/*

 * 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/barrierSet.hpp"

#include "gc/shared/barrierSetAssembler.hpp"

#include "gc/shared/barrierSetNMethod.hpp"

#include "gc/shared/collectedHeap.hpp"

#include "interpreter/interp_masm.hpp"

#include "memory/universe.hpp"

#include "runtime/jniHandles.hpp"

#include "runtime/thread.hpp"

#define __ masm->

void BarrierSetAssembler::load_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,

                                  Register dst, Address src, Register tmp1, Register tmp_thread) {

  bool in_heap = (decorators & IN_HEAP) != 0;

  bool in_native = (decorators & IN_NATIVE) != 0;

  bool is_not_null = (decorators & IS_NOT_NULL) != 0;

  bool atomic = (decorators & MO_RELAXED) != 0;

  switch (type) {

  case T_OBJECT:

  case T_ARRAY: {

    if (in_heap) {

#ifdef _LP64

      if (UseCompressedOops) {

        __ movl(dst, src);

        if (is_not_null) {

          __ decode_heap_oop_not_null(dst);

        } else {

          __ decode_heap_oop(dst);

        }

      } else

#endif

      {

        __ movptr(dst, src);

      }

    } else {

      assert(in_native, "why else?");

      __ movptr(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:     __ movl  (dst, src);              break;

  case T_ADDRESS: __ movptr(dst, src);              break;

  case T_FLOAT:

    assert(dst == noreg, "only to ftos");

    __ load_float(src);

    break;

  case T_DOUBLE:

    assert(dst == noreg, "only to dtos");

    __ load_double(src);

    break;

  case T_LONG:

    assert(dst == noreg, "only to ltos");

#ifdef _LP64

    __ movq(rax, src);

#else

    if (atomic) {

      __ fild_d(src);               // Must load atomically

      __ subptr(rsp,2*wordSize);    // Make space for store

      __ fistp_d(Address(rsp,0));

      __ pop(rax);

      __ pop(rdx);

    } else {

      __ movl(rax, src);

      __ movl(rdx, src.plus_disp(wordSize));

    }

#endif

    break;

  default: Unimplemented();

  }

}

void BarrierSetAssembler::store_at(MacroAssembler* masm, DecoratorSet decorators, BasicType type,

                                   Address dst, Register val, Register tmp1, Register tmp2) {

  bool in_heap = (decorators & IN_HEAP) != 0;

  bool in_native = (decorators & IN_NATIVE) != 0;

  bool is_not_null = (decorators & IS_NOT_NULL) != 0;

  bool atomic = (decorators & MO_RELAXED) != 0;

  switch (type) {

  case T_OBJECT:

  case T_ARRAY: {

    if (in_heap) {

      if (val == noreg) {

        assert(!is_not_null, "inconsistent access");

#ifdef _LP64

        if (UseCompressedOops) {

          __ movl(dst, (int32_t)NULL_WORD);

        } else {

          __ movslq(dst, (int32_t)NULL_WORD);

        }

#else

        __ movl(dst, (int32_t)NULL_WORD);

#endif

      } else {

#ifdef _LP64

        if (UseCompressedOops) {

          assert(!dst.uses(val), "not enough registers");

          if (is_not_null) {

            __ encode_heap_oop_not_null(val);

          } else {

            __ encode_heap_oop(val);

          }

          __ movl(dst, val);

        } else

#endif

        {

          __ movptr(dst, val);

        }

      }

    } else {

      assert(in_native, "why else?");

      assert(val != noreg, "not supported");

      __ movptr(dst, val);

    }

    break;

  }

  case T_BOOLEAN:

    __ andl(val, 0x1);  // boolean is true if LSB is 1

    __ movb(dst, val);

    break;

  case T_BYTE:

    __ movb(dst, val);

    break;

  case T_SHORT:

    __ movw(dst, val);

    break;

  case T_CHAR:

    __ movw(dst, val);

    break;

  case T_INT:

    __ movl(dst, val);

    break;

  case T_LONG:

    assert(val == noreg, "only tos");

#ifdef _LP64

    __ movq(dst, rax);

#else

    if (atomic) {

      __ push(rdx);

      __ push(rax);                 // Must update atomically with FIST

      __ fild_d(Address(rsp,0));    // So load into FPU register

      __ fistp_d(dst);              // and put into memory atomically

      __ addptr(rsp, 2*wordSize);

    } else {

      __ movptr(dst, rax);

      __ movptr(dst.plus_disp(wordSize), rdx);

    }

#endif

    break;

  case T_FLOAT:

    assert(val == noreg, "only tos");

    __ store_float(dst);

    break;

  case T_DOUBLE:

    assert(val == noreg, "only tos");

    __ store_double(dst);

    break;

  case T_ADDRESS:

    __ movptr(dst, val);

    break;

  default: Unimplemented();

  }

}

#ifndef _LP64

void BarrierSetAssembler::obj_equals(MacroAssembler* masm,

                                     Address obj1, jobject obj2) {

  __ cmpoop_raw(obj1, obj2);

}

void BarrierSetAssembler::obj_equals(MacroAssembler* masm,

                                     Register obj1, jobject obj2) {

  __ cmpoop_raw(obj1, obj2);

}

#endif

void BarrierSetAssembler::obj_equals(MacroAssembler* masm,

                                     Register obj1, Address obj2) {

  __ cmpptr(obj1, obj2);

}

void BarrierSetAssembler::obj_equals(MacroAssembler* masm,

                                     Register obj1, Register obj2) {

  __ cmpptr(obj1, obj2);

}

void BarrierSetAssembler::try_resolve_jobject_in_native(MacroAssembler* masm, Register jni_env,

                                                        Register obj, Register tmp, Label& slowpath) {

  __ clear_jweak_tag(obj);

  __ movptr(obj, Address(obj, 0));

}

void BarrierSetAssembler::tlab_allocate(MacroAssembler* masm,

                                        Register thread, Register obj,

                                        Register var_size_in_bytes,

                                        int con_size_in_bytes,

                                        Register t1,

                                        Register t2,

                                        Label& slow_case) {

  assert_different_registers(obj, t1, t2);

  assert_different_registers(obj, var_size_in_bytes, t1);

  Register end = t2;

  if (!thread->is_valid()) {

#ifdef _LP64

    thread = r15_thread;

#else

    assert(t1->is_valid(), "need temp reg");

    thread = t1;

    __ get_thread(thread);

#endif

  }

  __ verify_tlab();

  __ movptr(obj, Address(thread, JavaThread::tlab_top_offset()));

  if (var_size_in_bytes == noreg) {

    __ lea(end, Address(obj, con_size_in_bytes));

  } else {

    __ lea(end, Address(obj, var_size_in_bytes, Address::times_1));

  }

  __ cmpptr(end, Address(thread, JavaThread::tlab_end_offset()));

  __ jcc(Assembler::above, slow_case);

  // update the tlab top pointer

  __ movptr(Address(thread, JavaThread::tlab_top_offset()), end);

  // recover var_size_in_bytes if necessary

  if (var_size_in_bytes == end) {

    __ subptr(var_size_in_bytes, obj);

  }

  __ verify_tlab();

}

// Defines obj, preserves var_size_in_bytes

void BarrierSetAssembler::eden_allocate(MacroAssembler* masm,

                                        Register thread, Register obj,

                                        Register var_size_in_bytes,

                                        int con_size_in_bytes,

                                        Register t1,

                                        Label& slow_case) {

  assert(obj == rax, "obj must be in rax, for cmpxchg");

  assert_different_registers(obj, var_size_in_bytes, t1);

  if (!Universe::heap()->supports_inline_contig_alloc()) {

    __ jmp(slow_case);

  } else {

    Register end = t1;

    Label retry;

    __ bind(retry);

    ExternalAddress heap_top((address) Universe::heap()->top_addr());

    __ movptr(obj, heap_top);

    if (var_size_in_bytes == noreg) {

      __ lea(end, Address(obj, con_size_in_bytes));

    } else {

      __ lea(end, Address(obj, var_size_in_bytes, Address::times_1));

    }

    // if end < obj then we wrapped around => object too long => slow case

    __ cmpptr(end, obj);

    __ jcc(Assembler::below, slow_case);

    __ cmpptr(end, ExternalAddress((address) Universe::heap()->end_addr()));

    __ jcc(Assembler::above, slow_case);

    // Compare obj with the top addr, and if still equal, store the new top addr in

    // end at the address of the top addr pointer. Sets ZF if was equal, and clears

    // it otherwise. Use lock prefix for atomicity on MPs.

    __ locked_cmpxchgptr(end, heap_top);

    __ jcc(Assembler::notEqual, retry);

    incr_allocated_bytes(masm, thread, var_size_in_bytes, con_size_in_bytes, thread->is_valid() ? noreg : t1);

  }

}

void BarrierSetAssembler::incr_allocated_bytes(MacroAssembler* masm, Register thread,

                                               Register var_size_in_bytes,

                                               int con_size_in_bytes,

                                               Register t1) {

  if (!thread->is_valid()) {

#ifdef _LP64

    thread = r15_thread;

#else

    assert(t1->is_valid(), "need temp reg");

    thread = t1;

    __ get_thread(thread);

#endif

  }

#ifdef _LP64

  if (var_size_in_bytes->is_valid()) {

    __ addq(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), var_size_in_bytes);

  } else {

    __ addq(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), con_size_in_bytes);

  }

#else

  if (var_size_in_bytes->is_valid()) {

    __ addl(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), var_size_in_bytes);

  } else {

    __ addl(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())), con_size_in_bytes);

  }

  __ adcl(Address(thread, in_bytes(JavaThread::allocated_bytes_offset())+4), 0);

#endif

}

void BarrierSetAssembler::nmethod_entry_barrier(MacroAssembler* masm) {

  BarrierSetNMethod* bs_nm = BarrierSet::barrier_set()->barrier_set_nmethod();

  if (bs_nm == NULL) {

    return;

  }

#ifndef _LP64

  ShouldNotReachHere();

#else

  Label continuation;

  Register thread = LP64_ONLY(r15_thread);

  Address disarmed_addr(thread, in_bytes(bs_nm->thread_disarmed_offset()));

  __ align(8);

  __ cmpl(disarmed_addr, 0);

  __ jcc(Assembler::equal, continuation);

  __ call(RuntimeAddress(StubRoutines::x86::method_entry_barrier()));

  __ bind(continuation);

#endif

}