src/share/vm/opto/compile.cpp

Wed, 10 Aug 2016 14:59:21 +0200

author
simonis
date
Wed, 10 Aug 2016 14:59:21 +0200
changeset 8608
0d78aecb0948
parent 8536
371fd9bb8202
child 8604
04d83ba48607
child 8654
2e734e824d16
permissions
-rw-r--r--

8152172: PPC64: Support AES intrinsics
Summary: Add support for AES intrinsics on PPC64.
Reviewed-by: kvn, mdoerr, simonis, zmajo
Contributed-by: Hiroshi H Horii <horii@jp.ibm.com>

     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 //---------------------------------print_on------------------------------------
  1599 #ifndef PRODUCT
  1600 void Compile::AliasType::print_on(outputStream* st) {
  1601   if (index() < 10)
  1602         st->print("@ <%d> ", index());
  1603   else  st->print("@ <%d>",  index());
  1604   st->print(is_rewritable() ? "   " : " RO");
  1605   int offset = adr_type()->offset();
  1606   if (offset == Type::OffsetBot)
  1607         st->print(" +any");
  1608   else  st->print(" +%-3d", offset);
  1609   st->print(" in ");
  1610   adr_type()->dump_on(st);
  1611   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1612   if (field() != NULL && tjp) {
  1613     if (tjp->klass()  != field()->holder() ||
  1614         tjp->offset() != field()->offset_in_bytes()) {
  1615       st->print(" != ");
  1616       field()->print();
  1617       st->print(" ***");
  1622 void print_alias_types() {
  1623   Compile* C = Compile::current();
  1624   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1625   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1626     C->alias_type(idx)->print_on(tty);
  1627     tty->cr();
  1630 #endif
  1633 //----------------------------probe_alias_cache--------------------------------
  1634 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1635   intptr_t key = (intptr_t) adr_type;
  1636   key ^= key >> logAliasCacheSize;
  1637   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1641 //-----------------------------grow_alias_types--------------------------------
  1642 void Compile::grow_alias_types() {
  1643   const int old_ats  = _max_alias_types; // how many before?
  1644   const int new_ats  = old_ats;          // how many more?
  1645   const int grow_ats = old_ats+new_ats;  // how many now?
  1646   _max_alias_types = grow_ats;
  1647   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1648   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1649   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1650   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1654 //--------------------------------find_alias_type------------------------------
  1655 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
  1656   if (_AliasLevel == 0)
  1657     return alias_type(AliasIdxBot);
  1659   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1660   if (ace->_adr_type == adr_type) {
  1661     return alias_type(ace->_index);
  1664   // Handle special cases.
  1665   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1666   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1668   // Do it the slow way.
  1669   const TypePtr* flat = flatten_alias_type(adr_type);
  1671 #ifdef ASSERT
  1672   assert(flat == flatten_alias_type(flat), "idempotent");
  1673   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1674   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1675     const TypeOopPtr* foop = flat->is_oopptr();
  1676     // Scalarizable allocations have exact klass always.
  1677     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1678     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1679     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1681   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1682 #endif
  1684   int idx = AliasIdxTop;
  1685   for (int i = 0; i < num_alias_types(); i++) {
  1686     if (alias_type(i)->adr_type() == flat) {
  1687       idx = i;
  1688       break;
  1692   if (idx == AliasIdxTop) {
  1693     if (no_create)  return NULL;
  1694     // Grow the array if necessary.
  1695     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1696     // Add a new alias type.
  1697     idx = _num_alias_types++;
  1698     _alias_types[idx]->Init(idx, flat);
  1699     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1700     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1701     if (flat->isa_instptr()) {
  1702       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1703           && flat->is_instptr()->klass() == env()->Class_klass())
  1704         alias_type(idx)->set_rewritable(false);
  1706     if (flat->isa_aryptr()) {
  1707 #ifdef ASSERT
  1708       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1709       // (T_BYTE has the weakest alignment and size restrictions...)
  1710       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
  1711 #endif
  1712       if (flat->offset() == TypePtr::OffsetBot) {
  1713         alias_type(idx)->set_element(flat->is_aryptr()->elem());
  1716     if (flat->isa_klassptr()) {
  1717       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
  1718         alias_type(idx)->set_rewritable(false);
  1719       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
  1720         alias_type(idx)->set_rewritable(false);
  1721       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
  1722         alias_type(idx)->set_rewritable(false);
  1723       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
  1724         alias_type(idx)->set_rewritable(false);
  1726     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1727     // but the base pointer type is not distinctive enough to identify
  1728     // references into JavaThread.)
  1730     // Check for final fields.
  1731     const TypeInstPtr* tinst = flat->isa_instptr();
  1732     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1733       ciField* field;
  1734       if (tinst->const_oop() != NULL &&
  1735           tinst->klass() == ciEnv::current()->Class_klass() &&
  1736           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
  1737         // static field
  1738         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
  1739         field = k->get_field_by_offset(tinst->offset(), true);
  1740       } else {
  1741         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1742         field = k->get_field_by_offset(tinst->offset(), false);
  1744       assert(field == NULL ||
  1745              original_field == NULL ||
  1746              (field->holder() == original_field->holder() &&
  1747               field->offset() == original_field->offset() &&
  1748               field->is_static() == original_field->is_static()), "wrong field?");
  1749       // Set field() and is_rewritable() attributes.
  1750       if (field != NULL)  alias_type(idx)->set_field(field);
  1754   // Fill the cache for next time.
  1755   ace->_adr_type = adr_type;
  1756   ace->_index    = idx;
  1757   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1759   // Might as well try to fill the cache for the flattened version, too.
  1760   AliasCacheEntry* face = probe_alias_cache(flat);
  1761   if (face->_adr_type == NULL) {
  1762     face->_adr_type = flat;
  1763     face->_index    = idx;
  1764     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1767   return alias_type(idx);
  1771 Compile::AliasType* Compile::alias_type(ciField* field) {
  1772   const TypeOopPtr* t;
  1773   if (field->is_static())
  1774     t = TypeInstPtr::make(field->holder()->java_mirror());
  1775   else
  1776     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1777   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
  1778   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
  1779   return atp;
  1783 //------------------------------have_alias_type--------------------------------
  1784 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1785   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1786   if (ace->_adr_type == adr_type) {
  1787     return true;
  1790   // Handle special cases.
  1791   if (adr_type == NULL)             return true;
  1792   if (adr_type == TypePtr::BOTTOM)  return true;
  1794   return find_alias_type(adr_type, true, NULL) != NULL;
  1797 //-----------------------------must_alias--------------------------------------
  1798 // True if all values of the given address type are in the given alias category.
  1799 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1800   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1801   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1802   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1803   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1805   // the only remaining possible overlap is identity
  1806   int adr_idx = get_alias_index(adr_type);
  1807   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1808   assert(adr_idx == alias_idx ||
  1809          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1810           && adr_type                       != TypeOopPtr::BOTTOM),
  1811          "should not be testing for overlap with an unsafe pointer");
  1812   return adr_idx == alias_idx;
  1815 //------------------------------can_alias--------------------------------------
  1816 // True if any values of the given address type are in the given alias category.
  1817 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1818   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1819   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1820   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1821   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1823   // the only remaining possible overlap is identity
  1824   int adr_idx = get_alias_index(adr_type);
  1825   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1826   return adr_idx == alias_idx;
  1831 //---------------------------pop_warm_call-------------------------------------
  1832 WarmCallInfo* Compile::pop_warm_call() {
  1833   WarmCallInfo* wci = _warm_calls;
  1834   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1835   return wci;
  1838 //----------------------------Inline_Warm--------------------------------------
  1839 int Compile::Inline_Warm() {
  1840   // If there is room, try to inline some more warm call sites.
  1841   // %%% Do a graph index compaction pass when we think we're out of space?
  1842   if (!InlineWarmCalls)  return 0;
  1844   int calls_made_hot = 0;
  1845   int room_to_grow   = NodeCountInliningCutoff - unique();
  1846   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1847   int amount_grown   = 0;
  1848   WarmCallInfo* call;
  1849   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1850     int est_size = (int)call->size();
  1851     if (est_size > (room_to_grow - amount_grown)) {
  1852       // This one won't fit anyway.  Get rid of it.
  1853       call->make_cold();
  1854       continue;
  1856     call->make_hot();
  1857     calls_made_hot++;
  1858     amount_grown   += est_size;
  1859     amount_to_grow -= est_size;
  1862   if (calls_made_hot > 0)  set_major_progress();
  1863   return calls_made_hot;
  1867 //----------------------------Finish_Warm--------------------------------------
  1868 void Compile::Finish_Warm() {
  1869   if (!InlineWarmCalls)  return;
  1870   if (failing())  return;
  1871   if (warm_calls() == NULL)  return;
  1873   // Clean up loose ends, if we are out of space for inlining.
  1874   WarmCallInfo* call;
  1875   while ((call = pop_warm_call()) != NULL) {
  1876     call->make_cold();
  1880 //---------------------cleanup_loop_predicates-----------------------
  1881 // Remove the opaque nodes that protect the predicates so that all unused
  1882 // checks and uncommon_traps will be eliminated from the ideal graph
  1883 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1884   if (predicate_count()==0) return;
  1885   for (int i = predicate_count(); i > 0; i--) {
  1886     Node * n = predicate_opaque1_node(i-1);
  1887     assert(n->Opcode() == Op_Opaque1, "must be");
  1888     igvn.replace_node(n, n->in(1));
  1890   assert(predicate_count()==0, "should be clean!");
  1893 void Compile::add_range_check_cast(Node* n) {
  1894   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
  1895   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
  1896   _range_check_casts->append(n);
  1899 // Remove all range check dependent CastIINodes.
  1900 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
  1901   for (int i = range_check_cast_count(); i > 0; i--) {
  1902     Node* cast = range_check_cast_node(i-1);
  1903     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
  1904     igvn.replace_node(cast, cast->in(1));
  1906   assert(range_check_cast_count() == 0, "should be empty");
  1909 // StringOpts and late inlining of string methods
  1910 void Compile::inline_string_calls(bool parse_time) {
  1912     // remove useless nodes to make the usage analysis simpler
  1913     ResourceMark rm;
  1914     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  1918     ResourceMark rm;
  1919     print_method(PHASE_BEFORE_STRINGOPTS, 3);
  1920     PhaseStringOpts pso(initial_gvn(), for_igvn());
  1921     print_method(PHASE_AFTER_STRINGOPTS, 3);
  1924   // now inline anything that we skipped the first time around
  1925   if (!parse_time) {
  1926     _late_inlines_pos = _late_inlines.length();
  1929   while (_string_late_inlines.length() > 0) {
  1930     CallGenerator* cg = _string_late_inlines.pop();
  1931     cg->do_late_inline();
  1932     if (failing())  return;
  1934   _string_late_inlines.trunc_to(0);
  1937 // Late inlining of boxing methods
  1938 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
  1939   if (_boxing_late_inlines.length() > 0) {
  1940     assert(has_boxed_value(), "inconsistent");
  1942     PhaseGVN* gvn = initial_gvn();
  1943     set_inlining_incrementally(true);
  1945     assert( igvn._worklist.size() == 0, "should be done with igvn" );
  1946     for_igvn()->clear();
  1947     gvn->replace_with(&igvn);
  1949     _late_inlines_pos = _late_inlines.length();
  1951     while (_boxing_late_inlines.length() > 0) {
  1952       CallGenerator* cg = _boxing_late_inlines.pop();
  1953       cg->do_late_inline();
  1954       if (failing())  return;
  1956     _boxing_late_inlines.trunc_to(0);
  1959       ResourceMark rm;
  1960       PhaseRemoveUseless pru(gvn, for_igvn());
  1963     igvn = PhaseIterGVN(gvn);
  1964     igvn.optimize();
  1966     set_inlining_progress(false);
  1967     set_inlining_incrementally(false);
  1971 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
  1972   assert(IncrementalInline, "incremental inlining should be on");
  1973   PhaseGVN* gvn = initial_gvn();
  1975   set_inlining_progress(false);
  1976   for_igvn()->clear();
  1977   gvn->replace_with(&igvn);
  1979   int i = 0;
  1981   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
  1982     CallGenerator* cg = _late_inlines.at(i);
  1983     _late_inlines_pos = i+1;
  1984     cg->do_late_inline();
  1985     if (failing())  return;
  1987   int j = 0;
  1988   for (; i < _late_inlines.length(); i++, j++) {
  1989     _late_inlines.at_put(j, _late_inlines.at(i));
  1991   _late_inlines.trunc_to(j);
  1994     ResourceMark rm;
  1995     PhaseRemoveUseless pru(gvn, for_igvn());
  1998   igvn = PhaseIterGVN(gvn);
  2001 // Perform incremental inlining until bound on number of live nodes is reached
  2002 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
  2003   PhaseGVN* gvn = initial_gvn();
  2005   set_inlining_incrementally(true);
  2006   set_inlining_progress(true);
  2007   uint low_live_nodes = 0;
  2009   while(inlining_progress() && _late_inlines.length() > 0) {
  2011     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2012       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
  2013         // PhaseIdealLoop is expensive so we only try it once we are
  2014         // out of live nodes and we only try it again if the previous
  2015         // helped got the number of nodes down significantly
  2016         PhaseIdealLoop ideal_loop( igvn, false, true );
  2017         if (failing())  return;
  2018         low_live_nodes = live_nodes();
  2019         _major_progress = true;
  2022       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2023         break;
  2027     inline_incrementally_one(igvn);
  2029     if (failing())  return;
  2031     igvn.optimize();
  2033     if (failing())  return;
  2036   assert( igvn._worklist.size() == 0, "should be done with igvn" );
  2038   if (_string_late_inlines.length() > 0) {
  2039     assert(has_stringbuilder(), "inconsistent");
  2040     for_igvn()->clear();
  2041     initial_gvn()->replace_with(&igvn);
  2043     inline_string_calls(false);
  2045     if (failing())  return;
  2048       ResourceMark rm;
  2049       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  2052     igvn = PhaseIterGVN(gvn);
  2054     igvn.optimize();
  2057   set_inlining_incrementally(false);
  2061 //------------------------------Optimize---------------------------------------
  2062 // Given a graph, optimize it.
  2063 void Compile::Optimize() {
  2064   TracePhase t1("optimizer", &_t_optimizer, true);
  2066 #ifndef PRODUCT
  2067   if (env()->break_at_compile()) {
  2068     BREAKPOINT;
  2071 #endif
  2073   ResourceMark rm;
  2074   int          loop_opts_cnt;
  2076   NOT_PRODUCT( verify_graph_edges(); )
  2078   print_method(PHASE_AFTER_PARSING);
  2081   // Iterative Global Value Numbering, including ideal transforms
  2082   // Initialize IterGVN with types and values from parse-time GVN
  2083   PhaseIterGVN igvn(initial_gvn());
  2085     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  2086     igvn.optimize();
  2089   print_method(PHASE_ITER_GVN1, 2);
  2091   if (failing())  return;
  2094     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2095     inline_incrementally(igvn);
  2098   print_method(PHASE_INCREMENTAL_INLINE, 2);
  2100   if (failing())  return;
  2102   if (eliminate_boxing()) {
  2103     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2104     // Inline valueOf() methods now.
  2105     inline_boxing_calls(igvn);
  2107     if (AlwaysIncrementalInline) {
  2108       inline_incrementally(igvn);
  2111     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
  2113     if (failing())  return;
  2116   // Remove the speculative part of types and clean up the graph from
  2117   // the extra CastPP nodes whose only purpose is to carry them. Do
  2118   // that early so that optimizations are not disrupted by the extra
  2119   // CastPP nodes.
  2120   remove_speculative_types(igvn);
  2122   // No more new expensive nodes will be added to the list from here
  2123   // so keep only the actual candidates for optimizations.
  2124   cleanup_expensive_nodes(igvn);
  2126   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
  2127     NOT_PRODUCT(Compile::TracePhase t2("", &_t_renumberLive, TimeCompiler);)
  2128     initial_gvn()->replace_with(&igvn);
  2129     for_igvn()->clear();
  2130     Unique_Node_List new_worklist(C->comp_arena());
  2132       ResourceMark rm;
  2133       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
  2135     set_for_igvn(&new_worklist);
  2136     igvn = PhaseIterGVN(initial_gvn());
  2137     igvn.optimize();
  2140   // Perform escape analysis
  2141   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
  2142     if (has_loops()) {
  2143       // Cleanup graph (remove dead nodes).
  2144       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2145       PhaseIdealLoop ideal_loop( igvn, false, true );
  2146       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
  2147       if (failing())  return;
  2149     ConnectionGraph::do_analysis(this, &igvn);
  2151     if (failing())  return;
  2153     // Optimize out fields loads from scalar replaceable allocations.
  2154     igvn.optimize();
  2155     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
  2157     if (failing())  return;
  2159     if (congraph() != NULL && macro_count() > 0) {
  2160       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
  2161       PhaseMacroExpand mexp(igvn);
  2162       mexp.eliminate_macro_nodes();
  2163       igvn.set_delay_transform(false);
  2165       igvn.optimize();
  2166       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
  2168       if (failing())  return;
  2172   // Loop transforms on the ideal graph.  Range Check Elimination,
  2173   // peeling, unrolling, etc.
  2175   // Set loop opts counter
  2176   loop_opts_cnt = num_loop_opts();
  2177   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  2179       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2180       PhaseIdealLoop ideal_loop( igvn, true );
  2181       loop_opts_cnt--;
  2182       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
  2183       if (failing())  return;
  2185     // Loop opts pass if partial peeling occurred in previous pass
  2186     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  2187       TracePhase t3("idealLoop", &_t_idealLoop, true);
  2188       PhaseIdealLoop ideal_loop( igvn, false );
  2189       loop_opts_cnt--;
  2190       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
  2191       if (failing())  return;
  2193     // Loop opts pass for loop-unrolling before CCP
  2194     if(major_progress() && (loop_opts_cnt > 0)) {
  2195       TracePhase t4("idealLoop", &_t_idealLoop, true);
  2196       PhaseIdealLoop ideal_loop( igvn, false );
  2197       loop_opts_cnt--;
  2198       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
  2200     if (!failing()) {
  2201       // Verify that last round of loop opts produced a valid graph
  2202       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2203       PhaseIdealLoop::verify(igvn);
  2206   if (failing())  return;
  2208   // Conditional Constant Propagation;
  2209   PhaseCCP ccp( &igvn );
  2210   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  2212     TracePhase t2("ccp", &_t_ccp, true);
  2213     ccp.do_transform();
  2215   print_method(PHASE_CPP1, 2);
  2217   assert( true, "Break here to ccp.dump_old2new_map()");
  2219   // Iterative Global Value Numbering, including ideal transforms
  2221     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  2222     igvn = ccp;
  2223     igvn.optimize();
  2226   print_method(PHASE_ITER_GVN2, 2);
  2228   if (failing())  return;
  2230   // Loop transforms on the ideal graph.  Range Check Elimination,
  2231   // peeling, unrolling, etc.
  2232   if(loop_opts_cnt > 0) {
  2233     debug_only( int cnt = 0; );
  2234     while(major_progress() && (loop_opts_cnt > 0)) {
  2235       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2236       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  2237       PhaseIdealLoop ideal_loop( igvn, true);
  2238       loop_opts_cnt--;
  2239       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
  2240       if (failing())  return;
  2245     // Verify that all previous optimizations produced a valid graph
  2246     // at least to this point, even if no loop optimizations were done.
  2247     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2248     PhaseIdealLoop::verify(igvn);
  2251   if (range_check_cast_count() > 0) {
  2252     // No more loop optimizations. Remove all range check dependent CastIINodes.
  2253     C->remove_range_check_casts(igvn);
  2254     igvn.optimize();
  2258     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  2259     PhaseMacroExpand  mex(igvn);
  2260     if (mex.expand_macro_nodes()) {
  2261       assert(failing(), "must bail out w/ explicit message");
  2262       return;
  2266  } // (End scope of igvn; run destructor if necessary for asserts.)
  2268   dump_inlining();
  2269   // A method with only infinite loops has no edges entering loops from root
  2271     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  2272     if (final_graph_reshaping()) {
  2273       assert(failing(), "must bail out w/ explicit message");
  2274       return;
  2278   print_method(PHASE_OPTIMIZE_FINISHED, 2);
  2282 //------------------------------Code_Gen---------------------------------------
  2283 // Given a graph, generate code for it
  2284 void Compile::Code_Gen() {
  2285   if (failing()) {
  2286     return;
  2289   // Perform instruction selection.  You might think we could reclaim Matcher
  2290   // memory PDQ, but actually the Matcher is used in generating spill code.
  2291   // Internals of the Matcher (including some VectorSets) must remain live
  2292   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  2293   // set a bit in reclaimed memory.
  2295   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2296   // nodes.  Mapping is only valid at the root of each matched subtree.
  2297   NOT_PRODUCT( verify_graph_edges(); )
  2299   Matcher matcher;
  2300   _matcher = &matcher;
  2302     TracePhase t2("matcher", &_t_matcher, true);
  2303     matcher.match();
  2305   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2306   // nodes.  Mapping is only valid at the root of each matched subtree.
  2307   NOT_PRODUCT( verify_graph_edges(); )
  2309   // If you have too many nodes, or if matching has failed, bail out
  2310   check_node_count(0, "out of nodes matching instructions");
  2311   if (failing()) {
  2312     return;
  2315   // Build a proper-looking CFG
  2316   PhaseCFG cfg(node_arena(), root(), matcher);
  2317   _cfg = &cfg;
  2319     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  2320     bool success = cfg.do_global_code_motion();
  2321     if (!success) {
  2322       return;
  2325     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
  2326     NOT_PRODUCT( verify_graph_edges(); )
  2327     debug_only( cfg.verify(); )
  2330   PhaseChaitin regalloc(unique(), cfg, matcher);
  2331   _regalloc = &regalloc;
  2333     TracePhase t2("regalloc", &_t_registerAllocation, true);
  2334     // Perform register allocation.  After Chaitin, use-def chains are
  2335     // no longer accurate (at spill code) and so must be ignored.
  2336     // Node->LRG->reg mappings are still accurate.
  2337     _regalloc->Register_Allocate();
  2339     // Bail out if the allocator builds too many nodes
  2340     if (failing()) {
  2341       return;
  2345   // Prior to register allocation we kept empty basic blocks in case the
  2346   // the allocator needed a place to spill.  After register allocation we
  2347   // are not adding any new instructions.  If any basic block is empty, we
  2348   // can now safely remove it.
  2350     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  2351     cfg.remove_empty_blocks();
  2352     if (do_freq_based_layout()) {
  2353       PhaseBlockLayout layout(cfg);
  2354     } else {
  2355       cfg.set_loop_alignment();
  2357     cfg.fixup_flow();
  2360   // Apply peephole optimizations
  2361   if( OptoPeephole ) {
  2362     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  2363     PhasePeephole peep( _regalloc, cfg);
  2364     peep.do_transform();
  2367   // Do late expand if CPU requires this.
  2368   if (Matcher::require_postalloc_expand) {
  2369     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
  2370     cfg.postalloc_expand(_regalloc);
  2373   // Convert Nodes to instruction bits in a buffer
  2375     // %%%% workspace merge brought two timers together for one job
  2376     TracePhase t2a("output", &_t_output, true);
  2377     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  2378     Output();
  2381   print_method(PHASE_FINAL_CODE);
  2383   // He's dead, Jim.
  2384   _cfg     = (PhaseCFG*)0xdeadbeef;
  2385   _regalloc = (PhaseChaitin*)0xdeadbeef;
  2389 //------------------------------dump_asm---------------------------------------
  2390 // Dump formatted assembly
  2391 #ifndef PRODUCT
  2392 void Compile::dump_asm(int *pcs, uint pc_limit) {
  2393   bool cut_short = false;
  2394   tty->print_cr("#");
  2395   tty->print("#  ");  _tf->dump();  tty->cr();
  2396   tty->print_cr("#");
  2398   // For all blocks
  2399   int pc = 0x0;                 // Program counter
  2400   char starts_bundle = ' ';
  2401   _regalloc->dump_frame();
  2403   Node *n = NULL;
  2404   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  2405     if (VMThread::should_terminate()) {
  2406       cut_short = true;
  2407       break;
  2409     Block* block = _cfg->get_block(i);
  2410     if (block->is_connector() && !Verbose) {
  2411       continue;
  2413     n = block->head();
  2414     if (pcs && n->_idx < pc_limit) {
  2415       tty->print("%3.3x   ", pcs[n->_idx]);
  2416     } else {
  2417       tty->print("      ");
  2419     block->dump_head(_cfg);
  2420     if (block->is_connector()) {
  2421       tty->print_cr("        # Empty connector block");
  2422     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  2423       tty->print_cr("        # Block is sole successor of call");
  2426     // For all instructions
  2427     Node *delay = NULL;
  2428     for (uint j = 0; j < block->number_of_nodes(); j++) {
  2429       if (VMThread::should_terminate()) {
  2430         cut_short = true;
  2431         break;
  2433       n = block->get_node(j);
  2434       if (valid_bundle_info(n)) {
  2435         Bundle* bundle = node_bundling(n);
  2436         if (bundle->used_in_unconditional_delay()) {
  2437           delay = n;
  2438           continue;
  2440         if (bundle->starts_bundle()) {
  2441           starts_bundle = '+';
  2445       if (WizardMode) {
  2446         n->dump();
  2449       if( !n->is_Region() &&    // Dont print in the Assembly
  2450           !n->is_Phi() &&       // a few noisely useless nodes
  2451           !n->is_Proj() &&
  2452           !n->is_MachTemp() &&
  2453           !n->is_SafePointScalarObject() &&
  2454           !n->is_Catch() &&     // Would be nice to print exception table targets
  2455           !n->is_MergeMem() &&  // Not very interesting
  2456           !n->is_top() &&       // Debug info table constants
  2457           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  2458           ) {
  2459         if (pcs && n->_idx < pc_limit)
  2460           tty->print("%3.3x", pcs[n->_idx]);
  2461         else
  2462           tty->print("   ");
  2463         tty->print(" %c ", starts_bundle);
  2464         starts_bundle = ' ';
  2465         tty->print("\t");
  2466         n->format(_regalloc, tty);
  2467         tty->cr();
  2470       // If we have an instruction with a delay slot, and have seen a delay,
  2471       // then back up and print it
  2472       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  2473         assert(delay != NULL, "no unconditional delay instruction");
  2474         if (WizardMode) delay->dump();
  2476         if (node_bundling(delay)->starts_bundle())
  2477           starts_bundle = '+';
  2478         if (pcs && n->_idx < pc_limit)
  2479           tty->print("%3.3x", pcs[n->_idx]);
  2480         else
  2481           tty->print("   ");
  2482         tty->print(" %c ", starts_bundle);
  2483         starts_bundle = ' ';
  2484         tty->print("\t");
  2485         delay->format(_regalloc, tty);
  2486         tty->cr();
  2487         delay = NULL;
  2490       // Dump the exception table as well
  2491       if( n->is_Catch() && (Verbose || WizardMode) ) {
  2492         // Print the exception table for this offset
  2493         _handler_table.print_subtable_for(pc);
  2497     if (pcs && n->_idx < pc_limit)
  2498       tty->print_cr("%3.3x", pcs[n->_idx]);
  2499     else
  2500       tty->cr();
  2502     assert(cut_short || delay == NULL, "no unconditional delay branch");
  2504   } // End of per-block dump
  2505   tty->cr();
  2507   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  2509 #endif
  2511 //------------------------------Final_Reshape_Counts---------------------------
  2512 // This class defines counters to help identify when a method
  2513 // may/must be executed using hardware with only 24-bit precision.
  2514 struct Final_Reshape_Counts : public StackObj {
  2515   int  _call_count;             // count non-inlined 'common' calls
  2516   int  _float_count;            // count float ops requiring 24-bit precision
  2517   int  _double_count;           // count double ops requiring more precision
  2518   int  _java_call_count;        // count non-inlined 'java' calls
  2519   int  _inner_loop_count;       // count loops which need alignment
  2520   VectorSet _visited;           // Visitation flags
  2521   Node_List _tests;             // Set of IfNodes & PCTableNodes
  2523   Final_Reshape_Counts() :
  2524     _call_count(0), _float_count(0), _double_count(0),
  2525     _java_call_count(0), _inner_loop_count(0),
  2526     _visited( Thread::current()->resource_area() ) { }
  2528   void inc_call_count  () { _call_count  ++; }
  2529   void inc_float_count () { _float_count ++; }
  2530   void inc_double_count() { _double_count++; }
  2531   void inc_java_call_count() { _java_call_count++; }
  2532   void inc_inner_loop_count() { _inner_loop_count++; }
  2534   int  get_call_count  () const { return _call_count  ; }
  2535   int  get_float_count () const { return _float_count ; }
  2536   int  get_double_count() const { return _double_count; }
  2537   int  get_java_call_count() const { return _java_call_count; }
  2538   int  get_inner_loop_count() const { return _inner_loop_count; }
  2539 };
  2541 #ifdef ASSERT
  2542 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  2543   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  2544   // Make sure the offset goes inside the instance layout.
  2545   return k->contains_field_offset(tp->offset());
  2546   // Note that OffsetBot and OffsetTop are very negative.
  2548 #endif
  2550 // Eliminate trivially redundant StoreCMs and accumulate their
  2551 // precedence edges.
  2552 void Compile::eliminate_redundant_card_marks(Node* n) {
  2553   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
  2554   if (n->in(MemNode::Address)->outcnt() > 1) {
  2555     // There are multiple users of the same address so it might be
  2556     // possible to eliminate some of the StoreCMs
  2557     Node* mem = n->in(MemNode::Memory);
  2558     Node* adr = n->in(MemNode::Address);
  2559     Node* val = n->in(MemNode::ValueIn);
  2560     Node* prev = n;
  2561     bool done = false;
  2562     // Walk the chain of StoreCMs eliminating ones that match.  As
  2563     // long as it's a chain of single users then the optimization is
  2564     // safe.  Eliminating partially redundant StoreCMs would require
  2565     // cloning copies down the other paths.
  2566     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
  2567       if (adr == mem->in(MemNode::Address) &&
  2568           val == mem->in(MemNode::ValueIn)) {
  2569         // redundant StoreCM
  2570         if (mem->req() > MemNode::OopStore) {
  2571           // Hasn't been processed by this code yet.
  2572           n->add_prec(mem->in(MemNode::OopStore));
  2573         } else {
  2574           // Already converted to precedence edge
  2575           for (uint i = mem->req(); i < mem->len(); i++) {
  2576             // Accumulate any precedence edges
  2577             if (mem->in(i) != NULL) {
  2578               n->add_prec(mem->in(i));
  2581           // Everything above this point has been processed.
  2582           done = true;
  2584         // Eliminate the previous StoreCM
  2585         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
  2586         assert(mem->outcnt() == 0, "should be dead");
  2587         mem->disconnect_inputs(NULL, this);
  2588       } else {
  2589         prev = mem;
  2591       mem = prev->in(MemNode::Memory);
  2596 //------------------------------final_graph_reshaping_impl----------------------
  2597 // Implement items 1-5 from final_graph_reshaping below.
  2598 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
  2600   if ( n->outcnt() == 0 ) return; // dead node
  2601   uint nop = n->Opcode();
  2603   // Check for 2-input instruction with "last use" on right input.
  2604   // Swap to left input.  Implements item (2).
  2605   if( n->req() == 3 &&          // two-input instruction
  2606       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  2607       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  2608       n->in(2)->outcnt() == 1 &&// right use IS a last use
  2609       !n->in(2)->is_Con() ) {   // right use is not a constant
  2610     // Check for commutative opcode
  2611     switch( nop ) {
  2612     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  2613     case Op_MaxI:  case Op_MinI:
  2614     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  2615     case Op_AndL:  case Op_XorL:  case Op_OrL:
  2616     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  2617       // Move "last use" input to left by swapping inputs
  2618       n->swap_edges(1, 2);
  2619       break;
  2621     default:
  2622       break;
  2626 #ifdef ASSERT
  2627   if( n->is_Mem() ) {
  2628     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
  2629     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2630             // oop will be recorded in oop map if load crosses safepoint
  2631             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2632                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2633             "raw memory operations should have control edge");
  2635 #endif
  2636   // Count FPU ops and common calls, implements item (3)
  2637   switch( nop ) {
  2638   // Count all float operations that may use FPU
  2639   case Op_AddF:
  2640   case Op_SubF:
  2641   case Op_MulF:
  2642   case Op_DivF:
  2643   case Op_NegF:
  2644   case Op_ModF:
  2645   case Op_ConvI2F:
  2646   case Op_ConF:
  2647   case Op_CmpF:
  2648   case Op_CmpF3:
  2649   // case Op_ConvL2F: // longs are split into 32-bit halves
  2650     frc.inc_float_count();
  2651     break;
  2653   case Op_ConvF2D:
  2654   case Op_ConvD2F:
  2655     frc.inc_float_count();
  2656     frc.inc_double_count();
  2657     break;
  2659   // Count all double operations that may use FPU
  2660   case Op_AddD:
  2661   case Op_SubD:
  2662   case Op_MulD:
  2663   case Op_DivD:
  2664   case Op_NegD:
  2665   case Op_ModD:
  2666   case Op_ConvI2D:
  2667   case Op_ConvD2I:
  2668   // case Op_ConvL2D: // handled by leaf call
  2669   // case Op_ConvD2L: // handled by leaf call
  2670   case Op_ConD:
  2671   case Op_CmpD:
  2672   case Op_CmpD3:
  2673     frc.inc_double_count();
  2674     break;
  2675   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2676   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2677   case Op_Opaque3:
  2678     n->subsume_by(n->in(1), this);
  2679     break;
  2680   case Op_CallStaticJava:
  2681   case Op_CallJava:
  2682   case Op_CallDynamicJava:
  2683     frc.inc_java_call_count(); // Count java call site;
  2684   case Op_CallRuntime:
  2685   case Op_CallLeaf:
  2686   case Op_CallLeafNoFP: {
  2687     assert( n->is_Call(), "" );
  2688     CallNode *call = n->as_Call();
  2689     // Count call sites where the FP mode bit would have to be flipped.
  2690     // Do not count uncommon runtime calls:
  2691     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2692     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2693     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2694       frc.inc_call_count();   // Count the call site
  2695     } else {                  // See if uncommon argument is shared
  2696       Node *n = call->in(TypeFunc::Parms);
  2697       int nop = n->Opcode();
  2698       // Clone shared simple arguments to uncommon calls, item (1).
  2699       if( n->outcnt() > 1 &&
  2700           !n->is_Proj() &&
  2701           nop != Op_CreateEx &&
  2702           nop != Op_CheckCastPP &&
  2703           nop != Op_DecodeN &&
  2704           nop != Op_DecodeNKlass &&
  2705           !n->is_Mem() ) {
  2706         Node *x = n->clone();
  2707         call->set_req( TypeFunc::Parms, x );
  2710     break;
  2713   case Op_StoreD:
  2714   case Op_LoadD:
  2715   case Op_LoadD_unaligned:
  2716     frc.inc_double_count();
  2717     goto handle_mem;
  2718   case Op_StoreF:
  2719   case Op_LoadF:
  2720     frc.inc_float_count();
  2721     goto handle_mem;
  2723   case Op_StoreCM:
  2725       // Convert OopStore dependence into precedence edge
  2726       Node* prec = n->in(MemNode::OopStore);
  2727       n->del_req(MemNode::OopStore);
  2728       n->add_prec(prec);
  2729       eliminate_redundant_card_marks(n);
  2732     // fall through
  2734   case Op_StoreB:
  2735   case Op_StoreC:
  2736   case Op_StorePConditional:
  2737   case Op_StoreI:
  2738   case Op_StoreL:
  2739   case Op_StoreIConditional:
  2740   case Op_StoreLConditional:
  2741   case Op_CompareAndSwapI:
  2742   case Op_CompareAndSwapL:
  2743   case Op_CompareAndSwapP:
  2744   case Op_CompareAndSwapN:
  2745   case Op_GetAndAddI:
  2746   case Op_GetAndAddL:
  2747   case Op_GetAndSetI:
  2748   case Op_GetAndSetL:
  2749   case Op_GetAndSetP:
  2750   case Op_GetAndSetN:
  2751   case Op_StoreP:
  2752   case Op_StoreN:
  2753   case Op_StoreNKlass:
  2754   case Op_LoadB:
  2755   case Op_LoadUB:
  2756   case Op_LoadUS:
  2757   case Op_LoadI:
  2758   case Op_LoadKlass:
  2759   case Op_LoadNKlass:
  2760   case Op_LoadL:
  2761   case Op_LoadL_unaligned:
  2762   case Op_LoadPLocked:
  2763   case Op_LoadP:
  2764   case Op_LoadN:
  2765   case Op_LoadRange:
  2766   case Op_LoadS: {
  2767   handle_mem:
  2768 #ifdef ASSERT
  2769     if( VerifyOptoOopOffsets ) {
  2770       assert( n->is_Mem(), "" );
  2771       MemNode *mem  = (MemNode*)n;
  2772       // Check to see if address types have grounded out somehow.
  2773       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2774       assert( !tp || oop_offset_is_sane(tp), "" );
  2776 #endif
  2777     break;
  2780   case Op_AddP: {               // Assert sane base pointers
  2781     Node *addp = n->in(AddPNode::Address);
  2782     assert( !addp->is_AddP() ||
  2783             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2784             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2785             "Base pointers must match" );
  2786 #ifdef _LP64
  2787     if ((UseCompressedOops || UseCompressedClassPointers) &&
  2788         addp->Opcode() == Op_ConP &&
  2789         addp == n->in(AddPNode::Base) &&
  2790         n->in(AddPNode::Offset)->is_Con()) {
  2791       // Use addressing with narrow klass to load with offset on x86.
  2792       // On sparc loading 32-bits constant and decoding it have less
  2793       // instructions (4) then load 64-bits constant (7).
  2794       // Do this transformation here since IGVN will convert ConN back to ConP.
  2795       const Type* t = addp->bottom_type();
  2796       if (t->isa_oopptr() || t->isa_klassptr()) {
  2797         Node* nn = NULL;
  2799         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
  2801         // Look for existing ConN node of the same exact type.
  2802         Node* r  = root();
  2803         uint cnt = r->outcnt();
  2804         for (uint i = 0; i < cnt; i++) {
  2805           Node* m = r->raw_out(i);
  2806           if (m!= NULL && m->Opcode() == op &&
  2807               m->bottom_type()->make_ptr() == t) {
  2808             nn = m;
  2809             break;
  2812         if (nn != NULL) {
  2813           // Decode a narrow oop to match address
  2814           // [R12 + narrow_oop_reg<<3 + offset]
  2815           if (t->isa_oopptr()) {
  2816             nn = new (this) DecodeNNode(nn, t);
  2817           } else {
  2818             nn = new (this) DecodeNKlassNode(nn, t);
  2820           n->set_req(AddPNode::Base, nn);
  2821           n->set_req(AddPNode::Address, nn);
  2822           if (addp->outcnt() == 0) {
  2823             addp->disconnect_inputs(NULL, this);
  2828 #endif
  2829     break;
  2832 #ifdef _LP64
  2833   case Op_CastPP:
  2834     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2835       Node* in1 = n->in(1);
  2836       const Type* t = n->bottom_type();
  2837       Node* new_in1 = in1->clone();
  2838       new_in1->as_DecodeN()->set_type(t);
  2840       if (!Matcher::narrow_oop_use_complex_address()) {
  2841         //
  2842         // x86, ARM and friends can handle 2 adds in addressing mode
  2843         // and Matcher can fold a DecodeN node into address by using
  2844         // a narrow oop directly and do implicit NULL check in address:
  2845         //
  2846         // [R12 + narrow_oop_reg<<3 + offset]
  2847         // NullCheck narrow_oop_reg
  2848         //
  2849         // On other platforms (Sparc) we have to keep new DecodeN node and
  2850         // use it to do implicit NULL check in address:
  2851         //
  2852         // decode_not_null narrow_oop_reg, base_reg
  2853         // [base_reg + offset]
  2854         // NullCheck base_reg
  2855         //
  2856         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2857         // to keep the information to which NULL check the new DecodeN node
  2858         // corresponds to use it as value in implicit_null_check().
  2859         //
  2860         new_in1->set_req(0, n->in(0));
  2863       n->subsume_by(new_in1, this);
  2864       if (in1->outcnt() == 0) {
  2865         in1->disconnect_inputs(NULL, this);
  2868     break;
  2870   case Op_CmpP:
  2871     // Do this transformation here to preserve CmpPNode::sub() and
  2872     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2873     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
  2874       Node* in1 = n->in(1);
  2875       Node* in2 = n->in(2);
  2876       if (!in1->is_DecodeNarrowPtr()) {
  2877         in2 = in1;
  2878         in1 = n->in(2);
  2880       assert(in1->is_DecodeNarrowPtr(), "sanity");
  2882       Node* new_in2 = NULL;
  2883       if (in2->is_DecodeNarrowPtr()) {
  2884         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
  2885         new_in2 = in2->in(1);
  2886       } else if (in2->Opcode() == Op_ConP) {
  2887         const Type* t = in2->bottom_type();
  2888         if (t == TypePtr::NULL_PTR) {
  2889           assert(in1->is_DecodeN(), "compare klass to null?");
  2890           // Don't convert CmpP null check into CmpN if compressed
  2891           // oops implicit null check is not generated.
  2892           // This will allow to generate normal oop implicit null check.
  2893           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2894             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
  2895           //
  2896           // This transformation together with CastPP transformation above
  2897           // will generated code for implicit NULL checks for compressed oops.
  2898           //
  2899           // The original code after Optimize()
  2900           //
  2901           //    LoadN memory, narrow_oop_reg
  2902           //    decode narrow_oop_reg, base_reg
  2903           //    CmpP base_reg, NULL
  2904           //    CastPP base_reg // NotNull
  2905           //    Load [base_reg + offset], val_reg
  2906           //
  2907           // after these transformations will be
  2908           //
  2909           //    LoadN memory, narrow_oop_reg
  2910           //    CmpN narrow_oop_reg, NULL
  2911           //    decode_not_null narrow_oop_reg, base_reg
  2912           //    Load [base_reg + offset], val_reg
  2913           //
  2914           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2915           // since narrow oops can be used in debug info now (see the code in
  2916           // final_graph_reshaping_walk()).
  2917           //
  2918           // At the end the code will be matched to
  2919           // on x86:
  2920           //
  2921           //    Load_narrow_oop memory, narrow_oop_reg
  2922           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2923           //    NullCheck narrow_oop_reg
  2924           //
  2925           // and on sparc:
  2926           //
  2927           //    Load_narrow_oop memory, narrow_oop_reg
  2928           //    decode_not_null narrow_oop_reg, base_reg
  2929           //    Load [base_reg + offset], val_reg
  2930           //    NullCheck base_reg
  2931           //
  2932         } else if (t->isa_oopptr()) {
  2933           new_in2 = ConNode::make(this, t->make_narrowoop());
  2934         } else if (t->isa_klassptr()) {
  2935           new_in2 = ConNode::make(this, t->make_narrowklass());
  2938       if (new_in2 != NULL) {
  2939         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
  2940         n->subsume_by(cmpN, this);
  2941         if (in1->outcnt() == 0) {
  2942           in1->disconnect_inputs(NULL, this);
  2944         if (in2->outcnt() == 0) {
  2945           in2->disconnect_inputs(NULL, this);
  2949     break;
  2951   case Op_DecodeN:
  2952   case Op_DecodeNKlass:
  2953     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
  2954     // DecodeN could be pinned when it can't be fold into
  2955     // an address expression, see the code for Op_CastPP above.
  2956     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
  2957     break;
  2959   case Op_EncodeP:
  2960   case Op_EncodePKlass: {
  2961     Node* in1 = n->in(1);
  2962     if (in1->is_DecodeNarrowPtr()) {
  2963       n->subsume_by(in1->in(1), this);
  2964     } else if (in1->Opcode() == Op_ConP) {
  2965       const Type* t = in1->bottom_type();
  2966       if (t == TypePtr::NULL_PTR) {
  2967         assert(t->isa_oopptr(), "null klass?");
  2968         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
  2969       } else if (t->isa_oopptr()) {
  2970         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
  2971       } else if (t->isa_klassptr()) {
  2972         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
  2975     if (in1->outcnt() == 0) {
  2976       in1->disconnect_inputs(NULL, this);
  2978     break;
  2981   case Op_Proj: {
  2982     if (OptimizeStringConcat) {
  2983       ProjNode* p = n->as_Proj();
  2984       if (p->_is_io_use) {
  2985         // Separate projections were used for the exception path which
  2986         // are normally removed by a late inline.  If it wasn't inlined
  2987         // then they will hang around and should just be replaced with
  2988         // the original one.
  2989         Node* proj = NULL;
  2990         // Replace with just one
  2991         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  2992           Node *use = i.get();
  2993           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  2994             proj = use;
  2995             break;
  2998         assert(proj != NULL, "must be found");
  2999         p->subsume_by(proj, this);
  3002     break;
  3005   case Op_Phi:
  3006     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
  3007       // The EncodeP optimization may create Phi with the same edges
  3008       // for all paths. It is not handled well by Register Allocator.
  3009       Node* unique_in = n->in(1);
  3010       assert(unique_in != NULL, "");
  3011       uint cnt = n->req();
  3012       for (uint i = 2; i < cnt; i++) {
  3013         Node* m = n->in(i);
  3014         assert(m != NULL, "");
  3015         if (unique_in != m)
  3016           unique_in = NULL;
  3018       if (unique_in != NULL) {
  3019         n->subsume_by(unique_in, this);
  3022     break;
  3024 #endif
  3026 #ifdef ASSERT
  3027   case Op_CastII:
  3028     // Verify that all range check dependent CastII nodes were removed.
  3029     if (n->isa_CastII()->has_range_check()) {
  3030       n->dump(3);
  3031       assert(false, "Range check dependent CastII node was not removed");
  3033     break;
  3034 #endif
  3036   case Op_ModI:
  3037     if (UseDivMod) {
  3038       // Check if a%b and a/b both exist
  3039       Node* d = n->find_similar(Op_DivI);
  3040       if (d) {
  3041         // Replace them with a fused divmod if supported
  3042         if (Matcher::has_match_rule(Op_DivModI)) {
  3043           DivModINode* divmod = DivModINode::make(this, n);
  3044           d->subsume_by(divmod->div_proj(), this);
  3045           n->subsume_by(divmod->mod_proj(), this);
  3046         } else {
  3047           // replace a%b with a-((a/b)*b)
  3048           Node* mult = new (this) MulINode(d, d->in(2));
  3049           Node* sub  = new (this) SubINode(d->in(1), mult);
  3050           n->subsume_by(sub, this);
  3054     break;
  3056   case Op_ModL:
  3057     if (UseDivMod) {
  3058       // Check if a%b and a/b both exist
  3059       Node* d = n->find_similar(Op_DivL);
  3060       if (d) {
  3061         // Replace them with a fused divmod if supported
  3062         if (Matcher::has_match_rule(Op_DivModL)) {
  3063           DivModLNode* divmod = DivModLNode::make(this, n);
  3064           d->subsume_by(divmod->div_proj(), this);
  3065           n->subsume_by(divmod->mod_proj(), this);
  3066         } else {
  3067           // replace a%b with a-((a/b)*b)
  3068           Node* mult = new (this) MulLNode(d, d->in(2));
  3069           Node* sub  = new (this) SubLNode(d->in(1), mult);
  3070           n->subsume_by(sub, this);
  3074     break;
  3076   case Op_LoadVector:
  3077   case Op_StoreVector:
  3078     break;
  3080   case Op_PackB:
  3081   case Op_PackS:
  3082   case Op_PackI:
  3083   case Op_PackF:
  3084   case Op_PackL:
  3085   case Op_PackD:
  3086     if (n->req()-1 > 2) {
  3087       // Replace many operand PackNodes with a binary tree for matching
  3088       PackNode* p = (PackNode*) n;
  3089       Node* btp = p->binary_tree_pack(this, 1, n->req());
  3090       n->subsume_by(btp, this);
  3092     break;
  3093   case Op_Loop:
  3094   case Op_CountedLoop:
  3095     if (n->as_Loop()->is_inner_loop()) {
  3096       frc.inc_inner_loop_count();
  3098     break;
  3099   case Op_LShiftI:
  3100   case Op_RShiftI:
  3101   case Op_URShiftI:
  3102   case Op_LShiftL:
  3103   case Op_RShiftL:
  3104   case Op_URShiftL:
  3105     if (Matcher::need_masked_shift_count) {
  3106       // The cpu's shift instructions don't restrict the count to the
  3107       // lower 5/6 bits. We need to do the masking ourselves.
  3108       Node* in2 = n->in(2);
  3109       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
  3110       const TypeInt* t = in2->find_int_type();
  3111       if (t != NULL && t->is_con()) {
  3112         juint shift = t->get_con();
  3113         if (shift > mask) { // Unsigned cmp
  3114           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
  3116       } else {
  3117         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
  3118           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
  3119           n->set_req(2, shift);
  3122       if (in2->outcnt() == 0) { // Remove dead node
  3123         in2->disconnect_inputs(NULL, this);
  3126     break;
  3127   case Op_MemBarStoreStore:
  3128   case Op_MemBarRelease:
  3129     // Break the link with AllocateNode: it is no longer useful and
  3130     // confuses register allocation.
  3131     if (n->req() > MemBarNode::Precedent) {
  3132       n->set_req(MemBarNode::Precedent, top());
  3134     break;
  3135   default:
  3136     assert( !n->is_Call(), "" );
  3137     assert( !n->is_Mem(), "" );
  3138     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
  3139     break;
  3142   // Collect CFG split points
  3143   if (n->is_MultiBranch())
  3144     frc._tests.push(n);
  3147 //------------------------------final_graph_reshaping_walk---------------------
  3148 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  3149 // requires that the walk visits a node's inputs before visiting the node.
  3150 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  3151   ResourceArea *area = Thread::current()->resource_area();
  3152   Unique_Node_List sfpt(area);
  3154   frc._visited.set(root->_idx); // first, mark node as visited
  3155   uint cnt = root->req();
  3156   Node *n = root;
  3157   uint  i = 0;
  3158   while (true) {
  3159     if (i < cnt) {
  3160       // Place all non-visited non-null inputs onto stack
  3161       Node* m = n->in(i);
  3162       ++i;
  3163       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  3164         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
  3165           // compute worst case interpreter size in case of a deoptimization
  3166           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
  3168           sfpt.push(m);
  3170         cnt = m->req();
  3171         nstack.push(n, i); // put on stack parent and next input's index
  3172         n = m;
  3173         i = 0;
  3175     } else {
  3176       // Now do post-visit work
  3177       final_graph_reshaping_impl( n, frc );
  3178       if (nstack.is_empty())
  3179         break;             // finished
  3180       n = nstack.node();   // Get node from stack
  3181       cnt = n->req();
  3182       i = nstack.index();
  3183       nstack.pop();        // Shift to the next node on stack
  3187   // Skip next transformation if compressed oops are not used.
  3188   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
  3189       (!UseCompressedOops && !UseCompressedClassPointers))
  3190     return;
  3192   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
  3193   // It could be done for an uncommon traps or any safepoints/calls
  3194   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
  3195   while (sfpt.size() > 0) {
  3196     n = sfpt.pop();
  3197     JVMState *jvms = n->as_SafePoint()->jvms();
  3198     assert(jvms != NULL, "sanity");
  3199     int start = jvms->debug_start();
  3200     int end   = n->req();
  3201     bool is_uncommon = (n->is_CallStaticJava() &&
  3202                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  3203     for (int j = start; j < end; j++) {
  3204       Node* in = n->in(j);
  3205       if (in->is_DecodeNarrowPtr()) {
  3206         bool safe_to_skip = true;
  3207         if (!is_uncommon ) {
  3208           // Is it safe to skip?
  3209           for (uint i = 0; i < in->outcnt(); i++) {
  3210             Node* u = in->raw_out(i);
  3211             if (!u->is_SafePoint() ||
  3212                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  3213               safe_to_skip = false;
  3217         if (safe_to_skip) {
  3218           n->set_req(j, in->in(1));
  3220         if (in->outcnt() == 0) {
  3221           in->disconnect_inputs(NULL, this);
  3228 //------------------------------final_graph_reshaping--------------------------
  3229 // Final Graph Reshaping.
  3230 //
  3231 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  3232 //     and not commoned up and forced early.  Must come after regular
  3233 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  3234 //     inputs to Loop Phis; these will be split by the allocator anyways.
  3235 //     Remove Opaque nodes.
  3236 // (2) Move last-uses by commutative operations to the left input to encourage
  3237 //     Intel update-in-place two-address operations and better register usage
  3238 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  3239 //     calls canonicalizing them back.
  3240 // (3) Count the number of double-precision FP ops, single-precision FP ops
  3241 //     and call sites.  On Intel, we can get correct rounding either by
  3242 //     forcing singles to memory (requires extra stores and loads after each
  3243 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  3244 //     clearing the mode bit around call sites).  The mode bit is only used
  3245 //     if the relative frequency of single FP ops to calls is low enough.
  3246 //     This is a key transform for SPEC mpeg_audio.
  3247 // (4) Detect infinite loops; blobs of code reachable from above but not
  3248 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  3249 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  3250 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  3251 //     Detection is by looking for IfNodes where only 1 projection is
  3252 //     reachable from below or CatchNodes missing some targets.
  3253 // (5) Assert for insane oop offsets in debug mode.
  3255 bool Compile::final_graph_reshaping() {
  3256   // an infinite loop may have been eliminated by the optimizer,
  3257   // in which case the graph will be empty.
  3258   if (root()->req() == 1) {
  3259     record_method_not_compilable("trivial infinite loop");
  3260     return true;
  3263   // Expensive nodes have their control input set to prevent the GVN
  3264   // from freely commoning them. There's no GVN beyond this point so
  3265   // no need to keep the control input. We want the expensive nodes to
  3266   // be freely moved to the least frequent code path by gcm.
  3267   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
  3268   for (int i = 0; i < expensive_count(); i++) {
  3269     _expensive_nodes->at(i)->set_req(0, NULL);
  3272   Final_Reshape_Counts frc;
  3274   // Visit everybody reachable!
  3275   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
  3276   Node_Stack nstack(live_nodes() >> 1);
  3277   final_graph_reshaping_walk(nstack, root(), frc);
  3279   // Check for unreachable (from below) code (i.e., infinite loops).
  3280   for( uint i = 0; i < frc._tests.size(); i++ ) {
  3281     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  3282     // Get number of CFG targets.
  3283     // Note that PCTables include exception targets after calls.
  3284     uint required_outcnt = n->required_outcnt();
  3285     if (n->outcnt() != required_outcnt) {
  3286       // Check for a few special cases.  Rethrow Nodes never take the
  3287       // 'fall-thru' path, so expected kids is 1 less.
  3288       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  3289         if (n->in(0)->in(0)->is_Call()) {
  3290           CallNode *call = n->in(0)->in(0)->as_Call();
  3291           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  3292             required_outcnt--;      // Rethrow always has 1 less kid
  3293           } else if (call->req() > TypeFunc::Parms &&
  3294                      call->is_CallDynamicJava()) {
  3295             // Check for null receiver. In such case, the optimizer has
  3296             // detected that the virtual call will always result in a null
  3297             // pointer exception. The fall-through projection of this CatchNode
  3298             // will not be populated.
  3299             Node *arg0 = call->in(TypeFunc::Parms);
  3300             if (arg0->is_Type() &&
  3301                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  3302               required_outcnt--;
  3304           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  3305                      call->req() > TypeFunc::Parms+1 &&
  3306                      call->is_CallStaticJava()) {
  3307             // Check for negative array length. In such case, the optimizer has
  3308             // detected that the allocation attempt will always result in an
  3309             // exception. There is no fall-through projection of this CatchNode .
  3310             Node *arg1 = call->in(TypeFunc::Parms+1);
  3311             if (arg1->is_Type() &&
  3312                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  3313               required_outcnt--;
  3318       // Recheck with a better notion of 'required_outcnt'
  3319       if (n->outcnt() != required_outcnt) {
  3320         record_method_not_compilable("malformed control flow");
  3321         return true;            // Not all targets reachable!
  3324     // Check that I actually visited all kids.  Unreached kids
  3325     // must be infinite loops.
  3326     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  3327       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  3328         record_method_not_compilable("infinite loop");
  3329         return true;            // Found unvisited kid; must be unreach
  3333   // If original bytecodes contained a mixture of floats and doubles
  3334   // check if the optimizer has made it homogenous, item (3).
  3335   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  3336       frc.get_float_count() > 32 &&
  3337       frc.get_double_count() == 0 &&
  3338       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  3339     set_24_bit_selection_and_mode( false,  true );
  3342   set_java_calls(frc.get_java_call_count());
  3343   set_inner_loops(frc.get_inner_loop_count());
  3345   // No infinite loops, no reason to bail out.
  3346   return false;
  3349 //-----------------------------too_many_traps----------------------------------
  3350 // Report if there are too many traps at the current method and bci.
  3351 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  3352 bool Compile::too_many_traps(ciMethod* method,
  3353                              int bci,
  3354                              Deoptimization::DeoptReason reason) {
  3355   ciMethodData* md = method->method_data();
  3356   if (md->is_empty()) {
  3357     // Assume the trap has not occurred, or that it occurred only
  3358     // because of a transient condition during start-up in the interpreter.
  3359     return false;
  3361   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3362   if (md->has_trap_at(bci, m, reason) != 0) {
  3363     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  3364     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3365     // assume the worst.
  3366     if (log())
  3367       log()->elem("observe trap='%s' count='%d'",
  3368                   Deoptimization::trap_reason_name(reason),
  3369                   md->trap_count(reason));
  3370     return true;
  3371   } else {
  3372     // Ignore method/bci and see if there have been too many globally.
  3373     return too_many_traps(reason, md);
  3377 // Less-accurate variant which does not require a method and bci.
  3378 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  3379                              ciMethodData* logmd) {
  3380   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
  3381     // Too many traps globally.
  3382     // Note that we use cumulative trap_count, not just md->trap_count.
  3383     if (log()) {
  3384       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  3385       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  3386                   Deoptimization::trap_reason_name(reason),
  3387                   mcount, trap_count(reason));
  3389     return true;
  3390   } else {
  3391     // The coast is clear.
  3392     return false;
  3396 //--------------------------too_many_recompiles--------------------------------
  3397 // Report if there are too many recompiles at the current method and bci.
  3398 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  3399 // Is not eager to return true, since this will cause the compiler to use
  3400 // Action_none for a trap point, to avoid too many recompilations.
  3401 bool Compile::too_many_recompiles(ciMethod* method,
  3402                                   int bci,
  3403                                   Deoptimization::DeoptReason reason) {
  3404   ciMethodData* md = method->method_data();
  3405   if (md->is_empty()) {
  3406     // Assume the trap has not occurred, or that it occurred only
  3407     // because of a transient condition during start-up in the interpreter.
  3408     return false;
  3410   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  3411   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  3412   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  3413   Deoptimization::DeoptReason per_bc_reason
  3414     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  3415   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3416   if ((per_bc_reason == Deoptimization::Reason_none
  3417        || md->has_trap_at(bci, m, reason) != 0)
  3418       // The trap frequency measure we care about is the recompile count:
  3419       && md->trap_recompiled_at(bci, m)
  3420       && md->overflow_recompile_count() >= bc_cutoff) {
  3421     // Do not emit a trap here if it has already caused recompilations.
  3422     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3423     // assume the worst.
  3424     if (log())
  3425       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  3426                   Deoptimization::trap_reason_name(reason),
  3427                   md->trap_count(reason),
  3428                   md->overflow_recompile_count());
  3429     return true;
  3430   } else if (trap_count(reason) != 0
  3431              && decompile_count() >= m_cutoff) {
  3432     // Too many recompiles globally, and we have seen this sort of trap.
  3433     // Use cumulative decompile_count, not just md->decompile_count.
  3434     if (log())
  3435       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  3436                   Deoptimization::trap_reason_name(reason),
  3437                   md->trap_count(reason), trap_count(reason),
  3438                   md->decompile_count(), decompile_count());
  3439     return true;
  3440   } else {
  3441     // The coast is clear.
  3442     return false;
  3446 // Compute when not to trap. Used by matching trap based nodes and
  3447 // NullCheck optimization.
  3448 void Compile::set_allowed_deopt_reasons() {
  3449   _allowed_reasons = 0;
  3450   if (is_method_compilation()) {
  3451     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
  3452       assert(rs < BitsPerInt, "recode bit map");
  3453       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
  3454         _allowed_reasons |= nth_bit(rs);
  3460 #ifndef PRODUCT
  3461 //------------------------------verify_graph_edges---------------------------
  3462 // Walk the Graph and verify that there is a one-to-one correspondence
  3463 // between Use-Def edges and Def-Use edges in the graph.
  3464 void Compile::verify_graph_edges(bool no_dead_code) {
  3465   if (VerifyGraphEdges) {
  3466     ResourceArea *area = Thread::current()->resource_area();
  3467     Unique_Node_List visited(area);
  3468     // Call recursive graph walk to check edges
  3469     _root->verify_edges(visited);
  3470     if (no_dead_code) {
  3471       // Now make sure that no visited node is used by an unvisited node.
  3472       bool dead_nodes = 0;
  3473       Unique_Node_List checked(area);
  3474       while (visited.size() > 0) {
  3475         Node* n = visited.pop();
  3476         checked.push(n);
  3477         for (uint i = 0; i < n->outcnt(); i++) {
  3478           Node* use = n->raw_out(i);
  3479           if (checked.member(use))  continue;  // already checked
  3480           if (visited.member(use))  continue;  // already in the graph
  3481           if (use->is_Con())        continue;  // a dead ConNode is OK
  3482           // At this point, we have found a dead node which is DU-reachable.
  3483           if (dead_nodes++ == 0)
  3484             tty->print_cr("*** Dead nodes reachable via DU edges:");
  3485           use->dump(2);
  3486           tty->print_cr("---");
  3487           checked.push(use);  // No repeats; pretend it is now checked.
  3490       assert(dead_nodes == 0, "using nodes must be reachable from root");
  3495 // Verify GC barriers consistency
  3496 // Currently supported:
  3497 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
  3498 void Compile::verify_barriers() {
  3499   if (UseG1GC) {
  3500     // Verify G1 pre-barriers
  3501     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
  3503     ResourceArea *area = Thread::current()->resource_area();
  3504     Unique_Node_List visited(area);
  3505     Node_List worklist(area);
  3506     // We're going to walk control flow backwards starting from the Root
  3507     worklist.push(_root);
  3508     while (worklist.size() > 0) {
  3509       Node* x = worklist.pop();
  3510       if (x == NULL || x == top()) continue;
  3511       if (visited.member(x)) {
  3512         continue;
  3513       } else {
  3514         visited.push(x);
  3517       if (x->is_Region()) {
  3518         for (uint i = 1; i < x->req(); i++) {
  3519           worklist.push(x->in(i));
  3521       } else {
  3522         worklist.push(x->in(0));
  3523         // We are looking for the pattern:
  3524         //                            /->ThreadLocal
  3525         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
  3526         //              \->ConI(0)
  3527         // We want to verify that the If and the LoadB have the same control
  3528         // See GraphKit::g1_write_barrier_pre()
  3529         if (x->is_If()) {
  3530           IfNode *iff = x->as_If();
  3531           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
  3532             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
  3533             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
  3534                 && cmp->in(1)->is_Load()) {
  3535               LoadNode* load = cmp->in(1)->as_Load();
  3536               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
  3537                   && load->in(2)->in(3)->is_Con()
  3538                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
  3540                 Node* if_ctrl = iff->in(0);
  3541                 Node* load_ctrl = load->in(0);
  3543                 if (if_ctrl != load_ctrl) {
  3544                   // Skip possible CProj->NeverBranch in infinite loops
  3545                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
  3546                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
  3547                     if_ctrl = if_ctrl->in(0)->in(0);
  3550                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
  3560 #endif
  3562 // The Compile object keeps track of failure reasons separately from the ciEnv.
  3563 // This is required because there is not quite a 1-1 relation between the
  3564 // ciEnv and its compilation task and the Compile object.  Note that one
  3565 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  3566 // to backtrack and retry without subsuming loads.  Other than this backtracking
  3567 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  3568 // by the logic in C2Compiler.
  3569 void Compile::record_failure(const char* reason) {
  3570   if (log() != NULL) {
  3571     log()->elem("failure reason='%s' phase='compile'", reason);
  3573   if (_failure_reason == NULL) {
  3574     // Record the first failure reason.
  3575     _failure_reason = reason;
  3578   EventCompilerFailure event;
  3579   if (event.should_commit()) {
  3580     event.set_compileID(Compile::compile_id());
  3581     event.set_failure(reason);
  3582     event.commit();
  3585   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  3586     C->print_method(PHASE_FAILURE);
  3588   _root = NULL;  // flush the graph, too
  3591 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  3592   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
  3593     _phase_name(name), _dolog(dolog)
  3595   if (dolog) {
  3596     C = Compile::current();
  3597     _log = C->log();
  3598   } else {
  3599     C = NULL;
  3600     _log = NULL;
  3602   if (_log != NULL) {
  3603     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3604     _log->stamp();
  3605     _log->end_head();
  3609 Compile::TracePhase::~TracePhase() {
  3611   C = Compile::current();
  3612   if (_dolog) {
  3613     _log = C->log();
  3614   } else {
  3615     _log = NULL;
  3618 #ifdef ASSERT
  3619   if (PrintIdealNodeCount) {
  3620     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
  3621                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
  3624   if (VerifyIdealNodeCount) {
  3625     Compile::current()->print_missing_nodes();
  3627 #endif
  3629   if (_log != NULL) {
  3630     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3634 //=============================================================================
  3635 // Two Constant's are equal when the type and the value are equal.
  3636 bool Compile::Constant::operator==(const Constant& other) {
  3637   if (type()          != other.type()         )  return false;
  3638   if (can_be_reused() != other.can_be_reused())  return false;
  3639   // For floating point values we compare the bit pattern.
  3640   switch (type()) {
  3641   case T_FLOAT:   return (_v._value.i == other._v._value.i);
  3642   case T_LONG:
  3643   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
  3644   case T_OBJECT:
  3645   case T_ADDRESS: return (_v._value.l == other._v._value.l);
  3646   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
  3647   case T_METADATA: return (_v._metadata == other._v._metadata);
  3648   default: ShouldNotReachHere();
  3650   return false;
  3653 static int type_to_size_in_bytes(BasicType t) {
  3654   switch (t) {
  3655   case T_LONG:    return sizeof(jlong  );
  3656   case T_FLOAT:   return sizeof(jfloat );
  3657   case T_DOUBLE:  return sizeof(jdouble);
  3658   case T_METADATA: return sizeof(Metadata*);
  3659     // We use T_VOID as marker for jump-table entries (labels) which
  3660     // need an internal word relocation.
  3661   case T_VOID:
  3662   case T_ADDRESS:
  3663   case T_OBJECT:  return sizeof(jobject);
  3666   ShouldNotReachHere();
  3667   return -1;
  3670 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
  3671   // sort descending
  3672   if (a->freq() > b->freq())  return -1;
  3673   if (a->freq() < b->freq())  return  1;
  3674   return 0;
  3677 void Compile::ConstantTable::calculate_offsets_and_size() {
  3678   // First, sort the array by frequencies.
  3679   _constants.sort(qsort_comparator);
  3681 #ifdef ASSERT
  3682   // Make sure all jump-table entries were sorted to the end of the
  3683   // array (they have a negative frequency).
  3684   bool found_void = false;
  3685   for (int i = 0; i < _constants.length(); i++) {
  3686     Constant con = _constants.at(i);
  3687     if (con.type() == T_VOID)
  3688       found_void = true;  // jump-tables
  3689     else
  3690       assert(!found_void, "wrong sorting");
  3692 #endif
  3694   int offset = 0;
  3695   for (int i = 0; i < _constants.length(); i++) {
  3696     Constant* con = _constants.adr_at(i);
  3698     // Align offset for type.
  3699     int typesize = type_to_size_in_bytes(con->type());
  3700     offset = align_size_up(offset, typesize);
  3701     con->set_offset(offset);   // set constant's offset
  3703     if (con->type() == T_VOID) {
  3704       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
  3705       offset = offset + typesize * n->outcnt();  // expand jump-table
  3706     } else {
  3707       offset = offset + typesize;
  3711   // Align size up to the next section start (which is insts; see
  3712   // CodeBuffer::align_at_start).
  3713   assert(_size == -1, "already set?");
  3714   _size = align_size_up(offset, CodeEntryAlignment);
  3717 void Compile::ConstantTable::emit(CodeBuffer& cb) {
  3718   MacroAssembler _masm(&cb);
  3719   for (int i = 0; i < _constants.length(); i++) {
  3720     Constant con = _constants.at(i);
  3721     address constant_addr = NULL;
  3722     switch (con.type()) {
  3723     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
  3724     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
  3725     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
  3726     case T_OBJECT: {
  3727       jobject obj = con.get_jobject();
  3728       int oop_index = _masm.oop_recorder()->find_index(obj);
  3729       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
  3730       break;
  3732     case T_ADDRESS: {
  3733       address addr = (address) con.get_jobject();
  3734       constant_addr = _masm.address_constant(addr);
  3735       break;
  3737     // We use T_VOID as marker for jump-table entries (labels) which
  3738     // need an internal word relocation.
  3739     case T_VOID: {
  3740       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
  3741       // Fill the jump-table with a dummy word.  The real value is
  3742       // filled in later in fill_jump_table.
  3743       address dummy = (address) n;
  3744       constant_addr = _masm.address_constant(dummy);
  3745       // Expand jump-table
  3746       for (uint i = 1; i < n->outcnt(); i++) {
  3747         address temp_addr = _masm.address_constant(dummy + i);
  3748         assert(temp_addr, "consts section too small");
  3750       break;
  3752     case T_METADATA: {
  3753       Metadata* obj = con.get_metadata();
  3754       int metadata_index = _masm.oop_recorder()->find_index(obj);
  3755       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
  3756       break;
  3758     default: ShouldNotReachHere();
  3760     assert(constant_addr, "consts section too small");
  3761     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
  3762             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
  3766 int Compile::ConstantTable::find_offset(Constant& con) const {
  3767   int idx = _constants.find(con);
  3768   assert(idx != -1, "constant must be in constant table");
  3769   int offset = _constants.at(idx).offset();
  3770   assert(offset != -1, "constant table not emitted yet?");
  3771   return offset;
  3774 void Compile::ConstantTable::add(Constant& con) {
  3775   if (con.can_be_reused()) {
  3776     int idx = _constants.find(con);
  3777     if (idx != -1 && _constants.at(idx).can_be_reused()) {
  3778       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
  3779       return;
  3782   (void) _constants.append(con);
  3785 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
  3786   Block* b = Compile::current()->cfg()->get_block_for_node(n);
  3787   Constant con(type, value, b->_freq);
  3788   add(con);
  3789   return con;
  3792 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
  3793   Constant con(metadata);
  3794   add(con);
  3795   return con;
  3798 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
  3799   jvalue value;
  3800   BasicType type = oper->type()->basic_type();
  3801   switch (type) {
  3802   case T_LONG:    value.j = oper->constantL(); break;
  3803   case T_FLOAT:   value.f = oper->constantF(); break;
  3804   case T_DOUBLE:  value.d = oper->constantD(); break;
  3805   case T_OBJECT:
  3806   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
  3807   case T_METADATA: return add((Metadata*)oper->constant()); break;
  3808   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
  3810   return add(n, type, value);
  3813 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
  3814   jvalue value;
  3815   // We can use the node pointer here to identify the right jump-table
  3816   // as this method is called from Compile::Fill_buffer right before
  3817   // the MachNodes are emitted and the jump-table is filled (means the
  3818   // MachNode pointers do not change anymore).
  3819   value.l = (jobject) n;
  3820   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
  3821   add(con);
  3822   return con;
  3825 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
  3826   // If called from Compile::scratch_emit_size do nothing.
  3827   if (Compile::current()->in_scratch_emit_size())  return;
  3829   assert(labels.is_nonempty(), "must be");
  3830   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
  3832   // Since MachConstantNode::constant_offset() also contains
  3833   // table_base_offset() we need to subtract the table_base_offset()
  3834   // to get the plain offset into the constant table.
  3835   int offset = n->constant_offset() - table_base_offset();
  3837   MacroAssembler _masm(&cb);
  3838   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
  3840   for (uint i = 0; i < n->outcnt(); i++) {
  3841     address* constant_addr = &jump_table_base[i];
  3842     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)));
  3843     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
  3844     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
  3848 void Compile::dump_inlining() {
  3849   if (print_inlining() || print_intrinsics()) {
  3850     // Print inlining message for candidates that we couldn't inline
  3851     // for lack of space or non constant receiver
  3852     for (int i = 0; i < _late_inlines.length(); i++) {
  3853       CallGenerator* cg = _late_inlines.at(i);
  3854       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
  3856     Unique_Node_List useful;
  3857     useful.push(root());
  3858     for (uint next = 0; next < useful.size(); ++next) {
  3859       Node* n  = useful.at(next);
  3860       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
  3861         CallNode* call = n->as_Call();
  3862         CallGenerator* cg = call->generator();
  3863         cg->print_inlining_late("receiver not constant");
  3865       uint max = n->len();
  3866       for ( uint i = 0; i < max; ++i ) {
  3867         Node *m = n->in(i);
  3868         if ( m == NULL ) continue;
  3869         useful.push(m);
  3872     for (int i = 0; i < _print_inlining_list->length(); i++) {
  3873       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
  3878 // Dump inlining replay data to the stream.
  3879 // Don't change thread state and acquire any locks.
  3880 void Compile::dump_inline_data(outputStream* out) {
  3881   InlineTree* inl_tree = ilt();
  3882   if (inl_tree != NULL) {
  3883     out->print(" inline %d", inl_tree->count());
  3884     inl_tree->dump_replay_data(out);
  3888 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
  3889   if (n1->Opcode() < n2->Opcode())      return -1;
  3890   else if (n1->Opcode() > n2->Opcode()) return 1;
  3892   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()));
  3893   for (uint i = 1; i < n1->req(); i++) {
  3894     if (n1->in(i) < n2->in(i))      return -1;
  3895     else if (n1->in(i) > n2->in(i)) return 1;
  3898   return 0;
  3901 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
  3902   Node* n1 = *n1p;
  3903   Node* n2 = *n2p;
  3905   return cmp_expensive_nodes(n1, n2);
  3908 void Compile::sort_expensive_nodes() {
  3909   if (!expensive_nodes_sorted()) {
  3910     _expensive_nodes->sort(cmp_expensive_nodes);
  3914 bool Compile::expensive_nodes_sorted() const {
  3915   for (int i = 1; i < _expensive_nodes->length(); i++) {
  3916     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
  3917       return false;
  3920   return true;
  3923 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
  3924   if (_expensive_nodes->length() == 0) {
  3925     return false;
  3928   assert(OptimizeExpensiveOps, "optimization off?");
  3930   // Take this opportunity to remove dead nodes from the list
  3931   int j = 0;
  3932   for (int i = 0; i < _expensive_nodes->length(); i++) {
  3933     Node* n = _expensive_nodes->at(i);
  3934     if (!n->is_unreachable(igvn)) {
  3935       assert(n->is_expensive(), "should be expensive");
  3936       _expensive_nodes->at_put(j, n);
  3937       j++;
  3940   _expensive_nodes->trunc_to(j);
  3942   // Then sort the list so that similar nodes are next to each other
  3943   // and check for at least two nodes of identical kind with same data
  3944   // inputs.
  3945   sort_expensive_nodes();
  3947   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
  3948     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
  3949       return true;
  3953   return false;
  3956 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
  3957   if (_expensive_nodes->length() == 0) {
  3958     return;
  3961   assert(OptimizeExpensiveOps, "optimization off?");
  3963   // Sort to bring similar nodes next to each other and clear the
  3964   // control input of nodes for which there's only a single copy.
  3965   sort_expensive_nodes();
  3967   int j = 0;
  3968   int identical = 0;
  3969   int i = 0;
  3970   for (; i < _expensive_nodes->length()-1; i++) {
  3971     assert(j <= i, "can't write beyond current index");
  3972     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
  3973       identical++;
  3974       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3975       continue;
  3977     if (identical > 0) {
  3978       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3979       identical = 0;
  3980     } else {
  3981       Node* n = _expensive_nodes->at(i);
  3982       igvn.hash_delete(n);
  3983       n->set_req(0, NULL);
  3984       igvn.hash_insert(n);
  3987   if (identical > 0) {
  3988     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3989   } else if (_expensive_nodes->length() >= 1) {
  3990     Node* n = _expensive_nodes->at(i);
  3991     igvn.hash_delete(n);
  3992     n->set_req(0, NULL);
  3993     igvn.hash_insert(n);
  3995   _expensive_nodes->trunc_to(j);
  3998 void Compile::add_expensive_node(Node * n) {
  3999   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
  4000   assert(n->is_expensive(), "expensive nodes with non-null control here only");
  4001   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
  4002   if (OptimizeExpensiveOps) {
  4003     _expensive_nodes->append(n);
  4004   } else {
  4005     // Clear control input and let IGVN optimize expensive nodes if
  4006     // OptimizeExpensiveOps is off.
  4007     n->set_req(0, NULL);
  4011 /**
  4012  * Remove the speculative part of types and clean up the graph
  4013  */
  4014 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
  4015   if (UseTypeSpeculation) {
  4016     Unique_Node_List worklist;
  4017     worklist.push(root());
  4018     int modified = 0;
  4019     // Go over all type nodes that carry a speculative type, drop the
  4020     // speculative part of the type and enqueue the node for an igvn
  4021     // which may optimize it out.
  4022     for (uint next = 0; next < worklist.size(); ++next) {
  4023       Node *n  = worklist.at(next);
  4024       if (n->is_Type()) {
  4025         TypeNode* tn = n->as_Type();
  4026         const Type* t = tn->type();
  4027         const Type* t_no_spec = t->remove_speculative();
  4028         if (t_no_spec != t) {
  4029           bool in_hash = igvn.hash_delete(n);
  4030           assert(in_hash, "node should be in igvn hash table");
  4031           tn->set_type(t_no_spec);
  4032           igvn.hash_insert(n);
  4033           igvn._worklist.push(n); // give it a chance to go away
  4034           modified++;
  4037       uint max = n->len();
  4038       for( uint i = 0; i < max; ++i ) {
  4039         Node *m = n->in(i);
  4040         if (not_a_node(m))  continue;
  4041         worklist.push(m);
  4044     // Drop the speculative part of all types in the igvn's type table
  4045     igvn.remove_speculative_types();
  4046     if (modified > 0) {
  4047       igvn.optimize();
  4049 #ifdef ASSERT
  4050     // Verify that after the IGVN is over no speculative type has resurfaced
  4051     worklist.clear();
  4052     worklist.push(root());
  4053     for (uint next = 0; next < worklist.size(); ++next) {
  4054       Node *n  = worklist.at(next);
  4055       const Type* t = igvn.type_or_null(n);
  4056       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
  4057       if (n->is_Type()) {
  4058         t = n->as_Type()->type();
  4059         assert(t == t->remove_speculative(), "no more speculative types");
  4061       uint max = n->len();
  4062       for( uint i = 0; i < max; ++i ) {
  4063         Node *m = n->in(i);
  4064         if (not_a_node(m))  continue;
  4065         worklist.push(m);
  4068     igvn.check_no_speculative_types();
  4069 #endif
  4073 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
  4074 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
  4075   if (ctrl != NULL) {
  4076     // Express control dependency by a CastII node with a narrow type.
  4077     value = new (phase->C) CastIINode(value, itype, false, true /* range check dependency */);
  4078     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
  4079     // node from floating above the range check during loop optimizations. Otherwise, the
  4080     // ConvI2L node may be eliminated independently of the range check, causing the data path
  4081     // to become TOP while the control path is still there (although it's unreachable).
  4082     value->set_req(0, ctrl);
  4083     // Save CastII node to remove it after loop optimizations.
  4084     phase->C->add_range_check_cast(value);
  4085     value = phase->transform(value);
  4087   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
  4088   return phase->transform(new (phase->C) ConvI2LNode(value, ltype));
  4091 // Auxiliary method to support randomized stressing/fuzzing.
  4092 //
  4093 // This method can be called the arbitrary number of times, with current count
  4094 // as the argument. The logic allows selecting a single candidate from the
  4095 // running list of candidates as follows:
  4096 //    int count = 0;
  4097 //    Cand* selected = null;
  4098 //    while(cand = cand->next()) {
  4099 //      if (randomized_select(++count)) {
  4100 //        selected = cand;
  4101 //      }
  4102 //    }
  4103 //
  4104 // Including count equalizes the chances any candidate is "selected".
  4105 // This is useful when we don't have the complete list of candidates to choose
  4106 // from uniformly. In this case, we need to adjust the randomicity of the
  4107 // selection, or else we will end up biasing the selection towards the latter
  4108 // candidates.
  4109 //
  4110 // Quick back-envelope calculation shows that for the list of n candidates
  4111 // the equal probability for the candidate to persist as "best" can be
  4112 // achieved by replacing it with "next" k-th candidate with the probability
  4113 // of 1/k. It can be easily shown that by the end of the run, the
  4114 // probability for any candidate is converged to 1/n, thus giving the
  4115 // uniform distribution among all the candidates.
  4116 //
  4117 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
  4118 #define RANDOMIZED_DOMAIN_POW 29
  4119 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
  4120 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
  4121 bool Compile::randomized_select(int count) {
  4122   assert(count > 0, "only positive");
  4123   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);

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