/* * Copyright (c) 2005, 2011, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #include "precompiled.hpp" #include "compiler/compileLog.hpp" #include "libadt/vectset.hpp" #include "opto/addnode.hpp" #include "opto/callnode.hpp" #include "opto/cfgnode.hpp" #include "opto/compile.hpp" #include "opto/connode.hpp" #include "opto/locknode.hpp" #include "opto/loopnode.hpp" #include "opto/macro.hpp" #include "opto/memnode.hpp" #include "opto/node.hpp" #include "opto/phaseX.hpp" #include "opto/rootnode.hpp" #include "opto/runtime.hpp" #include "opto/subnode.hpp" #include "opto/type.hpp" #include "runtime/sharedRuntime.hpp" // // 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 != NULL && 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->set_req(0, C->root()); // reset control edge 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_bits_test(Node* ctrl, Node* region, int edge, Node* word, int mask, int bits, bool return_fast_path) { Node* cmp; if (mask != 0) { Node* and_node = transform_later(new (C, 3) AndXNode(word, MakeConX(mask))); cmp = transform_later(new (C, 3) CmpXNode(and_node, MakeConX(bits))); } else { cmp = word; } Node* bol = transform_later(new (C, 2) BoolNode(cmp, BoolTest::ne)); IfNode* iff = new (C, 2) IfNode( ctrl, bol, PROB_MIN, COUNT_UNKNOWN ); transform_later(iff); // Fast path taken. Node *fast_taken = transform_later( new (C, 1) IfFalseNode(iff) ); // Fast path not-taken, i.e. slow path Node *slow_taken = transform_later( new (C, 1) IfTrueNode(iff) ); if (return_fast_path) { region->init_req(edge, slow_taken); // Capture slow-control return fast_taken; } else { region->init_req(edge, fast_taken); // Capture fast-control 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.replace_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"); if (!UseG1GC) { // vanilla/CMS post barrier Node *shift = p2x->unique_out(); Node *addp = shift->unique_out(); for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) { Node *mem = addp->last_out(j); if (UseCondCardMark && mem->is_Load()) { assert(mem->Opcode() == Op_LoadB, "unexpected code shape"); // The load is checking if the card has been written so // replace it with zero to fold the test. _igvn.replace_node(mem, intcon(0)); continue; } assert(mem->is_Store(), "store required"); _igvn.replace_node(mem, mem->in(MemNode::Memory)); } } else { // G1 pre/post barriers assert(p2x->outcnt() == 2, "expects 2 users: Xor and URShift nodes"); // It could be only one user, URShift node, in Object.clone() instrinsic // but the new allocation is passed to arraycopy stub and it could not // be scalar replaced. So we don't check the case. // Remove G1 post barrier. // Search for CastP2X->Xor->URShift->Cmp path which // checks if the store done to a different from the value's region. // And replace Cmp with #0 (false) to collapse G1 post barrier. Node* xorx = NULL; for (DUIterator_Fast imax, i = p2x->fast_outs(imax); i < imax; i++) { Node* u = p2x->fast_out(i); if (u->Opcode() == Op_XorX) { xorx = u; break; } } assert(xorx != NULL, "missing G1 post barrier"); Node* shift = xorx->unique_out(); Node* cmpx = shift->unique_out(); assert(cmpx->is_Cmp() && cmpx->unique_out()->is_Bool() && cmpx->unique_out()->as_Bool()->_test._test == BoolTest::ne, "missing region check in G1 post barrier"); _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ)); // Remove G1 pre barrier. // Search "if (marking != 0)" check and set it to "false". Node* this_region = p2x->in(0); assert(this_region != NULL, ""); // There is no G1 pre barrier if previous stored value is NULL // (for example, after initialization). if (this_region->is_Region() && this_region->req() == 3) { int ind = 1; if (!this_region->in(ind)->is_IfFalse()) { ind = 2; } if (this_region->in(ind)->is_IfFalse()) { Node* bol = this_region->in(ind)->in(0)->in(1); assert(bol->is_Bool(), ""); cmpx = bol->in(1); if (bol->as_Bool()->_test._test == BoolTest::ne && cmpx->is_Cmp() && cmpx->in(2) == intcon(0) && cmpx->in(1)->is_Load()) { Node* adr = cmpx->in(1)->as_Load()->in(MemNode::Address); const int marking_offset = in_bytes(JavaThread::satb_mark_queue_offset() + PtrQueue::byte_offset_of_active()); if (adr->is_AddP() && adr->in(AddPNode::Base) == top() && adr->in(AddPNode::Address)->Opcode() == Op_ThreadLocal && adr->in(AddPNode::Offset) == MakeConX(marking_offset)) { _igvn.replace_node(cmpx, makecon(TypeInt::CC_EQ)); } } } } // Now CastP2X can be removed since it is used only on dead path // which currently still alive until igvn optimize it. assert(p2x->unique_out()->Opcode() == Op_URShiftX, ""); _igvn.replace_node(p2x, top()); } } // 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, PhaseGVN *phase) { Node *orig_mem = mem; Node *alloc_mem = alloc->in(TypeFunc::Memory); const TypeOopPtr *tinst = phase->C->get_adr_type(alias_idx)->isa_oopptr(); while (true) { if (mem == alloc_mem || mem == start_mem ) { return mem; // hit one of our sentinels } 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()) { CallNode *call = in->as_Call(); if (!call->may_modify(tinst, phase)) { mem = call->in(TypeFunc::Memory); } mem = in->in(TypeFunc::Memory); } else if (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 if (mem->is_ClearArray()) { if (!ClearArrayNode::step_through(&mem, alloc->_idx, phase)) { // Can not bypass initialization of the instance // we are looking. debug_only(intptr_t offset;) assert(alloc == AllocateNode::Ideal_allocation(mem->in(3), phase, offset), "sanity"); InitializeNode* init = alloc->as_Allocate()->initialization(); // We are looking for stored value, return Initialize node // or memory edge from Allocate node. if (init != NULL) return init; else return alloc->in(TypeFunc::Memory); // It will produce zero value (see callers). } // Otherwise skip it (the call updated 'mem' value). } else if (mem->Opcode() == Op_SCMemProj) { assert(mem->in(0)->is_LoadStore(), "sanity"); const TypePtr* atype = mem->in(0)->in(MemNode::Address)->bottom_type()->is_ptr(); int adr_idx = Compile::current()->get_alias_index(atype); if (adr_idx == alias_idx) { assert(false, "Object is not scalar replaceable if a LoadStore node access its field"); return NULL; } mem = mem->in(0)->in(MemNode::Memory); } else { return mem; } assert(mem != orig_mem, "dead memory loop"); } } // // 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, Node_Stack *value_phis, int level) { assert(mem->is_Phi(), "sanity"); int alias_idx = C->get_alias_index(adr_t); int offset = adr_t->offset(); int instance_id = adr_t->instance_id(); // Check if an appropriate value phi already exists. Node* region = mem->in(0); for (DUIterator_Fast kmax, k = region->fast_outs(kmax); k < kmax; k++) { Node* phi = region->fast_out(k); if (phi->is_Phi() && phi != mem && phi->as_Phi()->is_same_inst_field(phi_type, instance_id, alias_idx, offset)) { return phi; } } // Check if an appropriate new value phi already exists. Node* new_phi = value_phis->find(mem->_idx); if (new_phi != NULL) return new_phi; if (level <= 0) { return NULL; // Give up: phi tree too deep } Node *start_mem = C->start()->proj_out(TypeFunc::Memory); Node *alloc_mem = alloc->in(TypeFunc::Memory); uint length = mem->req(); GrowableArray values(length, length, NULL); // create a new Phi for the value PhiNode *phi = new (C, length) PhiNode(mem->in(0), phi_type, NULL, instance_id, alias_idx, offset); transform_later(phi); value_phis->push(phi, mem->_idx); 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, &_igvn); 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()) { val = value_from_mem_phi(val, ft, phi_type, adr_t, alloc, value_phis, level-1); if (val == NULL) { return NULL; } values.at_put(j, val); } else if (val->Opcode() == Op_SCMemProj) { assert(val->in(0)->is_LoadStore(), "sanity"); assert(false, "Object is not scalar replaceable if a LoadStore node access its field"); return NULL; } else { #ifdef ASSERT val->dump(); assert(false, "unknown node on this path"); #endif return NULL; // unknown node on this path } } } // Set Phi's inputs 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)); } } 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_known_instance_field(), "instance required"); int instance_id = adr_t->instance_id(); assert((uint)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); Arena *a = Thread::current()->resource_area(); VectorSet visited(a); 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, &_igvn); 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_known_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, &_igvn); 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_Stack value_phis(a, 8); Node * phi = value_from_mem_phi(mem, ft, ftype, adr_t, alloc, &value_phis, ValueSearchLimit); if (phi != NULL) { return phi; } else { // Kill all new Phis while(value_phis.is_nonempty()) { Node* n = value_phis.node(); _igvn.replace_node(n, C->top()); value_phis.pop(); } } } } // Something go wrong. return NULL; } // Check the possibility of scalar replacement. bool PhaseMacroExpand::can_eliminate_allocation(AllocateNode *alloc, GrowableArray & 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()) { 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() || n->is_LoadStore()) { 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->is_Call() && sfpt->as_Call()->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 & safepoints) { GrowableArray 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, C->root()); transform_later(sobj); // Scan object's fields adding an input to the safepoint for each field. for (int j = 0; j < nfields; j++) { intptr_t 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 * (intptr_t)element_size; } const Type *field_type; // The next code is taken from Parse::do_get_xxx(). if (basic_elem_type == T_OBJECT || basic_elem_type == T_ARRAY) { if (!elem_type->is_loaded()) { field_type = TypeInstPtr::BOTTOM; } else if (field != NULL && field->is_constant() && field->is_static()) { // 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()); } if (UseCompressedOops) { field_type = field_type->make_narrowoop(); basic_elem_type = T_NARROWOOP; } } 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. // 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; } if (UseCompressedOops && field_type->isa_narrowoop()) { // Enable "DecodeN(EncodeP(Allocate)) --> Allocate" transformation // to be able scalar replace the allocation. if (field_val->is_EncodeP()) { field_val = field_val->in(1); } else { field_val = transform_later(new (C, 2) DecodeNNode(field_val, field_val->bottom_type()->make_ptr())); } } 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()) { #ifdef ASSERT // Verify that there is no dependent MemBarVolatile nodes, // they should be removed during IGVN, see MemBarNode::Ideal(). for (DUIterator_Fast pmax, p = n->fast_outs(pmax); p < pmax; p++) { Node* mb = n->fast_out(p); assert(mb->is_Initialize() || !mb->is_MemBar() || mb->req() <= MemBarNode::Precedent || mb->in(MemBarNode::Precedent) != n, "MemBarVolatile should be eliminated for non-escaping object"); } #endif _igvn.replace_node(n, n->in(MemNode::Memory)); } else { eliminate_card_mark(n); } k -= (oc2 - use->outcnt()); } } else { 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.replace_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 safepoints; if (!can_eliminate_allocation(alloc, safepoints)) { return false; } if (!scalar_replacement(alloc, safepoints)) { return false; } CompileLog* log = C->log(); if (log != NULL) { Node* klass = alloc->in(AllocateNode::KlassNode); const TypeKlassPtr* tklass = _igvn.type(klass)->is_klassptr(); log->head("eliminate_allocation type='%d'", log->identify(tklass->klass())); JVMState* p = alloc->jvms(); while (p != NULL) { log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); p = p->caller(); } log->tail("eliminate_allocation"); } 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 = adr->bottom_type()->is_ptr(); 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); Node* storestore = alloc->storestore(); if (storestore != NULL) { // Break this link that is no longer useful and confuses register allocation storestore->set_req(MemBarNode::Precedent, top()); } assert(ctrl != NULL, "must have control"); // 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 (C->env()->dtrace_alloc_probes() || !UseTLAB && (!Universe::heap()->supports_inline_contig_alloc() || (UseConcMarkSweepGC && CMSIncrementalMode))) { // 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) { // Fast path modifies only raw memory. 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); // 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 they 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); // 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); // Name successful fast-path variables Node* fast_oop = old_eden_top; Node* fast_oop_ctrl; Node* fast_oop_rawmem; // Store (-conditional) the modified eden top back down. // StorePConditional produces flags for a test PLUS a modified raw // memory state. if (UseTLAB) { Node* 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 fast_oop_rawmem = store_eden_top; } else { Node* store_eden_top = new (C, 5) StorePConditionalNode(needgc_false, contended_phi_rawmem, eden_top_adr, new_eden_top, fast_oop/*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; // Bump total allocated bytes for this thread Node* thread = new (C, 1) ThreadLocalNode(); transform_later(thread); Node* alloc_bytes_adr = basic_plus_adr(top()/*not oop*/, thread, in_bytes(JavaThread::allocated_bytes_offset())); Node* alloc_bytes = make_load(fast_oop_ctrl, store_eden_top, alloc_bytes_adr, 0, TypeLong::LONG, T_LONG); #ifdef _LP64 Node* alloc_size = size_in_bytes; #else Node* alloc_size = new (C, 2) ConvI2LNode(size_in_bytes); transform_later(alloc_size); #endif Node* new_alloc_bytes = new (C, 3) AddLNode(alloc_bytes, alloc_size); transform_later(new_alloc_bytes); fast_oop_rawmem = make_store(fast_oop_ctrl, store_eden_top, alloc_bytes_adr, 0, new_alloc_bytes, T_LONG); } InitializeNode* init = alloc->initialization(); fast_oop_rawmem = initialize_object(alloc, fast_oop_ctrl, fast_oop_rawmem, fast_oop, klass_node, length, size_in_bytes); // If initialization is performed by an array copy, any required // MemBarStoreStore was already added. If the object does not // escape no need for a MemBarStoreStore. Otherwise we need a // MemBarStoreStore so that stores that initialize this object // can't be reordered with a subsequent store that makes this // object accessible by other threads. if (init == NULL || (!init->is_complete_with_arraycopy() && !init->does_not_escape())) { if (init == NULL || init->req() < InitializeNode::RawStores) { // No InitializeNode or no stores captured by zeroing // elimination. Simply add the MemBarStoreStore after object // initialization. MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot, fast_oop_rawmem); transform_later(mb); mb->init_req(TypeFunc::Memory, fast_oop_rawmem); mb->init_req(TypeFunc::Control, fast_oop_ctrl); fast_oop_ctrl = new (C, 1) ProjNode(mb,TypeFunc::Control); transform_later(fast_oop_ctrl); fast_oop_rawmem = new (C, 1) ProjNode(mb,TypeFunc::Memory); transform_later(fast_oop_rawmem); } else { // Add the MemBarStoreStore after the InitializeNode so that // all stores performing the initialization that were moved // before the InitializeNode happen before the storestore // barrier. Node* init_ctrl = init->proj_out(TypeFunc::Control); Node* init_mem = init->proj_out(TypeFunc::Memory); MemBarNode* mb = MemBarNode::make(C, Op_MemBarStoreStore, Compile::AliasIdxBot); transform_later(mb); Node* ctrl = new (C, 1) ProjNode(init,TypeFunc::Control); transform_later(ctrl); Node* mem = new (C, 1) ProjNode(init,TypeFunc::Memory); transform_later(mem); // The MemBarStoreStore depends on control and memory coming // from the InitializeNode mb->init_req(TypeFunc::Memory, mem); mb->init_req(TypeFunc::Control, ctrl); ctrl = new (C, 1) ProjNode(mb,TypeFunc::Control); transform_later(ctrl); mem = new (C, 1) ProjNode(mb,TypeFunc::Memory); transform_later(mem); // All nodes that depended on the InitializeNode for control // and memory must now depend on the MemBarNode that itself // depends on the InitializeNode _igvn.replace_node(init_ctrl, ctrl); _igvn.replace_node(init_mem, mem); } } if (C->env()->dtrace_extended_probes()) { // 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.replace_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; } } // 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.replace_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.replace_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(control, rawmem, klass_node, in_bytes(Klass::prototype_header_offset()), 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); 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) { enum { fall_in_path = 1, pf_path = 2 }; 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. 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) PrefetchAllocationNode( 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( UseTLAB && AllocatePrefetchStyle == 3 ) { // Insert a prefetch for each allocation. // This code is used for Sparc with BIS. Node *pf_region = new (C, 3) RegionNode(3); Node *pf_phi_rawmem = new (C, 3) PhiNode( pf_region, Type::MEMORY, TypeRawPtr::BOTTOM ); // Generate several prefetch instructions. uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines; uint step_size = AllocatePrefetchStepSize; uint distance = AllocatePrefetchDistance; // Next cache address. Node *cache_adr = new (C, 4) AddPNode(old_eden_top, old_eden_top, _igvn.MakeConX(distance)); transform_later(cache_adr); cache_adr = new (C, 2) CastP2XNode(needgc_false, cache_adr); transform_later(cache_adr); Node* mask = _igvn.MakeConX(~(intptr_t)(step_size-1)); cache_adr = new (C, 3) AndXNode(cache_adr, mask); transform_later(cache_adr); cache_adr = new (C, 2) CastX2PNode(cache_adr); transform_later(cache_adr); // Prefetch Node *prefetch = new (C, 3) PrefetchAllocationNode( contended_phi_rawmem, cache_adr ); prefetch->set_req(0, needgc_false); transform_later(prefetch); contended_phi_rawmem = prefetch; Node *prefetch_adr; distance = step_size; for ( uint i = 1; i < lines; i++ ) { prefetch_adr = new (C, 4) AddPNode( cache_adr, cache_adr, _igvn.MakeConX(distance) ); transform_later(prefetch_adr); prefetch = new (C, 3) PrefetchAllocationNode( contended_phi_rawmem, prefetch_adr ); transform_later(prefetch); distance += step_size; contended_phi_rawmem = prefetch; } } else if( AllocatePrefetchStyle > 0 ) { // Insert a prefetch for each allocation only on the fast-path Node *prefetch_adr; Node *prefetch; // Generate several prefetch instructions. uint lines = (length != NULL) ? AllocatePrefetchLines : AllocateInstancePrefetchLines; 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) PrefetchAllocationNode( 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); InitializeNode* init = alloc->initialization(); Node* klass_node = alloc->in(AllocateNode::KlassNode); ciKlass* k = _igvn.type(klass_node)->is_klassptr()->klass(); address slow_call_address; // Address of slow call if (init != NULL && init->is_complete_with_arraycopy() && k->is_type_array_klass()) { // Don't zero type array during slow allocation in VM since // it will be initialized later by arraycopy in compiled code. slow_call_address = OptoRuntime::new_array_nozero_Java(); } else { slow_call_address = OptoRuntime::new_array_Java(); } expand_allocate_common(alloc, length, OptoRuntime::new_array_Type(), slow_call_address); } //-----------------------mark_eliminated_locking_nodes----------------------- // During EA obj may point to several objects but after few ideal graph // transformations (CCP) it may point to only one non escaping object // (but still using phi), corresponding locks and unlocks will be marked // for elimination. Later obj could be replaced with a new node (new phi) // and which does not have escape information. And later after some graph // reshape other locks and unlocks (which were not marked for elimination // before) are connected to this new obj (phi) but they still will not be // marked for elimination since new obj has no escape information. // Mark all associated (same box and obj) lock and unlock nodes for // elimination if some of them marked already. void PhaseMacroExpand::mark_eliminated_locking_nodes(AbstractLockNode *alock) { if (!alock->is_eliminated()) { return; } if (!alock->is_coarsened()) { // Eliminated by EA // Create new "eliminated" BoxLock node and use it // in monitor debug info for the same object. BoxLockNode* oldbox = alock->box_node()->as_BoxLock(); Node* obj = alock->obj_node(); if (!oldbox->is_eliminated()) { BoxLockNode* newbox = oldbox->clone()->as_BoxLock(); // Note: BoxLock node is marked eliminated only here // and it is used to indicate that all associated lock // and unlock nodes are marked for elimination. newbox->set_eliminated(); transform_later(newbox); // Replace old box node with new box for all users // of the same object. for (uint i = 0; i < oldbox->outcnt();) { bool next_edge = true; Node* u = oldbox->raw_out(i); if (u->is_AbstractLock() && u->as_AbstractLock()->obj_node() == obj && u->as_AbstractLock()->box_node() == oldbox) { // Mark all associated locks and unlocks. u->as_AbstractLock()->set_eliminated(); _igvn.hash_delete(u); u->set_req(TypeFunc::Parms + 1, newbox); next_edge = false; } // Replace old box in monitor debug info. if (u->is_SafePoint() && u->as_SafePoint()->jvms()) { SafePointNode* sfn = u->as_SafePoint(); JVMState* youngest_jvms = sfn->jvms(); int max_depth = youngest_jvms->depth(); for (int depth = 1; depth <= max_depth; depth++) { JVMState* jvms = youngest_jvms->of_depth(depth); int num_mon = jvms->nof_monitors(); // Loop over monitors for (int idx = 0; idx < num_mon; idx++) { Node* obj_node = sfn->monitor_obj(jvms, idx); Node* box_node = sfn->monitor_box(jvms, idx); if (box_node == oldbox && obj_node == obj) { int j = jvms->monitor_box_offset(idx); _igvn.hash_delete(u); u->set_req(j, newbox); next_edge = false; } } // for (int idx = 0; } // for (int depth = 1; } // if (u->is_SafePoint() if (next_edge) i++; } // for (uint i = 0; i < oldbox->outcnt();) } // if (!oldbox->is_eliminated()) } // if (!alock->is_coarsened()) } // 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; } #ifdef ASSERT if (alock->is_Lock() && !alock->is_coarsened()) { // Check that new "eliminated" BoxLock node is created. BoxLockNode* oldbox = alock->box_node()->as_BoxLock(); assert(oldbox->is_eliminated(), "should be done already"); } #endif CompileLog* log = C->log(); if (log != NULL) { log->head("eliminate_lock lock='%d'", alock->is_Lock()); JVMState* p = alock->jvms(); while (p != NULL) { log->elem("jvms bci='%d' method='%d'", p->bci(), log->identify(p->method())); p = p->caller(); } log->tail("eliminate_lock"); } #ifndef PRODUCT if (PrintEliminateLocks) { if (alock->is_Lock()) { tty->print_cr("++++ Eliminated: %d Lock", alock->_idx); } else { tty->print_cr("++++ Eliminated: %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 MemBarAcquireLock node and delete it also. MemBarNode* membar = fallthroughproj->unique_ctrl_out()->as_MemBar(); assert(membar != NULL && membar->Opcode() == Op_MemBarAcquireLock, ""); Node* ctrlproj = membar->proj_out(TypeFunc::Control); Node* memproj = membar->proj_out(TypeFunc::Memory); _igvn.replace_node(ctrlproj, fallthroughproj); _igvn.replace_node(memproj, memproj_fallthrough); // Delete FastLock node also if this Lock node is unique user // (a loop peeling may clone a Lock node). Node* flock = alock->as_Lock()->fastlock_node(); if (flock->outcnt() == 1) { assert(flock->unique_out() == alock, "sanity"); _igvn.replace_node(flock, top()); } } // Seach for MemBarReleaseLock 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_MemBarReleaseLock && mem->is_Proj() && membar == mem->in(0), ""); _igvn.replace_node(fallthroughproj, ctrl); _igvn.replace_node(memproj_fallthrough, mem); fallthroughproj = ctrl; memproj_fallthrough = mem; ctrl = membar->in(TypeFunc::Control); mem = membar->in(TypeFunc::Memory); } _igvn.replace_node(fallthroughproj, ctrl); _igvn.replace_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; Node *mem_phi; Node *slow_path; if (UseOptoBiasInlining) { /* * See the full description in MacroAssembler::biased_locking_enter(). * * if( (mark_word & biased_lock_mask) == biased_lock_pattern ) { * // The object is biased. * proto_node = klass->prototype_header; * o_node = thread | proto_node; * x_node = o_node ^ mark_word; * if( (x_node & ~age_mask) == 0 ) { // Biased to the current thread ? * // Done. * } else { * if( (x_node & biased_lock_mask) != 0 ) { * // The klass's prototype header is no longer biased. * cas(&mark_word, mark_word, proto_node) * goto cas_lock; * } else { * // The klass's prototype header is still biased. * if( (x_node & epoch_mask) != 0 ) { // Expired epoch? * old = mark_word; * new = o_node; * } else { * // Different thread or anonymous biased. * old = mark_word & (epoch_mask | age_mask | biased_lock_mask); * new = thread | old; * } * // Try to rebias. * if( cas(&mark_word, old, new) == 0 ) { * // Done. * } else { * goto slow_path; // Failed. * } * } * } * } else { * // The object is not biased. * cas_lock: * if( FastLock(obj) == 0 ) { * // Done. * } else { * slow_path: * OptoRuntime::complete_monitor_locking_Java(obj); * } * } */ region = new (C, 5) RegionNode(5); // create a Phi for the memory state mem_phi = new (C, 5) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); Node* fast_lock_region = new (C, 3) RegionNode(3); Node* fast_lock_mem_phi = new (C, 3) PhiNode( fast_lock_region, Type::MEMORY, TypeRawPtr::BOTTOM); // First, check mark word for the biased lock pattern. Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type()); // Get fast path - mark word has the biased lock pattern. ctrl = opt_bits_test(ctrl, fast_lock_region, 1, mark_node, markOopDesc::biased_lock_mask_in_place, markOopDesc::biased_lock_pattern, true); // fast_lock_region->in(1) is set to slow path. fast_lock_mem_phi->init_req(1, mem); // Now check that the lock is biased to the current thread and has // the same epoch and bias as Klass::_prototype_header. // Special-case a fresh allocation to avoid building nodes: Node* klass_node = AllocateNode::Ideal_klass(obj, &_igvn); if (klass_node == NULL) { Node* k_adr = basic_plus_adr(obj, oopDesc::klass_offset_in_bytes()); klass_node = transform_later( LoadKlassNode::make(_igvn, mem, k_adr, _igvn.type(k_adr)->is_ptr()) ); #ifdef _LP64 if (UseCompressedOops && klass_node->is_DecodeN()) { assert(klass_node->in(1)->Opcode() == Op_LoadNKlass, "sanity"); klass_node->in(1)->init_req(0, ctrl); } else #endif klass_node->init_req(0, ctrl); } Node *proto_node = make_load(ctrl, mem, klass_node, in_bytes(Klass::prototype_header_offset()), TypeX_X, TypeX_X->basic_type()); Node* thread = transform_later(new (C, 1) ThreadLocalNode()); Node* cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread)); Node* o_node = transform_later(new (C, 3) OrXNode(cast_thread, proto_node)); Node* x_node = transform_later(new (C, 3) XorXNode(o_node, mark_node)); // Get slow path - mark word does NOT match the value. Node* not_biased_ctrl = opt_bits_test(ctrl, region, 3, x_node, (~markOopDesc::age_mask_in_place), 0); // region->in(3) is set to fast path - the object is biased to the current thread. mem_phi->init_req(3, mem); // Mark word does NOT match the value (thread | Klass::_prototype_header). // First, check biased pattern. // Get fast path - _prototype_header has the same biased lock pattern. ctrl = opt_bits_test(not_biased_ctrl, fast_lock_region, 2, x_node, markOopDesc::biased_lock_mask_in_place, 0, true); not_biased_ctrl = fast_lock_region->in(2); // Slow path // fast_lock_region->in(2) - the prototype header is no longer biased // and we have to revoke the bias on this object. // We are going to try to reset the mark of this object to the prototype // value and fall through to the CAS-based locking scheme. Node* adr = basic_plus_adr(obj, oopDesc::mark_offset_in_bytes()); Node* cas = new (C, 5) StoreXConditionalNode(not_biased_ctrl, mem, adr, proto_node, mark_node); transform_later(cas); Node* proj = transform_later( new (C, 1) SCMemProjNode(cas)); fast_lock_mem_phi->init_req(2, proj); // Second, check epoch bits. Node* rebiased_region = new (C, 3) RegionNode(3); Node* old_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X); Node* new_phi = new (C, 3) PhiNode( rebiased_region, TypeX_X); // Get slow path - mark word does NOT match epoch bits. Node* epoch_ctrl = opt_bits_test(ctrl, rebiased_region, 1, x_node, markOopDesc::epoch_mask_in_place, 0); // The epoch of the current bias is not valid, attempt to rebias the object // toward the current thread. rebiased_region->init_req(2, epoch_ctrl); old_phi->init_req(2, mark_node); new_phi->init_req(2, o_node); // rebiased_region->in(1) is set to fast path. // The epoch of the current bias is still valid but we know // nothing about the owner; it might be set or it might be clear. Node* cmask = MakeConX(markOopDesc::biased_lock_mask_in_place | markOopDesc::age_mask_in_place | markOopDesc::epoch_mask_in_place); Node* old = transform_later(new (C, 3) AndXNode(mark_node, cmask)); cast_thread = transform_later(new (C, 2) CastP2XNode(ctrl, thread)); Node* new_mark = transform_later(new (C, 3) OrXNode(cast_thread, old)); old_phi->init_req(1, old); new_phi->init_req(1, new_mark); transform_later(rebiased_region); transform_later(old_phi); transform_later(new_phi); // Try to acquire the bias of the object using an atomic operation. // If this fails we will go in to the runtime to revoke the object's bias. cas = new (C, 5) StoreXConditionalNode(rebiased_region, mem, adr, new_phi, old_phi); transform_later(cas); proj = transform_later( new (C, 1) SCMemProjNode(cas)); // Get slow path - Failed to CAS. not_biased_ctrl = opt_bits_test(rebiased_region, region, 4, cas, 0, 0); mem_phi->init_req(4, proj); // region->in(4) is set to fast path - the object is rebiased to the current thread. // Failed to CAS. slow_path = new (C, 3) RegionNode(3); Node *slow_mem = new (C, 3) PhiNode( slow_path, Type::MEMORY, TypeRawPtr::BOTTOM); slow_path->init_req(1, not_biased_ctrl); // Capture slow-control slow_mem->init_req(1, proj); // Call CAS-based locking scheme (FastLock node). transform_later(fast_lock_region); transform_later(fast_lock_mem_phi); // Get slow path - FastLock failed to lock the object. ctrl = opt_bits_test(fast_lock_region, region, 2, flock, 0, 0); mem_phi->init_req(2, fast_lock_mem_phi); // region->in(2) is set to fast path - the object is locked to the current thread. slow_path->init_req(2, ctrl); // Capture slow-control slow_mem->init_req(2, fast_lock_mem_phi); transform_later(slow_path); transform_later(slow_mem); // Reset lock's memory edge. lock->set_req(TypeFunc::Memory, slow_mem); } else { region = new (C, 3) RegionNode(3); // create a Phi for the memory state mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); // Optimize test; set region slot 2 slow_path = opt_bits_test(ctrl, region, 2, flock, 0, 0); mem_phi->init_req(2, mem); } // 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.replace_node(_fallthroughproj, region); Node *memproj = transform_later( new(C, 1) ProjNode(call, TypeFunc::Memory) ); mem_phi->init_req(1, memproj ); transform_later(mem_phi); _igvn.replace_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 Node *region; Node *mem_phi; if (UseOptoBiasInlining) { // Check for biased locking unlock case, which is a no-op. // See the full description in MacroAssembler::biased_locking_exit(). region = new (C, 4) RegionNode(4); // create a Phi for the memory state mem_phi = new (C, 4) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); mem_phi->init_req(3, mem); Node* mark_node = make_load(ctrl, mem, obj, oopDesc::mark_offset_in_bytes(), TypeX_X, TypeX_X->basic_type()); ctrl = opt_bits_test(ctrl, region, 3, mark_node, markOopDesc::biased_lock_mask_in_place, markOopDesc::biased_lock_pattern); } else { region = new (C, 3) RegionNode(3); // create a Phi for the memory state mem_phi = new (C, 3) PhiNode( region, Type::MEMORY, TypeRawPtr::BOTTOM); } FastUnlockNode *funlock = new (C, 3) FastUnlockNode( ctrl, obj, box ); funlock = transform_later( funlock )->as_FastUnlock(); // Optimize test; set region slot 2 Node *slow_path = opt_bits_test(ctrl, region, 2, funlock, 0, 0); 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.replace_node(_fallthroughproj, region); 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.replace_node(_memproj_fallthrough, mem_phi); } //---------------------------eliminate_macro_nodes---------------------- // Eliminate scalar replaced allocations and associated locks. void PhaseMacroExpand::eliminate_macro_nodes() { if (C->macro_count() == 0) return; // First, attempt to eliminate locks int cnt = C->macro_count(); for (int i=0; i < cnt; i++) { Node *n = C->macro_node(i); if (n->is_AbstractLock()) { // Lock and Unlock nodes // Before elimination mark all associated (same box and obj) // lock and unlock nodes. mark_eliminated_locking_nodes(n->as_AbstractLock()); } } 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();); if (n->is_AbstractLock()) { success = eliminate_locking_node(n->as_AbstractLock()); } assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); progress = progress || success; } } // Next, attempt to eliminate allocations 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: assert(!n->as_AbstractLock()->is_eliminated(), "sanity"); break; default: assert(n->Opcode() == Op_LoopLimit || n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2, "unknown node type in macro list"); } assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); progress = progress || success; } } } //------------------------------expand_macro_nodes---------------------- // Returns true if a failure occurred. bool PhaseMacroExpand::expand_macro_nodes() { // Last attempt to eliminate macro nodes. eliminate_macro_nodes(); // 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; // Eliminate Opaque and LoopLimit nodes. Do it after all loop optimizations. 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();); if (n->Opcode() == Op_LoopLimit) { // Remove it from macro list and put on IGVN worklist to optimize. C->remove_macro_node(n); _igvn._worklist.push(n); success = true; } else if (n->Opcode() == Op_Opaque1 || n->Opcode() == Op_Opaque2) { _igvn.replace_node(n, n->in(1)); success = true; } assert(success == (C->macro_count() < old_macro_count), "elimination reduces macro count"); progress = progress || success; } } // 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(); if (C->failing()) return true; return false; }