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/cardTable.hpp"
  28 #include "gc/shared/cardTableBarrierSet.hpp"
  29 #include "utilities/macros.hpp"
  30 
  31 #ifdef ASSERT
  32 #define __ gen->lir(__FILE__, __LINE__)->
  33 #else
  34 #define __ gen->lir()->
  35 #endif
  36 
  37 void CardTableBarrierSetC1::post_barrier(LIRAccess& access, LIR_OprDesc* addr, LIR_OprDesc* new_val) {
  38   DecoratorSet decorators = access.decorators();
  39   LIRGenerator* gen = access.gen();
  40   bool in_heap = (decorators & IN_HEAP) != 0;
  41   if (!in_heap) {
  42     return;
  43   }
  44 
  45   BarrierSet* bs = BarrierSet::barrier_set();
  46   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
  47   CardTable* ct = ctbs->card_table();
  48   assert(sizeof(*(ct->byte_map_base())) == sizeof(jbyte), "adjust this code");
  49   LIR_Const* card_table_base = new LIR_Const(ct->byte_map_base());
  50   if (addr->is_address()) {
  51     LIR_Address* address = addr->as_address_ptr();
  52     // ptr cannot be an object because we use this barrier for array card marks
  53     // and addr can point in the middle of an array.
  54     LIR_Opr ptr = gen->new_pointer_register();
  55     if (!address->index()->is_valid() && address->disp() == 0) {
  56       __ move(address->base(), ptr);
  57     } else {
  58       assert(address->disp() != max_jint, "lea doesn't support patched addresses!");
  59       __ leal(addr, ptr);
  60     }
  61     addr = ptr;
  62   }
  63   assert(addr->is_register(), "must be a register at this point");
  64 
  65 #ifdef CARDTABLEBARRIERSET_POST_BARRIER_HELPER
  66   gen->CardTableBarrierSet_post_barrier_helper(addr, card_table_base);
  67 #else
  68   LIR_Opr tmp = gen->new_pointer_register();
  69   if (TwoOperandLIRForm) {
  70     __ move(addr, tmp);
  71     __ unsigned_shift_right(tmp, CardTable::card_shift, tmp);
  72   } else {
  73     __ unsigned_shift_right(addr, CardTable::card_shift, tmp);
  74   }
  75 
  76   LIR_Address* card_addr;
  77   if (gen->can_inline_as_constant(card_table_base)) {
  78     card_addr = new LIR_Address(tmp, card_table_base->as_jint(), T_BYTE);
  79   } else {
  80     card_addr = new LIR_Address(tmp, gen->load_constant(card_table_base), T_BYTE);
  81   }
  82 
  83   LIR_Opr dirty = LIR_OprFact::intConst(CardTable::dirty_card_val());
  84   if (UseCondCardMark) {
  85     LIR_Opr cur_value = gen->new_register(T_INT);
  86     if (ct->scanned_concurrently()) {
  87       __ membar_storeload();
  88     }
  89     __ move(card_addr, cur_value);
  90 
  91     LabelObj* L_already_dirty = new LabelObj();
  92     __ cmp(lir_cond_equal, cur_value, dirty);
  93     __ branch(lir_cond_equal, T_BYTE, L_already_dirty->label());
  94     __ move(dirty, card_addr);
  95     __ branch_destination(L_already_dirty->label());
  96   } else {
  97     if (ct->scanned_concurrently()) {
  98       __ membar_storestore();
  99     }
 100     __ move(dirty, card_addr);
 101   }
 102 #endif
 103 }