1 2 /* 3 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "asm/macroAssembler.inline.hpp" 28 #include "gc/shared/barrierSet.hpp" 29 #include "gc/shared/cardTable.hpp" 30 #include "gc/shared/cardTableModRefBS.hpp" 31 #include "gc/shared/cardTableModRefBSCodeGen.hpp" 32 #include "gc/shared/collectedHeap.hpp" 33 #include "interpreter/interp_masm.hpp" 34 35 #define __ masm-> 36 37 #ifdef PRODUCT 38 #define BLOCK_COMMENT(str) /* nothing */ 39 #else 40 #define BLOCK_COMMENT(str) __ block_comment(str) 41 #endif 42 43 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":") 44 45 void CardTableModRefBSCodeGen::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr, Register count, Register tmp) { 46 CardTableModRefBS* ct = barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set()); 47 assert(sizeof(*ct->card_table()->byte_map_base()) == sizeof(jbyte), "adjust this code"); 48 assert_different_registers(addr, count, tmp); 49 50 Label L_loop; 51 52 __ sll_ptr(count, LogBytesPerHeapOop, count); 53 __ sub(count, BytesPerHeapOop, count); 54 __ add(count, addr, count); 55 // Use two shifts to clear out those low order two bits! (Cannot opt. into 1.) 56 __ srl_ptr(addr, CardTable::card_shift, addr); 57 __ srl_ptr(count, CardTable::card_shift, count); 58 __ sub(count, addr, count); 59 AddressLiteral rs((address)ct->card_table()->byte_map_base()); 60 __ set(rs, tmp); 61 __ BIND(L_loop); 62 __ stb(G0, tmp, addr); 63 __ subcc(count, 1, count); 64 __ brx(Assembler::greaterEqual, false, Assembler::pt, L_loop); 65 __ delayed()->add(addr, 1, addr); 66 } 67 68 void CardTableModRefBSCodeGen::card_table_write(MacroAssembler* masm, 69 jbyte* byte_map_base, 70 Register tmp, Register obj) { 71 #ifdef _LP64 72 __ srlx(obj, CardTable::card_shift, obj); 73 #else 74 __ srl(obj, CardTable::card_shift, obj); 75 #endif 76 assert(tmp != obj, "need separate temp reg"); 77 __ set((address) byte_map_base, tmp); 78 __ stb(G0, tmp, obj); 79 } 80 81 void CardTableModRefBSCodeGen::card_write_barrier_post(MacroAssembler* masm, Register store_addr, Register new_val, Register tmp) { 82 // If we're writing constant NULL, we can skip the write barrier. 83 if (new_val == G0) return; 84 CardTableModRefBS* bs = 85 barrier_set_cast<CardTableModRefBS>(Universe::heap()->barrier_set()); 86 card_table_write(masm, bs->card_table()->byte_map_base(), tmp, store_addr); 87 } 88 89 void CardTableModRefBSCodeGen::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 90 Register base, Register index, int offset, Register val, Register tmp) { 91 bool on_array = (decorators & ACCESS_ON_ARRAY) != 0; 92 bool on_anonymous = (decorators & ACCESS_ON_ANONYMOUS) != 0; 93 bool precise = on_array || on_anonymous; 94 BarrierSetCodeGen::store_at(masm, decorators, type, base, index, offset, val, tmp); 95 // No need for post barrier if storing NULL 96 if (val != G0) { 97 if (precise) { 98 if (index == noreg) { 99 __ add(base, offset, base); 100 } else { 101 __ add(base, index, base); 102 } 103 } 104 card_write_barrier_post(masm, base, val, tmp); 105 } 106 }