1 /*
   2  * Copyright (c) 2018, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 #include "precompiled.hpp"
  25 #include "c1/c1_IR.hpp"
  26 #include "gc/shared/satbMarkQueue.hpp"
  27 #include "gc/shenandoah/shenandoahBarrierSetAssembler.hpp"
  28 #include "gc/shenandoah/shenandoahBrooksPointer.hpp"
  29 #include "gc/shenandoah/shenandoahHeap.hpp"
  30 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
  31 #include "gc/shenandoah/shenandoahThreadLocalData.hpp"
  32 #include "gc/shenandoah/c1/shenandoahBarrierSetC1.hpp"
  33 
  34 #ifndef PATCHED_ADDR
  35 #define PATCHED_ADDR  (max_jint)
  36 #endif
  37 
  38 #ifdef ASSERT
  39 #define __ gen->lir(__FILE__, __LINE__)->
  40 #else
  41 #define __ gen->lir()->
  42 #endif
  43 
  44 void ShenandoahPreBarrierStub::emit_code(LIR_Assembler* ce) {
  45   ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
  46   bs->gen_pre_barrier_stub(ce, this);
  47 }
  48 
  49 void ShenandoahLoadReferenceBarrierStub::emit_code(LIR_Assembler* ce) {
  50   ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
  51   bs->gen_load_reference_barrier_stub(ce, this);
  52 }
  53 
  54 void ShenandoahBarrierSetC1::pre_barrier(LIRGenerator* gen, CodeEmitInfo* info, DecoratorSet decorators, LIR_Opr addr_opr, LIR_Opr pre_val) {
  55   // First we test whether marking is in progress.
  56   BasicType flag_type;
  57   bool patch = (decorators & C1_NEEDS_PATCHING) != 0;
  58   bool do_load = pre_val == LIR_OprFact::illegalOpr;
  59   if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
  60     flag_type = T_INT;
  61   } else {
  62     guarantee(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1,
  63               "Assumption");
  64     // Use unsigned type T_BOOLEAN here rather than signed T_BYTE since some platforms, eg. ARM,
  65     // need to use unsigned instructions to use the large offset to load the satb_mark_queue.
  66     flag_type = T_BOOLEAN;
  67   }
  68   LIR_Opr thrd = gen->getThreadPointer();
  69   LIR_Address* mark_active_flag_addr =
  70     new LIR_Address(thrd,
  71                     in_bytes(ShenandoahThreadLocalData::satb_mark_queue_active_offset()),
  72                     flag_type);
  73   // Read the marking-in-progress flag.
  74   LIR_Opr flag_val = gen->new_register(T_INT);
  75   __ load(mark_active_flag_addr, flag_val);
  76   __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));
  77 
  78   LIR_PatchCode pre_val_patch_code = lir_patch_none;
  79 
  80   CodeStub* slow;
  81 
  82   if (do_load) {
  83     assert(pre_val == LIR_OprFact::illegalOpr, "sanity");
  84     assert(addr_opr != LIR_OprFact::illegalOpr, "sanity");
  85 
  86     if (patch)
  87       pre_val_patch_code = lir_patch_normal;
  88 
  89     pre_val = gen->new_register(T_OBJECT);
  90 
  91     if (!addr_opr->is_address()) {
  92       assert(addr_opr->is_register(), "must be");
  93       addr_opr = LIR_OprFact::address(new LIR_Address(addr_opr, T_OBJECT));
  94     }
  95     slow = new ShenandoahPreBarrierStub(addr_opr, pre_val, pre_val_patch_code, info ? new CodeEmitInfo(info) : NULL);
  96   } else {
  97     assert(addr_opr == LIR_OprFact::illegalOpr, "sanity");
  98     assert(pre_val->is_register(), "must be");
  99     assert(pre_val->type() == T_OBJECT, "must be an object");
 100 
 101     slow = new ShenandoahPreBarrierStub(pre_val);
 102   }
 103 
 104   __ branch(lir_cond_notEqual, T_INT, slow);
 105   __ branch_destination(slow->continuation());
 106 }
 107 
 108 LIR_Opr ShenandoahBarrierSetC1::load_reference_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check) {
 109   if (ShenandoahLoadRefBarrier) {
 110     return load_reference_barrier_impl(gen, obj, info, need_null_check);
 111   } else {
 112     return obj;
 113   }
 114 }
 115 
 116 LIR_Opr ShenandoahBarrierSetC1::load_reference_barrier_impl(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check) {
 117   assert(ShenandoahLoadRefBarrier, "Should be enabled");
 118 
 119   obj = ensure_in_register(gen, obj);
 120   assert(obj->is_register(), "must be a register at this point");
 121   LIR_Opr result = gen->new_register(T_OBJECT);
 122   __ move(obj, result);
 123 
 124   LIR_Opr thrd = gen->getThreadPointer();
 125   LIR_Address* active_flag_addr =
 126     new LIR_Address(thrd,
 127                     in_bytes(ShenandoahThreadLocalData::gc_state_offset()),
 128                     T_BYTE);
 129   // Read and check the gc-state-flag.
 130   LIR_Opr flag_val = gen->new_register(T_INT);
 131   __ load(active_flag_addr, flag_val);
 132   LIR_Opr mask = LIR_OprFact::intConst(ShenandoahHeap::HAS_FORWARDED |
 133                                        ShenandoahHeap::EVACUATION |
 134                                        ShenandoahHeap::TRAVERSAL);
 135   LIR_Opr mask_reg = gen->new_register(T_INT);
 136   __ move(mask, mask_reg);
 137 
 138   if (TwoOperandLIRForm) {
 139     __ logical_and(flag_val, mask_reg, flag_val);
 140   } else {
 141     LIR_Opr masked_flag = gen->new_register(T_INT);
 142     __ logical_and(flag_val, mask_reg, masked_flag);
 143     flag_val = masked_flag;
 144   }
 145   __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));
 146 
 147   CodeStub* slow = new ShenandoahLoadReferenceBarrierStub(obj, result, info ? new CodeEmitInfo(info) : NULL, need_null_check);
 148   __ branch(lir_cond_notEqual, T_INT, slow);
 149   __ branch_destination(slow->continuation());
 150 
 151   return result;
 152 }
 153 
 154 LIR_Opr ShenandoahBarrierSetC1::ensure_in_register(LIRGenerator* gen, LIR_Opr obj) {
 155   if (!obj->is_register()) {
 156     LIR_Opr obj_reg = gen->new_register(T_OBJECT);
 157     if (obj->is_constant()) {
 158       __ move(obj, obj_reg);
 159     } else {
 160       __ leal(obj, obj_reg);
 161     }
 162     obj = obj_reg;
 163   }
 164   return obj;
 165 }
 166 
 167 LIR_Opr ShenandoahBarrierSetC1::storeval_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, DecoratorSet decorators) {
 168   if (ShenandoahStoreValEnqueueBarrier) {
 169     obj = ensure_in_register(gen, obj);
 170     pre_barrier(gen, info, decorators, LIR_OprFact::illegalOpr, obj);
 171   }
 172   return obj;
 173 }
 174 
 175 void ShenandoahBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {
 176   if (access.is_oop()) {
 177     if (ShenandoahSATBBarrier) {
 178       pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), access.resolved_addr(), LIR_OprFact::illegalOpr /* pre_val */);
 179     }
 180     value = storeval_barrier(access.gen(), value, access.access_emit_info(), access.decorators());
 181   }
 182   BarrierSetC1::store_at_resolved(access, value);
 183 }
 184 
 185 void ShenandoahBarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) {
 186   if (!access.is_oop()) {
 187     BarrierSetC1::load_at_resolved(access, result);
 188     return;
 189   }
 190 
 191   LIRGenerator *gen = access.gen();
 192 
 193   if (ShenandoahLoadRefBarrier) {
 194     LIR_Opr tmp = gen->new_register(T_OBJECT);
 195     BarrierSetC1::load_at_resolved(access, tmp);
 196     tmp = load_reference_barrier(access.gen(), tmp, access.access_emit_info(), true);
 197     __ move(tmp, result);
 198   } else {
 199     BarrierSetC1::load_at_resolved(access, result);
 200   }
 201 
 202   if (ShenandoahKeepAliveBarrier) {
 203     DecoratorSet decorators = access.decorators();
 204     bool is_weak = (decorators & ON_WEAK_OOP_REF) != 0;
 205     bool is_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;
 206     bool is_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
 207     if (is_weak || is_phantom || is_anonymous) {
 208       // Register the value in the referent field with the pre-barrier
 209       LabelObj *Lcont_anonymous;
 210       if (is_anonymous) {
 211         Lcont_anonymous = new LabelObj();
 212         generate_referent_check(access, Lcont_anonymous);
 213       }
 214       pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), LIR_OprFact::illegalOpr /* addr_opr */,
 215                   result /* pre_val */);
 216       if (is_anonymous) {
 217         __ branch_destination(Lcont_anonymous->label());
 218       }
 219     }
 220   }
 221 }
 222 
 223 class C1ShenandoahPreBarrierCodeGenClosure : public StubAssemblerCodeGenClosure {
 224   virtual OopMapSet* generate_code(StubAssembler* sasm) {
 225     ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();
 226     bs->generate_c1_pre_barrier_runtime_stub(sasm);
 227     return NULL;
 228   }
 229 };
 230 
 231 void ShenandoahBarrierSetC1::generate_c1_runtime_stubs(BufferBlob* buffer_blob) {
 232   C1ShenandoahPreBarrierCodeGenClosure pre_code_gen_cl;
 233   _pre_barrier_c1_runtime_code_blob = Runtime1::generate_blob(buffer_blob, -1,
 234                                                               "shenandoah_pre_barrier_slow",
 235                                                               false, &pre_code_gen_cl);
 236 }