int MultiBranchData::compute_cell_count(BytecodeStream* stream) {
int cell_count = 0;
if (stream->code() == Bytecodes::_tableswitch) {
Bytecode_tableswitch* sw = Bytecode_tableswitch_at(stream->bcp());
cell_count = 1 + per_case_cell_count * (1 + sw->length()); // 1 for default
} else {
Bytecode_lookupswitch* sw = Bytecode_lookupswitch_at(stream->bcp());
cell_count = 1 + per_case_cell_count * (sw->number_of_pairs() + 1); // 1 for default
}
return cell_count;
}
void MultiBranchData::post_initialize(BytecodeStream* stream,
methodDataOop mdo) {
assert(stream->bci() == bci(), "wrong pos");
int target;
int my_di;
int target_di;
int offset;
if (stream->code() == Bytecodes::_tableswitch) {
Bytecode_tableswitch* sw = Bytecode_tableswitch_at(stream->bcp());
int len = sw->length();
assert(array_len() == per_case_cell_count * (len + 1), "wrong len");
for (int count = 0; count < len; count++) {
target = sw->dest_offset_at(count) + bci();
my_di = mdo->dp_to_di(dp());
target_di = mdo->bci_to_di(target);
offset = target_di - my_di;
set_displacement_at(count, offset);
}
target = sw->default_offset() + bci();
my_di = mdo->dp_to_di(dp());
target_di = mdo->bci_to_di(target);
offset = target_di - my_di;
set_default_displacement(offset);
} else {
Bytecode_lookupswitch* sw = Bytecode_lookupswitch_at(stream->bcp());
int npairs = sw->number_of_pairs();
assert(array_len() == per_case_cell_count * (npairs + 1), "wrong len");
for (int count = 0; count < npairs; count++) {
LookupswitchPair *pair = sw->pair_at(count);
target = pair->offset() + bci();
my_di = mdo->dp_to_di(dp());
target_di = mdo->bci_to_di(target);
offset = target_di - my_di;
set_displacement_at(count, offset);
}
target = sw->default_offset() + bci();
my_di = mdo->dp_to_di(dp());
target_di = mdo->bci_to_di(target);
offset = target_di - my_di;
set_default_displacement(offset);
}
}
void BCEscapeAnalyzer::iterate_one_block(ciBlock *blk, StateInfo &state, GrowableArray<ciBlock *> &successors) {
blk->set_processed();
ciBytecodeStream s(method());
int limit_bci = blk->limit_bci();
bool fall_through = false;
ArgumentMap allocated_obj;
allocated_obj.add_allocated();
ArgumentMap unknown_obj;
unknown_obj.add_unknown();
ArgumentMap empty_map;
s.reset_to_bci(blk->start_bci());
while (s.next() != ciBytecodeStream::EOBC() && s.cur_bci() < limit_bci) {
fall_through = true;
switch (s.cur_bc()) {
case Bytecodes::_nop:
break;
case Bytecodes::_aconst_null:
state.apush(empty_map);
break;
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::_fconst_0:
case Bytecodes::_fconst_1:
case Bytecodes::_fconst_2:
case Bytecodes::_bipush:
case Bytecodes::_sipush:
state.spush();
break;
case Bytecodes::_lconst_0:
case Bytecodes::_lconst_1:
case Bytecodes::_dconst_0:
case Bytecodes::_dconst_1:
state.lpush();
break;
case Bytecodes::_ldc:
case Bytecodes::_ldc_w:
case Bytecodes::_ldc2_w:
if (type2size[s.get_constant().basic_type()] == 1) {
state.spush();
} else {
state.lpush();
}
break;
case Bytecodes::_aload:
state.apush(state._vars[s.get_index()]);
break;
case Bytecodes::_iload:
case Bytecodes::_fload:
case Bytecodes::_iload_0:
case Bytecodes::_iload_1:
case Bytecodes::_iload_2:
case Bytecodes::_iload_3:
case Bytecodes::_fload_0:
case Bytecodes::_fload_1:
case Bytecodes::_fload_2:
case Bytecodes::_fload_3:
state.spush();
break;
case Bytecodes::_lload:
case Bytecodes::_dload:
case Bytecodes::_lload_0:
case Bytecodes::_lload_1:
case Bytecodes::_lload_2:
case Bytecodes::_lload_3:
case Bytecodes::_dload_0:
case Bytecodes::_dload_1:
case Bytecodes::_dload_2:
case Bytecodes::_dload_3:
state.lpush();
break;
case Bytecodes::_aload_0:
state.apush(state._vars[0]);
break;
case Bytecodes::_aload_1:
state.apush(state._vars[1]);
break;
case Bytecodes::_aload_2:
state.apush(state._vars[2]);
break;
case Bytecodes::_aload_3:
state.apush(state._vars[3]);
break;
case Bytecodes::_iaload:
case Bytecodes::_faload:
case Bytecodes::_baload:
case Bytecodes::_caload:
case Bytecodes::_saload:
state.spop();
set_method_escape(state.apop());
state.spush();
break;
case Bytecodes::_laload:
case Bytecodes::_daload:
state.spop();
set_method_escape(state.apop());
state.lpush();
break;
case Bytecodes::_aaload:
{ state.spop();
ArgumentMap array = state.apop();
set_method_escape(array);
state.apush(unknown_obj);
set_dirty(array);
}
break;
case Bytecodes::_istore:
case Bytecodes::_fstore:
case Bytecodes::_istore_0:
case Bytecodes::_istore_1:
case Bytecodes::_istore_2:
case Bytecodes::_istore_3:
case Bytecodes::_fstore_0:
case Bytecodes::_fstore_1:
case Bytecodes::_fstore_2:
case Bytecodes::_fstore_3:
state.spop();
break;
case Bytecodes::_lstore:
case Bytecodes::_dstore:
case Bytecodes::_lstore_0:
case Bytecodes::_lstore_1:
case Bytecodes::_lstore_2:
case Bytecodes::_lstore_3:
case Bytecodes::_dstore_0:
case Bytecodes::_dstore_1:
case Bytecodes::_dstore_2:
case Bytecodes::_dstore_3:
state.lpop();
break;
case Bytecodes::_astore:
state._vars[s.get_index()] = state.apop();
break;
case Bytecodes::_astore_0:
state._vars[0] = state.apop();
break;
case Bytecodes::_astore_1:
state._vars[1] = state.apop();
break;
case Bytecodes::_astore_2:
state._vars[2] = state.apop();
break;
case Bytecodes::_astore_3:
state._vars[3] = state.apop();
break;
case Bytecodes::_iastore:
case Bytecodes::_fastore:
case Bytecodes::_bastore:
case Bytecodes::_castore:
case Bytecodes::_sastore:
{
state.spop();
state.spop();
ArgumentMap arr = state.apop();
set_method_escape(arr);
break;
}
case Bytecodes::_lastore:
case Bytecodes::_dastore:
{
state.lpop();
state.spop();
ArgumentMap arr = state.apop();
set_method_escape(arr);
break;
}
case Bytecodes::_aastore:
{
set_global_escape(state.apop());
state.spop();
ArgumentMap arr = state.apop();
break;
}
case Bytecodes::_pop:
state.raw_pop();
break;
case Bytecodes::_pop2:
state.raw_pop();
state.raw_pop();
break;
case Bytecodes::_dup:
{ ArgumentMap w1 = state.raw_pop();
state.raw_push(w1);
state.raw_push(w1);
}
break;
case Bytecodes::_dup_x1:
{ ArgumentMap w1 = state.raw_pop();
ArgumentMap w2 = state.raw_pop();
state.raw_push(w1);
state.raw_push(w2);
state.raw_push(w1);
}
break;
case Bytecodes::_dup_x2:
{ ArgumentMap w1 = state.raw_pop();
ArgumentMap w2 = state.raw_pop();
ArgumentMap w3 = state.raw_pop();
state.raw_push(w1);
state.raw_push(w3);
state.raw_push(w2);
state.raw_push(w1);
}
break;
case Bytecodes::_dup2:
{ ArgumentMap w1 = state.raw_pop();
ArgumentMap w2 = state.raw_pop();
state.raw_push(w2);
state.raw_push(w1);
state.raw_push(w2);
state.raw_push(w1);
}
break;
case Bytecodes::_dup2_x1:
{ ArgumentMap w1 = state.raw_pop();
ArgumentMap w2 = state.raw_pop();
ArgumentMap w3 = state.raw_pop();
state.raw_push(w2);
state.raw_push(w1);
state.raw_push(w3);
state.raw_push(w2);
state.raw_push(w1);
}
break;
case Bytecodes::_dup2_x2:
{ ArgumentMap w1 = state.raw_pop();
ArgumentMap w2 = state.raw_pop();
ArgumentMap w3 = state.raw_pop();
ArgumentMap w4 = state.raw_pop();
state.raw_push(w2);
state.raw_push(w1);
state.raw_push(w4);
state.raw_push(w3);
state.raw_push(w2);
state.raw_push(w1);
}
break;
case Bytecodes::_swap:
{ ArgumentMap w1 = state.raw_pop();
ArgumentMap w2 = state.raw_pop();
state.raw_push(w1);
state.raw_push(w2);
}
break;
case Bytecodes::_iadd:
case Bytecodes::_fadd:
case Bytecodes::_isub:
case Bytecodes::_fsub:
case Bytecodes::_imul:
case Bytecodes::_fmul:
case Bytecodes::_idiv:
case Bytecodes::_fdiv:
case Bytecodes::_irem:
case Bytecodes::_frem:
case Bytecodes::_iand:
case Bytecodes::_ior:
case Bytecodes::_ixor:
state.spop();
state.spop();
state.spush();
break;
case Bytecodes::_ladd:
case Bytecodes::_dadd:
case Bytecodes::_lsub:
case Bytecodes::_dsub:
case Bytecodes::_lmul:
case Bytecodes::_dmul:
case Bytecodes::_ldiv:
case Bytecodes::_ddiv:
case Bytecodes::_lrem:
case Bytecodes::_drem:
case Bytecodes::_land:
case Bytecodes::_lor:
case Bytecodes::_lxor:
state.lpop();
state.lpop();
state.lpush();
break;
case Bytecodes::_ishl:
case Bytecodes::_ishr:
case Bytecodes::_iushr:
state.spop();
state.spop();
state.spush();
break;
case Bytecodes::_lshl:
case Bytecodes::_lshr:
case Bytecodes::_lushr:
state.spop();
state.lpop();
state.lpush();
break;
case Bytecodes::_ineg:
case Bytecodes::_fneg:
state.spop();
state.spush();
break;
case Bytecodes::_lneg:
case Bytecodes::_dneg:
state.lpop();
state.lpush();
break;
case Bytecodes::_iinc:
break;
case Bytecodes::_i2l:
case Bytecodes::_i2d:
case Bytecodes::_f2l:
case Bytecodes::_f2d:
state.spop();
state.lpush();
break;
case Bytecodes::_i2f:
case Bytecodes::_f2i:
state.spop();
state.spush();
break;
case Bytecodes::_l2i:
case Bytecodes::_l2f:
case Bytecodes::_d2i:
case Bytecodes::_d2f:
state.lpop();
state.spush();
break;
case Bytecodes::_l2d:
case Bytecodes::_d2l:
state.lpop();
state.lpush();
break;
case Bytecodes::_i2b:
case Bytecodes::_i2c:
case Bytecodes::_i2s:
state.spop();
state.spush();
break;
case Bytecodes::_lcmp:
case Bytecodes::_dcmpl:
case Bytecodes::_dcmpg:
state.lpop();
state.lpop();
state.spush();
break;
case Bytecodes::_fcmpl:
case Bytecodes::_fcmpg:
state.spop();
state.spop();
state.spush();
break;
case Bytecodes::_ifeq:
case Bytecodes::_ifne:
case Bytecodes::_iflt:
case Bytecodes::_ifge:
case Bytecodes::_ifgt:
case Bytecodes::_ifle:
{
state.spop();
int dest_bci = s.get_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
successors.push(_methodBlocks->block_containing(dest_bci));
break;
}
case Bytecodes::_if_icmpeq:
case Bytecodes::_if_icmpne:
case Bytecodes::_if_icmplt:
case Bytecodes::_if_icmpge:
case Bytecodes::_if_icmpgt:
case Bytecodes::_if_icmple:
{
state.spop();
state.spop();
int dest_bci = s.get_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
successors.push(_methodBlocks->block_containing(dest_bci));
break;
}
case Bytecodes::_if_acmpeq:
case Bytecodes::_if_acmpne:
{
set_method_escape(state.apop());
set_method_escape(state.apop());
int dest_bci = s.get_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
successors.push(_methodBlocks->block_containing(dest_bci));
break;
}
case Bytecodes::_goto:
{
int dest_bci = s.get_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
successors.push(_methodBlocks->block_containing(dest_bci));
fall_through = false;
break;
}
case Bytecodes::_jsr:
{
int dest_bci = s.get_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
state.apush(empty_map);
successors.push(_methodBlocks->block_containing(dest_bci));
fall_through = false;
break;
}
case Bytecodes::_ret:
// we don't track the destination of a "ret" instruction
assert(s.next_bci() == limit_bci, "branch must end block");
fall_through = false;
break;
case Bytecodes::_return:
assert(s.next_bci() == limit_bci, "return must end block");
fall_through = false;
break;
case Bytecodes::_tableswitch:
{
state.spop();
Bytecode_tableswitch* switch_ = Bytecode_tableswitch_at(s.cur_bcp());
int len = switch_->length();
int dest_bci;
for (int i = 0; i < len; i++) {
dest_bci = s.cur_bci() + switch_->dest_offset_at(i);
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
successors.push(_methodBlocks->block_containing(dest_bci));
}
dest_bci = s.cur_bci() + switch_->default_offset();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
successors.push(_methodBlocks->block_containing(dest_bci));
assert(s.next_bci() == limit_bci, "branch must end block");
fall_through = false;
break;
}
case Bytecodes::_lookupswitch:
{
state.spop();
Bytecode_lookupswitch* switch_ = Bytecode_lookupswitch_at(s.cur_bcp());
int len = switch_->number_of_pairs();
int dest_bci;
for (int i = 0; i < len; i++) {
dest_bci = s.cur_bci() + switch_->pair_at(i)->offset();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
successors.push(_methodBlocks->block_containing(dest_bci));
}
dest_bci = s.cur_bci() + switch_->default_offset();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
successors.push(_methodBlocks->block_containing(dest_bci));
fall_through = false;
break;
}
case Bytecodes::_ireturn:
case Bytecodes::_freturn:
state.spop();
fall_through = false;
break;
case Bytecodes::_lreturn:
case Bytecodes::_dreturn:
state.lpop();
fall_through = false;
break;
case Bytecodes::_areturn:
set_returned(state.apop());
fall_through = false;
break;
case Bytecodes::_getstatic:
case Bytecodes::_getfield:
{ bool will_link;
ciField* field = s.get_field(will_link);
BasicType field_type = field->type()->basic_type();
if (s.cur_bc() != Bytecodes::_getstatic) {
set_method_escape(state.apop());
}
if (field_type == T_OBJECT || field_type == T_ARRAY) {
state.apush(unknown_obj);
} else if (type2size[field_type] == 1) {
state.spush();
} else {
state.lpush();
}
}
break;
case Bytecodes::_putstatic:
case Bytecodes::_putfield:
{ bool will_link;
ciField* field = s.get_field(will_link);
BasicType field_type = field->type()->basic_type();
if (field_type == T_OBJECT || field_type == T_ARRAY) {
set_global_escape(state.apop());
} else if (type2size[field_type] == 1) {
state.spop();
} else {
state.lpop();
}
if (s.cur_bc() != Bytecodes::_putstatic) {
ArgumentMap p = state.apop();
set_method_escape(p);
}
}
break;
case Bytecodes::_invokevirtual:
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
case Bytecodes::_invokeinterface:
{ bool will_link;
ciMethod* target = s.get_method(will_link);
ciKlass* holder = s.get_declared_method_holder();
invoke(state, s.cur_bc(), target, holder);
ciType* return_type = target->return_type();
if (!return_type->is_primitive_type()) {
state.apush(unknown_obj);
} else if (return_type->is_one_word()) {
state.spush();
} else if (return_type->is_two_word()) {
state.lpush();
}
}
break;
case Bytecodes::_xxxunusedxxx:
ShouldNotReachHere();
break;
case Bytecodes::_new:
state.apush(allocated_obj);
break;
case Bytecodes::_newarray:
case Bytecodes::_anewarray:
state.spop();
state.apush(allocated_obj);
break;
case Bytecodes::_multianewarray:
{ int i = s.cur_bcp()[3];
while (i-- > 0) state.spop();
state.apush(allocated_obj);
}
break;
case Bytecodes::_arraylength:
set_method_escape(state.apop());
state.spush();
break;
case Bytecodes::_athrow:
set_global_escape(state.apop());
fall_through = false;
break;
case Bytecodes::_checkcast:
{ ArgumentMap obj = state.apop();
set_method_escape(obj);
state.apush(obj);
}
break;
case Bytecodes::_instanceof:
set_method_escape(state.apop());
state.spush();
break;
case Bytecodes::_monitorenter:
case Bytecodes::_monitorexit:
state.apop();
break;
case Bytecodes::_wide:
ShouldNotReachHere();
break;
case Bytecodes::_ifnull:
case Bytecodes::_ifnonnull:
{
set_method_escape(state.apop());
int dest_bci = s.get_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
successors.push(_methodBlocks->block_containing(dest_bci));
break;
}
case Bytecodes::_goto_w:
{
int dest_bci = s.get_far_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
successors.push(_methodBlocks->block_containing(dest_bci));
fall_through = false;
break;
}
case Bytecodes::_jsr_w:
{
int dest_bci = s.get_far_dest();
assert(_methodBlocks->is_block_start(dest_bci), "branch destination must start a block");
assert(s.next_bci() == limit_bci, "branch must end block");
state.apush(empty_map);
successors.push(_methodBlocks->block_containing(dest_bci));
fall_through = false;
break;
}
case Bytecodes::_breakpoint:
break;
default:
ShouldNotReachHere();
break;
}
}
if (fall_through) {
int fall_through_bci = s.cur_bci();
if (fall_through_bci < _method->code_size()) {
assert(_methodBlocks->is_block_start(fall_through_bci), "must fall through to block start.");
successors.push(_methodBlocks->block_containing(fall_through_bci));
}
}
}
MethodLiveness::MethodLiveness(Arena* arena, ciMethod* method)
#ifdef COMPILER1
: _bci_block_start((uintptr_t*)arena->Amalloc((method->code_size() >> LogBitsPerByte) + 1), method->code_size())
#endif
{
_arena = arena;
_method = method;
_bit_map_size_bits = method->max_locals();
_bit_map_size_words = (_bit_map_size_bits / sizeof(unsigned int)) + 1;
#ifdef COMPILER1
_bci_block_start.clear();
#endif
}
void MethodLiveness::compute_liveness() {
#ifndef PRODUCT
if (TraceLivenessGen) {
tty->print_cr("################################################################");
tty->print("# Computing liveness information for ");
method()->print_short_name();
}
if (TimeLivenessAnalysis) _time_total.start();
#endif
{
TraceTime buildGraph(NULL, &_time_build_graph, TimeLivenessAnalysis);
init_basic_blocks();
}
{
TraceTime genKill(NULL, &_time_gen_kill, TimeLivenessAnalysis);
init_gen_kill();
}
{
TraceTime flow(NULL, &_time_flow, TimeLivenessAnalysis);
propagate_liveness();
}
#ifndef PRODUCT
if (TimeLivenessAnalysis) _time_total.stop();
if (TimeLivenessAnalysis) {
// Collect statistics
_total_bytes += method()->code_size();
_total_methods++;
int num_blocks = _block_count;
_total_blocks += num_blocks;
_max_method_blocks = MAX2(num_blocks,_max_method_blocks);
for (int i=0; i<num_blocks; i++) {
BasicBlock *block = _block_list[i];
int numEdges = block->_normal_predecessors->length();
int numExcEdges = block->_exception_predecessors->length();
_total_edges += numEdges;
_total_exc_edges += numExcEdges;
_max_block_edges = MAX2(numEdges,_max_block_edges);
_max_block_exc_edges = MAX2(numExcEdges,_max_block_exc_edges);
}
int numLocals = _bit_map_size_bits;
_total_method_locals += numLocals;
_max_method_locals = MAX2(numLocals,_max_method_locals);
}
#endif
}
void MethodLiveness::init_basic_blocks() {
bool bailout = false;
int method_len = method()->code_size();
ciMethodBlocks *mblocks = method()->get_method_blocks();
// Create an array to store the bci->BasicBlock mapping.
_block_map = new (arena()) GrowableArray<BasicBlock*>(arena(), method_len, method_len, NULL);
_block_count = mblocks->num_blocks();
_block_list = (BasicBlock **) arena()->Amalloc(sizeof(BasicBlock *) * _block_count);
// Used for patching up jsr/ret control flow.
GrowableArray<BasicBlock*>* jsr_exit_list = new GrowableArray<BasicBlock*>(5);
GrowableArray<BasicBlock*>* ret_list = new GrowableArray<BasicBlock*>(5);
// generate our block list from ciMethodBlocks
for (int blk = 0; blk < _block_count; blk++) {
ciBlock *cib = mblocks->block(blk);
int start_bci = cib->start_bci();
_block_list[blk] = new (arena()) BasicBlock(this, start_bci, cib->limit_bci());
_block_map->at_put(start_bci, _block_list[blk]);
#ifdef COMPILER1
// mark all bcis where a new basic block starts
_bci_block_start.set_bit(start_bci);
#endif // COMPILER1
}
// fill in the predecessors of blocks
ciBytecodeStream bytes(method());
for (int blk = 0; blk < _block_count; blk++) {
BasicBlock *current_block = _block_list[blk];
int bci = mblocks->block(blk)->control_bci();
if (bci == ciBlock::fall_through_bci) {
int limit = current_block->limit_bci();
if (limit < method_len) {
BasicBlock *next = _block_map->at(limit);
assert( next != NULL, "must be a block immediately following this one.");
next->add_normal_predecessor(current_block);
}
continue;
}
bytes.reset_to_bci(bci);
Bytecodes::Code code = bytes.next();
BasicBlock *dest;
// Now we need to interpret the instruction's effect
// on control flow.
assert (current_block != NULL, "we must have a current block");
switch (code) {
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:
// Two way branch. Set predecessors at each destination.
dest = _block_map->at(bytes.next_bci());
assert(dest != NULL, "must be a block immediately following this one.");
dest->add_normal_predecessor(current_block);
dest = _block_map->at(bytes.get_dest());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
break;
case Bytecodes::_goto:
dest = _block_map->at(bytes.get_dest());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
break;
case Bytecodes::_goto_w:
dest = _block_map->at(bytes.get_far_dest());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
break;
case Bytecodes::_tableswitch:
{
Bytecode_tableswitch *tableswitch =
Bytecode_tableswitch_at(bytes.cur_bcp());
int len = tableswitch->length();
dest = _block_map->at(bci + tableswitch->default_offset());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
while (--len >= 0) {
dest = _block_map->at(bci + tableswitch->dest_offset_at(len));
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
}
break;
}
case Bytecodes::_lookupswitch:
{
Bytecode_lookupswitch *lookupswitch =
Bytecode_lookupswitch_at(bytes.cur_bcp());
int npairs = lookupswitch->number_of_pairs();
dest = _block_map->at(bci + lookupswitch->default_offset());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
while(--npairs >= 0) {
LookupswitchPair *pair = lookupswitch->pair_at(npairs);
dest = _block_map->at( bci + pair->offset());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
}
break;
}
case Bytecodes::_jsr:
{
assert(bytes.is_wide()==false, "sanity check");
dest = _block_map->at(bytes.get_dest());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
BasicBlock *jsrExit = _block_map->at(current_block->limit_bci());
assert(jsrExit != NULL, "jsr return bci must start a block.");
jsr_exit_list->append(jsrExit);
break;
}
case Bytecodes::_jsr_w:
{
dest = _block_map->at(bytes.get_far_dest());
assert(dest != NULL, "branch desination must start a block.");
dest->add_normal_predecessor(current_block);
BasicBlock *jsrExit = _block_map->at(current_block->limit_bci());
assert(jsrExit != NULL, "jsr return bci must start a block.");
jsr_exit_list->append(jsrExit);
break;
}
case Bytecodes::_wide:
assert(false, "wide opcodes should not be seen here");
break;
case Bytecodes::_athrow:
case Bytecodes::_ireturn:
case Bytecodes::_lreturn:
case Bytecodes::_freturn:
case Bytecodes::_dreturn:
case Bytecodes::_areturn:
case Bytecodes::_return:
// These opcodes are not the normal predecessors of any other opcodes.
break;
case Bytecodes::_ret:
// We will patch up jsr/rets in a subsequent pass.
ret_list->append(current_block);
break;
case Bytecodes::_breakpoint:
// Bail out of there are breakpoints in here.
bailout = true;
break;
default:
// Do nothing.
break;
}
}
// Patch up the jsr/ret's. We conservatively assume that any ret
// can return to any jsr site.
int ret_list_len = ret_list->length();
int jsr_exit_list_len = jsr_exit_list->length();
if (ret_list_len > 0 && jsr_exit_list_len > 0) {
for (int i = jsr_exit_list_len - 1; i >= 0; i--) {
BasicBlock *jsrExit = jsr_exit_list->at(i);
for (int i = ret_list_len - 1; i >= 0; i--) {
jsrExit->add_normal_predecessor(ret_list->at(i));
}
}
}
// Compute exception edges.
for (int b=_block_count-1; b >= 0; b--) {
BasicBlock *block = _block_list[b];
int block_start = block->start_bci();
int block_limit = block->limit_bci();
ciExceptionHandlerStream handlers(method());
for (; !handlers.is_done(); handlers.next()) {
ciExceptionHandler* handler = handlers.handler();
int start = handler->start();
int limit = handler->limit();
int handler_bci = handler->handler_bci();
int intersect_start = MAX2(block_start, start);
int intersect_limit = MIN2(block_limit, limit);
if (intersect_start < intersect_limit) {
// The catch range has a nonempty intersection with this
// basic block. That means this basic block can be an
// exceptional predecessor.
_block_map->at(handler_bci)->add_exception_predecessor(block);
if (handler->is_catch_all()) {
// This is a catch-all block.
if (intersect_start == block_start && intersect_limit == block_limit) {
// The basic block is entirely contained in this catch-all block.
// Skip the rest of the exception handlers -- they can never be
// reached in execution.
break;
}
}
}
}
}
}
// Rewrites a method given the index_map information
void Rewriter::scan_method(methodOop method) {
int nof_jsrs = 0;
bool has_monitor_bytecodes = false;
{
// We cannot tolerate a GC in this block, because we've
// cached the bytecodes in 'code_base'. If the methodOop
// moves, the bytecodes will also move.
No_Safepoint_Verifier nsv;
Bytecodes::Code c;
// Bytecodes and their length
const address code_base = method->code_base();
const int code_length = method->code_size();
int bc_length;
for (int bci = 0; bci < code_length; bci += bc_length) {
address bcp = code_base + bci;
int prefix_length = 0;
c = (Bytecodes::Code)(*bcp);
// Since we have the code, see if we can get the length
// directly. Some more complicated bytecodes will report
// a length of zero, meaning we need to make another method
// call to calculate the length.
bc_length = Bytecodes::length_for(c);
if (bc_length == 0) {
bc_length = Bytecodes::length_at(bcp);
// length_at will put us at the bytecode after the one modified
// by 'wide'. We don't currently examine any of the bytecodes
// modified by wide, but in case we do in the future...
if (c == Bytecodes::_wide) {
prefix_length = 1;
c = (Bytecodes::Code)bcp[1];
}
}
assert(bc_length != 0, "impossible bytecode length");
switch (c) {
case Bytecodes::_lookupswitch : {
#ifndef CC_INTERP
Bytecode_lookupswitch* bc = Bytecode_lookupswitch_at(bcp);
bc->set_code(
bc->number_of_pairs() < BinarySwitchThreshold
? Bytecodes::_fast_linearswitch
: Bytecodes::_fast_binaryswitch
);
#endif
break;
}
case Bytecodes::_getstatic : // fall through
case Bytecodes::_putstatic : // fall through
case Bytecodes::_getfield : // fall through
case Bytecodes::_putfield : // fall through
case Bytecodes::_invokevirtual : // fall through
case Bytecodes::_invokespecial : // fall through
case Bytecodes::_invokestatic :
case Bytecodes::_invokeinterface:
rewrite_member_reference(bcp, prefix_length+1);
break;
case Bytecodes::_invokedynamic:
rewrite_invokedynamic(bcp, prefix_length+1, int(sizeof"@@@@DELETE ME"));
break;
case Bytecodes::_jsr : // fall through
case Bytecodes::_jsr_w : nof_jsrs++; break;
case Bytecodes::_monitorenter : // fall through
case Bytecodes::_monitorexit : has_monitor_bytecodes = true; break;
}
}
}
// Update access flags
if (has_monitor_bytecodes) {
method->set_has_monitor_bytecodes();
}
// The present of a jsr bytecode implies that the method might potentially
// have to be rewritten, so we run the oopMapGenerator on the method
if (nof_jsrs > 0) {
method->set_has_jsrs();
// Second pass will revisit this method.
assert(method->has_jsrs(), "");
}
}
void MethodLiveness::init_basic_blocks() {
bool bailout = false;
int method_len = method()->code_size();
// Create an array to store the bci->BasicBlock mapping.
_block_map = new (arena()) GrowableArray<BasicBlock*>(arena(), method_len, method_len, NULL);
_block_list = new (arena()) GrowableArray<BasicBlock*>(arena(), 128, 0, NULL);
// Used for patching up jsr/ret control flow.
GrowableArray<BasicBlock*>* jsr_exit_list = new GrowableArray<BasicBlock*>(5);
GrowableArray<BasicBlock*>* ret_list = new GrowableArray<BasicBlock*>(5);
// Make blocks begin at all exception handling instructions.
{
ciExceptionHandlerStream handlers(method());
for (; !handlers.is_done(); handlers.next()) {
ciExceptionHandler* handler = handlers.handler();
int handler_bci = handler->handler_bci();
make_block_at(handler_bci, NULL);
}
}
BasicBlock *current_block = NULL;
ciByteCodeStream bytes(method());
Bytecodes::Code code;
while ((code = bytes.next()) != ciByteCodeStream::EOBC && !bailout) {
int bci = bytes.cur_bci();
// Should we start a new block here?
BasicBlock *other = _block_map->at(bci);
if (other == NULL) {
// This bci has not yet been marked as the start of
// a new basic block. If current_block is NULL, then
// we are beginning a new block. Otherwise, we continue
// with the old block.
if (current_block == NULL) {
// Make a new block with no predecessors.
current_block = make_block_at(bci, NULL);
}
// Mark this index as belonging to the current block.
_block_map->at_put(bci, current_block);
} else {
// This bci has been marked as the start of a new basic
// block.
if (current_block != NULL) {
other->add_normal_predecessor(current_block);
current_block->set_limit_bci(bci);
}
current_block = other;
}
// Now we need to interpret the instruction's effect
// on control flow.
switch (code) {
assert (current_block != NULL, "we must have a current block");
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:
// Two way branch. Make a new block at each destination.
make_block_at(bytes.next_bci(), current_block);
make_block_at(bytes.get_dest(), current_block);
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
case Bytecodes::_goto:
make_block_at(bytes.get_dest(), current_block);
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
case Bytecodes::_goto_w:
make_block_at(bytes.get_far_dest(), current_block);
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
case Bytecodes::_tableswitch:
{
Bytecode_tableswitch *tableswitch =
Bytecode_tableswitch_at(bytes.cur_bcp());
int len = tableswitch->length();
make_block_at(bci + tableswitch->default_offset(), current_block);
while (--len >= 0) {
make_block_at(bci + tableswitch->dest_offset_at(len),
current_block);
}
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
}
// Some synthetic opcodes here
case Bytecodes::_fast_linearswitch:
case Bytecodes::_fast_binaryswitch:
case Bytecodes::_lookupswitch:
{
Bytecode_lookupswitch *lookupswitch =
Bytecode_lookupswitch_at(bytes.cur_bcp());
int npairs = lookupswitch->number_of_pairs();
make_block_at(bci + lookupswitch->default_offset(), current_block);
while(--npairs >= 0) {
LookupswitchPair *pair = lookupswitch->pair_at(npairs);
make_block_at(bci + pair->offset(), current_block);
}
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
}
case Bytecodes::_jsr:
{
assert(bytes.is_wide()==false, "sanity check");
make_block_at(bytes.get_dest(), current_block);
BasicBlock *jsrExit = make_block_at(bci + 3, NULL);
jsr_exit_list->append(jsrExit);
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
}
case Bytecodes::_jsr_w:
{
make_block_at(bytes.get_far_dest(), current_block);
BasicBlock *jsrExit = make_block_at(bci + 5, NULL);
jsr_exit_list->append(jsrExit);
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
}
case Bytecodes::_wide:
assert(false, "wide opcodes should not be seen here");
break;
case Bytecodes::_athrow:
case Bytecodes::_ireturn:
case Bytecodes::_lreturn:
case Bytecodes::_freturn:
case Bytecodes::_dreturn:
case Bytecodes::_areturn:
case Bytecodes::_return:
// We are done with the current block. These opcodes are
// not the normal predecessors of any other opcodes.
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
case Bytecodes::_ret:
// We will patch up jsr/rets in a subsequent pass.
ret_list->append(current_block);
current_block->set_limit_bci(bytes.next_bci());
current_block = NULL;
break;
case Bytecodes::_breakpoint:
// Bail out of there are breakpoints in here.
bailout = true;
break;
default:
// Do nothing.
break;
}
}
if (bailout) {
_block_list->clear();
_block_map = NULL; // do not use this field now!
return;
}
// Patch up the jsr/ret's. We conservatively assume that any ret
// can return to any jsr site.
int ret_list_len = ret_list->length();
int jsr_exit_list_len = jsr_exit_list->length();
if (ret_list_len > 0 && jsr_exit_list_len > 0) {
for (int i = jsr_exit_list_len - 1; i >= 0; i--) {
BasicBlock *jsrExit = jsr_exit_list->at(i);
for (int i = ret_list_len - 1; i >= 0; i--) {
jsrExit->add_normal_predecessor(ret_list->at(i));
}
}
}
// Compute exception edges.
for (int b=_block_list->length()-1; b >= 0; b--) {
BasicBlock *block = _block_list->at(b);
int block_start = block->start_bci();
int block_limit = block->limit_bci();
ciExceptionHandlerStream handlers(method());
for (; !handlers.is_done(); handlers.next()) {
ciExceptionHandler* handler = handlers.handler();
int start = handler->start();
int limit = handler->limit();
int handler_bci = handler->handler_bci();
int intersect_start = MAX2(block_start, start);
int intersect_limit = MIN2(block_limit, limit);
if (intersect_start < intersect_limit) {
// The catch range has a nonempty intersection with this
// basic block. That means this basic block can be an
// exceptional predecessor.
_block_map->at(handler_bci)->add_exception_predecessor(block);
if (handler->is_catch_all()) {
// This is a catch-all block.
if (intersect_start == block_start && intersect_limit == block_limit) {
// The basic block is entirely contained in this catch-all block.
// Skip the rest of the exception handlers -- they can never be
// reached in execution.
break;
}
}
}
}
}
}
void ciMethodBlocks::do_analysis() {
ciBytecodeStream s(_method);
ciBlock *cur_block = block_containing(0);
int limit_bci = _method->code_size();
while (s.next() != ciBytecodeStream::EOBC()) {
int bci = s.cur_bci();
// Determine if a new block has been made at the current bci. If
// this block differs from our current range, switch to the new
// one and end the old one.
assert(cur_block != NULL, "must always have a current block");
ciBlock *new_block = block_containing(bci);
if (new_block == NULL || new_block == cur_block) {
// We have not marked this bci as the start of a new block.
// Keep interpreting the current_range.
_bci_to_block[bci] = cur_block;
} else {
cur_block->set_limit_bci(bci);
cur_block = new_block;
}
switch (s.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 :
{
cur_block->set_control_bci(bci);
ciBlock *fall_through = make_block_at(s.next_bci());
int dest_bci = s.get_dest();
ciBlock *dest = make_block_at(dest_bci);
break;
}
case Bytecodes::_goto :
{
cur_block->set_control_bci(bci);
if (s.next_bci() < limit_bci) {
(void) make_block_at(s.next_bci());
}
int dest_bci = s.get_dest();
ciBlock *dest = make_block_at(dest_bci);
break;
}
case Bytecodes::_jsr :
{
cur_block->set_control_bci(bci);
ciBlock *ret = make_block_at(s.next_bci());
int dest_bci = s.get_dest();
ciBlock *dest = make_block_at(dest_bci);
break;
}
case Bytecodes::_tableswitch :
{
cur_block->set_control_bci(bci);
Bytecode_tableswitch* switch_ = Bytecode_tableswitch_at(s.cur_bcp());
int len = switch_->length();
ciBlock *dest;
int dest_bci;
for (int i = 0; i < len; i++) {
dest_bci = s.cur_bci() + switch_->dest_offset_at(i);
dest = make_block_at(dest_bci);
}
dest_bci = s.cur_bci() + switch_->default_offset();
make_block_at(dest_bci);
if (s.next_bci() < limit_bci) {
dest = make_block_at(s.next_bci());
}
}
break;
case Bytecodes::_lookupswitch:
{
cur_block->set_control_bci(bci);
Bytecode_lookupswitch* switch_ = Bytecode_lookupswitch_at(s.cur_bcp());
int len = switch_->number_of_pairs();
ciBlock *dest;
int dest_bci;
for (int i = 0; i < len; i++) {
dest_bci = s.cur_bci() + switch_->pair_at(i)->offset();
dest = make_block_at(dest_bci);
}
dest_bci = s.cur_bci() + switch_->default_offset();
dest = make_block_at(dest_bci);
if (s.next_bci() < limit_bci) {
dest = make_block_at(s.next_bci());
}
}
break;
case Bytecodes::_goto_w :
{
cur_block->set_control_bci(bci);
if (s.next_bci() < limit_bci) {
(void) make_block_at(s.next_bci());
}
int dest_bci = s.get_far_dest();
ciBlock *dest = make_block_at(dest_bci);
break;
}
case Bytecodes::_jsr_w :
{
cur_block->set_control_bci(bci);
ciBlock *ret = make_block_at(s.next_bci());
int dest_bci = s.get_far_dest();
ciBlock *dest = make_block_at(dest_bci);
break;
}
case Bytecodes::_athrow :
cur_block->set_may_throw();
// fall-through
case Bytecodes::_ret :
case Bytecodes::_ireturn :
case Bytecodes::_lreturn :
case Bytecodes::_freturn :
case Bytecodes::_dreturn :
case Bytecodes::_areturn :
case Bytecodes::_return :
cur_block->set_control_bci(bci);
if (s.next_bci() < limit_bci) {
(void) make_block_at(s.next_bci());
}
break;
}
}
// End the last block
cur_block->set_limit_bci(limit_bci);
}