--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/c2/zBarrierSetC2.cpp Tue Jun 12 17:40:28 2018 +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<LoadBarrierNode*>(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<ZBarrierSetC2State*>(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->in(2) == oop_phi) {
+ // 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