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   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 }