8031752: Failed speculative optimizations should be reattempted when root of compilation is different

Support for speculative traps that keep track of the root of the compilation in which a trap occurs.

Reviewed-by: kvn, twisti
This commit is contained in:
Roland Westrelin 2014-02-25 18:16:24 +01:00
parent 532b570e81
commit 493557fc90
16 changed files with 772 additions and 164 deletions

View file

@ -80,8 +80,42 @@ ProfileData::ProfileData() {
_data = NULL;
}
char* ProfileData::print_data_on_helper(const MethodData* md) const {
DataLayout* dp = md->extra_data_base();
DataLayout* end = md->extra_data_limit();
stringStream ss;
for (;; dp = MethodData::next_extra(dp)) {
assert(dp < end, "moved past end of extra data");
switch(dp->tag()) {
case DataLayout::speculative_trap_data_tag:
if (dp->bci() == bci()) {
SpeculativeTrapData* data = new SpeculativeTrapData(dp);
int trap = data->trap_state();
char buf[100];
ss.print("trap/");
data->method()->print_short_name(&ss);
ss.print("(%s) ", Deoptimization::format_trap_state(buf, sizeof(buf), trap));
}
break;
case DataLayout::bit_data_tag:
break;
case DataLayout::no_tag:
case DataLayout::arg_info_data_tag:
return ss.as_string();
break;
default:
fatal(err_msg("unexpected tag %d", dp->tag()));
}
}
return NULL;
}
void ProfileData::print_data_on(outputStream* st, const MethodData* md) const {
print_data_on(st, print_data_on_helper(md));
}
#ifndef PRODUCT
void ProfileData::print_shared(outputStream* st, const char* name) const {
void ProfileData::print_shared(outputStream* st, const char* name, const char* extra) const {
st->print("bci: %d", bci());
st->fill_to(tab_width_one);
st->print("%s", name);
@ -91,9 +125,13 @@ void ProfileData::print_shared(outputStream* st, const char* name) const {
char buf[100];
st->print("trap(%s) ", Deoptimization::format_trap_state(buf, sizeof(buf), trap));
}
if (extra != NULL) {
st->print(extra);
}
int flags = data()->flags();
if (flags != 0)
if (flags != 0) {
st->print("flags(%d) ", flags);
}
}
void ProfileData::tab(outputStream* st, bool first) const {
@ -109,8 +147,8 @@ void ProfileData::tab(outputStream* st, bool first) const {
#ifndef PRODUCT
void BitData::print_data_on(outputStream* st) const {
print_shared(st, "BitData");
void BitData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "BitData", extra);
}
#endif // !PRODUCT
@ -120,8 +158,8 @@ void BitData::print_data_on(outputStream* st) const {
// A CounterData corresponds to a simple counter.
#ifndef PRODUCT
void CounterData::print_data_on(outputStream* st) const {
print_shared(st, "CounterData");
void CounterData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "CounterData", extra);
st->print_cr("count(%u)", count());
}
#endif // !PRODUCT
@ -150,8 +188,8 @@ void JumpData::post_initialize(BytecodeStream* stream, MethodData* mdo) {
}
#ifndef PRODUCT
void JumpData::print_data_on(outputStream* st) const {
print_shared(st, "JumpData");
void JumpData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "JumpData", extra);
st->print_cr("taken(%u) displacement(%d)", taken(), displacement());
}
#endif // !PRODUCT
@ -332,8 +370,8 @@ void ReturnTypeEntry::print_data_on(outputStream* st) const {
st->cr();
}
void CallTypeData::print_data_on(outputStream* st) const {
CounterData::print_data_on(st);
void CallTypeData::print_data_on(outputStream* st, const char* extra) const {
CounterData::print_data_on(st, extra);
if (has_arguments()) {
tab(st, true);
st->print("argument types");
@ -346,8 +384,8 @@ void CallTypeData::print_data_on(outputStream* st) const {
}
}
void VirtualCallTypeData::print_data_on(outputStream* st) const {
VirtualCallData::print_data_on(st);
void VirtualCallTypeData::print_data_on(outputStream* st, const char* extra) const {
VirtualCallData::print_data_on(st, extra);
if (has_arguments()) {
tab(st, true);
st->print("argument types");
@ -400,12 +438,12 @@ void ReceiverTypeData::print_receiver_data_on(outputStream* st) const {
}
}
}
void ReceiverTypeData::print_data_on(outputStream* st) const {
print_shared(st, "ReceiverTypeData");
void ReceiverTypeData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "ReceiverTypeData", extra);
print_receiver_data_on(st);
}
void VirtualCallData::print_data_on(outputStream* st) const {
print_shared(st, "VirtualCallData");
void VirtualCallData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "VirtualCallData", extra);
print_receiver_data_on(st);
}
#endif // !PRODUCT
@ -461,8 +499,8 @@ DataLayout* RetData::advance(MethodData *md, int bci) {
#endif // CC_INTERP
#ifndef PRODUCT
void RetData::print_data_on(outputStream* st) const {
print_shared(st, "RetData");
void RetData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "RetData", extra);
uint row;
int entries = 0;
for (row = 0; row < row_limit(); row++) {
@ -496,8 +534,8 @@ void BranchData::post_initialize(BytecodeStream* stream, MethodData* mdo) {
}
#ifndef PRODUCT
void BranchData::print_data_on(outputStream* st) const {
print_shared(st, "BranchData");
void BranchData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "BranchData", extra);
st->print_cr("taken(%u) displacement(%d)",
taken(), displacement());
tab(st);
@ -570,8 +608,8 @@ void MultiBranchData::post_initialize(BytecodeStream* stream,
}
#ifndef PRODUCT
void MultiBranchData::print_data_on(outputStream* st) const {
print_shared(st, "MultiBranchData");
void MultiBranchData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "MultiBranchData", extra);
st->print_cr("default_count(%u) displacement(%d)",
default_count(), default_displacement());
int cases = number_of_cases();
@ -584,8 +622,8 @@ void MultiBranchData::print_data_on(outputStream* st) const {
#endif
#ifndef PRODUCT
void ArgInfoData::print_data_on(outputStream* st) const {
print_shared(st, "ArgInfoData");
void ArgInfoData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "ArgInfoData", extra);
int nargs = number_of_args();
for (int i = 0; i < nargs; i++) {
st->print(" 0x%x", arg_modified(i));
@ -616,10 +654,17 @@ bool ParametersTypeData::profiling_enabled() {
}
#ifndef PRODUCT
void ParametersTypeData::print_data_on(outputStream* st) const {
st->print("parameter types");
void ParametersTypeData::print_data_on(outputStream* st, const char* extra) const {
st->print("parameter types", extra);
_parameters.print_data_on(st);
}
void SpeculativeTrapData::print_data_on(outputStream* st, const char* extra) const {
print_shared(st, "SpeculativeTrapData", extra);
tab(st);
method()->print_short_name(st);
st->cr();
}
#endif
// ==================================================================
@ -745,7 +790,27 @@ int MethodData::compute_data_size(BytecodeStream* stream) {
return DataLayout::compute_size_in_bytes(cell_count);
}
int MethodData::compute_extra_data_count(int data_size, int empty_bc_count) {
bool MethodData::is_speculative_trap_bytecode(Bytecodes::Code code) {
// Bytecodes for which we may use speculation
switch (code) {
case Bytecodes::_checkcast:
case Bytecodes::_instanceof:
case Bytecodes::_aastore:
case Bytecodes::_invokevirtual:
case Bytecodes::_invokeinterface:
case Bytecodes::_if_acmpeq:
case Bytecodes::_if_acmpne:
case Bytecodes::_invokestatic:
#ifdef COMPILER2
return UseTypeSpeculation;
#endif
default:
return false;
}
return false;
}
int MethodData::compute_extra_data_count(int data_size, int empty_bc_count, bool needs_speculative_traps) {
if (ProfileTraps) {
// Assume that up to 3% of BCIs with no MDP will need to allocate one.
int extra_data_count = (uint)(empty_bc_count * 3) / 128 + 1;
@ -756,7 +821,18 @@ int MethodData::compute_extra_data_count(int data_size, int empty_bc_count) {
extra_data_count = one_percent_of_data;
if (extra_data_count > empty_bc_count)
extra_data_count = empty_bc_count; // no need for more
return extra_data_count;
// Make sure we have a minimum number of extra data slots to
// allocate SpeculativeTrapData entries. We would want to have one
// entry per compilation that inlines this method and for which
// some type speculation assumption fails. So the room we need for
// the SpeculativeTrapData entries doesn't directly depend on the
// size of the method. Because it's hard to estimate, we reserve
// space for an arbitrary number of entries.
int spec_data_count = (needs_speculative_traps ? SpecTrapLimitExtraEntries : 0) *
(SpeculativeTrapData::static_cell_count() + DataLayout::header_size_in_cells());
return MAX2(extra_data_count, spec_data_count);
} else {
return 0;
}
@ -769,15 +845,17 @@ int MethodData::compute_allocation_size_in_bytes(methodHandle method) {
BytecodeStream stream(method);
Bytecodes::Code c;
int empty_bc_count = 0; // number of bytecodes lacking data
bool needs_speculative_traps = false;
while ((c = stream.next()) >= 0) {
int size_in_bytes = compute_data_size(&stream);
data_size += size_in_bytes;
if (size_in_bytes == 0) empty_bc_count += 1;
needs_speculative_traps = needs_speculative_traps || is_speculative_trap_bytecode(c);
}
int object_size = in_bytes(data_offset()) + data_size;
// Add some extra DataLayout cells (at least one) to track stray traps.
int extra_data_count = compute_extra_data_count(data_size, empty_bc_count);
int extra_data_count = compute_extra_data_count(data_size, empty_bc_count, needs_speculative_traps);
object_size += extra_data_count * DataLayout::compute_size_in_bytes(0);
// Add a cell to record information about modified arguments.
@ -1009,18 +1087,23 @@ MethodData::MethodData(methodHandle method, int size, TRAPS) {
_data[0] = 0; // apparently not set below.
BytecodeStream stream(method);
Bytecodes::Code c;
bool needs_speculative_traps = false;
while ((c = stream.next()) >= 0) {
int size_in_bytes = initialize_data(&stream, data_size);
data_size += size_in_bytes;
if (size_in_bytes == 0) empty_bc_count += 1;
needs_speculative_traps = needs_speculative_traps || is_speculative_trap_bytecode(c);
}
_data_size = data_size;
int object_size = in_bytes(data_offset()) + data_size;
// Add some extra DataLayout cells (at least one) to track stray traps.
int extra_data_count = compute_extra_data_count(data_size, empty_bc_count);
int extra_data_count = compute_extra_data_count(data_size, empty_bc_count, needs_speculative_traps);
int extra_size = extra_data_count * DataLayout::compute_size_in_bytes(0);
// Let's zero the space for the extra data
Copy::zero_to_bytes(((address)_data) + data_size, extra_size);
// Add a cell to record information about modified arguments.
// Set up _args_modified array after traps cells so that
// the code for traps cells works.
@ -1032,17 +1115,17 @@ MethodData::MethodData(methodHandle method, int size, TRAPS) {
int arg_data_size = DataLayout::compute_size_in_bytes(arg_size+1);
object_size += extra_size + arg_data_size;
int args_cell = ParametersTypeData::compute_cell_count(method());
int parms_cell = ParametersTypeData::compute_cell_count(method());
// If we are profiling parameters, we reserver an area near the end
// of the MDO after the slots for bytecodes (because there's no bci
// for method entry so they don't fit with the framework for the
// profiling of bytecodes). We store the offset within the MDO of
// this area (or -1 if no parameter is profiled)
if (args_cell > 0) {
object_size += DataLayout::compute_size_in_bytes(args_cell);
if (parms_cell > 0) {
object_size += DataLayout::compute_size_in_bytes(parms_cell);
_parameters_type_data_di = data_size + extra_size + arg_data_size;
DataLayout *dp = data_layout_at(data_size + extra_size + arg_data_size);
dp->initialize(DataLayout::parameters_type_data_tag, 0, args_cell);
dp->initialize(DataLayout::parameters_type_data_tag, 0, parms_cell);
} else {
_parameters_type_data_di = -1;
}
@ -1133,39 +1216,113 @@ ProfileData* MethodData::bci_to_data(int bci) {
break;
}
}
return bci_to_extra_data(bci, false);
return bci_to_extra_data(bci, NULL, false);
}
// Translate a bci to its corresponding extra data, or NULL.
ProfileData* MethodData::bci_to_extra_data(int bci, bool create_if_missing) {
DataLayout* dp = extra_data_base();
DataLayout* end = extra_data_limit();
DataLayout* avail = NULL;
for (; dp < end; dp = next_extra(dp)) {
DataLayout* MethodData::next_extra(DataLayout* dp) {
int nb_cells = 0;
switch(dp->tag()) {
case DataLayout::bit_data_tag:
case DataLayout::no_tag:
nb_cells = BitData::static_cell_count();
break;
case DataLayout::speculative_trap_data_tag:
nb_cells = SpeculativeTrapData::static_cell_count();
break;
default:
fatal(err_msg("unexpected tag %d", dp->tag()));
}
return (DataLayout*)((address)dp + DataLayout::compute_size_in_bytes(nb_cells));
}
ProfileData* MethodData::bci_to_extra_data_helper(int bci, Method* m, DataLayout*& dp) {
DataLayout* end = extra_data_limit();
for (;; dp = next_extra(dp)) {
assert(dp < end, "moved past end of extra data");
// No need for "OrderAccess::load_acquire" ops,
// since the data structure is monotonic.
if (dp->tag() == DataLayout::no_tag) break;
if (dp->tag() == DataLayout::arg_info_data_tag) {
dp = end; // ArgInfoData is at the end of extra data section.
switch(dp->tag()) {
case DataLayout::no_tag:
return NULL;
case DataLayout::arg_info_data_tag:
dp = end;
return NULL; // ArgInfoData is at the end of extra data section.
case DataLayout::bit_data_tag:
if (m == NULL && dp->bci() == bci) {
return new BitData(dp);
}
break;
}
if (dp->bci() == bci) {
assert(dp->tag() == DataLayout::bit_data_tag, "sane");
return new BitData(dp);
case DataLayout::speculative_trap_data_tag:
if (m != NULL) {
SpeculativeTrapData* data = new SpeculativeTrapData(dp);
// data->method() may be null in case of a concurrent
// allocation. Assume it's for the same method and use that
// entry in that case.
if (dp->bci() == bci) {
if (data->method() == NULL) {
return NULL;
} else if (data->method() == m) {
return data;
}
}
}
break;
default:
fatal(err_msg("unexpected tag %d", dp->tag()));
}
}
if (create_if_missing && dp < end) {
// Allocate this one. There is no mutual exclusion,
// so two threads could allocate different BCIs to the
// same data layout. This means these extra data
// records, like most other MDO contents, must not be
// trusted too much.
DataLayout temp;
temp.initialize(DataLayout::bit_data_tag, bci, 0);
dp->release_set_header(temp.header());
assert(dp->tag() == DataLayout::bit_data_tag, "sane");
//NO: assert(dp->bci() == bci, "no concurrent allocation");
return new BitData(dp);
return NULL;
}
// Translate a bci to its corresponding extra data, or NULL.
ProfileData* MethodData::bci_to_extra_data(int bci, Method* m, bool create_if_missing) {
// This code assumes an entry for a SpeculativeTrapData is 2 cells
assert(2*DataLayout::compute_size_in_bytes(BitData::static_cell_count()) ==
DataLayout::compute_size_in_bytes(SpeculativeTrapData::static_cell_count()),
"code needs to be adjusted");
DataLayout* dp = extra_data_base();
DataLayout* end = extra_data_limit();
// Allocation in the extra data space has to be atomic because not
// all entries have the same size and non atomic concurrent
// allocation would result in a corrupted extra data space.
while (true) {
ProfileData* result = bci_to_extra_data_helper(bci, m, dp);
if (result != NULL) {
return result;
}
if (create_if_missing && dp < end) {
assert(dp->tag() == DataLayout::no_tag || (dp->tag() == DataLayout::speculative_trap_data_tag && m != NULL), "should be free");
assert(next_extra(dp)->tag() == DataLayout::no_tag || next_extra(dp)->tag() == DataLayout::arg_info_data_tag, "should be free or arg info");
u1 tag = m == NULL ? DataLayout::bit_data_tag : DataLayout::speculative_trap_data_tag;
// SpeculativeTrapData is 2 slots. Make sure we have room.
if (m != NULL && next_extra(dp)->tag() != DataLayout::no_tag) {
return NULL;
}
DataLayout temp;
temp.initialize(tag, bci, 0);
// May have been set concurrently
if (dp->header() != temp.header() && !dp->atomic_set_header(temp.header())) {
// Allocation failure because of concurrent allocation. Try
// again.
continue;
}
assert(dp->tag() == tag, "sane");
assert(dp->bci() == bci, "no concurrent allocation");
if (tag == DataLayout::bit_data_tag) {
return new BitData(dp);
} else {
// If being allocated concurrently, one trap may be lost
SpeculativeTrapData* data = new SpeculativeTrapData(dp);
data->set_method(m);
return data;
}
}
return NULL;
}
return NULL;
}
@ -1210,25 +1367,35 @@ void MethodData::print_data_on(outputStream* st) const {
for ( ; is_valid(data); data = next_data(data)) {
st->print("%d", dp_to_di(data->dp()));
st->fill_to(6);
data->print_data_on(st);
data->print_data_on(st, this);
}
st->print_cr("--- Extra data:");
DataLayout* dp = extra_data_base();
DataLayout* end = extra_data_limit();
for (; dp < end; dp = next_extra(dp)) {
for (;; dp = next_extra(dp)) {
assert(dp < end, "moved past end of extra data");
// No need for "OrderAccess::load_acquire" ops,
// since the data structure is monotonic.
if (dp->tag() == DataLayout::no_tag) continue;
if (dp->tag() == DataLayout::bit_data_tag) {
switch(dp->tag()) {
case DataLayout::no_tag:
continue;
case DataLayout::bit_data_tag:
data = new BitData(dp);
} else {
assert(dp->tag() == DataLayout::arg_info_data_tag, "must be BitData or ArgInfo");
break;
case DataLayout::speculative_trap_data_tag:
data = new SpeculativeTrapData(dp);
break;
case DataLayout::arg_info_data_tag:
data = new ArgInfoData(dp);
dp = end; // ArgInfoData is at the end of extra data section.
break;
default:
fatal(err_msg("unexpected tag %d", dp->tag()));
}
st->print("%d", dp_to_di(data->dp()));
st->fill_to(6);
data->print_data_on(st);
if (dp >= end) return;
}
}
#endif
@ -1351,3 +1518,110 @@ bool MethodData::profile_parameters_for_method(methodHandle m) {
assert(profile_parameters_jsr292_only(), "inconsistent");
return m->is_compiled_lambda_form();
}
void MethodData::clean_extra_data_helper(DataLayout* dp, int shift, bool reset) {
if (shift == 0) {
return;
}
if (!reset) {
// Move all cells of trap entry at dp left by "shift" cells
intptr_t* start = (intptr_t*)dp;
intptr_t* end = (intptr_t*)next_extra(dp);
for (intptr_t* ptr = start; ptr < end; ptr++) {
*(ptr-shift) = *ptr;
}
} else {
// Reset "shift" cells stopping at dp
intptr_t* start = ((intptr_t*)dp) - shift;
intptr_t* end = (intptr_t*)dp;
for (intptr_t* ptr = start; ptr < end; ptr++) {
*ptr = 0;
}
}
}
// Remove SpeculativeTrapData entries that reference an unloaded
// method
void MethodData::clean_extra_data(BoolObjectClosure* is_alive) {
DataLayout* dp = extra_data_base();
DataLayout* end = extra_data_limit();
int shift = 0;
for (; dp < end; dp = next_extra(dp)) {
switch(dp->tag()) {
case DataLayout::speculative_trap_data_tag: {
SpeculativeTrapData* data = new SpeculativeTrapData(dp);
Method* m = data->method();
assert(m != NULL, "should have a method");
if (!m->method_holder()->is_loader_alive(is_alive)) {
// "shift" accumulates the number of cells for dead
// SpeculativeTrapData entries that have been seen so
// far. Following entries must be shifted left by that many
// cells to remove the dead SpeculativeTrapData entries.
shift += (int)((intptr_t*)next_extra(dp) - (intptr_t*)dp);
} else {
// Shift this entry left if it follows dead
// SpeculativeTrapData entries
clean_extra_data_helper(dp, shift);
}
break;
}
case DataLayout::bit_data_tag:
// Shift this entry left if it follows dead SpeculativeTrapData
// entries
clean_extra_data_helper(dp, shift);
continue;
case DataLayout::no_tag:
case DataLayout::arg_info_data_tag:
// We are at end of the live trap entries. The previous "shift"
// cells contain entries that are either dead or were shifted
// left. They need to be reset to no_tag
clean_extra_data_helper(dp, shift, true);
return;
default:
fatal(err_msg("unexpected tag %d", dp->tag()));
}
}
}
// Verify there's no unloaded method referenced by a
// SpeculativeTrapData entry
void MethodData::verify_extra_data_clean(BoolObjectClosure* is_alive) {
#ifdef ASSERT
DataLayout* dp = extra_data_base();
DataLayout* end = extra_data_limit();
for (; dp < end; dp = next_extra(dp)) {
switch(dp->tag()) {
case DataLayout::speculative_trap_data_tag: {
SpeculativeTrapData* data = new SpeculativeTrapData(dp);
Method* m = data->method();
assert(m != NULL && m->method_holder()->is_loader_alive(is_alive), "Method should exist");
break;
}
case DataLayout::bit_data_tag:
continue;
case DataLayout::no_tag:
case DataLayout::arg_info_data_tag:
return;
default:
fatal(err_msg("unexpected tag %d", dp->tag()));
}
}
#endif
}
void MethodData::clean_method_data(BoolObjectClosure* is_alive) {
for (ProfileData* data = first_data();
is_valid(data);
data = next_data(data)) {
data->clean_weak_klass_links(is_alive);
}
ParametersTypeData* parameters = parameters_type_data();
if (parameters != NULL) {
parameters->clean_weak_klass_links(is_alive);
}
clean_extra_data(is_alive);
verify_extra_data_clean(is_alive);
}