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 "asm/macroAssembler.inline.hpp" 27 #include "gc/shared/barrierSet.hpp" 28 #include "gc/shared/cardTable.hpp" 29 #include "gc/shared/cardTableBarrierSet.hpp" 30 #include "gc/shared/cardTableBarrierSetAssembler.hpp" 31 #include "interpreter/interp_masm.hpp" 32 33 #define __ masm-> 34 35 #ifdef PRODUCT 36 #define BLOCK_COMMENT(str) /* nothing */ 37 #else 38 #define BLOCK_COMMENT(str) __ block_comment(str) 39 #endif 40 41 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":") 42 43 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, 44 Register addr, Register count, Register tmp) { 45 CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set()); 46 CardTable* ct = ctbs->card_table(); 47 assert_different_registers(addr, count, tmp); 48 49 Label L_loop, L_done; 50 51 __ cmp_and_br_short(count, 0, Assembler::equal, Assembler::pt, L_done); // zero count - nothing to do 52 53 __ sll_ptr(count, LogBytesPerHeapOop, count); 54 __ sub(count, BytesPerHeapOop, count); 55 __ add(count, addr, count); 56 // Use two shifts to clear out those low order two bits! (Cannot opt. into 1.) 57 __ srl_ptr(addr, CardTable::card_shift, addr); 58 __ srl_ptr(count, CardTable::card_shift, count); 59 __ sub(count, addr, count); 60 AddressLiteral rs(ct->byte_map_base()); 61 __ set(rs, tmp); 62 __ BIND(L_loop); 63 __ stb(G0, tmp, addr); 64 __ subcc(count, 1, count); 65 __ brx(Assembler::greaterEqual, false, Assembler::pt, L_loop); 66 __ delayed()->add(addr, 1, addr); 67 68 __ BIND(L_done); 69 } 70 71 void CardTableBarrierSetAssembler::card_table_write(MacroAssembler* masm, 72 CardTable::CardValue* byte_map_base, 73 Register tmp, Register obj) { 74 __ srlx(obj, CardTable::card_shift, obj); 75 assert(tmp != obj, "need separate temp reg"); 76 __ set((address) byte_map_base, tmp); 77 __ stb(G0, tmp, obj); 78 } 79 80 void CardTableBarrierSetAssembler::card_write_barrier_post(MacroAssembler* masm, Register store_addr, Register new_val, Register tmp) { 81 // If we're writing constant NULL, we can skip the write barrier. 82 if (new_val == G0) return; 83 CardTableBarrierSet* bs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set()); 84 card_table_write(masm, bs->card_table()->byte_map_base(), tmp, store_addr); 85 } 86 87 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, 88 Register val, Address dst, Register tmp) { 89 bool in_heap = (decorators & IN_HEAP) != 0; 90 91 bool is_array = (decorators & IS_ARRAY) != 0; 92 bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; 93 bool precise = is_array || on_anonymous; 94 95 // No need for post barrier if storing NULL 96 bool needs_post_barrier = val != G0 && in_heap; 97 98 BarrierSetAssembler::store_at(masm, decorators, type, val, dst, tmp); 99 if (needs_post_barrier) { 100 Register base = dst.base(); 101 if (precise) { 102 if (!dst.has_index()) { 103 __ add(base, dst.disp(), base); 104 } else { 105 assert(!dst.has_disp(), "not supported yet"); 106 __ add(base, dst.index(), base); 107 } 108 } 109 card_write_barrier_post(masm, base, val, tmp); 110 } 111 }