1 /*
 2  * Copyright (c) 2018, 2021, 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 "gc/shared/gc_globals.hpp"
30 #include "utilities/macros.hpp"
31 
32 #ifdef ASSERT
33 #define __ gen->lir(__FILE__, __LINE__)->
34 #else
35 #define __ gen->lir()->
36 #endif
37 
38 void CardTableBarrierSetC1::post_barrier(LIRAccess& access, LIR_OprDesc* addr, LIR_OprDesc* new_val) {
39   DecoratorSet decorators = access.decorators();
40   LIRGenerator* gen = access.gen();
41   bool in_heap = (decorators & IN_HEAP) != 0;
42   if (!in_heap) {
43     return;
44   }
45 
46   BarrierSet* bs = BarrierSet::barrier_set();
47   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs);
48   CardTable* ct = ctbs->card_table();
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     LIR_Opr addr_opr = LIR_OprFact::address(new LIR_Address(addr, addr->type()));
71     __ leal(addr_opr, tmp);
72     __ unsigned_shift_right(tmp, CardTable::card_shift, tmp);
73   } else {
74     __ unsigned_shift_right(addr, CardTable::card_shift, tmp);
75   }
76 
77   LIR_Address* card_addr;
78   if (gen->can_inline_as_constant(card_table_base)) {
79     card_addr = new LIR_Address(tmp, card_table_base->as_jint(), T_BYTE);
80   } else {
81     card_addr = new LIR_Address(tmp, gen->load_constant(card_table_base), T_BYTE);
82   }
83 
84   LIR_Opr dirty = LIR_OprFact::intConst(CardTable::dirty_card_val());
85   if (UseCondCardMark) {
86     LIR_Opr cur_value = gen->new_register(T_INT);
87     __ move(card_addr, cur_value);
88 
89     LabelObj* L_already_dirty = new LabelObj();
90     __ cmp(lir_cond_equal, cur_value, dirty);
91     __ branch(lir_cond_equal, L_already_dirty->label());
92     __ move(dirty, card_addr);
93     __ branch_destination(L_already_dirty->label());
94   } else {
95     __ move(dirty, card_addr);
96   }
97 #endif
98 }