aoqi@0: /*
aoqi@0:  * Copyright (c) 2009, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "compiler/compileLog.hpp"
aoqi@0: #include "opto/addnode.hpp"
aoqi@0: #include "opto/callGenerator.hpp"
aoqi@0: #include "opto/callnode.hpp"
aoqi@0: #include "opto/divnode.hpp"
aoqi@0: #include "opto/graphKit.hpp"
aoqi@0: #include "opto/idealKit.hpp"
aoqi@0: #include "opto/rootnode.hpp"
aoqi@0: #include "opto/runtime.hpp"
aoqi@0: #include "opto/stringopts.hpp"
aoqi@0: #include "opto/subnode.hpp"
aoqi@0: 
aoqi@0: #define __ kit.
aoqi@0: 
aoqi@0: class StringConcat : public ResourceObj {
aoqi@0:  private:
aoqi@0:   PhaseStringOpts*    _stringopts;
aoqi@0:   Node*               _string_alloc;
aoqi@0:   AllocateNode*       _begin;          // The allocation the begins the pattern
aoqi@0:   CallStaticJavaNode* _end;            // The final call of the pattern.  Will either be
aoqi@0:                                        // SB.toString or or String.<init>(SB.toString)
aoqi@0:   bool                _multiple;       // indicates this is a fusion of two or more
aoqi@0:                                        // separate StringBuilders
aoqi@0: 
aoqi@0:   Node*               _arguments;      // The list of arguments to be concatenated
aoqi@0:   GrowableArray<int>  _mode;           // into a String along with a mode flag
aoqi@0:                                        // indicating how to treat the value.
aoqi@0:   Node_List           _constructors;   // List of constructors (many in case of stacked concat)
aoqi@0:   Node_List           _control;        // List of control nodes that will be deleted
aoqi@0:   Node_List           _uncommon_traps; // Uncommon traps that needs to be rewritten
aoqi@0:                                        // to restart at the initial JVMState.
aoqi@0: 
aoqi@0:  public:
aoqi@0:   // Mode for converting arguments to Strings
aoqi@0:   enum {
aoqi@0:     StringMode,
aoqi@0:     IntMode,
aoqi@0:     CharMode,
aoqi@0:     StringNullCheckMode
aoqi@0:   };
aoqi@0: 
aoqi@0:   StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
aoqi@0:     _end(end),
aoqi@0:     _begin(NULL),
aoqi@0:     _multiple(false),
aoqi@0:     _string_alloc(NULL),
aoqi@0:     _stringopts(stringopts) {
aoqi@0:     _arguments = new (_stringopts->C) Node(1);
aoqi@0:     _arguments->del_req(0);
aoqi@0:   }
aoqi@0: 
aoqi@0:   bool validate_mem_flow();
aoqi@0:   bool validate_control_flow();
aoqi@0: 
aoqi@0:   void merge_add() {
aoqi@0: #if 0
aoqi@0:     // XXX This is place holder code for reusing an existing String
aoqi@0:     // allocation but the logic for checking the state safety is
aoqi@0:     // probably inadequate at the moment.
aoqi@0:     CallProjections endprojs;
aoqi@0:     sc->end()->extract_projections(&endprojs, false);
aoqi@0:     if (endprojs.resproj != NULL) {
aoqi@0:       for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
aoqi@0:         CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
aoqi@0:         if (use != NULL && use->method() != NULL &&
aoqi@0:             use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
aoqi@0:             use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
aoqi@0:           // Found useless new String(sb.toString()) so reuse the newly allocated String
aoqi@0:           // when creating the result instead of allocating a new one.
aoqi@0:           sc->set_string_alloc(use->in(TypeFunc::Parms));
aoqi@0:           sc->set_end(use);
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0: #endif
aoqi@0:   }
aoqi@0: 
aoqi@0:   StringConcat* merge(StringConcat* other, Node* arg);
aoqi@0: 
aoqi@0:   void set_allocation(AllocateNode* alloc) {
aoqi@0:     _begin = alloc;
aoqi@0:   }
aoqi@0: 
aoqi@0:   void append(Node* value, int mode) {
aoqi@0:     _arguments->add_req(value);
aoqi@0:     _mode.append(mode);
aoqi@0:   }
aoqi@0:   void push(Node* value, int mode) {
aoqi@0:     _arguments->ins_req(0, value);
aoqi@0:     _mode.insert_before(0, mode);
aoqi@0:   }
aoqi@0: 
aoqi@0:   void push_string(Node* value) {
aoqi@0:     push(value, StringMode);
aoqi@0:   }
aoqi@0:   void push_string_null_check(Node* value) {
aoqi@0:     push(value, StringNullCheckMode);
aoqi@0:   }
aoqi@0:   void push_int(Node* value) {
aoqi@0:     push(value, IntMode);
aoqi@0:   }
aoqi@0:   void push_char(Node* value) {
aoqi@0:     push(value, CharMode);
aoqi@0:   }
aoqi@0: 
aoqi@0:   static bool is_SB_toString(Node* call) {
aoqi@0:     if (call->is_CallStaticJava()) {
aoqi@0:       CallStaticJavaNode* csj = call->as_CallStaticJava();
aoqi@0:       ciMethod* m = csj->method();
aoqi@0:       if (m != NULL &&
aoqi@0:           (m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
aoqi@0:            m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
aoqi@0:         return true;
aoqi@0:       }
aoqi@0:     }
aoqi@0:     return false;
aoqi@0:   }
aoqi@0: 
aoqi@0:   static Node* skip_string_null_check(Node* value) {
aoqi@0:     // Look for a diamond shaped Null check of toString() result
aoqi@0:     // (could be code from String.valueOf()):
aoqi@0:     // (Proj == NULL) ? "null":"CastPP(Proj)#NotNULL
aoqi@0:     if (value->is_Phi()) {
aoqi@0:       int true_path = value->as_Phi()->is_diamond_phi();
aoqi@0:       if (true_path != 0) {
aoqi@0:         // phi->region->if_proj->ifnode->bool
aoqi@0:         BoolNode* b = value->in(0)->in(1)->in(0)->in(1)->as_Bool();
aoqi@0:         Node* cmp = b->in(1);
aoqi@0:         Node* v1 = cmp->in(1);
aoqi@0:         Node* v2 = cmp->in(2);
aoqi@0:         // Null check of the return of toString which can simply be skipped.
aoqi@0:         if (b->_test._test == BoolTest::ne &&
aoqi@0:             v2->bottom_type() == TypePtr::NULL_PTR &&
aoqi@0:             value->in(true_path)->Opcode() == Op_CastPP &&
aoqi@0:             value->in(true_path)->in(1) == v1 &&
aoqi@0:             v1->is_Proj() && is_SB_toString(v1->in(0))) {
aoqi@0:           return v1;
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:     return value;
aoqi@0:   }
aoqi@0: 
aoqi@0:   Node* argument(int i) {
aoqi@0:     return _arguments->in(i);
aoqi@0:   }
aoqi@0:   Node* argument_uncast(int i) {
aoqi@0:     Node* arg = argument(i);
aoqi@0:     int amode = mode(i);
aoqi@0:     if (amode == StringConcat::StringMode ||
aoqi@0:         amode == StringConcat::StringNullCheckMode) {
aoqi@0:       arg = skip_string_null_check(arg);
aoqi@0:     }
aoqi@0:     return arg;
aoqi@0:   }
aoqi@0:   void set_argument(int i, Node* value) {
aoqi@0:     _arguments->set_req(i, value);
aoqi@0:   }
aoqi@0:   int num_arguments() {
aoqi@0:     return _mode.length();
aoqi@0:   }
aoqi@0:   int mode(int i) {
aoqi@0:     return _mode.at(i);
aoqi@0:   }
aoqi@0:   void add_control(Node* ctrl) {
aoqi@0:     assert(!_control.contains(ctrl), "only push once");
aoqi@0:     _control.push(ctrl);
aoqi@0:   }
aoqi@0:   void add_constructor(Node* init) {
aoqi@0:     assert(!_constructors.contains(init), "only push once");
aoqi@0:     _constructors.push(init);
aoqi@0:   }
aoqi@0:   CallStaticJavaNode* end() { return _end; }
aoqi@0:   AllocateNode* begin() { return _begin; }
aoqi@0:   Node* string_alloc() { return _string_alloc; }
aoqi@0: 
aoqi@0:   void eliminate_unneeded_control();
aoqi@0:   void eliminate_initialize(InitializeNode* init);
aoqi@0:   void eliminate_call(CallNode* call);
aoqi@0: 
aoqi@0:   void maybe_log_transform() {
aoqi@0:     CompileLog* log = _stringopts->C->log();
aoqi@0:     if (log != NULL) {
aoqi@0:       log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
aoqi@0:                 num_arguments(),
aoqi@0:                 _string_alloc != NULL,
aoqi@0:                 _multiple);
aoqi@0:       JVMState* p = _begin->jvms();
aoqi@0:       while (p != NULL) {
aoqi@0:         log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
aoqi@0:         p = p->caller();
aoqi@0:       }
aoqi@0:       log->tail("replace_string_concat");
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
aoqi@0:     for (uint u = 0; u < _uncommon_traps.size(); u++) {
aoqi@0:       Node* uct = _uncommon_traps.at(u);
aoqi@0: 
aoqi@0:       // Build a new call using the jvms state of the allocate
aoqi@0:       address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
aoqi@0:       const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
aoqi@0:       const TypePtr* no_memory_effects = NULL;
aoqi@0:       Compile* C = _stringopts->C;
aoqi@0:       CallStaticJavaNode* call = new (C) CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
aoqi@0:                                                             jvms->bci(), no_memory_effects);
aoqi@0:       for (int e = 0; e < TypeFunc::Parms; e++) {
aoqi@0:         call->init_req(e, uct->in(e));
aoqi@0:       }
aoqi@0:       // Set the trap request to record intrinsic failure if this trap
aoqi@0:       // is taken too many times.  Ideally we would handle then traps by
aoqi@0:       // doing the original bookkeeping in the MDO so that if it caused
aoqi@0:       // the code to be thrown out we could still recompile and use the
aoqi@0:       // optimization.  Failing the uncommon traps doesn't really mean
aoqi@0:       // that the optimization is a bad idea but there's no other way to
aoqi@0:       // do the MDO updates currently.
aoqi@0:       int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
aoqi@0:                                                            Deoptimization::Action_make_not_entrant);
aoqi@0:       call->init_req(TypeFunc::Parms, __ intcon(trap_request));
aoqi@0:       kit.add_safepoint_edges(call);
aoqi@0: 
aoqi@0:       _stringopts->gvn()->transform(call);
aoqi@0:       C->gvn_replace_by(uct, call);
aoqi@0:       uct->disconnect_inputs(NULL, C);
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   void cleanup() {
aoqi@0:     // disconnect the hook node
aoqi@0:     _arguments->disconnect_inputs(NULL, _stringopts->C);
aoqi@0:   }
aoqi@0: };
aoqi@0: 
aoqi@0: 
aoqi@0: void StringConcat::eliminate_unneeded_control() {
aoqi@0:   for (uint i = 0; i < _control.size(); i++) {
aoqi@0:     Node* n = _control.at(i);
aoqi@0:     if (n->is_Allocate()) {
aoqi@0:       eliminate_initialize(n->as_Allocate()->initialization());
aoqi@0:     }
aoqi@0:     if (n->is_Call()) {
aoqi@0:       if (n != _end) {
aoqi@0:         eliminate_call(n->as_Call());
aoqi@0:       }
aoqi@0:     } else if (n->is_IfTrue()) {
aoqi@0:       Compile* C = _stringopts->C;
aoqi@0:       C->gvn_replace_by(n, n->in(0)->in(0));
aoqi@0:       // get rid of the other projection
aoqi@0:       C->gvn_replace_by(n->in(0)->as_If()->proj_out(false), C->top());
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
aoqi@0:   StringConcat* result = new StringConcat(_stringopts, _end);
aoqi@0:   for (uint x = 0; x < _control.size(); x++) {
aoqi@0:     Node* n = _control.at(x);
aoqi@0:     if (n->is_Call()) {
aoqi@0:       result->_control.push(n);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   for (uint x = 0; x < other->_control.size(); x++) {
aoqi@0:     Node* n = other->_control.at(x);
aoqi@0:     if (n->is_Call()) {
aoqi@0:       result->_control.push(n);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   assert(result->_control.contains(other->_end), "what?");
aoqi@0:   assert(result->_control.contains(_begin), "what?");
aoqi@0:   for (int x = 0; x < num_arguments(); x++) {
aoqi@0:     Node* argx = argument_uncast(x);
aoqi@0:     if (argx == arg) {
aoqi@0:       // replace the toString result with the all the arguments that
aoqi@0:       // made up the other StringConcat
aoqi@0:       for (int y = 0; y < other->num_arguments(); y++) {
aoqi@0:         result->append(other->argument(y), other->mode(y));
aoqi@0:       }
aoqi@0:     } else {
aoqi@0:       result->append(argx, mode(x));
aoqi@0:     }
aoqi@0:   }
aoqi@0:   result->set_allocation(other->_begin);
aoqi@0:   for (uint i = 0; i < _constructors.size(); i++) {
aoqi@0:     result->add_constructor(_constructors.at(i));
aoqi@0:   }
aoqi@0:   for (uint i = 0; i < other->_constructors.size(); i++) {
aoqi@0:     result->add_constructor(other->_constructors.at(i));
aoqi@0:   }
aoqi@0:   result->_multiple = true;
aoqi@0:   return result;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void StringConcat::eliminate_call(CallNode* call) {
aoqi@0:   Compile* C = _stringopts->C;
aoqi@0:   CallProjections projs;
aoqi@0:   call->extract_projections(&projs, false);
aoqi@0:   if (projs.fallthrough_catchproj != NULL) {
aoqi@0:     C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
aoqi@0:   }
aoqi@0:   if (projs.fallthrough_memproj != NULL) {
aoqi@0:     C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
aoqi@0:   }
aoqi@0:   if (projs.catchall_memproj != NULL) {
aoqi@0:     C->gvn_replace_by(projs.catchall_memproj, C->top());
aoqi@0:   }
aoqi@0:   if (projs.fallthrough_ioproj != NULL) {
aoqi@0:     C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
aoqi@0:   }
aoqi@0:   if (projs.catchall_ioproj != NULL) {
aoqi@0:     C->gvn_replace_by(projs.catchall_ioproj, C->top());
aoqi@0:   }
aoqi@0:   if (projs.catchall_catchproj != NULL) {
aoqi@0:     // EA can't cope with the partially collapsed graph this
aoqi@0:     // creates so put it on the worklist to be collapsed later.
aoqi@0:     for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
aoqi@0:       Node *use = i.get();
aoqi@0:       int opc = use->Opcode();
aoqi@0:       if (opc == Op_CreateEx || opc == Op_Region) {
aoqi@0:         _stringopts->record_dead_node(use);
aoqi@0:       }
aoqi@0:     }
aoqi@0:     C->gvn_replace_by(projs.catchall_catchproj, C->top());
aoqi@0:   }
aoqi@0:   if (projs.resproj != NULL) {
aoqi@0:     C->gvn_replace_by(projs.resproj, C->top());
aoqi@0:   }
aoqi@0:   C->gvn_replace_by(call, C->top());
aoqi@0: }
aoqi@0: 
aoqi@0: void StringConcat::eliminate_initialize(InitializeNode* init) {
aoqi@0:   Compile* C = _stringopts->C;
aoqi@0: 
aoqi@0:   // Eliminate Initialize node.
aoqi@0:   assert(init->outcnt() <= 2, "only a control and memory projection expected");
aoqi@0:   assert(init->req() <= InitializeNode::RawStores, "no pending inits");
aoqi@0:   Node *ctrl_proj = init->proj_out(TypeFunc::Control);
aoqi@0:   if (ctrl_proj != NULL) {
aoqi@0:     C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
aoqi@0:   }
aoqi@0:   Node *mem_proj = init->proj_out(TypeFunc::Memory);
aoqi@0:   if (mem_proj != NULL) {
aoqi@0:     Node *mem = init->in(TypeFunc::Memory);
aoqi@0:     C->gvn_replace_by(mem_proj, mem);
aoqi@0:   }
aoqi@0:   C->gvn_replace_by(init, C->top());
aoqi@0:   init->disconnect_inputs(NULL, C);
aoqi@0: }
aoqi@0: 
aoqi@0: Node_List PhaseStringOpts::collect_toString_calls() {
aoqi@0:   Node_List string_calls;
aoqi@0:   Node_List worklist;
aoqi@0: 
aoqi@0:   _visited.Clear();
aoqi@0: 
aoqi@0:   // Prime the worklist
aoqi@0:   for (uint i = 1; i < C->root()->len(); i++) {
aoqi@0:     Node* n = C->root()->in(i);
aoqi@0:     if (n != NULL && !_visited.test_set(n->_idx)) {
aoqi@0:       worklist.push(n);
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   while (worklist.size() > 0) {
aoqi@0:     Node* ctrl = worklist.pop();
aoqi@0:     if (StringConcat::is_SB_toString(ctrl)) {
aoqi@0:       CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
aoqi@0:       string_calls.push(csj);
aoqi@0:     }
aoqi@0:     if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
aoqi@0:       worklist.push(ctrl->in(0));
aoqi@0:     }
aoqi@0:     if (ctrl->is_Region()) {
aoqi@0:       for (uint i = 1; i < ctrl->len(); i++) {
aoqi@0:         if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
aoqi@0:           worklist.push(ctrl->in(i));
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return string_calls;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
aoqi@0:   ciMethod* m = call->method();
aoqi@0:   ciSymbol* string_sig;
aoqi@0:   ciSymbol* int_sig;
aoqi@0:   ciSymbol* char_sig;
aoqi@0:   if (m->holder() == C->env()->StringBuilder_klass()) {
aoqi@0:     string_sig = ciSymbol::String_StringBuilder_signature();
aoqi@0:     int_sig = ciSymbol::int_StringBuilder_signature();
aoqi@0:     char_sig = ciSymbol::char_StringBuilder_signature();
aoqi@0:   } else if (m->holder() == C->env()->StringBuffer_klass()) {
aoqi@0:     string_sig = ciSymbol::String_StringBuffer_signature();
aoqi@0:     int_sig = ciSymbol::int_StringBuffer_signature();
aoqi@0:     char_sig = ciSymbol::char_StringBuffer_signature();
aoqi@0:   } else {
aoqi@0:     return NULL;
aoqi@0:   }
aoqi@0: #ifndef PRODUCT
aoqi@0:   if (PrintOptimizeStringConcat) {
aoqi@0:     tty->print("considering toString call in ");
aoqi@0:     call->jvms()->dump_spec(tty); tty->cr();
aoqi@0:   }
aoqi@0: #endif
aoqi@0: 
aoqi@0:   StringConcat* sc = new StringConcat(this, call);
aoqi@0: 
aoqi@0:   AllocateNode* alloc = NULL;
aoqi@0:   InitializeNode* init = NULL;
aoqi@0: 
aoqi@0:   // possible opportunity for StringBuilder fusion
aoqi@0:   CallStaticJavaNode* cnode = call;
aoqi@0:   while (cnode) {
aoqi@0:     Node* recv = cnode->in(TypeFunc::Parms)->uncast();
aoqi@0:     if (recv->is_Proj()) {
aoqi@0:       recv = recv->in(0);
aoqi@0:     }
aoqi@0:     cnode = recv->isa_CallStaticJava();
aoqi@0:     if (cnode == NULL) {
aoqi@0:       alloc = recv->isa_Allocate();
aoqi@0:       if (alloc == NULL) {
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       // Find the constructor call
aoqi@0:       Node* result = alloc->result_cast();
aoqi@0:       if (result == NULL || !result->is_CheckCastPP() || alloc->in(TypeFunc::Memory)->is_top()) {
aoqi@0:         // strange looking allocation
aoqi@0: #ifndef PRODUCT
aoqi@0:         if (PrintOptimizeStringConcat) {
aoqi@0:           tty->print("giving up because allocation looks strange ");
aoqi@0:           alloc->jvms()->dump_spec(tty); tty->cr();
aoqi@0:         }
aoqi@0: #endif
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       Node* constructor = NULL;
aoqi@0:       for (SimpleDUIterator i(result); i.has_next(); i.next()) {
aoqi@0:         CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
aoqi@0:         if (use != NULL &&
aoqi@0:             use->method() != NULL &&
aoqi@0:             !use->method()->is_static() &&
aoqi@0:             use->method()->name() == ciSymbol::object_initializer_name() &&
aoqi@0:             use->method()->holder() == m->holder()) {
aoqi@0:           // Matched the constructor.
aoqi@0:           ciSymbol* sig = use->method()->signature()->as_symbol();
aoqi@0:           if (sig == ciSymbol::void_method_signature() ||
aoqi@0:               sig == ciSymbol::int_void_signature() ||
aoqi@0:               sig == ciSymbol::string_void_signature()) {
aoqi@0:             if (sig == ciSymbol::string_void_signature()) {
aoqi@0:               // StringBuilder(String) so pick this up as the first argument
aoqi@0:               assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
aoqi@0:               const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1));
aoqi@0:               if (type == TypePtr::NULL_PTR) {
aoqi@0:                 // StringBuilder(null) throws exception.
aoqi@0: #ifndef PRODUCT
aoqi@0:                 if (PrintOptimizeStringConcat) {
aoqi@0:                   tty->print("giving up because StringBuilder(null) throws exception");
aoqi@0:                   alloc->jvms()->dump_spec(tty); tty->cr();
aoqi@0:                 }
aoqi@0: #endif
aoqi@0:                 return NULL;
aoqi@0:               }
aoqi@0:               // StringBuilder(str) argument needs null check.
aoqi@0:               sc->push_string_null_check(use->in(TypeFunc::Parms + 1));
aoqi@0:             }
aoqi@0:             // The int variant takes an initial size for the backing
aoqi@0:             // array so just treat it like the void version.
aoqi@0:             constructor = use;
aoqi@0:           } else {
aoqi@0: #ifndef PRODUCT
aoqi@0:             if (PrintOptimizeStringConcat) {
aoqi@0:               tty->print("unexpected constructor signature: %s", sig->as_utf8());
aoqi@0:             }
aoqi@0: #endif
aoqi@0:           }
aoqi@0:           break;
aoqi@0:         }
aoqi@0:       }
aoqi@0:       if (constructor == NULL) {
aoqi@0:         // couldn't find constructor
aoqi@0: #ifndef PRODUCT
aoqi@0:         if (PrintOptimizeStringConcat) {
aoqi@0:           tty->print("giving up because couldn't find constructor ");
aoqi@0:           alloc->jvms()->dump_spec(tty); tty->cr();
aoqi@0:         }
aoqi@0: #endif
aoqi@0:         break;
aoqi@0:       }
aoqi@0: 
aoqi@0:       // Walked all the way back and found the constructor call so see
aoqi@0:       // if this call converted into a direct string concatenation.
aoqi@0:       sc->add_control(call);
aoqi@0:       sc->add_control(constructor);
aoqi@0:       sc->add_control(alloc);
aoqi@0:       sc->set_allocation(alloc);
aoqi@0:       sc->add_constructor(constructor);
aoqi@0:       if (sc->validate_control_flow() && sc->validate_mem_flow()) {
aoqi@0:         return sc;
aoqi@0:       } else {
aoqi@0:         return NULL;
aoqi@0:       }
aoqi@0:     } else if (cnode->method() == NULL) {
aoqi@0:       break;
aoqi@0:     } else if (!cnode->method()->is_static() &&
aoqi@0:                cnode->method()->holder() == m->holder() &&
aoqi@0:                cnode->method()->name() == ciSymbol::append_name() &&
aoqi@0:                (cnode->method()->signature()->as_symbol() == string_sig ||
aoqi@0:                 cnode->method()->signature()->as_symbol() == char_sig ||
aoqi@0:                 cnode->method()->signature()->as_symbol() == int_sig)) {
aoqi@0:       sc->add_control(cnode);
aoqi@0:       Node* arg = cnode->in(TypeFunc::Parms + 1);
aoqi@0:       if (cnode->method()->signature()->as_symbol() == int_sig) {
aoqi@0:         sc->push_int(arg);
aoqi@0:       } else if (cnode->method()->signature()->as_symbol() == char_sig) {
aoqi@0:         sc->push_char(arg);
aoqi@0:       } else {
aoqi@0:         if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
aoqi@0:           CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
aoqi@0:           if (csj->method() != NULL &&
aoqi@0:               csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString &&
aoqi@0:               arg->outcnt() == 1) {
aoqi@0:             // _control is the list of StringBuilder calls nodes which
aoqi@0:             // will be replaced by new String code after this optimization.
aoqi@0:             // Integer::toString() call is not part of StringBuilder calls
aoqi@0:             // chain. It could be eliminated only if its result is used
aoqi@0:             // only by this SB calls chain.
aoqi@0:             // Another limitation: it should be used only once because
aoqi@0:             // it is unknown that it is used only by this SB calls chain
aoqi@0:             // until all related SB calls nodes are collected.
aoqi@0:             assert(arg->unique_out() == cnode, "sanity");
aoqi@0:             sc->add_control(csj);
aoqi@0:             sc->push_int(csj->in(TypeFunc::Parms));
aoqi@0:             continue;
aoqi@0:           }
aoqi@0:         }
aoqi@0:         sc->push_string(arg);
aoqi@0:       }
aoqi@0:       continue;
aoqi@0:     } else {
aoqi@0:       // some unhandled signature
aoqi@0: #ifndef PRODUCT
aoqi@0:       if (PrintOptimizeStringConcat) {
aoqi@0:         tty->print("giving up because encountered unexpected signature ");
aoqi@0:         cnode->tf()->dump(); tty->cr();
aoqi@0:         cnode->in(TypeFunc::Parms + 1)->dump();
aoqi@0:       }
aoqi@0: #endif
aoqi@0:       break;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return NULL;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
aoqi@0:   Phase(StringOpts),
aoqi@0:   _gvn(gvn),
aoqi@0:   _visited(Thread::current()->resource_area()) {
aoqi@0: 
aoqi@0:   assert(OptimizeStringConcat, "shouldn't be here");
aoqi@0: 
aoqi@0:   size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
aoqi@0:                                                                   ciSymbol::make("[I"), true);
aoqi@0:   if (size_table_field == NULL) {
aoqi@0:     // Something wrong so give up.
aoqi@0:     assert(false, "why can't we find Integer.sizeTable?");
aoqi@0:     return;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Collect the types needed to talk about the various slices of memory
aoqi@0:   char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS);
aoqi@0: 
aoqi@0:   // For each locally allocated StringBuffer see if the usages can be
aoqi@0:   // collapsed into a single String construction.
aoqi@0: 
aoqi@0:   // Run through the list of allocation looking for SB.toString to see
aoqi@0:   // if it's possible to fuse the usage of the SB into a single String
aoqi@0:   // construction.
aoqi@0:   GrowableArray<StringConcat*> concats;
aoqi@0:   Node_List toStrings = collect_toString_calls();
aoqi@0:   while (toStrings.size() > 0) {
aoqi@0:     StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
aoqi@0:     if (sc != NULL) {
aoqi@0:       concats.push(sc);
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   // try to coalesce separate concats
aoqi@0:  restart:
aoqi@0:   for (int c = 0; c < concats.length(); c++) {
aoqi@0:     StringConcat* sc = concats.at(c);
aoqi@0:     for (int i = 0; i < sc->num_arguments(); i++) {
aoqi@0:       Node* arg = sc->argument_uncast(i);
aoqi@0:       if (arg->is_Proj() && StringConcat::is_SB_toString(arg->in(0))) {
aoqi@0:         CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
aoqi@0:         for (int o = 0; o < concats.length(); o++) {
aoqi@0:           if (c == o) continue;
aoqi@0:           StringConcat* other = concats.at(o);
aoqi@0:           if (other->end() == csj) {
aoqi@0: #ifndef PRODUCT
aoqi@0:             if (PrintOptimizeStringConcat) {
aoqi@0:               tty->print_cr("considering stacked concats");
aoqi@0:             }
aoqi@0: #endif
aoqi@0: 
aoqi@0:             StringConcat* merged = sc->merge(other, arg);
aoqi@0:             if (merged->validate_control_flow() && merged->validate_mem_flow()) {
aoqi@0: #ifndef PRODUCT
aoqi@0:               if (PrintOptimizeStringConcat) {
aoqi@0:                 tty->print_cr("stacking would succeed");
aoqi@0:               }
aoqi@0: #endif
aoqi@0:               if (c < o) {
aoqi@0:                 concats.remove_at(o);
aoqi@0:                 concats.at_put(c, merged);
aoqi@0:               } else {
aoqi@0:                 concats.remove_at(c);
aoqi@0:                 concats.at_put(o, merged);
aoqi@0:               }
aoqi@0:               goto restart;
aoqi@0:             } else {
aoqi@0: #ifndef PRODUCT
aoqi@0:               if (PrintOptimizeStringConcat) {
aoqi@0:                 tty->print_cr("stacking would fail");
aoqi@0:               }
aoqi@0: #endif
aoqi@0:             }
aoqi@0:           }
aoqi@0:         }
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0: 
aoqi@0:   for (int c = 0; c < concats.length(); c++) {
aoqi@0:     StringConcat* sc = concats.at(c);
aoqi@0:     replace_string_concat(sc);
aoqi@0:   }
aoqi@0: 
aoqi@0:   remove_dead_nodes();
aoqi@0: }
aoqi@0: 
aoqi@0: void PhaseStringOpts::record_dead_node(Node* dead) {
aoqi@0:   dead_worklist.push(dead);
aoqi@0: }
aoqi@0: 
aoqi@0: void PhaseStringOpts::remove_dead_nodes() {
aoqi@0:   // Delete any dead nodes to make things clean enough that escape
aoqi@0:   // analysis doesn't get unhappy.
aoqi@0:   while (dead_worklist.size() > 0) {
aoqi@0:     Node* use = dead_worklist.pop();
aoqi@0:     int opc = use->Opcode();
aoqi@0:     switch (opc) {
aoqi@0:       case Op_Region: {
aoqi@0:         uint i = 1;
aoqi@0:         for (i = 1; i < use->req(); i++) {
aoqi@0:           if (use->in(i) != C->top()) {
aoqi@0:             break;
aoqi@0:           }
aoqi@0:         }
aoqi@0:         if (i >= use->req()) {
aoqi@0:           for (SimpleDUIterator i(use); i.has_next(); i.next()) {
aoqi@0:             Node* m = i.get();
aoqi@0:             if (m->is_Phi()) {
aoqi@0:               dead_worklist.push(m);
aoqi@0:             }
aoqi@0:           }
aoqi@0:           C->gvn_replace_by(use, C->top());
aoqi@0:         }
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       case Op_AddP:
aoqi@0:       case Op_CreateEx: {
aoqi@0:         // Recurisvely clean up references to CreateEx so EA doesn't
aoqi@0:         // get unhappy about the partially collapsed graph.
aoqi@0:         for (SimpleDUIterator i(use); i.has_next(); i.next()) {
aoqi@0:           Node* m = i.get();
aoqi@0:           if (m->is_AddP()) {
aoqi@0:             dead_worklist.push(m);
aoqi@0:           }
aoqi@0:         }
aoqi@0:         C->gvn_replace_by(use, C->top());
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       case Op_Phi:
aoqi@0:         if (use->in(0) == C->top()) {
aoqi@0:           C->gvn_replace_by(use, C->top());
aoqi@0:         }
aoqi@0:         break;
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool StringConcat::validate_mem_flow() {
aoqi@0:   Compile* C = _stringopts->C;
aoqi@0: 
aoqi@0:   for (uint i = 0; i < _control.size(); i++) {
aoqi@0: #ifndef PRODUCT
aoqi@0:     Node_List path;
aoqi@0: #endif
aoqi@0:     Node* curr = _control.at(i);
aoqi@0:     if (curr->is_Call() && curr != _begin) { // For all calls except the first allocation
aoqi@0:       // Now here's the main invariant in our case:
aoqi@0:       // For memory between the constructor, and appends, and toString we should only see bottom memory,
aoqi@0:       // produced by the previous call we know about.
aoqi@0:       if (!_constructors.contains(curr)) {
aoqi@0:         NOT_PRODUCT(path.push(curr);)
aoqi@0:         Node* mem = curr->in(TypeFunc::Memory);
aoqi@0:         assert(mem != NULL, "calls should have memory edge");
aoqi@0:         assert(!mem->is_Phi(), "should be handled by control flow validation");
aoqi@0:         NOT_PRODUCT(path.push(mem);)
aoqi@0:         while (mem->is_MergeMem()) {
aoqi@0:           for (uint i = 1; i < mem->req(); i++) {
aoqi@0:             if (i != Compile::AliasIdxBot && mem->in(i) != C->top()) {
aoqi@0: #ifndef PRODUCT
aoqi@0:               if (PrintOptimizeStringConcat) {
aoqi@0:                 tty->print("fusion has incorrect memory flow (side effects) for ");
aoqi@0:                 _begin->jvms()->dump_spec(tty); tty->cr();
aoqi@0:                 path.dump();
aoqi@0:               }
aoqi@0: #endif
aoqi@0:               return false;
aoqi@0:             }
aoqi@0:           }
aoqi@0:           // skip through a potential MergeMem chain, linked through Bot
aoqi@0:           mem = mem->in(Compile::AliasIdxBot);
aoqi@0:           NOT_PRODUCT(path.push(mem);)
aoqi@0:         }
aoqi@0:         // now let it fall through, and see if we have a projection
aoqi@0:         if (mem->is_Proj()) {
aoqi@0:           // Should point to a previous known call
aoqi@0:           Node *prev = mem->in(0);
aoqi@0:           NOT_PRODUCT(path.push(prev);)
aoqi@0:           if (!prev->is_Call() || !_control.contains(prev)) {
aoqi@0: #ifndef PRODUCT
aoqi@0:             if (PrintOptimizeStringConcat) {
aoqi@0:               tty->print("fusion has incorrect memory flow (unknown call) for ");
aoqi@0:               _begin->jvms()->dump_spec(tty); tty->cr();
aoqi@0:               path.dump();
aoqi@0:             }
aoqi@0: #endif
aoqi@0:             return false;
aoqi@0:           }
aoqi@0:         } else {
aoqi@0:           assert(mem->is_Store() || mem->is_LoadStore(), err_msg_res("unexpected node type: %s", mem->Name()));
aoqi@0: #ifndef PRODUCT
aoqi@0:           if (PrintOptimizeStringConcat) {
aoqi@0:             tty->print("fusion has incorrect memory flow (unexpected source) for ");
aoqi@0:             _begin->jvms()->dump_spec(tty); tty->cr();
aoqi@0:             path.dump();
aoqi@0:           }
aoqi@0: #endif
aoqi@0:           return false;
aoqi@0:         }
aoqi@0:       } else {
aoqi@0:         // For memory that feeds into constructors it's more complicated.
aoqi@0:         // However the advantage is that any side effect that happens between the Allocate/Initialize and
aoqi@0:         // the constructor will have to be control-dependent on Initialize.
aoqi@0:         // So we actually don't have to do anything, since it's going to be caught by the control flow
aoqi@0:         // analysis.
aoqi@0: #ifdef ASSERT
aoqi@0:         // Do a quick verification of the control pattern between the constructor and the initialize node
aoqi@0:         assert(curr->is_Call(), "constructor should be a call");
aoqi@0:         // Go up the control starting from the constructor call
aoqi@0:         Node* ctrl = curr->in(0);
aoqi@0:         IfNode* iff = NULL;
aoqi@0:         RegionNode* copy = NULL;
aoqi@0: 
aoqi@0:         while (true) {
aoqi@0:           // skip known check patterns
aoqi@0:           if (ctrl->is_Region()) {
aoqi@0:             if (ctrl->as_Region()->is_copy()) {
aoqi@0:               copy = ctrl->as_Region();
aoqi@0:               ctrl = copy->is_copy();
aoqi@0:             } else { // a cast
aoqi@0:               assert(ctrl->req() == 3 &&
aoqi@0:                      ctrl->in(1) != NULL && ctrl->in(1)->is_Proj() &&
aoqi@0:                      ctrl->in(2) != NULL && ctrl->in(2)->is_Proj() &&
aoqi@0:                      ctrl->in(1)->in(0) == ctrl->in(2)->in(0) &&
aoqi@0:                      ctrl->in(1)->in(0) != NULL && ctrl->in(1)->in(0)->is_If(),
aoqi@0:                      "must be a simple diamond");
aoqi@0:               Node* true_proj = ctrl->in(1)->is_IfTrue() ? ctrl->in(1) : ctrl->in(2);
aoqi@0:               for (SimpleDUIterator i(true_proj); i.has_next(); i.next()) {
aoqi@0:                 Node* use = i.get();
aoqi@0:                 assert(use == ctrl || use->is_ConstraintCast(),
aoqi@0:                        err_msg_res("unexpected user: %s", use->Name()));
aoqi@0:               }
aoqi@0: 
aoqi@0:               iff = ctrl->in(1)->in(0)->as_If();
aoqi@0:               ctrl = iff->in(0);
aoqi@0:             }
aoqi@0:           } else if (ctrl->is_IfTrue()) { // null checks, class checks
aoqi@0:             iff = ctrl->in(0)->as_If();
aoqi@0:             assert(iff->is_If(), "must be if");
aoqi@0:             // Verify that the other arm is an uncommon trap
aoqi@0:             Node* otherproj = iff->proj_out(1 - ctrl->as_Proj()->_con);
aoqi@0:             CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
aoqi@0:             assert(strcmp(call->_name, "uncommon_trap") == 0, "must be uncommond trap");
aoqi@0:             ctrl = iff->in(0);
aoqi@0:           } else {
aoqi@0:             break;
aoqi@0:           }
aoqi@0:         }
aoqi@0: 
aoqi@0:         assert(ctrl->is_Proj(), "must be a projection");
aoqi@0:         assert(ctrl->in(0)->is_Initialize(), "should be initialize");
aoqi@0:         for (SimpleDUIterator i(ctrl); i.has_next(); i.next()) {
aoqi@0:           Node* use = i.get();
aoqi@0:           assert(use == copy || use == iff || use == curr || use->is_CheckCastPP() || use->is_Load(),
aoqi@0:                  err_msg_res("unexpected user: %s", use->Name()));
aoqi@0:         }
aoqi@0: #endif // ASSERT
aoqi@0:       }
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0:   if (PrintOptimizeStringConcat) {
aoqi@0:     tty->print("fusion has correct memory flow for ");
aoqi@0:     _begin->jvms()->dump_spec(tty); tty->cr();
aoqi@0:     tty->cr();
aoqi@0:   }
aoqi@0: #endif
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: bool StringConcat::validate_control_flow() {
aoqi@0:   // We found all the calls and arguments now lets see if it's
aoqi@0:   // safe to transform the graph as we would expect.
aoqi@0: 
aoqi@0:   // Check to see if this resulted in too many uncommon traps previously
aoqi@0:   if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
aoqi@0:                         Deoptimization::Reason_intrinsic)) {
aoqi@0:     return false;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Walk backwards over the control flow from toString to the
aoqi@0:   // allocation and make sure all the control flow is ok.  This
aoqi@0:   // means it's either going to be eliminated once the calls are
aoqi@0:   // removed or it can safely be transformed into an uncommon
aoqi@0:   // trap.
aoqi@0: 
aoqi@0:   int null_check_count = 0;
aoqi@0:   Unique_Node_List ctrl_path;
aoqi@0: 
aoqi@0:   assert(_control.contains(_begin), "missing");
aoqi@0:   assert(_control.contains(_end), "missing");
aoqi@0: 
aoqi@0:   // Collect the nodes that we know about and will eliminate into ctrl_path
aoqi@0:   for (uint i = 0; i < _control.size(); i++) {
aoqi@0:     // Push the call and it's control projection
aoqi@0:     Node* n = _control.at(i);
aoqi@0:     if (n->is_Allocate()) {
aoqi@0:       AllocateNode* an = n->as_Allocate();
aoqi@0:       InitializeNode* init = an->initialization();
aoqi@0:       ctrl_path.push(init);
aoqi@0:       ctrl_path.push(init->as_Multi()->proj_out(0));
aoqi@0:     }
aoqi@0:     if (n->is_Call()) {
aoqi@0:       CallNode* cn = n->as_Call();
aoqi@0:       ctrl_path.push(cn);
aoqi@0:       ctrl_path.push(cn->proj_out(0));
aoqi@0:       ctrl_path.push(cn->proj_out(0)->unique_out());
aoqi@0:       if (cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0) != NULL) {
aoqi@0:         ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0));
aoqi@0:       }
aoqi@0:     } else {
aoqi@0:       ShouldNotReachHere();
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Skip backwards through the control checking for unexpected control flow
aoqi@0:   Node* ptr = _end;
aoqi@0:   bool fail = false;
aoqi@0:   while (ptr != _begin) {
aoqi@0:     if (ptr->is_Call() && ctrl_path.member(ptr)) {
aoqi@0:       ptr = ptr->in(0);
aoqi@0:     } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
aoqi@0:       ptr = ptr->in(0)->in(0)->in(0);
aoqi@0:       assert(ctrl_path.member(ptr), "should be a known piece of control");
aoqi@0:     } else if (ptr->is_IfTrue()) {
aoqi@0:       IfNode* iff = ptr->in(0)->as_If();
aoqi@0:       BoolNode* b = iff->in(1)->isa_Bool();
aoqi@0: 
aoqi@0:       if (b == NULL) {
aoqi@0:         fail = true;
aoqi@0:         break;
aoqi@0:       }
aoqi@0: 
aoqi@0:       Node* cmp = b->in(1);
aoqi@0:       Node* v1 = cmp->in(1);
aoqi@0:       Node* v2 = cmp->in(2);
aoqi@0:       Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
aoqi@0: 
aoqi@0:       // Null check of the return of append which can simply be eliminated
aoqi@0:       if (b->_test._test == BoolTest::ne &&
aoqi@0:           v2->bottom_type() == TypePtr::NULL_PTR &&
aoqi@0:           v1->is_Proj() && ctrl_path.member(v1->in(0))) {
aoqi@0:         // NULL check of the return value of the append
aoqi@0:         null_check_count++;
aoqi@0:         if (otherproj->outcnt() == 1) {
aoqi@0:           CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
aoqi@0:           if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
aoqi@0:             ctrl_path.push(call);
aoqi@0:           }
aoqi@0:         }
aoqi@0:         _control.push(ptr);
aoqi@0:         ptr = ptr->in(0)->in(0);
aoqi@0:         continue;
aoqi@0:       }
aoqi@0: 
aoqi@0:       // A test which leads to an uncommon trap which should be safe.
aoqi@0:       // Later this trap will be converted into a trap that restarts
aoqi@0:       // at the beginning.
aoqi@0:       if (otherproj->outcnt() == 1) {
aoqi@0:         CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
aoqi@0:         if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
aoqi@0:           // control flow leads to uct so should be ok
aoqi@0:           _uncommon_traps.push(call);
aoqi@0:           ctrl_path.push(call);
aoqi@0:           ptr = ptr->in(0)->in(0);
aoqi@0:           continue;
aoqi@0:         }
aoqi@0:       }
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0:       // Some unexpected control flow we don't know how to handle.
aoqi@0:       if (PrintOptimizeStringConcat) {
aoqi@0:         tty->print_cr("failing with unknown test");
aoqi@0:         b->dump();
aoqi@0:         cmp->dump();
aoqi@0:         v1->dump();
aoqi@0:         v2->dump();
aoqi@0:         tty->cr();
aoqi@0:       }
aoqi@0: #endif
aoqi@0:       fail = true;
aoqi@0:       break;
aoqi@0:     } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
aoqi@0:       ptr = ptr->in(0)->in(0);
aoqi@0:     } else if (ptr->is_Region()) {
aoqi@0:       Node* copy = ptr->as_Region()->is_copy();
aoqi@0:       if (copy != NULL) {
aoqi@0:         ptr = copy;
aoqi@0:         continue;
aoqi@0:       }
aoqi@0:       if (ptr->req() == 3 &&
aoqi@0:           ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
aoqi@0:           ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
aoqi@0:           ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
aoqi@0:           ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
aoqi@0:         // Simple diamond.
aoqi@0:         // XXX should check for possibly merging stores.  simple data merges are ok.
aoqi@0:         // The IGVN will make this simple diamond go away when it
aoqi@0:         // transforms the Region. Make sure it sees it.
aoqi@0:         Compile::current()->record_for_igvn(ptr);
aoqi@0:         ptr = ptr->in(1)->in(0)->in(0);
aoqi@0:         continue;
aoqi@0:       }
aoqi@0: #ifndef PRODUCT
aoqi@0:       if (PrintOptimizeStringConcat) {
aoqi@0:         tty->print_cr("fusion would fail for region");
aoqi@0:         _begin->dump();
aoqi@0:         ptr->dump(2);
aoqi@0:       }
aoqi@0: #endif
aoqi@0:       fail = true;
aoqi@0:       break;
aoqi@0:     } else {
aoqi@0:       // other unknown control
aoqi@0:       if (!fail) {
aoqi@0: #ifndef PRODUCT
aoqi@0:         if (PrintOptimizeStringConcat) {
aoqi@0:           tty->print_cr("fusion would fail for");
aoqi@0:           _begin->dump();
aoqi@0:         }
aoqi@0: #endif
aoqi@0:         fail = true;
aoqi@0:       }
aoqi@0: #ifndef PRODUCT
aoqi@0:       if (PrintOptimizeStringConcat) {
aoqi@0:         ptr->dump();
aoqi@0:       }
aoqi@0: #endif
aoqi@0:       ptr = ptr->in(0);
aoqi@0:     }
aoqi@0:   }
aoqi@0: #ifndef PRODUCT
aoqi@0:   if (PrintOptimizeStringConcat && fail) {
aoqi@0:     tty->cr();
aoqi@0:   }
aoqi@0: #endif
aoqi@0:   if (fail) return !fail;
aoqi@0: 
aoqi@0:   // Validate that all these results produced are contained within
aoqi@0:   // this cluster of objects.  First collect all the results produced
aoqi@0:   // by calls in the region.
aoqi@0:   _stringopts->_visited.Clear();
aoqi@0:   Node_List worklist;
aoqi@0:   Node* final_result = _end->proj_out(TypeFunc::Parms);
aoqi@0:   for (uint i = 0; i < _control.size(); i++) {
aoqi@0:     CallNode* cnode = _control.at(i)->isa_Call();
aoqi@0:     if (cnode != NULL) {
aoqi@0:       _stringopts->_visited.test_set(cnode->_idx);
aoqi@0:     }
aoqi@0:     Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL;
aoqi@0:     if (result != NULL && result != final_result) {
aoqi@0:       worklist.push(result);
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   Node* last_result = NULL;
aoqi@0:   while (worklist.size() > 0) {
aoqi@0:     Node* result = worklist.pop();
aoqi@0:     if (_stringopts->_visited.test_set(result->_idx))
aoqi@0:       continue;
aoqi@0:     for (SimpleDUIterator i(result); i.has_next(); i.next()) {
aoqi@0:       Node *use = i.get();
aoqi@0:       if (ctrl_path.member(use)) {
aoqi@0:         // already checked this
aoqi@0:         continue;
aoqi@0:       }
aoqi@0:       int opc = use->Opcode();
aoqi@0:       if (opc == Op_CmpP || opc == Op_Node) {
aoqi@0:         ctrl_path.push(use);
aoqi@0:         continue;
aoqi@0:       }
aoqi@0:       if (opc == Op_CastPP || opc == Op_CheckCastPP) {
aoqi@0:         for (SimpleDUIterator j(use); j.has_next(); j.next()) {
aoqi@0:           worklist.push(j.get());
aoqi@0:         }
aoqi@0:         worklist.push(use->in(1));
aoqi@0:         ctrl_path.push(use);
aoqi@0:         continue;
aoqi@0:       }
aoqi@0: #ifndef PRODUCT
aoqi@0:       if (PrintOptimizeStringConcat) {
aoqi@0:         if (result != last_result) {
aoqi@0:           last_result = result;
aoqi@0:           tty->print_cr("extra uses for result:");
aoqi@0:           last_result->dump();
aoqi@0:         }
aoqi@0:         use->dump();
aoqi@0:       }
aoqi@0: #endif
aoqi@0:       fail = true;
aoqi@0:       break;
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0:   if (PrintOptimizeStringConcat && !fail) {
aoqi@0:     ttyLocker ttyl;
aoqi@0:     tty->cr();
aoqi@0:     tty->print("fusion has correct control flow (%d %d) for ", null_check_count, _uncommon_traps.size());
aoqi@0:     _begin->jvms()->dump_spec(tty); tty->cr();
aoqi@0:     for (int i = 0; i < num_arguments(); i++) {
aoqi@0:       argument(i)->dump();
aoqi@0:     }
aoqi@0:     _control.dump();
aoqi@0:     tty->cr();
aoqi@0:   }
aoqi@0: #endif
aoqi@0: 
aoqi@0:   return !fail;
aoqi@0: }
aoqi@0: 
aoqi@0: Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
aoqi@0:   const TypeInstPtr* mirror_type = TypeInstPtr::make(field->holder()->java_mirror());
aoqi@0:   Node* klass_node = __ makecon(mirror_type);
aoqi@0:   BasicType bt = field->layout_type();
aoqi@0:   ciType* field_klass = field->type();
aoqi@0: 
aoqi@0:   const Type *type;
aoqi@0:   if( bt == T_OBJECT ) {
aoqi@0:     if (!field->type()->is_loaded()) {
aoqi@0:       type = TypeInstPtr::BOTTOM;
aoqi@0:     } else if (field->is_constant()) {
aoqi@0:       // This can happen if the constant oop is non-perm.
aoqi@0:       ciObject* con = field->constant_value().as_object();
aoqi@0:       // Do not "join" in the previous type; it doesn't add value,
aoqi@0:       // and may yield a vacuous result if the field is of interface type.
aoqi@0:       type = TypeOopPtr::make_from_constant(con, true)->isa_oopptr();
aoqi@0:       assert(type != NULL, "field singleton type must be consistent");
aoqi@0:       return __ makecon(type);
aoqi@0:     } else {
aoqi@0:       type = TypeOopPtr::make_from_klass(field_klass->as_klass());
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     type = Type::get_const_basic_type(bt);
aoqi@0:   }
aoqi@0: 
aoqi@0:   return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
aoqi@0:                        type, T_OBJECT,
aoqi@0:                        C->get_alias_index(mirror_type->add_offset(field->offset_in_bytes())),
aoqi@0:                        MemNode::unordered);
aoqi@0: }
aoqi@0: 
aoqi@0: Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
aoqi@0:   RegionNode *final_merge = new (C) RegionNode(3);
aoqi@0:   kit.gvn().set_type(final_merge, Type::CONTROL);
aoqi@0:   Node* final_size = new (C) PhiNode(final_merge, TypeInt::INT);
aoqi@0:   kit.gvn().set_type(final_size, TypeInt::INT);
aoqi@0: 
aoqi@0:   IfNode* iff = kit.create_and_map_if(kit.control(),
aoqi@0:                                       __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
aoqi@0:                                       PROB_FAIR, COUNT_UNKNOWN);
aoqi@0:   Node* is_min = __ IfFalse(iff);
aoqi@0:   final_merge->init_req(1, is_min);
aoqi@0:   final_size->init_req(1, __ intcon(11));
aoqi@0: 
aoqi@0:   kit.set_control(__ IfTrue(iff));
aoqi@0:   if (kit.stopped()) {
aoqi@0:     final_merge->init_req(2, C->top());
aoqi@0:     final_size->init_req(2, C->top());
aoqi@0:   } else {
aoqi@0: 
aoqi@0:     // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
aoqi@0:     RegionNode *r = new (C) RegionNode(3);
aoqi@0:     kit.gvn().set_type(r, Type::CONTROL);
aoqi@0:     Node *phi = new (C) PhiNode(r, TypeInt::INT);
aoqi@0:     kit.gvn().set_type(phi, TypeInt::INT);
aoqi@0:     Node *size = new (C) PhiNode(r, TypeInt::INT);
aoqi@0:     kit.gvn().set_type(size, TypeInt::INT);
aoqi@0:     Node* chk = __ CmpI(arg, __ intcon(0));
aoqi@0:     Node* p = __ Bool(chk, BoolTest::lt);
aoqi@0:     IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
aoqi@0:     Node* lessthan = __ IfTrue(iff);
aoqi@0:     Node* greaterequal = __ IfFalse(iff);
aoqi@0:     r->init_req(1, lessthan);
aoqi@0:     phi->init_req(1, __ SubI(__ intcon(0), arg));
aoqi@0:     size->init_req(1, __ intcon(1));
aoqi@0:     r->init_req(2, greaterequal);
aoqi@0:     phi->init_req(2, arg);
aoqi@0:     size->init_req(2, __ intcon(0));
aoqi@0:     kit.set_control(r);
aoqi@0:     C->record_for_igvn(r);
aoqi@0:     C->record_for_igvn(phi);
aoqi@0:     C->record_for_igvn(size);
aoqi@0: 
aoqi@0:     // for (int i=0; ; i++)
aoqi@0:     //   if (x <= sizeTable[i])
aoqi@0:     //     return i+1;
aoqi@0: 
aoqi@0:     // Add loop predicate first.
aoqi@0:     kit.add_predicate();
aoqi@0: 
aoqi@0:     RegionNode *loop = new (C) RegionNode(3);
aoqi@0:     loop->init_req(1, kit.control());
aoqi@0:     kit.gvn().set_type(loop, Type::CONTROL);
aoqi@0: 
aoqi@0:     Node *index = new (C) PhiNode(loop, TypeInt::INT);
aoqi@0:     index->init_req(1, __ intcon(0));
aoqi@0:     kit.gvn().set_type(index, TypeInt::INT);
aoqi@0:     kit.set_control(loop);
aoqi@0:     Node* sizeTable = fetch_static_field(kit, size_table_field);
aoqi@0: 
aoqi@0:     Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
aoqi@0:     C->record_for_igvn(value);
aoqi@0:     Node* limit = __ CmpI(phi, value);
aoqi@0:     Node* limitb = __ Bool(limit, BoolTest::le);
aoqi@0:     IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
aoqi@0:     Node* lessEqual = __ IfTrue(iff2);
aoqi@0:     Node* greater = __ IfFalse(iff2);
aoqi@0: 
aoqi@0:     loop->init_req(2, greater);
aoqi@0:     index->init_req(2, __ AddI(index, __ intcon(1)));
aoqi@0: 
aoqi@0:     kit.set_control(lessEqual);
aoqi@0:     C->record_for_igvn(loop);
aoqi@0:     C->record_for_igvn(index);
aoqi@0: 
aoqi@0:     final_merge->init_req(2, kit.control());
aoqi@0:     final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
aoqi@0:   }
aoqi@0: 
aoqi@0:   kit.set_control(final_merge);
aoqi@0:   C->record_for_igvn(final_merge);
aoqi@0:   C->record_for_igvn(final_size);
aoqi@0: 
aoqi@0:   return final_size;
aoqi@0: }
aoqi@0: 
aoqi@0: void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) {
aoqi@0:   RegionNode *final_merge = new (C) RegionNode(4);
aoqi@0:   kit.gvn().set_type(final_merge, Type::CONTROL);
aoqi@0:   Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
aoqi@0:   kit.gvn().set_type(final_mem, Type::MEMORY);
aoqi@0: 
aoqi@0:   // need to handle Integer.MIN_VALUE specially because negating doesn't make it positive
aoqi@0:   {
aoqi@0:     // i == MIN_VALUE
aoqi@0:     IfNode* iff = kit.create_and_map_if(kit.control(),
aoqi@0:                                         __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
aoqi@0:                                         PROB_FAIR, COUNT_UNKNOWN);
aoqi@0: 
aoqi@0:     Node* old_mem = kit.memory(char_adr_idx);
aoqi@0: 
aoqi@0:     kit.set_control(__ IfFalse(iff));
aoqi@0:     if (kit.stopped()) {
aoqi@0:       // Statically not equal to MIN_VALUE so this path is dead
aoqi@0:       final_merge->init_req(3, kit.control());
aoqi@0:     } else {
aoqi@0:       copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
aoqi@0:                   char_array, start);
aoqi@0:       final_merge->init_req(3, kit.control());
aoqi@0:       final_mem->init_req(3, kit.memory(char_adr_idx));
aoqi@0:     }
aoqi@0: 
aoqi@0:     kit.set_control(__ IfTrue(iff));
aoqi@0:     kit.set_memory(old_mem, char_adr_idx);
aoqi@0:   }
aoqi@0: 
aoqi@0: 
aoqi@0:   // Simplified version of Integer.getChars
aoqi@0: 
aoqi@0:   // int q, r;
aoqi@0:   // int charPos = index;
aoqi@0:   Node* charPos = end;
aoqi@0: 
aoqi@0:   // char sign = 0;
aoqi@0: 
aoqi@0:   Node* i = arg;
aoqi@0:   Node* sign = __ intcon(0);
aoqi@0: 
aoqi@0:   // if (i < 0) {
aoqi@0:   //     sign = '-';
aoqi@0:   //     i = -i;
aoqi@0:   // }
aoqi@0:   {
aoqi@0:     IfNode* iff = kit.create_and_map_if(kit.control(),
aoqi@0:                                         __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
aoqi@0:                                         PROB_FAIR, COUNT_UNKNOWN);
aoqi@0: 
aoqi@0:     RegionNode *merge = new (C) RegionNode(3);
aoqi@0:     kit.gvn().set_type(merge, Type::CONTROL);
aoqi@0:     i = new (C) PhiNode(merge, TypeInt::INT);
aoqi@0:     kit.gvn().set_type(i, TypeInt::INT);
aoqi@0:     sign = new (C) PhiNode(merge, TypeInt::INT);
aoqi@0:     kit.gvn().set_type(sign, TypeInt::INT);
aoqi@0: 
aoqi@0:     merge->init_req(1, __ IfTrue(iff));
aoqi@0:     i->init_req(1, __ SubI(__ intcon(0), arg));
aoqi@0:     sign->init_req(1, __ intcon('-'));
aoqi@0:     merge->init_req(2, __ IfFalse(iff));
aoqi@0:     i->init_req(2, arg);
aoqi@0:     sign->init_req(2, __ intcon(0));
aoqi@0: 
aoqi@0:     kit.set_control(merge);
aoqi@0: 
aoqi@0:     C->record_for_igvn(merge);
aoqi@0:     C->record_for_igvn(i);
aoqi@0:     C->record_for_igvn(sign);
aoqi@0:   }
aoqi@0: 
aoqi@0:   // for (;;) {
aoqi@0:   //     q = i / 10;
aoqi@0:   //     r = i - ((q << 3) + (q << 1));  // r = i-(q*10) ...
aoqi@0:   //     buf [--charPos] = digits [r];
aoqi@0:   //     i = q;
aoqi@0:   //     if (i == 0) break;
aoqi@0:   // }
aoqi@0: 
aoqi@0:   {
aoqi@0:     // Add loop predicate first.
aoqi@0:     kit.add_predicate();
aoqi@0: 
aoqi@0:     RegionNode *head = new (C) RegionNode(3);
aoqi@0:     head->init_req(1, kit.control());
aoqi@0:     kit.gvn().set_type(head, Type::CONTROL);
aoqi@0:     Node *i_phi = new (C) PhiNode(head, TypeInt::INT);
aoqi@0:     i_phi->init_req(1, i);
aoqi@0:     kit.gvn().set_type(i_phi, TypeInt::INT);
aoqi@0:     charPos = PhiNode::make(head, charPos);
aoqi@0:     kit.gvn().set_type(charPos, TypeInt::INT);
aoqi@0:     Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
aoqi@0:     kit.gvn().set_type(mem, Type::MEMORY);
aoqi@0:     kit.set_control(head);
aoqi@0:     kit.set_memory(mem, char_adr_idx);
aoqi@0: 
aoqi@0:     Node* q = __ DivI(NULL, i_phi, __ intcon(10));
aoqi@0:     Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
aoqi@0:                                      __ LShiftI(q, __ intcon(1))));
aoqi@0:     Node* m1 = __ SubI(charPos, __ intcon(1));
aoqi@0:     Node* ch = __ AddI(r, __ intcon('0'));
aoqi@0: 
aoqi@0:     Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
aoqi@0:                                   ch, T_CHAR, char_adr_idx, MemNode::unordered);
aoqi@0: 
aoqi@0: 
aoqi@0:     IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
aoqi@0:                                         PROB_FAIR, COUNT_UNKNOWN);
aoqi@0:     Node* ne = __ IfTrue(iff);
aoqi@0:     Node* eq = __ IfFalse(iff);
aoqi@0: 
aoqi@0:     head->init_req(2, ne);
aoqi@0:     mem->init_req(2, st);
aoqi@0:     i_phi->init_req(2, q);
aoqi@0:     charPos->init_req(2, m1);
aoqi@0: 
aoqi@0:     charPos = m1;
aoqi@0: 
aoqi@0:     kit.set_control(eq);
aoqi@0:     kit.set_memory(st, char_adr_idx);
aoqi@0: 
aoqi@0:     C->record_for_igvn(head);
aoqi@0:     C->record_for_igvn(mem);
aoqi@0:     C->record_for_igvn(i_phi);
aoqi@0:     C->record_for_igvn(charPos);
aoqi@0:   }
aoqi@0: 
aoqi@0:   {
aoqi@0:     // if (sign != 0) {
aoqi@0:     //     buf [--charPos] = sign;
aoqi@0:     // }
aoqi@0:     IfNode* iff = kit.create_and_map_if(kit.control(),
aoqi@0:                                         __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
aoqi@0:                                         PROB_FAIR, COUNT_UNKNOWN);
aoqi@0: 
aoqi@0:     final_merge->init_req(2, __ IfFalse(iff));
aoqi@0:     final_mem->init_req(2, kit.memory(char_adr_idx));
aoqi@0: 
aoqi@0:     kit.set_control(__ IfTrue(iff));
aoqi@0:     if (kit.stopped()) {
aoqi@0:       final_merge->init_req(1, C->top());
aoqi@0:       final_mem->init_req(1, C->top());
aoqi@0:     } else {
aoqi@0:       Node* m1 = __ SubI(charPos, __ intcon(1));
aoqi@0:       Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
aoqi@0:                                     sign, T_CHAR, char_adr_idx, MemNode::unordered);
aoqi@0: 
aoqi@0:       final_merge->init_req(1, kit.control());
aoqi@0:       final_mem->init_req(1, st);
aoqi@0:     }
aoqi@0: 
aoqi@0:     kit.set_control(final_merge);
aoqi@0:     kit.set_memory(final_mem, char_adr_idx);
aoqi@0: 
aoqi@0:     C->record_for_igvn(final_merge);
aoqi@0:     C->record_for_igvn(final_mem);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) {
aoqi@0:   Node* string = str;
aoqi@0:   Node* offset = kit.load_String_offset(kit.control(), string);
aoqi@0:   Node* count  = kit.load_String_length(kit.control(), string);
aoqi@0:   Node* value  = kit.load_String_value (kit.control(), string);
aoqi@0: 
aoqi@0:   // copy the contents
aoqi@0:   if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) {
aoqi@0:     // For small constant strings just emit individual stores.
aoqi@0:     // A length of 6 seems like a good space/speed tradeof.
aoqi@0:     int c = count->get_int();
aoqi@0:     int o = offset->get_int();
aoqi@0:     const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr();
aoqi@0:     ciTypeArray* value_array = t->const_oop()->as_type_array();
aoqi@0:     for (int e = 0; e < c; e++) {
aoqi@0:       __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
aoqi@0:                          __ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx,
aoqi@0:                          MemNode::unordered);
aoqi@0:       start = __ AddI(start, __ intcon(1));
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     Node* src_ptr = kit.array_element_address(value, offset, T_CHAR);
aoqi@0:     Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR);
aoqi@0:     Node* c = count;
aoqi@0:     Node* extra = NULL;
aoqi@0: #ifdef _LP64
aoqi@0:     c = __ ConvI2L(c);
aoqi@0:     extra = C->top();
aoqi@0: #endif
aoqi@0:     Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP,
aoqi@0:                                        OptoRuntime::fast_arraycopy_Type(),
aoqi@0:                                        CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()),
aoqi@0:                                        "jshort_disjoint_arraycopy", TypeAryPtr::CHARS,
aoqi@0:                                        src_ptr, dst_ptr, c, extra);
aoqi@0:     start = __ AddI(start, count);
aoqi@0:   }
aoqi@0:   return start;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
aoqi@0:   // Log a little info about the transformation
aoqi@0:   sc->maybe_log_transform();
aoqi@0: 
aoqi@0:   // pull the JVMState of the allocation into a SafePointNode to serve as
aoqi@0:   // as a shim for the insertion of the new code.
aoqi@0:   JVMState* jvms     = sc->begin()->jvms()->clone_shallow(C);
aoqi@0:   uint size = sc->begin()->req();
aoqi@0:   SafePointNode* map = new (C) SafePointNode(size, jvms);
aoqi@0: 
aoqi@0:   // copy the control and memory state from the final call into our
aoqi@0:   // new starting state.  This allows any preceeding tests to feed
aoqi@0:   // into the new section of code.
aoqi@0:   for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
aoqi@0:     map->init_req(i1, sc->end()->in(i1));
aoqi@0:   }
aoqi@0:   // blow away old allocation arguments
aoqi@0:   for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
aoqi@0:     map->init_req(i1, C->top());
aoqi@0:   }
aoqi@0:   // Copy the rest of the inputs for the JVMState
aoqi@0:   for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
aoqi@0:     map->init_req(i1, sc->begin()->in(i1));
aoqi@0:   }
aoqi@0:   // Make sure the memory state is a MergeMem for parsing.
aoqi@0:   if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
aoqi@0:     map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
aoqi@0:   }
aoqi@0: 
aoqi@0:   jvms->set_map(map);
aoqi@0:   map->ensure_stack(jvms, jvms->method()->max_stack());
aoqi@0: 
aoqi@0: 
aoqi@0:   // disconnect all the old StringBuilder calls from the graph
aoqi@0:   sc->eliminate_unneeded_control();
aoqi@0: 
aoqi@0:   // At this point all the old work has been completely removed from
aoqi@0:   // the graph and the saved JVMState exists at the point where the
aoqi@0:   // final toString call used to be.
aoqi@0:   GraphKit kit(jvms);
aoqi@0: 
aoqi@0:   // There may be uncommon traps which are still using the
aoqi@0:   // intermediate states and these need to be rewritten to point at
aoqi@0:   // the JVMState at the beginning of the transformation.
aoqi@0:   sc->convert_uncommon_traps(kit, jvms);
aoqi@0: 
aoqi@0:   // Now insert the logic to compute the size of the string followed
aoqi@0:   // by all the logic to construct array and resulting string.
aoqi@0: 
aoqi@0:   Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
aoqi@0: 
aoqi@0:   // Create a region for the overflow checks to merge into.
aoqi@0:   int args = MAX2(sc->num_arguments(), 1);
aoqi@0:   RegionNode* overflow = new (C) RegionNode(args);
aoqi@0:   kit.gvn().set_type(overflow, Type::CONTROL);
aoqi@0: 
aoqi@0:   // Create a hook node to hold onto the individual sizes since they
aoqi@0:   // are need for the copying phase.
aoqi@0:   Node* string_sizes = new (C) Node(args);
aoqi@0: 
aoqi@0:   Node* length = __ intcon(0);
aoqi@0:   for (int argi = 0; argi < sc->num_arguments(); argi++) {
aoqi@0:     Node* arg = sc->argument(argi);
aoqi@0:     switch (sc->mode(argi)) {
aoqi@0:       case StringConcat::IntMode: {
aoqi@0:         Node* string_size = int_stringSize(kit, arg);
aoqi@0: 
aoqi@0:         // accumulate total
aoqi@0:         length = __ AddI(length, string_size);
aoqi@0: 
aoqi@0:         // Cache this value for the use by int_toString
aoqi@0:         string_sizes->init_req(argi, string_size);
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       case StringConcat::StringNullCheckMode: {
aoqi@0:         const Type* type = kit.gvn().type(arg);
aoqi@0:         assert(type != TypePtr::NULL_PTR, "missing check");
aoqi@0:         if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
aoqi@0:           // Null check with uncommont trap since
aoqi@0:           // StringBuilder(null) throws exception.
aoqi@0:           // Use special uncommon trap instead of
aoqi@0:           // calling normal do_null_check().
aoqi@0:           Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
aoqi@0:           IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
aoqi@0:           overflow->add_req(__ IfFalse(iff));
aoqi@0:           Node* notnull = __ IfTrue(iff);
aoqi@0:           kit.set_control(notnull); // set control for the cast_not_null
aoqi@0:           arg = kit.cast_not_null(arg, false);
aoqi@0:           sc->set_argument(argi, arg);
aoqi@0:         }
aoqi@0:         assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity");
aoqi@0:         // Fallthrough to add string length.
aoqi@0:       }
aoqi@0:       case StringConcat::StringMode: {
aoqi@0:         const Type* type = kit.gvn().type(arg);
aoqi@0:         if (type == TypePtr::NULL_PTR) {
aoqi@0:           // replace the argument with the null checked version
aoqi@0:           arg = null_string;
aoqi@0:           sc->set_argument(argi, arg);
aoqi@0:         } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
aoqi@0:           // s = s != null ? s : "null";
aoqi@0:           // length = length + (s.count - s.offset);
aoqi@0:           RegionNode *r = new (C) RegionNode(3);
aoqi@0:           kit.gvn().set_type(r, Type::CONTROL);
aoqi@0:           Node *phi = new (C) PhiNode(r, type);
aoqi@0:           kit.gvn().set_type(phi, phi->bottom_type());
aoqi@0:           Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
aoqi@0:           IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
aoqi@0:           Node* notnull = __ IfTrue(iff);
aoqi@0:           Node* isnull =  __ IfFalse(iff);
aoqi@0:           kit.set_control(notnull); // set control for the cast_not_null
aoqi@0:           r->init_req(1, notnull);
aoqi@0:           phi->init_req(1, kit.cast_not_null(arg, false));
aoqi@0:           r->init_req(2, isnull);
aoqi@0:           phi->init_req(2, null_string);
aoqi@0:           kit.set_control(r);
aoqi@0:           C->record_for_igvn(r);
aoqi@0:           C->record_for_igvn(phi);
aoqi@0:           // replace the argument with the null checked version
aoqi@0:           arg = phi;
aoqi@0:           sc->set_argument(argi, arg);
aoqi@0:         }
aoqi@0: 
aoqi@0:         Node* count = kit.load_String_length(kit.control(), arg);
aoqi@0: 
aoqi@0:         length = __ AddI(length, count);
aoqi@0:         string_sizes->init_req(argi, NULL);
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       case StringConcat::CharMode: {
aoqi@0:         // one character only
aoqi@0:         length = __ AddI(length, __ intcon(1));
aoqi@0:         break;
aoqi@0:       }
aoqi@0:       default:
aoqi@0:         ShouldNotReachHere();
aoqi@0:     }
aoqi@0:     if (argi > 0) {
aoqi@0:       // Check that the sum hasn't overflowed
aoqi@0:       IfNode* iff = kit.create_and_map_if(kit.control(),
aoqi@0:                                           __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
aoqi@0:                                           PROB_MIN, COUNT_UNKNOWN);
aoqi@0:       kit.set_control(__ IfFalse(iff));
aoqi@0:       overflow->set_req(argi, __ IfTrue(iff));
aoqi@0:     }
aoqi@0:   }
aoqi@0: 
aoqi@0:   {
aoqi@0:     // Hook
aoqi@0:     PreserveJVMState pjvms(&kit);
aoqi@0:     kit.set_control(overflow);
aoqi@0:     C->record_for_igvn(overflow);
aoqi@0:     kit.uncommon_trap(Deoptimization::Reason_intrinsic,
aoqi@0:                       Deoptimization::Action_make_not_entrant);
aoqi@0:   }
aoqi@0: 
aoqi@0:   Node* result;
aoqi@0:   if (!kit.stopped()) {
aoqi@0: 
aoqi@0:     // length now contains the number of characters needed for the
aoqi@0:     // char[] so create a new AllocateArray for the char[]
aoqi@0:     Node* char_array = NULL;
aoqi@0:     {
aoqi@0:       PreserveReexecuteState preexecs(&kit);
aoqi@0:       // The original jvms is for an allocation of either a String or
aoqi@0:       // StringBuffer so no stack adjustment is necessary for proper
aoqi@0:       // reexecution.  If we deoptimize in the slow path the bytecode
aoqi@0:       // will be reexecuted and the char[] allocation will be thrown away.
aoqi@0:       kit.jvms()->set_should_reexecute(true);
aoqi@0:       char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))),
aoqi@0:                                  length, 1);
aoqi@0:     }
aoqi@0: 
aoqi@0:     // Mark the allocation so that zeroing is skipped since the code
aoqi@0:     // below will overwrite the entire array
aoqi@0:     AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
aoqi@0:     char_alloc->maybe_set_complete(_gvn);
aoqi@0: 
aoqi@0:     // Now copy the string representations into the final char[]
aoqi@0:     Node* start = __ intcon(0);
aoqi@0:     for (int argi = 0; argi < sc->num_arguments(); argi++) {
aoqi@0:       Node* arg = sc->argument(argi);
aoqi@0:       switch (sc->mode(argi)) {
aoqi@0:         case StringConcat::IntMode: {
aoqi@0:           Node* end = __ AddI(start, string_sizes->in(argi));
aoqi@0:           // getChars words backwards so pass the ending point as well as the start
aoqi@0:           int_getChars(kit, arg, char_array, start, end);
aoqi@0:           start = end;
aoqi@0:           break;
aoqi@0:         }
aoqi@0:         case StringConcat::StringNullCheckMode:
aoqi@0:         case StringConcat::StringMode: {
aoqi@0:           start = copy_string(kit, arg, char_array, start);
aoqi@0:           break;
aoqi@0:         }
aoqi@0:         case StringConcat::CharMode: {
aoqi@0:           __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
aoqi@0:                              arg, T_CHAR, char_adr_idx, MemNode::unordered);
aoqi@0:           start = __ AddI(start, __ intcon(1));
aoqi@0:           break;
aoqi@0:         }
aoqi@0:         default:
aoqi@0:           ShouldNotReachHere();
aoqi@0:       }
aoqi@0:     }
aoqi@0: 
aoqi@0:     // If we're not reusing an existing String allocation then allocate one here.
aoqi@0:     result = sc->string_alloc();
aoqi@0:     if (result == NULL) {
aoqi@0:       PreserveReexecuteState preexecs(&kit);
aoqi@0:       // The original jvms is for an allocation of either a String or
aoqi@0:       // StringBuffer so no stack adjustment is necessary for proper
aoqi@0:       // reexecution.
aoqi@0:       kit.jvms()->set_should_reexecute(true);
aoqi@0:       result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
aoqi@0:     }
aoqi@0: 
aoqi@0:     // Intialize the string
aoqi@0:     if (java_lang_String::has_offset_field()) {
aoqi@0:       kit.store_String_offset(kit.control(), result, __ intcon(0));
aoqi@0:       kit.store_String_length(kit.control(), result, length);
aoqi@0:     }
aoqi@0:     kit.store_String_value(kit.control(), result, char_array);
aoqi@0:   } else {
aoqi@0:     result = C->top();
aoqi@0:   }
aoqi@0:   // hook up the outgoing control and result
aoqi@0:   kit.replace_call(sc->end(), result);
aoqi@0: 
aoqi@0:   // Unhook any hook nodes
aoqi@0:   string_sizes->disconnect_inputs(NULL, C);
aoqi@0:   sc->cleanup();
aoqi@0: }