src/share/vm/opto/compile.cpp

Thu, 01 Jun 2017 23:19:47 -0700

author
rraghavan
date
Thu, 01 Jun 2017 23:19:47 -0700
changeset 8777
09d0d56ca735
parent 8654
2e734e824d16
child 8856
ac27a9c85bea
child 9325
6ab57fe8b51f
permissions
-rw-r--r--

8175345: Reported null pointer dereference defect groups
Summary: Added required explicit NULL checks
Reviewed-by: thartmann, kvn

     1 /*
     2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "asm/macroAssembler.hpp"
    27 #include "asm/macroAssembler.inline.hpp"
    28 #include "ci/ciReplay.hpp"
    29 #include "classfile/systemDictionary.hpp"
    30 #include "code/exceptionHandlerTable.hpp"
    31 #include "code/nmethod.hpp"
    32 #include "compiler/compileLog.hpp"
    33 #include "compiler/disassembler.hpp"
    34 #include "compiler/oopMap.hpp"
    35 #include "opto/addnode.hpp"
    36 #include "opto/block.hpp"
    37 #include "opto/c2compiler.hpp"
    38 #include "opto/callGenerator.hpp"
    39 #include "opto/callnode.hpp"
    40 #include "opto/cfgnode.hpp"
    41 #include "opto/chaitin.hpp"
    42 #include "opto/compile.hpp"
    43 #include "opto/connode.hpp"
    44 #include "opto/divnode.hpp"
    45 #include "opto/escape.hpp"
    46 #include "opto/idealGraphPrinter.hpp"
    47 #include "opto/loopnode.hpp"
    48 #include "opto/machnode.hpp"
    49 #include "opto/macro.hpp"
    50 #include "opto/matcher.hpp"
    51 #include "opto/mathexactnode.hpp"
    52 #include "opto/memnode.hpp"
    53 #include "opto/mulnode.hpp"
    54 #include "opto/node.hpp"
    55 #include "opto/opcodes.hpp"
    56 #include "opto/output.hpp"
    57 #include "opto/parse.hpp"
    58 #include "opto/phaseX.hpp"
    59 #include "opto/rootnode.hpp"
    60 #include "opto/runtime.hpp"
    61 #include "opto/stringopts.hpp"
    62 #include "opto/type.hpp"
    63 #include "opto/vectornode.hpp"
    64 #include "runtime/arguments.hpp"
    65 #include "runtime/signature.hpp"
    66 #include "runtime/stubRoutines.hpp"
    67 #include "runtime/timer.hpp"
    68 #include "trace/tracing.hpp"
    69 #include "utilities/copy.hpp"
    70 #if defined AD_MD_HPP
    71 # include AD_MD_HPP
    72 #elif defined TARGET_ARCH_MODEL_x86_32
    73 # include "adfiles/ad_x86_32.hpp"
    74 #elif defined TARGET_ARCH_MODEL_x86_64
    75 # include "adfiles/ad_x86_64.hpp"
    76 #elif defined TARGET_ARCH_MODEL_sparc
    77 # include "adfiles/ad_sparc.hpp"
    78 #elif defined TARGET_ARCH_MODEL_zero
    79 # include "adfiles/ad_zero.hpp"
    80 #elif defined TARGET_ARCH_MODEL_ppc_64
    81 # include "adfiles/ad_ppc_64.hpp"
    82 #endif
    85 // -------------------- Compile::mach_constant_base_node -----------------------
    86 // Constant table base node singleton.
    87 MachConstantBaseNode* Compile::mach_constant_base_node() {
    88   if (_mach_constant_base_node == NULL) {
    89     _mach_constant_base_node = new (C) MachConstantBaseNode();
    90     _mach_constant_base_node->add_req(C->root());
    91   }
    92   return _mach_constant_base_node;
    93 }
    96 /// Support for intrinsics.
    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 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
   101 #ifdef ASSERT
   102   for (int i = 1; i < _intrinsics->length(); i++) {
   103     CallGenerator* cg1 = _intrinsics->at(i-1);
   104     CallGenerator* cg2 = _intrinsics->at(i);
   105     assert(cg1->method() != cg2->method()
   106            ? cg1->method()     < cg2->method()
   107            : cg1->is_virtual() < cg2->is_virtual(),
   108            "compiler intrinsics list must stay sorted");
   109   }
   110 #endif
   111   // Binary search sorted list, in decreasing intervals [lo, hi].
   112   int lo = 0, hi = _intrinsics->length()-1;
   113   while (lo <= hi) {
   114     int mid = (uint)(hi + lo) / 2;
   115     ciMethod* mid_m = _intrinsics->at(mid)->method();
   116     if (m < mid_m) {
   117       hi = mid-1;
   118     } else if (m > mid_m) {
   119       lo = mid+1;
   120     } else {
   121       // look at minor sort key
   122       bool mid_virt = _intrinsics->at(mid)->is_virtual();
   123       if (is_virtual < mid_virt) {
   124         hi = mid-1;
   125       } else if (is_virtual > mid_virt) {
   126         lo = mid+1;
   127       } else {
   128         return mid;  // exact match
   129       }
   130     }
   131   }
   132   return lo;  // inexact match
   133 }
   135 void Compile::register_intrinsic(CallGenerator* cg) {
   136   if (_intrinsics == NULL) {
   137     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
   138   }
   139   // This code is stolen from ciObjectFactory::insert.
   140   // Really, GrowableArray should have methods for
   141   // insert_at, remove_at, and binary_search.
   142   int len = _intrinsics->length();
   143   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
   144   if (index == len) {
   145     _intrinsics->append(cg);
   146   } else {
   147 #ifdef ASSERT
   148     CallGenerator* oldcg = _intrinsics->at(index);
   149     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
   150 #endif
   151     _intrinsics->append(_intrinsics->at(len-1));
   152     int pos;
   153     for (pos = len-2; pos >= index; pos--) {
   154       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
   155     }
   156     _intrinsics->at_put(index, cg);
   157   }
   158   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
   159 }
   161 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
   162   assert(m->is_loaded(), "don't try this on unloaded methods");
   163   if (_intrinsics != NULL) {
   164     int index = intrinsic_insertion_index(m, is_virtual);
   165     if (index < _intrinsics->length()
   166         && _intrinsics->at(index)->method() == m
   167         && _intrinsics->at(index)->is_virtual() == is_virtual) {
   168       return _intrinsics->at(index);
   169     }
   170   }
   171   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   172   if (m->intrinsic_id() != vmIntrinsics::_none &&
   173       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
   174     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
   175     if (cg != NULL) {
   176       // Save it for next time:
   177       register_intrinsic(cg);
   178       return cg;
   179     } else {
   180       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
   181     }
   182   }
   183   return NULL;
   184 }
   186 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
   187 // in library_call.cpp.
   190 #ifndef PRODUCT
   191 // statistics gathering...
   193 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
   194 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
   196 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   197   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   198   int oflags = _intrinsic_hist_flags[id];
   199   assert(flags != 0, "what happened?");
   200   if (is_virtual) {
   201     flags |= _intrinsic_virtual;
   202   }
   203   bool changed = (flags != oflags);
   204   if ((flags & _intrinsic_worked) != 0) {
   205     juint count = (_intrinsic_hist_count[id] += 1);
   206     if (count == 1) {
   207       changed = true;           // first time
   208     }
   209     // increment the overall count also:
   210     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   211   }
   212   if (changed) {
   213     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
   214       // Something changed about the intrinsic's virtuality.
   215       if ((flags & _intrinsic_virtual) != 0) {
   216         // This is the first use of this intrinsic as a virtual call.
   217         if (oflags != 0) {
   218           // We already saw it as a non-virtual, so note both cases.
   219           flags |= _intrinsic_both;
   220         }
   221       } else if ((oflags & _intrinsic_both) == 0) {
   222         // This is the first use of this intrinsic as a non-virtual
   223         flags |= _intrinsic_both;
   224       }
   225     }
   226     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   227   }
   228   // update the overall flags also:
   229   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   230   return changed;
   231 }
   233 static char* format_flags(int flags, char* buf) {
   234   buf[0] = 0;
   235   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   236   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   237   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   238   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   239   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   240   if (buf[0] == 0)  strcat(buf, ",");
   241   assert(buf[0] == ',', "must be");
   242   return &buf[1];
   243 }
   245 void Compile::print_intrinsic_statistics() {
   246   char flagsbuf[100];
   247   ttyLocker ttyl;
   248   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   249   tty->print_cr("Compiler intrinsic usage:");
   250   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   251   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   252   #define PRINT_STAT_LINE(name, c, f) \
   253     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   254   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
   255     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
   256     int   flags = _intrinsic_hist_flags[id];
   257     juint count = _intrinsic_hist_count[id];
   258     if ((flags | count) != 0) {
   259       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
   260     }
   261   }
   262   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   263   if (xtty != NULL)  xtty->tail("statistics");
   264 }
   266 void Compile::print_statistics() {
   267   { ttyLocker ttyl;
   268     if (xtty != NULL)  xtty->head("statistics type='opto'");
   269     Parse::print_statistics();
   270     PhaseCCP::print_statistics();
   271     PhaseRegAlloc::print_statistics();
   272     Scheduling::print_statistics();
   273     PhasePeephole::print_statistics();
   274     PhaseIdealLoop::print_statistics();
   275     if (xtty != NULL)  xtty->tail("statistics");
   276   }
   277   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
   278     // put this under its own <statistics> element.
   279     print_intrinsic_statistics();
   280   }
   281 }
   282 #endif //PRODUCT
   284 // Support for bundling info
   285 Bundle* Compile::node_bundling(const Node *n) {
   286   assert(valid_bundle_info(n), "oob");
   287   return &_node_bundling_base[n->_idx];
   288 }
   290 bool Compile::valid_bundle_info(const Node *n) {
   291   return (_node_bundling_limit > n->_idx);
   292 }
   295 void Compile::gvn_replace_by(Node* n, Node* nn) {
   296   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
   297     Node* use = n->last_out(i);
   298     bool is_in_table = initial_gvn()->hash_delete(use);
   299     uint uses_found = 0;
   300     for (uint j = 0; j < use->len(); j++) {
   301       if (use->in(j) == n) {
   302         if (j < use->req())
   303           use->set_req(j, nn);
   304         else
   305           use->set_prec(j, nn);
   306         uses_found++;
   307       }
   308     }
   309     if (is_in_table) {
   310       // reinsert into table
   311       initial_gvn()->hash_find_insert(use);
   312     }
   313     record_for_igvn(use);
   314     i -= uses_found;    // we deleted 1 or more copies of this edge
   315   }
   316 }
   319 static inline bool not_a_node(const Node* n) {
   320   if (n == NULL)                   return true;
   321   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
   322   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
   323   return false;
   324 }
   326 // Identify all nodes that are reachable from below, useful.
   327 // Use breadth-first pass that records state in a Unique_Node_List,
   328 // recursive traversal is slower.
   329 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   330   int estimated_worklist_size = live_nodes();
   331   useful.map( estimated_worklist_size, NULL );  // preallocate space
   333   // Initialize worklist
   334   if (root() != NULL)     { useful.push(root()); }
   335   // If 'top' is cached, declare it useful to preserve cached node
   336   if( cached_top_node() ) { useful.push(cached_top_node()); }
   338   // Push all useful nodes onto the list, breadthfirst
   339   for( uint next = 0; next < useful.size(); ++next ) {
   340     assert( next < unique(), "Unique useful nodes < total nodes");
   341     Node *n  = useful.at(next);
   342     uint max = n->len();
   343     for( uint i = 0; i < max; ++i ) {
   344       Node *m = n->in(i);
   345       if (not_a_node(m))  continue;
   346       useful.push(m);
   347     }
   348   }
   349 }
   351 // Update dead_node_list with any missing dead nodes using useful
   352 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
   353 void Compile::update_dead_node_list(Unique_Node_List &useful) {
   354   uint max_idx = unique();
   355   VectorSet& useful_node_set = useful.member_set();
   357   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
   358     // If node with index node_idx is not in useful set,
   359     // mark it as dead in dead node list.
   360     if (! useful_node_set.test(node_idx) ) {
   361       record_dead_node(node_idx);
   362     }
   363   }
   364 }
   366 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
   367   int shift = 0;
   368   for (int i = 0; i < inlines->length(); i++) {
   369     CallGenerator* cg = inlines->at(i);
   370     CallNode* call = cg->call_node();
   371     if (shift > 0) {
   372       inlines->at_put(i-shift, cg);
   373     }
   374     if (!useful.member(call)) {
   375       shift++;
   376     }
   377   }
   378   inlines->trunc_to(inlines->length()-shift);
   379 }
   381 // Disconnect all useless nodes by disconnecting those at the boundary.
   382 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   383   uint next = 0;
   384   while (next < useful.size()) {
   385     Node *n = useful.at(next++);
   386     if (n->is_SafePoint()) {
   387       // We're done with a parsing phase. Replaced nodes are not valid
   388       // beyond that point.
   389       n->as_SafePoint()->delete_replaced_nodes();
   390     }
   391     // Use raw traversal of out edges since this code removes out edges
   392     int max = n->outcnt();
   393     for (int j = 0; j < max; ++j) {
   394       Node* child = n->raw_out(j);
   395       if (! useful.member(child)) {
   396         assert(!child->is_top() || child != top(),
   397                "If top is cached in Compile object it is in useful list");
   398         // Only need to remove this out-edge to the useless node
   399         n->raw_del_out(j);
   400         --j;
   401         --max;
   402       }
   403     }
   404     if (n->outcnt() == 1 && n->has_special_unique_user()) {
   405       record_for_igvn(n->unique_out());
   406     }
   407   }
   408   // Remove useless macro and predicate opaq nodes
   409   for (int i = C->macro_count()-1; i >= 0; i--) {
   410     Node* n = C->macro_node(i);
   411     if (!useful.member(n)) {
   412       remove_macro_node(n);
   413     }
   414   }
   415   // Remove useless CastII nodes with range check dependency
   416   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
   417     Node* cast = range_check_cast_node(i);
   418     if (!useful.member(cast)) {
   419       remove_range_check_cast(cast);
   420     }
   421   }
   422   // Remove useless expensive node
   423   for (int i = C->expensive_count()-1; i >= 0; i--) {
   424     Node* n = C->expensive_node(i);
   425     if (!useful.member(n)) {
   426       remove_expensive_node(n);
   427     }
   428   }
   429   // clean up the late inline lists
   430   remove_useless_late_inlines(&_string_late_inlines, useful);
   431   remove_useless_late_inlines(&_boxing_late_inlines, useful);
   432   remove_useless_late_inlines(&_late_inlines, useful);
   433   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   434 }
   436 //------------------------------frame_size_in_words-----------------------------
   437 // frame_slots in units of words
   438 int Compile::frame_size_in_words() const {
   439   // shift is 0 in LP32 and 1 in LP64
   440   const int shift = (LogBytesPerWord - LogBytesPerInt);
   441   int words = _frame_slots >> shift;
   442   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   443   return words;
   444 }
   446 // To bang the stack of this compiled method we use the stack size
   447 // that the interpreter would need in case of a deoptimization. This
   448 // removes the need to bang the stack in the deoptimization blob which
   449 // in turn simplifies stack overflow handling.
   450 int Compile::bang_size_in_bytes() const {
   451   return MAX2(_interpreter_frame_size, frame_size_in_bytes());
   452 }
   454 // ============================================================================
   455 //------------------------------CompileWrapper---------------------------------
   456 class CompileWrapper : public StackObj {
   457   Compile *const _compile;
   458  public:
   459   CompileWrapper(Compile* compile);
   461   ~CompileWrapper();
   462 };
   464 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   465   // the Compile* pointer is stored in the current ciEnv:
   466   ciEnv* env = compile->env();
   467   assert(env == ciEnv::current(), "must already be a ciEnv active");
   468   assert(env->compiler_data() == NULL, "compile already active?");
   469   env->set_compiler_data(compile);
   470   assert(compile == Compile::current(), "sanity");
   472   compile->set_type_dict(NULL);
   473   compile->set_type_hwm(NULL);
   474   compile->set_type_last_size(0);
   475   compile->set_last_tf(NULL, NULL);
   476   compile->set_indexSet_arena(NULL);
   477   compile->set_indexSet_free_block_list(NULL);
   478   compile->init_type_arena();
   479   Type::Initialize(compile);
   480   _compile->set_scratch_buffer_blob(NULL);
   481   _compile->begin_method();
   482 }
   483 CompileWrapper::~CompileWrapper() {
   484   _compile->end_method();
   485   if (_compile->scratch_buffer_blob() != NULL)
   486     BufferBlob::free(_compile->scratch_buffer_blob());
   487   _compile->env()->set_compiler_data(NULL);
   488 }
   491 //----------------------------print_compile_messages---------------------------
   492 void Compile::print_compile_messages() {
   493 #ifndef PRODUCT
   494   // Check if recompiling
   495   if (_subsume_loads == false && PrintOpto) {
   496     // Recompiling without allowing machine instructions to subsume loads
   497     tty->print_cr("*********************************************************");
   498     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   499     tty->print_cr("*********************************************************");
   500   }
   501   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   502     // Recompiling without escape analysis
   503     tty->print_cr("*********************************************************");
   504     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   505     tty->print_cr("*********************************************************");
   506   }
   507   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
   508     // Recompiling without boxing elimination
   509     tty->print_cr("*********************************************************");
   510     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
   511     tty->print_cr("*********************************************************");
   512   }
   513   if (env()->break_at_compile()) {
   514     // Open the debugger when compiling this method.
   515     tty->print("### Breaking when compiling: ");
   516     method()->print_short_name();
   517     tty->cr();
   518     BREAKPOINT;
   519   }
   521   if( PrintOpto ) {
   522     if (is_osr_compilation()) {
   523       tty->print("[OSR]%3d", _compile_id);
   524     } else {
   525       tty->print("%3d", _compile_id);
   526     }
   527   }
   528 #endif
   529 }
   532 //-----------------------init_scratch_buffer_blob------------------------------
   533 // Construct a temporary BufferBlob and cache it for this compile.
   534 void Compile::init_scratch_buffer_blob(int const_size) {
   535   // If there is already a scratch buffer blob allocated and the
   536   // constant section is big enough, use it.  Otherwise free the
   537   // current and allocate a new one.
   538   BufferBlob* blob = scratch_buffer_blob();
   539   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
   540     // Use the current blob.
   541   } else {
   542     if (blob != NULL) {
   543       BufferBlob::free(blob);
   544     }
   546     ResourceMark rm;
   547     _scratch_const_size = const_size;
   548     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
   549     blob = BufferBlob::create("Compile::scratch_buffer", size);
   550     // Record the buffer blob for next time.
   551     set_scratch_buffer_blob(blob);
   552     // Have we run out of code space?
   553     if (scratch_buffer_blob() == NULL) {
   554       // Let CompilerBroker disable further compilations.
   555       record_failure("Not enough space for scratch buffer in CodeCache");
   556       return;
   557     }
   558   }
   560   // Initialize the relocation buffers
   561   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
   562   set_scratch_locs_memory(locs_buf);
   563 }
   566 //-----------------------scratch_emit_size-------------------------------------
   567 // Helper function that computes size by emitting code
   568 uint Compile::scratch_emit_size(const Node* n) {
   569   // Start scratch_emit_size section.
   570   set_in_scratch_emit_size(true);
   572   // Emit into a trash buffer and count bytes emitted.
   573   // This is a pretty expensive way to compute a size,
   574   // but it works well enough if seldom used.
   575   // All common fixed-size instructions are given a size
   576   // method by the AD file.
   577   // Note that the scratch buffer blob and locs memory are
   578   // allocated at the beginning of the compile task, and
   579   // may be shared by several calls to scratch_emit_size.
   580   // The allocation of the scratch buffer blob is particularly
   581   // expensive, since it has to grab the code cache lock.
   582   BufferBlob* blob = this->scratch_buffer_blob();
   583   assert(blob != NULL, "Initialize BufferBlob at start");
   584   assert(blob->size() > MAX_inst_size, "sanity");
   585   relocInfo* locs_buf = scratch_locs_memory();
   586   address blob_begin = blob->content_begin();
   587   address blob_end   = (address)locs_buf;
   588   assert(blob->content_contains(blob_end), "sanity");
   589   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   590   buf.initialize_consts_size(_scratch_const_size);
   591   buf.initialize_stubs_size(MAX_stubs_size);
   592   assert(locs_buf != NULL, "sanity");
   593   int lsize = MAX_locs_size / 3;
   594   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
   595   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
   596   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
   598   // Do the emission.
   600   Label fakeL; // Fake label for branch instructions.
   601   Label*   saveL = NULL;
   602   uint save_bnum = 0;
   603   bool is_branch = n->is_MachBranch();
   604   if (is_branch) {
   605     MacroAssembler masm(&buf);
   606     masm.bind(fakeL);
   607     n->as_MachBranch()->save_label(&saveL, &save_bnum);
   608     n->as_MachBranch()->label_set(&fakeL, 0);
   609   }
   610   n->emit(buf, this->regalloc());
   612   // Emitting into the scratch buffer should not fail
   613   assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
   615   if (is_branch) // Restore label.
   616     n->as_MachBranch()->label_set(saveL, save_bnum);
   618   // End scratch_emit_size section.
   619   set_in_scratch_emit_size(false);
   621   return buf.insts_size();
   622 }
   625 // ============================================================================
   626 //------------------------------Compile standard-------------------------------
   627 debug_only( int Compile::_debug_idx = 100000; )
   629 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   630 // the continuation bci for on stack replacement.
   633 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
   634                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
   635                 : Phase(Compiler),
   636                   _env(ci_env),
   637                   _log(ci_env->log()),
   638                   _compile_id(ci_env->compile_id()),
   639                   _save_argument_registers(false),
   640                   _stub_name(NULL),
   641                   _stub_function(NULL),
   642                   _stub_entry_point(NULL),
   643                   _method(target),
   644                   _entry_bci(osr_bci),
   645                   _initial_gvn(NULL),
   646                   _for_igvn(NULL),
   647                   _warm_calls(NULL),
   648                   _subsume_loads(subsume_loads),
   649                   _do_escape_analysis(do_escape_analysis),
   650                   _eliminate_boxing(eliminate_boxing),
   651                   _failure_reason(NULL),
   652                   _code_buffer("Compile::Fill_buffer"),
   653                   _orig_pc_slot(0),
   654                   _orig_pc_slot_offset_in_bytes(0),
   655                   _has_method_handle_invokes(false),
   656                   _mach_constant_base_node(NULL),
   657                   _node_bundling_limit(0),
   658                   _node_bundling_base(NULL),
   659                   _java_calls(0),
   660                   _inner_loops(0),
   661                   _scratch_const_size(-1),
   662                   _in_scratch_emit_size(false),
   663                   _dead_node_list(comp_arena()),
   664                   _dead_node_count(0),
   665 #ifndef PRODUCT
   666                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   667                   _in_dump_cnt(0),
   668                   _printer(IdealGraphPrinter::printer()),
   669 #endif
   670                   _congraph(NULL),
   671                   _comp_arena(mtCompiler),
   672                   _node_arena(mtCompiler),
   673                   _old_arena(mtCompiler),
   674                   _Compile_types(mtCompiler),
   675                   _replay_inline_data(NULL),
   676                   _late_inlines(comp_arena(), 2, 0, NULL),
   677                   _string_late_inlines(comp_arena(), 2, 0, NULL),
   678                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
   679                   _late_inlines_pos(0),
   680                   _number_of_mh_late_inlines(0),
   681                   _inlining_progress(false),
   682                   _inlining_incrementally(false),
   683                   _print_inlining_list(NULL),
   684                   _print_inlining_idx(0),
   685                   _interpreter_frame_size(0),
   686                   _max_node_limit(MaxNodeLimit) {
   687   C = this;
   689   CompileWrapper cw(this);
   690 #ifndef PRODUCT
   691   if (TimeCompiler2) {
   692     tty->print(" ");
   693     target->holder()->name()->print();
   694     tty->print(".");
   695     target->print_short_name();
   696     tty->print("  ");
   697   }
   698   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   699   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   700   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   701   if (!print_opto_assembly) {
   702     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   703     if (print_assembly && !Disassembler::can_decode()) {
   704       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   705       print_opto_assembly = true;
   706     }
   707   }
   708   set_print_assembly(print_opto_assembly);
   709   set_parsed_irreducible_loop(false);
   711   if (method()->has_option("ReplayInline")) {
   712     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
   713   }
   714 #endif
   715   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
   716   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
   717   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
   719   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
   720     // Make sure the method being compiled gets its own MDO,
   721     // so we can at least track the decompile_count().
   722     // Need MDO to record RTM code generation state.
   723     method()->ensure_method_data();
   724   }
   726   Init(::AliasLevel);
   729   print_compile_messages();
   731   _ilt = InlineTree::build_inline_tree_root();
   733   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   734   assert(num_alias_types() >= AliasIdxRaw, "");
   736 #define MINIMUM_NODE_HASH  1023
   737   // Node list that Iterative GVN will start with
   738   Unique_Node_List for_igvn(comp_arena());
   739   set_for_igvn(&for_igvn);
   741   // GVN that will be run immediately on new nodes
   742   uint estimated_size = method()->code_size()*4+64;
   743   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   744   PhaseGVN gvn(node_arena(), estimated_size);
   745   set_initial_gvn(&gvn);
   747   if (print_inlining() || print_intrinsics()) {
   748     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
   749   }
   750   { // Scope for timing the parser
   751     TracePhase t3("parse", &_t_parser, true);
   753     // Put top into the hash table ASAP.
   754     initial_gvn()->transform_no_reclaim(top());
   756     // Set up tf(), start(), and find a CallGenerator.
   757     CallGenerator* cg = NULL;
   758     if (is_osr_compilation()) {
   759       const TypeTuple *domain = StartOSRNode::osr_domain();
   760       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   761       init_tf(TypeFunc::make(domain, range));
   762       StartNode* s = new (this) StartOSRNode(root(), domain);
   763       initial_gvn()->set_type_bottom(s);
   764       init_start(s);
   765       cg = CallGenerator::for_osr(method(), entry_bci());
   766     } else {
   767       // Normal case.
   768       init_tf(TypeFunc::make(method()));
   769       StartNode* s = new (this) StartNode(root(), tf()->domain());
   770       initial_gvn()->set_type_bottom(s);
   771       init_start(s);
   772       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
   773         // With java.lang.ref.reference.get() we must go through the
   774         // intrinsic when G1 is enabled - even when get() is the root
   775         // method of the compile - so that, if necessary, the value in
   776         // the referent field of the reference object gets recorded by
   777         // the pre-barrier code.
   778         // Specifically, if G1 is enabled, the value in the referent
   779         // field is recorded by the G1 SATB pre barrier. This will
   780         // result in the referent being marked live and the reference
   781         // object removed from the list of discovered references during
   782         // reference processing.
   783         cg = find_intrinsic(method(), false);
   784       }
   785       if (cg == NULL) {
   786         float past_uses = method()->interpreter_invocation_count();
   787         float expected_uses = past_uses;
   788         cg = CallGenerator::for_inline(method(), expected_uses);
   789       }
   790     }
   791     if (failing())  return;
   792     if (cg == NULL) {
   793       record_method_not_compilable_all_tiers("cannot parse method");
   794       return;
   795     }
   796     JVMState* jvms = build_start_state(start(), tf());
   797     if ((jvms = cg->generate(jvms)) == NULL) {
   798       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
   799         record_method_not_compilable("method parse failed");
   800       }
   801       return;
   802     }
   803     GraphKit kit(jvms);
   805     if (!kit.stopped()) {
   806       // Accept return values, and transfer control we know not where.
   807       // This is done by a special, unique ReturnNode bound to root.
   808       return_values(kit.jvms());
   809     }
   811     if (kit.has_exceptions()) {
   812       // Any exceptions that escape from this call must be rethrown
   813       // to whatever caller is dynamically above us on the stack.
   814       // This is done by a special, unique RethrowNode bound to root.
   815       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   816     }
   818     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
   820     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
   821       inline_string_calls(true);
   822     }
   824     if (failing())  return;
   826     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
   828     // Remove clutter produced by parsing.
   829     if (!failing()) {
   830       ResourceMark rm;
   831       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   832     }
   833   }
   835   // Note:  Large methods are capped off in do_one_bytecode().
   836   if (failing())  return;
   838   // After parsing, node notes are no longer automagic.
   839   // They must be propagated by register_new_node_with_optimizer(),
   840   // clone(), or the like.
   841   set_default_node_notes(NULL);
   843   for (;;) {
   844     int successes = Inline_Warm();
   845     if (failing())  return;
   846     if (successes == 0)  break;
   847   }
   849   // Drain the list.
   850   Finish_Warm();
   851 #ifndef PRODUCT
   852   if (_printer) {
   853     _printer->print_inlining(this);
   854   }
   855 #endif
   857   if (failing())  return;
   858   NOT_PRODUCT( verify_graph_edges(); )
   860   // Now optimize
   861   Optimize();
   862   if (failing())  return;
   863   NOT_PRODUCT( verify_graph_edges(); )
   865 #ifndef PRODUCT
   866   if (PrintIdeal) {
   867     ttyLocker ttyl;  // keep the following output all in one block
   868     // This output goes directly to the tty, not the compiler log.
   869     // To enable tools to match it up with the compilation activity,
   870     // be sure to tag this tty output with the compile ID.
   871     if (xtty != NULL) {
   872       xtty->head("ideal compile_id='%d'%s", compile_id(),
   873                  is_osr_compilation()    ? " compile_kind='osr'" :
   874                  "");
   875     }
   876     root()->dump(9999);
   877     if (xtty != NULL) {
   878       xtty->tail("ideal");
   879     }
   880   }
   881 #endif
   883   NOT_PRODUCT( verify_barriers(); )
   885   // Dump compilation data to replay it.
   886   if (method()->has_option("DumpReplay")) {
   887     env()->dump_replay_data(_compile_id);
   888   }
   889   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
   890     env()->dump_inline_data(_compile_id);
   891   }
   893   // Now that we know the size of all the monitors we can add a fixed slot
   894   // for the original deopt pc.
   896   _orig_pc_slot =  fixed_slots();
   897   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   898   set_fixed_slots(next_slot);
   900   // Compute when to use implicit null checks. Used by matching trap based
   901   // nodes and NullCheck optimization.
   902   set_allowed_deopt_reasons();
   904   // Now generate code
   905   Code_Gen();
   906   if (failing())  return;
   908   // Check if we want to skip execution of all compiled code.
   909   {
   910 #ifndef PRODUCT
   911     if (OptoNoExecute) {
   912       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   913       return;
   914     }
   915     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   916 #endif
   918     if (is_osr_compilation()) {
   919       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   920       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   921     } else {
   922       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   923       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   924     }
   926     env()->register_method(_method, _entry_bci,
   927                            &_code_offsets,
   928                            _orig_pc_slot_offset_in_bytes,
   929                            code_buffer(),
   930                            frame_size_in_words(), _oop_map_set,
   931                            &_handler_table, &_inc_table,
   932                            compiler,
   933                            env()->comp_level(),
   934                            has_unsafe_access(),
   935                            SharedRuntime::is_wide_vector(max_vector_size()),
   936                            rtm_state()
   937                            );
   939     if (log() != NULL) // Print code cache state into compiler log
   940       log()->code_cache_state();
   941   }
   942 }
   944 //------------------------------Compile----------------------------------------
   945 // Compile a runtime stub
   946 Compile::Compile( ciEnv* ci_env,
   947                   TypeFunc_generator generator,
   948                   address stub_function,
   949                   const char *stub_name,
   950                   int is_fancy_jump,
   951                   bool pass_tls,
   952                   bool save_arg_registers,
   953                   bool return_pc )
   954   : Phase(Compiler),
   955     _env(ci_env),
   956     _log(ci_env->log()),
   957     _compile_id(0),
   958     _save_argument_registers(save_arg_registers),
   959     _method(NULL),
   960     _stub_name(stub_name),
   961     _stub_function(stub_function),
   962     _stub_entry_point(NULL),
   963     _entry_bci(InvocationEntryBci),
   964     _initial_gvn(NULL),
   965     _for_igvn(NULL),
   966     _warm_calls(NULL),
   967     _orig_pc_slot(0),
   968     _orig_pc_slot_offset_in_bytes(0),
   969     _subsume_loads(true),
   970     _do_escape_analysis(false),
   971     _eliminate_boxing(false),
   972     _failure_reason(NULL),
   973     _code_buffer("Compile::Fill_buffer"),
   974     _has_method_handle_invokes(false),
   975     _mach_constant_base_node(NULL),
   976     _node_bundling_limit(0),
   977     _node_bundling_base(NULL),
   978     _java_calls(0),
   979     _inner_loops(0),
   980 #ifndef PRODUCT
   981     _trace_opto_output(TraceOptoOutput),
   982     _in_dump_cnt(0),
   983     _printer(NULL),
   984 #endif
   985     _comp_arena(mtCompiler),
   986     _node_arena(mtCompiler),
   987     _old_arena(mtCompiler),
   988     _Compile_types(mtCompiler),
   989     _dead_node_list(comp_arena()),
   990     _dead_node_count(0),
   991     _congraph(NULL),
   992     _replay_inline_data(NULL),
   993     _number_of_mh_late_inlines(0),
   994     _inlining_progress(false),
   995     _inlining_incrementally(false),
   996     _print_inlining_list(NULL),
   997     _print_inlining_idx(0),
   998     _allowed_reasons(0),
   999     _interpreter_frame_size(0),
  1000     _max_node_limit(MaxNodeLimit) {
  1001   C = this;
  1003 #ifndef PRODUCT
  1004   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
  1005   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
  1006   set_print_assembly(PrintFrameConverterAssembly);
  1007   set_parsed_irreducible_loop(false);
  1008 #endif
  1009   set_has_irreducible_loop(false); // no loops
  1011   CompileWrapper cw(this);
  1012   Init(/*AliasLevel=*/ 0);
  1013   init_tf((*generator)());
  1016     // The following is a dummy for the sake of GraphKit::gen_stub
  1017     Unique_Node_List for_igvn(comp_arena());
  1018     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
  1019     PhaseGVN gvn(Thread::current()->resource_area(),255);
  1020     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
  1021     gvn.transform_no_reclaim(top());
  1023     GraphKit kit;
  1024     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
  1027   NOT_PRODUCT( verify_graph_edges(); )
  1028   Code_Gen();
  1029   if (failing())  return;
  1032   // Entry point will be accessed using compile->stub_entry_point();
  1033   if (code_buffer() == NULL) {
  1034     Matcher::soft_match_failure();
  1035   } else {
  1036     if (PrintAssembly && (WizardMode || Verbose))
  1037       tty->print_cr("### Stub::%s", stub_name);
  1039     if (!failing()) {
  1040       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
  1042       // Make the NMethod
  1043       // For now we mark the frame as never safe for profile stackwalking
  1044       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
  1045                                                       code_buffer(),
  1046                                                       CodeOffsets::frame_never_safe,
  1047                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
  1048                                                       frame_size_in_words(),
  1049                                                       _oop_map_set,
  1050                                                       save_arg_registers);
  1051       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
  1053       _stub_entry_point = rs->entry_point();
  1058 //------------------------------Init-------------------------------------------
  1059 // Prepare for a single compilation
  1060 void Compile::Init(int aliaslevel) {
  1061   _unique  = 0;
  1062   _regalloc = NULL;
  1064   _tf      = NULL;  // filled in later
  1065   _top     = NULL;  // cached later
  1066   _matcher = NULL;  // filled in later
  1067   _cfg     = NULL;  // filled in later
  1069   set_24_bit_selection_and_mode(Use24BitFP, false);
  1071   _node_note_array = NULL;
  1072   _default_node_notes = NULL;
  1074   _immutable_memory = NULL; // filled in at first inquiry
  1076   // Globally visible Nodes
  1077   // First set TOP to NULL to give safe behavior during creation of RootNode
  1078   set_cached_top_node(NULL);
  1079   set_root(new (this) RootNode());
  1080   // Now that you have a Root to point to, create the real TOP
  1081   set_cached_top_node( new (this) ConNode(Type::TOP) );
  1082   set_recent_alloc(NULL, NULL);
  1084   // Create Debug Information Recorder to record scopes, oopmaps, etc.
  1085   env()->set_oop_recorder(new OopRecorder(env()->arena()));
  1086   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
  1087   env()->set_dependencies(new Dependencies(env()));
  1089   _fixed_slots = 0;
  1090   set_has_split_ifs(false);
  1091   set_has_loops(has_method() && method()->has_loops()); // first approximation
  1092   set_has_stringbuilder(false);
  1093   set_has_boxed_value(false);
  1094   _trap_can_recompile = false;  // no traps emitted yet
  1095   _major_progress = true; // start out assuming good things will happen
  1096   set_has_unsafe_access(false);
  1097   set_max_vector_size(0);
  1098   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
  1099   set_decompile_count(0);
  1101   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
  1102   set_num_loop_opts(LoopOptsCount);
  1103   set_do_inlining(Inline);
  1104   set_max_inline_size(MaxInlineSize);
  1105   set_freq_inline_size(FreqInlineSize);
  1106   set_do_scheduling(OptoScheduling);
  1107   set_do_count_invocations(false);
  1108   set_do_method_data_update(false);
  1109   set_rtm_state(NoRTM); // No RTM lock eliding by default
  1110   method_has_option_value("MaxNodeLimit", _max_node_limit);
  1111 #if INCLUDE_RTM_OPT
  1112   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
  1113     int rtm_state = method()->method_data()->rtm_state();
  1114     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
  1115       // Don't generate RTM lock eliding code.
  1116       set_rtm_state(NoRTM);
  1117     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
  1118       // Generate RTM lock eliding code without abort ratio calculation code.
  1119       set_rtm_state(UseRTM);
  1120     } else if (UseRTMDeopt) {
  1121       // Generate RTM lock eliding code and include abort ratio calculation
  1122       // code if UseRTMDeopt is on.
  1123       set_rtm_state(ProfileRTM);
  1126 #endif
  1127   if (debug_info()->recording_non_safepoints()) {
  1128     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
  1129                         (comp_arena(), 8, 0, NULL));
  1130     set_default_node_notes(Node_Notes::make(this));
  1133   // // -- Initialize types before each compile --
  1134   // // Update cached type information
  1135   // if( _method && _method->constants() )
  1136   //   Type::update_loaded_types(_method, _method->constants());
  1138   // Init alias_type map.
  1139   if (!_do_escape_analysis && aliaslevel == 3)
  1140     aliaslevel = 2;  // No unique types without escape analysis
  1141   _AliasLevel = aliaslevel;
  1142   const int grow_ats = 16;
  1143   _max_alias_types = grow_ats;
  1144   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
  1145   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
  1146   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
  1148     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
  1150   // Initialize the first few types.
  1151   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
  1152   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
  1153   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
  1154   _num_alias_types = AliasIdxRaw+1;
  1155   // Zero out the alias type cache.
  1156   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
  1157   // A NULL adr_type hits in the cache right away.  Preload the right answer.
  1158   probe_alias_cache(NULL)->_index = AliasIdxTop;
  1160   _intrinsics = NULL;
  1161   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1162   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1163   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1164   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1165   register_library_intrinsics();
  1168 //---------------------------init_start----------------------------------------
  1169 // Install the StartNode on this compile object.
  1170 void Compile::init_start(StartNode* s) {
  1171   if (failing())
  1172     return; // already failing
  1173   assert(s == start(), "");
  1176 StartNode* Compile::start() const {
  1177   assert(!failing(), "");
  1178   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
  1179     Node* start = root()->fast_out(i);
  1180     if( start->is_Start() )
  1181       return start->as_Start();
  1183   fatal("Did not find Start node!");
  1184   return NULL;
  1187 //-------------------------------immutable_memory-------------------------------------
  1188 // Access immutable memory
  1189 Node* Compile::immutable_memory() {
  1190   if (_immutable_memory != NULL) {
  1191     return _immutable_memory;
  1193   StartNode* s = start();
  1194   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
  1195     Node *p = s->fast_out(i);
  1196     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
  1197       _immutable_memory = p;
  1198       return _immutable_memory;
  1201   ShouldNotReachHere();
  1202   return NULL;
  1205 //----------------------set_cached_top_node------------------------------------
  1206 // Install the cached top node, and make sure Node::is_top works correctly.
  1207 void Compile::set_cached_top_node(Node* tn) {
  1208   if (tn != NULL)  verify_top(tn);
  1209   Node* old_top = _top;
  1210   _top = tn;
  1211   // Calling Node::setup_is_top allows the nodes the chance to adjust
  1212   // their _out arrays.
  1213   if (_top != NULL)     _top->setup_is_top();
  1214   if (old_top != NULL)  old_top->setup_is_top();
  1215   assert(_top == NULL || top()->is_top(), "");
  1218 #ifdef ASSERT
  1219 uint Compile::count_live_nodes_by_graph_walk() {
  1220   Unique_Node_List useful(comp_arena());
  1221   // Get useful node list by walking the graph.
  1222   identify_useful_nodes(useful);
  1223   return useful.size();
  1226 void Compile::print_missing_nodes() {
  1228   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
  1229   if ((_log == NULL) && (! PrintIdealNodeCount)) {
  1230     return;
  1233   // This is an expensive function. It is executed only when the user
  1234   // specifies VerifyIdealNodeCount option or otherwise knows the
  1235   // additional work that needs to be done to identify reachable nodes
  1236   // by walking the flow graph and find the missing ones using
  1237   // _dead_node_list.
  1239   Unique_Node_List useful(comp_arena());
  1240   // Get useful node list by walking the graph.
  1241   identify_useful_nodes(useful);
  1243   uint l_nodes = C->live_nodes();
  1244   uint l_nodes_by_walk = useful.size();
  1246   if (l_nodes != l_nodes_by_walk) {
  1247     if (_log != NULL) {
  1248       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
  1249       _log->stamp();
  1250       _log->end_head();
  1252     VectorSet& useful_member_set = useful.member_set();
  1253     int last_idx = l_nodes_by_walk;
  1254     for (int i = 0; i < last_idx; i++) {
  1255       if (useful_member_set.test(i)) {
  1256         if (_dead_node_list.test(i)) {
  1257           if (_log != NULL) {
  1258             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
  1260           if (PrintIdealNodeCount) {
  1261             // Print the log message to tty
  1262               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
  1263               useful.at(i)->dump();
  1267       else if (! _dead_node_list.test(i)) {
  1268         if (_log != NULL) {
  1269           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
  1271         if (PrintIdealNodeCount) {
  1272           // Print the log message to tty
  1273           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
  1277     if (_log != NULL) {
  1278       _log->tail("mismatched_nodes");
  1282 #endif
  1284 #ifndef PRODUCT
  1285 void Compile::verify_top(Node* tn) const {
  1286   if (tn != NULL) {
  1287     assert(tn->is_Con(), "top node must be a constant");
  1288     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
  1289     assert(tn->in(0) != NULL, "must have live top node");
  1292 #endif
  1295 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1297 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1298   guarantee(arr != NULL, "");
  1299   int num_blocks = arr->length();
  1300   if (grow_by < num_blocks)  grow_by = num_blocks;
  1301   int num_notes = grow_by * _node_notes_block_size;
  1302   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1303   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1304   while (num_notes > 0) {
  1305     arr->append(notes);
  1306     notes     += _node_notes_block_size;
  1307     num_notes -= _node_notes_block_size;
  1309   assert(num_notes == 0, "exact multiple, please");
  1312 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1313   if (source == NULL || dest == NULL)  return false;
  1315   if (dest->is_Con())
  1316     return false;               // Do not push debug info onto constants.
  1318 #ifdef ASSERT
  1319   // Leave a bread crumb trail pointing to the original node:
  1320   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1321     dest->set_debug_orig(source);
  1323 #endif
  1325   if (node_note_array() == NULL)
  1326     return false;               // Not collecting any notes now.
  1328   // This is a copy onto a pre-existing node, which may already have notes.
  1329   // If both nodes have notes, do not overwrite any pre-existing notes.
  1330   Node_Notes* source_notes = node_notes_at(source->_idx);
  1331   if (source_notes == NULL || source_notes->is_clear())  return false;
  1332   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1333   if (dest_notes == NULL || dest_notes->is_clear()) {
  1334     return set_node_notes_at(dest->_idx, source_notes);
  1337   Node_Notes merged_notes = (*source_notes);
  1338   // The order of operations here ensures that dest notes will win...
  1339   merged_notes.update_from(dest_notes);
  1340   return set_node_notes_at(dest->_idx, &merged_notes);
  1344 //--------------------------allow_range_check_smearing-------------------------
  1345 // Gating condition for coalescing similar range checks.
  1346 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1347 // single covering check that is at least as strong as any of them.
  1348 // If the optimization succeeds, the simplified (strengthened) range check
  1349 // will always succeed.  If it fails, we will deopt, and then give up
  1350 // on the optimization.
  1351 bool Compile::allow_range_check_smearing() const {
  1352   // If this method has already thrown a range-check,
  1353   // assume it was because we already tried range smearing
  1354   // and it failed.
  1355   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1356   return !already_trapped;
  1360 //------------------------------flatten_alias_type-----------------------------
  1361 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1362   int offset = tj->offset();
  1363   TypePtr::PTR ptr = tj->ptr();
  1365   // Known instance (scalarizable allocation) alias only with itself.
  1366   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1367                        tj->is_oopptr()->is_known_instance();
  1369   // Process weird unsafe references.
  1370   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1371     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1372     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1373     tj = TypeOopPtr::BOTTOM;
  1374     ptr = tj->ptr();
  1375     offset = tj->offset();
  1378   // Array pointers need some flattening
  1379   const TypeAryPtr *ta = tj->isa_aryptr();
  1380   if (ta && ta->is_stable()) {
  1381     // Erase stability property for alias analysis.
  1382     tj = ta = ta->cast_to_stable(false);
  1384   if( ta && is_known_inst ) {
  1385     if ( offset != Type::OffsetBot &&
  1386          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1387       offset = Type::OffsetBot; // Flatten constant access into array body only
  1388       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1390   } else if( ta && _AliasLevel >= 2 ) {
  1391     // For arrays indexed by constant indices, we flatten the alias
  1392     // space to include all of the array body.  Only the header, klass
  1393     // and array length can be accessed un-aliased.
  1394     if( offset != Type::OffsetBot ) {
  1395       if( ta->const_oop() ) { // MethodData* or Method*
  1396         offset = Type::OffsetBot;   // Flatten constant access into array body
  1397         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1398       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1399         // range is OK as-is.
  1400         tj = ta = TypeAryPtr::RANGE;
  1401       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1402         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1403         ta = TypeAryPtr::RANGE; // generic ignored junk
  1404         ptr = TypePtr::BotPTR;
  1405       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1406         tj = TypeInstPtr::MARK;
  1407         ta = TypeAryPtr::RANGE; // generic ignored junk
  1408         ptr = TypePtr::BotPTR;
  1409       } else {                  // Random constant offset into array body
  1410         offset = Type::OffsetBot;   // Flatten constant access into array body
  1411         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1414     // Arrays of fixed size alias with arrays of unknown size.
  1415     if (ta->size() != TypeInt::POS) {
  1416       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1417       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1419     // Arrays of known objects become arrays of unknown objects.
  1420     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1421       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1422       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1424     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1425       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1426       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1428     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1429     // cannot be distinguished by bytecode alone.
  1430     if (ta->elem() == TypeInt::BOOL) {
  1431       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1432       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1433       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1435     // During the 2nd round of IterGVN, NotNull castings are removed.
  1436     // Make sure the Bottom and NotNull variants alias the same.
  1437     // Also, make sure exact and non-exact variants alias the same.
  1438     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
  1439       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1443   // Oop pointers need some flattening
  1444   const TypeInstPtr *to = tj->isa_instptr();
  1445   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1446     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1447     if( ptr == TypePtr::Constant ) {
  1448       if (to->klass() != ciEnv::current()->Class_klass() ||
  1449           offset < k->size_helper() * wordSize) {
  1450         // No constant oop pointers (such as Strings); they alias with
  1451         // unknown strings.
  1452         assert(!is_known_inst, "not scalarizable allocation");
  1453         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1455     } else if( is_known_inst ) {
  1456       tj = to; // Keep NotNull and klass_is_exact for instance type
  1457     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1458       // During the 2nd round of IterGVN, NotNull castings are removed.
  1459       // Make sure the Bottom and NotNull variants alias the same.
  1460       // Also, make sure exact and non-exact variants alias the same.
  1461       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1463     if (to->speculative() != NULL) {
  1464       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
  1466     // Canonicalize the holder of this field
  1467     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1468       // First handle header references such as a LoadKlassNode, even if the
  1469       // object's klass is unloaded at compile time (4965979).
  1470       if (!is_known_inst) { // Do it only for non-instance types
  1471         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1473     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1474       // Static fields are in the space above the normal instance
  1475       // fields in the java.lang.Class instance.
  1476       if (to->klass() != ciEnv::current()->Class_klass()) {
  1477         to = NULL;
  1478         tj = TypeOopPtr::BOTTOM;
  1479         offset = tj->offset();
  1481     } else {
  1482       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1483       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1484         if( is_known_inst ) {
  1485           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1486         } else {
  1487           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1493   // Klass pointers to object array klasses need some flattening
  1494   const TypeKlassPtr *tk = tj->isa_klassptr();
  1495   if( tk ) {
  1496     // If we are referencing a field within a Klass, we need
  1497     // to assume the worst case of an Object.  Both exact and
  1498     // inexact types must flatten to the same alias class so
  1499     // use NotNull as the PTR.
  1500     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1502       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
  1503                                    TypeKlassPtr::OBJECT->klass(),
  1504                                    offset);
  1507     ciKlass* klass = tk->klass();
  1508     if( klass->is_obj_array_klass() ) {
  1509       ciKlass* k = TypeAryPtr::OOPS->klass();
  1510       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1511         k = TypeInstPtr::BOTTOM->klass();
  1512       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1515     // Check for precise loads from the primary supertype array and force them
  1516     // to the supertype cache alias index.  Check for generic array loads from
  1517     // the primary supertype array and also force them to the supertype cache
  1518     // alias index.  Since the same load can reach both, we need to merge
  1519     // these 2 disparate memories into the same alias class.  Since the
  1520     // primary supertype array is read-only, there's no chance of confusion
  1521     // where we bypass an array load and an array store.
  1522     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
  1523     if (offset == Type::OffsetBot ||
  1524         (offset >= primary_supers_offset &&
  1525          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
  1526         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
  1527       offset = in_bytes(Klass::secondary_super_cache_offset());
  1528       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1532   // Flatten all Raw pointers together.
  1533   if (tj->base() == Type::RawPtr)
  1534     tj = TypeRawPtr::BOTTOM;
  1536   if (tj->base() == Type::AnyPtr)
  1537     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1539   // Flatten all to bottom for now
  1540   switch( _AliasLevel ) {
  1541   case 0:
  1542     tj = TypePtr::BOTTOM;
  1543     break;
  1544   case 1:                       // Flatten to: oop, static, field or array
  1545     switch (tj->base()) {
  1546     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1547     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1548     case Type::AryPtr:   // do not distinguish arrays at all
  1549     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1550     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1551     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1552     default: ShouldNotReachHere();
  1554     break;
  1555   case 2:                       // No collapsing at level 2; keep all splits
  1556   case 3:                       // No collapsing at level 3; keep all splits
  1557     break;
  1558   default:
  1559     Unimplemented();
  1562   offset = tj->offset();
  1563   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1565   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1566           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1567           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1568           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1569           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1570           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1571           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1572           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1573   assert( tj->ptr() != TypePtr::TopPTR &&
  1574           tj->ptr() != TypePtr::AnyNull &&
  1575           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1576 //    assert( tj->ptr() != TypePtr::Constant ||
  1577 //            tj->base() == Type::RawPtr ||
  1578 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1580   return tj;
  1583 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1584   _index = i;
  1585   _adr_type = at;
  1586   _field = NULL;
  1587   _element = NULL;
  1588   _is_rewritable = true; // default
  1589   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1590   if (atoop != NULL && atoop->is_known_instance()) {
  1591     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1592     _general_index = Compile::current()->get_alias_index(gt);
  1593   } else {
  1594     _general_index = 0;
  1598 BasicType Compile::AliasType::basic_type() const {
  1599   if (element() != NULL) {
  1600     const Type* element = adr_type()->is_aryptr()->elem();
  1601     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
  1602   } if (field() != NULL) {
  1603     return field()->layout_type();
  1604   } else {
  1605     return T_ILLEGAL; // unknown
  1609 //---------------------------------print_on------------------------------------
  1610 #ifndef PRODUCT
  1611 void Compile::AliasType::print_on(outputStream* st) {
  1612   if (index() < 10)
  1613         st->print("@ <%d> ", index());
  1614   else  st->print("@ <%d>",  index());
  1615   st->print(is_rewritable() ? "   " : " RO");
  1616   int offset = adr_type()->offset();
  1617   if (offset == Type::OffsetBot)
  1618         st->print(" +any");
  1619   else  st->print(" +%-3d", offset);
  1620   st->print(" in ");
  1621   adr_type()->dump_on(st);
  1622   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1623   if (field() != NULL && tjp) {
  1624     if (tjp->klass()  != field()->holder() ||
  1625         tjp->offset() != field()->offset_in_bytes()) {
  1626       st->print(" != ");
  1627       field()->print();
  1628       st->print(" ***");
  1633 void print_alias_types() {
  1634   Compile* C = Compile::current();
  1635   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1636   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1637     C->alias_type(idx)->print_on(tty);
  1638     tty->cr();
  1641 #endif
  1644 //----------------------------probe_alias_cache--------------------------------
  1645 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1646   intptr_t key = (intptr_t) adr_type;
  1647   key ^= key >> logAliasCacheSize;
  1648   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1652 //-----------------------------grow_alias_types--------------------------------
  1653 void Compile::grow_alias_types() {
  1654   const int old_ats  = _max_alias_types; // how many before?
  1655   const int new_ats  = old_ats;          // how many more?
  1656   const int grow_ats = old_ats+new_ats;  // how many now?
  1657   _max_alias_types = grow_ats;
  1658   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1659   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1660   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1661   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1665 //--------------------------------find_alias_type------------------------------
  1666 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
  1667   if (_AliasLevel == 0)
  1668     return alias_type(AliasIdxBot);
  1670   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1671   if (ace->_adr_type == adr_type) {
  1672     return alias_type(ace->_index);
  1675   // Handle special cases.
  1676   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1677   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1679   // Do it the slow way.
  1680   const TypePtr* flat = flatten_alias_type(adr_type);
  1682 #ifdef ASSERT
  1683   assert(flat == flatten_alias_type(flat), "idempotent");
  1684   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1685   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1686     const TypeOopPtr* foop = flat->is_oopptr();
  1687     // Scalarizable allocations have exact klass always.
  1688     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1689     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1690     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1692   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1693 #endif
  1695   int idx = AliasIdxTop;
  1696   for (int i = 0; i < num_alias_types(); i++) {
  1697     if (alias_type(i)->adr_type() == flat) {
  1698       idx = i;
  1699       break;
  1703   if (idx == AliasIdxTop) {
  1704     if (no_create)  return NULL;
  1705     // Grow the array if necessary.
  1706     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1707     // Add a new alias type.
  1708     idx = _num_alias_types++;
  1709     _alias_types[idx]->Init(idx, flat);
  1710     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1711     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1712     if (flat->isa_instptr()) {
  1713       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1714           && flat->is_instptr()->klass() == env()->Class_klass())
  1715         alias_type(idx)->set_rewritable(false);
  1717     if (flat->isa_aryptr()) {
  1718 #ifdef ASSERT
  1719       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1720       // (T_BYTE has the weakest alignment and size restrictions...)
  1721       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
  1722 #endif
  1723       if (flat->offset() == TypePtr::OffsetBot) {
  1724         alias_type(idx)->set_element(flat->is_aryptr()->elem());
  1727     if (flat->isa_klassptr()) {
  1728       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
  1729         alias_type(idx)->set_rewritable(false);
  1730       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
  1731         alias_type(idx)->set_rewritable(false);
  1732       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
  1733         alias_type(idx)->set_rewritable(false);
  1734       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
  1735         alias_type(idx)->set_rewritable(false);
  1737     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1738     // but the base pointer type is not distinctive enough to identify
  1739     // references into JavaThread.)
  1741     // Check for final fields.
  1742     const TypeInstPtr* tinst = flat->isa_instptr();
  1743     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1744       ciField* field;
  1745       if (tinst->const_oop() != NULL &&
  1746           tinst->klass() == ciEnv::current()->Class_klass() &&
  1747           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
  1748         // static field
  1749         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
  1750         field = k->get_field_by_offset(tinst->offset(), true);
  1751       } else {
  1752         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1753         field = k->get_field_by_offset(tinst->offset(), false);
  1755       assert(field == NULL ||
  1756              original_field == NULL ||
  1757              (field->holder() == original_field->holder() &&
  1758               field->offset() == original_field->offset() &&
  1759               field->is_static() == original_field->is_static()), "wrong field?");
  1760       // Set field() and is_rewritable() attributes.
  1761       if (field != NULL)  alias_type(idx)->set_field(field);
  1765   // Fill the cache for next time.
  1766   ace->_adr_type = adr_type;
  1767   ace->_index    = idx;
  1768   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1770   // Might as well try to fill the cache for the flattened version, too.
  1771   AliasCacheEntry* face = probe_alias_cache(flat);
  1772   if (face->_adr_type == NULL) {
  1773     face->_adr_type = flat;
  1774     face->_index    = idx;
  1775     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1778   return alias_type(idx);
  1782 Compile::AliasType* Compile::alias_type(ciField* field) {
  1783   const TypeOopPtr* t;
  1784   if (field->is_static())
  1785     t = TypeInstPtr::make(field->holder()->java_mirror());
  1786   else
  1787     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1788   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
  1789   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
  1790   return atp;
  1794 //------------------------------have_alias_type--------------------------------
  1795 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1796   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1797   if (ace->_adr_type == adr_type) {
  1798     return true;
  1801   // Handle special cases.
  1802   if (adr_type == NULL)             return true;
  1803   if (adr_type == TypePtr::BOTTOM)  return true;
  1805   return find_alias_type(adr_type, true, NULL) != NULL;
  1808 //-----------------------------must_alias--------------------------------------
  1809 // True if all values of the given address type are in the given alias category.
  1810 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1811   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1812   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1813   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1814   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1816   // the only remaining possible overlap is identity
  1817   int adr_idx = get_alias_index(adr_type);
  1818   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1819   assert(adr_idx == alias_idx ||
  1820          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1821           && adr_type                       != TypeOopPtr::BOTTOM),
  1822          "should not be testing for overlap with an unsafe pointer");
  1823   return adr_idx == alias_idx;
  1826 //------------------------------can_alias--------------------------------------
  1827 // True if any values of the given address type are in the given alias category.
  1828 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1829   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1830   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1831   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1832   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1834   // the only remaining possible overlap is identity
  1835   int adr_idx = get_alias_index(adr_type);
  1836   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1837   return adr_idx == alias_idx;
  1842 //---------------------------pop_warm_call-------------------------------------
  1843 WarmCallInfo* Compile::pop_warm_call() {
  1844   WarmCallInfo* wci = _warm_calls;
  1845   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1846   return wci;
  1849 //----------------------------Inline_Warm--------------------------------------
  1850 int Compile::Inline_Warm() {
  1851   // If there is room, try to inline some more warm call sites.
  1852   // %%% Do a graph index compaction pass when we think we're out of space?
  1853   if (!InlineWarmCalls)  return 0;
  1855   int calls_made_hot = 0;
  1856   int room_to_grow   = NodeCountInliningCutoff - unique();
  1857   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1858   int amount_grown   = 0;
  1859   WarmCallInfo* call;
  1860   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1861     int est_size = (int)call->size();
  1862     if (est_size > (room_to_grow - amount_grown)) {
  1863       // This one won't fit anyway.  Get rid of it.
  1864       call->make_cold();
  1865       continue;
  1867     call->make_hot();
  1868     calls_made_hot++;
  1869     amount_grown   += est_size;
  1870     amount_to_grow -= est_size;
  1873   if (calls_made_hot > 0)  set_major_progress();
  1874   return calls_made_hot;
  1878 //----------------------------Finish_Warm--------------------------------------
  1879 void Compile::Finish_Warm() {
  1880   if (!InlineWarmCalls)  return;
  1881   if (failing())  return;
  1882   if (warm_calls() == NULL)  return;
  1884   // Clean up loose ends, if we are out of space for inlining.
  1885   WarmCallInfo* call;
  1886   while ((call = pop_warm_call()) != NULL) {
  1887     call->make_cold();
  1891 //---------------------cleanup_loop_predicates-----------------------
  1892 // Remove the opaque nodes that protect the predicates so that all unused
  1893 // checks and uncommon_traps will be eliminated from the ideal graph
  1894 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1895   if (predicate_count()==0) return;
  1896   for (int i = predicate_count(); i > 0; i--) {
  1897     Node * n = predicate_opaque1_node(i-1);
  1898     assert(n->Opcode() == Op_Opaque1, "must be");
  1899     igvn.replace_node(n, n->in(1));
  1901   assert(predicate_count()==0, "should be clean!");
  1904 void Compile::add_range_check_cast(Node* n) {
  1905   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
  1906   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
  1907   _range_check_casts->append(n);
  1910 // Remove all range check dependent CastIINodes.
  1911 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
  1912   for (int i = range_check_cast_count(); i > 0; i--) {
  1913     Node* cast = range_check_cast_node(i-1);
  1914     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
  1915     igvn.replace_node(cast, cast->in(1));
  1917   assert(range_check_cast_count() == 0, "should be empty");
  1920 // StringOpts and late inlining of string methods
  1921 void Compile::inline_string_calls(bool parse_time) {
  1923     // remove useless nodes to make the usage analysis simpler
  1924     ResourceMark rm;
  1925     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  1929     ResourceMark rm;
  1930     print_method(PHASE_BEFORE_STRINGOPTS, 3);
  1931     PhaseStringOpts pso(initial_gvn(), for_igvn());
  1932     print_method(PHASE_AFTER_STRINGOPTS, 3);
  1935   // now inline anything that we skipped the first time around
  1936   if (!parse_time) {
  1937     _late_inlines_pos = _late_inlines.length();
  1940   while (_string_late_inlines.length() > 0) {
  1941     CallGenerator* cg = _string_late_inlines.pop();
  1942     cg->do_late_inline();
  1943     if (failing())  return;
  1945   _string_late_inlines.trunc_to(0);
  1948 // Late inlining of boxing methods
  1949 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
  1950   if (_boxing_late_inlines.length() > 0) {
  1951     assert(has_boxed_value(), "inconsistent");
  1953     PhaseGVN* gvn = initial_gvn();
  1954     set_inlining_incrementally(true);
  1956     assert( igvn._worklist.size() == 0, "should be done with igvn" );
  1957     for_igvn()->clear();
  1958     gvn->replace_with(&igvn);
  1960     _late_inlines_pos = _late_inlines.length();
  1962     while (_boxing_late_inlines.length() > 0) {
  1963       CallGenerator* cg = _boxing_late_inlines.pop();
  1964       cg->do_late_inline();
  1965       if (failing())  return;
  1967     _boxing_late_inlines.trunc_to(0);
  1970       ResourceMark rm;
  1971       PhaseRemoveUseless pru(gvn, for_igvn());
  1974     igvn = PhaseIterGVN(gvn);
  1975     igvn.optimize();
  1977     set_inlining_progress(false);
  1978     set_inlining_incrementally(false);
  1982 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
  1983   assert(IncrementalInline, "incremental inlining should be on");
  1984   PhaseGVN* gvn = initial_gvn();
  1986   set_inlining_progress(false);
  1987   for_igvn()->clear();
  1988   gvn->replace_with(&igvn);
  1990   int i = 0;
  1992   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
  1993     CallGenerator* cg = _late_inlines.at(i);
  1994     _late_inlines_pos = i+1;
  1995     cg->do_late_inline();
  1996     if (failing())  return;
  1998   int j = 0;
  1999   for (; i < _late_inlines.length(); i++, j++) {
  2000     _late_inlines.at_put(j, _late_inlines.at(i));
  2002   _late_inlines.trunc_to(j);
  2005     ResourceMark rm;
  2006     PhaseRemoveUseless pru(gvn, for_igvn());
  2009   igvn = PhaseIterGVN(gvn);
  2012 // Perform incremental inlining until bound on number of live nodes is reached
  2013 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
  2014   PhaseGVN* gvn = initial_gvn();
  2016   set_inlining_incrementally(true);
  2017   set_inlining_progress(true);
  2018   uint low_live_nodes = 0;
  2020   while(inlining_progress() && _late_inlines.length() > 0) {
  2022     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2023       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
  2024         // PhaseIdealLoop is expensive so we only try it once we are
  2025         // out of live nodes and we only try it again if the previous
  2026         // helped got the number of nodes down significantly
  2027         PhaseIdealLoop ideal_loop( igvn, false, true );
  2028         if (failing())  return;
  2029         low_live_nodes = live_nodes();
  2030         _major_progress = true;
  2033       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2034         break;
  2038     inline_incrementally_one(igvn);
  2040     if (failing())  return;
  2042     igvn.optimize();
  2044     if (failing())  return;
  2047   assert( igvn._worklist.size() == 0, "should be done with igvn" );
  2049   if (_string_late_inlines.length() > 0) {
  2050     assert(has_stringbuilder(), "inconsistent");
  2051     for_igvn()->clear();
  2052     initial_gvn()->replace_with(&igvn);
  2054     inline_string_calls(false);
  2056     if (failing())  return;
  2059       ResourceMark rm;
  2060       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  2063     igvn = PhaseIterGVN(gvn);
  2065     igvn.optimize();
  2068   set_inlining_incrementally(false);
  2072 //------------------------------Optimize---------------------------------------
  2073 // Given a graph, optimize it.
  2074 void Compile::Optimize() {
  2075   TracePhase t1("optimizer", &_t_optimizer, true);
  2077 #ifndef PRODUCT
  2078   if (env()->break_at_compile()) {
  2079     BREAKPOINT;
  2082 #endif
  2084   ResourceMark rm;
  2085   int          loop_opts_cnt;
  2087   NOT_PRODUCT( verify_graph_edges(); )
  2089   print_method(PHASE_AFTER_PARSING);
  2092   // Iterative Global Value Numbering, including ideal transforms
  2093   // Initialize IterGVN with types and values from parse-time GVN
  2094   PhaseIterGVN igvn(initial_gvn());
  2096     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  2097     igvn.optimize();
  2100   print_method(PHASE_ITER_GVN1, 2);
  2102   if (failing())  return;
  2105     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2106     inline_incrementally(igvn);
  2109   print_method(PHASE_INCREMENTAL_INLINE, 2);
  2111   if (failing())  return;
  2113   if (eliminate_boxing()) {
  2114     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2115     // Inline valueOf() methods now.
  2116     inline_boxing_calls(igvn);
  2118     if (AlwaysIncrementalInline) {
  2119       inline_incrementally(igvn);
  2122     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
  2124     if (failing())  return;
  2127   // Remove the speculative part of types and clean up the graph from
  2128   // the extra CastPP nodes whose only purpose is to carry them. Do
  2129   // that early so that optimizations are not disrupted by the extra
  2130   // CastPP nodes.
  2131   remove_speculative_types(igvn);
  2133   // No more new expensive nodes will be added to the list from here
  2134   // so keep only the actual candidates for optimizations.
  2135   cleanup_expensive_nodes(igvn);
  2137   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
  2138     NOT_PRODUCT(Compile::TracePhase t2("", &_t_renumberLive, TimeCompiler);)
  2139     initial_gvn()->replace_with(&igvn);
  2140     for_igvn()->clear();
  2141     Unique_Node_List new_worklist(C->comp_arena());
  2143       ResourceMark rm;
  2144       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
  2146     set_for_igvn(&new_worklist);
  2147     igvn = PhaseIterGVN(initial_gvn());
  2148     igvn.optimize();
  2151   // Perform escape analysis
  2152   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
  2153     if (has_loops()) {
  2154       // Cleanup graph (remove dead nodes).
  2155       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2156       PhaseIdealLoop ideal_loop( igvn, false, true );
  2157       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
  2158       if (failing())  return;
  2160     ConnectionGraph::do_analysis(this, &igvn);
  2162     if (failing())  return;
  2164     // Optimize out fields loads from scalar replaceable allocations.
  2165     igvn.optimize();
  2166     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
  2168     if (failing())  return;
  2170     if (congraph() != NULL && macro_count() > 0) {
  2171       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
  2172       PhaseMacroExpand mexp(igvn);
  2173       mexp.eliminate_macro_nodes();
  2174       igvn.set_delay_transform(false);
  2176       igvn.optimize();
  2177       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
  2179       if (failing())  return;
  2183   // Loop transforms on the ideal graph.  Range Check Elimination,
  2184   // peeling, unrolling, etc.
  2186   // Set loop opts counter
  2187   loop_opts_cnt = num_loop_opts();
  2188   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  2190       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2191       PhaseIdealLoop ideal_loop( igvn, true );
  2192       loop_opts_cnt--;
  2193       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
  2194       if (failing())  return;
  2196     // Loop opts pass if partial peeling occurred in previous pass
  2197     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  2198       TracePhase t3("idealLoop", &_t_idealLoop, true);
  2199       PhaseIdealLoop ideal_loop( igvn, false );
  2200       loop_opts_cnt--;
  2201       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
  2202       if (failing())  return;
  2204     // Loop opts pass for loop-unrolling before CCP
  2205     if(major_progress() && (loop_opts_cnt > 0)) {
  2206       TracePhase t4("idealLoop", &_t_idealLoop, true);
  2207       PhaseIdealLoop ideal_loop( igvn, false );
  2208       loop_opts_cnt--;
  2209       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
  2211     if (!failing()) {
  2212       // Verify that last round of loop opts produced a valid graph
  2213       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2214       PhaseIdealLoop::verify(igvn);
  2217   if (failing())  return;
  2219   // Conditional Constant Propagation;
  2220   PhaseCCP ccp( &igvn );
  2221   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  2223     TracePhase t2("ccp", &_t_ccp, true);
  2224     ccp.do_transform();
  2226   print_method(PHASE_CPP1, 2);
  2228   assert( true, "Break here to ccp.dump_old2new_map()");
  2230   // Iterative Global Value Numbering, including ideal transforms
  2232     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  2233     igvn = ccp;
  2234     igvn.optimize();
  2237   print_method(PHASE_ITER_GVN2, 2);
  2239   if (failing())  return;
  2241   // Loop transforms on the ideal graph.  Range Check Elimination,
  2242   // peeling, unrolling, etc.
  2243   if(loop_opts_cnt > 0) {
  2244     debug_only( int cnt = 0; );
  2245     while(major_progress() && (loop_opts_cnt > 0)) {
  2246       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2247       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  2248       PhaseIdealLoop ideal_loop( igvn, true);
  2249       loop_opts_cnt--;
  2250       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
  2251       if (failing())  return;
  2256     // Verify that all previous optimizations produced a valid graph
  2257     // at least to this point, even if no loop optimizations were done.
  2258     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2259     PhaseIdealLoop::verify(igvn);
  2262   if (range_check_cast_count() > 0) {
  2263     // No more loop optimizations. Remove all range check dependent CastIINodes.
  2264     C->remove_range_check_casts(igvn);
  2265     igvn.optimize();
  2269     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  2270     PhaseMacroExpand  mex(igvn);
  2271     if (mex.expand_macro_nodes()) {
  2272       assert(failing(), "must bail out w/ explicit message");
  2273       return;
  2277  } // (End scope of igvn; run destructor if necessary for asserts.)
  2279   dump_inlining();
  2280   // A method with only infinite loops has no edges entering loops from root
  2282     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  2283     if (final_graph_reshaping()) {
  2284       assert(failing(), "must bail out w/ explicit message");
  2285       return;
  2289   print_method(PHASE_OPTIMIZE_FINISHED, 2);
  2293 //------------------------------Code_Gen---------------------------------------
  2294 // Given a graph, generate code for it
  2295 void Compile::Code_Gen() {
  2296   if (failing()) {
  2297     return;
  2300   // Perform instruction selection.  You might think we could reclaim Matcher
  2301   // memory PDQ, but actually the Matcher is used in generating spill code.
  2302   // Internals of the Matcher (including some VectorSets) must remain live
  2303   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  2304   // set a bit in reclaimed memory.
  2306   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2307   // nodes.  Mapping is only valid at the root of each matched subtree.
  2308   NOT_PRODUCT( verify_graph_edges(); )
  2310   Matcher matcher;
  2311   _matcher = &matcher;
  2313     TracePhase t2("matcher", &_t_matcher, true);
  2314     matcher.match();
  2316   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2317   // nodes.  Mapping is only valid at the root of each matched subtree.
  2318   NOT_PRODUCT( verify_graph_edges(); )
  2320   // If you have too many nodes, or if matching has failed, bail out
  2321   check_node_count(0, "out of nodes matching instructions");
  2322   if (failing()) {
  2323     return;
  2326   // Build a proper-looking CFG
  2327   PhaseCFG cfg(node_arena(), root(), matcher);
  2328   _cfg = &cfg;
  2330     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  2331     bool success = cfg.do_global_code_motion();
  2332     if (!success) {
  2333       return;
  2336     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
  2337     NOT_PRODUCT( verify_graph_edges(); )
  2338     debug_only( cfg.verify(); )
  2341   PhaseChaitin regalloc(unique(), cfg, matcher);
  2342   _regalloc = &regalloc;
  2344     TracePhase t2("regalloc", &_t_registerAllocation, true);
  2345     // Perform register allocation.  After Chaitin, use-def chains are
  2346     // no longer accurate (at spill code) and so must be ignored.
  2347     // Node->LRG->reg mappings are still accurate.
  2348     _regalloc->Register_Allocate();
  2350     // Bail out if the allocator builds too many nodes
  2351     if (failing()) {
  2352       return;
  2356   // Prior to register allocation we kept empty basic blocks in case the
  2357   // the allocator needed a place to spill.  After register allocation we
  2358   // are not adding any new instructions.  If any basic block is empty, we
  2359   // can now safely remove it.
  2361     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  2362     cfg.remove_empty_blocks();
  2363     if (do_freq_based_layout()) {
  2364       PhaseBlockLayout layout(cfg);
  2365     } else {
  2366       cfg.set_loop_alignment();
  2368     cfg.fixup_flow();
  2371   // Apply peephole optimizations
  2372   if( OptoPeephole ) {
  2373     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  2374     PhasePeephole peep( _regalloc, cfg);
  2375     peep.do_transform();
  2378   // Do late expand if CPU requires this.
  2379   if (Matcher::require_postalloc_expand) {
  2380     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
  2381     cfg.postalloc_expand(_regalloc);
  2384   // Convert Nodes to instruction bits in a buffer
  2386     // %%%% workspace merge brought two timers together for one job
  2387     TracePhase t2a("output", &_t_output, true);
  2388     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  2389     Output();
  2392   print_method(PHASE_FINAL_CODE);
  2394   // He's dead, Jim.
  2395   _cfg     = (PhaseCFG*)0xdeadbeef;
  2396   _regalloc = (PhaseChaitin*)0xdeadbeef;
  2400 //------------------------------dump_asm---------------------------------------
  2401 // Dump formatted assembly
  2402 #ifndef PRODUCT
  2403 void Compile::dump_asm(int *pcs, uint pc_limit) {
  2404   bool cut_short = false;
  2405   tty->print_cr("#");
  2406   tty->print("#  ");  _tf->dump();  tty->cr();
  2407   tty->print_cr("#");
  2409   // For all blocks
  2410   int pc = 0x0;                 // Program counter
  2411   char starts_bundle = ' ';
  2412   _regalloc->dump_frame();
  2414   Node *n = NULL;
  2415   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  2416     if (VMThread::should_terminate()) {
  2417       cut_short = true;
  2418       break;
  2420     Block* block = _cfg->get_block(i);
  2421     if (block->is_connector() && !Verbose) {
  2422       continue;
  2424     n = block->head();
  2425     if (pcs && n->_idx < pc_limit) {
  2426       tty->print("%3.3x   ", pcs[n->_idx]);
  2427     } else {
  2428       tty->print("      ");
  2430     block->dump_head(_cfg);
  2431     if (block->is_connector()) {
  2432       tty->print_cr("        # Empty connector block");
  2433     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  2434       tty->print_cr("        # Block is sole successor of call");
  2437     // For all instructions
  2438     Node *delay = NULL;
  2439     for (uint j = 0; j < block->number_of_nodes(); j++) {
  2440       if (VMThread::should_terminate()) {
  2441         cut_short = true;
  2442         break;
  2444       n = block->get_node(j);
  2445       if (valid_bundle_info(n)) {
  2446         Bundle* bundle = node_bundling(n);
  2447         if (bundle->used_in_unconditional_delay()) {
  2448           delay = n;
  2449           continue;
  2451         if (bundle->starts_bundle()) {
  2452           starts_bundle = '+';
  2456       if (WizardMode) {
  2457         n->dump();
  2460       if( !n->is_Region() &&    // Dont print in the Assembly
  2461           !n->is_Phi() &&       // a few noisely useless nodes
  2462           !n->is_Proj() &&
  2463           !n->is_MachTemp() &&
  2464           !n->is_SafePointScalarObject() &&
  2465           !n->is_Catch() &&     // Would be nice to print exception table targets
  2466           !n->is_MergeMem() &&  // Not very interesting
  2467           !n->is_top() &&       // Debug info table constants
  2468           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  2469           ) {
  2470         if (pcs && n->_idx < pc_limit)
  2471           tty->print("%3.3x", pcs[n->_idx]);
  2472         else
  2473           tty->print("   ");
  2474         tty->print(" %c ", starts_bundle);
  2475         starts_bundle = ' ';
  2476         tty->print("\t");
  2477         n->format(_regalloc, tty);
  2478         tty->cr();
  2481       // If we have an instruction with a delay slot, and have seen a delay,
  2482       // then back up and print it
  2483       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  2484         assert(delay != NULL, "no unconditional delay instruction");
  2485         if (WizardMode) delay->dump();
  2487         if (node_bundling(delay)->starts_bundle())
  2488           starts_bundle = '+';
  2489         if (pcs && n->_idx < pc_limit)
  2490           tty->print("%3.3x", pcs[n->_idx]);
  2491         else
  2492           tty->print("   ");
  2493         tty->print(" %c ", starts_bundle);
  2494         starts_bundle = ' ';
  2495         tty->print("\t");
  2496         delay->format(_regalloc, tty);
  2497         tty->cr();
  2498         delay = NULL;
  2501       // Dump the exception table as well
  2502       if( n->is_Catch() && (Verbose || WizardMode) ) {
  2503         // Print the exception table for this offset
  2504         _handler_table.print_subtable_for(pc);
  2508     if (pcs && n->_idx < pc_limit)
  2509       tty->print_cr("%3.3x", pcs[n->_idx]);
  2510     else
  2511       tty->cr();
  2513     assert(cut_short || delay == NULL, "no unconditional delay branch");
  2515   } // End of per-block dump
  2516   tty->cr();
  2518   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  2520 #endif
  2522 //------------------------------Final_Reshape_Counts---------------------------
  2523 // This class defines counters to help identify when a method
  2524 // may/must be executed using hardware with only 24-bit precision.
  2525 struct Final_Reshape_Counts : public StackObj {
  2526   int  _call_count;             // count non-inlined 'common' calls
  2527   int  _float_count;            // count float ops requiring 24-bit precision
  2528   int  _double_count;           // count double ops requiring more precision
  2529   int  _java_call_count;        // count non-inlined 'java' calls
  2530   int  _inner_loop_count;       // count loops which need alignment
  2531   VectorSet _visited;           // Visitation flags
  2532   Node_List _tests;             // Set of IfNodes & PCTableNodes
  2534   Final_Reshape_Counts() :
  2535     _call_count(0), _float_count(0), _double_count(0),
  2536     _java_call_count(0), _inner_loop_count(0),
  2537     _visited( Thread::current()->resource_area() ) { }
  2539   void inc_call_count  () { _call_count  ++; }
  2540   void inc_float_count () { _float_count ++; }
  2541   void inc_double_count() { _double_count++; }
  2542   void inc_java_call_count() { _java_call_count++; }
  2543   void inc_inner_loop_count() { _inner_loop_count++; }
  2545   int  get_call_count  () const { return _call_count  ; }
  2546   int  get_float_count () const { return _float_count ; }
  2547   int  get_double_count() const { return _double_count; }
  2548   int  get_java_call_count() const { return _java_call_count; }
  2549   int  get_inner_loop_count() const { return _inner_loop_count; }
  2550 };
  2552 #ifdef ASSERT
  2553 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  2554   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  2555   // Make sure the offset goes inside the instance layout.
  2556   return k->contains_field_offset(tp->offset());
  2557   // Note that OffsetBot and OffsetTop are very negative.
  2559 #endif
  2561 // Eliminate trivially redundant StoreCMs and accumulate their
  2562 // precedence edges.
  2563 void Compile::eliminate_redundant_card_marks(Node* n) {
  2564   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
  2565   if (n->in(MemNode::Address)->outcnt() > 1) {
  2566     // There are multiple users of the same address so it might be
  2567     // possible to eliminate some of the StoreCMs
  2568     Node* mem = n->in(MemNode::Memory);
  2569     Node* adr = n->in(MemNode::Address);
  2570     Node* val = n->in(MemNode::ValueIn);
  2571     Node* prev = n;
  2572     bool done = false;
  2573     // Walk the chain of StoreCMs eliminating ones that match.  As
  2574     // long as it's a chain of single users then the optimization is
  2575     // safe.  Eliminating partially redundant StoreCMs would require
  2576     // cloning copies down the other paths.
  2577     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
  2578       if (adr == mem->in(MemNode::Address) &&
  2579           val == mem->in(MemNode::ValueIn)) {
  2580         // redundant StoreCM
  2581         if (mem->req() > MemNode::OopStore) {
  2582           // Hasn't been processed by this code yet.
  2583           n->add_prec(mem->in(MemNode::OopStore));
  2584         } else {
  2585           // Already converted to precedence edge
  2586           for (uint i = mem->req(); i < mem->len(); i++) {
  2587             // Accumulate any precedence edges
  2588             if (mem->in(i) != NULL) {
  2589               n->add_prec(mem->in(i));
  2592           // Everything above this point has been processed.
  2593           done = true;
  2595         // Eliminate the previous StoreCM
  2596         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
  2597         assert(mem->outcnt() == 0, "should be dead");
  2598         mem->disconnect_inputs(NULL, this);
  2599       } else {
  2600         prev = mem;
  2602       mem = prev->in(MemNode::Memory);
  2607 //------------------------------final_graph_reshaping_impl----------------------
  2608 // Implement items 1-5 from final_graph_reshaping below.
  2609 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
  2611   if ( n->outcnt() == 0 ) return; // dead node
  2612   uint nop = n->Opcode();
  2614   // Check for 2-input instruction with "last use" on right input.
  2615   // Swap to left input.  Implements item (2).
  2616   if( n->req() == 3 &&          // two-input instruction
  2617       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  2618       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  2619       n->in(2)->outcnt() == 1 &&// right use IS a last use
  2620       !n->in(2)->is_Con() ) {   // right use is not a constant
  2621     // Check for commutative opcode
  2622     switch( nop ) {
  2623     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  2624     case Op_MaxI:  case Op_MinI:
  2625     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  2626     case Op_AndL:  case Op_XorL:  case Op_OrL:
  2627     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  2628       // Move "last use" input to left by swapping inputs
  2629       n->swap_edges(1, 2);
  2630       break;
  2632     default:
  2633       break;
  2637 #ifdef ASSERT
  2638   if( n->is_Mem() ) {
  2639     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
  2640     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2641             // oop will be recorded in oop map if load crosses safepoint
  2642             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2643                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2644             "raw memory operations should have control edge");
  2646 #endif
  2647   // Count FPU ops and common calls, implements item (3)
  2648   switch( nop ) {
  2649   // Count all float operations that may use FPU
  2650   case Op_AddF:
  2651   case Op_SubF:
  2652   case Op_MulF:
  2653   case Op_DivF:
  2654   case Op_NegF:
  2655   case Op_ModF:
  2656   case Op_ConvI2F:
  2657   case Op_ConF:
  2658   case Op_CmpF:
  2659   case Op_CmpF3:
  2660   // case Op_ConvL2F: // longs are split into 32-bit halves
  2661     frc.inc_float_count();
  2662     break;
  2664   case Op_ConvF2D:
  2665   case Op_ConvD2F:
  2666     frc.inc_float_count();
  2667     frc.inc_double_count();
  2668     break;
  2670   // Count all double operations that may use FPU
  2671   case Op_AddD:
  2672   case Op_SubD:
  2673   case Op_MulD:
  2674   case Op_DivD:
  2675   case Op_NegD:
  2676   case Op_ModD:
  2677   case Op_ConvI2D:
  2678   case Op_ConvD2I:
  2679   // case Op_ConvL2D: // handled by leaf call
  2680   // case Op_ConvD2L: // handled by leaf call
  2681   case Op_ConD:
  2682   case Op_CmpD:
  2683   case Op_CmpD3:
  2684     frc.inc_double_count();
  2685     break;
  2686   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2687   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2688   case Op_Opaque3:
  2689     n->subsume_by(n->in(1), this);
  2690     break;
  2691   case Op_CallStaticJava:
  2692   case Op_CallJava:
  2693   case Op_CallDynamicJava:
  2694     frc.inc_java_call_count(); // Count java call site;
  2695   case Op_CallRuntime:
  2696   case Op_CallLeaf:
  2697   case Op_CallLeafNoFP: {
  2698     assert( n->is_Call(), "" );
  2699     CallNode *call = n->as_Call();
  2700     // Count call sites where the FP mode bit would have to be flipped.
  2701     // Do not count uncommon runtime calls:
  2702     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2703     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2704     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2705       frc.inc_call_count();   // Count the call site
  2706     } else {                  // See if uncommon argument is shared
  2707       Node *n = call->in(TypeFunc::Parms);
  2708       int nop = n->Opcode();
  2709       // Clone shared simple arguments to uncommon calls, item (1).
  2710       if( n->outcnt() > 1 &&
  2711           !n->is_Proj() &&
  2712           nop != Op_CreateEx &&
  2713           nop != Op_CheckCastPP &&
  2714           nop != Op_DecodeN &&
  2715           nop != Op_DecodeNKlass &&
  2716           !n->is_Mem() ) {
  2717         Node *x = n->clone();
  2718         call->set_req( TypeFunc::Parms, x );
  2721     break;
  2724   case Op_StoreD:
  2725   case Op_LoadD:
  2726   case Op_LoadD_unaligned:
  2727     frc.inc_double_count();
  2728     goto handle_mem;
  2729   case Op_StoreF:
  2730   case Op_LoadF:
  2731     frc.inc_float_count();
  2732     goto handle_mem;
  2734   case Op_StoreCM:
  2736       // Convert OopStore dependence into precedence edge
  2737       Node* prec = n->in(MemNode::OopStore);
  2738       n->del_req(MemNode::OopStore);
  2739       n->add_prec(prec);
  2740       eliminate_redundant_card_marks(n);
  2743     // fall through
  2745   case Op_StoreB:
  2746   case Op_StoreC:
  2747   case Op_StorePConditional:
  2748   case Op_StoreI:
  2749   case Op_StoreL:
  2750   case Op_StoreIConditional:
  2751   case Op_StoreLConditional:
  2752   case Op_CompareAndSwapI:
  2753   case Op_CompareAndSwapL:
  2754   case Op_CompareAndSwapP:
  2755   case Op_CompareAndSwapN:
  2756   case Op_GetAndAddI:
  2757   case Op_GetAndAddL:
  2758   case Op_GetAndSetI:
  2759   case Op_GetAndSetL:
  2760   case Op_GetAndSetP:
  2761   case Op_GetAndSetN:
  2762   case Op_StoreP:
  2763   case Op_StoreN:
  2764   case Op_StoreNKlass:
  2765   case Op_LoadB:
  2766   case Op_LoadUB:
  2767   case Op_LoadUS:
  2768   case Op_LoadI:
  2769   case Op_LoadKlass:
  2770   case Op_LoadNKlass:
  2771   case Op_LoadL:
  2772   case Op_LoadL_unaligned:
  2773   case Op_LoadPLocked:
  2774   case Op_LoadP:
  2775   case Op_LoadN:
  2776   case Op_LoadRange:
  2777   case Op_LoadS: {
  2778   handle_mem:
  2779 #ifdef ASSERT
  2780     if( VerifyOptoOopOffsets ) {
  2781       assert( n->is_Mem(), "" );
  2782       MemNode *mem  = (MemNode*)n;
  2783       // Check to see if address types have grounded out somehow.
  2784       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2785       assert( !tp || oop_offset_is_sane(tp), "" );
  2787 #endif
  2788     break;
  2791   case Op_AddP: {               // Assert sane base pointers
  2792     Node *addp = n->in(AddPNode::Address);
  2793     assert( !addp->is_AddP() ||
  2794             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2795             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2796             "Base pointers must match" );
  2797 #ifdef _LP64
  2798     if ((UseCompressedOops || UseCompressedClassPointers) &&
  2799         addp->Opcode() == Op_ConP &&
  2800         addp == n->in(AddPNode::Base) &&
  2801         n->in(AddPNode::Offset)->is_Con()) {
  2802       // Use addressing with narrow klass to load with offset on x86.
  2803       // On sparc loading 32-bits constant and decoding it have less
  2804       // instructions (4) then load 64-bits constant (7).
  2805       // Do this transformation here since IGVN will convert ConN back to ConP.
  2806       const Type* t = addp->bottom_type();
  2807       if (t->isa_oopptr() || t->isa_klassptr()) {
  2808         Node* nn = NULL;
  2810         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
  2812         // Look for existing ConN node of the same exact type.
  2813         Node* r  = root();
  2814         uint cnt = r->outcnt();
  2815         for (uint i = 0; i < cnt; i++) {
  2816           Node* m = r->raw_out(i);
  2817           if (m!= NULL && m->Opcode() == op &&
  2818               m->bottom_type()->make_ptr() == t) {
  2819             nn = m;
  2820             break;
  2823         if (nn != NULL) {
  2824           // Decode a narrow oop to match address
  2825           // [R12 + narrow_oop_reg<<3 + offset]
  2826           if (t->isa_oopptr()) {
  2827             nn = new (this) DecodeNNode(nn, t);
  2828           } else {
  2829             nn = new (this) DecodeNKlassNode(nn, t);
  2831           n->set_req(AddPNode::Base, nn);
  2832           n->set_req(AddPNode::Address, nn);
  2833           if (addp->outcnt() == 0) {
  2834             addp->disconnect_inputs(NULL, this);
  2839 #endif
  2840     break;
  2843 #ifdef _LP64
  2844   case Op_CastPP:
  2845     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2846       Node* in1 = n->in(1);
  2847       const Type* t = n->bottom_type();
  2848       Node* new_in1 = in1->clone();
  2849       new_in1->as_DecodeN()->set_type(t);
  2851       if (!Matcher::narrow_oop_use_complex_address()) {
  2852         //
  2853         // x86, ARM and friends can handle 2 adds in addressing mode
  2854         // and Matcher can fold a DecodeN node into address by using
  2855         // a narrow oop directly and do implicit NULL check in address:
  2856         //
  2857         // [R12 + narrow_oop_reg<<3 + offset]
  2858         // NullCheck narrow_oop_reg
  2859         //
  2860         // On other platforms (Sparc) we have to keep new DecodeN node and
  2861         // use it to do implicit NULL check in address:
  2862         //
  2863         // decode_not_null narrow_oop_reg, base_reg
  2864         // [base_reg + offset]
  2865         // NullCheck base_reg
  2866         //
  2867         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2868         // to keep the information to which NULL check the new DecodeN node
  2869         // corresponds to use it as value in implicit_null_check().
  2870         //
  2871         new_in1->set_req(0, n->in(0));
  2874       n->subsume_by(new_in1, this);
  2875       if (in1->outcnt() == 0) {
  2876         in1->disconnect_inputs(NULL, this);
  2879     break;
  2881   case Op_CmpP:
  2882     // Do this transformation here to preserve CmpPNode::sub() and
  2883     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2884     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
  2885       Node* in1 = n->in(1);
  2886       Node* in2 = n->in(2);
  2887       if (!in1->is_DecodeNarrowPtr()) {
  2888         in2 = in1;
  2889         in1 = n->in(2);
  2891       assert(in1->is_DecodeNarrowPtr(), "sanity");
  2893       Node* new_in2 = NULL;
  2894       if (in2->is_DecodeNarrowPtr()) {
  2895         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
  2896         new_in2 = in2->in(1);
  2897       } else if (in2->Opcode() == Op_ConP) {
  2898         const Type* t = in2->bottom_type();
  2899         if (t == TypePtr::NULL_PTR) {
  2900           assert(in1->is_DecodeN(), "compare klass to null?");
  2901           // Don't convert CmpP null check into CmpN if compressed
  2902           // oops implicit null check is not generated.
  2903           // This will allow to generate normal oop implicit null check.
  2904           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2905             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
  2906           //
  2907           // This transformation together with CastPP transformation above
  2908           // will generated code for implicit NULL checks for compressed oops.
  2909           //
  2910           // The original code after Optimize()
  2911           //
  2912           //    LoadN memory, narrow_oop_reg
  2913           //    decode narrow_oop_reg, base_reg
  2914           //    CmpP base_reg, NULL
  2915           //    CastPP base_reg // NotNull
  2916           //    Load [base_reg + offset], val_reg
  2917           //
  2918           // after these transformations will be
  2919           //
  2920           //    LoadN memory, narrow_oop_reg
  2921           //    CmpN narrow_oop_reg, NULL
  2922           //    decode_not_null narrow_oop_reg, base_reg
  2923           //    Load [base_reg + offset], val_reg
  2924           //
  2925           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2926           // since narrow oops can be used in debug info now (see the code in
  2927           // final_graph_reshaping_walk()).
  2928           //
  2929           // At the end the code will be matched to
  2930           // on x86:
  2931           //
  2932           //    Load_narrow_oop memory, narrow_oop_reg
  2933           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2934           //    NullCheck narrow_oop_reg
  2935           //
  2936           // and on sparc:
  2937           //
  2938           //    Load_narrow_oop memory, narrow_oop_reg
  2939           //    decode_not_null narrow_oop_reg, base_reg
  2940           //    Load [base_reg + offset], val_reg
  2941           //    NullCheck base_reg
  2942           //
  2943         } else if (t->isa_oopptr()) {
  2944           new_in2 = ConNode::make(this, t->make_narrowoop());
  2945         } else if (t->isa_klassptr()) {
  2946           new_in2 = ConNode::make(this, t->make_narrowklass());
  2949       if (new_in2 != NULL) {
  2950         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
  2951         n->subsume_by(cmpN, this);
  2952         if (in1->outcnt() == 0) {
  2953           in1->disconnect_inputs(NULL, this);
  2955         if (in2->outcnt() == 0) {
  2956           in2->disconnect_inputs(NULL, this);
  2960     break;
  2962   case Op_DecodeN:
  2963   case Op_DecodeNKlass:
  2964     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
  2965     // DecodeN could be pinned when it can't be fold into
  2966     // an address expression, see the code for Op_CastPP above.
  2967     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
  2968     break;
  2970   case Op_EncodeP:
  2971   case Op_EncodePKlass: {
  2972     Node* in1 = n->in(1);
  2973     if (in1->is_DecodeNarrowPtr()) {
  2974       n->subsume_by(in1->in(1), this);
  2975     } else if (in1->Opcode() == Op_ConP) {
  2976       const Type* t = in1->bottom_type();
  2977       if (t == TypePtr::NULL_PTR) {
  2978         assert(t->isa_oopptr(), "null klass?");
  2979         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
  2980       } else if (t->isa_oopptr()) {
  2981         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
  2982       } else if (t->isa_klassptr()) {
  2983         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
  2986     if (in1->outcnt() == 0) {
  2987       in1->disconnect_inputs(NULL, this);
  2989     break;
  2992   case Op_Proj: {
  2993     if (OptimizeStringConcat) {
  2994       ProjNode* p = n->as_Proj();
  2995       if (p->_is_io_use) {
  2996         // Separate projections were used for the exception path which
  2997         // are normally removed by a late inline.  If it wasn't inlined
  2998         // then they will hang around and should just be replaced with
  2999         // the original one.
  3000         Node* proj = NULL;
  3001         // Replace with just one
  3002         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  3003           Node *use = i.get();
  3004           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  3005             proj = use;
  3006             break;
  3009         assert(proj != NULL, "must be found");
  3010         p->subsume_by(proj, this);
  3013     break;
  3016   case Op_Phi:
  3017     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
  3018       // The EncodeP optimization may create Phi with the same edges
  3019       // for all paths. It is not handled well by Register Allocator.
  3020       Node* unique_in = n->in(1);
  3021       assert(unique_in != NULL, "");
  3022       uint cnt = n->req();
  3023       for (uint i = 2; i < cnt; i++) {
  3024         Node* m = n->in(i);
  3025         assert(m != NULL, "");
  3026         if (unique_in != m)
  3027           unique_in = NULL;
  3029       if (unique_in != NULL) {
  3030         n->subsume_by(unique_in, this);
  3033     break;
  3035 #endif
  3037 #ifdef ASSERT
  3038   case Op_CastII:
  3039     // Verify that all range check dependent CastII nodes were removed.
  3040     if (n->isa_CastII()->has_range_check()) {
  3041       n->dump(3);
  3042       assert(false, "Range check dependent CastII node was not removed");
  3044     break;
  3045 #endif
  3047   case Op_ModI:
  3048     if (UseDivMod) {
  3049       // Check if a%b and a/b both exist
  3050       Node* d = n->find_similar(Op_DivI);
  3051       if (d) {
  3052         // Replace them with a fused divmod if supported
  3053         if (Matcher::has_match_rule(Op_DivModI)) {
  3054           DivModINode* divmod = DivModINode::make(this, n);
  3055           d->subsume_by(divmod->div_proj(), this);
  3056           n->subsume_by(divmod->mod_proj(), this);
  3057         } else {
  3058           // replace a%b with a-((a/b)*b)
  3059           Node* mult = new (this) MulINode(d, d->in(2));
  3060           Node* sub  = new (this) SubINode(d->in(1), mult);
  3061           n->subsume_by(sub, this);
  3065     break;
  3067   case Op_ModL:
  3068     if (UseDivMod) {
  3069       // Check if a%b and a/b both exist
  3070       Node* d = n->find_similar(Op_DivL);
  3071       if (d) {
  3072         // Replace them with a fused divmod if supported
  3073         if (Matcher::has_match_rule(Op_DivModL)) {
  3074           DivModLNode* divmod = DivModLNode::make(this, n);
  3075           d->subsume_by(divmod->div_proj(), this);
  3076           n->subsume_by(divmod->mod_proj(), this);
  3077         } else {
  3078           // replace a%b with a-((a/b)*b)
  3079           Node* mult = new (this) MulLNode(d, d->in(2));
  3080           Node* sub  = new (this) SubLNode(d->in(1), mult);
  3081           n->subsume_by(sub, this);
  3085     break;
  3087   case Op_LoadVector:
  3088   case Op_StoreVector:
  3089     break;
  3091   case Op_PackB:
  3092   case Op_PackS:
  3093   case Op_PackI:
  3094   case Op_PackF:
  3095   case Op_PackL:
  3096   case Op_PackD:
  3097     if (n->req()-1 > 2) {
  3098       // Replace many operand PackNodes with a binary tree for matching
  3099       PackNode* p = (PackNode*) n;
  3100       Node* btp = p->binary_tree_pack(this, 1, n->req());
  3101       n->subsume_by(btp, this);
  3103     break;
  3104   case Op_Loop:
  3105   case Op_CountedLoop:
  3106     if (n->as_Loop()->is_inner_loop()) {
  3107       frc.inc_inner_loop_count();
  3109     break;
  3110   case Op_LShiftI:
  3111   case Op_RShiftI:
  3112   case Op_URShiftI:
  3113   case Op_LShiftL:
  3114   case Op_RShiftL:
  3115   case Op_URShiftL:
  3116     if (Matcher::need_masked_shift_count) {
  3117       // The cpu's shift instructions don't restrict the count to the
  3118       // lower 5/6 bits. We need to do the masking ourselves.
  3119       Node* in2 = n->in(2);
  3120       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
  3121       const TypeInt* t = in2->find_int_type();
  3122       if (t != NULL && t->is_con()) {
  3123         juint shift = t->get_con();
  3124         if (shift > mask) { // Unsigned cmp
  3125           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
  3127       } else {
  3128         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
  3129           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
  3130           n->set_req(2, shift);
  3133       if (in2->outcnt() == 0) { // Remove dead node
  3134         in2->disconnect_inputs(NULL, this);
  3137     break;
  3138   case Op_MemBarStoreStore:
  3139   case Op_MemBarRelease:
  3140     // Break the link with AllocateNode: it is no longer useful and
  3141     // confuses register allocation.
  3142     if (n->req() > MemBarNode::Precedent) {
  3143       n->set_req(MemBarNode::Precedent, top());
  3145     break;
  3146   default:
  3147     assert( !n->is_Call(), "" );
  3148     assert( !n->is_Mem(), "" );
  3149     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
  3150     break;
  3153   // Collect CFG split points
  3154   if (n->is_MultiBranch())
  3155     frc._tests.push(n);
  3158 //------------------------------final_graph_reshaping_walk---------------------
  3159 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  3160 // requires that the walk visits a node's inputs before visiting the node.
  3161 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  3162   ResourceArea *area = Thread::current()->resource_area();
  3163   Unique_Node_List sfpt(area);
  3165   frc._visited.set(root->_idx); // first, mark node as visited
  3166   uint cnt = root->req();
  3167   Node *n = root;
  3168   uint  i = 0;
  3169   while (true) {
  3170     if (i < cnt) {
  3171       // Place all non-visited non-null inputs onto stack
  3172       Node* m = n->in(i);
  3173       ++i;
  3174       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  3175         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
  3176           // compute worst case interpreter size in case of a deoptimization
  3177           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
  3179           sfpt.push(m);
  3181         cnt = m->req();
  3182         nstack.push(n, i); // put on stack parent and next input's index
  3183         n = m;
  3184         i = 0;
  3186     } else {
  3187       // Now do post-visit work
  3188       final_graph_reshaping_impl( n, frc );
  3189       if (nstack.is_empty())
  3190         break;             // finished
  3191       n = nstack.node();   // Get node from stack
  3192       cnt = n->req();
  3193       i = nstack.index();
  3194       nstack.pop();        // Shift to the next node on stack
  3198   // Skip next transformation if compressed oops are not used.
  3199   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
  3200       (!UseCompressedOops && !UseCompressedClassPointers))
  3201     return;
  3203   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
  3204   // It could be done for an uncommon traps or any safepoints/calls
  3205   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
  3206   while (sfpt.size() > 0) {
  3207     n = sfpt.pop();
  3208     JVMState *jvms = n->as_SafePoint()->jvms();
  3209     assert(jvms != NULL, "sanity");
  3210     int start = jvms->debug_start();
  3211     int end   = n->req();
  3212     bool is_uncommon = (n->is_CallStaticJava() &&
  3213                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  3214     for (int j = start; j < end; j++) {
  3215       Node* in = n->in(j);
  3216       if (in->is_DecodeNarrowPtr()) {
  3217         bool safe_to_skip = true;
  3218         if (!is_uncommon ) {
  3219           // Is it safe to skip?
  3220           for (uint i = 0; i < in->outcnt(); i++) {
  3221             Node* u = in->raw_out(i);
  3222             if (!u->is_SafePoint() ||
  3223                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  3224               safe_to_skip = false;
  3228         if (safe_to_skip) {
  3229           n->set_req(j, in->in(1));
  3231         if (in->outcnt() == 0) {
  3232           in->disconnect_inputs(NULL, this);
  3239 //------------------------------final_graph_reshaping--------------------------
  3240 // Final Graph Reshaping.
  3241 //
  3242 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  3243 //     and not commoned up and forced early.  Must come after regular
  3244 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  3245 //     inputs to Loop Phis; these will be split by the allocator anyways.
  3246 //     Remove Opaque nodes.
  3247 // (2) Move last-uses by commutative operations to the left input to encourage
  3248 //     Intel update-in-place two-address operations and better register usage
  3249 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  3250 //     calls canonicalizing them back.
  3251 // (3) Count the number of double-precision FP ops, single-precision FP ops
  3252 //     and call sites.  On Intel, we can get correct rounding either by
  3253 //     forcing singles to memory (requires extra stores and loads after each
  3254 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  3255 //     clearing the mode bit around call sites).  The mode bit is only used
  3256 //     if the relative frequency of single FP ops to calls is low enough.
  3257 //     This is a key transform for SPEC mpeg_audio.
  3258 // (4) Detect infinite loops; blobs of code reachable from above but not
  3259 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  3260 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  3261 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  3262 //     Detection is by looking for IfNodes where only 1 projection is
  3263 //     reachable from below or CatchNodes missing some targets.
  3264 // (5) Assert for insane oop offsets in debug mode.
  3266 bool Compile::final_graph_reshaping() {
  3267   // an infinite loop may have been eliminated by the optimizer,
  3268   // in which case the graph will be empty.
  3269   if (root()->req() == 1) {
  3270     record_method_not_compilable("trivial infinite loop");
  3271     return true;
  3274   // Expensive nodes have their control input set to prevent the GVN
  3275   // from freely commoning them. There's no GVN beyond this point so
  3276   // no need to keep the control input. We want the expensive nodes to
  3277   // be freely moved to the least frequent code path by gcm.
  3278   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
  3279   for (int i = 0; i < expensive_count(); i++) {
  3280     _expensive_nodes->at(i)->set_req(0, NULL);
  3283   Final_Reshape_Counts frc;
  3285   // Visit everybody reachable!
  3286   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
  3287   Node_Stack nstack(live_nodes() >> 1);
  3288   final_graph_reshaping_walk(nstack, root(), frc);
  3290   // Check for unreachable (from below) code (i.e., infinite loops).
  3291   for( uint i = 0; i < frc._tests.size(); i++ ) {
  3292     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  3293     // Get number of CFG targets.
  3294     // Note that PCTables include exception targets after calls.
  3295     uint required_outcnt = n->required_outcnt();
  3296     if (n->outcnt() != required_outcnt) {
  3297       // Check for a few special cases.  Rethrow Nodes never take the
  3298       // 'fall-thru' path, so expected kids is 1 less.
  3299       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  3300         if (n->in(0)->in(0)->is_Call()) {
  3301           CallNode *call = n->in(0)->in(0)->as_Call();
  3302           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  3303             required_outcnt--;      // Rethrow always has 1 less kid
  3304           } else if (call->req() > TypeFunc::Parms &&
  3305                      call->is_CallDynamicJava()) {
  3306             // Check for null receiver. In such case, the optimizer has
  3307             // detected that the virtual call will always result in a null
  3308             // pointer exception. The fall-through projection of this CatchNode
  3309             // will not be populated.
  3310             Node *arg0 = call->in(TypeFunc::Parms);
  3311             if (arg0->is_Type() &&
  3312                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  3313               required_outcnt--;
  3315           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  3316                      call->req() > TypeFunc::Parms+1 &&
  3317                      call->is_CallStaticJava()) {
  3318             // Check for negative array length. In such case, the optimizer has
  3319             // detected that the allocation attempt will always result in an
  3320             // exception. There is no fall-through projection of this CatchNode .
  3321             Node *arg1 = call->in(TypeFunc::Parms+1);
  3322             if (arg1->is_Type() &&
  3323                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  3324               required_outcnt--;
  3329       // Recheck with a better notion of 'required_outcnt'
  3330       if (n->outcnt() != required_outcnt) {
  3331         record_method_not_compilable("malformed control flow");
  3332         return true;            // Not all targets reachable!
  3335     // Check that I actually visited all kids.  Unreached kids
  3336     // must be infinite loops.
  3337     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  3338       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  3339         record_method_not_compilable("infinite loop");
  3340         return true;            // Found unvisited kid; must be unreach
  3344   // If original bytecodes contained a mixture of floats and doubles
  3345   // check if the optimizer has made it homogenous, item (3).
  3346   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  3347       frc.get_float_count() > 32 &&
  3348       frc.get_double_count() == 0 &&
  3349       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  3350     set_24_bit_selection_and_mode( false,  true );
  3353   set_java_calls(frc.get_java_call_count());
  3354   set_inner_loops(frc.get_inner_loop_count());
  3356   // No infinite loops, no reason to bail out.
  3357   return false;
  3360 //-----------------------------too_many_traps----------------------------------
  3361 // Report if there are too many traps at the current method and bci.
  3362 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  3363 bool Compile::too_many_traps(ciMethod* method,
  3364                              int bci,
  3365                              Deoptimization::DeoptReason reason) {
  3366   ciMethodData* md = method->method_data();
  3367   if (md->is_empty()) {
  3368     // Assume the trap has not occurred, or that it occurred only
  3369     // because of a transient condition during start-up in the interpreter.
  3370     return false;
  3372   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3373   if (md->has_trap_at(bci, m, reason) != 0) {
  3374     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  3375     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3376     // assume the worst.
  3377     if (log())
  3378       log()->elem("observe trap='%s' count='%d'",
  3379                   Deoptimization::trap_reason_name(reason),
  3380                   md->trap_count(reason));
  3381     return true;
  3382   } else {
  3383     // Ignore method/bci and see if there have been too many globally.
  3384     return too_many_traps(reason, md);
  3388 // Less-accurate variant which does not require a method and bci.
  3389 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  3390                              ciMethodData* logmd) {
  3391   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
  3392     // Too many traps globally.
  3393     // Note that we use cumulative trap_count, not just md->trap_count.
  3394     if (log()) {
  3395       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  3396       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  3397                   Deoptimization::trap_reason_name(reason),
  3398                   mcount, trap_count(reason));
  3400     return true;
  3401   } else {
  3402     // The coast is clear.
  3403     return false;
  3407 //--------------------------too_many_recompiles--------------------------------
  3408 // Report if there are too many recompiles at the current method and bci.
  3409 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  3410 // Is not eager to return true, since this will cause the compiler to use
  3411 // Action_none for a trap point, to avoid too many recompilations.
  3412 bool Compile::too_many_recompiles(ciMethod* method,
  3413                                   int bci,
  3414                                   Deoptimization::DeoptReason reason) {
  3415   ciMethodData* md = method->method_data();
  3416   if (md->is_empty()) {
  3417     // Assume the trap has not occurred, or that it occurred only
  3418     // because of a transient condition during start-up in the interpreter.
  3419     return false;
  3421   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  3422   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  3423   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  3424   Deoptimization::DeoptReason per_bc_reason
  3425     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  3426   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3427   if ((per_bc_reason == Deoptimization::Reason_none
  3428        || md->has_trap_at(bci, m, reason) != 0)
  3429       // The trap frequency measure we care about is the recompile count:
  3430       && md->trap_recompiled_at(bci, m)
  3431       && md->overflow_recompile_count() >= bc_cutoff) {
  3432     // Do not emit a trap here if it has already caused recompilations.
  3433     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3434     // assume the worst.
  3435     if (log())
  3436       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  3437                   Deoptimization::trap_reason_name(reason),
  3438                   md->trap_count(reason),
  3439                   md->overflow_recompile_count());
  3440     return true;
  3441   } else if (trap_count(reason) != 0
  3442              && decompile_count() >= m_cutoff) {
  3443     // Too many recompiles globally, and we have seen this sort of trap.
  3444     // Use cumulative decompile_count, not just md->decompile_count.
  3445     if (log())
  3446       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  3447                   Deoptimization::trap_reason_name(reason),
  3448                   md->trap_count(reason), trap_count(reason),
  3449                   md->decompile_count(), decompile_count());
  3450     return true;
  3451   } else {
  3452     // The coast is clear.
  3453     return false;
  3457 // Compute when not to trap. Used by matching trap based nodes and
  3458 // NullCheck optimization.
  3459 void Compile::set_allowed_deopt_reasons() {
  3460   _allowed_reasons = 0;
  3461   if (is_method_compilation()) {
  3462     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
  3463       assert(rs < BitsPerInt, "recode bit map");
  3464       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
  3465         _allowed_reasons |= nth_bit(rs);
  3471 #ifndef PRODUCT
  3472 //------------------------------verify_graph_edges---------------------------
  3473 // Walk the Graph and verify that there is a one-to-one correspondence
  3474 // between Use-Def edges and Def-Use edges in the graph.
  3475 void Compile::verify_graph_edges(bool no_dead_code) {
  3476   if (VerifyGraphEdges) {
  3477     ResourceArea *area = Thread::current()->resource_area();
  3478     Unique_Node_List visited(area);
  3479     // Call recursive graph walk to check edges
  3480     _root->verify_edges(visited);
  3481     if (no_dead_code) {
  3482       // Now make sure that no visited node is used by an unvisited node.
  3483       bool dead_nodes = 0;
  3484       Unique_Node_List checked(area);
  3485       while (visited.size() > 0) {
  3486         Node* n = visited.pop();
  3487         checked.push(n);
  3488         for (uint i = 0; i < n->outcnt(); i++) {
  3489           Node* use = n->raw_out(i);
  3490           if (checked.member(use))  continue;  // already checked
  3491           if (visited.member(use))  continue;  // already in the graph
  3492           if (use->is_Con())        continue;  // a dead ConNode is OK
  3493           // At this point, we have found a dead node which is DU-reachable.
  3494           if (dead_nodes++ == 0)
  3495             tty->print_cr("*** Dead nodes reachable via DU edges:");
  3496           use->dump(2);
  3497           tty->print_cr("---");
  3498           checked.push(use);  // No repeats; pretend it is now checked.
  3501       assert(dead_nodes == 0, "using nodes must be reachable from root");
  3506 // Verify GC barriers consistency
  3507 // Currently supported:
  3508 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
  3509 void Compile::verify_barriers() {
  3510   if (UseG1GC) {
  3511     // Verify G1 pre-barriers
  3512     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
  3514     ResourceArea *area = Thread::current()->resource_area();
  3515     Unique_Node_List visited(area);
  3516     Node_List worklist(area);
  3517     // We're going to walk control flow backwards starting from the Root
  3518     worklist.push(_root);
  3519     while (worklist.size() > 0) {
  3520       Node* x = worklist.pop();
  3521       if (x == NULL || x == top()) continue;
  3522       if (visited.member(x)) {
  3523         continue;
  3524       } else {
  3525         visited.push(x);
  3528       if (x->is_Region()) {
  3529         for (uint i = 1; i < x->req(); i++) {
  3530           worklist.push(x->in(i));
  3532       } else {
  3533         worklist.push(x->in(0));
  3534         // We are looking for the pattern:
  3535         //                            /->ThreadLocal
  3536         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
  3537         //              \->ConI(0)
  3538         // We want to verify that the If and the LoadB have the same control
  3539         // See GraphKit::g1_write_barrier_pre()
  3540         if (x->is_If()) {
  3541           IfNode *iff = x->as_If();
  3542           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
  3543             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
  3544             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
  3545                 && cmp->in(1)->is_Load()) {
  3546               LoadNode* load = cmp->in(1)->as_Load();
  3547               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
  3548                   && load->in(2)->in(3)->is_Con()
  3549                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
  3551                 Node* if_ctrl = iff->in(0);
  3552                 Node* load_ctrl = load->in(0);
  3554                 if (if_ctrl != load_ctrl) {
  3555                   // Skip possible CProj->NeverBranch in infinite loops
  3556                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
  3557                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
  3558                     if_ctrl = if_ctrl->in(0)->in(0);
  3561                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
  3571 #endif
  3573 // The Compile object keeps track of failure reasons separately from the ciEnv.
  3574 // This is required because there is not quite a 1-1 relation between the
  3575 // ciEnv and its compilation task and the Compile object.  Note that one
  3576 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  3577 // to backtrack and retry without subsuming loads.  Other than this backtracking
  3578 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  3579 // by the logic in C2Compiler.
  3580 void Compile::record_failure(const char* reason) {
  3581   if (log() != NULL) {
  3582     log()->elem("failure reason='%s' phase='compile'", reason);
  3584   if (_failure_reason == NULL) {
  3585     // Record the first failure reason.
  3586     _failure_reason = reason;
  3589   EventCompilerFailure event;
  3590   if (event.should_commit()) {
  3591     event.set_compileID(Compile::compile_id());
  3592     event.set_failure(reason);
  3593     event.commit();
  3596   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  3597     C->print_method(PHASE_FAILURE);
  3599   _root = NULL;  // flush the graph, too
  3602 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  3603   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
  3604     _phase_name(name), _dolog(dolog)
  3606   if (dolog) {
  3607     C = Compile::current();
  3608     _log = C->log();
  3609   } else {
  3610     C = NULL;
  3611     _log = NULL;
  3613   if (_log != NULL) {
  3614     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3615     _log->stamp();
  3616     _log->end_head();
  3620 Compile::TracePhase::~TracePhase() {
  3622   C = Compile::current();
  3623   if (_dolog) {
  3624     _log = C->log();
  3625   } else {
  3626     _log = NULL;
  3629 #ifdef ASSERT
  3630   if (PrintIdealNodeCount) {
  3631     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
  3632                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
  3635   if (VerifyIdealNodeCount) {
  3636     Compile::current()->print_missing_nodes();
  3638 #endif
  3640   if (_log != NULL) {
  3641     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3645 //=============================================================================
  3646 // Two Constant's are equal when the type and the value are equal.
  3647 bool Compile::Constant::operator==(const Constant& other) {
  3648   if (type()          != other.type()         )  return false;
  3649   if (can_be_reused() != other.can_be_reused())  return false;
  3650   // For floating point values we compare the bit pattern.
  3651   switch (type()) {
  3652   case T_FLOAT:   return (_v._value.i == other._v._value.i);
  3653   case T_LONG:
  3654   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
  3655   case T_OBJECT:
  3656   case T_ADDRESS: return (_v._value.l == other._v._value.l);
  3657   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
  3658   case T_METADATA: return (_v._metadata == other._v._metadata);
  3659   default: ShouldNotReachHere();
  3661   return false;
  3664 static int type_to_size_in_bytes(BasicType t) {
  3665   switch (t) {
  3666   case T_LONG:    return sizeof(jlong  );
  3667   case T_FLOAT:   return sizeof(jfloat );
  3668   case T_DOUBLE:  return sizeof(jdouble);
  3669   case T_METADATA: return sizeof(Metadata*);
  3670     // We use T_VOID as marker for jump-table entries (labels) which
  3671     // need an internal word relocation.
  3672   case T_VOID:
  3673   case T_ADDRESS:
  3674   case T_OBJECT:  return sizeof(jobject);
  3677   ShouldNotReachHere();
  3678   return -1;
  3681 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
  3682   // sort descending
  3683   if (a->freq() > b->freq())  return -1;
  3684   if (a->freq() < b->freq())  return  1;
  3685   return 0;
  3688 void Compile::ConstantTable::calculate_offsets_and_size() {
  3689   // First, sort the array by frequencies.
  3690   _constants.sort(qsort_comparator);
  3692 #ifdef ASSERT
  3693   // Make sure all jump-table entries were sorted to the end of the
  3694   // array (they have a negative frequency).
  3695   bool found_void = false;
  3696   for (int i = 0; i < _constants.length(); i++) {
  3697     Constant con = _constants.at(i);
  3698     if (con.type() == T_VOID)
  3699       found_void = true;  // jump-tables
  3700     else
  3701       assert(!found_void, "wrong sorting");
  3703 #endif
  3705   int offset = 0;
  3706   for (int i = 0; i < _constants.length(); i++) {
  3707     Constant* con = _constants.adr_at(i);
  3709     // Align offset for type.
  3710     int typesize = type_to_size_in_bytes(con->type());
  3711     offset = align_size_up(offset, typesize);
  3712     con->set_offset(offset);   // set constant's offset
  3714     if (con->type() == T_VOID) {
  3715       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
  3716       offset = offset + typesize * n->outcnt();  // expand jump-table
  3717     } else {
  3718       offset = offset + typesize;
  3722   // Align size up to the next section start (which is insts; see
  3723   // CodeBuffer::align_at_start).
  3724   assert(_size == -1, "already set?");
  3725   _size = align_size_up(offset, CodeEntryAlignment);
  3728 void Compile::ConstantTable::emit(CodeBuffer& cb) {
  3729   MacroAssembler _masm(&cb);
  3730   for (int i = 0; i < _constants.length(); i++) {
  3731     Constant con = _constants.at(i);
  3732     address constant_addr = NULL;
  3733     switch (con.type()) {
  3734     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
  3735     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
  3736     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
  3737     case T_OBJECT: {
  3738       jobject obj = con.get_jobject();
  3739       int oop_index = _masm.oop_recorder()->find_index(obj);
  3740       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
  3741       break;
  3743     case T_ADDRESS: {
  3744       address addr = (address) con.get_jobject();
  3745       constant_addr = _masm.address_constant(addr);
  3746       break;
  3748     // We use T_VOID as marker for jump-table entries (labels) which
  3749     // need an internal word relocation.
  3750     case T_VOID: {
  3751       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
  3752       // Fill the jump-table with a dummy word.  The real value is
  3753       // filled in later in fill_jump_table.
  3754       address dummy = (address) n;
  3755       constant_addr = _masm.address_constant(dummy);
  3756       // Expand jump-table
  3757       for (uint i = 1; i < n->outcnt(); i++) {
  3758         address temp_addr = _masm.address_constant(dummy + i);
  3759         assert(temp_addr, "consts section too small");
  3761       break;
  3763     case T_METADATA: {
  3764       Metadata* obj = con.get_metadata();
  3765       int metadata_index = _masm.oop_recorder()->find_index(obj);
  3766       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
  3767       break;
  3769     default: ShouldNotReachHere();
  3771     assert(constant_addr, "consts section too small");
  3772     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
  3773             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
  3777 int Compile::ConstantTable::find_offset(Constant& con) const {
  3778   int idx = _constants.find(con);
  3779   assert(idx != -1, "constant must be in constant table");
  3780   int offset = _constants.at(idx).offset();
  3781   assert(offset != -1, "constant table not emitted yet?");
  3782   return offset;
  3785 void Compile::ConstantTable::add(Constant& con) {
  3786   if (con.can_be_reused()) {
  3787     int idx = _constants.find(con);
  3788     if (idx != -1 && _constants.at(idx).can_be_reused()) {
  3789       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
  3790       return;
  3793   (void) _constants.append(con);
  3796 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
  3797   Block* b = Compile::current()->cfg()->get_block_for_node(n);
  3798   Constant con(type, value, b->_freq);
  3799   add(con);
  3800   return con;
  3803 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
  3804   Constant con(metadata);
  3805   add(con);
  3806   return con;
  3809 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
  3810   jvalue value;
  3811   BasicType type = oper->type()->basic_type();
  3812   switch (type) {
  3813   case T_LONG:    value.j = oper->constantL(); break;
  3814   case T_FLOAT:   value.f = oper->constantF(); break;
  3815   case T_DOUBLE:  value.d = oper->constantD(); break;
  3816   case T_OBJECT:
  3817   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
  3818   case T_METADATA: return add((Metadata*)oper->constant()); break;
  3819   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
  3821   return add(n, type, value);
  3824 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
  3825   jvalue value;
  3826   // We can use the node pointer here to identify the right jump-table
  3827   // as this method is called from Compile::Fill_buffer right before
  3828   // the MachNodes are emitted and the jump-table is filled (means the
  3829   // MachNode pointers do not change anymore).
  3830   value.l = (jobject) n;
  3831   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
  3832   add(con);
  3833   return con;
  3836 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
  3837   // If called from Compile::scratch_emit_size do nothing.
  3838   if (Compile::current()->in_scratch_emit_size())  return;
  3840   assert(labels.is_nonempty(), "must be");
  3841   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
  3843   // Since MachConstantNode::constant_offset() also contains
  3844   // table_base_offset() we need to subtract the table_base_offset()
  3845   // to get the plain offset into the constant table.
  3846   int offset = n->constant_offset() - table_base_offset();
  3848   MacroAssembler _masm(&cb);
  3849   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
  3851   for (uint i = 0; i < n->outcnt(); i++) {
  3852     address* constant_addr = &jump_table_base[i];
  3853     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, p2i(*constant_addr), p2i(((address) n) + i)));
  3854     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
  3855     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
  3859 void Compile::dump_inlining() {
  3860   if (print_inlining() || print_intrinsics()) {
  3861     // Print inlining message for candidates that we couldn't inline
  3862     // for lack of space or non constant receiver
  3863     for (int i = 0; i < _late_inlines.length(); i++) {
  3864       CallGenerator* cg = _late_inlines.at(i);
  3865       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
  3867     Unique_Node_List useful;
  3868     useful.push(root());
  3869     for (uint next = 0; next < useful.size(); ++next) {
  3870       Node* n  = useful.at(next);
  3871       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
  3872         CallNode* call = n->as_Call();
  3873         CallGenerator* cg = call->generator();
  3874         cg->print_inlining_late("receiver not constant");
  3876       uint max = n->len();
  3877       for ( uint i = 0; i < max; ++i ) {
  3878         Node *m = n->in(i);
  3879         if ( m == NULL ) continue;
  3880         useful.push(m);
  3883     for (int i = 0; i < _print_inlining_list->length(); i++) {
  3884       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
  3889 // Dump inlining replay data to the stream.
  3890 // Don't change thread state and acquire any locks.
  3891 void Compile::dump_inline_data(outputStream* out) {
  3892   InlineTree* inl_tree = ilt();
  3893   if (inl_tree != NULL) {
  3894     out->print(" inline %d", inl_tree->count());
  3895     inl_tree->dump_replay_data(out);
  3899 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
  3900   if (n1->Opcode() < n2->Opcode())      return -1;
  3901   else if (n1->Opcode() > n2->Opcode()) return 1;
  3903   assert(n1->req() == n2->req(), err_msg_res("can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req()));
  3904   for (uint i = 1; i < n1->req(); i++) {
  3905     if (n1->in(i) < n2->in(i))      return -1;
  3906     else if (n1->in(i) > n2->in(i)) return 1;
  3909   return 0;
  3912 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
  3913   Node* n1 = *n1p;
  3914   Node* n2 = *n2p;
  3916   return cmp_expensive_nodes(n1, n2);
  3919 void Compile::sort_expensive_nodes() {
  3920   if (!expensive_nodes_sorted()) {
  3921     _expensive_nodes->sort(cmp_expensive_nodes);
  3925 bool Compile::expensive_nodes_sorted() const {
  3926   for (int i = 1; i < _expensive_nodes->length(); i++) {
  3927     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
  3928       return false;
  3931   return true;
  3934 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
  3935   if (_expensive_nodes->length() == 0) {
  3936     return false;
  3939   assert(OptimizeExpensiveOps, "optimization off?");
  3941   // Take this opportunity to remove dead nodes from the list
  3942   int j = 0;
  3943   for (int i = 0; i < _expensive_nodes->length(); i++) {
  3944     Node* n = _expensive_nodes->at(i);
  3945     if (!n->is_unreachable(igvn)) {
  3946       assert(n->is_expensive(), "should be expensive");
  3947       _expensive_nodes->at_put(j, n);
  3948       j++;
  3951   _expensive_nodes->trunc_to(j);
  3953   // Then sort the list so that similar nodes are next to each other
  3954   // and check for at least two nodes of identical kind with same data
  3955   // inputs.
  3956   sort_expensive_nodes();
  3958   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
  3959     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
  3960       return true;
  3964   return false;
  3967 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
  3968   if (_expensive_nodes->length() == 0) {
  3969     return;
  3972   assert(OptimizeExpensiveOps, "optimization off?");
  3974   // Sort to bring similar nodes next to each other and clear the
  3975   // control input of nodes for which there's only a single copy.
  3976   sort_expensive_nodes();
  3978   int j = 0;
  3979   int identical = 0;
  3980   int i = 0;
  3981   for (; i < _expensive_nodes->length()-1; i++) {
  3982     assert(j <= i, "can't write beyond current index");
  3983     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
  3984       identical++;
  3985       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3986       continue;
  3988     if (identical > 0) {
  3989       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3990       identical = 0;
  3991     } else {
  3992       Node* n = _expensive_nodes->at(i);
  3993       igvn.hash_delete(n);
  3994       n->set_req(0, NULL);
  3995       igvn.hash_insert(n);
  3998   if (identical > 0) {
  3999     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  4000   } else if (_expensive_nodes->length() >= 1) {
  4001     Node* n = _expensive_nodes->at(i);
  4002     igvn.hash_delete(n);
  4003     n->set_req(0, NULL);
  4004     igvn.hash_insert(n);
  4006   _expensive_nodes->trunc_to(j);
  4009 void Compile::add_expensive_node(Node * n) {
  4010   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
  4011   assert(n->is_expensive(), "expensive nodes with non-null control here only");
  4012   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
  4013   if (OptimizeExpensiveOps) {
  4014     _expensive_nodes->append(n);
  4015   } else {
  4016     // Clear control input and let IGVN optimize expensive nodes if
  4017     // OptimizeExpensiveOps is off.
  4018     n->set_req(0, NULL);
  4022 /**
  4023  * Remove the speculative part of types and clean up the graph
  4024  */
  4025 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
  4026   if (UseTypeSpeculation) {
  4027     Unique_Node_List worklist;
  4028     worklist.push(root());
  4029     int modified = 0;
  4030     // Go over all type nodes that carry a speculative type, drop the
  4031     // speculative part of the type and enqueue the node for an igvn
  4032     // which may optimize it out.
  4033     for (uint next = 0; next < worklist.size(); ++next) {
  4034       Node *n  = worklist.at(next);
  4035       if (n->is_Type()) {
  4036         TypeNode* tn = n->as_Type();
  4037         const Type* t = tn->type();
  4038         const Type* t_no_spec = t->remove_speculative();
  4039         if (t_no_spec != t) {
  4040           bool in_hash = igvn.hash_delete(n);
  4041           assert(in_hash, "node should be in igvn hash table");
  4042           tn->set_type(t_no_spec);
  4043           igvn.hash_insert(n);
  4044           igvn._worklist.push(n); // give it a chance to go away
  4045           modified++;
  4048       uint max = n->len();
  4049       for( uint i = 0; i < max; ++i ) {
  4050         Node *m = n->in(i);
  4051         if (not_a_node(m))  continue;
  4052         worklist.push(m);
  4055     // Drop the speculative part of all types in the igvn's type table
  4056     igvn.remove_speculative_types();
  4057     if (modified > 0) {
  4058       igvn.optimize();
  4060 #ifdef ASSERT
  4061     // Verify that after the IGVN is over no speculative type has resurfaced
  4062     worklist.clear();
  4063     worklist.push(root());
  4064     for (uint next = 0; next < worklist.size(); ++next) {
  4065       Node *n  = worklist.at(next);
  4066       const Type* t = igvn.type_or_null(n);
  4067       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
  4068       if (n->is_Type()) {
  4069         t = n->as_Type()->type();
  4070         assert(t == t->remove_speculative(), "no more speculative types");
  4072       uint max = n->len();
  4073       for( uint i = 0; i < max; ++i ) {
  4074         Node *m = n->in(i);
  4075         if (not_a_node(m))  continue;
  4076         worklist.push(m);
  4079     igvn.check_no_speculative_types();
  4080 #endif
  4084 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
  4085 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
  4086   if (ctrl != NULL) {
  4087     // Express control dependency by a CastII node with a narrow type.
  4088     value = new (phase->C) CastIINode(value, itype, false, true /* range check dependency */);
  4089     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
  4090     // node from floating above the range check during loop optimizations. Otherwise, the
  4091     // ConvI2L node may be eliminated independently of the range check, causing the data path
  4092     // to become TOP while the control path is still there (although it's unreachable).
  4093     value->set_req(0, ctrl);
  4094     // Save CastII node to remove it after loop optimizations.
  4095     phase->C->add_range_check_cast(value);
  4096     value = phase->transform(value);
  4098   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
  4099   return phase->transform(new (phase->C) ConvI2LNode(value, ltype));
  4102 // Auxiliary method to support randomized stressing/fuzzing.
  4103 //
  4104 // This method can be called the arbitrary number of times, with current count
  4105 // as the argument. The logic allows selecting a single candidate from the
  4106 // running list of candidates as follows:
  4107 //    int count = 0;
  4108 //    Cand* selected = null;
  4109 //    while(cand = cand->next()) {
  4110 //      if (randomized_select(++count)) {
  4111 //        selected = cand;
  4112 //      }
  4113 //    }
  4114 //
  4115 // Including count equalizes the chances any candidate is "selected".
  4116 // This is useful when we don't have the complete list of candidates to choose
  4117 // from uniformly. In this case, we need to adjust the randomicity of the
  4118 // selection, or else we will end up biasing the selection towards the latter
  4119 // candidates.
  4120 //
  4121 // Quick back-envelope calculation shows that for the list of n candidates
  4122 // the equal probability for the candidate to persist as "best" can be
  4123 // achieved by replacing it with "next" k-th candidate with the probability
  4124 // of 1/k. It can be easily shown that by the end of the run, the
  4125 // probability for any candidate is converged to 1/n, thus giving the
  4126 // uniform distribution among all the candidates.
  4127 //
  4128 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
  4129 #define RANDOMIZED_DOMAIN_POW 29
  4130 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
  4131 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
  4132 bool Compile::randomized_select(int count) {
  4133   assert(count > 0, "only positive");
  4134   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);

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