src/share/vm/opto/compile.cpp

Thu, 24 May 2018 17:06:56 +0800

author
aoqi
date
Thu, 24 May 2018 17:06:56 +0800
changeset 8604
04d83ba48607
parent 8536
371fd9bb8202
parent 7994
04ff2f6cd0eb
child 8856
ac27a9c85bea
permissions
-rw-r--r--

Merge

     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 /*
    26  * This file has been modified by Loongson Technology in 2015. These
    27  * modifications are Copyright (c) 2015 Loongson Technology, and are made
    28  * available on the same license terms set forth above.
    29  */
    31 #include "precompiled.hpp"
    32 #include "asm/macroAssembler.hpp"
    33 #include "asm/macroAssembler.inline.hpp"
    34 #include "ci/ciReplay.hpp"
    35 #include "classfile/systemDictionary.hpp"
    36 #include "code/exceptionHandlerTable.hpp"
    37 #include "code/nmethod.hpp"
    38 #include "compiler/compileLog.hpp"
    39 #include "compiler/disassembler.hpp"
    40 #include "compiler/oopMap.hpp"
    41 #include "opto/addnode.hpp"
    42 #include "opto/block.hpp"
    43 #include "opto/c2compiler.hpp"
    44 #include "opto/callGenerator.hpp"
    45 #include "opto/callnode.hpp"
    46 #include "opto/cfgnode.hpp"
    47 #include "opto/chaitin.hpp"
    48 #include "opto/compile.hpp"
    49 #include "opto/connode.hpp"
    50 #include "opto/divnode.hpp"
    51 #include "opto/escape.hpp"
    52 #include "opto/idealGraphPrinter.hpp"
    53 #include "opto/loopnode.hpp"
    54 #include "opto/machnode.hpp"
    55 #include "opto/macro.hpp"
    56 #include "opto/matcher.hpp"
    57 #include "opto/mathexactnode.hpp"
    58 #include "opto/memnode.hpp"
    59 #include "opto/mulnode.hpp"
    60 #include "opto/node.hpp"
    61 #include "opto/opcodes.hpp"
    62 #include "opto/output.hpp"
    63 #include "opto/parse.hpp"
    64 #include "opto/phaseX.hpp"
    65 #include "opto/rootnode.hpp"
    66 #include "opto/runtime.hpp"
    67 #include "opto/stringopts.hpp"
    68 #include "opto/type.hpp"
    69 #include "opto/vectornode.hpp"
    70 #include "runtime/arguments.hpp"
    71 #include "runtime/signature.hpp"
    72 #include "runtime/stubRoutines.hpp"
    73 #include "runtime/timer.hpp"
    74 #include "trace/tracing.hpp"
    75 #include "utilities/copy.hpp"
    76 #if defined AD_MD_HPP
    77 # include AD_MD_HPP
    78 #elif defined TARGET_ARCH_MODEL_x86_32
    79 # include "adfiles/ad_x86_32.hpp"
    80 #elif defined TARGET_ARCH_MODEL_x86_64
    81 # include "adfiles/ad_x86_64.hpp"
    82 #elif defined TARGET_ARCH_MODEL_sparc
    83 # include "adfiles/ad_sparc.hpp"
    84 #elif defined TARGET_ARCH_MODEL_zero
    85 # include "adfiles/ad_zero.hpp"
    86 #elif defined TARGET_ARCH_MODEL_ppc_64
    87 # include "adfiles/ad_ppc_64.hpp"
    88 #elif defined TARGET_ARCH_MODEL_mips_64
    89 # include "adfiles/ad_mips_64.hpp"
    90 #endif
    93 // -------------------- Compile::mach_constant_base_node -----------------------
    94 // Constant table base node singleton.
    95 MachConstantBaseNode* Compile::mach_constant_base_node() {
    96   if (_mach_constant_base_node == NULL) {
    97     _mach_constant_base_node = new (C) MachConstantBaseNode();
    98     _mach_constant_base_node->add_req(C->root());
    99   }
   100   return _mach_constant_base_node;
   101 }
   104 /// Support for intrinsics.
   106 // Return the index at which m must be inserted (or already exists).
   107 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
   108 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
   109 #ifdef ASSERT
   110   for (int i = 1; i < _intrinsics->length(); i++) {
   111     CallGenerator* cg1 = _intrinsics->at(i-1);
   112     CallGenerator* cg2 = _intrinsics->at(i);
   113     assert(cg1->method() != cg2->method()
   114            ? cg1->method()     < cg2->method()
   115            : cg1->is_virtual() < cg2->is_virtual(),
   116            "compiler intrinsics list must stay sorted");
   117   }
   118 #endif
   119   // Binary search sorted list, in decreasing intervals [lo, hi].
   120   int lo = 0, hi = _intrinsics->length()-1;
   121   while (lo <= hi) {
   122     int mid = (uint)(hi + lo) / 2;
   123     ciMethod* mid_m = _intrinsics->at(mid)->method();
   124     if (m < mid_m) {
   125       hi = mid-1;
   126     } else if (m > mid_m) {
   127       lo = mid+1;
   128     } else {
   129       // look at minor sort key
   130       bool mid_virt = _intrinsics->at(mid)->is_virtual();
   131       if (is_virtual < mid_virt) {
   132         hi = mid-1;
   133       } else if (is_virtual > mid_virt) {
   134         lo = mid+1;
   135       } else {
   136         return mid;  // exact match
   137       }
   138     }
   139   }
   140   return lo;  // inexact match
   141 }
   143 void Compile::register_intrinsic(CallGenerator* cg) {
   144   if (_intrinsics == NULL) {
   145     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
   146   }
   147   // This code is stolen from ciObjectFactory::insert.
   148   // Really, GrowableArray should have methods for
   149   // insert_at, remove_at, and binary_search.
   150   int len = _intrinsics->length();
   151   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
   152   if (index == len) {
   153     _intrinsics->append(cg);
   154   } else {
   155 #ifdef ASSERT
   156     CallGenerator* oldcg = _intrinsics->at(index);
   157     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
   158 #endif
   159     _intrinsics->append(_intrinsics->at(len-1));
   160     int pos;
   161     for (pos = len-2; pos >= index; pos--) {
   162       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
   163     }
   164     _intrinsics->at_put(index, cg);
   165   }
   166   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
   167 }
   169 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
   170   assert(m->is_loaded(), "don't try this on unloaded methods");
   171   if (_intrinsics != NULL) {
   172     int index = intrinsic_insertion_index(m, is_virtual);
   173     if (index < _intrinsics->length()
   174         && _intrinsics->at(index)->method() == m
   175         && _intrinsics->at(index)->is_virtual() == is_virtual) {
   176       return _intrinsics->at(index);
   177     }
   178   }
   179   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   180   if (m->intrinsic_id() != vmIntrinsics::_none &&
   181       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
   182     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
   183     if (cg != NULL) {
   184       // Save it for next time:
   185       register_intrinsic(cg);
   186       return cg;
   187     } else {
   188       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
   189     }
   190   }
   191   return NULL;
   192 }
   194 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
   195 // in library_call.cpp.
   198 #ifndef PRODUCT
   199 // statistics gathering...
   201 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
   202 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
   204 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   205   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   206   int oflags = _intrinsic_hist_flags[id];
   207   assert(flags != 0, "what happened?");
   208   if (is_virtual) {
   209     flags |= _intrinsic_virtual;
   210   }
   211   bool changed = (flags != oflags);
   212   if ((flags & _intrinsic_worked) != 0) {
   213     juint count = (_intrinsic_hist_count[id] += 1);
   214     if (count == 1) {
   215       changed = true;           // first time
   216     }
   217     // increment the overall count also:
   218     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   219   }
   220   if (changed) {
   221     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
   222       // Something changed about the intrinsic's virtuality.
   223       if ((flags & _intrinsic_virtual) != 0) {
   224         // This is the first use of this intrinsic as a virtual call.
   225         if (oflags != 0) {
   226           // We already saw it as a non-virtual, so note both cases.
   227           flags |= _intrinsic_both;
   228         }
   229       } else if ((oflags & _intrinsic_both) == 0) {
   230         // This is the first use of this intrinsic as a non-virtual
   231         flags |= _intrinsic_both;
   232       }
   233     }
   234     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   235   }
   236   // update the overall flags also:
   237   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   238   return changed;
   239 }
   241 static char* format_flags(int flags, char* buf) {
   242   buf[0] = 0;
   243   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   244   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   245   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   246   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   247   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   248   if (buf[0] == 0)  strcat(buf, ",");
   249   assert(buf[0] == ',', "must be");
   250   return &buf[1];
   251 }
   253 void Compile::print_intrinsic_statistics() {
   254   char flagsbuf[100];
   255   ttyLocker ttyl;
   256   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   257   tty->print_cr("Compiler intrinsic usage:");
   258   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   259   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   260   #define PRINT_STAT_LINE(name, c, f) \
   261     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   262   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
   263     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
   264     int   flags = _intrinsic_hist_flags[id];
   265     juint count = _intrinsic_hist_count[id];
   266     if ((flags | count) != 0) {
   267       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
   268     }
   269   }
   270   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   271   if (xtty != NULL)  xtty->tail("statistics");
   272 }
   274 void Compile::print_statistics() {
   275   { ttyLocker ttyl;
   276     if (xtty != NULL)  xtty->head("statistics type='opto'");
   277     Parse::print_statistics();
   278     PhaseCCP::print_statistics();
   279     PhaseRegAlloc::print_statistics();
   280     Scheduling::print_statistics();
   281     PhasePeephole::print_statistics();
   282     PhaseIdealLoop::print_statistics();
   283     if (xtty != NULL)  xtty->tail("statistics");
   284   }
   285   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
   286     // put this under its own <statistics> element.
   287     print_intrinsic_statistics();
   288   }
   289 }
   290 #endif //PRODUCT
   292 // Support for bundling info
   293 Bundle* Compile::node_bundling(const Node *n) {
   294   assert(valid_bundle_info(n), "oob");
   295   return &_node_bundling_base[n->_idx];
   296 }
   298 bool Compile::valid_bundle_info(const Node *n) {
   299   return (_node_bundling_limit > n->_idx);
   300 }
   303 void Compile::gvn_replace_by(Node* n, Node* nn) {
   304   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
   305     Node* use = n->last_out(i);
   306     bool is_in_table = initial_gvn()->hash_delete(use);
   307     uint uses_found = 0;
   308     for (uint j = 0; j < use->len(); j++) {
   309       if (use->in(j) == n) {
   310         if (j < use->req())
   311           use->set_req(j, nn);
   312         else
   313           use->set_prec(j, nn);
   314         uses_found++;
   315       }
   316     }
   317     if (is_in_table) {
   318       // reinsert into table
   319       initial_gvn()->hash_find_insert(use);
   320     }
   321     record_for_igvn(use);
   322     i -= uses_found;    // we deleted 1 or more copies of this edge
   323   }
   324 }
   327 static inline bool not_a_node(const Node* n) {
   328   if (n == NULL)                   return true;
   329   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
   330   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
   331   return false;
   332 }
   334 // Identify all nodes that are reachable from below, useful.
   335 // Use breadth-first pass that records state in a Unique_Node_List,
   336 // recursive traversal is slower.
   337 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   338   int estimated_worklist_size = live_nodes();
   339   useful.map( estimated_worklist_size, NULL );  // preallocate space
   341   // Initialize worklist
   342   if (root() != NULL)     { useful.push(root()); }
   343   // If 'top' is cached, declare it useful to preserve cached node
   344   if( cached_top_node() ) { useful.push(cached_top_node()); }
   346   // Push all useful nodes onto the list, breadthfirst
   347   for( uint next = 0; next < useful.size(); ++next ) {
   348     assert( next < unique(), "Unique useful nodes < total nodes");
   349     Node *n  = useful.at(next);
   350     uint max = n->len();
   351     for( uint i = 0; i < max; ++i ) {
   352       Node *m = n->in(i);
   353       if (not_a_node(m))  continue;
   354       useful.push(m);
   355     }
   356   }
   357 }
   359 // Update dead_node_list with any missing dead nodes using useful
   360 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
   361 void Compile::update_dead_node_list(Unique_Node_List &useful) {
   362   uint max_idx = unique();
   363   VectorSet& useful_node_set = useful.member_set();
   365   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
   366     // If node with index node_idx is not in useful set,
   367     // mark it as dead in dead node list.
   368     if (! useful_node_set.test(node_idx) ) {
   369       record_dead_node(node_idx);
   370     }
   371   }
   372 }
   374 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
   375   int shift = 0;
   376   for (int i = 0; i < inlines->length(); i++) {
   377     CallGenerator* cg = inlines->at(i);
   378     CallNode* call = cg->call_node();
   379     if (shift > 0) {
   380       inlines->at_put(i-shift, cg);
   381     }
   382     if (!useful.member(call)) {
   383       shift++;
   384     }
   385   }
   386   inlines->trunc_to(inlines->length()-shift);
   387 }
   389 // Disconnect all useless nodes by disconnecting those at the boundary.
   390 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   391   uint next = 0;
   392   while (next < useful.size()) {
   393     Node *n = useful.at(next++);
   394     if (n->is_SafePoint()) {
   395       // We're done with a parsing phase. Replaced nodes are not valid
   396       // beyond that point.
   397       n->as_SafePoint()->delete_replaced_nodes();
   398     }
   399     // Use raw traversal of out edges since this code removes out edges
   400     int max = n->outcnt();
   401     for (int j = 0; j < max; ++j) {
   402       Node* child = n->raw_out(j);
   403       if (! useful.member(child)) {
   404         assert(!child->is_top() || child != top(),
   405                "If top is cached in Compile object it is in useful list");
   406         // Only need to remove this out-edge to the useless node
   407         n->raw_del_out(j);
   408         --j;
   409         --max;
   410       }
   411     }
   412     if (n->outcnt() == 1 && n->has_special_unique_user()) {
   413       record_for_igvn(n->unique_out());
   414     }
   415   }
   416   // Remove useless macro and predicate opaq nodes
   417   for (int i = C->macro_count()-1; i >= 0; i--) {
   418     Node* n = C->macro_node(i);
   419     if (!useful.member(n)) {
   420       remove_macro_node(n);
   421     }
   422   }
   423   // Remove useless CastII nodes with range check dependency
   424   for (int i = range_check_cast_count() - 1; i >= 0; i--) {
   425     Node* cast = range_check_cast_node(i);
   426     if (!useful.member(cast)) {
   427       remove_range_check_cast(cast);
   428     }
   429   }
   430   // Remove useless expensive node
   431   for (int i = C->expensive_count()-1; i >= 0; i--) {
   432     Node* n = C->expensive_node(i);
   433     if (!useful.member(n)) {
   434       remove_expensive_node(n);
   435     }
   436   }
   437   // clean up the late inline lists
   438   remove_useless_late_inlines(&_string_late_inlines, useful);
   439   remove_useless_late_inlines(&_boxing_late_inlines, useful);
   440   remove_useless_late_inlines(&_late_inlines, useful);
   441   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   442 }
   444 //------------------------------frame_size_in_words-----------------------------
   445 // frame_slots in units of words
   446 int Compile::frame_size_in_words() const {
   447   // shift is 0 in LP32 and 1 in LP64
   448   const int shift = (LogBytesPerWord - LogBytesPerInt);
   449   int words = _frame_slots >> shift;
   450   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   451   return words;
   452 }
   454 // To bang the stack of this compiled method we use the stack size
   455 // that the interpreter would need in case of a deoptimization. This
   456 // removes the need to bang the stack in the deoptimization blob which
   457 // in turn simplifies stack overflow handling.
   458 int Compile::bang_size_in_bytes() const {
   459   return MAX2(_interpreter_frame_size, frame_size_in_bytes());
   460 }
   462 // ============================================================================
   463 //------------------------------CompileWrapper---------------------------------
   464 class CompileWrapper : public StackObj {
   465   Compile *const _compile;
   466  public:
   467   CompileWrapper(Compile* compile);
   469   ~CompileWrapper();
   470 };
   472 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   473   // the Compile* pointer is stored in the current ciEnv:
   474   ciEnv* env = compile->env();
   475   assert(env == ciEnv::current(), "must already be a ciEnv active");
   476   assert(env->compiler_data() == NULL, "compile already active?");
   477   env->set_compiler_data(compile);
   478   assert(compile == Compile::current(), "sanity");
   480   compile->set_type_dict(NULL);
   481   compile->set_type_hwm(NULL);
   482   compile->set_type_last_size(0);
   483   compile->set_last_tf(NULL, NULL);
   484   compile->set_indexSet_arena(NULL);
   485   compile->set_indexSet_free_block_list(NULL);
   486   compile->init_type_arena();
   487   Type::Initialize(compile);
   488   _compile->set_scratch_buffer_blob(NULL);
   489   _compile->begin_method();
   490 }
   491 CompileWrapper::~CompileWrapper() {
   492   _compile->end_method();
   493   if (_compile->scratch_buffer_blob() != NULL)
   494     BufferBlob::free(_compile->scratch_buffer_blob());
   495   _compile->env()->set_compiler_data(NULL);
   496 }
   499 //----------------------------print_compile_messages---------------------------
   500 void Compile::print_compile_messages() {
   501 #ifndef PRODUCT
   502   // Check if recompiling
   503   if (_subsume_loads == false && PrintOpto) {
   504     // Recompiling without allowing machine instructions to subsume loads
   505     tty->print_cr("*********************************************************");
   506     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   507     tty->print_cr("*********************************************************");
   508   }
   509   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   510     // Recompiling without escape analysis
   511     tty->print_cr("*********************************************************");
   512     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   513     tty->print_cr("*********************************************************");
   514   }
   515   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
   516     // Recompiling without boxing elimination
   517     tty->print_cr("*********************************************************");
   518     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
   519     tty->print_cr("*********************************************************");
   520   }
   521   if (env()->break_at_compile()) {
   522     // Open the debugger when compiling this method.
   523     tty->print("### Breaking when compiling: ");
   524     method()->print_short_name();
   525     tty->cr();
   526     BREAKPOINT;
   527   }
   529   if( PrintOpto ) {
   530     if (is_osr_compilation()) {
   531       tty->print("[OSR]%3d", _compile_id);
   532     } else {
   533       tty->print("%3d", _compile_id);
   534     }
   535   }
   536 #endif
   537 }
   540 //-----------------------init_scratch_buffer_blob------------------------------
   541 // Construct a temporary BufferBlob and cache it for this compile.
   542 void Compile::init_scratch_buffer_blob(int const_size) {
   543   // If there is already a scratch buffer blob allocated and the
   544   // constant section is big enough, use it.  Otherwise free the
   545   // current and allocate a new one.
   546   BufferBlob* blob = scratch_buffer_blob();
   547   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
   548     // Use the current blob.
   549   } else {
   550     if (blob != NULL) {
   551       BufferBlob::free(blob);
   552     }
   554     ResourceMark rm;
   555     _scratch_const_size = const_size;
   556     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
   557     blob = BufferBlob::create("Compile::scratch_buffer", size);
   558     // Record the buffer blob for next time.
   559     set_scratch_buffer_blob(blob);
   560     // Have we run out of code space?
   561     if (scratch_buffer_blob() == NULL) {
   562       // Let CompilerBroker disable further compilations.
   563       record_failure("Not enough space for scratch buffer in CodeCache");
   564       return;
   565     }
   566   }
   568   // Initialize the relocation buffers
   569   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
   570   set_scratch_locs_memory(locs_buf);
   571 }
   574 //-----------------------scratch_emit_size-------------------------------------
   575 // Helper function that computes size by emitting code
   576 uint Compile::scratch_emit_size(const Node* n) {
   577   // Start scratch_emit_size section.
   578   set_in_scratch_emit_size(true);
   580   // Emit into a trash buffer and count bytes emitted.
   581   // This is a pretty expensive way to compute a size,
   582   // but it works well enough if seldom used.
   583   // All common fixed-size instructions are given a size
   584   // method by the AD file.
   585   // Note that the scratch buffer blob and locs memory are
   586   // allocated at the beginning of the compile task, and
   587   // may be shared by several calls to scratch_emit_size.
   588   // The allocation of the scratch buffer blob is particularly
   589   // expensive, since it has to grab the code cache lock.
   590   BufferBlob* blob = this->scratch_buffer_blob();
   591   assert(blob != NULL, "Initialize BufferBlob at start");
   592   assert(blob->size() > MAX_inst_size, "sanity");
   593   relocInfo* locs_buf = scratch_locs_memory();
   594   address blob_begin = blob->content_begin();
   595   address blob_end   = (address)locs_buf;
   596   assert(blob->content_contains(blob_end), "sanity");
   597   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   598   buf.initialize_consts_size(_scratch_const_size);
   599   buf.initialize_stubs_size(MAX_stubs_size);
   600   assert(locs_buf != NULL, "sanity");
   601   int lsize = MAX_locs_size / 3;
   602   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
   603   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
   604   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
   606   // Do the emission.
   608   Label fakeL; // Fake label for branch instructions.
   609   Label*   saveL = NULL;
   610   uint save_bnum = 0;
   611   bool is_branch = n->is_MachBranch();
   612   if (is_branch) {
   613     MacroAssembler masm(&buf);
   614     masm.bind(fakeL);
   615     n->as_MachBranch()->save_label(&saveL, &save_bnum);
   616     n->as_MachBranch()->label_set(&fakeL, 0);
   617   }
   618   n->emit(buf, this->regalloc());
   620   // Emitting into the scratch buffer should not fail
   621   assert (!failing(), err_msg_res("Must not have pending failure. Reason is: %s", failure_reason()));
   623   if (is_branch) // Restore label.
   624     n->as_MachBranch()->label_set(saveL, save_bnum);
   626   // End scratch_emit_size section.
   627   set_in_scratch_emit_size(false);
   629   return buf.insts_size();
   630 }
   633 // ============================================================================
   634 //------------------------------Compile standard-------------------------------
   635 debug_only( int Compile::_debug_idx = 100000; )
   637 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   638 // the continuation bci for on stack replacement.
   641 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
   642                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
   643                 : Phase(Compiler),
   644                   _env(ci_env),
   645                   _log(ci_env->log()),
   646                   _compile_id(ci_env->compile_id()),
   647                   _save_argument_registers(false),
   648                   _stub_name(NULL),
   649                   _stub_function(NULL),
   650                   _stub_entry_point(NULL),
   651                   _method(target),
   652                   _entry_bci(osr_bci),
   653                   _initial_gvn(NULL),
   654                   _for_igvn(NULL),
   655                   _warm_calls(NULL),
   656                   _subsume_loads(subsume_loads),
   657                   _do_escape_analysis(do_escape_analysis),
   658                   _eliminate_boxing(eliminate_boxing),
   659                   _failure_reason(NULL),
   660                   _code_buffer("Compile::Fill_buffer"),
   661                   _orig_pc_slot(0),
   662                   _orig_pc_slot_offset_in_bytes(0),
   663                   _has_method_handle_invokes(false),
   664                   _mach_constant_base_node(NULL),
   665                   _node_bundling_limit(0),
   666                   _node_bundling_base(NULL),
   667                   _java_calls(0),
   668                   _inner_loops(0),
   669                   _scratch_const_size(-1),
   670                   _in_scratch_emit_size(false),
   671                   _dead_node_list(comp_arena()),
   672                   _dead_node_count(0),
   673 #ifndef PRODUCT
   674                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   675                   _in_dump_cnt(0),
   676                   _printer(IdealGraphPrinter::printer()),
   677 #endif
   678                   _congraph(NULL),
   679                   _comp_arena(mtCompiler),
   680                   _node_arena(mtCompiler),
   681                   _old_arena(mtCompiler),
   682                   _Compile_types(mtCompiler),
   683                   _replay_inline_data(NULL),
   684                   _late_inlines(comp_arena(), 2, 0, NULL),
   685                   _string_late_inlines(comp_arena(), 2, 0, NULL),
   686                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
   687                   _late_inlines_pos(0),
   688                   _number_of_mh_late_inlines(0),
   689                   _inlining_progress(false),
   690                   _inlining_incrementally(false),
   691                   _print_inlining_list(NULL),
   692                   _print_inlining_idx(0),
   693                   _interpreter_frame_size(0),
   694                   _max_node_limit(MaxNodeLimit) {
   695   C = this;
   697   CompileWrapper cw(this);
   698 #ifndef PRODUCT
   699   if (TimeCompiler2) {
   700     tty->print(" ");
   701     target->holder()->name()->print();
   702     tty->print(".");
   703     target->print_short_name();
   704     tty->print("  ");
   705   }
   706   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   707   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   708   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   709   if (!print_opto_assembly) {
   710     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   711     if (print_assembly && !Disassembler::can_decode()) {
   712       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   713       print_opto_assembly = true;
   714     }
   715   }
   716   set_print_assembly(print_opto_assembly);
   717   set_parsed_irreducible_loop(false);
   719   if (method()->has_option("ReplayInline")) {
   720     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
   721   }
   722 #endif
   723   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
   724   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
   725   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
   727   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
   728     // Make sure the method being compiled gets its own MDO,
   729     // so we can at least track the decompile_count().
   730     // Need MDO to record RTM code generation state.
   731     method()->ensure_method_data();
   732   }
   734   Init(::AliasLevel);
   737   print_compile_messages();
   739   _ilt = InlineTree::build_inline_tree_root();
   741   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   742   assert(num_alias_types() >= AliasIdxRaw, "");
   744 #define MINIMUM_NODE_HASH  1023
   745   // Node list that Iterative GVN will start with
   746   Unique_Node_List for_igvn(comp_arena());
   747   set_for_igvn(&for_igvn);
   749   // GVN that will be run immediately on new nodes
   750   uint estimated_size = method()->code_size()*4+64;
   751   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   752   PhaseGVN gvn(node_arena(), estimated_size);
   753   set_initial_gvn(&gvn);
   755   if (print_inlining() || print_intrinsics()) {
   756     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
   757   }
   758   { // Scope for timing the parser
   759     TracePhase t3("parse", &_t_parser, true);
   761     // Put top into the hash table ASAP.
   762     initial_gvn()->transform_no_reclaim(top());
   764     // Set up tf(), start(), and find a CallGenerator.
   765     CallGenerator* cg = NULL;
   766     if (is_osr_compilation()) {
   767       const TypeTuple *domain = StartOSRNode::osr_domain();
   768       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   769       init_tf(TypeFunc::make(domain, range));
   770       StartNode* s = new (this) StartOSRNode(root(), domain);
   771       initial_gvn()->set_type_bottom(s);
   772       init_start(s);
   773       cg = CallGenerator::for_osr(method(), entry_bci());
   774     } else {
   775       // Normal case.
   776       init_tf(TypeFunc::make(method()));
   777       StartNode* s = new (this) StartNode(root(), tf()->domain());
   778       initial_gvn()->set_type_bottom(s);
   779       init_start(s);
   780       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
   781         // With java.lang.ref.reference.get() we must go through the
   782         // intrinsic when G1 is enabled - even when get() is the root
   783         // method of the compile - so that, if necessary, the value in
   784         // the referent field of the reference object gets recorded by
   785         // the pre-barrier code.
   786         // Specifically, if G1 is enabled, the value in the referent
   787         // field is recorded by the G1 SATB pre barrier. This will
   788         // result in the referent being marked live and the reference
   789         // object removed from the list of discovered references during
   790         // reference processing.
   791         cg = find_intrinsic(method(), false);
   792       }
   793       if (cg == NULL) {
   794         float past_uses = method()->interpreter_invocation_count();
   795         float expected_uses = past_uses;
   796         cg = CallGenerator::for_inline(method(), expected_uses);
   797       }
   798     }
   799     if (failing())  return;
   800     if (cg == NULL) {
   801       record_method_not_compilable_all_tiers("cannot parse method");
   802       return;
   803     }
   804     JVMState* jvms = build_start_state(start(), tf());
   805     if ((jvms = cg->generate(jvms)) == NULL) {
   806       if (!failure_reason_is(C2Compiler::retry_class_loading_during_parsing())) {
   807         record_method_not_compilable("method parse failed");
   808       }
   809       return;
   810     }
   811     GraphKit kit(jvms);
   813     if (!kit.stopped()) {
   814       // Accept return values, and transfer control we know not where.
   815       // This is done by a special, unique ReturnNode bound to root.
   816       return_values(kit.jvms());
   817     }
   819     if (kit.has_exceptions()) {
   820       // Any exceptions that escape from this call must be rethrown
   821       // to whatever caller is dynamically above us on the stack.
   822       // This is done by a special, unique RethrowNode bound to root.
   823       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   824     }
   826     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
   828     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
   829       inline_string_calls(true);
   830     }
   832     if (failing())  return;
   834     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
   836     // Remove clutter produced by parsing.
   837     if (!failing()) {
   838       ResourceMark rm;
   839       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   840     }
   841   }
   843   // Note:  Large methods are capped off in do_one_bytecode().
   844   if (failing())  return;
   846   // After parsing, node notes are no longer automagic.
   847   // They must be propagated by register_new_node_with_optimizer(),
   848   // clone(), or the like.
   849   set_default_node_notes(NULL);
   851   for (;;) {
   852     int successes = Inline_Warm();
   853     if (failing())  return;
   854     if (successes == 0)  break;
   855   }
   857   // Drain the list.
   858   Finish_Warm();
   859 #ifndef PRODUCT
   860   if (_printer) {
   861     _printer->print_inlining(this);
   862   }
   863 #endif
   865   if (failing())  return;
   866   NOT_PRODUCT( verify_graph_edges(); )
   868   // Now optimize
   869   Optimize();
   870   if (failing())  return;
   871   NOT_PRODUCT( verify_graph_edges(); )
   873 #ifndef PRODUCT
   874   if (PrintIdeal) {
   875     ttyLocker ttyl;  // keep the following output all in one block
   876     // This output goes directly to the tty, not the compiler log.
   877     // To enable tools to match it up with the compilation activity,
   878     // be sure to tag this tty output with the compile ID.
   879     if (xtty != NULL) {
   880       xtty->head("ideal compile_id='%d'%s", compile_id(),
   881                  is_osr_compilation()    ? " compile_kind='osr'" :
   882                  "");
   883     }
   884     root()->dump(9999);
   885     if (xtty != NULL) {
   886       xtty->tail("ideal");
   887     }
   888   }
   889 #endif
   891   NOT_PRODUCT( verify_barriers(); )
   893   // Dump compilation data to replay it.
   894   if (method()->has_option("DumpReplay")) {
   895     env()->dump_replay_data(_compile_id);
   896   }
   897   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
   898     env()->dump_inline_data(_compile_id);
   899   }
   901   // Now that we know the size of all the monitors we can add a fixed slot
   902   // for the original deopt pc.
   904   _orig_pc_slot =  fixed_slots();
   905   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   906   set_fixed_slots(next_slot);
   908   // Compute when to use implicit null checks. Used by matching trap based
   909   // nodes and NullCheck optimization.
   910   set_allowed_deopt_reasons();
   912   // Now generate code
   913   Code_Gen();
   914   if (failing())  return;
   916   // Check if we want to skip execution of all compiled code.
   917   {
   918 #ifndef PRODUCT
   919     if (OptoNoExecute) {
   920       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   921       return;
   922     }
   923     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   924 #endif
   926     if (is_osr_compilation()) {
   927       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   928       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   929     } else {
   930       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   931       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   932     }
   934     env()->register_method(_method, _entry_bci,
   935                            &_code_offsets,
   936                            _orig_pc_slot_offset_in_bytes,
   937                            code_buffer(),
   938                            frame_size_in_words(), _oop_map_set,
   939                            &_handler_table, &_inc_table,
   940                            compiler,
   941                            env()->comp_level(),
   942                            has_unsafe_access(),
   943                            SharedRuntime::is_wide_vector(max_vector_size()),
   944                            rtm_state()
   945                            );
   947     if (log() != NULL) // Print code cache state into compiler log
   948       log()->code_cache_state();
   949   }
   950 }
   952 //------------------------------Compile----------------------------------------
   953 // Compile a runtime stub
   954 Compile::Compile( ciEnv* ci_env,
   955                   TypeFunc_generator generator,
   956                   address stub_function,
   957                   const char *stub_name,
   958                   int is_fancy_jump,
   959                   bool pass_tls,
   960                   bool save_arg_registers,
   961                   bool return_pc )
   962   : Phase(Compiler),
   963     _env(ci_env),
   964     _log(ci_env->log()),
   965     _compile_id(0),
   966     _save_argument_registers(save_arg_registers),
   967     _method(NULL),
   968     _stub_name(stub_name),
   969     _stub_function(stub_function),
   970     _stub_entry_point(NULL),
   971     _entry_bci(InvocationEntryBci),
   972     _initial_gvn(NULL),
   973     _for_igvn(NULL),
   974     _warm_calls(NULL),
   975     _orig_pc_slot(0),
   976     _orig_pc_slot_offset_in_bytes(0),
   977     _subsume_loads(true),
   978     _do_escape_analysis(false),
   979     _eliminate_boxing(false),
   980     _failure_reason(NULL),
   981     _code_buffer("Compile::Fill_buffer"),
   982     _has_method_handle_invokes(false),
   983     _mach_constant_base_node(NULL),
   984     _node_bundling_limit(0),
   985     _node_bundling_base(NULL),
   986     _java_calls(0),
   987     _inner_loops(0),
   988 #ifndef PRODUCT
   989     _trace_opto_output(TraceOptoOutput),
   990     _in_dump_cnt(0),
   991     _printer(NULL),
   992 #endif
   993     _comp_arena(mtCompiler),
   994     _node_arena(mtCompiler),
   995     _old_arena(mtCompiler),
   996     _Compile_types(mtCompiler),
   997     _dead_node_list(comp_arena()),
   998     _dead_node_count(0),
   999     _congraph(NULL),
  1000     _replay_inline_data(NULL),
  1001     _number_of_mh_late_inlines(0),
  1002     _inlining_progress(false),
  1003     _inlining_incrementally(false),
  1004     _print_inlining_list(NULL),
  1005     _print_inlining_idx(0),
  1006     _allowed_reasons(0),
  1007     _interpreter_frame_size(0),
  1008     _max_node_limit(MaxNodeLimit) {
  1009   C = this;
  1011 #ifndef PRODUCT
  1012   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
  1013   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
  1014   set_print_assembly(PrintFrameConverterAssembly);
  1015   set_parsed_irreducible_loop(false);
  1016 #endif
  1017   set_has_irreducible_loop(false); // no loops
  1019   CompileWrapper cw(this);
  1020   Init(/*AliasLevel=*/ 0);
  1021   init_tf((*generator)());
  1024     // The following is a dummy for the sake of GraphKit::gen_stub
  1025     Unique_Node_List for_igvn(comp_arena());
  1026     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
  1027     PhaseGVN gvn(Thread::current()->resource_area(),255);
  1028     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
  1029     gvn.transform_no_reclaim(top());
  1031     GraphKit kit;
  1032     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
  1035   NOT_PRODUCT( verify_graph_edges(); )
  1036   Code_Gen();
  1037   if (failing())  return;
  1040   // Entry point will be accessed using compile->stub_entry_point();
  1041   if (code_buffer() == NULL) {
  1042     Matcher::soft_match_failure();
  1043   } else {
  1044     if (PrintAssembly && (WizardMode || Verbose))
  1045       tty->print_cr("### Stub::%s", stub_name);
  1047     if (!failing()) {
  1048       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
  1050       // Make the NMethod
  1051       // For now we mark the frame as never safe for profile stackwalking
  1052       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
  1053                                                       code_buffer(),
  1054                                                       CodeOffsets::frame_never_safe,
  1055                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
  1056                                                       frame_size_in_words(),
  1057                                                       _oop_map_set,
  1058                                                       save_arg_registers);
  1059       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
  1061       _stub_entry_point = rs->entry_point();
  1066 //------------------------------Init-------------------------------------------
  1067 // Prepare for a single compilation
  1068 void Compile::Init(int aliaslevel) {
  1069   _unique  = 0;
  1070   _regalloc = NULL;
  1072   _tf      = NULL;  // filled in later
  1073   _top     = NULL;  // cached later
  1074   _matcher = NULL;  // filled in later
  1075   _cfg     = NULL;  // filled in later
  1077   set_24_bit_selection_and_mode(Use24BitFP, false);
  1079   _node_note_array = NULL;
  1080   _default_node_notes = NULL;
  1082   _immutable_memory = NULL; // filled in at first inquiry
  1084   // Globally visible Nodes
  1085   // First set TOP to NULL to give safe behavior during creation of RootNode
  1086   set_cached_top_node(NULL);
  1087   set_root(new (this) RootNode());
  1088   // Now that you have a Root to point to, create the real TOP
  1089   set_cached_top_node( new (this) ConNode(Type::TOP) );
  1090   set_recent_alloc(NULL, NULL);
  1092   // Create Debug Information Recorder to record scopes, oopmaps, etc.
  1093   env()->set_oop_recorder(new OopRecorder(env()->arena()));
  1094   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
  1095   env()->set_dependencies(new Dependencies(env()));
  1097   _fixed_slots = 0;
  1098   set_has_split_ifs(false);
  1099   set_has_loops(has_method() && method()->has_loops()); // first approximation
  1100   set_has_stringbuilder(false);
  1101   set_has_boxed_value(false);
  1102   _trap_can_recompile = false;  // no traps emitted yet
  1103   _major_progress = true; // start out assuming good things will happen
  1104   set_has_unsafe_access(false);
  1105   set_max_vector_size(0);
  1106   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
  1107   set_decompile_count(0);
  1109   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
  1110   set_num_loop_opts(LoopOptsCount);
  1111   set_do_inlining(Inline);
  1112   set_max_inline_size(MaxInlineSize);
  1113   set_freq_inline_size(FreqInlineSize);
  1114   set_do_scheduling(OptoScheduling);
  1115   set_do_count_invocations(false);
  1116   set_do_method_data_update(false);
  1117   set_rtm_state(NoRTM); // No RTM lock eliding by default
  1118   method_has_option_value("MaxNodeLimit", _max_node_limit);
  1119 #if INCLUDE_RTM_OPT
  1120   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
  1121     int rtm_state = method()->method_data()->rtm_state();
  1122     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
  1123       // Don't generate RTM lock eliding code.
  1124       set_rtm_state(NoRTM);
  1125     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
  1126       // Generate RTM lock eliding code without abort ratio calculation code.
  1127       set_rtm_state(UseRTM);
  1128     } else if (UseRTMDeopt) {
  1129       // Generate RTM lock eliding code and include abort ratio calculation
  1130       // code if UseRTMDeopt is on.
  1131       set_rtm_state(ProfileRTM);
  1134 #endif
  1135   if (debug_info()->recording_non_safepoints()) {
  1136     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
  1137                         (comp_arena(), 8, 0, NULL));
  1138     set_default_node_notes(Node_Notes::make(this));
  1141   // // -- Initialize types before each compile --
  1142   // // Update cached type information
  1143   // if( _method && _method->constants() )
  1144   //   Type::update_loaded_types(_method, _method->constants());
  1146   // Init alias_type map.
  1147   if (!_do_escape_analysis && aliaslevel == 3)
  1148     aliaslevel = 2;  // No unique types without escape analysis
  1149   _AliasLevel = aliaslevel;
  1150   const int grow_ats = 16;
  1151   _max_alias_types = grow_ats;
  1152   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
  1153   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
  1154   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
  1156     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
  1158   // Initialize the first few types.
  1159   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
  1160   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
  1161   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
  1162   _num_alias_types = AliasIdxRaw+1;
  1163   // Zero out the alias type cache.
  1164   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
  1165   // A NULL adr_type hits in the cache right away.  Preload the right answer.
  1166   probe_alias_cache(NULL)->_index = AliasIdxTop;
  1168   _intrinsics = NULL;
  1169   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1170   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1171   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1172   _range_check_casts = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1173   register_library_intrinsics();
  1176 //---------------------------init_start----------------------------------------
  1177 // Install the StartNode on this compile object.
  1178 void Compile::init_start(StartNode* s) {
  1179   if (failing())
  1180     return; // already failing
  1181   assert(s == start(), "");
  1184 StartNode* Compile::start() const {
  1185   assert(!failing(), "");
  1186   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
  1187     Node* start = root()->fast_out(i);
  1188     if( start->is_Start() )
  1189       return start->as_Start();
  1191   fatal("Did not find Start node!");
  1192   return NULL;
  1195 //-------------------------------immutable_memory-------------------------------------
  1196 // Access immutable memory
  1197 Node* Compile::immutable_memory() {
  1198   if (_immutable_memory != NULL) {
  1199     return _immutable_memory;
  1201   StartNode* s = start();
  1202   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
  1203     Node *p = s->fast_out(i);
  1204     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
  1205       _immutable_memory = p;
  1206       return _immutable_memory;
  1209   ShouldNotReachHere();
  1210   return NULL;
  1213 //----------------------set_cached_top_node------------------------------------
  1214 // Install the cached top node, and make sure Node::is_top works correctly.
  1215 void Compile::set_cached_top_node(Node* tn) {
  1216   if (tn != NULL)  verify_top(tn);
  1217   Node* old_top = _top;
  1218   _top = tn;
  1219   // Calling Node::setup_is_top allows the nodes the chance to adjust
  1220   // their _out arrays.
  1221   if (_top != NULL)     _top->setup_is_top();
  1222   if (old_top != NULL)  old_top->setup_is_top();
  1223   assert(_top == NULL || top()->is_top(), "");
  1226 #ifdef ASSERT
  1227 uint Compile::count_live_nodes_by_graph_walk() {
  1228   Unique_Node_List useful(comp_arena());
  1229   // Get useful node list by walking the graph.
  1230   identify_useful_nodes(useful);
  1231   return useful.size();
  1234 void Compile::print_missing_nodes() {
  1236   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
  1237   if ((_log == NULL) && (! PrintIdealNodeCount)) {
  1238     return;
  1241   // This is an expensive function. It is executed only when the user
  1242   // specifies VerifyIdealNodeCount option or otherwise knows the
  1243   // additional work that needs to be done to identify reachable nodes
  1244   // by walking the flow graph and find the missing ones using
  1245   // _dead_node_list.
  1247   Unique_Node_List useful(comp_arena());
  1248   // Get useful node list by walking the graph.
  1249   identify_useful_nodes(useful);
  1251   uint l_nodes = C->live_nodes();
  1252   uint l_nodes_by_walk = useful.size();
  1254   if (l_nodes != l_nodes_by_walk) {
  1255     if (_log != NULL) {
  1256       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
  1257       _log->stamp();
  1258       _log->end_head();
  1260     VectorSet& useful_member_set = useful.member_set();
  1261     int last_idx = l_nodes_by_walk;
  1262     for (int i = 0; i < last_idx; i++) {
  1263       if (useful_member_set.test(i)) {
  1264         if (_dead_node_list.test(i)) {
  1265           if (_log != NULL) {
  1266             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
  1268           if (PrintIdealNodeCount) {
  1269             // Print the log message to tty
  1270               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
  1271               useful.at(i)->dump();
  1275       else if (! _dead_node_list.test(i)) {
  1276         if (_log != NULL) {
  1277           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
  1279         if (PrintIdealNodeCount) {
  1280           // Print the log message to tty
  1281           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
  1285     if (_log != NULL) {
  1286       _log->tail("mismatched_nodes");
  1290 #endif
  1292 #ifndef PRODUCT
  1293 void Compile::verify_top(Node* tn) const {
  1294   if (tn != NULL) {
  1295     assert(tn->is_Con(), "top node must be a constant");
  1296     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
  1297     assert(tn->in(0) != NULL, "must have live top node");
  1300 #endif
  1303 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1305 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1306   guarantee(arr != NULL, "");
  1307   int num_blocks = arr->length();
  1308   if (grow_by < num_blocks)  grow_by = num_blocks;
  1309   int num_notes = grow_by * _node_notes_block_size;
  1310   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1311   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1312   while (num_notes > 0) {
  1313     arr->append(notes);
  1314     notes     += _node_notes_block_size;
  1315     num_notes -= _node_notes_block_size;
  1317   assert(num_notes == 0, "exact multiple, please");
  1320 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1321   if (source == NULL || dest == NULL)  return false;
  1323   if (dest->is_Con())
  1324     return false;               // Do not push debug info onto constants.
  1326 #ifdef ASSERT
  1327   // Leave a bread crumb trail pointing to the original node:
  1328   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1329     dest->set_debug_orig(source);
  1331 #endif
  1333   if (node_note_array() == NULL)
  1334     return false;               // Not collecting any notes now.
  1336   // This is a copy onto a pre-existing node, which may already have notes.
  1337   // If both nodes have notes, do not overwrite any pre-existing notes.
  1338   Node_Notes* source_notes = node_notes_at(source->_idx);
  1339   if (source_notes == NULL || source_notes->is_clear())  return false;
  1340   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1341   if (dest_notes == NULL || dest_notes->is_clear()) {
  1342     return set_node_notes_at(dest->_idx, source_notes);
  1345   Node_Notes merged_notes = (*source_notes);
  1346   // The order of operations here ensures that dest notes will win...
  1347   merged_notes.update_from(dest_notes);
  1348   return set_node_notes_at(dest->_idx, &merged_notes);
  1352 //--------------------------allow_range_check_smearing-------------------------
  1353 // Gating condition for coalescing similar range checks.
  1354 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1355 // single covering check that is at least as strong as any of them.
  1356 // If the optimization succeeds, the simplified (strengthened) range check
  1357 // will always succeed.  If it fails, we will deopt, and then give up
  1358 // on the optimization.
  1359 bool Compile::allow_range_check_smearing() const {
  1360   // If this method has already thrown a range-check,
  1361   // assume it was because we already tried range smearing
  1362   // and it failed.
  1363   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1364   return !already_trapped;
  1368 //------------------------------flatten_alias_type-----------------------------
  1369 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1370   int offset = tj->offset();
  1371   TypePtr::PTR ptr = tj->ptr();
  1373   // Known instance (scalarizable allocation) alias only with itself.
  1374   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1375                        tj->is_oopptr()->is_known_instance();
  1377   // Process weird unsafe references.
  1378   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1379     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1380     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1381     tj = TypeOopPtr::BOTTOM;
  1382     ptr = tj->ptr();
  1383     offset = tj->offset();
  1386   // Array pointers need some flattening
  1387   const TypeAryPtr *ta = tj->isa_aryptr();
  1388   if (ta && ta->is_stable()) {
  1389     // Erase stability property for alias analysis.
  1390     tj = ta = ta->cast_to_stable(false);
  1392   if( ta && is_known_inst ) {
  1393     if ( offset != Type::OffsetBot &&
  1394          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1395       offset = Type::OffsetBot; // Flatten constant access into array body only
  1396       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1398   } else if( ta && _AliasLevel >= 2 ) {
  1399     // For arrays indexed by constant indices, we flatten the alias
  1400     // space to include all of the array body.  Only the header, klass
  1401     // and array length can be accessed un-aliased.
  1402     if( offset != Type::OffsetBot ) {
  1403       if( ta->const_oop() ) { // MethodData* or Method*
  1404         offset = Type::OffsetBot;   // Flatten constant access into array body
  1405         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1406       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1407         // range is OK as-is.
  1408         tj = ta = TypeAryPtr::RANGE;
  1409       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1410         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1411         ta = TypeAryPtr::RANGE; // generic ignored junk
  1412         ptr = TypePtr::BotPTR;
  1413       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1414         tj = TypeInstPtr::MARK;
  1415         ta = TypeAryPtr::RANGE; // generic ignored junk
  1416         ptr = TypePtr::BotPTR;
  1417       } else {                  // Random constant offset into array body
  1418         offset = Type::OffsetBot;   // Flatten constant access into array body
  1419         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1422     // Arrays of fixed size alias with arrays of unknown size.
  1423     if (ta->size() != TypeInt::POS) {
  1424       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1425       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1427     // Arrays of known objects become arrays of unknown objects.
  1428     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1429       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1430       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1432     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1433       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1434       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1436     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1437     // cannot be distinguished by bytecode alone.
  1438     if (ta->elem() == TypeInt::BOOL) {
  1439       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1440       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1441       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1443     // During the 2nd round of IterGVN, NotNull castings are removed.
  1444     // Make sure the Bottom and NotNull variants alias the same.
  1445     // Also, make sure exact and non-exact variants alias the same.
  1446     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
  1447       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1451   // Oop pointers need some flattening
  1452   const TypeInstPtr *to = tj->isa_instptr();
  1453   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1454     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1455     if( ptr == TypePtr::Constant ) {
  1456       if (to->klass() != ciEnv::current()->Class_klass() ||
  1457           offset < k->size_helper() * wordSize) {
  1458         // No constant oop pointers (such as Strings); they alias with
  1459         // unknown strings.
  1460         assert(!is_known_inst, "not scalarizable allocation");
  1461         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1463     } else if( is_known_inst ) {
  1464       tj = to; // Keep NotNull and klass_is_exact for instance type
  1465     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1466       // During the 2nd round of IterGVN, NotNull castings are removed.
  1467       // Make sure the Bottom and NotNull variants alias the same.
  1468       // Also, make sure exact and non-exact variants alias the same.
  1469       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1471     if (to->speculative() != NULL) {
  1472       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
  1474     // Canonicalize the holder of this field
  1475     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1476       // First handle header references such as a LoadKlassNode, even if the
  1477       // object's klass is unloaded at compile time (4965979).
  1478       if (!is_known_inst) { // Do it only for non-instance types
  1479         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1481     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1482       // Static fields are in the space above the normal instance
  1483       // fields in the java.lang.Class instance.
  1484       if (to->klass() != ciEnv::current()->Class_klass()) {
  1485         to = NULL;
  1486         tj = TypeOopPtr::BOTTOM;
  1487         offset = tj->offset();
  1489     } else {
  1490       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1491       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1492         if( is_known_inst ) {
  1493           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1494         } else {
  1495           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1501   // Klass pointers to object array klasses need some flattening
  1502   const TypeKlassPtr *tk = tj->isa_klassptr();
  1503   if( tk ) {
  1504     // If we are referencing a field within a Klass, we need
  1505     // to assume the worst case of an Object.  Both exact and
  1506     // inexact types must flatten to the same alias class so
  1507     // use NotNull as the PTR.
  1508     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1510       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
  1511                                    TypeKlassPtr::OBJECT->klass(),
  1512                                    offset);
  1515     ciKlass* klass = tk->klass();
  1516     if( klass->is_obj_array_klass() ) {
  1517       ciKlass* k = TypeAryPtr::OOPS->klass();
  1518       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1519         k = TypeInstPtr::BOTTOM->klass();
  1520       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1523     // Check for precise loads from the primary supertype array and force them
  1524     // to the supertype cache alias index.  Check for generic array loads from
  1525     // the primary supertype array and also force them to the supertype cache
  1526     // alias index.  Since the same load can reach both, we need to merge
  1527     // these 2 disparate memories into the same alias class.  Since the
  1528     // primary supertype array is read-only, there's no chance of confusion
  1529     // where we bypass an array load and an array store.
  1530     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
  1531     if (offset == Type::OffsetBot ||
  1532         (offset >= primary_supers_offset &&
  1533          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
  1534         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
  1535       offset = in_bytes(Klass::secondary_super_cache_offset());
  1536       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1540   // Flatten all Raw pointers together.
  1541   if (tj->base() == Type::RawPtr)
  1542     tj = TypeRawPtr::BOTTOM;
  1544   if (tj->base() == Type::AnyPtr)
  1545     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1547   // Flatten all to bottom for now
  1548   switch( _AliasLevel ) {
  1549   case 0:
  1550     tj = TypePtr::BOTTOM;
  1551     break;
  1552   case 1:                       // Flatten to: oop, static, field or array
  1553     switch (tj->base()) {
  1554     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1555     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1556     case Type::AryPtr:   // do not distinguish arrays at all
  1557     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1558     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1559     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1560     default: ShouldNotReachHere();
  1562     break;
  1563   case 2:                       // No collapsing at level 2; keep all splits
  1564   case 3:                       // No collapsing at level 3; keep all splits
  1565     break;
  1566   default:
  1567     Unimplemented();
  1570   offset = tj->offset();
  1571   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1573   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1574           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1575           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1576           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1577           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1578           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1579           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1580           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1581   assert( tj->ptr() != TypePtr::TopPTR &&
  1582           tj->ptr() != TypePtr::AnyNull &&
  1583           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1584 //    assert( tj->ptr() != TypePtr::Constant ||
  1585 //            tj->base() == Type::RawPtr ||
  1586 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1588   return tj;
  1591 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1592   _index = i;
  1593   _adr_type = at;
  1594   _field = NULL;
  1595   _element = NULL;
  1596   _is_rewritable = true; // default
  1597   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1598   if (atoop != NULL && atoop->is_known_instance()) {
  1599     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1600     _general_index = Compile::current()->get_alias_index(gt);
  1601   } else {
  1602     _general_index = 0;
  1606 //---------------------------------print_on------------------------------------
  1607 #ifndef PRODUCT
  1608 void Compile::AliasType::print_on(outputStream* st) {
  1609   if (index() < 10)
  1610         st->print("@ <%d> ", index());
  1611   else  st->print("@ <%d>",  index());
  1612   st->print(is_rewritable() ? "   " : " RO");
  1613   int offset = adr_type()->offset();
  1614   if (offset == Type::OffsetBot)
  1615         st->print(" +any");
  1616   else  st->print(" +%-3d", offset);
  1617   st->print(" in ");
  1618   adr_type()->dump_on(st);
  1619   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1620   if (field() != NULL && tjp) {
  1621     if (tjp->klass()  != field()->holder() ||
  1622         tjp->offset() != field()->offset_in_bytes()) {
  1623       st->print(" != ");
  1624       field()->print();
  1625       st->print(" ***");
  1630 void print_alias_types() {
  1631   Compile* C = Compile::current();
  1632   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1633   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1634     C->alias_type(idx)->print_on(tty);
  1635     tty->cr();
  1638 #endif
  1641 //----------------------------probe_alias_cache--------------------------------
  1642 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1643   intptr_t key = (intptr_t) adr_type;
  1644   key ^= key >> logAliasCacheSize;
  1645   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1649 //-----------------------------grow_alias_types--------------------------------
  1650 void Compile::grow_alias_types() {
  1651   const int old_ats  = _max_alias_types; // how many before?
  1652   const int new_ats  = old_ats;          // how many more?
  1653   const int grow_ats = old_ats+new_ats;  // how many now?
  1654   _max_alias_types = grow_ats;
  1655   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1656   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1657   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1658   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1662 //--------------------------------find_alias_type------------------------------
  1663 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
  1664   if (_AliasLevel == 0)
  1665     return alias_type(AliasIdxBot);
  1667   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1668   if (ace->_adr_type == adr_type) {
  1669     return alias_type(ace->_index);
  1672   // Handle special cases.
  1673   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1674   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1676   // Do it the slow way.
  1677   const TypePtr* flat = flatten_alias_type(adr_type);
  1679 #ifdef ASSERT
  1680   assert(flat == flatten_alias_type(flat), "idempotent");
  1681   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1682   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1683     const TypeOopPtr* foop = flat->is_oopptr();
  1684     // Scalarizable allocations have exact klass always.
  1685     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1686     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1687     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1689   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1690 #endif
  1692   int idx = AliasIdxTop;
  1693   for (int i = 0; i < num_alias_types(); i++) {
  1694     if (alias_type(i)->adr_type() == flat) {
  1695       idx = i;
  1696       break;
  1700   if (idx == AliasIdxTop) {
  1701     if (no_create)  return NULL;
  1702     // Grow the array if necessary.
  1703     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1704     // Add a new alias type.
  1705     idx = _num_alias_types++;
  1706     _alias_types[idx]->Init(idx, flat);
  1707     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1708     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1709     if (flat->isa_instptr()) {
  1710       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1711           && flat->is_instptr()->klass() == env()->Class_klass())
  1712         alias_type(idx)->set_rewritable(false);
  1714     if (flat->isa_aryptr()) {
  1715 #ifdef ASSERT
  1716       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1717       // (T_BYTE has the weakest alignment and size restrictions...)
  1718       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
  1719 #endif
  1720       if (flat->offset() == TypePtr::OffsetBot) {
  1721         alias_type(idx)->set_element(flat->is_aryptr()->elem());
  1724     if (flat->isa_klassptr()) {
  1725       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
  1726         alias_type(idx)->set_rewritable(false);
  1727       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
  1728         alias_type(idx)->set_rewritable(false);
  1729       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
  1730         alias_type(idx)->set_rewritable(false);
  1731       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
  1732         alias_type(idx)->set_rewritable(false);
  1734     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1735     // but the base pointer type is not distinctive enough to identify
  1736     // references into JavaThread.)
  1738     // Check for final fields.
  1739     const TypeInstPtr* tinst = flat->isa_instptr();
  1740     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1741       ciField* field;
  1742       if (tinst->const_oop() != NULL &&
  1743           tinst->klass() == ciEnv::current()->Class_klass() &&
  1744           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
  1745         // static field
  1746         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
  1747         field = k->get_field_by_offset(tinst->offset(), true);
  1748       } else {
  1749         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1750         field = k->get_field_by_offset(tinst->offset(), false);
  1752       assert(field == NULL ||
  1753              original_field == NULL ||
  1754              (field->holder() == original_field->holder() &&
  1755               field->offset() == original_field->offset() &&
  1756               field->is_static() == original_field->is_static()), "wrong field?");
  1757       // Set field() and is_rewritable() attributes.
  1758       if (field != NULL)  alias_type(idx)->set_field(field);
  1762   // Fill the cache for next time.
  1763   ace->_adr_type = adr_type;
  1764   ace->_index    = idx;
  1765   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1767   // Might as well try to fill the cache for the flattened version, too.
  1768   AliasCacheEntry* face = probe_alias_cache(flat);
  1769   if (face->_adr_type == NULL) {
  1770     face->_adr_type = flat;
  1771     face->_index    = idx;
  1772     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1775   return alias_type(idx);
  1779 Compile::AliasType* Compile::alias_type(ciField* field) {
  1780   const TypeOopPtr* t;
  1781   if (field->is_static())
  1782     t = TypeInstPtr::make(field->holder()->java_mirror());
  1783   else
  1784     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1785   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
  1786   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
  1787   return atp;
  1791 //------------------------------have_alias_type--------------------------------
  1792 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1793   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1794   if (ace->_adr_type == adr_type) {
  1795     return true;
  1798   // Handle special cases.
  1799   if (adr_type == NULL)             return true;
  1800   if (adr_type == TypePtr::BOTTOM)  return true;
  1802   return find_alias_type(adr_type, true, NULL) != NULL;
  1805 //-----------------------------must_alias--------------------------------------
  1806 // True if all values of the given address type are in the given alias category.
  1807 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1808   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1809   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1810   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1811   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1813   // the only remaining possible overlap is identity
  1814   int adr_idx = get_alias_index(adr_type);
  1815   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1816   assert(adr_idx == alias_idx ||
  1817          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1818           && adr_type                       != TypeOopPtr::BOTTOM),
  1819          "should not be testing for overlap with an unsafe pointer");
  1820   return adr_idx == alias_idx;
  1823 //------------------------------can_alias--------------------------------------
  1824 // True if any values of the given address type are in the given alias category.
  1825 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1826   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1827   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1828   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1829   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1831   // the only remaining possible overlap is identity
  1832   int adr_idx = get_alias_index(adr_type);
  1833   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1834   return adr_idx == alias_idx;
  1839 //---------------------------pop_warm_call-------------------------------------
  1840 WarmCallInfo* Compile::pop_warm_call() {
  1841   WarmCallInfo* wci = _warm_calls;
  1842   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1843   return wci;
  1846 //----------------------------Inline_Warm--------------------------------------
  1847 int Compile::Inline_Warm() {
  1848   // If there is room, try to inline some more warm call sites.
  1849   // %%% Do a graph index compaction pass when we think we're out of space?
  1850   if (!InlineWarmCalls)  return 0;
  1852   int calls_made_hot = 0;
  1853   int room_to_grow   = NodeCountInliningCutoff - unique();
  1854   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1855   int amount_grown   = 0;
  1856   WarmCallInfo* call;
  1857   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1858     int est_size = (int)call->size();
  1859     if (est_size > (room_to_grow - amount_grown)) {
  1860       // This one won't fit anyway.  Get rid of it.
  1861       call->make_cold();
  1862       continue;
  1864     call->make_hot();
  1865     calls_made_hot++;
  1866     amount_grown   += est_size;
  1867     amount_to_grow -= est_size;
  1870   if (calls_made_hot > 0)  set_major_progress();
  1871   return calls_made_hot;
  1875 //----------------------------Finish_Warm--------------------------------------
  1876 void Compile::Finish_Warm() {
  1877   if (!InlineWarmCalls)  return;
  1878   if (failing())  return;
  1879   if (warm_calls() == NULL)  return;
  1881   // Clean up loose ends, if we are out of space for inlining.
  1882   WarmCallInfo* call;
  1883   while ((call = pop_warm_call()) != NULL) {
  1884     call->make_cold();
  1888 //---------------------cleanup_loop_predicates-----------------------
  1889 // Remove the opaque nodes that protect the predicates so that all unused
  1890 // checks and uncommon_traps will be eliminated from the ideal graph
  1891 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1892   if (predicate_count()==0) return;
  1893   for (int i = predicate_count(); i > 0; i--) {
  1894     Node * n = predicate_opaque1_node(i-1);
  1895     assert(n->Opcode() == Op_Opaque1, "must be");
  1896     igvn.replace_node(n, n->in(1));
  1898   assert(predicate_count()==0, "should be clean!");
  1901 void Compile::add_range_check_cast(Node* n) {
  1902   assert(n->isa_CastII()->has_range_check(), "CastII should have range check dependency");
  1903   assert(!_range_check_casts->contains(n), "duplicate entry in range check casts");
  1904   _range_check_casts->append(n);
  1907 // Remove all range check dependent CastIINodes.
  1908 void Compile::remove_range_check_casts(PhaseIterGVN &igvn) {
  1909   for (int i = range_check_cast_count(); i > 0; i--) {
  1910     Node* cast = range_check_cast_node(i-1);
  1911     assert(cast->isa_CastII()->has_range_check(), "CastII should have range check dependency");
  1912     igvn.replace_node(cast, cast->in(1));
  1914   assert(range_check_cast_count() == 0, "should be empty");
  1917 // StringOpts and late inlining of string methods
  1918 void Compile::inline_string_calls(bool parse_time) {
  1920     // remove useless nodes to make the usage analysis simpler
  1921     ResourceMark rm;
  1922     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  1926     ResourceMark rm;
  1927     print_method(PHASE_BEFORE_STRINGOPTS, 3);
  1928     PhaseStringOpts pso(initial_gvn(), for_igvn());
  1929     print_method(PHASE_AFTER_STRINGOPTS, 3);
  1932   // now inline anything that we skipped the first time around
  1933   if (!parse_time) {
  1934     _late_inlines_pos = _late_inlines.length();
  1937   while (_string_late_inlines.length() > 0) {
  1938     CallGenerator* cg = _string_late_inlines.pop();
  1939     cg->do_late_inline();
  1940     if (failing())  return;
  1942   _string_late_inlines.trunc_to(0);
  1945 // Late inlining of boxing methods
  1946 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
  1947   if (_boxing_late_inlines.length() > 0) {
  1948     assert(has_boxed_value(), "inconsistent");
  1950     PhaseGVN* gvn = initial_gvn();
  1951     set_inlining_incrementally(true);
  1953     assert( igvn._worklist.size() == 0, "should be done with igvn" );
  1954     for_igvn()->clear();
  1955     gvn->replace_with(&igvn);
  1957     _late_inlines_pos = _late_inlines.length();
  1959     while (_boxing_late_inlines.length() > 0) {
  1960       CallGenerator* cg = _boxing_late_inlines.pop();
  1961       cg->do_late_inline();
  1962       if (failing())  return;
  1964     _boxing_late_inlines.trunc_to(0);
  1967       ResourceMark rm;
  1968       PhaseRemoveUseless pru(gvn, for_igvn());
  1971     igvn = PhaseIterGVN(gvn);
  1972     igvn.optimize();
  1974     set_inlining_progress(false);
  1975     set_inlining_incrementally(false);
  1979 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
  1980   assert(IncrementalInline, "incremental inlining should be on");
  1981   PhaseGVN* gvn = initial_gvn();
  1983   set_inlining_progress(false);
  1984   for_igvn()->clear();
  1985   gvn->replace_with(&igvn);
  1987   int i = 0;
  1989   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
  1990     CallGenerator* cg = _late_inlines.at(i);
  1991     _late_inlines_pos = i+1;
  1992     cg->do_late_inline();
  1993     if (failing())  return;
  1995   int j = 0;
  1996   for (; i < _late_inlines.length(); i++, j++) {
  1997     _late_inlines.at_put(j, _late_inlines.at(i));
  1999   _late_inlines.trunc_to(j);
  2002     ResourceMark rm;
  2003     PhaseRemoveUseless pru(gvn, for_igvn());
  2006   igvn = PhaseIterGVN(gvn);
  2009 // Perform incremental inlining until bound on number of live nodes is reached
  2010 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
  2011   PhaseGVN* gvn = initial_gvn();
  2013   set_inlining_incrementally(true);
  2014   set_inlining_progress(true);
  2015   uint low_live_nodes = 0;
  2017   while(inlining_progress() && _late_inlines.length() > 0) {
  2019     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2020       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
  2021         // PhaseIdealLoop is expensive so we only try it once we are
  2022         // out of live nodes and we only try it again if the previous
  2023         // helped got the number of nodes down significantly
  2024         PhaseIdealLoop ideal_loop( igvn, false, true );
  2025         if (failing())  return;
  2026         low_live_nodes = live_nodes();
  2027         _major_progress = true;
  2030       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2031         break;
  2035     inline_incrementally_one(igvn);
  2037     if (failing())  return;
  2039     igvn.optimize();
  2041     if (failing())  return;
  2044   assert( igvn._worklist.size() == 0, "should be done with igvn" );
  2046   if (_string_late_inlines.length() > 0) {
  2047     assert(has_stringbuilder(), "inconsistent");
  2048     for_igvn()->clear();
  2049     initial_gvn()->replace_with(&igvn);
  2051     inline_string_calls(false);
  2053     if (failing())  return;
  2056       ResourceMark rm;
  2057       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  2060     igvn = PhaseIterGVN(gvn);
  2062     igvn.optimize();
  2065   set_inlining_incrementally(false);
  2069 //------------------------------Optimize---------------------------------------
  2070 // Given a graph, optimize it.
  2071 void Compile::Optimize() {
  2072   TracePhase t1("optimizer", &_t_optimizer, true);
  2074 #ifndef PRODUCT
  2075   if (env()->break_at_compile()) {
  2076     BREAKPOINT;
  2079 #endif
  2081   ResourceMark rm;
  2082   int          loop_opts_cnt;
  2084   NOT_PRODUCT( verify_graph_edges(); )
  2086   print_method(PHASE_AFTER_PARSING);
  2089   // Iterative Global Value Numbering, including ideal transforms
  2090   // Initialize IterGVN with types and values from parse-time GVN
  2091   PhaseIterGVN igvn(initial_gvn());
  2093     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  2094     igvn.optimize();
  2097   print_method(PHASE_ITER_GVN1, 2);
  2099   if (failing())  return;
  2102     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2103     inline_incrementally(igvn);
  2106   print_method(PHASE_INCREMENTAL_INLINE, 2);
  2108   if (failing())  return;
  2110   if (eliminate_boxing()) {
  2111     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2112     // Inline valueOf() methods now.
  2113     inline_boxing_calls(igvn);
  2115     if (AlwaysIncrementalInline) {
  2116       inline_incrementally(igvn);
  2119     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
  2121     if (failing())  return;
  2124   // Remove the speculative part of types and clean up the graph from
  2125   // the extra CastPP nodes whose only purpose is to carry them. Do
  2126   // that early so that optimizations are not disrupted by the extra
  2127   // CastPP nodes.
  2128   remove_speculative_types(igvn);
  2130   // No more new expensive nodes will be added to the list from here
  2131   // so keep only the actual candidates for optimizations.
  2132   cleanup_expensive_nodes(igvn);
  2134   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
  2135     NOT_PRODUCT(Compile::TracePhase t2("", &_t_renumberLive, TimeCompiler);)
  2136     initial_gvn()->replace_with(&igvn);
  2137     for_igvn()->clear();
  2138     Unique_Node_List new_worklist(C->comp_arena());
  2140       ResourceMark rm;
  2141       PhaseRenumberLive prl = PhaseRenumberLive(initial_gvn(), for_igvn(), &new_worklist);
  2143     set_for_igvn(&new_worklist);
  2144     igvn = PhaseIterGVN(initial_gvn());
  2145     igvn.optimize();
  2148   // Perform escape analysis
  2149   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
  2150     if (has_loops()) {
  2151       // Cleanup graph (remove dead nodes).
  2152       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2153       PhaseIdealLoop ideal_loop( igvn, false, true );
  2154       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
  2155       if (failing())  return;
  2157     ConnectionGraph::do_analysis(this, &igvn);
  2159     if (failing())  return;
  2161     // Optimize out fields loads from scalar replaceable allocations.
  2162     igvn.optimize();
  2163     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
  2165     if (failing())  return;
  2167     if (congraph() != NULL && macro_count() > 0) {
  2168       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
  2169       PhaseMacroExpand mexp(igvn);
  2170       mexp.eliminate_macro_nodes();
  2171       igvn.set_delay_transform(false);
  2173       igvn.optimize();
  2174       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
  2176       if (failing())  return;
  2180   // Loop transforms on the ideal graph.  Range Check Elimination,
  2181   // peeling, unrolling, etc.
  2183   // Set loop opts counter
  2184   loop_opts_cnt = num_loop_opts();
  2185   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  2187       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2188       PhaseIdealLoop ideal_loop( igvn, true );
  2189       loop_opts_cnt--;
  2190       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
  2191       if (failing())  return;
  2193     // Loop opts pass if partial peeling occurred in previous pass
  2194     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  2195       TracePhase t3("idealLoop", &_t_idealLoop, true);
  2196       PhaseIdealLoop ideal_loop( igvn, false );
  2197       loop_opts_cnt--;
  2198       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
  2199       if (failing())  return;
  2201     // Loop opts pass for loop-unrolling before CCP
  2202     if(major_progress() && (loop_opts_cnt > 0)) {
  2203       TracePhase t4("idealLoop", &_t_idealLoop, true);
  2204       PhaseIdealLoop ideal_loop( igvn, false );
  2205       loop_opts_cnt--;
  2206       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
  2208     if (!failing()) {
  2209       // Verify that last round of loop opts produced a valid graph
  2210       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2211       PhaseIdealLoop::verify(igvn);
  2214   if (failing())  return;
  2216   // Conditional Constant Propagation;
  2217   PhaseCCP ccp( &igvn );
  2218   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  2220     TracePhase t2("ccp", &_t_ccp, true);
  2221     ccp.do_transform();
  2223   print_method(PHASE_CPP1, 2);
  2225   assert( true, "Break here to ccp.dump_old2new_map()");
  2227   // Iterative Global Value Numbering, including ideal transforms
  2229     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  2230     igvn = ccp;
  2231     igvn.optimize();
  2234   print_method(PHASE_ITER_GVN2, 2);
  2236   if (failing())  return;
  2238   // Loop transforms on the ideal graph.  Range Check Elimination,
  2239   // peeling, unrolling, etc.
  2240   if(loop_opts_cnt > 0) {
  2241     debug_only( int cnt = 0; );
  2242     while(major_progress() && (loop_opts_cnt > 0)) {
  2243       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2244       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  2245       PhaseIdealLoop ideal_loop( igvn, true);
  2246       loop_opts_cnt--;
  2247       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
  2248       if (failing())  return;
  2253     // Verify that all previous optimizations produced a valid graph
  2254     // at least to this point, even if no loop optimizations were done.
  2255     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2256     PhaseIdealLoop::verify(igvn);
  2259   if (range_check_cast_count() > 0) {
  2260     // No more loop optimizations. Remove all range check dependent CastIINodes.
  2261     C->remove_range_check_casts(igvn);
  2262     igvn.optimize();
  2266     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  2267     PhaseMacroExpand  mex(igvn);
  2268     if (mex.expand_macro_nodes()) {
  2269       assert(failing(), "must bail out w/ explicit message");
  2270       return;
  2274  } // (End scope of igvn; run destructor if necessary for asserts.)
  2276   dump_inlining();
  2277   // A method with only infinite loops has no edges entering loops from root
  2279     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  2280     if (final_graph_reshaping()) {
  2281       assert(failing(), "must bail out w/ explicit message");
  2282       return;
  2286   print_method(PHASE_OPTIMIZE_FINISHED, 2);
  2290 //------------------------------Code_Gen---------------------------------------
  2291 // Given a graph, generate code for it
  2292 void Compile::Code_Gen() {
  2293   if (failing()) {
  2294     return;
  2297   // Perform instruction selection.  You might think we could reclaim Matcher
  2298   // memory PDQ, but actually the Matcher is used in generating spill code.
  2299   // Internals of the Matcher (including some VectorSets) must remain live
  2300   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  2301   // set a bit in reclaimed memory.
  2303   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2304   // nodes.  Mapping is only valid at the root of each matched subtree.
  2305   NOT_PRODUCT( verify_graph_edges(); )
  2307   Matcher matcher;
  2308   _matcher = &matcher;
  2310     TracePhase t2("matcher", &_t_matcher, true);
  2311     matcher.match();
  2313   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2314   // nodes.  Mapping is only valid at the root of each matched subtree.
  2315   NOT_PRODUCT( verify_graph_edges(); )
  2317   // If you have too many nodes, or if matching has failed, bail out
  2318   check_node_count(0, "out of nodes matching instructions");
  2319   if (failing()) {
  2320     return;
  2323   // Build a proper-looking CFG
  2324   PhaseCFG cfg(node_arena(), root(), matcher);
  2325   _cfg = &cfg;
  2327     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  2328     bool success = cfg.do_global_code_motion();
  2329     if (!success) {
  2330       return;
  2333     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
  2334     NOT_PRODUCT( verify_graph_edges(); )
  2335     debug_only( cfg.verify(); )
  2338   PhaseChaitin regalloc(unique(), cfg, matcher);
  2339   _regalloc = &regalloc;
  2341     TracePhase t2("regalloc", &_t_registerAllocation, true);
  2342     // Perform register allocation.  After Chaitin, use-def chains are
  2343     // no longer accurate (at spill code) and so must be ignored.
  2344     // Node->LRG->reg mappings are still accurate.
  2345     _regalloc->Register_Allocate();
  2347     // Bail out if the allocator builds too many nodes
  2348     if (failing()) {
  2349       return;
  2353   // Prior to register allocation we kept empty basic blocks in case the
  2354   // the allocator needed a place to spill.  After register allocation we
  2355   // are not adding any new instructions.  If any basic block is empty, we
  2356   // can now safely remove it.
  2358     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  2359     cfg.remove_empty_blocks();
  2360     if (do_freq_based_layout()) {
  2361       PhaseBlockLayout layout(cfg);
  2362     } else {
  2363       cfg.set_loop_alignment();
  2365     cfg.fixup_flow();
  2368   // Apply peephole optimizations
  2369   if( OptoPeephole ) {
  2370     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  2371     PhasePeephole peep( _regalloc, cfg);
  2372     peep.do_transform();
  2375   // Do late expand if CPU requires this.
  2376   if (Matcher::require_postalloc_expand) {
  2377     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
  2378     cfg.postalloc_expand(_regalloc);
  2381   // Convert Nodes to instruction bits in a buffer
  2383     // %%%% workspace merge brought two timers together for one job
  2384     TracePhase t2a("output", &_t_output, true);
  2385     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  2386     Output();
  2389   print_method(PHASE_FINAL_CODE);
  2391   // He's dead, Jim.
  2392   _cfg     = (PhaseCFG*)0xdeadbeef;
  2393   _regalloc = (PhaseChaitin*)0xdeadbeef;
  2397 //------------------------------dump_asm---------------------------------------
  2398 // Dump formatted assembly
  2399 #ifndef PRODUCT
  2400 void Compile::dump_asm(int *pcs, uint pc_limit) {
  2401   bool cut_short = false;
  2402   tty->print_cr("#");
  2403   tty->print("#  ");  _tf->dump();  tty->cr();
  2404   tty->print_cr("#");
  2406   // For all blocks
  2407   int pc = 0x0;                 // Program counter
  2408   char starts_bundle = ' ';
  2409   _regalloc->dump_frame();
  2411   Node *n = NULL;
  2412   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  2413     if (VMThread::should_terminate()) {
  2414       cut_short = true;
  2415       break;
  2417     Block* block = _cfg->get_block(i);
  2418     if (block->is_connector() && !Verbose) {
  2419       continue;
  2421     n = block->head();
  2422     if (pcs && n->_idx < pc_limit) {
  2423       tty->print("%3.3x   ", pcs[n->_idx]);
  2424     } else {
  2425       tty->print("      ");
  2427     block->dump_head(_cfg);
  2428     if (block->is_connector()) {
  2429       tty->print_cr("        # Empty connector block");
  2430     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  2431       tty->print_cr("        # Block is sole successor of call");
  2434     // For all instructions
  2435     Node *delay = NULL;
  2436     for (uint j = 0; j < block->number_of_nodes(); j++) {
  2437       if (VMThread::should_terminate()) {
  2438         cut_short = true;
  2439         break;
  2441       n = block->get_node(j);
  2442       if (valid_bundle_info(n)) {
  2443         Bundle* bundle = node_bundling(n);
  2444         if (bundle->used_in_unconditional_delay()) {
  2445           delay = n;
  2446           continue;
  2448         if (bundle->starts_bundle()) {
  2449           starts_bundle = '+';
  2453       if (WizardMode) {
  2454         n->dump();
  2457       if( !n->is_Region() &&    // Dont print in the Assembly
  2458           !n->is_Phi() &&       // a few noisely useless nodes
  2459           !n->is_Proj() &&
  2460           !n->is_MachTemp() &&
  2461           !n->is_SafePointScalarObject() &&
  2462           !n->is_Catch() &&     // Would be nice to print exception table targets
  2463           !n->is_MergeMem() &&  // Not very interesting
  2464           !n->is_top() &&       // Debug info table constants
  2465           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  2466           ) {
  2467         if (pcs && n->_idx < pc_limit)
  2468           tty->print("%3.3x", pcs[n->_idx]);
  2469         else
  2470           tty->print("   ");
  2471         tty->print(" %c ", starts_bundle);
  2472         starts_bundle = ' ';
  2473         tty->print("\t");
  2474         n->format(_regalloc, tty);
  2475         tty->cr();
  2478       // If we have an instruction with a delay slot, and have seen a delay,
  2479       // then back up and print it
  2480       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  2481         assert(delay != NULL, "no unconditional delay instruction");
  2482         if (WizardMode) delay->dump();
  2484         if (node_bundling(delay)->starts_bundle())
  2485           starts_bundle = '+';
  2486         if (pcs && n->_idx < pc_limit)
  2487           tty->print("%3.3x", pcs[n->_idx]);
  2488         else
  2489           tty->print("   ");
  2490         tty->print(" %c ", starts_bundle);
  2491         starts_bundle = ' ';
  2492         tty->print("\t");
  2493         delay->format(_regalloc, tty);
  2494         tty->cr();
  2495         delay = NULL;
  2498       // Dump the exception table as well
  2499       if( n->is_Catch() && (Verbose || WizardMode) ) {
  2500         // Print the exception table for this offset
  2501         _handler_table.print_subtable_for(pc);
  2505     if (pcs && n->_idx < pc_limit)
  2506       tty->print_cr("%3.3x", pcs[n->_idx]);
  2507     else
  2508       tty->cr();
  2510     assert(cut_short || delay == NULL, "no unconditional delay branch");
  2512   } // End of per-block dump
  2513   tty->cr();
  2515   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  2517 #endif
  2519 //------------------------------Final_Reshape_Counts---------------------------
  2520 // This class defines counters to help identify when a method
  2521 // may/must be executed using hardware with only 24-bit precision.
  2522 struct Final_Reshape_Counts : public StackObj {
  2523   int  _call_count;             // count non-inlined 'common' calls
  2524   int  _float_count;            // count float ops requiring 24-bit precision
  2525   int  _double_count;           // count double ops requiring more precision
  2526   int  _java_call_count;        // count non-inlined 'java' calls
  2527   int  _inner_loop_count;       // count loops which need alignment
  2528   VectorSet _visited;           // Visitation flags
  2529   Node_List _tests;             // Set of IfNodes & PCTableNodes
  2531   Final_Reshape_Counts() :
  2532     _call_count(0), _float_count(0), _double_count(0),
  2533     _java_call_count(0), _inner_loop_count(0),
  2534     _visited( Thread::current()->resource_area() ) { }
  2536   void inc_call_count  () { _call_count  ++; }
  2537   void inc_float_count () { _float_count ++; }
  2538   void inc_double_count() { _double_count++; }
  2539   void inc_java_call_count() { _java_call_count++; }
  2540   void inc_inner_loop_count() { _inner_loop_count++; }
  2542   int  get_call_count  () const { return _call_count  ; }
  2543   int  get_float_count () const { return _float_count ; }
  2544   int  get_double_count() const { return _double_count; }
  2545   int  get_java_call_count() const { return _java_call_count; }
  2546   int  get_inner_loop_count() const { return _inner_loop_count; }
  2547 };
  2549 #ifdef ASSERT
  2550 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  2551   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  2552   // Make sure the offset goes inside the instance layout.
  2553   return k->contains_field_offset(tp->offset());
  2554   // Note that OffsetBot and OffsetTop are very negative.
  2556 #endif
  2558 // Eliminate trivially redundant StoreCMs and accumulate their
  2559 // precedence edges.
  2560 void Compile::eliminate_redundant_card_marks(Node* n) {
  2561   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
  2562   if (n->in(MemNode::Address)->outcnt() > 1) {
  2563     // There are multiple users of the same address so it might be
  2564     // possible to eliminate some of the StoreCMs
  2565     Node* mem = n->in(MemNode::Memory);
  2566     Node* adr = n->in(MemNode::Address);
  2567     Node* val = n->in(MemNode::ValueIn);
  2568     Node* prev = n;
  2569     bool done = false;
  2570     // Walk the chain of StoreCMs eliminating ones that match.  As
  2571     // long as it's a chain of single users then the optimization is
  2572     // safe.  Eliminating partially redundant StoreCMs would require
  2573     // cloning copies down the other paths.
  2574     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
  2575       if (adr == mem->in(MemNode::Address) &&
  2576           val == mem->in(MemNode::ValueIn)) {
  2577         // redundant StoreCM
  2578         if (mem->req() > MemNode::OopStore) {
  2579           // Hasn't been processed by this code yet.
  2580           n->add_prec(mem->in(MemNode::OopStore));
  2581         } else {
  2582           // Already converted to precedence edge
  2583           for (uint i = mem->req(); i < mem->len(); i++) {
  2584             // Accumulate any precedence edges
  2585             if (mem->in(i) != NULL) {
  2586               n->add_prec(mem->in(i));
  2589           // Everything above this point has been processed.
  2590           done = true;
  2592         // Eliminate the previous StoreCM
  2593         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
  2594         assert(mem->outcnt() == 0, "should be dead");
  2595         mem->disconnect_inputs(NULL, this);
  2596       } else {
  2597         prev = mem;
  2599       mem = prev->in(MemNode::Memory);
  2604 //------------------------------final_graph_reshaping_impl----------------------
  2605 // Implement items 1-5 from final_graph_reshaping below.
  2606 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
  2608   if ( n->outcnt() == 0 ) return; // dead node
  2609   uint nop = n->Opcode();
  2611   // Check for 2-input instruction with "last use" on right input.
  2612   // Swap to left input.  Implements item (2).
  2613   if( n->req() == 3 &&          // two-input instruction
  2614       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  2615       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  2616       n->in(2)->outcnt() == 1 &&// right use IS a last use
  2617       !n->in(2)->is_Con() ) {   // right use is not a constant
  2618     // Check for commutative opcode
  2619     switch( nop ) {
  2620     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  2621     case Op_MaxI:  case Op_MinI:
  2622     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  2623     case Op_AndL:  case Op_XorL:  case Op_OrL:
  2624     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  2625       // Move "last use" input to left by swapping inputs
  2626       n->swap_edges(1, 2);
  2627       break;
  2629     default:
  2630       break;
  2634 #ifdef ASSERT
  2635   if( n->is_Mem() ) {
  2636     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
  2637     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2638             // oop will be recorded in oop map if load crosses safepoint
  2639             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2640                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2641             "raw memory operations should have control edge");
  2643 #endif
  2644   // Count FPU ops and common calls, implements item (3)
  2645   switch( nop ) {
  2646   // Count all float operations that may use FPU
  2647   case Op_AddF:
  2648   case Op_SubF:
  2649   case Op_MulF:
  2650   case Op_DivF:
  2651   case Op_NegF:
  2652   case Op_ModF:
  2653   case Op_ConvI2F:
  2654   case Op_ConF:
  2655   case Op_CmpF:
  2656   case Op_CmpF3:
  2657   // case Op_ConvL2F: // longs are split into 32-bit halves
  2658     frc.inc_float_count();
  2659     break;
  2661   case Op_ConvF2D:
  2662   case Op_ConvD2F:
  2663     frc.inc_float_count();
  2664     frc.inc_double_count();
  2665     break;
  2667   // Count all double operations that may use FPU
  2668   case Op_AddD:
  2669   case Op_SubD:
  2670   case Op_MulD:
  2671   case Op_DivD:
  2672   case Op_NegD:
  2673   case Op_ModD:
  2674   case Op_ConvI2D:
  2675   case Op_ConvD2I:
  2676   // case Op_ConvL2D: // handled by leaf call
  2677   // case Op_ConvD2L: // handled by leaf call
  2678   case Op_ConD:
  2679   case Op_CmpD:
  2680   case Op_CmpD3:
  2681     frc.inc_double_count();
  2682     break;
  2683   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2684   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2685   case Op_Opaque3:
  2686     n->subsume_by(n->in(1), this);
  2687     break;
  2688   case Op_CallStaticJava:
  2689   case Op_CallJava:
  2690   case Op_CallDynamicJava:
  2691     frc.inc_java_call_count(); // Count java call site;
  2692   case Op_CallRuntime:
  2693   case Op_CallLeaf:
  2694   case Op_CallLeafNoFP: {
  2695     assert( n->is_Call(), "" );
  2696     CallNode *call = n->as_Call();
  2697     // Count call sites where the FP mode bit would have to be flipped.
  2698     // Do not count uncommon runtime calls:
  2699     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2700     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2701     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2702       frc.inc_call_count();   // Count the call site
  2703     } else {                  // See if uncommon argument is shared
  2704       Node *n = call->in(TypeFunc::Parms);
  2705       int nop = n->Opcode();
  2706       // Clone shared simple arguments to uncommon calls, item (1).
  2707       if( n->outcnt() > 1 &&
  2708           !n->is_Proj() &&
  2709           nop != Op_CreateEx &&
  2710           nop != Op_CheckCastPP &&
  2711           nop != Op_DecodeN &&
  2712           nop != Op_DecodeNKlass &&
  2713           !n->is_Mem() ) {
  2714         Node *x = n->clone();
  2715         call->set_req( TypeFunc::Parms, x );
  2718     break;
  2721   case Op_StoreD:
  2722   case Op_LoadD:
  2723   case Op_LoadD_unaligned:
  2724     frc.inc_double_count();
  2725     goto handle_mem;
  2726   case Op_StoreF:
  2727   case Op_LoadF:
  2728     frc.inc_float_count();
  2729     goto handle_mem;
  2731   case Op_StoreCM:
  2733       // Convert OopStore dependence into precedence edge
  2734       Node* prec = n->in(MemNode::OopStore);
  2735       n->del_req(MemNode::OopStore);
  2736       n->add_prec(prec);
  2737       eliminate_redundant_card_marks(n);
  2740     // fall through
  2742   case Op_StoreB:
  2743   case Op_StoreC:
  2744   case Op_StorePConditional:
  2745   case Op_StoreI:
  2746   case Op_StoreL:
  2747   case Op_StoreIConditional:
  2748   case Op_StoreLConditional:
  2749   case Op_CompareAndSwapI:
  2750   case Op_CompareAndSwapL:
  2751   case Op_CompareAndSwapP:
  2752   case Op_CompareAndSwapN:
  2753   case Op_GetAndAddI:
  2754   case Op_GetAndAddL:
  2755   case Op_GetAndSetI:
  2756   case Op_GetAndSetL:
  2757   case Op_GetAndSetP:
  2758   case Op_GetAndSetN:
  2759   case Op_StoreP:
  2760   case Op_StoreN:
  2761   case Op_StoreNKlass:
  2762   case Op_LoadB:
  2763   case Op_LoadUB:
  2764   case Op_LoadUS:
  2765   case Op_LoadI:
  2766   case Op_LoadKlass:
  2767   case Op_LoadNKlass:
  2768   case Op_LoadL:
  2769   case Op_LoadL_unaligned:
  2770   case Op_LoadPLocked:
  2771   case Op_LoadP:
  2772   case Op_LoadN:
  2773   case Op_LoadRange:
  2774   case Op_LoadS: {
  2775   handle_mem:
  2776 #ifdef ASSERT
  2777     if( VerifyOptoOopOffsets ) {
  2778       assert( n->is_Mem(), "" );
  2779       MemNode *mem  = (MemNode*)n;
  2780       // Check to see if address types have grounded out somehow.
  2781       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2782       assert( !tp || oop_offset_is_sane(tp), "" );
  2784 #endif
  2785     break;
  2788   case Op_AddP: {               // Assert sane base pointers
  2789     Node *addp = n->in(AddPNode::Address);
  2790     assert( !addp->is_AddP() ||
  2791             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2792             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2793             "Base pointers must match" );
  2794 #ifdef _LP64
  2795     if ((UseCompressedOops || UseCompressedClassPointers) &&
  2796         addp->Opcode() == Op_ConP &&
  2797         addp == n->in(AddPNode::Base) &&
  2798         n->in(AddPNode::Offset)->is_Con()) {
  2799       // Use addressing with narrow klass to load with offset on x86.
  2800       // On sparc loading 32-bits constant and decoding it have less
  2801       // instructions (4) then load 64-bits constant (7).
  2802       // Do this transformation here since IGVN will convert ConN back to ConP.
  2803       const Type* t = addp->bottom_type();
  2804       if (t->isa_oopptr() || t->isa_klassptr()) {
  2805         Node* nn = NULL;
  2807         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
  2809         // Look for existing ConN node of the same exact type.
  2810         Node* r  = root();
  2811         uint cnt = r->outcnt();
  2812         for (uint i = 0; i < cnt; i++) {
  2813           Node* m = r->raw_out(i);
  2814           if (m!= NULL && m->Opcode() == op &&
  2815               m->bottom_type()->make_ptr() == t) {
  2816             nn = m;
  2817             break;
  2820         if (nn != NULL) {
  2821           // Decode a narrow oop to match address
  2822           // [R12 + narrow_oop_reg<<3 + offset]
  2823           if (t->isa_oopptr()) {
  2824             nn = new (this) DecodeNNode(nn, t);
  2825           } else {
  2826             nn = new (this) DecodeNKlassNode(nn, t);
  2828           n->set_req(AddPNode::Base, nn);
  2829           n->set_req(AddPNode::Address, nn);
  2830           if (addp->outcnt() == 0) {
  2831             addp->disconnect_inputs(NULL, this);
  2836 #endif
  2837     break;
  2840 #ifdef _LP64
  2841   case Op_CastPP:
  2842     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2843       Node* in1 = n->in(1);
  2844       const Type* t = n->bottom_type();
  2845       Node* new_in1 = in1->clone();
  2846       new_in1->as_DecodeN()->set_type(t);
  2848       if (!Matcher::narrow_oop_use_complex_address()) {
  2849         //
  2850         // x86, ARM and friends can handle 2 adds in addressing mode
  2851         // and Matcher can fold a DecodeN node into address by using
  2852         // a narrow oop directly and do implicit NULL check in address:
  2853         //
  2854         // [R12 + narrow_oop_reg<<3 + offset]
  2855         // NullCheck narrow_oop_reg
  2856         //
  2857         // On other platforms (Sparc) we have to keep new DecodeN node and
  2858         // use it to do implicit NULL check in address:
  2859         //
  2860         // decode_not_null narrow_oop_reg, base_reg
  2861         // [base_reg + offset]
  2862         // NullCheck base_reg
  2863         //
  2864         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2865         // to keep the information to which NULL check the new DecodeN node
  2866         // corresponds to use it as value in implicit_null_check().
  2867         //
  2868         new_in1->set_req(0, n->in(0));
  2871       n->subsume_by(new_in1, this);
  2872       if (in1->outcnt() == 0) {
  2873         in1->disconnect_inputs(NULL, this);
  2876     break;
  2878   case Op_CmpP:
  2879     // Do this transformation here to preserve CmpPNode::sub() and
  2880     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2881     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
  2882       Node* in1 = n->in(1);
  2883       Node* in2 = n->in(2);
  2884       if (!in1->is_DecodeNarrowPtr()) {
  2885         in2 = in1;
  2886         in1 = n->in(2);
  2888       assert(in1->is_DecodeNarrowPtr(), "sanity");
  2890       Node* new_in2 = NULL;
  2891       if (in2->is_DecodeNarrowPtr()) {
  2892         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
  2893         new_in2 = in2->in(1);
  2894       } else if (in2->Opcode() == Op_ConP) {
  2895         const Type* t = in2->bottom_type();
  2896         if (t == TypePtr::NULL_PTR) {
  2897           assert(in1->is_DecodeN(), "compare klass to null?");
  2898           // Don't convert CmpP null check into CmpN if compressed
  2899           // oops implicit null check is not generated.
  2900           // This will allow to generate normal oop implicit null check.
  2901           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2902             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
  2903           //
  2904           // This transformation together with CastPP transformation above
  2905           // will generated code for implicit NULL checks for compressed oops.
  2906           //
  2907           // The original code after Optimize()
  2908           //
  2909           //    LoadN memory, narrow_oop_reg
  2910           //    decode narrow_oop_reg, base_reg
  2911           //    CmpP base_reg, NULL
  2912           //    CastPP base_reg // NotNull
  2913           //    Load [base_reg + offset], val_reg
  2914           //
  2915           // after these transformations will be
  2916           //
  2917           //    LoadN memory, narrow_oop_reg
  2918           //    CmpN narrow_oop_reg, NULL
  2919           //    decode_not_null narrow_oop_reg, base_reg
  2920           //    Load [base_reg + offset], val_reg
  2921           //
  2922           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2923           // since narrow oops can be used in debug info now (see the code in
  2924           // final_graph_reshaping_walk()).
  2925           //
  2926           // At the end the code will be matched to
  2927           // on x86:
  2928           //
  2929           //    Load_narrow_oop memory, narrow_oop_reg
  2930           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2931           //    NullCheck narrow_oop_reg
  2932           //
  2933           // and on sparc:
  2934           //
  2935           //    Load_narrow_oop memory, narrow_oop_reg
  2936           //    decode_not_null narrow_oop_reg, base_reg
  2937           //    Load [base_reg + offset], val_reg
  2938           //    NullCheck base_reg
  2939           //
  2940         } else if (t->isa_oopptr()) {
  2941           new_in2 = ConNode::make(this, t->make_narrowoop());
  2942         } else if (t->isa_klassptr()) {
  2943           new_in2 = ConNode::make(this, t->make_narrowklass());
  2946       if (new_in2 != NULL) {
  2947         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
  2948         n->subsume_by(cmpN, this);
  2949         if (in1->outcnt() == 0) {
  2950           in1->disconnect_inputs(NULL, this);
  2952         if (in2->outcnt() == 0) {
  2953           in2->disconnect_inputs(NULL, this);
  2957     break;
  2959   case Op_DecodeN:
  2960   case Op_DecodeNKlass:
  2961     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
  2962     // DecodeN could be pinned when it can't be fold into
  2963     // an address expression, see the code for Op_CastPP above.
  2964     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
  2965     break;
  2967   case Op_EncodeP:
  2968   case Op_EncodePKlass: {
  2969     Node* in1 = n->in(1);
  2970     if (in1->is_DecodeNarrowPtr()) {
  2971       n->subsume_by(in1->in(1), this);
  2972     } else if (in1->Opcode() == Op_ConP) {
  2973       const Type* t = in1->bottom_type();
  2974       if (t == TypePtr::NULL_PTR) {
  2975         assert(t->isa_oopptr(), "null klass?");
  2976         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
  2977       } else if (t->isa_oopptr()) {
  2978         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
  2979       } else if (t->isa_klassptr()) {
  2980         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
  2983     if (in1->outcnt() == 0) {
  2984       in1->disconnect_inputs(NULL, this);
  2986     break;
  2989   case Op_Proj: {
  2990     if (OptimizeStringConcat) {
  2991       ProjNode* p = n->as_Proj();
  2992       if (p->_is_io_use) {
  2993         // Separate projections were used for the exception path which
  2994         // are normally removed by a late inline.  If it wasn't inlined
  2995         // then they will hang around and should just be replaced with
  2996         // the original one.
  2997         Node* proj = NULL;
  2998         // Replace with just one
  2999         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  3000           Node *use = i.get();
  3001           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  3002             proj = use;
  3003             break;
  3006         assert(proj != NULL, "must be found");
  3007         p->subsume_by(proj, this);
  3010     break;
  3013   case Op_Phi:
  3014     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
  3015       // The EncodeP optimization may create Phi with the same edges
  3016       // for all paths. It is not handled well by Register Allocator.
  3017       Node* unique_in = n->in(1);
  3018       assert(unique_in != NULL, "");
  3019       uint cnt = n->req();
  3020       for (uint i = 2; i < cnt; i++) {
  3021         Node* m = n->in(i);
  3022         assert(m != NULL, "");
  3023         if (unique_in != m)
  3024           unique_in = NULL;
  3026       if (unique_in != NULL) {
  3027         n->subsume_by(unique_in, this);
  3030     break;
  3032 #endif
  3034 #ifdef ASSERT
  3035   case Op_CastII:
  3036     // Verify that all range check dependent CastII nodes were removed.
  3037     if (n->isa_CastII()->has_range_check()) {
  3038       n->dump(3);
  3039       assert(false, "Range check dependent CastII node was not removed");
  3041     break;
  3042 #endif
  3044   case Op_ModI:
  3045     if (UseDivMod) {
  3046       // Check if a%b and a/b both exist
  3047       Node* d = n->find_similar(Op_DivI);
  3048       if (d) {
  3049         // Replace them with a fused divmod if supported
  3050         if (Matcher::has_match_rule(Op_DivModI)) {
  3051           DivModINode* divmod = DivModINode::make(this, n);
  3052           d->subsume_by(divmod->div_proj(), this);
  3053           n->subsume_by(divmod->mod_proj(), this);
  3054         } else {
  3055           // replace a%b with a-((a/b)*b)
  3056           Node* mult = new (this) MulINode(d, d->in(2));
  3057           Node* sub  = new (this) SubINode(d->in(1), mult);
  3058           n->subsume_by(sub, this);
  3062     break;
  3064   case Op_ModL:
  3065     if (UseDivMod) {
  3066       // Check if a%b and a/b both exist
  3067       Node* d = n->find_similar(Op_DivL);
  3068       if (d) {
  3069         // Replace them with a fused divmod if supported
  3070         if (Matcher::has_match_rule(Op_DivModL)) {
  3071           DivModLNode* divmod = DivModLNode::make(this, n);
  3072           d->subsume_by(divmod->div_proj(), this);
  3073           n->subsume_by(divmod->mod_proj(), this);
  3074         } else {
  3075           // replace a%b with a-((a/b)*b)
  3076           Node* mult = new (this) MulLNode(d, d->in(2));
  3077           Node* sub  = new (this) SubLNode(d->in(1), mult);
  3078           n->subsume_by(sub, this);
  3082     break;
  3084   case Op_LoadVector:
  3085   case Op_StoreVector:
  3086     break;
  3088   case Op_PackB:
  3089   case Op_PackS:
  3090   case Op_PackI:
  3091   case Op_PackF:
  3092   case Op_PackL:
  3093   case Op_PackD:
  3094     if (n->req()-1 > 2) {
  3095       // Replace many operand PackNodes with a binary tree for matching
  3096       PackNode* p = (PackNode*) n;
  3097       Node* btp = p->binary_tree_pack(this, 1, n->req());
  3098       n->subsume_by(btp, this);
  3100     break;
  3101   case Op_Loop:
  3102   case Op_CountedLoop:
  3103     if (n->as_Loop()->is_inner_loop()) {
  3104       frc.inc_inner_loop_count();
  3106     break;
  3107   case Op_LShiftI:
  3108   case Op_RShiftI:
  3109   case Op_URShiftI:
  3110   case Op_LShiftL:
  3111   case Op_RShiftL:
  3112   case Op_URShiftL:
  3113     if (Matcher::need_masked_shift_count) {
  3114       // The cpu's shift instructions don't restrict the count to the
  3115       // lower 5/6 bits. We need to do the masking ourselves.
  3116       Node* in2 = n->in(2);
  3117       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
  3118       const TypeInt* t = in2->find_int_type();
  3119       if (t != NULL && t->is_con()) {
  3120         juint shift = t->get_con();
  3121         if (shift > mask) { // Unsigned cmp
  3122           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
  3124       } else {
  3125         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
  3126           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
  3127           n->set_req(2, shift);
  3130       if (in2->outcnt() == 0) { // Remove dead node
  3131         in2->disconnect_inputs(NULL, this);
  3134     break;
  3135   case Op_MemBarStoreStore:
  3136   case Op_MemBarRelease:
  3137     // Break the link with AllocateNode: it is no longer useful and
  3138     // confuses register allocation.
  3139     if (n->req() > MemBarNode::Precedent) {
  3140       n->set_req(MemBarNode::Precedent, top());
  3142     break;
  3143   default:
  3144     assert( !n->is_Call(), "" );
  3145     assert( !n->is_Mem(), "" );
  3146     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
  3147     break;
  3150   // Collect CFG split points
  3151   if (n->is_MultiBranch())
  3152     frc._tests.push(n);
  3155 //------------------------------final_graph_reshaping_walk---------------------
  3156 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  3157 // requires that the walk visits a node's inputs before visiting the node.
  3158 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  3159   ResourceArea *area = Thread::current()->resource_area();
  3160   Unique_Node_List sfpt(area);
  3162   frc._visited.set(root->_idx); // first, mark node as visited
  3163   uint cnt = root->req();
  3164   Node *n = root;
  3165   uint  i = 0;
  3166   while (true) {
  3167     if (i < cnt) {
  3168       // Place all non-visited non-null inputs onto stack
  3169       Node* m = n->in(i);
  3170       ++i;
  3171       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  3172         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
  3173           // compute worst case interpreter size in case of a deoptimization
  3174           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
  3176           sfpt.push(m);
  3178         cnt = m->req();
  3179         nstack.push(n, i); // put on stack parent and next input's index
  3180         n = m;
  3181         i = 0;
  3183     } else {
  3184       // Now do post-visit work
  3185       final_graph_reshaping_impl( n, frc );
  3186       if (nstack.is_empty())
  3187         break;             // finished
  3188       n = nstack.node();   // Get node from stack
  3189       cnt = n->req();
  3190       i = nstack.index();
  3191       nstack.pop();        // Shift to the next node on stack
  3195   // Skip next transformation if compressed oops are not used.
  3196   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
  3197       (!UseCompressedOops && !UseCompressedClassPointers))
  3198     return;
  3200   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
  3201   // It could be done for an uncommon traps or any safepoints/calls
  3202   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
  3203   while (sfpt.size() > 0) {
  3204     n = sfpt.pop();
  3205     JVMState *jvms = n->as_SafePoint()->jvms();
  3206     assert(jvms != NULL, "sanity");
  3207     int start = jvms->debug_start();
  3208     int end   = n->req();
  3209     bool is_uncommon = (n->is_CallStaticJava() &&
  3210                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  3211     for (int j = start; j < end; j++) {
  3212       Node* in = n->in(j);
  3213       if (in->is_DecodeNarrowPtr()) {
  3214         bool safe_to_skip = true;
  3215         if (!is_uncommon ) {
  3216           // Is it safe to skip?
  3217           for (uint i = 0; i < in->outcnt(); i++) {
  3218             Node* u = in->raw_out(i);
  3219             if (!u->is_SafePoint() ||
  3220                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  3221               safe_to_skip = false;
  3225         if (safe_to_skip) {
  3226           n->set_req(j, in->in(1));
  3228         if (in->outcnt() == 0) {
  3229           in->disconnect_inputs(NULL, this);
  3236 //------------------------------final_graph_reshaping--------------------------
  3237 // Final Graph Reshaping.
  3238 //
  3239 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  3240 //     and not commoned up and forced early.  Must come after regular
  3241 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  3242 //     inputs to Loop Phis; these will be split by the allocator anyways.
  3243 //     Remove Opaque nodes.
  3244 // (2) Move last-uses by commutative operations to the left input to encourage
  3245 //     Intel update-in-place two-address operations and better register usage
  3246 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  3247 //     calls canonicalizing them back.
  3248 // (3) Count the number of double-precision FP ops, single-precision FP ops
  3249 //     and call sites.  On Intel, we can get correct rounding either by
  3250 //     forcing singles to memory (requires extra stores and loads after each
  3251 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  3252 //     clearing the mode bit around call sites).  The mode bit is only used
  3253 //     if the relative frequency of single FP ops to calls is low enough.
  3254 //     This is a key transform for SPEC mpeg_audio.
  3255 // (4) Detect infinite loops; blobs of code reachable from above but not
  3256 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  3257 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  3258 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  3259 //     Detection is by looking for IfNodes where only 1 projection is
  3260 //     reachable from below or CatchNodes missing some targets.
  3261 // (5) Assert for insane oop offsets in debug mode.
  3263 bool Compile::final_graph_reshaping() {
  3264   // an infinite loop may have been eliminated by the optimizer,
  3265   // in which case the graph will be empty.
  3266   if (root()->req() == 1) {
  3267     record_method_not_compilable("trivial infinite loop");
  3268     return true;
  3271   // Expensive nodes have their control input set to prevent the GVN
  3272   // from freely commoning them. There's no GVN beyond this point so
  3273   // no need to keep the control input. We want the expensive nodes to
  3274   // be freely moved to the least frequent code path by gcm.
  3275   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
  3276   for (int i = 0; i < expensive_count(); i++) {
  3277     _expensive_nodes->at(i)->set_req(0, NULL);
  3280   Final_Reshape_Counts frc;
  3282   // Visit everybody reachable!
  3283   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
  3284   Node_Stack nstack(live_nodes() >> 1);
  3285   final_graph_reshaping_walk(nstack, root(), frc);
  3287   // Check for unreachable (from below) code (i.e., infinite loops).
  3288   for( uint i = 0; i < frc._tests.size(); i++ ) {
  3289     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  3290     // Get number of CFG targets.
  3291     // Note that PCTables include exception targets after calls.
  3292     uint required_outcnt = n->required_outcnt();
  3293     if (n->outcnt() != required_outcnt) {
  3294       // Check for a few special cases.  Rethrow Nodes never take the
  3295       // 'fall-thru' path, so expected kids is 1 less.
  3296       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  3297         if (n->in(0)->in(0)->is_Call()) {
  3298           CallNode *call = n->in(0)->in(0)->as_Call();
  3299           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  3300             required_outcnt--;      // Rethrow always has 1 less kid
  3301           } else if (call->req() > TypeFunc::Parms &&
  3302                      call->is_CallDynamicJava()) {
  3303             // Check for null receiver. In such case, the optimizer has
  3304             // detected that the virtual call will always result in a null
  3305             // pointer exception. The fall-through projection of this CatchNode
  3306             // will not be populated.
  3307             Node *arg0 = call->in(TypeFunc::Parms);
  3308             if (arg0->is_Type() &&
  3309                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  3310               required_outcnt--;
  3312           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  3313                      call->req() > TypeFunc::Parms+1 &&
  3314                      call->is_CallStaticJava()) {
  3315             // Check for negative array length. In such case, the optimizer has
  3316             // detected that the allocation attempt will always result in an
  3317             // exception. There is no fall-through projection of this CatchNode .
  3318             Node *arg1 = call->in(TypeFunc::Parms+1);
  3319             if (arg1->is_Type() &&
  3320                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  3321               required_outcnt--;
  3326       // Recheck with a better notion of 'required_outcnt'
  3327       if (n->outcnt() != required_outcnt) {
  3328         record_method_not_compilable("malformed control flow");
  3329         return true;            // Not all targets reachable!
  3332     // Check that I actually visited all kids.  Unreached kids
  3333     // must be infinite loops.
  3334     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  3335       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  3336         record_method_not_compilable("infinite loop");
  3337         return true;            // Found unvisited kid; must be unreach
  3341   // If original bytecodes contained a mixture of floats and doubles
  3342   // check if the optimizer has made it homogenous, item (3).
  3343   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  3344       frc.get_float_count() > 32 &&
  3345       frc.get_double_count() == 0 &&
  3346       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  3347     set_24_bit_selection_and_mode( false,  true );
  3350   set_java_calls(frc.get_java_call_count());
  3351   set_inner_loops(frc.get_inner_loop_count());
  3353   // No infinite loops, no reason to bail out.
  3354   return false;
  3357 //-----------------------------too_many_traps----------------------------------
  3358 // Report if there are too many traps at the current method and bci.
  3359 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  3360 bool Compile::too_many_traps(ciMethod* method,
  3361                              int bci,
  3362                              Deoptimization::DeoptReason reason) {
  3363   ciMethodData* md = method->method_data();
  3364   if (md->is_empty()) {
  3365     // Assume the trap has not occurred, or that it occurred only
  3366     // because of a transient condition during start-up in the interpreter.
  3367     return false;
  3369   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3370   if (md->has_trap_at(bci, m, reason) != 0) {
  3371     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  3372     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3373     // assume the worst.
  3374     if (log())
  3375       log()->elem("observe trap='%s' count='%d'",
  3376                   Deoptimization::trap_reason_name(reason),
  3377                   md->trap_count(reason));
  3378     return true;
  3379   } else {
  3380     // Ignore method/bci and see if there have been too many globally.
  3381     return too_many_traps(reason, md);
  3385 // Less-accurate variant which does not require a method and bci.
  3386 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  3387                              ciMethodData* logmd) {
  3388   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
  3389     // Too many traps globally.
  3390     // Note that we use cumulative trap_count, not just md->trap_count.
  3391     if (log()) {
  3392       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  3393       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  3394                   Deoptimization::trap_reason_name(reason),
  3395                   mcount, trap_count(reason));
  3397     return true;
  3398   } else {
  3399     // The coast is clear.
  3400     return false;
  3404 //--------------------------too_many_recompiles--------------------------------
  3405 // Report if there are too many recompiles at the current method and bci.
  3406 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  3407 // Is not eager to return true, since this will cause the compiler to use
  3408 // Action_none for a trap point, to avoid too many recompilations.
  3409 bool Compile::too_many_recompiles(ciMethod* method,
  3410                                   int bci,
  3411                                   Deoptimization::DeoptReason reason) {
  3412   ciMethodData* md = method->method_data();
  3413   if (md->is_empty()) {
  3414     // Assume the trap has not occurred, or that it occurred only
  3415     // because of a transient condition during start-up in the interpreter.
  3416     return false;
  3418   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  3419   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  3420   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  3421   Deoptimization::DeoptReason per_bc_reason
  3422     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  3423   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3424   if ((per_bc_reason == Deoptimization::Reason_none
  3425        || md->has_trap_at(bci, m, reason) != 0)
  3426       // The trap frequency measure we care about is the recompile count:
  3427       && md->trap_recompiled_at(bci, m)
  3428       && md->overflow_recompile_count() >= bc_cutoff) {
  3429     // Do not emit a trap here if it has already caused recompilations.
  3430     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3431     // assume the worst.
  3432     if (log())
  3433       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  3434                   Deoptimization::trap_reason_name(reason),
  3435                   md->trap_count(reason),
  3436                   md->overflow_recompile_count());
  3437     return true;
  3438   } else if (trap_count(reason) != 0
  3439              && decompile_count() >= m_cutoff) {
  3440     // Too many recompiles globally, and we have seen this sort of trap.
  3441     // Use cumulative decompile_count, not just md->decompile_count.
  3442     if (log())
  3443       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  3444                   Deoptimization::trap_reason_name(reason),
  3445                   md->trap_count(reason), trap_count(reason),
  3446                   md->decompile_count(), decompile_count());
  3447     return true;
  3448   } else {
  3449     // The coast is clear.
  3450     return false;
  3454 // Compute when not to trap. Used by matching trap based nodes and
  3455 // NullCheck optimization.
  3456 void Compile::set_allowed_deopt_reasons() {
  3457   _allowed_reasons = 0;
  3458   if (is_method_compilation()) {
  3459     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
  3460       assert(rs < BitsPerInt, "recode bit map");
  3461       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
  3462         _allowed_reasons |= nth_bit(rs);
  3468 #ifndef PRODUCT
  3469 //------------------------------verify_graph_edges---------------------------
  3470 // Walk the Graph and verify that there is a one-to-one correspondence
  3471 // between Use-Def edges and Def-Use edges in the graph.
  3472 void Compile::verify_graph_edges(bool no_dead_code) {
  3473   if (VerifyGraphEdges) {
  3474     ResourceArea *area = Thread::current()->resource_area();
  3475     Unique_Node_List visited(area);
  3476     // Call recursive graph walk to check edges
  3477     _root->verify_edges(visited);
  3478     if (no_dead_code) {
  3479       // Now make sure that no visited node is used by an unvisited node.
  3480       bool dead_nodes = 0;
  3481       Unique_Node_List checked(area);
  3482       while (visited.size() > 0) {
  3483         Node* n = visited.pop();
  3484         checked.push(n);
  3485         for (uint i = 0; i < n->outcnt(); i++) {
  3486           Node* use = n->raw_out(i);
  3487           if (checked.member(use))  continue;  // already checked
  3488           if (visited.member(use))  continue;  // already in the graph
  3489           if (use->is_Con())        continue;  // a dead ConNode is OK
  3490           // At this point, we have found a dead node which is DU-reachable.
  3491           if (dead_nodes++ == 0)
  3492             tty->print_cr("*** Dead nodes reachable via DU edges:");
  3493           use->dump(2);
  3494           tty->print_cr("---");
  3495           checked.push(use);  // No repeats; pretend it is now checked.
  3498       assert(dead_nodes == 0, "using nodes must be reachable from root");
  3503 // Verify GC barriers consistency
  3504 // Currently supported:
  3505 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
  3506 void Compile::verify_barriers() {
  3507   if (UseG1GC) {
  3508     // Verify G1 pre-barriers
  3509     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
  3511     ResourceArea *area = Thread::current()->resource_area();
  3512     Unique_Node_List visited(area);
  3513     Node_List worklist(area);
  3514     // We're going to walk control flow backwards starting from the Root
  3515     worklist.push(_root);
  3516     while (worklist.size() > 0) {
  3517       Node* x = worklist.pop();
  3518       if (x == NULL || x == top()) continue;
  3519       if (visited.member(x)) {
  3520         continue;
  3521       } else {
  3522         visited.push(x);
  3525       if (x->is_Region()) {
  3526         for (uint i = 1; i < x->req(); i++) {
  3527           worklist.push(x->in(i));
  3529       } else {
  3530         worklist.push(x->in(0));
  3531         // We are looking for the pattern:
  3532         //                            /->ThreadLocal
  3533         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
  3534         //              \->ConI(0)
  3535         // We want to verify that the If and the LoadB have the same control
  3536         // See GraphKit::g1_write_barrier_pre()
  3537         if (x->is_If()) {
  3538           IfNode *iff = x->as_If();
  3539           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
  3540             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
  3541             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
  3542                 && cmp->in(1)->is_Load()) {
  3543               LoadNode* load = cmp->in(1)->as_Load();
  3544               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
  3545                   && load->in(2)->in(3)->is_Con()
  3546                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
  3548                 Node* if_ctrl = iff->in(0);
  3549                 Node* load_ctrl = load->in(0);
  3551                 if (if_ctrl != load_ctrl) {
  3552                   // Skip possible CProj->NeverBranch in infinite loops
  3553                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
  3554                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
  3555                     if_ctrl = if_ctrl->in(0)->in(0);
  3558                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
  3568 #endif
  3570 // The Compile object keeps track of failure reasons separately from the ciEnv.
  3571 // This is required because there is not quite a 1-1 relation between the
  3572 // ciEnv and its compilation task and the Compile object.  Note that one
  3573 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  3574 // to backtrack and retry without subsuming loads.  Other than this backtracking
  3575 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  3576 // by the logic in C2Compiler.
  3577 void Compile::record_failure(const char* reason) {
  3578   if (log() != NULL) {
  3579     log()->elem("failure reason='%s' phase='compile'", reason);
  3581   if (_failure_reason == NULL) {
  3582     // Record the first failure reason.
  3583     _failure_reason = reason;
  3586   EventCompilerFailure event;
  3587   if (event.should_commit()) {
  3588     event.set_compileID(Compile::compile_id());
  3589     event.set_failure(reason);
  3590     event.commit();
  3593   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  3594     C->print_method(PHASE_FAILURE);
  3596   _root = NULL;  // flush the graph, too
  3599 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  3600   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
  3601     _phase_name(name), _dolog(dolog)
  3603   if (dolog) {
  3604     C = Compile::current();
  3605     _log = C->log();
  3606   } else {
  3607     C = NULL;
  3608     _log = NULL;
  3610   if (_log != NULL) {
  3611     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3612     _log->stamp();
  3613     _log->end_head();
  3617 Compile::TracePhase::~TracePhase() {
  3619   C = Compile::current();
  3620   if (_dolog) {
  3621     _log = C->log();
  3622   } else {
  3623     _log = NULL;
  3626 #ifdef ASSERT
  3627   if (PrintIdealNodeCount) {
  3628     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
  3629                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
  3632   if (VerifyIdealNodeCount) {
  3633     Compile::current()->print_missing_nodes();
  3635 #endif
  3637   if (_log != NULL) {
  3638     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3642 //=============================================================================
  3643 // Two Constant's are equal when the type and the value are equal.
  3644 bool Compile::Constant::operator==(const Constant& other) {
  3645   if (type()          != other.type()         )  return false;
  3646   if (can_be_reused() != other.can_be_reused())  return false;
  3647   // For floating point values we compare the bit pattern.
  3648   switch (type()) {
  3649   case T_FLOAT:   return (_v._value.i == other._v._value.i);
  3650   case T_LONG:
  3651   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
  3652   case T_OBJECT:
  3653   case T_ADDRESS: return (_v._value.l == other._v._value.l);
  3654   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
  3655   case T_METADATA: return (_v._metadata == other._v._metadata);
  3656   default: ShouldNotReachHere();
  3658   return false;
  3661 static int type_to_size_in_bytes(BasicType t) {
  3662   switch (t) {
  3663   case T_LONG:    return sizeof(jlong  );
  3664   case T_FLOAT:   return sizeof(jfloat );
  3665   case T_DOUBLE:  return sizeof(jdouble);
  3666   case T_METADATA: return sizeof(Metadata*);
  3667     // We use T_VOID as marker for jump-table entries (labels) which
  3668     // need an internal word relocation.
  3669   case T_VOID:
  3670   case T_ADDRESS:
  3671   case T_OBJECT:  return sizeof(jobject);
  3674   ShouldNotReachHere();
  3675   return -1;
  3678 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
  3679   // sort descending
  3680   if (a->freq() > b->freq())  return -1;
  3681   if (a->freq() < b->freq())  return  1;
  3682   return 0;
  3685 void Compile::ConstantTable::calculate_offsets_and_size() {
  3686   // First, sort the array by frequencies.
  3687   _constants.sort(qsort_comparator);
  3689 #ifdef ASSERT
  3690   // Make sure all jump-table entries were sorted to the end of the
  3691   // array (they have a negative frequency).
  3692   bool found_void = false;
  3693   for (int i = 0; i < _constants.length(); i++) {
  3694     Constant con = _constants.at(i);
  3695     if (con.type() == T_VOID)
  3696       found_void = true;  // jump-tables
  3697     else
  3698       assert(!found_void, "wrong sorting");
  3700 #endif
  3702   int offset = 0;
  3703   for (int i = 0; i < _constants.length(); i++) {
  3704     Constant* con = _constants.adr_at(i);
  3706     // Align offset for type.
  3707     int typesize = type_to_size_in_bytes(con->type());
  3708     offset = align_size_up(offset, typesize);
  3709     con->set_offset(offset);   // set constant's offset
  3711     if (con->type() == T_VOID) {
  3712       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
  3713       offset = offset + typesize * n->outcnt();  // expand jump-table
  3714     } else {
  3715       offset = offset + typesize;
  3719   // Align size up to the next section start (which is insts; see
  3720   // CodeBuffer::align_at_start).
  3721   assert(_size == -1, "already set?");
  3722   _size = align_size_up(offset, CodeEntryAlignment);
  3725 void Compile::ConstantTable::emit(CodeBuffer& cb) {
  3726   MacroAssembler _masm(&cb);
  3727   for (int i = 0; i < _constants.length(); i++) {
  3728     Constant con = _constants.at(i);
  3729     address constant_addr = NULL;
  3730     switch (con.type()) {
  3731     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
  3732     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
  3733     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
  3734     case T_OBJECT: {
  3735       jobject obj = con.get_jobject();
  3736       int oop_index = _masm.oop_recorder()->find_index(obj);
  3737       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
  3738       break;
  3740     case T_ADDRESS: {
  3741       address addr = (address) con.get_jobject();
  3742       constant_addr = _masm.address_constant(addr);
  3743       break;
  3745     // We use T_VOID as marker for jump-table entries (labels) which
  3746     // need an internal word relocation.
  3747     case T_VOID: {
  3748       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
  3749       // Fill the jump-table with a dummy word.  The real value is
  3750       // filled in later in fill_jump_table.
  3751       address dummy = (address) n;
  3752       constant_addr = _masm.address_constant(dummy);
  3753       // Expand jump-table
  3754       for (uint i = 1; i < n->outcnt(); i++) {
  3755         address temp_addr = _masm.address_constant(dummy + i);
  3756         assert(temp_addr, "consts section too small");
  3758       break;
  3760     case T_METADATA: {
  3761       Metadata* obj = con.get_metadata();
  3762       int metadata_index = _masm.oop_recorder()->find_index(obj);
  3763       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
  3764       break;
  3766     default: ShouldNotReachHere();
  3768     assert(constant_addr, "consts section too small");
  3769     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
  3770             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
  3774 int Compile::ConstantTable::find_offset(Constant& con) const {
  3775   int idx = _constants.find(con);
  3776   assert(idx != -1, "constant must be in constant table");
  3777   int offset = _constants.at(idx).offset();
  3778   assert(offset != -1, "constant table not emitted yet?");
  3779   return offset;
  3782 void Compile::ConstantTable::add(Constant& con) {
  3783   if (con.can_be_reused()) {
  3784     int idx = _constants.find(con);
  3785     if (idx != -1 && _constants.at(idx).can_be_reused()) {
  3786       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
  3787       return;
  3790   (void) _constants.append(con);
  3793 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
  3794   Block* b = Compile::current()->cfg()->get_block_for_node(n);
  3795   Constant con(type, value, b->_freq);
  3796   add(con);
  3797   return con;
  3800 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
  3801   Constant con(metadata);
  3802   add(con);
  3803   return con;
  3806 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
  3807   jvalue value;
  3808   BasicType type = oper->type()->basic_type();
  3809   switch (type) {
  3810   case T_LONG:    value.j = oper->constantL(); break;
  3811   case T_FLOAT:   value.f = oper->constantF(); break;
  3812   case T_DOUBLE:  value.d = oper->constantD(); break;
  3813   case T_OBJECT:
  3814   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
  3815   case T_METADATA: return add((Metadata*)oper->constant()); break;
  3816   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
  3818   return add(n, type, value);
  3821 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
  3822   jvalue value;
  3823   // We can use the node pointer here to identify the right jump-table
  3824   // as this method is called from Compile::Fill_buffer right before
  3825   // the MachNodes are emitted and the jump-table is filled (means the
  3826   // MachNode pointers do not change anymore).
  3827   value.l = (jobject) n;
  3828   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
  3829   add(con);
  3830   return con;
  3833 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
  3834   // If called from Compile::scratch_emit_size do nothing.
  3835   if (Compile::current()->in_scratch_emit_size())  return;
  3837   assert(labels.is_nonempty(), "must be");
  3838   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
  3840   // Since MachConstantNode::constant_offset() also contains
  3841   // table_base_offset() we need to subtract the table_base_offset()
  3842   // to get the plain offset into the constant table.
  3843   int offset = n->constant_offset() - table_base_offset();
  3845   MacroAssembler _masm(&cb);
  3846   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
  3848   for (uint i = 0; i < n->outcnt(); i++) {
  3849     address* constant_addr = &jump_table_base[i];
  3850     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)));
  3851     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
  3852     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
  3856 void Compile::dump_inlining() {
  3857   if (print_inlining() || print_intrinsics()) {
  3858     // Print inlining message for candidates that we couldn't inline
  3859     // for lack of space or non constant receiver
  3860     for (int i = 0; i < _late_inlines.length(); i++) {
  3861       CallGenerator* cg = _late_inlines.at(i);
  3862       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
  3864     Unique_Node_List useful;
  3865     useful.push(root());
  3866     for (uint next = 0; next < useful.size(); ++next) {
  3867       Node* n  = useful.at(next);
  3868       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
  3869         CallNode* call = n->as_Call();
  3870         CallGenerator* cg = call->generator();
  3871         cg->print_inlining_late("receiver not constant");
  3873       uint max = n->len();
  3874       for ( uint i = 0; i < max; ++i ) {
  3875         Node *m = n->in(i);
  3876         if ( m == NULL ) continue;
  3877         useful.push(m);
  3880     for (int i = 0; i < _print_inlining_list->length(); i++) {
  3881       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
  3886 // Dump inlining replay data to the stream.
  3887 // Don't change thread state and acquire any locks.
  3888 void Compile::dump_inline_data(outputStream* out) {
  3889   InlineTree* inl_tree = ilt();
  3890   if (inl_tree != NULL) {
  3891     out->print(" inline %d", inl_tree->count());
  3892     inl_tree->dump_replay_data(out);
  3896 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
  3897   if (n1->Opcode() < n2->Opcode())      return -1;
  3898   else if (n1->Opcode() > n2->Opcode()) return 1;
  3900   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()));
  3901   for (uint i = 1; i < n1->req(); i++) {
  3902     if (n1->in(i) < n2->in(i))      return -1;
  3903     else if (n1->in(i) > n2->in(i)) return 1;
  3906   return 0;
  3909 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
  3910   Node* n1 = *n1p;
  3911   Node* n2 = *n2p;
  3913   return cmp_expensive_nodes(n1, n2);
  3916 void Compile::sort_expensive_nodes() {
  3917   if (!expensive_nodes_sorted()) {
  3918     _expensive_nodes->sort(cmp_expensive_nodes);
  3922 bool Compile::expensive_nodes_sorted() const {
  3923   for (int i = 1; i < _expensive_nodes->length(); i++) {
  3924     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
  3925       return false;
  3928   return true;
  3931 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
  3932   if (_expensive_nodes->length() == 0) {
  3933     return false;
  3936   assert(OptimizeExpensiveOps, "optimization off?");
  3938   // Take this opportunity to remove dead nodes from the list
  3939   int j = 0;
  3940   for (int i = 0; i < _expensive_nodes->length(); i++) {
  3941     Node* n = _expensive_nodes->at(i);
  3942     if (!n->is_unreachable(igvn)) {
  3943       assert(n->is_expensive(), "should be expensive");
  3944       _expensive_nodes->at_put(j, n);
  3945       j++;
  3948   _expensive_nodes->trunc_to(j);
  3950   // Then sort the list so that similar nodes are next to each other
  3951   // and check for at least two nodes of identical kind with same data
  3952   // inputs.
  3953   sort_expensive_nodes();
  3955   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
  3956     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
  3957       return true;
  3961   return false;
  3964 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
  3965   if (_expensive_nodes->length() == 0) {
  3966     return;
  3969   assert(OptimizeExpensiveOps, "optimization off?");
  3971   // Sort to bring similar nodes next to each other and clear the
  3972   // control input of nodes for which there's only a single copy.
  3973   sort_expensive_nodes();
  3975   int j = 0;
  3976   int identical = 0;
  3977   int i = 0;
  3978   for (; i < _expensive_nodes->length()-1; i++) {
  3979     assert(j <= i, "can't write beyond current index");
  3980     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
  3981       identical++;
  3982       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3983       continue;
  3985     if (identical > 0) {
  3986       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3987       identical = 0;
  3988     } else {
  3989       Node* n = _expensive_nodes->at(i);
  3990       igvn.hash_delete(n);
  3991       n->set_req(0, NULL);
  3992       igvn.hash_insert(n);
  3995   if (identical > 0) {
  3996     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3997   } else if (_expensive_nodes->length() >= 1) {
  3998     Node* n = _expensive_nodes->at(i);
  3999     igvn.hash_delete(n);
  4000     n->set_req(0, NULL);
  4001     igvn.hash_insert(n);
  4003   _expensive_nodes->trunc_to(j);
  4006 void Compile::add_expensive_node(Node * n) {
  4007   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
  4008   assert(n->is_expensive(), "expensive nodes with non-null control here only");
  4009   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
  4010   if (OptimizeExpensiveOps) {
  4011     _expensive_nodes->append(n);
  4012   } else {
  4013     // Clear control input and let IGVN optimize expensive nodes if
  4014     // OptimizeExpensiveOps is off.
  4015     n->set_req(0, NULL);
  4019 /**
  4020  * Remove the speculative part of types and clean up the graph
  4021  */
  4022 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
  4023   if (UseTypeSpeculation) {
  4024     Unique_Node_List worklist;
  4025     worklist.push(root());
  4026     int modified = 0;
  4027     // Go over all type nodes that carry a speculative type, drop the
  4028     // speculative part of the type and enqueue the node for an igvn
  4029     // which may optimize it out.
  4030     for (uint next = 0; next < worklist.size(); ++next) {
  4031       Node *n  = worklist.at(next);
  4032       if (n->is_Type()) {
  4033         TypeNode* tn = n->as_Type();
  4034         const Type* t = tn->type();
  4035         const Type* t_no_spec = t->remove_speculative();
  4036         if (t_no_spec != t) {
  4037           bool in_hash = igvn.hash_delete(n);
  4038           assert(in_hash, "node should be in igvn hash table");
  4039           tn->set_type(t_no_spec);
  4040           igvn.hash_insert(n);
  4041           igvn._worklist.push(n); // give it a chance to go away
  4042           modified++;
  4045       uint max = n->len();
  4046       for( uint i = 0; i < max; ++i ) {
  4047         Node *m = n->in(i);
  4048         if (not_a_node(m))  continue;
  4049         worklist.push(m);
  4052     // Drop the speculative part of all types in the igvn's type table
  4053     igvn.remove_speculative_types();
  4054     if (modified > 0) {
  4055       igvn.optimize();
  4057 #ifdef ASSERT
  4058     // Verify that after the IGVN is over no speculative type has resurfaced
  4059     worklist.clear();
  4060     worklist.push(root());
  4061     for (uint next = 0; next < worklist.size(); ++next) {
  4062       Node *n  = worklist.at(next);
  4063       const Type* t = igvn.type_or_null(n);
  4064       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
  4065       if (n->is_Type()) {
  4066         t = n->as_Type()->type();
  4067         assert(t == t->remove_speculative(), "no more speculative types");
  4069       uint max = n->len();
  4070       for( uint i = 0; i < max; ++i ) {
  4071         Node *m = n->in(i);
  4072         if (not_a_node(m))  continue;
  4073         worklist.push(m);
  4076     igvn.check_no_speculative_types();
  4077 #endif
  4081 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
  4082 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl) {
  4083   if (ctrl != NULL) {
  4084     // Express control dependency by a CastII node with a narrow type.
  4085     value = new (phase->C) CastIINode(value, itype, false, true /* range check dependency */);
  4086     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
  4087     // node from floating above the range check during loop optimizations. Otherwise, the
  4088     // ConvI2L node may be eliminated independently of the range check, causing the data path
  4089     // to become TOP while the control path is still there (although it's unreachable).
  4090     value->set_req(0, ctrl);
  4091     // Save CastII node to remove it after loop optimizations.
  4092     phase->C->add_range_check_cast(value);
  4093     value = phase->transform(value);
  4095   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
  4096   return phase->transform(new (phase->C) ConvI2LNode(value, ltype));
  4099 // Auxiliary method to support randomized stressing/fuzzing.
  4100 //
  4101 // This method can be called the arbitrary number of times, with current count
  4102 // as the argument. The logic allows selecting a single candidate from the
  4103 // running list of candidates as follows:
  4104 //    int count = 0;
  4105 //    Cand* selected = null;
  4106 //    while(cand = cand->next()) {
  4107 //      if (randomized_select(++count)) {
  4108 //        selected = cand;
  4109 //      }
  4110 //    }
  4111 //
  4112 // Including count equalizes the chances any candidate is "selected".
  4113 // This is useful when we don't have the complete list of candidates to choose
  4114 // from uniformly. In this case, we need to adjust the randomicity of the
  4115 // selection, or else we will end up biasing the selection towards the latter
  4116 // candidates.
  4117 //
  4118 // Quick back-envelope calculation shows that for the list of n candidates
  4119 // the equal probability for the candidate to persist as "best" can be
  4120 // achieved by replacing it with "next" k-th candidate with the probability
  4121 // of 1/k. It can be easily shown that by the end of the run, the
  4122 // probability for any candidate is converged to 1/n, thus giving the
  4123 // uniform distribution among all the candidates.
  4124 //
  4125 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
  4126 #define RANDOMIZED_DOMAIN_POW 29
  4127 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
  4128 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
  4129 bool Compile::randomized_select(int count) {
  4130   assert(count > 0, "only positive");
  4131   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);

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