 = in1->clone();
3218       new_in1->as_DecodeN()->set_type(t);
3219 
3220       if (!Matcher::narrow_oop_use_complex_address()) {
3221         //
3222         // x86, ARM and friends can handle 2 adds in addressing mode
3223         // and Matcher can fold a DecodeN node into address by using
3224         // a narrow oop directly and do implicit NULL check in address:
3225         //
3226         // [R12 + narrow_oop_reg<<3 + offset]
3227         // NullCheck narrow_oop_reg
3228         //
3229         // On other platforms (Sparc) we have to keep new DecodeN node and
3230         // use it to do implicit NULL check in address:
3231         //
3232         // decode_not_null narrow_oop_reg, base_reg
3233         // [base_reg + offset]
3234         // NullCheck base_reg
3235         //
3236         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3237         // to keep the information to which NULL check the new DecodeN node
3238         // corresponds to use it as value in implicit_null_check().
3239         //
3240         new_in1->set_req(0, n->in(0));
3241       }
3242 
3243       n->subsume_by(new_in1, this);
3244       if (in1->outcnt() == 0) {
3245         in1->disconnect_inputs(this);
3246       }
3247     } else {
3248       n->subsume_by(n->in(1), this);
3249       if (n->outcnt() == 0) {
3250         n->disconnect_inputs(this);
3251       }
3252     }
3253     break;
3254   }
3255 #ifdef _LP64
3256   case Op_CmpP:
3257     // Do this transformation here to preserve CmpPNode::sub() and
3258     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3259     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3260       Node* in1 = n->in(1);
3261       Node* in2 = n->in(2);
3262       if (!in1->is_DecodeNarrowPtr()) {
3263         in2 = in1;
3264         in1 = n->in(2);
3265       }
3266       assert(in1->is_DecodeNarrowPtr(), "sanity");
3267 
3268       Node* new_in2 = NULL;
3269       if (in2->is_DecodeNarrowPtr()) {
3270         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3271         new_in2 = in2->in(1);
3272       } else if (in2->Opcode() == Op_ConP) {
3273         const Type* t = in2->bottom_type();
3274         if (t == TypePtr::NULL_PTR) {
3275           assert(in1->is_DecodeN(), "compare klass to null?");
3276           // Don't convert CmpP null check into CmpN if compressed
3277           // oops implicit null check is not generated.
3278           // This will allow to generate normal oop implicit null check.
3279           if (Matcher::gen_narrow_oop_implicit_null_checks())
3280             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3281           //
3282           // This transformation together with CastPP transformation above
3283           // will generated code for implicit NULL checks for compressed oops.
3284           //
3285           // The original code after Optimize()
3286           //
3287           //    LoadN memory, narrow_oop_reg
3288           //    decode narrow_oop_reg, base_reg
3289           //    CmpP base_reg, NULL
3290           //    CastPP base_reg // NotNull
3291           //    Load [base_reg + offset], val_reg
3292           //
3293           // after these transformations will be
3294           //
3295           //    LoadN memory, narrow_oop_reg
3296           //    CmpN narrow_oop_reg, NULL
3297           //    decode_not_null narrow_oop_reg, base_reg
3298           //    Load [base_reg + offset], val_reg
3299           //
3300           // and the uncommon path (== NULL) will use narrow_oop_reg directly
3301           // since narrow oops can be used in debug info now (see the code in
3302           // final_graph_reshaping_walk()).
3303           //
3304           // At the end the code will be matched to
3305           // on x86:
3306           //
3307           //    Load_narrow_oop memory, narrow_oop_reg
3308           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3309           //    NullCheck narrow_oop_reg
3310           //
3311           // and on sparc:
3312           //
3313           //    Load_narrow_oop memory, narrow_oop_reg
3314           //    decode_not_null narrow_oop_reg, base_reg
3315           //    Load [base_reg + offset], val_reg
3316           //    NullCheck base_reg
3317           //
3318         } else if (t->isa_oopptr()) {
3319           new_in2 = ConNode::make(t->make_narrowoop());
3320         } else if (t->isa_klassptr()) {
3321           new_in2 = ConNode::make(t->make_narrowklass());
3322         }
3323       }
3324       if (new_in2 != NULL) {
3325         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3326         n->subsume_by(cmpN, this);
3327         if (in1->outcnt() == 0) {
3328           in1->disconnect_inputs(this);
3329         }
3330         if (in2->outcnt() == 0) {
3331           in2->disconnect_inputs(this);
3332         }
3333       }
3334     }
3335     break;
3336 
3337   case Op_DecodeN:
3338   case Op_DecodeNKlass:
3339     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3340     // DecodeN could be pinned when it can't be fold into
3341     // an address expression, see the code for Op_CastPP above.
3342     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3343     break;
3344 
3345   case Op_EncodeP:
3346   case Op_EncodePKlass: {
3347     Node* in1 = n->in(1);
3348     if (in1->is_DecodeNarrowPtr()) {
3349       n->subsume_by(in1->in(1), this);
3350     } else if (in1->Opcode() == Op_ConP) {
3351       const Type* t = in1->bottom_type();
3352       if (t == TypePtr::NULL_PTR) {
3353         assert(t->isa_oopptr(), "null klass?");
3354         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3355       } else if (t->isa_oopptr()) {
3356         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3357       } else if (t->isa_klassptr()) {
3358         n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3359       }
3360     }
3361     if (in1->outcnt() == 0) {
3362       in1->disconnect_inputs(this);
3363     }
3364     break;
3365   }
3366 
3367   case Op_Proj: {
3368     if (OptimizeStringConcat || IncrementalInline) {
3369       ProjNode* proj = n->as_Proj();
3370       if (proj->_is_io_use) {
3371         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3372         // Separate projections were used for the exception path which
3373         // are normally removed by a late inline.  If it wasn't inlined
3374         // then they will hang around and should just be replaced with
3375         // the original one. Merge them.
3376         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3377         if (non_io_proj  != NULL) {
3378           proj->subsume_by(non_io_proj , this);
3379         }
3380       }
3381     }
3382     break;
3383   }
3384 
3385   case Op_Phi:
3386     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3387       // The EncodeP optimization may create Phi with the same edges
3388       // for all paths. It is not handled well by Register Allocator.
3389       Node* unique_in = n->in(1);
3390       assert(unique_in != NULL, "");
3391       uint cnt = n->req();
3392       for (uint i = 2; i < cnt; i++) {
3393         Node* m = n->in(i);
3394         assert(m != NULL, "");
3395         if (unique_in != m)
3396           unique_in = NULL;
3397       }
3398       if (unique_in != NULL) {
3399         n->subsume_by(unique_in, this);
3400       }
3401     }
3402     break;
3403 
3404 #endif
3405 
3406 #ifdef ASSERT
3407   case Op_CastII:
3408     // Verify that all range check dependent CastII nodes were removed.
3409     if (n->isa_CastII()->has_range_check()) {
3410       n->dump(3);
3411       assert(false, "Range check dependent CastII node was not removed");
3412     }
3413     break;
3414 #endif
3415 
3416   case Op_ModI:
3417     if (UseDivMod) {
3418       // Check if a%b and a/b both exist
3419       Node* d = n->find_similar(Op_DivI);
3420       if (d) {
3421         // Replace them with a fused divmod if supported
3422         if (Matcher::has_match_rule(Op_DivModI)) {
3423           DivModINode* divmod = DivModINode::make(n);
3424           d->subsume_by(divmod->div_proj(), this);
3425           n->subsume_by(divmod->mod_proj(), this);
3426         } else {
3427           // replace a%b with a-((a/b)*b)
3428           Node* mult = new MulINode(d, d->in(2));
3429           Node* sub  = new SubINode(d->in(1), mult);
3430           n->subsume_by(sub, this);
3431         }
3432       }
3433     }
3434     break;
3435 
3436   case Op_ModL:
3437     if (UseDivMod) {
3438       // Check if a%b and a/b both exist
3439       Node* d = n->find_similar(Op_DivL);
3440       if (d) {
3441         // Replace them with a fused divmod if supported
3442         if (Matcher::has_match_rule(Op_DivModL)) {
3443           DivModLNode* divmod = DivModLNode::make(n);
3444           d->subsume_by(divmod->div_proj(), this);
3445           n->subsume_by(divmod->mod_proj(), this);
3446         } else {
3447           // replace a%b with a-((a/b)*b)
3448           Node* mult = new MulLNode(d, d->in(2));
3449           Node* sub  = new SubLNode(d->in(1), mult);
3450           n->subsume_by(sub, this);
3451         }
3452       }
3453     }
3454     break;
3455 
3456   case Op_LoadVector:
3457   case Op_StoreVector:
3458   case Op_LoadVectorGather:
3459   case Op_StoreVectorScatter:
3460   case Op_VectorMaskGen:
3461   case Op_LoadVectorMasked:
3462   case Op_StoreVectorMasked:
3463     break;
3464 
3465   case Op_AddReductionVI:
3466   case Op_AddReductionVL:
3467   case Op_AddReductionVF:
3468   case Op_AddReductionVD:
3469   case Op_MulReductionVI:
3470   case Op_MulReductionVL:
3471   case Op_MulReductionVF:
3472   case Op_MulReductionVD:
3473   case Op_MinReductionV:
3474   case Op_MaxReductionV:
3475   case Op_AndReductionV:
3476   case Op_OrReductionV:
3477   case Op_XorReductionV:
3478     break;
3479 
3480   case Op_PackB:
3481   case Op_PackS:
3482   case Op_PackI:
3483   case Op_PackF:
3484   case Op_PackL:
3485   case Op_PackD:
3486     if (n->req()-1 > 2) {
3487       // Replace many operand PackNodes with a binary tree for matching
3488       PackNode* p = (PackNode*) n;
3489       Node* btp = p->binary_tree_pack(1, n->req());
3490       n->subsume_by(btp, this);
3491     }
3492     break;
3493   case Op_Loop:
3494     assert(!n->as_Loop()->is_transformed_long_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3495   case Op_CountedLoop:
3496   case Op_LongCountedLoop:
3497   case Op_OuterStripMinedLoop:
3498     if (n->as_Loop()->is_inner_loop()) {
3499       frc.inc_inner_loop_count();
3500     }
3501     n->as_Loop()->verify_strip_mined(0);
3502     break;
3503   case Op_LShiftI:
3504   case Op_RShiftI:
3505   case Op_URShiftI:
3506   case Op_LShiftL:
3507   case Op_RShiftL:
3508   case Op_URShiftL:
3509     if (Matcher::need_masked_shift_count) {
3510       // The cpu's shift instructions don't restrict the count to the
3511       // lower 5/6 bits. We need to do the masking ourselves.
3512       Node* in2 = n->in(2);
3513       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3514       const TypeInt* t = in2->find_int_type();
3515       if (t != NULL && t->is_con()) {
3516         juint shift = t->get_con();
3517         if (shift > mask) { // Unsigned cmp
3518           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3519         }
3520       } else {
3521         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
3522           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3523           n->set_req(2, shift);
3524         }
3525       }
3526       if (in2->outcnt() == 0) { // Remove dead node
3527         in2->disconnect_inputs(this);
3528       }
3529     }
3530     break;
3531   case Op_MemBarStoreStore:
3532   case Op_MemBarRelease:
3533     // Break the link with AllocateNode: it is no longer useful and
3534     // confuses register allocation.
3535     if (n->req() > MemBarNode::Precedent) {
3536       n->set_req(MemBarNode::Precedent, top());
3537     }
3538     break;
3539   case Op_MemBarAcquire: {
3540     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3541       // At parse time, the trailing MemBarAcquire for a volatile load
3542       // is created with an edge to the load. After optimizations,
3543       // that input may be a chain of Phis. If those phis have no
3544       // other use, then the MemBarAcquire keeps them alive and
3545       // register allocation can be confused.
3546       ResourceMark rm;
3547       Unique_Node_List wq;
3548       wq.push(n->in(MemBarNode::Precedent));
3549       n->set_req(MemBarNode::Precedent, top());
3550       while (wq.size() > 0) {
3551         Node* m = wq.pop();
3552         if (m->outcnt() == 0) {
3553           for (uint j = 0; j < m->req(); j++) {
3554             Node* in = m->in(j);
3555             if (in != NULL) {
3556               wq.push(in);
3557             }
3558           }
3559           m->disconnect_inputs(this);
3560         }
3561       }
3562     }
3563     break;
3564   }
3565   case Op_RangeCheck: {
3566     RangeCheckNode* rc = n->as_RangeCheck();
3567     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3568     n->subsume_by(iff, this);
3569     frc._tests.push(iff);
3570     break;
3571   }
3572   case Op_ConvI2L: {
3573     if (!Matcher::convi2l_type_required) {
3574       // Code generation on some platforms doesn't need accurate
3575       // ConvI2L types. Widening the type can help remove redundant
3576       // address computations.
3577       n->as_Type()->set_type(TypeLong::INT);
3578       ResourceMark rm;
3579       Unique_Node_List wq;
3580       wq.push(n);
3581       for (uint next = 0; next < wq.size(); next++) {
3582         Node *m = wq.at(next);
3583 
3584         for(;;) {
3585           // Loop over all nodes with identical inputs edges as m
3586           Node* k = m->find_similar(m->Opcode());
3587           if (k == NULL) {
3588             break;
3589           }
3590           // Push their uses so we get a chance to remove node made
3591           // redundant
3592           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3593             Node* u = k->fast_out(i);
3594             if (u->Opcode() == Op_LShiftL ||
3595                 u->Opcode() == Op_AddL ||
3596                 u->Opcode() == Op_SubL ||
3597                 u->Opcode() == Op_AddP) {
3598               wq.push(u);
3599             }
3600           }
3601           // Replace all nodes with identical edges as m with m
3602           k->subsume_by(m, this);
3603         }
3604       }
3605     }
3606     break;
3607   }
3608   case Op_CmpUL: {
3609     if (!Matcher::has_match_rule(Op_CmpUL)) {
3610       // No support for unsigned long comparisons
3611       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3612       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3613       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3614       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3615       Node* andl = new AndLNode(orl, remove_sign_mask);
3616       Node* cmp = new CmpLNode(andl, n->in(2));
3617       n->subsume_by(cmp, this);
3618     }
3619     break;
3620   }
3621   default:
3622     assert(!n->is_Call(), "");
3623     assert(!n->is_Mem(), "");
3624     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3625     break;
3626   }
3627 }
3628 
3629 //------------------------------final_graph_reshaping_walk---------------------
3630 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3631 // requires that the walk visits a node's inputs before visiting the node.
final_graph_reshaping_walk(Node_Stack & nstack,Node * root,Final_Reshape_Counts & frc)3632 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
3633   Unique_Node_List sfpt;
3634 
3635   frc._visited.set(root->_idx); // first, mark node as visited
3636   uint cnt = root->req();
3637   Node *n = root;
3638   uint  i = 0;
3639   while (true) {
3640     if (i < cnt) {
3641       // Place all non-visited non-null inputs onto stack
3642       Node* m = n->in(i);
3643       ++i;
3644       if (m != NULL && !frc._visited.test_set(m->_idx)) {
3645         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
3646           // compute worst case interpreter size in case of a deoptimization
3647           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3648 
3649           sfpt.push(m);
3650         }
3651         cnt = m->req();
3652         nstack.push(n, i); // put on stack parent and next input's index
3653         n = m;
3654         i = 0;
3655       }
3656     } else {
3657       // Now do post-visit work
3658       final_graph_reshaping_impl( n, frc );
3659       if (nstack.is_empty())
3660         break;             // finished
3661       n = nstack.node();   // Get node from stack
3662       cnt = n->req();
3663       i = nstack.index();
3664       nstack.pop();        // Shift to the next node on stack
3665     }
3666   }
3667 
3668   // Skip next transformation if compressed oops are not used.
3669   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
3670       (!UseCompressedOops && !UseCompressedClassPointers))
3671     return;
3672 
3673   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
3674   // It could be done for an uncommon traps or any safepoints/calls
3675   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
3676   while (sfpt.size() > 0) {
3677     n = sfpt.pop();
3678     JVMState *jvms = n->as_SafePoint()->jvms();
3679     assert(jvms != NULL, "sanity");
3680     int start = jvms->debug_start();
3681     int end   = n->req();
3682     bool is_uncommon = (n->is_CallStaticJava() &&
3683                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
3684     for (int j = start; j < end; j++) {
3685       Node* in = n->in(j);
3686       if (in->is_DecodeNarrowPtr()) {
3687         bool safe_to_skip = true;
3688         if (!is_uncommon ) {
3689           // Is it safe to skip?
3690           for (uint i = 0; i < in->outcnt(); i++) {
3691             Node* u = in->raw_out(i);
3692             if (!u->is_SafePoint() ||
3693                 (u->is_Call() && u->as_Call()->has_non_debug_use(n))) {
3694               safe_to_skip = false;
3695             }
3696           }
3697         }
3698         if (safe_to_skip) {
3699           n->set_req(j, in->in(1));
3700         }
3701         if (in->outcnt() == 0) {
3702           in->disconnect_inputs(this);
3703         }
3704       }
3705     }
3706   }
3707 }
3708 
3709 //------------------------------final_graph_reshaping--------------------------
3710 // Final Graph Reshaping.
3711 //
3712 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
3713 //     and not commoned up and forced early.  Must come after regular
3714 //     optimizations to avoid GVN undoing the cloning.  Clone constant
3715 //     inputs to Loop Phis; these will be split by the allocator anyways.
3716 //     Remove Opaque nodes.
3717 // (2) Move last-uses by commutative operations to the left input to encourage
3718 //     Intel update-in-place two-address operations and better register usage
3719 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
3720 //     calls canonicalizing them back.
3721 // (3) Count the number of double-precision FP ops, single-precision FP ops
3722 //     and call sites.  On Intel, we can get correct rounding either by
3723 //     forcing singles to memory (requires extra stores and loads after each
3724 //     FP bytecode) or we can set a rounding mode bit (requires setting and
3725 //     clearing the mode bit around call sites).  The mode bit is only used
3726 //     if the relative frequency of single FP ops to calls is low enough.
3727 //     This is a key transform for SPEC mpeg_audio.
3728 // (4) Detect infinite loops; blobs of code reachable from above but not
3729 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
3730 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
3731 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
3732 //     Detection is by looking for IfNodes where only 1 projection is
3733 //     reachable from below or CatchNodes missing some targets.
3734 // (5) Assert for insane oop offsets in debug mode.
3735 
final_graph_reshaping()3736 bool Compile::final_graph_reshaping() {
3737   // an infinite loop may have been eliminated by the optimizer,
3738   // in which case the graph will be empty.
3739   if (root()->req() == 1) {
3740     record_method_not_compilable("trivial infinite loop");
3741     return true;
3742   }
3743 
3744   // Expensive nodes have their control input set to prevent the GVN
3745   // from freely commoning them. There's no GVN beyond this point so
3746   // no need to keep the control input. We want the expensive nodes to
3747   // be freely moved to the least frequent code path by gcm.
3748   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
3749   for (int i = 0; i < expensive_count(); i++) {
3750     _expensive_nodes.at(i)->set_req(0, NULL);
3751   }
3752 
3753   Final_Reshape_Counts frc;
3754 
3755   // Visit everybody reachable!
3756   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
3757   Node_Stack nstack(live_nodes() >> 1);
3758   final_graph_reshaping_walk(nstack, root(), frc);
3759 
3760   // Check for unreachable (from below) code (i.e., infinite loops).
3761   for( uint i = 0; i < frc._tests.size(); i++ ) {
3762     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
3763     // Get number of CFG targets.
3764     // Note that PCTables include exception targets after calls.
3765     uint required_outcnt = n->required_outcnt();
3766     if (n->outcnt() != required_outcnt) {
3767       // Check for a few special cases.  Rethrow Nodes never take the
3768       // 'fall-thru' path, so expected kids is 1 less.
3769       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
3770         if (n->in(0)->in(0)->is_Call()) {
3771           CallNode *call = n->in(0)->in(0)->as_Call();
3772           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
3773             required_outcnt--;      // Rethrow always has 1 less kid
3774           } else if (call->req() > TypeFunc::Parms &&
3775                      call->is_CallDynamicJava()) {
3776             // Check for null receiver. In such case, the optimizer has
3777             // detected that the virtual call will always result in a null
3778             // pointer exception. The fall-through projection of this CatchNode
3779             // will not be populated.
3780             Node *arg0 = call->in(TypeFunc::Parms);
3781             if (arg0->is_Type() &&
3782                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
3783               required_outcnt--;
3784             }
3785           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
3786                      call->req() > TypeFunc::Parms+1 &&
3787                      call->is_CallStaticJava()) {
3788             // Check for negative array length. In such case, the optimizer has
3789             // detected that the allocation attempt will always result in an
3790             // exception. There is no fall-through projection of this CatchNode .
3791             Node *arg1 = call->in(TypeFunc::Parms+1);
3792             if (arg1->is_Type() &&
3793                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
3794               required_outcnt--;
3795             }
3796           }
3797         }
3798       }
3799       // Recheck with a better notion of 'required_outcnt'
3800       if (n->outcnt() != required_outcnt) {
3801         record_method_not_compilable("malformed control flow");
3802         return true;            // Not all targets reachable!
3803       }
3804     }
3805     // Check that I actually visited all kids.  Unreached kids
3806     // must be infinite loops.
3807     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
3808       if (!frc._visited.test(n->fast_out(j)->_idx)) {
3809         record_method_not_compilable("infinite loop");
3810         return true;            // Found unvisited kid; must be unreach
3811       }
3812 
3813     // Here so verification code in final_graph_reshaping_walk()
3814     // always see an OuterStripMinedLoopEnd
3815     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
3816       IfNode* init_iff = n->as_If();
3817       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
3818       n->subsume_by(iff, this);
3819     }
3820   }
3821 
3822 #ifdef IA32
3823   // If original bytecodes contained a mixture of floats and doubles
3824   // check if the optimizer has made it homogenous, item (3).
3825   if (UseSSE == 0 &&
3826       frc.get_float_count() > 32 &&
3827       frc.get_double_count() == 0 &&
3828       (10 * frc.get_call_count() < frc.get_float_count()) ) {
3829     set_24_bit_selection_and_mode(false, true);
3830   }
3831 #endif // IA32
3832 
3833   set_java_calls(frc.get_java_call_count());
3834   set_inner_loops(frc.get_inner_loop_count());
3835 
3836   // No infinite loops, no reason to bail out.
3837   return false;
3838 }
3839 
3840 //-----------------------------too_many_traps----------------------------------
3841 // Report if there are too many traps at the current method and bci.
3842 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
too_many_traps(ciMethod * method,int bci,Deoptimization::DeoptReason reason)3843 bool Compile::too_many_traps(ciMethod* method,
3844                              int bci,
3845                              Deoptimization::DeoptReason reason) {
3846   ciMethodData* md = method->method_data();
3847   if (md->is_empty()) {
3848     // Assume the trap has not occurred, or that it occurred only
3849     // because of a transient condition during start-up in the interpreter.
3850     return false;
3851   }
3852   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3853   if (md->has_trap_at(bci, m, reason) != 0) {
3854     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
3855     // Also, if there are multiple reasons, or if there is no per-BCI record,
3856     // assume the worst.
3857     if (log())
3858       log()->elem("observe trap='%s' count='%d'",
3859                   Deoptimization::trap_reason_name(reason),
3860                   md->trap_count(reason));
3861     return true;
3862   } else {
3863     // Ignore method/bci and see if there have been too many globally.
3864     return too_many_traps(reason, md);
3865   }
3866 }
3867 
3868 // Less-accurate variant which does not require a method and bci.
too_many_traps(Deoptimization::DeoptReason reason,ciMethodData * logmd)3869 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
3870                              ciMethodData* logmd) {
3871   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
3872     // Too many traps globally.
3873     // Note that we use cumulative trap_count, not just md->trap_count.
3874     if (log()) {
3875       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
3876       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
3877                   Deoptimization::trap_reason_name(reason),
3878                   mcount, trap_count(reason));
3879     }
3880     return true;
3881   } else {
3882     // The coast is clear.
3883     return false;
3884   }
3885 }
3886 
3887 //--------------------------too_many_recompiles--------------------------------
3888 // Report if there are too many recompiles at the current method and bci.
3889 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
3890 // Is not eager to return true, since this will cause the compiler to use
3891 // Action_none for a trap point, to avoid too many recompilations.
too_many_recompiles(ciMethod * method,int bci,Deoptimization::DeoptReason reason)3892 bool Compile::too_many_recompiles(ciMethod* method,
3893                                   int bci,
3894                                   Deoptimization::DeoptReason reason) {
3895   ciMethodData* md = method->method_data();
3896   if (md->is_empty()) {
3897     // Assume the trap has not occurred, or that it occurred only
3898     // because of a transient condition during start-up in the interpreter.
3899     return false;
3900   }
3901   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
3902   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
3903   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
3904   Deoptimization::DeoptReason per_bc_reason
3905     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
3906   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
3907   if ((per_bc_reason == Deoptimization::Reason_none
3908        || md->has_trap_at(bci, m, reason) != 0)
3909       // The trap frequency measure we care about is the recompile count:
3910       && md->trap_recompiled_at(bci, m)
3911       && md->overflow_recompile_count() >= bc_cutoff) {
3912     // Do not emit a trap here if it has already caused recompilations.
3913     // Also, if there are multiple reasons, or if there is no per-BCI record,
3914     // assume the worst.
3915     if (log())
3916       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
3917                   Deoptimization::trap_reason_name(reason),
3918                   md->trap_count(reason),
3919                   md->overflow_recompile_count());
3920     return true;
3921   } else if (trap_count(reason) != 0
3922              && decompile_count() >= m_cutoff) {
3923     // Too many recompiles globally, and we have seen this sort of trap.
3924     // Use cumulative decompile_count, not just md->decompile_count.
3925     if (log())
3926       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
3927                   Deoptimization::trap_reason_name(reason),
3928                   md->trap_count(reason), trap_count(reason),
3929                   md->decompile_count(), decompile_count());
3930     return true;
3931   } else {
3932     // The coast is clear.
3933     return false;
3934   }
3935 }
3936 
3937 // Compute when not to trap. Used by matching trap based nodes and
3938 // NullCheck optimization.
set_allowed_deopt_reasons()3939 void Compile::set_allowed_deopt_reasons() {
3940   _allowed_reasons = 0;
3941   if (is_method_compilation()) {
3942     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
3943       assert(rs < BitsPerInt, "recode bit map");
3944       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
3945         _allowed_reasons |= nth_bit(rs);
3946       }
3947     }
3948   }
3949 }
3950 
needs_clinit_barrier(ciMethod * method,ciMethod * accessing_method)3951 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
3952   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
3953 }
3954 
needs_clinit_barrier(ciField * field,ciMethod * accessing_method)3955 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
3956   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
3957 }
3958 
needs_clinit_barrier(ciInstanceKlass * holder,ciMethod * accessing_method)3959 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
3960   if (holder->is_initialized()) {
3961     return false;
3962   }
3963   if (holder->is_being_initialized()) {
3964     if (accessing_method->holder() == holder) {
3965       // Access inside a class. The barrier can be elided when access happens in <clinit>,
3966       // <init>, or a static method. In all those cases, there was an initialization
3967       // barrier on the holder klass passed.
3968       if (accessing_method->is_static_initializer() ||
3969           accessing_method->is_object_initializer() ||
3970           accessing_method->is_static()) {
3971         return false;
3972       }
3973     } else if (accessing_method->holder()->is_subclass_of(holder)) {
3974       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
3975       // In case of <init> or a static method, the barrier is on the subclass is not enough:
3976       // child class can become fully initialized while its parent class is still being initialized.
3977       if (accessing_method->is_static_initializer()) {
3978         return false;
3979       }
3980     }
3981     ciMethod* root = method(); // the root method of compilation
3982     if (root != accessing_method) {
3983       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
3984     }
3985   }
3986   return true;
3987 }
3988 
3989 #ifndef PRODUCT
3990 //------------------------------verify_graph_edges---------------------------
3991 // Walk the Graph and verify that there is a one-to-one correspondence
3992 // between Use-Def edges and Def-Use edges in the graph.
verify_graph_edges(bool no_dead_code)3993 void Compile::verify_graph_edges(bool no_dead_code) {
3994   if (VerifyGraphEdges) {
3995     Unique_Node_List visited;
3996     // Call recursive graph walk to check edges
3997     _root->verify_edges(visited);
3998     if (no_dead_code) {
3999       // Now make sure that no visited node is used by an unvisited node.
4000       bool dead_nodes = false;
4001       Unique_Node_List checked;
4002       while (visited.size() > 0) {
4003         Node* n = visited.pop();
4004         checked.push(n);
4005         for (uint i = 0; i < n->outcnt(); i++) {
4006           Node* use = n->raw_out(i);
4007           if (checked.member(use))  continue;  // already checked
4008           if (visited.member(use))  continue;  // already in the graph
4009           if (use->is_Con())        continue;  // a dead ConNode is OK
4010           // At this point, we have found a dead node which is DU-reachable.
4011           if (!dead_nodes) {
4012             tty->print_cr("*** Dead nodes reachable via DU edges:");
4013             dead_nodes = true;
4014           }
4015           use->dump(2);
4016           tty->print_cr("---");
4017           checked.push(use);  // No repeats; pretend it is now checked.
4018         }
4019       }
4020       assert(!dead_nodes, "using nodes must be reachable from root");
4021     }
4022   }
4023 }
4024 #endif
4025 
4026 // The Compile object keeps track of failure reasons separately from the ciEnv.
4027 // This is required because there is not quite a 1-1 relation between the
4028 // ciEnv and its compilation task and the Compile object.  Note that one
4029 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4030 // to backtrack and retry without subsuming loads.  Other than this backtracking
4031 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4032 // by the logic in C2Compiler.
record_failure(const char * reason)4033 void Compile::record_failure(const char* reason) {
4034   if (log() != NULL) {
4035     log()->elem("failure reason='%s' phase='compile'", reason);
4036   }
4037   if (_failure_reason == NULL) {
4038     // Record the first failure reason.
4039     _failure_reason = reason;
4040   }
4041 
4042   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4043     C->print_method(PHASE_FAILURE);
4044   }
4045   _root = NULL;  // flush the graph, too
4046 }
4047 
TracePhase(const char * name,elapsedTimer * accumulator)4048 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator)
4049   : TraceTime(name, accumulator, CITime, CITimeVerbose),
4050     _phase_name(name), _dolog(CITimeVerbose)
4051 {
4052   if (_dolog) {
4053     C = Compile::current();
4054     _log = C->log();
4055   } else {
4056     C = NULL;
4057     _log = NULL;
4058   }
4059   if (_log != NULL) {
4060     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4061     _log->stamp();
4062     _log->end_head();
4063   }
4064 }
4065 
~TracePhase()4066 Compile::TracePhase::~TracePhase() {
4067 
4068   C = Compile::current();
4069   if (_dolog) {
4070     _log = C->log();
4071   } else {
4072     _log = NULL;
4073   }
4074 
4075 #ifdef ASSERT
4076   if (PrintIdealNodeCount) {
4077     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4078                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
4079   }
4080 
4081   if (VerifyIdealNodeCount) {
4082     Compile::current()->print_missing_nodes();
4083   }
4084 #endif
4085 
4086   if (_log != NULL) {
4087     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
4088   }
4089 }
4090 
4091 //----------------------------static_subtype_check-----------------------------
4092 // Shortcut important common cases when superklass is exact:
4093 // (0) superklass is java.lang.Object (can occur in reflective code)
4094 // (1) subklass is already limited to a subtype of superklass => always ok
4095 // (2) subklass does not overlap with superklass => always fail
4096 // (3) superklass has NO subtypes and we can check with a simple compare.
static_subtype_check(ciKlass * superk,ciKlass * subk)4097 int Compile::static_subtype_check(ciKlass* superk, ciKlass* subk) {
4098   if (StressReflectiveCode) {
4099     return SSC_full_test;       // Let caller generate the general case.
4100   }
4101 
4102   if (superk == env()->Object_klass()) {
4103     return SSC_always_true;     // (0) this test cannot fail
4104   }
4105 
4106   ciType* superelem = superk;
4107   if (superelem->is_array_klass())
4108     superelem = superelem->as_array_klass()->base_element_type();
4109 
4110   if (!subk->is_interface()) {  // cannot trust static interface types yet
4111     if (subk->is_subtype_of(superk)) {
4112       return SSC_always_true;   // (1) false path dead; no dynamic test needed
4113     }
4114     if (!(superelem->is_klass() && superelem->as_klass()->is_interface()) &&
4115         !superk->is_subtype_of(subk)) {
4116       return SSC_always_false;
4117     }
4118   }
4119 
4120   // If casting to an instance klass, it must have no subtypes
4121   if (superk->is_interface()) {
4122     // Cannot trust interfaces yet.
4123     // %%% S.B. superk->nof_implementors() == 1
4124   } else if (superelem->is_instance_klass()) {
4125     ciInstanceKlass* ik = superelem->as_instance_klass();
4126     if (!ik->has_subklass() && !ik->is_interface()) {
4127       if (!ik->is_final()) {
4128         // Add a dependency if there is a chance of a later subclass.
4129         dependencies()->assert_leaf_type(ik);
4130       }
4131       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4132     }
4133   } else {
4134     // A primitive array type has no subtypes.
4135     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4136   }
4137 
4138   return SSC_full_test;
4139 }
4140 
conv_I2X_index(PhaseGVN * phase,Node * idx,const TypeInt * sizetype,Node * ctrl)4141 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4142 #ifdef _LP64
4143   // The scaled index operand to AddP must be a clean 64-bit value.
4144   // Java allows a 32-bit int to be incremented to a negative
4145   // value, which appears in a 64-bit register as a large
4146   // positive number.  Using that large positive number as an
4147   // operand in pointer arithmetic has bad consequences.
4148   // On the other hand, 32-bit overflow is rare, and the possibility
4149   // can often be excluded, if we annotate the ConvI2L node with
4150   // a type assertion that its value is known to be a small positive
4151   // number.  (The prior range check has ensured this.)
4152   // This assertion is used by ConvI2LNode::Ideal.
4153   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4154   if (sizetype != NULL) index_max = sizetype->_hi - 1;
4155   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4156   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4157 #endif
4158   return idx;
4159 }
4160 
4161 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
constrained_convI2L(PhaseGVN * phase,Node * value,const TypeInt * itype,Node * ctrl)4162 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
4163   if (ctrl != NULL) {
4164     // Express control dependency by a CastII node with a narrow type.
4165     value = new CastIINode(value, itype, false, true /* range check dependency */);
4166     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4167     // node from floating above the range check during loop optimizations. Otherwise, the
4168     // ConvI2L node may be eliminated independently of the range check, causing the data path
4169     // to become TOP while the control path is still there (although it's unreachable).
4170     value->set_req(0, ctrl);
4171     value = phase->transform(value);
4172   }
4173   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4174   return phase->transform(new ConvI2LNode(value, ltype));
4175 }
4176 
print_inlining_stream_free()4177 void Compile::print_inlining_stream_free() {
4178   if (_print_inlining_stream != NULL) {
4179     _print_inlining_stream->~stringStream();
4180     _print_inlining_stream = NULL;
4181   }
4182 }
4183 
4184 // The message about the current inlining is accumulated in
4185 // _print_inlining_stream and transfered into the _print_inlining_list
4186 // once we know whether inlining succeeds or not. For regular
4187 // inlining, messages are appended to the buffer pointed by
4188 // _print_inlining_idx in the _print_inlining_list. For late inlining,
4189 // a new buffer is added after _print_inlining_idx in the list. This
4190 // way we can update the inlining message for late inlining call site
4191 // when the inlining is attempted again.
print_inlining_init()4192 void Compile::print_inlining_init() {
4193   if (print_inlining() || print_intrinsics()) {
4194     // print_inlining_init is actually called several times.
4195     print_inlining_stream_free();
4196     _print_inlining_stream = new stringStream();
4197     // Watch out: The memory initialized by the constructor call PrintInliningBuffer()
4198     // will be copied into the only initial element. The default destructor of
4199     // PrintInliningBuffer will be called when leaving the scope here. If it
4200     // would destuct the  enclosed stringStream _print_inlining_list[0]->_ss
4201     // would be destructed, too!
4202     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
4203   }
4204 }
4205 
print_inlining_reinit()4206 void Compile::print_inlining_reinit() {
4207   if (print_inlining() || print_intrinsics()) {
4208     print_inlining_stream_free();
4209     // Re allocate buffer when we change ResourceMark
4210     _print_inlining_stream = new stringStream();
4211   }
4212 }
4213 
print_inlining_reset()4214 void Compile::print_inlining_reset() {
4215   _print_inlining_stream->reset();
4216 }
4217 
print_inlining_commit()4218 void Compile::print_inlining_commit() {
4219   assert(print_inlining() || print_intrinsics(), "PrintInlining off?");
4220   // Transfer the message from _print_inlining_stream to the current
4221   // _print_inlining_list buffer and clear _print_inlining_stream.
4222   _print_inlining_list->at(_print_inlining_idx).ss()->write(_print_inlining_stream->base(), _print_inlining_stream->size());
4223   print_inlining_reset();
4224 }
4225 
print_inlining_push()4226 void Compile::print_inlining_push() {
4227   // Add new buffer to the _print_inlining_list at current position
4228   _print_inlining_idx++;
4229   _print_inlining_list->insert_before(_print_inlining_idx, PrintInliningBuffer());
4230 }
4231 
print_inlining_current()4232 Compile::PrintInliningBuffer& Compile::print_inlining_current() {
4233   return _print_inlining_list->at(_print_inlining_idx);
4234 }
4235 
print_inlining_update(CallGenerator * cg)4236 void Compile::print_inlining_update(CallGenerator* cg) {
4237   if (print_inlining() || print_intrinsics()) {
4238     if (cg->is_late_inline()) {
4239       if (print_inlining_current().cg() != cg &&
4240           (print_inlining_current().cg() != NULL ||
4241            print_inlining_current().ss()->size() != 0)) {
4242         print_inlining_push();
4243       }
4244       print_inlining_commit();
4245       print_inlining_current().set_cg(cg);
4246     } else {
4247       if (print_inlining_current().cg() != NULL) {
4248         print_inlining_push();
4249       }
4250       print_inlining_commit();
4251     }
4252   }
4253 }
4254 
print_inlining_move_to(CallGenerator * cg)4255 void Compile::print_inlining_move_to(CallGenerator* cg) {
4256   // We resume inlining at a late inlining call site. Locate the
4257   // corresponding inlining buffer so that we can update it.
4258   if (print_inlining() || print_intrinsics()) {
4259     for (int i = 0; i < _print_inlining_list->length(); i++) {
4260       if (_print_inlining_list->adr_at(i)->cg() == cg) {
4261         _print_inlining_idx = i;
4262         return;
4263       }
4264     }
4265     ShouldNotReachHere();
4266   }
4267 }
4268 
print_inlining_update_delayed(CallGenerator * cg)4269 void Compile::print_inlining_update_delayed(CallGenerator* cg) {
4270   if (print_inlining() || print_intrinsics()) {
4271     assert(_print_inlining_stream->size() > 0, "missing inlining msg");
4272     assert(print_inlining_current().cg() == cg, "wrong entry");
4273     // replace message with new message
4274     _print_inlining_list->at_put(_print_inlining_idx, PrintInliningBuffer());
4275     print_inlining_commit();
4276     print_inlining_current().set_cg(cg);
4277   }
4278 }
4279 
print_inlining_assert_ready()4280 void Compile::print_inlining_assert_ready() {
4281   assert(!_print_inlining || _print_inlining_stream->size() == 0, "loosing data");
4282 }
4283 
process_print_inlining()4284 void Compile::process_print_inlining() {
4285   assert(_late_inlines.length() == 0, "not drained yet");
4286   if (print_inlining() || print_intrinsics()) {
4287     ResourceMark rm;
4288     stringStream ss;
4289     assert(_print_inlining_list != NULL, "process_print_inlining should be called only once.");
4290     for (int i = 0; i < _print_inlining_list->length(); i++) {
4291       ss.print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
4292       _print_inlining_list->at(i).freeStream();
4293     }
4294     // Reset _print_inlining_list, it only contains destructed objects.
4295     // It is on the arena, so it will be freed when the arena is reset.
4296     _print_inlining_list = NULL;
4297     // _print_inlining_stream won't be used anymore, either.
4298     print_inlining_stream_free();
4299     size_t end = ss.size();
4300     _print_inlining_output = NEW_ARENA_ARRAY(comp_arena(), char, end+1);
4301     strncpy(_print_inlining_output, ss.base(), end+1);
4302     _print_inlining_output[end] = 0;
4303   }
4304 }
4305 
dump_print_inlining()4306 void Compile::dump_print_inlining() {
4307   if (_print_inlining_output != NULL) {
4308     tty->print_raw(_print_inlining_output);
4309   }
4310 }
4311 
log_late_inline(CallGenerator * cg)4312 void Compile::log_late_inline(CallGenerator* cg) {
4313   if (log() != NULL) {
4314     log()->head("late_inline method='%d'  inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4315                 cg->unique_id());
4316     JVMState* p = cg->call_node()->jvms();
4317     while (p != NULL) {
4318       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4319       p = p->caller();
4320     }
4321     log()->tail("late_inline");
4322   }
4323 }
4324 
log_late_inline_failure(CallGenerator * cg,const char * msg)4325 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4326   log_late_inline(cg);
4327   if (log() != NULL) {
4328     log()->inline_fail(msg);
4329   }
4330 }
4331 
log_inline_id(CallGenerator * cg)4332 void Compile::log_inline_id(CallGenerator* cg) {
4333   if (log() != NULL) {
4334     // The LogCompilation tool needs a unique way to identify late
4335     // inline call sites. This id must be unique for this call site in
4336     // this compilation. Try to have it unique across compilations as
4337     // well because it can be convenient when grepping through the log
4338     // file.
4339     // Distinguish OSR compilations from others in case CICountOSR is
4340     // on.
4341     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4342     cg->set_unique_id(id);
4343     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4344   }
4345 }
4346 
log_inline_failure(const char * msg)4347 void Compile::log_inline_failure(const char* msg) {
4348   if (C->log() != NULL) {
4349     C->log()->inline_fail(msg);
4350   }
4351 }
4352 
4353 
4354 // Dump inlining replay data to the stream.
4355 // Don't change thread state and acquire any locks.
dump_inline_data(outputStream * out)4356 void Compile::dump_inline_data(outputStream* out) {
4357   InlineTree* inl_tree = ilt();
4358   if (inl_tree != NULL) {
4359     out->print(" inline %d", inl_tree->count());
4360     inl_tree->dump_replay_data(out);
4361   }
4362 }
4363 
cmp_expensive_nodes(Node * n1,Node * n2)4364 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4365   if (n1->Opcode() < n2->Opcode())      return -1;
4366   else if (n1->Opcode() > n2->Opcode()) return 1;
4367 
4368   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4369   for (uint i = 1; i < n1->req(); i++) {
4370     if (n1->in(i) < n2->in(i))      return -1;
4371     else if (n1->in(i) > n2->in(i)) return 1;
4372   }
4373 
4374   return 0;
4375 }
4376 
cmp_expensive_nodes(Node ** n1p,Node ** n2p)4377 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4378   Node* n1 = *n1p;
4379   Node* n2 = *n2p;
4380 
4381   return cmp_expensive_nodes(n1, n2);
4382 }
4383 
sort_expensive_nodes()4384 void Compile::sort_expensive_nodes() {
4385   if (!expensive_nodes_sorted()) {
4386     _expensive_nodes.sort(cmp_expensive_nodes);
4387   }
4388 }
4389 
expensive_nodes_sorted() const4390 bool Compile::expensive_nodes_sorted() const {
4391   for (int i = 1; i < _expensive_nodes.length(); i++) {
4392     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4393       return false;
4394     }
4395   }
4396   return true;
4397 }
4398 
should_optimize_expensive_nodes(PhaseIterGVN & igvn)4399 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4400   if (_expensive_nodes.length() == 0) {
4401     return false;
4402   }
4403 
4404   assert(OptimizeExpensiveOps, "optimization off?");
4405 
4406   // Take this opportunity to remove dead nodes from the list
4407   int j = 0;
4408   for (int i = 0; i < _expensive_nodes.length(); i++) {
4409     Node* n = _expensive_nodes.at(i);
4410     if (!n->is_unreachable(igvn)) {
4411       assert(n->is_expensive(), "should be expensive");
4412       _expensive_nodes.at_put(j, n);
4413       j++;
4414     }
4415   }
4416   _expensive_nodes.trunc_to(j);
4417 
4418   // Then sort the list so that similar nodes are next to each other
4419   // and check for at least two nodes of identical kind with same data
4420   // inputs.
4421   sort_expensive_nodes();
4422 
4423   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4424     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4425       return true;
4426     }
4427   }
4428 
4429   return false;
4430 }
4431 
cleanup_expensive_nodes(PhaseIterGVN & igvn)4432 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4433   if (_expensive_nodes.length() == 0) {
4434     return;
4435   }
4436 
4437   assert(OptimizeExpensiveOps, "optimization off?");
4438 
4439   // Sort to bring similar nodes next to each other and clear the
4440   // control input of nodes for which there's only a single copy.
4441   sort_expensive_nodes();
4442 
4443   int j = 0;
4444   int identical = 0;
4445   int i = 0;
4446   bool modified = false;
4447   for (; i < _expensive_nodes.length()-1; i++) {
4448     assert(j <= i, "can't write beyond current index");
4449     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4450       identical++;
4451       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4452       continue;
4453     }
4454     if (identical > 0) {
4455       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4456       identical = 0;
4457     } else {
4458       Node* n = _expensive_nodes.at(i);
4459       igvn.replace_input_of(n, 0, NULL);
4460       igvn.hash_insert(n);
4461       modified = true;
4462     }
4463   }
4464   if (identical > 0) {
4465     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4466   } else if (_expensive_nodes.length() >= 1) {
4467     Node* n = _expensive_nodes.at(i);
4468     igvn.replace_input_of(n, 0, NULL);
4469     igvn.hash_insert(n);
4470     modified = true;
4471   }
4472   _expensive_nodes.trunc_to(j);
4473   if (modified) {
4474     igvn.optimize();
4475   }
4476 }
4477 
add_expensive_node(Node * n)4478 void Compile::add_expensive_node(Node * n) {
4479   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4480   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4481   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4482   if (OptimizeExpensiveOps) {
4483     _expensive_nodes.append(n);
4484   } else {
4485     // Clear control input and let IGVN optimize expensive nodes if
4486     // OptimizeExpensiveOps is off.
4487     n->set_req(0, NULL);
4488   }
4489 }
4490 
4491 /**
4492  * Remove the speculative part of types and clean up the graph
4493  */
remove_speculative_types(PhaseIterGVN & igvn)4494 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4495   if (UseTypeSpeculation) {
4496     Unique_Node_List worklist;
4497     worklist.push(root());
4498     int modified = 0;
4499     // Go over all type nodes that carry a speculative type, drop the
4500     // speculative part of the type and enqueue the node for an igvn
4501     // which may optimize it out.
4502     for (uint next = 0; next < worklist.size(); ++next) {
4503       Node *n  = worklist.at(next);
4504       if (n->is_Type()) {
4505         TypeNode* tn = n->as_Type();
4506         const Type* t = tn->type();
4507         const Type* t_no_spec = t->remove_speculative();
4508         if (t_no_spec != t) {
4509           bool in_hash = igvn.hash_delete(n);
4510           assert(in_hash, "node should be in igvn hash table");
4511           tn->set_type(t_no_spec);
4512           igvn.hash_insert(n);
4513           igvn._worklist.push(n); // give it a chance to go away
4514           modified++;
4515         }
4516       }
4517       uint max = n->len();
4518       for( uint i = 0; i < max; ++i ) {
4519         Node *m = n->in(i);
4520         if (not_a_node(m))  continue;
4521         worklist.push(m);
4522       }
4523     }
4524     // Drop the speculative part of all types in the igvn's type table
4525     igvn.remove_speculative_types();
4526     if (modified > 0) {
4527       igvn.optimize();
4528     }
4529 #ifdef ASSERT
4530     // Verify that after the IGVN is over no speculative type has resurfaced
4531     worklist.clear();
4532     worklist.push(root());
4533     for (uint next = 0; next < worklist.size(); ++next) {
4534       Node *n  = worklist.at(next);
4535       const Type* t = igvn.type_or_null(n);
4536       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
4537       if (n->is_Type()) {
4538         t = n->as_Type()->type();
4539         assert(t == t->remove_speculative(), "no more speculative types");
4540       }
4541       uint max = n->len();
4542       for( uint i = 0; i < max; ++i ) {
4543         Node *m = n->in(i);
4544         if (not_a_node(m))  continue;
4545         worklist.push(m);
4546       }
4547     }
4548     igvn.check_no_speculative_types();
4549 #endif
4550   }
4551 }
4552 
4553 // Auxiliary methods to support randomized stressing/fuzzing.
4554 
random()4555 int Compile::random() {
4556   _stress_seed = os::next_random(_stress_seed);
4557   return static_cast<int>(_stress_seed);
4558 }
4559 
4560 // This method can be called the arbitrary number of times, with current count
4561 // as the argument. The logic allows selecting a single candidate from the
4562 // running list of candidates as follows:
4563 //    int count = 0;
4564 //    Cand* selected = null;
4565 //    while(cand = cand->next()) {
4566 //      if (randomized_select(++count)) {
4567 //        selected = cand;
4568 //      }
4569 //    }
4570 //
4571 // Including count equalizes the chances any candidate is "selected".
4572 // This is useful when we don't have the complete list of candidates to choose
4573 // from uniformly. In this case, we need to adjust the randomicity of the
4574 // selection, or else we will end up biasing the selection towards the latter
4575 // candidates.
4576 //
4577 // Quick back-envelope calculation shows that for the list of n candidates
4578 // the equal probability for the candidate to persist as "best" can be
4579 // achieved by replacing it with "next" k-th candidate with the probability
4580 // of 1/k. It can be easily shown that by the end of the run, the
4581 // probability for any candidate is converged to 1/n, thus giving the
4582 // uniform distribution among all the candidates.
4583 //
4584 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
4585 #define RANDOMIZED_DOMAIN_POW 29
4586 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
4587 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
randomized_select(int count)4588 bool Compile::randomized_select(int count) {
4589   assert(count > 0, "only positive");
4590   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
4591 }
4592 
clone_map()4593 CloneMap&     Compile::clone_map()                 { return _clone_map; }
set_clone_map(Dict * d)4594 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
4595 
dump() const4596 void NodeCloneInfo::dump() const {
4597   tty->print(" {%d:%d} ", idx(), gen());
4598 }
4599 
clone(Node * old,Node * nnn,int gen)4600 void CloneMap::clone(Node* old, Node* nnn, int gen) {
4601   uint64_t val = value(old->_idx);
4602   NodeCloneInfo cio(val);
4603   assert(val != 0, "old node should be in the map");
4604   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
4605   insert(nnn->_idx, cin.get());
4606 #ifndef PRODUCT
4607   if (is_debug()) {
4608     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
4609   }
4610 #endif
4611 }
4612 
verify_insert_and_clone(Node * old,Node * nnn,int gen)4613 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
4614   NodeCloneInfo cio(value(old->_idx));
4615   if (cio.get() == 0) {
4616     cio.set(old->_idx, 0);
4617     insert(old->_idx, cio.get());
4618 #ifndef PRODUCT
4619     if (is_debug()) {
4620       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
4621     }
4622 #endif
4623   }
4624   clone(old, nnn, gen);
4625 }
4626 
max_gen() const4627 int CloneMap::max_gen() const {
4628   int g = 0;
4629   DictI di(_dict);
4630   for(; di.test(); ++di) {
4631     int t = gen(di._key);
4632     if (g < t) {
4633       g = t;
4634 #ifndef PRODUCT
4635       if (is_debug()) {
4636         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
4637       }
4638 #endif
4639     }
4640   }
4641   return g;
4642 }
4643 
dump(node_idx_t key) const4644 void CloneMap::dump(node_idx_t key) const {
4645   uint64_t val = value(key);
4646   if (val != 0) {
4647     NodeCloneInfo ni(val);
4648     ni.dump();
4649   }
4650 }
4651 
4652 // Move Allocate nodes to the start of the list
sort_macro_nodes()4653 void Compile::sort_macro_nodes() {
4654   int count = macro_count();
4655   int allocates = 0;
4656   for (int i = 0; i < count; i++) {
4657     Node* n = macro_node(i);
4658     if (n->is_Allocate()) {
4659       if (i != allocates) {
4660         Node* tmp = macro_node(allocates);
4661         _macro_nodes.at_put(allocates, n);
4662         _macro_nodes.at_put(i, tmp);
4663       }
4664       allocates++;
4665     }
4666   }
4667 }
4668 
print_method(CompilerPhaseType cpt,const char * name,int level,int idx)4669 void Compile::print_method(CompilerPhaseType cpt, const char *name, int level, int idx) {
4670   EventCompilerPhase event;
4671   if (event.should_commit()) {
4672     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, cpt, C->_compile_id, level);
4673   }
4674 #ifndef PRODUCT
4675   if (should_print(level)) {
4676     _printer->print_method(name, level);
4677   }
4678 #endif
4679   C->_latest_stage_start_counter.stamp();
4680 }
4681 
print_method(CompilerPhaseType cpt,int level,int idx)4682 void Compile::print_method(CompilerPhaseType cpt, int level, int idx) {
4683   char output[1024];
4684 #ifndef PRODUCT
4685   if (idx != 0) {
4686     jio_snprintf(output, sizeof(output), "%s:%d", CompilerPhaseTypeHelper::to_string(cpt), idx);
4687   } else {
4688     jio_snprintf(output, sizeof(output), "%s", CompilerPhaseTypeHelper::to_string(cpt));
4689   }
4690 #endif
4691   print_method(cpt, output, level, idx);
4692 }
4693 
print_method(CompilerPhaseType cpt,Node * n,int level)4694 void Compile::print_method(CompilerPhaseType cpt, Node* n, int level) {
4695   ResourceMark rm;
4696   stringStream ss;
4697   ss.print_raw(CompilerPhaseTypeHelper::to_string(cpt));
4698   if (n != NULL) {
4699     ss.print(": %d %s ", n->_idx, NodeClassNames[n->Opcode()]);
4700   } else {
4701     ss.print_raw(": NULL");
4702   }
4703   C->print_method(cpt, ss.as_string(), level);
4704 }
4705 
end_method(int level)4706 void Compile::end_method(int level) {
4707   EventCompilerPhase event;
4708   if (event.should_commit()) {
4709     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, level);
4710   }
4711 
4712 #ifndef PRODUCT
4713   if (_method != NULL && should_print(level)) {
4714     _printer->end_method();
4715   }
4716 #endif
4717 }
4718 
4719 
4720 #ifndef PRODUCT
4721 IdealGraphPrinter* Compile::_debug_file_printer = NULL;
4722 IdealGraphPrinter* Compile::_debug_network_printer = NULL;
4723 
4724 // Called from debugger. Prints method to the default file with the default phase name.
4725 // This works regardless of any Ideal Graph Visualizer flags set or not.
igv_print()4726 void igv_print() {
4727   Compile::current()->igv_print_method_to_file();
4728 }
4729 
4730 // Same as igv_print() above but with a specified phase name.
igv_print(const char * phase_name)4731 void igv_print(const char* phase_name) {
4732   Compile::current()->igv_print_method_to_file(phase_name);
4733 }
4734 
4735 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
4736 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
4737 // This works regardless of any Ideal Graph Visualizer flags set or not.
igv_print(bool network)4738 void igv_print(bool network) {
4739   if (network) {
4740     Compile::current()->igv_print_method_to_network();
4741   } else {
4742     Compile::current()->igv_print_method_to_file();
4743   }
4744 }
4745 
4746 // Same as igv_print(bool network) above but with a specified phase name.
igv_print(bool network,const char * phase_name)4747 void igv_print(bool network, const char* phase_name) {
4748   if (network) {
4749     Compile::current()->igv_print_method_to_network(phase_name);
4750   } else {
4751     Compile::current()->igv_print_method_to_file(phase_name);
4752   }
4753 }
4754 
4755 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
igv_print_default()4756 void igv_print_default() {
4757   Compile::current()->print_method(PHASE_DEBUG, 0, 0);
4758 }
4759 
4760 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
4761 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
4762 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
igv_append()4763 void igv_append() {
4764   Compile::current()->igv_print_method_to_file("Debug", true);
4765 }
4766 
4767 // Same as igv_append() above but with a specified phase name.
igv_append(const char * phase_name)4768 void igv_append(const char* phase_name) {
4769   Compile::current()->igv_print_method_to_file(phase_name, true);
4770 }
4771 
igv_print_method_to_file(const char * phase_name,bool append)4772 void Compile::igv_print_method_to_file(const char* phase_name, bool append) {
4773   const char* file_name = "custom_debug.xml";
4774   if (_debug_file_printer == NULL) {
4775     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
4776   } else {
4777     _debug_file_printer->update_compiled_method(C->method());
4778   }
4779   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
4780   _debug_file_printer->print_method(phase_name, 0);
4781 }
4782 
igv_print_method_to_network(const char * phase_name)4783 void Compile::igv_print_method_to_network(const char* phase_name) {
4784   if (_debug_network_printer == NULL) {
4785     _debug_network_printer = new IdealGraphPrinter(C);
4786   } else {
4787     _debug_network_printer->update_compiled_method(C->method());
4788   }
4789   tty->print_cr("Method printed over network stream to IGV");
4790   _debug_network_printer->print_method(phase_name, 0);
4791 }
4792 #endif
4793 
add_native_invoker(BufferBlob * stub)4794 void Compile::add_native_invoker(BufferBlob* stub) {
4795   _native_invokers.append(stub);
4796 }
4797