1 /*
  2  * Copyright (c) 2018, 2025, 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 "asm/macroAssembler.inline.hpp"
 26 #include "gc/shared/barrierSet.hpp"
 27 #include "gc/shared/cardTable.hpp"
 28 #include "gc/shared/cardTableBarrierSet.hpp"
 29 #include "gc/shared/cardTableBarrierSetAssembler.hpp"
 30 #include "gc/shared/gc_globals.hpp"
 31 #include "interpreter/interp_masm.hpp"
 32 
 33 #define __ masm->
 34 
 35 void CardTableBarrierSetAssembler::arraycopy_prologue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
 36                                                       Register src, Register dst, Register count, RegSet saved_regs) {
 37 
 38   if (is_oop) {
 39     gen_write_ref_array_pre_barrier(masm, decorators, dst, count, saved_regs);
 40   }
 41 }
 42 
 43 void CardTableBarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, bool is_oop,
 44                                                       Register start, Register count, Register tmp) {
 45   if (is_oop) {
 46     gen_write_ref_array_post_barrier(masm, decorators, start, count, tmp);
 47   }
 48 }
 49 
 50 void CardTableBarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
 51                                             Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
 52   if (is_reference_type(type)) {
 53     oop_store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
 54   } else {
 55     BarrierSetAssembler::store_at(masm, decorators, type, dst, val, tmp1, tmp2, tmp3);
 56   }
 57 }
 58 
 59 void CardTableBarrierSetAssembler::store_check(MacroAssembler* masm, Register obj, Address dst) {
 60 
 61   BarrierSet* bs = BarrierSet::barrier_set();
 62   assert(bs->kind() == BarrierSet::CardTableBarrierSet, "Wrong barrier set kind");
 63 
 64   __ lsr(obj, obj, CardTable::card_shift());
 65 
 66   assert(CardTable::dirty_card_val() == 0, "must be");
 67 
 68   __ load_byte_map_base(rscratch1);
 69 
 70   if (UseCondCardMark) {
 71     Label L_already_dirty;
 72     __ ldrb(rscratch2,  Address(obj, rscratch1));
 73     __ cbz(rscratch2, L_already_dirty);
 74     __ strb(zr, Address(obj, rscratch1));
 75     __ bind(L_already_dirty);
 76   } else {
 77     __ strb(zr, Address(obj, rscratch1));
 78   }
 79 }
 80 
 81 void CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
 82                                                                     Register start, Register count, Register scratch) {
 83   Label L_loop, L_done;
 84   const Register end = count;
 85 
 86   __ cbz(count, L_done); // zero count - nothing to do
 87 
 88   __ lea(end, Address(start, count, Address::lsl(LogBytesPerHeapOop))); // end = start + count << LogBytesPerHeapOop
 89   __ sub(end, end, BytesPerHeapOop); // last element address to make inclusive
 90   __ lsr(start, start, CardTable::card_shift());
 91   __ lsr(end, end, CardTable::card_shift());
 92   __ sub(count, end, start); // number of bytes to copy
 93 
 94   __ load_byte_map_base(scratch);
 95   __ add(start, start, scratch);
 96   __ bind(L_loop);
 97   __ strb(zr, Address(start, count));
 98   __ subs(count, count, 1);
 99   __ br(Assembler::GE, L_loop);
100   __ bind(L_done);
101 }
102 
103 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
104                                                 Address dst, Register val, Register tmp1, Register tmp2, Register tmp3) {
105   bool in_heap = (decorators & IN_HEAP) != 0;
106   bool is_array = (decorators & IS_ARRAY) != 0;
107   bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
108   bool precise = is_array || on_anonymous;
109 
110   bool needs_post_barrier = val != noreg && in_heap;

111   BarrierSetAssembler::store_at(masm, decorators, type, dst, val, noreg, noreg, noreg);
112   if (needs_post_barrier) {
113     // flatten object address if needed
114     if (!precise || (dst.index() == noreg && dst.offset() == 0)) {
115       store_check(masm, dst.base(), dst);








116     } else {
117       __ lea(tmp3, dst);
118       store_check(masm, tmp3, dst);
119     }
120   }
121 }
--- EOF ---