truffle: src/share/vm/opto/stringopts.cpp comparison

comparison src/share/vm/opto/stringopts.cpp @ 1080:7c57aead6d3e

6892658: C2 should optimize some stringbuilder patterns Reviewed-by: kvn, twisti

author	never
date	Thu, 12 Nov 2009 09:24:21 -0800
parents
children	3f5b7efb9642

comparison

equal deleted inserted replaced

-:8e7adf982378
+:7c57aead6d3e
+/*
+* Copyright 2009 Sun Microsystems, Inc.  All Rights Reserved.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* This code is free software; you can redistribute it and/or modify it
+* under the terms of the GNU General Public License version 2 only, as
+* published by the Free Software Foundation.
+*
+* This code is distributed in the hope that it will be useful, but WITHOUT
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+* version 2 for more details (a copy is included in the LICENSE file that
+* accompanied this code).
+*
+* You should have received a copy of the GNU General Public License version
+* 2 along with this work; if not, write to the Free Software Foundation,
+* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+* CA 95054 USA or visit www.sun.com if you need additional information or
+* have any questions.
+*
+*/
+#include "incls/_precompiled.incl"
+#include "incls/_stringopts.cpp.incl"
+#define __ kit.
+class StringConcat : public ResourceObj {
+private:
+PhaseStringOpts*    _stringopts;
+Node*               _string_alloc;
+AllocateNode*       _begin;          // The allocation the begins the pattern
+CallStaticJavaNode* _end;            // The final call of the pattern.  Will either be
+// SB.toString or or String.<init>(SB.toString)
+bool                _multiple;       // indicates this is a fusion of two or more
+// separate StringBuilders
+Node*               _arguments;      // The list of arguments to be concatenated
+GrowableArray<int>  _mode;           // into a String along with a mode flag
+// indicating how to treat the value.
+Node_List           _control;        // List of control nodes that will be deleted
+Node_List           _uncommon_traps; // Uncommon traps that needs to be rewritten
+// to restart at the initial JVMState.
+public:
+// Mode for converting arguments to Strings
+enum {
+StringMode,
+IntMode,
+CharMode
+};
+StringConcat(PhaseStringOpts* stringopts, CallStaticJavaNode* end):
+_end(end),
+_begin(NULL),
+_multiple(false),
+_string_alloc(NULL),
+_stringopts(stringopts) {
+_arguments = new (_stringopts->C, 1) Node(1);
+_arguments->del_req(0);
+}
+bool validate_control_flow();
+void merge_add() {
+#if 0
+// XXX This is place holder code for reusing an existing String
+// allocation but the logic for checking the state safety is
+// probably inadequate at the moment.
+CallProjections endprojs;
+sc->end()->extract_projections(&endprojs, false);
+if (endprojs.resproj != NULL) {
+for (SimpleDUIterator i(endprojs.resproj); i.has_next(); i.next()) {
+CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
+if (use != NULL && use->method() != NULL &&
+use->method()->holder() == C->env()->String_klass() &&
+use->method()->name() == ciSymbol::object_initializer_name() &&
+use->in(TypeFunc::Parms + 1) == endprojs.resproj) {
+// Found useless new String(sb.toString()) so reuse the newly allocated String
+// when creating the result instead of allocating a new one.
+sc->set_string_alloc(use->in(TypeFunc::Parms));
+sc->set_end(use);
+}
+}
+}
+#endif
+}
+StringConcat* merge(StringConcat* other, Node* arg);
+void set_allocation(AllocateNode* alloc) {
+_begin = alloc;
+}
+void append(Node* value, int mode) {
+_arguments->add_req(value);
+_mode.append(mode);
+}
+void push(Node* value, int mode) {
+_arguments->ins_req(0, value);
+_mode.insert_before(0, mode);
+}
+void push_string(Node* value) {
+push(value, StringMode);
+}
+void push_int(Node* value) {
+push(value, IntMode);
+}
+void push_char(Node* value) {
+push(value, CharMode);
+}
+Node* argument(int i) {
+return _arguments->in(i);
+}
+void set_argument(int i, Node* value) {
+_arguments->set_req(i, value);
+}
+int num_arguments() {
+return _mode.length();
+}
+int mode(int i) {
+return _mode.at(i);
+}
+void add_control(Node* ctrl) {
+assert(!_control.contains(ctrl), "only push once");
+_control.push(ctrl);
+}
+CallStaticJavaNode* end() { return _end; }
+AllocateNode* begin() { return _begin; }
+Node* string_alloc() { return _string_alloc; }
+void eliminate_unneeded_control();
+void eliminate_initialize(InitializeNode* init);
+void eliminate_call(CallNode* call);
+void maybe_log_transform() {
+CompileLog* log = _stringopts->C->log();
+if (log != NULL) {
+log->head("replace_string_concat arguments='%d' string_alloc='%d' multiple='%d'",
+num_arguments(),
+_string_alloc != NULL,
+_multiple);
+JVMState* p = _begin->jvms();
+while (p != NULL) {
+log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method()));
+p = p->caller();
+}
+log->tail("replace_string_concat");
+}
+}
+void convert_uncommon_traps(GraphKit& kit, const JVMState* jvms) {
+for (uint u = 0; u < _uncommon_traps.size(); u++) {
+Node* uct = _uncommon_traps.at(u);
+// Build a new call using the jvms state of the allocate
+address call_addr = SharedRuntime::uncommon_trap_blob()->instructions_begin();
+const TypeFunc* call_type = OptoRuntime::uncommon_trap_Type();
+int size = call_type->domain()->cnt();
+const TypePtr* no_memory_effects = NULL;
+Compile* C = _stringopts->C;
+CallStaticJavaNode* call = new (C, size) CallStaticJavaNode(call_type, call_addr, "uncommon_trap",
+jvms->bci(), no_memory_effects);
+for (int e = 0; e < TypeFunc::Parms; e++) {
+call->init_req(e, uct->in(e));
+}
+// Set the trap request to record intrinsic failure if this trap
+// is taken too many times.  Ideally we would handle then traps by
+// doing the original bookkeeping in the MDO so that if it caused
+// the code to be thrown out we could still recompile and use the
+// optimization.  Failing the uncommon traps doesn't really mean
+// that the optimization is a bad idea but there's no other way to
+// do the MDO updates currently.
+int trap_request = Deoptimization::make_trap_request(Deoptimization::Reason_intrinsic,
+Deoptimization::Action_make_not_entrant);
+call->init_req(TypeFunc::Parms, __ intcon(trap_request));
+kit.add_safepoint_edges(call);
+_stringopts->gvn()->transform(call);
+C->gvn_replace_by(uct, call);
+uct->disconnect_inputs(NULL);
+}
+}
+void cleanup() {
+// disconnect the hook node
+_arguments->disconnect_inputs(NULL);
+}
+};
+void StringConcat::eliminate_unneeded_control() {
+eliminate_initialize(begin()->initialization());
+for (uint i = 0; i < _control.size(); i++) {
+Node* n = _control.at(i);
+if (n->is_Call()) {
+if (n != _end) {
+eliminate_call(n->as_Call());
+}
+} else if (n->is_IfTrue()) {
+Compile* C = _stringopts->C;
+C->gvn_replace_by(n, n->in(0)->in(0));
+C->gvn_replace_by(n->in(0), C->top());
+}
+}
+}
+StringConcat* StringConcat::merge(StringConcat* other, Node* arg) {
+StringConcat* result = new StringConcat(_stringopts, _end);
+for (uint x = 0; x < _control.size(); x++) {
+Node* n = _control.at(x);
+if (n->is_Call()) {
+result->_control.push(n);
+}
+}
+for (uint x = 0; x < other->_control.size(); x++) {
+Node* n = other->_control.at(x);
+if (n->is_Call()) {
+result->_control.push(n);
+}
+}
+assert(result->_control.contains(other->_end), "what?");
+assert(result->_control.contains(_begin), "what?");
+for (int x = 0; x < num_arguments(); x++) {
+if (argument(x) == arg) {
+// replace the toString result with the all the arguments that
+// made up the other StringConcat
+for (int y = 0; y < other->num_arguments(); y++) {
+result->append(other->argument(y), other->mode(y));
+}
+} else {
+result->append(argument(x), mode(x));
+}
+}
+result->set_allocation(other->_begin);
+result->_multiple = true;
+return result;
+}
+void StringConcat::eliminate_call(CallNode* call) {
+Compile* C = _stringopts->C;
+CallProjections projs;
+call->extract_projections(&projs, false);
+if (projs.fallthrough_catchproj != NULL) {
+C->gvn_replace_by(projs.fallthrough_catchproj, call->in(TypeFunc::Control));
+}
+if (projs.fallthrough_memproj != NULL) {
+C->gvn_replace_by(projs.fallthrough_memproj, call->in(TypeFunc::Memory));
+}
+if (projs.catchall_memproj != NULL) {
+C->gvn_replace_by(projs.catchall_memproj, C->top());
+}
+if (projs.fallthrough_ioproj != NULL) {
+C->gvn_replace_by(projs.fallthrough_ioproj, call->in(TypeFunc::I_O));
+}
+if (projs.catchall_ioproj != NULL) {
+C->gvn_replace_by(projs.catchall_ioproj, C->top());
+}
+if (projs.catchall_catchproj != NULL) {
+// EA can't cope with the partially collapsed graph this
+// creates so put it on the worklist to be collapsed later.
+for (SimpleDUIterator i(projs.catchall_catchproj); i.has_next(); i.next()) {
+Node *use = i.get();
+int opc = use->Opcode();
+if (opc == Op_CreateEx || opc == Op_Region) {
+_stringopts->record_dead_node(use);
+}
+}
+C->gvn_replace_by(projs.catchall_catchproj, C->top());
+}
+if (projs.resproj != NULL) {
+C->gvn_replace_by(projs.resproj, C->top());
+}
+C->gvn_replace_by(call, C->top());
+}
+void StringConcat::eliminate_initialize(InitializeNode* init) {
+Compile* C = _stringopts->C;
+// Eliminate Initialize node.
+assert(init->outcnt() <= 2, "only a control and memory projection expected");
+assert(init->req() <= InitializeNode::RawStores, "no pending inits");
+Node *ctrl_proj = init->proj_out(TypeFunc::Control);
+if (ctrl_proj != NULL) {
+C->gvn_replace_by(ctrl_proj, init->in(TypeFunc::Control));
+}
+Node *mem_proj = init->proj_out(TypeFunc::Memory);
+if (mem_proj != NULL) {
+Node *mem = init->in(TypeFunc::Memory);
+C->gvn_replace_by(mem_proj, mem);
+}
+C->gvn_replace_by(init, C->top());
+init->disconnect_inputs(NULL);
+}
+Node_List PhaseStringOpts::collect_toString_calls() {
+Node_List string_calls;
+Node_List worklist;
+_visited.Clear();
+// Prime the worklist
+for (uint i = 1; i < C->root()->len(); i++) {
+Node* n = C->root()->in(i);
+if (n != NULL && !_visited.test_set(n->_idx)) {
+worklist.push(n);
+}
+}
+while (worklist.size() > 0) {
+Node* ctrl = worklist.pop();
+if (ctrl->is_CallStaticJava()) {
+CallStaticJavaNode* csj = ctrl->as_CallStaticJava();
+ciMethod* m = csj->method();
+if (m != NULL &&
+(m->intrinsic_id() == vmIntrinsics::_StringBuffer_toString ||
+m->intrinsic_id() == vmIntrinsics::_StringBuilder_toString)) {
+string_calls.push(csj);
+}
+}
+if (ctrl->in(0) != NULL && !_visited.test_set(ctrl->in(0)->_idx)) {
+worklist.push(ctrl->in(0));
+}
+if (ctrl->is_Region()) {
+for (uint i = 1; i < ctrl->len(); i++) {
+if (ctrl->in(i) != NULL && !_visited.test_set(ctrl->in(i)->_idx)) {
+worklist.push(ctrl->in(i));
+}
+}
+}
+}
+return string_calls;
+}
+StringConcat* PhaseStringOpts::build_candidate(CallStaticJavaNode* call) {
+ciMethod* m = call->method();
+ciSymbol* string_sig;
+ciSymbol* int_sig;
+ciSymbol* char_sig;
+if (m->holder() == C->env()->StringBuilder_klass()) {
+string_sig = ciSymbol::String_StringBuilder_signature();
+int_sig = ciSymbol::int_StringBuilder_signature();
+char_sig = ciSymbol::char_StringBuilder_signature();
+} else if (m->holder() == C->env()->StringBuffer_klass()) {
+string_sig = ciSymbol::String_StringBuffer_signature();
+int_sig = ciSymbol::int_StringBuffer_signature();
+char_sig = ciSymbol::char_StringBuffer_signature();
+} else {
+return NULL;
+}
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print("considering toString call in ");
+call->jvms()->dump_spec(tty); tty->cr();
+}
+#endif
+StringConcat* sc = new StringConcat(this, call);
+AllocateNode* alloc = NULL;
+InitializeNode* init = NULL;
+// possible opportunity for StringBuilder fusion
+CallStaticJavaNode* cnode = call;
+while (cnode) {
+Node* recv = cnode->in(TypeFunc::Parms)->uncast();
+if (recv->is_Proj()) {
+recv = recv->in(0);
+}
+cnode = recv->isa_CallStaticJava();
+if (cnode == NULL) {
+alloc = recv->isa_Allocate();
+if (alloc == NULL) {
+break;
+}
+// Find the constructor call
+Node* result = alloc->result_cast();
+if (result == NULL || !result->is_CheckCastPP()) {
+// strange looking allocation
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print("giving up because allocation looks strange ");
+alloc->jvms()->dump_spec(tty); tty->cr();
+}
+#endif
+break;
+}
+Node* constructor = NULL;
+for (SimpleDUIterator i(result); i.has_next(); i.next()) {
+CallStaticJavaNode *use = i.get()->isa_CallStaticJava();
+if (use != NULL && use->method() != NULL &&
+use->method()->name() == ciSymbol::object_initializer_name() &&
+use->method()->holder() == m->holder()) {
+// Matched the constructor.
+ciSymbol* sig = use->method()->signature()->as_symbol();
+if (sig == ciSymbol::void_method_signature() ||
+sig == ciSymbol::int_void_signature() ||
+sig == ciSymbol::string_void_signature()) {
+if (sig == ciSymbol::string_void_signature()) {
+// StringBuilder(String) so pick this up as the first argument
+assert(use->in(TypeFunc::Parms + 1) != NULL, "what?");
+sc->push_string(use->in(TypeFunc::Parms + 1));
+}
+// The int variant takes an initial size for the backing
+// array so just treat it like the void version.
+constructor = use;
+} else {
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print("unexpected constructor signature: %s", sig->as_utf8());
+}
+#endif
+}
+break;
+}
+}
+if (constructor == NULL) {
+// couldn't find constructor
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print("giving up because couldn't find constructor ");
+alloc->jvms()->dump_spec(tty);
+}
+#endif
+break;
+}
+// Walked all the way back and found the constructor call so see
+// if this call converted into a direct string concatenation.
+sc->add_control(call);
+sc->add_control(constructor);
+sc->add_control(alloc);
+sc->set_allocation(alloc);
+if (sc->validate_control_flow()) {
+return sc;
+} else {
+return NULL;
+}
+} else if (cnode->method() == NULL) {
+break;
+} else if (cnode->method()->holder() == m->holder() &&
+cnode->method()->name() == ciSymbol::append_name() &&
+(cnode->method()->signature()->as_symbol() == string_sig ||
+cnode->method()->signature()->as_symbol() == char_sig ||
+cnode->method()->signature()->as_symbol() == int_sig)) {
+sc->add_control(cnode);
+Node* arg = cnode->in(TypeFunc::Parms + 1);
+if (cnode->method()->signature()->as_symbol() == int_sig) {
+sc->push_int(arg);
+} else if (cnode->method()->signature()->as_symbol() == char_sig) {
+sc->push_char(arg);
+} else {
+if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
+CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
+if (csj->method() != NULL &&
+csj->method()->holder() == C->env()->Integer_klass() &&
+csj->method()->name() == ciSymbol::toString_name()) {
+sc->add_control(csj);
+sc->push_int(csj->in(TypeFunc::Parms));
+continue;
+}
+}
+sc->push_string(arg);
+}
+continue;
+} else {
+// some unhandled signature
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print("giving up because encountered unexpected signature ");
+cnode->tf()->dump(); tty->cr();
+cnode->in(TypeFunc::Parms + 1)->dump();
+}
+#endif
+break;
+}
+}
+return NULL;
+}
+PhaseStringOpts::PhaseStringOpts(PhaseGVN* gvn, Unique_Node_List*):
+Phase(StringOpts),
+_gvn(gvn),
+_visited(Thread::current()->resource_area()) {
+assert(OptimizeStringConcat, "shouldn't be here");
+size_table_field = C->env()->Integer_klass()->get_field_by_name(ciSymbol::make("sizeTable"),
+ciSymbol::make("[I"), true);
+if (size_table_field == NULL) {
+// Something wrong so give up.
+assert(false, "why can't we find Integer.sizeTable?");
+return;
+}
+// Collect the types needed to talk about the various slices of memory
+const TypeInstPtr* string_type = TypeInstPtr::make(TypePtr::NotNull, C->env()->String_klass(),
+false, NULL, 0);
+const TypePtr* value_field_type = string_type->add_offset(java_lang_String::value_offset_in_bytes());
+const TypePtr* offset_field_type = string_type->add_offset(java_lang_String::offset_offset_in_bytes());
+const TypePtr* count_field_type = string_type->add_offset(java_lang_String::count_offset_in_bytes());
+value_field_idx = C->get_alias_index(value_field_type);
+count_field_idx = C->get_alias_index(count_field_type);
+offset_field_idx = C->get_alias_index(offset_field_type);
+char_adr_idx = C->get_alias_index(TypeAryPtr::CHARS);
+// For each locally allocated StringBuffer see if the usages can be
+// collapsed into a single String construction.
+// Run through the list of allocation looking for SB.toString to see
+// if it's possible to fuse the usage of the SB into a single String
+// construction.
+GrowableArray<StringConcat*> concats;
+Node_List toStrings = collect_toString_calls();
+while (toStrings.size() > 0) {
+StringConcat* sc = build_candidate(toStrings.pop()->as_CallStaticJava());
+if (sc != NULL) {
+concats.push(sc);
+}
+}
+// try to coalesce separate concats
+restart:
+for (int c = 0; c < concats.length(); c++) {
+StringConcat* sc = concats.at(c);
+for (int i = 0; i < sc->num_arguments(); i++) {
+Node* arg = sc->argument(i);
+if (arg->is_Proj() && arg->in(0)->is_CallStaticJava()) {
+CallStaticJavaNode* csj = arg->in(0)->as_CallStaticJava();
+if (csj->method() != NULL &&
+(csj->method()->holder() == C->env()->StringBuffer_klass() ||
+csj->method()->holder() == C->env()->StringBuilder_klass()) &&
+csj->method()->name() == ciSymbol::toString_name()) {
+for (int o = 0; o < concats.length(); o++) {
+if (c == o) continue;
+StringConcat* other = concats.at(o);
+if (other->end() == csj) {
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print_cr("considering stacked concats");
+}
+#endif
+StringConcat* merged = sc->merge(other, arg);
+if (merged->validate_control_flow()) {
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print_cr("stacking would succeed");
+}
+#endif
+if (c < o) {
+concats.remove_at(o);
+concats.at_put(c, merged);
+} else {
+concats.remove_at(c);
+concats.at_put(o, merged);
+}
+goto restart;
+} else {
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print_cr("stacking would fail");
+}
+#endif
+}
+}
+}
+}
+}
+}
+}
+for (int c = 0; c < concats.length(); c++) {
+StringConcat* sc = concats.at(c);
+replace_string_concat(sc);
+}
+remove_dead_nodes();
+}
+void PhaseStringOpts::record_dead_node(Node* dead) {
+dead_worklist.push(dead);
+}
+void PhaseStringOpts::remove_dead_nodes() {
+// Delete any dead nodes to make things clean enough that escape
+// analysis doesn't get unhappy.
+while (dead_worklist.size() > 0) {
+Node* use = dead_worklist.pop();
+int opc = use->Opcode();
+switch (opc) {
+case Op_Region: {
+uint i = 1;
+for (i = 1; i < use->req(); i++) {
+if (use->in(i) != C->top()) {
+break;
+}
+}
+if (i >= use->req()) {
+for (SimpleDUIterator i(use); i.has_next(); i.next()) {
+Node* m = i.get();
+if (m->is_Phi()) {
+dead_worklist.push(m);
+}
+}
+C->gvn_replace_by(use, C->top());
+}
+break;
+}
+case Op_AddP:
+case Op_CreateEx: {
+// Recurisvely clean up references to CreateEx so EA doesn't
+// get unhappy about the partially collapsed graph.
+for (SimpleDUIterator i(use); i.has_next(); i.next()) {
+Node* m = i.get();
+if (m->is_AddP()) {
+dead_worklist.push(m);
+}
+}
+C->gvn_replace_by(use, C->top());
+break;
+}
+case Op_Phi:
+if (use->in(0) == C->top()) {
+C->gvn_replace_by(use, C->top());
+}
+break;
+}
+}
+}
+bool StringConcat::validate_control_flow() {
+// We found all the calls and arguments now lets see if it's
+// safe to transform the graph as we would expect.
+// Check to see if this resulted in too many uncommon traps previously
+if (Compile::current()->too_many_traps(_begin->jvms()->method(), _begin->jvms()->bci(),
+Deoptimization::Reason_intrinsic)) {
+return false;
+}
+// Walk backwards over the control flow from toString to the
+// allocation and make sure all the control flow is ok.  This
+// means it's either going to be eliminated once the calls are
+// removed or it can safely be transformed into an uncommon
+// trap.
+int null_check_count = 0;
+Unique_Node_List ctrl_path;
+assert(_control.contains(_begin), "missing");
+assert(_control.contains(_end), "missing");
+// Collect the nodes that we know about and will eliminate into ctrl_path
+for (uint i = 0; i < _control.size(); i++) {
+// Push the call and it's control projection
+Node* n = _control.at(i);
+if (n->is_Allocate()) {
+AllocateNode* an = n->as_Allocate();
+InitializeNode* init = an->initialization();
+ctrl_path.push(init);
+ctrl_path.push(init->as_Multi()->proj_out(0));
+}
+if (n->is_Call()) {
+CallNode* cn = n->as_Call();
+ctrl_path.push(cn);
+ctrl_path.push(cn->proj_out(0));
+ctrl_path.push(cn->proj_out(0)->unique_out());
+ctrl_path.push(cn->proj_out(0)->unique_out()->as_Catch()->proj_out(0));
+} else {
+ShouldNotReachHere();
+}
+}
+// Skip backwards through the control checking for unexpected contro flow
+Node* ptr = _end;
+bool fail = false;
+while (ptr != _begin) {
+if (ptr->is_Call() && ctrl_path.member(ptr)) {
+ptr = ptr->in(0);
+} else if (ptr->is_CatchProj() && ctrl_path.member(ptr)) {
+ptr = ptr->in(0)->in(0)->in(0);
+assert(ctrl_path.member(ptr), "should be a known piece of control");
+} else if (ptr->is_IfTrue()) {
+IfNode* iff = ptr->in(0)->as_If();
+BoolNode* b = iff->in(1)->isa_Bool();
+Node* cmp = b->in(1);
+Node* v1 = cmp->in(1);
+Node* v2 = cmp->in(2);
+Node* otherproj = iff->proj_out(1 - ptr->as_Proj()->_con);
+// Null check of the return of append which can simply be eliminated
+if (b->_test._test == BoolTest::ne &&
+v2->bottom_type() == TypePtr::NULL_PTR &&
+v1->is_Proj() && ctrl_path.member(v1->in(0))) {
+// NULL check of the return value of the append
+null_check_count++;
+if (otherproj->outcnt() == 1) {
+CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
+if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
+ctrl_path.push(call);
+}
+}
+_control.push(ptr);
+ptr = ptr->in(0)->in(0);
+continue;
+}
+// A test which leads to an uncommon trap which should be safe.
+// Later this trap will be converted into a trap that restarts
+// at the beginning.
+if (otherproj->outcnt() == 1) {
+CallStaticJavaNode* call = otherproj->unique_out()->isa_CallStaticJava();
+if (call != NULL && call->_name != NULL && strcmp(call->_name, "uncommon_trap") == 0) {
+// control flow leads to uct so should be ok
+_uncommon_traps.push(call);
+ctrl_path.push(call);
+ptr = ptr->in(0)->in(0);
+continue;
+}
+}
+#ifndef PRODUCT
+// Some unexpected control flow we don't know how to handle.
+if (PrintOptimizeStringConcat) {
+tty->print_cr("failing with unknown test");
+b->dump();
+cmp->dump();
+v1->dump();
+v2->dump();
+tty->cr();
+}
+#endif
+break;
+} else if (ptr->is_Proj() && ptr->in(0)->is_Initialize()) {
+ptr = ptr->in(0)->in(0);
+} else if (ptr->is_Region()) {
+Node* copy = ptr->as_Region()->is_copy();
+if (copy != NULL) {
+ptr = copy;
+continue;
+}
+if (ptr->req() == 3 &&
+ptr->in(1) != NULL && ptr->in(1)->is_Proj() &&
+ptr->in(2) != NULL && ptr->in(2)->is_Proj() &&
+ptr->in(1)->in(0) == ptr->in(2)->in(0) &&
+ptr->in(1)->in(0) != NULL && ptr->in(1)->in(0)->is_If()) {
+// Simple diamond.
+// XXX should check for possibly merging stores.  simple data merges are ok.
+ptr = ptr->in(1)->in(0)->in(0);
+continue;
+}
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print_cr("fusion would fail for region");
+_begin->dump();
+ptr->dump(2);
+}
+#endif
+fail = true;
+break;
+} else {
+// other unknown control
+if (!fail) {
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+tty->print_cr("fusion would fail for");
+_begin->dump();
+}
+#endif
+fail = true;
+}
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+ptr->dump();
+}
+#endif
+ptr = ptr->in(0);
+}
+}
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat && fail) {
+tty->cr();
+}
+#endif
+if (fail) return !fail;
+// Validate that all these results produced are contained within
+// this cluster of objects.  First collect all the results produced
+// by calls in the region.
+_stringopts->_visited.Clear();
+Node_List worklist;
+Node* final_result = _end->proj_out(TypeFunc::Parms);
+for (uint i = 0; i < _control.size(); i++) {
+CallNode* cnode = _control.at(i)->isa_Call();
+if (cnode != NULL) {
+_stringopts->_visited.test_set(cnode->_idx);
+}
+Node* result = cnode != NULL ? cnode->proj_out(TypeFunc::Parms) : NULL;
+if (result != NULL && result != final_result) {
+worklist.push(result);
+}
+}
+Node* last_result = NULL;
+while (worklist.size() > 0) {
+Node* result = worklist.pop();
+if (_stringopts->_visited.test_set(result->_idx))
+continue;
+for (SimpleDUIterator i(result); i.has_next(); i.next()) {
+Node *use = i.get();
+if (ctrl_path.member(use)) {
+// already checked this
+continue;
+}
+int opc = use->Opcode();
+if (opc == Op_CmpP || opc == Op_Node) {
+ctrl_path.push(use);
+continue;
+}
+if (opc == Op_CastPP || opc == Op_CheckCastPP) {
+for (SimpleDUIterator j(use); j.has_next(); j.next()) {
+worklist.push(j.get());
+}
+worklist.push(use->in(1));
+ctrl_path.push(use);
+continue;
+}
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat) {
+if (result != last_result) {
+last_result = result;
+tty->print_cr("extra uses for result:");
+last_result->dump();
+}
+use->dump();
+}
+#endif
+fail = true;
+break;
+}
+}
+#ifndef PRODUCT
+if (PrintOptimizeStringConcat && !fail) {
+ttyLocker ttyl;
+tty->cr();
+tty->print("fusion would succeed (%d %d) for ", null_check_count, _uncommon_traps.size());
+_begin->jvms()->dump_spec(tty); tty->cr();
+for (int i = 0; i < num_arguments(); i++) {
+argument(i)->dump();
+}
+_control.dump();
+tty->cr();
+}
+#endif
+return !fail;
+}
+Node* PhaseStringOpts::fetch_static_field(GraphKit& kit, ciField* field) {
+const TypeKlassPtr* klass_type = TypeKlassPtr::make(field->holder());
+Node* klass_node = __ makecon(klass_type);
+BasicType bt = field->layout_type();
+ciType* field_klass = field->type();
+const Type *type;
+if( bt == T_OBJECT ) {
+if (!field->type()->is_loaded()) {
+type = TypeInstPtr::BOTTOM;
+} else if (field->is_constant()) {
+// This can happen if the constant oop is non-perm.
+ciObject* con = field->constant_value().as_object();
+// Do not "join" in the previous type; it doesn't add value,
+// and may yield a vacuous result if the field is of interface type.
+type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
+assert(type != NULL, "field singleton type must be consistent");
+} else {
+type = TypeOopPtr::make_from_klass(field_klass->as_klass());
+}
+} else {
+type = Type::get_const_basic_type(bt);
+}
+return kit.make_load(NULL, kit.basic_plus_adr(klass_node, field->offset_in_bytes()),
+type, T_OBJECT,
+C->get_alias_index(klass_type->add_offset(field->offset_in_bytes())));
+}
+Node* PhaseStringOpts::int_stringSize(GraphKit& kit, Node* arg) {
+RegionNode *final_merge = new (C, 3) RegionNode(3);
+kit.gvn().set_type(final_merge, Type::CONTROL);
+Node* final_size = new (C, 3) PhiNode(final_merge, TypeInt::INT);
+kit.gvn().set_type(final_size, TypeInt::INT);
+IfNode* iff = kit.create_and_map_if(kit.control(),
+__ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
+PROB_FAIR, COUNT_UNKNOWN);
+Node* is_min = __ IfFalse(iff);
+final_merge->init_req(1, is_min);
+final_size->init_req(1, __ intcon(11));
+kit.set_control(__ IfTrue(iff));
+if (kit.stopped()) {
+final_merge->init_req(2, C->top());
+final_size->init_req(2, C->top());
+} else {
+// int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
+RegionNode *r = new (C, 3) RegionNode(3);
+kit.gvn().set_type(r, Type::CONTROL);
+Node *phi = new (C, 3) PhiNode(r, TypeInt::INT);
+kit.gvn().set_type(phi, TypeInt::INT);
+Node *size = new (C, 3) PhiNode(r, TypeInt::INT);
+kit.gvn().set_type(size, TypeInt::INT);
+Node* chk = __ CmpI(arg, __ intcon(0));
+Node* p = __ Bool(chk, BoolTest::lt);
+IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_FAIR, COUNT_UNKNOWN);
+Node* lessthan = __ IfTrue(iff);
+Node* greaterequal = __ IfFalse(iff);
+r->init_req(1, lessthan);
+phi->init_req(1, __ SubI(__ intcon(0), arg));
+size->init_req(1, __ intcon(1));
+r->init_req(2, greaterequal);
+phi->init_req(2, arg);
+size->init_req(2, __ intcon(0));
+kit.set_control(r);
+C->record_for_igvn(r);
+C->record_for_igvn(phi);
+C->record_for_igvn(size);
+// for (int i=0; ; i++)
+//   if (x <= sizeTable[i])
+//     return i+1;
+RegionNode *loop = new (C, 3) RegionNode(3);
+loop->init_req(1, kit.control());
+kit.gvn().set_type(loop, Type::CONTROL);
+Node *index = new (C, 3) PhiNode(loop, TypeInt::INT);
+index->init_req(1, __ intcon(0));
+kit.gvn().set_type(index, TypeInt::INT);
+kit.set_control(loop);
+Node* sizeTable = fetch_static_field(kit, size_table_field);
+Node* value = kit.load_array_element(NULL, sizeTable, index, TypeAryPtr::INTS);
+C->record_for_igvn(value);
+Node* limit = __ CmpI(phi, value);
+Node* limitb = __ Bool(limit, BoolTest::le);
+IfNode* iff2 = kit.create_and_map_if(kit.control(), limitb, PROB_MIN, COUNT_UNKNOWN);
+Node* lessEqual = __ IfTrue(iff2);
+Node* greater = __ IfFalse(iff2);
+loop->init_req(2, greater);
+index->init_req(2, __ AddI(index, __ intcon(1)));
+kit.set_control(lessEqual);
+C->record_for_igvn(loop);
+C->record_for_igvn(index);
+final_merge->init_req(2, kit.control());
+final_size->init_req(2, __ AddI(__ AddI(index, size), __ intcon(1)));
+}
+kit.set_control(final_merge);
+C->record_for_igvn(final_merge);
+C->record_for_igvn(final_size);
+return final_size;
+}
+void PhaseStringOpts::int_getChars(GraphKit& kit, Node* arg, Node* char_array, Node* start, Node* end) {
+RegionNode *final_merge = new (C, 4) RegionNode(4);
+kit.gvn().set_type(final_merge, Type::CONTROL);
+Node *final_mem = PhiNode::make(final_merge, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
+kit.gvn().set_type(final_mem, Type::MEMORY);
+// need to handle Integer.MIN_VALUE specially because negating doesn't make it positive
+{
+// i == MIN_VALUE
+IfNode* iff = kit.create_and_map_if(kit.control(),
+__ Bool(__ CmpI(arg, __ intcon(0x80000000)), BoolTest::ne),
+PROB_FAIR, COUNT_UNKNOWN);
+Node* old_mem = kit.memory(char_adr_idx);
+kit.set_control(__ IfFalse(iff));
+if (kit.stopped()) {
+// Statically not equal to MIN_VALUE so this path is dead
+final_merge->init_req(3, kit.control());
+} else {
+copy_string(kit, __ makecon(TypeInstPtr::make(C->env()->the_min_jint_string())),
+char_array, start);
+final_merge->init_req(3, kit.control());
+final_mem->init_req(3, kit.memory(char_adr_idx));
+}
+kit.set_control(__ IfTrue(iff));
+kit.set_memory(old_mem, char_adr_idx);
+}
+// Simplified version of Integer.getChars
+// int q, r;
+// int charPos = index;
+Node* charPos = end;
+// char sign = 0;
+Node* i = arg;
+Node* sign = __ intcon(0);
+// if (i < 0) {
+//     sign = '-';
+//     i = -i;
+// }
+{
+IfNode* iff = kit.create_and_map_if(kit.control(),
+__ Bool(__ CmpI(arg, __ intcon(0)), BoolTest::lt),
+PROB_FAIR, COUNT_UNKNOWN);
+RegionNode *merge = new (C, 3) RegionNode(3);
+kit.gvn().set_type(merge, Type::CONTROL);
+i = new (C, 3) PhiNode(merge, TypeInt::INT);
+kit.gvn().set_type(i, TypeInt::INT);
+sign = new (C, 3) PhiNode(merge, TypeInt::INT);
+kit.gvn().set_type(sign, TypeInt::INT);
+merge->init_req(1, __ IfTrue(iff));
+i->init_req(1, __ SubI(__ intcon(0), arg));
+sign->init_req(1, __ intcon('-'));
+merge->init_req(2, __ IfFalse(iff));
+i->init_req(2, arg);
+sign->init_req(2, __ intcon(0));
+kit.set_control(merge);
+C->record_for_igvn(merge);
+C->record_for_igvn(i);
+C->record_for_igvn(sign);
+}
+// for (;;) {
+//     q = i / 10;
+//     r = i - ((q << 3) + (q << 1));  // r = i-(q*10) ...
+//     buf [--charPos] = digits [r];
+//     i = q;
+//     if (i == 0) break;
+// }
+{
+RegionNode *head = new (C, 3) RegionNode(3);
+head->init_req(1, kit.control());
+kit.gvn().set_type(head, Type::CONTROL);
+Node *i_phi = new (C, 3) PhiNode(head, TypeInt::INT);
+i_phi->init_req(1, i);
+kit.gvn().set_type(i_phi, TypeInt::INT);
+charPos = PhiNode::make(head, charPos);
+kit.gvn().set_type(charPos, TypeInt::INT);
+Node *mem = PhiNode::make(head, kit.memory(char_adr_idx), Type::MEMORY, TypeAryPtr::CHARS);
+kit.gvn().set_type(mem, Type::MEMORY);
+kit.set_control(head);
+kit.set_memory(mem, char_adr_idx);
+Node* q = __ DivI(kit.null(), i_phi, __ intcon(10));
+Node* r = __ SubI(i_phi, __ AddI(__ LShiftI(q, __ intcon(3)),
+__ LShiftI(q, __ intcon(1))));
+Node* m1 = __ SubI(charPos, __ intcon(1));
+Node* ch = __ AddI(r, __ intcon('0'));
+Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
+ch, T_CHAR, char_adr_idx);
+IfNode* iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
+PROB_FAIR, COUNT_UNKNOWN);
+Node* ne = __ IfTrue(iff);
+Node* eq = __ IfFalse(iff);
+head->init_req(2, ne);
+mem->init_req(2, st);
+i_phi->init_req(2, q);
+charPos->init_req(2, m1);
+charPos = m1;
+kit.set_control(eq);
+kit.set_memory(st, char_adr_idx);
+C->record_for_igvn(head);
+C->record_for_igvn(mem);
+C->record_for_igvn(i_phi);
+C->record_for_igvn(charPos);
+}
+{
+// if (sign != 0) {
+//     buf [--charPos] = sign;
+// }
+IfNode* iff = kit.create_and_map_if(kit.control(),
+__ Bool(__ CmpI(sign, __ intcon(0)), BoolTest::ne),
+PROB_FAIR, COUNT_UNKNOWN);
+final_merge->init_req(2, __ IfFalse(iff));
+final_mem->init_req(2, kit.memory(char_adr_idx));
+kit.set_control(__ IfTrue(iff));
+if (kit.stopped()) {
+final_merge->init_req(1, C->top());
+final_mem->init_req(1, C->top());
+} else {
+Node* m1 = __ SubI(charPos, __ intcon(1));
+Node* st = __ store_to_memory(kit.control(), kit.array_element_address(char_array, m1, T_CHAR),
+sign, T_CHAR, char_adr_idx);
+final_merge->init_req(1, kit.control());
+final_mem->init_req(1, st);
+}
+kit.set_control(final_merge);
+kit.set_memory(final_mem, char_adr_idx);
+C->record_for_igvn(final_merge);
+C->record_for_igvn(final_mem);
+}
+}
+Node* PhaseStringOpts::copy_string(GraphKit& kit, Node* str, Node* char_array, Node* start) {
+Node* string = str;
+Node* offset = kit.make_load(NULL,
+kit.basic_plus_adr(string, string, java_lang_String::offset_offset_in_bytes()),
+TypeInt::INT, T_INT, offset_field_idx);
+Node* count = kit.make_load(NULL,
+kit.basic_plus_adr(string, string, java_lang_String::count_offset_in_bytes()),
+TypeInt::INT, T_INT, count_field_idx);
+const TypeAryPtr*  value_type = TypeAryPtr::make(TypePtr::NotNull,
+TypeAry::make(TypeInt::CHAR,TypeInt::POS),
+ciTypeArrayKlass::make(T_CHAR), true, 0);
+Node* value = kit.make_load(NULL,
+kit.basic_plus_adr(string, string, java_lang_String::value_offset_in_bytes()),
+value_type, T_OBJECT, value_field_idx);
+// copy the contents
+if (offset->is_Con() && count->is_Con() && value->is_Con() && count->get_int() < unroll_string_copy_length) {
+// For small constant strings just emit individual stores.
+// A length of 6 seems like a good space/speed tradeof.
+int c = count->get_int();
+int o = offset->get_int();
+const TypeOopPtr* t = kit.gvn().type(value)->isa_oopptr();
+ciTypeArray* value_array = t->const_oop()->as_type_array();
+for (int e = 0; e < c; e++) {
+__ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
+__ intcon(value_array->char_at(o + e)), T_CHAR, char_adr_idx);
+start = __ AddI(start, __ intcon(1));
+}
+} else {
+Node* src_ptr = kit.array_element_address(value, offset, T_CHAR);
+Node* dst_ptr = kit.array_element_address(char_array, start, T_CHAR);
+Node* c = count;
+Node* extra = NULL;
+#ifdef _LP64
+c = __ ConvI2L(c);
+extra = C->top();
+#endif
+Node* call = kit.make_runtime_call(GraphKit::RC_LEAF|GraphKit::RC_NO_FP,
+OptoRuntime::fast_arraycopy_Type(),
+CAST_FROM_FN_PTR(address, StubRoutines::jshort_disjoint_arraycopy()),
+"jshort_disjoint_arraycopy", TypeAryPtr::CHARS,
+src_ptr, dst_ptr, c, extra);
+start = __ AddI(start, count);
+}
+return start;
+}
+void PhaseStringOpts::replace_string_concat(StringConcat* sc) {
+// Log a little info about the transformation
+sc->maybe_log_transform();
+// pull the JVMState of the allocation into a SafePointNode to serve as
+// as a shim for the insertion of the new code.
+JVMState* jvms     = sc->begin()->jvms()->clone_shallow(C);
+uint size = sc->begin()->req();
+SafePointNode* map = new (C, size) SafePointNode(size, jvms);
+// copy the control and memory state from the final call into our
+// new starting state.  This allows any preceeding tests to feed
+// into the new section of code.
+for (uint i1 = 0; i1 < TypeFunc::Parms; i1++) {
+map->init_req(i1, sc->end()->in(i1));
+}
+// blow away old allocation arguments
+for (uint i1 = TypeFunc::Parms; i1 < jvms->debug_start(); i1++) {
+map->init_req(i1, C->top());
+}
+// Copy the rest of the inputs for the JVMState
+for (uint i1 = jvms->debug_start(); i1 < sc->begin()->req(); i1++) {
+map->init_req(i1, sc->begin()->in(i1));
+}
+// Make sure the memory state is a MergeMem for parsing.
+if (!map->in(TypeFunc::Memory)->is_MergeMem()) {
+map->set_req(TypeFunc::Memory, MergeMemNode::make(C, map->in(TypeFunc::Memory)));
+}
+jvms->set_map(map);
+map->ensure_stack(jvms, jvms->method()->max_stack());
+// disconnect all the old StringBuilder calls from the graph
+sc->eliminate_unneeded_control();
+// At this point all the old work has been completely removed from
+// the graph and the saved JVMState exists at the point where the
+// final toString call used to be.
+GraphKit kit(jvms);
+// There may be uncommon traps which are still using the
+// intermediate states and these need to be rewritten to point at
+// the JVMState at the beginning of the transformation.
+sc->convert_uncommon_traps(kit, jvms);
+// Now insert the logic to compute the size of the string followed
+// by all the logic to construct array and resulting string.
+Node* null_string = __ makecon(TypeInstPtr::make(C->env()->the_null_string()));
+// Create a region for the overflow checks to merge into.
+int args = MAX2(sc->num_arguments(), 1);
+RegionNode* overflow = new (C, args) RegionNode(args);
+kit.gvn().set_type(overflow, Type::CONTROL);
+// Create a hook node to hold onto the individual sizes since they
+// are need for the copying phase.
+Node* string_sizes = new (C, args) Node(args);
+Node* length = __ intcon(0);
+for (int argi = 0; argi < sc->num_arguments(); argi++) {
+Node* arg = sc->argument(argi);
+switch (sc->mode(argi)) {
+case StringConcat::IntMode: {
+Node* string_size = int_stringSize(kit, arg);
+// accumulate total
+length = __ AddI(length, string_size);
+// Cache this value for the use by int_toString
+string_sizes->init_req(argi, string_size);
+break;
+}
+case StringConcat::StringMode: {
+const Type* type = kit.gvn().type(arg);
+if (type == TypePtr::NULL_PTR) {
+// replace the argument with the null checked version
+arg = null_string;
+sc->set_argument(argi, arg);
+} else if (!type->higher_equal(TypeInstPtr::NOTNULL)) {
+// s = s != null ? s : "null";
+// length = length + (s.count - s.offset);
+RegionNode *r = new (C, 3) RegionNode(3);
+kit.gvn().set_type(r, Type::CONTROL);
+Node *phi = new (C, 3) PhiNode(r, type->join(TypeInstPtr::NOTNULL));
+kit.gvn().set_type(phi, phi->bottom_type());
+Node* p = __ Bool(__ CmpP(arg, kit.null()), BoolTest::ne);
+IfNode* iff = kit.create_and_map_if(kit.control(), p, PROB_MIN, COUNT_UNKNOWN);
+Node* notnull = __ IfTrue(iff);
+Node* isnull =  __ IfFalse(iff);
+r->init_req(1, notnull);
+phi->init_req(1, arg);
+r->init_req(2, isnull);
+phi->init_req(2, null_string);
+kit.set_control(r);
+C->record_for_igvn(r);
+C->record_for_igvn(phi);
+// replace the argument with the null checked version
+arg = phi;
+sc->set_argument(argi, arg);
+}
+//         Node* offset = kit.make_load(NULL, kit.basic_plus_adr(arg, arg, offset_offset),
+//                                      TypeInt::INT, T_INT, offset_field_idx);
+Node* count = kit.make_load(NULL, kit.basic_plus_adr(arg, arg, java_lang_String::count_offset_in_bytes()),
+TypeInt::INT, T_INT, count_field_idx);
+length = __ AddI(length, count);
+string_sizes->init_req(argi, NULL);
+break;
+}
+case StringConcat::CharMode: {
+// one character only
+length = __ AddI(length, __ intcon(1));
+break;
+}
+default:
+ShouldNotReachHere();
+}
+if (argi > 0) {
+// Check that the sum hasn't overflowed
+IfNode* iff = kit.create_and_map_if(kit.control(),
+__ Bool(__ CmpI(length, __ intcon(0)), BoolTest::lt),
+PROB_MIN, COUNT_UNKNOWN);
+kit.set_control(__ IfFalse(iff));
+overflow->set_req(argi, __ IfTrue(iff));
+}
+}
+{
+// Hook
+PreserveJVMState pjvms(&kit);
+kit.set_control(overflow);
+kit.uncommon_trap(Deoptimization::Reason_intrinsic,
+Deoptimization::Action_make_not_entrant);
+}
+// length now contains the number of characters needed for the
+// char[] so create a new AllocateArray for the char[]
+Node* char_array = NULL;
+{
+PreserveReexecuteState preexecs(&kit);
+// The original jvms is for an allocation of either a String or
+// StringBuffer so no stack adjustment is necessary for proper
+// reexecution.  If we deoptimize in the slow path the bytecode
+// will be reexecuted and the char[] allocation will be thrown away.
+kit.jvms()->set_should_reexecute(true);
+char_array = kit.new_array(__ makecon(TypeKlassPtr::make(ciTypeArrayKlass::make(T_CHAR))),
+length, 1);
+}
+// Mark the allocation so that zeroing is skipped since the code
+// below will overwrite the entire array
+AllocateArrayNode* char_alloc = AllocateArrayNode::Ideal_array_allocation(char_array, _gvn);
+char_alloc->maybe_set_complete(_gvn);
+// Now copy the string representations into the final char[]
+Node* start = __ intcon(0);
+for (int argi = 0; argi < sc->num_arguments(); argi++) {
+Node* arg = sc->argument(argi);
+switch (sc->mode(argi)) {
+case StringConcat::IntMode: {
+Node* end = __ AddI(start, string_sizes->in(argi));
+// getChars words backwards so pass the ending point as well as the start
+int_getChars(kit, arg, char_array, start, end);
+start = end;
+break;
+}
+case StringConcat::StringMode: {
+start = copy_string(kit, arg, char_array, start);
+break;
+}
+case StringConcat::CharMode: {
+__ store_to_memory(kit.control(), kit.array_element_address(char_array, start, T_CHAR),
+arg, T_CHAR, char_adr_idx);
+start = __ AddI(start, __ intcon(1));
+break;
+}
+default:
+ShouldNotReachHere();
+}
+}
+// If we're not reusing an existing String allocation then allocate one here.
+Node* result = sc->string_alloc();
+if (result == NULL) {
+PreserveReexecuteState preexecs(&kit);
+// The original jvms is for an allocation of either a String or
+// StringBuffer so no stack adjustment is necessary for proper
+// reexecution.
+kit.jvms()->set_should_reexecute(true);
+result = kit.new_instance(__ makecon(TypeKlassPtr::make(C->env()->String_klass())));
+}
+// Intialize the string
+kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::offset_offset_in_bytes()),
+__ intcon(0), T_INT, offset_field_idx);
+kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::count_offset_in_bytes()),
+length, T_INT, count_field_idx);
+kit.store_to_memory(kit.control(), kit.basic_plus_adr(result, java_lang_String::value_offset_in_bytes()),
+char_array, T_OBJECT, value_field_idx);
+// hook up the outgoing control and result
+kit.replace_call(sc->end(), result);
+// Unhook any hook nodes
+string_sizes->disconnect_inputs(NULL);
+sc->cleanup();
+}

Mercurial > hg > truffle

comparison src/share/vm/opto/stringopts.cpp @ 1080:7c57aead6d3e