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 "interpreter/interp_masm.hpp"
  32 #include "runtime/sharedRuntime.hpp"
  33 #include "runtime/thread.hpp"
  34 #include "utilities/macros.hpp"
  35 
  36 #define __ masm->
  37 
  38 #ifdef PRODUCT
  39 #define BLOCK_COMMENT(str) /* nothing */
  40 #else
  41 #define BLOCK_COMMENT(str) __ block_comment(str)
  42 #endif
  43 
  44 #define BIND(label) bind(label); BLOCK_COMMENT(#label ":")
  45 
  46 void G1BarrierSetAssembler::gen_write_ref_array_pre_barrier(MacroAssembler* masm, DecoratorSet decorators,
  47                                                             Register addr, Register count, int callee_saved_regs) {
  48   bool dest_uninitialized = (decorators & AS_DEST_NOT_INITIALIZED) != 0;
  49   if (!dest_uninitialized) {
  50     assert( addr->encoding() < callee_saved_regs, "addr must be saved");
  51     assert(count->encoding() < callee_saved_regs, "count must be saved");
  52 
  53     BLOCK_COMMENT("PreBarrier");
  54 
  55 #ifdef AARCH64
  56     callee_saved_regs = align_up(callee_saved_regs, 2);
  57     for (int i = 0; i < callee_saved_regs; i += 2) {
  58       __ raw_push(as_Register(i), as_Register(i+1));
  59     }
  60 #else
  61     RegisterSet saved_regs = RegisterSet(R0, as_Register(callee_saved_regs-1));
  62     __ push(saved_regs | R9ifScratched);
  63 #endif // AARCH64
  64 
  65     if (addr != R0) {
  66       assert_different_registers(count, R0);
  67       __ mov(R0, addr);
  68     }
  69 #ifdef AARCH64
  70     __ zero_extend(R1, count, 32); // G1BarrierSet::write_ref_array_pre_*_entry takes size_t
  71 #else
  72     if (count != R1) {
  73       __ mov(R1, count);
  74     }
  75 #endif // AARCH64
  76 
  77     if (UseCompressedOops) {
  78       __ call(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_narrow_oop_entry));
  79     } else {
  80       __ call(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_pre_oop_entry));
  81     }
  82 
  83 #ifdef AARCH64
  84     for (int i = callee_saved_regs - 2; i >= 0; i -= 2) {
  85       __ raw_pop(as_Register(i), as_Register(i+1));
  86     }
  87 #else
  88     __ pop(saved_regs | R9ifScratched);
  89 #endif // AARCH64
  90   }
  91 }
  92 
  93 void G1BarrierSetAssembler::gen_write_ref_array_post_barrier(MacroAssembler* masm, DecoratorSet decorators,
  94                                                              Register addr, Register count, Register tmp) {
  95 
  96   BLOCK_COMMENT("G1PostBarrier");
  97   if (addr != R0) {
  98     assert_different_registers(count, R0);
  99     __ mov(R0, addr);
 100   }
 101 #ifdef AARCH64
 102   __ zero_extend(R1, count, 32); // G1BarrierSet::write_ref_array_post_entry takes size_t
 103 #else
 104   if (count != R1) {
 105     __ mov(R1, count);
 106   }
 107 #if R9_IS_SCRATCHED
 108   // Safer to save R9 here since callers may have been written
 109   // assuming R9 survives. This is suboptimal but is not in
 110   // general worth optimizing for the few platforms where R9
 111   // is scratched. Note that the optimization might not be to
 112   // difficult for this particular call site.
 113   __ push(R9);
 114 #endif // !R9_IS_SCRATCHED
 115 #endif // !AARCH64
 116   __ call(CAST_FROM_FN_PTR(address, G1BarrierSet::write_ref_array_post_entry));
 117 #ifndef AARCH64
 118 #if R9_IS_SCRATCHED
 119   __ pop(R9);
 120 #endif // !R9_IS_SCRATCHED
 121 #endif // !AARCH64
 122 }