JDK14/Java14源码在线阅读
/*
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* 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
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*/
#include "precompiled.hpp"
#include "ci/ciConstant.hpp"
#include "ci/ciField.hpp"
#include "ci/ciMethod.hpp"
#include "ci/ciMethodData.hpp"
#include "ci/ciObjArrayKlass.hpp"
#include "ci/ciStreams.hpp"
#include "ci/ciTypeArrayKlass.hpp"
#include "ci/ciTypeFlow.hpp"
#include "compiler/compileLog.hpp"
#include "interpreter/bytecode.hpp"
#include "interpreter/bytecodes.hpp"
#include "memory/allocation.inline.hpp"
#include "memory/resourceArea.hpp"
#include "oops/oop.inline.hpp"
#include "opto/compile.hpp"
#include "opto/node.hpp"
#include "runtime/deoptimization.hpp"
#include "utilities/growableArray.hpp"
// ciTypeFlow::JsrSet
//
// A JsrSet represents some set of JsrRecords. This class
// is used to record a set of all jsr routines which we permit
// execution to return (ret) from.
//
// During abstract interpretation, JsrSets are used to determine
// whether two paths which reach a given block are unique, and
// should be cloned apart, or are compatible, and should merge
// together.
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::JsrSet
ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
if (arena != NULL) {
// Allocate growable array in Arena.
_set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
} else {
// Allocate growable array in current ResourceArea.
_set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
}
}
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::copy_into
void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
int len = size();
jsrs->_set->clear();
for (int i = 0; i < len; i++) {
jsrs->_set->append(_set->at(i));
}
}
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::is_compatible_with
//
// !!!! MISGIVINGS ABOUT THIS... disregard
//
// Is this JsrSet compatible with some other JsrSet?
//
// In set-theoretic terms, a JsrSet can be viewed as a partial function
// from entry addresses to return addresses. Two JsrSets A and B are
// compatible iff
//
// For any x,
// A(x) defined and B(x) defined implies A(x) == B(x)
//
// Less formally, two JsrSets are compatible when they have identical
// return addresses for any entry addresses they share in common.
bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
// Walk through both sets in parallel. If the same entry address
// appears in both sets, then the return address must match for
// the sets to be compatible.
int size1 = size();
int size2 = other->size();
// Special case. If nothing is on the jsr stack, then there can
// be no ret.
if (size2 == 0) {
return true;
} else if (size1 != size2) {
return false;
} else {
for (int i = 0; i < size1; i++) {
JsrRecord* record1 = record_at(i);
JsrRecord* record2 = other->record_at(i);
if (record1->entry_address() != record2->entry_address() ||
record1->return_address() != record2->return_address()) {
return false;
}
}
return true;
}
#if 0
int pos1 = 0;
int pos2 = 0;
int size1 = size();
int size2 = other->size();
while (pos1 < size1 && pos2 < size2) {
JsrRecord* record1 = record_at(pos1);
JsrRecord* record2 = other->record_at(pos2);
int entry1 = record1->entry_address();
int entry2 = record2->entry_address();
if (entry1 < entry2) {
pos1++;
} else if (entry1 > entry2) {
pos2++;
} else {
if (record1->return_address() == record2->return_address()) {
pos1++;
pos2++;
} else {
// These two JsrSets are incompatible.
return false;
}
}
}
// The two JsrSets agree.
return true;
#endif
}
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::insert_jsr_record
//
// Insert the given JsrRecord into the JsrSet, maintaining the order
// of the set and replacing any element with the same entry address.
void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
int len = size();
int entry = record->entry_address();
int pos = 0;
for ( ; pos < len; pos++) {
JsrRecord* current = record_at(pos);
if (entry == current->entry_address()) {
// Stomp over this entry.
_set->at_put(pos, record);
assert(size() == len, "must be same size");
return;
} else if (entry < current->entry_address()) {
break;
}
}
// Insert the record into the list.
JsrRecord* swap = record;
JsrRecord* temp = NULL;
for ( ; pos < len; pos++) {
temp = _set->at(pos);
_set->at_put(pos, swap);
swap = temp;
}
_set->append(swap);
assert(size() == len+1, "must be larger");
}
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::remove_jsr_record
//
// Remove the JsrRecord with the given return address from the JsrSet.
void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
int len = size();
for (int i = 0; i < len; i++) {
if (record_at(i)->return_address() == return_address) {
// We have found the proper entry. Remove it from the
// JsrSet and exit.
for (int j = i+1; j < len ; j++) {
_set->at_put(j-1, _set->at(j));
}
_set->trunc_to(len-1);
assert(size() == len-1, "must be smaller");
return;
}
}
assert(false, "verify: returning from invalid subroutine");
}
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::apply_control
//
// Apply the effect of a control-flow bytecode on the JsrSet. The
// only bytecodes that modify the JsrSet are jsr and ret.
void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
ciBytecodeStream* str,
ciTypeFlow::StateVector* state) {
Bytecodes::Code code = str->cur_bc();
if (code == Bytecodes::_jsr) {
JsrRecord* record =
analyzer->make_jsr_record(str->get_dest(), str->next_bci());
insert_jsr_record(record);
} else if (code == Bytecodes::_jsr_w) {
JsrRecord* record =
analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
insert_jsr_record(record);
} else if (code == Bytecodes::_ret) {
Cell local = state->local(str->get_index());
ciType* return_address = state->type_at(local);
assert(return_address->is_return_address(), "verify: wrong type");
if (size() == 0) {
// Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
// This can happen when a loop is inside a finally clause (4614060).
analyzer->record_failure("OSR in finally clause");
return;
}
remove_jsr_record(return_address->as_return_address()->bci());
}
}
#ifndef PRODUCT
// ------------------------------------------------------------------
// ciTypeFlow::JsrSet::print_on
void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
st->print("{ ");
int num_elements = size();
if (num_elements > 0) {
int i = 0;
for( ; i < num_elements - 1; i++) {
_set->at(i)->print_on(st);
st->print(", ");
}
_set->at(i)->print_on(st);
st->print(" ");
}
st->print("}");
}
#endif
// ciTypeFlow::StateVector
//
// A StateVector summarizes the type information at some point in
// the program.
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::type_meet
//
// Meet two types.
//
// The semi-lattice of types use by this analysis are modeled on those
// of the verifier. The lattice is as follows:
//
// top_type() >= all non-extremal types >= bottom_type
// and
// Every primitive type is comparable only with itself. The meet of
// reference types is determined by their kind: instance class,
// interface, or array class. The meet of two types of the same
// kind is their least common ancestor. The meet of two types of
// different kinds is always java.lang.Object.
ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
assert(t1 != t2, "checked in caller");
if (t1->equals(top_type())) {
return t2;
} else if (t2->equals(top_type())) {
return t1;
} else if (t1->is_primitive_type() || t2->is_primitive_type()) {
// Special case null_type. null_type meet any reference type T
// is T. null_type meet null_type is null_type.
if (t1->equals(null_type())) {
if (!t2->is_primitive_type() || t2->equals(null_type())) {
return t2;
}
} else if (t2->equals(null_type())) {
if (!t1->is_primitive_type()) {
return t1;
}
}
// At least one of the two types is a non-top primitive type.
// The other type is not equal to it. Fall to bottom.
return bottom_type();
} else {
// Both types are non-top non-primitive types. That is,
// both types are either instanceKlasses or arrayKlasses.
ciKlass* object_klass = analyzer->env()->Object_klass();
ciKlass* k1 = t1->as_klass();
ciKlass* k2 = t2->as_klass();
if (k1->equals(object_klass) || k2->equals(object_klass)) {
return object_klass;
} else if (!k1->is_loaded() || !k2->is_loaded()) {
// Unloaded classes fall to java.lang.Object at a merge.
return object_klass;
} else if (k1->is_interface() != k2->is_interface()) {
// When an interface meets a non-interface, we get Object;
// This is what the verifier does.
return object_klass;
} else if (k1->is_array_klass() || k2->is_array_klass()) {
// When an array meets a non-array, we get Object.
// When objArray meets typeArray, we also get Object.
// And when typeArray meets different typeArray, we again get Object.
// But when objArray meets objArray, we look carefully at element types.
if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
// Meet the element types, then construct the corresponding array type.
ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
// Do an easy shortcut if one type is a super of the other.
if (elem == elem1) {
assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
return k1;
} else if (elem == elem2) {
assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
return k2;
} else {
return ciObjArrayKlass::make(elem);
}
} else {
return object_klass;
}
} else {
// Must be two plain old instance klasses.
assert(k1->is_instance_klass(), "previous cases handle non-instances");
assert(k2->is_instance_klass(), "previous cases handle non-instances");
return k1->least_common_ancestor(k2);
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::StateVector
//
// Build a new state vector
ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
_outer = analyzer;
_stack_size = -1;
_monitor_count = -1;
// Allocate the _types array
int max_cells = analyzer->max_cells();
_types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
for (int i=0; i<max_cells; i++) {
_types[i] = top_type();
}
_trap_bci = -1;
_trap_index = 0;
_def_locals.clear();
}
// ------------------------------------------------------------------
// ciTypeFlow::get_start_state
//
// Set this vector to the method entry state.
const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
StateVector* state = new StateVector(this);
if (is_osr_flow()) {
ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
if (non_osr_flow->failing()) {
record_failure(non_osr_flow->failure_reason());
return NULL;
}
JsrSet* jsrs = new JsrSet(NULL, 16);
Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
if (non_osr_block == NULL) {
record_failure("cannot reach OSR point");
return NULL;
}
// load up the non-OSR state at this point
non_osr_block->copy_state_into(state);
int non_osr_start = non_osr_block->start();
if (non_osr_start != start_bci()) {
// must flow forward from it
if (CITraceTypeFlow) {
tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
}
Block* block = block_at(non_osr_start, jsrs);
assert(block->limit() == start_bci(), "must flow forward to start");
flow_block(block, state, jsrs);
}
return state;
// Note: The code below would be an incorrect for an OSR flow,
// even if it were possible for an OSR entry point to be at bci zero.
}
// "Push" the method signature into the first few locals.
state->set_stack_size(-max_locals());
if (!method()->is_static()) {
state->push(method()->holder());
assert(state->tos() == state->local(0), "");
}
for (ciSignatureStream str(method()->signature());
!str.at_return_type();
str.next()) {
state->push_translate(str.type());
}
// Set the rest of the locals to bottom.
Cell cell = state->next_cell(state->tos());
state->set_stack_size(0);
int limit = state->limit_cell();
for (; cell < limit; cell = state->next_cell(cell)) {
state->set_type_at(cell, state->bottom_type());
}
// Lock an object, if necessary.
state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
return state;
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::copy_into
//
// Copy our value into some other StateVector
void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
const {
copy->set_stack_size(stack_size());
copy->set_monitor_count(monitor_count());
Cell limit = limit_cell();
for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
copy->set_type_at(c, type_at(c));
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::meet
//
// Meets this StateVector with another, destructively modifying this
// one. Returns true if any modification takes place.
bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
if (monitor_count() == -1) {
set_monitor_count(incoming->monitor_count());
}
assert(monitor_count() == incoming->monitor_count(), "monitors must match");
if (stack_size() == -1) {
set_stack_size(incoming->stack_size());
Cell limit = limit_cell();
#ifdef ASSERT
{ for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
assert(type_at(c) == top_type(), "");
} }
#endif
// Make a simple copy of the incoming state.
for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
set_type_at(c, incoming->type_at(c));
}
return true; // it is always different the first time
}
#ifdef ASSERT
if (stack_size() != incoming->stack_size()) {
_outer->method()->print_codes();
tty->print_cr("!!!! Stack size conflict");
tty->print_cr("Current state:");
print_on(tty);
tty->print_cr("Incoming state:");
((StateVector*)incoming)->print_on(tty);
}
#endif
assert(stack_size() == incoming->stack_size(), "sanity");
bool different = false;
Cell limit = limit_cell();
for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
ciType* t1 = type_at(c);
ciType* t2 = incoming->type_at(c);
if (!t1->equals(t2)) {
ciType* new_type = type_meet(t1, t2);
if (!t1->equals(new_type)) {
set_type_at(c, new_type);
different = true;
}
}
}
return different;
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::meet_exception
//
// Meets this StateVector with another, destructively modifying this
// one. The incoming state is coming via an exception. Returns true
// if any modification takes place.
bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
const ciTypeFlow::StateVector* incoming) {
if (monitor_count() == -1) {
set_monitor_count(incoming->monitor_count());
}
assert(monitor_count() == incoming->monitor_count(), "monitors must match");
if (stack_size() == -1) {
set_stack_size(1);
}
assert(stack_size() == 1, "must have one-element stack");
bool different = false;
// Meet locals from incoming array.
Cell limit = local(_outer->max_locals()-1);
for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
ciType* t1 = type_at(c);
ciType* t2 = incoming->type_at(c);
if (!t1->equals(t2)) {
ciType* new_type = type_meet(t1, t2);
if (!t1->equals(new_type)) {
set_type_at(c, new_type);
different = true;
}
}
}
// Handle stack separately. When an exception occurs, the
// only stack entry is the exception instance.
ciType* tos_type = type_at_tos();
if (!tos_type->equals(exc)) {
ciType* new_type = type_meet(tos_type, exc);
if (!tos_type->equals(new_type)) {
set_type_at_tos(new_type);
different = true;
}
}
return different;
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::push_translate
void ciTypeFlow::StateVector::push_translate(ciType* type) {
BasicType basic_type = type->basic_type();
if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
basic_type == T_BYTE || basic_type == T_SHORT) {
push_int();
} else {
push(type);
if (type->is_two_word()) {
push(half_type(type));
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_aaload
void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
pop_int();
ciObjArrayKlass* array_klass = pop_objArray();
if (array_klass == NULL) {
// Did aaload on a null reference; push a null and ignore the exception.
// This instruction will never continue normally. All we have to do
// is report a value that will meet correctly with any downstream
// reference types on paths that will truly be executed. This null type
// meets with any reference type to yield that same reference type.
// (The compiler will generate an unconditional exception here.)
push(null_type());
return;
}
if (!array_klass->is_loaded()) {
// Only fails for some -Xcomp runs
trap(str, array_klass,
Deoptimization::make_trap_request
(Deoptimization::Reason_unloaded,
Deoptimization::Action_reinterpret));
return;
}
ciKlass* element_klass = array_klass->element_klass();
if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
Untested("unloaded array element class in ciTypeFlow");
trap(str, element_klass,
Deoptimization::make_trap_request
(Deoptimization::Reason_unloaded,
Deoptimization::Action_reinterpret));
} else {
push_object(element_klass);
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_checkcast
void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
bool will_link;
ciKlass* klass = str->get_klass(will_link);
if (!will_link) {
// VM's interpreter will not load 'klass' if object is NULL.
// Type flow after this block may still be needed in two situations:
// 1) C2 uses do_null_assert() and continues compilation for later blocks
// 2) C2 does an OSR compile in a later block (see bug 4778368).
pop_object();
do_null_assert(klass);
} else {
pop_object();
push_object(klass);
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_getfield
void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
// could add assert here for type of object.
pop_object();
do_getstatic(str);
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_getstatic
void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
bool will_link;
ciField* field = str->get_field(will_link);
if (!will_link) {
trap(str, field->holder(), str->get_field_holder_index());
} else {
ciType* field_type = field->type();
if (!field_type->is_loaded()) {
// Normally, we need the field's type to be loaded if we are to
// do anything interesting with its value.
// We used to do this: trap(str, str->get_field_signature_index());
//
// There is one good reason not to trap here. Execution can
// get past this "getfield" or "getstatic" if the value of
// the field is null. As long as the value is null, the class
// does not need to be loaded! The compiler must assume that
// the value of the unloaded class reference is null; if the code
// ever sees a non-null value, loading has occurred.
//
// This actually happens often enough to be annoying. If the
// compiler throws an uncommon trap at this bytecode, you can
// get an endless loop of recompilations, when all the code
// needs to do is load a series of null values. Also, a trap
// here can make an OSR entry point unreachable, triggering the
// assert on non_osr_block in ciTypeFlow::get_start_state.
// (See bug 4379915.)
do_null_assert(field_type->as_klass());
} else {
push_translate(field_type);
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_invoke
void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
bool has_receiver) {
bool will_link;
ciSignature* declared_signature = NULL;
ciMethod* callee = str->get_method(will_link, &declared_signature);
assert(declared_signature != NULL, "cannot be null");
if (!will_link) {
// We weren't able to find the method.
if (str->cur_bc() == Bytecodes::_invokedynamic) {
trap(str, NULL,
Deoptimization::make_trap_request
(Deoptimization::Reason_uninitialized,
Deoptimization::Action_reinterpret));
} else {
ciKlass* unloaded_holder = callee->holder();
trap(str, unloaded_holder, str->get_method_holder_index());
}
} else {
// We are using the declared signature here because it might be
// different from the callee signature (Cf. invokedynamic and
// invokehandle).
ciSignatureStream sigstr(declared_signature);
const int arg_size = declared_signature->size();
const int stack_base = stack_size() - arg_size;
int i = 0;
for( ; !sigstr.at_return_type(); sigstr.next()) {
ciType* type = sigstr.type();
ciType* stack_type = type_at(stack(stack_base + i++));
// Do I want to check this type?
// assert(stack_type->is_subtype_of(type), "bad type for field value");
if (type->is_two_word()) {
ciType* stack_type2 = type_at(stack(stack_base + i++));
assert(stack_type2->equals(half_type(type)), "must be 2nd half");
}
}
assert(arg_size == i, "must match");
for (int j = 0; j < arg_size; j++) {
pop();
}
if (has_receiver) {
// Check this?
pop_object();
}
assert(!sigstr.is_done(), "must have return type");
ciType* return_type = sigstr.type();
if (!return_type->is_void()) {
if (!return_type->is_loaded()) {
// As in do_getstatic(), generally speaking, we need the return type to
// be loaded if we are to do anything interesting with its value.
// We used to do this: trap(str, str->get_method_signature_index());
//
// We do not trap here since execution can get past this invoke if
// the return value is null. As long as the value is null, the class
// does not need to be loaded! The compiler must assume that
// the value of the unloaded class reference is null; if the code
// ever sees a non-null value, loading has occurred.
//
// See do_getstatic() for similar explanation, as well as bug 4684993.
do_null_assert(return_type->as_klass());
} else {
push_translate(return_type);
}
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_jsr
void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
push(ciReturnAddress::make(str->next_bci()));
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_ldc
void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
ciConstant con = str->get_constant();
BasicType basic_type = con.basic_type();
if (basic_type == T_ILLEGAL) {
// OutOfMemoryError in the CI while loading constant
push_null();
outer()->record_failure("ldc did not link");
return;
}
if (is_reference_type(basic_type)) {
ciObject* obj = con.as_object();
if (obj->is_null_object()) {
push_null();
} else {
assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
push_object(obj->klass());
}
} else {
push_translate(ciType::make(basic_type));
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_multianewarray
void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
int dimensions = str->get_dimensions();
bool will_link;
ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
if (!will_link) {
trap(str, array_klass, str->get_klass_index());
} else {
for (int i = 0; i < dimensions; i++) {
pop_int();
}
push_object(array_klass);
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_new
void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
bool will_link;
ciKlass* klass = str->get_klass(will_link);
if (!will_link || str->is_unresolved_klass()) {
trap(str, klass, str->get_klass_index());
} else {
push_object(klass);
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_newarray
void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
pop_int();
ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
push_object(klass);
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_putfield
void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
do_putstatic(str);
if (_trap_bci != -1) return; // unloaded field holder, etc.
// could add assert here for type of object.
pop_object();
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_putstatic
void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
bool will_link;
ciField* field = str->get_field(will_link);
if (!will_link) {
trap(str, field->holder(), str->get_field_holder_index());
} else {
ciType* field_type = field->type();
ciType* type = pop_value();
// Do I want to check this type?
// assert(type->is_subtype_of(field_type), "bad type for field value");
if (field_type->is_two_word()) {
ciType* type2 = pop_value();
assert(type2->is_two_word(), "must be 2nd half");
assert(type == half_type(type2), "must be 2nd half");
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_ret
void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
Cell index = local(str->get_index());
ciType* address = type_at(index);
assert(address->is_return_address(), "bad return address");
set_type_at(index, bottom_type());
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::trap
//
// Stop interpretation of this path with a trap.
void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
_trap_bci = str->cur_bci();
_trap_index = index;
// Log information about this trap:
CompileLog* log = outer()->env()->log();
if (log != NULL) {
int mid = log->identify(outer()->method());
int kid = (klass == NULL)? -1: log->identify(klass);
log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
char buf[100];
log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
index));
if (kid >= 0)
log->print(" klass='%d'", kid);
log->end_elem();
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::do_null_assert
// Corresponds to graphKit::do_null_assert.
void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
if (unloaded_klass->is_loaded()) {
// We failed to link, but we can still compute with this class,
// since it is loaded somewhere. The compiler will uncommon_trap
// if the object is not null, but the typeflow pass can not assume
// that the object will be null, otherwise it may incorrectly tell
// the parser that an object is known to be null. 4761344, 4807707
push_object(unloaded_klass);
} else {
// The class is not loaded anywhere. It is safe to model the
// null in the typestates, because we can compile in a null check
// which will deoptimize us if someone manages to load the
// class later.
push_null();
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::apply_one_bytecode
//
// Apply the effect of one bytecode to this StateVector
bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
_trap_bci = -1;
_trap_index = 0;
if (CITraceTypeFlow) {
tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
Bytecodes::name(str->cur_bc()));
}
switch(str->cur_bc()) {
case Bytecodes::_aaload: do_aaload(str); break;
case Bytecodes::_aastore:
{
pop_object();
pop_int();
pop_objArray();
break;
}
case Bytecodes::_aconst_null:
{
push_null();
break;
}
case Bytecodes::_aload: load_local_object(str->get_index()); break;
case Bytecodes::_aload_0: load_local_object(0); break;
case Bytecodes::_aload_1: load_local_object(1); break;
case Bytecodes::_aload_2: load_local_object(2); break;
case Bytecodes::_aload_3: load_local_object(3); break;
case Bytecodes::_anewarray:
{
pop_int();
bool will_link;
ciKlass* element_klass = str->get_klass(will_link);
if (!will_link) {
trap(str, element_klass, str->get_klass_index());
} else {
push_object(ciObjArrayKlass::make(element_klass));
}
break;
}
case Bytecodes::_areturn:
case Bytecodes::_ifnonnull:
case Bytecodes::_ifnull:
{
pop_object();
break;
}
case Bytecodes::_monitorenter:
{
pop_object();
set_monitor_count(monitor_count() + 1);
break;
}
case Bytecodes::_monitorexit:
{
pop_object();
assert(monitor_count() > 0, "must be a monitor to exit from");
set_monitor_count(monitor_count() - 1);
break;
}
case Bytecodes::_arraylength:
{
pop_array();
push_int();
break;
}
case Bytecodes::_astore: store_local_object(str->get_index()); break;
case Bytecodes::_astore_0: store_local_object(0); break;
case Bytecodes::_astore_1: store_local_object(1); break;
case Bytecodes::_astore_2: store_local_object(2); break;
case Bytecodes::_astore_3: store_local_object(3); break;
case Bytecodes::_athrow:
{
NEEDS_CLEANUP;
pop_object();
break;
}
case Bytecodes::_baload:
case Bytecodes::_caload:
case Bytecodes::_iaload:
case Bytecodes::_saload:
{
pop_int();
ciTypeArrayKlass* array_klass = pop_typeArray();
// Put assert here for right type?
push_int();
break;
}
case Bytecodes::_bastore:
case Bytecodes::_castore:
case Bytecodes::_iastore:
case Bytecodes::_sastore:
{
pop_int();
pop_int();
pop_typeArray();
// assert here?
break;
}
case Bytecodes::_bipush:
case Bytecodes::_iconst_m1:
case Bytecodes::_iconst_0:
case Bytecodes::_iconst_1:
case Bytecodes::_iconst_2:
case Bytecodes::_iconst_3:
case Bytecodes::_iconst_4:
case Bytecodes::_iconst_5:
case Bytecodes::_sipush:
{
push_int();
break;
}
case Bytecodes::_checkcast: do_checkcast(str); break;
case Bytecodes::_d2f:
{
pop_double();
push_float();
break;
}
case Bytecodes::_d2i:
{
pop_double();
push_int();
break;
}
case Bytecodes::_d2l:
{
pop_double();
push_long();
break;
}
case Bytecodes::_dadd:
case Bytecodes::_ddiv:
case Bytecodes::_dmul:
case Bytecodes::_drem:
case Bytecodes::_dsub:
{
pop_double();
pop_double();
push_double();
break;
}
case Bytecodes::_daload:
{
pop_int();
ciTypeArrayKlass* array_klass = pop_typeArray();
// Put assert here for right type?
push_double();
break;
}
case Bytecodes::_dastore:
{
pop_double();
pop_int();
pop_typeArray();
// assert here?
break;
}
case Bytecodes::_dcmpg:
case Bytecodes::_dcmpl:
{
pop_double();
pop_double();
push_int();
break;
}
case Bytecodes::_dconst_0:
case Bytecodes::_dconst_1:
{
push_double();
break;
}
case Bytecodes::_dload: load_local_double(str->get_index()); break;
case Bytecodes::_dload_0: load_local_double(0); break;
case Bytecodes::_dload_1: load_local_double(1); break;
case Bytecodes::_dload_2: load_local_double(2); break;
case Bytecodes::_dload_3: load_local_double(3); break;
case Bytecodes::_dneg:
{
pop_double();
push_double();
break;
}
case Bytecodes::_dreturn:
{
pop_double();
break;
}
case Bytecodes::_dstore: store_local_double(str->get_index()); break;
case Bytecodes::_dstore_0: store_local_double(0); break;
case Bytecodes::_dstore_1: store_local_double(1); break;
case Bytecodes::_dstore_2: store_local_double(2); break;
case Bytecodes::_dstore_3: store_local_double(3); break;
case Bytecodes::_dup:
{
push(type_at_tos());
break;
}
case Bytecodes::_dup_x1:
{
ciType* value1 = pop_value();
ciType* value2 = pop_value();
push(value1);
push(value2);
push(value1);
break;
}
case Bytecodes::_dup_x2:
{
ciType* value1 = pop_value();
ciType* value2 = pop_value();
ciType* value3 = pop_value();
push(value1);
push(value3);
push(value2);
push(value1);
break;
}
case Bytecodes::_dup2:
{
ciType* value1 = pop_value();
ciType* value2 = pop_value();
push(value2);
push(value1);
push(value2);
push(value1);
break;
}
case Bytecodes::_dup2_x1:
{
ciType* value1 = pop_value();
ciType* value2 = pop_value();
ciType* value3 = pop_value();
push(value2);
push(value1);
push(value3);
push(value2);
push(value1);
break;
}
case Bytecodes::_dup2_x2:
{
ciType* value1 = pop_value();
ciType* value2 = pop_value();
ciType* value3 = pop_value();
ciType* value4 = pop_value();
push(value2);
push(value1);
push(value4);
push(value3);
push(value2);
push(value1);
break;
}
case Bytecodes::_f2d:
{
pop_float();
push_double();
break;
}
case Bytecodes::_f2i:
{
pop_float();
push_int();
break;
}
case Bytecodes::_f2l:
{
pop_float();
push_long();
break;
}
case Bytecodes::_fadd:
case Bytecodes::_fdiv:
case Bytecodes::_fmul:
case Bytecodes::_frem:
case Bytecodes::_fsub:
{
pop_float();
pop_float();
push_float();
break;
}
case Bytecodes::_faload:
{
pop_int();
ciTypeArrayKlass* array_klass = pop_typeArray();
// Put assert here.
push_float();
break;
}
case Bytecodes::_fastore:
{
pop_float();
pop_int();
ciTypeArrayKlass* array_klass = pop_typeArray();
// Put assert here.
break;
}
case Bytecodes::_fcmpg:
case Bytecodes::_fcmpl:
{
pop_float();
pop_float();
push_int();
break;
}
case Bytecodes::_fconst_0:
case Bytecodes::_fconst_1:
case Bytecodes::_fconst_2:
{
push_float();
break;
}
case Bytecodes::_fload: load_local_float(str->get_index()); break;
case Bytecodes::_fload_0: load_local_float(0); break;
case Bytecodes::_fload_1: load_local_float(1); break;
case Bytecodes::_fload_2: load_local_float(2); break;
case Bytecodes::_fload_3: load_local_float(3); break;
case Bytecodes::_fneg:
{
pop_float();
push_float();
break;
}
case Bytecodes::_freturn:
{
pop_float();
break;
}
case Bytecodes::_fstore: store_local_float(str->get_index()); break;
case Bytecodes::_fstore_0: store_local_float(0); break;
case Bytecodes::_fstore_1: store_local_float(1); break;
case Bytecodes::_fstore_2: store_local_float(2); break;
case Bytecodes::_fstore_3: store_local_float(3); break;
case Bytecodes::_getfield: do_getfield(str); break;
case Bytecodes::_getstatic: do_getstatic(str); break;
case Bytecodes::_goto:
case Bytecodes::_goto_w:
case Bytecodes::_nop:
case Bytecodes::_return:
{
// do nothing.
break;
}
case Bytecodes::_i2b:
case Bytecodes::_i2c:
case Bytecodes::_i2s:
case Bytecodes::_ineg:
{
pop_int();
push_int();
break;
}
case Bytecodes::_i2d:
{
pop_int();
push_double();
break;
}
case Bytecodes::_i2f:
{
pop_int();
push_float();
break;
}
case Bytecodes::_i2l:
{
pop_int();
push_long();
break;
}
case Bytecodes::_iadd:
case Bytecodes::_iand:
case Bytecodes::_idiv:
case Bytecodes::_imul:
case Bytecodes::_ior:
case Bytecodes::_irem:
case Bytecodes::_ishl:
case Bytecodes::_ishr:
case Bytecodes::_isub:
case Bytecodes::_iushr:
case Bytecodes::_ixor:
{
pop_int();
pop_int();
push_int();
break;
}
case Bytecodes::_if_acmpeq:
case Bytecodes::_if_acmpne:
{
pop_object();
pop_object();
break;
}
case Bytecodes::_if_icmpeq:
case Bytecodes::_if_icmpge:
case Bytecodes::_if_icmpgt:
case Bytecodes::_if_icmple:
case Bytecodes::_if_icmplt:
case Bytecodes::_if_icmpne:
{
pop_int();
pop_int();
break;
}
case Bytecodes::_ifeq:
case Bytecodes::_ifle:
case Bytecodes::_iflt:
case Bytecodes::_ifge:
case Bytecodes::_ifgt:
case Bytecodes::_ifne:
case Bytecodes::_ireturn:
case Bytecodes::_lookupswitch:
case Bytecodes::_tableswitch:
{
pop_int();
break;
}
case Bytecodes::_iinc:
{
int lnum = str->get_index();
check_int(local(lnum));
store_to_local(lnum);
break;
}
case Bytecodes::_iload: load_local_int(str->get_index()); break;
case Bytecodes::_iload_0: load_local_int(0); break;
case Bytecodes::_iload_1: load_local_int(1); break;
case Bytecodes::_iload_2: load_local_int(2); break;
case Bytecodes::_iload_3: load_local_int(3); break;
case Bytecodes::_instanceof:
{
// Check for uncommon trap:
do_checkcast(str);
pop_object();
push_int();
break;
}
case Bytecodes::_invokeinterface: do_invoke(str, true); break;
case Bytecodes::_invokespecial: do_invoke(str, true); break;
case Bytecodes::_invokestatic: do_invoke(str, false); break;
case Bytecodes::_invokevirtual: do_invoke(str, true); break;
case Bytecodes::_invokedynamic: do_invoke(str, false); break;
case Bytecodes::_istore: store_local_int(str->get_index()); break;
case Bytecodes::_istore_0: store_local_int(0); break;
case Bytecodes::_istore_1: store_local_int(1); break;
case Bytecodes::_istore_2: store_local_int(2); break;
case Bytecodes::_istore_3: store_local_int(3); break;
case Bytecodes::_jsr:
case Bytecodes::_jsr_w: do_jsr(str); break;
case Bytecodes::_l2d:
{
pop_long();
push_double();
break;
}
case Bytecodes::_l2f:
{
pop_long();
push_float();
break;
}
case Bytecodes::_l2i:
{
pop_long();
push_int();
break;
}
case Bytecodes::_ladd:
case Bytecodes::_land:
case Bytecodes::_ldiv:
case Bytecodes::_lmul:
case Bytecodes::_lor:
case Bytecodes::_lrem:
case Bytecodes::_lsub:
case Bytecodes::_lxor:
{
pop_long();
pop_long();
push_long();
break;
}
case Bytecodes::_laload:
{
pop_int();
ciTypeArrayKlass* array_klass = pop_typeArray();
// Put assert here for right type?
push_long();
break;
}
case Bytecodes::_lastore:
{
pop_long();
pop_int();
pop_typeArray();
// assert here?
break;
}
case Bytecodes::_lcmp:
{
pop_long();
pop_long();
push_int();
break;
}
case Bytecodes::_lconst_0:
case Bytecodes::_lconst_1:
{
push_long();
break;
}
case Bytecodes::_ldc:
case Bytecodes::_ldc_w:
case Bytecodes::_ldc2_w:
{
do_ldc(str);
break;
}
case Bytecodes::_lload: load_local_long(str->get_index()); break;
case Bytecodes::_lload_0: load_local_long(0); break;
case Bytecodes::_lload_1: load_local_long(1); break;
case Bytecodes::_lload_2: load_local_long(2); break;
case Bytecodes::_lload_3: load_local_long(3); break;
case Bytecodes::_lneg:
{
pop_long();
push_long();
break;
}
case Bytecodes::_lreturn:
{
pop_long();
break;
}
case Bytecodes::_lshl:
case Bytecodes::_lshr:
case Bytecodes::_lushr:
{
pop_int();
pop_long();
push_long();
break;
}
case Bytecodes::_lstore: store_local_long(str->get_index()); break;
case Bytecodes::_lstore_0: store_local_long(0); break;
case Bytecodes::_lstore_1: store_local_long(1); break;
case Bytecodes::_lstore_2: store_local_long(2); break;
case Bytecodes::_lstore_3: store_local_long(3); break;
case Bytecodes::_multianewarray: do_multianewarray(str); break;
case Bytecodes::_new: do_new(str); break;
case Bytecodes::_newarray: do_newarray(str); break;
case Bytecodes::_pop:
{
pop();
break;
}
case Bytecodes::_pop2:
{
pop();
pop();
break;
}
case Bytecodes::_putfield: do_putfield(str); break;
case Bytecodes::_putstatic: do_putstatic(str); break;
case Bytecodes::_ret: do_ret(str); break;
case Bytecodes::_swap:
{
ciType* value1 = pop_value();
ciType* value2 = pop_value();
push(value1);
push(value2);
break;
}
case Bytecodes::_wide:
default:
{
// The iterator should skip this.
ShouldNotReachHere();
break;
}
}
if (CITraceTypeFlow) {
print_on(tty);
}
return (_trap_bci != -1);
}
#ifndef PRODUCT
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::print_cell_on
void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
ciType* type = type_at(c);
if (type == top_type()) {
st->print("top");
} else if (type == bottom_type()) {
st->print("bottom");
} else if (type == null_type()) {
st->print("null");
} else if (type == long2_type()) {
st->print("long2");
} else if (type == double2_type()) {
st->print("double2");
} else if (is_int(type)) {
st->print("int");
} else if (is_long(type)) {
st->print("long");
} else if (is_float(type)) {
st->print("float");
} else if (is_double(type)) {
st->print("double");
} else if (type->is_return_address()) {
st->print("address(%d)", type->as_return_address()->bci());
} else {
if (type->is_klass()) {
type->as_klass()->name()->print_symbol_on(st);
} else {
st->print("UNEXPECTED TYPE");
type->print();
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::StateVector::print_on
void ciTypeFlow::StateVector::print_on(outputStream* st) const {
int num_locals = _outer->max_locals();
int num_stack = stack_size();
int num_monitors = monitor_count();
st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
if (num_stack >= 0) {
int i;
for (i = 0; i < num_locals; i++) {
st->print(" local %2d : ", i);
print_cell_on(st, local(i));
st->cr();
}
for (i = 0; i < num_stack; i++) {
st->print(" stack %2d : ", i);
print_cell_on(st, stack(i));
st->cr();
}
}
}
#endif
// ------------------------------------------------------------------
// ciTypeFlow::SuccIter::next
//
void ciTypeFlow::SuccIter::next() {
int succ_ct = _pred->successors()->length();
int next = _index + 1;
if (next < succ_ct) {
_index = next;
_succ = _pred->successors()->at(next);
return;
}
for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
// Do not compile any code for unloaded exception types.
// Following compiler passes are responsible for doing this also.
ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
if (exception_klass->is_loaded()) {
_index = next;
_succ = _pred->exceptions()->at(i);
return;
}
next++;
}
_index = -1;
_succ = NULL;
}
// ------------------------------------------------------------------
// ciTypeFlow::SuccIter::set_succ
//
void ciTypeFlow::SuccIter::set_succ(Block* succ) {
int succ_ct = _pred->successors()->length();
if (_index < succ_ct) {
_pred->successors()->at_put(_index, succ);
} else {
int idx = _index - succ_ct;
_pred->exceptions()->at_put(idx, succ);
}
}
// ciTypeFlow::Block
//
// A basic block.
// ------------------------------------------------------------------
// ciTypeFlow::Block::Block
ciTypeFlow::Block::Block(ciTypeFlow* outer,
ciBlock *ciblk,
ciTypeFlow::JsrSet* jsrs) {
_ciblock = ciblk;
_exceptions = NULL;
_exc_klasses = NULL;
_successors = NULL;
_predecessors = new (outer->arena()) GrowableArray<Block*>(outer->arena(), 1, 0, NULL);
_state = new (outer->arena()) StateVector(outer);
JsrSet* new_jsrs =
new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
jsrs->copy_into(new_jsrs);
_jsrs = new_jsrs;
_next = NULL;
_on_work_list = false;
_backedge_copy = false;
_has_monitorenter = false;
_trap_bci = -1;
_trap_index = 0;
df_init();
if (CITraceTypeFlow) {
tty->print_cr(">> Created new block");
print_on(tty);
}
assert(this->outer() == outer, "outer link set up");
assert(!outer->have_block_count(), "must not have mapped blocks yet");
}
// ------------------------------------------------------------------
// ciTypeFlow::Block::df_init
void ciTypeFlow::Block::df_init() {
_pre_order = -1; assert(!has_pre_order(), "");
_post_order = -1; assert(!has_post_order(), "");
_loop = NULL;
_irreducible_entry = false;
_rpo_next = NULL;
}
// ------------------------------------------------------------------
// ciTypeFlow::Block::successors
//
// Get the successors for this Block.
GrowableArray<ciTypeFlow::Block*>*
ciTypeFlow::Block::successors(ciBytecodeStream* str,
ciTypeFlow::StateVector* state,
ciTypeFlow::JsrSet* jsrs) {
if (_successors == NULL) {
if (CITraceTypeFlow) {
tty->print(">> Computing successors for block ");
print_value_on(tty);
tty->cr();
}
ciTypeFlow* analyzer = outer();
Arena* arena = analyzer->arena();
Block* block = NULL;
bool has_successor = !has_trap() &&
(control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
if (!has_successor) {
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
// No successors
} else if (control() == ciBlock::fall_through_bci) {
assert(str->cur_bci() == limit(), "bad block end");
// This block simply falls through to the next.
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
Block* block = analyzer->block_at(limit(), _jsrs);
assert(_successors->length() == FALL_THROUGH, "");
_successors->append(block);
} else {
int current_bci = str->cur_bci();
int next_bci = str->next_bci();
int branch_bci = -1;
Block* target = NULL;
assert(str->next_bci() == limit(), "bad block end");
// This block is not a simple fall-though. Interpret
// the current bytecode to find our successors.
switch (str->cur_bc()) {
case Bytecodes::_ifeq: case Bytecodes::_ifne:
case Bytecodes::_iflt: case Bytecodes::_ifge:
case Bytecodes::_ifgt: case Bytecodes::_ifle:
case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
// Our successors are the branch target and the next bci.
branch_bci = str->get_dest();
_successors =
new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
assert(_successors->length() == IF_NOT_TAKEN, "");
_successors->append(analyzer->block_at(next_bci, jsrs));
assert(_successors->length() == IF_TAKEN, "");
_successors->append(analyzer->block_at(branch_bci, jsrs));
break;
case Bytecodes::_goto:
branch_bci = str->get_dest();
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
assert(_successors->length() == GOTO_TARGET, "");
_successors->append(analyzer->block_at(branch_bci, jsrs));
break;
case Bytecodes::_jsr:
branch_bci = str->get_dest();
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
assert(_successors->length() == GOTO_TARGET, "");
_successors->append(analyzer->block_at(branch_bci, jsrs));
break;
case Bytecodes::_goto_w:
case Bytecodes::_jsr_w:
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
assert(_successors->length() == GOTO_TARGET, "");
_successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
break;
case Bytecodes::_tableswitch: {
Bytecode_tableswitch tableswitch(str);
int len = tableswitch.length();
_successors =
new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
int bci = current_bci + tableswitch.default_offset();
Block* block = analyzer->block_at(bci, jsrs);
assert(_successors->length() == SWITCH_DEFAULT, "");
_successors->append(block);
while (--len >= 0) {
int bci = current_bci + tableswitch.dest_offset_at(len);
block = analyzer->block_at(bci, jsrs);
assert(_successors->length() >= SWITCH_CASES, "");
_successors->append_if_missing(block);
}
break;
}
case Bytecodes::_lookupswitch: {
Bytecode_lookupswitch lookupswitch(str);
int npairs = lookupswitch.number_of_pairs();
_successors =
new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
int bci = current_bci + lookupswitch.default_offset();
Block* block = analyzer->block_at(bci, jsrs);
assert(_successors->length() == SWITCH_DEFAULT, "");
_successors->append(block);
while(--npairs >= 0) {
LookupswitchPair pair = lookupswitch.pair_at(npairs);
int bci = current_bci + pair.offset();
Block* block = analyzer->block_at(bci, jsrs);
assert(_successors->length() >= SWITCH_CASES, "");
_successors->append_if_missing(block);
}
break;
}
case Bytecodes::_athrow: case Bytecodes::_ireturn:
case Bytecodes::_lreturn: case Bytecodes::_freturn:
case Bytecodes::_dreturn: case Bytecodes::_areturn:
case Bytecodes::_return:
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
// No successors
break;
case Bytecodes::_ret: {
_successors =
new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
Cell local = state->local(str->get_index());
ciType* return_address = state->type_at(local);
assert(return_address->is_return_address(), "verify: wrong type");
int bci = return_address->as_return_address()->bci();
assert(_successors->length() == GOTO_TARGET, "");
_successors->append(analyzer->block_at(bci, jsrs));
break;
}
case Bytecodes::_wide:
default:
ShouldNotReachHere();
break;
}
}
// Set predecessor information
for (int i = 0; i < _successors->length(); i++) {
Block* block = _successors->at(i);
block->predecessors()->append(this);
}
}
return _successors;
}
// ------------------------------------------------------------------
// ciTypeFlow::Block:compute_exceptions
//
// Compute the exceptional successors and types for this Block.
void ciTypeFlow::Block::compute_exceptions() {
assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
if (CITraceTypeFlow) {
tty->print(">> Computing exceptions for block ");
print_value_on(tty);
tty->cr();
}
ciTypeFlow* analyzer = outer();
Arena* arena = analyzer->arena();
// Any bci in the block will do.
ciExceptionHandlerStream str(analyzer->method(), start());
// Allocate our growable arrays.
int exc_count = str.count();
_exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
_exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
0, NULL);
for ( ; !str.is_done(); str.next()) {
ciExceptionHandler* handler = str.handler();
int bci = handler->handler_bci();
ciInstanceKlass* klass = NULL;
if (bci == -1) {
// There is no catch all. It is possible to exit the method.
break;
}
if (handler->is_catch_all()) {
klass = analyzer->env()->Throwable_klass();
} else {
klass = handler->catch_klass();
}
Block* block = analyzer->block_at(bci, _jsrs);
_exceptions->append(block);
block->predecessors()->append(this);
_exc_klasses->append(klass);
}
}
// ------------------------------------------------------------------
// ciTypeFlow::Block::set_backedge_copy
// Use this only to make a pre-existing public block into a backedge copy.
void ciTypeFlow::Block::set_backedge_copy(bool z) {
assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
_backedge_copy = z;
}
// ------------------------------------------------------------------
// ciTypeFlow::Block::is_clonable_exit
//
// At most 2 normal successors, one of which continues looping,
// and all exceptional successors must exit.
bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
int normal_cnt = 0;
int in_loop_cnt = 0;
for (SuccIter iter(this); !iter.done(); iter.next()) {
Block* succ = iter.succ();
if (iter.is_normal_ctrl()) {
if (++normal_cnt > 2) return false;
if (lp->contains(succ->loop())) {
if (++in_loop_cnt > 1) return false;
}
} else {
if (lp->contains(succ->loop())) return false;
}
}
return in_loop_cnt == 1;
}
// ------------------------------------------------------------------
// ciTypeFlow::Block::looping_succ
//
ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
assert(successors()->length() <= 2, "at most 2 normal successors");
for (SuccIter iter(this); !iter.done(); iter.next()) {
Block* succ = iter.succ();
if (lp->contains(succ->loop())) {
return succ;
}
}
return NULL;
}
#ifndef PRODUCT
// ------------------------------------------------------------------
// ciTypeFlow::Block::print_value_on
void ciTypeFlow::Block::print_value_on(outputStream* st) const {
if (has_pre_order()) st->print("#%-2d ", pre_order());
if (has_rpo()) st->print("rpo#%-2d ", rpo());
st->print("[%d - %d)", start(), limit());
if (is_loop_head()) st->print(" lphd");
if (is_irreducible_entry()) st->print(" irred");
if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
if (is_backedge_copy()) st->print("/backedge_copy");
}
// ------------------------------------------------------------------
// ciTypeFlow::Block::print_on
void ciTypeFlow::Block::print_on(outputStream* st) const {
if ((Verbose || WizardMode) && (limit() >= 0)) {
// Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
outer()->method()->print_codes_on(start(), limit(), st);
}
st->print_cr(" ==================================================== ");
st->print (" ");
print_value_on(st);
st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
if (loop() && loop()->parent() != NULL) {
st->print(" loops:");
Loop* lp = loop();
do {
st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
if (lp->is_irreducible()) st->print("(ir)");
lp = lp->parent();
} while (lp->parent() != NULL);
}
st->cr();
_state->print_on(st);
if (_successors == NULL) {
st->print_cr(" No successor information");
} else {
int num_successors = _successors->length();
st->print_cr(" Successors : %d", num_successors);
for (int i = 0; i < num_successors; i++) {
Block* successor = _successors->at(i);
st->print(" ");
successor->print_value_on(st);
st->cr();
}
}
if (_predecessors == NULL) {
st->print_cr(" No predecessor information");
} else {
int num_predecessors = _predecessors->length();
st->print_cr(" Predecessors : %d", num_predecessors);
for (int i = 0; i < num_predecessors; i++) {
Block* predecessor = _predecessors->at(i);
st->print(" ");
predecessor->print_value_on(st);
st->cr();
}
}
if (_exceptions == NULL) {
st->print_cr(" No exception information");
} else {
int num_exceptions = _exceptions->length();
st->print_cr(" Exceptions : %d", num_exceptions);
for (int i = 0; i < num_exceptions; i++) {
Block* exc_succ = _exceptions->at(i);
ciInstanceKlass* exc_klass = _exc_klasses->at(i);
st->print(" ");
exc_succ->print_value_on(st);
st->print(" -- ");
exc_klass->name()->print_symbol_on(st);
st->cr();
}
}
if (has_trap()) {
st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
}
st->print_cr(" ==================================================== ");
}
#endif
#ifndef PRODUCT
// ------------------------------------------------------------------
// ciTypeFlow::LocalSet::print_on
void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
st->print("{");
for (int i = 0; i < max; i++) {
if (test(i)) st->print(" %d", i);
}
if (limit > max) {
st->print(" %d..%d ", max, limit);
}
st->print(" }");
}
#endif
// ciTypeFlow
//
// This is a pass over the bytecodes which computes the following:
// basic block structure
// interpreter type-states (a la the verifier)
// ------------------------------------------------------------------
// ciTypeFlow::ciTypeFlow
ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
_env = env;
_method = method;
_methodBlocks = method->get_method_blocks();
_max_locals = method->max_locals();
_max_stack = method->max_stack();
_code_size = method->code_size();
_has_irreducible_entry = false;
_osr_bci = osr_bci;
_failure_reason = NULL;
assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
_work_list = NULL;
_ciblock_count = _methodBlocks->num_blocks();
_idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
for (int i = 0; i < _ciblock_count; i++) {
_idx_to_blocklist[i] = NULL;
}
_block_map = NULL; // until all blocks are seen
_jsr_count = 0;
_jsr_records = NULL;
}
// ------------------------------------------------------------------
// ciTypeFlow::work_list_next
//
// Get the next basic block from our work list.
ciTypeFlow::Block* ciTypeFlow::work_list_next() {
assert(!work_list_empty(), "work list must not be empty");
Block* next_block = _work_list;
_work_list = next_block->next();
next_block->set_next(NULL);
next_block->set_on_work_list(false);
return next_block;
}
// ------------------------------------------------------------------
// ciTypeFlow::add_to_work_list
//
// Add a basic block to our work list.
// List is sorted by decreasing postorder sort (same as increasing RPO)
void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
assert(!block->is_on_work_list(), "must not already be on work list");
if (CITraceTypeFlow) {
tty->print(">> Adding block ");
block->print_value_on(tty);
tty->print_cr(" to the work list : ");
}
block->set_on_work_list(true);
// decreasing post order sort
Block* prev = NULL;
Block* current = _work_list;
int po = block->post_order();
while (current != NULL) {
if (!current->has_post_order() || po > current->post_order())
break;
prev = current;
current = current->next();
}
if (prev == NULL) {
block->set_next(_work_list);
_work_list = block;
} else {
block->set_next(current);
prev->set_next(block);
}
if (CITraceTypeFlow) {
tty->cr();
}
}
// ------------------------------------------------------------------
// ciTypeFlow::block_at
//
// Return the block beginning at bci which has a JsrSet compatible
// with jsrs.
ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
// First find the right ciBlock.
if (CITraceTypeFlow) {
tty->print(">> Requesting block for %d/", bci);
jsrs->print_on(tty);
tty->cr();
}
ciBlock* ciblk = _methodBlocks->block_containing(bci);
assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
Block* block = get_block_for(ciblk->index(), jsrs, option);
assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
if (CITraceTypeFlow) {
if (block != NULL) {
tty->print(">> Found block ");
block->print_value_on(tty);
tty->cr();
} else {
tty->print_cr(">> No such block.");
}
}
return block;
}
// ------------------------------------------------------------------
// ciTypeFlow::make_jsr_record
//
// Make a JsrRecord for a given (entry, return) pair, if such a record
// does not already exist.
ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
int return_address) {
if (_jsr_records == NULL) {
_jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
_jsr_count,
0,
NULL);
}
JsrRecord* record = NULL;
int len = _jsr_records->length();
for (int i = 0; i < len; i++) {
JsrRecord* record = _jsr_records->at(i);
if (record->entry_address() == entry_address &&
record->return_address() == return_address) {
return record;
}
}
record = new (arena()) JsrRecord(entry_address, return_address);
_jsr_records->append(record);
return record;
}
// ------------------------------------------------------------------
// ciTypeFlow::flow_exceptions
//
// Merge the current state into all exceptional successors at the
// current point in the code.
void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
GrowableArray<ciInstanceKlass*>* exc_klasses,
ciTypeFlow::StateVector* state) {
int len = exceptions->length();
assert(exc_klasses->length() == len, "must have same length");
for (int i = 0; i < len; i++) {
Block* block = exceptions->at(i);
ciInstanceKlass* exception_klass = exc_klasses->at(i);
if (!exception_klass->is_loaded()) {
// Do not compile any code for unloaded exception types.
// Following compiler passes are responsible for doing this also.
continue;
}
if (block->meet_exception(exception_klass, state)) {
// Block was modified and has PO. Add it to the work list.
if (block->has_post_order() &&
!block->is_on_work_list()) {
add_to_work_list(block);
}
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::flow_successors
//
// Merge the current state into all successors at the current point
// in the code.
void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
ciTypeFlow::StateVector* state) {
int len = successors->length();
for (int i = 0; i < len; i++) {
Block* block = successors->at(i);
if (block->meet(state)) {
// Block was modified and has PO. Add it to the work list.
if (block->has_post_order() &&
!block->is_on_work_list()) {
add_to_work_list(block);
}
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::can_trap
//
// Tells if a given instruction is able to generate an exception edge.
bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
// Cf. GenerateOopMap::do_exception_edge.
if (!Bytecodes::can_trap(str.cur_bc())) return false;
switch (str.cur_bc()) {
// %%% FIXME: ldc of Class can generate an exception
case Bytecodes::_ldc:
case Bytecodes::_ldc_w:
case Bytecodes::_ldc2_w:
case Bytecodes::_aload_0:
// These bytecodes can trap for rewriting. We need to assume that
// they do not throw exceptions to make the monitor analysis work.
return false;
case Bytecodes::_ireturn:
case Bytecodes::_lreturn:
case Bytecodes::_freturn:
case Bytecodes::_dreturn:
case Bytecodes::_areturn:
case Bytecodes::_return:
// We can assume the monitor stack is empty in this analysis.
return false;
case Bytecodes::_monitorexit:
// We can assume monitors are matched in this analysis.
return false;
default:
return true;
}
}
// ------------------------------------------------------------------
// ciTypeFlow::clone_loop_heads
//
// Clone the loop heads
bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
bool rslt = false;
for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
lp = iter.current();
Block* head = lp->head();
if (lp == loop_tree_root() ||
lp->is_irreducible() ||
!head->is_clonable_exit(lp))
continue;
// Avoid BoxLock merge.
if (EliminateNestedLocks && head->has_monitorenter())
continue;
// check not already cloned
if (head->backedge_copy_count() != 0)
continue;
// Don't clone head of OSR loop to get correct types in start block.
if (is_osr_flow() && head->start() == start_bci())
continue;
// check _no_ shared head below us
Loop* ch;
for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
if (ch != NULL)
continue;
// Clone head
Block* new_head = head->looping_succ(lp);
Block* clone = clone_loop_head(lp, temp_vector, temp_set);
// Update lp's info
clone->set_loop(lp);
lp->set_head(new_head);
lp->set_tail(clone);
// And move original head into outer loop
head->set_loop(lp->parent());
rslt = true;
}
return rslt;
}
// ------------------------------------------------------------------
// ciTypeFlow::clone_loop_head
//
// Clone lp's head and replace tail's successors with clone.
//
// |
// v
// head <-> body
// |
// v
// exit
//
// new_head
//
// |
// v
// head ----------\
// | |
// | v
// | clone <-> body
// | |
// | /--/
// | |
// v v
// exit
//
ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
Block* head = lp->head();
Block* tail = lp->tail();
if (CITraceTypeFlow) {
tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
tty->print(" for predecessor "); tail->print_value_on(tty);
tty->cr();
}
Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
assert(!clone->has_pre_order(), "just created");
clone->set_next_pre_order();
// Insert clone after (orig) tail in reverse post order
clone->set_rpo_next(tail->rpo_next());
tail->set_rpo_next(clone);
// tail->head becomes tail->clone
for (SuccIter iter(tail); !iter.done(); iter.next()) {
if (iter.succ() == head) {
iter.set_succ(clone);
// Update predecessor information
head->predecessors()->remove(tail);
clone->predecessors()->append(tail);
}
}
flow_block(tail, temp_vector, temp_set);
if (head == tail) {
// For self-loops, clone->head becomes clone->clone
flow_block(clone, temp_vector, temp_set);
for (SuccIter iter(clone); !iter.done(); iter.next()) {
if (iter.succ() == head) {
iter.set_succ(clone);
// Update predecessor information
head->predecessors()->remove(clone);
clone->predecessors()->append(clone);
break;
}
}
}
flow_block(clone, temp_vector, temp_set);
return clone;
}
// ------------------------------------------------------------------
// ciTypeFlow::flow_block
//
// Interpret the effects of the bytecodes on the incoming state
// vector of a basic block. Push the changed state to succeeding
// basic blocks.
void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
ciTypeFlow::StateVector* state,
ciTypeFlow::JsrSet* jsrs) {
if (CITraceTypeFlow) {
tty->print("\n>> ANALYZING BLOCK : ");
tty->cr();
block->print_on(tty);
}
assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
int start = block->start();
int limit = block->limit();
int control = block->control();
if (control != ciBlock::fall_through_bci) {
limit = control;
}
// Grab the state from the current block.
block->copy_state_into(state);
state->def_locals()->clear();
GrowableArray<Block*>* exceptions = block->exceptions();
GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
bool has_exceptions = exceptions->length() > 0;
bool exceptions_used = false;
ciBytecodeStream str(method());
str.reset_to_bci(start);
Bytecodes::Code code;
while ((code = str.next()) != ciBytecodeStream::EOBC() &&
str.cur_bci() < limit) {
// Check for exceptional control flow from this point.
if (has_exceptions && can_trap(str)) {
flow_exceptions(exceptions, exc_klasses, state);
exceptions_used = true;
}
// Apply the effects of the current bytecode to our state.
bool res = state->apply_one_bytecode(&str);
// Watch for bailouts.
if (failing()) return;
if (str.cur_bc() == Bytecodes::_monitorenter) {
block->set_has_monitorenter();
}
if (res) {
// We have encountered a trap. Record it in this block.
block->set_trap(state->trap_bci(), state->trap_index());
if (CITraceTypeFlow) {
tty->print_cr(">> Found trap");
block->print_on(tty);
}
// Save set of locals defined in this block
block->def_locals()->add(state->def_locals());
// Record (no) successors.
block->successors(&str, state, jsrs);
assert(!has_exceptions || exceptions_used, "Not removing exceptions");
// Discontinue interpretation of this Block.
return;
}
}
GrowableArray<Block*>* successors = NULL;
if (control != ciBlock::fall_through_bci) {
// Check for exceptional control flow from this point.
if (has_exceptions && can_trap(str)) {
flow_exceptions(exceptions, exc_klasses, state);
exceptions_used = true;
}
// Fix the JsrSet to reflect effect of the bytecode.
block->copy_jsrs_into(jsrs);
jsrs->apply_control(this, &str, state);
// Find successor edges based on old state and new JsrSet.
successors = block->successors(&str, state, jsrs);
// Apply the control changes to the state.
state->apply_one_bytecode(&str);
} else {
// Fall through control
successors = block->successors(&str, NULL, NULL);
}
// Save set of locals defined in this block
block->def_locals()->add(state->def_locals());
// Remove untaken exception paths
if (!exceptions_used)
exceptions->clear();
// Pass our state to successors.
flow_successors(successors, state);
}
// ------------------------------------------------------------------
// ciTypeFlow::PreOrderLoops::next
//
// Advance to next loop tree using a preorder, left-to-right traversal.
void ciTypeFlow::PreorderLoops::next() {
assert(!done(), "must not be done.");
if (_current->child() != NULL) {
_current = _current->child();
} else if (_current->sibling() != NULL) {
_current = _current->sibling();
} else {
while (_current != _root && _current->sibling() == NULL) {
_current = _current->parent();
}
if (_current == _root) {
_current = NULL;
assert(done(), "must be done.");
} else {
assert(_current->sibling() != NULL, "must be more to do");
_current = _current->sibling();
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::Loop::sorted_merge
//
// Merge the branch lp into this branch, sorting on the loop head
// pre_orders. Returns the leaf of the merged branch.
// Child and sibling pointers will be setup later.
// Sort is (looking from leaf towards the root)
// descending on primary key: loop head's pre_order, and
// ascending on secondary key: loop tail's pre_order.
ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
Loop* leaf = this;
Loop* prev = NULL;
Loop* current = leaf;
while (lp != NULL) {
int lp_pre_order = lp->head()->pre_order();
// Find insertion point for "lp"
while (current != NULL) {
if (current == lp)
return leaf; // Already in list
if (current->head()->pre_order() < lp_pre_order)
break;
if (current->head()->pre_order() == lp_pre_order &&
current->tail()->pre_order() > lp->tail()->pre_order()) {
break;
}
prev = current;
current = current->parent();
}
Loop* next_lp = lp->parent(); // Save future list of items to insert
// Insert lp before current
lp->set_parent(current);
if (prev != NULL) {
prev->set_parent(lp);
} else {
leaf = lp;
}
prev = lp; // Inserted item is new prev[ious]
lp = next_lp; // Next item to insert
}
return leaf;
}
// ------------------------------------------------------------------
// ciTypeFlow::build_loop_tree
//
// Incrementally build loop tree.
void ciTypeFlow::build_loop_tree(Block* blk) {
assert(!blk->is_post_visited(), "precondition");
Loop* innermost = NULL; // merge of loop tree branches over all successors
for (SuccIter iter(blk); !iter.done(); iter.next()) {
Loop* lp = NULL;
Block* succ = iter.succ();
if (!succ->is_post_visited()) {
// Found backedge since predecessor post visited, but successor is not
assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
// Create a LoopNode to mark this loop.
lp = new (arena()) Loop(succ, blk);
if (succ->loop() == NULL)
succ->set_loop(lp);
// succ->loop will be updated to innermost loop on a later call, when blk==succ
} else { // Nested loop
lp = succ->loop();
// If succ is loop head, find outer loop.
while (lp != NULL && lp->head() == succ) {
lp = lp->parent();
}
if (lp == NULL) {
// Infinite loop, it's parent is the root
lp = loop_tree_root();
}
}
// Check for irreducible loop.
// Successor has already been visited. If the successor's loop head
// has already been post-visited, then this is another entry into the loop.
while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
_has_irreducible_entry = true;
lp->set_irreducible(succ);
if (!succ->is_on_work_list()) {
// Assume irreducible entries need more data flow
add_to_work_list(succ);
}
Loop* plp = lp->parent();
if (plp == NULL) {
// This only happens for some irreducible cases. The parent
// will be updated during a later pass.
break;
}
lp = plp;
}
// Merge loop tree branch for all successors.
innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
} // end loop
if (innermost == NULL) {
assert(blk->successors()->length() == 0, "CFG exit");
blk->set_loop(loop_tree_root());
} else if (innermost->head() == blk) {
// If loop header, complete the tree pointers
if (blk->loop() != innermost) {
#ifdef ASSERT
assert(blk->loop()->head() == innermost->head(), "same head");
Loop* dl;
for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
assert(dl == blk->loop(), "blk->loop() already in innermost list");
#endif
blk->set_loop(innermost);
}
innermost->def_locals()->add(blk->def_locals());
Loop* l = innermost;
Loop* p = l->parent();
while (p && l->head() == blk) {
l->set_sibling(p->child()); // Put self on parents 'next child'
p->set_child(l); // Make self the first child of parent
p->def_locals()->add(l->def_locals());
l = p; // Walk up the parent chain
p = l->parent();
}
} else {
blk->set_loop(innermost);
innermost->def_locals()->add(blk->def_locals());
}
}
// ------------------------------------------------------------------
// ciTypeFlow::Loop::contains
//
// Returns true if lp is nested loop.
bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
assert(lp != NULL, "");
if (this == lp || head() == lp->head()) return true;
int depth1 = depth();
int depth2 = lp->depth();
if (depth1 > depth2)
return false;
while (depth1 < depth2) {
depth2--;
lp = lp->parent();
}
return this == lp;
}
// ------------------------------------------------------------------
// ciTypeFlow::Loop::depth
//
// Loop depth
int ciTypeFlow::Loop::depth() const {
int dp = 0;
for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
dp++;
return dp;
}
#ifndef PRODUCT
// ------------------------------------------------------------------
// ciTypeFlow::Loop::print
void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
for (int i = 0; i < indent; i++) st->print(" ");
st->print("%d<-%d %s",
is_root() ? 0 : this->head()->pre_order(),
is_root() ? 0 : this->tail()->pre_order(),
is_irreducible()?" irr":"");
st->print(" defs: ");
def_locals()->print_on(st, _head->outer()->method()->max_locals());
st->cr();
for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
ch->print(st, indent+2);
}
#endif
// ------------------------------------------------------------------
// ciTypeFlow::df_flow_types
//
// Perform the depth first type flow analysis. Helper for flow_types.
void ciTypeFlow::df_flow_types(Block* start,
bool do_flow,
StateVector* temp_vector,
JsrSet* temp_set) {
int dft_len = 100;
GrowableArray<Block*> stk(dft_len);
ciBlock* dummy = _methodBlocks->make_dummy_block();
JsrSet* root_set = new JsrSet(NULL, 0);
Block* root_head = new (arena()) Block(this, dummy, root_set);
Block* root_tail = new (arena()) Block(this, dummy, root_set);
root_head->set_pre_order(0);
root_head->set_post_order(0);
root_tail->set_pre_order(max_jint);
root_tail->set_post_order(max_jint);
set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
stk.push(start);
_next_pre_order = 0; // initialize pre_order counter
_rpo_list = NULL;
int next_po = 0; // initialize post_order counter
// Compute RPO and the control flow graph
int size;
while ((size = stk.length()) > 0) {
Block* blk = stk.top(); // Leave node on stack
if (!blk->is_visited()) {
// forward arc in graph
assert (!blk->has_pre_order(), "");
blk->set_next_pre_order();
if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
// Too many basic blocks. Bail out.
// This can happen when try/finally constructs are nested to depth N,
// and there is O(2**N) cloning of jsr bodies. See bug 4697245!
// "MaxNodeLimit / 2" is used because probably the parser will
// generate at least twice that many nodes and bail out.
record_failure("too many basic blocks");
return;
}
if (do_flow) {
flow_block(blk, temp_vector, temp_set);
if (failing()) return; // Watch for bailouts.
}
} else if (!blk->is_post_visited()) {
// cross or back arc
for (SuccIter iter(blk); !iter.done(); iter.next()) {
Block* succ = iter.succ();
if (!succ->is_visited()) {
stk.push(succ);
}
}
if (stk.length() == size) {
// There were no additional children, post visit node now
stk.pop(); // Remove node from stack
build_loop_tree(blk);
blk->set_post_order(next_po++); // Assign post order
prepend_to_rpo_list(blk);
assert(blk->is_post_visited(), "");
if (blk->is_loop_head() && !blk->is_on_work_list()) {
// Assume loop heads need more data flow
add_to_work_list(blk);
}
}
} else {
stk.pop(); // Remove post-visited node from stack
}
}
}
// ------------------------------------------------------------------
// ciTypeFlow::flow_types
//
// Perform the type flow analysis, creating and cloning Blocks as
// necessary.
void ciTypeFlow::flow_types() {
ResourceMark rm;
StateVector* temp_vector = new StateVector(this);
JsrSet* temp_set = new JsrSet(NULL, 16);
// Create the method entry block.
Block* start = block_at(start_bci(), temp_set);
// Load the initial state into it.
const StateVector* start_state = get_start_state();
if (failing()) return;
start->meet(start_state);
// Depth first visit
df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
if (failing()) return;
assert(_rpo_list == start, "must be start");
// Any loops found?
if (loop_tree_root()->child() != NULL &&
env()->comp_level() >= CompLevel_full_optimization) {
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