src/share/vm/opto/compile.cpp

Tue, 17 Oct 2017 12:58:25 +0800

author
aoqi
date
Tue, 17 Oct 2017 12:58:25 +0800
changeset 7994
04ff2f6cd0eb
parent 7890
bf41eee321e5
parent 7535
7ae4e26cb1e0
child 8604
04d83ba48607
permissions
-rw-r--r--

merge

     1 /*
     2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 /*
    26  * This file has been modified by Loongson Technology in 2015. These
    27  * modifications are Copyright (c) 2015 Loongson Technology, and are made
    28  * available on the same license terms set forth above.
    29  */
    31 #include "precompiled.hpp"
    32 #include "asm/macroAssembler.hpp"
    33 #include "asm/macroAssembler.inline.hpp"
    34 #include "ci/ciReplay.hpp"
    35 #include "classfile/systemDictionary.hpp"
    36 #include "code/exceptionHandlerTable.hpp"
    37 #include "code/nmethod.hpp"
    38 #include "compiler/compileLog.hpp"
    39 #include "compiler/disassembler.hpp"
    40 #include "compiler/oopMap.hpp"
    41 #include "opto/addnode.hpp"
    42 #include "opto/block.hpp"
    43 #include "opto/c2compiler.hpp"
    44 #include "opto/callGenerator.hpp"
    45 #include "opto/callnode.hpp"
    46 #include "opto/cfgnode.hpp"
    47 #include "opto/chaitin.hpp"
    48 #include "opto/compile.hpp"
    49 #include "opto/connode.hpp"
    50 #include "opto/divnode.hpp"
    51 #include "opto/escape.hpp"
    52 #include "opto/idealGraphPrinter.hpp"
    53 #include "opto/loopnode.hpp"
    54 #include "opto/machnode.hpp"
    55 #include "opto/macro.hpp"
    56 #include "opto/matcher.hpp"
    57 #include "opto/mathexactnode.hpp"
    58 #include "opto/memnode.hpp"
    59 #include "opto/mulnode.hpp"
    60 #include "opto/node.hpp"
    61 #include "opto/opcodes.hpp"
    62 #include "opto/output.hpp"
    63 #include "opto/parse.hpp"
    64 #include "opto/phaseX.hpp"
    65 #include "opto/rootnode.hpp"
    66 #include "opto/runtime.hpp"
    67 #include "opto/stringopts.hpp"
    68 #include "opto/type.hpp"
    69 #include "opto/vectornode.hpp"
    70 #include "runtime/arguments.hpp"
    71 #include "runtime/signature.hpp"
    72 #include "runtime/stubRoutines.hpp"
    73 #include "runtime/timer.hpp"
    74 #include "trace/tracing.hpp"
    75 #include "utilities/copy.hpp"
    76 #if defined AD_MD_HPP
    77 # include AD_MD_HPP
    78 #elif defined TARGET_ARCH_MODEL_x86_32
    79 # include "adfiles/ad_x86_32.hpp"
    80 #elif defined TARGET_ARCH_MODEL_x86_64
    81 # include "adfiles/ad_x86_64.hpp"
    82 #elif defined TARGET_ARCH_MODEL_sparc
    83 # include "adfiles/ad_sparc.hpp"
    84 #elif defined TARGET_ARCH_MODEL_zero
    85 # include "adfiles/ad_zero.hpp"
    86 #elif defined TARGET_ARCH_MODEL_ppc_64
    87 # include "adfiles/ad_ppc_64.hpp"
    88 #elif defined TARGET_ARCH_MODEL_mips_64
    89 # include "adfiles/ad_mips_64.hpp"
    90 #endif
    93 // -------------------- Compile::mach_constant_base_node -----------------------
    94 // Constant table base node singleton.
    95 MachConstantBaseNode* Compile::mach_constant_base_node() {
    96   if (_mach_constant_base_node == NULL) {
    97     _mach_constant_base_node = new (C) MachConstantBaseNode();
    98     _mach_constant_base_node->add_req(C->root());
    99   }
   100   return _mach_constant_base_node;
   101 }
   104 /// Support for intrinsics.
   106 // Return the index at which m must be inserted (or already exists).
   107 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
   108 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
   109 #ifdef ASSERT
   110   for (int i = 1; i < _intrinsics->length(); i++) {
   111     CallGenerator* cg1 = _intrinsics->at(i-1);
   112     CallGenerator* cg2 = _intrinsics->at(i);
   113     assert(cg1->method() != cg2->method()
   114            ? cg1->method()     < cg2->method()
   115            : cg1->is_virtual() < cg2->is_virtual(),
   116            "compiler intrinsics list must stay sorted");
   117   }
   118 #endif
   119   // Binary search sorted list, in decreasing intervals [lo, hi].
   120   int lo = 0, hi = _intrinsics->length()-1;
   121   while (lo <= hi) {
   122     int mid = (uint)(hi + lo) / 2;
   123     ciMethod* mid_m = _intrinsics->at(mid)->method();
   124     if (m < mid_m) {
   125       hi = mid-1;
   126     } else if (m > mid_m) {
   127       lo = mid+1;
   128     } else {
   129       // look at minor sort key
   130       bool mid_virt = _intrinsics->at(mid)->is_virtual();
   131       if (is_virtual < mid_virt) {
   132         hi = mid-1;
   133       } else if (is_virtual > mid_virt) {
   134         lo = mid+1;
   135       } else {
   136         return mid;  // exact match
   137       }
   138     }
   139   }
   140   return lo;  // inexact match
   141 }
   143 void Compile::register_intrinsic(CallGenerator* cg) {
   144   if (_intrinsics == NULL) {
   145     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
   146   }
   147   // This code is stolen from ciObjectFactory::insert.
   148   // Really, GrowableArray should have methods for
   149   // insert_at, remove_at, and binary_search.
   150   int len = _intrinsics->length();
   151   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
   152   if (index == len) {
   153     _intrinsics->append(cg);
   154   } else {
   155 #ifdef ASSERT
   156     CallGenerator* oldcg = _intrinsics->at(index);
   157     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
   158 #endif
   159     _intrinsics->append(_intrinsics->at(len-1));
   160     int pos;
   161     for (pos = len-2; pos >= index; pos--) {
   162       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
   163     }
   164     _intrinsics->at_put(index, cg);
   165   }
   166   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
   167 }
   169 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
   170   assert(m->is_loaded(), "don't try this on unloaded methods");
   171   if (_intrinsics != NULL) {
   172     int index = intrinsic_insertion_index(m, is_virtual);
   173     if (index < _intrinsics->length()
   174         && _intrinsics->at(index)->method() == m
   175         && _intrinsics->at(index)->is_virtual() == is_virtual) {
   176       return _intrinsics->at(index);
   177     }
   178   }
   179   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   180   if (m->intrinsic_id() != vmIntrinsics::_none &&
   181       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
   182     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
   183     if (cg != NULL) {
   184       // Save it for next time:
   185       register_intrinsic(cg);
   186       return cg;
   187     } else {
   188       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
   189     }
   190   }
   191   return NULL;
   192 }
   194 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
   195 // in library_call.cpp.
   198 #ifndef PRODUCT
   199 // statistics gathering...
   201 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
   202 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
   204 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   205   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   206   int oflags = _intrinsic_hist_flags[id];
   207   assert(flags != 0, "what happened?");
   208   if (is_virtual) {
   209     flags |= _intrinsic_virtual;
   210   }
   211   bool changed = (flags != oflags);
   212   if ((flags & _intrinsic_worked) != 0) {
   213     juint count = (_intrinsic_hist_count[id] += 1);
   214     if (count == 1) {
   215       changed = true;           // first time
   216     }
   217     // increment the overall count also:
   218     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   219   }
   220   if (changed) {
   221     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
   222       // Something changed about the intrinsic's virtuality.
   223       if ((flags & _intrinsic_virtual) != 0) {
   224         // This is the first use of this intrinsic as a virtual call.
   225         if (oflags != 0) {
   226           // We already saw it as a non-virtual, so note both cases.
   227           flags |= _intrinsic_both;
   228         }
   229       } else if ((oflags & _intrinsic_both) == 0) {
   230         // This is the first use of this intrinsic as a non-virtual
   231         flags |= _intrinsic_both;
   232       }
   233     }
   234     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   235   }
   236   // update the overall flags also:
   237   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   238   return changed;
   239 }
   241 static char* format_flags(int flags, char* buf) {
   242   buf[0] = 0;
   243   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   244   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   245   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   246   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   247   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   248   if (buf[0] == 0)  strcat(buf, ",");
   249   assert(buf[0] == ',', "must be");
   250   return &buf[1];
   251 }
   253 void Compile::print_intrinsic_statistics() {
   254   char flagsbuf[100];
   255   ttyLocker ttyl;
   256   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   257   tty->print_cr("Compiler intrinsic usage:");
   258   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   259   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   260   #define PRINT_STAT_LINE(name, c, f) \
   261     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   262   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
   263     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
   264     int   flags = _intrinsic_hist_flags[id];
   265     juint count = _intrinsic_hist_count[id];
   266     if ((flags | count) != 0) {
   267       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
   268     }
   269   }
   270   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   271   if (xtty != NULL)  xtty->tail("statistics");
   272 }
   274 void Compile::print_statistics() {
   275   { ttyLocker ttyl;
   276     if (xtty != NULL)  xtty->head("statistics type='opto'");
   277     Parse::print_statistics();
   278     PhaseCCP::print_statistics();
   279     PhaseRegAlloc::print_statistics();
   280     Scheduling::print_statistics();
   281     PhasePeephole::print_statistics();
   282     PhaseIdealLoop::print_statistics();
   283     if (xtty != NULL)  xtty->tail("statistics");
   284   }
   285   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
   286     // put this under its own <statistics> element.
   287     print_intrinsic_statistics();
   288   }
   289 }
   290 #endif //PRODUCT
   292 // Support for bundling info
   293 Bundle* Compile::node_bundling(const Node *n) {
   294   assert(valid_bundle_info(n), "oob");
   295   return &_node_bundling_base[n->_idx];
   296 }
   298 bool Compile::valid_bundle_info(const Node *n) {
   299   return (_node_bundling_limit > n->_idx);
   300 }
   303 void Compile::gvn_replace_by(Node* n, Node* nn) {
   304   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
   305     Node* use = n->last_out(i);
   306     bool is_in_table = initial_gvn()->hash_delete(use);
   307     uint uses_found = 0;
   308     for (uint j = 0; j < use->len(); j++) {
   309       if (use->in(j) == n) {
   310         if (j < use->req())
   311           use->set_req(j, nn);
   312         else
   313           use->set_prec(j, nn);
   314         uses_found++;
   315       }
   316     }
   317     if (is_in_table) {
   318       // reinsert into table
   319       initial_gvn()->hash_find_insert(use);
   320     }
   321     record_for_igvn(use);
   322     i -= uses_found;    // we deleted 1 or more copies of this edge
   323   }
   324 }
   327 static inline bool not_a_node(const Node* n) {
   328   if (n == NULL)                   return true;
   329   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
   330   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
   331   return false;
   332 }
   334 // Identify all nodes that are reachable from below, useful.
   335 // Use breadth-first pass that records state in a Unique_Node_List,
   336 // recursive traversal is slower.
   337 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   338   int estimated_worklist_size = unique();
   339   useful.map( estimated_worklist_size, NULL );  // preallocate space
   341   // Initialize worklist
   342   if (root() != NULL)     { useful.push(root()); }
   343   // If 'top' is cached, declare it useful to preserve cached node
   344   if( cached_top_node() ) { useful.push(cached_top_node()); }
   346   // Push all useful nodes onto the list, breadthfirst
   347   for( uint next = 0; next < useful.size(); ++next ) {
   348     assert( next < unique(), "Unique useful nodes < total nodes");
   349     Node *n  = useful.at(next);
   350     uint max = n->len();
   351     for( uint i = 0; i < max; ++i ) {
   352       Node *m = n->in(i);
   353       if (not_a_node(m))  continue;
   354       useful.push(m);
   355     }
   356   }
   357 }
   359 // Update dead_node_list with any missing dead nodes using useful
   360 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
   361 void Compile::update_dead_node_list(Unique_Node_List &useful) {
   362   uint max_idx = unique();
   363   VectorSet& useful_node_set = useful.member_set();
   365   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
   366     // If node with index node_idx is not in useful set,
   367     // mark it as dead in dead node list.
   368     if (! useful_node_set.test(node_idx) ) {
   369       record_dead_node(node_idx);
   370     }
   371   }
   372 }
   374 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
   375   int shift = 0;
   376   for (int i = 0; i < inlines->length(); i++) {
   377     CallGenerator* cg = inlines->at(i);
   378     CallNode* call = cg->call_node();
   379     if (shift > 0) {
   380       inlines->at_put(i-shift, cg);
   381     }
   382     if (!useful.member(call)) {
   383       shift++;
   384     }
   385   }
   386   inlines->trunc_to(inlines->length()-shift);
   387 }
   389 // Disconnect all useless nodes by disconnecting those at the boundary.
   390 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   391   uint next = 0;
   392   while (next < useful.size()) {
   393     Node *n = useful.at(next++);
   394     if (n->is_SafePoint()) {
   395       // We're done with a parsing phase. Replaced nodes are not valid
   396       // beyond that point.
   397       n->as_SafePoint()->delete_replaced_nodes();
   398     }
   399     // Use raw traversal of out edges since this code removes out edges
   400     int max = n->outcnt();
   401     for (int j = 0; j < max; ++j) {
   402       Node* child = n->raw_out(j);
   403       if (! useful.member(child)) {
   404         assert(!child->is_top() || child != top(),
   405                "If top is cached in Compile object it is in useful list");
   406         // Only need to remove this out-edge to the useless node
   407         n->raw_del_out(j);
   408         --j;
   409         --max;
   410       }
   411     }
   412     if (n->outcnt() == 1 && n->has_special_unique_user()) {
   413       record_for_igvn(n->unique_out());
   414     }
   415   }
   416   // Remove useless macro and predicate opaq nodes
   417   for (int i = C->macro_count()-1; i >= 0; i--) {
   418     Node* n = C->macro_node(i);
   419     if (!useful.member(n)) {
   420       remove_macro_node(n);
   421     }
   422   }
   423   // Remove useless expensive node
   424   for (int i = C->expensive_count()-1; i >= 0; i--) {
   425     Node* n = C->expensive_node(i);
   426     if (!useful.member(n)) {
   427       remove_expensive_node(n);
   428     }
   429   }
   430   // clean up the late inline lists
   431   remove_useless_late_inlines(&_string_late_inlines, useful);
   432   remove_useless_late_inlines(&_boxing_late_inlines, useful);
   433   remove_useless_late_inlines(&_late_inlines, useful);
   434   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
   435 }
   437 //------------------------------frame_size_in_words-----------------------------
   438 // frame_slots in units of words
   439 int Compile::frame_size_in_words() const {
   440   // shift is 0 in LP32 and 1 in LP64
   441   const int shift = (LogBytesPerWord - LogBytesPerInt);
   442   int words = _frame_slots >> shift;
   443   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   444   return words;
   445 }
   447 // To bang the stack of this compiled method we use the stack size
   448 // that the interpreter would need in case of a deoptimization. This
   449 // removes the need to bang the stack in the deoptimization blob which
   450 // in turn simplifies stack overflow handling.
   451 int Compile::bang_size_in_bytes() const {
   452   return MAX2(_interpreter_frame_size, frame_size_in_bytes());
   453 }
   455 // ============================================================================
   456 //------------------------------CompileWrapper---------------------------------
   457 class CompileWrapper : public StackObj {
   458   Compile *const _compile;
   459  public:
   460   CompileWrapper(Compile* compile);
   462   ~CompileWrapper();
   463 };
   465 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   466   // the Compile* pointer is stored in the current ciEnv:
   467   ciEnv* env = compile->env();
   468   assert(env == ciEnv::current(), "must already be a ciEnv active");
   469   assert(env->compiler_data() == NULL, "compile already active?");
   470   env->set_compiler_data(compile);
   471   assert(compile == Compile::current(), "sanity");
   473   compile->set_type_dict(NULL);
   474   compile->set_type_hwm(NULL);
   475   compile->set_type_last_size(0);
   476   compile->set_last_tf(NULL, NULL);
   477   compile->set_indexSet_arena(NULL);
   478   compile->set_indexSet_free_block_list(NULL);
   479   compile->init_type_arena();
   480   Type::Initialize(compile);
   481   _compile->set_scratch_buffer_blob(NULL);
   482   _compile->begin_method();
   483 }
   484 CompileWrapper::~CompileWrapper() {
   485   _compile->end_method();
   486   if (_compile->scratch_buffer_blob() != NULL)
   487     BufferBlob::free(_compile->scratch_buffer_blob());
   488   _compile->env()->set_compiler_data(NULL);
   489 }
   492 //----------------------------print_compile_messages---------------------------
   493 void Compile::print_compile_messages() {
   494 #ifndef PRODUCT
   495   // Check if recompiling
   496   if (_subsume_loads == false && PrintOpto) {
   497     // Recompiling without allowing machine instructions to subsume loads
   498     tty->print_cr("*********************************************************");
   499     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
   500     tty->print_cr("*********************************************************");
   501   }
   502   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
   503     // Recompiling without escape analysis
   504     tty->print_cr("*********************************************************");
   505     tty->print_cr("** Bailout: Recompile without escape analysis          **");
   506     tty->print_cr("*********************************************************");
   507   }
   508   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
   509     // Recompiling without boxing elimination
   510     tty->print_cr("*********************************************************");
   511     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
   512     tty->print_cr("*********************************************************");
   513   }
   514   if (env()->break_at_compile()) {
   515     // Open the debugger when compiling this method.
   516     tty->print("### Breaking when compiling: ");
   517     method()->print_short_name();
   518     tty->cr();
   519     BREAKPOINT;
   520   }
   522   if( PrintOpto ) {
   523     if (is_osr_compilation()) {
   524       tty->print("[OSR]%3d", _compile_id);
   525     } else {
   526       tty->print("%3d", _compile_id);
   527     }
   528   }
   529 #endif
   530 }
   533 //-----------------------init_scratch_buffer_blob------------------------------
   534 // Construct a temporary BufferBlob and cache it for this compile.
   535 void Compile::init_scratch_buffer_blob(int const_size) {
   536   // If there is already a scratch buffer blob allocated and the
   537   // constant section is big enough, use it.  Otherwise free the
   538   // current and allocate a new one.
   539   BufferBlob* blob = scratch_buffer_blob();
   540   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
   541     // Use the current blob.
   542   } else {
   543     if (blob != NULL) {
   544       BufferBlob::free(blob);
   545     }
   547     ResourceMark rm;
   548     _scratch_const_size = const_size;
   549     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
   550     blob = BufferBlob::create("Compile::scratch_buffer", size);
   551     // Record the buffer blob for next time.
   552     set_scratch_buffer_blob(blob);
   553     // Have we run out of code space?
   554     if (scratch_buffer_blob() == NULL) {
   555       // Let CompilerBroker disable further compilations.
   556       record_failure("Not enough space for scratch buffer in CodeCache");
   557       return;
   558     }
   559   }
   561   // Initialize the relocation buffers
   562   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
   563   set_scratch_locs_memory(locs_buf);
   564 }
   567 //-----------------------scratch_emit_size-------------------------------------
   568 // Helper function that computes size by emitting code
   569 uint Compile::scratch_emit_size(const Node* n) {
   570   // Start scratch_emit_size section.
   571   set_in_scratch_emit_size(true);
   573   // Emit into a trash buffer and count bytes emitted.
   574   // This is a pretty expensive way to compute a size,
   575   // but it works well enough if seldom used.
   576   // All common fixed-size instructions are given a size
   577   // method by the AD file.
   578   // Note that the scratch buffer blob and locs memory are
   579   // allocated at the beginning of the compile task, and
   580   // may be shared by several calls to scratch_emit_size.
   581   // The allocation of the scratch buffer blob is particularly
   582   // expensive, since it has to grab the code cache lock.
   583   BufferBlob* blob = this->scratch_buffer_blob();
   584   assert(blob != NULL, "Initialize BufferBlob at start");
   585   assert(blob->size() > MAX_inst_size, "sanity");
   586   relocInfo* locs_buf = scratch_locs_memory();
   587   address blob_begin = blob->content_begin();
   588   address blob_end   = (address)locs_buf;
   589   assert(blob->content_contains(blob_end), "sanity");
   590   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   591   buf.initialize_consts_size(_scratch_const_size);
   592   buf.initialize_stubs_size(MAX_stubs_size);
   593   assert(locs_buf != NULL, "sanity");
   594   int lsize = MAX_locs_size / 3;
   595   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
   596   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
   597   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
   599   // Do the emission.
   601   Label fakeL; // Fake label for branch instructions.
   602   Label*   saveL = NULL;
   603   uint save_bnum = 0;
   604   bool is_branch = n->is_MachBranch();
   605   if (is_branch) {
   606     MacroAssembler masm(&buf);
   607     masm.bind(fakeL);
   608     n->as_MachBranch()->save_label(&saveL, &save_bnum);
   609     n->as_MachBranch()->label_set(&fakeL, 0);
   610   }
   611   n->emit(buf, this->regalloc());
   612   if (is_branch) // Restore label.
   613     n->as_MachBranch()->label_set(saveL, save_bnum);
   615   // End scratch_emit_size section.
   616   set_in_scratch_emit_size(false);
   618   return buf.insts_size();
   619 }
   622 // ============================================================================
   623 //------------------------------Compile standard-------------------------------
   624 debug_only( int Compile::_debug_idx = 100000; )
   626 // Compile a method.  entry_bci is -1 for normal compilations and indicates
   627 // the continuation bci for on stack replacement.
   630 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
   631                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
   632                 : Phase(Compiler),
   633                   _env(ci_env),
   634                   _log(ci_env->log()),
   635                   _compile_id(ci_env->compile_id()),
   636                   _save_argument_registers(false),
   637                   _stub_name(NULL),
   638                   _stub_function(NULL),
   639                   _stub_entry_point(NULL),
   640                   _method(target),
   641                   _entry_bci(osr_bci),
   642                   _initial_gvn(NULL),
   643                   _for_igvn(NULL),
   644                   _warm_calls(NULL),
   645                   _subsume_loads(subsume_loads),
   646                   _do_escape_analysis(do_escape_analysis),
   647                   _eliminate_boxing(eliminate_boxing),
   648                   _failure_reason(NULL),
   649                   _code_buffer("Compile::Fill_buffer"),
   650                   _orig_pc_slot(0),
   651                   _orig_pc_slot_offset_in_bytes(0),
   652                   _has_method_handle_invokes(false),
   653                   _mach_constant_base_node(NULL),
   654                   _node_bundling_limit(0),
   655                   _node_bundling_base(NULL),
   656                   _java_calls(0),
   657                   _inner_loops(0),
   658                   _scratch_const_size(-1),
   659                   _in_scratch_emit_size(false),
   660                   _dead_node_list(comp_arena()),
   661                   _dead_node_count(0),
   662 #ifndef PRODUCT
   663                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
   664                   _in_dump_cnt(0),
   665                   _printer(IdealGraphPrinter::printer()),
   666 #endif
   667                   _congraph(NULL),
   668                   _comp_arena(mtCompiler),
   669                   _node_arena(mtCompiler),
   670                   _old_arena(mtCompiler),
   671                   _Compile_types(mtCompiler),
   672                   _replay_inline_data(NULL),
   673                   _late_inlines(comp_arena(), 2, 0, NULL),
   674                   _string_late_inlines(comp_arena(), 2, 0, NULL),
   675                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
   676                   _late_inlines_pos(0),
   677                   _number_of_mh_late_inlines(0),
   678                   _inlining_progress(false),
   679                   _inlining_incrementally(false),
   680                   _print_inlining_list(NULL),
   681                   _print_inlining_idx(0),
   682                   _interpreter_frame_size(0),
   683                   _max_node_limit(MaxNodeLimit) {
   684   C = this;
   686   CompileWrapper cw(this);
   687 #ifndef PRODUCT
   688   if (TimeCompiler2) {
   689     tty->print(" ");
   690     target->holder()->name()->print();
   691     tty->print(".");
   692     target->print_short_name();
   693     tty->print("  ");
   694   }
   695   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   696   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   697   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   698   if (!print_opto_assembly) {
   699     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
   700     if (print_assembly && !Disassembler::can_decode()) {
   701       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
   702       print_opto_assembly = true;
   703     }
   704   }
   705   set_print_assembly(print_opto_assembly);
   706   set_parsed_irreducible_loop(false);
   708   if (method()->has_option("ReplayInline")) {
   709     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
   710   }
   711 #endif
   712   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
   713   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
   714   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
   716   if (ProfileTraps RTM_OPT_ONLY( || UseRTMLocking )) {
   717     // Make sure the method being compiled gets its own MDO,
   718     // so we can at least track the decompile_count().
   719     // Need MDO to record RTM code generation state.
   720     method()->ensure_method_data();
   721   }
   723   Init(::AliasLevel);
   726   print_compile_messages();
   728   _ilt = InlineTree::build_inline_tree_root();
   730   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   731   assert(num_alias_types() >= AliasIdxRaw, "");
   733 #define MINIMUM_NODE_HASH  1023
   734   // Node list that Iterative GVN will start with
   735   Unique_Node_List for_igvn(comp_arena());
   736   set_for_igvn(&for_igvn);
   738   // GVN that will be run immediately on new nodes
   739   uint estimated_size = method()->code_size()*4+64;
   740   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   741   PhaseGVN gvn(node_arena(), estimated_size);
   742   set_initial_gvn(&gvn);
   744   if (print_inlining() || print_intrinsics()) {
   745     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
   746   }
   747   { // Scope for timing the parser
   748     TracePhase t3("parse", &_t_parser, true);
   750     // Put top into the hash table ASAP.
   751     initial_gvn()->transform_no_reclaim(top());
   753     // Set up tf(), start(), and find a CallGenerator.
   754     CallGenerator* cg = NULL;
   755     if (is_osr_compilation()) {
   756       const TypeTuple *domain = StartOSRNode::osr_domain();
   757       const TypeTuple *range = TypeTuple::make_range(method()->signature());
   758       init_tf(TypeFunc::make(domain, range));
   759       StartNode* s = new (this) StartOSRNode(root(), domain);
   760       initial_gvn()->set_type_bottom(s);
   761       init_start(s);
   762       cg = CallGenerator::for_osr(method(), entry_bci());
   763     } else {
   764       // Normal case.
   765       init_tf(TypeFunc::make(method()));
   766       StartNode* s = new (this) StartNode(root(), tf()->domain());
   767       initial_gvn()->set_type_bottom(s);
   768       init_start(s);
   769       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
   770         // With java.lang.ref.reference.get() we must go through the
   771         // intrinsic when G1 is enabled - even when get() is the root
   772         // method of the compile - so that, if necessary, the value in
   773         // the referent field of the reference object gets recorded by
   774         // the pre-barrier code.
   775         // Specifically, if G1 is enabled, the value in the referent
   776         // field is recorded by the G1 SATB pre barrier. This will
   777         // result in the referent being marked live and the reference
   778         // object removed from the list of discovered references during
   779         // reference processing.
   780         cg = find_intrinsic(method(), false);
   781       }
   782       if (cg == NULL) {
   783         float past_uses = method()->interpreter_invocation_count();
   784         float expected_uses = past_uses;
   785         cg = CallGenerator::for_inline(method(), expected_uses);
   786       }
   787     }
   788     if (failing())  return;
   789     if (cg == NULL) {
   790       record_method_not_compilable_all_tiers("cannot parse method");
   791       return;
   792     }
   793     JVMState* jvms = build_start_state(start(), tf());
   794     if ((jvms = cg->generate(jvms)) == NULL) {
   795       record_method_not_compilable("method parse failed");
   796       return;
   797     }
   798     GraphKit kit(jvms);
   800     if (!kit.stopped()) {
   801       // Accept return values, and transfer control we know not where.
   802       // This is done by a special, unique ReturnNode bound to root.
   803       return_values(kit.jvms());
   804     }
   806     if (kit.has_exceptions()) {
   807       // Any exceptions that escape from this call must be rethrown
   808       // to whatever caller is dynamically above us on the stack.
   809       // This is done by a special, unique RethrowNode bound to root.
   810       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
   811     }
   813     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
   815     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
   816       inline_string_calls(true);
   817     }
   819     if (failing())  return;
   821     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
   823     // Remove clutter produced by parsing.
   824     if (!failing()) {
   825       ResourceMark rm;
   826       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
   827     }
   828   }
   830   // Note:  Large methods are capped off in do_one_bytecode().
   831   if (failing())  return;
   833   // After parsing, node notes are no longer automagic.
   834   // They must be propagated by register_new_node_with_optimizer(),
   835   // clone(), or the like.
   836   set_default_node_notes(NULL);
   838   for (;;) {
   839     int successes = Inline_Warm();
   840     if (failing())  return;
   841     if (successes == 0)  break;
   842   }
   844   // Drain the list.
   845   Finish_Warm();
   846 #ifndef PRODUCT
   847   if (_printer) {
   848     _printer->print_inlining(this);
   849   }
   850 #endif
   852   if (failing())  return;
   853   NOT_PRODUCT( verify_graph_edges(); )
   855   // Now optimize
   856   Optimize();
   857   if (failing())  return;
   858   NOT_PRODUCT( verify_graph_edges(); )
   860 #ifndef PRODUCT
   861   if (PrintIdeal) {
   862     ttyLocker ttyl;  // keep the following output all in one block
   863     // This output goes directly to the tty, not the compiler log.
   864     // To enable tools to match it up with the compilation activity,
   865     // be sure to tag this tty output with the compile ID.
   866     if (xtty != NULL) {
   867       xtty->head("ideal compile_id='%d'%s", compile_id(),
   868                  is_osr_compilation()    ? " compile_kind='osr'" :
   869                  "");
   870     }
   871     root()->dump(9999);
   872     if (xtty != NULL) {
   873       xtty->tail("ideal");
   874     }
   875   }
   876 #endif
   878   NOT_PRODUCT( verify_barriers(); )
   880   // Dump compilation data to replay it.
   881   if (method()->has_option("DumpReplay")) {
   882     env()->dump_replay_data(_compile_id);
   883   }
   884   if (method()->has_option("DumpInline") && (ilt() != NULL)) {
   885     env()->dump_inline_data(_compile_id);
   886   }
   888   // Now that we know the size of all the monitors we can add a fixed slot
   889   // for the original deopt pc.
   891   _orig_pc_slot =  fixed_slots();
   892   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   893   set_fixed_slots(next_slot);
   895   // Compute when to use implicit null checks. Used by matching trap based
   896   // nodes and NullCheck optimization.
   897   set_allowed_deopt_reasons();
   899   // Now generate code
   900   Code_Gen();
   901   if (failing())  return;
   903   // Check if we want to skip execution of all compiled code.
   904   {
   905 #ifndef PRODUCT
   906     if (OptoNoExecute) {
   907       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
   908       return;
   909     }
   910     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
   911 #endif
   913     if (is_osr_compilation()) {
   914       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
   915       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
   916     } else {
   917       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
   918       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
   919     }
   921     env()->register_method(_method, _entry_bci,
   922                            &_code_offsets,
   923                            _orig_pc_slot_offset_in_bytes,
   924                            code_buffer(),
   925                            frame_size_in_words(), _oop_map_set,
   926                            &_handler_table, &_inc_table,
   927                            compiler,
   928                            env()->comp_level(),
   929                            has_unsafe_access(),
   930                            SharedRuntime::is_wide_vector(max_vector_size()),
   931                            rtm_state()
   932                            );
   934     if (log() != NULL) // Print code cache state into compiler log
   935       log()->code_cache_state();
   936   }
   937 }
   939 //------------------------------Compile----------------------------------------
   940 // Compile a runtime stub
   941 Compile::Compile( ciEnv* ci_env,
   942                   TypeFunc_generator generator,
   943                   address stub_function,
   944                   const char *stub_name,
   945                   int is_fancy_jump,
   946                   bool pass_tls,
   947                   bool save_arg_registers,
   948                   bool return_pc )
   949   : Phase(Compiler),
   950     _env(ci_env),
   951     _log(ci_env->log()),
   952     _compile_id(0),
   953     _save_argument_registers(save_arg_registers),
   954     _method(NULL),
   955     _stub_name(stub_name),
   956     _stub_function(stub_function),
   957     _stub_entry_point(NULL),
   958     _entry_bci(InvocationEntryBci),
   959     _initial_gvn(NULL),
   960     _for_igvn(NULL),
   961     _warm_calls(NULL),
   962     _orig_pc_slot(0),
   963     _orig_pc_slot_offset_in_bytes(0),
   964     _subsume_loads(true),
   965     _do_escape_analysis(false),
   966     _eliminate_boxing(false),
   967     _failure_reason(NULL),
   968     _code_buffer("Compile::Fill_buffer"),
   969     _has_method_handle_invokes(false),
   970     _mach_constant_base_node(NULL),
   971     _node_bundling_limit(0),
   972     _node_bundling_base(NULL),
   973     _java_calls(0),
   974     _inner_loops(0),
   975 #ifndef PRODUCT
   976     _trace_opto_output(TraceOptoOutput),
   977     _in_dump_cnt(0),
   978     _printer(NULL),
   979 #endif
   980     _comp_arena(mtCompiler),
   981     _node_arena(mtCompiler),
   982     _old_arena(mtCompiler),
   983     _Compile_types(mtCompiler),
   984     _dead_node_list(comp_arena()),
   985     _dead_node_count(0),
   986     _congraph(NULL),
   987     _replay_inline_data(NULL),
   988     _number_of_mh_late_inlines(0),
   989     _inlining_progress(false),
   990     _inlining_incrementally(false),
   991     _print_inlining_list(NULL),
   992     _print_inlining_idx(0),
   993     _allowed_reasons(0),
   994     _interpreter_frame_size(0),
   995     _max_node_limit(MaxNodeLimit) {
   996   C = this;
   998 #ifndef PRODUCT
   999   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
  1000   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
  1001   set_print_assembly(PrintFrameConverterAssembly);
  1002   set_parsed_irreducible_loop(false);
  1003 #endif
  1004   set_has_irreducible_loop(false); // no loops
  1006   CompileWrapper cw(this);
  1007   Init(/*AliasLevel=*/ 0);
  1008   init_tf((*generator)());
  1011     // The following is a dummy for the sake of GraphKit::gen_stub
  1012     Unique_Node_List for_igvn(comp_arena());
  1013     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
  1014     PhaseGVN gvn(Thread::current()->resource_area(),255);
  1015     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
  1016     gvn.transform_no_reclaim(top());
  1018     GraphKit kit;
  1019     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
  1022   NOT_PRODUCT( verify_graph_edges(); )
  1023   Code_Gen();
  1024   if (failing())  return;
  1027   // Entry point will be accessed using compile->stub_entry_point();
  1028   if (code_buffer() == NULL) {
  1029     Matcher::soft_match_failure();
  1030   } else {
  1031     if (PrintAssembly && (WizardMode || Verbose))
  1032       tty->print_cr("### Stub::%s", stub_name);
  1034     if (!failing()) {
  1035       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
  1037       // Make the NMethod
  1038       // For now we mark the frame as never safe for profile stackwalking
  1039       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
  1040                                                       code_buffer(),
  1041                                                       CodeOffsets::frame_never_safe,
  1042                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
  1043                                                       frame_size_in_words(),
  1044                                                       _oop_map_set,
  1045                                                       save_arg_registers);
  1046       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
  1048       _stub_entry_point = rs->entry_point();
  1053 //------------------------------Init-------------------------------------------
  1054 // Prepare for a single compilation
  1055 void Compile::Init(int aliaslevel) {
  1056   _unique  = 0;
  1057   _regalloc = NULL;
  1059   _tf      = NULL;  // filled in later
  1060   _top     = NULL;  // cached later
  1061   _matcher = NULL;  // filled in later
  1062   _cfg     = NULL;  // filled in later
  1064   set_24_bit_selection_and_mode(Use24BitFP, false);
  1066   _node_note_array = NULL;
  1067   _default_node_notes = NULL;
  1069   _immutable_memory = NULL; // filled in at first inquiry
  1071   // Globally visible Nodes
  1072   // First set TOP to NULL to give safe behavior during creation of RootNode
  1073   set_cached_top_node(NULL);
  1074   set_root(new (this) RootNode());
  1075   // Now that you have a Root to point to, create the real TOP
  1076   set_cached_top_node( new (this) ConNode(Type::TOP) );
  1077   set_recent_alloc(NULL, NULL);
  1079   // Create Debug Information Recorder to record scopes, oopmaps, etc.
  1080   env()->set_oop_recorder(new OopRecorder(env()->arena()));
  1081   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
  1082   env()->set_dependencies(new Dependencies(env()));
  1084   _fixed_slots = 0;
  1085   set_has_split_ifs(false);
  1086   set_has_loops(has_method() && method()->has_loops()); // first approximation
  1087   set_has_stringbuilder(false);
  1088   set_has_boxed_value(false);
  1089   _trap_can_recompile = false;  // no traps emitted yet
  1090   _major_progress = true; // start out assuming good things will happen
  1091   set_has_unsafe_access(false);
  1092   set_max_vector_size(0);
  1093   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
  1094   set_decompile_count(0);
  1096   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
  1097   set_num_loop_opts(LoopOptsCount);
  1098   set_do_inlining(Inline);
  1099   set_max_inline_size(MaxInlineSize);
  1100   set_freq_inline_size(FreqInlineSize);
  1101   set_do_scheduling(OptoScheduling);
  1102   set_do_count_invocations(false);
  1103   set_do_method_data_update(false);
  1104   set_rtm_state(NoRTM); // No RTM lock eliding by default
  1105   method_has_option_value("MaxNodeLimit", _max_node_limit);
  1106 #if INCLUDE_RTM_OPT
  1107   if (UseRTMLocking && has_method() && (method()->method_data_or_null() != NULL)) {
  1108     int rtm_state = method()->method_data()->rtm_state();
  1109     if (method_has_option("NoRTMLockEliding") || ((rtm_state & NoRTM) != 0)) {
  1110       // Don't generate RTM lock eliding code.
  1111       set_rtm_state(NoRTM);
  1112     } else if (method_has_option("UseRTMLockEliding") || ((rtm_state & UseRTM) != 0) || !UseRTMDeopt) {
  1113       // Generate RTM lock eliding code without abort ratio calculation code.
  1114       set_rtm_state(UseRTM);
  1115     } else if (UseRTMDeopt) {
  1116       // Generate RTM lock eliding code and include abort ratio calculation
  1117       // code if UseRTMDeopt is on.
  1118       set_rtm_state(ProfileRTM);
  1121 #endif
  1122   if (debug_info()->recording_non_safepoints()) {
  1123     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
  1124                         (comp_arena(), 8, 0, NULL));
  1125     set_default_node_notes(Node_Notes::make(this));
  1128   // // -- Initialize types before each compile --
  1129   // // Update cached type information
  1130   // if( _method && _method->constants() )
  1131   //   Type::update_loaded_types(_method, _method->constants());
  1133   // Init alias_type map.
  1134   if (!_do_escape_analysis && aliaslevel == 3)
  1135     aliaslevel = 2;  // No unique types without escape analysis
  1136   _AliasLevel = aliaslevel;
  1137   const int grow_ats = 16;
  1138   _max_alias_types = grow_ats;
  1139   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
  1140   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
  1141   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
  1143     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
  1145   // Initialize the first few types.
  1146   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
  1147   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
  1148   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
  1149   _num_alias_types = AliasIdxRaw+1;
  1150   // Zero out the alias type cache.
  1151   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
  1152   // A NULL adr_type hits in the cache right away.  Preload the right answer.
  1153   probe_alias_cache(NULL)->_index = AliasIdxTop;
  1155   _intrinsics = NULL;
  1156   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1157   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1158   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
  1159   register_library_intrinsics();
  1162 //---------------------------init_start----------------------------------------
  1163 // Install the StartNode on this compile object.
  1164 void Compile::init_start(StartNode* s) {
  1165   if (failing())
  1166     return; // already failing
  1167   assert(s == start(), "");
  1170 StartNode* Compile::start() const {
  1171   assert(!failing(), "");
  1172   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
  1173     Node* start = root()->fast_out(i);
  1174     if( start->is_Start() )
  1175       return start->as_Start();
  1177   fatal("Did not find Start node!");
  1178   return NULL;
  1181 //-------------------------------immutable_memory-------------------------------------
  1182 // Access immutable memory
  1183 Node* Compile::immutable_memory() {
  1184   if (_immutable_memory != NULL) {
  1185     return _immutable_memory;
  1187   StartNode* s = start();
  1188   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
  1189     Node *p = s->fast_out(i);
  1190     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
  1191       _immutable_memory = p;
  1192       return _immutable_memory;
  1195   ShouldNotReachHere();
  1196   return NULL;
  1199 //----------------------set_cached_top_node------------------------------------
  1200 // Install the cached top node, and make sure Node::is_top works correctly.
  1201 void Compile::set_cached_top_node(Node* tn) {
  1202   if (tn != NULL)  verify_top(tn);
  1203   Node* old_top = _top;
  1204   _top = tn;
  1205   // Calling Node::setup_is_top allows the nodes the chance to adjust
  1206   // their _out arrays.
  1207   if (_top != NULL)     _top->setup_is_top();
  1208   if (old_top != NULL)  old_top->setup_is_top();
  1209   assert(_top == NULL || top()->is_top(), "");
  1212 #ifdef ASSERT
  1213 uint Compile::count_live_nodes_by_graph_walk() {
  1214   Unique_Node_List useful(comp_arena());
  1215   // Get useful node list by walking the graph.
  1216   identify_useful_nodes(useful);
  1217   return useful.size();
  1220 void Compile::print_missing_nodes() {
  1222   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
  1223   if ((_log == NULL) && (! PrintIdealNodeCount)) {
  1224     return;
  1227   // This is an expensive function. It is executed only when the user
  1228   // specifies VerifyIdealNodeCount option or otherwise knows the
  1229   // additional work that needs to be done to identify reachable nodes
  1230   // by walking the flow graph and find the missing ones using
  1231   // _dead_node_list.
  1233   Unique_Node_List useful(comp_arena());
  1234   // Get useful node list by walking the graph.
  1235   identify_useful_nodes(useful);
  1237   uint l_nodes = C->live_nodes();
  1238   uint l_nodes_by_walk = useful.size();
  1240   if (l_nodes != l_nodes_by_walk) {
  1241     if (_log != NULL) {
  1242       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
  1243       _log->stamp();
  1244       _log->end_head();
  1246     VectorSet& useful_member_set = useful.member_set();
  1247     int last_idx = l_nodes_by_walk;
  1248     for (int i = 0; i < last_idx; i++) {
  1249       if (useful_member_set.test(i)) {
  1250         if (_dead_node_list.test(i)) {
  1251           if (_log != NULL) {
  1252             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
  1254           if (PrintIdealNodeCount) {
  1255             // Print the log message to tty
  1256               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
  1257               useful.at(i)->dump();
  1261       else if (! _dead_node_list.test(i)) {
  1262         if (_log != NULL) {
  1263           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
  1265         if (PrintIdealNodeCount) {
  1266           // Print the log message to tty
  1267           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
  1271     if (_log != NULL) {
  1272       _log->tail("mismatched_nodes");
  1276 #endif
  1278 #ifndef PRODUCT
  1279 void Compile::verify_top(Node* tn) const {
  1280   if (tn != NULL) {
  1281     assert(tn->is_Con(), "top node must be a constant");
  1282     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
  1283     assert(tn->in(0) != NULL, "must have live top node");
  1286 #endif
  1289 ///-------------------Managing Per-Node Debug & Profile Info-------------------
  1291 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
  1292   guarantee(arr != NULL, "");
  1293   int num_blocks = arr->length();
  1294   if (grow_by < num_blocks)  grow_by = num_blocks;
  1295   int num_notes = grow_by * _node_notes_block_size;
  1296   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
  1297   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
  1298   while (num_notes > 0) {
  1299     arr->append(notes);
  1300     notes     += _node_notes_block_size;
  1301     num_notes -= _node_notes_block_size;
  1303   assert(num_notes == 0, "exact multiple, please");
  1306 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
  1307   if (source == NULL || dest == NULL)  return false;
  1309   if (dest->is_Con())
  1310     return false;               // Do not push debug info onto constants.
  1312 #ifdef ASSERT
  1313   // Leave a bread crumb trail pointing to the original node:
  1314   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
  1315     dest->set_debug_orig(source);
  1317 #endif
  1319   if (node_note_array() == NULL)
  1320     return false;               // Not collecting any notes now.
  1322   // This is a copy onto a pre-existing node, which may already have notes.
  1323   // If both nodes have notes, do not overwrite any pre-existing notes.
  1324   Node_Notes* source_notes = node_notes_at(source->_idx);
  1325   if (source_notes == NULL || source_notes->is_clear())  return false;
  1326   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
  1327   if (dest_notes == NULL || dest_notes->is_clear()) {
  1328     return set_node_notes_at(dest->_idx, source_notes);
  1331   Node_Notes merged_notes = (*source_notes);
  1332   // The order of operations here ensures that dest notes will win...
  1333   merged_notes.update_from(dest_notes);
  1334   return set_node_notes_at(dest->_idx, &merged_notes);
  1338 //--------------------------allow_range_check_smearing-------------------------
  1339 // Gating condition for coalescing similar range checks.
  1340 // Sometimes we try 'speculatively' replacing a series of a range checks by a
  1341 // single covering check that is at least as strong as any of them.
  1342 // If the optimization succeeds, the simplified (strengthened) range check
  1343 // will always succeed.  If it fails, we will deopt, and then give up
  1344 // on the optimization.
  1345 bool Compile::allow_range_check_smearing() const {
  1346   // If this method has already thrown a range-check,
  1347   // assume it was because we already tried range smearing
  1348   // and it failed.
  1349   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
  1350   return !already_trapped;
  1354 //------------------------------flatten_alias_type-----------------------------
  1355 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
  1356   int offset = tj->offset();
  1357   TypePtr::PTR ptr = tj->ptr();
  1359   // Known instance (scalarizable allocation) alias only with itself.
  1360   bool is_known_inst = tj->isa_oopptr() != NULL &&
  1361                        tj->is_oopptr()->is_known_instance();
  1363   // Process weird unsafe references.
  1364   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
  1365     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
  1366     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
  1367     tj = TypeOopPtr::BOTTOM;
  1368     ptr = tj->ptr();
  1369     offset = tj->offset();
  1372   // Array pointers need some flattening
  1373   const TypeAryPtr *ta = tj->isa_aryptr();
  1374   if (ta && ta->is_stable()) {
  1375     // Erase stability property for alias analysis.
  1376     tj = ta = ta->cast_to_stable(false);
  1378   if( ta && is_known_inst ) {
  1379     if ( offset != Type::OffsetBot &&
  1380          offset > arrayOopDesc::length_offset_in_bytes() ) {
  1381       offset = Type::OffsetBot; // Flatten constant access into array body only
  1382       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
  1384   } else if( ta && _AliasLevel >= 2 ) {
  1385     // For arrays indexed by constant indices, we flatten the alias
  1386     // space to include all of the array body.  Only the header, klass
  1387     // and array length can be accessed un-aliased.
  1388     if( offset != Type::OffsetBot ) {
  1389       if( ta->const_oop() ) { // MethodData* or Method*
  1390         offset = Type::OffsetBot;   // Flatten constant access into array body
  1391         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
  1392       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
  1393         // range is OK as-is.
  1394         tj = ta = TypeAryPtr::RANGE;
  1395       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
  1396         tj = TypeInstPtr::KLASS; // all klass loads look alike
  1397         ta = TypeAryPtr::RANGE; // generic ignored junk
  1398         ptr = TypePtr::BotPTR;
  1399       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
  1400         tj = TypeInstPtr::MARK;
  1401         ta = TypeAryPtr::RANGE; // generic ignored junk
  1402         ptr = TypePtr::BotPTR;
  1403       } else {                  // Random constant offset into array body
  1404         offset = Type::OffsetBot;   // Flatten constant access into array body
  1405         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
  1408     // Arrays of fixed size alias with arrays of unknown size.
  1409     if (ta->size() != TypeInt::POS) {
  1410       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
  1411       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
  1413     // Arrays of known objects become arrays of unknown objects.
  1414     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
  1415       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
  1416       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1418     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
  1419       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
  1420       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
  1422     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
  1423     // cannot be distinguished by bytecode alone.
  1424     if (ta->elem() == TypeInt::BOOL) {
  1425       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
  1426       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
  1427       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
  1429     // During the 2nd round of IterGVN, NotNull castings are removed.
  1430     // Make sure the Bottom and NotNull variants alias the same.
  1431     // Also, make sure exact and non-exact variants alias the same.
  1432     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
  1433       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
  1437   // Oop pointers need some flattening
  1438   const TypeInstPtr *to = tj->isa_instptr();
  1439   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
  1440     ciInstanceKlass *k = to->klass()->as_instance_klass();
  1441     if( ptr == TypePtr::Constant ) {
  1442       if (to->klass() != ciEnv::current()->Class_klass() ||
  1443           offset < k->size_helper() * wordSize) {
  1444         // No constant oop pointers (such as Strings); they alias with
  1445         // unknown strings.
  1446         assert(!is_known_inst, "not scalarizable allocation");
  1447         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1449     } else if( is_known_inst ) {
  1450       tj = to; // Keep NotNull and klass_is_exact for instance type
  1451     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
  1452       // During the 2nd round of IterGVN, NotNull castings are removed.
  1453       // Make sure the Bottom and NotNull variants alias the same.
  1454       // Also, make sure exact and non-exact variants alias the same.
  1455       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
  1457     if (to->speculative() != NULL) {
  1458       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
  1460     // Canonicalize the holder of this field
  1461     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
  1462       // First handle header references such as a LoadKlassNode, even if the
  1463       // object's klass is unloaded at compile time (4965979).
  1464       if (!is_known_inst) { // Do it only for non-instance types
  1465         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
  1467     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
  1468       // Static fields are in the space above the normal instance
  1469       // fields in the java.lang.Class instance.
  1470       if (to->klass() != ciEnv::current()->Class_klass()) {
  1471         to = NULL;
  1472         tj = TypeOopPtr::BOTTOM;
  1473         offset = tj->offset();
  1475     } else {
  1476       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
  1477       if (!k->equals(canonical_holder) || tj->offset() != offset) {
  1478         if( is_known_inst ) {
  1479           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
  1480         } else {
  1481           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
  1487   // Klass pointers to object array klasses need some flattening
  1488   const TypeKlassPtr *tk = tj->isa_klassptr();
  1489   if( tk ) {
  1490     // If we are referencing a field within a Klass, we need
  1491     // to assume the worst case of an Object.  Both exact and
  1492     // inexact types must flatten to the same alias class so
  1493     // use NotNull as the PTR.
  1494     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
  1496       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
  1497                                    TypeKlassPtr::OBJECT->klass(),
  1498                                    offset);
  1501     ciKlass* klass = tk->klass();
  1502     if( klass->is_obj_array_klass() ) {
  1503       ciKlass* k = TypeAryPtr::OOPS->klass();
  1504       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
  1505         k = TypeInstPtr::BOTTOM->klass();
  1506       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
  1509     // Check for precise loads from the primary supertype array and force them
  1510     // to the supertype cache alias index.  Check for generic array loads from
  1511     // the primary supertype array and also force them to the supertype cache
  1512     // alias index.  Since the same load can reach both, we need to merge
  1513     // these 2 disparate memories into the same alias class.  Since the
  1514     // primary supertype array is read-only, there's no chance of confusion
  1515     // where we bypass an array load and an array store.
  1516     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
  1517     if (offset == Type::OffsetBot ||
  1518         (offset >= primary_supers_offset &&
  1519          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
  1520         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
  1521       offset = in_bytes(Klass::secondary_super_cache_offset());
  1522       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
  1526   // Flatten all Raw pointers together.
  1527   if (tj->base() == Type::RawPtr)
  1528     tj = TypeRawPtr::BOTTOM;
  1530   if (tj->base() == Type::AnyPtr)
  1531     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
  1533   // Flatten all to bottom for now
  1534   switch( _AliasLevel ) {
  1535   case 0:
  1536     tj = TypePtr::BOTTOM;
  1537     break;
  1538   case 1:                       // Flatten to: oop, static, field or array
  1539     switch (tj->base()) {
  1540     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
  1541     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
  1542     case Type::AryPtr:   // do not distinguish arrays at all
  1543     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
  1544     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
  1545     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
  1546     default: ShouldNotReachHere();
  1548     break;
  1549   case 2:                       // No collapsing at level 2; keep all splits
  1550   case 3:                       // No collapsing at level 3; keep all splits
  1551     break;
  1552   default:
  1553     Unimplemented();
  1556   offset = tj->offset();
  1557   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
  1559   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
  1560           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
  1561           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
  1562           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
  1563           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1564           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
  1565           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
  1566           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
  1567   assert( tj->ptr() != TypePtr::TopPTR &&
  1568           tj->ptr() != TypePtr::AnyNull &&
  1569           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
  1570 //    assert( tj->ptr() != TypePtr::Constant ||
  1571 //            tj->base() == Type::RawPtr ||
  1572 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
  1574   return tj;
  1577 void Compile::AliasType::Init(int i, const TypePtr* at) {
  1578   _index = i;
  1579   _adr_type = at;
  1580   _field = NULL;
  1581   _element = NULL;
  1582   _is_rewritable = true; // default
  1583   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
  1584   if (atoop != NULL && atoop->is_known_instance()) {
  1585     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
  1586     _general_index = Compile::current()->get_alias_index(gt);
  1587   } else {
  1588     _general_index = 0;
  1592 //---------------------------------print_on------------------------------------
  1593 #ifndef PRODUCT
  1594 void Compile::AliasType::print_on(outputStream* st) {
  1595   if (index() < 10)
  1596         st->print("@ <%d> ", index());
  1597   else  st->print("@ <%d>",  index());
  1598   st->print(is_rewritable() ? "   " : " RO");
  1599   int offset = adr_type()->offset();
  1600   if (offset == Type::OffsetBot)
  1601         st->print(" +any");
  1602   else  st->print(" +%-3d", offset);
  1603   st->print(" in ");
  1604   adr_type()->dump_on(st);
  1605   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
  1606   if (field() != NULL && tjp) {
  1607     if (tjp->klass()  != field()->holder() ||
  1608         tjp->offset() != field()->offset_in_bytes()) {
  1609       st->print(" != ");
  1610       field()->print();
  1611       st->print(" ***");
  1616 void print_alias_types() {
  1617   Compile* C = Compile::current();
  1618   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
  1619   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
  1620     C->alias_type(idx)->print_on(tty);
  1621     tty->cr();
  1624 #endif
  1627 //----------------------------probe_alias_cache--------------------------------
  1628 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
  1629   intptr_t key = (intptr_t) adr_type;
  1630   key ^= key >> logAliasCacheSize;
  1631   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
  1635 //-----------------------------grow_alias_types--------------------------------
  1636 void Compile::grow_alias_types() {
  1637   const int old_ats  = _max_alias_types; // how many before?
  1638   const int new_ats  = old_ats;          // how many more?
  1639   const int grow_ats = old_ats+new_ats;  // how many now?
  1640   _max_alias_types = grow_ats;
  1641   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
  1642   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
  1643   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
  1644   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
  1648 //--------------------------------find_alias_type------------------------------
  1649 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
  1650   if (_AliasLevel == 0)
  1651     return alias_type(AliasIdxBot);
  1653   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1654   if (ace->_adr_type == adr_type) {
  1655     return alias_type(ace->_index);
  1658   // Handle special cases.
  1659   if (adr_type == NULL)             return alias_type(AliasIdxTop);
  1660   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
  1662   // Do it the slow way.
  1663   const TypePtr* flat = flatten_alias_type(adr_type);
  1665 #ifdef ASSERT
  1666   assert(flat == flatten_alias_type(flat), "idempotent");
  1667   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
  1668   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
  1669     const TypeOopPtr* foop = flat->is_oopptr();
  1670     // Scalarizable allocations have exact klass always.
  1671     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
  1672     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
  1673     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
  1675   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
  1676 #endif
  1678   int idx = AliasIdxTop;
  1679   for (int i = 0; i < num_alias_types(); i++) {
  1680     if (alias_type(i)->adr_type() == flat) {
  1681       idx = i;
  1682       break;
  1686   if (idx == AliasIdxTop) {
  1687     if (no_create)  return NULL;
  1688     // Grow the array if necessary.
  1689     if (_num_alias_types == _max_alias_types)  grow_alias_types();
  1690     // Add a new alias type.
  1691     idx = _num_alias_types++;
  1692     _alias_types[idx]->Init(idx, flat);
  1693     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
  1694     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
  1695     if (flat->isa_instptr()) {
  1696       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
  1697           && flat->is_instptr()->klass() == env()->Class_klass())
  1698         alias_type(idx)->set_rewritable(false);
  1700     if (flat->isa_aryptr()) {
  1701 #ifdef ASSERT
  1702       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
  1703       // (T_BYTE has the weakest alignment and size restrictions...)
  1704       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
  1705 #endif
  1706       if (flat->offset() == TypePtr::OffsetBot) {
  1707         alias_type(idx)->set_element(flat->is_aryptr()->elem());
  1710     if (flat->isa_klassptr()) {
  1711       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
  1712         alias_type(idx)->set_rewritable(false);
  1713       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
  1714         alias_type(idx)->set_rewritable(false);
  1715       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
  1716         alias_type(idx)->set_rewritable(false);
  1717       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
  1718         alias_type(idx)->set_rewritable(false);
  1720     // %%% (We would like to finalize JavaThread::threadObj_offset(),
  1721     // but the base pointer type is not distinctive enough to identify
  1722     // references into JavaThread.)
  1724     // Check for final fields.
  1725     const TypeInstPtr* tinst = flat->isa_instptr();
  1726     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
  1727       ciField* field;
  1728       if (tinst->const_oop() != NULL &&
  1729           tinst->klass() == ciEnv::current()->Class_klass() &&
  1730           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
  1731         // static field
  1732         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
  1733         field = k->get_field_by_offset(tinst->offset(), true);
  1734       } else {
  1735         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
  1736         field = k->get_field_by_offset(tinst->offset(), false);
  1738       assert(field == NULL ||
  1739              original_field == NULL ||
  1740              (field->holder() == original_field->holder() &&
  1741               field->offset() == original_field->offset() &&
  1742               field->is_static() == original_field->is_static()), "wrong field?");
  1743       // Set field() and is_rewritable() attributes.
  1744       if (field != NULL)  alias_type(idx)->set_field(field);
  1748   // Fill the cache for next time.
  1749   ace->_adr_type = adr_type;
  1750   ace->_index    = idx;
  1751   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
  1753   // Might as well try to fill the cache for the flattened version, too.
  1754   AliasCacheEntry* face = probe_alias_cache(flat);
  1755   if (face->_adr_type == NULL) {
  1756     face->_adr_type = flat;
  1757     face->_index    = idx;
  1758     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
  1761   return alias_type(idx);
  1765 Compile::AliasType* Compile::alias_type(ciField* field) {
  1766   const TypeOopPtr* t;
  1767   if (field->is_static())
  1768     t = TypeInstPtr::make(field->holder()->java_mirror());
  1769   else
  1770     t = TypeOopPtr::make_from_klass_raw(field->holder());
  1771   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
  1772   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
  1773   return atp;
  1777 //------------------------------have_alias_type--------------------------------
  1778 bool Compile::have_alias_type(const TypePtr* adr_type) {
  1779   AliasCacheEntry* ace = probe_alias_cache(adr_type);
  1780   if (ace->_adr_type == adr_type) {
  1781     return true;
  1784   // Handle special cases.
  1785   if (adr_type == NULL)             return true;
  1786   if (adr_type == TypePtr::BOTTOM)  return true;
  1788   return find_alias_type(adr_type, true, NULL) != NULL;
  1791 //-----------------------------must_alias--------------------------------------
  1792 // True if all values of the given address type are in the given alias category.
  1793 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
  1794   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1795   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
  1796   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1797   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
  1799   // the only remaining possible overlap is identity
  1800   int adr_idx = get_alias_index(adr_type);
  1801   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1802   assert(adr_idx == alias_idx ||
  1803          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
  1804           && adr_type                       != TypeOopPtr::BOTTOM),
  1805          "should not be testing for overlap with an unsafe pointer");
  1806   return adr_idx == alias_idx;
  1809 //------------------------------can_alias--------------------------------------
  1810 // True if any values of the given address type are in the given alias category.
  1811 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
  1812   if (alias_idx == AliasIdxTop)         return false; // the empty category
  1813   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
  1814   if (alias_idx == AliasIdxBot)         return true;  // the universal category
  1815   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
  1817   // the only remaining possible overlap is identity
  1818   int adr_idx = get_alias_index(adr_type);
  1819   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
  1820   return adr_idx == alias_idx;
  1825 //---------------------------pop_warm_call-------------------------------------
  1826 WarmCallInfo* Compile::pop_warm_call() {
  1827   WarmCallInfo* wci = _warm_calls;
  1828   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
  1829   return wci;
  1832 //----------------------------Inline_Warm--------------------------------------
  1833 int Compile::Inline_Warm() {
  1834   // If there is room, try to inline some more warm call sites.
  1835   // %%% Do a graph index compaction pass when we think we're out of space?
  1836   if (!InlineWarmCalls)  return 0;
  1838   int calls_made_hot = 0;
  1839   int room_to_grow   = NodeCountInliningCutoff - unique();
  1840   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
  1841   int amount_grown   = 0;
  1842   WarmCallInfo* call;
  1843   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
  1844     int est_size = (int)call->size();
  1845     if (est_size > (room_to_grow - amount_grown)) {
  1846       // This one won't fit anyway.  Get rid of it.
  1847       call->make_cold();
  1848       continue;
  1850     call->make_hot();
  1851     calls_made_hot++;
  1852     amount_grown   += est_size;
  1853     amount_to_grow -= est_size;
  1856   if (calls_made_hot > 0)  set_major_progress();
  1857   return calls_made_hot;
  1861 //----------------------------Finish_Warm--------------------------------------
  1862 void Compile::Finish_Warm() {
  1863   if (!InlineWarmCalls)  return;
  1864   if (failing())  return;
  1865   if (warm_calls() == NULL)  return;
  1867   // Clean up loose ends, if we are out of space for inlining.
  1868   WarmCallInfo* call;
  1869   while ((call = pop_warm_call()) != NULL) {
  1870     call->make_cold();
  1874 //---------------------cleanup_loop_predicates-----------------------
  1875 // Remove the opaque nodes that protect the predicates so that all unused
  1876 // checks and uncommon_traps will be eliminated from the ideal graph
  1877 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
  1878   if (predicate_count()==0) return;
  1879   for (int i = predicate_count(); i > 0; i--) {
  1880     Node * n = predicate_opaque1_node(i-1);
  1881     assert(n->Opcode() == Op_Opaque1, "must be");
  1882     igvn.replace_node(n, n->in(1));
  1884   assert(predicate_count()==0, "should be clean!");
  1887 // StringOpts and late inlining of string methods
  1888 void Compile::inline_string_calls(bool parse_time) {
  1890     // remove useless nodes to make the usage analysis simpler
  1891     ResourceMark rm;
  1892     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  1896     ResourceMark rm;
  1897     print_method(PHASE_BEFORE_STRINGOPTS, 3);
  1898     PhaseStringOpts pso(initial_gvn(), for_igvn());
  1899     print_method(PHASE_AFTER_STRINGOPTS, 3);
  1902   // now inline anything that we skipped the first time around
  1903   if (!parse_time) {
  1904     _late_inlines_pos = _late_inlines.length();
  1907   while (_string_late_inlines.length() > 0) {
  1908     CallGenerator* cg = _string_late_inlines.pop();
  1909     cg->do_late_inline();
  1910     if (failing())  return;
  1912   _string_late_inlines.trunc_to(0);
  1915 // Late inlining of boxing methods
  1916 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
  1917   if (_boxing_late_inlines.length() > 0) {
  1918     assert(has_boxed_value(), "inconsistent");
  1920     PhaseGVN* gvn = initial_gvn();
  1921     set_inlining_incrementally(true);
  1923     assert( igvn._worklist.size() == 0, "should be done with igvn" );
  1924     for_igvn()->clear();
  1925     gvn->replace_with(&igvn);
  1927     _late_inlines_pos = _late_inlines.length();
  1929     while (_boxing_late_inlines.length() > 0) {
  1930       CallGenerator* cg = _boxing_late_inlines.pop();
  1931       cg->do_late_inline();
  1932       if (failing())  return;
  1934     _boxing_late_inlines.trunc_to(0);
  1937       ResourceMark rm;
  1938       PhaseRemoveUseless pru(gvn, for_igvn());
  1941     igvn = PhaseIterGVN(gvn);
  1942     igvn.optimize();
  1944     set_inlining_progress(false);
  1945     set_inlining_incrementally(false);
  1949 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
  1950   assert(IncrementalInline, "incremental inlining should be on");
  1951   PhaseGVN* gvn = initial_gvn();
  1953   set_inlining_progress(false);
  1954   for_igvn()->clear();
  1955   gvn->replace_with(&igvn);
  1957   int i = 0;
  1959   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
  1960     CallGenerator* cg = _late_inlines.at(i);
  1961     _late_inlines_pos = i+1;
  1962     cg->do_late_inline();
  1963     if (failing())  return;
  1965   int j = 0;
  1966   for (; i < _late_inlines.length(); i++, j++) {
  1967     _late_inlines.at_put(j, _late_inlines.at(i));
  1969   _late_inlines.trunc_to(j);
  1972     ResourceMark rm;
  1973     PhaseRemoveUseless pru(gvn, for_igvn());
  1976   igvn = PhaseIterGVN(gvn);
  1979 // Perform incremental inlining until bound on number of live nodes is reached
  1980 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
  1981   PhaseGVN* gvn = initial_gvn();
  1983   set_inlining_incrementally(true);
  1984   set_inlining_progress(true);
  1985   uint low_live_nodes = 0;
  1987   while(inlining_progress() && _late_inlines.length() > 0) {
  1989     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  1990       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
  1991         // PhaseIdealLoop is expensive so we only try it once we are
  1992         // out of live nodes and we only try it again if the previous
  1993         // helped got the number of nodes down significantly
  1994         PhaseIdealLoop ideal_loop( igvn, false, true );
  1995         if (failing())  return;
  1996         low_live_nodes = live_nodes();
  1997         _major_progress = true;
  2000       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
  2001         break;
  2005     inline_incrementally_one(igvn);
  2007     if (failing())  return;
  2009     igvn.optimize();
  2011     if (failing())  return;
  2014   assert( igvn._worklist.size() == 0, "should be done with igvn" );
  2016   if (_string_late_inlines.length() > 0) {
  2017     assert(has_stringbuilder(), "inconsistent");
  2018     for_igvn()->clear();
  2019     initial_gvn()->replace_with(&igvn);
  2021     inline_string_calls(false);
  2023     if (failing())  return;
  2026       ResourceMark rm;
  2027       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
  2030     igvn = PhaseIterGVN(gvn);
  2032     igvn.optimize();
  2035   set_inlining_incrementally(false);
  2039 //------------------------------Optimize---------------------------------------
  2040 // Given a graph, optimize it.
  2041 void Compile::Optimize() {
  2042   TracePhase t1("optimizer", &_t_optimizer, true);
  2044 #ifndef PRODUCT
  2045   if (env()->break_at_compile()) {
  2046     BREAKPOINT;
  2049 #endif
  2051   ResourceMark rm;
  2052   int          loop_opts_cnt;
  2054   NOT_PRODUCT( verify_graph_edges(); )
  2056   print_method(PHASE_AFTER_PARSING);
  2059   // Iterative Global Value Numbering, including ideal transforms
  2060   // Initialize IterGVN with types and values from parse-time GVN
  2061   PhaseIterGVN igvn(initial_gvn());
  2063     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
  2064     igvn.optimize();
  2067   print_method(PHASE_ITER_GVN1, 2);
  2069   if (failing())  return;
  2072     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2073     inline_incrementally(igvn);
  2076   print_method(PHASE_INCREMENTAL_INLINE, 2);
  2078   if (failing())  return;
  2080   if (eliminate_boxing()) {
  2081     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
  2082     // Inline valueOf() methods now.
  2083     inline_boxing_calls(igvn);
  2085     if (AlwaysIncrementalInline) {
  2086       inline_incrementally(igvn);
  2089     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
  2091     if (failing())  return;
  2094   // Remove the speculative part of types and clean up the graph from
  2095   // the extra CastPP nodes whose only purpose is to carry them. Do
  2096   // that early so that optimizations are not disrupted by the extra
  2097   // CastPP nodes.
  2098   remove_speculative_types(igvn);
  2100   // No more new expensive nodes will be added to the list from here
  2101   // so keep only the actual candidates for optimizations.
  2102   cleanup_expensive_nodes(igvn);
  2104   // Perform escape analysis
  2105   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
  2106     if (has_loops()) {
  2107       // Cleanup graph (remove dead nodes).
  2108       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2109       PhaseIdealLoop ideal_loop( igvn, false, true );
  2110       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
  2111       if (failing())  return;
  2113     ConnectionGraph::do_analysis(this, &igvn);
  2115     if (failing())  return;
  2117     // Optimize out fields loads from scalar replaceable allocations.
  2118     igvn.optimize();
  2119     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
  2121     if (failing())  return;
  2123     if (congraph() != NULL && macro_count() > 0) {
  2124       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
  2125       PhaseMacroExpand mexp(igvn);
  2126       mexp.eliminate_macro_nodes();
  2127       igvn.set_delay_transform(false);
  2129       igvn.optimize();
  2130       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
  2132       if (failing())  return;
  2136   // Loop transforms on the ideal graph.  Range Check Elimination,
  2137   // peeling, unrolling, etc.
  2139   // Set loop opts counter
  2140   loop_opts_cnt = num_loop_opts();
  2141   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
  2143       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2144       PhaseIdealLoop ideal_loop( igvn, true );
  2145       loop_opts_cnt--;
  2146       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
  2147       if (failing())  return;
  2149     // Loop opts pass if partial peeling occurred in previous pass
  2150     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
  2151       TracePhase t3("idealLoop", &_t_idealLoop, true);
  2152       PhaseIdealLoop ideal_loop( igvn, false );
  2153       loop_opts_cnt--;
  2154       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
  2155       if (failing())  return;
  2157     // Loop opts pass for loop-unrolling before CCP
  2158     if(major_progress() && (loop_opts_cnt > 0)) {
  2159       TracePhase t4("idealLoop", &_t_idealLoop, true);
  2160       PhaseIdealLoop ideal_loop( igvn, false );
  2161       loop_opts_cnt--;
  2162       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
  2164     if (!failing()) {
  2165       // Verify that last round of loop opts produced a valid graph
  2166       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2167       PhaseIdealLoop::verify(igvn);
  2170   if (failing())  return;
  2172   // Conditional Constant Propagation;
  2173   PhaseCCP ccp( &igvn );
  2174   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
  2176     TracePhase t2("ccp", &_t_ccp, true);
  2177     ccp.do_transform();
  2179   print_method(PHASE_CPP1, 2);
  2181   assert( true, "Break here to ccp.dump_old2new_map()");
  2183   // Iterative Global Value Numbering, including ideal transforms
  2185     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
  2186     igvn = ccp;
  2187     igvn.optimize();
  2190   print_method(PHASE_ITER_GVN2, 2);
  2192   if (failing())  return;
  2194   // Loop transforms on the ideal graph.  Range Check Elimination,
  2195   // peeling, unrolling, etc.
  2196   if(loop_opts_cnt > 0) {
  2197     debug_only( int cnt = 0; );
  2198     while(major_progress() && (loop_opts_cnt > 0)) {
  2199       TracePhase t2("idealLoop", &_t_idealLoop, true);
  2200       assert( cnt++ < 40, "infinite cycle in loop optimization" );
  2201       PhaseIdealLoop ideal_loop( igvn, true);
  2202       loop_opts_cnt--;
  2203       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
  2204       if (failing())  return;
  2209     // Verify that all previous optimizations produced a valid graph
  2210     // at least to this point, even if no loop optimizations were done.
  2211     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
  2212     PhaseIdealLoop::verify(igvn);
  2216     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
  2217     PhaseMacroExpand  mex(igvn);
  2218     if (mex.expand_macro_nodes()) {
  2219       assert(failing(), "must bail out w/ explicit message");
  2220       return;
  2224  } // (End scope of igvn; run destructor if necessary for asserts.)
  2226   dump_inlining();
  2227   // A method with only infinite loops has no edges entering loops from root
  2229     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
  2230     if (final_graph_reshaping()) {
  2231       assert(failing(), "must bail out w/ explicit message");
  2232       return;
  2236   print_method(PHASE_OPTIMIZE_FINISHED, 2);
  2240 //------------------------------Code_Gen---------------------------------------
  2241 // Given a graph, generate code for it
  2242 void Compile::Code_Gen() {
  2243   if (failing()) {
  2244     return;
  2247   // Perform instruction selection.  You might think we could reclaim Matcher
  2248   // memory PDQ, but actually the Matcher is used in generating spill code.
  2249   // Internals of the Matcher (including some VectorSets) must remain live
  2250   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
  2251   // set a bit in reclaimed memory.
  2253   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2254   // nodes.  Mapping is only valid at the root of each matched subtree.
  2255   NOT_PRODUCT( verify_graph_edges(); )
  2257   Matcher matcher;
  2258   _matcher = &matcher;
  2260     TracePhase t2("matcher", &_t_matcher, true);
  2261     matcher.match();
  2263   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
  2264   // nodes.  Mapping is only valid at the root of each matched subtree.
  2265   NOT_PRODUCT( verify_graph_edges(); )
  2267   // If you have too many nodes, or if matching has failed, bail out
  2268   check_node_count(0, "out of nodes matching instructions");
  2269   if (failing()) {
  2270     return;
  2273   // Build a proper-looking CFG
  2274   PhaseCFG cfg(node_arena(), root(), matcher);
  2275   _cfg = &cfg;
  2277     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
  2278     bool success = cfg.do_global_code_motion();
  2279     if (!success) {
  2280       return;
  2283     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
  2284     NOT_PRODUCT( verify_graph_edges(); )
  2285     debug_only( cfg.verify(); )
  2288   PhaseChaitin regalloc(unique(), cfg, matcher);
  2289   _regalloc = &regalloc;
  2291     TracePhase t2("regalloc", &_t_registerAllocation, true);
  2292     // Perform register allocation.  After Chaitin, use-def chains are
  2293     // no longer accurate (at spill code) and so must be ignored.
  2294     // Node->LRG->reg mappings are still accurate.
  2295     _regalloc->Register_Allocate();
  2297     // Bail out if the allocator builds too many nodes
  2298     if (failing()) {
  2299       return;
  2303   // Prior to register allocation we kept empty basic blocks in case the
  2304   // the allocator needed a place to spill.  After register allocation we
  2305   // are not adding any new instructions.  If any basic block is empty, we
  2306   // can now safely remove it.
  2308     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
  2309     cfg.remove_empty_blocks();
  2310     if (do_freq_based_layout()) {
  2311       PhaseBlockLayout layout(cfg);
  2312     } else {
  2313       cfg.set_loop_alignment();
  2315     cfg.fixup_flow();
  2318   // Apply peephole optimizations
  2319   if( OptoPeephole ) {
  2320     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
  2321     PhasePeephole peep( _regalloc, cfg);
  2322     peep.do_transform();
  2325   // Do late expand if CPU requires this.
  2326   if (Matcher::require_postalloc_expand) {
  2327     NOT_PRODUCT(TracePhase t2c("postalloc_expand", &_t_postalloc_expand, true));
  2328     cfg.postalloc_expand(_regalloc);
  2331   // Convert Nodes to instruction bits in a buffer
  2333     // %%%% workspace merge brought two timers together for one job
  2334     TracePhase t2a("output", &_t_output, true);
  2335     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
  2336     Output();
  2339   print_method(PHASE_FINAL_CODE);
  2341   // He's dead, Jim.
  2342   _cfg     = (PhaseCFG*)0xdeadbeef;
  2343   _regalloc = (PhaseChaitin*)0xdeadbeef;
  2347 //------------------------------dump_asm---------------------------------------
  2348 // Dump formatted assembly
  2349 #ifndef PRODUCT
  2350 void Compile::dump_asm(int *pcs, uint pc_limit) {
  2351   bool cut_short = false;
  2352   tty->print_cr("#");
  2353   tty->print("#  ");  _tf->dump();  tty->cr();
  2354   tty->print_cr("#");
  2356   // For all blocks
  2357   int pc = 0x0;                 // Program counter
  2358   char starts_bundle = ' ';
  2359   _regalloc->dump_frame();
  2361   Node *n = NULL;
  2362   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
  2363     if (VMThread::should_terminate()) {
  2364       cut_short = true;
  2365       break;
  2367     Block* block = _cfg->get_block(i);
  2368     if (block->is_connector() && !Verbose) {
  2369       continue;
  2371     n = block->head();
  2372     if (pcs && n->_idx < pc_limit) {
  2373       tty->print("%3.3x   ", pcs[n->_idx]);
  2374     } else {
  2375       tty->print("      ");
  2377     block->dump_head(_cfg);
  2378     if (block->is_connector()) {
  2379       tty->print_cr("        # Empty connector block");
  2380     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
  2381       tty->print_cr("        # Block is sole successor of call");
  2384     // For all instructions
  2385     Node *delay = NULL;
  2386     for (uint j = 0; j < block->number_of_nodes(); j++) {
  2387       if (VMThread::should_terminate()) {
  2388         cut_short = true;
  2389         break;
  2391       n = block->get_node(j);
  2392       if (valid_bundle_info(n)) {
  2393         Bundle* bundle = node_bundling(n);
  2394         if (bundle->used_in_unconditional_delay()) {
  2395           delay = n;
  2396           continue;
  2398         if (bundle->starts_bundle()) {
  2399           starts_bundle = '+';
  2403       if (WizardMode) {
  2404         n->dump();
  2407       if( !n->is_Region() &&    // Dont print in the Assembly
  2408           !n->is_Phi() &&       // a few noisely useless nodes
  2409           !n->is_Proj() &&
  2410           !n->is_MachTemp() &&
  2411           !n->is_SafePointScalarObject() &&
  2412           !n->is_Catch() &&     // Would be nice to print exception table targets
  2413           !n->is_MergeMem() &&  // Not very interesting
  2414           !n->is_top() &&       // Debug info table constants
  2415           !(n->is_Con() && !n->is_Mach())// Debug info table constants
  2416           ) {
  2417         if (pcs && n->_idx < pc_limit)
  2418           tty->print("%3.3x", pcs[n->_idx]);
  2419         else
  2420           tty->print("   ");
  2421         tty->print(" %c ", starts_bundle);
  2422         starts_bundle = ' ';
  2423         tty->print("\t");
  2424         n->format(_regalloc, tty);
  2425         tty->cr();
  2428       // If we have an instruction with a delay slot, and have seen a delay,
  2429       // then back up and print it
  2430       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
  2431         assert(delay != NULL, "no unconditional delay instruction");
  2432         if (WizardMode) delay->dump();
  2434         if (node_bundling(delay)->starts_bundle())
  2435           starts_bundle = '+';
  2436         if (pcs && n->_idx < pc_limit)
  2437           tty->print("%3.3x", pcs[n->_idx]);
  2438         else
  2439           tty->print("   ");
  2440         tty->print(" %c ", starts_bundle);
  2441         starts_bundle = ' ';
  2442         tty->print("\t");
  2443         delay->format(_regalloc, tty);
  2444         tty->cr();
  2445         delay = NULL;
  2448       // Dump the exception table as well
  2449       if( n->is_Catch() && (Verbose || WizardMode) ) {
  2450         // Print the exception table for this offset
  2451         _handler_table.print_subtable_for(pc);
  2455     if (pcs && n->_idx < pc_limit)
  2456       tty->print_cr("%3.3x", pcs[n->_idx]);
  2457     else
  2458       tty->cr();
  2460     assert(cut_short || delay == NULL, "no unconditional delay branch");
  2462   } // End of per-block dump
  2463   tty->cr();
  2465   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
  2467 #endif
  2469 //------------------------------Final_Reshape_Counts---------------------------
  2470 // This class defines counters to help identify when a method
  2471 // may/must be executed using hardware with only 24-bit precision.
  2472 struct Final_Reshape_Counts : public StackObj {
  2473   int  _call_count;             // count non-inlined 'common' calls
  2474   int  _float_count;            // count float ops requiring 24-bit precision
  2475   int  _double_count;           // count double ops requiring more precision
  2476   int  _java_call_count;        // count non-inlined 'java' calls
  2477   int  _inner_loop_count;       // count loops which need alignment
  2478   VectorSet _visited;           // Visitation flags
  2479   Node_List _tests;             // Set of IfNodes & PCTableNodes
  2481   Final_Reshape_Counts() :
  2482     _call_count(0), _float_count(0), _double_count(0),
  2483     _java_call_count(0), _inner_loop_count(0),
  2484     _visited( Thread::current()->resource_area() ) { }
  2486   void inc_call_count  () { _call_count  ++; }
  2487   void inc_float_count () { _float_count ++; }
  2488   void inc_double_count() { _double_count++; }
  2489   void inc_java_call_count() { _java_call_count++; }
  2490   void inc_inner_loop_count() { _inner_loop_count++; }
  2492   int  get_call_count  () const { return _call_count  ; }
  2493   int  get_float_count () const { return _float_count ; }
  2494   int  get_double_count() const { return _double_count; }
  2495   int  get_java_call_count() const { return _java_call_count; }
  2496   int  get_inner_loop_count() const { return _inner_loop_count; }
  2497 };
  2499 #ifdef ASSERT
  2500 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
  2501   ciInstanceKlass *k = tp->klass()->as_instance_klass();
  2502   // Make sure the offset goes inside the instance layout.
  2503   return k->contains_field_offset(tp->offset());
  2504   // Note that OffsetBot and OffsetTop are very negative.
  2506 #endif
  2508 // Eliminate trivially redundant StoreCMs and accumulate their
  2509 // precedence edges.
  2510 void Compile::eliminate_redundant_card_marks(Node* n) {
  2511   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
  2512   if (n->in(MemNode::Address)->outcnt() > 1) {
  2513     // There are multiple users of the same address so it might be
  2514     // possible to eliminate some of the StoreCMs
  2515     Node* mem = n->in(MemNode::Memory);
  2516     Node* adr = n->in(MemNode::Address);
  2517     Node* val = n->in(MemNode::ValueIn);
  2518     Node* prev = n;
  2519     bool done = false;
  2520     // Walk the chain of StoreCMs eliminating ones that match.  As
  2521     // long as it's a chain of single users then the optimization is
  2522     // safe.  Eliminating partially redundant StoreCMs would require
  2523     // cloning copies down the other paths.
  2524     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
  2525       if (adr == mem->in(MemNode::Address) &&
  2526           val == mem->in(MemNode::ValueIn)) {
  2527         // redundant StoreCM
  2528         if (mem->req() > MemNode::OopStore) {
  2529           // Hasn't been processed by this code yet.
  2530           n->add_prec(mem->in(MemNode::OopStore));
  2531         } else {
  2532           // Already converted to precedence edge
  2533           for (uint i = mem->req(); i < mem->len(); i++) {
  2534             // Accumulate any precedence edges
  2535             if (mem->in(i) != NULL) {
  2536               n->add_prec(mem->in(i));
  2539           // Everything above this point has been processed.
  2540           done = true;
  2542         // Eliminate the previous StoreCM
  2543         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
  2544         assert(mem->outcnt() == 0, "should be dead");
  2545         mem->disconnect_inputs(NULL, this);
  2546       } else {
  2547         prev = mem;
  2549       mem = prev->in(MemNode::Memory);
  2554 //------------------------------final_graph_reshaping_impl----------------------
  2555 // Implement items 1-5 from final_graph_reshaping below.
  2556 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
  2558   if ( n->outcnt() == 0 ) return; // dead node
  2559   uint nop = n->Opcode();
  2561   // Check for 2-input instruction with "last use" on right input.
  2562   // Swap to left input.  Implements item (2).
  2563   if( n->req() == 3 &&          // two-input instruction
  2564       n->in(1)->outcnt() > 1 && // left use is NOT a last use
  2565       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
  2566       n->in(2)->outcnt() == 1 &&// right use IS a last use
  2567       !n->in(2)->is_Con() ) {   // right use is not a constant
  2568     // Check for commutative opcode
  2569     switch( nop ) {
  2570     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
  2571     case Op_MaxI:  case Op_MinI:
  2572     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
  2573     case Op_AndL:  case Op_XorL:  case Op_OrL:
  2574     case Op_AndI:  case Op_XorI:  case Op_OrI: {
  2575       // Move "last use" input to left by swapping inputs
  2576       n->swap_edges(1, 2);
  2577       break;
  2579     default:
  2580       break;
  2584 #ifdef ASSERT
  2585   if( n->is_Mem() ) {
  2586     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
  2587     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
  2588             // oop will be recorded in oop map if load crosses safepoint
  2589             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
  2590                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
  2591             "raw memory operations should have control edge");
  2593 #endif
  2594   // Count FPU ops and common calls, implements item (3)
  2595   switch( nop ) {
  2596   // Count all float operations that may use FPU
  2597   case Op_AddF:
  2598   case Op_SubF:
  2599   case Op_MulF:
  2600   case Op_DivF:
  2601   case Op_NegF:
  2602   case Op_ModF:
  2603   case Op_ConvI2F:
  2604   case Op_ConF:
  2605   case Op_CmpF:
  2606   case Op_CmpF3:
  2607   // case Op_ConvL2F: // longs are split into 32-bit halves
  2608     frc.inc_float_count();
  2609     break;
  2611   case Op_ConvF2D:
  2612   case Op_ConvD2F:
  2613     frc.inc_float_count();
  2614     frc.inc_double_count();
  2615     break;
  2617   // Count all double operations that may use FPU
  2618   case Op_AddD:
  2619   case Op_SubD:
  2620   case Op_MulD:
  2621   case Op_DivD:
  2622   case Op_NegD:
  2623   case Op_ModD:
  2624   case Op_ConvI2D:
  2625   case Op_ConvD2I:
  2626   // case Op_ConvL2D: // handled by leaf call
  2627   // case Op_ConvD2L: // handled by leaf call
  2628   case Op_ConD:
  2629   case Op_CmpD:
  2630   case Op_CmpD3:
  2631     frc.inc_double_count();
  2632     break;
  2633   case Op_Opaque1:              // Remove Opaque Nodes before matching
  2634   case Op_Opaque2:              // Remove Opaque Nodes before matching
  2635   case Op_Opaque3:
  2636     n->subsume_by(n->in(1), this);
  2637     break;
  2638   case Op_CallStaticJava:
  2639   case Op_CallJava:
  2640   case Op_CallDynamicJava:
  2641     frc.inc_java_call_count(); // Count java call site;
  2642   case Op_CallRuntime:
  2643   case Op_CallLeaf:
  2644   case Op_CallLeafNoFP: {
  2645     assert( n->is_Call(), "" );
  2646     CallNode *call = n->as_Call();
  2647     // Count call sites where the FP mode bit would have to be flipped.
  2648     // Do not count uncommon runtime calls:
  2649     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
  2650     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
  2651     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
  2652       frc.inc_call_count();   // Count the call site
  2653     } else {                  // See if uncommon argument is shared
  2654       Node *n = call->in(TypeFunc::Parms);
  2655       int nop = n->Opcode();
  2656       // Clone shared simple arguments to uncommon calls, item (1).
  2657       if( n->outcnt() > 1 &&
  2658           !n->is_Proj() &&
  2659           nop != Op_CreateEx &&
  2660           nop != Op_CheckCastPP &&
  2661           nop != Op_DecodeN &&
  2662           nop != Op_DecodeNKlass &&
  2663           !n->is_Mem() ) {
  2664         Node *x = n->clone();
  2665         call->set_req( TypeFunc::Parms, x );
  2668     break;
  2671   case Op_StoreD:
  2672   case Op_LoadD:
  2673   case Op_LoadD_unaligned:
  2674     frc.inc_double_count();
  2675     goto handle_mem;
  2676   case Op_StoreF:
  2677   case Op_LoadF:
  2678     frc.inc_float_count();
  2679     goto handle_mem;
  2681   case Op_StoreCM:
  2683       // Convert OopStore dependence into precedence edge
  2684       Node* prec = n->in(MemNode::OopStore);
  2685       n->del_req(MemNode::OopStore);
  2686       n->add_prec(prec);
  2687       eliminate_redundant_card_marks(n);
  2690     // fall through
  2692   case Op_StoreB:
  2693   case Op_StoreC:
  2694   case Op_StorePConditional:
  2695   case Op_StoreI:
  2696   case Op_StoreL:
  2697   case Op_StoreIConditional:
  2698   case Op_StoreLConditional:
  2699   case Op_CompareAndSwapI:
  2700   case Op_CompareAndSwapL:
  2701   case Op_CompareAndSwapP:
  2702   case Op_CompareAndSwapN:
  2703   case Op_GetAndAddI:
  2704   case Op_GetAndAddL:
  2705   case Op_GetAndSetI:
  2706   case Op_GetAndSetL:
  2707   case Op_GetAndSetP:
  2708   case Op_GetAndSetN:
  2709   case Op_StoreP:
  2710   case Op_StoreN:
  2711   case Op_StoreNKlass:
  2712   case Op_LoadB:
  2713   case Op_LoadUB:
  2714   case Op_LoadUS:
  2715   case Op_LoadI:
  2716   case Op_LoadKlass:
  2717   case Op_LoadNKlass:
  2718   case Op_LoadL:
  2719   case Op_LoadL_unaligned:
  2720   case Op_LoadPLocked:
  2721   case Op_LoadP:
  2722   case Op_LoadN:
  2723   case Op_LoadRange:
  2724   case Op_LoadS: {
  2725   handle_mem:
  2726 #ifdef ASSERT
  2727     if( VerifyOptoOopOffsets ) {
  2728       assert( n->is_Mem(), "" );
  2729       MemNode *mem  = (MemNode*)n;
  2730       // Check to see if address types have grounded out somehow.
  2731       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
  2732       assert( !tp || oop_offset_is_sane(tp), "" );
  2734 #endif
  2735     break;
  2738   case Op_AddP: {               // Assert sane base pointers
  2739     Node *addp = n->in(AddPNode::Address);
  2740     assert( !addp->is_AddP() ||
  2741             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
  2742             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
  2743             "Base pointers must match" );
  2744 #ifdef _LP64
  2745     if ((UseCompressedOops || UseCompressedClassPointers) &&
  2746         addp->Opcode() == Op_ConP &&
  2747         addp == n->in(AddPNode::Base) &&
  2748         n->in(AddPNode::Offset)->is_Con()) {
  2749       // Use addressing with narrow klass to load with offset on x86.
  2750       // On sparc loading 32-bits constant and decoding it have less
  2751       // instructions (4) then load 64-bits constant (7).
  2752       // Do this transformation here since IGVN will convert ConN back to ConP.
  2753       const Type* t = addp->bottom_type();
  2754       if (t->isa_oopptr() || t->isa_klassptr()) {
  2755         Node* nn = NULL;
  2757         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
  2759         // Look for existing ConN node of the same exact type.
  2760         Node* r  = root();
  2761         uint cnt = r->outcnt();
  2762         for (uint i = 0; i < cnt; i++) {
  2763           Node* m = r->raw_out(i);
  2764           if (m!= NULL && m->Opcode() == op &&
  2765               m->bottom_type()->make_ptr() == t) {
  2766             nn = m;
  2767             break;
  2770         if (nn != NULL) {
  2771           // Decode a narrow oop to match address
  2772           // [R12 + narrow_oop_reg<<3 + offset]
  2773           if (t->isa_oopptr()) {
  2774             nn = new (this) DecodeNNode(nn, t);
  2775           } else {
  2776             nn = new (this) DecodeNKlassNode(nn, t);
  2778           n->set_req(AddPNode::Base, nn);
  2779           n->set_req(AddPNode::Address, nn);
  2780           if (addp->outcnt() == 0) {
  2781             addp->disconnect_inputs(NULL, this);
  2786 #endif
  2787     break;
  2790 #ifdef _LP64
  2791   case Op_CastPP:
  2792     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
  2793       Node* in1 = n->in(1);
  2794       const Type* t = n->bottom_type();
  2795       Node* new_in1 = in1->clone();
  2796       new_in1->as_DecodeN()->set_type(t);
  2798       if (!Matcher::narrow_oop_use_complex_address()) {
  2799         //
  2800         // x86, ARM and friends can handle 2 adds in addressing mode
  2801         // and Matcher can fold a DecodeN node into address by using
  2802         // a narrow oop directly and do implicit NULL check in address:
  2803         //
  2804         // [R12 + narrow_oop_reg<<3 + offset]
  2805         // NullCheck narrow_oop_reg
  2806         //
  2807         // On other platforms (Sparc) we have to keep new DecodeN node and
  2808         // use it to do implicit NULL check in address:
  2809         //
  2810         // decode_not_null narrow_oop_reg, base_reg
  2811         // [base_reg + offset]
  2812         // NullCheck base_reg
  2813         //
  2814         // Pin the new DecodeN node to non-null path on these platform (Sparc)
  2815         // to keep the information to which NULL check the new DecodeN node
  2816         // corresponds to use it as value in implicit_null_check().
  2817         //
  2818         new_in1->set_req(0, n->in(0));
  2821       n->subsume_by(new_in1, this);
  2822       if (in1->outcnt() == 0) {
  2823         in1->disconnect_inputs(NULL, this);
  2826     break;
  2828   case Op_CmpP:
  2829     // Do this transformation here to preserve CmpPNode::sub() and
  2830     // other TypePtr related Ideal optimizations (for example, ptr nullness).
  2831     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
  2832       Node* in1 = n->in(1);
  2833       Node* in2 = n->in(2);
  2834       if (!in1->is_DecodeNarrowPtr()) {
  2835         in2 = in1;
  2836         in1 = n->in(2);
  2838       assert(in1->is_DecodeNarrowPtr(), "sanity");
  2840       Node* new_in2 = NULL;
  2841       if (in2->is_DecodeNarrowPtr()) {
  2842         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
  2843         new_in2 = in2->in(1);
  2844       } else if (in2->Opcode() == Op_ConP) {
  2845         const Type* t = in2->bottom_type();
  2846         if (t == TypePtr::NULL_PTR) {
  2847           assert(in1->is_DecodeN(), "compare klass to null?");
  2848           // Don't convert CmpP null check into CmpN if compressed
  2849           // oops implicit null check is not generated.
  2850           // This will allow to generate normal oop implicit null check.
  2851           if (Matcher::gen_narrow_oop_implicit_null_checks())
  2852             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
  2853           //
  2854           // This transformation together with CastPP transformation above
  2855           // will generated code for implicit NULL checks for compressed oops.
  2856           //
  2857           // The original code after Optimize()
  2858           //
  2859           //    LoadN memory, narrow_oop_reg
  2860           //    decode narrow_oop_reg, base_reg
  2861           //    CmpP base_reg, NULL
  2862           //    CastPP base_reg // NotNull
  2863           //    Load [base_reg + offset], val_reg
  2864           //
  2865           // after these transformations will be
  2866           //
  2867           //    LoadN memory, narrow_oop_reg
  2868           //    CmpN narrow_oop_reg, NULL
  2869           //    decode_not_null narrow_oop_reg, base_reg
  2870           //    Load [base_reg + offset], val_reg
  2871           //
  2872           // and the uncommon path (== NULL) will use narrow_oop_reg directly
  2873           // since narrow oops can be used in debug info now (see the code in
  2874           // final_graph_reshaping_walk()).
  2875           //
  2876           // At the end the code will be matched to
  2877           // on x86:
  2878           //
  2879           //    Load_narrow_oop memory, narrow_oop_reg
  2880           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
  2881           //    NullCheck narrow_oop_reg
  2882           //
  2883           // and on sparc:
  2884           //
  2885           //    Load_narrow_oop memory, narrow_oop_reg
  2886           //    decode_not_null narrow_oop_reg, base_reg
  2887           //    Load [base_reg + offset], val_reg
  2888           //    NullCheck base_reg
  2889           //
  2890         } else if (t->isa_oopptr()) {
  2891           new_in2 = ConNode::make(this, t->make_narrowoop());
  2892         } else if (t->isa_klassptr()) {
  2893           new_in2 = ConNode::make(this, t->make_narrowklass());
  2896       if (new_in2 != NULL) {
  2897         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
  2898         n->subsume_by(cmpN, this);
  2899         if (in1->outcnt() == 0) {
  2900           in1->disconnect_inputs(NULL, this);
  2902         if (in2->outcnt() == 0) {
  2903           in2->disconnect_inputs(NULL, this);
  2907     break;
  2909   case Op_DecodeN:
  2910   case Op_DecodeNKlass:
  2911     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
  2912     // DecodeN could be pinned when it can't be fold into
  2913     // an address expression, see the code for Op_CastPP above.
  2914     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
  2915     break;
  2917   case Op_EncodeP:
  2918   case Op_EncodePKlass: {
  2919     Node* in1 = n->in(1);
  2920     if (in1->is_DecodeNarrowPtr()) {
  2921       n->subsume_by(in1->in(1), this);
  2922     } else if (in1->Opcode() == Op_ConP) {
  2923       const Type* t = in1->bottom_type();
  2924       if (t == TypePtr::NULL_PTR) {
  2925         assert(t->isa_oopptr(), "null klass?");
  2926         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
  2927       } else if (t->isa_oopptr()) {
  2928         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
  2929       } else if (t->isa_klassptr()) {
  2930         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
  2933     if (in1->outcnt() == 0) {
  2934       in1->disconnect_inputs(NULL, this);
  2936     break;
  2939   case Op_Proj: {
  2940     if (OptimizeStringConcat) {
  2941       ProjNode* p = n->as_Proj();
  2942       if (p->_is_io_use) {
  2943         // Separate projections were used for the exception path which
  2944         // are normally removed by a late inline.  If it wasn't inlined
  2945         // then they will hang around and should just be replaced with
  2946         // the original one.
  2947         Node* proj = NULL;
  2948         // Replace with just one
  2949         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
  2950           Node *use = i.get();
  2951           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
  2952             proj = use;
  2953             break;
  2956         assert(proj != NULL, "must be found");
  2957         p->subsume_by(proj, this);
  2960     break;
  2963   case Op_Phi:
  2964     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
  2965       // The EncodeP optimization may create Phi with the same edges
  2966       // for all paths. It is not handled well by Register Allocator.
  2967       Node* unique_in = n->in(1);
  2968       assert(unique_in != NULL, "");
  2969       uint cnt = n->req();
  2970       for (uint i = 2; i < cnt; i++) {
  2971         Node* m = n->in(i);
  2972         assert(m != NULL, "");
  2973         if (unique_in != m)
  2974           unique_in = NULL;
  2976       if (unique_in != NULL) {
  2977         n->subsume_by(unique_in, this);
  2980     break;
  2982 #endif
  2984   case Op_ModI:
  2985     if (UseDivMod) {
  2986       // Check if a%b and a/b both exist
  2987       Node* d = n->find_similar(Op_DivI);
  2988       if (d) {
  2989         // Replace them with a fused divmod if supported
  2990         if (Matcher::has_match_rule(Op_DivModI)) {
  2991           DivModINode* divmod = DivModINode::make(this, n);
  2992           d->subsume_by(divmod->div_proj(), this);
  2993           n->subsume_by(divmod->mod_proj(), this);
  2994         } else {
  2995           // replace a%b with a-((a/b)*b)
  2996           Node* mult = new (this) MulINode(d, d->in(2));
  2997           Node* sub  = new (this) SubINode(d->in(1), mult);
  2998           n->subsume_by(sub, this);
  3002     break;
  3004   case Op_ModL:
  3005     if (UseDivMod) {
  3006       // Check if a%b and a/b both exist
  3007       Node* d = n->find_similar(Op_DivL);
  3008       if (d) {
  3009         // Replace them with a fused divmod if supported
  3010         if (Matcher::has_match_rule(Op_DivModL)) {
  3011           DivModLNode* divmod = DivModLNode::make(this, n);
  3012           d->subsume_by(divmod->div_proj(), this);
  3013           n->subsume_by(divmod->mod_proj(), this);
  3014         } else {
  3015           // replace a%b with a-((a/b)*b)
  3016           Node* mult = new (this) MulLNode(d, d->in(2));
  3017           Node* sub  = new (this) SubLNode(d->in(1), mult);
  3018           n->subsume_by(sub, this);
  3022     break;
  3024   case Op_LoadVector:
  3025   case Op_StoreVector:
  3026     break;
  3028   case Op_PackB:
  3029   case Op_PackS:
  3030   case Op_PackI:
  3031   case Op_PackF:
  3032   case Op_PackL:
  3033   case Op_PackD:
  3034     if (n->req()-1 > 2) {
  3035       // Replace many operand PackNodes with a binary tree for matching
  3036       PackNode* p = (PackNode*) n;
  3037       Node* btp = p->binary_tree_pack(this, 1, n->req());
  3038       n->subsume_by(btp, this);
  3040     break;
  3041   case Op_Loop:
  3042   case Op_CountedLoop:
  3043     if (n->as_Loop()->is_inner_loop()) {
  3044       frc.inc_inner_loop_count();
  3046     break;
  3047   case Op_LShiftI:
  3048   case Op_RShiftI:
  3049   case Op_URShiftI:
  3050   case Op_LShiftL:
  3051   case Op_RShiftL:
  3052   case Op_URShiftL:
  3053     if (Matcher::need_masked_shift_count) {
  3054       // The cpu's shift instructions don't restrict the count to the
  3055       // lower 5/6 bits. We need to do the masking ourselves.
  3056       Node* in2 = n->in(2);
  3057       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
  3058       const TypeInt* t = in2->find_int_type();
  3059       if (t != NULL && t->is_con()) {
  3060         juint shift = t->get_con();
  3061         if (shift > mask) { // Unsigned cmp
  3062           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
  3064       } else {
  3065         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
  3066           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
  3067           n->set_req(2, shift);
  3070       if (in2->outcnt() == 0) { // Remove dead node
  3071         in2->disconnect_inputs(NULL, this);
  3074     break;
  3075   case Op_MemBarStoreStore:
  3076   case Op_MemBarRelease:
  3077     // Break the link with AllocateNode: it is no longer useful and
  3078     // confuses register allocation.
  3079     if (n->req() > MemBarNode::Precedent) {
  3080       n->set_req(MemBarNode::Precedent, top());
  3082     break;
  3083   default:
  3084     assert( !n->is_Call(), "" );
  3085     assert( !n->is_Mem(), "" );
  3086     assert( nop != Op_ProfileBoolean, "should be eliminated during IGVN");
  3087     break;
  3090   // Collect CFG split points
  3091   if (n->is_MultiBranch())
  3092     frc._tests.push(n);
  3095 //------------------------------final_graph_reshaping_walk---------------------
  3096 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
  3097 // requires that the walk visits a node's inputs before visiting the node.
  3098 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
  3099   ResourceArea *area = Thread::current()->resource_area();
  3100   Unique_Node_List sfpt(area);
  3102   frc._visited.set(root->_idx); // first, mark node as visited
  3103   uint cnt = root->req();
  3104   Node *n = root;
  3105   uint  i = 0;
  3106   while (true) {
  3107     if (i < cnt) {
  3108       // Place all non-visited non-null inputs onto stack
  3109       Node* m = n->in(i);
  3110       ++i;
  3111       if (m != NULL && !frc._visited.test_set(m->_idx)) {
  3112         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL) {
  3113           // compute worst case interpreter size in case of a deoptimization
  3114           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
  3116           sfpt.push(m);
  3118         cnt = m->req();
  3119         nstack.push(n, i); // put on stack parent and next input's index
  3120         n = m;
  3121         i = 0;
  3123     } else {
  3124       // Now do post-visit work
  3125       final_graph_reshaping_impl( n, frc );
  3126       if (nstack.is_empty())
  3127         break;             // finished
  3128       n = nstack.node();   // Get node from stack
  3129       cnt = n->req();
  3130       i = nstack.index();
  3131       nstack.pop();        // Shift to the next node on stack
  3135   // Skip next transformation if compressed oops are not used.
  3136   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
  3137       (!UseCompressedOops && !UseCompressedClassPointers))
  3138     return;
  3140   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
  3141   // It could be done for an uncommon traps or any safepoints/calls
  3142   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
  3143   while (sfpt.size() > 0) {
  3144     n = sfpt.pop();
  3145     JVMState *jvms = n->as_SafePoint()->jvms();
  3146     assert(jvms != NULL, "sanity");
  3147     int start = jvms->debug_start();
  3148     int end   = n->req();
  3149     bool is_uncommon = (n->is_CallStaticJava() &&
  3150                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
  3151     for (int j = start; j < end; j++) {
  3152       Node* in = n->in(j);
  3153       if (in->is_DecodeNarrowPtr()) {
  3154         bool safe_to_skip = true;
  3155         if (!is_uncommon ) {
  3156           // Is it safe to skip?
  3157           for (uint i = 0; i < in->outcnt(); i++) {
  3158             Node* u = in->raw_out(i);
  3159             if (!u->is_SafePoint() ||
  3160                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
  3161               safe_to_skip = false;
  3165         if (safe_to_skip) {
  3166           n->set_req(j, in->in(1));
  3168         if (in->outcnt() == 0) {
  3169           in->disconnect_inputs(NULL, this);
  3176 //------------------------------final_graph_reshaping--------------------------
  3177 // Final Graph Reshaping.
  3178 //
  3179 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
  3180 //     and not commoned up and forced early.  Must come after regular
  3181 //     optimizations to avoid GVN undoing the cloning.  Clone constant
  3182 //     inputs to Loop Phis; these will be split by the allocator anyways.
  3183 //     Remove Opaque nodes.
  3184 // (2) Move last-uses by commutative operations to the left input to encourage
  3185 //     Intel update-in-place two-address operations and better register usage
  3186 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
  3187 //     calls canonicalizing them back.
  3188 // (3) Count the number of double-precision FP ops, single-precision FP ops
  3189 //     and call sites.  On Intel, we can get correct rounding either by
  3190 //     forcing singles to memory (requires extra stores and loads after each
  3191 //     FP bytecode) or we can set a rounding mode bit (requires setting and
  3192 //     clearing the mode bit around call sites).  The mode bit is only used
  3193 //     if the relative frequency of single FP ops to calls is low enough.
  3194 //     This is a key transform for SPEC mpeg_audio.
  3195 // (4) Detect infinite loops; blobs of code reachable from above but not
  3196 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
  3197 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
  3198 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
  3199 //     Detection is by looking for IfNodes where only 1 projection is
  3200 //     reachable from below or CatchNodes missing some targets.
  3201 // (5) Assert for insane oop offsets in debug mode.
  3203 bool Compile::final_graph_reshaping() {
  3204   // an infinite loop may have been eliminated by the optimizer,
  3205   // in which case the graph will be empty.
  3206   if (root()->req() == 1) {
  3207     record_method_not_compilable("trivial infinite loop");
  3208     return true;
  3211   // Expensive nodes have their control input set to prevent the GVN
  3212   // from freely commoning them. There's no GVN beyond this point so
  3213   // no need to keep the control input. We want the expensive nodes to
  3214   // be freely moved to the least frequent code path by gcm.
  3215   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
  3216   for (int i = 0; i < expensive_count(); i++) {
  3217     _expensive_nodes->at(i)->set_req(0, NULL);
  3220   Final_Reshape_Counts frc;
  3222   // Visit everybody reachable!
  3223   // Allocate stack of size C->unique()/2 to avoid frequent realloc
  3224   Node_Stack nstack(unique() >> 1);
  3225   final_graph_reshaping_walk(nstack, root(), frc);
  3227   // Check for unreachable (from below) code (i.e., infinite loops).
  3228   for( uint i = 0; i < frc._tests.size(); i++ ) {
  3229     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
  3230     // Get number of CFG targets.
  3231     // Note that PCTables include exception targets after calls.
  3232     uint required_outcnt = n->required_outcnt();
  3233     if (n->outcnt() != required_outcnt) {
  3234       // Check for a few special cases.  Rethrow Nodes never take the
  3235       // 'fall-thru' path, so expected kids is 1 less.
  3236       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
  3237         if (n->in(0)->in(0)->is_Call()) {
  3238           CallNode *call = n->in(0)->in(0)->as_Call();
  3239           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
  3240             required_outcnt--;      // Rethrow always has 1 less kid
  3241           } else if (call->req() > TypeFunc::Parms &&
  3242                      call->is_CallDynamicJava()) {
  3243             // Check for null receiver. In such case, the optimizer has
  3244             // detected that the virtual call will always result in a null
  3245             // pointer exception. The fall-through projection of this CatchNode
  3246             // will not be populated.
  3247             Node *arg0 = call->in(TypeFunc::Parms);
  3248             if (arg0->is_Type() &&
  3249                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
  3250               required_outcnt--;
  3252           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
  3253                      call->req() > TypeFunc::Parms+1 &&
  3254                      call->is_CallStaticJava()) {
  3255             // Check for negative array length. In such case, the optimizer has
  3256             // detected that the allocation attempt will always result in an
  3257             // exception. There is no fall-through projection of this CatchNode .
  3258             Node *arg1 = call->in(TypeFunc::Parms+1);
  3259             if (arg1->is_Type() &&
  3260                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
  3261               required_outcnt--;
  3266       // Recheck with a better notion of 'required_outcnt'
  3267       if (n->outcnt() != required_outcnt) {
  3268         record_method_not_compilable("malformed control flow");
  3269         return true;            // Not all targets reachable!
  3272     // Check that I actually visited all kids.  Unreached kids
  3273     // must be infinite loops.
  3274     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
  3275       if (!frc._visited.test(n->fast_out(j)->_idx)) {
  3276         record_method_not_compilable("infinite loop");
  3277         return true;            // Found unvisited kid; must be unreach
  3281   // If original bytecodes contained a mixture of floats and doubles
  3282   // check if the optimizer has made it homogenous, item (3).
  3283   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
  3284       frc.get_float_count() > 32 &&
  3285       frc.get_double_count() == 0 &&
  3286       (10 * frc.get_call_count() < frc.get_float_count()) ) {
  3287     set_24_bit_selection_and_mode( false,  true );
  3290   set_java_calls(frc.get_java_call_count());
  3291   set_inner_loops(frc.get_inner_loop_count());
  3293   // No infinite loops, no reason to bail out.
  3294   return false;
  3297 //-----------------------------too_many_traps----------------------------------
  3298 // Report if there are too many traps at the current method and bci.
  3299 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
  3300 bool Compile::too_many_traps(ciMethod* method,
  3301                              int bci,
  3302                              Deoptimization::DeoptReason reason) {
  3303   ciMethodData* md = method->method_data();
  3304   if (md->is_empty()) {
  3305     // Assume the trap has not occurred, or that it occurred only
  3306     // because of a transient condition during start-up in the interpreter.
  3307     return false;
  3309   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3310   if (md->has_trap_at(bci, m, reason) != 0) {
  3311     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
  3312     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3313     // assume the worst.
  3314     if (log())
  3315       log()->elem("observe trap='%s' count='%d'",
  3316                   Deoptimization::trap_reason_name(reason),
  3317                   md->trap_count(reason));
  3318     return true;
  3319   } else {
  3320     // Ignore method/bci and see if there have been too many globally.
  3321     return too_many_traps(reason, md);
  3325 // Less-accurate variant which does not require a method and bci.
  3326 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
  3327                              ciMethodData* logmd) {
  3328   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
  3329     // Too many traps globally.
  3330     // Note that we use cumulative trap_count, not just md->trap_count.
  3331     if (log()) {
  3332       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
  3333       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
  3334                   Deoptimization::trap_reason_name(reason),
  3335                   mcount, trap_count(reason));
  3337     return true;
  3338   } else {
  3339     // The coast is clear.
  3340     return false;
  3344 //--------------------------too_many_recompiles--------------------------------
  3345 // Report if there are too many recompiles at the current method and bci.
  3346 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
  3347 // Is not eager to return true, since this will cause the compiler to use
  3348 // Action_none for a trap point, to avoid too many recompilations.
  3349 bool Compile::too_many_recompiles(ciMethod* method,
  3350                                   int bci,
  3351                                   Deoptimization::DeoptReason reason) {
  3352   ciMethodData* md = method->method_data();
  3353   if (md->is_empty()) {
  3354     // Assume the trap has not occurred, or that it occurred only
  3355     // because of a transient condition during start-up in the interpreter.
  3356     return false;
  3358   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
  3359   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
  3360   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
  3361   Deoptimization::DeoptReason per_bc_reason
  3362     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
  3363   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : NULL;
  3364   if ((per_bc_reason == Deoptimization::Reason_none
  3365        || md->has_trap_at(bci, m, reason) != 0)
  3366       // The trap frequency measure we care about is the recompile count:
  3367       && md->trap_recompiled_at(bci, m)
  3368       && md->overflow_recompile_count() >= bc_cutoff) {
  3369     // Do not emit a trap here if it has already caused recompilations.
  3370     // Also, if there are multiple reasons, or if there is no per-BCI record,
  3371     // assume the worst.
  3372     if (log())
  3373       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
  3374                   Deoptimization::trap_reason_name(reason),
  3375                   md->trap_count(reason),
  3376                   md->overflow_recompile_count());
  3377     return true;
  3378   } else if (trap_count(reason) != 0
  3379              && decompile_count() >= m_cutoff) {
  3380     // Too many recompiles globally, and we have seen this sort of trap.
  3381     // Use cumulative decompile_count, not just md->decompile_count.
  3382     if (log())
  3383       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
  3384                   Deoptimization::trap_reason_name(reason),
  3385                   md->trap_count(reason), trap_count(reason),
  3386                   md->decompile_count(), decompile_count());
  3387     return true;
  3388   } else {
  3389     // The coast is clear.
  3390     return false;
  3394 // Compute when not to trap. Used by matching trap based nodes and
  3395 // NullCheck optimization.
  3396 void Compile::set_allowed_deopt_reasons() {
  3397   _allowed_reasons = 0;
  3398   if (is_method_compilation()) {
  3399     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
  3400       assert(rs < BitsPerInt, "recode bit map");
  3401       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
  3402         _allowed_reasons |= nth_bit(rs);
  3408 #ifndef PRODUCT
  3409 //------------------------------verify_graph_edges---------------------------
  3410 // Walk the Graph and verify that there is a one-to-one correspondence
  3411 // between Use-Def edges and Def-Use edges in the graph.
  3412 void Compile::verify_graph_edges(bool no_dead_code) {
  3413   if (VerifyGraphEdges) {
  3414     ResourceArea *area = Thread::current()->resource_area();
  3415     Unique_Node_List visited(area);
  3416     // Call recursive graph walk to check edges
  3417     _root->verify_edges(visited);
  3418     if (no_dead_code) {
  3419       // Now make sure that no visited node is used by an unvisited node.
  3420       bool dead_nodes = 0;
  3421       Unique_Node_List checked(area);
  3422       while (visited.size() > 0) {
  3423         Node* n = visited.pop();
  3424         checked.push(n);
  3425         for (uint i = 0; i < n->outcnt(); i++) {
  3426           Node* use = n->raw_out(i);
  3427           if (checked.member(use))  continue;  // already checked
  3428           if (visited.member(use))  continue;  // already in the graph
  3429           if (use->is_Con())        continue;  // a dead ConNode is OK
  3430           // At this point, we have found a dead node which is DU-reachable.
  3431           if (dead_nodes++ == 0)
  3432             tty->print_cr("*** Dead nodes reachable via DU edges:");
  3433           use->dump(2);
  3434           tty->print_cr("---");
  3435           checked.push(use);  // No repeats; pretend it is now checked.
  3438       assert(dead_nodes == 0, "using nodes must be reachable from root");
  3443 // Verify GC barriers consistency
  3444 // Currently supported:
  3445 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
  3446 void Compile::verify_barriers() {
  3447   if (UseG1GC) {
  3448     // Verify G1 pre-barriers
  3449     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
  3451     ResourceArea *area = Thread::current()->resource_area();
  3452     Unique_Node_List visited(area);
  3453     Node_List worklist(area);
  3454     // We're going to walk control flow backwards starting from the Root
  3455     worklist.push(_root);
  3456     while (worklist.size() > 0) {
  3457       Node* x = worklist.pop();
  3458       if (x == NULL || x == top()) continue;
  3459       if (visited.member(x)) {
  3460         continue;
  3461       } else {
  3462         visited.push(x);
  3465       if (x->is_Region()) {
  3466         for (uint i = 1; i < x->req(); i++) {
  3467           worklist.push(x->in(i));
  3469       } else {
  3470         worklist.push(x->in(0));
  3471         // We are looking for the pattern:
  3472         //                            /->ThreadLocal
  3473         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
  3474         //              \->ConI(0)
  3475         // We want to verify that the If and the LoadB have the same control
  3476         // See GraphKit::g1_write_barrier_pre()
  3477         if (x->is_If()) {
  3478           IfNode *iff = x->as_If();
  3479           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
  3480             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
  3481             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
  3482                 && cmp->in(1)->is_Load()) {
  3483               LoadNode* load = cmp->in(1)->as_Load();
  3484               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
  3485                   && load->in(2)->in(3)->is_Con()
  3486                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
  3488                 Node* if_ctrl = iff->in(0);
  3489                 Node* load_ctrl = load->in(0);
  3491                 if (if_ctrl != load_ctrl) {
  3492                   // Skip possible CProj->NeverBranch in infinite loops
  3493                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
  3494                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
  3495                     if_ctrl = if_ctrl->in(0)->in(0);
  3498                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
  3508 #endif
  3510 // The Compile object keeps track of failure reasons separately from the ciEnv.
  3511 // This is required because there is not quite a 1-1 relation between the
  3512 // ciEnv and its compilation task and the Compile object.  Note that one
  3513 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
  3514 // to backtrack and retry without subsuming loads.  Other than this backtracking
  3515 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
  3516 // by the logic in C2Compiler.
  3517 void Compile::record_failure(const char* reason) {
  3518   if (log() != NULL) {
  3519     log()->elem("failure reason='%s' phase='compile'", reason);
  3521   if (_failure_reason == NULL) {
  3522     // Record the first failure reason.
  3523     _failure_reason = reason;
  3526   EventCompilerFailure event;
  3527   if (event.should_commit()) {
  3528     event.set_compileID(Compile::compile_id());
  3529     event.set_failure(reason);
  3530     event.commit();
  3533   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
  3534     C->print_method(PHASE_FAILURE);
  3536   _root = NULL;  // flush the graph, too
  3539 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
  3540   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
  3541     _phase_name(name), _dolog(dolog)
  3543   if (dolog) {
  3544     C = Compile::current();
  3545     _log = C->log();
  3546   } else {
  3547     C = NULL;
  3548     _log = NULL;
  3550   if (_log != NULL) {
  3551     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3552     _log->stamp();
  3553     _log->end_head();
  3557 Compile::TracePhase::~TracePhase() {
  3559   C = Compile::current();
  3560   if (_dolog) {
  3561     _log = C->log();
  3562   } else {
  3563     _log = NULL;
  3566 #ifdef ASSERT
  3567   if (PrintIdealNodeCount) {
  3568     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
  3569                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
  3572   if (VerifyIdealNodeCount) {
  3573     Compile::current()->print_missing_nodes();
  3575 #endif
  3577   if (_log != NULL) {
  3578     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
  3582 //=============================================================================
  3583 // Two Constant's are equal when the type and the value are equal.
  3584 bool Compile::Constant::operator==(const Constant& other) {
  3585   if (type()          != other.type()         )  return false;
  3586   if (can_be_reused() != other.can_be_reused())  return false;
  3587   // For floating point values we compare the bit pattern.
  3588   switch (type()) {
  3589   case T_FLOAT:   return (_v._value.i == other._v._value.i);
  3590   case T_LONG:
  3591   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
  3592   case T_OBJECT:
  3593   case T_ADDRESS: return (_v._value.l == other._v._value.l);
  3594   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
  3595   case T_METADATA: return (_v._metadata == other._v._metadata);
  3596   default: ShouldNotReachHere();
  3598   return false;
  3601 static int type_to_size_in_bytes(BasicType t) {
  3602   switch (t) {
  3603   case T_LONG:    return sizeof(jlong  );
  3604   case T_FLOAT:   return sizeof(jfloat );
  3605   case T_DOUBLE:  return sizeof(jdouble);
  3606   case T_METADATA: return sizeof(Metadata*);
  3607     // We use T_VOID as marker for jump-table entries (labels) which
  3608     // need an internal word relocation.
  3609   case T_VOID:
  3610   case T_ADDRESS:
  3611   case T_OBJECT:  return sizeof(jobject);
  3614   ShouldNotReachHere();
  3615   return -1;
  3618 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
  3619   // sort descending
  3620   if (a->freq() > b->freq())  return -1;
  3621   if (a->freq() < b->freq())  return  1;
  3622   return 0;
  3625 void Compile::ConstantTable::calculate_offsets_and_size() {
  3626   // First, sort the array by frequencies.
  3627   _constants.sort(qsort_comparator);
  3629 #ifdef ASSERT
  3630   // Make sure all jump-table entries were sorted to the end of the
  3631   // array (they have a negative frequency).
  3632   bool found_void = false;
  3633   for (int i = 0; i < _constants.length(); i++) {
  3634     Constant con = _constants.at(i);
  3635     if (con.type() == T_VOID)
  3636       found_void = true;  // jump-tables
  3637     else
  3638       assert(!found_void, "wrong sorting");
  3640 #endif
  3642   int offset = 0;
  3643   for (int i = 0; i < _constants.length(); i++) {
  3644     Constant* con = _constants.adr_at(i);
  3646     // Align offset for type.
  3647     int typesize = type_to_size_in_bytes(con->type());
  3648     offset = align_size_up(offset, typesize);
  3649     con->set_offset(offset);   // set constant's offset
  3651     if (con->type() == T_VOID) {
  3652       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
  3653       offset = offset + typesize * n->outcnt();  // expand jump-table
  3654     } else {
  3655       offset = offset + typesize;
  3659   // Align size up to the next section start (which is insts; see
  3660   // CodeBuffer::align_at_start).
  3661   assert(_size == -1, "already set?");
  3662   _size = align_size_up(offset, CodeEntryAlignment);
  3665 void Compile::ConstantTable::emit(CodeBuffer& cb) {
  3666   MacroAssembler _masm(&cb);
  3667   for (int i = 0; i < _constants.length(); i++) {
  3668     Constant con = _constants.at(i);
  3669     address constant_addr;
  3670     switch (con.type()) {
  3671     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
  3672     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
  3673     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
  3674     case T_OBJECT: {
  3675       jobject obj = con.get_jobject();
  3676       int oop_index = _masm.oop_recorder()->find_index(obj);
  3677       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
  3678       break;
  3680     case T_ADDRESS: {
  3681       address addr = (address) con.get_jobject();
  3682       constant_addr = _masm.address_constant(addr);
  3683       break;
  3685     // We use T_VOID as marker for jump-table entries (labels) which
  3686     // need an internal word relocation.
  3687     case T_VOID: {
  3688       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
  3689       // Fill the jump-table with a dummy word.  The real value is
  3690       // filled in later in fill_jump_table.
  3691       address dummy = (address) n;
  3692       constant_addr = _masm.address_constant(dummy);
  3693       // Expand jump-table
  3694       for (uint i = 1; i < n->outcnt(); i++) {
  3695         address temp_addr = _masm.address_constant(dummy + i);
  3696         assert(temp_addr, "consts section too small");
  3698       break;
  3700     case T_METADATA: {
  3701       Metadata* obj = con.get_metadata();
  3702       int metadata_index = _masm.oop_recorder()->find_index(obj);
  3703       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
  3704       break;
  3706     default: ShouldNotReachHere();
  3708     assert(constant_addr, "consts section too small");
  3709     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(),
  3710             err_msg_res("must be: %d == %d", (int) (constant_addr - _masm.code()->consts()->start()), (int)(con.offset())));
  3714 int Compile::ConstantTable::find_offset(Constant& con) const {
  3715   int idx = _constants.find(con);
  3716   assert(idx != -1, "constant must be in constant table");
  3717   int offset = _constants.at(idx).offset();
  3718   assert(offset != -1, "constant table not emitted yet?");
  3719   return offset;
  3722 void Compile::ConstantTable::add(Constant& con) {
  3723   if (con.can_be_reused()) {
  3724     int idx = _constants.find(con);
  3725     if (idx != -1 && _constants.at(idx).can_be_reused()) {
  3726       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
  3727       return;
  3730   (void) _constants.append(con);
  3733 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
  3734   Block* b = Compile::current()->cfg()->get_block_for_node(n);
  3735   Constant con(type, value, b->_freq);
  3736   add(con);
  3737   return con;
  3740 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
  3741   Constant con(metadata);
  3742   add(con);
  3743   return con;
  3746 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
  3747   jvalue value;
  3748   BasicType type = oper->type()->basic_type();
  3749   switch (type) {
  3750   case T_LONG:    value.j = oper->constantL(); break;
  3751   case T_FLOAT:   value.f = oper->constantF(); break;
  3752   case T_DOUBLE:  value.d = oper->constantD(); break;
  3753   case T_OBJECT:
  3754   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
  3755   case T_METADATA: return add((Metadata*)oper->constant()); break;
  3756   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
  3758   return add(n, type, value);
  3761 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
  3762   jvalue value;
  3763   // We can use the node pointer here to identify the right jump-table
  3764   // as this method is called from Compile::Fill_buffer right before
  3765   // the MachNodes are emitted and the jump-table is filled (means the
  3766   // MachNode pointers do not change anymore).
  3767   value.l = (jobject) n;
  3768   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
  3769   add(con);
  3770   return con;
  3773 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
  3774   // If called from Compile::scratch_emit_size do nothing.
  3775   if (Compile::current()->in_scratch_emit_size())  return;
  3777   assert(labels.is_nonempty(), "must be");
  3778   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
  3780   // Since MachConstantNode::constant_offset() also contains
  3781   // table_base_offset() we need to subtract the table_base_offset()
  3782   // to get the plain offset into the constant table.
  3783   int offset = n->constant_offset() - table_base_offset();
  3785   MacroAssembler _masm(&cb);
  3786   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
  3788   for (uint i = 0; i < n->outcnt(); i++) {
  3789     address* constant_addr = &jump_table_base[i];
  3790     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)));
  3791     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
  3792     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
  3796 void Compile::dump_inlining() {
  3797   if (print_inlining() || print_intrinsics()) {
  3798     // Print inlining message for candidates that we couldn't inline
  3799     // for lack of space or non constant receiver
  3800     for (int i = 0; i < _late_inlines.length(); i++) {
  3801       CallGenerator* cg = _late_inlines.at(i);
  3802       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
  3804     Unique_Node_List useful;
  3805     useful.push(root());
  3806     for (uint next = 0; next < useful.size(); ++next) {
  3807       Node* n  = useful.at(next);
  3808       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
  3809         CallNode* call = n->as_Call();
  3810         CallGenerator* cg = call->generator();
  3811         cg->print_inlining_late("receiver not constant");
  3813       uint max = n->len();
  3814       for ( uint i = 0; i < max; ++i ) {
  3815         Node *m = n->in(i);
  3816         if ( m == NULL ) continue;
  3817         useful.push(m);
  3820     for (int i = 0; i < _print_inlining_list->length(); i++) {
  3821       tty->print("%s", _print_inlining_list->adr_at(i)->ss()->as_string());
  3826 // Dump inlining replay data to the stream.
  3827 // Don't change thread state and acquire any locks.
  3828 void Compile::dump_inline_data(outputStream* out) {
  3829   InlineTree* inl_tree = ilt();
  3830   if (inl_tree != NULL) {
  3831     out->print(" inline %d", inl_tree->count());
  3832     inl_tree->dump_replay_data(out);
  3836 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
  3837   if (n1->Opcode() < n2->Opcode())      return -1;
  3838   else if (n1->Opcode() > n2->Opcode()) return 1;
  3840   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()));
  3841   for (uint i = 1; i < n1->req(); i++) {
  3842     if (n1->in(i) < n2->in(i))      return -1;
  3843     else if (n1->in(i) > n2->in(i)) return 1;
  3846   return 0;
  3849 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
  3850   Node* n1 = *n1p;
  3851   Node* n2 = *n2p;
  3853   return cmp_expensive_nodes(n1, n2);
  3856 void Compile::sort_expensive_nodes() {
  3857   if (!expensive_nodes_sorted()) {
  3858     _expensive_nodes->sort(cmp_expensive_nodes);
  3862 bool Compile::expensive_nodes_sorted() const {
  3863   for (int i = 1; i < _expensive_nodes->length(); i++) {
  3864     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
  3865       return false;
  3868   return true;
  3871 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
  3872   if (_expensive_nodes->length() == 0) {
  3873     return false;
  3876   assert(OptimizeExpensiveOps, "optimization off?");
  3878   // Take this opportunity to remove dead nodes from the list
  3879   int j = 0;
  3880   for (int i = 0; i < _expensive_nodes->length(); i++) {
  3881     Node* n = _expensive_nodes->at(i);
  3882     if (!n->is_unreachable(igvn)) {
  3883       assert(n->is_expensive(), "should be expensive");
  3884       _expensive_nodes->at_put(j, n);
  3885       j++;
  3888   _expensive_nodes->trunc_to(j);
  3890   // Then sort the list so that similar nodes are next to each other
  3891   // and check for at least two nodes of identical kind with same data
  3892   // inputs.
  3893   sort_expensive_nodes();
  3895   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
  3896     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
  3897       return true;
  3901   return false;
  3904 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
  3905   if (_expensive_nodes->length() == 0) {
  3906     return;
  3909   assert(OptimizeExpensiveOps, "optimization off?");
  3911   // Sort to bring similar nodes next to each other and clear the
  3912   // control input of nodes for which there's only a single copy.
  3913   sort_expensive_nodes();
  3915   int j = 0;
  3916   int identical = 0;
  3917   int i = 0;
  3918   for (; i < _expensive_nodes->length()-1; i++) {
  3919     assert(j <= i, "can't write beyond current index");
  3920     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
  3921       identical++;
  3922       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3923       continue;
  3925     if (identical > 0) {
  3926       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3927       identical = 0;
  3928     } else {
  3929       Node* n = _expensive_nodes->at(i);
  3930       igvn.hash_delete(n);
  3931       n->set_req(0, NULL);
  3932       igvn.hash_insert(n);
  3935   if (identical > 0) {
  3936     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
  3937   } else if (_expensive_nodes->length() >= 1) {
  3938     Node* n = _expensive_nodes->at(i);
  3939     igvn.hash_delete(n);
  3940     n->set_req(0, NULL);
  3941     igvn.hash_insert(n);
  3943   _expensive_nodes->trunc_to(j);
  3946 void Compile::add_expensive_node(Node * n) {
  3947   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
  3948   assert(n->is_expensive(), "expensive nodes with non-null control here only");
  3949   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
  3950   if (OptimizeExpensiveOps) {
  3951     _expensive_nodes->append(n);
  3952   } else {
  3953     // Clear control input and let IGVN optimize expensive nodes if
  3954     // OptimizeExpensiveOps is off.
  3955     n->set_req(0, NULL);
  3959 /**
  3960  * Remove the speculative part of types and clean up the graph
  3961  */
  3962 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
  3963   if (UseTypeSpeculation) {
  3964     Unique_Node_List worklist;
  3965     worklist.push(root());
  3966     int modified = 0;
  3967     // Go over all type nodes that carry a speculative type, drop the
  3968     // speculative part of the type and enqueue the node for an igvn
  3969     // which may optimize it out.
  3970     for (uint next = 0; next < worklist.size(); ++next) {
  3971       Node *n  = worklist.at(next);
  3972       if (n->is_Type()) {
  3973         TypeNode* tn = n->as_Type();
  3974         const Type* t = tn->type();
  3975         const Type* t_no_spec = t->remove_speculative();
  3976         if (t_no_spec != t) {
  3977           bool in_hash = igvn.hash_delete(n);
  3978           assert(in_hash, "node should be in igvn hash table");
  3979           tn->set_type(t_no_spec);
  3980           igvn.hash_insert(n);
  3981           igvn._worklist.push(n); // give it a chance to go away
  3982           modified++;
  3985       uint max = n->len();
  3986       for( uint i = 0; i < max; ++i ) {
  3987         Node *m = n->in(i);
  3988         if (not_a_node(m))  continue;
  3989         worklist.push(m);
  3992     // Drop the speculative part of all types in the igvn's type table
  3993     igvn.remove_speculative_types();
  3994     if (modified > 0) {
  3995       igvn.optimize();
  3997 #ifdef ASSERT
  3998     // Verify that after the IGVN is over no speculative type has resurfaced
  3999     worklist.clear();
  4000     worklist.push(root());
  4001     for (uint next = 0; next < worklist.size(); ++next) {
  4002       Node *n  = worklist.at(next);
  4003       const Type* t = igvn.type_or_null(n);
  4004       assert((t == NULL) || (t == t->remove_speculative()), "no more speculative types");
  4005       if (n->is_Type()) {
  4006         t = n->as_Type()->type();
  4007         assert(t == t->remove_speculative(), "no more speculative types");
  4009       uint max = n->len();
  4010       for( uint i = 0; i < max; ++i ) {
  4011         Node *m = n->in(i);
  4012         if (not_a_node(m))  continue;
  4013         worklist.push(m);
  4016     igvn.check_no_speculative_types();
  4017 #endif
  4021 // Auxiliary method to support randomized stressing/fuzzing.
  4022 //
  4023 // This method can be called the arbitrary number of times, with current count
  4024 // as the argument. The logic allows selecting a single candidate from the
  4025 // running list of candidates as follows:
  4026 //    int count = 0;
  4027 //    Cand* selected = null;
  4028 //    while(cand = cand->next()) {
  4029 //      if (randomized_select(++count)) {
  4030 //        selected = cand;
  4031 //      }
  4032 //    }
  4033 //
  4034 // Including count equalizes the chances any candidate is "selected".
  4035 // This is useful when we don't have the complete list of candidates to choose
  4036 // from uniformly. In this case, we need to adjust the randomicity of the
  4037 // selection, or else we will end up biasing the selection towards the latter
  4038 // candidates.
  4039 //
  4040 // Quick back-envelope calculation shows that for the list of n candidates
  4041 // the equal probability for the candidate to persist as "best" can be
  4042 // achieved by replacing it with "next" k-th candidate with the probability
  4043 // of 1/k. It can be easily shown that by the end of the run, the
  4044 // probability for any candidate is converged to 1/n, thus giving the
  4045 // uniform distribution among all the candidates.
  4046 //
  4047 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
  4048 #define RANDOMIZED_DOMAIN_POW 29
  4049 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
  4050 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
  4051 bool Compile::randomized_select(int count) {
  4052   assert(count > 0, "only positive");
  4053   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);

mercurial