--- /dev/null 2018-04-03 12:55:20.301839954 +0200 +++ new/src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp 2018-06-08 19:45:49.088370998 +0200 @@ -0,0 +1,1480 @@ +/* + * Copyright (c) 2015, 2018, 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 "opto/compile.hpp" +#include "opto/castnode.hpp" +#include "opto/graphKit.hpp" +#include "opto/idealKit.hpp" +#include "opto/loopnode.hpp" +#include "opto/macro.hpp" +#include "opto/node.hpp" +#include "opto/type.hpp" +#include "utilities/macros.hpp" +#include "gc/z/c2/zBarrierSetC2.hpp" +#include "gc/z/zThreadLocalData.hpp" +#include "gc/z/zBarrierSetRuntime.hpp" + +ZBarrierSetC2State::ZBarrierSetC2State(Arena* comp_arena) + : _load_barrier_nodes(new (comp_arena) GrowableArray(comp_arena, 8, 0, NULL)) {} + +int ZBarrierSetC2State::load_barrier_count() const { + return _load_barrier_nodes->length(); +} + +void ZBarrierSetC2State::add_load_barrier_node(LoadBarrierNode * n) { + assert(!_load_barrier_nodes->contains(n), " duplicate entry in expand list"); + _load_barrier_nodes->append(n); +} + +void ZBarrierSetC2State::remove_load_barrier_node(LoadBarrierNode * n) { + // this function may be called twice for a node so check + // that the node is in the array before attempting to remove it + if (_load_barrier_nodes->contains(n)) { + _load_barrier_nodes->remove(n); + } +} + +LoadBarrierNode* ZBarrierSetC2State::load_barrier_node(int idx) const { + return _load_barrier_nodes->at(idx); +} + +void* ZBarrierSetC2::create_barrier_state(Arena* comp_arena) const { + return new(comp_arena) ZBarrierSetC2State(comp_arena); +} + +ZBarrierSetC2State* ZBarrierSetC2::state() const { + return reinterpret_cast(Compile::current()->barrier_set_state()); +} + +bool ZBarrierSetC2::is_gc_barrier_node(Node* node) const { + return node->is_LoadBarrier(); +} + +void ZBarrierSetC2::register_potential_barrier_node(Node* node) const { + if (node->is_LoadBarrier()) { + state()->add_load_barrier_node(node->as_LoadBarrier()); + } +} + +void ZBarrierSetC2::unregister_potential_barrier_node(Node* node) const { + if (node->is_LoadBarrier()) { + state()->remove_load_barrier_node(node->as_LoadBarrier()); + } +} + +void ZBarrierSetC2::eliminate_useless_gc_barriers(Unique_Node_List &useful) const { + // Remove useless LoadBarrier nodes + ZBarrierSetC2State* s = state(); + for (int i = s->load_barrier_count()-1; i >= 0; i--) { + LoadBarrierNode* n = s->load_barrier_node(i); + if (!useful.member(n)) { + unregister_potential_barrier_node(n); + } + } +} + +void ZBarrierSetC2::enqueue_useful_gc_barrier(Unique_Node_List &worklist, Node* node) const { + if (node->is_LoadBarrier() && !node->as_LoadBarrier()->has_true_uses()) { + worklist.push(node); + } +} + +void ZBarrierSetC2::find_dominating_barriers(PhaseIterGVN& igvn) { + // Look for dominating barriers on the same address only once all + // other loop opts are over: loop opts may cause a safepoint to be + // inserted between a barrier and its dominating barrier. + Compile* C = Compile::current(); + ZBarrierSetC2* bs = (ZBarrierSetC2*)BarrierSet::barrier_set()->barrier_set_c2(); + ZBarrierSetC2State* s = bs->state(); + if (s->load_barrier_count() >= 2) { + Compile::TracePhase tp("idealLoop", &C->timers[Phase::_t_idealLoop]); + PhaseIdealLoop ideal_loop(igvn, true, false, true); + if (C->major_progress()) C->print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2); + } +} + +void ZBarrierSetC2::add_users_to_worklist(Unique_Node_List* worklist) const { + // Permanent temporary workaround + // Loadbarriers may have non-obvious dead uses keeping them alive during parsing. The use is + // removed by RemoveUseless (after parsing, before optimize) but the barriers won't be added to + // the worklist. Unless we add them explicitly they are not guaranteed to end up there. + ZBarrierSetC2State* s = state(); + + for (int i = 0; i < s->load_barrier_count(); i++) { + LoadBarrierNode* n = s->load_barrier_node(i); + worklist->push(n); + } +} + +const TypeFunc* ZBarrierSetC2::load_barrier_Type() const { + const Type** fields; + + // Create input types (domain) + fields = TypeTuple::fields(2); + fields[TypeFunc::Parms+0] = TypeInstPtr::NOTNULL; + fields[TypeFunc::Parms+1] = TypeOopPtr::BOTTOM; + const TypeTuple *domain = TypeTuple::make(TypeFunc::Parms+2, fields); + + // Create result type (range) + fields = TypeTuple::fields(1); + fields[TypeFunc::Parms+0] = TypeInstPtr::BOTTOM; + const TypeTuple *range = TypeTuple::make(TypeFunc::Parms+1, fields); + + return TypeFunc::make(domain, range); +} + +// == LoadBarrierNode == + +LoadBarrierNode::LoadBarrierNode(Compile* C, + Node* c, + Node* mem, + Node* val, + Node* adr, + bool weak, + bool writeback, + bool oop_reload_allowed) : + MultiNode(Number_of_Inputs), + _weak(weak), + _writeback(writeback), + _oop_reload_allowed(oop_reload_allowed) { + init_req(Control, c); + init_req(Memory, mem); + init_req(Oop, val); + init_req(Address, adr); + init_req(Similar, C->top()); + + init_class_id(Class_LoadBarrier); + BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2(); + bs->register_potential_barrier_node(this); +} + +const Type *LoadBarrierNode::bottom_type() const { + const Type** floadbarrier = (const Type **)(Compile::current()->type_arena()->Amalloc_4((Number_of_Outputs)*sizeof(Type*))); + Node* in_oop = in(Oop); + floadbarrier[Control] = Type::CONTROL; + floadbarrier[Memory] = Type::MEMORY; + floadbarrier[Oop] = in_oop == NULL ? Type::TOP : in_oop->bottom_type(); + return TypeTuple::make(Number_of_Outputs, floadbarrier); +} + +const Type *LoadBarrierNode::Value(PhaseGVN *phase) const { + const Type** floadbarrier = (const Type **)(phase->C->type_arena()->Amalloc_4((Number_of_Outputs)*sizeof(Type*))); + const Type* val_t = phase->type(in(Oop)); + floadbarrier[Control] = Type::CONTROL; + floadbarrier[Memory] = Type::MEMORY; + floadbarrier[Oop] = val_t; + return TypeTuple::make(Number_of_Outputs, floadbarrier); +} + +bool LoadBarrierNode::is_dominator(PhaseIdealLoop* phase, bool linear_only, Node *d, Node *n) { + if (phase != NULL) { + return phase->is_dominator(d, n); + } + + for (int i = 0; i < 10 && n != NULL; i++) { + n = IfNode::up_one_dom(n, linear_only); + if (n == d) { + return true; + } + } + + return false; +} + +LoadBarrierNode* LoadBarrierNode::has_dominating_barrier(PhaseIdealLoop* phase, bool linear_only, bool look_for_similar) { + Node* val = in(LoadBarrierNode::Oop); + if (in(Similar)->is_Proj() && in(Similar)->in(0)->is_LoadBarrier()) { + LoadBarrierNode* lb = in(Similar)->in(0)->as_LoadBarrier(); + assert(lb->in(Address) == in(Address), ""); + // Load barrier on Similar edge dominates so if it now has the Oop field it can replace this barrier. + if (lb->in(Oop) == in(Oop)) { + return lb; + } + // Follow chain of load barrier through Similar edges + while (!lb->in(Similar)->is_top()) { + lb = lb->in(Similar)->in(0)->as_LoadBarrier(); + assert(lb->in(Address) == in(Address), ""); + } + if (lb != in(Similar)->in(0)) { + return lb; + } + } + for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) { + Node* u = val->fast_out(i); + if (u != this && u->is_LoadBarrier() && u->in(Oop) == val && u->as_LoadBarrier()->has_true_uses()) { + Node* this_ctrl = in(LoadBarrierNode::Control); + Node* other_ctrl = u->in(LoadBarrierNode::Control); + if (is_dominator(phase, linear_only, other_ctrl, this_ctrl)) { + return u->as_LoadBarrier(); + } + } + } + + if (ZVerifyLoadBarriers || can_be_eliminated()) { + return NULL; + } + + if (!look_for_similar) { + return NULL; + } + + Node* addr = in(LoadBarrierNode::Address); + for (DUIterator_Fast imax, i = addr->fast_outs(imax); i < imax; i++) { + Node* u = addr->fast_out(i); + if (u != this && u->is_LoadBarrier() && u->as_LoadBarrier()->has_true_uses()) { + Node* this_ctrl = in(LoadBarrierNode::Control); + Node* other_ctrl = u->in(LoadBarrierNode::Control); + if (is_dominator(phase, linear_only, other_ctrl, this_ctrl)) { + ResourceMark rm; + Unique_Node_List wq; + wq.push(in(LoadBarrierNode::Control)); + bool ok = true; + bool dom_found = false; + for (uint next = 0; next < wq.size(); ++next) { + Node *n = wq.at(next); + if (n->is_top()) { + return NULL; + } + assert(n->is_CFG(), ""); + if (n->is_SafePoint()) { + ok = false; + break; + } + if (n == u) { + dom_found = true; + continue; + } + if (n->is_Region()) { + for (uint i = 1; i < n->req(); i++) { + Node* m = n->in(i); + if (m != NULL) { + wq.push(m); + } + } + } else { + Node* m = n->in(0); + if (m != NULL) { + wq.push(m); + } + } + } + if (ok) { + assert(dom_found, ""); + return u->as_LoadBarrier();; + } + break; + } + } + } + + return NULL; +} + +void LoadBarrierNode::push_dominated_barriers(PhaseIterGVN* igvn) const { + // change to that barrier may affect a dominated barrier so re-push those + Node* val = in(LoadBarrierNode::Oop); + + for (DUIterator_Fast imax, i = val->fast_outs(imax); i < imax; i++) { + Node* u = val->fast_out(i); + if (u != this && u->is_LoadBarrier() && u->in(Oop) == val) { + Node* this_ctrl = in(Control); + Node* other_ctrl = u->in(Control); + if (is_dominator(NULL, false, this_ctrl, other_ctrl)) { + igvn->_worklist.push(u); + } + } + + Node* addr = in(LoadBarrierNode::Address); + for (DUIterator_Fast imax, i = addr->fast_outs(imax); i < imax; i++) { + Node* u = addr->fast_out(i); + if (u != this && u->is_LoadBarrier() && u->in(Similar)->is_top()) { + Node* this_ctrl = in(Control); + Node* other_ctrl = u->in(Control); + if (is_dominator(NULL, false, this_ctrl, other_ctrl)) { + igvn->_worklist.push(u); + } + } + } + } +} + +Node *LoadBarrierNode::Identity(PhaseGVN *phase) { + if (!phase->C->directive()->ZOptimizeLoadBarriersOption) { + return this; + } + + bool redundant_addr = false; + LoadBarrierNode* dominating_barrier = has_dominating_barrier(NULL, true, false); + if (dominating_barrier != NULL) { + assert(dominating_barrier->in(Oop) == in(Oop), ""); + return dominating_barrier; + } + + return this; +} + +Node *LoadBarrierNode::Ideal(PhaseGVN *phase, bool can_reshape) { + if (remove_dead_region(phase, can_reshape)) { + return this; + } + + Node* val = in(Oop); + Node* mem = in(Memory); + Node* ctrl = in(Control); + Node* adr = in(Address); + assert(val->Opcode() != Op_LoadN, ""); + + if (mem->is_MergeMem()) { + Node* new_mem = mem->as_MergeMem()->memory_at(Compile::AliasIdxRaw); + set_req(Memory, new_mem); + if (mem->outcnt() == 0 && can_reshape) { + phase->is_IterGVN()->_worklist.push(mem); + } + + return this; + } + + bool optimizeLoadBarriers = phase->C->directive()->ZOptimizeLoadBarriersOption; + LoadBarrierNode* dominating_barrier = optimizeLoadBarriers ? has_dominating_barrier(NULL, !can_reshape, !phase->C->major_progress()) : NULL; + if (dominating_barrier != NULL && dominating_barrier->in(Oop) != in(Oop)) { + assert(in(Address) == dominating_barrier->in(Address), ""); + set_req(Similar, dominating_barrier->proj_out(Oop)); + return this; + } + + bool eliminate = (optimizeLoadBarriers && !(val->is_Phi() || val->Opcode() == Op_LoadP || val->Opcode() == Op_GetAndSetP || val->is_DecodeN())) || + (can_reshape && (dominating_barrier != NULL || !has_true_uses())); + + if (eliminate) { + if (can_reshape) { + PhaseIterGVN* igvn = phase->is_IterGVN(); + Node* out_ctrl = proj_out_or_null(Control); + Node* out_res = proj_out_or_null(Oop); + + if (out_ctrl != NULL) { + igvn->replace_node(out_ctrl, ctrl); + } + + // That transformation may cause the Similar edge on the load barrier to be invalid + fix_similar_in_uses(igvn); + if (out_res != NULL) { + if (dominating_barrier != NULL) { + igvn->replace_node(out_res, dominating_barrier->proj_out(Oop)); + } else { + igvn->replace_node(out_res, val); + } + } + } + + return new ConINode(TypeInt::ZERO); + } + + // If the Similar edge is no longer a load barrier, clear it + Node* similar = in(Similar); + if (!similar->is_top() && !(similar->is_Proj() && similar->in(0)->is_LoadBarrier())) { + set_req(Similar, phase->C->top()); + return this; + } + + if (can_reshape) { + // If this barrier is linked through the Similar edge by a + // dominated barrier and both barriers have the same Oop field, + // the dominated barrier can go away, so push it for reprocessing. + // We also want to avoid a barrier to depend on another dominating + // barrier through its Similar edge that itself depend on another + // barrier through its Similar edge and rather have the first + // depend on the third. + PhaseIterGVN* igvn = phase->is_IterGVN(); + Node* out_res = proj_out(Oop); + for (DUIterator_Fast imax, i = out_res->fast_outs(imax); i < imax; i++) { + Node* u = out_res->fast_out(i); + if (u->is_LoadBarrier() && u->in(Similar) == out_res && + (u->in(Oop) == val || !u->in(Similar)->is_top())) { + igvn->_worklist.push(u); + } + } + + push_dominated_barriers(igvn); + } + + return NULL; +} + +void LoadBarrierNode::fix_similar_in_uses(PhaseIterGVN* igvn) { + Node* out_res = proj_out_or_null(Oop); + if (out_res == NULL) { + return; + } + + for (DUIterator_Fast imax, i = out_res->fast_outs(imax); i < imax; i++) { + Node* u = out_res->fast_out(i); + if (u->is_LoadBarrier() && u->in(Similar) == out_res) { + igvn->replace_input_of(u, Similar, igvn->C->top()); + --i; + --imax; + } + } +} + +bool LoadBarrierNode::has_true_uses() const { + Node* out_res = proj_out_or_null(Oop); + if (out_res == NULL) { + return false; + } + + for (DUIterator_Fast imax, i = out_res->fast_outs(imax); i < imax; i++) { + Node* u = out_res->fast_out(i); + if (!u->is_LoadBarrier() || u->in(Similar) != out_res) { + return true; + } + } + + return false; +} + +// == Accesses == + +Node* ZBarrierSetC2::make_cas_loadbarrier(C2AtomicAccess& access) const { + assert(!UseCompressedOops, "Not allowed"); + CompareAndSwapNode* cas = (CompareAndSwapNode*)access.raw_access(); + PhaseGVN& gvn = access.kit()->gvn(); + Compile* C = Compile::current(); + GraphKit* kit = access.kit(); + + Node* in_ctrl = cas->in(MemNode::Control); + Node* in_mem = cas->in(MemNode::Memory); + Node* in_adr = cas->in(MemNode::Address); + Node* in_val = cas->in(MemNode::ValueIn); + Node* in_expected = cas->in(LoadStoreConditionalNode::ExpectedIn); + + float likely = PROB_LIKELY(0.999); + + const TypePtr *adr_type = gvn.type(in_adr)->isa_ptr(); + Compile::AliasType* alias_type = C->alias_type(adr_type); + int alias_idx = C->get_alias_index(adr_type); + + // Outer check - true: continue, false: load and check + Node* region = new RegionNode(3); + Node* phi = new PhiNode(region, TypeInt::BOOL); + Node* phi_mem = new PhiNode(region, Type::MEMORY, adr_type); + + // Inner check - is the healed ref equal to the expected + Node* region2 = new RegionNode(3); + Node* phi2 = new PhiNode(region2, TypeInt::BOOL); + Node* phi_mem2 = new PhiNode(region2, Type::MEMORY, adr_type); + + // CAS node returns 0 or 1 + Node* cmp = gvn.transform(new CmpINode(cas, kit->intcon(0))); + Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::ne))->as_Bool(); + IfNode* iff = gvn.transform(new IfNode(in_ctrl, bol, likely, COUNT_UNKNOWN))->as_If(); + Node* then = gvn.transform(new IfTrueNode(iff)); + Node* elsen = gvn.transform(new IfFalseNode(iff)); + + Node* scmemproj1 = gvn.transform(new SCMemProjNode(cas)); + + kit->set_memory(scmemproj1, alias_idx); + phi_mem->init_req(1, scmemproj1); + phi_mem2->init_req(2, scmemproj1); + + // CAS fail - reload and heal oop + Node* reload = kit->make_load(elsen, in_adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered); + Node* barrier = gvn.transform(new LoadBarrierNode(C, elsen, scmemproj1, reload, in_adr, false, true, false)); + Node* barrierctrl = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Control)); + Node* barrierdata = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Oop)); + + // Check load + Node* tmpX = gvn.transform(new CastP2XNode(NULL, barrierdata)); + Node* in_expX = gvn.transform(new CastP2XNode(NULL, in_expected)); + Node* cmp2 = gvn.transform(new CmpXNode(tmpX, in_expX)); + Node *bol2 = gvn.transform(new BoolNode(cmp2, BoolTest::ne))->as_Bool(); + IfNode* iff2 = gvn.transform(new IfNode(barrierctrl, bol2, likely, COUNT_UNKNOWN))->as_If(); + Node* then2 = gvn.transform(new IfTrueNode(iff2)); + Node* elsen2 = gvn.transform(new IfFalseNode(iff2)); + + // redo CAS + Node* cas2 = gvn.transform(new CompareAndSwapPNode(elsen2, kit->memory(alias_idx), in_adr, in_val, in_expected, cas->order())); + Node* scmemproj2 = gvn.transform(new SCMemProjNode(cas2)); + kit->set_control(elsen2); + kit->set_memory(scmemproj2, alias_idx); + + // Merge inner flow - check if healed oop was equal too expected. + region2->set_req(1, kit->control()); + region2->set_req(2, then2); + phi2->set_req(1, cas2); + phi2->set_req(2, kit->intcon(0)); + phi_mem2->init_req(1, scmemproj2); + kit->set_memory(phi_mem2, alias_idx); + + // Merge outer flow - then check if first cas succeded + region->set_req(1, then); + region->set_req(2, region2); + phi->set_req(1, kit->intcon(1)); + phi->set_req(2, phi2); + phi_mem->init_req(2, phi_mem2); + kit->set_memory(phi_mem, alias_idx); + + gvn.transform(region2); + gvn.transform(phi2); + gvn.transform(phi_mem2); + gvn.transform(region); + gvn.transform(phi); + gvn.transform(phi_mem); + + kit->set_control(region); + kit->insert_mem_bar(Op_MemBarCPUOrder); + + return phi; +} + +Node* ZBarrierSetC2::make_cmpx_loadbarrier(C2AtomicAccess& access) const { + CompareAndExchangePNode* cmpx = (CompareAndExchangePNode*)access.raw_access(); + GraphKit* kit = access.kit(); + PhaseGVN& gvn = kit->gvn(); + Compile* C = Compile::current(); + + Node* in_ctrl = cmpx->in(MemNode::Control); + Node* in_mem = cmpx->in(MemNode::Memory); + Node* in_adr = cmpx->in(MemNode::Address); + Node* in_val = cmpx->in(MemNode::ValueIn); + Node* in_expected = cmpx->in(LoadStoreConditionalNode::ExpectedIn); + + float likely = PROB_LIKELY(0.999); + + const TypePtr *adr_type = cmpx->get_ptr_type(); + Compile::AliasType* alias_type = C->alias_type(adr_type); + int alias_idx = C->get_alias_index(adr_type); + + // Outer check - true: continue, false: load and check + Node* region = new RegionNode(3); + Node* phi = new PhiNode(region, adr_type); + + // Inner check - is the healed ref equal to the expected + Node* region2 = new RegionNode(3); + Node* phi2 = new PhiNode(region2, adr_type); + + // Check if cmpx succeded + Node* cmp = gvn.transform(new CmpPNode(cmpx, in_expected)); + Node* bol = gvn.transform(new BoolNode(cmp, BoolTest::eq))->as_Bool(); + IfNode* iff = gvn.transform(new IfNode(in_ctrl, bol, likely, COUNT_UNKNOWN))->as_If(); + Node* then = gvn.transform(new IfTrueNode(iff)); + Node* elsen = gvn.transform(new IfFalseNode(iff)); + + Node* scmemproj1 = gvn.transform(new SCMemProjNode(cmpx)); + kit->set_memory(scmemproj1, alias_idx); + + // CAS fail - reload and heal oop + Node* reload = kit->make_load(elsen, in_adr, TypeOopPtr::BOTTOM, T_OBJECT, MemNode::unordered); + Node* barrier = gvn.transform(new LoadBarrierNode(C, elsen, scmemproj1, reload, in_adr, false, true, false)); + Node* barrierctrl = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Control)); + Node* barrierdata = gvn.transform(new ProjNode(barrier, LoadBarrierNode::Oop)); + + // Check load + Node* tmpX = gvn.transform(new CastP2XNode(NULL, barrierdata)); + Node* in_expX = gvn.transform(new CastP2XNode(NULL, in_expected)); + Node* cmp2 = gvn.transform(new CmpXNode(tmpX, in_expX)); + Node *bol2 = gvn.transform(new BoolNode(cmp2, BoolTest::ne))->as_Bool(); + IfNode* iff2 = gvn.transform(new IfNode(barrierctrl, bol2, likely, COUNT_UNKNOWN))->as_If(); + Node* then2 = gvn.transform(new IfTrueNode(iff2)); + Node* elsen2 = gvn.transform(new IfFalseNode(iff2)); + + // Redo CAS + Node* cmpx2 = gvn.transform(new CompareAndExchangePNode(elsen2, kit->memory(alias_idx), in_adr, in_val, in_expected, adr_type, cmpx->get_ptr_type(), cmpx->order())); + Node* scmemproj2 = gvn.transform(new SCMemProjNode(cmpx2)); + kit->set_control(elsen2); + kit->set_memory(scmemproj2, alias_idx); + + // Merge inner flow - check if healed oop was equal too expected. + region2->set_req(1, kit->control()); + region2->set_req(2, then2); + phi2->set_req(1, cmpx2); + phi2->set_req(2, barrierdata); + + // Merge outer flow - then check if first cas succeded + region->set_req(1, then); + region->set_req(2, region2); + phi->set_req(1, cmpx); + phi->set_req(2, phi2); + + gvn.transform(region2); + gvn.transform(phi2); + gvn.transform(region); + gvn.transform(phi); + + kit->set_control(region); + kit->set_memory(in_mem, alias_idx); + kit->insert_mem_bar(Op_MemBarCPUOrder); + + return phi; +} + +Node* ZBarrierSetC2::load_barrier(GraphKit* kit, Node* val, Node* adr, bool weak, bool writeback, bool oop_reload_allowed) const { + PhaseGVN& gvn = kit->gvn(); + Node* barrier = new LoadBarrierNode(Compile::current(), kit->control(), kit->memory(TypeRawPtr::BOTTOM), val, adr, weak, writeback, oop_reload_allowed); + Node* transformed_barrier = gvn.transform(barrier); + + if (transformed_barrier->is_LoadBarrier()) { + if (barrier == transformed_barrier) { + kit->set_control(gvn.transform(new ProjNode(barrier, LoadBarrierNode::Control))); + } + return gvn.transform(new ProjNode(transformed_barrier, LoadBarrierNode::Oop)); + } else { + return val; + } +} + +static bool barrier_needed(C2Access access) { + return ZBarrierSet::barrier_needed(access.decorators(), access.type()); +} + +Node* ZBarrierSetC2::load_at_resolved(C2Access& access, const Type* val_type) const { + Node* p = BarrierSetC2::load_at_resolved(access, val_type); + if (!barrier_needed(access)) { + return p; + } + + bool conc_root = (access.decorators() & IN_CONCURRENT_ROOT) != 0; + bool weak = (access.decorators() & ON_WEAK_OOP_REF) != 0; + + GraphKit* kit = access.kit(); + PhaseGVN& gvn = kit->gvn(); + Node* adr = access.addr().node(); + Node* heap_base_oop = access.base(); + bool unsafe = (access.decorators() & C2_UNSAFE_ACCESS) != 0; + if (unsafe) { + if (!ZVerifyLoadBarriers) { + p = load_barrier(kit, p, adr); + } else { + if (!TypePtr::NULL_PTR->higher_equal(gvn.type(heap_base_oop))) { + p = load_barrier(kit, p, adr); + } else { + IdealKit ideal(kit); + IdealVariable res(ideal); +#define __ ideal. + __ declarations_done(); + __ set(res, p); + __ if_then(heap_base_oop, BoolTest::ne, kit->null(), PROB_UNLIKELY(0.999)); { + kit->sync_kit(ideal); + p = load_barrier(kit, p, adr); + __ set(res, p); + __ sync_kit(kit); + } __ end_if(); + kit->final_sync(ideal); + p = __ value(res); +#undef __ + } + } + return p; + } else { + return load_barrier(access.kit(), p, access.addr().node(), weak, true, true); + } +} + +Node* ZBarrierSetC2::atomic_cmpxchg_val_at_resolved(C2AtomicAccess& access, Node* expected_val, + Node* new_val, const Type* val_type) const { + Node* result = BarrierSetC2::atomic_cmpxchg_val_at_resolved(access, expected_val, new_val, val_type); + if (!barrier_needed(access)) { + return result; + } + + access.set_needs_pinning(false); + return make_cmpx_loadbarrier(access); +} + +Node* ZBarrierSetC2::atomic_cmpxchg_bool_at_resolved(C2AtomicAccess& access, Node* expected_val, + Node* new_val, const Type* value_type) const { + Node* result = BarrierSetC2::atomic_cmpxchg_bool_at_resolved(access, expected_val, new_val, value_type); + if (!barrier_needed(access)) { + return result; + } + + Node* load_store = access.raw_access(); + bool weak_cas = (access.decorators() & C2_WEAK_CMPXCHG) != 0; + bool expected_is_null = (expected_val->get_ptr_type() == TypePtr::NULL_PTR); + + if (!expected_is_null) { + if (weak_cas) { + access.set_needs_pinning(false); + load_store = make_cas_loadbarrier(access); + } else { + access.set_needs_pinning(false); + load_store = make_cas_loadbarrier(access); + } + } + + return load_store; +} + +Node* ZBarrierSetC2::atomic_xchg_at_resolved(C2AtomicAccess& access, Node* new_val, const Type* val_type) const { + Node* result = BarrierSetC2::atomic_xchg_at_resolved(access, new_val, val_type); + if (!barrier_needed(access)) { + return result; + } + + Node* load_store = access.raw_access(); + Node* adr = access.addr().node(); + + return load_barrier(access.kit(), load_store, adr, false, false, false); +} + +// == Macro Expansion == + +void ZBarrierSetC2::expand_loadbarrier_node(PhaseMacroExpand* phase, LoadBarrierNode* barrier) const { + Node* in_ctrl = barrier->in(LoadBarrierNode::Control); + Node* in_mem = barrier->in(LoadBarrierNode::Memory); + Node* in_val = barrier->in(LoadBarrierNode::Oop); + Node* in_adr = barrier->in(LoadBarrierNode::Address); + + Node* out_ctrl = barrier->proj_out(LoadBarrierNode::Control); + Node* out_res = barrier->proj_out(LoadBarrierNode::Oop); + + PhaseIterGVN &igvn = phase->igvn(); + + if (ZVerifyLoadBarriers) { + igvn.replace_node(out_res, in_val); + igvn.replace_node(out_ctrl, in_ctrl); + return; + } + + if (barrier->can_be_eliminated()) { + // Clone and pin the load for this barrier below the dominating + // barrier: the load cannot be allowed to float above the + // dominating barrier + Node* load = in_val; + + if (load->is_Load()) { + Node* new_load = load->clone(); + Node* addp = new_load->in(MemNode::Address); + assert(addp->is_AddP() || addp->is_Phi() || addp->is_Load(), "bad address"); + Node* cast = new CastPPNode(addp, igvn.type(addp), true); + Node* ctrl = NULL; + Node* similar = barrier->in(LoadBarrierNode::Similar); + if (similar->is_Phi()) { + // already expanded + ctrl = similar->in(0); + } else { + assert(similar->is_Proj() && similar->in(0)->is_LoadBarrier(), "unexpected graph shape"); + ctrl = similar->in(0)->as_LoadBarrier()->proj_out(LoadBarrierNode::Control); + } + assert(ctrl != NULL, "bad control"); + cast->set_req(0, ctrl); + igvn.transform(cast); + new_load->set_req(MemNode::Address, cast); + igvn.transform(new_load); + + igvn.replace_node(out_res, new_load); + igvn.replace_node(out_ctrl, in_ctrl); + return; + } + // cannot eliminate + } + + // There are two cases that require the basic loadbarrier + // 1) When the writeback of a healed oop must be avoided (swap) + // 2) When we must guarantee that no reload of is done (swap, cas, cmpx) + if (!barrier->is_writeback()) { + assert(!barrier->oop_reload_allowed(), "writeback barriers should be marked as requires oop"); + } + + if (!barrier->oop_reload_allowed()) { + expand_loadbarrier_basic(phase, barrier); + } else { + expand_loadbarrier_optimized(phase, barrier); + } +} + +// Basic loadbarrier using conventional arg passing +void ZBarrierSetC2::expand_loadbarrier_basic(PhaseMacroExpand* phase, LoadBarrierNode *barrier) const { + PhaseIterGVN &igvn = phase->igvn(); + + Node* in_ctrl = barrier->in(LoadBarrierNode::Control); + Node* in_mem = barrier->in(LoadBarrierNode::Memory); + Node* in_val = barrier->in(LoadBarrierNode::Oop); + Node* in_adr = barrier->in(LoadBarrierNode::Address); + + Node* out_ctrl = barrier->proj_out(LoadBarrierNode::Control); + Node* out_res = barrier->proj_out(LoadBarrierNode::Oop); + + float unlikely = PROB_UNLIKELY(0.999); + const Type* in_val_maybe_null_t = igvn.type(in_val); + + Node* jthread = igvn.transform(new ThreadLocalNode()); + Node* adr = phase->basic_plus_adr(jthread, in_bytes(ZThreadLocalData::address_bad_mask_offset())); + Node* bad_mask = igvn.transform(LoadNode::make(igvn, in_ctrl, in_mem, adr, TypeRawPtr::BOTTOM, TypeX_X, TypeX_X->basic_type(), MemNode::unordered)); + Node* cast = igvn.transform(new CastP2XNode(in_ctrl, in_val)); + Node* obj_masked = igvn.transform(new AndXNode(cast, bad_mask)); + Node* cmp = igvn.transform(new CmpXNode(obj_masked, igvn.zerocon(TypeX_X->basic_type()))); + Node *bol = igvn.transform(new BoolNode(cmp, BoolTest::ne))->as_Bool(); + IfNode* iff = igvn.transform(new IfNode(in_ctrl, bol, unlikely, COUNT_UNKNOWN))->as_If(); + Node* then = igvn.transform(new IfTrueNode(iff)); + Node* elsen = igvn.transform(new IfFalseNode(iff)); + + Node* result_region; + Node* result_val; + + result_region = new RegionNode(3); + result_val = new PhiNode(result_region, TypeInstPtr::BOTTOM); + + result_region->set_req(1, elsen); + Node* res = igvn.transform(new CastPPNode(in_val, in_val_maybe_null_t)); + res->init_req(0, elsen); + result_val->set_req(1, res); + + const TypeFunc *tf = load_barrier_Type(); + Node* call; + if (barrier->is_weak()) { + call = new CallLeafNode(tf, + ZBarrierSetRuntime::load_barrier_on_weak_oop_field_preloaded_addr(), + "ZBarrierSetRuntime::load_barrier_on_weak_oop_field_preloaded", + TypeRawPtr::BOTTOM); + } else { + call = new CallLeafNode(tf, + ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded_addr(), + "ZBarrierSetRuntime::load_barrier_on_oop_field_preloaded", + TypeRawPtr::BOTTOM); + } + + call->init_req(TypeFunc::Control, then); + call->init_req(TypeFunc::I_O , phase->top()); + call->init_req(TypeFunc::Memory , in_mem); + call->init_req(TypeFunc::FramePtr, phase->top()); + call->init_req(TypeFunc::ReturnAdr, phase->top()); + call->init_req(TypeFunc::Parms+0, in_val); + if (barrier->is_writeback()) { + call->init_req(TypeFunc::Parms+1, in_adr); + } else { + // when slow path is called with a null adr, the healed oop will not be written back + call->init_req(TypeFunc::Parms+1, igvn.zerocon(T_OBJECT)); + } + call = igvn.transform(call); + + Node* ctrl = igvn.transform(new ProjNode(call, TypeFunc::Control)); + res = igvn.transform(new ProjNode(call, TypeFunc::Parms)); + res = igvn.transform(new CheckCastPPNode(ctrl, res, in_val_maybe_null_t)); + + result_region->set_req(2, ctrl); + result_val->set_req(2, res); + + result_region = igvn.transform(result_region); + result_val = igvn.transform(result_val); + + if (out_ctrl != NULL) { // added if cond + igvn.replace_node(out_ctrl, result_region); + } + igvn.replace_node(out_res, result_val); +} + +// Optimized, low spill, loadbarrier variant using stub specialized on register used +void ZBarrierSetC2::expand_loadbarrier_optimized(PhaseMacroExpand* phase, LoadBarrierNode *barrier) const { + PhaseIterGVN &igvn = phase->igvn(); +#ifdef PRINT_NODE_TRAVERSALS + Node* preceding_barrier_node = barrier->in(LoadBarrierNode::Oop); +#endif + + Node* in_ctrl = barrier->in(LoadBarrierNode::Control); + Node* in_mem = barrier->in(LoadBarrierNode::Memory); + Node* in_val = barrier->in(LoadBarrierNode::Oop); + Node* in_adr = barrier->in(LoadBarrierNode::Address); + + Node* out_ctrl = barrier->proj_out(LoadBarrierNode::Control); + Node* out_res = barrier->proj_out(LoadBarrierNode::Oop); + + assert(barrier->in(LoadBarrierNode::Oop) != NULL, "oop to loadbarrier node cannot be null"); + +#ifdef PRINT_NODE_TRAVERSALS + tty->print("\n\n\nBefore barrier optimization:\n"); + traverse(barrier, out_ctrl, out_res, -1); + + tty->print("\nBefore barrier optimization: preceding_barrier_node\n"); + traverse(preceding_barrier_node, out_ctrl, out_res, -1); +#endif + + float unlikely = PROB_UNLIKELY(0.999); + + Node* jthread = igvn.transform(new ThreadLocalNode()); + Node* adr = phase->basic_plus_adr(jthread, in_bytes(ZThreadLocalData::address_bad_mask_offset())); + Node* bad_mask = igvn.transform(LoadNode::make(igvn, in_ctrl, in_mem, adr, + TypeRawPtr::BOTTOM, TypeX_X, TypeX_X->basic_type(), + MemNode::unordered)); + Node* cast = igvn.transform(new CastP2XNode(in_ctrl, in_val)); + Node* obj_masked = igvn.transform(new AndXNode(cast, bad_mask)); + Node* cmp = igvn.transform(new CmpXNode(obj_masked, igvn.zerocon(TypeX_X->basic_type()))); + Node *bol = igvn.transform(new BoolNode(cmp, BoolTest::ne))->as_Bool(); + IfNode* iff = igvn.transform(new IfNode(in_ctrl, bol, unlikely, COUNT_UNKNOWN))->as_If(); + Node* then = igvn.transform(new IfTrueNode(iff)); + Node* elsen = igvn.transform(new IfFalseNode(iff)); + + Node* slow_path_surrogate; + if (!barrier->is_weak()) { + slow_path_surrogate = igvn.transform(new LoadBarrierSlowRegNode(then, in_mem, in_adr, in_val->adr_type(), + (const TypePtr*) in_val->bottom_type(), MemNode::unordered)); + } else { + slow_path_surrogate = igvn.transform(new LoadBarrierWeakSlowRegNode(then, in_mem, in_adr, in_val->adr_type(), + (const TypePtr*) in_val->bottom_type(), MemNode::unordered)); + } + + Node *new_loadp; + new_loadp = slow_path_surrogate; + // create the final region/phi pair to converge cntl/data paths to downstream code + Node* result_region = igvn.transform(new RegionNode(3)); + result_region->set_req(1, then); + result_region->set_req(2, elsen); + + Node* result_phi = igvn.transform(new PhiNode(result_region, TypeInstPtr::BOTTOM)); + result_phi->set_req(1, new_loadp); + result_phi->set_req(2, barrier->in(LoadBarrierNode::Oop)); + + // finally, connect the original outputs to the barrier region and phi to complete the expansion/substitution + // igvn.replace_node(out_ctrl, result_region); + if (out_ctrl != NULL) { // added if cond + igvn.replace_node(out_ctrl, result_region); + } + igvn.replace_node(out_res, result_phi); + + assert(barrier->outcnt() == 0,"LoadBarrier macro node has non-null outputs after expansion!"); + +#ifdef PRINT_NODE_TRAVERSALS + tty->print("\nAfter barrier optimization: old out_ctrl\n"); + traverse(out_ctrl, out_ctrl, out_res, -1); + tty->print("\nAfter barrier optimization: old out_res\n"); + traverse(out_res, out_ctrl, out_res, -1); + tty->print("\nAfter barrier optimization: old barrier\n"); + traverse(barrier, out_ctrl, out_res, -1); + tty->print("\nAfter barrier optimization: preceding_barrier_node\n"); + traverse(preceding_barrier_node, result_region, result_phi, -1); +#endif + + return; +} + +bool ZBarrierSetC2::expand_macro_nodes(PhaseMacroExpand* macro) const { + Compile* C = Compile::current(); + PhaseIterGVN &igvn = macro->igvn(); + ZBarrierSetC2State* s = state(); + if (s->load_barrier_count() > 0) { +#ifdef ASSERT + verify_gc_barriers(false); +#endif + igvn.set_delay_transform(true); + int skipped = 0; + while (s->load_barrier_count() > skipped) { + int load_barrier_count = s->load_barrier_count(); + LoadBarrierNode * n = s->load_barrier_node(load_barrier_count-1-skipped); + if (igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())) { + // node is unreachable, so don't try to expand it + s->remove_load_barrier_node(n); + continue; + } + if (!n->can_be_eliminated()) { + skipped++; + continue; + } + expand_loadbarrier_node(macro, n); + assert(s->load_barrier_count() < load_barrier_count, "must have deleted a node from load barrier list"); + if (C->failing()) return true; + } + while (s->load_barrier_count() > 0) { + int load_barrier_count = s->load_barrier_count(); + LoadBarrierNode* n = s->load_barrier_node(load_barrier_count - 1); + assert(!(igvn.type(n) == Type::TOP || (n->in(0) != NULL && n->in(0)->is_top())), "should have been processed already"); + assert(!n->can_be_eliminated(), "should have been processed already"); + expand_loadbarrier_node(macro, n); + assert(s->load_barrier_count() < load_barrier_count, "must have deleted a node from load barrier list"); + if (C->failing()) return true; + } + igvn.set_delay_transform(false); + igvn.optimize(); + if (C->failing()) return true; + } + return false; +} + +// == Loop optimization == + +static bool replace_with_dominating_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, bool last_round) { + PhaseIterGVN &igvn = phase->igvn(); + Compile* C = Compile::current(); + + LoadBarrierNode* lb2 = lb->has_dominating_barrier(phase, false, last_round); + if (lb2 != NULL) { + if (lb->in(LoadBarrierNode::Oop) != lb2->in(LoadBarrierNode::Oop)) { + assert(lb->in(LoadBarrierNode::Address) == lb2->in(LoadBarrierNode::Address), ""); + igvn.replace_input_of(lb, LoadBarrierNode::Similar, lb2->proj_out(LoadBarrierNode::Oop)); + C->set_major_progress(); + } else { + // That transformation may cause the Similar edge on dominated load barriers to be invalid + lb->fix_similar_in_uses(&igvn); + + Node* val = lb->proj_out(LoadBarrierNode::Oop); + assert(lb2->has_true_uses(), ""); + assert(lb2->in(LoadBarrierNode::Oop) == lb->in(LoadBarrierNode::Oop), ""); + + phase->lazy_update(lb, lb->in(LoadBarrierNode::Control)); + phase->lazy_replace(lb->proj_out(LoadBarrierNode::Control), lb->in(LoadBarrierNode::Control)); + igvn.replace_node(val, lb2->proj_out(LoadBarrierNode::Oop)); + + return true; + } + } + return false; +} + +static Node* find_dominating_memory(PhaseIdealLoop* phase, Node* mem, Node* dom, int i) { + assert(dom->is_Region() || i == -1, ""); + Node* m = mem; + while(phase->is_dominator(dom, phase->has_ctrl(m) ? phase->get_ctrl(m) : m->in(0))) { + if (m->is_Mem()) { + assert(m->as_Mem()->adr_type() == TypeRawPtr::BOTTOM, ""); + m = m->in(MemNode::Memory); + } else if (m->is_MergeMem()) { + m = m->as_MergeMem()->memory_at(Compile::AliasIdxRaw); + } else if (m->is_Phi()) { + if (m->in(0) == dom && i != -1) { + m = m->in(i); + break; + } else { + m = m->in(LoopNode::EntryControl); + } + } else if (m->is_Proj()) { + m = m->in(0); + } else if (m->is_SafePoint() || m->is_MemBar()) { + m = m->in(TypeFunc::Memory); + } else { +#ifdef ASSERT + m->dump(); +#endif + ShouldNotReachHere(); + } + } + return m; +} + +static LoadBarrierNode* clone_load_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, Node* ctl, Node* mem, Node* oop_in) { + PhaseIterGVN &igvn = phase->igvn(); + Compile* C = Compile::current(); + Node* the_clone = lb->clone(); + the_clone->set_req(LoadBarrierNode::Control, ctl); + the_clone->set_req(LoadBarrierNode::Memory, mem); + if (oop_in != NULL) { + the_clone->set_req(LoadBarrierNode::Oop, oop_in); + } + + LoadBarrierNode* new_lb = the_clone->as_LoadBarrier(); + igvn.register_new_node_with_optimizer(new_lb); + IdealLoopTree *loop = phase->get_loop(new_lb->in(0)); + phase->set_ctrl(new_lb, new_lb->in(0)); + phase->set_loop(new_lb, loop); + phase->set_idom(new_lb, new_lb->in(0), phase->dom_depth(new_lb->in(0))+1); + if (!loop->_child) { + loop->_body.push(new_lb); + } + + Node* proj_ctl = new ProjNode(new_lb, LoadBarrierNode::Control); + igvn.register_new_node_with_optimizer(proj_ctl); + phase->set_ctrl(proj_ctl, proj_ctl->in(0)); + phase->set_loop(proj_ctl, loop); + phase->set_idom(proj_ctl, new_lb, phase->dom_depth(new_lb)+1); + if (!loop->_child) { + loop->_body.push(proj_ctl); + } + + Node* proj_oop = new ProjNode(new_lb, LoadBarrierNode::Oop); + phase->register_new_node(proj_oop, new_lb); + + if (!new_lb->in(LoadBarrierNode::Similar)->is_top()) { + LoadBarrierNode* similar = new_lb->in(LoadBarrierNode::Similar)->in(0)->as_LoadBarrier(); + if (!phase->is_dominator(similar, ctl)) { + igvn.replace_input_of(new_lb, LoadBarrierNode::Similar, C->top()); + } + } + + return new_lb; +} + +static void replace_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, Node* new_val) { + PhaseIterGVN &igvn = phase->igvn(); + Node* val = lb->proj_out(LoadBarrierNode::Oop); + igvn.replace_node(val, new_val); + phase->lazy_update(lb, lb->in(LoadBarrierNode::Control)); + phase->lazy_replace(lb->proj_out(LoadBarrierNode::Control), lb->in(LoadBarrierNode::Control)); +} + +static bool split_barrier_thru_phi(PhaseIdealLoop* phase, LoadBarrierNode* lb) { + PhaseIterGVN &igvn = phase->igvn(); + Compile* C = Compile::current(); + + if (lb->in(LoadBarrierNode::Oop)->is_Phi()) { + Node* oop_phi = lb->in(LoadBarrierNode::Oop); + + if (oop_phi->req() == 2) { + // Ignore phis with only one input + return false; + } + + if (phase->is_dominator(phase->get_ctrl(lb->in(LoadBarrierNode::Address)), + oop_phi->in(0)) && phase->get_ctrl(lb->in(LoadBarrierNode::Address)) != oop_phi->in(0)) { + // That transformation may cause the Similar edge on dominated load barriers to be invalid + lb->fix_similar_in_uses(&igvn); + + RegionNode* region = oop_phi->in(0)->as_Region(); + + int backedge = LoopNode::LoopBackControl; + if (region->is_Loop() && region->in(backedge)->is_Proj() && region->in(backedge)->in(0)->is_If()) { + Node* c = region->in(backedge)->in(0)->in(0); + assert(c->unique_ctrl_out() == region->in(backedge)->in(0), ""); + Node* oop = lb->in(LoadBarrierNode::Oop)->in(backedge); + Node* oop_c = phase->has_ctrl(oop) ? phase->get_ctrl(oop) : oop; + if (!phase->is_dominator(oop_c, c)) { + return false; + } + } + + // If the node on the backedge above the phi is the node itself - we have a self loop. + // Don't clone - this will be folded later. + if (oop_phi->in(LoopNode::LoopBackControl) == lb->proj_out(LoadBarrierNode::Oop)) { + return false; + } + + bool is_strip_mined = region->is_CountedLoop() && region->as_CountedLoop()->is_strip_mined(); + Node *phi = oop_phi->clone(); + + for (uint i = 1; i < region->req(); i++) { + Node* ctrl = region->in(i); + if (ctrl != C->top()) { + assert(!phase->is_dominator(ctrl, region) || region->is_Loop(), ""); + + Node* mem = lb->in(LoadBarrierNode::Memory); + Node* m = find_dominating_memory(phase, mem, region, i); + + if (region->is_Loop() && i == LoopNode::LoopBackControl && ctrl->is_Proj() && ctrl->in(0)->is_If()) { + ctrl = ctrl->in(0)->in(0); + } else if (region->is_Loop() && is_strip_mined) { + // If this is a strip mined loop, control must move above OuterStripMinedLoop + assert(i == LoopNode::EntryControl, "check"); + assert(ctrl->is_OuterStripMinedLoop(), "sanity"); + ctrl = ctrl->as_OuterStripMinedLoop()->in(LoopNode::EntryControl); + } + + LoadBarrierNode* new_lb = clone_load_barrier(phase, lb, ctrl, m, lb->in(LoadBarrierNode::Oop)->in(i)); + Node* out_ctrl = new_lb->proj_out(LoadBarrierNode::Control); + + if (is_strip_mined && (i == LoopNode::EntryControl)) { + assert(region->in(i)->is_OuterStripMinedLoop(), ""); + igvn.replace_input_of(region->in(i), i, out_ctrl); + } else if (ctrl == region->in(i)) { + igvn.replace_input_of(region, i, out_ctrl); + } else { + Node* iff = region->in(i)->in(0); + igvn.replace_input_of(iff, 0, out_ctrl); + phase->set_idom(iff, out_ctrl, phase->dom_depth(out_ctrl)+1); + } + phi->set_req(i, new_lb->proj_out(LoadBarrierNode::Oop)); + } + } + phase->register_new_node(phi, region); + replace_barrier(phase, lb, phi); + + if (region->is_Loop()) { + // Load barrier moved to the back edge of the Loop may now + // have a safepoint on the path to the barrier on the Similar + // edge + igvn.replace_input_of(phi->in(LoopNode::LoopBackControl)->in(0), LoadBarrierNode::Similar, C->top()); + Node* head = region->in(LoopNode::EntryControl); + phase->set_idom(region, head, phase->dom_depth(head)+1); + phase->recompute_dom_depth(); + if (head->is_CountedLoop() && head->as_CountedLoop()->is_main_loop()) { + head->as_CountedLoop()->set_normal_loop(); + } + } + + return true; + } + } + + return false; +} + +static bool move_out_of_loop(PhaseIdealLoop* phase, LoadBarrierNode* lb) { + PhaseIterGVN &igvn = phase->igvn(); + IdealLoopTree *lb_loop = phase->get_loop(lb->in(0)); + if (lb_loop != phase->ltree_root() && !lb_loop->_irreducible) { + Node* oop_ctrl = phase->get_ctrl(lb->in(LoadBarrierNode::Oop)); + IdealLoopTree *oop_loop = phase->get_loop(oop_ctrl); + IdealLoopTree* adr_loop = phase->get_loop(phase->get_ctrl(lb->in(LoadBarrierNode::Address))); + if (!lb_loop->is_member(oop_loop) && !lb_loop->is_member(adr_loop)) { + // That transformation may cause the Similar edge on dominated load barriers to be invalid + lb->fix_similar_in_uses(&igvn); + + Node* head = lb_loop->_head; + assert(head->is_Loop(), ""); + + if (phase->is_dominator(head, oop_ctrl)) { + assert(oop_ctrl->Opcode() == Op_CProj && oop_ctrl->in(0)->Opcode() == Op_NeverBranch, ""); + assert(lb_loop->is_member(phase->get_loop(oop_ctrl->in(0)->in(0))), ""); + return false; + } + + if (head->is_CountedLoop()) { + CountedLoopNode* cloop = head->as_CountedLoop(); + if (cloop->is_main_loop()) { + cloop->set_normal_loop(); + } + // When we are moving barrier out of a counted loop, + // make sure we move it all the way out of the strip mined outer loop. + if (cloop->is_strip_mined()) { + head = cloop->outer_loop(); + } + } + + Node* mem = lb->in(LoadBarrierNode::Memory); + Node* m = find_dominating_memory(phase, mem, head, -1); + + LoadBarrierNode* new_lb = clone_load_barrier(phase, lb, head->in(LoopNode::EntryControl), m, NULL); + + assert(phase->idom(head) == head->in(LoopNode::EntryControl), ""); + Node* proj_ctl = new_lb->proj_out(LoadBarrierNode::Control); + igvn.replace_input_of(head, LoopNode::EntryControl, proj_ctl); + phase->set_idom(head, proj_ctl, phase->dom_depth(proj_ctl) + 1); + + replace_barrier(phase, lb, new_lb->proj_out(LoadBarrierNode::Oop)); + + phase->recompute_dom_depth(); + + return true; + } + } + + return false; +} + +static bool common_barriers(PhaseIdealLoop* phase, LoadBarrierNode* lb) { + PhaseIterGVN &igvn = phase->igvn(); + Node* in_val = lb->in(LoadBarrierNode::Oop); + for (DUIterator_Fast imax, i = in_val->fast_outs(imax); i < imax; i++) { + Node* u = in_val->fast_out(i); + if (u != lb && u->is_LoadBarrier() && u->as_LoadBarrier()->has_true_uses()) { + Node* this_ctrl = lb->in(LoadBarrierNode::Control); + Node* other_ctrl = u->in(LoadBarrierNode::Control); + + Node* lca = phase->dom_lca(this_ctrl, other_ctrl); + bool ok = true; + + Node* proj1 = NULL; + Node* proj2 = NULL; + + while (this_ctrl != lca && ok) { + if (this_ctrl->in(0) != NULL && + this_ctrl->in(0)->is_MultiBranch()) { + if (this_ctrl->in(0)->in(0) == lca) { + assert(proj1 == NULL, ""); + assert(this_ctrl->is_Proj(), ""); + proj1 = this_ctrl; + } else if (!(this_ctrl->in(0)->is_If() && this_ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none))) { + ok = false; + } + } + this_ctrl = phase->idom(this_ctrl); + } + while (other_ctrl != lca && ok) { + if (other_ctrl->in(0) != NULL && + other_ctrl->in(0)->is_MultiBranch()) { + if (other_ctrl->in(0)->in(0) == lca) { + assert(other_ctrl->is_Proj(), ""); + assert(proj2 == NULL, ""); + proj2 = other_ctrl; + } else if (!(other_ctrl->in(0)->is_If() && other_ctrl->as_Proj()->is_uncommon_trap_if_pattern(Deoptimization::Reason_none))) { + ok = false; + } + } + other_ctrl = phase->idom(other_ctrl); + } + assert(proj1 == NULL || proj2 == NULL || proj1->in(0) == proj2->in(0), ""); + if (ok && proj1 && proj2 && proj1 != proj2 && proj1->in(0)->is_If()) { + // That transformation may cause the Similar edge on dominated load barriers to be invalid + lb->fix_similar_in_uses(&igvn); + u->as_LoadBarrier()->fix_similar_in_uses(&igvn); + + Node* split = lca->unique_ctrl_out(); + assert(split->in(0) == lca, ""); + + Node* mem = lb->in(LoadBarrierNode::Memory); + Node* m = find_dominating_memory(phase, mem, split, -1); + LoadBarrierNode* new_lb = clone_load_barrier(phase, lb, lca, m, NULL); + + Node* proj_ctl = new_lb->proj_out(LoadBarrierNode::Control); + igvn.replace_input_of(split, 0, new_lb->proj_out(LoadBarrierNode::Control)); + phase->set_idom(split, proj_ctl, phase->dom_depth(proj_ctl)+1); + + Node* proj_oop = new_lb->proj_out(LoadBarrierNode::Oop); + replace_barrier(phase, lb, proj_oop); + replace_barrier(phase, u->as_LoadBarrier(), proj_oop); + + phase->recompute_dom_depth(); + + return true; + } + } + } + + return false; +} + +static void optimize_load_barrier(PhaseIdealLoop* phase, LoadBarrierNode* lb, bool last_round) { + Compile* C = Compile::current(); + + if (!C->directive()->ZOptimizeLoadBarriersOption) { + return; + } + + if (lb->has_true_uses()) { + if (replace_with_dominating_barrier(phase, lb, last_round)) { + return; + } + + if (split_barrier_thru_phi(phase, lb)) { + return; + } + + if (move_out_of_loop(phase, lb)) { + return; + } + + if (common_barriers(phase, lb)) { + return; + } + } +} + +void ZBarrierSetC2::loop_optimize_gc_barrier(PhaseIdealLoop* phase, Node* node, bool last_round) { + if (node->is_LoadBarrier()) { + optimize_load_barrier(phase, node->as_LoadBarrier(), last_round); + } +} + +// == Verification == + +#ifdef ASSERT + +static bool look_for_barrier(Node* n, bool post_parse, VectorSet& visited) { + if (visited.test_set(n->_idx)) { + return true; + } + + for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) { + Node* u = n->fast_out(i); + if (u->is_LoadBarrier()) { + } else if ((u->is_Phi() || u->is_CMove()) && !post_parse) { + if (!look_for_barrier(u, post_parse, visited)) { + return false; + } + } else if (u->Opcode() == Op_EncodeP || u->Opcode() == Op_DecodeN) { + if (!look_for_barrier(u, post_parse, visited)) { + return false; + } + } else if (u->Opcode() != Op_SCMemProj) { + tty->print("bad use"); u->dump(); + return false; + } + } + + return true; +} + +void ZBarrierSetC2::verify_gc_barriers(bool post_parse) const { + ZBarrierSetC2State* s = state(); + Compile* C = Compile::current(); + ResourceMark rm; + VectorSet visited(Thread::current()->resource_area()); + for (int i = 0; i < s->load_barrier_count(); i++) { + LoadBarrierNode* n = s->load_barrier_node(i); + + // The dominating barrier on the same address if it exists and + // this barrier must not be applied on the value from the same + // load otherwise the value is not reloaded before it's used the + // second time. + assert(n->in(LoadBarrierNode::Similar)->is_top() || + (n->in(LoadBarrierNode::Similar)->in(0)->is_LoadBarrier() && + n->in(LoadBarrierNode::Similar)->in(0)->in(LoadBarrierNode::Address) == n->in(LoadBarrierNode::Address) && + n->in(LoadBarrierNode::Similar)->in(0)->in(LoadBarrierNode::Oop) != n->in(LoadBarrierNode::Oop)), + "broken similar edge"); + + assert(post_parse || n->as_LoadBarrier()->has_true_uses(), + "found unneeded load barrier"); + + // Several load barrier nodes chained through their Similar edge + // break the code that remove the barriers in final graph reshape. + assert(n->in(LoadBarrierNode::Similar)->is_top() || + (n->in(LoadBarrierNode::Similar)->in(0)->is_LoadBarrier() && + n->in(LoadBarrierNode::Similar)->in(0)->in(LoadBarrierNode::Similar)->is_top()), + "chain of Similar load barriers"); + + if (!n->in(LoadBarrierNode::Similar)->is_top()) { + ResourceMark rm; + Unique_Node_List wq; + Node* other = n->in(LoadBarrierNode::Similar)->in(0); + wq.push(n); + bool ok = true; + bool dom_found = false; + for (uint next = 0; next < wq.size(); ++next) { + Node *n = wq.at(next); + assert(n->is_CFG(), ""); + assert(!n->is_SafePoint(), ""); + + if (n == other) { + continue; + } + + if (n->is_Region()) { + for (uint i = 1; i < n->req(); i++) { + Node* m = n->in(i); + if (m != NULL) { + wq.push(m); + } + } + } else { + Node* m = n->in(0); + if (m != NULL) { + wq.push(m); + } + } + } + } + + if (ZVerifyLoadBarriers) { + if ((n->is_Load() || n->is_LoadStore()) && n->bottom_type()->make_oopptr() != NULL) { + visited.Clear(); + bool found = look_for_barrier(n, post_parse, visited); + if (!found) { + n->dump(1); + n->dump(-3); + stringStream ss; + C->method()->print_short_name(&ss); + tty->print_cr("-%s-", ss.as_string()); + assert(found, ""); + } + } + } + } +} + +#endif