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 "gc/shared/barrierSetAssembler.hpp"
  28 #include "interpreter/interp_masm.hpp"
  29 
  30 #define __ masm->
  31 
  32 void BarrierSetAssembler::arraycopy_epilogue(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
  33                                              Register dst, Register count, bool do_return) {
  34   if (do_return) { __ z_br(Z_R14); }
  35 }
  36 
  37 void BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
  38                                   const Address& addr, Register dst, Register tmp1, Register tmp2, Label *is_null) {
  39   bool on_heap = (decorators & IN_HEAP) != 0;
  40   bool on_root = (decorators & IN_ROOT) != 0;
  41   assert(on_heap || on_root, "where?");
  42 
  43   switch (type) {
  44   case T_ARRAY:
  45   case T_OBJECT: {
  46     if (UseCompressedOops && on_heap) {
  47       __ z_llgf(dst, addr);
  48       if (is_null) {
  49         __ compareU32_and_branch(dst, (intptr_t)0, Assembler::bcondEqual, *is_null);
  50         __ oop_decoder(dst, dst, false);
  51       } else {
  52         __ oop_decoder(dst, dst, true);
  53       }
  54     } else {
  55       __ z_lg(dst, addr);
  56       if (is_null) {
  57         __ compareU64_and_branch(dst, (intptr_t)0, Assembler::bcondEqual, *is_null);
  58       }
  59     }
  60     break;
  61   }
  62   default: Unimplemented();
  63   }
  64 }
  65 
  66 void BarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
  67                                    const Address& addr, Register val, Register tmp1, Register tmp2, Register tmp3) {
  68   bool on_heap  = (decorators & IN_HEAP) != 0;
  69   bool on_root  = (decorators & IN_ROOT) != 0;
  70   bool not_null = (decorators & OOP_NOT_NULL) != 0;
  71   assert(on_heap || on_root, "where?");
  72   assert_different_registers(val, tmp1, tmp2);
  73 
  74   switch (type) {
  75   case T_ARRAY:
  76   case T_OBJECT: {
  77     if (UseCompressedOops && on_heap) {
  78       if (val == noreg) {
  79         __ clear_mem(addr, 4);
  80       } else if (Universe::narrow_oop_mode() == Universe::UnscaledNarrowOop) {
  81         __ z_st(val, addr);
  82       } else {
  83         Register tmp = (tmp1 != Z_R1) ? tmp1 : tmp2; // Avoid tmp == Z_R1 (see oop_encoder).
  84         __ oop_encoder(tmp, val, !not_null);
  85         __ z_st(tmp, addr);
  86       }
  87     } else {
  88       if (val == noreg) {
  89         __ clear_mem(addr, 8);
  90       } else {
  91         __ z_stg(val, addr);
  92       }
  93     }
  94     break;
  95   }
  96   default: Unimplemented();
  97   }
  98 }
  99 
 100 void BarrierSetAssembler::resolve_jobject(MacroAssembler* masm, Register value, Register tmp1, Register tmp2) {
 101   NearLabel Ldone;
 102   __ z_ltgr(tmp1, value);
 103   __ z_bre(Ldone);          // Use NULL result as-is.
 104 
 105   __ z_nill(value, ~JNIHandles::weak_tag_mask);
 106   __ z_lg(value, 0, value); // Resolve (untagged) jobject.
 107 
 108   __ verify_oop(value);
 109   __ bind(Ldone);
 110 }