1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2018, SAP SE. 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/cardTableBarrierSet.hpp"
  31 #include "gc/shared/cardTableBarrierSetAssembler.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 CardTableBarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators, Register addr,
  46                                                                     Register count, Register preserve) {
  47   CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(Universe::heap()->barrier_set());
  48   CardTable* ct = ctbs->card_table();
  49   assert(sizeof(*ct->byte_map_base()) == sizeof(jbyte), "adjust this code");
  50   assert_different_registers(addr, count, R0);
  51 
  52   Label Lskip_loop, Lstore_loop;
  53 
  54   if (UseConcMarkSweepGC) { __ membar(Assembler::StoreStore); }
  55 
  56   __ sldi_(count, count, LogBytesPerHeapOop);
  57   __ beq(CCR0, Lskip_loop); // zero length
  58   __ addi(count, count, -BytesPerHeapOop);
  59   __ add(count, addr, count);
  60   // Use two shifts to clear out those low order two bits! (Cannot opt. into 1.)
  61   __ srdi(addr, addr, CardTable::card_shift);
  62   __ srdi(count, count, CardTable::card_shift);
  63   __ subf(count, addr, count);
  64   __ add_const_optimized(addr, addr, (address)ct->byte_map_base(), R0);
  65   __ addi(count, count, 1);
  66   __ li(R0, 0);
  67   __ mtctr(count);
  68   // Byte store loop
  69   __ bind(Lstore_loop);
  70   __ stb(R0, 0, addr);
  71   __ addi(addr, addr, 1);
  72   __ bdnz(Lstore_loop);
  73   __ bind(Lskip_loop);
  74 }
  75 
  76 void CardTableBarrierSetAssembler::card_table_write(MacroAssembler* masm,
  77                                                     jbyte* byte_map_base,
  78                                                     Register tmp, Register obj) {
  79   assert_different_registers(obj, tmp, R0);
  80   __ load_const_optimized(tmp, (address)byte_map_base, R0);
  81   __ srdi(obj, obj, CardTable::card_shift);
  82   __ li(R0, CardTable::dirty_card_val());
  83   if (UseConcMarkSweepGC) { __ membar(Assembler::StoreStore); }
  84   __ stbx(R0, tmp, obj);
  85 }
  86 
  87 void CardTableBarrierSetAssembler::card_write_barrier_post(MacroAssembler* masm, Register store_addr, Register tmp) {
  88   CardTableBarrierSet* bs = barrier_set_cast<CardTableBarrierSet>(Universe::heap()->barrier_set());
  89   card_table_write(masm, bs->card_table()->byte_map_base(), tmp, store_addr);
  90 }
  91 
  92 void CardTableBarrierSetAssembler::oop_store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
  93                                                 Register base, RegisterOrConstant ind_or_offs, Register val,
  94                                                 Register tmp1, Register tmp2, Register tmp3, bool needs_frame) {
  95   bool on_array = (decorators & IN_HEAP_ARRAY) != 0;
  96   bool on_anonymous = (decorators & ON_UNKNOWN_OOP_REF) != 0;
  97   bool precise = on_array || on_anonymous;
  98 
  99   BarrierSetAssembler::store_at(masm, decorators, type, base, ind_or_offs, val, tmp1, tmp2, tmp3, needs_frame);
 100 
 101   // No need for post barrier if storing NULL
 102   if (val != noreg) {
 103     if (precise) {
 104       if (ind_or_offs.is_constant()) {
 105         __ add_const_optimized(base, base, ind_or_offs.as_constant(), tmp1);
 106       } else {
 107         __ add(base, ind_or_offs.as_register(), base);
 108       }
 109     }
 110     card_write_barrier_post(masm, base, tmp1);
 111   }
 112 }