graal-compiler: src/share/vm/ci/ciTypeFlow.cpp comparison

comparison src/share/vm/ci/ciTypeFlow.cpp @ 0:a61af66fc99e jdk7-b24

Initial load

author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	194b8e3a2fc4

comparison

equal deleted inserted replaced

--1:000000000000
+:a61af66fc99e
+/*
+* Copyright 2000-2007 Sun Microsystems, Inc.  All Rights Reserved.
+* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+*
+* This code is free software; you can redistribute it and/or modify it
+* under the terms of the GNU General Public License version 2 only, as
+* published by the Free Software Foundation.
+*
+* This code is distributed in the hope that it will be useful, but WITHOUT
+* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+* version 2 for more details (a copy is included in the LICENSE file that
+* accompanied this code).
+*
+* You should have received a copy of the GNU General Public License version
+* 2 along with this work; if not, write to the Free Software Foundation,
+* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+*
+* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+* CA 95054 USA or visit www.sun.com if you need additional information or
+* have any questions.
+*
+*/
+#include "incls/_precompiled.incl"
+#include "incls/_ciTypeFlow.cpp.incl"
+// 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;
+}
+// ------------------------------------------------------------------
+// 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 unconditonal 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;
+ciMethod* method = str->get_method(will_link);
+if (!will_link) {
+// We weren't able to find the method.
+ciKlass* unloaded_holder = method->holder();
+trap(str, unloaded_holder, str->get_method_holder_index());
+} else {
+ciSignature* signature = method->signature();
+ciSignatureStream sigstr(signature);
+int arg_size = signature->size();
+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 (basic_type == T_OBJECT || basic_type == T_ARRAY) {
+ciObject* obj = con.as_object();
+if (obj->is_null_object()) {
+push_null();
+} else if (obj->is_klass()) {
+// The type of ldc <class> is java.lang.Class
+push_object(outer()->env()->Class_klass());
+} else {
+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) {
+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:
+{
+check_int(local(str->get_index()));
+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::_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::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;
+_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;
+_pre_order = -1; assert(!has_pre_order(), "");
+_private_copy = false;
+_trap_bci = -1;
+_trap_index = 0;
+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::clone_loop_head
+//
+ciTypeFlow::Block*
+ciTypeFlow::Block::clone_loop_head(ciTypeFlow* analyzer,
+int branch_bci,
+ciTypeFlow::Block* target,
+ciTypeFlow::JsrSet* jsrs) {
+// Loop optimizations are not performed on Tier1 compiles. Do nothing.
+if (analyzer->env()->comp_level() < CompLevel_full_optimization) {
+return target;
+}
+// The current block ends with a branch.
+//
+// If the target block appears to be the test-clause of a for loop, and
+// it is not too large, and it has not yet been cloned, clone it.
+// The pre-existing copy becomes the private clone used only by
+// the initial iteration of the loop.  (We know we are simulating
+// the initial iteration right now, since we have never calculated
+// successors before for this block.)
+if (branch_bci <= start()
+&& (target->limit() - target->start()) <= CICloneLoopTestLimit
+&& target->private_copy_count() == 0) {
+// Setting the private_copy bit ensures that the target block cannot be
+// reached by any other paths, such as fall-in from the loop body.
+// The private copy will be accessible only on successor lists
+// created up to this point.
+target->set_private_copy(true);
+if (CITraceTypeFlow) {
+tty->print(">> Cloning a test-clause block ");
+print_value_on(tty);
+tty->cr();
+}
+// If the target is the current block, then later on a new copy of the
+// target block will be created when its bytecodes are reached by
+// an alternate path. (This is the case for loops with the loop
+// head at the bci-wise bottom of the loop, as with pre-1.4.2 javac.)
+//
+// Otherwise, duplicate the target block now and use it immediately.
+// (The case for loops with the loop head at the bci-wise top of the
+// loop, as with 1.4.2 javac.)
+//
+// In either case, the new copy of the block will remain public.
+if (target != this) {
+target = analyzer->block_at(branch_bci, jsrs);
+}
+}
+return target;
+}
+// ------------------------------------------------------------------
+// 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();
+clone_loop_head(analyzer, branch_bci, this, jsrs);
+_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, "");
+target = analyzer->block_at(branch_bci, jsrs);
+// If the target block has not been visited yet, and looks like
+// a two-way branch, attempt to clone it if it is a loop head.
+if (target->_successors != NULL
+&& target->_successors->length() == (IF_TAKEN + 1)) {
+target = clone_loop_head(analyzer, branch_bci, target, jsrs);
+}
+_successors->append(target);
+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 =
+Bytecode_tableswitch_at(str->cur_bcp());
+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 =
+Bytecode_lookupswitch_at(str->cur_bcp());
+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;
+}
+}
+}
+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();
+}
+_exceptions->append(analyzer->block_at(bci, _jsrs));
+_exc_klasses->append(klass);
+}
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::Block::is_simpler_than
+//
+// A relation used to order our work list.  We work on a block earlier
+// if it has a smaller jsr stack or it occurs earlier in the program
+// text.
+//
+// Note: maybe we should redo this functionality to make blocks
+// which correspond to exceptions lower priority.
+bool ciTypeFlow::Block::is_simpler_than(ciTypeFlow::Block* other) {
+if (other == NULL) {
+return true;
+} else {
+int size1 = _jsrs->size();
+int size2 = other->_jsrs->size();
+if (size1 < size2) {
+return true;
+} else if (size2 < size1) {
+return false;
+} else {
+#if 0
+if (size1 > 0) {
+int r1 = _jsrs->record_at(0)->return_address();
+int r2 = _jsrs->record_at(0)->return_address();
+if (r1 < r2) {
+return true;
+} else if (r2 < r1) {
+return false;
+} else {
+int e1 = _jsrs->record_at(0)->return_address();
+int e2 = _jsrs->record_at(0)->return_address();
+if (e1 < e2) {
+return true;
+} else if (e2 < e1) {
+return false;
+}
+}
+}
+#endif
+return (start() <= other->start());
+}
+}
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::Block::set_private_copy
+// Use this only to make a pre-existing public block into a private copy.
+void ciTypeFlow::Block::set_private_copy(bool z) {
+assert(z || (z == is_private_copy()), "cannot make a private copy public");
+_private_copy = z;
+}
+#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());
+st->print("[%d - %d)", start(), limit());
+if (_jsrs->size() > 0) { st->print("/");  _jsrs->print_on(st); }
+if (is_private_copy())  st->print("/private_copy");
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::Block::print_on
+void ciTypeFlow::Block::print_on(outputStream* st) const {
+if ((Verbose || WizardMode)) {
+outer()->method()->print_codes_on(start(), limit(), st);
+}
+st->print_cr("  ====================================================  ");
+st->print ("  ");
+print_value_on(st);
+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 (_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
+// 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();
+_osr_bci = osr_bci;
+_failure_reason = NULL;
+assert(start_bci() >= 0 && start_bci() < code_size() , "correct osr_bci argument");
+_work_list = NULL;
+_next_pre_order = 0;
+_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);
+if (!next_block->has_pre_order()) {
+// Assign "pre_order" as each new block is taken from the work list.
+// This number may be used by following phases to order block visits.
+assert(!have_block_count(), "must not have mapped blocks yet")
+next_block->set_pre_order(_next_pre_order++);
+}
+return next_block;
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::add_to_work_list
+//
+// Add a basic block to our work list.
+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%s ", block->has_pre_order() ? " (again)" : "");
+block->print_value_on(tty);
+tty->print_cr(" to the work list : ");
+}
+block->set_on_work_list(true);
+if (block->is_simpler_than(_work_list)) {
+block->set_next(_work_list);
+_work_list = block;
+} else {
+Block *temp = _work_list;
+while (!block->is_simpler_than(temp->next())) {
+if (CITraceTypeFlow) {
+tty->print(".");
+}
+temp = temp->next();
+}
+block->set_next(temp->next());
+temp->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_private_copy() == (option == create_private_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.  Add it to the work list.
+if (!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.  Add it to the work list.
+if (!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()) {
+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;
+}
+return true;
+}
+// ------------------------------------------------------------------
+// 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);
+GrowableArray<Block*>*           exceptions = block->exceptions();
+GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
+bool has_exceptions = exceptions->length() > 0;
+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);
+}
+// Apply the effects of the current bytecode to our state.
+bool res = state->apply_one_bytecode(&str);
+// Watch for bailouts.
+if (failing())  return;
+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);
+}
+// Record (no) successors.
+block->successors(&str, state, jsrs);
+// 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);
+}
+// 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);
+}
+// Pass our state to successors.
+flow_successors(successors, state);
+}
+// ------------------------------------------------------------------
+// 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* block = block_at(start_bci(), temp_set);
+block->set_pre_order(_next_pre_order++);
+assert(block->is_start(), "start block must have order #0");
+// Load the initial state into it.
+const StateVector* start_state = get_start_state();
+if (failing())  return;
+block->meet(start_state);
+add_to_work_list(block);
+// Trickle away.
+while (!work_list_empty()) {
+Block* block = work_list_next();
+flow_block(block, temp_vector, temp_set);
+// NodeCountCutoff is the number of nodes at which the parser
+// will bail out.  Probably if we already have lots of BBs,
+// the parser will generate at least twice that many nodes and bail out.
+// Therefore, this is a conservatively large limit at which to
+// bail out in the pre-parse typeflow pass.
+int block_limit = MaxNodeLimit / 2;
+if (_next_pre_order >= block_limit) {
+// 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!
+record_failure("too many basic blocks");
+return;
+}
+// Watch for bailouts.
+if (failing())  return;
+}
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::map_blocks
+//
+// Create the block map, which indexes blocks in pre_order.
+void ciTypeFlow::map_blocks() {
+assert(_block_map == NULL, "single initialization");
+int pre_order_limit = _next_pre_order;
+_block_map = NEW_ARENA_ARRAY(arena(), Block*, pre_order_limit);
+assert(pre_order_limit == block_count(), "");
+int po;
+for (po = 0; po < pre_order_limit; po++) {
+debug_only(_block_map[po] = NULL);
+}
+ciMethodBlocks *mblks = _methodBlocks;
+ciBlock* current = NULL;
+int limit_bci = code_size();
+for (int bci = 0; bci < limit_bci; bci++) {
+ciBlock* ciblk = mblks->block_containing(bci);
+if (ciblk != NULL && ciblk != current) {
+current = ciblk;
+int curidx = ciblk->index();
+int block_count = (_idx_to_blocklist[curidx] == NULL) ? 0 : _idx_to_blocklist[curidx]->length();
+for (int i = 0; i < block_count; i++) {
+Block* block = _idx_to_blocklist[curidx]->at(i);
+if (!block->has_pre_order())  continue;
+int po = block->pre_order();
+assert(_block_map[po] == NULL, "unique ref to block");
+assert(0 <= po && po < pre_order_limit, "");
+_block_map[po] = block;
+}
+}
+}
+for (po = 0; po < pre_order_limit; po++) {
+assert(_block_map[po] != NULL, "must not drop any blocks");
+Block* block = _block_map[po];
+// Remove dead blocks from successor lists:
+for (int e = 0; e <= 1; e++) {
+GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
+for (int i = 0; i < l->length(); i++) {
+Block* s = l->at(i);
+if (!s->has_pre_order()) {
+if (CITraceTypeFlow) {
+tty->print("Removing dead %s successor of #%d: ", (e? "exceptional":  "normal"), block->pre_order());
+s->print_value_on(tty);
+tty->cr();
+}
+l->remove(s);
+--i;
+}
+}
+}
+}
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::get_block_for
+//
+// Find a block with this ciBlock which has a compatible JsrSet.
+// If no such block exists, create it, unless the option is no_create.
+// If the option is create_private_copy, always create a fresh private copy.
+ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
+Arena* a = arena();
+GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
+if (blocks == NULL) {
+// Query only?
+if (option == no_create)  return NULL;
+// Allocate the growable array.
+blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
+_idx_to_blocklist[ciBlockIndex] = blocks;
+}
+if (option != create_private_copy) {
+int len = blocks->length();
+for (int i = 0; i < len; i++) {
+Block* block = blocks->at(i);
+if (!block->is_private_copy() && block->is_compatible_with(jsrs)) {
+return block;
+}
+}
+}
+// Query only?
+if (option == no_create)  return NULL;
+// We did not find a compatible block.  Create one.
+Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
+if (option == create_private_copy)  new_block->set_private_copy(true);
+blocks->append(new_block);
+return new_block;
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::private_copy_count
+//
+int ciTypeFlow::private_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
+GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
+if (blocks == NULL) {
+return 0;
+}
+int count = 0;
+int len = blocks->length();
+for (int i = 0; i < len; i++) {
+Block* block = blocks->at(i);
+if (block->is_private_copy() && block->is_compatible_with(jsrs)) {
+count++;
+}
+}
+return count;
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::do_flow
+//
+// Perform type inference flow analysis.
+void ciTypeFlow::do_flow() {
+if (CITraceTypeFlow) {
+tty->print_cr("\nPerforming flow analysis on method");
+method()->print();
+if (is_osr_flow())  tty->print(" at OSR bci %d", start_bci());
+tty->cr();
+method()->print_codes();
+}
+if (CITraceTypeFlow) {
+tty->print_cr("Initial CI Blocks");
+print_on(tty);
+}
+flow_types();
+// Watch for bailouts.
+if (failing()) {
+return;
+}
+if (CIPrintTypeFlow || CITraceTypeFlow) {
+print_on(tty);
+}
+map_blocks();
+}
+// ------------------------------------------------------------------
+// ciTypeFlow::record_failure()
+// The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
+// This is required because there is not a 1-1 relation between the ciEnv and
+// the TypeFlow passes within a compilation task.  For example, if the compiler
+// is considering inlining a method, it will request a TypeFlow.  If that fails,
+// the compilation as a whole may continue without the inlining.  Some TypeFlow
+// requests are not optional; if they fail the requestor is responsible for
+// copying the failure reason up to the ciEnv.  (See Parse::Parse.)
+void ciTypeFlow::record_failure(const char* reason) {
+if (env()->log() != NULL) {
+env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
+}
+if (_failure_reason == NULL) {
+// Record the first failure reason.
+_failure_reason = reason;
+}
+}
+#ifndef PRODUCT
+// ------------------------------------------------------------------
+// ciTypeFlow::print_on
+void ciTypeFlow::print_on(outputStream* st) const {
+// Walk through CI blocks
+st->print_cr("********************************************************");
+st->print   ("TypeFlow for ");
+method()->name()->print_symbol_on(st);
+int limit_bci = code_size();
+st->print_cr("  %d bytes", limit_bci);
+ciMethodBlocks  *mblks = _methodBlocks;
+ciBlock* current = NULL;
+for (int bci = 0; bci < limit_bci; bci++) {
+ciBlock* blk = mblks->block_containing(bci);
+if (blk != NULL && blk != current) {
+current = blk;
+current->print_on(st);
+GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
+int num_blocks = (blocks == NULL) ? 0 : blocks->length();
+if (num_blocks == 0) {
+st->print_cr("  No Blocks");
+} else {
+for (int i = 0; i < num_blocks; i++) {
+Block* block = blocks->at(i);
+block->print_on(st);
+}
+}
+st->print_cr("--------------------------------------------------------");
+st->cr();
+}
+}
+st->print_cr("********************************************************");
+st->cr();
+}
+#endif

Mercurial > hg > graal-compiler

comparison src/share/vm/ci/ciTypeFlow.cpp @ 0:a61af66fc99e jdk7-b24