6420645: Create a vm that uses compressed oops for up to 32gb heapsizes
Summary: Compressed oops in instances, arrays, and headers. Code contributors are coleenp, phh, never, swamyv
Reviewed-by: jmasa, kamg, acorn, tbell, kvn, rasbold
/*
* Copyright 2005-2007 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/_macro.cpp.incl"
//
// Replace any references to "oldref" in inputs to "use" with "newref".
// Returns the number of replacements made.
//
int PhaseMacroExpand::replace_input(Node *use, Node *oldref, Node *newref) {
int nreplacements = 0;
uint req = use->req();
for (uint j = 0; j < use->len(); j++) {
Node *uin = use->in(j);
if (uin == oldref) {
if (j < req)
use->set_req(j, newref);
else
use->set_prec(j, newref);
nreplacements++;
} else if (j >= req && uin == NULL) {
break;
}
}
return nreplacements;
}
void PhaseMacroExpand::copy_call_debug_info(CallNode *oldcall, CallNode * newcall) {
// Copy debug information and adjust JVMState information
uint old_dbg_start = oldcall->tf()->domain()->cnt();
uint new_dbg_start = newcall->tf()->domain()->cnt();
int jvms_adj = new_dbg_start - old_dbg_start;
assert (new_dbg_start == newcall->req(), "argument count mismatch");
Dict* sosn_map = new Dict(cmpkey,hashkey);
for (uint i = old_dbg_start; i < oldcall->req(); i++) {
Node* old_in = oldcall->in(i);
// Clone old SafePointScalarObjectNodes, adjusting their field contents.
if (old_in->is_SafePointScalarObject()) {
SafePointScalarObjectNode* old_sosn = old_in->as_SafePointScalarObject();
uint old_unique = C->unique();
Node* new_in = old_sosn->clone(jvms_adj, sosn_map);
if (old_unique != C->unique()) {
new_in = transform_later(new_in); // Register new node.
}
old_in = new_in;
}
newcall->add_req(old_in);
}
newcall->set_jvms(oldcall->jvms());
for (JVMState *jvms = newcall->jvms(); jvms != NULL; jvms = jvms->caller()) {
jvms->set_map(newcall);
jvms->set_locoff(jvms->locoff()+jvms_adj);
jvms->set_stkoff(jvms->stkoff()+jvms_adj);
jvms->set_monoff(jvms->monoff()+jvms_adj);
jvms->set_scloff(jvms->scloff()+jvms_adj);
jvms->set_endoff(jvms->endoff()+jvms_adj);
}
}
Node* PhaseMacroExpand::opt_iff(Node* region, Node* iff) {
IfNode *opt_iff = transform_later(iff)->as_If();
// Fast path taken; set region slot 2
Node *fast_taken = transform_later( new (C, 1) IfFalseNode(opt_iff) );
region->init_req(2,fast_taken); // Capture fast-control
// Fast path not-taken, i.e. slow path
Node *slow_taken = transform_later( new (C, 1) IfTrueNode(opt_iff) );
return slow_taken;
}
//--------------------copy_predefined_input_for_runtime_call--------------------
void PhaseMacroExpand::copy_predefined_input_for_runtime_call(Node * ctrl, CallNode* oldcall, CallNode* call) {
// Set fixed predefined input arguments
call->init_req( TypeFunc::Control, ctrl );
call->init_req( TypeFunc::I_O , oldcall->in( TypeFunc::I_O) );
call->init_req( TypeFunc::Memory , oldcall->in( TypeFunc::Memory ) ); // ?????
call->init_req( TypeFunc::ReturnAdr, oldcall->in( TypeFunc::ReturnAdr ) );
call->init_req( TypeFunc::FramePtr, oldcall->in( TypeFunc::FramePtr ) );
}
//------------------------------make_slow_call---------------------------------
CallNode* PhaseMacroExpand::make_slow_call(CallNode *oldcall, const TypeFunc* slow_call_type, address slow_call, const char* leaf_name, Node* slow_path, Node* parm0, Node* parm1) {
// Slow-path call
int size = slow_call_type->domain()->cnt();
CallNode *call = leaf_name
? (CallNode*)new (C, size) CallLeafNode ( slow_call_type, slow_call, leaf_name, TypeRawPtr::BOTTOM )
: (CallNode*)new (C, size) CallStaticJavaNode( slow_call_type, slow_call, OptoRuntime::stub_name(slow_call), oldcall->jvms()->bci(), TypeRawPtr::BOTTOM );
// Slow path call has no side-effects, uses few values
copy_predefined_input_for_runtime_call(slow_path, oldcall, call );
if (parm0 != NULL) call->init_req(TypeFunc::Parms+0, parm0);
if (parm1 != NULL) call->init_req(TypeFunc::Parms+1, parm1);
copy_call_debug_info(oldcall, call);
call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
_igvn.hash_delete(oldcall);
_igvn.subsume_node(oldcall, call);
transform_later(call);
return call;
}
void PhaseMacroExpand::extract_call_projections(CallNode *call) {
_fallthroughproj = NULL;
_fallthroughcatchproj = NULL;
_ioproj_fallthrough = NULL;
_ioproj_catchall = NULL;
_catchallcatchproj = NULL;
_memproj_fallthrough = NULL;
_memproj_catchall = NULL;
_resproj = NULL;
for (DUIterator_Fast imax, i = call->fast_outs(imax); i < imax; i++) {
ProjNode *pn = call->fast_out(i)->as_Proj();
switch (pn->_con) {
case TypeFunc::Control:
{
// For Control (fallthrough) and I_O (catch_all_index) we have CatchProj -> Catch -> Proj
_fallthroughproj = pn;
DUIterator_Fast jmax, j = pn->fast_outs(jmax);
const Node *cn = pn->fast_out(j);
if (cn->is_Catch()) {
ProjNode *cpn = NULL;
for (DUIterator_Fast kmax, k = cn->fast_outs(kmax); k < kmax; k++) {
cpn = cn->fast_out(k)->as_Proj();
assert(cpn->is_CatchProj(), "must be a CatchProjNode");
if (cpn->_con == CatchProjNode::fall_through_index)
_fallthroughcatchproj = cpn;
else {
assert(cpn->_con == CatchProjNode::catch_all_index, "must be correct index.");
_catchallcatchproj = cpn;
}
}
}
break;
}
case TypeFunc::I_O:
if (pn->_is_io_use)
_ioproj_catchall = pn;
else
_ioproj_fallthrough = pn;
break;
case TypeFunc::Memory:
if (pn->_is_io_use)
_memproj_catchall = pn;
else
_memproj_fallthrough = pn;
break;
case TypeFunc::Parms:
_resproj = pn;
break;
default:
assert(false, "unexpected projection from allocation node.");
}
}
}
// Eliminate a card mark sequence. p2x is a ConvP2XNode
void PhaseMacroExpand::eliminate_card_mark(Node *p2x) {
assert(p2x->Opcode() == Op_CastP2X, "ConvP2XNode required");
Node *shift = p2x->unique_out();
Node *addp = shift->unique_out();
for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
Node *st = addp->last_out(j);
assert(st->is_Store(), "store required");
_igvn.replace_node(st, st->in(MemNode::Memory));
}
}
// Search for a memory operation for the specified memory slice.
static Node *scan_mem_chain(Node *mem, int alias_idx, int offset, Node *start_mem, Node *alloc) {
Node *orig_mem = mem;
Node *alloc_mem = alloc->in(TypeFunc::Memory);
while (true) {
if (mem == alloc_mem || mem == start_mem ) {
return mem; // hit one of our sentinals
} else if (mem->is_MergeMem()) {
mem = mem->as_MergeMem()->memory_at(alias_idx);
} else if (mem->is_Proj() && mem->as_Proj()->_con == TypeFunc::Memory) {
Node *in = mem->in(0);
// we can safely skip over safepoints, calls, locks and membars because we
// already know that the object is safe to eliminate.
if (in->is_Initialize() && in->as_Initialize()->allocation() == alloc) {
return in;
} else if (in->is_Call() || in->is_MemBar()) {
mem = in->in(TypeFunc::Memory);
} else {
assert(false, "unexpected projection");
}
} else if (mem->is_Store()) {
const TypePtr* atype = mem->as_Store()->adr_type();
int adr_idx = Compile::current()->get_alias_index(atype);
if (adr_idx == alias_idx) {
assert(atype->isa_oopptr(), "address type must be oopptr");
int adr_offset = atype->offset();
uint adr_iid = atype->is_oopptr()->instance_id();
// Array elements references have the same alias_idx
// but different offset and different instance_id.
if (adr_offset == offset && adr_iid == alloc->_idx)
return mem;
} else {
assert(adr_idx == Compile::AliasIdxRaw, "address must match or be raw");
}
mem = mem->in(MemNode::Memory);
} else {
return mem;
}
if (mem == orig_mem)
return mem;
}
}
//
// Given a Memory Phi, compute a value Phi containing the values from stores
// on the input paths.
// Note: this function is recursive, its depth is limied by the "level" argument
// Returns the computed Phi, or NULL if it cannot compute it.
Node *PhaseMacroExpand::value_from_mem_phi(Node *mem, BasicType ft, const Type *phi_type, const TypeOopPtr *adr_t, Node *alloc, int level) {
if (level <= 0) {
return NULL;
}
int alias_idx = C->get_alias_index(adr_t);
int offset = adr_t->offset();
int instance_id = adr_t->instance_id();
Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
Node *alloc_mem = alloc->in(TypeFunc::Memory);
uint length = mem->req();
GrowableArray <Node *> values(length, length, NULL);
for (uint j = 1; j < length; j++) {
Node *in = mem->in(j);
if (in == NULL || in->is_top()) {
values.at_put(j, in);
} else {
Node *val = scan_mem_chain(in, alias_idx, offset, start_mem, alloc);
if (val == start_mem || val == alloc_mem) {
// hit a sentinel, return appropriate 0 value
values.at_put(j, _igvn.zerocon(ft));
continue;
}
if (val->is_Initialize()) {
val = val->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
}
if (val == NULL) {
return NULL; // can't find a value on this path
}
if (val == mem) {
values.at_put(j, mem);
} else if (val->is_Store()) {
values.at_put(j, val->in(MemNode::ValueIn));
} else if(val->is_Proj() && val->in(0) == alloc) {
values.at_put(j, _igvn.zerocon(ft));
} else if (val->is_Phi()) {
// Check if an appropriate node already exists.
Node* region = val->in(0);
Node* old_phi = NULL;
for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) {
Node* phi = region->fast_out(k);
if (phi->is_Phi() && phi != val &&
phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) {
old_phi = phi;
break;
}
}
if (old_phi == NULL) {
val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, level-1);
if (val == NULL) {
return NULL;
}
values.at_put(j, val);
} else {
values.at_put(j, old_phi);
}
} else {
return NULL; // unknown node on this path
}
}
}
// create a new Phi for the value
PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset);
for (uint j = 1; j < length; j++) {
if (values.at(j) == mem) {
phi->init_req(j, phi);
} else {
phi->init_req(j, values.at(j));
}
}
transform_later(phi);
return phi;
}
// Search the last value stored into the object's field.
Node *PhaseMacroExpand::value_from_mem(Node *sfpt_mem, BasicType ft, const Type *ftype, const TypeOopPtr *adr_t, Node *alloc) {
assert(adr_t->is_instance_field(), "instance required");
uint instance_id = adr_t->instance_id();
assert(instance_id == alloc->_idx, "wrong allocation");
int alias_idx = C->get_alias_index(adr_t);
int offset = adr_t->offset();
Node *start_mem = C->start()->proj_out(TypeFunc::Memory);
Node *alloc_ctrl = alloc->in(TypeFunc::Control);
Node *alloc_mem = alloc->in(TypeFunc::Memory);
VectorSet visited(Thread::current()->resource_area());
bool done = sfpt_mem == alloc_mem;
Node *mem = sfpt_mem;
while (!done) {
if (visited.test_set(mem->_idx)) {
return NULL; // found a loop, give up
}
mem = scan_mem_chain(mem, alias_idx, offset, start_mem, alloc);
if (mem == start_mem || mem == alloc_mem) {
done = true; // hit a sentinel, return appropriate 0 value
} else if (mem->is_Initialize()) {
mem = mem->as_Initialize()->find_captured_store(offset, type2aelembytes(ft), &_igvn);
if (mem == NULL) {
done = true; // Something go wrong.
} else if (mem->is_Store()) {
const TypePtr* atype = mem->as_Store()->adr_type();
assert(C->get_alias_index(atype) == Compile::AliasIdxRaw, "store is correct memory slice");
done = true;
}
} else if (mem->is_Store()) {
const TypeOopPtr* atype = mem->as_Store()->adr_type()->isa_oopptr();
assert(atype != NULL, "address type must be oopptr");
assert(C->get_alias_index(atype) == alias_idx &&
atype->is_instance_field() && atype->offset() == offset &&
atype->instance_id() == instance_id, "store is correct memory slice");
done = true;
} else if (mem->is_Phi()) {
// try to find a phi's unique input
Node *unique_input = NULL;
Node *top = C->top();
for (uint i = 1; i < mem->req(); i++) {
Node *n = scan_mem_chain(mem->in(i), alias_idx, offset, start_mem, alloc);
if (n == NULL || n == top || n == mem) {
continue;
} else if (unique_input == NULL) {
unique_input = n;
} else if (unique_input != n) {
unique_input = top;
break;
}
}
if (unique_input != NULL && unique_input != top) {
mem = unique_input;
} else {
done = true;
}
} else {
assert(false, "unexpected node");
}
}
if (mem != NULL) {
if (mem == start_mem || mem == alloc_mem) {
// hit a sentinel, return appropriate 0 value
return _igvn.zerocon(ft);
} else if (mem->is_Store()) {
return mem->in(MemNode::ValueIn);
} else if (mem->is_Phi()) {
// attempt to produce a Phi reflecting the values on the input paths of the Phi
Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, 8);
if (phi != NULL) {
return phi;
}
}
}
// Something go wrong.
return NULL;
}
// Check the possibility of scalar replacement.
bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
// Scan the uses of the allocation to check for anything that would
// prevent us from eliminating it.
NOT_PRODUCT( const char* fail_eliminate = NULL; )
DEBUG_ONLY( Node* disq_node = NULL; )
bool can_eliminate = true;
Node* res = alloc->result_cast();
const TypeOopPtr* res_type = NULL;
if (res == NULL) {
// All users were eliminated.
} else if (!res->is_CheckCastPP()) {
alloc->_is_scalar_replaceable = false; // don't try again
NOT_PRODUCT(fail_eliminate = "Allocation does not have unique CheckCastPP";)
can_eliminate = false;
} else {
res_type = _igvn.type(res)->isa_oopptr();
if (res_type == NULL) {
NOT_PRODUCT(fail_eliminate = "Neither instance or array allocation";)
can_eliminate = false;
} else if (res_type->isa_aryptr()) {
int length = alloc->in(AllocateNode::ALength)->find_int_con(-1);
if (length < 0) {
NOT_PRODUCT(fail_eliminate = "Array's size is not constant";)
can_eliminate = false;
}
}
}
if (can_eliminate && res != NULL) {
for (DUIterator_Fast jmax, j = res->fast_outs(jmax);
j < jmax && can_eliminate; j++) {
Node* use = res->fast_out(j);
if (use->is_AddP()) {
const TypePtr* addp_type = _igvn.type(use)->is_ptr();
int offset = addp_type->offset();
if (offset == Type::OffsetTop || offset == Type::OffsetBot) {
NOT_PRODUCT(fail_eliminate = "Undefined field referrence";)
can_eliminate = false;
break;
}
for (DUIterator_Fast kmax, k = use->fast_outs(kmax);
k < kmax && can_eliminate; k++) {
Node* n = use->fast_out(k);
if (!n->is_Store() && n->Opcode() != Op_CastP2X) {
DEBUG_ONLY(disq_node = n;)
if (n->is_Load()) {
NOT_PRODUCT(fail_eliminate = "Field load";)
} else {
NOT_PRODUCT(fail_eliminate = "Not store field referrence";)
}
can_eliminate = false;
}
}
} else if (use->is_SafePoint()) {
SafePointNode* sfpt = use->as_SafePoint();
if (sfpt->has_non_debug_use(res)) {
// Object is passed as argument.
DEBUG_ONLY(disq_node = use;)
NOT_PRODUCT(fail_eliminate = "Object is passed as argument";)
can_eliminate = false;
}
Node* sfptMem = sfpt->memory();
if (sfptMem == NULL || sfptMem->is_top()) {
DEBUG_ONLY(disq_node = use;)
NOT_PRODUCT(fail_eliminate = "NULL or TOP memory";)
can_eliminate = false;
} else {
safepoints.append_if_missing(sfpt);
}
} else if (use->Opcode() != Op_CastP2X) { // CastP2X is used by card mark
if (use->is_Phi()) {
if (use->outcnt() == 1 && use->unique_out()->Opcode() == Op_Return) {
NOT_PRODUCT(fail_eliminate = "Object is return value";)
} else {
NOT_PRODUCT(fail_eliminate = "Object is referenced by Phi";)
}
DEBUG_ONLY(disq_node = use;)
} else {
if (use->Opcode() == Op_Return) {
NOT_PRODUCT(fail_eliminate = "Object is return value";)
}else {
NOT_PRODUCT(fail_eliminate = "Object is referenced by node";)
}
DEBUG_ONLY(disq_node = use;)
}
can_eliminate = false;
}
}
}
#ifndef PRODUCT
if (PrintEliminateAllocations) {
if (can_eliminate) {
tty->print("Scalar ");
if (res == NULL)
alloc->dump();
else
res->dump();
} else {
tty->print("NotScalar (%s)", fail_eliminate);
if (res == NULL)
alloc->dump();
else
res->dump();
#ifdef ASSERT
if (disq_node != NULL) {
tty->print(" >>>> ");
disq_node->dump();
}
#endif /*ASSERT*/
}
}
#endif
return can_eliminate;
}
// Do scalar replacement.
bool PhaseMacroExpand::scalar_replacement(AllocateNode *alloc, GrowableArray <SafePointNode *>& safepoints) {
GrowableArray <SafePointNode *> safepoints_done;
ciKlass* klass = NULL;
ciInstanceKlass* iklass = NULL;
int nfields = 0;
int array_base;
int element_size;
BasicType basic_elem_type;
ciType* elem_type;
Node* res = alloc->result_cast();
const TypeOopPtr* res_type = NULL;
if (res != NULL) { // Could be NULL when there are no users
res_type = _igvn.type(res)->isa_oopptr();
}
if (res != NULL) {
klass = res_type->klass();
if (res_type->isa_instptr()) {
// find the fields of the class which will be needed for safepoint debug information
assert(klass->is_instance_klass(), "must be an instance klass.");
iklass = klass->as_instance_klass();
nfields = iklass->nof_nonstatic_fields();
} else {
// find the array's elements which will be needed for safepoint debug information
nfields = alloc->in(AllocateNode::ALength)->find_int_con(-1);
assert(klass->is_array_klass() && nfields >= 0, "must be an array klass.");
elem_type = klass->as_array_klass()->element_type();
basic_elem_type = elem_type->basic_type();
array_base = arrayOopDesc::base_offset_in_bytes(basic_elem_type);
element_size = type2aelembytes(basic_elem_type);
}
}
//
// Process the safepoint uses
//
while (safepoints.length() > 0) {
SafePointNode* sfpt = safepoints.pop();
Node* mem = sfpt->memory();
uint first_ind = sfpt->req();
SafePointScalarObjectNode* sobj = new (C, 1) SafePointScalarObjectNode(res_type,
#ifdef ASSERT
alloc,
#endif
first_ind, nfields);
sobj->init_req(0, sfpt->in(TypeFunc::Control));
transform_later(sobj);
// Scan object's fields adding an input to the safepoint for each field.
for (int j = 0; j < nfields; j++) {
int offset;
ciField* field = NULL;
if (iklass != NULL) {
field = iklass->nonstatic_field_at(j);
offset = field->offset();
elem_type = field->type();
basic_elem_type = field->layout_type();
} else {
offset = array_base + j * element_size;
}
const Type *field_type;
// The next code is taken from Parse::do_get_xxx().
if (basic_elem_type == T_OBJECT) {
if (!elem_type->is_loaded()) {
field_type = TypeInstPtr::BOTTOM;
} else if (field != NULL && field->is_constant()) {
// This can happen if the constant oop is non-perm.
ciObject* con = field->constant_value().as_object();
// Do not "join" in the previous type; it doesn't add value,
// and may yield a vacuous result if the field is of interface type.
field_type = TypeOopPtr::make_from_constant(con)->isa_oopptr();
assert(field_type != NULL, "field singleton type must be consistent");
} else {
field_type = TypeOopPtr::make_from_klass(elem_type->as_klass());
}
} else {
field_type = Type::get_const_basic_type(basic_elem_type);
}
const TypeOopPtr *field_addr_type = res_type->add_offset(offset)->isa_oopptr();
Node *field_val = value_from_mem(mem, basic_elem_type, field_type, field_addr_type, alloc);
if (field_val == NULL) {
// we weren't able to find a value for this field,
// give up on eliminating this allocation
alloc->_is_scalar_replaceable = false; // don't try again
// remove any extra entries we added to the safepoint
uint last = sfpt->req() - 1;
for (int k = 0; k < j; k++) {
sfpt->del_req(last--);
}
// rollback processed safepoints
while (safepoints_done.length() > 0) {
SafePointNode* sfpt_done = safepoints_done.pop();
// remove any extra entries we added to the safepoint
last = sfpt_done->req() - 1;
for (int k = 0; k < nfields; k++) {
sfpt_done->del_req(last--);
}
JVMState *jvms = sfpt_done->jvms();
jvms->set_endoff(sfpt_done->req());
// Now make a pass over the debug information replacing any references
// to SafePointScalarObjectNode with the allocated object.
int start = jvms->debug_start();
int end = jvms->debug_end();
for (int i = start; i < end; i++) {
if (sfpt_done->in(i)->is_SafePointScalarObject()) {
SafePointScalarObjectNode* scobj = sfpt_done->in(i)->as_SafePointScalarObject();
if (scobj->first_index() == sfpt_done->req() &&
scobj->n_fields() == (uint)nfields) {
assert(scobj->alloc() == alloc, "sanity");
sfpt_done->set_req(i, res);
}
}
}
}
#ifndef PRODUCT
if (PrintEliminateAllocations) {
if (field != NULL) {
tty->print("=== At SafePoint node %d can't find value of Field: ",
sfpt->_idx);
field->print();
int field_idx = C->get_alias_index(field_addr_type);
tty->print(" (alias_idx=%d)", field_idx);
} else { // Array's element
tty->print("=== At SafePoint node %d can't find value of array element [%d]",
sfpt->_idx, j);
}
tty->print(", which prevents elimination of: ");
if (res == NULL)
alloc->dump();
else
res->dump();
}
#endif
return false;
}
sfpt->add_req(field_val);
}
JVMState *jvms = sfpt->jvms();
jvms->set_endoff(sfpt->req());
// Now make a pass over the debug information replacing any references
// to the allocated object with "sobj"
int start = jvms->debug_start();
int end = jvms->debug_end();
for (int i = start; i < end; i++) {
if (sfpt->in(i) == res) {
sfpt->set_req(i, sobj);
}
}
safepoints_done.append_if_missing(sfpt); // keep it for rollback
}
return true;
}
// Process users of eliminated allocation.
void PhaseMacroExpand::process_users_of_allocation(AllocateNode *alloc) {
Node* res = alloc->result_cast();
if (res != NULL) {
for (DUIterator_Last jmin, j = res->last_outs(jmin); j >= jmin; ) {
Node *use = res->last_out(j);
uint oc1 = res->outcnt();
if (use->is_AddP()) {
for (DUIterator_Last kmin, k = use->last_outs(kmin); k >= kmin; ) {
Node *n = use->last_out(k);
uint oc2 = use->outcnt();
if (n->is_Store()) {
_igvn.replace_node(n, n->in(MemNode::Memory));
} else {
assert( n->Opcode() == Op_CastP2X, "CastP2X required");
eliminate_card_mark(n);
}
k -= (oc2 - use->outcnt());
}
} else {
assert( !use->is_SafePoint(), "safepoint uses must have been already elimiated");
assert( use->Opcode() == Op_CastP2X, "CastP2X required");
eliminate_card_mark(use);
}
j -= (oc1 - res->outcnt());
}
assert(res->outcnt() == 0, "all uses of allocated objects must be deleted");
_igvn.remove_dead_node(res);
}
//
// Process other users of allocation's projections
//
if (_resproj != NULL && _resproj->outcnt() != 0) {
for (DUIterator_Last jmin, j = _resproj->last_outs(jmin); j >= jmin; ) {
Node *use = _resproj->last_out(j);
uint oc1 = _resproj->outcnt();
if (use->is_Initialize()) {
// Eliminate Initialize node.
InitializeNode *init = use->as_Initialize();
assert(init->outcnt() <= 2, "only a control and memory projection expected");
Node *ctrl_proj = init->proj_out(TypeFunc::Control);
if (ctrl_proj != NULL) {
assert(init->in(TypeFunc::Control) == _fallthroughcatchproj, "allocation control projection");
_igvn.replace_node(ctrl_proj, _fallthroughcatchproj);
}
Node *mem_proj = init->proj_out(TypeFunc::Memory);
if (mem_proj != NULL) {
Node *mem = init->in(TypeFunc::Memory);
#ifdef ASSERT
if (mem->is_MergeMem()) {
assert(mem->in(TypeFunc::Memory) == _memproj_fallthrough, "allocation memory projection");
} else {
assert(mem == _memproj_fallthrough, "allocation memory projection");
}
#endif
_igvn.replace_node(mem_proj, mem);
}
} else if (use->is_AddP()) {
// raw memory addresses used only by the initialization
_igvn.hash_delete(use);
_igvn.subsume_node(use, C->top());
} else {
assert(false, "only Initialize or AddP expected");
}
j -= (oc1 - _resproj->outcnt());
}
}
if (_fallthroughcatchproj != NULL) {
_igvn.replace_node(_fallthroughcatchproj, alloc->in(TypeFunc::Control));
}
if (_memproj_fallthrough != NULL) {
_igvn.replace_node(_memproj_fallthrough, alloc->in(TypeFunc::Memory));
}
if (_memproj_catchall != NULL) {
_igvn.replace_node(_memproj_catchall, C->top());
}
if (_ioproj_fallthrough != NULL) {
_igvn.replace_node(_ioproj_fallthrough, alloc->in(TypeFunc::I_O));
}
if (_ioproj_catchall != NULL) {
_igvn.replace_node(_ioproj_catchall, C->top());
}
if (_catchallcatchproj != NULL) {
_igvn.replace_node(_catchallcatchproj, C->top());
}
}
bool PhaseMacroExpand::eliminate_allocate_node(AllocateNode *alloc) {
if (!EliminateAllocations || !alloc->_is_scalar_replaceable) {
return false;
}
extract_call_projections(alloc);
GrowableArray <SafePointNode *> safepoints;
if (!can_eliminate_allocation(alloc, safepoints)) {
return false;
}
if (!scalar_replacement(alloc, safepoints)) {
return false;
}
process_users_of_allocation(alloc);
#ifndef PRODUCT
if (PrintEliminateAllocations) {
if (alloc->is_AllocateArray())
tty->print_cr("++++ Eliminated: %d AllocateArray", alloc->_idx);
else
tty->print_cr("++++ Eliminated: %d Allocate", alloc->_idx);
}
#endif
return true;
}
//---------------------------set_eden_pointers-------------------------
void PhaseMacroExpand::set_eden_pointers(Node* &eden_top_adr, Node* &eden_end_adr) {
if (UseTLAB) { // Private allocation: load from TLS
Node* thread = transform_later(new (C, 1) ThreadLocalNode());
int tlab_top_offset = in_bytes(JavaThread::tlab_top_offset());
int tlab_end_offset = in_bytes(JavaThread::tlab_end_offset());
eden_top_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_top_offset);
eden_end_adr = basic_plus_adr(top()/*not oop*/, thread, tlab_end_offset);
} else { // Shared allocation: load from globals
CollectedHeap* ch = Universe::heap();
address top_adr = (address)ch->top_addr();
address end_adr = (address)ch->end_addr();
eden_top_adr = makecon(TypeRawPtr::make(top_adr));
eden_end_adr = basic_plus_adr(eden_top_adr, end_adr - top_adr);
}
}
Node* PhaseMacroExpand::make_load(Node* ctl, Node* mem, Node* base, int offset, const Type* value_type, BasicType bt) {
Node* adr = basic_plus_adr(base, offset);
const TypePtr* adr_type = TypeRawPtr::BOTTOM;
Node* value = LoadNode::make(_igvn, ctl, mem, adr, adr_type, value_type, bt);
transform_later(value);
return value;
}
Node* PhaseMacroExpand::make_store(Node* ctl, Node* mem, Node* base, int offset, Node* value, BasicType bt) {
Node* adr = basic_plus_adr(base, offset);
mem = StoreNode::make(_igvn, ctl, mem, adr, NULL, value, bt);
transform_later(mem);
return mem;
}
//=============================================================================
//
// A L L O C A T I O N
//
// Allocation attempts to be fast in the case of frequent small objects.
// It breaks down like this:
//
// 1) Size in doublewords is computed. This is a constant for objects and
// variable for most arrays. Doubleword units are used to avoid size
// overflow of huge doubleword arrays. We need doublewords in the end for
// rounding.
//
// 2) Size is checked for being 'too large'. Too-large allocations will go
// the slow path into the VM. The slow path can throw any required
// exceptions, and does all the special checks for very large arrays. The
// size test can constant-fold away for objects. For objects with
// finalizers it constant-folds the otherway: you always go slow with
// finalizers.
//
// 3) If NOT using TLABs, this is the contended loop-back point.
// Load-Locked the heap top. If using TLABs normal-load the heap top.
//
// 4) Check that heap top + size*8 < max. If we fail go the slow ` route.
// NOTE: "top+size*8" cannot wrap the 4Gig line! Here's why: for largish
// "size*8" we always enter the VM, where "largish" is a constant picked small
// enough that there's always space between the eden max and 4Gig (old space is
// there so it's quite large) and large enough that the cost of entering the VM
// is dwarfed by the cost to initialize the space.
//
// 5) If NOT using TLABs, Store-Conditional the adjusted heap top back
// down. If contended, repeat at step 3. If using TLABs normal-store
// adjusted heap top back down; there is no contention.
//
// 6) If !ZeroTLAB then Bulk-clear the object/array. Fill in klass & mark
// fields.
//
// 7) Merge with the slow-path; cast the raw memory pointer to the correct
// oop flavor.
//
//=============================================================================
// FastAllocateSizeLimit value is in DOUBLEWORDS.
// Allocations bigger than this always go the slow route.
// This value must be small enough that allocation attempts that need to
// trigger exceptions go the slow route. Also, it must be small enough so
// that heap_top + size_in_bytes does not wrap around the 4Gig limit.
//=============================================================================j//
// %%% Here is an old comment from parseHelper.cpp; is it outdated?
// The allocator will coalesce int->oop copies away. See comment in
// coalesce.cpp about how this works. It depends critically on the exact
// code shape produced here, so if you are changing this code shape
// make sure the GC info for the heap-top is correct in and around the
// slow-path call.
//
void PhaseMacroExpand::expand_allocate_common(
AllocateNode* alloc, // allocation node to be expanded
Node* length, // array length for an array allocation
const TypeFunc* slow_call_type, // Type of slow call
address slow_call_address // Address of slow call
)
{
Node* ctrl = alloc->in(TypeFunc::Control);
Node* mem = alloc->in(TypeFunc::Memory);
Node* i_o = alloc->in(TypeFunc::I_O);
Node* size_in_bytes = alloc->in(AllocateNode::AllocSize);
Node* klass_node = alloc->in(AllocateNode::KlassNode);
Node* initial_slow_test = alloc->in(AllocateNode::InitialTest);
// With escape analysis, the entire memory state was needed to be able to
// eliminate the allocation. Since the allocations cannot be eliminated,
// optimize it to the raw slice.
if (mem->is_MergeMem()) {
mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw);
}
Node* eden_top_adr;
Node* eden_end_adr;
set_eden_pointers(eden_top_adr, eden_end_adr);
uint raw_idx = C->get_alias_index(TypeRawPtr::BOTTOM);
assert(ctrl != NULL, "must have control");
// Load Eden::end. Loop invariant and hoisted.
//
// Note: We set the control input on "eden_end" and "old_eden_top" when using
// a TLAB to work around a bug where these values were being moved across
// a safepoint. These are not oops, so they cannot be include in the oop
// map, but the can be changed by a GC. The proper way to fix this would
// be to set the raw memory state when generating a SafepointNode. However
// this will require extensive changes to the loop optimization in order to
// prevent a degradation of the optimization.
// See comment in memnode.hpp, around line 227 in class LoadPNode.
Node* eden_end = make_load(ctrl, mem, eden_end_adr, 0, TypeRawPtr::BOTTOM, T_ADDRESS);
// We need a Region and corresponding Phi's to merge the slow-path and fast-path results.
// they will not be used if "always_slow" is set
enum { slow_result_path = 1, fast_result_path = 2 };
Node *result_region;
Node *result_phi_rawmem;
Node *result_phi_rawoop;
Node *result_phi_i_o;
// The initial slow comparison is a size check, the comparison
// we want to do is a BoolTest::gt
bool always_slow = false;
int tv = _igvn.find_int_con(initial_slow_test, -1);
if (tv >= 0) {
always_slow = (tv == 1);
initial_slow_test = NULL;
} else {
initial_slow_test = BoolNode::make_predicate(initial_slow_test, &_igvn);
}
if (DTraceAllocProbes) {
// Force slow-path allocation
always_slow = true;
initial_slow_test = NULL;
}
enum { too_big_or_final_path = 1, need_gc_path = 2 };
Node *slow_region = NULL;
Node *toobig_false = ctrl;
assert (initial_slow_test == NULL || !always_slow, "arguments must be consistent");
// generate the initial test if necessary
if (initial_slow_test != NULL ) {
slow_region = new (C, 3) RegionNode(3);
// Now make the initial failure test. Usually a too-big test but
// might be a TRUE for finalizers or a fancy class check for
// newInstance0.
IfNode *toobig_iff = new (C, 2) IfNode(ctrl, initial_slow_test, PROB_MIN, COUNT_UNKNOWN);
transform_later(toobig_iff);
// Plug the failing-too-big test into the slow-path region
Node *toobig_true = new (C, 1) IfTrueNode( toobig_iff );
transform_later(toobig_true);
slow_region ->init_req( too_big_or_final_path, toobig_true );
toobig_false = new (C, 1) IfFalseNode( toobig_iff );
transform_later(toobig_false);
} else { // No initial test, just fall into next case
toobig_false = ctrl;
debug_only(slow_region = NodeSentinel);
}
Node *slow_mem = mem; // save the current memory state for slow path
// generate the fast allocation code unless we know that the initial test will always go slow
if (!always_slow) {
// allocate the Region and Phi nodes for the result
result_region = new (C, 3) RegionNode(3);
result_phi_rawmem = new (C, 3) PhiNode( result_region, Type::MEMORY, TypeRawPtr::BOTTOM );
result_phi_rawoop = new (C, 3) PhiNode( result_region, TypeRawPtr::BOTTOM );
result_phi_i_o = new (C, 3) PhiNode( result_region, Type::ABIO ); // I/O is used for Prefetch
// We need a Region for the loop-back contended case.
enum { fall_in_path = 1, contended_loopback_path = 2 };
Node *contended_region;
Node *contended_phi_rawmem;
if( UseTLAB ) {
contended_region = toobig_false;
contended_phi_rawmem = mem;
} else {
contended_region = new (C, 3) RegionNode(3);
contended_phi_rawmem = new (C, 3) PhiNode( contended_region, Type::MEMORY, TypeRawPtr::BOTTOM);
// Now handle the passing-too-big test. We fall into the contended
// loop-back merge point.
contended_region ->init_req( fall_in_path, toobig_false );
contended_phi_rawmem->init_req( fall_in_path, mem );
transform_later(contended_region);
transform_later(contended_phi_rawmem);
}
// Load(-locked) the heap top.
// See note above concerning the control input when using a TLAB
Node *old_eden_top = UseTLAB
? new (C, 3) LoadPNode ( ctrl, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM )
: new (C, 3) LoadPLockedNode( contended_region, contended_phi_rawmem, eden_top_adr );
transform_later(old_eden_top);
// Add to heap top to get a new heap top
Node *new_eden_top = new (C, 4) AddPNode( top(), old_eden_top, size_in_bytes );
transform_later(new_eden_top);
// Check for needing a GC; compare against heap end
Node *needgc_cmp = new (C, 3) CmpPNode( new_eden_top, eden_end );
transform_later(needgc_cmp);
Node *needgc_bol = new (C, 2) BoolNode( needgc_cmp, BoolTest::ge );
transform_later(needgc_bol);
IfNode *needgc_iff = new (C, 2) IfNode(contended_region, needgc_bol, PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
transform_later(needgc_iff);
// Plug the failing-heap-space-need-gc test into the slow-path region
Node *needgc_true = new (C, 1) IfTrueNode( needgc_iff );
transform_later(needgc_true);
if( initial_slow_test ) {
slow_region ->init_req( need_gc_path, needgc_true );
// This completes all paths into the slow merge point
transform_later(slow_region);
} else { // No initial slow path needed!
// Just fall from the need-GC path straight into the VM call.
slow_region = needgc_true;
}
// No need for a GC. Setup for the Store-Conditional
Node *needgc_false = new (C, 1) IfFalseNode( needgc_iff );
transform_later(needgc_false);
// Grab regular I/O before optional prefetch may change it.
// Slow-path does no I/O so just set it to the original I/O.
result_phi_i_o->init_req( slow_result_path, i_o );
i_o = prefetch_allocation(i_o, needgc_false, contended_phi_rawmem,
old_eden_top, new_eden_top, length);
// Store (-conditional) the modified eden top back down.
// StorePConditional produces flags for a test PLUS a modified raw
// memory state.
Node *store_eden_top;
Node *fast_oop_ctrl;
if( UseTLAB ) {
store_eden_top = new (C, 4) StorePNode( needgc_false, contended_phi_rawmem, eden_top_adr, TypeRawPtr::BOTTOM, new_eden_top );
transform_later(store_eden_top);
fast_oop_ctrl = needgc_false; // No contention, so this is the fast path
} else {
store_eden_top = new (C, 5) StorePConditionalNode( needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, old_eden_top );
transform_later(store_eden_top);
Node *contention_check = new (C, 2) BoolNode( store_eden_top, BoolTest::ne );
transform_later(contention_check);
store_eden_top = new (C, 1) SCMemProjNode(store_eden_top);
transform_later(store_eden_top);
// If not using TLABs, check to see if there was contention.
IfNode *contention_iff = new (C, 2) IfNode ( needgc_false, contention_check, PROB_MIN, COUNT_UNKNOWN );
transform_later(contention_iff);
Node *contention_true = new (C, 1) IfTrueNode( contention_iff );
transform_later(contention_true);
// If contention, loopback and try again.
contended_region->init_req( contended_loopback_path, contention_true );
contended_phi_rawmem->init_req( contended_loopback_path, store_eden_top );
// Fast-path succeeded with no contention!
Node *contention_false = new (C, 1) IfFalseNode( contention_iff );
transform_later(contention_false);
fast_oop_ctrl = contention_false;
}
// Rename successful fast-path variables to make meaning more obvious
Node* fast_oop = old_eden_top;
Node* fast_oop_rawmem = store_eden_top;
fast_oop_rawmem = initialize_object(alloc,
fast_oop_ctrl, fast_oop_rawmem, fast_oop,
klass_node, length, size_in_bytes);
if (ExtendedDTraceProbes) {
// Slow-path call
int size = TypeFunc::Parms + 2;
CallLeafNode *call = new (C, size) CallLeafNode(OptoRuntime::dtrace_object_alloc_Type(),
CAST_FROM_FN_PTR(address, SharedRuntime::dtrace_object_alloc_base),
"dtrace_object_alloc",
TypeRawPtr::BOTTOM);
// Get base of thread-local storage area
Node* thread = new (C, 1) ThreadLocalNode();
transform_later(thread);
call->init_req(TypeFunc::Parms+0, thread);
call->init_req(TypeFunc::Parms+1, fast_oop);
call->init_req( TypeFunc::Control, fast_oop_ctrl );
call->init_req( TypeFunc::I_O , top() ) ; // does no i/o
call->init_req( TypeFunc::Memory , fast_oop_rawmem );
call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
transform_later(call);
fast_oop_ctrl = new (C, 1) ProjNode(call,TypeFunc::Control);
transform_later(fast_oop_ctrl);
fast_oop_rawmem = new (C, 1) ProjNode(call,TypeFunc::Memory);
transform_later(fast_oop_rawmem);
}
// Plug in the successful fast-path into the result merge point
result_region ->init_req( fast_result_path, fast_oop_ctrl );
result_phi_rawoop->init_req( fast_result_path, fast_oop );
result_phi_i_o ->init_req( fast_result_path, i_o );
result_phi_rawmem->init_req( fast_result_path, fast_oop_rawmem );
} else {
slow_region = ctrl;
}
// Generate slow-path call
CallNode *call = new (C, slow_call_type->domain()->cnt())
CallStaticJavaNode(slow_call_type, slow_call_address,
OptoRuntime::stub_name(slow_call_address),
alloc->jvms()->bci(),
TypePtr::BOTTOM);
call->init_req( TypeFunc::Control, slow_region );
call->init_req( TypeFunc::I_O , top() ) ; // does no i/o
call->init_req( TypeFunc::Memory , slow_mem ); // may gc ptrs
call->init_req( TypeFunc::ReturnAdr, alloc->in(TypeFunc::ReturnAdr) );
call->init_req( TypeFunc::FramePtr, alloc->in(TypeFunc::FramePtr) );
call->init_req(TypeFunc::Parms+0, klass_node);
if (length != NULL) {
call->init_req(TypeFunc::Parms+1, length);
}
// Copy debug information and adjust JVMState information, then replace
// allocate node with the call
copy_call_debug_info((CallNode *) alloc, call);
if (!always_slow) {
call->set_cnt(PROB_UNLIKELY_MAG(4)); // Same effect as RC_UNCOMMON.
}
_igvn.hash_delete(alloc);
_igvn.subsume_node(alloc, call);
transform_later(call);
// Identify the output projections from the allocate node and
// adjust any references to them.
// The control and io projections look like:
//
// v---Proj(ctrl) <-----+ v---CatchProj(ctrl)
// Allocate Catch
// ^---Proj(io) <-------+ ^---CatchProj(io)
//
// We are interested in the CatchProj nodes.
//
extract_call_projections(call);
// An allocate node has separate memory projections for the uses on the control and i_o paths
// Replace uses of the control memory projection with result_phi_rawmem (unless we are only generating a slow call)
if (!always_slow && _memproj_fallthrough != NULL) {
for (DUIterator_Fast imax, i = _memproj_fallthrough->fast_outs(imax); i < imax; i++) {
Node *use = _memproj_fallthrough->fast_out(i);
_igvn.hash_delete(use);
imax -= replace_input(use, _memproj_fallthrough, result_phi_rawmem);
_igvn._worklist.push(use);
// back up iterator
--i;
}
}
// Now change uses of _memproj_catchall to use _memproj_fallthrough and delete _memproj_catchall so
// we end up with a call that has only 1 memory projection
if (_memproj_catchall != NULL ) {
if (_memproj_fallthrough == NULL) {
_memproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::Memory);
transform_later(_memproj_fallthrough);
}
for (DUIterator_Fast imax, i = _memproj_catchall->fast_outs(imax); i < imax; i++) {
Node *use = _memproj_catchall->fast_out(i);
_igvn.hash_delete(use);
imax -= replace_input(use, _memproj_catchall, _memproj_fallthrough);
_igvn._worklist.push(use);
// back up iterator
--i;
}
}
mem = result_phi_rawmem;
// An allocate node has separate i_o projections for the uses on the control and i_o paths
// Replace uses of the control i_o projection with result_phi_i_o (unless we are only generating a slow call)
if (_ioproj_fallthrough == NULL) {
_ioproj_fallthrough = new (C, 1) ProjNode(call, TypeFunc::I_O);
transform_later(_ioproj_fallthrough);
} else if (!always_slow) {
for (DUIterator_Fast imax, i = _ioproj_fallthrough->fast_outs(imax); i < imax; i++) {
Node *use = _ioproj_fallthrough->fast_out(i);
_igvn.hash_delete(use);
imax -= replace_input(use, _ioproj_fallthrough, result_phi_i_o);
_igvn._worklist.push(use);
// back up iterator
--i;
}
}
// Now change uses of _ioproj_catchall to use _ioproj_fallthrough and delete _ioproj_catchall so
// we end up with a call that has only 1 control projection
if (_ioproj_catchall != NULL ) {
for (DUIterator_Fast imax, i = _ioproj_catchall->fast_outs(imax); i < imax; i++) {
Node *use = _ioproj_catchall->fast_out(i);
_igvn.hash_delete(use);
imax -= replace_input(use, _ioproj_catchall, _ioproj_fallthrough);
_igvn._worklist.push(use);
// back up iterator
--i;
}
}
// if we generated only a slow call, we are done
if (always_slow)
return;
if (_fallthroughcatchproj != NULL) {
ctrl = _fallthroughcatchproj->clone();
transform_later(ctrl);
_igvn.hash_delete(_fallthroughcatchproj);
_igvn.subsume_node(_fallthroughcatchproj, result_region);
} else {
ctrl = top();
}
Node *slow_result;
if (_resproj == NULL) {
// no uses of the allocation result
slow_result = top();
} else {
slow_result = _resproj->clone();
transform_later(slow_result);
_igvn.hash_delete(_resproj);
_igvn.subsume_node(_resproj, result_phi_rawoop);
}
// Plug slow-path into result merge point
result_region ->init_req( slow_result_path, ctrl );
result_phi_rawoop->init_req( slow_result_path, slow_result);
result_phi_rawmem->init_req( slow_result_path, _memproj_fallthrough );
transform_later(result_region);
transform_later(result_phi_rawoop);
transform_later(result_phi_rawmem);
transform_later(result_phi_i_o);
// This completes all paths into the result merge point
}
// Helper for PhaseMacroExpand::expand_allocate_common.
// Initializes the newly-allocated storage.
Node*
PhaseMacroExpand::initialize_object(AllocateNode* alloc,
Node* control, Node* rawmem, Node* object,
Node* klass_node, Node* length,
Node* size_in_bytes) {
InitializeNode* init = alloc->initialization();
// Store the klass & mark bits
Node* mark_node = NULL;
// For now only enable fast locking for non-array types
if (UseBiasedLocking && (length == NULL)) {
mark_node = make_load(NULL, rawmem, klass_node, Klass::prototype_header_offset_in_bytes() + sizeof(oopDesc), TypeRawPtr::BOTTOM, T_ADDRESS);
} else {
mark_node = makecon(TypeRawPtr::make((address)markOopDesc::prototype()));
}
rawmem = make_store(control, rawmem, object, oopDesc::mark_offset_in_bytes(), mark_node, T_ADDRESS);
if (UseCompressedOops) {
Node *zeronode = makecon(TypeInt::ZERO);
// store uncompressed 0 into klass ptr to zero out gap. The gap is
// used for primitive fields and has to be zeroed.
rawmem = make_store(control, rawmem, object, oopDesc::klass_gap_offset_in_bytes(), zeronode, T_INT);
}
rawmem = make_store(control, rawmem, object, oopDesc::klass_offset_in_bytes(), klass_node, T_OBJECT);
int header_size = alloc->minimum_header_size(); // conservatively small
// Array length
if (length != NULL) { // Arrays need length field
rawmem = make_store(control, rawmem, object, arrayOopDesc::length_offset_in_bytes(), length, T_INT);
// conservatively small header size:
header_size = arrayOopDesc::base_offset_in_bytes(T_BYTE);
ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass();
if (k->is_array_klass()) // we know the exact header size in most cases:
header_size = Klass::layout_helper_header_size(k->layout_helper());
}
// Clear the object body, if necessary.
if (init == NULL) {
// The init has somehow disappeared; be cautious and clear everything.
//
// This can happen if a node is allocated but an uncommon trap occurs
// immediately. In this case, the Initialize gets associated with the
// trap, and may be placed in a different (outer) loop, if the Allocate
// is in a loop. If (this is rare) the inner loop gets unrolled, then
// there can be two Allocates to one Initialize. The answer in all these
// edge cases is safety first. It is always safe to clear immediately
// within an Allocate, and then (maybe or maybe not) clear some more later.
if (!ZeroTLAB)
rawmem = ClearArrayNode::clear_memory(control, rawmem, object,
header_size, size_in_bytes,
&_igvn);
} else {
if (!init->is_complete()) {
// Try to win by zeroing only what the init does not store.
// We can also try to do some peephole optimizations,
// such as combining some adjacent subword stores.
rawmem = init->complete_stores(control, rawmem, object,
header_size, size_in_bytes, &_igvn);
}
// We have no more use for this link, since the AllocateNode goes away:
init->set_req(InitializeNode::RawAddress, top());
// (If we keep the link, it just confuses the register allocator,
// who thinks he sees a real use of the address by the membar.)
}
return rawmem;
}
// Generate prefetch instructions for next allocations.
Node* PhaseMacroExpand::prefetch_allocation(Node* i_o, Node*& needgc_false,
Node*& contended_phi_rawmem,
Node* old_eden_top, Node* new_eden_top,
Node* length) {
if( UseTLAB && AllocatePrefetchStyle == 2 ) {
// Generate prefetch allocation with watermark check.
// As an allocation hits the watermark, we will prefetch starting
// at a "distance" away from watermark.
enum { fall_in_path = 1, pf_path = 2 };
Node *pf_region = new (C, 3) RegionNode(3);
Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY,
TypeRawPtr::BOTTOM );
// I/O is used for Prefetch
Node *pf_phi_abio = new (C, 3) PhiNode( pf_region, Type::ABIO );
Node *thread = new (C, 1) ThreadLocalNode();
transform_later(thread);
Node *eden_pf_adr = new (C, 4) AddPNode( top()/*not oop*/, thread,
_igvn.MakeConX(in_bytes(JavaThread::tlab_pf_top_offset())) );
transform_later(eden_pf_adr);
Node *old_pf_wm = new (C, 3) LoadPNode( needgc_false,
contended_phi_rawmem, eden_pf_adr,
TypeRawPtr::BOTTOM, TypeRawPtr::BOTTOM );
transform_later(old_pf_wm);
// check against new_eden_top
Node *need_pf_cmp = new (C, 3) CmpPNode( new_eden_top, old_pf_wm );
transform_later(need_pf_cmp);
Node *need_pf_bol = new (C, 2) BoolNode( need_pf_cmp, BoolTest::ge );
transform_later(need_pf_bol);
IfNode *need_pf_iff = new (C, 2) IfNode( needgc_false, need_pf_bol,
PROB_UNLIKELY_MAG(4), COUNT_UNKNOWN );
transform_later(need_pf_iff);
// true node, add prefetchdistance
Node *need_pf_true = new (C, 1) IfTrueNode( need_pf_iff );
transform_later(need_pf_true);
Node *need_pf_false = new (C, 1) IfFalseNode( need_pf_iff );
transform_later(need_pf_false);
Node *new_pf_wmt = new (C, 4) AddPNode( top(), old_pf_wm,
_igvn.MakeConX(AllocatePrefetchDistance) );
transform_later(new_pf_wmt );
new_pf_wmt->set_req(0, need_pf_true);
Node *store_new_wmt = new (C, 4) StorePNode( need_pf_true,
contended_phi_rawmem, eden_pf_adr,
TypeRawPtr::BOTTOM, new_pf_wmt );
transform_later(store_new_wmt);
// adding prefetches
pf_phi_abio->init_req( fall_in_path, i_o );
Node *prefetch_adr;
Node *prefetch;
uint lines = AllocatePrefetchDistance / AllocatePrefetchStepSize;
uint step_size = AllocatePrefetchStepSize;
uint distance = 0;
for ( uint i = 0; i < lines; i++ ) {
prefetch_adr = new (C, 4) AddPNode( old_pf_wm, new_pf_wmt,
_igvn.MakeConX(distance) );
transform_later(prefetch_adr);
prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
transform_later(prefetch);
distance += step_size;
i_o = prefetch;
}
pf_phi_abio->set_req( pf_path, i_o );
pf_region->init_req( fall_in_path, need_pf_false );
pf_region->init_req( pf_path, need_pf_true );
pf_phi_rawmem->init_req( fall_in_path, contended_phi_rawmem );
pf_phi_rawmem->init_req( pf_path, store_new_wmt );
transform_later(pf_region);
transform_later(pf_phi_rawmem);
transform_later(pf_phi_abio);
needgc_false = pf_region;
contended_phi_rawmem = pf_phi_rawmem;
i_o = pf_phi_abio;
} else if( AllocatePrefetchStyle > 0 ) {
// Insert a prefetch for each allocation only on the fast-path
Node *prefetch_adr;
Node *prefetch;
// Generate several prefetch instructions only for arrays.
uint lines = (length != NULL) ? AllocatePrefetchLines : 1;
uint step_size = AllocatePrefetchStepSize;
uint distance = AllocatePrefetchDistance;
for ( uint i = 0; i < lines; i++ ) {
prefetch_adr = new (C, 4) AddPNode( old_eden_top, new_eden_top,
_igvn.MakeConX(distance) );
transform_later(prefetch_adr);
prefetch = new (C, 3) PrefetchWriteNode( i_o, prefetch_adr );
// Do not let it float too high, since if eden_top == eden_end,
// both might be null.
if( i == 0 ) { // Set control for first prefetch, next follows it
prefetch->init_req(0, needgc_false);
}
transform_later(prefetch);
distance += step_size;
i_o = prefetch;
}
}
return i_o;
}
void PhaseMacroExpand::expand_allocate(AllocateNode *alloc) {
expand_allocate_common(alloc, NULL,
OptoRuntime::new_instance_Type(),
OptoRuntime::new_instance_Java());
}
void PhaseMacroExpand::expand_allocate_array(AllocateArrayNode *alloc) {
Node* length = alloc->in(AllocateNode::ALength);
expand_allocate_common(alloc, length,
OptoRuntime::new_array_Type(),
OptoRuntime::new_array_Java());
}
// we have determined that this lock/unlock can be eliminated, we simply
// eliminate the node without expanding it.
//
// Note: The membar's associated with the lock/unlock are currently not
// eliminated. This should be investigated as a future enhancement.
//
bool PhaseMacroExpand::eliminate_locking_node(AbstractLockNode *alock) {
if (!alock->is_eliminated()) {
return false;
}
// Mark the box lock as eliminated if all correspondent locks are eliminated
// to construct correct debug info.
BoxLockNode* box = alock->box_node()->as_BoxLock();
if (!box->is_eliminated()) {
bool eliminate = true;
for (DUIterator_Fast imax, i = box->fast_outs(imax); i < imax; i++) {
Node *lck = box->fast_out(i);
if (lck->is_Lock() && !lck->as_AbstractLock()->is_eliminated()) {
eliminate = false;
break;
}
}
if (eliminate)
box->set_eliminated();
}
#ifndef PRODUCT
if (PrintEliminateLocks) {
if (alock->is_Lock()) {
tty->print_cr("++++ Eliminating: %d Lock", alock->_idx);
} else {
tty->print_cr("++++ Eliminating: %d Unlock", alock->_idx);
}
}
#endif
Node* mem = alock->in(TypeFunc::Memory);
Node* ctrl = alock->in(TypeFunc::Control);
extract_call_projections(alock);
// There are 2 projections from the lock. The lock node will
// be deleted when its last use is subsumed below.
assert(alock->outcnt() == 2 &&
_fallthroughproj != NULL &&
_memproj_fallthrough != NULL,
"Unexpected projections from Lock/Unlock");
Node* fallthroughproj = _fallthroughproj;
Node* memproj_fallthrough = _memproj_fallthrough;
// The memory projection from a lock/unlock is RawMem
// The input to a Lock is merged memory, so extract its RawMem input
// (unless the MergeMem has been optimized away.)
if (alock->is_Lock()) {
// Seach for MemBarAcquire node and delete it also.
MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar();
assert(membar != NULL && membar->Opcode() == Op_MemBarAcquire, "");
Node* ctrlproj = membar->proj_out(TypeFunc::Control);
Node* memproj = membar->proj_out(TypeFunc::Memory);
_igvn.hash_delete(ctrlproj);
_igvn.subsume_node(ctrlproj, fallthroughproj);
_igvn.hash_delete(memproj);
_igvn.subsume_node(memproj, memproj_fallthrough);
}
// Seach for MemBarRelease node and delete it also.
if (alock->is_Unlock() && ctrl != NULL && ctrl->is_Proj() &&
ctrl->in(0)->is_MemBar()) {
MemBarNode* membar = ctrl->in(0)->as_MemBar();
assert(membar->Opcode() == Op_MemBarRelease &&
mem->is_Proj() && membar == mem->in(0), "");
_igvn.hash_delete(fallthroughproj);
_igvn.subsume_node(fallthroughproj, ctrl);
_igvn.hash_delete(memproj_fallthrough);
_igvn.subsume_node(memproj_fallthrough, mem);
fallthroughproj = ctrl;
memproj_fallthrough = mem;
ctrl = membar->in(TypeFunc::Control);
mem = membar->in(TypeFunc::Memory);
}
_igvn.hash_delete(fallthroughproj);
_igvn.subsume_node(fallthroughproj, ctrl);
_igvn.hash_delete(memproj_fallthrough);
_igvn.subsume_node(memproj_fallthrough, mem);
return true;
}
//------------------------------expand_lock_node----------------------
void PhaseMacroExpand::expand_lock_node(LockNode *lock) {
Node* ctrl = lock->in(TypeFunc::Control);
Node* mem = lock->in(TypeFunc::Memory);
Node* obj = lock->obj_node();
Node* box = lock->box_node();
Node* flock = lock->fastlock_node();
// Make the merge point
Node *region = new (C, 3) RegionNode(3);
Node *bol = transform_later(new (C, 2) BoolNode(flock,BoolTest::ne));
Node *iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
// Optimize test; set region slot 2
Node *slow_path = opt_iff(region,iff);
// Make slow path call
CallNode *call = make_slow_call( (CallNode *) lock, OptoRuntime::complete_monitor_enter_Type(), OptoRuntime::complete_monitor_locking_Java(), NULL, slow_path, obj, box );
extract_call_projections(call);
// Slow path can only throw asynchronous exceptions, which are always
// de-opted. So the compiler thinks the slow-call can never throw an
// exception. If it DOES throw an exception we would need the debug
// info removed first (since if it throws there is no monitor).
assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
_memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
// Capture slow path
// disconnect fall-through projection from call and create a new one
// hook up users of fall-through projection to region
Node *slow_ctrl = _fallthroughproj->clone();
transform_later(slow_ctrl);
_igvn.hash_delete(_fallthroughproj);
_fallthroughproj->disconnect_inputs(NULL);
region->init_req(1, slow_ctrl);
// region inputs are now complete
transform_later(region);
_igvn.subsume_node(_fallthroughproj, region);
// create a Phi for the memory state
Node *mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
Node *memproj = transform_later( new (C, 1) ProjNode(call, TypeFunc::Memory) );
mem_phi->init_req(1, memproj );
mem_phi->init_req(2, mem);
transform_later(mem_phi);
_igvn.hash_delete(_memproj_fallthrough);
_igvn.subsume_node(_memproj_fallthrough, mem_phi);
}
//------------------------------expand_unlock_node----------------------
void PhaseMacroExpand::expand_unlock_node(UnlockNode *unlock) {
Node* ctrl = unlock->in(TypeFunc::Control);
Node* mem = unlock->in(TypeFunc::Memory);
Node* obj = unlock->obj_node();
Node* box = unlock->box_node();
// No need for a null check on unlock
// Make the merge point
RegionNode *region = new (C, 3) RegionNode(3);
FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box );
funlock = transform_later( funlock )->as_FastUnlock();
Node *bol = transform_later(new (C, 2) BoolNode(funlock,BoolTest::ne));
Node *iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN );
// Optimize test; set region slot 2
Node *slow_path = opt_iff(region,iff);
CallNode *call = make_slow_call( (CallNode *) unlock, OptoRuntime::complete_monitor_exit_Type(), CAST_FROM_FN_PTR(address, SharedRuntime::complete_monitor_unlocking_C), "complete_monitor_unlocking_C", slow_path, obj, box );
extract_call_projections(call);
assert ( _ioproj_fallthrough == NULL && _ioproj_catchall == NULL &&
_memproj_catchall == NULL && _catchallcatchproj == NULL, "Unexpected projection from Lock");
// No exceptions for unlocking
// Capture slow path
// disconnect fall-through projection from call and create a new one
// hook up users of fall-through projection to region
Node *slow_ctrl = _fallthroughproj->clone();
transform_later(slow_ctrl);
_igvn.hash_delete(_fallthroughproj);
_fallthroughproj->disconnect_inputs(NULL);
region->init_req(1, slow_ctrl);
// region inputs are now complete
transform_later(region);
_igvn.subsume_node(_fallthroughproj, region);
// create a Phi for the memory state
Node *mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM);
Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) );
mem_phi->init_req(1, memproj );
mem_phi->init_req(2, mem);
transform_later(mem_phi);
_igvn.hash_delete(_memproj_fallthrough);
_igvn.subsume_node(_memproj_fallthrough, mem_phi);
}
//------------------------------expand_macro_nodes----------------------
// Returns true if a failure occurred.
bool PhaseMacroExpand::expand_macro_nodes() {
if (C->macro_count() == 0)
return false;
// attempt to eliminate allocations
bool progress = true;
while (progress) {
progress = false;
for (int i = C->macro_count(); i > 0; i--) {
Node * n = C->macro_node(i-1);
bool success = false;
debug_only(int old_macro_count = C->macro_count(););
switch (n->class_id()) {
case Node::Class_Allocate:
case Node::Class_AllocateArray:
success = eliminate_allocate_node(n->as_Allocate());
break;
case Node::Class_Lock:
case Node::Class_Unlock:
success = eliminate_locking_node(n->as_AbstractLock());
break;
default:
assert(false, "unknown node type in macro list");
}
assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count");
progress = progress || success;
}
}
// Make sure expansion will not cause node limit to be exceeded.
// Worst case is a macro node gets expanded into about 50 nodes.
// Allow 50% more for optimization.
if (C->check_node_count(C->macro_count() * 75, "out of nodes before macro expansion" ) )
return true;
// expand "macro" nodes
// nodes are removed from the macro list as they are processed
while (C->macro_count() > 0) {
int macro_count = C->macro_count();
Node * n = C->macro_node(macro_count-1);
assert(n->is_macro(), "only macro nodes expected here");
if (_igvn.type(n) == Type::TOP || n->in(0)->is_top() ) {
// node is unreachable, so don't try to expand it
C->remove_macro_node(n);
continue;
}
switch (n->class_id()) {
case Node::Class_Allocate:
expand_allocate(n->as_Allocate());
break;
case Node::Class_AllocateArray:
expand_allocate_array(n->as_AllocateArray());
break;
case Node::Class_Lock:
expand_lock_node(n->as_Lock());
break;
case Node::Class_Unlock:
expand_unlock_node(n->as_Unlock());
break;
default:
assert(false, "unknown node type in macro list");
}
assert(C->macro_count() < macro_count, "must have deleted a node from macro list");
if (C->failing()) return true;
}
_igvn.set_delay_transform(false);
_igvn.optimize();
return false;
}