/*
* Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "c1/c1_IR.hpp"
#include "c1/c1_InstructionPrinter.hpp"
#include "c1/c1_ValueStack.hpp"
// Implementation of ValueStack
ValueStack::ValueStack(IRScope* scope, ValueStack* caller_state)
: _scope(scope)
, _caller_state(caller_state)
, _bci(-99)
, _kind(Parsing)
, _locals(scope->method()->max_locals(), NULL)
, _stack(scope->method()->max_stack())
, _locks()
{
verify();
}
ValueStack::ValueStack(ValueStack* copy_from, Kind kind, int bci)
: _scope(copy_from->scope())
, _caller_state(copy_from->caller_state())
, _bci(bci)
, _kind(kind)
, _locals()
, _stack()
, _locks(copy_from->locks_size())
{
assert(kind != EmptyExceptionState || !Compilation::current()->env()->jvmti_can_access_local_variables(), "need locals");
if (kind != EmptyExceptionState) {
// only allocate space if we need to copy the locals-array
_locals = Values(copy_from->locals_size());
_locals.appendAll(&copy_from->_locals);
}
if (kind != ExceptionState && kind != EmptyExceptionState) {
if (kind == Parsing) {
// stack will be modified, so reserve enough space to avoid resizing
_stack = Values(scope()->method()->max_stack());
} else {
// stack will not be modified, so do not waste space
_stack = Values(copy_from->stack_size());
}
_stack.appendAll(&copy_from->_stack);
}
_locks.appendAll(&copy_from->_locks);
verify();
}
bool ValueStack::is_same(ValueStack* s) {
if (scope() != s->scope()) return false;
if (caller_state() != s->caller_state()) return false;
if (locals_size() != s->locals_size()) return false;
if (stack_size() != s->stack_size()) return false;
if (locks_size() != s->locks_size()) return false;
// compare each stack element with the corresponding stack element of s
int index;
Value value;
for_each_stack_value(this, index, value) {
if (value->type()->tag() != s->stack_at(index)->type()->tag()) return false;
}
for_each_lock_value(this, index, value) {
if (value != s->lock_at(index)) return false;
}
return true;
}
void ValueStack::clear_locals() {
for (int i = _locals.length() - 1; i >= 0; i--) {
_locals.at_put(i, NULL);
}
}
void ValueStack::pin_stack_for_linear_scan() {
for_each_state_value(this, v,
if (v->as_Constant() == NULL && v->as_Local() == NULL) {
v->pin(Instruction::PinStackForStateSplit);
}
);
}
// apply function to all values of a list; factored out from values_do(f)
void ValueStack::apply(Values list, ValueVisitor* f) {
for (int i = 0; i < list.length(); i++) {
Value* va = list.adr_at(i);
Value v0 = *va;
if (v0 != NULL && !v0->type()->is_illegal()) {
f->visit(va);
#ifdef ASSERT
Value v1 = *va;
assert(v1->type()->is_illegal() || v0->type()->tag() == v1->type()->tag(), "types must match");
assert(!v1->type()->is_double_word() || list.at(i + 1) == NULL, "hi-word of doubleword value must be NULL");
#endif
if (v0->type()->is_double_word()) i++;
}
}
}
void ValueStack::values_do(ValueVisitor* f) {
ValueStack* state = this;
for_each_state(state) {
apply(state->_locals, f);
apply(state->_stack, f);
apply(state->_locks, f);
}
}
Values* ValueStack::pop_arguments(int argument_size) {
assert(stack_size() >= argument_size, "stack too small or too many arguments");
int base = stack_size() - argument_size;
Values* args = new Values(argument_size);
for (int i = base; i < stack_size();) args->push(stack_at_inc(i));
truncate_stack(base);
return args;
}
int ValueStack::total_locks_size() const {
int num_locks = 0;
const ValueStack* state = this;
for_each_state(state) {
num_locks += state->locks_size();
}
return num_locks;
}
int ValueStack::lock(Value obj) {
_locks.push(obj);
int num_locks = total_locks_size();
scope()->set_min_number_of_locks(num_locks);
return num_locks - 1;
}
int ValueStack::unlock() {
_locks.pop();
return total_locks_size();
}
void ValueStack::setup_phi_for_stack(BlockBegin* b, int index) {
assert(stack_at(index)->as_Phi() == NULL || stack_at(index)->as_Phi()->block() != b, "phi function already created");
ValueType* t = stack_at(index)->type();
Value phi = new Phi(t, b, -index - 1);
_stack[index] = phi;
assert(!t->is_double_word() || _stack.at(index + 1) == NULL, "hi-word of doubleword value must be NULL");
}
void ValueStack::setup_phi_for_local(BlockBegin* b, int index) {
assert(local_at(index)->as_Phi() == NULL || local_at(index)->as_Phi()->block() != b, "phi function already created");
ValueType* t = local_at(index)->type();
Value phi = new Phi(t, b, index);
store_local(index, phi);
}
#ifndef PRODUCT
void ValueStack::print() {
scope()->method()->print_name();
tty->cr();
if (stack_is_empty()) {
tty->print_cr("empty stack");
} else {
InstructionPrinter ip;
for (int i = 0; i < stack_size();) {
Value t = stack_at_inc(i);
tty->print("%2d ", i);
tty->print("%c%d ", t->type()->tchar(), t->id());
ip.print_instr(t);
tty->cr();
}
}
if (!no_active_locks()) {
InstructionPrinter ip;
for (int i = 0; i < locks_size(); i++) {
Value t = lock_at(i);
tty->print("lock %2d ", i);
if (t == NULL) {
tty->print("this");
} else {
tty->print("%c%d ", t->type()->tchar(), t->id());
ip.print_instr(t);
}
tty->cr();
}
}
if (locals_size() > 0) {
InstructionPrinter ip;
for (int i = 0; i < locals_size();) {
Value l = _locals[i];
tty->print("local %d ", i);
if (l == NULL) {
tty->print("null");
i ++;
} else {
tty->print("%c%d ", l->type()->tchar(), l->id());
ip.print_instr(l);
if (l->type()->is_illegal() || l->type()->is_single_word()) i ++; else i += 2;
}
tty->cr();
}
}
if (caller_state() != NULL) {
caller_state()->print();
}
}
void ValueStack::verify() {
assert(scope() != NULL, "scope must exist");
if (caller_state() != NULL) {
assert(caller_state()->scope() == scope()->caller(), "invalid caller scope");
caller_state()->verify();
}
if (kind() == Parsing) {
assert(bci() == -99, "bci not defined during parsing");
} else {
assert(bci() >= -1, "bci out of range");
assert(bci() < scope()->method()->code_size(), "bci out of range");
assert(bci() == SynchronizationEntryBCI || Bytecodes::is_defined(scope()->method()->java_code_at_bci(bci())), "make sure bci points at a real bytecode");
assert(scope()->method()->liveness_at_bci(bci()).is_valid(), "liveness at bci must be valid");
}
int i;
for (i = 0; i < stack_size(); i++) {
Value v = _stack.at(i);
if (v == NULL) {
assert(_stack.at(i - 1)->type()->is_double_word(), "only hi-words are NULL on stack");
} else if (v->type()->is_double_word()) {
assert(_stack.at(i + 1) == NULL, "hi-word must be NULL");
}
}
for (i = 0; i < locals_size(); i++) {
Value v = _locals.at(i);
if (v != NULL && v->type()->is_double_word()) {
assert(_locals.at(i + 1) == NULL, "hi-word must be NULL");
}
}
for_each_state_value(this, v,
assert(v != NULL, "just test if state-iteration succeeds");
);
}
#endif // PRODUCT