/*
 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "gc/shared/barrierSetAssembler.hpp"
#include "runtime/jniHandles.hpp"

#define __ masm->

void BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                  Register dst, Address src, Register tmp1, Register tmp_thread) {

  // LR is live.  It must be saved around calls.

  bool on_heap = (decorators & IN_HEAP) != 0;
  bool on_root = (decorators & IN_ROOT) != 0;
  bool oop_not_null = (decorators & OOP_NOT_NULL) != 0;
  switch (type) {
  case T_OBJECT:
  case T_ARRAY: {
    if (on_heap) {
      if (UseCompressedOops) {
        __ ldrw(dst, src);
        if (oop_not_null) {
          __ decode_heap_oop_not_null(dst);
        } else {
          __ decode_heap_oop(dst);
        }
      } else {
        __ ldr(dst, src);
      }
    } else {
      assert(on_root, "why else?");
      __ ldr(dst, src);
    }
    break;
  }
  case T_BOOLEAN: __ load_unsigned_byte (dst, src); break;
  case T_BYTE:    __ load_signed_byte   (dst, src); break;
  case T_CHAR:    __ load_unsigned_short(dst, src); break;
  case T_SHORT:   __ load_signed_short  (dst, src); break;
  case T_INT:     __ ldrw               (dst, src); break;
  case T_LONG:    __ ldr                (dst, src); break;
  case T_ADDRESS: __ ldr                (dst, src); break;
  case T_FLOAT:   __ ldrs               (v0, src);  break;
  case T_DOUBLE:  __ ldrd               (v0, src);  break;
  default: Unimplemented();
  }
}

void BarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,
                                   Address dst, Register val, Register tmp1, Register tmp2) {
  bool on_heap = (decorators & IN_HEAP) != 0;
  bool on_root = (decorators & IN_ROOT) != 0;
  switch (type) {
  case T_OBJECT:
  case T_ARRAY: {
    val = val == noreg ? zr : val;
    if (on_heap) {
      if (UseCompressedOops) {
        assert(!dst.uses(val), "not enough registers");
        if (val != zr) {
          __ encode_heap_oop(val);
        }
        __ strw(val, dst);
      } else {
        __ str(val, dst);
      }
    } else {
      assert(on_root, "why else?");
      __ str(val, dst);
    }
    break;
  }
  case T_BOOLEAN:
    __ andw(val, val, 0x1);  // boolean is true if LSB is 1
    __ strb(val, dst);
    break;
  case T_BYTE:    __ strb(val, dst); break;
  case T_CHAR:    __ strh(val, dst); break;
  case T_SHORT:   __ strh(val, dst); break;
  case T_INT:     __ strw(val, dst); break;
  case T_LONG:    __ str (val, dst); break;
  case T_ADDRESS: __ str (val, dst); break;
  case T_FLOAT:   __ strs(v0,  dst); break;
  case T_DOUBLE:  __ strd(v0,  dst); break;
  default: Unimplemented();
  }
}

void BarrierSetAssembler::obj_equals(MacroAssembler* masm, DecoratorSet decorators,
                                     Register obj1, Register obj2) {
  __ cmp(obj1, obj2);
}

void BarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,
                                                        Register obj, Register tmp, Label& slowpath) {
  // If mask changes we need to ensure that the inverse is still encodable as an immediate
  STATIC_ASSERT(JNIHandles::weak_tag_mask == 1);
  __ andr(obj, obj, ~JNIHandles::weak_tag_mask);
  __ ldr(obj, Address(obj, 0));             // *obj
}