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