jdk8-mips64-public/hotspot: src/share/vm/opto/stringopts.cpp@f90c822e73f8 (annotated)

src/share/vm/opto/stringopts.cpp@f90c822e73f8 (annotated)

src/share/vm/opto/stringopts.cpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

Initial load
http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 2009, 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 "compiler/compileLog.hpp"
 #include "opto/addnode.hpp"
 #include "opto/callGenerator.hpp"
 #include "opto/callnode.hpp"
 #include "opto/divnode.hpp"
 #include "opto/graphKit.hpp"
 #include "opto/idealKit.hpp"
 #include "opto/rootnode.hpp"
 #include "opto/runtime.hpp"
 #include "opto/stringopts.hpp"
 #include "opto/subnode.hpp"
 #define __ kit.
 class StringConcat : public ResourceObj {
  private:
   PhaseStringOpts*    _stringopts;
   Node*               _string_alloc;
   AllocateNode*       _begin;          // The allocation the begins the pattern
   CallStaticJavaNode* _end;            // The final call of the pattern.  Will either be
                                        // SB.toString or or String.<init>(SB.toString)
   bool                _multiple;       // indicates this is a fusion of two or more
                                        // separate StringBuilders
   Node*               _arguments;      // The list of arguments to be concatenated
   GrowableArray<int>  _mode;           // into a String along with a mode flag
                                        // indicating how to treat the value.
   Node_List           _constructors;   // List of constructors (many in case of stacked concat)
   Node_List           _control;        // List of control nodes that will be deleted
   Node_List           _uncommon_traps; // Uncommon traps that needs to be rewritten
                                        // to restart at the initial JVMState.
  public:
   // Mode for converting arguments to Strings
   enum {
     StringMode,
     IntMode,
     CharMode,
     StringNullCheckMode
   };
   StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
     _end(end),
     _begin(NULL),
     _multiple(false),
     _string_alloc(NULL),
     _stringopts(stringopts) {
     _arguments = new (_stringopts->C) Node(1);
     _arguments->del_req(0);
   }
   bool validate_mem_flow();
   bool validate_control_flow();
   void merge_add() {
 #if 0
     // XXX This is place holder code for reusing an existing String
     // allocation but the logic for checking the state safety is
     // probably inadequate at the moment.
     CallProjections endprojs;
     sc->end()->extract_projections(&endprojs, false);
     if (endprojs.resproj != NULL) {
       for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
         CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
         if (use != NULL && use->method() != NULL &&
             use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
             use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
           // Found useless new String(sb.toString()) so reuse the newly allocated String
           // when creating the result instead of allocating a new one.
           sc->set_string_alloc(use->in(TypeFunc::Parms));
           sc->set_end(use);
         }
       }
     }
 #endif
   }
   StringConcat* merge(StringConcat* other, Node* arg);
   void set_allocation(AllocateNode* alloc) {
     _begin = alloc;
   }
   void append(Node* value, int mode) {
     _arguments->add_req(value);
     _mode.append(mode);
   }
   void push(Node* value, int mode) {
     _arguments->ins_req(0, value);
     _mode.insert_before(0, mode);
   }
   void push_string(Node* value) {
     push(value, StringMode);
   }
   void push_string_null_check(Node* value) {
     push(value, StringNullCheckMode);
   }
   void push_int(Node* value) {
     push(value, IntMode);
   }
   void push_char(Node* value) {
     push(value, CharMode);
   }
   static bool is_SB_toString(Node* call) {
     if (call->is_CallStaticJava()) {
       CallStaticJavaNode* csj = call->as_CallStaticJava();
       ciMethod* m = csj->method();
       if (m != NULL &&
           (m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
            m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
         return true;
       }
     }
     return false;
   }
   static Node* skip_string_null_check(Node* value) {
     // Look for a diamond shaped Null check of toString() result
     // (could be code from String.valueOf()):
     // (Proj == NULL) ? "null":"CastPP(Proj)#NotNULL
     if (value->is_Phi()) {
       int true_path = value->as_Phi()->is_diamond_phi();
       if (true_path != 0) {
         // phi->region->if_proj->ifnode->bool
         BoolNode* b = value->in(0)->in(1)->in(0)->in(1)->as_Bool();
         Node* cmp = b->in(1);
         Node* v1 = cmp->in(1);
         Node* v2 = cmp->in(2);
         // Null check of the return of toString which can simply be skipped.
         if (b->_test._test == BoolTest::ne &&
             v2->bottom_type() == TypePtr::NULL_PTR &&
             value->in(true_path)->Opcode() == Op_CastPP &&
             value->in(true_path)->in(1) == v1 &&
             v1->is_Proj() && is_SB_toString(v1->in(0))) {
           return v1;
         }
       }
     }
     return value;
   }
   Node* argument(int i) {
     return _arguments->in(i);
   }
   Node* argument_uncast(int i) {
     Node* arg = argument(i);
     int amode = mode(i);
     if (amode == StringConcat::StringMode ||
         amode == StringConcat::StringNullCheckMode) {
       arg = skip_string_null_check(arg);
     }
     return arg;
   }
   void set_argument(int i, Node* value) {
     _arguments->set_req(i, value);
   }
   int num_arguments() {
     return _mode.length();
   }
   int mode(int i) {
     return _mode.at(i);
   }
   void add_control(Node* ctrl) {
     assert(!_control.contains(ctrl), "only push once");
     _control.push(ctrl);
   }
   void add_constructor(Node* init) {
     assert(!_constructors.contains(init), "only push once");
     _constructors.push(init);
   }
   CallStaticJavaNode* end() { return _end; }
   AllocateNode* begin() { return _begin; }
   Node* string_alloc() { return _string_alloc; }
   void eliminate_unneeded_control();
   void eliminate_initialize(InitializeNode* init);
   void eliminate_call(CallNode* call);
   void maybe_log_transform() {
     CompileLog* log = _stringopts->C->log();
     if (log != NULL) {
       log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
                 num_arguments(),
                 _string_alloc != NULL,
                 _multiple);
       JVMState* p = _begin->jvms();
       while (p != NULL) {
         log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
         p = p->caller();
       }
       log->tail("replace_string_concat");
     }
   }
   void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
     for (uint u = 0; u < _uncommon_traps.size(); u++) {
       Node* uct = _uncommon_traps.at(u);
       // Build a new call using the jvms state of the allocate
       address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
       const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
       const TypePtr* no_memory_effects = NULL;
       Compile* C = _stringopts->C;
       CallStaticJavaNode* call = new (C) CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
                                                             jvms->bci(), no_memory_effects);
       for (int e = 0; e < TypeFunc::Parms; e++) {
         call->init_req(e, uct->in(e));
       }
       // Set the trap request to record intrinsic failure if this trap
       // is taken too many times.  Ideally we would handle then traps by
       // doing the original bookkeeping in the MDO so that if it caused
       // the code to be thrown out we could still recompile and use the
       // optimization.  Failing the uncommon traps doesn't really mean
       // that the optimization is a bad idea but there's no other way to
       // do the MDO updates currently.
       int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
                                                            Deoptimization::Action_make_not_entrant);
       call->init_req(TypeFunc::Parms, __ intcon(trap_request));
       kit.add_safepoint_edges(call);
       _stringopts->gvn()->transform(call);
       C->gvn_replace_by(uct, call);
       uct->disconnect_inputs(NULL, C);
     }
   }
   void cleanup() {
     // disconnect the hook node
     _arguments->disconnect_inputs(NULL, _stringopts->C);
   }
 };
 void StringConcat::eliminate_unneeded_control() {
   for (uint i = 0; i < _control.size(); i++) {
     Node* n = _control.at(i);
     if (n->is_Allocate()) {
       eliminate_initialize(n->as_Allocate()->initialization());
     }
     if (n->is_Call()) {
       if (n != _end) {
         eliminate_call(n->as_Call());
       }
     } else if (n->is_IfTrue()) {
       Compile* C = _stringopts->C;
       C->gvn_replace_by(n, n->in(0)->in(0));
       // get rid of the other projection
       C->gvn_replace_by(n->in(0)->as_If()->proj_out(false), C->top());
     }
   }
 }
 StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
   StringConcat* result = new StringConcat(_stringopts, _end);
   for (uint x = 0; x < _control.size(); x++) {
     Node* n = _control.at(x);
     if (n->is_Call()) {
       result->_control.push(n);
     }
   }
   for (uint x = 0; x < other->_control.size(); x++) {
     Node* n = other->_control.at(x);
     if (n->is_Call()) {
       result->_control.push(n);
     }
   }
   assert(result->_control.contains(other->_end), "what?");
   assert(result->_control.contains(_begin), "what?");
   for (int x = 0; x < num_arguments(); x++) {
     Node* argx = argument_uncast(x);
     if (argx == arg) {
       // replace the toString result with the all the arguments that
       // made up the other StringConcat
       for (int y = 0; y < other->num_arguments(); y++) {
         result->append(other->argument(y), other->mode(y));
       }
     } else {
       result->append(argx, mode(x));
     }
   }
   result->set_allocation(other->_begin);
   for (uint i = 0; i < _constructors.size(); i++) {
     result->add_constructor(_constructors.at(i));
   }
   for (uint i = 0; i < other->_constructors.size(); i++) {
     result->add_constructor(other->_constructors.at(i));
   }
   result->_multiple = true;
   return result;
 }
 void StringConcat::eliminate_call(CallNode* call) {
   Compile* C = _stringopts->C;
   CallProjections projs;
   call->extract_projections(&projs, false);
   if (projs.fallthrough_catchproj != NULL) {
     C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
   }
   if (projs.fallthrough_memproj != NULL) {
     C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
   }
   if (projs.catchall_memproj != NULL) {
     C->gvn_replace_by(projs.catchall_memproj, C->top());
   }
   if (projs.fallthrough_ioproj != NULL) {
     C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
   }
   if (projs.catchall_ioproj != NULL) {
     C->gvn_replace_by(projs.catchall_ioproj, C->top());
   }
   if (projs.catchall_catchproj != NULL) {
     // EA can't cope with the partially collapsed graph this
     // creates so put it on the worklist to be collapsed later.
     for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
       Node *use = i.get();
       int opc = use->Opcode();
       if (opc == Op_CreateEx || opc == Op_Region) {
         _stringopts->record_dead_node(use);
       }
     }
     C->gvn_replace_by(projs.catchall_catchproj, C->top());
   }
   if (projs.resproj != NULL) {
     C->gvn_replace_by(projs.resproj, C->top());
   }
   C->gvn_replace_by(call, C->top());
 }
 void StringConcat::eliminate_initialize(InitializeNode* init) {
   Compile* C = _stringopts->C;
   // Eliminate Initialize node.
   assert(init->outcnt() <= 2, "only a control and memory projection expected");
   assert(init->req() <= InitializeNode::RawStores, "no pending inits");
   Node *ctrl_proj = init->proj_out(TypeFunc::Control);
   if (ctrl_proj != NULL) {
     C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
   }
   Node *mem_proj = init->proj_out(TypeFunc::Memory);
   if (mem_proj != NULL) {
     Node *mem = init->in(TypeFunc::Memory);
     C->gvn_replace_by(mem_proj, mem);
   }
   C->gvn_replace_by(init, C->top());
   init->disconnect_inputs(NULL, C);
 }
 Node_List PhaseStringOpts::collect_toString_calls() {
   Node_List string_calls;
   Node_List worklist;
   _visited.Clear();
   // Prime the worklist
   for (uint i = 1; i < C->root()->len(); i++) {
     Node* n = C->root()->in(i);
     if (n != NULL && !_visited.test_set(n->_idx)) {
       worklist.push(n);
     }
   }
   while (worklist.size() > 0) {
     Node* ctrl = worklist.pop();
     if (StringConcat::is_SB_toString(ctrl)) {
       CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
       string_calls.push(csj);
     }
     if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
       worklist.push(ctrl->in(0));
     }
     if (ctrl->is_Region()) {
       for (uint i = 1; i < ctrl->len(); i++) {
         if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
           worklist.push(ctrl->in(i));
         }
       }
     }
   }
   return string_calls;
 }
 StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
   ciMethod* m = call->method();
   ciSymbol* string_sig;
   ciSymbol* int_sig;
   ciSymbol* char_sig;
   if (m->holder() == C->env()->StringBuilder_klass()) {
     string_sig = ciSymbol::String_StringBuilder_signature();
     int_sig = ciSymbol::int_StringBuilder_signature();
     char_sig = ciSymbol::char_StringBuilder_signature();
   } else if (m->holder() == C->env()->StringBuffer_klass()) {
     string_sig = ciSymbol::String_StringBuffer_signature();
     int_sig = ciSymbol::int_StringBuffer_signature();
     char_sig = ciSymbol::char_StringBuffer_signature();
   } else {
     return NULL;
   }
 #ifndef PRODUCT
   if (PrintOptimizeStringConcat) {
     tty->print("considering toString call in ");
     call->jvms()->dump_spec(tty); tty->cr();
   }
 #endif
   StringConcat* sc = new StringConcat(this, call);
   AllocateNode* alloc = NULL;
   InitializeNode* init = NULL;
   // possible opportunity for StringBuilder fusion
   CallStaticJavaNode* cnode = call;
   while (cnode) {
     Node* recv = cnode->in(TypeFunc::Parms)->uncast();
     if (recv->is_Proj()) {
       recv = recv->in(0);
     }
     cnode = recv->isa_CallStaticJava();
     if (cnode == NULL) {
       alloc = recv->isa_Allocate();
       if (alloc == NULL) {
         break;
       }
       // Find the constructor call
       Node* result = alloc->result_cast();
       if (result == NULL || !result->is_CheckCastPP() || alloc->in(TypeFunc::Memory)->is_top()) {
         // strange looking allocation
 #ifndef PRODUCT
         if (PrintOptimizeStringConcat) {
           tty->print("giving up because allocation looks strange ");
           alloc->jvms()->dump_spec(tty); tty->cr();
         }
 #endif
         break;
       }
       Node* constructor = NULL;
       for (SimpleDUIterator i(result); i.has_next(); i.next()) {
         CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
         if (use != NULL &&
             use->method() != NULL &&
             !use->method()->is_static() &&
             use->method()->name() == ciSymbol::object_initializer_name() &&
             use->method()->holder() == m->holder()) {
           // Matched the constructor.
           ciSymbol* sig = use->method()->signature()->as_symbol();
           if (sig == ciSymbol::void_method_signature() ||
               sig == ciSymbol::int_void_signature() ||
               sig == ciSymbol::string_void_signature()) {
             if (sig == ciSymbol::string_void_signature()) {
               // StringBuilder(String) so pick this up as the first argument
               assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
               const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1));
               if (type == TypePtr::NULL_PTR) {
                 // StringBuilder(null) throws exception.
 #ifndef PRODUCT
                 if (PrintOptimizeStringConcat) {
                   tty->print("giving up because StringBuilder(null) throws exception");
                   alloc->jvms()->dump_spec(tty); tty->cr();
                 }
 #endif
                 return NULL;
               }
               // StringBuilder(str) argument needs null check.
               sc->push_string_null_check(use->in(TypeFunc::Parms + 1));
             }
             // The int variant takes an initial size for the backing
             // array so just treat it like the void version.
             constructor = use;
           } else {
 #ifndef PRODUCT
             if (PrintOptimizeStringConcat) {
               tty->print("unexpected constructor signature: %s", sig->as_utf8());
             }
 #endif
           }
           break;
         }
       }
       if (constructor == NULL) {
         // couldn't find constructor
 #ifndef PRODUCT
         if (PrintOptimizeStringConcat) {
           tty->print("giving up because couldn't find constructor ");
           alloc->jvms()->dump_spec(tty); tty->cr();
         }
 #endif
         break;
       }
       // Walked all the way back and found the constructor call so see
       // if this call converted into a direct string concatenation.
       sc->add_control(call);
       sc->add_control(constructor);
       sc->add_control(alloc);
       sc->set_allocation(alloc);
       sc->add_constructor(constructor);
       if (sc->validate_control_flow() && sc->validate_mem_flow()) {
         return sc;
       } else {
         return NULL;
       }
     } else if (cnode->method() == NULL) {
       break;
     } else if (!cnode->method()->is_static() &&
                cnode->method()->holder() == m->holder() &&
                cnode->method()->name() == ciSymbol::append_name() &&
                (cnode->method()->signature()->as_symbol() == string_sig ||
                 cnode->method()->signature()->as_symbol() == char_sig ||
                 cnode->method()->signature()->as_symbol() == int_sig)) {
       sc->add_control(cnode);
       Node* arg = cnode->in(TypeFunc::Parms + 1);
       if (cnode->method()->signature()->as_symbol() == int_sig) {
         sc->push_int(arg);
       } else if (cnode->method()->signature()->as_symbol() == char_sig) {
         sc->push_char(arg);
       } else {
         if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
           CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
           if (csj->method() != NULL &&
               csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
               arg->outcnt() == 1) {
             // _control is the list of StringBuilder calls nodes which
             // will be replaced by new String code after this optimization.
             // Integer::toString() call is not part of StringBuilder calls
             // chain. It could be eliminated only if its result is used
             // only by this SB calls chain.
             // Another limitation: it should be used only once because
             // it is unknown that it is used only by this SB calls chain
             // until all related SB calls nodes are collected.
             assert(arg->unique_out() == cnode, "sanity");
             sc->add_control(csj);
             sc->push_int(csj->in(TypeFunc::Parms));
             continue;
           }
         }
         sc->push_string(arg);
       }
       continue;
     } else {
       // some unhandled signature
 #ifndef PRODUCT
       if (PrintOptimizeStringConcat) {
         tty->print("giving up because encountered unexpected signature ");
         cnode->tf()->dump(); tty->cr();
         cnode->in(TypeFunc::Parms + 1)->dump();
       }
 #endif
       break;
     }
   }
   return NULL;
 }
 PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
   Phase(StringOpts),
   _gvn(gvn),
   _visited(Thread::current()->resource_area()) {
   assert(OptimizeStringConcat, "shouldn't be here");
   size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
                                                                   ciSymbol::make("[I"), true);
   if (size_table_field == NULL) {
     // Something wrong so give up.
     assert(false, "why can't we find Integer.sizeTable?");
     return;
   }
   // Collect the types needed to talk about the various slices of memory
   char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS);
   // For each locally allocated StringBuffer see if the usages can be
   // collapsed into a single String construction.
   // Run through the list of allocation looking for SB.toString to see
   // if it's possible to fuse the usage of the SB into a single String
   // construction.
   GrowableArray<StringConcat*> concats;
   Node_List toStrings = collect_toString_calls();
   while (toStrings.size() > 0) {
     StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
     if (sc != NULL) {
       concats.push(sc);
     }
   }
   // try to coalesce separate concats
  restart:
   for (int c = 0; c < concats.length(); c++) {
     StringConcat* sc = concats.at(c);
     for (int i = 0; i < sc->num_arguments(); i++) {
       Node* arg = sc->argument_uncast(i);
       if (arg->is_Proj() && StringConcat::is_SB_toString(arg->in(0))) {
         CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
         for (int o = 0; o < concats.length(); o++) {
           if (c == o) continue;
           StringConcat* other = concats.at(o);
           if (other->end() == csj) {
 #ifndef PRODUCT
             if (PrintOptimizeStringConcat) {
               tty->print_cr("considering stacked concats");
             }
 #endif
             StringConcat* merged = sc->merge(other, arg);
             if (merged->validate_control_flow() && merged->validate_mem_flow()) {
 #ifndef PRODUCT
               if (PrintOptimizeStringConcat) {
                 tty->print_cr("stacking would succeed");
               }
 #endif
               if (c < o) {
                 concats.remove_at(o);
                 concats.at_put(c, merged);
               } else {
                 concats.remove_at(c);
                 concats.at_put(o, merged);
               }
               goto restart;
             } else {
 #ifndef PRODUCT
               if (PrintOptimizeStringConcat) {
                 tty->print_cr("stacking would fail");
               }
 #endif
             }
           }
         }
       }
     }
   }
   for (int c = 0; c < concats.length(); c++) {
     StringConcat* sc = concats.at(c);
     replace_string_concat(sc);
   }
   remove_dead_nodes();
 }
 void PhaseStringOpts::record_dead_node(Node* dead) {
   dead_worklist.push(dead);
 }
 void PhaseStringOpts::remove_dead_nodes() {
   // Delete any dead nodes to make things clean enough that escape
   // analysis doesn't get unhappy.
   while (dead_worklist.size() > 0) {
     Node* use = dead_worklist.pop();
     int opc = use->Opcode();
     switch (opc) {
       case Op_Region: {
         uint i = 1;
         for (i = 1; i < use->req(); i++) {
           if (use->in(i) != C->top()) {
             break;
           }
         }
         if (i >= use->req()) {
           for (SimpleDUIterator i(use); i.has_next(); i.next()) {
             Node* m = i.get();
             if (m->is_Phi()) {
               dead_worklist.push(m);
             }
           }
           C->gvn_replace_by(use, C->top());
         }
         break;
       }
       case Op_AddP:
       case Op_CreateEx: {
         // Recurisvely clean up references to CreateEx so EA doesn't
         // get unhappy about the partially collapsed graph.
         for (SimpleDUIterator i(use); i.has_next(); i.next()) {
           Node* m = i.get();
           if (m->is_AddP()) {
             dead_worklist.push(m);
           }
         }
         C->gvn_replace_by(use, C->top());
         break;
       }
       case Op_Phi:
         if (use->in(0) == C->top()) {
           C->gvn_replace_by(use, C->top());
         }
         break;
     }
   }
 }
 bool StringConcat::validate_mem_flow() {
   Compile* C = _stringopts->C;
   for (uint i = 0; i < _control.size(); i++) {
 #ifndef PRODUCT
     Node_List path;
 #endif
     Node* curr = _control.at(i);
     if (curr->is_Call() && curr != _begin) { // For all calls except the first allocation
       // Now here's the main invariant in our case:
       // For memory between the constructor, and appends, and toString we should only see bottom memory,
       // produced by the previous call we know about.
       if (!_constructors.contains(curr)) {
         NOT_PRODUCT(path.push(curr);)
         Node* mem = curr->in(TypeFunc::Memory);
         assert(mem != NULL, "calls should have memory edge");
         assert(!mem->is_Phi(), "should be handled by control flow validation");
         NOT_PRODUCT(path.push(mem);)
         while (mem->is_MergeMem()) {
           for (uint i = 1; i < mem->req(); i++) {
             if (i != Compile::AliasIdxBot && mem->in(i) != C->top()) {
 #ifndef PRODUCT
               if (PrintOptimizeStringConcat) {
                 tty->print("fusion has incorrect memory flow (side effects) for ");
                 _begin->jvms()->dump_spec(tty); tty->cr();
                 path.dump();
               }
 #endif
               return false;
             }
           }
           // skip through a potential MergeMem chain, linked through Bot
           mem = mem->in(Compile::AliasIdxBot);
           NOT_PRODUCT(path.push(mem);)
         }
         // now let it fall through, and see if we have a projection
         if (mem->is_Proj()) {
           // Should point to a previous known call
           Node *prev = mem->in(0);
           NOT_PRODUCT(path.push(prev);)
           if (!prev->is_Call() || !_control.contains(prev)) {
 #ifndef PRODUCT
             if (PrintOptimizeStringConcat) {
               tty->print("fusion has incorrect memory flow (unknown call) for ");
               _begin->jvms()->dump_spec(tty); tty->cr();
               path.dump();
             }
 #endif
             return false;
           }
         } else {
           assert(mem->is_Store() || mem->is_LoadStore(), err_msg_res("unexpected node type: %s", mem->Name()));
 #ifndef PRODUCT
           if (PrintOptimizeStringConcat) {
             tty->print("fusion has incorrect memory flow (unexpected source) for ");
             _begin->jvms()->dump_spec(tty); tty->cr();
             path.dump();
           }
 #endif
           return false;
         }
       } else {
         // For memory that feeds into constructors it's more complicated.
         // However the advantage is that any side effect that happens between the Allocate/Initialize and
         // the constructor will have to be control-dependent on Initialize.
         // So we actually don't have to do anything, since it's going to be caught by the control flow
         // analysis.
 #ifdef ASSERT
         // Do a quick verification of the control pattern between the constructor and the initialize node
         assert(curr->is_Call(), "constructor should be a call");
         // Go up the control starting from the constructor call
         Node* ctrl = curr->in(0);
         IfNode* iff = NULL;
         RegionNode* copy = NULL;
         while (true) {
           // skip known check patterns
           if (ctrl->is_Region()) {
             if (ctrl->as_Region()->is_copy()) {
               copy = ctrl->as_Region();
               ctrl = copy->is_copy();
             } else { // a cast
               assert(ctrl->req() == 3 &&
                      ctrl->in(1) != NULL && ctrl->in(1)->is_Proj() &&
                      ctrl->in(2) != NULL && ctrl->in(2)->is_Proj() &&
                      ctrl->in(1)->in(0) == ctrl->in(2)->in(0) &&
                      ctrl->in(1)->in(0) != NULL && ctrl->in(1)->in(0)->is_If(),
                      "must be a simple diamond");
               Node* true_proj = ctrl->in(1)->is_IfTrue() ? ctrl->in(1) : ctrl->in(2);
               for (SimpleDUIterator i(true_proj); i.has_next(); i.next()) {
                 Node* use = i.get();
                 assert(use == ctrl || use->is_ConstraintCast(),
                        err_msg_res("unexpected user: %s", use->Name()));
               }
               iff = ctrl->in(1)->in(0)->as_If();
               ctrl = iff->in(0);
             }
           } else if (ctrl->is_IfTrue()) { // null checks, class checks
             iff = ctrl->in(0)->as_If();
             assert(iff->is_If(), "must be if");
             // Verify that the other arm is an uncommon trap
             Node* otherproj = iff->proj_out(1 - ctrl->as_Proj()->_con);
             CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
             assert(strcmp(call->_name, "uncommon_trap") == 0, "must be uncommond trap");
             ctrl = iff->in(0);
           } else {
             break;
           }
         }
         assert(ctrl->is_Proj(), "must be a projection");
         assert(ctrl->in(0)->is_Initialize(), "should be initialize");
         for (SimpleDUIterator i(ctrl); i.has_next(); i.next()) {
           Node* use = i.get();
           assert(use == copy || use == iff || use == curr || use->is_CheckCastPP() || use->is_Load(),
                  err_msg_res("unexpected user: %s", use->Name()));
         }
 #endif // ASSERT
       }
     }
   }
 #ifndef PRODUCT
   if (PrintOptimizeStringConcat) {
     tty->print("fusion has correct memory flow for ");
     _begin->jvms()->dump_spec(tty); tty->cr();
     tty->cr();
   }
 #endif
   return true;
 }
 bool StringConcat::validate_control_flow() {
   // We found all the calls and arguments now lets see if it's
   // safe to transform the graph as we would expect.
   // Check to see if this resulted in too many uncommon traps previously
   if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
                         Deoptimization::Reason_intrinsic)) {
     return false;
   }
   // Walk backwards over the control flow from toString to the
   // allocation and make sure all the control flow is ok.  This
   // means it's either going to be eliminated once the calls are
   // removed or it can safely be transformed into an uncommon
   // trap.
   int null_check_count = 0;
   Unique_Node_List ctrl_path;
   assert(_control.contains(_begin), "missing");
   assert(_control.contains(_end), "missing");
   // Collect the nodes that we know about and will eliminate into ctrl_path
   for (uint i = 0; i < _control.size(); i++) {
     // Push the call and it's control projection
     Node* n = _control.at(i);
     if (n->is_Allocate()) {
       AllocateNode* an = n->as_Allocate();
       InitializeNode* init = an->initialization();
       ctrl_path.push(init);
       ctrl_path.push(init->as_Multi()->proj_out(0));
     }
     if (n->is_Call()) {
       CallNode* cn = n->as_Call();
       ctrl_path.push(cn);
       ctrl_path.push(cn->proj_out(0));
       ctrl_path.push(cn->proj_out(0)->unique_out());
       if (cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0) != NULL) {
         ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0));
       }
     } else {
       ShouldNotReachHere();
     }
   }
   // Skip backwards through the control checking for unexpected control flow
   Node* ptr = _end;
   bool fail = false;
   while (ptr != _begin) {
     if (ptr->is_Call() && ctrl_path.member(ptr)) {
       ptr = ptr->in(0);
     } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
       ptr = ptr->in(0)->in(0)->in(0);
       assert(ctrl_path.member(ptr), "should be a known piece of control");
     } else if (ptr->is_IfTrue()) {
       IfNode* iff = ptr->in(0)->as_If();
       BoolNode* b = iff->in(1)->isa_Bool();
       if (b == NULL) {
         fail = true;
         break;
       }
       Node* cmp = b->in(1);
       Node* v1 = cmp->in(1);
       Node* v2 = cmp->in(2);
       Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
       // Null check of the return of append which can simply be eliminated
       if (b->_test._test == BoolTest::ne &&
           v2->bottom_type() == TypePtr::NULL_PTR &&
           v1->is_Proj() && ctrl_path.member(v1->in(0))) {
         // NULL check of the return value of the append
         null_check_count++;
         if (otherproj->outcnt() == 1) {
           CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
           if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
             ctrl_path.push(call);
           }
         }
         _control.push(ptr);
         ptr = ptr->in(0)->in(0);
         continue;
       }
       // A test which leads to an uncommon trap which should be safe.
       // Later this trap will be converted into a trap that restarts
       // at the beginning.
       if (otherproj->outcnt() == 1) {
         CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
         if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
           // control flow leads to uct so should be ok
           _uncommon_traps.push(call);
           ctrl_path.push(call);
           ptr = ptr->in(0)->in(0);
           continue;
         }
       }
 #ifndef PRODUCT
       // Some unexpected control flow we don't know how to handle.
       if (PrintOptimizeStringConcat) {
         tty->print_cr("failing with unknown test");
         b->dump();
         cmp->dump();
         v1->dump();
         v2->dump();
         tty->cr();
       }
 #endif
       fail = true;
       break;
     } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
       ptr = ptr->in(0)->in(0);
     } else if (ptr->is_Region()) {
       Node* copy = ptr->as_Region()->is_copy();
       if (copy != NULL) {
         ptr = copy;
         continue;
       }
       if (ptr->req() == 3 &&
           ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
           ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
           ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
           ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
         // Simple diamond.
         // XXX should check for possibly merging stores.  simple data merges are ok.
         // The IGVN will make this simple diamond go away when it
         // transforms the Region. Make sure it sees it.
         Compile::current()->record_for_igvn(ptr);
         ptr = ptr->in(1)->in(0)->in(0);
         continue;
       }
 #ifndef PRODUCT
       if (PrintOptimizeStringConcat) {
         tty->print_cr("fusion would fail for region");
         _begin->dump();
         ptr->dump(2);
       }
 #endif
       fail = true;
       break;
     } else {
       // other unknown control
       if (!fail) {
 #ifndef PRODUCT
         if (PrintOptimizeStringConcat) {
           tty->print_cr("fusion would fail for");
           _begin->dump();
         }
 #endif
         fail = true;
       }
 #ifndef PRODUCT
       if (PrintOptimizeStringConcat) {
         ptr->dump();
       }
 #endif
       ptr = ptr->in(0);
     }
   }
 #ifndef PRODUCT
   if (PrintOptimizeStringConcat && fail) {
     tty->cr();
   }
 #endif
   if (fail) return !fail;
   // Validate that all these results produced are contained within
   // this cluster of objects.  First collect all the results produced
   // by calls in the region.
   _stringopts->_visited.Clear();
   Node_List worklist;
   Node* final_result = _end->proj_out(TypeFunc::Parms);
   for (uint i = 0; i < _control.size(); i++) {
     CallNode* cnode = _control.at(i)->isa_Call();
     if (cnode != NULL) {
       _stringopts->_visited.test_set(cnode->_idx);
     }
     Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL;
     if (result != NULL && result != final_result) {
       worklist.push(result);
     }
   }
   Node* last_result = NULL;
   while (worklist.size() > 0) {
     Node* result = worklist.pop();
     if (_stringopts->_visited.test_set(result->_idx))
       continue;
     for (SimpleDUIterator i(result); i.has_next(); i.next()) {
       Node *use = i.get();
       if (ctrl_path.member(use)) {
         // already checked this
         continue;
       }
       int opc = use->Opcode();
       if (opc == Op_CmpP || opc == Op_Node) {
         ctrl_path.push(use);
         continue;
       }
       if (opc == Op_CastPP || opc == Op_CheckCastPP) {
         for (SimpleDUIterator j(use); j.has_next(); j.next()) {
           worklist.push(j.get());
         }
         worklist.push(use->in(1));
         ctrl_path.push(use);
         continue;
       }
 #ifndef PRODUCT
       if (PrintOptimizeStringConcat) {
         if (result != last_result) {
           last_result = result;
           tty->print_cr("extra uses for result:");
           last_result->dump();
         }
         use->dump();
       }
 #endif
       fail = true;
       break;
     }
   }
 #ifndef PRODUCT
   if (PrintOptimizeStringConcat && !fail) {
     ttyLocker ttyl;
     tty->cr();
     tty->print("fusion has correct control flow (%d %d) for ", null_check_count, _uncommon_traps.size());
     _begin->jvms()->dump_spec(tty); tty->cr();
     for (int i = 0; i < num_arguments(); i++) {
       argument(i)->dump();
     }
     _control.dump();
     tty->cr();
   }
 #endif
   return !fail;
 }
 Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
   const TypeInstPtr* mirror_type = TypeInstPtr::make(field->holder()->java_mirror());
   Node* klass_node = __ makecon(mirror_type);
   BasicType bt = field->layout_type();
   ciType* field_klass = field->type();
   const Type *type;
   if( bt == T_OBJECT ) {
     if (!field->type()->is_loaded()) {
       type = TypeInstPtr::BOTTOM;
     } else if (field->is_constant()) {
       // This can happen if the constant oop is non-perm.
       ciObject* con = field->constant_value().as_object();
       // Do not "join" in the previous type; it doesn't add value,
       // and may yield a vacuous result if the field is of interface type.
       type = TypeOopPtr::make_from_constant(con, true)->isa_oopptr();
       assert(type != NULL, "field singleton type must be consistent");
       return __ makecon(type);
     } else {
       type = TypeOopPtr::make_from_klass(field_klass->as_klass());
     }
   } else {
     type = Type::get_const_basic_type(bt);
   }
   return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
                        type, T_OBJECT,
                        C->get_alias_index(mirror_type->add_offset(field->offset_in_bytes())),
                        MemNode::unordered);
 }
 Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
   RegionNode *final_merge = new (C) RegionNode(3);
   kit.gvn().set_type(final_merge, Type::CONTROL);
   Node* final_size = new (C) PhiNode(final_merge, TypeInt::INT);
   kit.gvn().set_type(final_size, TypeInt::INT);
   IfNode* iff = kit.create_and_map_if(kit.control(),
                                       __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
                                       PROB_FAIR, COUNT_UNKNOWN);
   Node* is_min = __ IfFalse(iff);
   final_merge->init_req(1, is_min);
   final_size->init_req(1, __ intcon(11));
   kit.set_control(__ IfTrue(iff));
   if (kit.stopped()) {
     final_merge->init_req(2, C->top());
     final_size->init_req(2, C->top());
   } else {
     // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
     RegionNode *r = new (C) RegionNode(3);
     kit.gvn().set_type(r, Type::CONTROL);
     Node *phi = new (C) PhiNode(r, TypeInt::INT);
     kit.gvn().set_type(phi, TypeInt::INT);
     Node *size = new (C) PhiNode(r, TypeInt::INT);
     kit.gvn().set_type(size, TypeInt::INT);
     Node* chk = __ CmpI(arg, __ intcon(0));
     Node* p = __ Bool(chk, BoolTest::lt);
     IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
     Node* lessthan = __ IfTrue(iff);
     Node* greaterequal = __ IfFalse(iff);
     r->init_req(1, lessthan);
     phi->init_req(1, __ SubI(__ intcon(0), arg));
     size->init_req(1, __ intcon(1));
     r->init_req(2, greaterequal);
     phi->init_req(2, arg);
     size->init_req(2, __ intcon(0));
     kit.set_control(r);
     C->record_for_igvn(r);
     C->record_for_igvn(phi);
     C->record_for_igvn(size);
     // for (int i=0; ; i++)
     //   if (x <= sizeTable[i])
     //     return i+1;
     // Add loop predicate first.
     kit.add_predicate();
     RegionNode *loop = new (C) RegionNode(3);
     loop->init_req(1, kit.control());
     kit.gvn().set_type(loop, Type::CONTROL);
     Node *index = new (C) PhiNode(loop, TypeInt::INT);
     index->init_req(1, __ intcon(0));
     kit.gvn().set_type(index, TypeInt::INT);
     kit.set_control(loop);
     Node* sizeTable = fetch_static_field(kit, size_table_field);
     Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
     C->record_for_igvn(value);
     Node* limit = __ CmpI(phi, value);
     Node* limitb = __ Bool(limit, BoolTest::le);
     IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
     Node* lessEqual = __ IfTrue(iff2);
     Node* greater = __ IfFalse(iff2);
     loop->init_req(2, greater);
     index->init_req(2, __ AddI(index, __ intcon(1)));
     kit.set_control(lessEqual);
     C->record_for_igvn(loop);
     C->record_for_igvn(index);
     final_merge->init_req(2, kit.control());
     final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
   }
   kit.set_control(final_merge);
   C->record_for_igvn(final_merge);
   C->record_for_igvn(final_size);
   return final_size;
 }
 void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) {
   RegionNode *final_merge = new (C) RegionNode(4);
   kit.gvn().set_type(final_merge, Type::CONTROL);
   Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
   kit.gvn().set_type(final_mem, Type::MEMORY);
   // need to handle Integer.MIN_VALUE specially because negating doesn't make it positive
   {
     // i == MIN_VALUE
     IfNode* iff = kit.create_and_map_if(kit.control(),
                                         __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
                                         PROB_FAIR, COUNT_UNKNOWN);
     Node* old_mem = kit.memory(char_adr_idx);
     kit.set_control(__ IfFalse(iff));
     if (kit.stopped()) {
       // Statically not equal to MIN_VALUE so this path is dead
       final_merge->init_req(3, kit.control());
     } else {
       copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
                   char_array, start);
       final_merge->init_req(3, kit.control());
       final_mem->init_req(3, kit.memory(char_adr_idx));
     }
     kit.set_control(__ IfTrue(iff));
     kit.set_memory(old_mem, char_adr_idx);
   }
   // Simplified version of Integer.getChars
   // int q, r;
   // int charPos = index;
   Node* charPos = end;
   // char sign = 0;
   Node* i = arg;
   Node* sign = __ intcon(0);
   // if (i < 0) {
   //     sign = '-';
   //     i = -i;
   // }
   {
     IfNode* iff = kit.create_and_map_if(kit.control(),
                                         __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
                                         PROB_FAIR, COUNT_UNKNOWN);
     RegionNode *merge = new (C) RegionNode(3);
     kit.gvn().set_type(merge, Type::CONTROL);
     i = new (C) PhiNode(merge, TypeInt::INT);
     kit.gvn().set_type(i, TypeInt::INT);
     sign = new (C) PhiNode(merge, TypeInt::INT);
     kit.gvn().set_type(sign, TypeInt::INT);
     merge->init_req(1, __ IfTrue(iff));
     i->init_req(1, __ SubI(__ intcon(0), arg));
     sign->init_req(1, __ intcon('-'));
     merge->init_req(2, __ IfFalse(iff));
     i->init_req(2, arg);
     sign->init_req(2, __ intcon(0));
     kit.set_control(merge);
     C->record_for_igvn(merge);
     C->record_for_igvn(i);
     C->record_for_igvn(sign);
   }
   // for (;;) {
   //     q = i / 10;
   //     r = i - ((q << 3) + (q << 1));  // r = i-(q*10) ...
   //     buf [--charPos] = digits [r];
   //     i = q;
   //     if (i == 0) break;
   // }
   {
     // Add loop predicate first.
     kit.add_predicate();
     RegionNode *head = new (C) RegionNode(3);
     head->init_req(1, kit.control());
     kit.gvn().set_type(head, Type::CONTROL);
     Node *i_phi = new (C) PhiNode(head, TypeInt::INT);
     i_phi->init_req(1, i);
     kit.gvn().set_type(i_phi, TypeInt::INT);
     charPos = PhiNode::make(head, charPos);
     kit.gvn().set_type(charPos, TypeInt::INT);
     Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
     kit.gvn().set_type(mem, Type::MEMORY);
     kit.set_control(head);
     kit.set_memory(mem, char_adr_idx);
     Node* q = __ DivI(NULL, i_phi, __ intcon(10));
     Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
                                      __ LShiftI(q, __ intcon(1))));
     Node* m1 = __ SubI(charPos, __ intcon(1));
     Node* ch = __ AddI(r, __ intcon('0'));
     Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
                                   ch, T_CHAR, char_adr_idx, MemNode::unordered);
     IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
                                         PROB_FAIR, COUNT_UNKNOWN);
     Node* ne = __ IfTrue(iff);
     Node* eq = __ IfFalse(iff);
     head->init_req(2, ne);
     mem->init_req(2, st);
     i_phi->init_req(2, q);
     charPos->init_req(2, m1);
     charPos = m1;
     kit.set_control(eq);
     kit.set_memory(st, char_adr_idx);
     C->record_for_igvn(head);
     C->record_for_igvn(mem);
     C->record_for_igvn(i_phi);
     C->record_for_igvn(charPos);
   }
   {
     // if (sign != 0) {
     //     buf [--charPos] = sign;
     // }
     IfNode* iff = kit.create_and_map_if(kit.control(),
                                         __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
                                         PROB_FAIR, COUNT_UNKNOWN);
     final_merge->init_req(2, __ IfFalse(iff));
     final_mem->init_req(2, kit.memory(char_adr_idx));
     kit.set_control(__ IfTrue(iff));
     if (kit.stopped()) {
       final_merge->init_req(1, C->top());
       final_mem->init_req(1, C->top());
     } else {
       Node* m1 = __ SubI(charPos, __ intcon(1));
       Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
                                     sign, T_CHAR, char_adr_idx, MemNode::unordered);
       final_merge->init_req(1, kit.control());
       final_mem->init_req(1, st);
     }
     kit.set_control(final_merge);
     kit.set_memory(final_mem, char_adr_idx);
     C->record_for_igvn(final_merge);
     C->record_for_igvn(final_mem);
   }
 }
 Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) {
   Node* string = str;
   Node* offset = kit.load_String_offset(kit.control(), string);
   Node* count  = kit.load_String_length(kit.control(), string);
   Node* value  = kit.load_String_value (kit.control(), string);
   // copy the contents
   if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) {
     // For small constant strings just emit individual stores.
     // A length of 6 seems like a good space/speed tradeof.
     int c = count->get_int();
     int o = offset->get_int();
     const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr();
     ciTypeArray* value_array = t->const_oop()->as_type_array();
     for (int e = 0; e < c; e++) {
       __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
                          __ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx,
                          MemNode::unordered);
       start = __ AddI(start, __ intcon(1));
     }
   } else {
     Node* src_ptr = kit.array_element_address(value, offset, T_CHAR);
     Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR);
     Node* c = count;
     Node* extra = NULL;
 #ifdef _LP64
     c = __ ConvI2L(c);
     extra = C->top();
 #endif
     Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP,
                                        OptoRuntime::fast_arraycopy_Type(),
                                        CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()),
                                        "jshort_disjoint_arraycopy", TypeAryPtr::CHARS,
                                        src_ptr, dst_ptr, c, extra);
     start = __ AddI(start, count);
   }
   return start;
 }
 void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
   // Log a little info about the transformation
   sc->maybe_log_transform();
   // pull the JVMState of the allocation into a SafePointNode to serve as
   // as a shim for the insertion of the new code.
   JVMState* jvms     = sc->begin()->jvms()->clone_shallow(C);
   uint size = sc->begin()->req();
   SafePointNode* map = new (C) SafePointNode(size, jvms);
   // copy the control and memory state from the final call into our
   // new starting state.  This allows any preceeding tests to feed
   // into the new section of code.
   for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
     map->init_req(i1, sc->end()->in(i1));
   }
   // blow away old allocation arguments
   for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
     map->init_req(i1, C->top());
   }
   // Copy the rest of the inputs for the JVMState
   for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
     map->init_req(i1, sc->begin()->in(i1));
   }
   // Make sure the memory state is a MergeMem for parsing.
   if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
     map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
   }
   jvms->set_map(map);
   map->ensure_stack(jvms, jvms->method()->max_stack());
   // disconnect all the old StringBuilder calls from the graph
   sc->eliminate_unneeded_control();
   // At this point all the old work has been completely removed from
   // the graph and the saved JVMState exists at the point where the
   // final toString call used to be.
   GraphKit kit(jvms);
   // There may be uncommon traps which are still using the
   // intermediate states and these need to be rewritten to point at
   // the JVMState at the beginning of the transformation.
   sc->convert_uncommon_traps(kit, jvms);
   // Now insert the logic to compute the size of the string followed
   // by all the logic to construct array and resulting string.
   Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
   // Create a region for the overflow checks to merge into.
   int args = MAX2(sc->num_arguments(), 1);
   RegionNode* overflow = new (C) RegionNode(args);
   kit.gvn().set_type(overflow, Type::CONTROL);
   // Create a hook node to hold onto the individual sizes since they
   // are need for the copying phase.
   Node* string_sizes = new (C) Node(args);
   Node* length = __ intcon(0);
   for (int argi = 0; argi < sc->num_arguments(); argi++) {
     Node* arg = sc->argument(argi);
     switch (sc->mode(argi)) {
       case StringConcat::IntMode: {
         Node* string_size = int_stringSize(kit, arg);
         // accumulate total
         length = __ AddI(length, string_size);
         // Cache this value for the use by int_toString
         string_sizes->init_req(argi, string_size);
         break;
       }
       case StringConcat::StringNullCheckMode: {
         const Type* type = kit.gvn().type(arg);
         assert(type != TypePtr::NULL_PTR, "missing check");
         if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
           // Null check with uncommont trap since
           // StringBuilder(null) throws exception.
           // Use special uncommon trap instead of
           // calling normal do_null_check().
           Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
           IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
           overflow->add_req(__ IfFalse(iff));
           Node* notnull = __ IfTrue(iff);
           kit.set_control(notnull); // set control for the cast_not_null
           arg = kit.cast_not_null(arg, false);
           sc->set_argument(argi, arg);
         }
         assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity");
         // Fallthrough to add string length.
       }
       case StringConcat::StringMode: {
         const Type* type = kit.gvn().type(arg);
         if (type == TypePtr::NULL_PTR) {
           // replace the argument with the null checked version
           arg = null_string;
           sc->set_argument(argi, arg);
         } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
           // s = s != null ? s : "null";
           // length = length + (s.count - s.offset);
           RegionNode *r = new (C) RegionNode(3);
           kit.gvn().set_type(r, Type::CONTROL);
           Node *phi = new (C) PhiNode(r, type);
           kit.gvn().set_type(phi, phi->bottom_type());
           Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
           IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
           Node* notnull = __ IfTrue(iff);
           Node* isnull =  __ IfFalse(iff);
           kit.set_control(notnull); // set control for the cast_not_null
           r->init_req(1, notnull);
           phi->init_req(1, kit.cast_not_null(arg, false));
           r->init_req(2, isnull);
           phi->init_req(2, null_string);
           kit.set_control(r);
           C->record_for_igvn(r);
           C->record_for_igvn(phi);
           // replace the argument with the null checked version
           arg = phi;
           sc->set_argument(argi, arg);
         }
         Node* count = kit.load_String_length(kit.control(), arg);
         length = __ AddI(length, count);
         string_sizes->init_req(argi, NULL);
         break;
       }
       case StringConcat::CharMode: {
         // one character only
         length = __ AddI(length, __ intcon(1));
         break;
       }
       default:
         ShouldNotReachHere();
     }
     if (argi > 0) {
       // Check that the sum hasn't overflowed
       IfNode* iff = kit.create_and_map_if(kit.control(),
                                           __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
                                           PROB_MIN, COUNT_UNKNOWN);
       kit.set_control(__ IfFalse(iff));
       overflow->set_req(argi, __ IfTrue(iff));
     }
   }
   {
     // Hook
     PreserveJVMState pjvms(&kit);
     kit.set_control(overflow);
     C->record_for_igvn(overflow);
     kit.uncommon_trap(Deoptimization::Reason_intrinsic,
                       Deoptimization::Action_make_not_entrant);
   }
   Node* result;
   if (!kit.stopped()) {
     // length now contains the number of characters needed for the
     // char[] so create a new AllocateArray for the char[]
     Node* char_array = NULL;
     {
       PreserveReexecuteState preexecs(&kit);
       // The original jvms is for an allocation of either a String or
       // StringBuffer so no stack adjustment is necessary for proper
       // reexecution.  If we deoptimize in the slow path the bytecode
       // will be reexecuted and the char[] allocation will be thrown away.
       kit.jvms()->set_should_reexecute(true);
       char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))),
                                  length, 1);
     }
     // Mark the allocation so that zeroing is skipped since the code
     // below will overwrite the entire array
     AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
     char_alloc->maybe_set_complete(_gvn);
     // Now copy the string representations into the final char[]
     Node* start = __ intcon(0);
     for (int argi = 0; argi < sc->num_arguments(); argi++) {
       Node* arg = sc->argument(argi);
       switch (sc->mode(argi)) {
         case StringConcat::IntMode: {
           Node* end = __ AddI(start, string_sizes->in(argi));
           // getChars words backwards so pass the ending point as well as the start
           int_getChars(kit, arg, char_array, start, end);
           start = end;
           break;
         }
         case StringConcat::StringNullCheckMode:
         case StringConcat::StringMode: {
           start = copy_string(kit, arg, char_array, start);
           break;
         }
         case StringConcat::CharMode: {
           __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
                              arg, T_CHAR, char_adr_idx, MemNode::unordered);
           start = __ AddI(start, __ intcon(1));
           break;
         }
         default:
           ShouldNotReachHere();
       }
     }
     // If we're not reusing an existing String allocation then allocate one here.
     result = sc->string_alloc();
     if (result == NULL) {
       PreserveReexecuteState preexecs(&kit);
       // The original jvms is for an allocation of either a String or
       // StringBuffer so no stack adjustment is necessary for proper
       // reexecution.
       kit.jvms()->set_should_reexecute(true);
       result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
     }
     // Intialize the string
     if (java_lang_String::has_offset_field()) {
       kit.store_String_offset(kit.control(), result, __ intcon(0));
       kit.store_String_length(kit.control(), result, length);
     }
     kit.store_String_value(kit.control(), result, char_array);
   } else {
     result = C->top();
   }
   // hook up the outgoing control and result
   kit.replace_call(sc->end(), result);
   // Unhook any hook nodes
   string_sizes->disconnect_inputs(NULL, C);
   sc->cleanup();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/opto/stringopts.cpp@f90c822e73f8 (annotated)

src/share/vm/opto/stringopts.cpp