src/share/vm/opto/compile.cpp

Tue, 24 Feb 2015 15:04:52 -0500

author
dlong
date
Tue, 24 Feb 2015 15:04:52 -0500
changeset 7598
ddce0b7cee93
parent 7385
9e69e8d1c900
child 7789
eb8b5cc64669
permissions
-rw-r--r--

8072383: resolve conflicts between open and closed ports
Summary: refactor close to remove references to closed ports
Reviewed-by: kvn, simonis, sgehwolf, dholmes

     1 /*
     2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "asm/macroAssembler.hpp"
    27 #include "asm/macroAssembler.inline.hpp"
    28 #include "ci/ciReplay.hpp"
    29 #include "classfile/systemDictionary.hpp"
    30 #include "code/exceptionHandlerTable.hpp"
    31 #include "code/nmethod.hpp"
    32 #include "compiler/compileLog.hpp"
    33 #include "compiler/disassembler.hpp"
    34 #include "compiler/oopMap.hpp"
    35 #include "opto/addnode.hpp"
    36 #include "opto/block.hpp"
    37 #include "opto/c2compiler.hpp"
    38 #include "opto/callGenerator.hpp"
    39 #include "opto/callnode.hpp"
    40 #include "opto/cfgnode.hpp"
    41 #include "opto/chaitin.hpp"
    42 #include "opto/compile.hpp"
    43 #include "opto/connode.hpp"
    44 #include "opto/divnode.hpp"
    45 #include "opto/escape.hpp"
    46 #include "opto/idealGraphPrinter.hpp"
    47 #include "opto/loopnode.hpp"
    48 #include "opto/machnode.hpp"
    49 #include "opto/macro.hpp"
    50 #include "opto/matcher.hpp"
    51 #include "opto/mathexactnode.hpp"
    52 #include "opto/memnode.hpp"
    53 #include "opto/mulnode.hpp"
    54 #include "opto/node.hpp"
    55 #include "opto/opcodes.hpp"
    56 #include "opto/output.hpp"
    57 #include "opto/parse.hpp"
    58 #include "opto/phaseX.hpp"
    59 #include "opto/rootnode.hpp"
    60 #include "opto/runtime.hpp"
    61 #include "opto/stringopts.hpp"
    62 #include "opto/type.hpp"
    63 #include "opto/vectornode.hpp"
    64 #include "runtime/arguments.hpp"
    65 #include "runtime/signature.hpp"
    66 #include "runtime/stubRoutines.hpp"
    67 #include "runtime/timer.hpp"
    68 #include "trace/tracing.hpp"
    69 #include "utilities/copy.hpp"
    70 #if defined AD_MD_HPP
    71 # include AD_MD_HPP
    72 #elif defined TARGET_ARCH_MODEL_x86_32
    73 # include "adfiles/ad_x86_32.hpp"
    74 #elif defined TARGET_ARCH_MODEL_x86_64
    75 # include "adfiles/ad_x86_64.hpp"
    76 #elif defined TARGET_ARCH_MODEL_sparc
    77 # include "adfiles/ad_sparc.hpp"
    78 #elif defined TARGET_ARCH_MODEL_zero
    79 # include "adfiles/ad_zero.hpp"
    80 #elif defined TARGET_ARCH_MODEL_ppc_64
    81 # include "adfiles/ad_ppc_64.hpp"
    82 #endif
    85 // -------------------- Compile::mach_constant_base_node -----------------------
    86 // Constant table base node singleton.
    87 MachConstantBaseNode* Compile::mach_constant_base_node() {
    88   if (_mach_constant_base_node == NULL) {
    89     _mach_constant_base_node = new (C) MachConstantBaseNode();
    90     _mach_constant_base_node->add_req(C->root());
    91   }
    92   return _mach_constant_base_node;
    93 }
    96 /// Support for intrinsics.
    98 // Return the index at which m must be inserted (or already exists).
    99 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
   100 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
   101 #ifdef ASSERT
   102   for (int i = 1; i < _intrinsics->length(); i++) {
   103     CallGenerator* cg1 = _intrinsics->at(i-1);
   104     CallGenerator* cg2 = _intrinsics->at(i);
   105     assert(cg1->method() != cg2->method()
   106            ? cg1->method()     < cg2->method()
   107            : cg1->is_virtual() < cg2->is_virtual(),
   108            "compiler intrinsics list must stay sorted");
   109   }
   110 #endif
   111   // Binary search sorted list, in decreasing intervals [lo, hi].
   112   int lo = 0, hi = _intrinsics->length()-1;
   113   while (lo <= hi) {
   114     int mid = (uint)(hi + lo) / 2;
   115     ciMethod* mid_m = _intrinsics->at(mid)->method();
   116     if (m < mid_m) {
   117       hi = mid-1;
   118     } else if (m > mid_m) {
   119       lo = mid+1;
   120     } else {
   121       // look at minor sort key
   122       bool mid_virt = _intrinsics->at(mid)->is_virtual();
   123       if (is_virtual < mid_virt) {
   124         hi = mid-1;
   125       } else if (is_virtual > mid_virt) {
   126         lo = mid+1;
   127       } else {
   128         return mid;  // exact match
   129       }
   130     }
   131   }
   132   return lo;  // inexact match
   133 }
   135 void Compile::register_intrinsic(CallGenerator* cg) {
   136   if (_intrinsics == NULL) {
   137     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
   138   }
   139   // This code is stolen from ciObjectFactory::insert.
   140   // Really, GrowableArray should have methods for
   141   // insert_at, remove_at, and binary_search.
   142   int len = _intrinsics->length();
   143   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
   144   if (index == len) {
   145     _intrinsics->append(cg);
   146   } else {
   147 #ifdef ASSERT
   148     CallGenerator* oldcg = _intrinsics->at(index);
   149     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
   150 #endif
   151     _intrinsics->append(_intrinsics->at(len-1));
   152     int pos;
   153     for (pos = len-2; pos >= index; pos--) {
   154       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
   155     }
   156     _intrinsics->at_put(index, cg);
   157   }
   158   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
   159 }
   161 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
   162   assert(m->is_loaded(), "don't try this on unloaded methods");
   163   if (_intrinsics != NULL) {
   164     int index = intrinsic_insertion_index(m, is_virtual);
   165     if (index < _intrinsics->length()
   166         && _intrinsics->at(index)->method() == m
   167         && _intrinsics->at(index)->is_virtual() == is_virtual) {
   168       return _intrinsics->at(index);
   169     }
   170   }
   171   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   172   if (m->intrinsic_id() != vmIntrinsics::_none &&
   173       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
   174     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
   175     if (cg != NULL) {
   176       // Save it for next time:
   177       register_intrinsic(cg);
   178       return cg;
   179     } else {
   180       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
   181     }
   182   }
   183   return NULL;
   184 }
   186 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
   187 // in library_call.cpp.
   190 #ifndef PRODUCT
   191 // statistics gathering...
   193 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
   194 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
   196 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   197   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   198   int oflags = _intrinsic_hist_flags[id];
   199   assert(flags != 0, "what happened?");
   200   if (is_virtual) {
   201     flags |= _intrinsic_virtual;
   202   }
   203   bool changed = (flags != oflags);
   204   if ((flags & _intrinsic_worked) != 0) {
   205     juint count = (_intrinsic_hist_count[id] += 1);
   206     if (count == 1) {
   207       changed = true;           // first time
   208     }
   209     // increment the overall count also:
   210     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   211   }
   212   if (changed) {
   213     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
   214       // Something changed about the intrinsic's virtuality.
   215       if ((flags & _intrinsic_virtual) != 0) {
   216         // This is the first use of this intrinsic as a virtual call.
   217         if (oflags != 0) {
   218           // We already saw it as a non-virtual, so note both cases.
   219           flags |= _intrinsic_both;
   220         }
   221       } else if ((oflags & _intrinsic_both) == 0) {
   222         // This is the first use of this intrinsic as a non-virtual
   223         flags |= _intrinsic_both;
   224       }
   225     }
   226     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   227   }
   228   // update the overall flags also:
   229   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   230   return changed;
   231 }
   233 static char* format_flags(int flags, char* buf) {
   234   buf[0] = 0;
   235   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   236   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   237   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   238   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   239   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   240   if (buf[0] == 0)  strcat(buf, ",");
   241   assert(buf[0] == ',', "must be");
   242   return &buf[1];
   243 }
   245 void Compile::print_intrinsic_statistics() {
   246   char flagsbuf[100];
   247   ttyLocker ttyl;
   248   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   249   tty->print_cr("Compiler intrinsic usage:");
   250   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   251   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   252   #define PRINT_STAT_LINE(name, c, f) \
   253     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   254   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
   255     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
   256     int   flags = _intrinsic_hist_flags[id];
   257     juint count = _intrinsic_hist_count[id];
   258     if ((flags | count) != 0) {
   259       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
   260     }
   261   }
   262   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   263   if (xtty != NULL)  xtty->tail("statistics");
   264 }
   266 void Compile::print_statistics() {
   267   { ttyLocker ttyl;
   268     if (xtty != NULL)  xtty->head("statistics type='opto'");
   269     Parse::print_statistics();
   270     PhaseCCP::print_statistics();
   271     PhaseRegAlloc::print_statistics();
   272     Scheduling::print_statistics();
   273     PhasePeephole::print_statistics();
   274     PhaseIdealLoop::print_statistics();
   275     if (xtty != NULL)  xtty->tail("statistics");
   276   }
   277   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
   278     // put this under its own <statistics> element.
   279     print_intrinsic_statistics();
   280   }
   281 }
   282 #endif //PRODUCT
   284 // Support for bundling info
   285 Bundle* Compile::node_bundling(const Node *n) {
   286   assert(valid_bundle_info(n), "oob");
   287   return &_node_bundling_base[n->_idx];
   288 }
   290 bool Compile::valid_bundle_info(const Node *n) {
   291   return (_node_bundling_limit > n->_idx);
   292 }
   295 void Compile::gvn_replace_by(Node* n, Node* nn) {
   296   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
   297     Node* use = n->last_out(i);
   298     bool is_in_table = initial_gvn()->hash_delete(use);
   299     uint uses_found = 0;
   300     for (uint j = 0; j < use->len(); j++) {
   301       if (use->in(j) == n) {
   302         if (j < use->req())
   303           use->set_req(j, nn);
   304         else
   305           use->set_prec(j, nn);
   306         uses_found++;
   307       }
   308     }
   309     if (is_in_table) {
   310       // reinsert into table
   311       initial_gvn()->hash_find_insert(use);
   312     }
   313     record_for_igvn(use);
   314     i -= uses_found;    // we deleted 1 or more copies of this edge
   315   }
   316 }
   319 static inline bool not_a_node(const Node* n) {
   320   if (n == NULL)                   return true;
   321   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
   322   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
   323   return false;
   324 }
   326 // Identify all nodes that are reachable from below, useful.
   327 // Use breadth-first pass that records state in a Unique_Node_List,
   328 // recursive traversal is slower.
   329 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   330   int estimated_worklist_size = unique();
   331   useful.map( estimated_worklist_size, NULL );  // preallocate space
   333   // Initialize worklist
   334   if (root() != NULL)     { useful.push(root()); }
   335   // If 'top' is cached, declare it useful to preserve cached node
   336   if( cached_top_node() ) { useful.push(cached_top_node()); }
   338   // Push all useful nodes onto the list, breadthfirst
   339   for( uint next = 0; next < useful.size(); ++next ) {
   340     assert( next < unique(), "Unique useful nodes < total nodes");
   341     Node *n  = useful.at(next);
   342     uint max = n->len();
   343     for( uint i = 0; i < max; ++i ) {
   344       Node *m = n->in(i);
   345       if (not_a_node(m))  continue;
   346       useful.push(m);
   347     }
   348   }
   349 }
   351 // Update dead_node_list with any missing dead nodes using useful
   352 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
   353 void Compile::update_dead_node_list(Unique_Node_List &useful) {
   354   uint max_idx = unique();
   355   VectorSet& useful_node_set = useful.member_set();
   357   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
   358     // If node with index node_idx is not in useful set,
   359     // mark it as dead in dead node list.
   360     if (! useful_node_set.test(node_idx) ) {
   361       record_dead_node(node_idx);
   362     }
   363   }
   364 }
   366 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
   367   int shift = 0;
   368   for (int i = 0; i < inlines->length(); i++) {
   369     CallGenerator* cg = inlines->at(i);
   370     CallNode* call = cg->call_node();
   371     if (shift > 0) {
   372       inlines->at_put(i-shift, cg);
   373     }
   374     if (!useful.member(call)) {
   375       shift++;
   376     }
   377   }
   378   inlines->trunc_to(inlines->length()-shift);
   379 }
   381 // Disconnect all useless nodes by disconnecting those at the boundary.
   382 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   383   uint next = 0;
   384   while (next < useful.size()) {
   385     Node *n = useful.at(next++);
   386     if (n->is_SafePoint()) {
   387       // We're done with a parsing phase. Replaced nodes are not valid
   388       // beyond that point.
   389       n->as_SafePoint()->delete_replaced_nodes();
   390     }
   391     // Use raw traversal of out edges since this code removes out edges
   392     int max = n->outcnt();
   393     for (int j = 0; j < max; ++j) {
   394       Node* child = n->raw_out(j);
   395       if (! useful.member(child)) {
   396         assert(!child->is_top() || child != top(),
   397                "If top is cached in Compile object it is in useful list");
   398         // Only need to remove this out-edge to the useless node
   399         n->raw_del_out(j);
   400         --j;
   401         --max;
   402       }
   403     }
   404     if (n->outcnt() == 1 && n->has_special_unique_user()) {
   405       record_for_igvn(n->unique_out());
   406     }
   407   }
   408   // Remove useless macro and predicate opaq nodes
   409   for (int i = C->macro_count()-1; i >= 0; i--) {
   410     Node* n = C->macro_node(i);
   411     if (!useful.member(n)) {
   412       remove_macro_node(n);
   413     }
   414   }
   415   // Remove useless expensive node
   416   for (int i = C->expensive_count()-1; i >= 0; i--) {
   417     Node* n = C->expensive_node(i);
   418     if (!useful.member(n)) {
   419       remove_expensive_node(n);
   420     }
   421   }
   422   // clean up the late inline lists
   423   remove_useless_late_inlines(&_string_late_inlines, useful);
   424   remove_useless_late_inlines(&_boxing_late_inlines, useful);
   425   remove_useless_late_inlines(&_late_inlines, useful);
   426   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   427 }
   429 //------------------------------frame_size_in_words-----------------------------
   430 // frame_slots in units of words
   431 int Compile::frame_size_in_words() const {
   432   // shift is 0 in LP32 and 1 in LP64
   433   const int shift = (LogBytesPerWord - LogBytesPerInt);
   434   int words = _frame_slots >> shift;
   435   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   436   return words;
   437 }
   439 // To bang the stack of this compiled method we use the stack size
   440 // that the interpreter would need in case of a deoptimization. This
   441 // removes the need to bang the stack in the deoptimization blob which
   442 // in turn simplifies stack overflow handling.
   443 int Compile::bang_size_in_bytes() const {
   444   return MAX2(_interpreter_frame_size, frame_size_in_bytes());
   445 }
   447 // ============================================================================
   448 //------------------------------CompileWrapper---------------------------------
   449 class CompileWrapper : public StackObj {
   450   Compile *const _compile;
   451  public:
   452   CompileWrapper(Compile* compile);
   454   ~CompileWrapper();
   455 };
   457 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   458   // the Compile* pointer is stored in the current ciEnv:
   459   ciEnv* env = compile->env();
   460   assert(env == ciEnv::current(), "must already be a ciEnv active");
   461   assert(env->compiler_data() == NULL, "compile already active?");
   462   env->set_compiler_data(compile);
   463   assert(compile == Compile::current(), "sanity");
   465   compile->set_type_dict(NULL);
   466   compile->set_type_hwm(NULL);
   467   compile->set_type_last_size(0);
   468   compile->set_last_tf(NULL, NULL);
   469   compile->set_indexSet_arena(NULL);
   470   compile->set_indexSet_free_block_list(NULL);
   471   compile->init_type_arena();
   472   Type::Initialize(compile);
   473   _compile->set_scratch_buffer_blob(NULL);
   474   _compile->begin_method();
   475 }
   476 CompileWrapper::~CompileWrapper() {
   477   _compile->end_method();
   478   if (_compile->scratch_buffer_blob() != NULL)
   479     BufferBlob::free(_compile->scratch_buffer_blob());
   480   _compile->env()->set_compiler_data(NULL);
   481 }
   484 //----------------------------print_compile_messages---------------------------
   485 void Compile::print_compile_messages() {
   486 #ifndef PRODUCT
   487   // Check if recompiling
   488   if (_subsume_loads == false && PrintOpto) {
   489     // Recompiling without allowing machine instructions to subsume loads
   490     tty->print_cr("*********************************************************");
   491     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   492     tty->print_cr("*********************************************************");
   493   }
   494   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   495     // Recompiling without escape analysis
   496     tty->print_cr("*********************************************************");
   497     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   498     tty->print_cr("*********************************************************");
   499   }
   500   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
   501     // Recompiling without boxing elimination
   502     tty->print_cr("*********************************************************");
   503     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
   504     tty->print_cr("*********************************************************");
   505   }
   506   if (env()->break_at_compile()) {
   507     // Open the debugger when compiling this method.
   508     tty->print("### Breaking when compiling: ");
   509     method()->print_short_name();
   510     tty->cr();
   511     BREAKPOINT;
   512   }
   514   if( PrintOpto ) {
   515     if (is_osr_compilation()) {
   516       tty->print("[OSR]%3d", _compile_id);
   517     } else {
   518       tty->print("%3d", _compile_id);
   519     }
   520   }
   521 #endif
   522 }
   525 //-----------------------init_scratch_buffer_blob------------------------------
   526 // Construct a temporary BufferBlob and cache it for this compile.
   527 void Compile::init_scratch_buffer_blob(int const_size) {
   528   // If there is already a scratch buffer blob allocated and the
   529   // constant section is big enough, use it.  Otherwise free the
   530   // current and allocate a new one.
   531   BufferBlob* blob = scratch_buffer_blob();
   532   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
   533     // Use the current blob.
   534   } else {
   535     if (blob != NULL) {
   536       BufferBlob::free(blob);
   537     }
   539     ResourceMark rm;
   540     _scratch_const_size = const_size;
   541     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
   542     blob = BufferBlob::create("Compile::scratch_buffer", size);
   543     // Record the buffer blob for next time.
   544     set_scratch_buffer_blob(blob);
   545     // Have we run out of code space?
   546     if (scratch_buffer_blob() == NULL) {
   547       // Let CompilerBroker disable further compilations.
   548       record_failure("Not enough space for scratch buffer in CodeCache");
   549       return;
   550     }
   551   }
   553   // Initialize the relocation buffers
   554   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
   555   set_scratch_locs_memory(locs_buf);
   556 }
   559 //-----------------------scratch_emit_size-------------------------------------
   560 // Helper function that computes size by emitting code
   561 uint Compile::scratch_emit_size(const Node* n) {
   562   // Start scratch_emit_size section.
   563   set_in_scratch_emit_size(true);
   565   // Emit into a trash buffer and count bytes emitted.
   566   // This is a pretty expensive way to compute a size,
   567   // but it works well enough if seldom used.
   568   // All common fixed-size instructions are given a size
   569   // method by the AD file.
   570   // Note that the scratch buffer blob and locs memory are
   571   // allocated at the beginning of the compile task, and
   572   // may be shared by several calls to scratch_emit_size.
   573   // The allocation of the scratch buffer blob is particularly
   574   // expensive, since it has to grab the code cache lock.
   575   BufferBlob* blob = this->scratch_buffer_blob();
   576   assert(blob != NULL, "Initialize BufferBlob at start");
   577   assert(blob->size() > MAX_inst_size, "sanity");
   578   relocInfo* locs_buf = scratch_locs_memory();
   579   address blob_begin = blob->content_begin();
   580   address blob_end   = (address)locs_buf;
   581   assert(blob->content_contains(blob_end), "sanity");
   582   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   583   buf.initialize_consts_size(_scratch_const_size);
   584   buf.initialize_stubs_size(MAX_stubs_size);
   585   assert(locs_buf != NULL, "sanity");
   586   int lsize = MAX_locs_size / 3;
   587   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
   588   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
   589   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
   591   // Do the emission.
   593   Label fakeL; // Fake label for branch instructions.
   594   Label*   saveL = NULL;
   595   uint save_bnum = 0;
   596   bool is_branch = n->is_MachBranch();
   597   if (is_branch) {
   598     MacroAssembler masm(&buf);
   599     masm.bind(fakeL);
   600     n->as_MachBranch()->save_label(&saveL, &save_bnum);
   601     n->as_MachBranch()->label_set(&fakeL, 0);
   602   }
   603   n->emit(buf, this->regalloc());
   604   if (is_branch) // Restore label.
   605     n->as_MachBranch()->label_set(saveL, save_bnum);
   607   // End scratch_emit_size section.
   608   set_in_scratch_emit_size(false);
   610   return buf.insts_size();
   611 }
   614 // ============================================================================
   615 //------------------------------Compile standard-------------------------------
   616 debug_only( int Compile::_debug_idx = 100000; )
   618 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   619 // the continuation bci for on stack replacement.
   622 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
   623                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
   624                 : Phase(Compiler),
   625                   _env(ci_env),
   626                   _log(ci_env->log()),
   627                   _compile_id(ci_env->compile_id()),
   628                   _save_argument_registers(false),
   629                   _stub_name(NULL),
   630                   _stub_function(NULL),
   631                   _stub_entry_point(NULL),
   632                   _method(target),
   633                   _entry_bci(osr_bci),
   634                   _initial_gvn(NULL),
   635                   _for_igvn(NULL),
   636                   _warm_calls(NULL),
   637                   _subsume_loads(subsume_loads),
   638                   _do_escape_analysis(do_escape_analysis),
   639                   _eliminate_boxing(eliminate_boxing),
   640                   _failure_reason(NULL),
   641                   _code_buffer("Compile::Fill_buffer"),
   642                   _orig_pc_slot(0),
   643                   _orig_pc_slot_offset_in_bytes(0),
   644                   _has_method_handle_invokes(false),
   645                   _mach_constant_base_node(NULL),
   646                   _node_bundling_limit(0),
   647                   _node_bundling_base(NULL),
   648                   _java_calls(0),
   649                   _inner_loops(0),
   650                   _scratch_const_size(-1),
   651                   _in_scratch_emit_size(false),
   652                   _dead_node_list(comp_arena()),
   653                   _dead_node_count(0),
   654 #ifndef PRODUCT
   655                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   656                   _in_dump_cnt(0),
   657                   _printer(IdealGraphPrinter::printer()),
   658 #endif
   659                   _congraph(NULL),
   660                   _comp_arena(mtCompiler),
   661                   _node_arena(mtCompiler),
   662                   _old_arena(mtCompiler),
   663                   _Compile_types(mtCompiler),
   664                   _replay_inline_data(NULL),
   665                   _late_inlines(comp_arena(), 2, 0, NULL),
   666                   _string_late_inlines(comp_arena(), 2, 0, NULL),
   667                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
   668                   _late_inlines_pos(0),
   669                   _number_of_mh_late_inlines(0),
   670                   _inlining_progress(false),
   671                   _inlining_incrementally(false),
   672                   _print_inlining_list(NULL),
   673                   _print_inlining_idx(0),
   674                   _interpreter_frame_size(0),
   675                   _max_node_limit(MaxNodeLimit) {
   676   C = this;
   678   CompileWrapper cw(this);
   679 #ifndef PRODUCT
   680   if (TimeCompiler2) {
   681     tty->print(" ");
   682     target->holder()->name()->print();
   683     tty->print(".");
   684     target->print_short_name();
   685     tty->print("  ");
   686   }
   687   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   688   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   689   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   690   if (!print_opto_assembly) {
   691     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   692     if (print_assembly && !Disassembler::can_decode()) {
   693       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   694       print_opto_assembly = true;
   695     }
   696   }
   697   set_print_assembly(print_opto_assembly);
   698   set_parsed_irreducible_loop(false);
   700   if (method()->has_option("ReplayInline")) {
   701     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
   702   }
   703 #endif
   704   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
   705   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
   706   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
   708   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
   709     // Make sure the method being compiled gets its own MDO,
   710     // so we can at least track the decompile_count().
   711     // Need MDO to record RTM code generation state.
   712     method()->ensure_method_data();
   713   }
   715   Init(::AliasLevel);
   718   print_compile_messages();
   720   _ilt = InlineTree::build_inline_tree_root();
   722   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   723   assert(num_alias_types() >= AliasIdxRaw, "");
   725 #define MINIMUM_NODE_HASH  1023
   726   // Node list that Iterative GVN will start with
   727   Unique_Node_List for_igvn(comp_arena());
   728   set_for_igvn(&for_igvn);
   730   // GVN that will be run immediately on new nodes
   731   uint estimated_size = method()->code_size()*4+64;
   732   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   733   PhaseGVN gvn(node_arena(), estimated_size);
   734   set_initial_gvn(&gvn);
   736   if (print_inlining() || print_intrinsics()) {
   737     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
   738   }
   739   { // Scope for timing the parser
   740     TracePhase t3("parse", &_t_parser, true);
   742     // Put top into the hash table ASAP.
   743     initial_gvn()->transform_no_reclaim(top());
   745     // Set up tf(), start(), and find a CallGenerator.
   746     CallGenerator* cg = NULL;
   747     if (is_osr_compilation()) {
   748       const TypeTuple *domain = StartOSRNode::osr_domain();
   749       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   750       init_tf(TypeFunc::make(domain, range));
   751       StartNode* s = new (this) StartOSRNode(root(), domain);
   752       initial_gvn()->set_type_bottom(s);
   753       init_start(s);
   754       cg = CallGenerator::for_osr(method(), entry_bci());
   755     } else {
   756       // Normal case.
   757       init_tf(TypeFunc::make(method()));
   758       StartNode* s = new (this) StartNode(root(), tf()->domain());
   759       initial_gvn()->set_type_bottom(s);
   760       init_start(s);
   761       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
   762         // With java.lang.ref.reference.get() we must go through the
   763         // intrinsic when G1 is enabled - even when get() is the root
   764         // method of the compile - so that, if necessary, the value in
   765         // the referent field of the reference object gets recorded by
   766         // the pre-barrier code.
   767         // Specifically, if G1 is enabled, the value in the referent
   768         // field is recorded by the G1 SATB pre barrier. This will
   769         // result in the referent being marked live and the reference
   770         // object removed from the list of discovered references during
   771         // reference processing.
   772         cg = find_intrinsic(method(), false);
   773       }
   774       if (cg == NULL) {
   775         float past_uses = method()->interpreter_invocation_count();
   776         float expected_uses = past_uses;
   777         cg = CallGenerator::for_inline(method(), expected_uses);
   778       }
   779     }
   780     if (failing())  return;
   781     if (cg == NULL) {
   782       record_method_not_compilable_all_tiers("cannot parse method");
   783       return;
   784     }
   785     JVMState* jvms = build_start_state(start(), tf());
   786     if ((jvms = cg->generate(jvms)) == NULL) {
   787       record_method_not_compilable("method parse failed");
   788       return;
   789     }
   790     GraphKit kit(jvms);
   792     if (!kit.stopped()) {
   793       // Accept return values, and transfer control we know not where.
   794       // This is done by a special, unique ReturnNode bound to root.
   795       return_values(kit.jvms());
   796     }
   798     if (kit.has_exceptions()) {
   799       // Any exceptions that escape from this call must be rethrown
   800       // to whatever caller is dynamically above us on the stack.
   801       // This is done by a special, unique RethrowNode bound to root.
   802       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   803     }
   805     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
   807     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
   808       inline_string_calls(true);
   809     }
   811     if (failing())  return;
   813     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
   815     // Remove clutter produced by parsing.
   816     if (!failing()) {
   817       ResourceMark rm;
   818       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   819     }
   820   }
   822   // Note:  Large methods are capped off in do_one_bytecode().
   823   if (failing())  return;
   825   // After parsing, node notes are no longer automagic.
   826   // They must be propagated by register_new_node_with_optimizer(),
   827   // clone(), or the like.
   828   set_default_node_notes(NULL);
   830   for (;;) {
   831     int successes = Inline_Warm();
   832     if (failing())  return;
   833     if (successes == 0)  break;
   834   }
   836   // Drain the list.
   837   Finish_Warm();
   838 #ifndef PRODUCT
   839   if (_printer) {
   840     _printer->print_inlining(this);
   841   }
   842 #endif
   844   if (failing())  return;
   845   NOT_PRODUCT( verify_graph_edges(); )
   847   // Now optimize
   848   Optimize();
   849   if (failing())  return;
   850   NOT_PRODUCT( verify_graph_edges(); )
   852 #ifndef PRODUCT
   853   if (PrintIdeal) {
   854     ttyLocker ttyl;  // keep the following output all in one block
   855     // This output goes directly to the tty, not the compiler log.
   856     // To enable tools to match it up with the compilation activity,
   857     // be sure to tag this tty output with the compile ID.
   858     if (xtty != NULL) {
   859       xtty->head("ideal compile_id='%d'%s", compile_id(),
   860                  is_osr_compilation()    ? " compile_kind='osr'" :
   861                  "");
   862     }
   863     root()->dump(9999);
   864     if (xtty != NULL) {
   865       xtty->tail("ideal");
   866     }
   867   }
   868 #endif
   870   NOT_PRODUCT( verify_barriers(); )
   872   // Dump compilation data to replay it.
   873   if (method()->has_option("DumpReplay")) {
   874     env()->dump_replay_data(_compile_id);
   875   }
   876   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
   877     env()->dump_inline_data(_compile_id);
   878   }
   880   // Now that we know the size of all the monitors we can add a fixed slot
   881   // for the original deopt pc.
   883   _orig_pc_slot =  fixed_slots();
   884   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   885   set_fixed_slots(next_slot);
   887   // Compute when to use implicit null checks. Used by matching trap based
   888   // nodes and NullCheck optimization.
   889   set_allowed_deopt_reasons();
   891   // Now generate code
   892   Code_Gen();
   893   if (failing())  return;
   895   // Check if we want to skip execution of all compiled code.
   896   {
   897 #ifndef PRODUCT
   898     if (OptoNoExecute) {
   899       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   900       return;
   901     }
   902     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   903 #endif
   905     if (is_osr_compilation()) {
   906       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   907       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   908     } else {
   909       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   910       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   911     }
   913     env()->register_method(_method, _entry_bci,
   914                            &_code_offsets,
   915                            _orig_pc_slot_offset_in_bytes,
   916                            code_buffer(),
   917                            frame_size_in_words(), _oop_map_set,
   918                            &_handler_table, &_inc_table,
   919                            compiler,
   920                            env()->comp_level(),
   921                            has_unsafe_access(),
   922                            SharedRuntime::is_wide_vector(max_vector_size()),
   923                            rtm_state()
   924                            );
   926     if (log() != NULL) // Print code cache state into compiler log
   927       log()->code_cache_state();
   928   }
   929 }
   931 //------------------------------Compile----------------------------------------
   932 // Compile a runtime stub
   933 Compile::Compile( ciEnv* ci_env,
   934                   TypeFunc_generator generator,
   935                   address stub_function,
   936                   const char *stub_name,
   937                   int is_fancy_jump,
   938                   bool pass_tls,
   939                   bool save_arg_registers,
   940                   bool return_pc )
   941   : Phase(Compiler),
   942     _env(ci_env),
   943     _log(ci_env->log()),
   944     _compile_id(0),
   945     _save_argument_registers(save_arg_registers),
   946     _method(NULL),
   947     _stub_name(stub_name),
   948     _stub_function(stub_function),
   949     _stub_entry_point(NULL),
   950     _entry_bci(InvocationEntryBci),
   951     _initial_gvn(NULL),
   952     _for_igvn(NULL),
   953     _warm_calls(NULL),
   954     _orig_pc_slot(0),
   955     _orig_pc_slot_offset_in_bytes(0),
   956     _subsume_loads(true),
   957     _do_escape_analysis(false),
   958     _eliminate_boxing(false),
   959     _failure_reason(NULL),
   960     _code_buffer("Compile::Fill_buffer"),
   961     _has_method_handle_invokes(false),
   962     _mach_constant_base_node(NULL),
   963     _node_bundling_limit(0),
   964     _node_bundling_base(NULL),
   965     _java_calls(0),
   966     _inner_loops(0),
   967 #ifndef PRODUCT
   968     _trace_opto_output(TraceOptoOutput),
   969     _in_dump_cnt(0),
   970     _printer(NULL),
   971 #endif
   972     _comp_arena(mtCompiler),
   973     _node_arena(mtCompiler),
   974     _old_arena(mtCompiler),
   975     _Compile_types(mtCompiler),
   976     _dead_node_list(comp_arena()),
   977     _dead_node_count(0),
   978     _congraph(NULL),
   979     _replay_inline_data(NULL),
   980     _number_of_mh_late_inlines(0),
   981     _inlining_progress(false),
   982     _inlining_incrementally(false),
   983     _print_inlining_list(NULL),
   984     _print_inlining_idx(0),
   985     _allowed_reasons(0),
   986     _interpreter_frame_size(0),
   987     _max_node_limit(MaxNodeLimit) {
   988   C = this;
   990 #ifndef PRODUCT
   991   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   992   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   993   set_print_assembly(PrintFrameConverterAssembly);
   994   set_parsed_irreducible_loop(false);
   995 #endif
   996   set_has_irreducible_loop(false); // no loops
   998   CompileWrapper cw(this);
   999   Init(/*AliasLevel=*/ 0);
  1000   init_tf((*generator)());
  1003     // The following is a dummy for the sake of GraphKit::gen_stub
  1004     Unique_Node_List for_igvn(comp_arena());
  1005     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
  1006     PhaseGVN gvn(Thread::current()->resource_area(),255);
  1007     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
  1008     gvn.transform_no_reclaim(top());
  1010     GraphKit kit;
  1011     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
  1014   NOT_PRODUCT( verify_graph_edges(); )
  1015   Code_Gen();
  1016   if (failing())  return;
  1019   // Entry point will be accessed using compile->stub_entry_point();
  1020   if (code_buffer() == NULL) {
  1021     Matcher::soft_match_failure();
  1022   } else {
  1023     if (PrintAssembly && (WizardMode || Verbose))
  1024       tty->print_cr("### Stub::%s", stub_name);
  1026     if (!failing()) {
  1027       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
  1029       // Make the NMethod
  1030       // For now we mark the frame as never safe for profile stackwalking
  1031       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
  1032                                                       code_buffer(),
  1033                                                       CodeOffsets::frame_never_safe,
  1034                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
  1035                                                       frame_size_in_words(),
  1036                                                       _oop_map_set,
  1037                                                       save_arg_registers);
  1038       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
  1040       _stub_entry_point = rs->entry_point();
  1045 //------------------------------Init-------------------------------------------
  1046 // Prepare for a single compilation
  1047 void Compile::Init(int aliaslevel) {
  1048   _unique  = 0;
  1049   _regalloc = NULL;
  1051   _tf      = NULL;  // filled in later
  1052   _top     = NULL;  // cached later
  1053   _matcher = NULL;  // filled in later
  1054   _cfg     = NULL;  // filled in later
  1056   set_24_bit_selection_and_mode(Use24BitFP, false);
  1058   _node_note_array = NULL;
  1059   _default_node_notes = NULL;
  1061   _immutable_memory = NULL; // filled in at first inquiry
  1063   // Globally visible Nodes
  1064   // First set TOP to NULL to give safe behavior during creation of RootNode
  1065   set_cached_top_node(NULL);
  1066   set_root(new (this) RootNode());
  1067   // Now that you have a Root to point to, create the real TOP
  1068   set_cached_top_node( new (this) ConNode(Type::TOP) );
  1069   set_recent_alloc(NULL, NULL);
  1071   // Create Debug Information Recorder to record scopes, oopmaps, etc.
  1072   env()->set_oop_recorder(new OopRecorder(env()->arena()));
  1073   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
  1074   env()->set_dependencies(new Dependencies(env()));
  1076   _fixed_slots = 0;
  1077   set_has_split_ifs(false);
  1078   set_has_loops(has_method() && method()->has_loops()); // first approximation
  1079   set_has_stringbuilder(false);
  1080   set_has_boxed_value(false);
  1081   _trap_can_recompile = false;  // no traps emitted yet
  1082   _major_progress = true; // start out assuming good things will happen
  1083   set_has_unsafe_access(false);
  1084   set_max_vector_size(0);
  1085   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
  1086   set_decompile_count(0);
  1088   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
  1089   set_num_loop_opts(LoopOptsCount);
  1090   set_do_inlining(Inline);
  1091   set_max_inline_size(MaxInlineSize);
  1092   set_freq_inline_size(FreqInlineSize);
  1093   set_do_scheduling(OptoScheduling);
  1094   set_do_count_invocations(false);
  1095   set_do_method_data_update(false);
  1096   set_rtm_state(NoRTM); // No RTM lock eliding by default
  1097   method_has_option_value("MaxNodeLimit", _max_node_limit);
  1098 #if INCLUDE_RTM_OPT
  1099   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
  1100     int rtm_state = method()->method_data()->rtm_state();
  1101     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
  1102       // Don't generate RTM lock eliding code.
  1103       set_rtm_state(NoRTM);
  1104     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
  1105       // Generate RTM lock eliding code without abort ratio calculation code.
  1106       set_rtm_state(UseRTM);
  1107     } else if (UseRTMDeopt) {
  1108       // Generate RTM lock eliding code and include abort ratio calculation
  1109       // code if UseRTMDeopt is on.
  1110       set_rtm_state(ProfileRTM);
  1113 #endif
  1114   if (debug_info()->recording_non_safepoints()) {
  1115     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
  1116                         (comp_arena(), 8, 0, NULL));
  1117     set_default_node_notes(Node_Notes::make(this));
  1120   // // -- Initialize types before each compile --
  1121   // // Update cached type information
  1122   // if( _method && _method->constants() )
  1123   //   Type::update_loaded_types(_method, _method->constants());
  1125   // Init alias_type map.
  1126   if (!_do_escape_analysis && aliaslevel == 3)
  1127     aliaslevel = 2;  // No unique types without escape analysis
  1128   _AliasLevel = aliaslevel;
  1129   const int grow_ats = 16;
  1130   _max_alias_types = grow_ats;
  1131   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
  1132   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
  1133   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
  1135     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
  1137   // Initialize the first few types.
  1138   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
  1139   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
  1140   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
  1141   _num_alias_types = AliasIdxRaw+1;
  1142   // Zero out the alias type cache.
  1143   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
  1144   // A NULL adr_type hits in the cache right away.  Preload the right answer.
  1145   probe_alias_cache(NULL)->_index = AliasIdxTop;
  1147   _intrinsics = NULL;
  1148   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1149   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1150   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1151   register_library_intrinsics();
  1154 //---------------------------init_start----------------------------------------
  1155 // Install the StartNode on this compile object.
  1156 void Compile::init_start(StartNode* s) {
  1157   if (failing())
  1158     return; // already failing
  1159   assert(s == start(), "");
  1162 StartNode* Compile::start() const {
  1163   assert(!failing(), "");
  1164   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
  1165     Node* start = root()->fast_out(i);
  1166     if( start->is_Start() )
  1167       return start->as_Start();
  1169   fatal("Did not find Start node!");
  1170   return NULL;
  1173 //-------------------------------immutable_memory-------------------------------------
  1174 // Access immutable memory
  1175 Node* Compile::immutable_memory() {
  1176   if (_immutable_memory != NULL) {
  1177     return _immutable_memory;
  1179   StartNode* s = start();
  1180   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
  1181     Node *p = s->fast_out(i);
  1182     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
  1183       _immutable_memory = p;
  1184       return _immutable_memory;
  1187   ShouldNotReachHere();
  1188   return NULL;
  1191 //----------------------set_cached_top_node------------------------------------
  1192 // Install the cached top node, and make sure Node::is_top works correctly.
  1193 void Compile::set_cached_top_node(Node* tn) {
  1194   if (tn != NULL)  verify_top(tn);
  1195   Node* old_top = _top;
  1196   _top = tn;
  1197   // Calling Node::setup_is_top allows the nodes the chance to adjust
  1198   // their _out arrays.
  1199   if (_top != NULL)     _top->setup_is_top();
  1200   if (old_top != NULL)  old_top->setup_is_top();
  1201   assert(_top == NULL || top()->is_top(), "");
  1204 #ifdef ASSERT
  1205 uint Compile::count_live_nodes_by_graph_walk() {
  1206   Unique_Node_List useful(comp_arena());
  1207   // Get useful node list by walking the graph.
  1208   identify_useful_nodes(useful);
  1209   return useful.size();
  1212 void Compile::print_missing_nodes() {
  1214   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
  1215   if ((_log == NULL) && (! PrintIdealNodeCount)) {
  1216     return;
  1219   // This is an expensive function. It is executed only when the user
  1220   // specifies VerifyIdealNodeCount option or otherwise knows the
  1221   // additional work that needs to be done to identify reachable nodes
  1222   // by walking the flow graph and find the missing ones using
  1223   // _dead_node_list.
  1225   Unique_Node_List useful(comp_arena());
  1226   // Get useful node list by walking the graph.
  1227   identify_useful_nodes(useful);
  1229   uint l_nodes = C->live_nodes();
  1230   uint l_nodes_by_walk = useful.size();
  1232   if (l_nodes != l_nodes_by_walk) {
  1233     if (_log != NULL) {
  1234       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
  1235       _log->stamp();
  1236       _log->end_head();
  1238     VectorSet& useful_member_set = useful.member_set();
  1239     int last_idx = l_nodes_by_walk;
  1240     for (int i = 0; i < last_idx; i++) {
  1241       if (useful_member_set.test(i)) {
  1242         if (_dead_node_list.test(i)) {
  1243           if (_log != NULL) {
  1244             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
  1246           if (PrintIdealNodeCount) {
  1247             // Print the log message to tty
  1248               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
  1249               useful.at(i)->dump();
  1253       else if (! _dead_node_list.test(i)) {
  1254         if (_log != NULL) {
  1255           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
  1257         if (PrintIdealNodeCount) {
  1258           // Print the log message to tty
  1259           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
  1263     if (_log != NULL) {
  1264       _log->tail("mismatched_nodes");
  1268 #endif
  1270 #ifndef PRODUCT
  1271 void Compile::verify_top(Node* tn) const {
  1272   if (tn != NULL) {
  1273     assert(tn->is_Con(), "top node must be a constant");
  1274     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
  1275     assert(tn->in(0) != NULL, "must have live top node");
  1278 #endif
  1281 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1283 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1284   guarantee(arr != NULL, "");
  1285   int num_blocks = arr->length();
  1286   if (grow_by < num_blocks)  grow_by = num_blocks;
  1287   int num_notes = grow_by * _node_notes_block_size;
  1288   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1289   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1290   while (num_notes > 0) {
  1291     arr->append(notes);
  1292     notes     += _node_notes_block_size;
  1293     num_notes -= _node_notes_block_size;
  1295   assert(num_notes == 0, "exact multiple, please");
  1298 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1299   if (source == NULL || dest == NULL)  return false;
  1301   if (dest->is_Con())
  1302     return false;               // Do not push debug info onto constants.
  1304 #ifdef ASSERT
  1305   // Leave a bread crumb trail pointing to the original node:
  1306   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1307     dest->set_debug_orig(source);
  1309 #endif
  1311   if (node_note_array() == NULL)
  1312     return false;               // Not collecting any notes now.
  1314   // This is a copy onto a pre-existing node, which may already have notes.
  1315   // If both nodes have notes, do not overwrite any pre-existing notes.
  1316   Node_Notes* source_notes = node_notes_at(source->_idx);
  1317   if (source_notes == NULL || source_notes->is_clear())  return false;
  1318   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1319   if (dest_notes == NULL || dest_notes->is_clear()) {
  1320     return set_node_notes_at(dest->_idx, source_notes);
  1323   Node_Notes merged_notes = (*source_notes);
  1324   // The order of operations here ensures that dest notes will win...
  1325   merged_notes.update_from(dest_notes);
  1326   return set_node_notes_at(dest->_idx, &merged_notes);
  1330 //--------------------------allow_range_check_smearing-------------------------
  1331 // Gating condition for coalescing similar range checks.
  1332 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1333 // single covering check that is at least as strong as any of them.
  1334 // If the optimization succeeds, the simplified (strengthened) range check
  1335 // will always succeed.  If it fails, we will deopt, and then give up
  1336 // on the optimization.
  1337 bool Compile::allow_range_check_smearing() const {
  1338   // If this method has already thrown a range-check,
  1339   // assume it was because we already tried range smearing
  1340   // and it failed.
  1341   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1342   return !already_trapped;
  1346 //------------------------------flatten_alias_type-----------------------------
  1347 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1348   int offset = tj->offset();
  1349   TypePtr::PTR ptr = tj->ptr();
  1351   // Known instance (scalarizable allocation) alias only with itself.
  1352   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1353                        tj->is_oopptr()->is_known_instance();
  1355   // Process weird unsafe references.
  1356   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1357     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1358     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1359     tj = TypeOopPtr::BOTTOM;
  1360     ptr = tj->ptr();
  1361     offset = tj->offset();
  1364   // Array pointers need some flattening
  1365   const TypeAryPtr *ta = tj->isa_aryptr();
  1366   if (ta && ta->is_stable()) {
  1367     // Erase stability property for alias analysis.
  1368     tj = ta = ta->cast_to_stable(false);
  1370   if( ta && is_known_inst ) {
  1371     if ( offset != Type::OffsetBot &&
  1372          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1373       offset = Type::OffsetBot; // Flatten constant access into array body only
  1374       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1376   } else if( ta && _AliasLevel >= 2 ) {
  1377     // For arrays indexed by constant indices, we flatten the alias
  1378     // space to include all of the array body.  Only the header, klass
  1379     // and array length can be accessed un-aliased.
  1380     if( offset != Type::OffsetBot ) {
  1381       if( ta->const_oop() ) { // MethodData* or Method*
  1382         offset = Type::OffsetBot;   // Flatten constant access into array body
  1383         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1384       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1385         // range is OK as-is.
  1386         tj = ta = TypeAryPtr::RANGE;
  1387       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1388         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1389         ta = TypeAryPtr::RANGE; // generic ignored junk
  1390         ptr = TypePtr::BotPTR;
  1391       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1392         tj = TypeInstPtr::MARK;
  1393         ta = TypeAryPtr::RANGE; // generic ignored junk
  1394         ptr = TypePtr::BotPTR;
  1395       } else {                  // Random constant offset into array body
  1396         offset = Type::OffsetBot;   // Flatten constant access into array body
  1397         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1400     // Arrays of fixed size alias with arrays of unknown size.
  1401     if (ta->size() != TypeInt::POS) {
  1402       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1403       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1405     // Arrays of known objects become arrays of unknown objects.
  1406     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1407       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1408       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1410     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1411       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1412       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1414     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1415     // cannot be distinguished by bytecode alone.
  1416     if (ta->elem() == TypeInt::BOOL) {
  1417       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1418       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1419       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1421     // During the 2nd round of IterGVN, NotNull castings are removed.
  1422     // Make sure the Bottom and NotNull variants alias the same.
  1423     // Also, make sure exact and non-exact variants alias the same.
  1424     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
  1425       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1429   // Oop pointers need some flattening
  1430   const TypeInstPtr *to = tj->isa_instptr();
  1431   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1432     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1433     if( ptr == TypePtr::Constant ) {
  1434       if (to->klass() != ciEnv::current()->Class_klass() ||
  1435           offset < k->size_helper() * wordSize) {
  1436         // No constant oop pointers (such as Strings); they alias with
  1437         // unknown strings.
  1438         assert(!is_known_inst, "not scalarizable allocation");
  1439         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1441     } else if( is_known_inst ) {
  1442       tj = to; // Keep NotNull and klass_is_exact for instance type
  1443     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1444       // During the 2nd round of IterGVN, NotNull castings are removed.
  1445       // Make sure the Bottom and NotNull variants alias the same.
  1446       // Also, make sure exact and non-exact variants alias the same.
  1447       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1449     if (to->speculative() != NULL) {
  1450       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
  1452     // Canonicalize the holder of this field
  1453     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1454       // First handle header references such as a LoadKlassNode, even if the
  1455       // object's klass is unloaded at compile time (4965979).
  1456       if (!is_known_inst) { // Do it only for non-instance types
  1457         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1459     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1460       // Static fields are in the space above the normal instance
  1461       // fields in the java.lang.Class instance.
  1462       if (to->klass() != ciEnv::current()->Class_klass()) {
  1463         to = NULL;
  1464         tj = TypeOopPtr::BOTTOM;
  1465         offset = tj->offset();
  1467     } else {
  1468       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1469       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1470         if( is_known_inst ) {
  1471           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1472         } else {
  1473           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1479   // Klass pointers to object array klasses need some flattening
  1480   const TypeKlassPtr *tk = tj->isa_klassptr();
  1481   if( tk ) {
  1482     // If we are referencing a field within a Klass, we need
  1483     // to assume the worst case of an Object.  Both exact and
  1484     // inexact types must flatten to the same alias class so
  1485     // use NotNull as the PTR.
  1486     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1488       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
  1489                                    TypeKlassPtr::OBJECT->klass(),
  1490                                    offset);
  1493     ciKlass* klass = tk->klass();
  1494     if( klass->is_obj_array_klass() ) {
  1495       ciKlass* k = TypeAryPtr::OOPS->klass();
  1496       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1497         k = TypeInstPtr::BOTTOM->klass();
  1498       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1501     // Check for precise loads from the primary supertype array and force them
  1502     // to the supertype cache alias index.  Check for generic array loads from
  1503     // the primary supertype array and also force them to the supertype cache
  1504     // alias index.  Since the same load can reach both, we need to merge
  1505     // these 2 disparate memories into the same alias class.  Since the
  1506     // primary supertype array is read-only, there's no chance of confusion
  1507     // where we bypass an array load and an array store.
  1508     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
  1509     if (offset == Type::OffsetBot ||
  1510         (offset >= primary_supers_offset &&
  1511          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
  1512         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
  1513       offset = in_bytes(Klass::secondary_super_cache_offset());
  1514       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1518   // Flatten all Raw pointers together.
  1519   if (tj->base() == Type::RawPtr)
  1520     tj = TypeRawPtr::BOTTOM;
  1522   if (tj->base() == Type::AnyPtr)
  1523     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1525   // Flatten all to bottom for now
  1526   switch( _AliasLevel ) {
  1527   case 0:
  1528     tj = TypePtr::BOTTOM;
  1529     break;
  1530   case 1:                       // Flatten to: oop, static, field or array
  1531     switch (tj->base()) {
  1532     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1533     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1534     case Type::AryPtr:   // do not distinguish arrays at all
  1535     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1536     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1537     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1538     default: ShouldNotReachHere();
  1540     break;
  1541   case 2:                       // No collapsing at level 2; keep all splits
  1542   case 3:                       // No collapsing at level 3; keep all splits
  1543     break;
  1544   default:
  1545     Unimplemented();
  1548   offset = tj->offset();
  1549   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1551   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1552           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1553           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1554           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1555           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1556           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1557           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1558           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1559   assert( tj->ptr() != TypePtr::TopPTR &&
  1560           tj->ptr() != TypePtr::AnyNull &&
  1561           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1562 //    assert( tj->ptr() != TypePtr::Constant ||
  1563 //            tj->base() == Type::RawPtr ||
  1564 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1566   return tj;
  1569 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1570   _index = i;
  1571   _adr_type = at;
  1572   _field = NULL;
  1573   _element = NULL;
  1574   _is_rewritable = true; // default
  1575   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1576   if (atoop != NULL && atoop->is_known_instance()) {
  1577     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1578     _general_index = Compile::current()->get_alias_index(gt);
  1579   } else {
  1580     _general_index = 0;
  1584 //---------------------------------print_on------------------------------------
  1585 #ifndef PRODUCT
  1586 void Compile::AliasType::print_on(outputStream* st) {
  1587   if (index() < 10)
  1588         st->print("@ <%d> ", index());
  1589   else  st->print("@ <%d>",  index());
  1590   st->print(is_rewritable() ? "   " : " RO");
  1591   int offset = adr_type()->offset();
  1592   if (offset == Type::OffsetBot)
  1593         st->print(" +any");
  1594   else  st->print(" +%-3d", offset);
  1595   st->print(" in ");
  1596   adr_type()->dump_on(st);
  1597   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1598   if (field() != NULL && tjp) {
  1599     if (tjp->klass()  != field()->holder() ||
  1600         tjp->offset() != field()->offset_in_bytes()) {
  1601       st->print(" != ");
  1602       field()->print();
  1603       st->print(" ***");
  1608 void print_alias_types() {
  1609   Compile* C = Compile::current();
  1610   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1611   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1612     C->alias_type(idx)->print_on(tty);
  1613     tty->cr();
  1616 #endif
  1619 //----------------------------probe_alias_cache--------------------------------
  1620 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1621   intptr_t key = (intptr_t) adr_type;
  1622   key ^= key >> logAliasCacheSize;
  1623   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1627 //-----------------------------grow_alias_types--------------------------------
  1628 void Compile::grow_alias_types() {
  1629   const int old_ats  = _max_alias_types; // how many before?
  1630   const int new_ats  = old_ats;          // how many more?
  1631   const int grow_ats = old_ats+new_ats;  // how many now?
  1632   _max_alias_types = grow_ats;
  1633   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1634   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1635   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1636   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1640 //--------------------------------find_alias_type------------------------------
  1641 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
  1642   if (_AliasLevel == 0)
  1643     return alias_type(AliasIdxBot);
  1645   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1646   if (ace->_adr_type == adr_type) {
  1647     return alias_type(ace->_index);
  1650   // Handle special cases.
  1651   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1652   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1654   // Do it the slow way.
  1655   const TypePtr* flat = flatten_alias_type(adr_type);
  1657 #ifdef ASSERT
  1658   assert(flat == flatten_alias_type(flat), "idempotent");
  1659   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1660   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1661     const TypeOopPtr* foop = flat->is_oopptr();
  1662     // Scalarizable allocations have exact klass always.
  1663     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1664     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1665     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1667   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1668 #endif
  1670   int idx = AliasIdxTop;
  1671   for (int i = 0; i < num_alias_types(); i++) {
  1672     if (alias_type(i)->adr_type() == flat) {
  1673       idx = i;
  1674       break;
  1678   if (idx == AliasIdxTop) {
  1679     if (no_create)  return NULL;
  1680     // Grow the array if necessary.
  1681     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1682     // Add a new alias type.
  1683     idx = _num_alias_types++;
  1684     _alias_types[idx]->Init(idx, flat);
  1685     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1686     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1687     if (flat->isa_instptr()) {
  1688       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1689           && flat->is_instptr()->klass() == env()->Class_klass())
  1690         alias_type(idx)->set_rewritable(false);
  1692     if (flat->isa_aryptr()) {
  1693 #ifdef ASSERT
  1694       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1695       // (T_BYTE has the weakest alignment and size restrictions...)
  1696       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
  1697 #endif
  1698       if (flat->offset() == TypePtr::OffsetBot) {
  1699         alias_type(idx)->set_element(flat->is_aryptr()->elem());
  1702     if (flat->isa_klassptr()) {
  1703       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
  1704         alias_type(idx)->set_rewritable(false);
  1705       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
  1706         alias_type(idx)->set_rewritable(false);
  1707       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
  1708         alias_type(idx)->set_rewritable(false);
  1709       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
  1710         alias_type(idx)->set_rewritable(false);
  1712     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1713     // but the base pointer type is not distinctive enough to identify
  1714     // references into JavaThread.)
  1716     // Check for final fields.
  1717     const TypeInstPtr* tinst = flat->isa_instptr();
  1718     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1719       ciField* field;
  1720       if (tinst->const_oop() != NULL &&
  1721           tinst->klass() == ciEnv::current()->Class_klass() &&
  1722           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
  1723         // static field
  1724         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
  1725         field = k->get_field_by_offset(tinst->offset(), true);
  1726       } else {
  1727         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1728         field = k->get_field_by_offset(tinst->offset(), false);
  1730       assert(field == NULL ||
  1731              original_field == NULL ||
  1732              (field->holder() == original_field->holder() &&
  1733               field->offset() == original_field->offset() &&
  1734               field->is_static() == original_field->is_static()), "wrong field?");
  1735       // Set field() and is_rewritable() attributes.
  1736       if (field != NULL)  alias_type(idx)->set_field(field);
  1740   // Fill the cache for next time.
  1741   ace->_adr_type = adr_type;
  1742   ace->_index    = idx;
  1743   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1745   // Might as well try to fill the cache for the flattened version, too.
  1746   AliasCacheEntry* face = probe_alias_cache(flat);
  1747   if (face->_adr_type == NULL) {
  1748     face->_adr_type = flat;
  1749     face->_index    = idx;
  1750     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1753   return alias_type(idx);
  1757 Compile::AliasType* Compile::alias_type(ciField* field) {
  1758   const TypeOopPtr* t;
  1759   if (field->is_static())
  1760     t = TypeInstPtr::make(field->holder()->java_mirror());
  1761   else
  1762     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1763   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
  1764   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
  1765   return atp;
  1769 //------------------------------have_alias_type--------------------------------
  1770 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1771   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1772   if (ace->_adr_type == adr_type) {
  1773     return true;
  1776   // Handle special cases.
  1777   if (adr_type == NULL)             return true;
  1778   if (adr_type == TypePtr::BOTTOM)  return true;
  1780   return find_alias_type(adr_type, true, NULL) != NULL;
  1783 //-----------------------------must_alias--------------------------------------
  1784 // True if all values of the given address type are in the given alias category.
  1785 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1786   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1787   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1788   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1789   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1791   // the only remaining possible overlap is identity
  1792   int adr_idx = get_alias_index(adr_type);
  1793   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1794   assert(adr_idx == alias_idx ||
  1795          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1796           && adr_type                       != TypeOopPtr::BOTTOM),
  1797          "should not be testing for overlap with an unsafe pointer");
  1798   return adr_idx == alias_idx;
  1801 //------------------------------can_alias--------------------------------------
  1802 // True if any values of the given address type are in the given alias category.
  1803 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1804   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1805   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1806   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1807   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1809   // the only remaining possible overlap is identity
  1810   int adr_idx = get_alias_index(adr_type);
  1811   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1812   return adr_idx == alias_idx;
  1817 //---------------------------pop_warm_call-------------------------------------
  1818 WarmCallInfo* Compile::pop_warm_call() {
  1819   WarmCallInfo* wci = _warm_calls;
  1820   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1821   return wci;
  1824 //----------------------------Inline_Warm--------------------------------------
  1825 int Compile::Inline_Warm() {
  1826   // If there is room, try to inline some more warm call sites.
  1827   // %%% Do a graph index compaction pass when we think we're out of space?
  1828   if (!InlineWarmCalls)  return 0;
  1830   int calls_made_hot = 0;
  1831   int room_to_grow   = NodeCountInliningCutoff - unique();
  1832   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1833   int amount_grown   = 0;
  1834   WarmCallInfo* call;
  1835   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1836     int est_size = (int)call->size();
  1837     if (est_size > (room_to_grow - amount_grown)) {
  1838       // This one won't fit anyway.  Get rid of it.
  1839       call->make_cold();
  1840       continue;
  1842     call->make_hot();
  1843     calls_made_hot++;
  1844     amount_grown   += est_size;
  1845     amount_to_grow -= est_size;
  1848   if (calls_made_hot > 0)  set_major_progress();
  1849   return calls_made_hot;
  1853 //----------------------------Finish_Warm--------------------------------------
  1854 void Compile::Finish_Warm() {
  1855   if (!InlineWarmCalls)  return;
  1856   if (failing())  return;
  1857   if (warm_calls() == NULL)  return;
  1859   // Clean up loose ends, if we are out of space for inlining.
  1860   WarmCallInfo* call;
  1861   while ((call = pop_warm_call()) != NULL) {
  1862     call->make_cold();
  1866 //---------------------cleanup_loop_predicates-----------------------
  1867 // Remove the opaque nodes that protect the predicates so that all unused
  1868 // checks and uncommon_traps will be eliminated from the ideal graph
  1869 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1870   if (predicate_count()==0) return;
  1871   for (int i = predicate_count(); i > 0; i--) {
  1872     Node * n = predicate_opaque1_node(i-1);
  1873     assert(n->Opcode() == Op_Opaque1, "must be");
  1874     igvn.replace_node(n, n->in(1));
  1876   assert(predicate_count()==0, "should be clean!");
  1879 // StringOpts and late inlining of string methods
  1880 void Compile::inline_string_calls(bool parse_time) {
  1882     // remove useless nodes to make the usage analysis simpler
  1883     ResourceMark rm;
  1884     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  1888     ResourceMark rm;
  1889     print_method(PHASE_BEFORE_STRINGOPTS, 3);
  1890     PhaseStringOpts pso(initial_gvn(), for_igvn());
  1891     print_method(PHASE_AFTER_STRINGOPTS, 3);
  1894   // now inline anything that we skipped the first time around
  1895   if (!parse_time) {
  1896     _late_inlines_pos = _late_inlines.length();
  1899   while (_string_late_inlines.length() > 0) {
  1900     CallGenerator* cg = _string_late_inlines.pop();
  1901     cg->do_late_inline();
  1902     if (failing())  return;
  1904   _string_late_inlines.trunc_to(0);
  1907 // Late inlining of boxing methods
  1908 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
  1909   if (_boxing_late_inlines.length() > 0) {
  1910     assert(has_boxed_value(), "inconsistent");
  1912     PhaseGVN* gvn = initial_gvn();
  1913     set_inlining_incrementally(true);
  1915     assert( igvn._worklist.size() == 0, "should be done with igvn" );
  1916     for_igvn()->clear();
  1917     gvn->replace_with(&igvn);
  1919     _late_inlines_pos = _late_inlines.length();
  1921     while (_boxing_late_inlines.length() > 0) {
  1922       CallGenerator* cg = _boxing_late_inlines.pop();
  1923       cg->do_late_inline();
  1924       if (failing())  return;
  1926     _boxing_late_inlines.trunc_to(0);
  1929       ResourceMark rm;
  1930       PhaseRemoveUseless pru(gvn, for_igvn());
  1933     igvn = PhaseIterGVN(gvn);
  1934     igvn.optimize();
  1936     set_inlining_progress(false);
  1937     set_inlining_incrementally(false);
  1941 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
  1942   assert(IncrementalInline, "incremental inlining should be on");
  1943   PhaseGVN* gvn = initial_gvn();
  1945   set_inlining_progress(false);
  1946   for_igvn()->clear();
  1947   gvn->replace_with(&igvn);
  1949   int i = 0;
  1951   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
  1952     CallGenerator* cg = _late_inlines.at(i);
  1953     _late_inlines_pos = i+1;
  1954     cg->do_late_inline();
  1955     if (failing())  return;
  1957   int j = 0;
  1958   for (; i < _late_inlines.length(); i++, j++) {
  1959     _late_inlines.at_put(j, _late_inlines.at(i));
  1961   _late_inlines.trunc_to(j);
  1964     ResourceMark rm;
  1965     PhaseRemoveUseless pru(gvn, for_igvn());
  1968   igvn = PhaseIterGVN(gvn);
  1971 // Perform incremental inlining until bound on number of live nodes is reached
  1972 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
  1973   PhaseGVN* gvn = initial_gvn();
  1975   set_inlining_incrementally(true);
  1976   set_inlining_progress(true);
  1977   uint low_live_nodes = 0;
  1979   while(inlining_progress() && _late_inlines.length() > 0) {
  1981     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  1982       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
  1983         // PhaseIdealLoop is expensive so we only try it once we are
  1984         // out of live nodes and we only try it again if the previous
  1985         // helped got the number of nodes down significantly
  1986         PhaseIdealLoop ideal_loop( igvn, false, true );
  1987         if (failing())  return;
  1988         low_live_nodes = live_nodes();
  1989         _major_progress = true;
  1992       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  1993         break;
  1997     inline_incrementally_one(igvn);
  1999     if (failing())  return;
  2001     igvn.optimize();
  2003     if (failing())  return;
  2006   assert( igvn._worklist.size() == 0, "should be done with igvn" );
  2008   if (_string_late_inlines.length() > 0) {
  2009     assert(has_stringbuilder(), "inconsistent");
  2010     for_igvn()->clear();
  2011     initial_gvn()->replace_with(&igvn);
  2013     inline_string_calls(false);
  2015     if (failing())  return;
  2018       ResourceMark rm;
  2019       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  2022     igvn = PhaseIterGVN(gvn);
  2024     igvn.optimize();
  2027   set_inlining_incrementally(false);
  2031 //------------------------------Optimize---------------------------------------
  2032 // Given a graph, optimize it.
  2033 void Compile::Optimize() {
  2034   TracePhase t1("optimizer", &_t_optimizer, true);
  2036 #ifndef PRODUCT
  2037   if (env()->break_at_compile()) {
  2038     BREAKPOINT;
  2041 #endif
  2043   ResourceMark rm;
  2044   int          loop_opts_cnt;
  2046   NOT_PRODUCT( verify_graph_edges(); )
  2048   print_method(PHASE_AFTER_PARSING);
  2051   // Iterative Global Value Numbering, including ideal transforms
  2052   // Initialize IterGVN with types and values from parse-time GVN
  2053   PhaseIterGVN igvn(initial_gvn());
  2055     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  2056     igvn.optimize();
  2059   print_method(PHASE_ITER_GVN1, 2);
  2061   if (failing())  return;
  2064     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2065     inline_incrementally(igvn);
  2068   print_method(PHASE_INCREMENTAL_INLINE, 2);
  2070   if (failing())  return;
  2072   if (eliminate_boxing()) {
  2073     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2074     // Inline valueOf() methods now.
  2075     inline_boxing_calls(igvn);
  2077     if (AlwaysIncrementalInline) {
  2078       inline_incrementally(igvn);
  2081     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
  2083     if (failing())  return;
  2086   // Remove the speculative part of types and clean up the graph from
  2087   // the extra CastPP nodes whose only purpose is to carry them. Do
  2088   // that early so that optimizations are not disrupted by the extra
  2089   // CastPP nodes.
  2090   remove_speculative_types(igvn);
  2092   // No more new expensive nodes will be added to the list from here
  2093   // so keep only the actual candidates for optimizations.
  2094   cleanup_expensive_nodes(igvn);
  2096   // Perform escape analysis
  2097   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
  2098     if (has_loops()) {
  2099       // Cleanup graph (remove dead nodes).
  2100       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2101       PhaseIdealLoop ideal_loop( igvn, false, true );
  2102       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
  2103       if (failing())  return;
  2105     ConnectionGraph::do_analysis(this, &igvn);
  2107     if (failing())  return;
  2109     // Optimize out fields loads from scalar replaceable allocations.
  2110     igvn.optimize();
  2111     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
  2113     if (failing())  return;
  2115     if (congraph() != NULL && macro_count() > 0) {
  2116       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
  2117       PhaseMacroExpand mexp(igvn);
  2118       mexp.eliminate_macro_nodes();
  2119       igvn.set_delay_transform(false);
  2121       igvn.optimize();
  2122       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
  2124       if (failing())  return;
  2128   // Loop transforms on the ideal graph.  Range Check Elimination,
  2129   // peeling, unrolling, etc.
  2131   // Set loop opts counter
  2132   loop_opts_cnt = num_loop_opts();
  2133   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  2135       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2136       PhaseIdealLoop ideal_loop( igvn, true );
  2137       loop_opts_cnt--;
  2138       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
  2139       if (failing())  return;
  2141     // Loop opts pass if partial peeling occurred in previous pass
  2142     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  2143       TracePhase t3("idealLoop", &_t_idealLoop, true);
  2144       PhaseIdealLoop ideal_loop( igvn, false );
  2145       loop_opts_cnt--;
  2146       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
  2147       if (failing())  return;
  2149     // Loop opts pass for loop-unrolling before CCP
  2150     if(major_progress() && (loop_opts_cnt > 0)) {
  2151       TracePhase t4("idealLoop", &_t_idealLoop, true);
  2152       PhaseIdealLoop ideal_loop( igvn, false );
  2153       loop_opts_cnt--;
  2154       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
  2156     if (!failing()) {
  2157       // Verify that last round of loop opts produced a valid graph
  2158       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2159       PhaseIdealLoop::verify(igvn);
  2162   if (failing())  return;
  2164   // Conditional Constant Propagation;
  2165   PhaseCCP ccp( &igvn );
  2166   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  2168     TracePhase t2("ccp", &_t_ccp, true);
  2169     ccp.do_transform();
  2171   print_method(PHASE_CPP1, 2);
  2173   assert( true, "Break here to ccp.dump_old2new_map()");
  2175   // Iterative Global Value Numbering, including ideal transforms
  2177     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  2178     igvn = ccp;
  2179     igvn.optimize();
  2182   print_method(PHASE_ITER_GVN2, 2);
  2184   if (failing())  return;
  2186   // Loop transforms on the ideal graph.  Range Check Elimination,
  2187   // peeling, unrolling, etc.
  2188   if(loop_opts_cnt > 0) {
  2189     debug_only( int cnt = 0; );
  2190     while(major_progress() && (loop_opts_cnt > 0)) {
  2191       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2192       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  2193       PhaseIdealLoop ideal_loop( igvn, true);
  2194       loop_opts_cnt--;
  2195       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
  2196       if (failing())  return;
  2201     // Verify that all previous optimizations produced a valid graph
  2202     // at least to this point, even if no loop optimizations were done.
  2203     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2204     PhaseIdealLoop::verify(igvn);
  2208     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  2209     PhaseMacroExpand  mex(igvn);
  2210     if (mex.expand_macro_nodes()) {
  2211       assert(failing(), "must bail out w/ explicit message");
  2212       return;
  2216  } // (End scope of igvn; run destructor if necessary for asserts.)
  2218   dump_inlining();
  2219   // A method with only infinite loops has no edges entering loops from root
  2221     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  2222     if (final_graph_reshaping()) {
  2223       assert(failing(), "must bail out w/ explicit message");
  2224       return;
  2228   print_method(PHASE_OPTIMIZE_FINISHED, 2);
  2232 //------------------------------Code_Gen---------------------------------------
  2233 // Given a graph, generate code for it
  2234 void Compile::Code_Gen() {
  2235   if (failing()) {
  2236     return;
  2239   // Perform instruction selection.  You might think we could reclaim Matcher
  2240   // memory PDQ, but actually the Matcher is used in generating spill code.
  2241   // Internals of the Matcher (including some VectorSets) must remain live
  2242   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  2243   // set a bit in reclaimed memory.
  2245   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2246   // nodes.  Mapping is only valid at the root of each matched subtree.
  2247   NOT_PRODUCT( verify_graph_edges(); )
  2249   Matcher matcher;
  2250   _matcher = &matcher;
  2252     TracePhase t2("matcher", &_t_matcher, true);
  2253     matcher.match();
  2255   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2256   // nodes.  Mapping is only valid at the root of each matched subtree.
  2257   NOT_PRODUCT( verify_graph_edges(); )
  2259   // If you have too many nodes, or if matching has failed, bail out
  2260   check_node_count(0, "out of nodes matching instructions");
  2261   if (failing()) {
  2262     return;
  2265   // Build a proper-looking CFG
  2266   PhaseCFG cfg(node_arena(), root(), matcher);
  2267   _cfg = &cfg;
  2269     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  2270     bool success = cfg.do_global_code_motion();
  2271     if (!success) {
  2272       return;
  2275     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
  2276     NOT_PRODUCT( verify_graph_edges(); )
  2277     debug_only( cfg.verify(); )
  2280   PhaseChaitin regalloc(unique(), cfg, matcher);
  2281   _regalloc = &regalloc;
  2283     TracePhase t2("regalloc", &_t_registerAllocation, true);
  2284     // Perform register allocation.  After Chaitin, use-def chains are
  2285     // no longer accurate (at spill code) and so must be ignored.
  2286     // Node->LRG->reg mappings are still accurate.
  2287     _regalloc->Register_Allocate();
  2289     // Bail out if the allocator builds too many nodes
  2290     if (failing()) {
  2291       return;
  2295   // Prior to register allocation we kept empty basic blocks in case the
  2296   // the allocator needed a place to spill.  After register allocation we
  2297   // are not adding any new instructions.  If any basic block is empty, we
  2298   // can now safely remove it.
  2300     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  2301     cfg.remove_empty_blocks();
  2302     if (do_freq_based_layout()) {
  2303       PhaseBlockLayout layout(cfg);
  2304     } else {
  2305       cfg.set_loop_alignment();
  2307     cfg.fixup_flow();
  2310   // Apply peephole optimizations
  2311   if( OptoPeephole ) {
  2312     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  2313     PhasePeephole peep( _regalloc, cfg);
  2314     peep.do_transform();
  2317   // Do late expand if CPU requires this.
  2318   if (Matcher::require_postalloc_expand) {
  2319     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
  2320     cfg.postalloc_expand(_regalloc);
  2323   // Convert Nodes to instruction bits in a buffer
  2325     // %%%% workspace merge brought two timers together for one job
  2326     TracePhase t2a("output", &_t_output, true);
  2327     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  2328     Output();
  2331   print_method(PHASE_FINAL_CODE);
  2333   // He's dead, Jim.
  2334   _cfg     = (PhaseCFG*)0xdeadbeef;
  2335   _regalloc = (PhaseChaitin*)0xdeadbeef;
  2339 //------------------------------dump_asm---------------------------------------
  2340 // Dump formatted assembly
  2341 #ifndef PRODUCT
  2342 void Compile::dump_asm(int *pcs, uint pc_limit) {
  2343   bool cut_short = false;
  2344   tty->print_cr("#");
  2345   tty->print("#  ");  _tf->dump();  tty->cr();
  2346   tty->print_cr("#");
  2348   // For all blocks
  2349   int pc = 0x0;                 // Program counter
  2350   char starts_bundle = ' ';
  2351   _regalloc->dump_frame();
  2353   Node *n = NULL;
  2354   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  2355     if (VMThread::should_terminate()) {
  2356       cut_short = true;
  2357       break;
  2359     Block* block = _cfg->get_block(i);
  2360     if (block->is_connector() && !Verbose) {
  2361       continue;
  2363     n = block->head();
  2364     if (pcs && n->_idx < pc_limit) {
  2365       tty->print("%3.3x   ", pcs[n->_idx]);
  2366     } else {
  2367       tty->print("      ");
  2369     block->dump_head(_cfg);
  2370     if (block->is_connector()) {
  2371       tty->print_cr("        # Empty connector block");
  2372     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  2373       tty->print_cr("        # Block is sole successor of call");
  2376     // For all instructions
  2377     Node *delay = NULL;
  2378     for (uint j = 0; j < block->number_of_nodes(); j++) {
  2379       if (VMThread::should_terminate()) {
  2380         cut_short = true;
  2381         break;
  2383       n = block->get_node(j);
  2384       if (valid_bundle_info(n)) {
  2385         Bundle* bundle = node_bundling(n);
  2386         if (bundle->used_in_unconditional_delay()) {
  2387           delay = n;
  2388           continue;
  2390         if (bundle->starts_bundle()) {
  2391           starts_bundle = '+';
  2395       if (WizardMode) {
  2396         n->dump();
  2399       if( !n->is_Region() &&    // Dont print in the Assembly
  2400           !n->is_Phi() &&       // a few noisely useless nodes
  2401           !n->is_Proj() &&
  2402           !n->is_MachTemp() &&
  2403           !n->is_SafePointScalarObject() &&
  2404           !n->is_Catch() &&     // Would be nice to print exception table targets
  2405           !n->is_MergeMem() &&  // Not very interesting
  2406           !n->is_top() &&       // Debug info table constants
  2407           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  2408           ) {
  2409         if (pcs && n->_idx < pc_limit)
  2410           tty->print("%3.3x", pcs[n->_idx]);
  2411         else
  2412           tty->print("   ");
  2413         tty->print(" %c ", starts_bundle);
  2414         starts_bundle = ' ';
  2415         tty->print("\t");
  2416         n->format(_regalloc, tty);
  2417         tty->cr();
  2420       // If we have an instruction with a delay slot, and have seen a delay,
  2421       // then back up and print it
  2422       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  2423         assert(delay != NULL, "no unconditional delay instruction");
  2424         if (WizardMode) delay->dump();
  2426         if (node_bundling(delay)->starts_bundle())
  2427           starts_bundle = '+';
  2428         if (pcs && n->_idx < pc_limit)
  2429           tty->print("%3.3x", pcs[n->_idx]);
  2430         else
  2431           tty->print("   ");
  2432         tty->print(" %c ", starts_bundle);
  2433         starts_bundle = ' ';
  2434         tty->print("\t");
  2435         delay->format(_regalloc, tty);
  2436         tty->cr();
  2437         delay = NULL;
  2440       // Dump the exception table as well
  2441       if( n->is_Catch() && (Verbose || WizardMode) ) {
  2442         // Print the exception table for this offset
  2443         _handler_table.print_subtable_for(pc);
  2447     if (pcs && n->_idx < pc_limit)
  2448       tty->print_cr("%3.3x", pcs[n->_idx]);
  2449     else
  2450       tty->cr();
  2452     assert(cut_short || delay == NULL, "no unconditional delay branch");
  2454   } // End of per-block dump
  2455   tty->cr();
  2457   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  2459 #endif
  2461 //------------------------------Final_Reshape_Counts---------------------------
  2462 // This class defines counters to help identify when a method
  2463 // may/must be executed using hardware with only 24-bit precision.
  2464 struct Final_Reshape_Counts : public StackObj {
  2465   int  _call_count;             // count non-inlined 'common' calls
  2466   int  _float_count;            // count float ops requiring 24-bit precision
  2467   int  _double_count;           // count double ops requiring more precision
  2468   int  _java_call_count;        // count non-inlined 'java' calls
  2469   int  _inner_loop_count;       // count loops which need alignment
  2470   VectorSet _visited;           // Visitation flags
  2471   Node_List _tests;             // Set of IfNodes & PCTableNodes
  2473   Final_Reshape_Counts() :
  2474     _call_count(0), _float_count(0), _double_count(0),
  2475     _java_call_count(0), _inner_loop_count(0),
  2476     _visited( Thread::current()->resource_area() ) { }
  2478   void inc_call_count  () { _call_count  ++; }
  2479   void inc_float_count () { _float_count ++; }
  2480   void inc_double_count() { _double_count++; }
  2481   void inc_java_call_count() { _java_call_count++; }
  2482   void inc_inner_loop_count() { _inner_loop_count++; }
  2484   int  get_call_count  () const { return _call_count  ; }
  2485   int  get_float_count () const { return _float_count ; }
  2486   int  get_double_count() const { return _double_count; }
  2487   int  get_java_call_count() const { return _java_call_count; }
  2488   int  get_inner_loop_count() const { return _inner_loop_count; }
  2489 };
  2491 #ifdef ASSERT
  2492 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  2493   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  2494   // Make sure the offset goes inside the instance layout.
  2495   return k->contains_field_offset(tp->offset());
  2496   // Note that OffsetBot and OffsetTop are very negative.
  2498 #endif
  2500 // Eliminate trivially redundant StoreCMs and accumulate their
  2501 // precedence edges.
  2502 void Compile::eliminate_redundant_card_marks(Node* n) {
  2503   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
  2504   if (n->in(MemNode::Address)->outcnt() > 1) {
  2505     // There are multiple users of the same address so it might be
  2506     // possible to eliminate some of the StoreCMs
  2507     Node* mem = n->in(MemNode::Memory);
  2508     Node* adr = n->in(MemNode::Address);
  2509     Node* val = n->in(MemNode::ValueIn);
  2510     Node* prev = n;
  2511     bool done = false;
  2512     // Walk the chain of StoreCMs eliminating ones that match.  As
  2513     // long as it's a chain of single users then the optimization is
  2514     // safe.  Eliminating partially redundant StoreCMs would require
  2515     // cloning copies down the other paths.
  2516     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
  2517       if (adr == mem->in(MemNode::Address) &&
  2518           val == mem->in(MemNode::ValueIn)) {
  2519         // redundant StoreCM
  2520         if (mem->req() > MemNode::OopStore) {
  2521           // Hasn't been processed by this code yet.
  2522           n->add_prec(mem->in(MemNode::OopStore));
  2523         } else {
  2524           // Already converted to precedence edge
  2525           for (uint i = mem->req(); i < mem->len(); i++) {
  2526             // Accumulate any precedence edges
  2527             if (mem->in(i) != NULL) {
  2528               n->add_prec(mem->in(i));
  2531           // Everything above this point has been processed.
  2532           done = true;
  2534         // Eliminate the previous StoreCM
  2535         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
  2536         assert(mem->outcnt() == 0, "should be dead");
  2537         mem->disconnect_inputs(NULL, this);
  2538       } else {
  2539         prev = mem;
  2541       mem = prev->in(MemNode::Memory);
  2546 //------------------------------final_graph_reshaping_impl----------------------
  2547 // Implement items 1-5 from final_graph_reshaping below.
  2548 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
  2550   if ( n->outcnt() == 0 ) return; // dead node
  2551   uint nop = n->Opcode();
  2553   // Check for 2-input instruction with "last use" on right input.
  2554   // Swap to left input.  Implements item (2).
  2555   if( n->req() == 3 &&          // two-input instruction
  2556       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  2557       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  2558       n->in(2)->outcnt() == 1 &&// right use IS a last use
  2559       !n->in(2)->is_Con() ) {   // right use is not a constant
  2560     // Check for commutative opcode
  2561     switch( nop ) {
  2562     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  2563     case Op_MaxI:  case Op_MinI:
  2564     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  2565     case Op_AndL:  case Op_XorL:  case Op_OrL:
  2566     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  2567       // Move "last use" input to left by swapping inputs
  2568       n->swap_edges(1, 2);
  2569       break;
  2571     default:
  2572       break;
  2576 #ifdef ASSERT
  2577   if( n->is_Mem() ) {
  2578     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
  2579     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2580             // oop will be recorded in oop map if load crosses safepoint
  2581             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2582                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2583             "raw memory operations should have control edge");
  2585 #endif
  2586   // Count FPU ops and common calls, implements item (3)
  2587   switch( nop ) {
  2588   // Count all float operations that may use FPU
  2589   case Op_AddF:
  2590   case Op_SubF:
  2591   case Op_MulF:
  2592   case Op_DivF:
  2593   case Op_NegF:
  2594   case Op_ModF:
  2595   case Op_ConvI2F:
  2596   case Op_ConF:
  2597   case Op_CmpF:
  2598   case Op_CmpF3:
  2599   // case Op_ConvL2F: // longs are split into 32-bit halves
  2600     frc.inc_float_count();
  2601     break;
  2603   case Op_ConvF2D:
  2604   case Op_ConvD2F:
  2605     frc.inc_float_count();
  2606     frc.inc_double_count();
  2607     break;
  2609   // Count all double operations that may use FPU
  2610   case Op_AddD:
  2611   case Op_SubD:
  2612   case Op_MulD:
  2613   case Op_DivD:
  2614   case Op_NegD:
  2615   case Op_ModD:
  2616   case Op_ConvI2D:
  2617   case Op_ConvD2I:
  2618   // case Op_ConvL2D: // handled by leaf call
  2619   // case Op_ConvD2L: // handled by leaf call
  2620   case Op_ConD:
  2621   case Op_CmpD:
  2622   case Op_CmpD3:
  2623     frc.inc_double_count();
  2624     break;
  2625   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2626   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2627   case Op_Opaque3:
  2628     n->subsume_by(n->in(1), this);
  2629     break;
  2630   case Op_CallStaticJava:
  2631   case Op_CallJava:
  2632   case Op_CallDynamicJava:
  2633     frc.inc_java_call_count(); // Count java call site;
  2634   case Op_CallRuntime:
  2635   case Op_CallLeaf:
  2636   case Op_CallLeafNoFP: {
  2637     assert( n->is_Call(), "" );
  2638     CallNode *call = n->as_Call();
  2639     // Count call sites where the FP mode bit would have to be flipped.
  2640     // Do not count uncommon runtime calls:
  2641     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2642     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2643     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2644       frc.inc_call_count();   // Count the call site
  2645     } else {                  // See if uncommon argument is shared
  2646       Node *n = call->in(TypeFunc::Parms);
  2647       int nop = n->Opcode();
  2648       // Clone shared simple arguments to uncommon calls, item (1).
  2649       if( n->outcnt() > 1 &&
  2650           !n->is_Proj() &&
  2651           nop != Op_CreateEx &&
  2652           nop != Op_CheckCastPP &&
  2653           nop != Op_DecodeN &&
  2654           nop != Op_DecodeNKlass &&
  2655           !n->is_Mem() ) {
  2656         Node *x = n->clone();
  2657         call->set_req( TypeFunc::Parms, x );
  2660     break;
  2663   case Op_StoreD:
  2664   case Op_LoadD:
  2665   case Op_LoadD_unaligned:
  2666     frc.inc_double_count();
  2667     goto handle_mem;
  2668   case Op_StoreF:
  2669   case Op_LoadF:
  2670     frc.inc_float_count();
  2671     goto handle_mem;
  2673   case Op_StoreCM:
  2675       // Convert OopStore dependence into precedence edge
  2676       Node* prec = n->in(MemNode::OopStore);
  2677       n->del_req(MemNode::OopStore);
  2678       n->add_prec(prec);
  2679       eliminate_redundant_card_marks(n);
  2682     // fall through
  2684   case Op_StoreB:
  2685   case Op_StoreC:
  2686   case Op_StorePConditional:
  2687   case Op_StoreI:
  2688   case Op_StoreL:
  2689   case Op_StoreIConditional:
  2690   case Op_StoreLConditional:
  2691   case Op_CompareAndSwapI:
  2692   case Op_CompareAndSwapL:
  2693   case Op_CompareAndSwapP:
  2694   case Op_CompareAndSwapN:
  2695   case Op_GetAndAddI:
  2696   case Op_GetAndAddL:
  2697   case Op_GetAndSetI:
  2698   case Op_GetAndSetL:
  2699   case Op_GetAndSetP:
  2700   case Op_GetAndSetN:
  2701   case Op_StoreP:
  2702   case Op_StoreN:
  2703   case Op_StoreNKlass:
  2704   case Op_LoadB:
  2705   case Op_LoadUB:
  2706   case Op_LoadUS:
  2707   case Op_LoadI:
  2708   case Op_LoadKlass:
  2709   case Op_LoadNKlass:
  2710   case Op_LoadL:
  2711   case Op_LoadL_unaligned:
  2712   case Op_LoadPLocked:
  2713   case Op_LoadP:
  2714   case Op_LoadN:
  2715   case Op_LoadRange:
  2716   case Op_LoadS: {
  2717   handle_mem:
  2718 #ifdef ASSERT
  2719     if( VerifyOptoOopOffsets ) {
  2720       assert( n->is_Mem(), "" );
  2721       MemNode *mem  = (MemNode*)n;
  2722       // Check to see if address types have grounded out somehow.
  2723       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2724       assert( !tp || oop_offset_is_sane(tp), "" );
  2726 #endif
  2727     break;
  2730   case Op_AddP: {               // Assert sane base pointers
  2731     Node *addp = n->in(AddPNode::Address);
  2732     assert( !addp->is_AddP() ||
  2733             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2734             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2735             "Base pointers must match" );
  2736 #ifdef _LP64
  2737     if ((UseCompressedOops || UseCompressedClassPointers) &&
  2738         addp->Opcode() == Op_ConP &&
  2739         addp == n->in(AddPNode::Base) &&
  2740         n->in(AddPNode::Offset)->is_Con()) {
  2741       // Use addressing with narrow klass to load with offset on x86.
  2742       // On sparc loading 32-bits constant and decoding it have less
  2743       // instructions (4) then load 64-bits constant (7).
  2744       // Do this transformation here since IGVN will convert ConN back to ConP.
  2745       const Type* t = addp->bottom_type();
  2746       if (t->isa_oopptr() || t->isa_klassptr()) {
  2747         Node* nn = NULL;
  2749         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
  2751         // Look for existing ConN node of the same exact type.
  2752         Node* r  = root();
  2753         uint cnt = r->outcnt();
  2754         for (uint i = 0; i < cnt; i++) {
  2755           Node* m = r->raw_out(i);
  2756           if (m!= NULL && m->Opcode() == op &&
  2757               m->bottom_type()->make_ptr() == t) {
  2758             nn = m;
  2759             break;
  2762         if (nn != NULL) {
  2763           // Decode a narrow oop to match address
  2764           // [R12 + narrow_oop_reg<<3 + offset]
  2765           if (t->isa_oopptr()) {
  2766             nn = new (this) DecodeNNode(nn, t);
  2767           } else {
  2768             nn = new (this) DecodeNKlassNode(nn, t);
  2770           n->set_req(AddPNode::Base, nn);
  2771           n->set_req(AddPNode::Address, nn);
  2772           if (addp->outcnt() == 0) {
  2773             addp->disconnect_inputs(NULL, this);
  2778 #endif
  2779     break;
  2782 #ifdef _LP64
  2783   case Op_CastPP:
  2784     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2785       Node* in1 = n->in(1);
  2786       const Type* t = n->bottom_type();
  2787       Node* new_in1 = in1->clone();
  2788       new_in1->as_DecodeN()->set_type(t);
  2790       if (!Matcher::narrow_oop_use_complex_address()) {
  2791         //
  2792         // x86, ARM and friends can handle 2 adds in addressing mode
  2793         // and Matcher can fold a DecodeN node into address by using
  2794         // a narrow oop directly and do implicit NULL check in address:
  2795         //
  2796         // [R12 + narrow_oop_reg<<3 + offset]
  2797         // NullCheck narrow_oop_reg
  2798         //
  2799         // On other platforms (Sparc) we have to keep new DecodeN node and
  2800         // use it to do implicit NULL check in address:
  2801         //
  2802         // decode_not_null narrow_oop_reg, base_reg
  2803         // [base_reg + offset]
  2804         // NullCheck base_reg
  2805         //
  2806         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2807         // to keep the information to which NULL check the new DecodeN node
  2808         // corresponds to use it as value in implicit_null_check().
  2809         //
  2810         new_in1->set_req(0, n->in(0));
  2813       n->subsume_by(new_in1, this);
  2814       if (in1->outcnt() == 0) {
  2815         in1->disconnect_inputs(NULL, this);
  2818     break;
  2820   case Op_CmpP:
  2821     // Do this transformation here to preserve CmpPNode::sub() and
  2822     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2823     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
  2824       Node* in1 = n->in(1);
  2825       Node* in2 = n->in(2);
  2826       if (!in1->is_DecodeNarrowPtr()) {
  2827         in2 = in1;
  2828         in1 = n->in(2);
  2830       assert(in1->is_DecodeNarrowPtr(), "sanity");
  2832       Node* new_in2 = NULL;
  2833       if (in2->is_DecodeNarrowPtr()) {
  2834         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
  2835         new_in2 = in2->in(1);
  2836       } else if (in2->Opcode() == Op_ConP) {
  2837         const Type* t = in2->bottom_type();
  2838         if (t == TypePtr::NULL_PTR) {
  2839           assert(in1->is_DecodeN(), "compare klass to null?");
  2840           // Don't convert CmpP null check into CmpN if compressed
  2841           // oops implicit null check is not generated.
  2842           // This will allow to generate normal oop implicit null check.
  2843           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2844             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
  2845           //
  2846           // This transformation together with CastPP transformation above
  2847           // will generated code for implicit NULL checks for compressed oops.
  2848           //
  2849           // The original code after Optimize()
  2850           //
  2851           //    LoadN memory, narrow_oop_reg
  2852           //    decode narrow_oop_reg, base_reg
  2853           //    CmpP base_reg, NULL
  2854           //    CastPP base_reg // NotNull
  2855           //    Load [base_reg + offset], val_reg
  2856           //
  2857           // after these transformations will be
  2858           //
  2859           //    LoadN memory, narrow_oop_reg
  2860           //    CmpN narrow_oop_reg, NULL
  2861           //    decode_not_null narrow_oop_reg, base_reg
  2862           //    Load [base_reg + offset], val_reg
  2863           //
  2864           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2865           // since narrow oops can be used in debug info now (see the code in
  2866           // final_graph_reshaping_walk()).
  2867           //
  2868           // At the end the code will be matched to
  2869           // on x86:
  2870           //
  2871           //    Load_narrow_oop memory, narrow_oop_reg
  2872           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2873           //    NullCheck narrow_oop_reg
  2874           //
  2875           // and on sparc:
  2876           //
  2877           //    Load_narrow_oop memory, narrow_oop_reg
  2878           //    decode_not_null narrow_oop_reg, base_reg
  2879           //    Load [base_reg + offset], val_reg
  2880           //    NullCheck base_reg
  2881           //
  2882         } else if (t->isa_oopptr()) {
  2883           new_in2 = ConNode::make(this, t->make_narrowoop());
  2884         } else if (t->isa_klassptr()) {
  2885           new_in2 = ConNode::make(this, t->make_narrowklass());
  2888       if (new_in2 != NULL) {
  2889         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
  2890         n->subsume_by(cmpN, this);
  2891         if (in1->outcnt() == 0) {
  2892           in1->disconnect_inputs(NULL, this);
  2894         if (in2->outcnt() == 0) {
  2895           in2->disconnect_inputs(NULL, this);
  2899     break;
  2901   case Op_DecodeN:
  2902   case Op_DecodeNKlass:
  2903     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
  2904     // DecodeN could be pinned when it can't be fold into
  2905     // an address expression, see the code for Op_CastPP above.
  2906     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
  2907     break;
  2909   case Op_EncodeP:
  2910   case Op_EncodePKlass: {
  2911     Node* in1 = n->in(1);
  2912     if (in1->is_DecodeNarrowPtr()) {
  2913       n->subsume_by(in1->in(1), this);
  2914     } else if (in1->Opcode() == Op_ConP) {
  2915       const Type* t = in1->bottom_type();
  2916       if (t == TypePtr::NULL_PTR) {
  2917         assert(t->isa_oopptr(), "null klass?");
  2918         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
  2919       } else if (t->isa_oopptr()) {
  2920         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
  2921       } else if (t->isa_klassptr()) {
  2922         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
  2925     if (in1->outcnt() == 0) {
  2926       in1->disconnect_inputs(NULL, this);
  2928     break;
  2931   case Op_Proj: {
  2932     if (OptimizeStringConcat) {
  2933       ProjNode* p = n->as_Proj();
  2934       if (p->_is_io_use) {
  2935         // Separate projections were used for the exception path which
  2936         // are normally removed by a late inline.  If it wasn't inlined
  2937         // then they will hang around and should just be replaced with
  2938         // the original one.
  2939         Node* proj = NULL;
  2940         // Replace with just one
  2941         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  2942           Node *use = i.get();
  2943           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  2944             proj = use;
  2945             break;
  2948         assert(proj != NULL, "must be found");
  2949         p->subsume_by(proj, this);
  2952     break;
  2955   case Op_Phi:
  2956     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
  2957       // The EncodeP optimization may create Phi with the same edges
  2958       // for all paths. It is not handled well by Register Allocator.
  2959       Node* unique_in = n->in(1);
  2960       assert(unique_in != NULL, "");
  2961       uint cnt = n->req();
  2962       for (uint i = 2; i < cnt; i++) {
  2963         Node* m = n->in(i);
  2964         assert(m != NULL, "");
  2965         if (unique_in != m)
  2966           unique_in = NULL;
  2968       if (unique_in != NULL) {
  2969         n->subsume_by(unique_in, this);
  2972     break;
  2974 #endif
  2976   case Op_ModI:
  2977     if (UseDivMod) {
  2978       // Check if a%b and a/b both exist
  2979       Node* d = n->find_similar(Op_DivI);
  2980       if (d) {
  2981         // Replace them with a fused divmod if supported
  2982         if (Matcher::has_match_rule(Op_DivModI)) {
  2983           DivModINode* divmod = DivModINode::make(this, n);
  2984           d->subsume_by(divmod->div_proj(), this);
  2985           n->subsume_by(divmod->mod_proj(), this);
  2986         } else {
  2987           // replace a%b with a-((a/b)*b)
  2988           Node* mult = new (this) MulINode(d, d->in(2));
  2989           Node* sub  = new (this) SubINode(d->in(1), mult);
  2990           n->subsume_by(sub, this);
  2994     break;
  2996   case Op_ModL:
  2997     if (UseDivMod) {
  2998       // Check if a%b and a/b both exist
  2999       Node* d = n->find_similar(Op_DivL);
  3000       if (d) {
  3001         // Replace them with a fused divmod if supported
  3002         if (Matcher::has_match_rule(Op_DivModL)) {
  3003           DivModLNode* divmod = DivModLNode::make(this, n);
  3004           d->subsume_by(divmod->div_proj(), this);
  3005           n->subsume_by(divmod->mod_proj(), this);
  3006         } else {
  3007           // replace a%b with a-((a/b)*b)
  3008           Node* mult = new (this) MulLNode(d, d->in(2));
  3009           Node* sub  = new (this) SubLNode(d->in(1), mult);
  3010           n->subsume_by(sub, this);
  3014     break;
  3016   case Op_LoadVector:
  3017   case Op_StoreVector:
  3018     break;
  3020   case Op_PackB:
  3021   case Op_PackS:
  3022   case Op_PackI:
  3023   case Op_PackF:
  3024   case Op_PackL:
  3025   case Op_PackD:
  3026     if (n->req()-1 > 2) {
  3027       // Replace many operand PackNodes with a binary tree for matching
  3028       PackNode* p = (PackNode*) n;
  3029       Node* btp = p->binary_tree_pack(this, 1, n->req());
  3030       n->subsume_by(btp, this);
  3032     break;
  3033   case Op_Loop:
  3034   case Op_CountedLoop:
  3035     if (n->as_Loop()->is_inner_loop()) {
  3036       frc.inc_inner_loop_count();
  3038     break;
  3039   case Op_LShiftI:
  3040   case Op_RShiftI:
  3041   case Op_URShiftI:
  3042   case Op_LShiftL:
  3043   case Op_RShiftL:
  3044   case Op_URShiftL:
  3045     if (Matcher::need_masked_shift_count) {
  3046       // The cpu's shift instructions don't restrict the count to the
  3047       // lower 5/6 bits. We need to do the masking ourselves.
  3048       Node* in2 = n->in(2);
  3049       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
  3050       const TypeInt* t = in2->find_int_type();
  3051       if (t != NULL && t->is_con()) {
  3052         juint shift = t->get_con();
  3053         if (shift > mask) { // Unsigned cmp
  3054           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
  3056       } else {
  3057         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
  3058           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
  3059           n->set_req(2, shift);
  3062       if (in2->outcnt() == 0) { // Remove dead node
  3063         in2->disconnect_inputs(NULL, this);
  3066     break;
  3067   case Op_MemBarStoreStore:
  3068   case Op_MemBarRelease:
  3069     // Break the link with AllocateNode: it is no longer useful and
  3070     // confuses register allocation.
  3071     if (n->req() > MemBarNode::Precedent) {
  3072       n->set_req(MemBarNode::Precedent, top());
  3074     break;
  3075   default:
  3076     assert( !n->is_Call(), "" );
  3077     assert( !n->is_Mem(), "" );
  3078     break;
  3081   // Collect CFG split points
  3082   if (n->is_MultiBranch())
  3083     frc._tests.push(n);
  3086 //------------------------------final_graph_reshaping_walk---------------------
  3087 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  3088 // requires that the walk visits a node's inputs before visiting the node.
  3089 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  3090   ResourceArea *area = Thread::current()->resource_area();
  3091   Unique_Node_List sfpt(area);
  3093   frc._visited.set(root->_idx); // first, mark node as visited
  3094   uint cnt = root->req();
  3095   Node *n = root;
  3096   uint  i = 0;
  3097   while (true) {
  3098     if (i < cnt) {
  3099       // Place all non-visited non-null inputs onto stack
  3100       Node* m = n->in(i);
  3101       ++i;
  3102       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  3103         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
  3104           // compute worst case interpreter size in case of a deoptimization
  3105           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
  3107           sfpt.push(m);
  3109         cnt = m->req();
  3110         nstack.push(n, i); // put on stack parent and next input's index
  3111         n = m;
  3112         i = 0;
  3114     } else {
  3115       // Now do post-visit work
  3116       final_graph_reshaping_impl( n, frc );
  3117       if (nstack.is_empty())
  3118         break;             // finished
  3119       n = nstack.node();   // Get node from stack
  3120       cnt = n->req();
  3121       i = nstack.index();
  3122       nstack.pop();        // Shift to the next node on stack
  3126   // Skip next transformation if compressed oops are not used.
  3127   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
  3128       (!UseCompressedOops && !UseCompressedClassPointers))
  3129     return;
  3131   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
  3132   // It could be done for an uncommon traps or any safepoints/calls
  3133   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
  3134   while (sfpt.size() > 0) {
  3135     n = sfpt.pop();
  3136     JVMState *jvms = n->as_SafePoint()->jvms();
  3137     assert(jvms != NULL, "sanity");
  3138     int start = jvms->debug_start();
  3139     int end   = n->req();
  3140     bool is_uncommon = (n->is_CallStaticJava() &&
  3141                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  3142     for (int j = start; j < end; j++) {
  3143       Node* in = n->in(j);
  3144       if (in->is_DecodeNarrowPtr()) {
  3145         bool safe_to_skip = true;
  3146         if (!is_uncommon ) {
  3147           // Is it safe to skip?
  3148           for (uint i = 0; i < in->outcnt(); i++) {
  3149             Node* u = in->raw_out(i);
  3150             if (!u->is_SafePoint() ||
  3151                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  3152               safe_to_skip = false;
  3156         if (safe_to_skip) {
  3157           n->set_req(j, in->in(1));
  3159         if (in->outcnt() == 0) {
  3160           in->disconnect_inputs(NULL, this);
  3167 //------------------------------final_graph_reshaping--------------------------
  3168 // Final Graph Reshaping.
  3169 //
  3170 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  3171 //     and not commoned up and forced early.  Must come after regular
  3172 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  3173 //     inputs to Loop Phis; these will be split by the allocator anyways.
  3174 //     Remove Opaque nodes.
  3175 // (2) Move last-uses by commutative operations to the left input to encourage
  3176 //     Intel update-in-place two-address operations and better register usage
  3177 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  3178 //     calls canonicalizing them back.
  3179 // (3) Count the number of double-precision FP ops, single-precision FP ops
  3180 //     and call sites.  On Intel, we can get correct rounding either by
  3181 //     forcing singles to memory (requires extra stores and loads after each
  3182 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  3183 //     clearing the mode bit around call sites).  The mode bit is only used
  3184 //     if the relative frequency of single FP ops to calls is low enough.
  3185 //     This is a key transform for SPEC mpeg_audio.
  3186 // (4) Detect infinite loops; blobs of code reachable from above but not
  3187 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  3188 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  3189 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  3190 //     Detection is by looking for IfNodes where only 1 projection is
  3191 //     reachable from below or CatchNodes missing some targets.
  3192 // (5) Assert for insane oop offsets in debug mode.
  3194 bool Compile::final_graph_reshaping() {
  3195   // an infinite loop may have been eliminated by the optimizer,
  3196   // in which case the graph will be empty.
  3197   if (root()->req() == 1) {
  3198     record_method_not_compilable("trivial infinite loop");
  3199     return true;
  3202   // Expensive nodes have their control input set to prevent the GVN
  3203   // from freely commoning them. There's no GVN beyond this point so
  3204   // no need to keep the control input. We want the expensive nodes to
  3205   // be freely moved to the least frequent code path by gcm.
  3206   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
  3207   for (int i = 0; i < expensive_count(); i++) {
  3208     _expensive_nodes->at(i)->set_req(0, NULL);
  3211   Final_Reshape_Counts frc;
  3213   // Visit everybody reachable!
  3214   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  3215   Node_Stack nstack(unique() >> 1);
  3216   final_graph_reshaping_walk(nstack, root(), frc);
  3218   // Check for unreachable (from below) code (i.e., infinite loops).
  3219   for( uint i = 0; i < frc._tests.size(); i++ ) {
  3220     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  3221     // Get number of CFG targets.
  3222     // Note that PCTables include exception targets after calls.
  3223     uint required_outcnt = n->required_outcnt();
  3224     if (n->outcnt() != required_outcnt) {
  3225       // Check for a few special cases.  Rethrow Nodes never take the
  3226       // 'fall-thru' path, so expected kids is 1 less.
  3227       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  3228         if (n->in(0)->in(0)->is_Call()) {
  3229           CallNode *call = n->in(0)->in(0)->as_Call();
  3230           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  3231             required_outcnt--;      // Rethrow always has 1 less kid
  3232           } else if (call->req() > TypeFunc::Parms &&
  3233                      call->is_CallDynamicJava()) {
  3234             // Check for null receiver. In such case, the optimizer has
  3235             // detected that the virtual call will always result in a null
  3236             // pointer exception. The fall-through projection of this CatchNode
  3237             // will not be populated.
  3238             Node *arg0 = call->in(TypeFunc::Parms);
  3239             if (arg0->is_Type() &&
  3240                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  3241               required_outcnt--;
  3243           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  3244                      call->req() > TypeFunc::Parms+1 &&
  3245                      call->is_CallStaticJava()) {
  3246             // Check for negative array length. In such case, the optimizer has
  3247             // detected that the allocation attempt will always result in an
  3248             // exception. There is no fall-through projection of this CatchNode .
  3249             Node *arg1 = call->in(TypeFunc::Parms+1);
  3250             if (arg1->is_Type() &&
  3251                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  3252               required_outcnt--;
  3257       // Recheck with a better notion of 'required_outcnt'
  3258       if (n->outcnt() != required_outcnt) {
  3259         record_method_not_compilable("malformed control flow");
  3260         return true;            // Not all targets reachable!
  3263     // Check that I actually visited all kids.  Unreached kids
  3264     // must be infinite loops.
  3265     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  3266       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  3267         record_method_not_compilable("infinite loop");
  3268         return true;            // Found unvisited kid; must be unreach
  3272   // If original bytecodes contained a mixture of floats and doubles
  3273   // check if the optimizer has made it homogenous, item (3).
  3274   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  3275       frc.get_float_count() > 32 &&
  3276       frc.get_double_count() == 0 &&
  3277       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  3278     set_24_bit_selection_and_mode( false,  true );
  3281   set_java_calls(frc.get_java_call_count());
  3282   set_inner_loops(frc.get_inner_loop_count());
  3284   // No infinite loops, no reason to bail out.
  3285   return false;
  3288 //-----------------------------too_many_traps----------------------------------
  3289 // Report if there are too many traps at the current method and bci.
  3290 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  3291 bool Compile::too_many_traps(ciMethod* method,
  3292                              int bci,
  3293                              Deoptimization::DeoptReason reason) {
  3294   ciMethodData* md = method->method_data();
  3295   if (md->is_empty()) {
  3296     // Assume the trap has not occurred, or that it occurred only
  3297     // because of a transient condition during start-up in the interpreter.
  3298     return false;
  3300   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3301   if (md->has_trap_at(bci, m, reason) != 0) {
  3302     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  3303     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3304     // assume the worst.
  3305     if (log())
  3306       log()->elem("observe trap='%s' count='%d'",
  3307                   Deoptimization::trap_reason_name(reason),
  3308                   md->trap_count(reason));
  3309     return true;
  3310   } else {
  3311     // Ignore method/bci and see if there have been too many globally.
  3312     return too_many_traps(reason, md);
  3316 // Less-accurate variant which does not require a method and bci.
  3317 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  3318                              ciMethodData* logmd) {
  3319   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
  3320     // Too many traps globally.
  3321     // Note that we use cumulative trap_count, not just md->trap_count.
  3322     if (log()) {
  3323       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  3324       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  3325                   Deoptimization::trap_reason_name(reason),
  3326                   mcount, trap_count(reason));
  3328     return true;
  3329   } else {
  3330     // The coast is clear.
  3331     return false;
  3335 //--------------------------too_many_recompiles--------------------------------
  3336 // Report if there are too many recompiles at the current method and bci.
  3337 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  3338 // Is not eager to return true, since this will cause the compiler to use
  3339 // Action_none for a trap point, to avoid too many recompilations.
  3340 bool Compile::too_many_recompiles(ciMethod* method,
  3341                                   int bci,
  3342                                   Deoptimization::DeoptReason reason) {
  3343   ciMethodData* md = method->method_data();
  3344   if (md->is_empty()) {
  3345     // Assume the trap has not occurred, or that it occurred only
  3346     // because of a transient condition during start-up in the interpreter.
  3347     return false;
  3349   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  3350   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  3351   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  3352   Deoptimization::DeoptReason per_bc_reason
  3353     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  3354   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3355   if ((per_bc_reason == Deoptimization::Reason_none
  3356        || md->has_trap_at(bci, m, reason) != 0)
  3357       // The trap frequency measure we care about is the recompile count:
  3358       && md->trap_recompiled_at(bci, m)
  3359       && md->overflow_recompile_count() >= bc_cutoff) {
  3360     // Do not emit a trap here if it has already caused recompilations.
  3361     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3362     // assume the worst.
  3363     if (log())
  3364       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  3365                   Deoptimization::trap_reason_name(reason),
  3366                   md->trap_count(reason),
  3367                   md->overflow_recompile_count());
  3368     return true;
  3369   } else if (trap_count(reason) != 0
  3370              && decompile_count() >= m_cutoff) {
  3371     // Too many recompiles globally, and we have seen this sort of trap.
  3372     // Use cumulative decompile_count, not just md->decompile_count.
  3373     if (log())
  3374       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  3375                   Deoptimization::trap_reason_name(reason),
  3376                   md->trap_count(reason), trap_count(reason),
  3377                   md->decompile_count(), decompile_count());
  3378     return true;
  3379   } else {
  3380     // The coast is clear.
  3381     return false;
  3385 // Compute when not to trap. Used by matching trap based nodes and
  3386 // NullCheck optimization.
  3387 void Compile::set_allowed_deopt_reasons() {
  3388   _allowed_reasons = 0;
  3389   if (is_method_compilation()) {
  3390     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
  3391       assert(rs < BitsPerInt, "recode bit map");
  3392       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
  3393         _allowed_reasons |= nth_bit(rs);
  3399 #ifndef PRODUCT
  3400 //------------------------------verify_graph_edges---------------------------
  3401 // Walk the Graph and verify that there is a one-to-one correspondence
  3402 // between Use-Def edges and Def-Use edges in the graph.
  3403 void Compile::verify_graph_edges(bool no_dead_code) {
  3404   if (VerifyGraphEdges) {
  3405     ResourceArea *area = Thread::current()->resource_area();
  3406     Unique_Node_List visited(area);
  3407     // Call recursive graph walk to check edges
  3408     _root->verify_edges(visited);
  3409     if (no_dead_code) {
  3410       // Now make sure that no visited node is used by an unvisited node.
  3411       bool dead_nodes = 0;
  3412       Unique_Node_List checked(area);
  3413       while (visited.size() > 0) {
  3414         Node* n = visited.pop();
  3415         checked.push(n);
  3416         for (uint i = 0; i < n->outcnt(); i++) {
  3417           Node* use = n->raw_out(i);
  3418           if (checked.member(use))  continue;  // already checked
  3419           if (visited.member(use))  continue;  // already in the graph
  3420           if (use->is_Con())        continue;  // a dead ConNode is OK
  3421           // At this point, we have found a dead node which is DU-reachable.
  3422           if (dead_nodes++ == 0)
  3423             tty->print_cr("*** Dead nodes reachable via DU edges:");
  3424           use->dump(2);
  3425           tty->print_cr("---");
  3426           checked.push(use);  // No repeats; pretend it is now checked.
  3429       assert(dead_nodes == 0, "using nodes must be reachable from root");
  3434 // Verify GC barriers consistency
  3435 // Currently supported:
  3436 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
  3437 void Compile::verify_barriers() {
  3438   if (UseG1GC) {
  3439     // Verify G1 pre-barriers
  3440     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
  3442     ResourceArea *area = Thread::current()->resource_area();
  3443     Unique_Node_List visited(area);
  3444     Node_List worklist(area);
  3445     // We're going to walk control flow backwards starting from the Root
  3446     worklist.push(_root);
  3447     while (worklist.size() > 0) {
  3448       Node* x = worklist.pop();
  3449       if (x == NULL || x == top()) continue;
  3450       if (visited.member(x)) {
  3451         continue;
  3452       } else {
  3453         visited.push(x);
  3456       if (x->is_Region()) {
  3457         for (uint i = 1; i < x->req(); i++) {
  3458           worklist.push(x->in(i));
  3460       } else {
  3461         worklist.push(x->in(0));
  3462         // We are looking for the pattern:
  3463         //                            /->ThreadLocal
  3464         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
  3465         //              \->ConI(0)
  3466         // We want to verify that the If and the LoadB have the same control
  3467         // See GraphKit::g1_write_barrier_pre()
  3468         if (x->is_If()) {
  3469           IfNode *iff = x->as_If();
  3470           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
  3471             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
  3472             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
  3473                 && cmp->in(1)->is_Load()) {
  3474               LoadNode* load = cmp->in(1)->as_Load();
  3475               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
  3476                   && load->in(2)->in(3)->is_Con()
  3477                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
  3479                 Node* if_ctrl = iff->in(0);
  3480                 Node* load_ctrl = load->in(0);
  3482                 if (if_ctrl != load_ctrl) {
  3483                   // Skip possible CProj->NeverBranch in infinite loops
  3484                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
  3485                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
  3486                     if_ctrl = if_ctrl->in(0)->in(0);
  3489                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
  3499 #endif
  3501 // The Compile object keeps track of failure reasons separately from the ciEnv.
  3502 // This is required because there is not quite a 1-1 relation between the
  3503 // ciEnv and its compilation task and the Compile object.  Note that one
  3504 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  3505 // to backtrack and retry without subsuming loads.  Other than this backtracking
  3506 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  3507 // by the logic in C2Compiler.
  3508 void Compile::record_failure(const char* reason) {
  3509   if (log() != NULL) {
  3510     log()->elem("failure reason='%s' phase='compile'", reason);
  3512   if (_failure_reason == NULL) {
  3513     // Record the first failure reason.
  3514     _failure_reason = reason;
  3517   EventCompilerFailure event;
  3518   if (event.should_commit()) {
  3519     event.set_compileID(Compile::compile_id());
  3520     event.set_failure(reason);
  3521     event.commit();
  3524   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  3525     C->print_method(PHASE_FAILURE);
  3527   _root = NULL;  // flush the graph, too
  3530 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  3531   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
  3532     _phase_name(name), _dolog(dolog)
  3534   if (dolog) {
  3535     C = Compile::current();
  3536     _log = C->log();
  3537   } else {
  3538     C = NULL;
  3539     _log = NULL;
  3541   if (_log != NULL) {
  3542     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3543     _log->stamp();
  3544     _log->end_head();
  3548 Compile::TracePhase::~TracePhase() {
  3550   C = Compile::current();
  3551   if (_dolog) {
  3552     _log = C->log();
  3553   } else {
  3554     _log = NULL;
  3557 #ifdef ASSERT
  3558   if (PrintIdealNodeCount) {
  3559     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
  3560                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
  3563   if (VerifyIdealNodeCount) {
  3564     Compile::current()->print_missing_nodes();
  3566 #endif
  3568   if (_log != NULL) {
  3569     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3573 //=============================================================================
  3574 // Two Constant's are equal when the type and the value are equal.
  3575 bool Compile::Constant::operator==(const Constant& other) {
  3576   if (type()          != other.type()         )  return false;
  3577   if (can_be_reused() != other.can_be_reused())  return false;
  3578   // For floating point values we compare the bit pattern.
  3579   switch (type()) {
  3580   case T_FLOAT:   return (_v._value.i == other._v._value.i);
  3581   case T_LONG:
  3582   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
  3583   case T_OBJECT:
  3584   case T_ADDRESS: return (_v._value.l == other._v._value.l);
  3585   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
  3586   case T_METADATA: return (_v._metadata == other._v._metadata);
  3587   default: ShouldNotReachHere();
  3589   return false;
  3592 static int type_to_size_in_bytes(BasicType t) {
  3593   switch (t) {
  3594   case T_LONG:    return sizeof(jlong  );
  3595   case T_FLOAT:   return sizeof(jfloat );
  3596   case T_DOUBLE:  return sizeof(jdouble);
  3597   case T_METADATA: return sizeof(Metadata*);
  3598     // We use T_VOID as marker for jump-table entries (labels) which
  3599     // need an internal word relocation.
  3600   case T_VOID:
  3601   case T_ADDRESS:
  3602   case T_OBJECT:  return sizeof(jobject);
  3605   ShouldNotReachHere();
  3606   return -1;
  3609 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
  3610   // sort descending
  3611   if (a->freq() > b->freq())  return -1;
  3612   if (a->freq() < b->freq())  return  1;
  3613   return 0;
  3616 void Compile::ConstantTable::calculate_offsets_and_size() {
  3617   // First, sort the array by frequencies.
  3618   _constants.sort(qsort_comparator);
  3620 #ifdef ASSERT
  3621   // Make sure all jump-table entries were sorted to the end of the
  3622   // array (they have a negative frequency).
  3623   bool found_void = false;
  3624   for (int i = 0; i < _constants.length(); i++) {
  3625     Constant con = _constants.at(i);
  3626     if (con.type() == T_VOID)
  3627       found_void = true;  // jump-tables
  3628     else
  3629       assert(!found_void, "wrong sorting");
  3631 #endif
  3633   int offset = 0;
  3634   for (int i = 0; i < _constants.length(); i++) {
  3635     Constant* con = _constants.adr_at(i);
  3637     // Align offset for type.
  3638     int typesize = type_to_size_in_bytes(con->type());
  3639     offset = align_size_up(offset, typesize);
  3640     con->set_offset(offset);   // set constant's offset
  3642     if (con->type() == T_VOID) {
  3643       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
  3644       offset = offset + typesize * n->outcnt();  // expand jump-table
  3645     } else {
  3646       offset = offset + typesize;
  3650   // Align size up to the next section start (which is insts; see
  3651   // CodeBuffer::align_at_start).
  3652   assert(_size == -1, "already set?");
  3653   _size = align_size_up(offset, CodeEntryAlignment);
  3656 void Compile::ConstantTable::emit(CodeBuffer& cb) {
  3657   MacroAssembler _masm(&cb);
  3658   for (int i = 0; i < _constants.length(); i++) {
  3659     Constant con = _constants.at(i);
  3660     address constant_addr;
  3661     switch (con.type()) {
  3662     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
  3663     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
  3664     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
  3665     case T_OBJECT: {
  3666       jobject obj = con.get_jobject();
  3667       int oop_index = _masm.oop_recorder()->find_index(obj);
  3668       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
  3669       break;
  3671     case T_ADDRESS: {
  3672       address addr = (address) con.get_jobject();
  3673       constant_addr = _masm.address_constant(addr);
  3674       break;
  3676     // We use T_VOID as marker for jump-table entries (labels) which
  3677     // need an internal word relocation.
  3678     case T_VOID: {
  3679       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
  3680       // Fill the jump-table with a dummy word.  The real value is
  3681       // filled in later in fill_jump_table.
  3682       address dummy = (address) n;
  3683       constant_addr = _masm.address_constant(dummy);
  3684       // Expand jump-table
  3685       for (uint i = 1; i < n->outcnt(); i++) {
  3686         address temp_addr = _masm.address_constant(dummy + i);
  3687         assert(temp_addr, "consts section too small");
  3689       break;
  3691     case T_METADATA: {
  3692       Metadata* obj = con.get_metadata();
  3693       int metadata_index = _masm.oop_recorder()->find_index(obj);
  3694       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
  3695       break;
  3697     default: ShouldNotReachHere();
  3699     assert(constant_addr, "consts section too small");
  3700     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
  3701             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
  3705 int Compile::ConstantTable::find_offset(Constant& con) const {
  3706   int idx = _constants.find(con);
  3707   assert(idx != -1, "constant must be in constant table");
  3708   int offset = _constants.at(idx).offset();
  3709   assert(offset != -1, "constant table not emitted yet?");
  3710   return offset;
  3713 void Compile::ConstantTable::add(Constant& con) {
  3714   if (con.can_be_reused()) {
  3715     int idx = _constants.find(con);
  3716     if (idx != -1 && _constants.at(idx).can_be_reused()) {
  3717       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
  3718       return;
  3721   (void) _constants.append(con);
  3724 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
  3725   Block* b = Compile::current()->cfg()->get_block_for_node(n);
  3726   Constant con(type, value, b->_freq);
  3727   add(con);
  3728   return con;
  3731 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
  3732   Constant con(metadata);
  3733   add(con);
  3734   return con;
  3737 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
  3738   jvalue value;
  3739   BasicType type = oper->type()->basic_type();
  3740   switch (type) {
  3741   case T_LONG:    value.j = oper->constantL(); break;
  3742   case T_FLOAT:   value.f = oper->constantF(); break;
  3743   case T_DOUBLE:  value.d = oper->constantD(); break;
  3744   case T_OBJECT:
  3745   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
  3746   case T_METADATA: return add((Metadata*)oper->constant()); break;
  3747   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
  3749   return add(n, type, value);
  3752 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
  3753   jvalue value;
  3754   // We can use the node pointer here to identify the right jump-table
  3755   // as this method is called from Compile::Fill_buffer right before
  3756   // the MachNodes are emitted and the jump-table is filled (means the
  3757   // MachNode pointers do not change anymore).
  3758   value.l = (jobject) n;
  3759   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
  3760   add(con);
  3761   return con;
  3764 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
  3765   // If called from Compile::scratch_emit_size do nothing.
  3766   if (Compile::current()->in_scratch_emit_size())  return;
  3768   assert(labels.is_nonempty(), "must be");
  3769   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
  3771   // Since MachConstantNode::constant_offset() also contains
  3772   // table_base_offset() we need to subtract the table_base_offset()
  3773   // to get the plain offset into the constant table.
  3774   int offset = n->constant_offset() - table_base_offset();
  3776   MacroAssembler _masm(&cb);
  3777   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
  3779   for (uint i = 0; i < n->outcnt(); i++) {
  3780     address* constant_addr = &jump_table_base[i];
  3781     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)));
  3782     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
  3783     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
  3787 void Compile::dump_inlining() {
  3788   if (print_inlining() || print_intrinsics()) {
  3789     // Print inlining message for candidates that we couldn't inline
  3790     // for lack of space or non constant receiver
  3791     for (int i = 0; i < _late_inlines.length(); i++) {
  3792       CallGenerator* cg = _late_inlines.at(i);
  3793       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
  3795     Unique_Node_List useful;
  3796     useful.push(root());
  3797     for (uint next = 0; next < useful.size(); ++next) {
  3798       Node* n  = useful.at(next);
  3799       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
  3800         CallNode* call = n->as_Call();
  3801         CallGenerator* cg = call->generator();
  3802         cg->print_inlining_late("receiver not constant");
  3804       uint max = n->len();
  3805       for ( uint i = 0; i < max; ++i ) {
  3806         Node *m = n->in(i);
  3807         if ( m == NULL ) continue;
  3808         useful.push(m);
  3811     for (int i = 0; i < _print_inlining_list->length(); i++) {
  3812       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
  3817 // Dump inlining replay data to the stream.
  3818 // Don't change thread state and acquire any locks.
  3819 void Compile::dump_inline_data(outputStream* out) {
  3820   InlineTree* inl_tree = ilt();
  3821   if (inl_tree != NULL) {
  3822     out->print(" inline %d", inl_tree->count());
  3823     inl_tree->dump_replay_data(out);
  3827 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
  3828   if (n1->Opcode() < n2->Opcode())      return -1;
  3829   else if (n1->Opcode() > n2->Opcode()) return 1;
  3831   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()));
  3832   for (uint i = 1; i < n1->req(); i++) {
  3833     if (n1->in(i) < n2->in(i))      return -1;
  3834     else if (n1->in(i) > n2->in(i)) return 1;
  3837   return 0;
  3840 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
  3841   Node* n1 = *n1p;
  3842   Node* n2 = *n2p;
  3844   return cmp_expensive_nodes(n1, n2);
  3847 void Compile::sort_expensive_nodes() {
  3848   if (!expensive_nodes_sorted()) {
  3849     _expensive_nodes->sort(cmp_expensive_nodes);
  3853 bool Compile::expensive_nodes_sorted() const {
  3854   for (int i = 1; i < _expensive_nodes->length(); i++) {
  3855     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
  3856       return false;
  3859   return true;
  3862 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
  3863   if (_expensive_nodes->length() == 0) {
  3864     return false;
  3867   assert(OptimizeExpensiveOps, "optimization off?");
  3869   // Take this opportunity to remove dead nodes from the list
  3870   int j = 0;
  3871   for (int i = 0; i < _expensive_nodes->length(); i++) {
  3872     Node* n = _expensive_nodes->at(i);
  3873     if (!n->is_unreachable(igvn)) {
  3874       assert(n->is_expensive(), "should be expensive");
  3875       _expensive_nodes->at_put(j, n);
  3876       j++;
  3879   _expensive_nodes->trunc_to(j);
  3881   // Then sort the list so that similar nodes are next to each other
  3882   // and check for at least two nodes of identical kind with same data
  3883   // inputs.
  3884   sort_expensive_nodes();
  3886   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
  3887     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
  3888       return true;
  3892   return false;
  3895 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
  3896   if (_expensive_nodes->length() == 0) {
  3897     return;
  3900   assert(OptimizeExpensiveOps, "optimization off?");
  3902   // Sort to bring similar nodes next to each other and clear the
  3903   // control input of nodes for which there's only a single copy.
  3904   sort_expensive_nodes();
  3906   int j = 0;
  3907   int identical = 0;
  3908   int i = 0;
  3909   for (; i < _expensive_nodes->length()-1; i++) {
  3910     assert(j <= i, "can't write beyond current index");
  3911     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
  3912       identical++;
  3913       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3914       continue;
  3916     if (identical > 0) {
  3917       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3918       identical = 0;
  3919     } else {
  3920       Node* n = _expensive_nodes->at(i);
  3921       igvn.hash_delete(n);
  3922       n->set_req(0, NULL);
  3923       igvn.hash_insert(n);
  3926   if (identical > 0) {
  3927     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3928   } else if (_expensive_nodes->length() >= 1) {
  3929     Node* n = _expensive_nodes->at(i);
  3930     igvn.hash_delete(n);
  3931     n->set_req(0, NULL);
  3932     igvn.hash_insert(n);
  3934   _expensive_nodes->trunc_to(j);
  3937 void Compile::add_expensive_node(Node * n) {
  3938   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
  3939   assert(n->is_expensive(), "expensive nodes with non-null control here only");
  3940   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
  3941   if (OptimizeExpensiveOps) {
  3942     _expensive_nodes->append(n);
  3943   } else {
  3944     // Clear control input and let IGVN optimize expensive nodes if
  3945     // OptimizeExpensiveOps is off.
  3946     n->set_req(0, NULL);
  3950 /**
  3951  * Remove the speculative part of types and clean up the graph
  3952  */
  3953 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
  3954   if (UseTypeSpeculation) {
  3955     Unique_Node_List worklist;
  3956     worklist.push(root());
  3957     int modified = 0;
  3958     // Go over all type nodes that carry a speculative type, drop the
  3959     // speculative part of the type and enqueue the node for an igvn
  3960     // which may optimize it out.
  3961     for (uint next = 0; next < worklist.size(); ++next) {
  3962       Node *n  = worklist.at(next);
  3963       if (n->is_Type()) {
  3964         TypeNode* tn = n->as_Type();
  3965         const Type* t = tn->type();
  3966         const Type* t_no_spec = t->remove_speculative();
  3967         if (t_no_spec != t) {
  3968           bool in_hash = igvn.hash_delete(n);
  3969           assert(in_hash, "node should be in igvn hash table");
  3970           tn->set_type(t_no_spec);
  3971           igvn.hash_insert(n);
  3972           igvn._worklist.push(n); // give it a chance to go away
  3973           modified++;
  3976       uint max = n->len();
  3977       for( uint i = 0; i < max; ++i ) {
  3978         Node *m = n->in(i);
  3979         if (not_a_node(m))  continue;
  3980         worklist.push(m);
  3983     // Drop the speculative part of all types in the igvn's type table
  3984     igvn.remove_speculative_types();
  3985     if (modified > 0) {
  3986       igvn.optimize();
  3988 #ifdef ASSERT
  3989     // Verify that after the IGVN is over no speculative type has resurfaced
  3990     worklist.clear();
  3991     worklist.push(root());
  3992     for (uint next = 0; next < worklist.size(); ++next) {
  3993       Node *n  = worklist.at(next);
  3994       const Type* t = igvn.type_or_null(n);
  3995       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
  3996       if (n->is_Type()) {
  3997         t = n->as_Type()->type();
  3998         assert(t == t->remove_speculative(), "no more speculative types");
  4000       uint max = n->len();
  4001       for( uint i = 0; i < max; ++i ) {
  4002         Node *m = n->in(i);
  4003         if (not_a_node(m))  continue;
  4004         worklist.push(m);
  4007     igvn.check_no_speculative_types();
  4008 #endif
  4012 // Auxiliary method to support randomized stressing/fuzzing.
  4013 //
  4014 // This method can be called the arbitrary number of times, with current count
  4015 // as the argument. The logic allows selecting a single candidate from the
  4016 // running list of candidates as follows:
  4017 //    int count = 0;
  4018 //    Cand* selected = null;
  4019 //    while(cand = cand->next()) {
  4020 //      if (randomized_select(++count)) {
  4021 //        selected = cand;
  4022 //      }
  4023 //    }
  4024 //
  4025 // Including count equalizes the chances any candidate is "selected".
  4026 // This is useful when we don't have the complete list of candidates to choose
  4027 // from uniformly. In this case, we need to adjust the randomicity of the
  4028 // selection, or else we will end up biasing the selection towards the latter
  4029 // candidates.
  4030 //
  4031 // Quick back-envelope calculation shows that for the list of n candidates
  4032 // the equal probability for the candidate to persist as "best" can be
  4033 // achieved by replacing it with "next" k-th candidate with the probability
  4034 // of 1/k. It can be easily shown that by the end of the run, the
  4035 // probability for any candidate is converged to 1/n, thus giving the
  4036 // uniform distribution among all the candidates.
  4037 //
  4038 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
  4039 #define RANDOMIZED_DOMAIN_POW 29
  4040 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
  4041 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
  4042 bool Compile::randomized_select(int count) {
  4043   assert(count > 0, "only positive");
  4044   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);

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