src/share/vm/opto/compile.cpp

Wed, 27 Aug 2014 08:19:12 -0400

author
zgu
date
Wed, 27 Aug 2014 08:19:12 -0400
changeset 7074
833b0f92429a
parent 7041
411e30e5fbb8
child 7385
9e69e8d1c900
permissions
-rw-r--r--

8046598: Scalable Native memory tracking development
Summary: Enhance scalability of native memory tracking
Reviewed-by: coleenp, ctornqvi, gtriantafill

     1 /*
     2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "asm/macroAssembler.hpp"
    27 #include "asm/macroAssembler.inline.hpp"
    28 #include "ci/ciReplay.hpp"
    29 #include "classfile/systemDictionary.hpp"
    30 #include "code/exceptionHandlerTable.hpp"
    31 #include "code/nmethod.hpp"
    32 #include "compiler/compileLog.hpp"
    33 #include "compiler/disassembler.hpp"
    34 #include "compiler/oopMap.hpp"
    35 #include "opto/addnode.hpp"
    36 #include "opto/block.hpp"
    37 #include "opto/c2compiler.hpp"
    38 #include "opto/callGenerator.hpp"
    39 #include "opto/callnode.hpp"
    40 #include "opto/cfgnode.hpp"
    41 #include "opto/chaitin.hpp"
    42 #include "opto/compile.hpp"
    43 #include "opto/connode.hpp"
    44 #include "opto/divnode.hpp"
    45 #include "opto/escape.hpp"
    46 #include "opto/idealGraphPrinter.hpp"
    47 #include "opto/loopnode.hpp"
    48 #include "opto/machnode.hpp"
    49 #include "opto/macro.hpp"
    50 #include "opto/matcher.hpp"
    51 #include "opto/mathexactnode.hpp"
    52 #include "opto/memnode.hpp"
    53 #include "opto/mulnode.hpp"
    54 #include "opto/node.hpp"
    55 #include "opto/opcodes.hpp"
    56 #include "opto/output.hpp"
    57 #include "opto/parse.hpp"
    58 #include "opto/phaseX.hpp"
    59 #include "opto/rootnode.hpp"
    60 #include "opto/runtime.hpp"
    61 #include "opto/stringopts.hpp"
    62 #include "opto/type.hpp"
    63 #include "opto/vectornode.hpp"
    64 #include "runtime/arguments.hpp"
    65 #include "runtime/signature.hpp"
    66 #include "runtime/stubRoutines.hpp"
    67 #include "runtime/timer.hpp"
    68 #include "trace/tracing.hpp"
    69 #include "utilities/copy.hpp"
    70 #ifdef TARGET_ARCH_MODEL_x86_32
    71 # include "adfiles/ad_x86_32.hpp"
    72 #endif
    73 #ifdef TARGET_ARCH_MODEL_x86_64
    74 # include "adfiles/ad_x86_64.hpp"
    75 #endif
    76 #ifdef TARGET_ARCH_MODEL_sparc
    77 # include "adfiles/ad_sparc.hpp"
    78 #endif
    79 #ifdef TARGET_ARCH_MODEL_zero
    80 # include "adfiles/ad_zero.hpp"
    81 #endif
    82 #ifdef TARGET_ARCH_MODEL_arm
    83 # include "adfiles/ad_arm.hpp"
    84 #endif
    85 #ifdef TARGET_ARCH_MODEL_ppc_32
    86 # include "adfiles/ad_ppc_32.hpp"
    87 #endif
    88 #ifdef TARGET_ARCH_MODEL_ppc_64
    89 # include "adfiles/ad_ppc_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 = unique();
   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 expensive node
   424   for (int i = C->expensive_count()-1; i >= 0; i--) {
   425     Node* n = C->expensive_node(i);
   426     if (!useful.member(n)) {
   427       remove_expensive_node(n);
   428     }
   429   }
   430   // clean up the late inline lists
   431   remove_useless_late_inlines(&_string_late_inlines, useful);
   432   remove_useless_late_inlines(&_boxing_late_inlines, useful);
   433   remove_useless_late_inlines(&_late_inlines, useful);
   434   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   435 }
   437 //------------------------------frame_size_in_words-----------------------------
   438 // frame_slots in units of words
   439 int Compile::frame_size_in_words() const {
   440   // shift is 0 in LP32 and 1 in LP64
   441   const int shift = (LogBytesPerWord - LogBytesPerInt);
   442   int words = _frame_slots >> shift;
   443   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   444   return words;
   445 }
   447 // To bang the stack of this compiled method we use the stack size
   448 // that the interpreter would need in case of a deoptimization. This
   449 // removes the need to bang the stack in the deoptimization blob which
   450 // in turn simplifies stack overflow handling.
   451 int Compile::bang_size_in_bytes() const {
   452   return MAX2(_interpreter_frame_size, frame_size_in_bytes());
   453 }
   455 // ============================================================================
   456 //------------------------------CompileWrapper---------------------------------
   457 class CompileWrapper : public StackObj {
   458   Compile *const _compile;
   459  public:
   460   CompileWrapper(Compile* compile);
   462   ~CompileWrapper();
   463 };
   465 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   466   // the Compile* pointer is stored in the current ciEnv:
   467   ciEnv* env = compile->env();
   468   assert(env == ciEnv::current(), "must already be a ciEnv active");
   469   assert(env->compiler_data() == NULL, "compile already active?");
   470   env->set_compiler_data(compile);
   471   assert(compile == Compile::current(), "sanity");
   473   compile->set_type_dict(NULL);
   474   compile->set_type_hwm(NULL);
   475   compile->set_type_last_size(0);
   476   compile->set_last_tf(NULL, NULL);
   477   compile->set_indexSet_arena(NULL);
   478   compile->set_indexSet_free_block_list(NULL);
   479   compile->init_type_arena();
   480   Type::Initialize(compile);
   481   _compile->set_scratch_buffer_blob(NULL);
   482   _compile->begin_method();
   483 }
   484 CompileWrapper::~CompileWrapper() {
   485   _compile->end_method();
   486   if (_compile->scratch_buffer_blob() != NULL)
   487     BufferBlob::free(_compile->scratch_buffer_blob());
   488   _compile->env()->set_compiler_data(NULL);
   489 }
   492 //----------------------------print_compile_messages---------------------------
   493 void Compile::print_compile_messages() {
   494 #ifndef PRODUCT
   495   // Check if recompiling
   496   if (_subsume_loads == false && PrintOpto) {
   497     // Recompiling without allowing machine instructions to subsume loads
   498     tty->print_cr("*********************************************************");
   499     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   500     tty->print_cr("*********************************************************");
   501   }
   502   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   503     // Recompiling without escape analysis
   504     tty->print_cr("*********************************************************");
   505     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   506     tty->print_cr("*********************************************************");
   507   }
   508   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
   509     // Recompiling without boxing elimination
   510     tty->print_cr("*********************************************************");
   511     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
   512     tty->print_cr("*********************************************************");
   513   }
   514   if (env()->break_at_compile()) {
   515     // Open the debugger when compiling this method.
   516     tty->print("### Breaking when compiling: ");
   517     method()->print_short_name();
   518     tty->cr();
   519     BREAKPOINT;
   520   }
   522   if( PrintOpto ) {
   523     if (is_osr_compilation()) {
   524       tty->print("[OSR]%3d", _compile_id);
   525     } else {
   526       tty->print("%3d", _compile_id);
   527     }
   528   }
   529 #endif
   530 }
   533 //-----------------------init_scratch_buffer_blob------------------------------
   534 // Construct a temporary BufferBlob and cache it for this compile.
   535 void Compile::init_scratch_buffer_blob(int const_size) {
   536   // If there is already a scratch buffer blob allocated and the
   537   // constant section is big enough, use it.  Otherwise free the
   538   // current and allocate a new one.
   539   BufferBlob* blob = scratch_buffer_blob();
   540   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
   541     // Use the current blob.
   542   } else {
   543     if (blob != NULL) {
   544       BufferBlob::free(blob);
   545     }
   547     ResourceMark rm;
   548     _scratch_const_size = const_size;
   549     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
   550     blob = BufferBlob::create("Compile::scratch_buffer", size);
   551     // Record the buffer blob for next time.
   552     set_scratch_buffer_blob(blob);
   553     // Have we run out of code space?
   554     if (scratch_buffer_blob() == NULL) {
   555       // Let CompilerBroker disable further compilations.
   556       record_failure("Not enough space for scratch buffer in CodeCache");
   557       return;
   558     }
   559   }
   561   // Initialize the relocation buffers
   562   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
   563   set_scratch_locs_memory(locs_buf);
   564 }
   567 //-----------------------scratch_emit_size-------------------------------------
   568 // Helper function that computes size by emitting code
   569 uint Compile::scratch_emit_size(const Node* n) {
   570   // Start scratch_emit_size section.
   571   set_in_scratch_emit_size(true);
   573   // Emit into a trash buffer and count bytes emitted.
   574   // This is a pretty expensive way to compute a size,
   575   // but it works well enough if seldom used.
   576   // All common fixed-size instructions are given a size
   577   // method by the AD file.
   578   // Note that the scratch buffer blob and locs memory are
   579   // allocated at the beginning of the compile task, and
   580   // may be shared by several calls to scratch_emit_size.
   581   // The allocation of the scratch buffer blob is particularly
   582   // expensive, since it has to grab the code cache lock.
   583   BufferBlob* blob = this->scratch_buffer_blob();
   584   assert(blob != NULL, "Initialize BufferBlob at start");
   585   assert(blob->size() > MAX_inst_size, "sanity");
   586   relocInfo* locs_buf = scratch_locs_memory();
   587   address blob_begin = blob->content_begin();
   588   address blob_end   = (address)locs_buf;
   589   assert(blob->content_contains(blob_end), "sanity");
   590   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   591   buf.initialize_consts_size(_scratch_const_size);
   592   buf.initialize_stubs_size(MAX_stubs_size);
   593   assert(locs_buf != NULL, "sanity");
   594   int lsize = MAX_locs_size / 3;
   595   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
   596   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
   597   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
   599   // Do the emission.
   601   Label fakeL; // Fake label for branch instructions.
   602   Label*   saveL = NULL;
   603   uint save_bnum = 0;
   604   bool is_branch = n->is_MachBranch();
   605   if (is_branch) {
   606     MacroAssembler masm(&buf);
   607     masm.bind(fakeL);
   608     n->as_MachBranch()->save_label(&saveL, &save_bnum);
   609     n->as_MachBranch()->label_set(&fakeL, 0);
   610   }
   611   n->emit(buf, this->regalloc());
   612   if (is_branch) // Restore label.
   613     n->as_MachBranch()->label_set(saveL, save_bnum);
   615   // End scratch_emit_size section.
   616   set_in_scratch_emit_size(false);
   618   return buf.insts_size();
   619 }
   622 // ============================================================================
   623 //------------------------------Compile standard-------------------------------
   624 debug_only( int Compile::_debug_idx = 100000; )
   626 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   627 // the continuation bci for on stack replacement.
   630 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
   631                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
   632                 : Phase(Compiler),
   633                   _env(ci_env),
   634                   _log(ci_env->log()),
   635                   _compile_id(ci_env->compile_id()),
   636                   _save_argument_registers(false),
   637                   _stub_name(NULL),
   638                   _stub_function(NULL),
   639                   _stub_entry_point(NULL),
   640                   _method(target),
   641                   _entry_bci(osr_bci),
   642                   _initial_gvn(NULL),
   643                   _for_igvn(NULL),
   644                   _warm_calls(NULL),
   645                   _subsume_loads(subsume_loads),
   646                   _do_escape_analysis(do_escape_analysis),
   647                   _eliminate_boxing(eliminate_boxing),
   648                   _failure_reason(NULL),
   649                   _code_buffer("Compile::Fill_buffer"),
   650                   _orig_pc_slot(0),
   651                   _orig_pc_slot_offset_in_bytes(0),
   652                   _has_method_handle_invokes(false),
   653                   _mach_constant_base_node(NULL),
   654                   _node_bundling_limit(0),
   655                   _node_bundling_base(NULL),
   656                   _java_calls(0),
   657                   _inner_loops(0),
   658                   _scratch_const_size(-1),
   659                   _in_scratch_emit_size(false),
   660                   _dead_node_list(comp_arena()),
   661                   _dead_node_count(0),
   662 #ifndef PRODUCT
   663                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   664                   _in_dump_cnt(0),
   665                   _printer(IdealGraphPrinter::printer()),
   666 #endif
   667                   _congraph(NULL),
   668                   _comp_arena(mtCompiler),
   669                   _node_arena(mtCompiler),
   670                   _old_arena(mtCompiler),
   671                   _Compile_types(mtCompiler),
   672                   _replay_inline_data(NULL),
   673                   _late_inlines(comp_arena(), 2, 0, NULL),
   674                   _string_late_inlines(comp_arena(), 2, 0, NULL),
   675                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
   676                   _late_inlines_pos(0),
   677                   _number_of_mh_late_inlines(0),
   678                   _inlining_progress(false),
   679                   _inlining_incrementally(false),
   680                   _print_inlining_list(NULL),
   681                   _print_inlining_idx(0),
   682                   _interpreter_frame_size(0) {
   683   C = this;
   685   CompileWrapper cw(this);
   686 #ifndef PRODUCT
   687   if (TimeCompiler2) {
   688     tty->print(" ");
   689     target->holder()->name()->print();
   690     tty->print(".");
   691     target->print_short_name();
   692     tty->print("  ");
   693   }
   694   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   695   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   696   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   697   if (!print_opto_assembly) {
   698     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   699     if (print_assembly && !Disassembler::can_decode()) {
   700       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   701       print_opto_assembly = true;
   702     }
   703   }
   704   set_print_assembly(print_opto_assembly);
   705   set_parsed_irreducible_loop(false);
   707   if (method()->has_option("ReplayInline")) {
   708     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
   709   }
   710 #endif
   711   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
   712   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
   713   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
   715   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
   716     // Make sure the method being compiled gets its own MDO,
   717     // so we can at least track the decompile_count().
   718     // Need MDO to record RTM code generation state.
   719     method()->ensure_method_data();
   720   }
   722   Init(::AliasLevel);
   725   print_compile_messages();
   727   _ilt = InlineTree::build_inline_tree_root();
   729   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   730   assert(num_alias_types() >= AliasIdxRaw, "");
   732 #define MINIMUM_NODE_HASH  1023
   733   // Node list that Iterative GVN will start with
   734   Unique_Node_List for_igvn(comp_arena());
   735   set_for_igvn(&for_igvn);
   737   // GVN that will be run immediately on new nodes
   738   uint estimated_size = method()->code_size()*4+64;
   739   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   740   PhaseGVN gvn(node_arena(), estimated_size);
   741   set_initial_gvn(&gvn);
   743   if (print_inlining() || print_intrinsics()) {
   744     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
   745   }
   746   { // Scope for timing the parser
   747     TracePhase t3("parse", &_t_parser, true);
   749     // Put top into the hash table ASAP.
   750     initial_gvn()->transform_no_reclaim(top());
   752     // Set up tf(), start(), and find a CallGenerator.
   753     CallGenerator* cg = NULL;
   754     if (is_osr_compilation()) {
   755       const TypeTuple *domain = StartOSRNode::osr_domain();
   756       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   757       init_tf(TypeFunc::make(domain, range));
   758       StartNode* s = new (this) StartOSRNode(root(), domain);
   759       initial_gvn()->set_type_bottom(s);
   760       init_start(s);
   761       cg = CallGenerator::for_osr(method(), entry_bci());
   762     } else {
   763       // Normal case.
   764       init_tf(TypeFunc::make(method()));
   765       StartNode* s = new (this) StartNode(root(), tf()->domain());
   766       initial_gvn()->set_type_bottom(s);
   767       init_start(s);
   768       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
   769         // With java.lang.ref.reference.get() we must go through the
   770         // intrinsic when G1 is enabled - even when get() is the root
   771         // method of the compile - so that, if necessary, the value in
   772         // the referent field of the reference object gets recorded by
   773         // the pre-barrier code.
   774         // Specifically, if G1 is enabled, the value in the referent
   775         // field is recorded by the G1 SATB pre barrier. This will
   776         // result in the referent being marked live and the reference
   777         // object removed from the list of discovered references during
   778         // reference processing.
   779         cg = find_intrinsic(method(), false);
   780       }
   781       if (cg == NULL) {
   782         float past_uses = method()->interpreter_invocation_count();
   783         float expected_uses = past_uses;
   784         cg = CallGenerator::for_inline(method(), expected_uses);
   785       }
   786     }
   787     if (failing())  return;
   788     if (cg == NULL) {
   789       record_method_not_compilable_all_tiers("cannot parse method");
   790       return;
   791     }
   792     JVMState* jvms = build_start_state(start(), tf());
   793     if ((jvms = cg->generate(jvms)) == NULL) {
   794       record_method_not_compilable("method parse failed");
   795       return;
   796     }
   797     GraphKit kit(jvms);
   799     if (!kit.stopped()) {
   800       // Accept return values, and transfer control we know not where.
   801       // This is done by a special, unique ReturnNode bound to root.
   802       return_values(kit.jvms());
   803     }
   805     if (kit.has_exceptions()) {
   806       // Any exceptions that escape from this call must be rethrown
   807       // to whatever caller is dynamically above us on the stack.
   808       // This is done by a special, unique RethrowNode bound to root.
   809       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   810     }
   812     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
   814     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
   815       inline_string_calls(true);
   816     }
   818     if (failing())  return;
   820     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
   822     // Remove clutter produced by parsing.
   823     if (!failing()) {
   824       ResourceMark rm;
   825       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   826     }
   827   }
   829   // Note:  Large methods are capped off in do_one_bytecode().
   830   if (failing())  return;
   832   // After parsing, node notes are no longer automagic.
   833   // They must be propagated by register_new_node_with_optimizer(),
   834   // clone(), or the like.
   835   set_default_node_notes(NULL);
   837   for (;;) {
   838     int successes = Inline_Warm();
   839     if (failing())  return;
   840     if (successes == 0)  break;
   841   }
   843   // Drain the list.
   844   Finish_Warm();
   845 #ifndef PRODUCT
   846   if (_printer) {
   847     _printer->print_inlining(this);
   848   }
   849 #endif
   851   if (failing())  return;
   852   NOT_PRODUCT( verify_graph_edges(); )
   854   // Now optimize
   855   Optimize();
   856   if (failing())  return;
   857   NOT_PRODUCT( verify_graph_edges(); )
   859 #ifndef PRODUCT
   860   if (PrintIdeal) {
   861     ttyLocker ttyl;  // keep the following output all in one block
   862     // This output goes directly to the tty, not the compiler log.
   863     // To enable tools to match it up with the compilation activity,
   864     // be sure to tag this tty output with the compile ID.
   865     if (xtty != NULL) {
   866       xtty->head("ideal compile_id='%d'%s", compile_id(),
   867                  is_osr_compilation()    ? " compile_kind='osr'" :
   868                  "");
   869     }
   870     root()->dump(9999);
   871     if (xtty != NULL) {
   872       xtty->tail("ideal");
   873     }
   874   }
   875 #endif
   877   NOT_PRODUCT( verify_barriers(); )
   879   // Dump compilation data to replay it.
   880   if (method()->has_option("DumpReplay")) {
   881     env()->dump_replay_data(_compile_id);
   882   }
   883   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
   884     env()->dump_inline_data(_compile_id);
   885   }
   887   // Now that we know the size of all the monitors we can add a fixed slot
   888   // for the original deopt pc.
   890   _orig_pc_slot =  fixed_slots();
   891   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   892   set_fixed_slots(next_slot);
   894   // Compute when to use implicit null checks. Used by matching trap based
   895   // nodes and NullCheck optimization.
   896   set_allowed_deopt_reasons();
   898   // Now generate code
   899   Code_Gen();
   900   if (failing())  return;
   902   // Check if we want to skip execution of all compiled code.
   903   {
   904 #ifndef PRODUCT
   905     if (OptoNoExecute) {
   906       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   907       return;
   908     }
   909     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   910 #endif
   912     if (is_osr_compilation()) {
   913       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   914       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   915     } else {
   916       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   917       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   918     }
   920     env()->register_method(_method, _entry_bci,
   921                            &_code_offsets,
   922                            _orig_pc_slot_offset_in_bytes,
   923                            code_buffer(),
   924                            frame_size_in_words(), _oop_map_set,
   925                            &_handler_table, &_inc_table,
   926                            compiler,
   927                            env()->comp_level(),
   928                            has_unsafe_access(),
   929                            SharedRuntime::is_wide_vector(max_vector_size()),
   930                            rtm_state()
   931                            );
   933     if (log() != NULL) // Print code cache state into compiler log
   934       log()->code_cache_state();
   935   }
   936 }
   938 //------------------------------Compile----------------------------------------
   939 // Compile a runtime stub
   940 Compile::Compile( ciEnv* ci_env,
   941                   TypeFunc_generator generator,
   942                   address stub_function,
   943                   const char *stub_name,
   944                   int is_fancy_jump,
   945                   bool pass_tls,
   946                   bool save_arg_registers,
   947                   bool return_pc )
   948   : Phase(Compiler),
   949     _env(ci_env),
   950     _log(ci_env->log()),
   951     _compile_id(0),
   952     _save_argument_registers(save_arg_registers),
   953     _method(NULL),
   954     _stub_name(stub_name),
   955     _stub_function(stub_function),
   956     _stub_entry_point(NULL),
   957     _entry_bci(InvocationEntryBci),
   958     _initial_gvn(NULL),
   959     _for_igvn(NULL),
   960     _warm_calls(NULL),
   961     _orig_pc_slot(0),
   962     _orig_pc_slot_offset_in_bytes(0),
   963     _subsume_loads(true),
   964     _do_escape_analysis(false),
   965     _eliminate_boxing(false),
   966     _failure_reason(NULL),
   967     _code_buffer("Compile::Fill_buffer"),
   968     _has_method_handle_invokes(false),
   969     _mach_constant_base_node(NULL),
   970     _node_bundling_limit(0),
   971     _node_bundling_base(NULL),
   972     _java_calls(0),
   973     _inner_loops(0),
   974 #ifndef PRODUCT
   975     _trace_opto_output(TraceOptoOutput),
   976     _in_dump_cnt(0),
   977     _printer(NULL),
   978 #endif
   979     _comp_arena(mtCompiler),
   980     _node_arena(mtCompiler),
   981     _old_arena(mtCompiler),
   982     _Compile_types(mtCompiler),
   983     _dead_node_list(comp_arena()),
   984     _dead_node_count(0),
   985     _congraph(NULL),
   986     _replay_inline_data(NULL),
   987     _number_of_mh_late_inlines(0),
   988     _inlining_progress(false),
   989     _inlining_incrementally(false),
   990     _print_inlining_list(NULL),
   991     _print_inlining_idx(0),
   992     _allowed_reasons(0),
   993     _interpreter_frame_size(0) {
   994   C = this;
   996 #ifndef PRODUCT
   997   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   998   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   999   set_print_assembly(PrintFrameConverterAssembly);
  1000   set_parsed_irreducible_loop(false);
  1001 #endif
  1002   set_has_irreducible_loop(false); // no loops
  1004   CompileWrapper cw(this);
  1005   Init(/*AliasLevel=*/ 0);
  1006   init_tf((*generator)());
  1009     // The following is a dummy for the sake of GraphKit::gen_stub
  1010     Unique_Node_List for_igvn(comp_arena());
  1011     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
  1012     PhaseGVN gvn(Thread::current()->resource_area(),255);
  1013     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
  1014     gvn.transform_no_reclaim(top());
  1016     GraphKit kit;
  1017     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
  1020   NOT_PRODUCT( verify_graph_edges(); )
  1021   Code_Gen();
  1022   if (failing())  return;
  1025   // Entry point will be accessed using compile->stub_entry_point();
  1026   if (code_buffer() == NULL) {
  1027     Matcher::soft_match_failure();
  1028   } else {
  1029     if (PrintAssembly && (WizardMode || Verbose))
  1030       tty->print_cr("### Stub::%s", stub_name);
  1032     if (!failing()) {
  1033       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
  1035       // Make the NMethod
  1036       // For now we mark the frame as never safe for profile stackwalking
  1037       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
  1038                                                       code_buffer(),
  1039                                                       CodeOffsets::frame_never_safe,
  1040                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
  1041                                                       frame_size_in_words(),
  1042                                                       _oop_map_set,
  1043                                                       save_arg_registers);
  1044       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
  1046       _stub_entry_point = rs->entry_point();
  1051 //------------------------------Init-------------------------------------------
  1052 // Prepare for a single compilation
  1053 void Compile::Init(int aliaslevel) {
  1054   _unique  = 0;
  1055   _regalloc = NULL;
  1057   _tf      = NULL;  // filled in later
  1058   _top     = NULL;  // cached later
  1059   _matcher = NULL;  // filled in later
  1060   _cfg     = NULL;  // filled in later
  1062   set_24_bit_selection_and_mode(Use24BitFP, false);
  1064   _node_note_array = NULL;
  1065   _default_node_notes = NULL;
  1067   _immutable_memory = NULL; // filled in at first inquiry
  1069   // Globally visible Nodes
  1070   // First set TOP to NULL to give safe behavior during creation of RootNode
  1071   set_cached_top_node(NULL);
  1072   set_root(new (this) RootNode());
  1073   // Now that you have a Root to point to, create the real TOP
  1074   set_cached_top_node( new (this) ConNode(Type::TOP) );
  1075   set_recent_alloc(NULL, NULL);
  1077   // Create Debug Information Recorder to record scopes, oopmaps, etc.
  1078   env()->set_oop_recorder(new OopRecorder(env()->arena()));
  1079   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
  1080   env()->set_dependencies(new Dependencies(env()));
  1082   _fixed_slots = 0;
  1083   set_has_split_ifs(false);
  1084   set_has_loops(has_method() && method()->has_loops()); // first approximation
  1085   set_has_stringbuilder(false);
  1086   set_has_boxed_value(false);
  1087   _trap_can_recompile = false;  // no traps emitted yet
  1088   _major_progress = true; // start out assuming good things will happen
  1089   set_has_unsafe_access(false);
  1090   set_max_vector_size(0);
  1091   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
  1092   set_decompile_count(0);
  1094   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
  1095   set_num_loop_opts(LoopOptsCount);
  1096   set_do_inlining(Inline);
  1097   set_max_inline_size(MaxInlineSize);
  1098   set_freq_inline_size(FreqInlineSize);
  1099   set_do_scheduling(OptoScheduling);
  1100   set_do_count_invocations(false);
  1101   set_do_method_data_update(false);
  1102   set_rtm_state(NoRTM); // No RTM lock eliding by default
  1103 #if INCLUDE_RTM_OPT
  1104   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
  1105     int rtm_state = method()->method_data()->rtm_state();
  1106     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
  1107       // Don't generate RTM lock eliding code.
  1108       set_rtm_state(NoRTM);
  1109     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
  1110       // Generate RTM lock eliding code without abort ratio calculation code.
  1111       set_rtm_state(UseRTM);
  1112     } else if (UseRTMDeopt) {
  1113       // Generate RTM lock eliding code and include abort ratio calculation
  1114       // code if UseRTMDeopt is on.
  1115       set_rtm_state(ProfileRTM);
  1118 #endif
  1119   if (debug_info()->recording_non_safepoints()) {
  1120     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
  1121                         (comp_arena(), 8, 0, NULL));
  1122     set_default_node_notes(Node_Notes::make(this));
  1125   // // -- Initialize types before each compile --
  1126   // // Update cached type information
  1127   // if( _method && _method->constants() )
  1128   //   Type::update_loaded_types(_method, _method->constants());
  1130   // Init alias_type map.
  1131   if (!_do_escape_analysis && aliaslevel == 3)
  1132     aliaslevel = 2;  // No unique types without escape analysis
  1133   _AliasLevel = aliaslevel;
  1134   const int grow_ats = 16;
  1135   _max_alias_types = grow_ats;
  1136   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
  1137   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
  1138   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
  1140     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
  1142   // Initialize the first few types.
  1143   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
  1144   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
  1145   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
  1146   _num_alias_types = AliasIdxRaw+1;
  1147   // Zero out the alias type cache.
  1148   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
  1149   // A NULL adr_type hits in the cache right away.  Preload the right answer.
  1150   probe_alias_cache(NULL)->_index = AliasIdxTop;
  1152   _intrinsics = NULL;
  1153   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1154   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1155   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1156   register_library_intrinsics();
  1159 //---------------------------init_start----------------------------------------
  1160 // Install the StartNode on this compile object.
  1161 void Compile::init_start(StartNode* s) {
  1162   if (failing())
  1163     return; // already failing
  1164   assert(s == start(), "");
  1167 StartNode* Compile::start() const {
  1168   assert(!failing(), "");
  1169   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
  1170     Node* start = root()->fast_out(i);
  1171     if( start->is_Start() )
  1172       return start->as_Start();
  1174   fatal("Did not find Start node!");
  1175   return NULL;
  1178 //-------------------------------immutable_memory-------------------------------------
  1179 // Access immutable memory
  1180 Node* Compile::immutable_memory() {
  1181   if (_immutable_memory != NULL) {
  1182     return _immutable_memory;
  1184   StartNode* s = start();
  1185   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
  1186     Node *p = s->fast_out(i);
  1187     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
  1188       _immutable_memory = p;
  1189       return _immutable_memory;
  1192   ShouldNotReachHere();
  1193   return NULL;
  1196 //----------------------set_cached_top_node------------------------------------
  1197 // Install the cached top node, and make sure Node::is_top works correctly.
  1198 void Compile::set_cached_top_node(Node* tn) {
  1199   if (tn != NULL)  verify_top(tn);
  1200   Node* old_top = _top;
  1201   _top = tn;
  1202   // Calling Node::setup_is_top allows the nodes the chance to adjust
  1203   // their _out arrays.
  1204   if (_top != NULL)     _top->setup_is_top();
  1205   if (old_top != NULL)  old_top->setup_is_top();
  1206   assert(_top == NULL || top()->is_top(), "");
  1209 #ifdef ASSERT
  1210 uint Compile::count_live_nodes_by_graph_walk() {
  1211   Unique_Node_List useful(comp_arena());
  1212   // Get useful node list by walking the graph.
  1213   identify_useful_nodes(useful);
  1214   return useful.size();
  1217 void Compile::print_missing_nodes() {
  1219   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
  1220   if ((_log == NULL) && (! PrintIdealNodeCount)) {
  1221     return;
  1224   // This is an expensive function. It is executed only when the user
  1225   // specifies VerifyIdealNodeCount option or otherwise knows the
  1226   // additional work that needs to be done to identify reachable nodes
  1227   // by walking the flow graph and find the missing ones using
  1228   // _dead_node_list.
  1230   Unique_Node_List useful(comp_arena());
  1231   // Get useful node list by walking the graph.
  1232   identify_useful_nodes(useful);
  1234   uint l_nodes = C->live_nodes();
  1235   uint l_nodes_by_walk = useful.size();
  1237   if (l_nodes != l_nodes_by_walk) {
  1238     if (_log != NULL) {
  1239       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
  1240       _log->stamp();
  1241       _log->end_head();
  1243     VectorSet& useful_member_set = useful.member_set();
  1244     int last_idx = l_nodes_by_walk;
  1245     for (int i = 0; i < last_idx; i++) {
  1246       if (useful_member_set.test(i)) {
  1247         if (_dead_node_list.test(i)) {
  1248           if (_log != NULL) {
  1249             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
  1251           if (PrintIdealNodeCount) {
  1252             // Print the log message to tty
  1253               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
  1254               useful.at(i)->dump();
  1258       else if (! _dead_node_list.test(i)) {
  1259         if (_log != NULL) {
  1260           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
  1262         if (PrintIdealNodeCount) {
  1263           // Print the log message to tty
  1264           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
  1268     if (_log != NULL) {
  1269       _log->tail("mismatched_nodes");
  1273 #endif
  1275 #ifndef PRODUCT
  1276 void Compile::verify_top(Node* tn) const {
  1277   if (tn != NULL) {
  1278     assert(tn->is_Con(), "top node must be a constant");
  1279     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
  1280     assert(tn->in(0) != NULL, "must have live top node");
  1283 #endif
  1286 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1288 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1289   guarantee(arr != NULL, "");
  1290   int num_blocks = arr->length();
  1291   if (grow_by < num_blocks)  grow_by = num_blocks;
  1292   int num_notes = grow_by * _node_notes_block_size;
  1293   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1294   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1295   while (num_notes > 0) {
  1296     arr->append(notes);
  1297     notes     += _node_notes_block_size;
  1298     num_notes -= _node_notes_block_size;
  1300   assert(num_notes == 0, "exact multiple, please");
  1303 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1304   if (source == NULL || dest == NULL)  return false;
  1306   if (dest->is_Con())
  1307     return false;               // Do not push debug info onto constants.
  1309 #ifdef ASSERT
  1310   // Leave a bread crumb trail pointing to the original node:
  1311   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1312     dest->set_debug_orig(source);
  1314 #endif
  1316   if (node_note_array() == NULL)
  1317     return false;               // Not collecting any notes now.
  1319   // This is a copy onto a pre-existing node, which may already have notes.
  1320   // If both nodes have notes, do not overwrite any pre-existing notes.
  1321   Node_Notes* source_notes = node_notes_at(source->_idx);
  1322   if (source_notes == NULL || source_notes->is_clear())  return false;
  1323   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1324   if (dest_notes == NULL || dest_notes->is_clear()) {
  1325     return set_node_notes_at(dest->_idx, source_notes);
  1328   Node_Notes merged_notes = (*source_notes);
  1329   // The order of operations here ensures that dest notes will win...
  1330   merged_notes.update_from(dest_notes);
  1331   return set_node_notes_at(dest->_idx, &merged_notes);
  1335 //--------------------------allow_range_check_smearing-------------------------
  1336 // Gating condition for coalescing similar range checks.
  1337 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1338 // single covering check that is at least as strong as any of them.
  1339 // If the optimization succeeds, the simplified (strengthened) range check
  1340 // will always succeed.  If it fails, we will deopt, and then give up
  1341 // on the optimization.
  1342 bool Compile::allow_range_check_smearing() const {
  1343   // If this method has already thrown a range-check,
  1344   // assume it was because we already tried range smearing
  1345   // and it failed.
  1346   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1347   return !already_trapped;
  1351 //------------------------------flatten_alias_type-----------------------------
  1352 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1353   int offset = tj->offset();
  1354   TypePtr::PTR ptr = tj->ptr();
  1356   // Known instance (scalarizable allocation) alias only with itself.
  1357   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1358                        tj->is_oopptr()->is_known_instance();
  1360   // Process weird unsafe references.
  1361   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1362     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1363     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1364     tj = TypeOopPtr::BOTTOM;
  1365     ptr = tj->ptr();
  1366     offset = tj->offset();
  1369   // Array pointers need some flattening
  1370   const TypeAryPtr *ta = tj->isa_aryptr();
  1371   if (ta && ta->is_stable()) {
  1372     // Erase stability property for alias analysis.
  1373     tj = ta = ta->cast_to_stable(false);
  1375   if( ta && is_known_inst ) {
  1376     if ( offset != Type::OffsetBot &&
  1377          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1378       offset = Type::OffsetBot; // Flatten constant access into array body only
  1379       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1381   } else if( ta && _AliasLevel >= 2 ) {
  1382     // For arrays indexed by constant indices, we flatten the alias
  1383     // space to include all of the array body.  Only the header, klass
  1384     // and array length can be accessed un-aliased.
  1385     if( offset != Type::OffsetBot ) {
  1386       if( ta->const_oop() ) { // MethodData* or Method*
  1387         offset = Type::OffsetBot;   // Flatten constant access into array body
  1388         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1389       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1390         // range is OK as-is.
  1391         tj = ta = TypeAryPtr::RANGE;
  1392       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1393         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1394         ta = TypeAryPtr::RANGE; // generic ignored junk
  1395         ptr = TypePtr::BotPTR;
  1396       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1397         tj = TypeInstPtr::MARK;
  1398         ta = TypeAryPtr::RANGE; // generic ignored junk
  1399         ptr = TypePtr::BotPTR;
  1400       } else {                  // Random constant offset into array body
  1401         offset = Type::OffsetBot;   // Flatten constant access into array body
  1402         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1405     // Arrays of fixed size alias with arrays of unknown size.
  1406     if (ta->size() != TypeInt::POS) {
  1407       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1408       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1410     // Arrays of known objects become arrays of unknown objects.
  1411     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1412       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1413       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1415     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1416       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1417       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1419     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1420     // cannot be distinguished by bytecode alone.
  1421     if (ta->elem() == TypeInt::BOOL) {
  1422       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1423       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1424       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1426     // During the 2nd round of IterGVN, NotNull castings are removed.
  1427     // Make sure the Bottom and NotNull variants alias the same.
  1428     // Also, make sure exact and non-exact variants alias the same.
  1429     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
  1430       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1434   // Oop pointers need some flattening
  1435   const TypeInstPtr *to = tj->isa_instptr();
  1436   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1437     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1438     if( ptr == TypePtr::Constant ) {
  1439       if (to->klass() != ciEnv::current()->Class_klass() ||
  1440           offset < k->size_helper() * wordSize) {
  1441         // No constant oop pointers (such as Strings); they alias with
  1442         // unknown strings.
  1443         assert(!is_known_inst, "not scalarizable allocation");
  1444         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1446     } else if( is_known_inst ) {
  1447       tj = to; // Keep NotNull and klass_is_exact for instance type
  1448     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1449       // During the 2nd round of IterGVN, NotNull castings are removed.
  1450       // Make sure the Bottom and NotNull variants alias the same.
  1451       // Also, make sure exact and non-exact variants alias the same.
  1452       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1454     if (to->speculative() != NULL) {
  1455       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
  1457     // Canonicalize the holder of this field
  1458     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1459       // First handle header references such as a LoadKlassNode, even if the
  1460       // object's klass is unloaded at compile time (4965979).
  1461       if (!is_known_inst) { // Do it only for non-instance types
  1462         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1464     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1465       // Static fields are in the space above the normal instance
  1466       // fields in the java.lang.Class instance.
  1467       if (to->klass() != ciEnv::current()->Class_klass()) {
  1468         to = NULL;
  1469         tj = TypeOopPtr::BOTTOM;
  1470         offset = tj->offset();
  1472     } else {
  1473       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1474       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1475         if( is_known_inst ) {
  1476           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1477         } else {
  1478           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1484   // Klass pointers to object array klasses need some flattening
  1485   const TypeKlassPtr *tk = tj->isa_klassptr();
  1486   if( tk ) {
  1487     // If we are referencing a field within a Klass, we need
  1488     // to assume the worst case of an Object.  Both exact and
  1489     // inexact types must flatten to the same alias class so
  1490     // use NotNull as the PTR.
  1491     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1493       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
  1494                                    TypeKlassPtr::OBJECT->klass(),
  1495                                    offset);
  1498     ciKlass* klass = tk->klass();
  1499     if( klass->is_obj_array_klass() ) {
  1500       ciKlass* k = TypeAryPtr::OOPS->klass();
  1501       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1502         k = TypeInstPtr::BOTTOM->klass();
  1503       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1506     // Check for precise loads from the primary supertype array and force them
  1507     // to the supertype cache alias index.  Check for generic array loads from
  1508     // the primary supertype array and also force them to the supertype cache
  1509     // alias index.  Since the same load can reach both, we need to merge
  1510     // these 2 disparate memories into the same alias class.  Since the
  1511     // primary supertype array is read-only, there's no chance of confusion
  1512     // where we bypass an array load and an array store.
  1513     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
  1514     if (offset == Type::OffsetBot ||
  1515         (offset >= primary_supers_offset &&
  1516          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
  1517         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
  1518       offset = in_bytes(Klass::secondary_super_cache_offset());
  1519       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1523   // Flatten all Raw pointers together.
  1524   if (tj->base() == Type::RawPtr)
  1525     tj = TypeRawPtr::BOTTOM;
  1527   if (tj->base() == Type::AnyPtr)
  1528     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1530   // Flatten all to bottom for now
  1531   switch( _AliasLevel ) {
  1532   case 0:
  1533     tj = TypePtr::BOTTOM;
  1534     break;
  1535   case 1:                       // Flatten to: oop, static, field or array
  1536     switch (tj->base()) {
  1537     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1538     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1539     case Type::AryPtr:   // do not distinguish arrays at all
  1540     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1541     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1542     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1543     default: ShouldNotReachHere();
  1545     break;
  1546   case 2:                       // No collapsing at level 2; keep all splits
  1547   case 3:                       // No collapsing at level 3; keep all splits
  1548     break;
  1549   default:
  1550     Unimplemented();
  1553   offset = tj->offset();
  1554   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1556   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1557           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1558           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1559           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1560           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1561           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1562           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1563           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1564   assert( tj->ptr() != TypePtr::TopPTR &&
  1565           tj->ptr() != TypePtr::AnyNull &&
  1566           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1567 //    assert( tj->ptr() != TypePtr::Constant ||
  1568 //            tj->base() == Type::RawPtr ||
  1569 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1571   return tj;
  1574 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1575   _index = i;
  1576   _adr_type = at;
  1577   _field = NULL;
  1578   _element = NULL;
  1579   _is_rewritable = true; // default
  1580   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1581   if (atoop != NULL && atoop->is_known_instance()) {
  1582     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1583     _general_index = Compile::current()->get_alias_index(gt);
  1584   } else {
  1585     _general_index = 0;
  1589 //---------------------------------print_on------------------------------------
  1590 #ifndef PRODUCT
  1591 void Compile::AliasType::print_on(outputStream* st) {
  1592   if (index() < 10)
  1593         st->print("@ <%d> ", index());
  1594   else  st->print("@ <%d>",  index());
  1595   st->print(is_rewritable() ? "   " : " RO");
  1596   int offset = adr_type()->offset();
  1597   if (offset == Type::OffsetBot)
  1598         st->print(" +any");
  1599   else  st->print(" +%-3d", offset);
  1600   st->print(" in ");
  1601   adr_type()->dump_on(st);
  1602   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1603   if (field() != NULL && tjp) {
  1604     if (tjp->klass()  != field()->holder() ||
  1605         tjp->offset() != field()->offset_in_bytes()) {
  1606       st->print(" != ");
  1607       field()->print();
  1608       st->print(" ***");
  1613 void print_alias_types() {
  1614   Compile* C = Compile::current();
  1615   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1616   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1617     C->alias_type(idx)->print_on(tty);
  1618     tty->cr();
  1621 #endif
  1624 //----------------------------probe_alias_cache--------------------------------
  1625 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1626   intptr_t key = (intptr_t) adr_type;
  1627   key ^= key >> logAliasCacheSize;
  1628   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1632 //-----------------------------grow_alias_types--------------------------------
  1633 void Compile::grow_alias_types() {
  1634   const int old_ats  = _max_alias_types; // how many before?
  1635   const int new_ats  = old_ats;          // how many more?
  1636   const int grow_ats = old_ats+new_ats;  // how many now?
  1637   _max_alias_types = grow_ats;
  1638   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1639   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1640   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1641   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1645 //--------------------------------find_alias_type------------------------------
  1646 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
  1647   if (_AliasLevel == 0)
  1648     return alias_type(AliasIdxBot);
  1650   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1651   if (ace->_adr_type == adr_type) {
  1652     return alias_type(ace->_index);
  1655   // Handle special cases.
  1656   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1657   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1659   // Do it the slow way.
  1660   const TypePtr* flat = flatten_alias_type(adr_type);
  1662 #ifdef ASSERT
  1663   assert(flat == flatten_alias_type(flat), "idempotent");
  1664   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1665   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1666     const TypeOopPtr* foop = flat->is_oopptr();
  1667     // Scalarizable allocations have exact klass always.
  1668     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1669     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1670     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1672   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1673 #endif
  1675   int idx = AliasIdxTop;
  1676   for (int i = 0; i < num_alias_types(); i++) {
  1677     if (alias_type(i)->adr_type() == flat) {
  1678       idx = i;
  1679       break;
  1683   if (idx == AliasIdxTop) {
  1684     if (no_create)  return NULL;
  1685     // Grow the array if necessary.
  1686     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1687     // Add a new alias type.
  1688     idx = _num_alias_types++;
  1689     _alias_types[idx]->Init(idx, flat);
  1690     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1691     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1692     if (flat->isa_instptr()) {
  1693       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1694           && flat->is_instptr()->klass() == env()->Class_klass())
  1695         alias_type(idx)->set_rewritable(false);
  1697     if (flat->isa_aryptr()) {
  1698 #ifdef ASSERT
  1699       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1700       // (T_BYTE has the weakest alignment and size restrictions...)
  1701       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
  1702 #endif
  1703       if (flat->offset() == TypePtr::OffsetBot) {
  1704         alias_type(idx)->set_element(flat->is_aryptr()->elem());
  1707     if (flat->isa_klassptr()) {
  1708       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
  1709         alias_type(idx)->set_rewritable(false);
  1710       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
  1711         alias_type(idx)->set_rewritable(false);
  1712       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
  1713         alias_type(idx)->set_rewritable(false);
  1714       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
  1715         alias_type(idx)->set_rewritable(false);
  1717     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1718     // but the base pointer type is not distinctive enough to identify
  1719     // references into JavaThread.)
  1721     // Check for final fields.
  1722     const TypeInstPtr* tinst = flat->isa_instptr();
  1723     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1724       ciField* field;
  1725       if (tinst->const_oop() != NULL &&
  1726           tinst->klass() == ciEnv::current()->Class_klass() &&
  1727           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
  1728         // static field
  1729         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
  1730         field = k->get_field_by_offset(tinst->offset(), true);
  1731       } else {
  1732         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1733         field = k->get_field_by_offset(tinst->offset(), false);
  1735       assert(field == NULL ||
  1736              original_field == NULL ||
  1737              (field->holder() == original_field->holder() &&
  1738               field->offset() == original_field->offset() &&
  1739               field->is_static() == original_field->is_static()), "wrong field?");
  1740       // Set field() and is_rewritable() attributes.
  1741       if (field != NULL)  alias_type(idx)->set_field(field);
  1745   // Fill the cache for next time.
  1746   ace->_adr_type = adr_type;
  1747   ace->_index    = idx;
  1748   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1750   // Might as well try to fill the cache for the flattened version, too.
  1751   AliasCacheEntry* face = probe_alias_cache(flat);
  1752   if (face->_adr_type == NULL) {
  1753     face->_adr_type = flat;
  1754     face->_index    = idx;
  1755     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1758   return alias_type(idx);
  1762 Compile::AliasType* Compile::alias_type(ciField* field) {
  1763   const TypeOopPtr* t;
  1764   if (field->is_static())
  1765     t = TypeInstPtr::make(field->holder()->java_mirror());
  1766   else
  1767     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1768   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
  1769   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
  1770   return atp;
  1774 //------------------------------have_alias_type--------------------------------
  1775 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1776   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1777   if (ace->_adr_type == adr_type) {
  1778     return true;
  1781   // Handle special cases.
  1782   if (adr_type == NULL)             return true;
  1783   if (adr_type == TypePtr::BOTTOM)  return true;
  1785   return find_alias_type(adr_type, true, NULL) != NULL;
  1788 //-----------------------------must_alias--------------------------------------
  1789 // True if all values of the given address type are in the given alias category.
  1790 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1791   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1792   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1793   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1794   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1796   // the only remaining possible overlap is identity
  1797   int adr_idx = get_alias_index(adr_type);
  1798   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1799   assert(adr_idx == alias_idx ||
  1800          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1801           && adr_type                       != TypeOopPtr::BOTTOM),
  1802          "should not be testing for overlap with an unsafe pointer");
  1803   return adr_idx == alias_idx;
  1806 //------------------------------can_alias--------------------------------------
  1807 // True if any values of the given address type are in the given alias category.
  1808 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1809   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1810   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1811   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1812   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1814   // the only remaining possible overlap is identity
  1815   int adr_idx = get_alias_index(adr_type);
  1816   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1817   return adr_idx == alias_idx;
  1822 //---------------------------pop_warm_call-------------------------------------
  1823 WarmCallInfo* Compile::pop_warm_call() {
  1824   WarmCallInfo* wci = _warm_calls;
  1825   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1826   return wci;
  1829 //----------------------------Inline_Warm--------------------------------------
  1830 int Compile::Inline_Warm() {
  1831   // If there is room, try to inline some more warm call sites.
  1832   // %%% Do a graph index compaction pass when we think we're out of space?
  1833   if (!InlineWarmCalls)  return 0;
  1835   int calls_made_hot = 0;
  1836   int room_to_grow   = NodeCountInliningCutoff - unique();
  1837   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1838   int amount_grown   = 0;
  1839   WarmCallInfo* call;
  1840   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1841     int est_size = (int)call->size();
  1842     if (est_size > (room_to_grow - amount_grown)) {
  1843       // This one won't fit anyway.  Get rid of it.
  1844       call->make_cold();
  1845       continue;
  1847     call->make_hot();
  1848     calls_made_hot++;
  1849     amount_grown   += est_size;
  1850     amount_to_grow -= est_size;
  1853   if (calls_made_hot > 0)  set_major_progress();
  1854   return calls_made_hot;
  1858 //----------------------------Finish_Warm--------------------------------------
  1859 void Compile::Finish_Warm() {
  1860   if (!InlineWarmCalls)  return;
  1861   if (failing())  return;
  1862   if (warm_calls() == NULL)  return;
  1864   // Clean up loose ends, if we are out of space for inlining.
  1865   WarmCallInfo* call;
  1866   while ((call = pop_warm_call()) != NULL) {
  1867     call->make_cold();
  1871 //---------------------cleanup_loop_predicates-----------------------
  1872 // Remove the opaque nodes that protect the predicates so that all unused
  1873 // checks and uncommon_traps will be eliminated from the ideal graph
  1874 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1875   if (predicate_count()==0) return;
  1876   for (int i = predicate_count(); i > 0; i--) {
  1877     Node * n = predicate_opaque1_node(i-1);
  1878     assert(n->Opcode() == Op_Opaque1, "must be");
  1879     igvn.replace_node(n, n->in(1));
  1881   assert(predicate_count()==0, "should be clean!");
  1884 // StringOpts and late inlining of string methods
  1885 void Compile::inline_string_calls(bool parse_time) {
  1887     // remove useless nodes to make the usage analysis simpler
  1888     ResourceMark rm;
  1889     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  1893     ResourceMark rm;
  1894     print_method(PHASE_BEFORE_STRINGOPTS, 3);
  1895     PhaseStringOpts pso(initial_gvn(), for_igvn());
  1896     print_method(PHASE_AFTER_STRINGOPTS, 3);
  1899   // now inline anything that we skipped the first time around
  1900   if (!parse_time) {
  1901     _late_inlines_pos = _late_inlines.length();
  1904   while (_string_late_inlines.length() > 0) {
  1905     CallGenerator* cg = _string_late_inlines.pop();
  1906     cg->do_late_inline();
  1907     if (failing())  return;
  1909   _string_late_inlines.trunc_to(0);
  1912 // Late inlining of boxing methods
  1913 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
  1914   if (_boxing_late_inlines.length() > 0) {
  1915     assert(has_boxed_value(), "inconsistent");
  1917     PhaseGVN* gvn = initial_gvn();
  1918     set_inlining_incrementally(true);
  1920     assert( igvn._worklist.size() == 0, "should be done with igvn" );
  1921     for_igvn()->clear();
  1922     gvn->replace_with(&igvn);
  1924     _late_inlines_pos = _late_inlines.length();
  1926     while (_boxing_late_inlines.length() > 0) {
  1927       CallGenerator* cg = _boxing_late_inlines.pop();
  1928       cg->do_late_inline();
  1929       if (failing())  return;
  1931     _boxing_late_inlines.trunc_to(0);
  1934       ResourceMark rm;
  1935       PhaseRemoveUseless pru(gvn, for_igvn());
  1938     igvn = PhaseIterGVN(gvn);
  1939     igvn.optimize();
  1941     set_inlining_progress(false);
  1942     set_inlining_incrementally(false);
  1946 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
  1947   assert(IncrementalInline, "incremental inlining should be on");
  1948   PhaseGVN* gvn = initial_gvn();
  1950   set_inlining_progress(false);
  1951   for_igvn()->clear();
  1952   gvn->replace_with(&igvn);
  1954   int i = 0;
  1956   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
  1957     CallGenerator* cg = _late_inlines.at(i);
  1958     _late_inlines_pos = i+1;
  1959     cg->do_late_inline();
  1960     if (failing())  return;
  1962   int j = 0;
  1963   for (; i < _late_inlines.length(); i++, j++) {
  1964     _late_inlines.at_put(j, _late_inlines.at(i));
  1966   _late_inlines.trunc_to(j);
  1969     ResourceMark rm;
  1970     PhaseRemoveUseless pru(gvn, for_igvn());
  1973   igvn = PhaseIterGVN(gvn);
  1976 // Perform incremental inlining until bound on number of live nodes is reached
  1977 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
  1978   PhaseGVN* gvn = initial_gvn();
  1980   set_inlining_incrementally(true);
  1981   set_inlining_progress(true);
  1982   uint low_live_nodes = 0;
  1984   while(inlining_progress() && _late_inlines.length() > 0) {
  1986     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  1987       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
  1988         // PhaseIdealLoop is expensive so we only try it once we are
  1989         // out of live nodes and we only try it again if the previous
  1990         // helped got the number of nodes down significantly
  1991         PhaseIdealLoop ideal_loop( igvn, false, true );
  1992         if (failing())  return;
  1993         low_live_nodes = live_nodes();
  1994         _major_progress = true;
  1997       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  1998         break;
  2002     inline_incrementally_one(igvn);
  2004     if (failing())  return;
  2006     igvn.optimize();
  2008     if (failing())  return;
  2011   assert( igvn._worklist.size() == 0, "should be done with igvn" );
  2013   if (_string_late_inlines.length() > 0) {
  2014     assert(has_stringbuilder(), "inconsistent");
  2015     for_igvn()->clear();
  2016     initial_gvn()->replace_with(&igvn);
  2018     inline_string_calls(false);
  2020     if (failing())  return;
  2023       ResourceMark rm;
  2024       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  2027     igvn = PhaseIterGVN(gvn);
  2029     igvn.optimize();
  2032   set_inlining_incrementally(false);
  2036 //------------------------------Optimize---------------------------------------
  2037 // Given a graph, optimize it.
  2038 void Compile::Optimize() {
  2039   TracePhase t1("optimizer", &_t_optimizer, true);
  2041 #ifndef PRODUCT
  2042   if (env()->break_at_compile()) {
  2043     BREAKPOINT;
  2046 #endif
  2048   ResourceMark rm;
  2049   int          loop_opts_cnt;
  2051   NOT_PRODUCT( verify_graph_edges(); )
  2053   print_method(PHASE_AFTER_PARSING);
  2056   // Iterative Global Value Numbering, including ideal transforms
  2057   // Initialize IterGVN with types and values from parse-time GVN
  2058   PhaseIterGVN igvn(initial_gvn());
  2060     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  2061     igvn.optimize();
  2064   print_method(PHASE_ITER_GVN1, 2);
  2066   if (failing())  return;
  2069     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2070     inline_incrementally(igvn);
  2073   print_method(PHASE_INCREMENTAL_INLINE, 2);
  2075   if (failing())  return;
  2077   if (eliminate_boxing()) {
  2078     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2079     // Inline valueOf() methods now.
  2080     inline_boxing_calls(igvn);
  2082     if (AlwaysIncrementalInline) {
  2083       inline_incrementally(igvn);
  2086     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
  2088     if (failing())  return;
  2091   // Remove the speculative part of types and clean up the graph from
  2092   // the extra CastPP nodes whose only purpose is to carry them. Do
  2093   // that early so that optimizations are not disrupted by the extra
  2094   // CastPP nodes.
  2095   remove_speculative_types(igvn);
  2097   // No more new expensive nodes will be added to the list from here
  2098   // so keep only the actual candidates for optimizations.
  2099   cleanup_expensive_nodes(igvn);
  2101   // Perform escape analysis
  2102   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
  2103     if (has_loops()) {
  2104       // Cleanup graph (remove dead nodes).
  2105       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2106       PhaseIdealLoop ideal_loop( igvn, false, true );
  2107       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
  2108       if (failing())  return;
  2110     ConnectionGraph::do_analysis(this, &igvn);
  2112     if (failing())  return;
  2114     // Optimize out fields loads from scalar replaceable allocations.
  2115     igvn.optimize();
  2116     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
  2118     if (failing())  return;
  2120     if (congraph() != NULL && macro_count() > 0) {
  2121       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
  2122       PhaseMacroExpand mexp(igvn);
  2123       mexp.eliminate_macro_nodes();
  2124       igvn.set_delay_transform(false);
  2126       igvn.optimize();
  2127       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
  2129       if (failing())  return;
  2133   // Loop transforms on the ideal graph.  Range Check Elimination,
  2134   // peeling, unrolling, etc.
  2136   // Set loop opts counter
  2137   loop_opts_cnt = num_loop_opts();
  2138   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  2140       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2141       PhaseIdealLoop ideal_loop( igvn, true );
  2142       loop_opts_cnt--;
  2143       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
  2144       if (failing())  return;
  2146     // Loop opts pass if partial peeling occurred in previous pass
  2147     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  2148       TracePhase t3("idealLoop", &_t_idealLoop, true);
  2149       PhaseIdealLoop ideal_loop( igvn, false );
  2150       loop_opts_cnt--;
  2151       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
  2152       if (failing())  return;
  2154     // Loop opts pass for loop-unrolling before CCP
  2155     if(major_progress() && (loop_opts_cnt > 0)) {
  2156       TracePhase t4("idealLoop", &_t_idealLoop, true);
  2157       PhaseIdealLoop ideal_loop( igvn, false );
  2158       loop_opts_cnt--;
  2159       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
  2161     if (!failing()) {
  2162       // Verify that last round of loop opts produced a valid graph
  2163       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2164       PhaseIdealLoop::verify(igvn);
  2167   if (failing())  return;
  2169   // Conditional Constant Propagation;
  2170   PhaseCCP ccp( &igvn );
  2171   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  2173     TracePhase t2("ccp", &_t_ccp, true);
  2174     ccp.do_transform();
  2176   print_method(PHASE_CPP1, 2);
  2178   assert( true, "Break here to ccp.dump_old2new_map()");
  2180   // Iterative Global Value Numbering, including ideal transforms
  2182     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  2183     igvn = ccp;
  2184     igvn.optimize();
  2187   print_method(PHASE_ITER_GVN2, 2);
  2189   if (failing())  return;
  2191   // Loop transforms on the ideal graph.  Range Check Elimination,
  2192   // peeling, unrolling, etc.
  2193   if(loop_opts_cnt > 0) {
  2194     debug_only( int cnt = 0; );
  2195     while(major_progress() && (loop_opts_cnt > 0)) {
  2196       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2197       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  2198       PhaseIdealLoop ideal_loop( igvn, true);
  2199       loop_opts_cnt--;
  2200       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
  2201       if (failing())  return;
  2206     // Verify that all previous optimizations produced a valid graph
  2207     // at least to this point, even if no loop optimizations were done.
  2208     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2209     PhaseIdealLoop::verify(igvn);
  2213     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  2214     PhaseMacroExpand  mex(igvn);
  2215     if (mex.expand_macro_nodes()) {
  2216       assert(failing(), "must bail out w/ explicit message");
  2217       return;
  2221  } // (End scope of igvn; run destructor if necessary for asserts.)
  2223   dump_inlining();
  2224   // A method with only infinite loops has no edges entering loops from root
  2226     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  2227     if (final_graph_reshaping()) {
  2228       assert(failing(), "must bail out w/ explicit message");
  2229       return;
  2233   print_method(PHASE_OPTIMIZE_FINISHED, 2);
  2237 //------------------------------Code_Gen---------------------------------------
  2238 // Given a graph, generate code for it
  2239 void Compile::Code_Gen() {
  2240   if (failing()) {
  2241     return;
  2244   // Perform instruction selection.  You might think we could reclaim Matcher
  2245   // memory PDQ, but actually the Matcher is used in generating spill code.
  2246   // Internals of the Matcher (including some VectorSets) must remain live
  2247   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  2248   // set a bit in reclaimed memory.
  2250   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2251   // nodes.  Mapping is only valid at the root of each matched subtree.
  2252   NOT_PRODUCT( verify_graph_edges(); )
  2254   Matcher matcher;
  2255   _matcher = &matcher;
  2257     TracePhase t2("matcher", &_t_matcher, true);
  2258     matcher.match();
  2260   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2261   // nodes.  Mapping is only valid at the root of each matched subtree.
  2262   NOT_PRODUCT( verify_graph_edges(); )
  2264   // If you have too many nodes, or if matching has failed, bail out
  2265   check_node_count(0, "out of nodes matching instructions");
  2266   if (failing()) {
  2267     return;
  2270   // Build a proper-looking CFG
  2271   PhaseCFG cfg(node_arena(), root(), matcher);
  2272   _cfg = &cfg;
  2274     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  2275     bool success = cfg.do_global_code_motion();
  2276     if (!success) {
  2277       return;
  2280     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
  2281     NOT_PRODUCT( verify_graph_edges(); )
  2282     debug_only( cfg.verify(); )
  2285   PhaseChaitin regalloc(unique(), cfg, matcher);
  2286   _regalloc = &regalloc;
  2288     TracePhase t2("regalloc", &_t_registerAllocation, true);
  2289     // Perform register allocation.  After Chaitin, use-def chains are
  2290     // no longer accurate (at spill code) and so must be ignored.
  2291     // Node->LRG->reg mappings are still accurate.
  2292     _regalloc->Register_Allocate();
  2294     // Bail out if the allocator builds too many nodes
  2295     if (failing()) {
  2296       return;
  2300   // Prior to register allocation we kept empty basic blocks in case the
  2301   // the allocator needed a place to spill.  After register allocation we
  2302   // are not adding any new instructions.  If any basic block is empty, we
  2303   // can now safely remove it.
  2305     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  2306     cfg.remove_empty_blocks();
  2307     if (do_freq_based_layout()) {
  2308       PhaseBlockLayout layout(cfg);
  2309     } else {
  2310       cfg.set_loop_alignment();
  2312     cfg.fixup_flow();
  2315   // Apply peephole optimizations
  2316   if( OptoPeephole ) {
  2317     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  2318     PhasePeephole peep( _regalloc, cfg);
  2319     peep.do_transform();
  2322   // Do late expand if CPU requires this.
  2323   if (Matcher::require_postalloc_expand) {
  2324     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
  2325     cfg.postalloc_expand(_regalloc);
  2328   // Convert Nodes to instruction bits in a buffer
  2330     // %%%% workspace merge brought two timers together for one job
  2331     TracePhase t2a("output", &_t_output, true);
  2332     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  2333     Output();
  2336   print_method(PHASE_FINAL_CODE);
  2338   // He's dead, Jim.
  2339   _cfg     = (PhaseCFG*)0xdeadbeef;
  2340   _regalloc = (PhaseChaitin*)0xdeadbeef;
  2344 //------------------------------dump_asm---------------------------------------
  2345 // Dump formatted assembly
  2346 #ifndef PRODUCT
  2347 void Compile::dump_asm(int *pcs, uint pc_limit) {
  2348   bool cut_short = false;
  2349   tty->print_cr("#");
  2350   tty->print("#  ");  _tf->dump();  tty->cr();
  2351   tty->print_cr("#");
  2353   // For all blocks
  2354   int pc = 0x0;                 // Program counter
  2355   char starts_bundle = ' ';
  2356   _regalloc->dump_frame();
  2358   Node *n = NULL;
  2359   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  2360     if (VMThread::should_terminate()) {
  2361       cut_short = true;
  2362       break;
  2364     Block* block = _cfg->get_block(i);
  2365     if (block->is_connector() && !Verbose) {
  2366       continue;
  2368     n = block->head();
  2369     if (pcs && n->_idx < pc_limit) {
  2370       tty->print("%3.3x   ", pcs[n->_idx]);
  2371     } else {
  2372       tty->print("      ");
  2374     block->dump_head(_cfg);
  2375     if (block->is_connector()) {
  2376       tty->print_cr("        # Empty connector block");
  2377     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  2378       tty->print_cr("        # Block is sole successor of call");
  2381     // For all instructions
  2382     Node *delay = NULL;
  2383     for (uint j = 0; j < block->number_of_nodes(); j++) {
  2384       if (VMThread::should_terminate()) {
  2385         cut_short = true;
  2386         break;
  2388       n = block->get_node(j);
  2389       if (valid_bundle_info(n)) {
  2390         Bundle* bundle = node_bundling(n);
  2391         if (bundle->used_in_unconditional_delay()) {
  2392           delay = n;
  2393           continue;
  2395         if (bundle->starts_bundle()) {
  2396           starts_bundle = '+';
  2400       if (WizardMode) {
  2401         n->dump();
  2404       if( !n->is_Region() &&    // Dont print in the Assembly
  2405           !n->is_Phi() &&       // a few noisely useless nodes
  2406           !n->is_Proj() &&
  2407           !n->is_MachTemp() &&
  2408           !n->is_SafePointScalarObject() &&
  2409           !n->is_Catch() &&     // Would be nice to print exception table targets
  2410           !n->is_MergeMem() &&  // Not very interesting
  2411           !n->is_top() &&       // Debug info table constants
  2412           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  2413           ) {
  2414         if (pcs && n->_idx < pc_limit)
  2415           tty->print("%3.3x", pcs[n->_idx]);
  2416         else
  2417           tty->print("   ");
  2418         tty->print(" %c ", starts_bundle);
  2419         starts_bundle = ' ';
  2420         tty->print("\t");
  2421         n->format(_regalloc, tty);
  2422         tty->cr();
  2425       // If we have an instruction with a delay slot, and have seen a delay,
  2426       // then back up and print it
  2427       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  2428         assert(delay != NULL, "no unconditional delay instruction");
  2429         if (WizardMode) delay->dump();
  2431         if (node_bundling(delay)->starts_bundle())
  2432           starts_bundle = '+';
  2433         if (pcs && n->_idx < pc_limit)
  2434           tty->print("%3.3x", pcs[n->_idx]);
  2435         else
  2436           tty->print("   ");
  2437         tty->print(" %c ", starts_bundle);
  2438         starts_bundle = ' ';
  2439         tty->print("\t");
  2440         delay->format(_regalloc, tty);
  2441         tty->cr();
  2442         delay = NULL;
  2445       // Dump the exception table as well
  2446       if( n->is_Catch() && (Verbose || WizardMode) ) {
  2447         // Print the exception table for this offset
  2448         _handler_table.print_subtable_for(pc);
  2452     if (pcs && n->_idx < pc_limit)
  2453       tty->print_cr("%3.3x", pcs[n->_idx]);
  2454     else
  2455       tty->cr();
  2457     assert(cut_short || delay == NULL, "no unconditional delay branch");
  2459   } // End of per-block dump
  2460   tty->cr();
  2462   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  2464 #endif
  2466 //------------------------------Final_Reshape_Counts---------------------------
  2467 // This class defines counters to help identify when a method
  2468 // may/must be executed using hardware with only 24-bit precision.
  2469 struct Final_Reshape_Counts : public StackObj {
  2470   int  _call_count;             // count non-inlined 'common' calls
  2471   int  _float_count;            // count float ops requiring 24-bit precision
  2472   int  _double_count;           // count double ops requiring more precision
  2473   int  _java_call_count;        // count non-inlined 'java' calls
  2474   int  _inner_loop_count;       // count loops which need alignment
  2475   VectorSet _visited;           // Visitation flags
  2476   Node_List _tests;             // Set of IfNodes & PCTableNodes
  2478   Final_Reshape_Counts() :
  2479     _call_count(0), _float_count(0), _double_count(0),
  2480     _java_call_count(0), _inner_loop_count(0),
  2481     _visited( Thread::current()->resource_area() ) { }
  2483   void inc_call_count  () { _call_count  ++; }
  2484   void inc_float_count () { _float_count ++; }
  2485   void inc_double_count() { _double_count++; }
  2486   void inc_java_call_count() { _java_call_count++; }
  2487   void inc_inner_loop_count() { _inner_loop_count++; }
  2489   int  get_call_count  () const { return _call_count  ; }
  2490   int  get_float_count () const { return _float_count ; }
  2491   int  get_double_count() const { return _double_count; }
  2492   int  get_java_call_count() const { return _java_call_count; }
  2493   int  get_inner_loop_count() const { return _inner_loop_count; }
  2494 };
  2496 #ifdef ASSERT
  2497 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  2498   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  2499   // Make sure the offset goes inside the instance layout.
  2500   return k->contains_field_offset(tp->offset());
  2501   // Note that OffsetBot and OffsetTop are very negative.
  2503 #endif
  2505 // Eliminate trivially redundant StoreCMs and accumulate their
  2506 // precedence edges.
  2507 void Compile::eliminate_redundant_card_marks(Node* n) {
  2508   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
  2509   if (n->in(MemNode::Address)->outcnt() > 1) {
  2510     // There are multiple users of the same address so it might be
  2511     // possible to eliminate some of the StoreCMs
  2512     Node* mem = n->in(MemNode::Memory);
  2513     Node* adr = n->in(MemNode::Address);
  2514     Node* val = n->in(MemNode::ValueIn);
  2515     Node* prev = n;
  2516     bool done = false;
  2517     // Walk the chain of StoreCMs eliminating ones that match.  As
  2518     // long as it's a chain of single users then the optimization is
  2519     // safe.  Eliminating partially redundant StoreCMs would require
  2520     // cloning copies down the other paths.
  2521     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
  2522       if (adr == mem->in(MemNode::Address) &&
  2523           val == mem->in(MemNode::ValueIn)) {
  2524         // redundant StoreCM
  2525         if (mem->req() > MemNode::OopStore) {
  2526           // Hasn't been processed by this code yet.
  2527           n->add_prec(mem->in(MemNode::OopStore));
  2528         } else {
  2529           // Already converted to precedence edge
  2530           for (uint i = mem->req(); i < mem->len(); i++) {
  2531             // Accumulate any precedence edges
  2532             if (mem->in(i) != NULL) {
  2533               n->add_prec(mem->in(i));
  2536           // Everything above this point has been processed.
  2537           done = true;
  2539         // Eliminate the previous StoreCM
  2540         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
  2541         assert(mem->outcnt() == 0, "should be dead");
  2542         mem->disconnect_inputs(NULL, this);
  2543       } else {
  2544         prev = mem;
  2546       mem = prev->in(MemNode::Memory);
  2551 //------------------------------final_graph_reshaping_impl----------------------
  2552 // Implement items 1-5 from final_graph_reshaping below.
  2553 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
  2555   if ( n->outcnt() == 0 ) return; // dead node
  2556   uint nop = n->Opcode();
  2558   // Check for 2-input instruction with "last use" on right input.
  2559   // Swap to left input.  Implements item (2).
  2560   if( n->req() == 3 &&          // two-input instruction
  2561       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  2562       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  2563       n->in(2)->outcnt() == 1 &&// right use IS a last use
  2564       !n->in(2)->is_Con() ) {   // right use is not a constant
  2565     // Check for commutative opcode
  2566     switch( nop ) {
  2567     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  2568     case Op_MaxI:  case Op_MinI:
  2569     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  2570     case Op_AndL:  case Op_XorL:  case Op_OrL:
  2571     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  2572       // Move "last use" input to left by swapping inputs
  2573       n->swap_edges(1, 2);
  2574       break;
  2576     default:
  2577       break;
  2581 #ifdef ASSERT
  2582   if( n->is_Mem() ) {
  2583     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
  2584     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2585             // oop will be recorded in oop map if load crosses safepoint
  2586             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2587                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2588             "raw memory operations should have control edge");
  2590 #endif
  2591   // Count FPU ops and common calls, implements item (3)
  2592   switch( nop ) {
  2593   // Count all float operations that may use FPU
  2594   case Op_AddF:
  2595   case Op_SubF:
  2596   case Op_MulF:
  2597   case Op_DivF:
  2598   case Op_NegF:
  2599   case Op_ModF:
  2600   case Op_ConvI2F:
  2601   case Op_ConF:
  2602   case Op_CmpF:
  2603   case Op_CmpF3:
  2604   // case Op_ConvL2F: // longs are split into 32-bit halves
  2605     frc.inc_float_count();
  2606     break;
  2608   case Op_ConvF2D:
  2609   case Op_ConvD2F:
  2610     frc.inc_float_count();
  2611     frc.inc_double_count();
  2612     break;
  2614   // Count all double operations that may use FPU
  2615   case Op_AddD:
  2616   case Op_SubD:
  2617   case Op_MulD:
  2618   case Op_DivD:
  2619   case Op_NegD:
  2620   case Op_ModD:
  2621   case Op_ConvI2D:
  2622   case Op_ConvD2I:
  2623   // case Op_ConvL2D: // handled by leaf call
  2624   // case Op_ConvD2L: // handled by leaf call
  2625   case Op_ConD:
  2626   case Op_CmpD:
  2627   case Op_CmpD3:
  2628     frc.inc_double_count();
  2629     break;
  2630   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2631   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2632   case Op_Opaque3:
  2633     n->subsume_by(n->in(1), this);
  2634     break;
  2635   case Op_CallStaticJava:
  2636   case Op_CallJava:
  2637   case Op_CallDynamicJava:
  2638     frc.inc_java_call_count(); // Count java call site;
  2639   case Op_CallRuntime:
  2640   case Op_CallLeaf:
  2641   case Op_CallLeafNoFP: {
  2642     assert( n->is_Call(), "" );
  2643     CallNode *call = n->as_Call();
  2644     // Count call sites where the FP mode bit would have to be flipped.
  2645     // Do not count uncommon runtime calls:
  2646     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2647     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2648     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2649       frc.inc_call_count();   // Count the call site
  2650     } else {                  // See if uncommon argument is shared
  2651       Node *n = call->in(TypeFunc::Parms);
  2652       int nop = n->Opcode();
  2653       // Clone shared simple arguments to uncommon calls, item (1).
  2654       if( n->outcnt() > 1 &&
  2655           !n->is_Proj() &&
  2656           nop != Op_CreateEx &&
  2657           nop != Op_CheckCastPP &&
  2658           nop != Op_DecodeN &&
  2659           nop != Op_DecodeNKlass &&
  2660           !n->is_Mem() ) {
  2661         Node *x = n->clone();
  2662         call->set_req( TypeFunc::Parms, x );
  2665     break;
  2668   case Op_StoreD:
  2669   case Op_LoadD:
  2670   case Op_LoadD_unaligned:
  2671     frc.inc_double_count();
  2672     goto handle_mem;
  2673   case Op_StoreF:
  2674   case Op_LoadF:
  2675     frc.inc_float_count();
  2676     goto handle_mem;
  2678   case Op_StoreCM:
  2680       // Convert OopStore dependence into precedence edge
  2681       Node* prec = n->in(MemNode::OopStore);
  2682       n->del_req(MemNode::OopStore);
  2683       n->add_prec(prec);
  2684       eliminate_redundant_card_marks(n);
  2687     // fall through
  2689   case Op_StoreB:
  2690   case Op_StoreC:
  2691   case Op_StorePConditional:
  2692   case Op_StoreI:
  2693   case Op_StoreL:
  2694   case Op_StoreIConditional:
  2695   case Op_StoreLConditional:
  2696   case Op_CompareAndSwapI:
  2697   case Op_CompareAndSwapL:
  2698   case Op_CompareAndSwapP:
  2699   case Op_CompareAndSwapN:
  2700   case Op_GetAndAddI:
  2701   case Op_GetAndAddL:
  2702   case Op_GetAndSetI:
  2703   case Op_GetAndSetL:
  2704   case Op_GetAndSetP:
  2705   case Op_GetAndSetN:
  2706   case Op_StoreP:
  2707   case Op_StoreN:
  2708   case Op_StoreNKlass:
  2709   case Op_LoadB:
  2710   case Op_LoadUB:
  2711   case Op_LoadUS:
  2712   case Op_LoadI:
  2713   case Op_LoadKlass:
  2714   case Op_LoadNKlass:
  2715   case Op_LoadL:
  2716   case Op_LoadL_unaligned:
  2717   case Op_LoadPLocked:
  2718   case Op_LoadP:
  2719   case Op_LoadN:
  2720   case Op_LoadRange:
  2721   case Op_LoadS: {
  2722   handle_mem:
  2723 #ifdef ASSERT
  2724     if( VerifyOptoOopOffsets ) {
  2725       assert( n->is_Mem(), "" );
  2726       MemNode *mem  = (MemNode*)n;
  2727       // Check to see if address types have grounded out somehow.
  2728       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2729       assert( !tp || oop_offset_is_sane(tp), "" );
  2731 #endif
  2732     break;
  2735   case Op_AddP: {               // Assert sane base pointers
  2736     Node *addp = n->in(AddPNode::Address);
  2737     assert( !addp->is_AddP() ||
  2738             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2739             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2740             "Base pointers must match" );
  2741 #ifdef _LP64
  2742     if ((UseCompressedOops || UseCompressedClassPointers) &&
  2743         addp->Opcode() == Op_ConP &&
  2744         addp == n->in(AddPNode::Base) &&
  2745         n->in(AddPNode::Offset)->is_Con()) {
  2746       // Use addressing with narrow klass to load with offset on x86.
  2747       // On sparc loading 32-bits constant and decoding it have less
  2748       // instructions (4) then load 64-bits constant (7).
  2749       // Do this transformation here since IGVN will convert ConN back to ConP.
  2750       const Type* t = addp->bottom_type();
  2751       if (t->isa_oopptr() || t->isa_klassptr()) {
  2752         Node* nn = NULL;
  2754         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
  2756         // Look for existing ConN node of the same exact type.
  2757         Node* r  = root();
  2758         uint cnt = r->outcnt();
  2759         for (uint i = 0; i < cnt; i++) {
  2760           Node* m = r->raw_out(i);
  2761           if (m!= NULL && m->Opcode() == op &&
  2762               m->bottom_type()->make_ptr() == t) {
  2763             nn = m;
  2764             break;
  2767         if (nn != NULL) {
  2768           // Decode a narrow oop to match address
  2769           // [R12 + narrow_oop_reg<<3 + offset]
  2770           if (t->isa_oopptr()) {
  2771             nn = new (this) DecodeNNode(nn, t);
  2772           } else {
  2773             nn = new (this) DecodeNKlassNode(nn, t);
  2775           n->set_req(AddPNode::Base, nn);
  2776           n->set_req(AddPNode::Address, nn);
  2777           if (addp->outcnt() == 0) {
  2778             addp->disconnect_inputs(NULL, this);
  2783 #endif
  2784     break;
  2787 #ifdef _LP64
  2788   case Op_CastPP:
  2789     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2790       Node* in1 = n->in(1);
  2791       const Type* t = n->bottom_type();
  2792       Node* new_in1 = in1->clone();
  2793       new_in1->as_DecodeN()->set_type(t);
  2795       if (!Matcher::narrow_oop_use_complex_address()) {
  2796         //
  2797         // x86, ARM and friends can handle 2 adds in addressing mode
  2798         // and Matcher can fold a DecodeN node into address by using
  2799         // a narrow oop directly and do implicit NULL check in address:
  2800         //
  2801         // [R12 + narrow_oop_reg<<3 + offset]
  2802         // NullCheck narrow_oop_reg
  2803         //
  2804         // On other platforms (Sparc) we have to keep new DecodeN node and
  2805         // use it to do implicit NULL check in address:
  2806         //
  2807         // decode_not_null narrow_oop_reg, base_reg
  2808         // [base_reg + offset]
  2809         // NullCheck base_reg
  2810         //
  2811         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2812         // to keep the information to which NULL check the new DecodeN node
  2813         // corresponds to use it as value in implicit_null_check().
  2814         //
  2815         new_in1->set_req(0, n->in(0));
  2818       n->subsume_by(new_in1, this);
  2819       if (in1->outcnt() == 0) {
  2820         in1->disconnect_inputs(NULL, this);
  2823     break;
  2825   case Op_CmpP:
  2826     // Do this transformation here to preserve CmpPNode::sub() and
  2827     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2828     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
  2829       Node* in1 = n->in(1);
  2830       Node* in2 = n->in(2);
  2831       if (!in1->is_DecodeNarrowPtr()) {
  2832         in2 = in1;
  2833         in1 = n->in(2);
  2835       assert(in1->is_DecodeNarrowPtr(), "sanity");
  2837       Node* new_in2 = NULL;
  2838       if (in2->is_DecodeNarrowPtr()) {
  2839         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
  2840         new_in2 = in2->in(1);
  2841       } else if (in2->Opcode() == Op_ConP) {
  2842         const Type* t = in2->bottom_type();
  2843         if (t == TypePtr::NULL_PTR) {
  2844           assert(in1->is_DecodeN(), "compare klass to null?");
  2845           // Don't convert CmpP null check into CmpN if compressed
  2846           // oops implicit null check is not generated.
  2847           // This will allow to generate normal oop implicit null check.
  2848           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2849             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
  2850           //
  2851           // This transformation together with CastPP transformation above
  2852           // will generated code for implicit NULL checks for compressed oops.
  2853           //
  2854           // The original code after Optimize()
  2855           //
  2856           //    LoadN memory, narrow_oop_reg
  2857           //    decode narrow_oop_reg, base_reg
  2858           //    CmpP base_reg, NULL
  2859           //    CastPP base_reg // NotNull
  2860           //    Load [base_reg + offset], val_reg
  2861           //
  2862           // after these transformations will be
  2863           //
  2864           //    LoadN memory, narrow_oop_reg
  2865           //    CmpN narrow_oop_reg, NULL
  2866           //    decode_not_null narrow_oop_reg, base_reg
  2867           //    Load [base_reg + offset], val_reg
  2868           //
  2869           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2870           // since narrow oops can be used in debug info now (see the code in
  2871           // final_graph_reshaping_walk()).
  2872           //
  2873           // At the end the code will be matched to
  2874           // on x86:
  2875           //
  2876           //    Load_narrow_oop memory, narrow_oop_reg
  2877           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2878           //    NullCheck narrow_oop_reg
  2879           //
  2880           // and on sparc:
  2881           //
  2882           //    Load_narrow_oop memory, narrow_oop_reg
  2883           //    decode_not_null narrow_oop_reg, base_reg
  2884           //    Load [base_reg + offset], val_reg
  2885           //    NullCheck base_reg
  2886           //
  2887         } else if (t->isa_oopptr()) {
  2888           new_in2 = ConNode::make(this, t->make_narrowoop());
  2889         } else if (t->isa_klassptr()) {
  2890           new_in2 = ConNode::make(this, t->make_narrowklass());
  2893       if (new_in2 != NULL) {
  2894         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
  2895         n->subsume_by(cmpN, this);
  2896         if (in1->outcnt() == 0) {
  2897           in1->disconnect_inputs(NULL, this);
  2899         if (in2->outcnt() == 0) {
  2900           in2->disconnect_inputs(NULL, this);
  2904     break;
  2906   case Op_DecodeN:
  2907   case Op_DecodeNKlass:
  2908     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
  2909     // DecodeN could be pinned when it can't be fold into
  2910     // an address expression, see the code for Op_CastPP above.
  2911     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
  2912     break;
  2914   case Op_EncodeP:
  2915   case Op_EncodePKlass: {
  2916     Node* in1 = n->in(1);
  2917     if (in1->is_DecodeNarrowPtr()) {
  2918       n->subsume_by(in1->in(1), this);
  2919     } else if (in1->Opcode() == Op_ConP) {
  2920       const Type* t = in1->bottom_type();
  2921       if (t == TypePtr::NULL_PTR) {
  2922         assert(t->isa_oopptr(), "null klass?");
  2923         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
  2924       } else if (t->isa_oopptr()) {
  2925         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
  2926       } else if (t->isa_klassptr()) {
  2927         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
  2930     if (in1->outcnt() == 0) {
  2931       in1->disconnect_inputs(NULL, this);
  2933     break;
  2936   case Op_Proj: {
  2937     if (OptimizeStringConcat) {
  2938       ProjNode* p = n->as_Proj();
  2939       if (p->_is_io_use) {
  2940         // Separate projections were used for the exception path which
  2941         // are normally removed by a late inline.  If it wasn't inlined
  2942         // then they will hang around and should just be replaced with
  2943         // the original one.
  2944         Node* proj = NULL;
  2945         // Replace with just one
  2946         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  2947           Node *use = i.get();
  2948           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  2949             proj = use;
  2950             break;
  2953         assert(proj != NULL, "must be found");
  2954         p->subsume_by(proj, this);
  2957     break;
  2960   case Op_Phi:
  2961     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
  2962       // The EncodeP optimization may create Phi with the same edges
  2963       // for all paths. It is not handled well by Register Allocator.
  2964       Node* unique_in = n->in(1);
  2965       assert(unique_in != NULL, "");
  2966       uint cnt = n->req();
  2967       for (uint i = 2; i < cnt; i++) {
  2968         Node* m = n->in(i);
  2969         assert(m != NULL, "");
  2970         if (unique_in != m)
  2971           unique_in = NULL;
  2973       if (unique_in != NULL) {
  2974         n->subsume_by(unique_in, this);
  2977     break;
  2979 #endif
  2981   case Op_ModI:
  2982     if (UseDivMod) {
  2983       // Check if a%b and a/b both exist
  2984       Node* d = n->find_similar(Op_DivI);
  2985       if (d) {
  2986         // Replace them with a fused divmod if supported
  2987         if (Matcher::has_match_rule(Op_DivModI)) {
  2988           DivModINode* divmod = DivModINode::make(this, n);
  2989           d->subsume_by(divmod->div_proj(), this);
  2990           n->subsume_by(divmod->mod_proj(), this);
  2991         } else {
  2992           // replace a%b with a-((a/b)*b)
  2993           Node* mult = new (this) MulINode(d, d->in(2));
  2994           Node* sub  = new (this) SubINode(d->in(1), mult);
  2995           n->subsume_by(sub, this);
  2999     break;
  3001   case Op_ModL:
  3002     if (UseDivMod) {
  3003       // Check if a%b and a/b both exist
  3004       Node* d = n->find_similar(Op_DivL);
  3005       if (d) {
  3006         // Replace them with a fused divmod if supported
  3007         if (Matcher::has_match_rule(Op_DivModL)) {
  3008           DivModLNode* divmod = DivModLNode::make(this, n);
  3009           d->subsume_by(divmod->div_proj(), this);
  3010           n->subsume_by(divmod->mod_proj(), this);
  3011         } else {
  3012           // replace a%b with a-((a/b)*b)
  3013           Node* mult = new (this) MulLNode(d, d->in(2));
  3014           Node* sub  = new (this) SubLNode(d->in(1), mult);
  3015           n->subsume_by(sub, this);
  3019     break;
  3021   case Op_LoadVector:
  3022   case Op_StoreVector:
  3023     break;
  3025   case Op_PackB:
  3026   case Op_PackS:
  3027   case Op_PackI:
  3028   case Op_PackF:
  3029   case Op_PackL:
  3030   case Op_PackD:
  3031     if (n->req()-1 > 2) {
  3032       // Replace many operand PackNodes with a binary tree for matching
  3033       PackNode* p = (PackNode*) n;
  3034       Node* btp = p->binary_tree_pack(this, 1, n->req());
  3035       n->subsume_by(btp, this);
  3037     break;
  3038   case Op_Loop:
  3039   case Op_CountedLoop:
  3040     if (n->as_Loop()->is_inner_loop()) {
  3041       frc.inc_inner_loop_count();
  3043     break;
  3044   case Op_LShiftI:
  3045   case Op_RShiftI:
  3046   case Op_URShiftI:
  3047   case Op_LShiftL:
  3048   case Op_RShiftL:
  3049   case Op_URShiftL:
  3050     if (Matcher::need_masked_shift_count) {
  3051       // The cpu's shift instructions don't restrict the count to the
  3052       // lower 5/6 bits. We need to do the masking ourselves.
  3053       Node* in2 = n->in(2);
  3054       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
  3055       const TypeInt* t = in2->find_int_type();
  3056       if (t != NULL && t->is_con()) {
  3057         juint shift = t->get_con();
  3058         if (shift > mask) { // Unsigned cmp
  3059           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
  3061       } else {
  3062         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
  3063           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
  3064           n->set_req(2, shift);
  3067       if (in2->outcnt() == 0) { // Remove dead node
  3068         in2->disconnect_inputs(NULL, this);
  3071     break;
  3072   case Op_MemBarStoreStore:
  3073   case Op_MemBarRelease:
  3074     // Break the link with AllocateNode: it is no longer useful and
  3075     // confuses register allocation.
  3076     if (n->req() > MemBarNode::Precedent) {
  3077       n->set_req(MemBarNode::Precedent, top());
  3079     break;
  3080   default:
  3081     assert( !n->is_Call(), "" );
  3082     assert( !n->is_Mem(), "" );
  3083     break;
  3086   // Collect CFG split points
  3087   if (n->is_MultiBranch())
  3088     frc._tests.push(n);
  3091 //------------------------------final_graph_reshaping_walk---------------------
  3092 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  3093 // requires that the walk visits a node's inputs before visiting the node.
  3094 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  3095   ResourceArea *area = Thread::current()->resource_area();
  3096   Unique_Node_List sfpt(area);
  3098   frc._visited.set(root->_idx); // first, mark node as visited
  3099   uint cnt = root->req();
  3100   Node *n = root;
  3101   uint  i = 0;
  3102   while (true) {
  3103     if (i < cnt) {
  3104       // Place all non-visited non-null inputs onto stack
  3105       Node* m = n->in(i);
  3106       ++i;
  3107       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  3108         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
  3109           // compute worst case interpreter size in case of a deoptimization
  3110           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
  3112           sfpt.push(m);
  3114         cnt = m->req();
  3115         nstack.push(n, i); // put on stack parent and next input's index
  3116         n = m;
  3117         i = 0;
  3119     } else {
  3120       // Now do post-visit work
  3121       final_graph_reshaping_impl( n, frc );
  3122       if (nstack.is_empty())
  3123         break;             // finished
  3124       n = nstack.node();   // Get node from stack
  3125       cnt = n->req();
  3126       i = nstack.index();
  3127       nstack.pop();        // Shift to the next node on stack
  3131   // Skip next transformation if compressed oops are not used.
  3132   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
  3133       (!UseCompressedOops && !UseCompressedClassPointers))
  3134     return;
  3136   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
  3137   // It could be done for an uncommon traps or any safepoints/calls
  3138   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
  3139   while (sfpt.size() > 0) {
  3140     n = sfpt.pop();
  3141     JVMState *jvms = n->as_SafePoint()->jvms();
  3142     assert(jvms != NULL, "sanity");
  3143     int start = jvms->debug_start();
  3144     int end   = n->req();
  3145     bool is_uncommon = (n->is_CallStaticJava() &&
  3146                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  3147     for (int j = start; j < end; j++) {
  3148       Node* in = n->in(j);
  3149       if (in->is_DecodeNarrowPtr()) {
  3150         bool safe_to_skip = true;
  3151         if (!is_uncommon ) {
  3152           // Is it safe to skip?
  3153           for (uint i = 0; i < in->outcnt(); i++) {
  3154             Node* u = in->raw_out(i);
  3155             if (!u->is_SafePoint() ||
  3156                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  3157               safe_to_skip = false;
  3161         if (safe_to_skip) {
  3162           n->set_req(j, in->in(1));
  3164         if (in->outcnt() == 0) {
  3165           in->disconnect_inputs(NULL, this);
  3172 //------------------------------final_graph_reshaping--------------------------
  3173 // Final Graph Reshaping.
  3174 //
  3175 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  3176 //     and not commoned up and forced early.  Must come after regular
  3177 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  3178 //     inputs to Loop Phis; these will be split by the allocator anyways.
  3179 //     Remove Opaque nodes.
  3180 // (2) Move last-uses by commutative operations to the left input to encourage
  3181 //     Intel update-in-place two-address operations and better register usage
  3182 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  3183 //     calls canonicalizing them back.
  3184 // (3) Count the number of double-precision FP ops, single-precision FP ops
  3185 //     and call sites.  On Intel, we can get correct rounding either by
  3186 //     forcing singles to memory (requires extra stores and loads after each
  3187 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  3188 //     clearing the mode bit around call sites).  The mode bit is only used
  3189 //     if the relative frequency of single FP ops to calls is low enough.
  3190 //     This is a key transform for SPEC mpeg_audio.
  3191 // (4) Detect infinite loops; blobs of code reachable from above but not
  3192 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  3193 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  3194 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  3195 //     Detection is by looking for IfNodes where only 1 projection is
  3196 //     reachable from below or CatchNodes missing some targets.
  3197 // (5) Assert for insane oop offsets in debug mode.
  3199 bool Compile::final_graph_reshaping() {
  3200   // an infinite loop may have been eliminated by the optimizer,
  3201   // in which case the graph will be empty.
  3202   if (root()->req() == 1) {
  3203     record_method_not_compilable("trivial infinite loop");
  3204     return true;
  3207   // Expensive nodes have their control input set to prevent the GVN
  3208   // from freely commoning them. There's no GVN beyond this point so
  3209   // no need to keep the control input. We want the expensive nodes to
  3210   // be freely moved to the least frequent code path by gcm.
  3211   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
  3212   for (int i = 0; i < expensive_count(); i++) {
  3213     _expensive_nodes->at(i)->set_req(0, NULL);
  3216   Final_Reshape_Counts frc;
  3218   // Visit everybody reachable!
  3219   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  3220   Node_Stack nstack(unique() >> 1);
  3221   final_graph_reshaping_walk(nstack, root(), frc);
  3223   // Check for unreachable (from below) code (i.e., infinite loops).
  3224   for( uint i = 0; i < frc._tests.size(); i++ ) {
  3225     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  3226     // Get number of CFG targets.
  3227     // Note that PCTables include exception targets after calls.
  3228     uint required_outcnt = n->required_outcnt();
  3229     if (n->outcnt() != required_outcnt) {
  3230       // Check for a few special cases.  Rethrow Nodes never take the
  3231       // 'fall-thru' path, so expected kids is 1 less.
  3232       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  3233         if (n->in(0)->in(0)->is_Call()) {
  3234           CallNode *call = n->in(0)->in(0)->as_Call();
  3235           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  3236             required_outcnt--;      // Rethrow always has 1 less kid
  3237           } else if (call->req() > TypeFunc::Parms &&
  3238                      call->is_CallDynamicJava()) {
  3239             // Check for null receiver. In such case, the optimizer has
  3240             // detected that the virtual call will always result in a null
  3241             // pointer exception. The fall-through projection of this CatchNode
  3242             // will not be populated.
  3243             Node *arg0 = call->in(TypeFunc::Parms);
  3244             if (arg0->is_Type() &&
  3245                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  3246               required_outcnt--;
  3248           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  3249                      call->req() > TypeFunc::Parms+1 &&
  3250                      call->is_CallStaticJava()) {
  3251             // Check for negative array length. In such case, the optimizer has
  3252             // detected that the allocation attempt will always result in an
  3253             // exception. There is no fall-through projection of this CatchNode .
  3254             Node *arg1 = call->in(TypeFunc::Parms+1);
  3255             if (arg1->is_Type() &&
  3256                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  3257               required_outcnt--;
  3262       // Recheck with a better notion of 'required_outcnt'
  3263       if (n->outcnt() != required_outcnt) {
  3264         record_method_not_compilable("malformed control flow");
  3265         return true;            // Not all targets reachable!
  3268     // Check that I actually visited all kids.  Unreached kids
  3269     // must be infinite loops.
  3270     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  3271       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  3272         record_method_not_compilable("infinite loop");
  3273         return true;            // Found unvisited kid; must be unreach
  3277   // If original bytecodes contained a mixture of floats and doubles
  3278   // check if the optimizer has made it homogenous, item (3).
  3279   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  3280       frc.get_float_count() > 32 &&
  3281       frc.get_double_count() == 0 &&
  3282       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  3283     set_24_bit_selection_and_mode( false,  true );
  3286   set_java_calls(frc.get_java_call_count());
  3287   set_inner_loops(frc.get_inner_loop_count());
  3289   // No infinite loops, no reason to bail out.
  3290   return false;
  3293 //-----------------------------too_many_traps----------------------------------
  3294 // Report if there are too many traps at the current method and bci.
  3295 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  3296 bool Compile::too_many_traps(ciMethod* method,
  3297                              int bci,
  3298                              Deoptimization::DeoptReason reason) {
  3299   ciMethodData* md = method->method_data();
  3300   if (md->is_empty()) {
  3301     // Assume the trap has not occurred, or that it occurred only
  3302     // because of a transient condition during start-up in the interpreter.
  3303     return false;
  3305   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3306   if (md->has_trap_at(bci, m, reason) != 0) {
  3307     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  3308     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3309     // assume the worst.
  3310     if (log())
  3311       log()->elem("observe trap='%s' count='%d'",
  3312                   Deoptimization::trap_reason_name(reason),
  3313                   md->trap_count(reason));
  3314     return true;
  3315   } else {
  3316     // Ignore method/bci and see if there have been too many globally.
  3317     return too_many_traps(reason, md);
  3321 // Less-accurate variant which does not require a method and bci.
  3322 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  3323                              ciMethodData* logmd) {
  3324   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
  3325     // Too many traps globally.
  3326     // Note that we use cumulative trap_count, not just md->trap_count.
  3327     if (log()) {
  3328       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  3329       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  3330                   Deoptimization::trap_reason_name(reason),
  3331                   mcount, trap_count(reason));
  3333     return true;
  3334   } else {
  3335     // The coast is clear.
  3336     return false;
  3340 //--------------------------too_many_recompiles--------------------------------
  3341 // Report if there are too many recompiles at the current method and bci.
  3342 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  3343 // Is not eager to return true, since this will cause the compiler to use
  3344 // Action_none for a trap point, to avoid too many recompilations.
  3345 bool Compile::too_many_recompiles(ciMethod* method,
  3346                                   int bci,
  3347                                   Deoptimization::DeoptReason reason) {
  3348   ciMethodData* md = method->method_data();
  3349   if (md->is_empty()) {
  3350     // Assume the trap has not occurred, or that it occurred only
  3351     // because of a transient condition during start-up in the interpreter.
  3352     return false;
  3354   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  3355   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  3356   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  3357   Deoptimization::DeoptReason per_bc_reason
  3358     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  3359   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3360   if ((per_bc_reason == Deoptimization::Reason_none
  3361        || md->has_trap_at(bci, m, reason) != 0)
  3362       // The trap frequency measure we care about is the recompile count:
  3363       && md->trap_recompiled_at(bci, m)
  3364       && md->overflow_recompile_count() >= bc_cutoff) {
  3365     // Do not emit a trap here if it has already caused recompilations.
  3366     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3367     // assume the worst.
  3368     if (log())
  3369       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  3370                   Deoptimization::trap_reason_name(reason),
  3371                   md->trap_count(reason),
  3372                   md->overflow_recompile_count());
  3373     return true;
  3374   } else if (trap_count(reason) != 0
  3375              && decompile_count() >= m_cutoff) {
  3376     // Too many recompiles globally, and we have seen this sort of trap.
  3377     // Use cumulative decompile_count, not just md->decompile_count.
  3378     if (log())
  3379       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  3380                   Deoptimization::trap_reason_name(reason),
  3381                   md->trap_count(reason), trap_count(reason),
  3382                   md->decompile_count(), decompile_count());
  3383     return true;
  3384   } else {
  3385     // The coast is clear.
  3386     return false;
  3390 // Compute when not to trap. Used by matching trap based nodes and
  3391 // NullCheck optimization.
  3392 void Compile::set_allowed_deopt_reasons() {
  3393   _allowed_reasons = 0;
  3394   if (is_method_compilation()) {
  3395     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
  3396       assert(rs < BitsPerInt, "recode bit map");
  3397       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
  3398         _allowed_reasons |= nth_bit(rs);
  3404 #ifndef PRODUCT
  3405 //------------------------------verify_graph_edges---------------------------
  3406 // Walk the Graph and verify that there is a one-to-one correspondence
  3407 // between Use-Def edges and Def-Use edges in the graph.
  3408 void Compile::verify_graph_edges(bool no_dead_code) {
  3409   if (VerifyGraphEdges) {
  3410     ResourceArea *area = Thread::current()->resource_area();
  3411     Unique_Node_List visited(area);
  3412     // Call recursive graph walk to check edges
  3413     _root->verify_edges(visited);
  3414     if (no_dead_code) {
  3415       // Now make sure that no visited node is used by an unvisited node.
  3416       bool dead_nodes = 0;
  3417       Unique_Node_List checked(area);
  3418       while (visited.size() > 0) {
  3419         Node* n = visited.pop();
  3420         checked.push(n);
  3421         for (uint i = 0; i < n->outcnt(); i++) {
  3422           Node* use = n->raw_out(i);
  3423           if (checked.member(use))  continue;  // already checked
  3424           if (visited.member(use))  continue;  // already in the graph
  3425           if (use->is_Con())        continue;  // a dead ConNode is OK
  3426           // At this point, we have found a dead node which is DU-reachable.
  3427           if (dead_nodes++ == 0)
  3428             tty->print_cr("*** Dead nodes reachable via DU edges:");
  3429           use->dump(2);
  3430           tty->print_cr("---");
  3431           checked.push(use);  // No repeats; pretend it is now checked.
  3434       assert(dead_nodes == 0, "using nodes must be reachable from root");
  3439 // Verify GC barriers consistency
  3440 // Currently supported:
  3441 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
  3442 void Compile::verify_barriers() {
  3443   if (UseG1GC) {
  3444     // Verify G1 pre-barriers
  3445     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
  3447     ResourceArea *area = Thread::current()->resource_area();
  3448     Unique_Node_List visited(area);
  3449     Node_List worklist(area);
  3450     // We're going to walk control flow backwards starting from the Root
  3451     worklist.push(_root);
  3452     while (worklist.size() > 0) {
  3453       Node* x = worklist.pop();
  3454       if (x == NULL || x == top()) continue;
  3455       if (visited.member(x)) {
  3456         continue;
  3457       } else {
  3458         visited.push(x);
  3461       if (x->is_Region()) {
  3462         for (uint i = 1; i < x->req(); i++) {
  3463           worklist.push(x->in(i));
  3465       } else {
  3466         worklist.push(x->in(0));
  3467         // We are looking for the pattern:
  3468         //                            /->ThreadLocal
  3469         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
  3470         //              \->ConI(0)
  3471         // We want to verify that the If and the LoadB have the same control
  3472         // See GraphKit::g1_write_barrier_pre()
  3473         if (x->is_If()) {
  3474           IfNode *iff = x->as_If();
  3475           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
  3476             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
  3477             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
  3478                 && cmp->in(1)->is_Load()) {
  3479               LoadNode* load = cmp->in(1)->as_Load();
  3480               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
  3481                   && load->in(2)->in(3)->is_Con()
  3482                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
  3484                 Node* if_ctrl = iff->in(0);
  3485                 Node* load_ctrl = load->in(0);
  3487                 if (if_ctrl != load_ctrl) {
  3488                   // Skip possible CProj->NeverBranch in infinite loops
  3489                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
  3490                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
  3491                     if_ctrl = if_ctrl->in(0)->in(0);
  3494                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
  3504 #endif
  3506 // The Compile object keeps track of failure reasons separately from the ciEnv.
  3507 // This is required because there is not quite a 1-1 relation between the
  3508 // ciEnv and its compilation task and the Compile object.  Note that one
  3509 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  3510 // to backtrack and retry without subsuming loads.  Other than this backtracking
  3511 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  3512 // by the logic in C2Compiler.
  3513 void Compile::record_failure(const char* reason) {
  3514   if (log() != NULL) {
  3515     log()->elem("failure reason='%s' phase='compile'", reason);
  3517   if (_failure_reason == NULL) {
  3518     // Record the first failure reason.
  3519     _failure_reason = reason;
  3522   EventCompilerFailure event;
  3523   if (event.should_commit()) {
  3524     event.set_compileID(Compile::compile_id());
  3525     event.set_failure(reason);
  3526     event.commit();
  3529   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  3530     C->print_method(PHASE_FAILURE);
  3532   _root = NULL;  // flush the graph, too
  3535 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  3536   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
  3537     _phase_name(name), _dolog(dolog)
  3539   if (dolog) {
  3540     C = Compile::current();
  3541     _log = C->log();
  3542   } else {
  3543     C = NULL;
  3544     _log = NULL;
  3546   if (_log != NULL) {
  3547     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3548     _log->stamp();
  3549     _log->end_head();
  3553 Compile::TracePhase::~TracePhase() {
  3555   C = Compile::current();
  3556   if (_dolog) {
  3557     _log = C->log();
  3558   } else {
  3559     _log = NULL;
  3562 #ifdef ASSERT
  3563   if (PrintIdealNodeCount) {
  3564     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
  3565                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
  3568   if (VerifyIdealNodeCount) {
  3569     Compile::current()->print_missing_nodes();
  3571 #endif
  3573   if (_log != NULL) {
  3574     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3578 //=============================================================================
  3579 // Two Constant's are equal when the type and the value are equal.
  3580 bool Compile::Constant::operator==(const Constant& other) {
  3581   if (type()          != other.type()         )  return false;
  3582   if (can_be_reused() != other.can_be_reused())  return false;
  3583   // For floating point values we compare the bit pattern.
  3584   switch (type()) {
  3585   case T_FLOAT:   return (_v._value.i == other._v._value.i);
  3586   case T_LONG:
  3587   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
  3588   case T_OBJECT:
  3589   case T_ADDRESS: return (_v._value.l == other._v._value.l);
  3590   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
  3591   case T_METADATA: return (_v._metadata == other._v._metadata);
  3592   default: ShouldNotReachHere();
  3594   return false;
  3597 static int type_to_size_in_bytes(BasicType t) {
  3598   switch (t) {
  3599   case T_LONG:    return sizeof(jlong  );
  3600   case T_FLOAT:   return sizeof(jfloat );
  3601   case T_DOUBLE:  return sizeof(jdouble);
  3602   case T_METADATA: return sizeof(Metadata*);
  3603     // We use T_VOID as marker for jump-table entries (labels) which
  3604     // need an internal word relocation.
  3605   case T_VOID:
  3606   case T_ADDRESS:
  3607   case T_OBJECT:  return sizeof(jobject);
  3610   ShouldNotReachHere();
  3611   return -1;
  3614 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
  3615   // sort descending
  3616   if (a->freq() > b->freq())  return -1;
  3617   if (a->freq() < b->freq())  return  1;
  3618   return 0;
  3621 void Compile::ConstantTable::calculate_offsets_and_size() {
  3622   // First, sort the array by frequencies.
  3623   _constants.sort(qsort_comparator);
  3625 #ifdef ASSERT
  3626   // Make sure all jump-table entries were sorted to the end of the
  3627   // array (they have a negative frequency).
  3628   bool found_void = false;
  3629   for (int i = 0; i < _constants.length(); i++) {
  3630     Constant con = _constants.at(i);
  3631     if (con.type() == T_VOID)
  3632       found_void = true;  // jump-tables
  3633     else
  3634       assert(!found_void, "wrong sorting");
  3636 #endif
  3638   int offset = 0;
  3639   for (int i = 0; i < _constants.length(); i++) {
  3640     Constant* con = _constants.adr_at(i);
  3642     // Align offset for type.
  3643     int typesize = type_to_size_in_bytes(con->type());
  3644     offset = align_size_up(offset, typesize);
  3645     con->set_offset(offset);   // set constant's offset
  3647     if (con->type() == T_VOID) {
  3648       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
  3649       offset = offset + typesize * n->outcnt();  // expand jump-table
  3650     } else {
  3651       offset = offset + typesize;
  3655   // Align size up to the next section start (which is insts; see
  3656   // CodeBuffer::align_at_start).
  3657   assert(_size == -1, "already set?");
  3658   _size = align_size_up(offset, CodeEntryAlignment);
  3661 void Compile::ConstantTable::emit(CodeBuffer& cb) {
  3662   MacroAssembler _masm(&cb);
  3663   for (int i = 0; i < _constants.length(); i++) {
  3664     Constant con = _constants.at(i);
  3665     address constant_addr;
  3666     switch (con.type()) {
  3667     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
  3668     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
  3669     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
  3670     case T_OBJECT: {
  3671       jobject obj = con.get_jobject();
  3672       int oop_index = _masm.oop_recorder()->find_index(obj);
  3673       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
  3674       break;
  3676     case T_ADDRESS: {
  3677       address addr = (address) con.get_jobject();
  3678       constant_addr = _masm.address_constant(addr);
  3679       break;
  3681     // We use T_VOID as marker for jump-table entries (labels) which
  3682     // need an internal word relocation.
  3683     case T_VOID: {
  3684       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
  3685       // Fill the jump-table with a dummy word.  The real value is
  3686       // filled in later in fill_jump_table.
  3687       address dummy = (address) n;
  3688       constant_addr = _masm.address_constant(dummy);
  3689       // Expand jump-table
  3690       for (uint i = 1; i < n->outcnt(); i++) {
  3691         address temp_addr = _masm.address_constant(dummy + i);
  3692         assert(temp_addr, "consts section too small");
  3694       break;
  3696     case T_METADATA: {
  3697       Metadata* obj = con.get_metadata();
  3698       int metadata_index = _masm.oop_recorder()->find_index(obj);
  3699       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
  3700       break;
  3702     default: ShouldNotReachHere();
  3704     assert(constant_addr, "consts section too small");
  3705     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
  3706             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
  3710 int Compile::ConstantTable::find_offset(Constant& con) const {
  3711   int idx = _constants.find(con);
  3712   assert(idx != -1, "constant must be in constant table");
  3713   int offset = _constants.at(idx).offset();
  3714   assert(offset != -1, "constant table not emitted yet?");
  3715   return offset;
  3718 void Compile::ConstantTable::add(Constant& con) {
  3719   if (con.can_be_reused()) {
  3720     int idx = _constants.find(con);
  3721     if (idx != -1 && _constants.at(idx).can_be_reused()) {
  3722       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
  3723       return;
  3726   (void) _constants.append(con);
  3729 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
  3730   Block* b = Compile::current()->cfg()->get_block_for_node(n);
  3731   Constant con(type, value, b->_freq);
  3732   add(con);
  3733   return con;
  3736 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
  3737   Constant con(metadata);
  3738   add(con);
  3739   return con;
  3742 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
  3743   jvalue value;
  3744   BasicType type = oper->type()->basic_type();
  3745   switch (type) {
  3746   case T_LONG:    value.j = oper->constantL(); break;
  3747   case T_FLOAT:   value.f = oper->constantF(); break;
  3748   case T_DOUBLE:  value.d = oper->constantD(); break;
  3749   case T_OBJECT:
  3750   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
  3751   case T_METADATA: return add((Metadata*)oper->constant()); break;
  3752   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
  3754   return add(n, type, value);
  3757 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
  3758   jvalue value;
  3759   // We can use the node pointer here to identify the right jump-table
  3760   // as this method is called from Compile::Fill_buffer right before
  3761   // the MachNodes are emitted and the jump-table is filled (means the
  3762   // MachNode pointers do not change anymore).
  3763   value.l = (jobject) n;
  3764   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
  3765   add(con);
  3766   return con;
  3769 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
  3770   // If called from Compile::scratch_emit_size do nothing.
  3771   if (Compile::current()->in_scratch_emit_size())  return;
  3773   assert(labels.is_nonempty(), "must be");
  3774   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
  3776   // Since MachConstantNode::constant_offset() also contains
  3777   // table_base_offset() we need to subtract the table_base_offset()
  3778   // to get the plain offset into the constant table.
  3779   int offset = n->constant_offset() - table_base_offset();
  3781   MacroAssembler _masm(&cb);
  3782   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
  3784   for (uint i = 0; i < n->outcnt(); i++) {
  3785     address* constant_addr = &jump_table_base[i];
  3786     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)));
  3787     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
  3788     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
  3792 void Compile::dump_inlining() {
  3793   if (print_inlining() || print_intrinsics()) {
  3794     // Print inlining message for candidates that we couldn't inline
  3795     // for lack of space or non constant receiver
  3796     for (int i = 0; i < _late_inlines.length(); i++) {
  3797       CallGenerator* cg = _late_inlines.at(i);
  3798       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
  3800     Unique_Node_List useful;
  3801     useful.push(root());
  3802     for (uint next = 0; next < useful.size(); ++next) {
  3803       Node* n  = useful.at(next);
  3804       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
  3805         CallNode* call = n->as_Call();
  3806         CallGenerator* cg = call->generator();
  3807         cg->print_inlining_late("receiver not constant");
  3809       uint max = n->len();
  3810       for ( uint i = 0; i < max; ++i ) {
  3811         Node *m = n->in(i);
  3812         if ( m == NULL ) continue;
  3813         useful.push(m);
  3816     for (int i = 0; i < _print_inlining_list->length(); i++) {
  3817       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
  3822 // Dump inlining replay data to the stream.
  3823 // Don't change thread state and acquire any locks.
  3824 void Compile::dump_inline_data(outputStream* out) {
  3825   InlineTree* inl_tree = ilt();
  3826   if (inl_tree != NULL) {
  3827     out->print(" inline %d", inl_tree->count());
  3828     inl_tree->dump_replay_data(out);
  3832 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
  3833   if (n1->Opcode() < n2->Opcode())      return -1;
  3834   else if (n1->Opcode() > n2->Opcode()) return 1;
  3836   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()));
  3837   for (uint i = 1; i < n1->req(); i++) {
  3838     if (n1->in(i) < n2->in(i))      return -1;
  3839     else if (n1->in(i) > n2->in(i)) return 1;
  3842   return 0;
  3845 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
  3846   Node* n1 = *n1p;
  3847   Node* n2 = *n2p;
  3849   return cmp_expensive_nodes(n1, n2);
  3852 void Compile::sort_expensive_nodes() {
  3853   if (!expensive_nodes_sorted()) {
  3854     _expensive_nodes->sort(cmp_expensive_nodes);
  3858 bool Compile::expensive_nodes_sorted() const {
  3859   for (int i = 1; i < _expensive_nodes->length(); i++) {
  3860     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
  3861       return false;
  3864   return true;
  3867 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
  3868   if (_expensive_nodes->length() == 0) {
  3869     return false;
  3872   assert(OptimizeExpensiveOps, "optimization off?");
  3874   // Take this opportunity to remove dead nodes from the list
  3875   int j = 0;
  3876   for (int i = 0; i < _expensive_nodes->length(); i++) {
  3877     Node* n = _expensive_nodes->at(i);
  3878     if (!n->is_unreachable(igvn)) {
  3879       assert(n->is_expensive(), "should be expensive");
  3880       _expensive_nodes->at_put(j, n);
  3881       j++;
  3884   _expensive_nodes->trunc_to(j);
  3886   // Then sort the list so that similar nodes are next to each other
  3887   // and check for at least two nodes of identical kind with same data
  3888   // inputs.
  3889   sort_expensive_nodes();
  3891   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
  3892     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
  3893       return true;
  3897   return false;
  3900 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
  3901   if (_expensive_nodes->length() == 0) {
  3902     return;
  3905   assert(OptimizeExpensiveOps, "optimization off?");
  3907   // Sort to bring similar nodes next to each other and clear the
  3908   // control input of nodes for which there's only a single copy.
  3909   sort_expensive_nodes();
  3911   int j = 0;
  3912   int identical = 0;
  3913   int i = 0;
  3914   for (; i < _expensive_nodes->length()-1; i++) {
  3915     assert(j <= i, "can't write beyond current index");
  3916     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
  3917       identical++;
  3918       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3919       continue;
  3921     if (identical > 0) {
  3922       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3923       identical = 0;
  3924     } else {
  3925       Node* n = _expensive_nodes->at(i);
  3926       igvn.hash_delete(n);
  3927       n->set_req(0, NULL);
  3928       igvn.hash_insert(n);
  3931   if (identical > 0) {
  3932     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3933   } else if (_expensive_nodes->length() >= 1) {
  3934     Node* n = _expensive_nodes->at(i);
  3935     igvn.hash_delete(n);
  3936     n->set_req(0, NULL);
  3937     igvn.hash_insert(n);
  3939   _expensive_nodes->trunc_to(j);
  3942 void Compile::add_expensive_node(Node * n) {
  3943   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
  3944   assert(n->is_expensive(), "expensive nodes with non-null control here only");
  3945   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
  3946   if (OptimizeExpensiveOps) {
  3947     _expensive_nodes->append(n);
  3948   } else {
  3949     // Clear control input and let IGVN optimize expensive nodes if
  3950     // OptimizeExpensiveOps is off.
  3951     n->set_req(0, NULL);
  3955 /**
  3956  * Remove the speculative part of types and clean up the graph
  3957  */
  3958 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
  3959   if (UseTypeSpeculation) {
  3960     Unique_Node_List worklist;
  3961     worklist.push(root());
  3962     int modified = 0;
  3963     // Go over all type nodes that carry a speculative type, drop the
  3964     // speculative part of the type and enqueue the node for an igvn
  3965     // which may optimize it out.
  3966     for (uint next = 0; next < worklist.size(); ++next) {
  3967       Node *n  = worklist.at(next);
  3968       if (n->is_Type()) {
  3969         TypeNode* tn = n->as_Type();
  3970         const Type* t = tn->type();
  3971         const Type* t_no_spec = t->remove_speculative();
  3972         if (t_no_spec != t) {
  3973           bool in_hash = igvn.hash_delete(n);
  3974           assert(in_hash, "node should be in igvn hash table");
  3975           tn->set_type(t_no_spec);
  3976           igvn.hash_insert(n);
  3977           igvn._worklist.push(n); // give it a chance to go away
  3978           modified++;
  3981       uint max = n->len();
  3982       for( uint i = 0; i < max; ++i ) {
  3983         Node *m = n->in(i);
  3984         if (not_a_node(m))  continue;
  3985         worklist.push(m);
  3988     // Drop the speculative part of all types in the igvn's type table
  3989     igvn.remove_speculative_types();
  3990     if (modified > 0) {
  3991       igvn.optimize();
  3993 #ifdef ASSERT
  3994     // Verify that after the IGVN is over no speculative type has resurfaced
  3995     worklist.clear();
  3996     worklist.push(root());
  3997     for (uint next = 0; next < worklist.size(); ++next) {
  3998       Node *n  = worklist.at(next);
  3999       const Type* t = igvn.type_or_null(n);
  4000       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
  4001       if (n->is_Type()) {
  4002         t = n->as_Type()->type();
  4003         assert(t == t->remove_speculative(), "no more speculative types");
  4005       uint max = n->len();
  4006       for( uint i = 0; i < max; ++i ) {
  4007         Node *m = n->in(i);
  4008         if (not_a_node(m))  continue;
  4009         worklist.push(m);
  4012     igvn.check_no_speculative_types();
  4013 #endif
  4017 // Auxiliary method to support randomized stressing/fuzzing.
  4018 //
  4019 // This method can be called the arbitrary number of times, with current count
  4020 // as the argument. The logic allows selecting a single candidate from the
  4021 // running list of candidates as follows:
  4022 //    int count = 0;
  4023 //    Cand* selected = null;
  4024 //    while(cand = cand->next()) {
  4025 //      if (randomized_select(++count)) {
  4026 //        selected = cand;
  4027 //      }
  4028 //    }
  4029 //
  4030 // Including count equalizes the chances any candidate is "selected".
  4031 // This is useful when we don't have the complete list of candidates to choose
  4032 // from uniformly. In this case, we need to adjust the randomicity of the
  4033 // selection, or else we will end up biasing the selection towards the latter
  4034 // candidates.
  4035 //
  4036 // Quick back-envelope calculation shows that for the list of n candidates
  4037 // the equal probability for the candidate to persist as "best" can be
  4038 // achieved by replacing it with "next" k-th candidate with the probability
  4039 // of 1/k. It can be easily shown that by the end of the run, the
  4040 // probability for any candidate is converged to 1/n, thus giving the
  4041 // uniform distribution among all the candidates.
  4042 //
  4043 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
  4044 #define RANDOMIZED_DOMAIN_POW 29
  4045 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
  4046 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
  4047 bool Compile::randomized_select(int count) {
  4048   assert(count > 0, "only positive");
  4049   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);

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