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/g1/g1BarrierSet.hpp"
  28 #include "gc/g1/g1BarrierSetAssembler.hpp"
  29 #include "gc/g1/g1CardTable.hpp"
  30 #include "gc/g1/heapRegion.hpp"
  31 #include "gc/shared/collectedHeap.hpp"
  32 #include "interpreter/interp_masm.hpp"
  33 #include "runtime/sharedRuntime.hpp"
  34 #include "runtime/thread.hpp"
  35 #include "utilities/macros.hpp"
  36 
  37 #define __ masm->
  38 
  39 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,
  40                                                             Register addr, Register count) {
  41   bool dest_uninitialized = (decorators & AS_DEST_NOT_INITIALIZED) != 0;
  42 
  43   if (!dest_uninitialized) {
  44     Register thread = NOT_LP64(rax) LP64_ONLY(r15_thread);
  45 #ifndef _LP64
  46     __ push(thread);
  47     __ get_thread(thread);
  48 #endif
  49 
  50     Label filtered;
  51     Address in_progress(thread, in_bytes(JavaThread::satb_mark_queue_offset() +
  52                                          SATBMarkQueue::byte_offset_of_active()));
  53     // Is marking active?
  54     if (in_bytes(SATBMarkQueue::byte_width_of_active()) == 4) {
  55       __ cmpl(in_progress, 0);
  56     } else {
  57       assert(in_bytes(SATBMarkQueue::byte_width_of_active()) == 1, "Assumption");
  58       __ cmpb(in_progress, 0);
  59     }
  60 
  61     NOT_LP64(__ pop(thread);)
  62 
  63     __ jcc(Assembler::equal, filtered);
  64 
  65     __ pusha();                      // push registers
  66 #ifdef _LP64
  67     if (count == c_rarg0) {
  68       if (addr == c_rarg1) {
  69         // exactly backwards!!
  70         __ xchgptr(c_rarg1, c_rarg0);
  71       } else {
  72         __ movptr(c_rarg1, count);
  73         __ movptr(c_rarg0, addr);
  74       }
  75     } else {
  76       __ movptr(c_rarg0, addr);
  77       __ movptr(c_rarg1, count);
  78     }
  79     if (UseCompressedOops) {
  80       __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_narrow_oop_entry), 2);
  81     } else {
  82       __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_oop_entry), 2);
  83     }
  84 #else
  85     __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_oop_entry),
  86                     addr, count);
  87 #endif
  88     __ popa();
  89 
  90     __ bind(filtered);
  91   }
  92 }
  93 
  94 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
  95                                                              Register addr, Register count, Register tmp) {
  96   __ pusha();             // push registers (overkill)
  97 #ifdef _LP64
  98   if (c_rarg0 == count) { // On win64 c_rarg0 == rcx
  99     assert_different_registers(c_rarg1, addr);
 100     __ mov(c_rarg1, count);
 101     __ mov(c_rarg0, addr);
 102   } else {
 103     assert_different_registers(c_rarg0, count);
 104     __ mov(c_rarg0, addr);
 105     __ mov(c_rarg1, count);
 106   }
 107   __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_post_entry), 2);
 108 #else
 109   __ call_VM_leaf(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_post_entry),
 110                   addr, count);
 111 #endif
 112   __ popa();
 113 }