jdk8-mips64-public/hotspot: src/share/vm/opto/compile.cpp@55fb97c4c58d (annotated)

src/share/vm/opto/compile.cpp@55fb97c4c58d (annotated)

src/share/vm/opto/compile.cpp

Tue, 24 Dec 2013 11:48:39 -0800

author: mikael
date: Tue, 24 Dec 2013 11:48:39 -0800
changeset 6198: 55fb97c4c58d
parent 6071: 613e6a6fc328
child 6217: 849eb7bfceac
child 6485: da862781b584
permissions: -rw-r--r--

8029233: Update copyright year to match last edit in jdk8 hotspot repository for 2013
Summary: Copyright year updated for files modified during 2013
Reviewed-by: twisti, iveresov

 /*
  * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "asm/macroAssembler.hpp"
 #include "asm/macroAssembler.inline.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "code/exceptionHandlerTable.hpp"
 #include "code/nmethod.hpp"
 #include "compiler/compileLog.hpp"
 #include "compiler/disassembler.hpp"
 #include "compiler/oopMap.hpp"
 #include "opto/addnode.hpp"
 #include "opto/block.hpp"
 #include "opto/c2compiler.hpp"
 #include "opto/callGenerator.hpp"
 #include "opto/callnode.hpp"
 #include "opto/cfgnode.hpp"
 #include "opto/chaitin.hpp"
 #include "opto/compile.hpp"
 #include "opto/connode.hpp"
 #include "opto/divnode.hpp"
 #include "opto/escape.hpp"
 #include "opto/idealGraphPrinter.hpp"
 #include "opto/loopnode.hpp"
 #include "opto/machnode.hpp"
 #include "opto/macro.hpp"
 #include "opto/matcher.hpp"
 #include "opto/mathexactnode.hpp"
 #include "opto/memnode.hpp"
 #include "opto/mulnode.hpp"
 #include "opto/node.hpp"
 #include "opto/opcodes.hpp"
 #include "opto/output.hpp"
 #include "opto/parse.hpp"
 #include "opto/phaseX.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/runtime.hpp"
 #include "opto/stringopts.hpp"
 #include "opto/type.hpp"
 #include "opto/vectornode.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/signature.hpp"
 #include "runtime/stubRoutines.hpp"
 #include "runtime/timer.hpp"
 #include "trace/tracing.hpp"
 #include "utilities/copy.hpp"
 #ifdef TARGET_ARCH_MODEL_x86_32
 # include "adfiles/ad_x86_32.hpp"
 #endif
 #ifdef TARGET_ARCH_MODEL_x86_64
 # include "adfiles/ad_x86_64.hpp"
 #endif
 #ifdef TARGET_ARCH_MODEL_sparc
 # include "adfiles/ad_sparc.hpp"
 #endif
 #ifdef TARGET_ARCH_MODEL_zero
 # include "adfiles/ad_zero.hpp"
 #endif
 #ifdef TARGET_ARCH_MODEL_arm
 # include "adfiles/ad_arm.hpp"
 #endif
 #ifdef TARGET_ARCH_MODEL_ppc
 # include "adfiles/ad_ppc.hpp"
 #endif
 // -------------------- Compile::mach_constant_base_node -----------------------
 // Constant table base node singleton.
 MachConstantBaseNode* Compile::mach_constant_base_node() {
   if (_mach_constant_base_node == NULL) {
     _mach_constant_base_node = new (C) MachConstantBaseNode();
     _mach_constant_base_node->add_req(C->root());
   }
   return _mach_constant_base_node;
 }
 /// Support for intrinsics.
 // Return the index at which m must be inserted (or already exists).
 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual) {
 #ifdef ASSERT
   for (int i = 1; i < _intrinsics->length(); i++) {
     CallGenerator* cg1 = _intrinsics->at(i-1);
     CallGenerator* cg2 = _intrinsics->at(i);
     assert(cg1->method() != cg2->method()
            ? cg1->method()     < cg2->method()
            : cg1->is_virtual() < cg2->is_virtual(),
            "compiler intrinsics list must stay sorted");
   }
 #endif
   // Binary search sorted list, in decreasing intervals [lo, hi].
   int lo = 0, hi = _intrinsics->length()-1;
   while (lo <= hi) {
     int mid = (uint)(hi + lo) / 2;
     ciMethod* mid_m = _intrinsics->at(mid)->method();
     if (m < mid_m) {
       hi = mid-1;
     } else if (m > mid_m) {
       lo = mid+1;
     } else {
       // look at minor sort key
       bool mid_virt = _intrinsics->at(mid)->is_virtual();
       if (is_virtual < mid_virt) {
         hi = mid-1;
       } else if (is_virtual > mid_virt) {
         lo = mid+1;
       } else {
         return mid;  // exact match
       }
     }
   }
   return lo;  // inexact match
 }
 void Compile::register_intrinsic(CallGenerator* cg) {
   if (_intrinsics == NULL) {
     _intrinsics = new (comp_arena())GrowableArray<CallGenerator*>(comp_arena(), 60, 0, NULL);
   }
   // This code is stolen from ciObjectFactory::insert.
   // Really, GrowableArray should have methods for
   // insert_at, remove_at, and binary_search.
   int len = _intrinsics->length();
   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual());
   if (index == len) {
     _intrinsics->append(cg);
   } else {
 #ifdef ASSERT
     CallGenerator* oldcg = _intrinsics->at(index);
     assert(oldcg->method() != cg->method() || oldcg->is_virtual() != cg->is_virtual(), "don't register twice");
 #endif
     _intrinsics->append(_intrinsics->at(len-1));
     int pos;
     for (pos = len-2; pos >= index; pos--) {
       _intrinsics->at_put(pos+1,_intrinsics->at(pos));
     }
     _intrinsics->at_put(index, cg);
   }
   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 }
 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
   assert(m->is_loaded(), "don't try this on unloaded methods");
   if (_intrinsics != NULL) {
     int index = intrinsic_insertion_index(m, is_virtual);
     if (index < _intrinsics->length()
         && _intrinsics->at(index)->method() == m
         && _intrinsics->at(index)->is_virtual() == is_virtual) {
       return _intrinsics->at(index);
     }
   }
   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
   if (m->intrinsic_id() != vmIntrinsics::_none &&
       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
     if (cg != NULL) {
       // Save it for next time:
       register_intrinsic(cg);
       return cg;
     } else {
       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
     }
   }
   return NULL;
 }
 // Compile:: register_library_intrinsics and make_vm_intrinsic are defined
 // in library_call.cpp.
 #ifndef PRODUCT
 // statistics gathering...
 juint  Compile::_intrinsic_hist_count[vmIntrinsics::ID_LIMIT] = {0};
 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::ID_LIMIT] = {0};
 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
   int oflags = _intrinsic_hist_flags[id];
   assert(flags != 0, "what happened?");
   if (is_virtual) {
     flags |= _intrinsic_virtual;
   }
   bool changed = (flags != oflags);
   if ((flags & _intrinsic_worked) != 0) {
     juint count = (_intrinsic_hist_count[id] += 1);
     if (count == 1) {
       changed = true;           // first time
     }
     // increment the overall count also:
     _intrinsic_hist_count[vmIntrinsics::_none] += 1;
   }
   if (changed) {
     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
       // Something changed about the intrinsic's virtuality.
       if ((flags & _intrinsic_virtual) != 0) {
         // This is the first use of this intrinsic as a virtual call.
         if (oflags != 0) {
           // We already saw it as a non-virtual, so note both cases.
           flags |= _intrinsic_both;
         }
       } else if ((oflags & _intrinsic_both) == 0) {
         // This is the first use of this intrinsic as a non-virtual
         flags |= _intrinsic_both;
       }
     }
     _intrinsic_hist_flags[id] = (jubyte) (oflags | flags);
   }
   // update the overall flags also:
   _intrinsic_hist_flags[vmIntrinsics::_none] |= (jubyte) flags;
   return changed;
 }
 static char* format_flags(int flags, char* buf) {
   buf[0] = 0;
   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
   if (buf[0] == 0)  strcat(buf, ",");
   assert(buf[0] == ',', "must be");
   return &buf[1];
 }
 void Compile::print_intrinsic_statistics() {
   char flagsbuf[100];
   ttyLocker ttyl;
   if (xtty != NULL)  xtty->head("statistics type='intrinsic'");
   tty->print_cr("Compiler intrinsic usage:");
   juint total = _intrinsic_hist_count[vmIntrinsics::_none];
   if (total == 0)  total = 1;  // avoid div0 in case of no successes
   #define PRINT_STAT_LINE(name, c, f) \
     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
   for (int index = 1 + (int)vmIntrinsics::_none; index < (int)vmIntrinsics::ID_LIMIT; index++) {
     vmIntrinsics::ID id = (vmIntrinsics::ID) index;
     int   flags = _intrinsic_hist_flags[id];
     juint count = _intrinsic_hist_count[id];
     if ((flags | count) != 0) {
       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
     }
   }
   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[vmIntrinsics::_none], flagsbuf));
   if (xtty != NULL)  xtty->tail("statistics");
 }
 void Compile::print_statistics() {
   { ttyLocker ttyl;
     if (xtty != NULL)  xtty->head("statistics type='opto'");
     Parse::print_statistics();
     PhaseCCP::print_statistics();
     PhaseRegAlloc::print_statistics();
     Scheduling::print_statistics();
     PhasePeephole::print_statistics();
     PhaseIdealLoop::print_statistics();
     if (xtty != NULL)  xtty->tail("statistics");
   }
   if (_intrinsic_hist_flags[vmIntrinsics::_none] != 0) {
     // put this under its own <statistics> element.
     print_intrinsic_statistics();
   }
 }
 #endif //PRODUCT
 // Support for bundling info
 Bundle* Compile::node_bundling(const Node *n) {
   assert(valid_bundle_info(n), "oob");
   return &_node_bundling_base[n->_idx];
 }
 bool Compile::valid_bundle_info(const Node *n) {
   return (_node_bundling_limit > n->_idx);
 }
 void Compile::gvn_replace_by(Node* n, Node* nn) {
   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
     Node* use = n->last_out(i);
     bool is_in_table = initial_gvn()->hash_delete(use);
     uint uses_found = 0;
     for (uint j = 0; j < use->len(); j++) {
       if (use->in(j) == n) {
         if (j < use->req())
           use->set_req(j, nn);
         else
           use->set_prec(j, nn);
         uses_found++;
       }
     }
     if (is_in_table) {
       // reinsert into table
       initial_gvn()->hash_find_insert(use);
     }
     record_for_igvn(use);
     i -= uses_found;    // we deleted 1 or more copies of this edge
   }
 }
 static inline bool not_a_node(const Node* n) {
   if (n == NULL)                   return true;
   if (((intptr_t)n & 1) != 0)      return true;  // uninitialized, etc.
   if (*(address*)n == badAddress)  return true;  // kill by Node::destruct
   return false;
 }
 // Identify all nodes that are reachable from below, useful.
 // Use breadth-first pass that records state in a Unique_Node_List,
 // recursive traversal is slower.
 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
   int estimated_worklist_size = unique();
   useful.map( estimated_worklist_size, NULL );  // preallocate space
   // Initialize worklist
   if (root() != NULL)     { useful.push(root()); }
   // If 'top' is cached, declare it useful to preserve cached node
   if( cached_top_node() ) { useful.push(cached_top_node()); }
   // Push all useful nodes onto the list, breadthfirst
   for( uint next = 0; next < useful.size(); ++next ) {
     assert( next < unique(), "Unique useful nodes < total nodes");
     Node *n  = useful.at(next);
     uint max = n->len();
     for( uint i = 0; i < max; ++i ) {
       Node *m = n->in(i);
       if (not_a_node(m))  continue;
       useful.push(m);
     }
   }
 }
 // Update dead_node_list with any missing dead nodes using useful
 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 void Compile::update_dead_node_list(Unique_Node_List &useful) {
   uint max_idx = unique();
   VectorSet& useful_node_set = useful.member_set();
   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
     // If node with index node_idx is not in useful set,
     // mark it as dead in dead node list.
     if (! useful_node_set.test(node_idx) ) {
       record_dead_node(node_idx);
     }
   }
 }
 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
   int shift = 0;
   for (int i = 0; i < inlines->length(); i++) {
     CallGenerator* cg = inlines->at(i);
     CallNode* call = cg->call_node();
     if (shift > 0) {
       inlines->at_put(i-shift, cg);
     }
     if (!useful.member(call)) {
       shift++;
     }
   }
   inlines->trunc_to(inlines->length()-shift);
 }
 // Disconnect all useless nodes by disconnecting those at the boundary.
 void Compile::remove_useless_nodes(Unique_Node_List &useful) {
   uint next = 0;
   while (next < useful.size()) {
     Node *n = useful.at(next++);
     // Use raw traversal of out edges since this code removes out edges
     int max = n->outcnt();
     for (int j = 0; j < max; ++j) {
       Node* child = n->raw_out(j);
       if (! useful.member(child)) {
         assert(!child->is_top() || child != top(),
                "If top is cached in Compile object it is in useful list");
         // Only need to remove this out-edge to the useless node
         n->raw_del_out(j);
         --j;
         --max;
       }
     }
     if (n->outcnt() == 1 && n->has_special_unique_user()) {
       record_for_igvn(n->unique_out());
     }
   }
   // Remove useless macro and predicate opaq nodes
   for (int i = C->macro_count()-1; i >= 0; i--) {
     Node* n = C->macro_node(i);
     if (!useful.member(n)) {
       remove_macro_node(n);
     }
   }
   // Remove useless expensive node
   for (int i = C->expensive_count()-1; i >= 0; i--) {
     Node* n = C->expensive_node(i);
     if (!useful.member(n)) {
       remove_expensive_node(n);
     }
   }
   // clean up the late inline lists
   remove_useless_late_inlines(&_string_late_inlines, useful);
   remove_useless_late_inlines(&_boxing_late_inlines, useful);
   remove_useless_late_inlines(&_late_inlines, useful);
   debug_only(verify_graph_edges(true/*check for no_dead_code*/);)
 }
 //------------------------------frame_size_in_words-----------------------------
 // frame_slots in units of words
 int Compile::frame_size_in_words() const {
   // shift is 0 in LP32 and 1 in LP64
   const int shift = (LogBytesPerWord - LogBytesPerInt);
   int words = _frame_slots >> shift;
   assert( words << shift == _frame_slots, "frame size must be properly aligned in LP64" );
   return words;
 }
 // ============================================================================
 //------------------------------CompileWrapper---------------------------------
 class CompileWrapper : public StackObj {
   Compile *const _compile;
  public:
   CompileWrapper(Compile* compile);
   ~CompileWrapper();
 };
 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
   // the Compile* pointer is stored in the current ciEnv:
   ciEnv* env = compile->env();
   assert(env == ciEnv::current(), "must already be a ciEnv active");
   assert(env->compiler_data() == NULL, "compile already active?");
   env->set_compiler_data(compile);
   assert(compile == Compile::current(), "sanity");
   compile->set_type_dict(NULL);
   compile->set_type_hwm(NULL);
   compile->set_type_last_size(0);
   compile->set_last_tf(NULL, NULL);
   compile->set_indexSet_arena(NULL);
   compile->set_indexSet_free_block_list(NULL);
   compile->init_type_arena();
   Type::Initialize(compile);
   _compile->set_scratch_buffer_blob(NULL);
   _compile->begin_method();
 }
 CompileWrapper::~CompileWrapper() {
   _compile->end_method();
   if (_compile->scratch_buffer_blob() != NULL)
     BufferBlob::free(_compile->scratch_buffer_blob());
   _compile->env()->set_compiler_data(NULL);
 }
 //----------------------------print_compile_messages---------------------------
 void Compile::print_compile_messages() {
 #ifndef PRODUCT
   // Check if recompiling
   if (_subsume_loads == false && PrintOpto) {
     // Recompiling without allowing machine instructions to subsume loads
     tty->print_cr("*********************************************************");
     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
     tty->print_cr("*********************************************************");
   }
   if (_do_escape_analysis != DoEscapeAnalysis && PrintOpto) {
     // Recompiling without escape analysis
     tty->print_cr("*********************************************************");
     tty->print_cr("** Bailout: Recompile without escape analysis          **");
     tty->print_cr("*********************************************************");
   }
   if (_eliminate_boxing != EliminateAutoBox && PrintOpto) {
     // Recompiling without boxing elimination
     tty->print_cr("*********************************************************");
     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
     tty->print_cr("*********************************************************");
   }
   if (env()->break_at_compile()) {
     // Open the debugger when compiling this method.
     tty->print("### Breaking when compiling: ");
     method()->print_short_name();
     tty->cr();
     BREAKPOINT;
   }
   if( PrintOpto ) {
     if (is_osr_compilation()) {
       tty->print("[OSR]%3d", _compile_id);
     } else {
       tty->print("%3d", _compile_id);
     }
   }
 #endif
 }
 //-----------------------init_scratch_buffer_blob------------------------------
 // Construct a temporary BufferBlob and cache it for this compile.
 void Compile::init_scratch_buffer_blob(int const_size) {
   // If there is already a scratch buffer blob allocated and the
   // constant section is big enough, use it.  Otherwise free the
   // current and allocate a new one.
   BufferBlob* blob = scratch_buffer_blob();
   if ((blob != NULL) && (const_size <= _scratch_const_size)) {
     // Use the current blob.
   } else {
     if (blob != NULL) {
       BufferBlob::free(blob);
     }
     ResourceMark rm;
     _scratch_const_size = const_size;
     int size = (MAX_inst_size + MAX_stubs_size + _scratch_const_size);
     blob = BufferBlob::create("Compile::scratch_buffer", size);
     // Record the buffer blob for next time.
     set_scratch_buffer_blob(blob);
     // Have we run out of code space?
     if (scratch_buffer_blob() == NULL) {
       // Let CompilerBroker disable further compilations.
       record_failure("Not enough space for scratch buffer in CodeCache");
       return;
     }
   }
   // Initialize the relocation buffers
   relocInfo* locs_buf = (relocInfo*) blob->content_end() - MAX_locs_size;
   set_scratch_locs_memory(locs_buf);
 }
 //-----------------------scratch_emit_size-------------------------------------
 // Helper function that computes size by emitting code
 uint Compile::scratch_emit_size(const Node* n) {
   // Start scratch_emit_size section.
   set_in_scratch_emit_size(true);
   // Emit into a trash buffer and count bytes emitted.
   // This is a pretty expensive way to compute a size,
   // but it works well enough if seldom used.
   // All common fixed-size instructions are given a size
   // method by the AD file.
   // Note that the scratch buffer blob and locs memory are
   // allocated at the beginning of the compile task, and
   // may be shared by several calls to scratch_emit_size.
   // The allocation of the scratch buffer blob is particularly
   // expensive, since it has to grab the code cache lock.
   BufferBlob* blob = this->scratch_buffer_blob();
   assert(blob != NULL, "Initialize BufferBlob at start");
   assert(blob->size() > MAX_inst_size, "sanity");
   relocInfo* locs_buf = scratch_locs_memory();
   address blob_begin = blob->content_begin();
   address blob_end   = (address)locs_buf;
   assert(blob->content_contains(blob_end), "sanity");
   CodeBuffer buf(blob_begin, blob_end - blob_begin);
   buf.initialize_consts_size(_scratch_const_size);
   buf.initialize_stubs_size(MAX_stubs_size);
   assert(locs_buf != NULL, "sanity");
   int lsize = MAX_locs_size / 3;
   buf.consts()->initialize_shared_locs(&locs_buf[lsize * 0], lsize);
   buf.insts()->initialize_shared_locs( &locs_buf[lsize * 1], lsize);
   buf.stubs()->initialize_shared_locs( &locs_buf[lsize * 2], lsize);
   // Do the emission.
   Label fakeL; // Fake label for branch instructions.
   Label*   saveL = NULL;
   uint save_bnum = 0;
   bool is_branch = n->is_MachBranch();
   if (is_branch) {
     MacroAssembler masm(&buf);
     masm.bind(fakeL);
     n->as_MachBranch()->save_label(&saveL, &save_bnum);
     n->as_MachBranch()->label_set(&fakeL, 0);
   }
   n->emit(buf, this->regalloc());
   if (is_branch) // Restore label.
     n->as_MachBranch()->label_set(saveL, save_bnum);
   // End scratch_emit_size section.
   set_in_scratch_emit_size(false);
   return buf.insts_size();
 }
 // ============================================================================
 //------------------------------Compile standard-------------------------------
 debug_only( int Compile::_debug_idx = 100000; )
 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 // the continuation bci for on stack replacement.
 Compile::Compile( ciEnv* ci_env, C2Compiler* compiler, ciMethod* target, int osr_bci,
                   bool subsume_loads, bool do_escape_analysis, bool eliminate_boxing )
                 : Phase(Compiler),
                   _env(ci_env),
                   _log(ci_env->log()),
                   _compile_id(ci_env->compile_id()),
                   _save_argument_registers(false),
                   _stub_name(NULL),
                   _stub_function(NULL),
                   _stub_entry_point(NULL),
                   _method(target),
                   _entry_bci(osr_bci),
                   _initial_gvn(NULL),
                   _for_igvn(NULL),
                   _warm_calls(NULL),
                   _subsume_loads(subsume_loads),
                   _do_escape_analysis(do_escape_analysis),
                   _eliminate_boxing(eliminate_boxing),
                   _failure_reason(NULL),
                   _code_buffer("Compile::Fill_buffer"),
                   _orig_pc_slot(0),
                   _orig_pc_slot_offset_in_bytes(0),
                   _has_method_handle_invokes(false),
                   _mach_constant_base_node(NULL),
                   _node_bundling_limit(0),
                   _node_bundling_base(NULL),
                   _java_calls(0),
                   _inner_loops(0),
                   _scratch_const_size(-1),
                   _in_scratch_emit_size(false),
                   _dead_node_list(comp_arena()),
                   _dead_node_count(0),
 #ifndef PRODUCT
                   _trace_opto_output(TraceOptoOutput || method()->has_option("TraceOptoOutput")),
                   _printer(IdealGraphPrinter::printer()),
 #endif
                   _congraph(NULL),
                   _late_inlines(comp_arena(), 2, 0, NULL),
                   _string_late_inlines(comp_arena(), 2, 0, NULL),
                   _boxing_late_inlines(comp_arena(), 2, 0, NULL),
                   _late_inlines_pos(0),
                   _number_of_mh_late_inlines(0),
                   _inlining_progress(false),
                   _inlining_incrementally(false),
                   _print_inlining_list(NULL),
                   _print_inlining_idx(0),
                   _preserve_jvm_state(0) {
   C = this;
   CompileWrapper cw(this);
 #ifndef PRODUCT
   if (TimeCompiler2) {
     tty->print(" ");
     target->holder()->name()->print();
     tty->print(".");
     target->print_short_name();
     tty->print("  ");
   }
   TraceTime t1("Total compilation time", &_t_totalCompilation, TimeCompiler, TimeCompiler2);
   TraceTime t2(NULL, &_t_methodCompilation, TimeCompiler, false);
   bool print_opto_assembly = PrintOptoAssembly || _method->has_option("PrintOptoAssembly");
   if (!print_opto_assembly) {
     bool print_assembly = (PrintAssembly || _method->should_print_assembly());
     if (print_assembly && !Disassembler::can_decode()) {
       tty->print_cr("PrintAssembly request changed to PrintOptoAssembly");
       print_opto_assembly = true;
     }
   }
   set_print_assembly(print_opto_assembly);
   set_parsed_irreducible_loop(false);
 #endif
   set_print_inlining(PrintInlining || method()->has_option("PrintInlining") NOT_PRODUCT( || PrintOptoInlining));
   set_print_intrinsics(PrintIntrinsics || method()->has_option("PrintIntrinsics"));
   if (ProfileTraps) {
     // Make sure the method being compiled gets its own MDO,
     // so we can at least track the decompile_count().
     method()->ensure_method_data();
   }
   Init(::AliasLevel);
   print_compile_messages();
   if (UseOldInlining || PrintCompilation NOT_PRODUCT( || PrintOpto) )
     _ilt = InlineTree::build_inline_tree_root();
   else
     _ilt = NULL;
   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
   assert(num_alias_types() >= AliasIdxRaw, "");
 #define MINIMUM_NODE_HASH  1023
   // Node list that Iterative GVN will start with
   Unique_Node_List for_igvn(comp_arena());
   set_for_igvn(&for_igvn);
   // GVN that will be run immediately on new nodes
   uint estimated_size = method()->code_size()*4+64;
   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
   PhaseGVN gvn(node_arena(), estimated_size);
   set_initial_gvn(&gvn);
   if (print_inlining() || print_intrinsics()) {
     _print_inlining_list = new (comp_arena())GrowableArray<PrintInliningBuffer>(comp_arena(), 1, 1, PrintInliningBuffer());
   }
   { // Scope for timing the parser
     TracePhase t3("parse", &_t_parser, true);
     // Put top into the hash table ASAP.
     initial_gvn()->transform_no_reclaim(top());
     // Set up tf(), start(), and find a CallGenerator.
     CallGenerator* cg = NULL;
     if (is_osr_compilation()) {
       const TypeTuple *domain = StartOSRNode::osr_domain();
       const TypeTuple *range = TypeTuple::make_range(method()->signature());
       init_tf(TypeFunc::make(domain, range));
       StartNode* s = new (this) StartOSRNode(root(), domain);
       initial_gvn()->set_type_bottom(s);
       init_start(s);
       cg = CallGenerator::for_osr(method(), entry_bci());
     } else {
       // Normal case.
       init_tf(TypeFunc::make(method()));
       StartNode* s = new (this) StartNode(root(), tf()->domain());
       initial_gvn()->set_type_bottom(s);
       init_start(s);
       if (method()->intrinsic_id() == vmIntrinsics::_Reference_get && UseG1GC) {
         // With java.lang.ref.reference.get() we must go through the
         // intrinsic when G1 is enabled - even when get() is the root
         // method of the compile - so that, if necessary, the value in
         // the referent field of the reference object gets recorded by
         // the pre-barrier code.
         // Specifically, if G1 is enabled, the value in the referent
         // field is recorded by the G1 SATB pre barrier. This will
         // result in the referent being marked live and the reference
         // object removed from the list of discovered references during
         // reference processing.
         cg = find_intrinsic(method(), false);
       }
       if (cg == NULL) {
         float past_uses = method()->interpreter_invocation_count();
         float expected_uses = past_uses;
         cg = CallGenerator::for_inline(method(), expected_uses);
       }
     }
     if (failing())  return;
     if (cg == NULL) {
       record_method_not_compilable_all_tiers("cannot parse method");
       return;
     }
     JVMState* jvms = build_start_state(start(), tf());
     if ((jvms = cg->generate(jvms, NULL)) == NULL) {
       record_method_not_compilable("method parse failed");
       return;
     }
     GraphKit kit(jvms);
     if (!kit.stopped()) {
       // Accept return values, and transfer control we know not where.
       // This is done by a special, unique ReturnNode bound to root.
       return_values(kit.jvms());
     }
     if (kit.has_exceptions()) {
       // Any exceptions that escape from this call must be rethrown
       // to whatever caller is dynamically above us on the stack.
       // This is done by a special, unique RethrowNode bound to root.
       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
     }
     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
       inline_string_calls(true);
     }
     if (failing())  return;
     print_method(PHASE_BEFORE_REMOVEUSELESS, 3);
     // Remove clutter produced by parsing.
     if (!failing()) {
       ResourceMark rm;
       PhaseRemoveUseless pru(initial_gvn(), &for_igvn);
     }
   }
   // Note:  Large methods are capped off in do_one_bytecode().
   if (failing())  return;
   // After parsing, node notes are no longer automagic.
   // They must be propagated by register_new_node_with_optimizer(),
   // clone(), or the like.
   set_default_node_notes(NULL);
   for (;;) {
     int successes = Inline_Warm();
     if (failing())  return;
     if (successes == 0)  break;
   }
   // Drain the list.
   Finish_Warm();
 #ifndef PRODUCT
   if (_printer) {
     _printer->print_inlining(this);
   }
 #endif
   if (failing())  return;
   NOT_PRODUCT( verify_graph_edges(); )
   // Now optimize
   Optimize();
   if (failing())  return;
   NOT_PRODUCT( verify_graph_edges(); )
 #ifndef PRODUCT
   if (PrintIdeal) {
     ttyLocker ttyl;  // keep the following output all in one block
     // This output goes directly to the tty, not the compiler log.
     // To enable tools to match it up with the compilation activity,
     // be sure to tag this tty output with the compile ID.
     if (xtty != NULL) {
       xtty->head("ideal compile_id='%d'%s", compile_id(),
                  is_osr_compilation()    ? " compile_kind='osr'" :
                  "");
     }
     root()->dump(9999);
     if (xtty != NULL) {
       xtty->tail("ideal");
     }
   }
 #endif
   NOT_PRODUCT( verify_barriers(); )
   // Now that we know the size of all the monitors we can add a fixed slot
   // for the original deopt pc.
   _orig_pc_slot =  fixed_slots();
   int next_slot = _orig_pc_slot + (sizeof(address) / VMRegImpl::stack_slot_size);
   set_fixed_slots(next_slot);
   // Now generate code
   Code_Gen();
   if (failing())  return;
   // Check if we want to skip execution of all compiled code.
   {
 #ifndef PRODUCT
     if (OptoNoExecute) {
       record_method_not_compilable("+OptoNoExecute");  // Flag as failed
       return;
     }
     TracePhase t2("install_code", &_t_registerMethod, TimeCompiler);
 #endif
     if (is_osr_compilation()) {
       _code_offsets.set_value(CodeOffsets::Verified_Entry, 0);
       _code_offsets.set_value(CodeOffsets::OSR_Entry, _first_block_size);
     } else {
       _code_offsets.set_value(CodeOffsets::Verified_Entry, _first_block_size);
       _code_offsets.set_value(CodeOffsets::OSR_Entry, 0);
     }
     env()->register_method(_method, _entry_bci,
                            &_code_offsets,
                            _orig_pc_slot_offset_in_bytes,
                            code_buffer(),
                            frame_size_in_words(), _oop_map_set,
                            &_handler_table, &_inc_table,
                            compiler,
                            env()->comp_level(),
                            has_unsafe_access(),
                            SharedRuntime::is_wide_vector(max_vector_size())
                            );
     if (log() != NULL) // Print code cache state into compiler log
       log()->code_cache_state();
   }
 }
 //------------------------------Compile----------------------------------------
 // Compile a runtime stub
 Compile::Compile( ciEnv* ci_env,
                   TypeFunc_generator generator,
                   address stub_function,
                   const char *stub_name,
                   int is_fancy_jump,
                   bool pass_tls,
                   bool save_arg_registers,
                   bool return_pc )
   : Phase(Compiler),
     _env(ci_env),
     _log(ci_env->log()),
     _compile_id(0),
     _save_argument_registers(save_arg_registers),
     _method(NULL),
     _stub_name(stub_name),
     _stub_function(stub_function),
     _stub_entry_point(NULL),
     _entry_bci(InvocationEntryBci),
     _initial_gvn(NULL),
     _for_igvn(NULL),
     _warm_calls(NULL),
     _orig_pc_slot(0),
     _orig_pc_slot_offset_in_bytes(0),
     _subsume_loads(true),
     _do_escape_analysis(false),
     _eliminate_boxing(false),
     _failure_reason(NULL),
     _code_buffer("Compile::Fill_buffer"),
     _has_method_handle_invokes(false),
     _mach_constant_base_node(NULL),
     _node_bundling_limit(0),
     _node_bundling_base(NULL),
     _java_calls(0),
     _inner_loops(0),
 #ifndef PRODUCT
     _trace_opto_output(TraceOptoOutput),
     _printer(NULL),
 #endif
     _dead_node_list(comp_arena()),
     _dead_node_count(0),
     _congraph(NULL),
     _number_of_mh_late_inlines(0),
     _inlining_progress(false),
     _inlining_incrementally(false),
     _print_inlining_list(NULL),
     _print_inlining_idx(0),
     _preserve_jvm_state(0) {
   C = this;
 #ifndef PRODUCT
   TraceTime t1(NULL, &_t_totalCompilation, TimeCompiler, false);
   TraceTime t2(NULL, &_t_stubCompilation, TimeCompiler, false);
   set_print_assembly(PrintFrameConverterAssembly);
   set_parsed_irreducible_loop(false);
 #endif
   CompileWrapper cw(this);
   Init(/*AliasLevel=*/ 0);
   init_tf((*generator)());
   {
     // The following is a dummy for the sake of GraphKit::gen_stub
     Unique_Node_List for_igvn(comp_arena());
     set_for_igvn(&for_igvn);  // not used, but some GraphKit guys push on this
     PhaseGVN gvn(Thread::current()->resource_area(),255);
     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
     gvn.transform_no_reclaim(top());
     GraphKit kit;
     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
   }
   NOT_PRODUCT( verify_graph_edges(); )
   Code_Gen();
   if (failing())  return;
   // Entry point will be accessed using compile->stub_entry_point();
   if (code_buffer() == NULL) {
     Matcher::soft_match_failure();
   } else {
     if (PrintAssembly && (WizardMode || Verbose))
       tty->print_cr("### Stub::%s", stub_name);
     if (!failing()) {
       assert(_fixed_slots == 0, "no fixed slots used for runtime stubs");
       // Make the NMethod
       // For now we mark the frame as never safe for profile stackwalking
       RuntimeStub *rs = RuntimeStub::new_runtime_stub(stub_name,
                                                       code_buffer(),
                                                       CodeOffsets::frame_never_safe,
                                                       // _code_offsets.value(CodeOffsets::Frame_Complete),
                                                       frame_size_in_words(),
                                                       _oop_map_set,
                                                       save_arg_registers);
       assert(rs != NULL && rs->is_runtime_stub(), "sanity check");
       _stub_entry_point = rs->entry_point();
     }
   }
 }
 //------------------------------Init-------------------------------------------
 // Prepare for a single compilation
 void Compile::Init(int aliaslevel) {
   _unique  = 0;
   _regalloc = NULL;
   _tf      = NULL;  // filled in later
   _top     = NULL;  // cached later
   _matcher = NULL;  // filled in later
   _cfg     = NULL;  // filled in later
   set_24_bit_selection_and_mode(Use24BitFP, false);
   _node_note_array = NULL;
   _default_node_notes = NULL;
   _immutable_memory = NULL; // filled in at first inquiry
   // Globally visible Nodes
   // First set TOP to NULL to give safe behavior during creation of RootNode
   set_cached_top_node(NULL);
   set_root(new (this) RootNode());
   // Now that you have a Root to point to, create the real TOP
   set_cached_top_node( new (this) ConNode(Type::TOP) );
   set_recent_alloc(NULL, NULL);
   // Create Debug Information Recorder to record scopes, oopmaps, etc.
   env()->set_oop_recorder(new OopRecorder(env()->arena()));
   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
   env()->set_dependencies(new Dependencies(env()));
   _fixed_slots = 0;
   set_has_split_ifs(false);
   set_has_loops(has_method() && method()->has_loops()); // first approximation
   set_has_stringbuilder(false);
   set_has_boxed_value(false);
   _trap_can_recompile = false;  // no traps emitted yet
   _major_progress = true; // start out assuming good things will happen
   set_has_unsafe_access(false);
   set_max_vector_size(0);
   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
   set_decompile_count(0);
   set_do_freq_based_layout(BlockLayoutByFrequency || method_has_option("BlockLayoutByFrequency"));
   set_num_loop_opts(LoopOptsCount);
   set_do_inlining(Inline);
   set_max_inline_size(MaxInlineSize);
   set_freq_inline_size(FreqInlineSize);
   set_do_scheduling(OptoScheduling);
   set_do_count_invocations(false);
   set_do_method_data_update(false);
   if (debug_info()->recording_non_safepoints()) {
     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
                         (comp_arena(), 8, 0, NULL));
     set_default_node_notes(Node_Notes::make(this));
   }
   // // -- Initialize types before each compile --
   // // Update cached type information
   // if( _method && _method->constants() )
   //   Type::update_loaded_types(_method, _method->constants());
   // Init alias_type map.
   if (!_do_escape_analysis && aliaslevel == 3)
     aliaslevel = 2;  // No unique types without escape analysis
   _AliasLevel = aliaslevel;
   const int grow_ats = 16;
   _max_alias_types = grow_ats;
   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
   {
     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
   }
   // Initialize the first few types.
   _alias_types[AliasIdxTop]->Init(AliasIdxTop, NULL);
   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
   _num_alias_types = AliasIdxRaw+1;
   // Zero out the alias type cache.
   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
   // A NULL adr_type hits in the cache right away.  Preload the right answer.
   probe_alias_cache(NULL)->_index = AliasIdxTop;
   _intrinsics = NULL;
   _macro_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   _predicate_opaqs = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   _expensive_nodes = new(comp_arena()) GrowableArray<Node*>(comp_arena(), 8,  0, NULL);
   register_library_intrinsics();
 }
 //---------------------------init_start----------------------------------------
 // Install the StartNode on this compile object.
 void Compile::init_start(StartNode* s) {
   if (failing())
     return; // already failing
   assert(s == start(), "");
 }
 StartNode* Compile::start() const {
   assert(!failing(), "");
   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
     Node* start = root()->fast_out(i);
     if( start->is_Start() )
       return start->as_Start();
   }
   ShouldNotReachHere();
   return NULL;
 }
 //-------------------------------immutable_memory-------------------------------------
 // Access immutable memory
 Node* Compile::immutable_memory() {
   if (_immutable_memory != NULL) {
     return _immutable_memory;
   }
   StartNode* s = start();
   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
     Node *p = s->fast_out(i);
     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
       _immutable_memory = p;
       return _immutable_memory;
     }
   }
   ShouldNotReachHere();
   return NULL;
 }
 //----------------------set_cached_top_node------------------------------------
 // Install the cached top node, and make sure Node::is_top works correctly.
 void Compile::set_cached_top_node(Node* tn) {
   if (tn != NULL)  verify_top(tn);
   Node* old_top = _top;
   _top = tn;
   // Calling Node::setup_is_top allows the nodes the chance to adjust
   // their _out arrays.
   if (_top != NULL)     _top->setup_is_top();
   if (old_top != NULL)  old_top->setup_is_top();
   assert(_top == NULL || top()->is_top(), "");
 }
 #ifdef ASSERT
 uint Compile::count_live_nodes_by_graph_walk() {
   Unique_Node_List useful(comp_arena());
   // Get useful node list by walking the graph.
   identify_useful_nodes(useful);
   return useful.size();
 }
 void Compile::print_missing_nodes() {
   // Return if CompileLog is NULL and PrintIdealNodeCount is false.
   if ((_log == NULL) && (! PrintIdealNodeCount)) {
     return;
   }
   // This is an expensive function. It is executed only when the user
   // specifies VerifyIdealNodeCount option or otherwise knows the
   // additional work that needs to be done to identify reachable nodes
   // by walking the flow graph and find the missing ones using
   // _dead_node_list.
   Unique_Node_List useful(comp_arena());
   // Get useful node list by walking the graph.
   identify_useful_nodes(useful);
   uint l_nodes = C->live_nodes();
   uint l_nodes_by_walk = useful.size();
   if (l_nodes != l_nodes_by_walk) {
     if (_log != NULL) {
       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
       _log->stamp();
       _log->end_head();
     }
     VectorSet& useful_member_set = useful.member_set();
     int last_idx = l_nodes_by_walk;
     for (int i = 0; i < last_idx; i++) {
       if (useful_member_set.test(i)) {
         if (_dead_node_list.test(i)) {
           if (_log != NULL) {
             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
           }
           if (PrintIdealNodeCount) {
             // Print the log message to tty
               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
               useful.at(i)->dump();
           }
         }
       }
       else if (! _dead_node_list.test(i)) {
         if (_log != NULL) {
           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
         }
         if (PrintIdealNodeCount) {
           // Print the log message to tty
           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
         }
       }
     }
     if (_log != NULL) {
       _log->tail("mismatched_nodes");
     }
   }
 }
 #endif
 #ifndef PRODUCT
 void Compile::verify_top(Node* tn) const {
   if (tn != NULL) {
     assert(tn->is_Con(), "top node must be a constant");
     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
     assert(tn->in(0) != NULL, "must have live top node");
   }
 }
 #endif
 ///-------------------Managing Per-Node Debug & Profile Info-------------------
 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
   guarantee(arr != NULL, "");
   int num_blocks = arr->length();
   if (grow_by < num_blocks)  grow_by = num_blocks;
   int num_notes = grow_by * _node_notes_block_size;
   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
   while (num_notes > 0) {
     arr->append(notes);
     notes     += _node_notes_block_size;
     num_notes -= _node_notes_block_size;
   }
   assert(num_notes == 0, "exact multiple, please");
 }
 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
   if (source == NULL || dest == NULL)  return false;
   if (dest->is_Con())
     return false;               // Do not push debug info onto constants.
 #ifdef ASSERT
   // Leave a bread crumb trail pointing to the original node:
   if (dest != NULL && dest != source && dest->debug_orig() == NULL) {
     dest->set_debug_orig(source);
   }
 #endif
   if (node_note_array() == NULL)
     return false;               // Not collecting any notes now.
   // This is a copy onto a pre-existing node, which may already have notes.
   // If both nodes have notes, do not overwrite any pre-existing notes.
   Node_Notes* source_notes = node_notes_at(source->_idx);
   if (source_notes == NULL || source_notes->is_clear())  return false;
   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
   if (dest_notes == NULL || dest_notes->is_clear()) {
     return set_node_notes_at(dest->_idx, source_notes);
   }
   Node_Notes merged_notes = (*source_notes);
   // The order of operations here ensures that dest notes will win...
   merged_notes.update_from(dest_notes);
   return set_node_notes_at(dest->_idx, &merged_notes);
 }
 //--------------------------allow_range_check_smearing-------------------------
 // Gating condition for coalescing similar range checks.
 // Sometimes we try 'speculatively' replacing a series of a range checks by a
 // single covering check that is at least as strong as any of them.
 // If the optimization succeeds, the simplified (strengthened) range check
 // will always succeed.  If it fails, we will deopt, and then give up
 // on the optimization.
 bool Compile::allow_range_check_smearing() const {
   // If this method has already thrown a range-check,
   // assume it was because we already tried range smearing
   // and it failed.
   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
   return !already_trapped;
 }
 //------------------------------flatten_alias_type-----------------------------
 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
   int offset = tj->offset();
   TypePtr::PTR ptr = tj->ptr();
   // Known instance (scalarizable allocation) alias only with itself.
   bool is_known_inst = tj->isa_oopptr() != NULL &&
                        tj->is_oopptr()->is_known_instance();
   // Process weird unsafe references.
   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
     assert(InlineUnsafeOps, "indeterminate pointers come only from unsafe ops");
     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
     tj = TypeOopPtr::BOTTOM;
     ptr = tj->ptr();
     offset = tj->offset();
   }
   // Array pointers need some flattening
   const TypeAryPtr *ta = tj->isa_aryptr();
   if (ta && ta->is_stable()) {
     // Erase stability property for alias analysis.
     tj = ta = ta->cast_to_stable(false);
   }
   if( ta && is_known_inst ) {
     if ( offset != Type::OffsetBot &&
          offset > arrayOopDesc::length_offset_in_bytes() ) {
       offset = Type::OffsetBot; // Flatten constant access into array body only
       tj = ta = TypeAryPtr::make(ptr, ta->ary(), ta->klass(), true, offset, ta->instance_id());
     }
   } else if( ta && _AliasLevel >= 2 ) {
     // For arrays indexed by constant indices, we flatten the alias
     // space to include all of the array body.  Only the header, klass
     // and array length can be accessed un-aliased.
     if( offset != Type::OffsetBot ) {
       if( ta->const_oop() ) { // MethodData* or Method*
         offset = Type::OffsetBot;   // Flatten constant access into array body
         tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),ta->ary(),ta->klass(),false,offset);
       } else if( offset == arrayOopDesc::length_offset_in_bytes() ) {
         // range is OK as-is.
         tj = ta = TypeAryPtr::RANGE;
       } else if( offset == oopDesc::klass_offset_in_bytes() ) {
         tj = TypeInstPtr::KLASS; // all klass loads look alike
         ta = TypeAryPtr::RANGE; // generic ignored junk
         ptr = TypePtr::BotPTR;
       } else if( offset == oopDesc::mark_offset_in_bytes() ) {
         tj = TypeInstPtr::MARK;
         ta = TypeAryPtr::RANGE; // generic ignored junk
         ptr = TypePtr::BotPTR;
       } else {                  // Random constant offset into array body
         offset = Type::OffsetBot;   // Flatten constant access into array body
         tj = ta = TypeAryPtr::make(ptr,ta->ary(),ta->klass(),false,offset);
       }
     }
     // Arrays of fixed size alias with arrays of unknown size.
     if (ta->size() != TypeInt::POS) {
       const TypeAry *tary = TypeAry::make(ta->elem(), TypeInt::POS);
       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,ta->klass(),false,offset);
     }
     // Arrays of known objects become arrays of unknown objects.
     if (ta->elem()->isa_narrowoop() && ta->elem() != TypeNarrowOop::BOTTOM) {
       const TypeAry *tary = TypeAry::make(TypeNarrowOop::BOTTOM, ta->size());
       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
     }
     if (ta->elem()->isa_oopptr() && ta->elem() != TypeInstPtr::BOTTOM) {
       const TypeAry *tary = TypeAry::make(TypeInstPtr::BOTTOM, ta->size());
       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,NULL,false,offset);
     }
     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
     // cannot be distinguished by bytecode alone.
     if (ta->elem() == TypeInt::BOOL) {
       const TypeAry *tary = TypeAry::make(TypeInt::BYTE, ta->size());
       ciKlass* aklass = ciTypeArrayKlass::make(T_BYTE);
       tj = ta = TypeAryPtr::make(ptr,ta->const_oop(),tary,aklass,false,offset);
     }
     // During the 2nd round of IterGVN, NotNull castings are removed.
     // Make sure the Bottom and NotNull variants alias the same.
     // Also, make sure exact and non-exact variants alias the same.
     if (ptr == TypePtr::NotNull || ta->klass_is_exact() || ta->speculative() != NULL) {
       tj = ta = TypeAryPtr::make(TypePtr::BotPTR,ta->ary(),ta->klass(),false,offset);
     }
   }
   // Oop pointers need some flattening
   const TypeInstPtr *to = tj->isa_instptr();
   if( to && _AliasLevel >= 2 && to != TypeOopPtr::BOTTOM ) {
     ciInstanceKlass *k = to->klass()->as_instance_klass();
     if( ptr == TypePtr::Constant ) {
       if (to->klass() != ciEnv::current()->Class_klass() ||
           offset < k->size_helper() * wordSize) {
         // No constant oop pointers (such as Strings); they alias with
         // unknown strings.
         assert(!is_known_inst, "not scalarizable allocation");
         tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
       }
     } else if( is_known_inst ) {
       tj = to; // Keep NotNull and klass_is_exact for instance type
     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
       // During the 2nd round of IterGVN, NotNull castings are removed.
       // Make sure the Bottom and NotNull variants alias the same.
       // Also, make sure exact and non-exact variants alias the same.
       tj = to = TypeInstPtr::make(TypePtr::BotPTR,to->klass(),false,0,offset);
     }
     if (to->speculative() != NULL) {
       tj = to = TypeInstPtr::make(to->ptr(),to->klass(),to->klass_is_exact(),to->const_oop(),to->offset(), to->instance_id());
     }
     // Canonicalize the holder of this field
     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
       // First handle header references such as a LoadKlassNode, even if the
       // object's klass is unloaded at compile time (4965979).
       if (!is_known_inst) { // Do it only for non-instance types
         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, NULL, offset);
       }
     } else if (offset < 0 || offset >= k->size_helper() * wordSize) {
       // Static fields are in the space above the normal instance
       // fields in the java.lang.Class instance.
       if (to->klass() != ciEnv::current()->Class_klass()) {
         to = NULL;
         tj = TypeOopPtr::BOTTOM;
         offset = tj->offset();
       }
     } else {
       ciInstanceKlass *canonical_holder = k->get_canonical_holder(offset);
       if (!k->equals(canonical_holder) || tj->offset() != offset) {
         if( is_known_inst ) {
           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, true, NULL, offset, to->instance_id());
         } else {
           tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, false, NULL, offset);
         }
       }
     }
   }
   // Klass pointers to object array klasses need some flattening
   const TypeKlassPtr *tk = tj->isa_klassptr();
   if( tk ) {
     // If we are referencing a field within a Klass, we need
     // to assume the worst case of an Object.  Both exact and
     // inexact types must flatten to the same alias class so
     // use NotNull as the PTR.
     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
       tj = tk = TypeKlassPtr::make(TypePtr::NotNull,
                                    TypeKlassPtr::OBJECT->klass(),
                                    offset);
     }
     ciKlass* klass = tk->klass();
     if( klass->is_obj_array_klass() ) {
       ciKlass* k = TypeAryPtr::OOPS->klass();
       if( !k || !k->is_loaded() )                  // Only fails for some -Xcomp runs
         k = TypeInstPtr::BOTTOM->klass();
       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, k, offset );
     }
     // Check for precise loads from the primary supertype array and force them
     // to the supertype cache alias index.  Check for generic array loads from
     // the primary supertype array and also force them to the supertype cache
     // alias index.  Since the same load can reach both, we need to merge
     // these 2 disparate memories into the same alias class.  Since the
     // primary supertype array is read-only, there's no chance of confusion
     // where we bypass an array load and an array store.
     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
     if (offset == Type::OffsetBot ||
         (offset >= primary_supers_offset &&
          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
       offset = in_bytes(Klass::secondary_super_cache_offset());
       tj = tk = TypeKlassPtr::make( TypePtr::NotNull, tk->klass(), offset );
     }
   }
   // Flatten all Raw pointers together.
   if (tj->base() == Type::RawPtr)
     tj = TypeRawPtr::BOTTOM;
   if (tj->base() == Type::AnyPtr)
     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
   // Flatten all to bottom for now
   switch( _AliasLevel ) {
   case 0:
     tj = TypePtr::BOTTOM;
     break;
   case 1:                       // Flatten to: oop, static, field or array
     switch (tj->base()) {
     //case Type::AryPtr: tj = TypeAryPtr::RANGE;    break;
     case Type::RawPtr:   tj = TypeRawPtr::BOTTOM;   break;
     case Type::AryPtr:   // do not distinguish arrays at all
     case Type::InstPtr:  tj = TypeInstPtr::BOTTOM;  break;
     case Type::KlassPtr: tj = TypeKlassPtr::OBJECT; break;
     case Type::AnyPtr:   tj = TypePtr::BOTTOM;      break;  // caller checks it
     default: ShouldNotReachHere();
     }
     break;
   case 2:                       // No collapsing at level 2; keep all splits
   case 3:                       // No collapsing at level 3; keep all splits
     break;
   default:
     Unimplemented();
   }
   offset = tj->offset();
   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr)  ,
           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
   assert( tj->ptr() != TypePtr::TopPTR &&
           tj->ptr() != TypePtr::AnyNull &&
           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
 //    assert( tj->ptr() != TypePtr::Constant ||
 //            tj->base() == Type::RawPtr ||
 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
   return tj;
 }
 void Compile::AliasType::Init(int i, const TypePtr* at) {
   _index = i;
   _adr_type = at;
   _field = NULL;
   _element = NULL;
   _is_rewritable = true; // default
   const TypeOopPtr *atoop = (at != NULL) ? at->isa_oopptr() : NULL;
   if (atoop != NULL && atoop->is_known_instance()) {
     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
     _general_index = Compile::current()->get_alias_index(gt);
   } else {
     _general_index = 0;
   }
 }
 //---------------------------------print_on------------------------------------
 #ifndef PRODUCT
 void Compile::AliasType::print_on(outputStream* st) {
   if (index() < 10)
         st->print("@ <%d> ", index());
   else  st->print("@ <%d>",  index());
   st->print(is_rewritable() ? "   " : " RO");
   int offset = adr_type()->offset();
   if (offset == Type::OffsetBot)
         st->print(" +any");
   else  st->print(" +%-3d", offset);
   st->print(" in ");
   adr_type()->dump_on(st);
   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
   if (field() != NULL && tjp) {
     if (tjp->klass()  != field()->holder() ||
         tjp->offset() != field()->offset_in_bytes()) {
       st->print(" != ");
       field()->print();
       st->print(" ***");
     }
   }
 }
 void print_alias_types() {
   Compile* C = Compile::current();
   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
     C->alias_type(idx)->print_on(tty);
     tty->cr();
   }
 }
 #endif
 //----------------------------probe_alias_cache--------------------------------
 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
   intptr_t key = (intptr_t) adr_type;
   key ^= key >> logAliasCacheSize;
   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
 }
 //-----------------------------grow_alias_types--------------------------------
 void Compile::grow_alias_types() {
   const int old_ats  = _max_alias_types; // how many before?
   const int new_ats  = old_ats;          // how many more?
   const int grow_ats = old_ats+new_ats;  // how many now?
   _max_alias_types = grow_ats;
   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), AliasType*, _alias_types, old_ats, grow_ats);
   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
 }
 //--------------------------------find_alias_type------------------------------
 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
   if (_AliasLevel == 0)
     return alias_type(AliasIdxBot);
   AliasCacheEntry* ace = probe_alias_cache(adr_type);
   if (ace->_adr_type == adr_type) {
     return alias_type(ace->_index);
   }
   // Handle special cases.
   if (adr_type == NULL)             return alias_type(AliasIdxTop);
   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
   // Do it the slow way.
   const TypePtr* flat = flatten_alias_type(adr_type);
 #ifdef ASSERT
   assert(flat == flatten_alias_type(flat), "idempotent");
   assert(flat != TypePtr::BOTTOM,     "cannot alias-analyze an untyped ptr");
   if (flat->isa_oopptr() && !flat->isa_klassptr()) {
     const TypeOopPtr* foop = flat->is_oopptr();
     // Scalarizable allocations have exact klass always.
     bool exact = !foop->klass_is_exact() || foop->is_known_instance();
     const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
     assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type");
   }
   assert(flat == flatten_alias_type(flat), "exact bit doesn't matter");
 #endif
   int idx = AliasIdxTop;
   for (int i = 0; i < num_alias_types(); i++) {
     if (alias_type(i)->adr_type() == flat) {
       idx = i;
       break;
     }
   }
   if (idx == AliasIdxTop) {
     if (no_create)  return NULL;
     // Grow the array if necessary.
     if (_num_alias_types == _max_alias_types)  grow_alias_types();
     // Add a new alias type.
     idx = _num_alias_types++;
     _alias_types[idx]->Init(idx, flat);
     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
     if (flat->isa_instptr()) {
       if (flat->offset() == java_lang_Class::klass_offset_in_bytes()
           && flat->is_instptr()->klass() == env()->Class_klass())
         alias_type(idx)->set_rewritable(false);
     }
     if (flat->isa_aryptr()) {
 #ifdef ASSERT
       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
       // (T_BYTE has the weakest alignment and size restrictions...)
       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
 #endif
       if (flat->offset() == TypePtr::OffsetBot) {
         alias_type(idx)->set_element(flat->is_aryptr()->elem());
       }
     }
     if (flat->isa_klassptr()) {
       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
         alias_type(idx)->set_rewritable(false);
       if (flat->offset() == in_bytes(Klass::modifier_flags_offset()))
         alias_type(idx)->set_rewritable(false);
       if (flat->offset() == in_bytes(Klass::access_flags_offset()))
         alias_type(idx)->set_rewritable(false);
       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
         alias_type(idx)->set_rewritable(false);
     }
     // %%% (We would like to finalize JavaThread::threadObj_offset(),
     // but the base pointer type is not distinctive enough to identify
     // references into JavaThread.)
     // Check for final fields.
     const TypeInstPtr* tinst = flat->isa_instptr();
     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
       ciField* field;
       if (tinst->const_oop() != NULL &&
           tinst->klass() == ciEnv::current()->Class_klass() &&
           tinst->offset() >= (tinst->klass()->as_instance_klass()->size_helper() * wordSize)) {
         // static field
         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
         field = k->get_field_by_offset(tinst->offset(), true);
       } else {
         ciInstanceKlass *k = tinst->klass()->as_instance_klass();
         field = k->get_field_by_offset(tinst->offset(), false);
       }
       assert(field == NULL ||
              original_field == NULL ||
              (field->holder() == original_field->holder() &&
               field->offset() == original_field->offset() &&
               field->is_static() == original_field->is_static()), "wrong field?");
       // Set field() and is_rewritable() attributes.
       if (field != NULL)  alias_type(idx)->set_field(field);
     }
   }
   // Fill the cache for next time.
   ace->_adr_type = adr_type;
   ace->_index    = idx;
   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
   // Might as well try to fill the cache for the flattened version, too.
   AliasCacheEntry* face = probe_alias_cache(flat);
   if (face->_adr_type == NULL) {
     face->_adr_type = flat;
     face->_index    = idx;
     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
   }
   return alias_type(idx);
 }
 Compile::AliasType* Compile::alias_type(ciField* field) {
   const TypeOopPtr* t;
   if (field->is_static())
     t = TypeInstPtr::make(field->holder()->java_mirror());
   else
     t = TypeOopPtr::make_from_klass_raw(field->holder());
   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
   return atp;
 }
 //------------------------------have_alias_type--------------------------------
 bool Compile::have_alias_type(const TypePtr* adr_type) {
   AliasCacheEntry* ace = probe_alias_cache(adr_type);
   if (ace->_adr_type == adr_type) {
     return true;
   }
   // Handle special cases.
   if (adr_type == NULL)             return true;
   if (adr_type == TypePtr::BOTTOM)  return true;
   return find_alias_type(adr_type, true, NULL) != NULL;
 }
 //-----------------------------must_alias--------------------------------------
 // True if all values of the given address type are in the given alias category.
 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
   if (alias_idx == AliasIdxBot)         return true;  // the universal category
   if (adr_type == NULL)                 return true;  // NULL serves as TypePtr::TOP
   if (alias_idx == AliasIdxTop)         return false; // the empty category
   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
   // the only remaining possible overlap is identity
   int adr_idx = get_alias_index(adr_type);
   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
   assert(adr_idx == alias_idx ||
          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
           && adr_type                       != TypeOopPtr::BOTTOM),
          "should not be testing for overlap with an unsafe pointer");
   return adr_idx == alias_idx;
 }
 //------------------------------can_alias--------------------------------------
 // True if any values of the given address type are in the given alias category.
 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
   if (alias_idx == AliasIdxTop)         return false; // the empty category
   if (adr_type == NULL)                 return false; // NULL serves as TypePtr::TOP
   if (alias_idx == AliasIdxBot)         return true;  // the universal category
   if (adr_type->base() == Type::AnyPtr) return true;  // TypePtr::BOTTOM or its twins
   // the only remaining possible overlap is identity
   int adr_idx = get_alias_index(adr_type);
   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
   return adr_idx == alias_idx;
 }
 //---------------------------pop_warm_call-------------------------------------
 WarmCallInfo* Compile::pop_warm_call() {
   WarmCallInfo* wci = _warm_calls;
   if (wci != NULL)  _warm_calls = wci->remove_from(wci);
   return wci;
 }
 //----------------------------Inline_Warm--------------------------------------
 int Compile::Inline_Warm() {
   // If there is room, try to inline some more warm call sites.
   // %%% Do a graph index compaction pass when we think we're out of space?
   if (!InlineWarmCalls)  return 0;
   int calls_made_hot = 0;
   int room_to_grow   = NodeCountInliningCutoff - unique();
   int amount_to_grow = MIN2(room_to_grow, (int)NodeCountInliningStep);
   int amount_grown   = 0;
   WarmCallInfo* call;
   while (amount_to_grow > 0 && (call = pop_warm_call()) != NULL) {
     int est_size = (int)call->size();
     if (est_size > (room_to_grow - amount_grown)) {
       // This one won't fit anyway.  Get rid of it.
       call->make_cold();
       continue;
     }
     call->make_hot();
     calls_made_hot++;
     amount_grown   += est_size;
     amount_to_grow -= est_size;
   }
   if (calls_made_hot > 0)  set_major_progress();
   return calls_made_hot;
 }
 //----------------------------Finish_Warm--------------------------------------
 void Compile::Finish_Warm() {
   if (!InlineWarmCalls)  return;
   if (failing())  return;
   if (warm_calls() == NULL)  return;
   // Clean up loose ends, if we are out of space for inlining.
   WarmCallInfo* call;
   while ((call = pop_warm_call()) != NULL) {
     call->make_cold();
   }
 }
 //---------------------cleanup_loop_predicates-----------------------
 // Remove the opaque nodes that protect the predicates so that all unused
 // checks and uncommon_traps will be eliminated from the ideal graph
 void Compile::cleanup_loop_predicates(PhaseIterGVN &igvn) {
   if (predicate_count()==0) return;
   for (int i = predicate_count(); i > 0; i--) {
     Node * n = predicate_opaque1_node(i-1);
     assert(n->Opcode() == Op_Opaque1, "must be");
     igvn.replace_node(n, n->in(1));
   }
   assert(predicate_count()==0, "should be clean!");
 }
 // StringOpts and late inlining of string methods
 void Compile::inline_string_calls(bool parse_time) {
   {
     // remove useless nodes to make the usage analysis simpler
     ResourceMark rm;
     PhaseRemoveUseless pru(initial_gvn(), for_igvn());
   }
   {
     ResourceMark rm;
     print_method(PHASE_BEFORE_STRINGOPTS, 3);
     PhaseStringOpts pso(initial_gvn(), for_igvn());
     print_method(PHASE_AFTER_STRINGOPTS, 3);
   }
   // now inline anything that we skipped the first time around
   if (!parse_time) {
     _late_inlines_pos = _late_inlines.length();
   }
   while (_string_late_inlines.length() > 0) {
     CallGenerator* cg = _string_late_inlines.pop();
     cg->do_late_inline();
     if (failing())  return;
   }
   _string_late_inlines.trunc_to(0);
 }
 // Late inlining of boxing methods
 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
   if (_boxing_late_inlines.length() > 0) {
     assert(has_boxed_value(), "inconsistent");
     PhaseGVN* gvn = initial_gvn();
     set_inlining_incrementally(true);
     assert( igvn._worklist.size() == 0, "should be done with igvn" );
     for_igvn()->clear();
     gvn->replace_with(&igvn);
     while (_boxing_late_inlines.length() > 0) {
       CallGenerator* cg = _boxing_late_inlines.pop();
       cg->do_late_inline();
       if (failing())  return;
     }
     _boxing_late_inlines.trunc_to(0);
     {
       ResourceMark rm;
       PhaseRemoveUseless pru(gvn, for_igvn());
     }
     igvn = PhaseIterGVN(gvn);
     igvn.optimize();
     set_inlining_progress(false);
     set_inlining_incrementally(false);
   }
 }
 void Compile::inline_incrementally_one(PhaseIterGVN& igvn) {
   assert(IncrementalInline, "incremental inlining should be on");
   PhaseGVN* gvn = initial_gvn();
   set_inlining_progress(false);
   for_igvn()->clear();
   gvn->replace_with(&igvn);
   int i = 0;
   for (; i <_late_inlines.length() && !inlining_progress(); i++) {
     CallGenerator* cg = _late_inlines.at(i);
     _late_inlines_pos = i+1;
     cg->do_late_inline();
     if (failing())  return;
   }
   int j = 0;
   for (; i < _late_inlines.length(); i++, j++) {
     _late_inlines.at_put(j, _late_inlines.at(i));
   }
   _late_inlines.trunc_to(j);
   {
     ResourceMark rm;
     PhaseRemoveUseless pru(gvn, for_igvn());
   }
   igvn = PhaseIterGVN(gvn);
 }
 // Perform incremental inlining until bound on number of live nodes is reached
 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
   PhaseGVN* gvn = initial_gvn();
   set_inlining_incrementally(true);
   set_inlining_progress(true);
   uint low_live_nodes = 0;
   while(inlining_progress() && _late_inlines.length() > 0) {
     if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
       if (low_live_nodes < (uint)LiveNodeCountInliningCutoff * 8 / 10) {
         // PhaseIdealLoop is expensive so we only try it once we are
         // out of loop and we only try it again if the previous helped
         // got the number of nodes down significantly
         PhaseIdealLoop ideal_loop( igvn, false, true );
         if (failing())  return;
         low_live_nodes = live_nodes();
         _major_progress = true;
       }
       if (live_nodes() > (uint)LiveNodeCountInliningCutoff) {
         break;
       }
     }
     inline_incrementally_one(igvn);
     if (failing())  return;
     igvn.optimize();
     if (failing())  return;
   }
   assert( igvn._worklist.size() == 0, "should be done with igvn" );
   if (_string_late_inlines.length() > 0) {
     assert(has_stringbuilder(), "inconsistent");
     for_igvn()->clear();
     initial_gvn()->replace_with(&igvn);
     inline_string_calls(false);
     if (failing())  return;
     {
       ResourceMark rm;
       PhaseRemoveUseless pru(initial_gvn(), for_igvn());
     }
     igvn = PhaseIterGVN(gvn);
     igvn.optimize();
   }
   set_inlining_incrementally(false);
 }
 //------------------------------Optimize---------------------------------------
 // Given a graph, optimize it.
 void Compile::Optimize() {
   TracePhase t1("optimizer", &_t_optimizer, true);
 #ifndef PRODUCT
   if (env()->break_at_compile()) {
     BREAKPOINT;
   }
 #endif
   ResourceMark rm;
   int          loop_opts_cnt;
   NOT_PRODUCT( verify_graph_edges(); )
   print_method(PHASE_AFTER_PARSING);
  {
   // Iterative Global Value Numbering, including ideal transforms
   // Initialize IterGVN with types and values from parse-time GVN
   PhaseIterGVN igvn(initial_gvn());
   {
     NOT_PRODUCT( TracePhase t2("iterGVN", &_t_iterGVN, TimeCompiler); )
     igvn.optimize();
   }
   print_method(PHASE_ITER_GVN1, 2);
   if (failing())  return;
   {
     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
     inline_incrementally(igvn);
   }
   print_method(PHASE_INCREMENTAL_INLINE, 2);
   if (failing())  return;
   if (eliminate_boxing()) {
     NOT_PRODUCT( TracePhase t2("incrementalInline", &_t_incrInline, TimeCompiler); )
     // Inline valueOf() methods now.
     inline_boxing_calls(igvn);
     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
     if (failing())  return;
   }
   // Remove the speculative part of types and clean up the graph from
   // the extra CastPP nodes whose only purpose is to carry them. Do
   // that early so that optimizations are not disrupted by the extra
   // CastPP nodes.
   remove_speculative_types(igvn);
   // No more new expensive nodes will be added to the list from here
   // so keep only the actual candidates for optimizations.
   cleanup_expensive_nodes(igvn);
   // Perform escape analysis
   if (_do_escape_analysis && ConnectionGraph::has_candidates(this)) {
     if (has_loops()) {
       // Cleanup graph (remove dead nodes).
       TracePhase t2("idealLoop", &_t_idealLoop, true);
       PhaseIdealLoop ideal_loop( igvn, false, true );
       if (major_progress()) print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
       if (failing())  return;
     }
     ConnectionGraph::do_analysis(this, &igvn);
     if (failing())  return;
     // Optimize out fields loads from scalar replaceable allocations.
     igvn.optimize();
     print_method(PHASE_ITER_GVN_AFTER_EA, 2);
     if (failing())  return;
     if (congraph() != NULL && macro_count() > 0) {
       NOT_PRODUCT( TracePhase t2("macroEliminate", &_t_macroEliminate, TimeCompiler); )
       PhaseMacroExpand mexp(igvn);
       mexp.eliminate_macro_nodes();
       igvn.set_delay_transform(false);
       igvn.optimize();
       print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
       if (failing())  return;
     }
   }
   // Loop transforms on the ideal graph.  Range Check Elimination,
   // peeling, unrolling, etc.
   // Set loop opts counter
   loop_opts_cnt = num_loop_opts();
   if((loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
     {
       TracePhase t2("idealLoop", &_t_idealLoop, true);
       PhaseIdealLoop ideal_loop( igvn, true );
       loop_opts_cnt--;
       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
       if (failing())  return;
     }
     // Loop opts pass if partial peeling occurred in previous pass
     if(PartialPeelLoop && major_progress() && (loop_opts_cnt > 0)) {
       TracePhase t3("idealLoop", &_t_idealLoop, true);
       PhaseIdealLoop ideal_loop( igvn, false );
       loop_opts_cnt--;
       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
       if (failing())  return;
     }
     // Loop opts pass for loop-unrolling before CCP
     if(major_progress() && (loop_opts_cnt > 0)) {
       TracePhase t4("idealLoop", &_t_idealLoop, true);
       PhaseIdealLoop ideal_loop( igvn, false );
       loop_opts_cnt--;
       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
     }
     if (!failing()) {
       // Verify that last round of loop opts produced a valid graph
       NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
       PhaseIdealLoop::verify(igvn);
     }
   }
   if (failing())  return;
   // Conditional Constant Propagation;
   PhaseCCP ccp( &igvn );
   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
   {
     TracePhase t2("ccp", &_t_ccp, true);
     ccp.do_transform();
   }
   print_method(PHASE_CPP1, 2);
   assert( true, "Break here to ccp.dump_old2new_map()");
   // Iterative Global Value Numbering, including ideal transforms
   {
     NOT_PRODUCT( TracePhase t2("iterGVN2", &_t_iterGVN2, TimeCompiler); )
     igvn = ccp;
     igvn.optimize();
   }
   print_method(PHASE_ITER_GVN2, 2);
   if (failing())  return;
   // Loop transforms on the ideal graph.  Range Check Elimination,
   // peeling, unrolling, etc.
   if(loop_opts_cnt > 0) {
     debug_only( int cnt = 0; );
     while(major_progress() && (loop_opts_cnt > 0)) {
       TracePhase t2("idealLoop", &_t_idealLoop, true);
       assert( cnt++ < 40, "infinite cycle in loop optimization" );
       PhaseIdealLoop ideal_loop( igvn, true);
       loop_opts_cnt--;
       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
       if (failing())  return;
     }
   }
   {
     // Verify that all previous optimizations produced a valid graph
     // at least to this point, even if no loop optimizations were done.
     NOT_PRODUCT( TracePhase t2("idealLoopVerify", &_t_idealLoopVerify, TimeCompiler); )
     PhaseIdealLoop::verify(igvn);
   }
   {
     NOT_PRODUCT( TracePhase t2("macroExpand", &_t_macroExpand, TimeCompiler); )
     PhaseMacroExpand  mex(igvn);
     if (mex.expand_macro_nodes()) {
       assert(failing(), "must bail out w/ explicit message");
       return;
     }
   }
  } // (End scope of igvn; run destructor if necessary for asserts.)
   dump_inlining();
   // A method with only infinite loops has no edges entering loops from root
   {
     NOT_PRODUCT( TracePhase t2("graphReshape", &_t_graphReshaping, TimeCompiler); )
     if (final_graph_reshaping()) {
       assert(failing(), "must bail out w/ explicit message");
       return;
     }
   }
   print_method(PHASE_OPTIMIZE_FINISHED, 2);
 }
 //------------------------------Code_Gen---------------------------------------
 // Given a graph, generate code for it
 void Compile::Code_Gen() {
   if (failing()) {
     return;
   }
   // Perform instruction selection.  You might think we could reclaim Matcher
   // memory PDQ, but actually the Matcher is used in generating spill code.
   // Internals of the Matcher (including some VectorSets) must remain live
   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
   // set a bit in reclaimed memory.
   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
   // nodes.  Mapping is only valid at the root of each matched subtree.
   NOT_PRODUCT( verify_graph_edges(); )
   Matcher matcher;
   _matcher = &matcher;
   {
     TracePhase t2("matcher", &_t_matcher, true);
     matcher.match();
   }
   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
   // nodes.  Mapping is only valid at the root of each matched subtree.
   NOT_PRODUCT( verify_graph_edges(); )
   // If you have too many nodes, or if matching has failed, bail out
   check_node_count(0, "out of nodes matching instructions");
   if (failing()) {
     return;
   }
   // Build a proper-looking CFG
   PhaseCFG cfg(node_arena(), root(), matcher);
   _cfg = &cfg;
   {
     NOT_PRODUCT( TracePhase t2("scheduler", &_t_scheduler, TimeCompiler); )
     bool success = cfg.do_global_code_motion();
     if (!success) {
       return;
     }
     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
     NOT_PRODUCT( verify_graph_edges(); )
     debug_only( cfg.verify(); )
   }
   PhaseChaitin regalloc(unique(), cfg, matcher);
   _regalloc = &regalloc;
   {
     TracePhase t2("regalloc", &_t_registerAllocation, true);
     // Perform register allocation.  After Chaitin, use-def chains are
     // no longer accurate (at spill code) and so must be ignored.
     // Node->LRG->reg mappings are still accurate.
     _regalloc->Register_Allocate();
     // Bail out if the allocator builds too many nodes
     if (failing()) {
       return;
     }
   }
   // Prior to register allocation we kept empty basic blocks in case the
   // the allocator needed a place to spill.  After register allocation we
   // are not adding any new instructions.  If any basic block is empty, we
   // can now safely remove it.
   {
     NOT_PRODUCT( TracePhase t2("blockOrdering", &_t_blockOrdering, TimeCompiler); )
     cfg.remove_empty_blocks();
     if (do_freq_based_layout()) {
       PhaseBlockLayout layout(cfg);
     } else {
       cfg.set_loop_alignment();
     }
     cfg.fixup_flow();
   }
   // Apply peephole optimizations
   if( OptoPeephole ) {
     NOT_PRODUCT( TracePhase t2("peephole", &_t_peephole, TimeCompiler); )
     PhasePeephole peep( _regalloc, cfg);
     peep.do_transform();
   }
   // Convert Nodes to instruction bits in a buffer
   {
     // %%%% workspace merge brought two timers together for one job
     TracePhase t2a("output", &_t_output, true);
     NOT_PRODUCT( TraceTime t2b(NULL, &_t_codeGeneration, TimeCompiler, false); )
     Output();
   }
   print_method(PHASE_FINAL_CODE);
   // He's dead, Jim.
   _cfg     = (PhaseCFG*)0xdeadbeef;
   _regalloc = (PhaseChaitin*)0xdeadbeef;
 }
 //------------------------------dump_asm---------------------------------------
 // Dump formatted assembly
 #ifndef PRODUCT
 void Compile::dump_asm(int *pcs, uint pc_limit) {
   bool cut_short = false;
   tty->print_cr("#");
   tty->print("#  ");  _tf->dump();  tty->cr();
   tty->print_cr("#");
   // For all blocks
   int pc = 0x0;                 // Program counter
   char starts_bundle = ' ';
   _regalloc->dump_frame();
   Node *n = NULL;
   for (uint i = 0; i < _cfg->number_of_blocks(); i++) {
     if (VMThread::should_terminate()) {
       cut_short = true;
       break;
     }
     Block* block = _cfg->get_block(i);
     if (block->is_connector() && !Verbose) {
       continue;
     }
     n = block->head();
     if (pcs && n->_idx < pc_limit) {
       tty->print("%3.3x   ", pcs[n->_idx]);
     } else {
       tty->print("      ");
     }
     block->dump_head(_cfg);
     if (block->is_connector()) {
       tty->print_cr("        # Empty connector block");
     } else if (block->num_preds() == 2 && block->pred(1)->is_CatchProj() && block->pred(1)->as_CatchProj()->_con == CatchProjNode::fall_through_index) {
       tty->print_cr("        # Block is sole successor of call");
     }
     // For all instructions
     Node *delay = NULL;
     for (uint j = 0; j < block->number_of_nodes(); j++) {
       if (VMThread::should_terminate()) {
         cut_short = true;
         break;
       }
       n = block->get_node(j);
       if (valid_bundle_info(n)) {
         Bundle* bundle = node_bundling(n);
         if (bundle->used_in_unconditional_delay()) {
           delay = n;
           continue;
         }
         if (bundle->starts_bundle()) {
           starts_bundle = '+';
         }
       }
       if (WizardMode) {
         n->dump();
       }
       if( !n->is_Region() &&    // Dont print in the Assembly
           !n->is_Phi() &&       // a few noisely useless nodes
           !n->is_Proj() &&
           !n->is_MachTemp() &&
           !n->is_SafePointScalarObject() &&
           !n->is_Catch() &&     // Would be nice to print exception table targets
           !n->is_MergeMem() &&  // Not very interesting
           !n->is_top() &&       // Debug info table constants
           !(n->is_Con() && !n->is_Mach())// Debug info table constants
           ) {
         if (pcs && n->_idx < pc_limit)
           tty->print("%3.3x", pcs[n->_idx]);
         else
           tty->print("   ");
         tty->print(" %c ", starts_bundle);
         starts_bundle = ' ';
         tty->print("\t");
         n->format(_regalloc, tty);
         tty->cr();
       }
       // If we have an instruction with a delay slot, and have seen a delay,
       // then back up and print it
       if (valid_bundle_info(n) && node_bundling(n)->use_unconditional_delay()) {
         assert(delay != NULL, "no unconditional delay instruction");
         if (WizardMode) delay->dump();
         if (node_bundling(delay)->starts_bundle())
           starts_bundle = '+';
         if (pcs && n->_idx < pc_limit)
           tty->print("%3.3x", pcs[n->_idx]);
         else
           tty->print("   ");
         tty->print(" %c ", starts_bundle);
         starts_bundle = ' ';
         tty->print("\t");
         delay->format(_regalloc, tty);
         tty->print_cr("");
         delay = NULL;
       }
       // Dump the exception table as well
       if( n->is_Catch() && (Verbose || WizardMode) ) {
         // Print the exception table for this offset
         _handler_table.print_subtable_for(pc);
       }
     }
     if (pcs && n->_idx < pc_limit)
       tty->print_cr("%3.3x", pcs[n->_idx]);
     else
       tty->print_cr("");
     assert(cut_short || delay == NULL, "no unconditional delay branch");
   } // End of per-block dump
   tty->print_cr("");
   if (cut_short)  tty->print_cr("*** disassembly is cut short ***");
 }
 #endif
 //------------------------------Final_Reshape_Counts---------------------------
 // This class defines counters to help identify when a method
 // may/must be executed using hardware with only 24-bit precision.
 struct Final_Reshape_Counts : public StackObj {
   int  _call_count;             // count non-inlined 'common' calls
   int  _float_count;            // count float ops requiring 24-bit precision
   int  _double_count;           // count double ops requiring more precision
   int  _java_call_count;        // count non-inlined 'java' calls
   int  _inner_loop_count;       // count loops which need alignment
   VectorSet _visited;           // Visitation flags
   Node_List _tests;             // Set of IfNodes & PCTableNodes
   Final_Reshape_Counts() :
     _call_count(0), _float_count(0), _double_count(0),
     _java_call_count(0), _inner_loop_count(0),
     _visited( Thread::current()->resource_area() ) { }
   void inc_call_count  () { _call_count  ++; }
   void inc_float_count () { _float_count ++; }
   void inc_double_count() { _double_count++; }
   void inc_java_call_count() { _java_call_count++; }
   void inc_inner_loop_count() { _inner_loop_count++; }
   int  get_call_count  () const { return _call_count  ; }
   int  get_float_count () const { return _float_count ; }
   int  get_double_count() const { return _double_count; }
   int  get_java_call_count() const { return _java_call_count; }
   int  get_inner_loop_count() const { return _inner_loop_count; }
 };
 #ifdef ASSERT
 static bool oop_offset_is_sane(const TypeInstPtr* tp) {
   ciInstanceKlass *k = tp->klass()->as_instance_klass();
   // Make sure the offset goes inside the instance layout.
   return k->contains_field_offset(tp->offset());
   // Note that OffsetBot and OffsetTop are very negative.
 }
 #endif
 // Eliminate trivially redundant StoreCMs and accumulate their
 // precedence edges.
 void Compile::eliminate_redundant_card_marks(Node* n) {
   assert(n->Opcode() == Op_StoreCM, "expected StoreCM");
   if (n->in(MemNode::Address)->outcnt() > 1) {
     // There are multiple users of the same address so it might be
     // possible to eliminate some of the StoreCMs
     Node* mem = n->in(MemNode::Memory);
     Node* adr = n->in(MemNode::Address);
     Node* val = n->in(MemNode::ValueIn);
     Node* prev = n;
     bool done = false;
     // Walk the chain of StoreCMs eliminating ones that match.  As
     // long as it's a chain of single users then the optimization is
     // safe.  Eliminating partially redundant StoreCMs would require
     // cloning copies down the other paths.
     while (mem->Opcode() == Op_StoreCM && mem->outcnt() == 1 && !done) {
       if (adr == mem->in(MemNode::Address) &&
           val == mem->in(MemNode::ValueIn)) {
         // redundant StoreCM
         if (mem->req() > MemNode::OopStore) {
           // Hasn't been processed by this code yet.
           n->add_prec(mem->in(MemNode::OopStore));
         } else {
           // Already converted to precedence edge
           for (uint i = mem->req(); i < mem->len(); i++) {
             // Accumulate any precedence edges
             if (mem->in(i) != NULL) {
               n->add_prec(mem->in(i));
             }
           }
           // Everything above this point has been processed.
           done = true;
         }
         // Eliminate the previous StoreCM
         prev->set_req(MemNode::Memory, mem->in(MemNode::Memory));
         assert(mem->outcnt() == 0, "should be dead");
         mem->disconnect_inputs(NULL, this);
       } else {
         prev = mem;
       }
       mem = prev->in(MemNode::Memory);
     }
   }
 }
 //------------------------------final_graph_reshaping_impl----------------------
 // Implement items 1-5 from final_graph_reshaping below.
 void Compile::final_graph_reshaping_impl( Node *n, Final_Reshape_Counts &frc) {
   if ( n->outcnt() == 0 ) return; // dead node
   uint nop = n->Opcode();
   // Check for 2-input instruction with "last use" on right input.
   // Swap to left input.  Implements item (2).
   if( n->req() == 3 &&          // two-input instruction
       n->in(1)->outcnt() > 1 && // left use is NOT a last use
       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
       n->in(2)->outcnt() == 1 &&// right use IS a last use
       !n->in(2)->is_Con() ) {   // right use is not a constant
     // Check for commutative opcode
     switch( nop ) {
     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddL:
     case Op_MaxI:  case Op_MinI:
     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulL:
     case Op_AndL:  case Op_XorL:  case Op_OrL:
     case Op_AndI:  case Op_XorI:  case Op_OrI: {
       // Move "last use" input to left by swapping inputs
       n->swap_edges(1, 2);
       break;
     }
     default:
       break;
     }
   }
 #ifdef ASSERT
   if( n->is_Mem() ) {
     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
     assert( n->in(0) != NULL || alias_idx != Compile::AliasIdxRaw ||
             // oop will be recorded in oop map if load crosses safepoint
             n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
                              LoadNode::is_immutable_value(n->in(MemNode::Address))),
             "raw memory operations should have control edge");
   }
 #endif
   // Count FPU ops and common calls, implements item (3)
   switch( nop ) {
   // Count all float operations that may use FPU
   case Op_AddF:
   case Op_SubF:
   case Op_MulF:
   case Op_DivF:
   case Op_NegF:
   case Op_ModF:
   case Op_ConvI2F:
   case Op_ConF:
   case Op_CmpF:
   case Op_CmpF3:
   // case Op_ConvL2F: // longs are split into 32-bit halves
     frc.inc_float_count();
     break;
   case Op_ConvF2D:
   case Op_ConvD2F:
     frc.inc_float_count();
     frc.inc_double_count();
     break;
   // Count all double operations that may use FPU
   case Op_AddD:
   case Op_SubD:
   case Op_MulD:
   case Op_DivD:
   case Op_NegD:
   case Op_ModD:
   case Op_ConvI2D:
   case Op_ConvD2I:
   // case Op_ConvL2D: // handled by leaf call
   // case Op_ConvD2L: // handled by leaf call
   case Op_ConD:
   case Op_CmpD:
   case Op_CmpD3:
     frc.inc_double_count();
     break;
   case Op_Opaque1:              // Remove Opaque Nodes before matching
   case Op_Opaque2:              // Remove Opaque Nodes before matching
     n->subsume_by(n->in(1), this);
     break;
   case Op_CallStaticJava:
   case Op_CallJava:
   case Op_CallDynamicJava:
     frc.inc_java_call_count(); // Count java call site;
   case Op_CallRuntime:
   case Op_CallLeaf:
   case Op_CallLeafNoFP: {
     assert( n->is_Call(), "" );
     CallNode *call = n->as_Call();
     // Count call sites where the FP mode bit would have to be flipped.
     // Do not count uncommon runtime calls:
     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
     if( !call->is_CallStaticJava() || !call->as_CallStaticJava()->_name ) {
       frc.inc_call_count();   // Count the call site
     } else {                  // See if uncommon argument is shared
       Node *n = call->in(TypeFunc::Parms);
       int nop = n->Opcode();
       // Clone shared simple arguments to uncommon calls, item (1).
       if( n->outcnt() > 1 &&
           !n->is_Proj() &&
           nop != Op_CreateEx &&
           nop != Op_CheckCastPP &&
           nop != Op_DecodeN &&
           nop != Op_DecodeNKlass &&
           !n->is_Mem() ) {
         Node *x = n->clone();
         call->set_req( TypeFunc::Parms, x );
       }
     }
     break;
   }
   case Op_StoreD:
   case Op_LoadD:
   case Op_LoadD_unaligned:
     frc.inc_double_count();
     goto handle_mem;
   case Op_StoreF:
   case Op_LoadF:
     frc.inc_float_count();
     goto handle_mem;
   case Op_StoreCM:
     {
       // Convert OopStore dependence into precedence edge
       Node* prec = n->in(MemNode::OopStore);
       n->del_req(MemNode::OopStore);
       n->add_prec(prec);
       eliminate_redundant_card_marks(n);
     }
     // fall through
   case Op_StoreB:
   case Op_StoreC:
   case Op_StorePConditional:
   case Op_StoreI:
   case Op_StoreL:
   case Op_StoreIConditional:
   case Op_StoreLConditional:
   case Op_CompareAndSwapI:
   case Op_CompareAndSwapL:
   case Op_CompareAndSwapP:
   case Op_CompareAndSwapN:
   case Op_GetAndAddI:
   case Op_GetAndAddL:
   case Op_GetAndSetI:
   case Op_GetAndSetL:
   case Op_GetAndSetP:
   case Op_GetAndSetN:
   case Op_StoreP:
   case Op_StoreN:
   case Op_StoreNKlass:
   case Op_LoadB:
   case Op_LoadUB:
   case Op_LoadUS:
   case Op_LoadI:
   case Op_LoadKlass:
   case Op_LoadNKlass:
   case Op_LoadL:
   case Op_LoadL_unaligned:
   case Op_LoadPLocked:
   case Op_LoadP:
   case Op_LoadN:
   case Op_LoadRange:
   case Op_LoadS: {
   handle_mem:
 #ifdef ASSERT
     if( VerifyOptoOopOffsets ) {
       assert( n->is_Mem(), "" );
       MemNode *mem  = (MemNode*)n;
       // Check to see if address types have grounded out somehow.
       const TypeInstPtr *tp = mem->in(MemNode::Address)->bottom_type()->isa_instptr();
       assert( !tp || oop_offset_is_sane(tp), "" );
     }
 #endif
     break;
   }
   case Op_AddP: {               // Assert sane base pointers
     Node *addp = n->in(AddPNode::Address);
     assert( !addp->is_AddP() ||
             addp->in(AddPNode::Base)->is_top() || // Top OK for allocation
             addp->in(AddPNode::Base) == n->in(AddPNode::Base),
             "Base pointers must match" );
 #ifdef _LP64
     if ((UseCompressedOops || UseCompressedClassPointers) &&
         addp->Opcode() == Op_ConP &&
         addp == n->in(AddPNode::Base) &&
         n->in(AddPNode::Offset)->is_Con()) {
       // Use addressing with narrow klass to load with offset on x86.
       // On sparc loading 32-bits constant and decoding it have less
       // instructions (4) then load 64-bits constant (7).
       // Do this transformation here since IGVN will convert ConN back to ConP.
       const Type* t = addp->bottom_type();
       if (t->isa_oopptr() || t->isa_klassptr()) {
         Node* nn = NULL;
         int op = t->isa_oopptr() ? Op_ConN : Op_ConNKlass;
         // Look for existing ConN node of the same exact type.
         Node* r  = root();
         uint cnt = r->outcnt();
         for (uint i = 0; i < cnt; i++) {
           Node* m = r->raw_out(i);
           if (m!= NULL && m->Opcode() == op &&
               m->bottom_type()->make_ptr() == t) {
             nn = m;
             break;
           }
         }
         if (nn != NULL) {
           // Decode a narrow oop to match address
           // [R12 + narrow_oop_reg<<3 + offset]
           if (t->isa_oopptr()) {
             nn = new (this) DecodeNNode(nn, t);
           } else {
             nn = new (this) DecodeNKlassNode(nn, t);
           }
           n->set_req(AddPNode::Base, nn);
           n->set_req(AddPNode::Address, nn);
           if (addp->outcnt() == 0) {
             addp->disconnect_inputs(NULL, this);
           }
         }
       }
     }
 #endif
     break;
   }
 #ifdef _LP64
   case Op_CastPP:
     if (n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
       Node* in1 = n->in(1);
       const Type* t = n->bottom_type();
       Node* new_in1 = in1->clone();
       new_in1->as_DecodeN()->set_type(t);
       if (!Matcher::narrow_oop_use_complex_address()) {
         //
         // x86, ARM and friends can handle 2 adds in addressing mode
         // and Matcher can fold a DecodeN node into address by using
         // a narrow oop directly and do implicit NULL check in address:
         //
         // [R12 + narrow_oop_reg<<3 + offset]
         // NullCheck narrow_oop_reg
         //
         // On other platforms (Sparc) we have to keep new DecodeN node and
         // use it to do implicit NULL check in address:
         //
         // decode_not_null narrow_oop_reg, base_reg
         // [base_reg + offset]
         // NullCheck base_reg
         //
         // Pin the new DecodeN node to non-null path on these platform (Sparc)
         // to keep the information to which NULL check the new DecodeN node
         // corresponds to use it as value in implicit_null_check().
         //
         new_in1->set_req(0, n->in(0));
       }
       n->subsume_by(new_in1, this);
       if (in1->outcnt() == 0) {
         in1->disconnect_inputs(NULL, this);
       }
     }
     break;
   case Op_CmpP:
     // Do this transformation here to preserve CmpPNode::sub() and
     // other TypePtr related Ideal optimizations (for example, ptr nullness).
     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
       Node* in1 = n->in(1);
       Node* in2 = n->in(2);
       if (!in1->is_DecodeNarrowPtr()) {
         in2 = in1;
         in1 = n->in(2);
       }
       assert(in1->is_DecodeNarrowPtr(), "sanity");
       Node* new_in2 = NULL;
       if (in2->is_DecodeNarrowPtr()) {
         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
         new_in2 = in2->in(1);
       } else if (in2->Opcode() == Op_ConP) {
         const Type* t = in2->bottom_type();
         if (t == TypePtr::NULL_PTR) {
           assert(in1->is_DecodeN(), "compare klass to null?");
           // Don't convert CmpP null check into CmpN if compressed
           // oops implicit null check is not generated.
           // This will allow to generate normal oop implicit null check.
           if (Matcher::gen_narrow_oop_implicit_null_checks())
             new_in2 = ConNode::make(this, TypeNarrowOop::NULL_PTR);
           //
           // This transformation together with CastPP transformation above
           // will generated code for implicit NULL checks for compressed oops.
           //
           // The original code after Optimize()
           //
           //    LoadN memory, narrow_oop_reg
           //    decode narrow_oop_reg, base_reg
           //    CmpP base_reg, NULL
           //    CastPP base_reg // NotNull
           //    Load [base_reg + offset], val_reg
           //
           // after these transformations will be
           //
           //    LoadN memory, narrow_oop_reg
           //    CmpN narrow_oop_reg, NULL
           //    decode_not_null narrow_oop_reg, base_reg
           //    Load [base_reg + offset], val_reg
           //
           // and the uncommon path (== NULL) will use narrow_oop_reg directly
           // since narrow oops can be used in debug info now (see the code in
           // final_graph_reshaping_walk()).
           //
           // At the end the code will be matched to
           // on x86:
           //
           //    Load_narrow_oop memory, narrow_oop_reg
           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
           //    NullCheck narrow_oop_reg
           //
           // and on sparc:
           //
           //    Load_narrow_oop memory, narrow_oop_reg
           //    decode_not_null narrow_oop_reg, base_reg
           //    Load [base_reg + offset], val_reg
           //    NullCheck base_reg
           //
         } else if (t->isa_oopptr()) {
           new_in2 = ConNode::make(this, t->make_narrowoop());
         } else if (t->isa_klassptr()) {
           new_in2 = ConNode::make(this, t->make_narrowklass());
         }
       }
       if (new_in2 != NULL) {
         Node* cmpN = new (this) CmpNNode(in1->in(1), new_in2);
         n->subsume_by(cmpN, this);
         if (in1->outcnt() == 0) {
           in1->disconnect_inputs(NULL, this);
         }
         if (in2->outcnt() == 0) {
           in2->disconnect_inputs(NULL, this);
         }
       }
     }
     break;
   case Op_DecodeN:
   case Op_DecodeNKlass:
     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
     // DecodeN could be pinned when it can't be fold into
     // an address expression, see the code for Op_CastPP above.
     assert(n->in(0) == NULL || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
     break;
   case Op_EncodeP:
   case Op_EncodePKlass: {
     Node* in1 = n->in(1);
     if (in1->is_DecodeNarrowPtr()) {
       n->subsume_by(in1->in(1), this);
     } else if (in1->Opcode() == Op_ConP) {
       const Type* t = in1->bottom_type();
       if (t == TypePtr::NULL_PTR) {
         assert(t->isa_oopptr(), "null klass?");
         n->subsume_by(ConNode::make(this, TypeNarrowOop::NULL_PTR), this);
       } else if (t->isa_oopptr()) {
         n->subsume_by(ConNode::make(this, t->make_narrowoop()), this);
       } else if (t->isa_klassptr()) {
         n->subsume_by(ConNode::make(this, t->make_narrowklass()), this);
       }
     }
     if (in1->outcnt() == 0) {
       in1->disconnect_inputs(NULL, this);
     }
     break;
   }
   case Op_Proj: {
     if (OptimizeStringConcat) {
       ProjNode* p = n->as_Proj();
       if (p->_is_io_use) {
         // Separate projections were used for the exception path which
         // are normally removed by a late inline.  If it wasn't inlined
         // then they will hang around and should just be replaced with
         // the original one.
         Node* proj = NULL;
         // Replace with just one
         for (SimpleDUIterator i(p->in(0)); i.has_next(); i.next()) {
           Node *use = i.get();
           if (use->is_Proj() && p != use && use->as_Proj()->_con == p->_con) {
             proj = use;
             break;
           }
         }
         assert(proj != NULL, "must be found");
         p->subsume_by(proj, this);
       }
     }
     break;
   }
   case Op_Phi:
     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
       // The EncodeP optimization may create Phi with the same edges
       // for all paths. It is not handled well by Register Allocator.
       Node* unique_in = n->in(1);
       assert(unique_in != NULL, "");
       uint cnt = n->req();
       for (uint i = 2; i < cnt; i++) {
         Node* m = n->in(i);
         assert(m != NULL, "");
         if (unique_in != m)
           unique_in = NULL;
       }
       if (unique_in != NULL) {
         n->subsume_by(unique_in, this);
       }
     }
     break;
 #endif
   case Op_ModI:
     if (UseDivMod) {
       // Check if a%b and a/b both exist
       Node* d = n->find_similar(Op_DivI);
       if (d) {
         // Replace them with a fused divmod if supported
         if (Matcher::has_match_rule(Op_DivModI)) {
           DivModINode* divmod = DivModINode::make(this, n);
           d->subsume_by(divmod->div_proj(), this);
           n->subsume_by(divmod->mod_proj(), this);
         } else {
           // replace a%b with a-((a/b)*b)
           Node* mult = new (this) MulINode(d, d->in(2));
           Node* sub  = new (this) SubINode(d->in(1), mult);
           n->subsume_by(sub, this);
         }
       }
     }
     break;
   case Op_ModL:
     if (UseDivMod) {
       // Check if a%b and a/b both exist
       Node* d = n->find_similar(Op_DivL);
       if (d) {
         // Replace them with a fused divmod if supported
         if (Matcher::has_match_rule(Op_DivModL)) {
           DivModLNode* divmod = DivModLNode::make(this, n);
           d->subsume_by(divmod->div_proj(), this);
           n->subsume_by(divmod->mod_proj(), this);
         } else {
           // replace a%b with a-((a/b)*b)
           Node* mult = new (this) MulLNode(d, d->in(2));
           Node* sub  = new (this) SubLNode(d->in(1), mult);
           n->subsume_by(sub, this);
         }
       }
     }
     break;
   case Op_LoadVector:
   case Op_StoreVector:
     break;
   case Op_PackB:
   case Op_PackS:
   case Op_PackI:
   case Op_PackF:
   case Op_PackL:
   case Op_PackD:
     if (n->req()-1 > 2) {
       // Replace many operand PackNodes with a binary tree for matching
       PackNode* p = (PackNode*) n;
       Node* btp = p->binary_tree_pack(this, 1, n->req());
       n->subsume_by(btp, this);
     }
     break;
   case Op_Loop:
   case Op_CountedLoop:
     if (n->as_Loop()->is_inner_loop()) {
       frc.inc_inner_loop_count();
     }
     break;
   case Op_LShiftI:
   case Op_RShiftI:
   case Op_URShiftI:
   case Op_LShiftL:
   case Op_RShiftL:
   case Op_URShiftL:
     if (Matcher::need_masked_shift_count) {
       // The cpu's shift instructions don't restrict the count to the
       // lower 5/6 bits. We need to do the masking ourselves.
       Node* in2 = n->in(2);
       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
       const TypeInt* t = in2->find_int_type();
       if (t != NULL && t->is_con()) {
         juint shift = t->get_con();
         if (shift > mask) { // Unsigned cmp
           n->set_req(2, ConNode::make(this, TypeInt::make(shift & mask)));
         }
       } else {
         if (t == NULL || t->_lo < 0 || t->_hi > (int)mask) {
           Node* shift = new (this) AndINode(in2, ConNode::make(this, TypeInt::make(mask)));
           n->set_req(2, shift);
         }
       }
       if (in2->outcnt() == 0) { // Remove dead node
         in2->disconnect_inputs(NULL, this);
       }
     }
     break;
   case Op_MemBarStoreStore:
   case Op_MemBarRelease:
     // Break the link with AllocateNode: it is no longer useful and
     // confuses register allocation.
     if (n->req() > MemBarNode::Precedent) {
       n->set_req(MemBarNode::Precedent, top());
     }
     break;
     // Must set a control edge on all nodes that produce a FlagsProj
     // so they can't escape the block that consumes the flags.
     // Must also set the non throwing branch as the control
     // for all nodes that depends on the result. Unless the node
     // already have a control that isn't the control of the
     // flag producer
   case Op_FlagsProj:
     {
       MathExactNode* math = (MathExactNode*)  n->in(0);
       Node* ctrl = math->control_node();
       Node* non_throwing = math->non_throwing_branch();
       math->set_req(0, ctrl);
       Node* result = math->result_node();
       if (result != NULL) {
         for (DUIterator_Fast jmax, j = result->fast_outs(jmax); j < jmax; j++) {
           Node* out = result->fast_out(j);
           // Phi nodes shouldn't be moved. They would only match below if they
           // had the same control as the MathExactNode. The only time that
           // would happen is if the Phi is also an input to the MathExact
           //
           // Cmp nodes shouldn't have control set at all.
           if (out->is_Phi() ||
               out->is_Cmp()) {
             continue;
           }
           if (out->in(0) == NULL) {
             out->set_req(0, non_throwing);
           } else if (out->in(0) == ctrl) {
             out->set_req(0, non_throwing);
           }
         }
       }
     }
     break;
   default:
     assert( !n->is_Call(), "" );
     assert( !n->is_Mem(), "" );
     break;
   }
   // Collect CFG split points
   if (n->is_MultiBranch())
     frc._tests.push(n);
 }
 //------------------------------final_graph_reshaping_walk---------------------
 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
 // requires that the walk visits a node's inputs before visiting the node.
 void Compile::final_graph_reshaping_walk( Node_Stack &nstack, Node *root, Final_Reshape_Counts &frc ) {
   ResourceArea *area = Thread::current()->resource_area();
   Unique_Node_List sfpt(area);
   frc._visited.set(root->_idx); // first, mark node as visited
   uint cnt = root->req();
   Node *n = root;
   uint  i = 0;
   while (true) {
     if (i < cnt) {
       // Place all non-visited non-null inputs onto stack
       Node* m = n->in(i);
       ++i;
       if (m != NULL && !frc._visited.test_set(m->_idx)) {
         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != NULL)
           sfpt.push(m);
         cnt = m->req();
         nstack.push(n, i); // put on stack parent and next input's index
         n = m;
         i = 0;
       }
     } else {
       // Now do post-visit work
       final_graph_reshaping_impl( n, frc );
       if (nstack.is_empty())
         break;             // finished
       n = nstack.node();   // Get node from stack
       cnt = n->req();
       i = nstack.index();
       nstack.pop();        // Shift to the next node on stack
     }
   }
   // Skip next transformation if compressed oops are not used.
   if ((UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks()) ||
       (!UseCompressedOops && !UseCompressedClassPointers))
     return;
   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
   // It could be done for an uncommon traps or any safepoints/calls
   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
   while (sfpt.size() > 0) {
     n = sfpt.pop();
     JVMState *jvms = n->as_SafePoint()->jvms();
     assert(jvms != NULL, "sanity");
     int start = jvms->debug_start();
     int end   = n->req();
     bool is_uncommon = (n->is_CallStaticJava() &&
                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
     for (int j = start; j < end; j++) {
       Node* in = n->in(j);
       if (in->is_DecodeNarrowPtr()) {
         bool safe_to_skip = true;
         if (!is_uncommon ) {
           // Is it safe to skip?
           for (uint i = 0; i < in->outcnt(); i++) {
             Node* u = in->raw_out(i);
             if (!u->is_SafePoint() ||
                  u->is_Call() && u->as_Call()->has_non_debug_use(n)) {
               safe_to_skip = false;
             }
           }
         }
         if (safe_to_skip) {
           n->set_req(j, in->in(1));
         }
         if (in->outcnt() == 0) {
           in->disconnect_inputs(NULL, this);
         }
       }
     }
   }
 }
 //------------------------------final_graph_reshaping--------------------------
 // Final Graph Reshaping.
 //
 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
 //     and not commoned up and forced early.  Must come after regular
 //     optimizations to avoid GVN undoing the cloning.  Clone constant
 //     inputs to Loop Phis; these will be split by the allocator anyways.
 //     Remove Opaque nodes.
 // (2) Move last-uses by commutative operations to the left input to encourage
 //     Intel update-in-place two-address operations and better register usage
 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
 //     calls canonicalizing them back.
 // (3) Count the number of double-precision FP ops, single-precision FP ops
 //     and call sites.  On Intel, we can get correct rounding either by
 //     forcing singles to memory (requires extra stores and loads after each
 //     FP bytecode) or we can set a rounding mode bit (requires setting and
 //     clearing the mode bit around call sites).  The mode bit is only used
 //     if the relative frequency of single FP ops to calls is low enough.
 //     This is a key transform for SPEC mpeg_audio.
 // (4) Detect infinite loops; blobs of code reachable from above but not
 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
 //     Detection is by looking for IfNodes where only 1 projection is
 //     reachable from below or CatchNodes missing some targets.
 // (5) Assert for insane oop offsets in debug mode.
 bool Compile::final_graph_reshaping() {
   // an infinite loop may have been eliminated by the optimizer,
   // in which case the graph will be empty.
   if (root()->req() == 1) {
     record_method_not_compilable("trivial infinite loop");
     return true;
   }
   // Expensive nodes have their control input set to prevent the GVN
   // from freely commoning them. There's no GVN beyond this point so
   // no need to keep the control input. We want the expensive nodes to
   // be freely moved to the least frequent code path by gcm.
   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
   for (int i = 0; i < expensive_count(); i++) {
     _expensive_nodes->at(i)->set_req(0, NULL);
   }
   Final_Reshape_Counts frc;
   // Visit everybody reachable!
   // Allocate stack of size C->unique()/2 to avoid frequent realloc
   Node_Stack nstack(unique() >> 1);
   final_graph_reshaping_walk(nstack, root(), frc);
   // Check for unreachable (from below) code (i.e., infinite loops).
   for( uint i = 0; i < frc._tests.size(); i++ ) {
     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
     // Get number of CFG targets.
     // Note that PCTables include exception targets after calls.
     uint required_outcnt = n->required_outcnt();
     if (n->outcnt() != required_outcnt) {
       // Check for a few special cases.  Rethrow Nodes never take the
       // 'fall-thru' path, so expected kids is 1 less.
       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
         if (n->in(0)->in(0)->is_Call()) {
           CallNode *call = n->in(0)->in(0)->as_Call();
           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
             required_outcnt--;      // Rethrow always has 1 less kid
           } else if (call->req() > TypeFunc::Parms &&
                      call->is_CallDynamicJava()) {
             // Check for null receiver. In such case, the optimizer has
             // detected that the virtual call will always result in a null
             // pointer exception. The fall-through projection of this CatchNode
             // will not be populated.
             Node *arg0 = call->in(TypeFunc::Parms);
             if (arg0->is_Type() &&
                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
               required_outcnt--;
             }
           } else if (call->entry_point() == OptoRuntime::new_array_Java() &&
                      call->req() > TypeFunc::Parms+1 &&
                      call->is_CallStaticJava()) {
             // Check for negative array length. In such case, the optimizer has
             // detected that the allocation attempt will always result in an
             // exception. There is no fall-through projection of this CatchNode .
             Node *arg1 = call->in(TypeFunc::Parms+1);
             if (arg1->is_Type() &&
                 arg1->as_Type()->type()->join(TypeInt::POS)->empty()) {
               required_outcnt--;
             }
           }
         }
       }
       // Recheck with a better notion of 'required_outcnt'
       if (n->outcnt() != required_outcnt) {
         record_method_not_compilable("malformed control flow");
         return true;            // Not all targets reachable!
       }
     }
     // Check that I actually visited all kids.  Unreached kids
     // must be infinite loops.
     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
       if (!frc._visited.test(n->fast_out(j)->_idx)) {
         record_method_not_compilable("infinite loop");
         return true;            // Found unvisited kid; must be unreach
       }
   }
   // If original bytecodes contained a mixture of floats and doubles
   // check if the optimizer has made it homogenous, item (3).
   if( Use24BitFPMode && Use24BitFP && UseSSE == 0 &&
       frc.get_float_count() > 32 &&
       frc.get_double_count() == 0 &&
       (10 * frc.get_call_count() < frc.get_float_count()) ) {
     set_24_bit_selection_and_mode( false,  true );
   }
   set_java_calls(frc.get_java_call_count());
   set_inner_loops(frc.get_inner_loop_count());
   // No infinite loops, no reason to bail out.
   return false;
 }
 //-----------------------------too_many_traps----------------------------------
 // Report if there are too many traps at the current method and bci.
 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
 bool Compile::too_many_traps(ciMethod* method,
                              int bci,
                              Deoptimization::DeoptReason reason) {
   ciMethodData* md = method->method_data();
   if (md->is_empty()) {
     // Assume the trap has not occurred, or that it occurred only
     // because of a transient condition during start-up in the interpreter.
     return false;
   }
   if (md->has_trap_at(bci, reason) != 0) {
     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
     // Also, if there are multiple reasons, or if there is no per-BCI record,
     // assume the worst.
     if (log())
       log()->elem("observe trap='%s' count='%d'",
                   Deoptimization::trap_reason_name(reason),
                   md->trap_count(reason));
     return true;
   } else {
     // Ignore method/bci and see if there have been too many globally.
     return too_many_traps(reason, md);
   }
 }
 // Less-accurate variant which does not require a method and bci.
 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
                              ciMethodData* logmd) {
  if (trap_count(reason) >= (uint)PerMethodTrapLimit) {
     // Too many traps globally.
     // Note that we use cumulative trap_count, not just md->trap_count.
     if (log()) {
       int mcount = (logmd == NULL)? -1: (int)logmd->trap_count(reason);
       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
                   Deoptimization::trap_reason_name(reason),
                   mcount, trap_count(reason));
     }
     return true;
   } else {
     // The coast is clear.
     return false;
   }
 }
 //--------------------------too_many_recompiles--------------------------------
 // Report if there are too many recompiles at the current method and bci.
 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
 // Is not eager to return true, since this will cause the compiler to use
 // Action_none for a trap point, to avoid too many recompilations.
 bool Compile::too_many_recompiles(ciMethod* method,
                                   int bci,
                                   Deoptimization::DeoptReason reason) {
   ciMethodData* md = method->method_data();
   if (md->is_empty()) {
     // Assume the trap has not occurred, or that it occurred only
     // because of a transient condition during start-up in the interpreter.
     return false;
   }
   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
   Deoptimization::DeoptReason per_bc_reason
     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
   if ((per_bc_reason == Deoptimization::Reason_none
        || md->has_trap_at(bci, reason) != 0)
       // The trap frequency measure we care about is the recompile count:
       && md->trap_recompiled_at(bci)
       && md->overflow_recompile_count() >= bc_cutoff) {
     // Do not emit a trap here if it has already caused recompilations.
     // Also, if there are multiple reasons, or if there is no per-BCI record,
     // assume the worst.
     if (log())
       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
                   Deoptimization::trap_reason_name(reason),
                   md->trap_count(reason),
                   md->overflow_recompile_count());
     return true;
   } else if (trap_count(reason) != 0
              && decompile_count() >= m_cutoff) {
     // Too many recompiles globally, and we have seen this sort of trap.
     // Use cumulative decompile_count, not just md->decompile_count.
     if (log())
       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
                   Deoptimization::trap_reason_name(reason),
                   md->trap_count(reason), trap_count(reason),
                   md->decompile_count(), decompile_count());
     return true;
   } else {
     // The coast is clear.
     return false;
   }
 }
 #ifndef PRODUCT
 //------------------------------verify_graph_edges---------------------------
 // Walk the Graph and verify that there is a one-to-one correspondence
 // between Use-Def edges and Def-Use edges in the graph.
 void Compile::verify_graph_edges(bool no_dead_code) {
   if (VerifyGraphEdges) {
     ResourceArea *area = Thread::current()->resource_area();
     Unique_Node_List visited(area);
     // Call recursive graph walk to check edges
     _root->verify_edges(visited);
     if (no_dead_code) {
       // Now make sure that no visited node is used by an unvisited node.
       bool dead_nodes = 0;
       Unique_Node_List checked(area);
       while (visited.size() > 0) {
         Node* n = visited.pop();
         checked.push(n);
         for (uint i = 0; i < n->outcnt(); i++) {
           Node* use = n->raw_out(i);
           if (checked.member(use))  continue;  // already checked
           if (visited.member(use))  continue;  // already in the graph
           if (use->is_Con())        continue;  // a dead ConNode is OK
           // At this point, we have found a dead node which is DU-reachable.
           if (dead_nodes++ == 0)
             tty->print_cr("*** Dead nodes reachable via DU edges:");
           use->dump(2);
           tty->print_cr("---");
           checked.push(use);  // No repeats; pretend it is now checked.
         }
       }
       assert(dead_nodes == 0, "using nodes must be reachable from root");
     }
   }
 }
 // Verify GC barriers consistency
 // Currently supported:
 // - G1 pre-barriers (see GraphKit::g1_write_barrier_pre())
 void Compile::verify_barriers() {
   if (UseG1GC) {
     // Verify G1 pre-barriers
     const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active());
     ResourceArea *area = Thread::current()->resource_area();
     Unique_Node_List visited(area);
     Node_List worklist(area);
     // We're going to walk control flow backwards starting from the Root
     worklist.push(_root);
     while (worklist.size() > 0) {
       Node* x = worklist.pop();
       if (x == NULL || x == top()) continue;
       if (visited.member(x)) {
         continue;
       } else {
         visited.push(x);
       }
       if (x->is_Region()) {
         for (uint i = 1; i < x->req(); i++) {
           worklist.push(x->in(i));
         }
       } else {
         worklist.push(x->in(0));
         // We are looking for the pattern:
         //                            /->ThreadLocal
         // If->Bool->CmpI->LoadB->AddP->ConL(marking_offset)
         //              \->ConI(0)
         // We want to verify that the If and the LoadB have the same control
         // See GraphKit::g1_write_barrier_pre()
         if (x->is_If()) {
           IfNode *iff = x->as_If();
           if (iff->in(1)->is_Bool() && iff->in(1)->in(1)->is_Cmp()) {
             CmpNode *cmp = iff->in(1)->in(1)->as_Cmp();
             if (cmp->Opcode() == Op_CmpI && cmp->in(2)->is_Con() && cmp->in(2)->bottom_type()->is_int()->get_con() == 0
                 && cmp->in(1)->is_Load()) {
               LoadNode* load = cmp->in(1)->as_Load();
               if (load->Opcode() == Op_LoadB && load->in(2)->is_AddP() && load->in(2)->in(2)->Opcode() == Op_ThreadLocal
                   && load->in(2)->in(3)->is_Con()
                   && load->in(2)->in(3)->bottom_type()->is_intptr_t()->get_con() == marking_offset) {
                 Node* if_ctrl = iff->in(0);
                 Node* load_ctrl = load->in(0);
                 if (if_ctrl != load_ctrl) {
                   // Skip possible CProj->NeverBranch in infinite loops
                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
                       && (if_ctrl->in(0)->is_MultiBranch() && if_ctrl->in(0)->Opcode() == Op_NeverBranch)) {
                     if_ctrl = if_ctrl->in(0)->in(0);
                   }
                 }
                 assert(load_ctrl != NULL && if_ctrl == load_ctrl, "controls must match");
               }
             }
           }
         }
       }
     }
   }
 }
 #endif
 // The Compile object keeps track of failure reasons separately from the ciEnv.
 // This is required because there is not quite a 1-1 relation between the
 // ciEnv and its compilation task and the Compile object.  Note that one
 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
 // to backtrack and retry without subsuming loads.  Other than this backtracking
 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
 // by the logic in C2Compiler.
 void Compile::record_failure(const char* reason) {
   if (log() != NULL) {
     log()->elem("failure reason='%s' phase='compile'", reason);
   }
   if (_failure_reason == NULL) {
     // Record the first failure reason.
     _failure_reason = reason;
   }
   EventCompilerFailure event;
   if (event.should_commit()) {
     event.set_compileID(Compile::compile_id());
     event.set_failure(reason);
     event.commit();
   }
   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
     C->print_method(PHASE_FAILURE);
   }
   _root = NULL;  // flush the graph, too
 }
 Compile::TracePhase::TracePhase(const char* name, elapsedTimer* accumulator, bool dolog)
   : TraceTime(NULL, accumulator, false NOT_PRODUCT( || TimeCompiler ), false),
     _phase_name(name), _dolog(dolog)
 {
   if (dolog) {
     C = Compile::current();
     _log = C->log();
   } else {
     C = NULL;
     _log = NULL;
   }
   if (_log != NULL) {
     _log->begin_head("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
     _log->stamp();
     _log->end_head();
   }
 }
 Compile::TracePhase::~TracePhase() {
   C = Compile::current();
   if (_dolog) {
     _log = C->log();
   } else {
     _log = NULL;
   }
 #ifdef ASSERT
   if (PrintIdealNodeCount) {
     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
                   _phase_name, C->unique(), C->live_nodes(), C->count_live_nodes_by_graph_walk());
   }
   if (VerifyIdealNodeCount) {
     Compile::current()->print_missing_nodes();
   }
 #endif
   if (_log != NULL) {
     _log->done("phase name='%s' nodes='%d' live='%d'", _phase_name, C->unique(), C->live_nodes());
   }
 }
 //=============================================================================
 // Two Constant's are equal when the type and the value are equal.
 bool Compile::Constant::operator==(const Constant& other) {
   if (type()          != other.type()         )  return false;
   if (can_be_reused() != other.can_be_reused())  return false;
   // For floating point values we compare the bit pattern.
   switch (type()) {
   case T_FLOAT:   return (_v._value.i == other._v._value.i);
   case T_LONG:
   case T_DOUBLE:  return (_v._value.j == other._v._value.j);
   case T_OBJECT:
   case T_ADDRESS: return (_v._value.l == other._v._value.l);
   case T_VOID:    return (_v._value.l == other._v._value.l);  // jump-table entries
   case T_METADATA: return (_v._metadata == other._v._metadata);
   default: ShouldNotReachHere();
   }
   return false;
 }
 static int type_to_size_in_bytes(BasicType t) {
   switch (t) {
   case T_LONG:    return sizeof(jlong  );
   case T_FLOAT:   return sizeof(jfloat );
   case T_DOUBLE:  return sizeof(jdouble);
   case T_METADATA: return sizeof(Metadata*);
     // We use T_VOID as marker for jump-table entries (labels) which
     // need an internal word relocation.
   case T_VOID:
   case T_ADDRESS:
   case T_OBJECT:  return sizeof(jobject);
   }
   ShouldNotReachHere();
   return -1;
 }
 int Compile::ConstantTable::qsort_comparator(Constant* a, Constant* b) {
   // sort descending
   if (a->freq() > b->freq())  return -1;
   if (a->freq() < b->freq())  return  1;
   return 0;
 }
 void Compile::ConstantTable::calculate_offsets_and_size() {
   // First, sort the array by frequencies.
   _constants.sort(qsort_comparator);
 #ifdef ASSERT
   // Make sure all jump-table entries were sorted to the end of the
   // array (they have a negative frequency).
   bool found_void = false;
   for (int i = 0; i < _constants.length(); i++) {
     Constant con = _constants.at(i);
     if (con.type() == T_VOID)
       found_void = true;  // jump-tables
     else
       assert(!found_void, "wrong sorting");
   }
 #endif
   int offset = 0;
   for (int i = 0; i < _constants.length(); i++) {
     Constant* con = _constants.adr_at(i);
     // Align offset for type.
     int typesize = type_to_size_in_bytes(con->type());
     offset = align_size_up(offset, typesize);
     con->set_offset(offset);   // set constant's offset
     if (con->type() == T_VOID) {
       MachConstantNode* n = (MachConstantNode*) con->get_jobject();
       offset = offset + typesize * n->outcnt();  // expand jump-table
     } else {
       offset = offset + typesize;
     }
   }
   // Align size up to the next section start (which is insts; see
   // CodeBuffer::align_at_start).
   assert(_size == -1, "already set?");
   _size = align_size_up(offset, CodeEntryAlignment);
 }
 void Compile::ConstantTable::emit(CodeBuffer& cb) {
   MacroAssembler _masm(&cb);
   for (int i = 0; i < _constants.length(); i++) {
     Constant con = _constants.at(i);
     address constant_addr;
     switch (con.type()) {
     case T_LONG:   constant_addr = _masm.long_constant(  con.get_jlong()  ); break;
     case T_FLOAT:  constant_addr = _masm.float_constant( con.get_jfloat() ); break;
     case T_DOUBLE: constant_addr = _masm.double_constant(con.get_jdouble()); break;
     case T_OBJECT: {
       jobject obj = con.get_jobject();
       int oop_index = _masm.oop_recorder()->find_index(obj);
       constant_addr = _masm.address_constant((address) obj, oop_Relocation::spec(oop_index));
       break;
     }
     case T_ADDRESS: {
       address addr = (address) con.get_jobject();
       constant_addr = _masm.address_constant(addr);
       break;
     }
     // We use T_VOID as marker for jump-table entries (labels) which
     // need an internal word relocation.
     case T_VOID: {
       MachConstantNode* n = (MachConstantNode*) con.get_jobject();
       // Fill the jump-table with a dummy word.  The real value is
       // filled in later in fill_jump_table.
       address dummy = (address) n;
       constant_addr = _masm.address_constant(dummy);
       // Expand jump-table
       for (uint i = 1; i < n->outcnt(); i++) {
         address temp_addr = _masm.address_constant(dummy + i);
         assert(temp_addr, "consts section too small");
       }
       break;
     }
     case T_METADATA: {
       Metadata* obj = con.get_metadata();
       int metadata_index = _masm.oop_recorder()->find_index(obj);
       constant_addr = _masm.address_constant((address) obj, metadata_Relocation::spec(metadata_index));
       break;
     }
     default: ShouldNotReachHere();
     }
     assert(constant_addr, "consts section too small");
     assert((constant_addr - _masm.code()->consts()->start()) == con.offset(), err_msg_res("must be: %d == %d", constant_addr - _masm.code()->consts()->start(), con.offset()));
   }
 }
 int Compile::ConstantTable::find_offset(Constant& con) const {
   int idx = _constants.find(con);
   assert(idx != -1, "constant must be in constant table");
   int offset = _constants.at(idx).offset();
   assert(offset != -1, "constant table not emitted yet?");
   return offset;
 }
 void Compile::ConstantTable::add(Constant& con) {
   if (con.can_be_reused()) {
     int idx = _constants.find(con);
     if (idx != -1 && _constants.at(idx).can_be_reused()) {
       _constants.adr_at(idx)->inc_freq(con.freq());  // increase the frequency by the current value
       return;
     }
   }
   (void) _constants.append(con);
 }
 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, BasicType type, jvalue value) {
   Block* b = Compile::current()->cfg()->get_block_for_node(n);
   Constant con(type, value, b->_freq);
   add(con);
   return con;
 }
 Compile::Constant Compile::ConstantTable::add(Metadata* metadata) {
   Constant con(metadata);
   add(con);
   return con;
 }
 Compile::Constant Compile::ConstantTable::add(MachConstantNode* n, MachOper* oper) {
   jvalue value;
   BasicType type = oper->type()->basic_type();
   switch (type) {
   case T_LONG:    value.j = oper->constantL(); break;
   case T_FLOAT:   value.f = oper->constantF(); break;
   case T_DOUBLE:  value.d = oper->constantD(); break;
   case T_OBJECT:
   case T_ADDRESS: value.l = (jobject) oper->constant(); break;
   case T_METADATA: return add((Metadata*)oper->constant()); break;
   default: guarantee(false, err_msg_res("unhandled type: %s", type2name(type)));
   }
   return add(n, type, value);
 }
 Compile::Constant Compile::ConstantTable::add_jump_table(MachConstantNode* n) {
   jvalue value;
   // We can use the node pointer here to identify the right jump-table
   // as this method is called from Compile::Fill_buffer right before
   // the MachNodes are emitted and the jump-table is filled (means the
   // MachNode pointers do not change anymore).
   value.l = (jobject) n;
   Constant con(T_VOID, value, next_jump_table_freq(), false);  // Labels of a jump-table cannot be reused.
   add(con);
   return con;
 }
 void Compile::ConstantTable::fill_jump_table(CodeBuffer& cb, MachConstantNode* n, GrowableArray<Label*> labels) const {
   // If called from Compile::scratch_emit_size do nothing.
   if (Compile::current()->in_scratch_emit_size())  return;
   assert(labels.is_nonempty(), "must be");
   assert((uint) labels.length() == n->outcnt(), err_msg_res("must be equal: %d == %d", labels.length(), n->outcnt()));
   // Since MachConstantNode::constant_offset() also contains
   // table_base_offset() we need to subtract the table_base_offset()
   // to get the plain offset into the constant table.
   int offset = n->constant_offset() - table_base_offset();
   MacroAssembler _masm(&cb);
   address* jump_table_base = (address*) (_masm.code()->consts()->start() + offset);
   for (uint i = 0; i < n->outcnt(); i++) {
     address* constant_addr = &jump_table_base[i];
     assert(*constant_addr == (((address) n) + i), err_msg_res("all jump-table entries must contain adjusted node pointer: " INTPTR_FORMAT " == " INTPTR_FORMAT, *constant_addr, (((address) n) + i)));
     *constant_addr = cb.consts()->target(*labels.at(i), (address) constant_addr);
     cb.consts()->relocate((address) constant_addr, relocInfo::internal_word_type);
   }
 }
 void Compile::dump_inlining() {
   if (print_inlining() || print_intrinsics()) {
     // Print inlining message for candidates that we couldn't inline
     // for lack of space or non constant receiver
     for (int i = 0; i < _late_inlines.length(); i++) {
       CallGenerator* cg = _late_inlines.at(i);
       cg->print_inlining_late("live nodes > LiveNodeCountInliningCutoff");
     }
     Unique_Node_List useful;
     useful.push(root());
     for (uint next = 0; next < useful.size(); ++next) {
       Node* n  = useful.at(next);
       if (n->is_Call() && n->as_Call()->generator() != NULL && n->as_Call()->generator()->call_node() == n) {
         CallNode* call = n->as_Call();
         CallGenerator* cg = call->generator();
         cg->print_inlining_late("receiver not constant");
       }
       uint max = n->len();
       for ( uint i = 0; i < max; ++i ) {
         Node *m = n->in(i);
         if ( m == NULL ) continue;
         useful.push(m);
       }
     }
     for (int i = 0; i < _print_inlining_list->length(); i++) {
       tty->print(_print_inlining_list->adr_at(i)->ss()->as_string());
     }
   }
 }
 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
   if (n1->Opcode() < n2->Opcode())      return -1;
   else if (n1->Opcode() > n2->Opcode()) return 1;
   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()));
   for (uint i = 1; i < n1->req(); i++) {
     if (n1->in(i) < n2->in(i))      return -1;
     else if (n1->in(i) > n2->in(i)) return 1;
   }
   return 0;
 }
 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
   Node* n1 = *n1p;
   Node* n2 = *n2p;
   return cmp_expensive_nodes(n1, n2);
 }
 void Compile::sort_expensive_nodes() {
   if (!expensive_nodes_sorted()) {
     _expensive_nodes->sort(cmp_expensive_nodes);
   }
 }
 bool Compile::expensive_nodes_sorted() const {
   for (int i = 1; i < _expensive_nodes->length(); i++) {
     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i-1)) < 0) {
       return false;
     }
   }
   return true;
 }
 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
   if (_expensive_nodes->length() == 0) {
     return false;
   }
   assert(OptimizeExpensiveOps, "optimization off?");
   // Take this opportunity to remove dead nodes from the list
   int j = 0;
   for (int i = 0; i < _expensive_nodes->length(); i++) {
     Node* n = _expensive_nodes->at(i);
     if (!n->is_unreachable(igvn)) {
       assert(n->is_expensive(), "should be expensive");
       _expensive_nodes->at_put(j, n);
       j++;
     }
   }
   _expensive_nodes->trunc_to(j);
   // Then sort the list so that similar nodes are next to each other
   // and check for at least two nodes of identical kind with same data
   // inputs.
   sort_expensive_nodes();
   for (int i = 0; i < _expensive_nodes->length()-1; i++) {
     if (cmp_expensive_nodes(_expensive_nodes->adr_at(i), _expensive_nodes->adr_at(i+1)) == 0) {
       return true;
     }
   }
   return false;
 }
 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
   if (_expensive_nodes->length() == 0) {
     return;
   }
   assert(OptimizeExpensiveOps, "optimization off?");
   // Sort to bring similar nodes next to each other and clear the
   // control input of nodes for which there's only a single copy.
   sort_expensive_nodes();
   int j = 0;
   int identical = 0;
   int i = 0;
   for (; i < _expensive_nodes->length()-1; i++) {
     assert(j <= i, "can't write beyond current index");
     if (_expensive_nodes->at(i)->Opcode() == _expensive_nodes->at(i+1)->Opcode()) {
       identical++;
       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
       continue;
     }
     if (identical > 0) {
       _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
       identical = 0;
     } else {
       Node* n = _expensive_nodes->at(i);
       igvn.hash_delete(n);
       n->set_req(0, NULL);
       igvn.hash_insert(n);
     }
   }
   if (identical > 0) {
     _expensive_nodes->at_put(j++, _expensive_nodes->at(i));
   } else if (_expensive_nodes->length() >= 1) {
     Node* n = _expensive_nodes->at(i);
     igvn.hash_delete(n);
     n->set_req(0, NULL);
     igvn.hash_insert(n);
   }
   _expensive_nodes->trunc_to(j);
 }
 void Compile::add_expensive_node(Node * n) {
   assert(!_expensive_nodes->contains(n), "duplicate entry in expensive list");
   assert(n->is_expensive(), "expensive nodes with non-null control here only");
   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
   if (OptimizeExpensiveOps) {
     _expensive_nodes->append(n);
   } else {
     // Clear control input and let IGVN optimize expensive nodes if
     // OptimizeExpensiveOps is off.
     n->set_req(0, NULL);
   }
 }
 /**
  * Remove the speculative part of types and clean up the graph
  */
 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
   if (UseTypeSpeculation) {
     Unique_Node_List worklist;
     worklist.push(root());
     int modified = 0;
     // Go over all type nodes that carry a speculative type, drop the
     // speculative part of the type and enqueue the node for an igvn
     // which may optimize it out.
     for (uint next = 0; next < worklist.size(); ++next) {
       Node *n  = worklist.at(next);
       if (n->is_Type() && n->as_Type()->type()->isa_oopptr() != NULL &&
           n->as_Type()->type()->is_oopptr()->speculative() != NULL) {
         TypeNode* tn = n->as_Type();
         const TypeOopPtr* t = tn->type()->is_oopptr();
         bool in_hash = igvn.hash_delete(n);
         assert(in_hash, "node should be in igvn hash table");
         tn->set_type(t->remove_speculative());
         igvn.hash_insert(n);
         igvn._worklist.push(n); // give it a chance to go away
         modified++;
       }
       uint max = n->len();
       for( uint i = 0; i < max; ++i ) {
         Node *m = n->in(i);
         if (not_a_node(m))  continue;
         worklist.push(m);
       }
     }
     // Drop the speculative part of all types in the igvn's type table
     igvn.remove_speculative_types();
     if (modified > 0) {
       igvn.optimize();
     }
   }
 }
 // Auxiliary method to support randomized stressing/fuzzing.
 //
 // This method can be called the arbitrary number of times, with current count
 // as the argument. The logic allows selecting a single candidate from the
 // running list of candidates as follows:
 //    int count = 0;
 //    Cand* selected = null;
 //    while(cand = cand->next()) {
 //      if (randomized_select(++count)) {
 //        selected = cand;
 //      }
 //    }
 //
 // Including count equalizes the chances any candidate is "selected".
 // This is useful when we don't have the complete list of candidates to choose
 // from uniformly. In this case, we need to adjust the randomicity of the
 // selection, or else we will end up biasing the selection towards the latter
 // candidates.
 //
 // Quick back-envelope calculation shows that for the list of n candidates
 // the equal probability for the candidate to persist as "best" can be
 // achieved by replacing it with "next" k-th candidate with the probability
 // of 1/k. It can be easily shown that by the end of the run, the
 // probability for any candidate is converged to 1/n, thus giving the
 // uniform distribution among all the candidates.
 //
 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
 #define RANDOMIZED_DOMAIN_POW 29
 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
 bool Compile::randomized_select(int count) {
   assert(count > 0, "only positive");
   return (os::random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/compile.cpp@55fb97c4c58d (annotated)

src/share/vm/opto/compile.cpp