never@1515: /*
trims@1907:  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
never@1515:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
never@1515:  *
never@1515:  * This code is free software; you can redistribute it and/or modify it
never@1515:  * under the terms of the GNU General Public License version 2 only, as
never@1515:  * published by the Free Software Foundation.
never@1515:  *
never@1515:  * This code is distributed in the hope that it will be useful, but WITHOUT
never@1515:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
never@1515:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
never@1515:  * version 2 for more details (a copy is included in the LICENSE file that
never@1515:  * accompanied this code).
never@1515:  *
never@1515:  * You should have received a copy of the GNU General Public License version
never@1515:  * 2 along with this work; if not, write to the Free Software Foundation,
never@1515:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
never@1515:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
never@1515:  *
never@1515:  */
never@1515: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "compiler/compileLog.hpp"
stefank@2314: #include "opto/addnode.hpp"
stefank@2314: #include "opto/callGenerator.hpp"
stefank@2314: #include "opto/callnode.hpp"
stefank@2314: #include "opto/divnode.hpp"
stefank@2314: #include "opto/graphKit.hpp"
stefank@2314: #include "opto/idealKit.hpp"
stefank@2314: #include "opto/rootnode.hpp"
stefank@2314: #include "opto/runtime.hpp"
stefank@2314: #include "opto/stringopts.hpp"
stefank@2314: #include "opto/subnode.hpp"
never@1515: 
never@1515: #define __ kit.
never@1515: 
never@1515: class StringConcat : public ResourceObj {
never@1515:  private:
never@1515:   PhaseStringOpts*    _stringopts;
never@1515:   Node*               _string_alloc;
never@1515:   AllocateNode*       _begin;          // The allocation the begins the pattern
never@1515:   CallStaticJavaNode* _end;            // The final call of the pattern.  Will either be
never@1515:                                        // SB.toString or or String.<init>(SB.toString)
never@1515:   bool                _multiple;       // indicates this is a fusion of two or more
never@1515:                                        // separate StringBuilders
never@1515: 
never@1515:   Node*               _arguments;      // The list of arguments to be concatenated
never@1515:   GrowableArray<int>  _mode;           // into a String along with a mode flag
never@1515:                                        // indicating how to treat the value.
never@1515: 
never@1515:   Node_List           _control;        // List of control nodes that will be deleted
never@1515:   Node_List           _uncommon_traps; // Uncommon traps that needs to be rewritten
never@1515:                                        // to restart at the initial JVMState.
never@1515:  public:
never@1515:   // Mode for converting arguments to Strings
never@1515:   enum {
never@1515:     StringMode,
never@1515:     IntMode,
kvn@2413:     CharMode,
kvn@2413:     StringNullCheckMode
never@1515:   };
never@1515: 
never@1515:   StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
never@1515:     _end(end),
never@1515:     _begin(NULL),
never@1515:     _multiple(false),
never@1515:     _string_alloc(NULL),
never@1515:     _stringopts(stringopts) {
never@1515:     _arguments = new (_stringopts->C, 1) Node(1);
never@1515:     _arguments->del_req(0);
never@1515:   }
never@1515: 
never@1515:   bool validate_control_flow();
never@1515: 
never@1515:   void merge_add() {
never@1515: #if 0
never@1515:     // XXX This is place holder code for reusing an existing String
never@1515:     // allocation but the logic for checking the state safety is
never@1515:     // probably inadequate at the moment.
never@1515:     CallProjections endprojs;
never@1515:     sc->end()->extract_projections(&endprojs, false);
never@1515:     if (endprojs.resproj != NULL) {
never@1515:       for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
never@1515:         CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
never@1515:         if (use != NULL && use->method() != NULL &&
never@2172:             use->method()->intrinsic_id() == vmIntrinsics::_String_String &&
never@1515:             use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
never@1515:           // Found useless new String(sb.toString()) so reuse the newly allocated String
never@1515:           // when creating the result instead of allocating a new one.
never@1515:           sc->set_string_alloc(use->in(TypeFunc::Parms));
never@1515:           sc->set_end(use);
never@1515:         }
never@1515:       }
never@1515:     }
never@1515: #endif
never@1515:   }
never@1515: 
never@1515:   StringConcat* merge(StringConcat* other, Node* arg);
never@1515: 
never@1515:   void set_allocation(AllocateNode* alloc) {
never@1515:     _begin = alloc;
never@1515:   }
never@1515: 
never@1515:   void append(Node* value, int mode) {
never@1515:     _arguments->add_req(value);
never@1515:     _mode.append(mode);
never@1515:   }
never@1515:   void push(Node* value, int mode) {
never@1515:     _arguments->ins_req(0, value);
never@1515:     _mode.insert_before(0, mode);
never@1515:   }
never@1515:   void push_string(Node* value) {
never@1515:     push(value, StringMode);
never@1515:   }
kvn@2413:   void push_string_null_check(Node* value) {
kvn@2413:     push(value, StringNullCheckMode);
kvn@2413:   }
never@1515:   void push_int(Node* value) {
never@1515:     push(value, IntMode);
never@1515:   }
never@1515:   void push_char(Node* value) {
never@1515:     push(value, CharMode);
never@1515:   }
never@1515: 
never@1515:   Node* argument(int i) {
never@1515:     return _arguments->in(i);
never@1515:   }
never@1515:   void set_argument(int i, Node* value) {
never@1515:     _arguments->set_req(i, value);
never@1515:   }
never@1515:   int num_arguments() {
never@1515:     return _mode.length();
never@1515:   }
never@1515:   int mode(int i) {
never@1515:     return _mode.at(i);
never@1515:   }
never@1515:   void add_control(Node* ctrl) {
never@1515:     assert(!_control.contains(ctrl), "only push once");
never@1515:     _control.push(ctrl);
never@1515:   }
never@1515:   CallStaticJavaNode* end() { return _end; }
never@1515:   AllocateNode* begin() { return _begin; }
never@1515:   Node* string_alloc() { return _string_alloc; }
never@1515: 
never@1515:   void eliminate_unneeded_control();
never@1515:   void eliminate_initialize(InitializeNode* init);
never@1515:   void eliminate_call(CallNode* call);
never@1515: 
never@1515:   void maybe_log_transform() {
never@1515:     CompileLog* log = _stringopts->C->log();
never@1515:     if (log != NULL) {
never@1515:       log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
never@1515:                 num_arguments(),
never@1515:                 _string_alloc != NULL,
never@1515:                 _multiple);
never@1515:       JVMState* p = _begin->jvms();
never@1515:       while (p != NULL) {
never@1515:         log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
never@1515:         p = p->caller();
never@1515:       }
never@1515:       log->tail("replace_string_concat");
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
never@1515:     for (uint u = 0; u < _uncommon_traps.size(); u++) {
never@1515:       Node* uct = _uncommon_traps.at(u);
never@1515: 
never@1515:       // Build a new call using the jvms state of the allocate
twisti@2103:       address call_addr = SharedRuntime::uncommon_trap_blob()->entry_point();
never@1515:       const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
never@1515:       int size = call_type->domain()->cnt();
never@1515:       const TypePtr* no_memory_effects = NULL;
never@1515:       Compile* C = _stringopts->C;
never@1515:       CallStaticJavaNode* call = new (C, size) CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
never@1515:                                                                   jvms->bci(), no_memory_effects);
never@1515:       for (int e = 0; e < TypeFunc::Parms; e++) {
never@1515:         call->init_req(e, uct->in(e));
never@1515:       }
never@1515:       // Set the trap request to record intrinsic failure if this trap
never@1515:       // is taken too many times.  Ideally we would handle then traps by
never@1515:       // doing the original bookkeeping in the MDO so that if it caused
never@1515:       // the code to be thrown out we could still recompile and use the
never@1515:       // optimization.  Failing the uncommon traps doesn't really mean
never@1515:       // that the optimization is a bad idea but there's no other way to
never@1515:       // do the MDO updates currently.
never@1515:       int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
never@1515:                                                            Deoptimization::Action_make_not_entrant);
never@1515:       call->init_req(TypeFunc::Parms, __ intcon(trap_request));
never@1515:       kit.add_safepoint_edges(call);
never@1515: 
never@1515:       _stringopts->gvn()->transform(call);
never@1515:       C->gvn_replace_by(uct, call);
never@1515:       uct->disconnect_inputs(NULL);
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   void cleanup() {
never@1515:     // disconnect the hook node
never@1515:     _arguments->disconnect_inputs(NULL);
never@1515:   }
never@1515: };
never@1515: 
never@1515: 
never@1515: void StringConcat::eliminate_unneeded_control() {
never@1515:   eliminate_initialize(begin()->initialization());
never@1515:   for (uint i = 0; i < _control.size(); i++) {
never@1515:     Node* n = _control.at(i);
never@1515:     if (n->is_Call()) {
never@1515:       if (n != _end) {
never@1515:         eliminate_call(n->as_Call());
never@1515:       }
never@1515:     } else if (n->is_IfTrue()) {
never@1515:       Compile* C = _stringopts->C;
never@1515:       C->gvn_replace_by(n, n->in(0)->in(0));
never@1515:       C->gvn_replace_by(n->in(0), C->top());
never@1515:     }
never@1515:   }
never@1515: }
never@1515: 
never@1515: 
never@1515: StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
never@1515:   StringConcat* result = new StringConcat(_stringopts, _end);
never@1515:   for (uint x = 0; x < _control.size(); x++) {
never@1515:     Node* n = _control.at(x);
never@1515:     if (n->is_Call()) {
never@1515:       result->_control.push(n);
never@1515:     }
never@1515:   }
never@1515:   for (uint x = 0; x < other->_control.size(); x++) {
never@1515:     Node* n = other->_control.at(x);
never@1515:     if (n->is_Call()) {
never@1515:       result->_control.push(n);
never@1515:     }
never@1515:   }
never@1515:   assert(result->_control.contains(other->_end), "what?");
never@1515:   assert(result->_control.contains(_begin), "what?");
never@1515:   for (int x = 0; x < num_arguments(); x++) {
never@1515:     if (argument(x) == arg) {
never@1515:       // replace the toString result with the all the arguments that
never@1515:       // made up the other StringConcat
never@1515:       for (int y = 0; y < other->num_arguments(); y++) {
never@1515:         result->append(other->argument(y), other->mode(y));
never@1515:       }
never@1515:     } else {
never@1515:       result->append(argument(x), mode(x));
never@1515:     }
never@1515:   }
never@1515:   result->set_allocation(other->_begin);
never@1515:   result->_multiple = true;
never@1515:   return result;
never@1515: }
never@1515: 
never@1515: 
never@1515: void StringConcat::eliminate_call(CallNode* call) {
never@1515:   Compile* C = _stringopts->C;
never@1515:   CallProjections projs;
never@1515:   call->extract_projections(&projs, false);
never@1515:   if (projs.fallthrough_catchproj != NULL) {
never@1515:     C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
never@1515:   }
never@1515:   if (projs.fallthrough_memproj != NULL) {
never@1515:     C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
never@1515:   }
never@1515:   if (projs.catchall_memproj != NULL) {
never@1515:     C->gvn_replace_by(projs.catchall_memproj, C->top());
never@1515:   }
never@1515:   if (projs.fallthrough_ioproj != NULL) {
never@1515:     C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
never@1515:   }
never@1515:   if (projs.catchall_ioproj != NULL) {
never@1515:     C->gvn_replace_by(projs.catchall_ioproj, C->top());
never@1515:   }
never@1515:   if (projs.catchall_catchproj != NULL) {
never@1515:     // EA can't cope with the partially collapsed graph this
never@1515:     // creates so put it on the worklist to be collapsed later.
never@1515:     for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
never@1515:       Node *use = i.get();
never@1515:       int opc = use->Opcode();
never@1515:       if (opc == Op_CreateEx || opc == Op_Region) {
never@1515:         _stringopts->record_dead_node(use);
never@1515:       }
never@1515:     }
never@1515:     C->gvn_replace_by(projs.catchall_catchproj, C->top());
never@1515:   }
never@1515:   if (projs.resproj != NULL) {
never@1515:     C->gvn_replace_by(projs.resproj, C->top());
never@1515:   }
never@1515:   C->gvn_replace_by(call, C->top());
never@1515: }
never@1515: 
never@1515: void StringConcat::eliminate_initialize(InitializeNode* init) {
never@1515:   Compile* C = _stringopts->C;
never@1515: 
never@1515:   // Eliminate Initialize node.
never@1515:   assert(init->outcnt() <= 2, "only a control and memory projection expected");
never@1515:   assert(init->req() <= InitializeNode::RawStores, "no pending inits");
never@1515:   Node *ctrl_proj = init->proj_out(TypeFunc::Control);
never@1515:   if (ctrl_proj != NULL) {
never@1515:     C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
never@1515:   }
never@1515:   Node *mem_proj = init->proj_out(TypeFunc::Memory);
never@1515:   if (mem_proj != NULL) {
never@1515:     Node *mem = init->in(TypeFunc::Memory);
never@1515:     C->gvn_replace_by(mem_proj, mem);
never@1515:   }
never@1515:   C->gvn_replace_by(init, C->top());
never@1515:   init->disconnect_inputs(NULL);
never@1515: }
never@1515: 
never@1515: Node_List PhaseStringOpts::collect_toString_calls() {
never@1515:   Node_List string_calls;
never@1515:   Node_List worklist;
never@1515: 
never@1515:   _visited.Clear();
never@1515: 
never@1515:   // Prime the worklist
never@1515:   for (uint i = 1; i < C->root()->len(); i++) {
never@1515:     Node* n = C->root()->in(i);
never@1515:     if (n != NULL && !_visited.test_set(n->_idx)) {
never@1515:       worklist.push(n);
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   while (worklist.size() > 0) {
never@1515:     Node* ctrl = worklist.pop();
never@1515:     if (ctrl->is_CallStaticJava()) {
never@1515:       CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
never@1515:       ciMethod* m = csj->method();
never@1515:       if (m != NULL &&
never@1515:           (m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
never@1515:            m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString)) {
never@1515:         string_calls.push(csj);
never@1515:       }
never@1515:     }
never@1515:     if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
never@1515:       worklist.push(ctrl->in(0));
never@1515:     }
never@1515:     if (ctrl->is_Region()) {
never@1515:       for (uint i = 1; i < ctrl->len(); i++) {
never@1515:         if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
never@1515:           worklist.push(ctrl->in(i));
never@1515:         }
never@1515:       }
never@1515:     }
never@1515:   }
never@1515:   return string_calls;
never@1515: }
never@1515: 
never@1515: 
never@1515: StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
never@1515:   ciMethod* m = call->method();
never@1515:   ciSymbol* string_sig;
never@1515:   ciSymbol* int_sig;
never@1515:   ciSymbol* char_sig;
never@1515:   if (m->holder() == C->env()->StringBuilder_klass()) {
never@1515:     string_sig = ciSymbol::String_StringBuilder_signature();
never@1515:     int_sig = ciSymbol::int_StringBuilder_signature();
never@1515:     char_sig = ciSymbol::char_StringBuilder_signature();
never@1515:   } else if (m->holder() == C->env()->StringBuffer_klass()) {
never@1515:     string_sig = ciSymbol::String_StringBuffer_signature();
never@1515:     int_sig = ciSymbol::int_StringBuffer_signature();
never@1515:     char_sig = ciSymbol::char_StringBuffer_signature();
never@1515:   } else {
never@1515:     return NULL;
never@1515:   }
never@1515: #ifndef PRODUCT
never@1515:   if (PrintOptimizeStringConcat) {
never@1515:     tty->print("considering toString call in ");
never@1515:     call->jvms()->dump_spec(tty); tty->cr();
never@1515:   }
never@1515: #endif
never@1515: 
never@1515:   StringConcat* sc = new StringConcat(this, call);
never@1515: 
never@1515:   AllocateNode* alloc = NULL;
never@1515:   InitializeNode* init = NULL;
never@1515: 
never@1515:   // possible opportunity for StringBuilder fusion
never@1515:   CallStaticJavaNode* cnode = call;
never@1515:   while (cnode) {
never@1515:     Node* recv = cnode->in(TypeFunc::Parms)->uncast();
never@1515:     if (recv->is_Proj()) {
never@1515:       recv = recv->in(0);
never@1515:     }
never@1515:     cnode = recv->isa_CallStaticJava();
never@1515:     if (cnode == NULL) {
never@1515:       alloc = recv->isa_Allocate();
never@1515:       if (alloc == NULL) {
never@1515:         break;
never@1515:       }
never@1515:       // Find the constructor call
never@1515:       Node* result = alloc->result_cast();
never@1515:       if (result == NULL || !result->is_CheckCastPP()) {
never@1515:         // strange looking allocation
never@1515: #ifndef PRODUCT
never@1515:         if (PrintOptimizeStringConcat) {
never@1515:           tty->print("giving up because allocation looks strange ");
never@1515:           alloc->jvms()->dump_spec(tty); tty->cr();
never@1515:         }
never@1515: #endif
never@1515:         break;
never@1515:       }
never@1515:       Node* constructor = NULL;
never@1515:       for (SimpleDUIterator i(result); i.has_next(); i.next()) {
never@1515:         CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
never@2172:         if (use != NULL &&
never@2172:             use->method() != NULL &&
never@2172:             !use->method()->is_static() &&
never@1515:             use->method()->name() == ciSymbol::object_initializer_name() &&
never@1515:             use->method()->holder() == m->holder()) {
never@1515:           // Matched the constructor.
never@1515:           ciSymbol* sig = use->method()->signature()->as_symbol();
never@1515:           if (sig == ciSymbol::void_method_signature() ||
never@1515:               sig == ciSymbol::int_void_signature() ||
never@1515:               sig == ciSymbol::string_void_signature()) {
never@1515:             if (sig == ciSymbol::string_void_signature()) {
never@1515:               // StringBuilder(String) so pick this up as the first argument
never@1515:               assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
kvn@2413:               const Type* type = _gvn->type(use->in(TypeFunc::Parms + 1));
kvn@2413:               if (type == TypePtr::NULL_PTR) {
kvn@2413:                 // StringBuilder(null) throws exception.
kvn@2413: #ifndef PRODUCT
kvn@2413:                 if (PrintOptimizeStringConcat) {
kvn@2413:                   tty->print("giving up because StringBuilder(null) throws exception");
kvn@2413:                   alloc->jvms()->dump_spec(tty); tty->cr();
kvn@2413:                 }
kvn@2413: #endif
kvn@2413:                 return NULL;
kvn@2413:               }
kvn@2413:               // StringBuilder(str) argument needs null check.
kvn@2413:               sc->push_string_null_check(use->in(TypeFunc::Parms + 1));
never@1515:             }
never@1515:             // The int variant takes an initial size for the backing
never@1515:             // array so just treat it like the void version.
never@1515:             constructor = use;
never@1515:           } else {
never@1515: #ifndef PRODUCT
never@1515:             if (PrintOptimizeStringConcat) {
never@1515:               tty->print("unexpected constructor signature: %s", sig->as_utf8());
never@1515:             }
never@1515: #endif
never@1515:           }
never@1515:           break;
never@1515:         }
never@1515:       }
never@1515:       if (constructor == NULL) {
never@1515:         // couldn't find constructor
never@1515: #ifndef PRODUCT
never@1515:         if (PrintOptimizeStringConcat) {
never@1515:           tty->print("giving up because couldn't find constructor ");
kvn@2413:           alloc->jvms()->dump_spec(tty); tty->cr();
never@1515:         }
never@1515: #endif
never@1515:         break;
never@1515:       }
never@1515: 
never@1515:       // Walked all the way back and found the constructor call so see
never@1515:       // if this call converted into a direct string concatenation.
never@1515:       sc->add_control(call);
never@1515:       sc->add_control(constructor);
never@1515:       sc->add_control(alloc);
never@1515:       sc->set_allocation(alloc);
never@1515:       if (sc->validate_control_flow()) {
never@1515:         return sc;
never@1515:       } else {
never@1515:         return NULL;
never@1515:       }
never@1515:     } else if (cnode->method() == NULL) {
never@1515:       break;
never@2172:     } else if (!cnode->method()->is_static() &&
never@2172:                cnode->method()->holder() == m->holder() &&
never@1515:                cnode->method()->name() == ciSymbol::append_name() &&
never@1515:                (cnode->method()->signature()->as_symbol() == string_sig ||
never@1515:                 cnode->method()->signature()->as_symbol() == char_sig ||
never@1515:                 cnode->method()->signature()->as_symbol() == int_sig)) {
never@1515:       sc->add_control(cnode);
never@1515:       Node* arg = cnode->in(TypeFunc::Parms + 1);
never@1515:       if (cnode->method()->signature()->as_symbol() == int_sig) {
never@1515:         sc->push_int(arg);
never@1515:       } else if (cnode->method()->signature()->as_symbol() == char_sig) {
never@1515:         sc->push_char(arg);
never@1515:       } else {
never@1515:         if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
never@1515:           CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
never@1515:           if (csj->method() != NULL &&
never@2172:               csj->method()->intrinsic_id() == vmIntrinsics::_Integer_toString) {
never@1515:             sc->add_control(csj);
never@1515:             sc->push_int(csj->in(TypeFunc::Parms));
never@1515:             continue;
never@1515:           }
never@1515:         }
never@1515:         sc->push_string(arg);
never@1515:       }
never@1515:       continue;
never@1515:     } else {
never@1515:       // some unhandled signature
never@1515: #ifndef PRODUCT
never@1515:       if (PrintOptimizeStringConcat) {
never@1515:         tty->print("giving up because encountered unexpected signature ");
never@1515:         cnode->tf()->dump(); tty->cr();
never@1515:         cnode->in(TypeFunc::Parms + 1)->dump();
never@1515:       }
never@1515: #endif
never@1515:       break;
never@1515:     }
never@1515:   }
never@1515:   return NULL;
never@1515: }
never@1515: 
never@1515: 
never@1515: PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
never@1515:   Phase(StringOpts),
never@1515:   _gvn(gvn),
never@1515:   _visited(Thread::current()->resource_area()) {
never@1515: 
never@1515:   assert(OptimizeStringConcat, "shouldn't be here");
never@1515: 
never@1515:   size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
never@1515:                                                                   ciSymbol::make("[I"), true);
never@1515:   if (size_table_field == NULL) {
never@1515:     // Something wrong so give up.
never@1515:     assert(false, "why can't we find Integer.sizeTable?");
never@1515:     return;
never@1515:   }
never@1515: 
never@1515:   // Collect the types needed to talk about the various slices of memory
never@1515:   const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
never@1515:                                                      false, NULL, 0);
never@1515: 
never@1515:   const TypePtr* value_field_type = string_type->add_offset(java_lang_String::value_offset_in_bytes());
never@1515:   const TypePtr* offset_field_type = string_type->add_offset(java_lang_String::offset_offset_in_bytes());
never@1515:   const TypePtr* count_field_type = string_type->add_offset(java_lang_String::count_offset_in_bytes());
never@1515: 
never@1515:   value_field_idx = C->get_alias_index(value_field_type);
never@1515:   count_field_idx = C->get_alias_index(count_field_type);
never@1515:   offset_field_idx = C->get_alias_index(offset_field_type);
never@1515:   char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS);
never@1515: 
never@1515:   // For each locally allocated StringBuffer see if the usages can be
never@1515:   // collapsed into a single String construction.
never@1515: 
never@1515:   // Run through the list of allocation looking for SB.toString to see
never@1515:   // if it's possible to fuse the usage of the SB into a single String
never@1515:   // construction.
never@1515:   GrowableArray<StringConcat*> concats;
never@1515:   Node_List toStrings = collect_toString_calls();
never@1515:   while (toStrings.size() > 0) {
never@1515:     StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
never@1515:     if (sc != NULL) {
never@1515:       concats.push(sc);
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   // try to coalesce separate concats
never@1515:  restart:
never@1515:   for (int c = 0; c < concats.length(); c++) {
never@1515:     StringConcat* sc = concats.at(c);
never@1515:     for (int i = 0; i < sc->num_arguments(); i++) {
never@1515:       Node* arg = sc->argument(i);
never@1515:       if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
never@1515:         CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
never@1515:         if (csj->method() != NULL &&
never@2172:             (csj->method()->intrinsic_id() == vmIntrinsics::_StringBuilder_toString ||
never@2172:              csj->method()->intrinsic_id() == vmIntrinsics::_StringBuffer_toString)) {
never@1515:           for (int o = 0; o < concats.length(); o++) {
never@1515:             if (c == o) continue;
never@1515:             StringConcat* other = concats.at(o);
never@1515:             if (other->end() == csj) {
never@1515: #ifndef PRODUCT
never@1515:               if (PrintOptimizeStringConcat) {
never@1515:                 tty->print_cr("considering stacked concats");
never@1515:               }
never@1515: #endif
never@1515: 
never@1515:               StringConcat* merged = sc->merge(other, arg);
never@1515:               if (merged->validate_control_flow()) {
never@1515: #ifndef PRODUCT
never@1515:                 if (PrintOptimizeStringConcat) {
never@1515:                   tty->print_cr("stacking would succeed");
never@1515:                 }
never@1515: #endif
never@1515:                 if (c < o) {
never@1515:                   concats.remove_at(o);
never@1515:                   concats.at_put(c, merged);
never@1515:                 } else {
never@1515:                   concats.remove_at(c);
never@1515:                   concats.at_put(o, merged);
never@1515:                 }
never@1515:                 goto restart;
never@1515:               } else {
never@1515: #ifndef PRODUCT
never@1515:                 if (PrintOptimizeStringConcat) {
never@1515:                   tty->print_cr("stacking would fail");
never@1515:                 }
never@1515: #endif
never@1515:               }
never@1515:             }
never@1515:           }
never@1515:         }
never@1515:       }
never@1515:     }
never@1515:   }
never@1515: 
never@1515: 
never@1515:   for (int c = 0; c < concats.length(); c++) {
never@1515:     StringConcat* sc = concats.at(c);
never@1515:     replace_string_concat(sc);
never@1515:   }
never@1515: 
never@1515:   remove_dead_nodes();
never@1515: }
never@1515: 
never@1515: void PhaseStringOpts::record_dead_node(Node* dead) {
never@1515:   dead_worklist.push(dead);
never@1515: }
never@1515: 
never@1515: void PhaseStringOpts::remove_dead_nodes() {
never@1515:   // Delete any dead nodes to make things clean enough that escape
never@1515:   // analysis doesn't get unhappy.
never@1515:   while (dead_worklist.size() > 0) {
never@1515:     Node* use = dead_worklist.pop();
never@1515:     int opc = use->Opcode();
never@1515:     switch (opc) {
never@1515:       case Op_Region: {
never@1515:         uint i = 1;
never@1515:         for (i = 1; i < use->req(); i++) {
never@1515:           if (use->in(i) != C->top()) {
never@1515:             break;
never@1515:           }
never@1515:         }
never@1515:         if (i >= use->req()) {
never@1515:           for (SimpleDUIterator i(use); i.has_next(); i.next()) {
never@1515:             Node* m = i.get();
never@1515:             if (m->is_Phi()) {
never@1515:               dead_worklist.push(m);
never@1515:             }
never@1515:           }
never@1515:           C->gvn_replace_by(use, C->top());
never@1515:         }
never@1515:         break;
never@1515:       }
never@1515:       case Op_AddP:
never@1515:       case Op_CreateEx: {
never@1515:         // Recurisvely clean up references to CreateEx so EA doesn't
never@1515:         // get unhappy about the partially collapsed graph.
never@1515:         for (SimpleDUIterator i(use); i.has_next(); i.next()) {
never@1515:           Node* m = i.get();
never@1515:           if (m->is_AddP()) {
never@1515:             dead_worklist.push(m);
never@1515:           }
never@1515:         }
never@1515:         C->gvn_replace_by(use, C->top());
never@1515:         break;
never@1515:       }
never@1515:       case Op_Phi:
never@1515:         if (use->in(0) == C->top()) {
never@1515:           C->gvn_replace_by(use, C->top());
never@1515:         }
never@1515:         break;
never@1515:     }
never@1515:   }
never@1515: }
never@1515: 
never@1515: 
never@1515: bool StringConcat::validate_control_flow() {
never@1515:   // We found all the calls and arguments now lets see if it's
never@1515:   // safe to transform the graph as we would expect.
never@1515: 
never@1515:   // Check to see if this resulted in too many uncommon traps previously
never@1515:   if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
never@1515:                         Deoptimization::Reason_intrinsic)) {
never@1515:     return false;
never@1515:   }
never@1515: 
never@1515:   // Walk backwards over the control flow from toString to the
never@1515:   // allocation and make sure all the control flow is ok.  This
never@1515:   // means it's either going to be eliminated once the calls are
never@1515:   // removed or it can safely be transformed into an uncommon
never@1515:   // trap.
never@1515: 
never@1515:   int null_check_count = 0;
never@1515:   Unique_Node_List ctrl_path;
never@1515: 
never@1515:   assert(_control.contains(_begin), "missing");
never@1515:   assert(_control.contains(_end), "missing");
never@1515: 
never@1515:   // Collect the nodes that we know about and will eliminate into ctrl_path
never@1515:   for (uint i = 0; i < _control.size(); i++) {
never@1515:     // Push the call and it's control projection
never@1515:     Node* n = _control.at(i);
never@1515:     if (n->is_Allocate()) {
never@1515:       AllocateNode* an = n->as_Allocate();
never@1515:       InitializeNode* init = an->initialization();
never@1515:       ctrl_path.push(init);
never@1515:       ctrl_path.push(init->as_Multi()->proj_out(0));
never@1515:     }
never@1515:     if (n->is_Call()) {
never@1515:       CallNode* cn = n->as_Call();
never@1515:       ctrl_path.push(cn);
never@1515:       ctrl_path.push(cn->proj_out(0));
never@1515:       ctrl_path.push(cn->proj_out(0)->unique_out());
never@1515:       ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0));
never@1515:     } else {
never@1515:       ShouldNotReachHere();
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   // Skip backwards through the control checking for unexpected contro flow
never@1515:   Node* ptr = _end;
never@1515:   bool fail = false;
never@1515:   while (ptr != _begin) {
never@1515:     if (ptr->is_Call() && ctrl_path.member(ptr)) {
never@1515:       ptr = ptr->in(0);
never@1515:     } else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
never@1515:       ptr = ptr->in(0)->in(0)->in(0);
never@1515:       assert(ctrl_path.member(ptr), "should be a known piece of control");
never@1515:     } else if (ptr->is_IfTrue()) {
never@1515:       IfNode* iff = ptr->in(0)->as_If();
never@1515:       BoolNode* b = iff->in(1)->isa_Bool();
never@1515:       Node* cmp = b->in(1);
never@1515:       Node* v1 = cmp->in(1);
never@1515:       Node* v2 = cmp->in(2);
never@1515:       Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
never@1515: 
never@1515:       // Null check of the return of append which can simply be eliminated
never@1515:       if (b->_test._test == BoolTest::ne &&
never@1515:           v2->bottom_type() == TypePtr::NULL_PTR &&
never@1515:           v1->is_Proj() && ctrl_path.member(v1->in(0))) {
never@1515:         // NULL check of the return value of the append
never@1515:         null_check_count++;
never@1515:         if (otherproj->outcnt() == 1) {
never@1515:           CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
never@1515:           if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
never@1515:             ctrl_path.push(call);
never@1515:           }
never@1515:         }
never@1515:         _control.push(ptr);
never@1515:         ptr = ptr->in(0)->in(0);
never@1515:         continue;
never@1515:       }
never@1515: 
never@1515:       // A test which leads to an uncommon trap which should be safe.
never@1515:       // Later this trap will be converted into a trap that restarts
never@1515:       // at the beginning.
never@1515:       if (otherproj->outcnt() == 1) {
never@1515:         CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
never@1515:         if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
never@1515:           // control flow leads to uct so should be ok
never@1515:           _uncommon_traps.push(call);
never@1515:           ctrl_path.push(call);
never@1515:           ptr = ptr->in(0)->in(0);
never@1515:           continue;
never@1515:         }
never@1515:       }
never@1515: 
never@1515: #ifndef PRODUCT
never@1515:       // Some unexpected control flow we don't know how to handle.
never@1515:       if (PrintOptimizeStringConcat) {
never@1515:         tty->print_cr("failing with unknown test");
never@1515:         b->dump();
never@1515:         cmp->dump();
never@1515:         v1->dump();
never@1515:         v2->dump();
never@1515:         tty->cr();
never@1515:       }
never@1515: #endif
never@1515:       break;
never@1515:     } else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
never@1515:       ptr = ptr->in(0)->in(0);
never@1515:     } else if (ptr->is_Region()) {
never@1515:       Node* copy = ptr->as_Region()->is_copy();
never@1515:       if (copy != NULL) {
never@1515:         ptr = copy;
never@1515:         continue;
never@1515:       }
never@1515:       if (ptr->req() == 3 &&
never@1515:           ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
never@1515:           ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
never@1515:           ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
never@1515:           ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
never@1515:         // Simple diamond.
never@1515:         // XXX should check for possibly merging stores.  simple data merges are ok.
never@1515:         ptr = ptr->in(1)->in(0)->in(0);
never@1515:         continue;
never@1515:       }
never@1515: #ifndef PRODUCT
never@1515:       if (PrintOptimizeStringConcat) {
never@1515:         tty->print_cr("fusion would fail for region");
never@1515:         _begin->dump();
never@1515:         ptr->dump(2);
never@1515:       }
never@1515: #endif
never@1515:       fail = true;
never@1515:       break;
never@1515:     } else {
never@1515:       // other unknown control
never@1515:       if (!fail) {
never@1515: #ifndef PRODUCT
never@1515:         if (PrintOptimizeStringConcat) {
never@1515:           tty->print_cr("fusion would fail for");
never@1515:           _begin->dump();
never@1515:         }
never@1515: #endif
never@1515:         fail = true;
never@1515:       }
never@1515: #ifndef PRODUCT
never@1515:       if (PrintOptimizeStringConcat) {
never@1515:         ptr->dump();
never@1515:       }
never@1515: #endif
never@1515:       ptr = ptr->in(0);
never@1515:     }
never@1515:   }
never@1515: #ifndef PRODUCT
never@1515:   if (PrintOptimizeStringConcat && fail) {
never@1515:     tty->cr();
never@1515:   }
never@1515: #endif
never@1515:   if (fail) return !fail;
never@1515: 
never@1515:   // Validate that all these results produced are contained within
never@1515:   // this cluster of objects.  First collect all the results produced
never@1515:   // by calls in the region.
never@1515:   _stringopts->_visited.Clear();
never@1515:   Node_List worklist;
never@1515:   Node* final_result = _end->proj_out(TypeFunc::Parms);
never@1515:   for (uint i = 0; i < _control.size(); i++) {
never@1515:     CallNode* cnode = _control.at(i)->isa_Call();
never@1515:     if (cnode != NULL) {
never@1515:       _stringopts->_visited.test_set(cnode->_idx);
never@1515:     }
never@1515:     Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL;
never@1515:     if (result != NULL && result != final_result) {
never@1515:       worklist.push(result);
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   Node* last_result = NULL;
never@1515:   while (worklist.size() > 0) {
never@1515:     Node* result = worklist.pop();
never@1515:     if (_stringopts->_visited.test_set(result->_idx))
never@1515:       continue;
never@1515:     for (SimpleDUIterator i(result); i.has_next(); i.next()) {
never@1515:       Node *use = i.get();
never@1515:       if (ctrl_path.member(use)) {
never@1515:         // already checked this
never@1515:         continue;
never@1515:       }
never@1515:       int opc = use->Opcode();
never@1515:       if (opc == Op_CmpP || opc == Op_Node) {
never@1515:         ctrl_path.push(use);
never@1515:         continue;
never@1515:       }
never@1515:       if (opc == Op_CastPP || opc == Op_CheckCastPP) {
never@1515:         for (SimpleDUIterator j(use); j.has_next(); j.next()) {
never@1515:           worklist.push(j.get());
never@1515:         }
never@1515:         worklist.push(use->in(1));
never@1515:         ctrl_path.push(use);
never@1515:         continue;
never@1515:       }
never@1515: #ifndef PRODUCT
never@1515:       if (PrintOptimizeStringConcat) {
never@1515:         if (result != last_result) {
never@1515:           last_result = result;
never@1515:           tty->print_cr("extra uses for result:");
never@1515:           last_result->dump();
never@1515:         }
never@1515:         use->dump();
never@1515:       }
never@1515: #endif
never@1515:       fail = true;
never@1515:       break;
never@1515:     }
never@1515:   }
never@1515: 
never@1515: #ifndef PRODUCT
never@1515:   if (PrintOptimizeStringConcat && !fail) {
never@1515:     ttyLocker ttyl;
never@1515:     tty->cr();
never@1515:     tty->print("fusion would succeed (%d %d) for ", null_check_count, _uncommon_traps.size());
never@1515:     _begin->jvms()->dump_spec(tty); tty->cr();
never@1515:     for (int i = 0; i < num_arguments(); i++) {
never@1515:       argument(i)->dump();
never@1515:     }
never@1515:     _control.dump();
never@1515:     tty->cr();
never@1515:   }
never@1515: #endif
never@1515: 
never@1515:   return !fail;
never@1515: }
never@1515: 
never@1515: Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
never@1515:   const TypeKlassPtr* klass_type = TypeKlassPtr::make(field->holder());
never@1515:   Node* klass_node = __ makecon(klass_type);
never@1515:   BasicType bt = field->layout_type();
never@1515:   ciType* field_klass = field->type();
never@1515: 
never@1515:   const Type *type;
never@1515:   if( bt == T_OBJECT ) {
never@1515:     if (!field->type()->is_loaded()) {
never@1515:       type = TypeInstPtr::BOTTOM;
never@1515:     } else if (field->is_constant()) {
never@1515:       // This can happen if the constant oop is non-perm.
never@1515:       ciObject* con = field->constant_value().as_object();
never@1515:       // Do not "join" in the previous type; it doesn't add value,
never@1515:       // and may yield a vacuous result if the field is of interface type.
never@1515:       type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
never@1515:       assert(type != NULL, "field singleton type must be consistent");
never@1515:     } else {
never@1515:       type = TypeOopPtr::make_from_klass(field_klass->as_klass());
never@1515:     }
never@1515:   } else {
never@1515:     type = Type::get_const_basic_type(bt);
never@1515:   }
never@1515: 
never@1515:   return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
never@1515:                        type, T_OBJECT,
never@1515:                        C->get_alias_index(klass_type->add_offset(field->offset_in_bytes())));
never@1515: }
never@1515: 
never@1515: Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
never@1515:   RegionNode *final_merge = new (C, 3) RegionNode(3);
never@1515:   kit.gvn().set_type(final_merge, Type::CONTROL);
never@1515:   Node* final_size = new (C, 3) PhiNode(final_merge, TypeInt::INT);
never@1515:   kit.gvn().set_type(final_size, TypeInt::INT);
never@1515: 
never@1515:   IfNode* iff = kit.create_and_map_if(kit.control(),
never@1515:                                       __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
never@1515:                                       PROB_FAIR, COUNT_UNKNOWN);
never@1515:   Node* is_min = __ IfFalse(iff);
never@1515:   final_merge->init_req(1, is_min);
never@1515:   final_size->init_req(1, __ intcon(11));
never@1515: 
never@1515:   kit.set_control(__ IfTrue(iff));
never@1515:   if (kit.stopped()) {
never@1515:     final_merge->init_req(2, C->top());
never@1515:     final_size->init_req(2, C->top());
never@1515:   } else {
never@1515: 
never@1515:     // int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
never@1515:     RegionNode *r = new (C, 3) RegionNode(3);
never@1515:     kit.gvn().set_type(r, Type::CONTROL);
never@1515:     Node *phi = new (C, 3) PhiNode(r, TypeInt::INT);
never@1515:     kit.gvn().set_type(phi, TypeInt::INT);
never@1515:     Node *size = new (C, 3) PhiNode(r, TypeInt::INT);
never@1515:     kit.gvn().set_type(size, TypeInt::INT);
never@1515:     Node* chk = __ CmpI(arg, __ intcon(0));
never@1515:     Node* p = __ Bool(chk, BoolTest::lt);
never@1515:     IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
never@1515:     Node* lessthan = __ IfTrue(iff);
never@1515:     Node* greaterequal = __ IfFalse(iff);
never@1515:     r->init_req(1, lessthan);
never@1515:     phi->init_req(1, __ SubI(__ intcon(0), arg));
never@1515:     size->init_req(1, __ intcon(1));
never@1515:     r->init_req(2, greaterequal);
never@1515:     phi->init_req(2, arg);
never@1515:     size->init_req(2, __ intcon(0));
never@1515:     kit.set_control(r);
never@1515:     C->record_for_igvn(r);
never@1515:     C->record_for_igvn(phi);
never@1515:     C->record_for_igvn(size);
never@1515: 
never@1515:     // for (int i=0; ; i++)
never@1515:     //   if (x <= sizeTable[i])
never@1515:     //     return i+1;
never@1515:     RegionNode *loop = new (C, 3) RegionNode(3);
never@1515:     loop->init_req(1, kit.control());
never@1515:     kit.gvn().set_type(loop, Type::CONTROL);
never@1515: 
never@1515:     Node *index = new (C, 3) PhiNode(loop, TypeInt::INT);
never@1515:     index->init_req(1, __ intcon(0));
never@1515:     kit.gvn().set_type(index, TypeInt::INT);
never@1515:     kit.set_control(loop);
never@1515:     Node* sizeTable = fetch_static_field(kit, size_table_field);
never@1515: 
never@1515:     Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
never@1515:     C->record_for_igvn(value);
never@1515:     Node* limit = __ CmpI(phi, value);
never@1515:     Node* limitb = __ Bool(limit, BoolTest::le);
never@1515:     IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
never@1515:     Node* lessEqual = __ IfTrue(iff2);
never@1515:     Node* greater = __ IfFalse(iff2);
never@1515: 
never@1515:     loop->init_req(2, greater);
never@1515:     index->init_req(2, __ AddI(index, __ intcon(1)));
never@1515: 
never@1515:     kit.set_control(lessEqual);
never@1515:     C->record_for_igvn(loop);
never@1515:     C->record_for_igvn(index);
never@1515: 
never@1515:     final_merge->init_req(2, kit.control());
never@1515:     final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
never@1515:   }
never@1515: 
never@1515:   kit.set_control(final_merge);
never@1515:   C->record_for_igvn(final_merge);
never@1515:   C->record_for_igvn(final_size);
never@1515: 
never@1515:   return final_size;
never@1515: }
never@1515: 
never@1515: void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) {
never@1515:   RegionNode *final_merge = new (C, 4) RegionNode(4);
never@1515:   kit.gvn().set_type(final_merge, Type::CONTROL);
never@1515:   Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
never@1515:   kit.gvn().set_type(final_mem, Type::MEMORY);
never@1515: 
never@1515:   // need to handle Integer.MIN_VALUE specially because negating doesn't make it positive
never@1515:   {
never@1515:     // i == MIN_VALUE
never@1515:     IfNode* iff = kit.create_and_map_if(kit.control(),
never@1515:                                         __ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
never@1515:                                         PROB_FAIR, COUNT_UNKNOWN);
never@1515: 
never@1515:     Node* old_mem = kit.memory(char_adr_idx);
never@1515: 
never@1515:     kit.set_control(__ IfFalse(iff));
never@1515:     if (kit.stopped()) {
never@1515:       // Statically not equal to MIN_VALUE so this path is dead
never@1515:       final_merge->init_req(3, kit.control());
never@1515:     } else {
never@1515:       copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
never@1515:                   char_array, start);
never@1515:       final_merge->init_req(3, kit.control());
never@1515:       final_mem->init_req(3, kit.memory(char_adr_idx));
never@1515:     }
never@1515: 
never@1515:     kit.set_control(__ IfTrue(iff));
never@1515:     kit.set_memory(old_mem, char_adr_idx);
never@1515:   }
never@1515: 
never@1515: 
never@1515:   // Simplified version of Integer.getChars
never@1515: 
never@1515:   // int q, r;
never@1515:   // int charPos = index;
never@1515:   Node* charPos = end;
never@1515: 
never@1515:   // char sign = 0;
never@1515: 
never@1515:   Node* i = arg;
never@1515:   Node* sign = __ intcon(0);
never@1515: 
never@1515:   // if (i < 0) {
never@1515:   //     sign = '-';
never@1515:   //     i = -i;
never@1515:   // }
never@1515:   {
never@1515:     IfNode* iff = kit.create_and_map_if(kit.control(),
never@1515:                                         __ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
never@1515:                                         PROB_FAIR, COUNT_UNKNOWN);
never@1515: 
never@1515:     RegionNode *merge = new (C, 3) RegionNode(3);
never@1515:     kit.gvn().set_type(merge, Type::CONTROL);
never@1515:     i = new (C, 3) PhiNode(merge, TypeInt::INT);
never@1515:     kit.gvn().set_type(i, TypeInt::INT);
never@1515:     sign = new (C, 3) PhiNode(merge, TypeInt::INT);
never@1515:     kit.gvn().set_type(sign, TypeInt::INT);
never@1515: 
never@1515:     merge->init_req(1, __ IfTrue(iff));
never@1515:     i->init_req(1, __ SubI(__ intcon(0), arg));
never@1515:     sign->init_req(1, __ intcon('-'));
never@1515:     merge->init_req(2, __ IfFalse(iff));
never@1515:     i->init_req(2, arg);
never@1515:     sign->init_req(2, __ intcon(0));
never@1515: 
never@1515:     kit.set_control(merge);
never@1515: 
never@1515:     C->record_for_igvn(merge);
never@1515:     C->record_for_igvn(i);
never@1515:     C->record_for_igvn(sign);
never@1515:   }
never@1515: 
never@1515:   // for (;;) {
never@1515:   //     q = i / 10;
never@1515:   //     r = i - ((q << 3) + (q << 1));  // r = i-(q*10) ...
never@1515:   //     buf [--charPos] = digits [r];
never@1515:   //     i = q;
never@1515:   //     if (i == 0) break;
never@1515:   // }
never@1515: 
never@1515:   {
never@1515:     RegionNode *head = new (C, 3) RegionNode(3);
never@1515:     head->init_req(1, kit.control());
never@1515:     kit.gvn().set_type(head, Type::CONTROL);
never@1515:     Node *i_phi = new (C, 3) PhiNode(head, TypeInt::INT);
never@1515:     i_phi->init_req(1, i);
never@1515:     kit.gvn().set_type(i_phi, TypeInt::INT);
never@1515:     charPos = PhiNode::make(head, charPos);
never@1515:     kit.gvn().set_type(charPos, TypeInt::INT);
never@1515:     Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
never@1515:     kit.gvn().set_type(mem, Type::MEMORY);
never@1515:     kit.set_control(head);
never@1515:     kit.set_memory(mem, char_adr_idx);
never@1515: 
never@1685:     Node* q = __ DivI(NULL, i_phi, __ intcon(10));
never@1515:     Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
never@1515:                                      __ LShiftI(q, __ intcon(1))));
never@1515:     Node* m1 = __ SubI(charPos, __ intcon(1));
never@1515:     Node* ch = __ AddI(r, __ intcon('0'));
never@1515: 
never@1515:     Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
never@1515:                                   ch, T_CHAR, char_adr_idx);
never@1515: 
never@1515: 
never@1515:     IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
never@1515:                                         PROB_FAIR, COUNT_UNKNOWN);
never@1515:     Node* ne = __ IfTrue(iff);
never@1515:     Node* eq = __ IfFalse(iff);
never@1515: 
never@1515:     head->init_req(2, ne);
never@1515:     mem->init_req(2, st);
never@1515:     i_phi->init_req(2, q);
never@1515:     charPos->init_req(2, m1);
never@1515: 
never@1515:     charPos = m1;
never@1515: 
never@1515:     kit.set_control(eq);
never@1515:     kit.set_memory(st, char_adr_idx);
never@1515: 
never@1515:     C->record_for_igvn(head);
never@1515:     C->record_for_igvn(mem);
never@1515:     C->record_for_igvn(i_phi);
never@1515:     C->record_for_igvn(charPos);
never@1515:   }
never@1515: 
never@1515:   {
never@1515:     // if (sign != 0) {
never@1515:     //     buf [--charPos] = sign;
never@1515:     // }
never@1515:     IfNode* iff = kit.create_and_map_if(kit.control(),
never@1515:                                         __ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
never@1515:                                         PROB_FAIR, COUNT_UNKNOWN);
never@1515: 
never@1515:     final_merge->init_req(2, __ IfFalse(iff));
never@1515:     final_mem->init_req(2, kit.memory(char_adr_idx));
never@1515: 
never@1515:     kit.set_control(__ IfTrue(iff));
never@1515:     if (kit.stopped()) {
never@1515:       final_merge->init_req(1, C->top());
never@1515:       final_mem->init_req(1, C->top());
never@1515:     } else {
never@1515:       Node* m1 = __ SubI(charPos, __ intcon(1));
never@1515:       Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
never@1515:                                     sign, T_CHAR, char_adr_idx);
never@1515: 
never@1515:       final_merge->init_req(1, kit.control());
never@1515:       final_mem->init_req(1, st);
never@1515:     }
never@1515: 
never@1515:     kit.set_control(final_merge);
never@1515:     kit.set_memory(final_mem, char_adr_idx);
never@1515: 
never@1515:     C->record_for_igvn(final_merge);
never@1515:     C->record_for_igvn(final_mem);
never@1515:   }
never@1515: }
never@1515: 
never@1515: 
never@1515: Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) {
never@1515:   Node* string = str;
never@1515:   Node* offset = kit.make_load(NULL,
never@1515:                                kit.basic_plus_adr(string, string, java_lang_String::offset_offset_in_bytes()),
never@1515:                                TypeInt::INT, T_INT, offset_field_idx);
never@1515:   Node* count = kit.make_load(NULL,
never@1515:                               kit.basic_plus_adr(string, string, java_lang_String::count_offset_in_bytes()),
never@1515:                               TypeInt::INT, T_INT, count_field_idx);
never@1515:   const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
never@1515:                                                    TypeAry::make(TypeInt::CHAR,TypeInt::POS),
never@1515:                                                    ciTypeArrayKlass::make(T_CHAR), true, 0);
never@1515:   Node* value = kit.make_load(NULL,
never@1515:                               kit.basic_plus_adr(string, string, java_lang_String::value_offset_in_bytes()),
never@1515:                               value_type, T_OBJECT, value_field_idx);
never@1515: 
never@1515:   // copy the contents
never@1515:   if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) {
never@1515:     // For small constant strings just emit individual stores.
never@1515:     // A length of 6 seems like a good space/speed tradeof.
never@1515:     int c = count->get_int();
never@1515:     int o = offset->get_int();
never@1515:     const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr();
never@1515:     ciTypeArray* value_array = t->const_oop()->as_type_array();
never@1515:     for (int e = 0; e < c; e++) {
never@1515:       __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
never@1515:                          __ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx);
never@1515:       start = __ AddI(start, __ intcon(1));
never@1515:     }
never@1515:   } else {
never@1515:     Node* src_ptr = kit.array_element_address(value, offset, T_CHAR);
never@1515:     Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR);
never@1515:     Node* c = count;
never@1515:     Node* extra = NULL;
never@1515: #ifdef _LP64
never@1515:     c = __ ConvI2L(c);
never@1515:     extra = C->top();
never@1515: #endif
never@1515:     Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP,
never@1515:                                        OptoRuntime::fast_arraycopy_Type(),
never@1515:                                        CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()),
never@1515:                                        "jshort_disjoint_arraycopy", TypeAryPtr::CHARS,
never@1515:                                        src_ptr, dst_ptr, c, extra);
never@1515:     start = __ AddI(start, count);
never@1515:   }
never@1515:   return start;
never@1515: }
never@1515: 
never@1515: 
never@1515: void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
never@1515:   // Log a little info about the transformation
never@1515:   sc->maybe_log_transform();
never@1515: 
never@1515:   // pull the JVMState of the allocation into a SafePointNode to serve as
never@1515:   // as a shim for the insertion of the new code.
never@1515:   JVMState* jvms     = sc->begin()->jvms()->clone_shallow(C);
never@1515:   uint size = sc->begin()->req();
never@1515:   SafePointNode* map = new (C, size) SafePointNode(size, jvms);
never@1515: 
never@1515:   // copy the control and memory state from the final call into our
never@1515:   // new starting state.  This allows any preceeding tests to feed
never@1515:   // into the new section of code.
never@1515:   for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
never@1515:     map->init_req(i1, sc->end()->in(i1));
never@1515:   }
never@1515:   // blow away old allocation arguments
never@1515:   for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
never@1515:     map->init_req(i1, C->top());
never@1515:   }
never@1515:   // Copy the rest of the inputs for the JVMState
never@1515:   for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
never@1515:     map->init_req(i1, sc->begin()->in(i1));
never@1515:   }
never@1515:   // Make sure the memory state is a MergeMem for parsing.
never@1515:   if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
never@1515:     map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
never@1515:   }
never@1515: 
never@1515:   jvms->set_map(map);
never@1515:   map->ensure_stack(jvms, jvms->method()->max_stack());
never@1515: 
never@1515: 
never@1515:   // disconnect all the old StringBuilder calls from the graph
never@1515:   sc->eliminate_unneeded_control();
never@1515: 
never@1515:   // At this point all the old work has been completely removed from
never@1515:   // the graph and the saved JVMState exists at the point where the
never@1515:   // final toString call used to be.
never@1515:   GraphKit kit(jvms);
never@1515: 
never@1515:   // There may be uncommon traps which are still using the
never@1515:   // intermediate states and these need to be rewritten to point at
never@1515:   // the JVMState at the beginning of the transformation.
never@1515:   sc->convert_uncommon_traps(kit, jvms);
never@1515: 
never@1515:   // Now insert the logic to compute the size of the string followed
never@1515:   // by all the logic to construct array and resulting string.
never@1515: 
never@1515:   Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
never@1515: 
never@1515:   // Create a region for the overflow checks to merge into.
never@1515:   int args = MAX2(sc->num_arguments(), 1);
never@1515:   RegionNode* overflow = new (C, args) RegionNode(args);
never@1515:   kit.gvn().set_type(overflow, Type::CONTROL);
never@1515: 
never@1515:   // Create a hook node to hold onto the individual sizes since they
never@1515:   // are need for the copying phase.
never@1515:   Node* string_sizes = new (C, args) Node(args);
never@1515: 
never@1515:   Node* length = __ intcon(0);
never@1515:   for (int argi = 0; argi < sc->num_arguments(); argi++) {
never@1515:     Node* arg = sc->argument(argi);
never@1515:     switch (sc->mode(argi)) {
never@1515:       case StringConcat::IntMode: {
never@1515:         Node* string_size = int_stringSize(kit, arg);
never@1515: 
never@1515:         // accumulate total
never@1515:         length = __ AddI(length, string_size);
never@1515: 
never@1515:         // Cache this value for the use by int_toString
never@1515:         string_sizes->init_req(argi, string_size);
never@1515:         break;
never@1515:       }
kvn@2413:       case StringConcat::StringNullCheckMode: {
kvn@2413:         const Type* type = kit.gvn().type(arg);
kvn@2413:         assert(type != TypePtr::NULL_PTR, "missing check");
kvn@2413:         if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
kvn@2413:           // Null check with uncommont trap since
kvn@2413:           // StringBuilder(null) throws exception.
kvn@2413:           // Use special uncommon trap instead of
kvn@2413:           // calling normal do_null_check().
kvn@2413:           Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
kvn@2413:           IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
kvn@2413:           overflow->add_req(__ IfFalse(iff));
kvn@2413:           Node* notnull = __ IfTrue(iff);
kvn@2413:           kit.set_control(notnull); // set control for the cast_not_null
kvn@2413:           arg = kit.cast_not_null(arg, false);
kvn@2413:           sc->set_argument(argi, arg);
kvn@2413:         }
kvn@2413:         assert(kit.gvn().type(arg)->higher_equal(TypeInstPtr::NOTNULL), "sanity");
kvn@2413:         // Fallthrough to add string length.
kvn@2413:       }
never@1515:       case StringConcat::StringMode: {
never@1515:         const Type* type = kit.gvn().type(arg);
never@1515:         if (type == TypePtr::NULL_PTR) {
never@1515:           // replace the argument with the null checked version
never@1515:           arg = null_string;
never@1515:           sc->set_argument(argi, arg);
never@1515:         } else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
never@1515:           // s = s != null ? s : "null";
never@1515:           // length = length + (s.count - s.offset);
never@1515:           RegionNode *r = new (C, 3) RegionNode(3);
never@1515:           kit.gvn().set_type(r, Type::CONTROL);
never@1685:           Node *phi = new (C, 3) PhiNode(r, type);
never@1515:           kit.gvn().set_type(phi, phi->bottom_type());
never@1515:           Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
never@1515:           IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
never@1515:           Node* notnull = __ IfTrue(iff);
never@1515:           Node* isnull =  __ IfFalse(iff);
never@1685:           kit.set_control(notnull); // set control for the cast_not_null
never@1515:           r->init_req(1, notnull);
never@1685:           phi->init_req(1, kit.cast_not_null(arg, false));
never@1515:           r->init_req(2, isnull);
never@1515:           phi->init_req(2, null_string);
never@1515:           kit.set_control(r);
never@1515:           C->record_for_igvn(r);
never@1515:           C->record_for_igvn(phi);
never@1515:           // replace the argument with the null checked version
never@1515:           arg = phi;
never@1515:           sc->set_argument(argi, arg);
never@1515:         }
never@1515:         //         Node* offset = kit.make_load(NULL, kit.basic_plus_adr(arg, arg, offset_offset),
never@1515:         //                                      TypeInt::INT, T_INT, offset_field_idx);
never@1515:         Node* count = kit.make_load(NULL, kit.basic_plus_adr(arg, arg, java_lang_String::count_offset_in_bytes()),
never@1515:                                     TypeInt::INT, T_INT, count_field_idx);
never@1515:         length = __ AddI(length, count);
never@1515:         string_sizes->init_req(argi, NULL);
never@1515:         break;
never@1515:       }
never@1515:       case StringConcat::CharMode: {
never@1515:         // one character only
never@1515:         length = __ AddI(length, __ intcon(1));
never@1515:         break;
never@1515:       }
never@1515:       default:
never@1515:         ShouldNotReachHere();
never@1515:     }
never@1515:     if (argi > 0) {
never@1515:       // Check that the sum hasn't overflowed
never@1515:       IfNode* iff = kit.create_and_map_if(kit.control(),
never@1515:                                           __ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
never@1515:                                           PROB_MIN, COUNT_UNKNOWN);
never@1515:       kit.set_control(__ IfFalse(iff));
never@1515:       overflow->set_req(argi, __ IfTrue(iff));
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   {
never@1515:     // Hook
never@1515:     PreserveJVMState pjvms(&kit);
never@1515:     kit.set_control(overflow);
kvn@2413:     C->record_for_igvn(overflow);
never@1515:     kit.uncommon_trap(Deoptimization::Reason_intrinsic,
never@1515:                       Deoptimization::Action_make_not_entrant);
never@1515:   }
never@1515: 
never@1515:   // length now contains the number of characters needed for the
never@1515:   // char[] so create a new AllocateArray for the char[]
never@1515:   Node* char_array = NULL;
never@1515:   {
never@1515:     PreserveReexecuteState preexecs(&kit);
never@1515:     // The original jvms is for an allocation of either a String or
never@1515:     // StringBuffer so no stack adjustment is necessary for proper
never@1515:     // reexecution.  If we deoptimize in the slow path the bytecode
never@1515:     // will be reexecuted and the char[] allocation will be thrown away.
never@1515:     kit.jvms()->set_should_reexecute(true);
never@1515:     char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))),
never@1515:                                length, 1);
never@1515:   }
never@1515: 
never@1515:   // Mark the allocation so that zeroing is skipped since the code
never@1515:   // below will overwrite the entire array
never@1515:   AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
never@1515:   char_alloc->maybe_set_complete(_gvn);
never@1515: 
never@1515:   // Now copy the string representations into the final char[]
never@1515:   Node* start = __ intcon(0);
never@1515:   for (int argi = 0; argi < sc->num_arguments(); argi++) {
never@1515:     Node* arg = sc->argument(argi);
never@1515:     switch (sc->mode(argi)) {
never@1515:       case StringConcat::IntMode: {
never@1515:         Node* end = __ AddI(start, string_sizes->in(argi));
never@1515:         // getChars words backwards so pass the ending point as well as the start
never@1515:         int_getChars(kit, arg, char_array, start, end);
never@1515:         start = end;
never@1515:         break;
never@1515:       }
kvn@2413:       case StringConcat::StringNullCheckMode:
never@1515:       case StringConcat::StringMode: {
never@1515:         start = copy_string(kit, arg, char_array, start);
never@1515:         break;
never@1515:       }
never@1515:       case StringConcat::CharMode: {
never@1515:         __ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
never@1515:                            arg, T_CHAR, char_adr_idx);
never@1515:         start = __ AddI(start, __ intcon(1));
never@1515:         break;
never@1515:       }
never@1515:       default:
never@1515:         ShouldNotReachHere();
never@1515:     }
never@1515:   }
never@1515: 
never@1515:   // If we're not reusing an existing String allocation then allocate one here.
never@1515:   Node* result = sc->string_alloc();
never@1515:   if (result == NULL) {
never@1515:     PreserveReexecuteState preexecs(&kit);
never@1515:     // The original jvms is for an allocation of either a String or
never@1515:     // StringBuffer so no stack adjustment is necessary for proper
never@1515:     // reexecution.
never@1515:     kit.jvms()->set_should_reexecute(true);
never@1515:     result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
never@1515:   }
never@1515: 
never@1515:   // Intialize the string
never@1515:   kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::offset_offset_in_bytes()),
never@1515:                       __ intcon(0), T_INT, offset_field_idx);
never@1515:   kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::count_offset_in_bytes()),
never@1515:                       length, T_INT, count_field_idx);
never@1515:   kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::value_offset_in_bytes()),
never@1515:                       char_array, T_OBJECT, value_field_idx);
never@1515: 
never@1515:   // hook up the outgoing control and result
never@1515:   kit.replace_call(sc->end(), result);
never@1515: 
never@1515:   // Unhook any hook nodes
never@1515:   string_sizes->disconnect_inputs(NULL);
never@1515:   sc->cleanup();
never@1515: }