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 ShenandoahWriteBarrierStub::emit_code(LIR_Assembler* ce) {

    50   ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();

    51   bs->gen_write_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::read_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check) {

   109   if (UseShenandoahGC && ShenandoahReadBarrier) {

   110     return read_barrier_impl(gen, obj, info, need_null_check);

   111   } else {

   112     return obj;

   113   }

   114 }

   115 

   116 LIR_Opr ShenandoahBarrierSetC1::read_barrier_impl(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check) {

   117   assert(UseShenandoahGC && (ShenandoahReadBarrier || ShenandoahStoreValReadBarrier), "Should be enabled");

   118   LabelObj* done = new LabelObj();

   119   LIR_Opr result = gen->new_register(T_OBJECT);

   120   __ move(obj, result);

   121   if (need_null_check) {

   122     __ cmp(lir_cond_equal, result, LIR_OprFact::oopConst(NULL));

   123     __ branch(lir_cond_equal, T_LONG, done->label());

   124   }

   125   LIR_Address* brooks_ptr_address = gen->generate_address(result, ShenandoahBrooksPointer::byte_offset(), T_ADDRESS);

   126   __ load(brooks_ptr_address, result, info ? new CodeEmitInfo(info) : NULL, lir_patch_none);

   127 

   128   __ branch_destination(done->label());

   129   return result;

   130 }

   131 

   132 LIR_Opr ShenandoahBarrierSetC1::write_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check) {

   133   if (UseShenandoahGC && ShenandoahWriteBarrier) {

   134     return write_barrier_impl(gen, obj, info, need_null_check);

   135   } else {

   136     return obj;

   137   }

   138 }

   139 

   140 LIR_Opr ShenandoahBarrierSetC1::write_barrier_impl(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, bool need_null_check) {

   141   assert(UseShenandoahGC && (ShenandoahWriteBarrier || ShenandoahStoreValEnqueueBarrier), "Should be enabled");

   142 

   143   obj = ensure_in_register(gen, obj);

   144   assert(obj->is_register(), "must be a register at this point");

   145   LIR_Opr result = gen->new_register(T_OBJECT);

   146   __ move(obj, result);

   147 

   148   LIR_Opr thrd = gen->getThreadPointer();

   149   LIR_Address* active_flag_addr =

   150     new LIR_Address(thrd,

   151                     in_bytes(ShenandoahThreadLocalData::gc_state_offset()),

   152                     T_BYTE);

   153   // Read and check the gc-state-flag.

   154   LIR_Opr flag_val = gen->new_register(T_INT);

   155   __ load(active_flag_addr, flag_val);

   156   LIR_Opr mask = LIR_OprFact::intConst(ShenandoahHeap::HAS_FORWARDED |

   157                                        ShenandoahHeap::EVACUATION |

   158                                        ShenandoahHeap::TRAVERSAL);

   159   LIR_Opr mask_reg = gen->new_register(T_INT);

   160   __ move(mask, mask_reg);

   161 

   162   if (TwoOperandLIRForm) {

   163     __ logical_and(flag_val, mask_reg, flag_val);

   164   } else {

   165     LIR_Opr masked_flag = gen->new_register(T_INT);

   166     __ logical_and(flag_val, mask_reg, masked_flag);

   167     flag_val = masked_flag;

   168   }

   169   __ cmp(lir_cond_notEqual, flag_val, LIR_OprFact::intConst(0));

   170 

   171   CodeStub* slow = new ShenandoahWriteBarrierStub(obj, result, info ? new CodeEmitInfo(info) : NULL, need_null_check);

   172   __ branch(lir_cond_notEqual, T_INT, slow);

   173   __ branch_destination(slow->continuation());

   174 

   175   return result;

   176 }

   177 

   178 LIR_Opr ShenandoahBarrierSetC1::ensure_in_register(LIRGenerator* gen, LIR_Opr obj) {

   179   if (!obj->is_register()) {

   180     LIR_Opr obj_reg = gen->new_register(T_OBJECT);

   181     if (obj->is_constant()) {

   182       __ move(obj, obj_reg);

   183     } else {

   184       __ leal(obj, obj_reg);

   185     }

   186     obj = obj_reg;

   187   }

   188   return obj;

   189 }

   190 

   191 LIR_Opr ShenandoahBarrierSetC1::storeval_barrier(LIRGenerator* gen, LIR_Opr obj, CodeEmitInfo* info, DecoratorSet decorators) {

   192   bool need_null_check = (decorators & IS_NOT_NULL) == 0;

   193   if (ShenandoahStoreValEnqueueBarrier) {

   194     obj = write_barrier_impl(gen, obj, info, need_null_check);

   195     pre_barrier(gen, info, decorators, LIR_OprFact::illegalOpr, obj);

   196   }

   197   if (ShenandoahStoreValReadBarrier) {

   198     obj = read_barrier_impl(gen, obj, info, true /*need_null_check*/);

   199   }

   200   return obj;

   201 }

   202 

   203 LIR_Opr ShenandoahBarrierSetC1::resolve_address(LIRAccess& access, bool resolve_in_register) {

   204   DecoratorSet decorators = access.decorators();

   205   bool is_array = (decorators & IS_ARRAY) != 0;

   206   bool needs_patching = (decorators & C1_NEEDS_PATCHING) != 0;

   207 

   208   bool is_write = (decorators & ACCESS_WRITE) != 0;

   209   bool needs_null_check = (decorators & IS_NOT_NULL) == 0;

   210 

   211   LIR_Opr base = access.base().item().result();

   212   LIR_Opr offset = access.offset().opr();

   213   LIRGenerator* gen = access.gen();

   214 

   215   if (is_write) {

   216     base = write_barrier(gen, base, access.access_emit_info(), needs_null_check);

   217   } else {

   218     base = read_barrier(gen, base, access.access_emit_info(), needs_null_check);

   219   }

   220 

   221   LIR_Opr addr_opr;

   222   if (is_array) {

   223     addr_opr = LIR_OprFact::address(gen->emit_array_address(base, offset, access.type()));

   224   } else if (needs_patching) {

   225     // we need to patch the offset in the instruction so don't allow

   226     // generate_address to try to be smart about emitting the -1.

   227     // Otherwise the patching code won't know how to find the

   228     // instruction to patch.

   229     addr_opr = LIR_OprFact::address(new LIR_Address(base, PATCHED_ADDR, access.type()));

   230   } else {

   231     addr_opr = LIR_OprFact::address(gen->generate_address(base, offset, 0, 0, access.type()));

   232   }

   233 

   234   if (resolve_in_register) {

   235     LIR_Opr resolved_addr = gen->new_pointer_register();

   236     __ leal(addr_opr, resolved_addr);

   237     resolved_addr = LIR_OprFact::address(new LIR_Address(resolved_addr, access.type()));

   238     return resolved_addr;

   239   } else {

   240     return addr_opr;

   241   }

   242 }

   243 

   244 void ShenandoahBarrierSetC1::store_at_resolved(LIRAccess& access, LIR_Opr value) {

   245   if (access.is_oop()) {

   246     if (ShenandoahSATBBarrier) {

   247       pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), access.resolved_addr(), LIR_OprFact::illegalOpr /* pre_val */);

   248     }

   249     value = storeval_barrier(access.gen(), value, access.access_emit_info(), access.decorators());

   250   }

   251   BarrierSetC1::store_at_resolved(access, value);

   252 }

   253 

   254 void ShenandoahBarrierSetC1::load_at_resolved(LIRAccess& access, LIR_Opr result) {

   255   BarrierSetC1::load_at_resolved(access, result);

   256 

   257   if (ShenandoahKeepAliveBarrier) {

   258     DecoratorSet decorators = access.decorators();

   259     bool is_weak = (decorators & ON_WEAK_OOP_REF) != 0;

   260     bool is_phantom = (decorators & ON_PHANTOM_OOP_REF) != 0;

   261     bool is_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;

   262     LIRGenerator *gen = access.gen();

   263     if (access.is_oop() && (is_weak || is_phantom || is_anonymous)) {

   264       // Register the value in the referent field with the pre-barrier

   265       LabelObj *Lcont_anonymous;

   266       if (is_anonymous) {

   267         Lcont_anonymous = new LabelObj();

   268         generate_referent_check(access, Lcont_anonymous);

   269       }

   270       pre_barrier(access.gen(), access.access_emit_info(), access.decorators(), LIR_OprFact::illegalOpr /* addr_opr */,

   271                   result /* pre_val */);

   272       if (is_anonymous) {

   273         __ branch_destination(Lcont_anonymous->label());

   274       }

   275     }

   276   }

   277 }

   278 

   279 LIR_Opr ShenandoahBarrierSetC1::atomic_add_at_resolved(LIRAccess& access, LIRItem& value) {

   280   return BarrierSetC1::atomic_add_at_resolved(access, value);

   281 }

   282 

   283 LIR_Opr ShenandoahBarrierSetC1::resolve(LIRGenerator* gen, DecoratorSet decorators, LIR_Opr obj) {

   284   bool is_write = decorators & ACCESS_WRITE;

   285   if (is_write) {

   286     return write_barrier(gen, obj, NULL, (decorators & IS_NOT_NULL) == 0);

   287   } else {

   288     return read_barrier(gen, obj, NULL, (decorators & IS_NOT_NULL) == 0);

   289   }

   290 }

   291 

   292 class C1ShenandoahPreBarrierCodeGenClosure : public StubAssemblerCodeGenClosure {

   293   virtual OopMapSet* generate_code(StubAssembler* sasm) {

   294     ShenandoahBarrierSetAssembler* bs = (ShenandoahBarrierSetAssembler*)BarrierSet::barrier_set()->barrier_set_assembler();

   295     bs->generate_c1_pre_barrier_runtime_stub(sasm);

   296     return NULL;

   297   }

   298 };

   299 

   300 void ShenandoahBarrierSetC1::generate_c1_runtime_stubs(BufferBlob* buffer_blob) {

   301   C1ShenandoahPreBarrierCodeGenClosure pre_code_gen_cl;

   302   _pre_barrier_c1_runtime_code_blob = Runtime1::generate_blob(buffer_blob, -1,

   303                                                               "shenandoah_pre_barrier_slow",

   304                                                               false, &pre_code_gen_cl);

   305 }