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
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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 
post_barrier(LIRAccess & access,LIR_OprDesc * addr,LIR_OprDesc * new_val)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   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 }
103