| /* |
| * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #include "precompiled.hpp" |
| #include "asm/macroAssembler.inline.hpp" |
| #include "gc/shared/barrierSet.hpp" |
| #include "gc/shared/cardTable.hpp" |
| #include "gc/shared/cardTableBarrierSet.hpp" |
| #include "gc/shared/cardTableBarrierSetAssembler.hpp" |
| #include "gc/shared/collectedHeap.hpp" |
| #include "runtime/globals.hpp" |
| |
| #define __ masm-> |
| |
| #ifdef PRODUCT |
| #define BLOCK_COMMENT(str) /* nothing */ |
| #else |
| #define BLOCK_COMMENT(str) __ block_comment(str) |
| #endif |
| |
| #define BIND(label) bind(label); BLOCK_COMMENT(#label ":") |
| |
| void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, |
| Register addr, Register count, Register tmp) { |
| BLOCK_COMMENT("CardTablePostBarrier"); |
| BarrierSet* bs = BarrierSet::barrier_set(); |
| CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs); |
| CardTable* ct = ctbs->card_table(); |
| assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code"); |
| |
| Label L_cardtable_loop, L_done; |
| |
| __ cbz_32(count, L_done); // zero count - nothing to do |
| |
| __ add_ptr_scaled_int32(count, addr, count, LogBytesPerHeapOop); |
| __ sub(count, count, BytesPerHeapOop); // last addr |
| |
| __ logical_shift_right(addr, addr, CardTable::card_shift); |
| __ logical_shift_right(count, count, CardTable::card_shift); |
| __ sub(count, count, addr); // nb of cards |
| |
| // warning: Rthread has not been preserved |
| __ mov_address(tmp, (address) ct->byte_map_base(), symbolic_Relocation::card_table_reference); |
| __ add(addr,tmp, addr); |
| |
| Register zero = __ zero_register(tmp); |
| |
| __ BIND(L_cardtable_loop); |
| __ strb(zero, Address(addr, 1, post_indexed)); |
| __ subs(count, count, 1); |
| __ b(L_cardtable_loop, ge); |
| __ BIND(L_done); |
| } |
| |
| void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type, |
| Address obj, Register new_val, Register tmp1, Register tmp2, Register tmp3, bool is_null) { |
| bool is_array = (decorators & IS_ARRAY) != 0; |
| bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0; |
| bool precise = is_array || on_anonymous; |
| |
| if (is_null) { |
| BarrierSetAssembler::store_at(masm, decorators, type, obj, new_val, tmp1, tmp2, tmp3, true); |
| } else { |
| assert (!precise || (obj.index() == noreg && obj.disp() == 0), |
| "store check address should be calculated beforehand"); |
| |
| store_check_part1(masm, tmp1); |
| BarrierSetAssembler::store_at(masm, decorators, type, obj, new_val, tmp1, tmp2, tmp3, false); |
| new_val = noreg; |
| store_check_part2(masm, obj.base(), tmp1, tmp2); |
| } |
| } |
| |
| // The 1st part of the store check. |
| // Sets card_table_base register. |
| void CardTableBarrierSetAssembler::store_check_part1(MacroAssembler* masm, Register card_table_base) { |
| // Check barrier set type (should be card table) and element size |
| BarrierSet* bs = BarrierSet::barrier_set(); |
| assert(bs->kind() == BarrierSet::CardTableBarrierSet, |
| "Wrong barrier set kind"); |
| |
| CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs); |
| CardTable* ct = ctbs->card_table(); |
| assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "Adjust store check code"); |
| |
| // Load card table base address. |
| |
| /* Performance note. |
| |
| There is an alternative way of loading card table base address |
| from thread descriptor, which may look more efficient: |
| |
| ldr(card_table_base, Address(Rthread, JavaThread::card_table_base_offset())); |
| |
| However, performance measurements of micro benchmarks and specJVM98 |
| showed that loading of card table base from thread descriptor is |
| 7-18% slower compared to loading of literal embedded into the code. |
| Possible cause is a cache miss (card table base address resides in a |
| rarely accessed area of thread descriptor). |
| */ |
| // TODO-AARCH64 Investigate if mov_slow is faster than ldr from Rthread on AArch64 |
| __ mov_address(card_table_base, (address)ct->byte_map_base(), symbolic_Relocation::card_table_reference); |
| } |
| |
| // The 2nd part of the store check. |
| void CardTableBarrierSetAssembler::store_check_part2(MacroAssembler* masm, Register obj, Register card_table_base, Register tmp) { |
| assert_different_registers(obj, card_table_base, tmp); |
| |
| BarrierSet* bs = BarrierSet::barrier_set(); |
| assert(bs->kind() == BarrierSet::CardTableBarrierSet, |
| "Wrong barrier set kind"); |
| |
| CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(bs); |
| CardTable* ct = ctbs->card_table(); |
| assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "Adjust store check code"); |
| |
| assert(CardTable::dirty_card_val() == 0, "Dirty card value must be 0 due to optimizations."); |
| #ifdef AARCH64 |
| add(card_table_base, card_table_base, AsmOperand(obj, lsr, CardTable::card_shift)); |
| Address card_table_addr(card_table_base); |
| #else |
| Address card_table_addr(card_table_base, obj, lsr, CardTable::card_shift); |
| #endif |
| |
| if (UseCondCardMark) { |
| if (ct->scanned_concurrently()) { |
| __ membar(MacroAssembler::Membar_mask_bits(MacroAssembler::StoreLoad), noreg); |
| } |
| Label already_dirty; |
| |
| __ ldrb(tmp, card_table_addr); |
| __ cbz(tmp, already_dirty); |
| |
| set_card(masm, card_table_base, card_table_addr, tmp); |
| __ bind(already_dirty); |
| |
| } else { |
| if (ct->scanned_concurrently()) { |
| __ membar(MacroAssembler::Membar_mask_bits(MacroAssembler::StoreStore), noreg); |
| } |
| set_card(masm, card_table_base, card_table_addr, tmp); |
| } |
| } |
| |
| void CardTableBarrierSetAssembler::set_card(MacroAssembler* masm, Register card_table_base, Address card_table_addr, Register tmp) { |
| #ifdef AARCH64 |
| strb(ZR, card_table_addr); |
| #else |
| CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set()); |
| CardTable* ct = ctbs->card_table(); |
| if ((((uintptr_t)ct->byte_map_base() & 0xff) == 0)) { |
| // Card table is aligned so the lowest byte of the table address base is zero. |
| // This works only if the code is not saved for later use, possibly |
| // in a context where the base would no longer be aligned. |
| __ strb(card_table_base, card_table_addr); |
| } else { |
| __ mov(tmp, 0); |
| __ strb(tmp, card_table_addr); |
| } |
| #endif // AARCH64 |
| } |