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src/hotspot/share/gc/shenandoah/c2/shenandoahBarrierSetC2.cpp

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 948 
 949     ctrl = phase->transform_later(new ProjNode(call, TypeFunc::Control));
 950     mem = phase->transform_later(new ProjNode(call, TypeFunc::Memory));
 951     region->init_req(_heap_unstable, ctrl);
 952     mem_phi->init_req(_heap_unstable, mem);
 953 
 954     // Wire up the actual arraycopy stub now
 955     ctrl = phase->transform_later(region);
 956     mem = phase->transform_later(mem_phi);
 957 
 958     const char* name = "arraycopy";
 959     call = phase->make_leaf_call(ctrl, mem,
 960                                  OptoRuntime::fast_arraycopy_Type(),
 961                                  phase->basictype2arraycopy(T_LONG, nullptr, nullptr, true, name, true),
 962                                  name, TypeRawPtr::BOTTOM,
 963                                  src, dest, length
 964                                  LP64_ONLY(COMMA phase->top()));
 965     call = phase->transform_later(call);
 966 
 967     // Hook up the whole thing into the graph
 968     phase->igvn().replace_node(ac, call);
 969   } else {
 970     BarrierSetC2::clone_at_expansion(phase, ac);
 971   }
 972 }
 973 
 974 
 975 // Support for macro expanded GC barriers
 976 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
 977   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 978     state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
 979   }
 980 }
 981 
 982 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
 983   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 984     state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
 985   }
 986 }
 987 
 988 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseMacroExpand* macro, Node* node) const {
 989   if (is_shenandoah_wb_pre_call(node)) {
 990     shenandoah_eliminate_wb_pre(node, &macro->igvn());
 991   }
 992   if (ShenandoahCardBarrier && node->Opcode() == Op_CastP2X) {
 993     Node* shift = node->unique_out();
 994     Node* addp = shift->unique_out();
 995     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 996       Node* mem = addp->last_out(j);
 997       if (UseCondCardMark && mem->is_Load()) {
 998         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 999         // The load is checking if the card has been written so
1000         // replace it with zero to fold the test.
1001         macro->replace_node(mem, macro->intcon(0));
1002         continue;
1003       }
1004       assert(mem->is_Store(), "store required");
1005       macro->replace_node(mem, mem->in(MemNode::Memory));
1006     }
1007   }
1008 }
1009 
1010 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
1011   assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
1012   Node* c = call->as_Call()->proj_out(TypeFunc::Control);
1013   c = c->unique_ctrl_out();
1014   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1015   c = c->unique_ctrl_out();
1016   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1017   Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1018   assert(iff->is_If(), "expect test");
1019   if (!is_shenandoah_marking_if(igvn, iff)) {
1020     c = c->unique_ctrl_out();
1021     assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1022     iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1023     assert(is_shenandoah_marking_if(igvn, iff), "expect marking test");
1024   }
1025   Node* cmpx = iff->in(1)->in(1);

1117                 if (if_ctrl != load_ctrl) {
1118                   // Skip possible CProj->NeverBranch in infinite loops
1119                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
1120                       && if_ctrl->in(0)->is_NeverBranch()) {
1121                     if_ctrl = if_ctrl->in(0)->in(0);
1122                   }
1123                 }
1124                 assert(load_ctrl != nullptr && if_ctrl == load_ctrl, "controls must match");
1125               }
1126             }
1127           }
1128         }
1129       }
1130     }
1131   }
1132 }
1133 #endif
1134 
1135 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const {
1136   if (is_shenandoah_wb_pre_call(n)) {
1137     uint cnt = ShenandoahBarrierSetC2::write_barrier_pre_Type()->domain()->cnt();
1138     if (n->req() > cnt) {
1139       Node* addp = n->in(cnt);
1140       if (has_only_shenandoah_wb_pre_uses(addp)) {
1141         n->del_req(cnt);
1142         if (can_reshape) {
1143           phase->is_IterGVN()->_worklist.push(addp);
1144         }
1145         return n;
1146       }
1147     }
1148   }
1149   if (n->Opcode() == Op_CmpP) {
1150     Node* in1 = n->in(1);
1151     Node* in2 = n->in(2);
1152 
1153     // If one input is null, then step over the strong LRB barriers on the other input
1154     if (in1->bottom_type() == TypePtr::NULL_PTR &&
1155         !((in2->Opcode() == Op_ShenandoahLoadReferenceBarrier) &&
1156           !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in2)->decorators()))) {
1157       in2 = step_over_gc_barrier(in2);

1203   return nullptr;
1204 }
1205 
1206 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1207   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1208     Node* u = n->fast_out(i);
1209     if (!is_shenandoah_wb_pre_call(u)) {
1210       return false;
1211     }
1212   }
1213   return n->outcnt() > 0;
1214 }
1215 
1216 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode, Unique_Node_List& dead_nodes) const {
1217   switch (opcode) {
1218     case Op_CallLeaf:
1219     case Op_CallLeafNoFP: {
1220       assert (n->is_Call(), "");
1221       CallNode *call = n->as_Call();
1222       if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) {
1223         uint cnt = ShenandoahBarrierSetC2::write_barrier_pre_Type()->domain()->cnt();
1224         if (call->req() > cnt) {
1225           assert(call->req() == cnt + 1, "only one extra input");
1226           Node *addp = call->in(cnt);
1227           assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?");
1228           call->del_req(cnt);
1229         }
1230       }
1231       return false;
1232     }
1233     case Op_ShenandoahCompareAndSwapP:
1234     case Op_ShenandoahCompareAndSwapN:
1235     case Op_ShenandoahWeakCompareAndSwapN:
1236     case Op_ShenandoahWeakCompareAndSwapP:
1237     case Op_ShenandoahCompareAndExchangeP:
1238     case Op_ShenandoahCompareAndExchangeN:
1239       return true;
1240     case Op_ShenandoahLoadReferenceBarrier:
1241       assert(false, "should have been expanded already");
1242       return true;
1243     default:

 948 
 949     ctrl = phase->transform_later(new ProjNode(call, TypeFunc::Control));
 950     mem = phase->transform_later(new ProjNode(call, TypeFunc::Memory));
 951     region->init_req(_heap_unstable, ctrl);
 952     mem_phi->init_req(_heap_unstable, mem);
 953 
 954     // Wire up the actual arraycopy stub now
 955     ctrl = phase->transform_later(region);
 956     mem = phase->transform_later(mem_phi);
 957 
 958     const char* name = "arraycopy";
 959     call = phase->make_leaf_call(ctrl, mem,
 960                                  OptoRuntime::fast_arraycopy_Type(),
 961                                  phase->basictype2arraycopy(T_LONG, nullptr, nullptr, true, name, true),
 962                                  name, TypeRawPtr::BOTTOM,
 963                                  src, dest, length
 964                                  LP64_ONLY(COMMA phase->top()));
 965     call = phase->transform_later(call);
 966 
 967     // Hook up the whole thing into the graph
 968     phase->replace_node(ac, call);
 969   } else {
 970     BarrierSetC2::clone_at_expansion(phase, ac);
 971   }
 972 }
 973 
 974 
 975 // Support for macro expanded GC barriers
 976 void ShenandoahBarrierSetC2::register_potential_barrier_node(Node* node) const {
 977   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 978     state()->add_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
 979   }
 980 }
 981 
 982 void ShenandoahBarrierSetC2::unregister_potential_barrier_node(Node* node) const {
 983   if (node->Opcode() == Op_ShenandoahLoadReferenceBarrier) {
 984     state()->remove_load_reference_barrier((ShenandoahLoadReferenceBarrierNode*) node);
 985   }
 986 }
 987 
 988 void ShenandoahBarrierSetC2::eliminate_gc_barrier(PhaseIterGVN* igvn, Node* node) const {
 989   if (is_shenandoah_wb_pre_call(node)) {
 990     shenandoah_eliminate_wb_pre(node, igvn);
 991   }
 992   if (ShenandoahCardBarrier && node->Opcode() == Op_CastP2X) {
 993     Node* shift = node->unique_out();
 994     Node* addp = shift->unique_out();
 995     for (DUIterator_Last jmin, j = addp->last_outs(jmin); j >= jmin; --j) {
 996       Node* mem = addp->last_out(j);
 997       if (UseCondCardMark && mem->is_Load()) {
 998         assert(mem->Opcode() == Op_LoadB, "unexpected code shape");
 999         // The load is checking if the card has been written so
1000         // replace it with zero to fold the test.
1001         igvn->replace_node(mem, igvn->intcon(0));
1002         continue;
1003       }
1004       assert(mem->is_Store(), "store required");
1005       igvn->replace_node(mem, mem->in(MemNode::Memory));
1006     }
1007   }
1008 }
1009 
1010 void ShenandoahBarrierSetC2::shenandoah_eliminate_wb_pre(Node* call, PhaseIterGVN* igvn) const {
1011   assert(UseShenandoahGC && is_shenandoah_wb_pre_call(call), "");
1012   Node* c = call->as_Call()->proj_out(TypeFunc::Control);
1013   c = c->unique_ctrl_out();
1014   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1015   c = c->unique_ctrl_out();
1016   assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1017   Node* iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1018   assert(iff->is_If(), "expect test");
1019   if (!is_shenandoah_marking_if(igvn, iff)) {
1020     c = c->unique_ctrl_out();
1021     assert(c->is_Region() && c->req() == 3, "where's the pre barrier control flow?");
1022     iff = c->in(1)->is_IfProj() ? c->in(1)->in(0) : c->in(2)->in(0);
1023     assert(is_shenandoah_marking_if(igvn, iff), "expect marking test");
1024   }
1025   Node* cmpx = iff->in(1)->in(1);

1117                 if (if_ctrl != load_ctrl) {
1118                   // Skip possible CProj->NeverBranch in infinite loops
1119                   if ((if_ctrl->is_Proj() && if_ctrl->Opcode() == Op_CProj)
1120                       && if_ctrl->in(0)->is_NeverBranch()) {
1121                     if_ctrl = if_ctrl->in(0)->in(0);
1122                   }
1123                 }
1124                 assert(load_ctrl != nullptr && if_ctrl == load_ctrl, "controls must match");
1125               }
1126             }
1127           }
1128         }
1129       }
1130     }
1131   }
1132 }
1133 #endif
1134 
1135 Node* ShenandoahBarrierSetC2::ideal_node(PhaseGVN* phase, Node* n, bool can_reshape) const {
1136   if (is_shenandoah_wb_pre_call(n)) {
1137     uint cnt = ShenandoahBarrierSetC2::write_barrier_pre_Type()->domain_sig()->cnt();
1138     if (n->req() > cnt) {
1139       Node* addp = n->in(cnt);
1140       if (has_only_shenandoah_wb_pre_uses(addp)) {
1141         n->del_req(cnt);
1142         if (can_reshape) {
1143           phase->is_IterGVN()->_worklist.push(addp);
1144         }
1145         return n;
1146       }
1147     }
1148   }
1149   if (n->Opcode() == Op_CmpP) {
1150     Node* in1 = n->in(1);
1151     Node* in2 = n->in(2);
1152 
1153     // If one input is null, then step over the strong LRB barriers on the other input
1154     if (in1->bottom_type() == TypePtr::NULL_PTR &&
1155         !((in2->Opcode() == Op_ShenandoahLoadReferenceBarrier) &&
1156           !ShenandoahBarrierSet::is_strong_access(((ShenandoahLoadReferenceBarrierNode*)in2)->decorators()))) {
1157       in2 = step_over_gc_barrier(in2);

1203   return nullptr;
1204 }
1205 
1206 bool ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(Node* n) {
1207   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
1208     Node* u = n->fast_out(i);
1209     if (!is_shenandoah_wb_pre_call(u)) {
1210       return false;
1211     }
1212   }
1213   return n->outcnt() > 0;
1214 }
1215 
1216 bool ShenandoahBarrierSetC2::final_graph_reshaping(Compile* compile, Node* n, uint opcode, Unique_Node_List& dead_nodes) const {
1217   switch (opcode) {
1218     case Op_CallLeaf:
1219     case Op_CallLeafNoFP: {
1220       assert (n->is_Call(), "");
1221       CallNode *call = n->as_Call();
1222       if (ShenandoahBarrierSetC2::is_shenandoah_wb_pre_call(call)) {
1223         uint cnt = ShenandoahBarrierSetC2::write_barrier_pre_Type()->domain_sig()->cnt();
1224         if (call->req() > cnt) {
1225           assert(call->req() == cnt + 1, "only one extra input");
1226           Node *addp = call->in(cnt);
1227           assert(!ShenandoahBarrierSetC2::has_only_shenandoah_wb_pre_uses(addp), "useless address computation?");
1228           call->del_req(cnt);
1229         }
1230       }
1231       return false;
1232     }
1233     case Op_ShenandoahCompareAndSwapP:
1234     case Op_ShenandoahCompareAndSwapN:
1235     case Op_ShenandoahWeakCompareAndSwapN:
1236     case Op_ShenandoahWeakCompareAndSwapP:
1237     case Op_ShenandoahCompareAndExchangeP:
1238     case Op_ShenandoahCompareAndExchangeN:
1239       return true;
1240     case Op_ShenandoahLoadReferenceBarrier:
1241       assert(false, "should have been expanded already");
1242       return true;
1243     default:
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