1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc/shared/c1/cardTableBarrierSetC1.hpp"
  27 #include "gc/shared/cardTableBarrierSet.hpp"
  28 #include "utilities/macros.hpp"
  29 
  30 #ifdef ASSERT
  31 #define __ gen->lir(__FILE__, __LINE__)->
  32 #else
  33 #define __ gen->lir()->
  34 #endif
  35 
  36 void CardTableBarrierSetC1::post_barrier(LIRAccess& access, LIR_OprDesc* addr, LIR_OprDesc* new_val) {
  37   DecoratorSet decorators = access.decorators();
  38   LIRGenerator* gen = access.gen();
  39   bool in_heap = (decorators & IN_HEAP) != 0;
  40   if (!in_heap) {
  41     return;
  42   }
  43 
  44   BarrierSet* bs = BarrierSet::barrier_set();
  45   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
  46   CardTable* ct = ctbs->card_table();
  47   assert(sizeof(*(ct->byte_map_base())) == sizeof(jbyte), "adjust this code");
  48   LIR_Const* card_table_base = new LIR_Const(ct->byte_map_base());
  49   if (addr->is_address()) {
  50     LIR_Address* address = addr->as_address_ptr();
  51     // ptr cannot be an object because we use this barrier for array card marks
  52     // and addr can point in the middle of an array.
  53     LIR_Opr ptr = gen->new_pointer_register();
  54     if (!address->index()->is_valid() && address->disp() == 0) {
  55       __ move(address->base(), ptr);
  56     } else {
  57       assert(address->disp() != max_jint, "lea doesn't support patched addresses!");
  58       __ leal(addr, ptr);
  59     }
  60     addr = ptr;
  61   }
  62   assert(addr->is_register(), "must be a register at this point");
  63 
  64 #ifdef CARDTABLEBARRIERSET_POST_BARRIER_HELPER
  65   gen->CardTableBarrierSet_post_barrier_helper(addr, card_table_base);
  66 #else
  67   LIR_Opr tmp = gen->new_pointer_register();
  68   if (TwoOperandLIRForm) {
  69     __ move(addr, tmp);
  70     __ unsigned_shift_right(tmp, CardTable::card_shift, tmp);
  71   } else {
  72     __ unsigned_shift_right(addr, CardTable::card_shift, tmp);
  73   }
  74 
  75   LIR_Address* card_addr;
  76   if (gen->can_inline_as_constant(card_table_base)) {
  77     card_addr = new LIR_Address(tmp, card_table_base->as_jint(), T_BYTE);
  78   } else {
  79     card_addr = new LIR_Address(tmp, gen->load_constant(card_table_base), T_BYTE);
  80   }
  81 
  82   LIR_Opr dirty = LIR_OprFact::intConst(CardTable::dirty_card_val());
  83   if (UseCondCardMark) {
  84     LIR_Opr cur_value = gen->new_register(T_INT);
  85     if (ct->scanned_concurrently()) {
  86       __ membar_storeload();
  87     }
  88     __ move(card_addr, cur_value);
  89 
  90     LabelObj* L_already_dirty = new LabelObj();
  91     __ cmp(lir_cond_equal, cur_value, dirty);
  92     __ branch(lir_cond_equal, T_BYTE, L_already_dirty->label());
  93     __ move(dirty, card_addr);
  94     __ branch_destination(L_already_dirty->label());
  95   } else {
  96     if (ct->scanned_concurrently()) {
  97       __ membar_storestore();
  98     }
  99     __ move(dirty, card_addr);
 100   }
 101 #endif
 102 }