/*

 * Copyright (c) 1998, 2011, 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 "asm/assembler.inline.hpp"

#include "assembler_x86.inline.hpp"

#include "code/relocInfo.hpp"

#include "nativeInst_x86.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/safepoint.hpp"

void Relocation::pd_set_data_value(address x, intptr_t o, bool verify_only) {

#ifdef AMD64

  x += o;

  typedef Assembler::WhichOperand WhichOperand;

  WhichOperand which = (WhichOperand) format(); // that is, disp32 or imm, call32, narrow oop

  assert(which == Assembler::disp32_operand ||

         which == Assembler::narrow_oop_operand ||

         which == Assembler::imm_operand, "format unpacks ok");

  if (which == Assembler::imm_operand) {

    if (verify_only) {

      assert(*pd_address_in_code() == x, "instructions must match");

    } else {

      *pd_address_in_code() = x;

    }

  } else if (which == Assembler::narrow_oop_operand) {

    address disp = Assembler::locate_operand(addr(), which);

    if (verify_only) {

      assert(*(uint32_t*) disp == oopDesc::encode_heap_oop((oop)x), "instructions must match");

    } else {

      *(int32_t*) disp = oopDesc::encode_heap_oop((oop)x);

    }

  } else {

    // Note:  Use runtime_call_type relocations for call32_operand.

    address ip = addr();

    address disp = Assembler::locate_operand(ip, which);

    address next_ip = Assembler::locate_next_instruction(ip);

    if (verify_only) {

      assert(*(int32_t*) disp == (x - next_ip), "instructions must match");

    } else {

      *(int32_t*) disp = x - next_ip;

    }

  }

#else

  if (verify_only) {

    assert(*pd_address_in_code() == (x + o), "instructions must match");

  } else {

    *pd_address_in_code() = x + o;

  }

#endif // AMD64

}

address Relocation::pd_call_destination(address orig_addr) {

  intptr_t adj = 0;

  if (orig_addr != NULL) {

    // We just moved this call instruction from orig_addr to addr().

    // This means its target will appear to have grown by addr() - orig_addr.

    adj = -( addr() - orig_addr );

  }

  NativeInstruction* ni = nativeInstruction_at(addr());

  if (ni->is_call()) {

    return nativeCall_at(addr())->destination() + adj;

  } else if (ni->is_jump()) {

    return nativeJump_at(addr())->jump_destination() + adj;

  } else if (ni->is_cond_jump()) {

    return nativeGeneralJump_at(addr())->jump_destination() + adj;

  } else if (ni->is_mov_literal64()) {

    return (address) ((NativeMovConstReg*)ni)->data();

  } else {

    ShouldNotReachHere();

    return NULL;

  }

}

void Relocation::pd_set_call_destination(address x) {

  NativeInstruction* ni = nativeInstruction_at(addr());

  if (ni->is_call()) {

    nativeCall_at(addr())->set_destination(x);

  } else if (ni->is_jump()) {

    NativeJump* nj = nativeJump_at(addr());

    // Unresolved jumps are recognized by a destination of -1

    // However 64bit can't actually produce such an address

    // and encodes a jump to self but jump_destination will

    // return a -1 as the signal. We must not relocate this

    // jmp or the ic code will not see it as unresolved.

    if (nj->jump_destination() == (address) -1) {

      x = addr(); // jump to self

    }

    nj->set_jump_destination(x);

  } else if (ni->is_cond_jump()) {

    // %%%% kludge this, for now, until we get a jump_destination method

    address old_dest = nativeGeneralJump_at(addr())->jump_destination();

    address disp = Assembler::locate_operand(addr(), Assembler::call32_operand);

    *(jint*)disp += (x - old_dest);

  } else if (ni->is_mov_literal64()) {

    ((NativeMovConstReg*)ni)->set_data((intptr_t)x);

  } else {

    ShouldNotReachHere();

  }

}

address* Relocation::pd_address_in_code() {

  // All embedded Intel addresses are stored in 32-bit words.

  // Since the addr points at the start of the instruction,

  // we must parse the instruction a bit to find the embedded word.

  assert(is_data(), "must be a DataRelocation");

  typedef Assembler::WhichOperand WhichOperand;

  WhichOperand which = (WhichOperand) format(); // that is, disp32 or imm/imm32

#ifdef AMD64

  assert(which == Assembler::disp32_operand ||

         which == Assembler::call32_operand ||

         which == Assembler::imm_operand, "format unpacks ok");

  if (which != Assembler::imm_operand) {

    // The "address" in the code is a displacement can't return it as

    // and address* since it is really a jint*

    ShouldNotReachHere();

    return NULL;

  }

#else

  assert(which == Assembler::disp32_operand || which == Assembler::imm_operand, "format unpacks ok");

#endif // AMD64

  return (address*) Assembler::locate_operand(addr(), which);

}

address Relocation::pd_get_address_from_code() {

#ifdef AMD64

  // All embedded Intel addresses are stored in 32-bit words.

  // Since the addr points at the start of the instruction,

  // we must parse the instruction a bit to find the embedded word.

  assert(is_data(), "must be a DataRelocation");

  typedef Assembler::WhichOperand WhichOperand;

  WhichOperand which = (WhichOperand) format(); // that is, disp32 or imm/imm32

  assert(which == Assembler::disp32_operand ||

         which == Assembler::call32_operand ||

         which == Assembler::imm_operand, "format unpacks ok");

  if (which != Assembler::imm_operand) {

    address ip = addr();

    address disp = Assembler::locate_operand(ip, which);

    address next_ip = Assembler::locate_next_instruction(ip);

    address a = next_ip + *(int32_t*) disp;

    return a;

  }

#endif // AMD64

  return *pd_address_in_code();

}

int Relocation::pd_breakpoint_size() {

  // minimum breakpoint size, in short words

  return NativeIllegalInstruction::instruction_size / sizeof(short);

}

void Relocation::pd_swap_in_breakpoint(address x, short* instrs, int instrlen) {

  Untested("pd_swap_in_breakpoint");

  if (instrs != NULL) {

    assert(instrlen * sizeof(short) == NativeIllegalInstruction::instruction_size, "enough instrlen in reloc. data");

    for (int i = 0; i < instrlen; i++) {

      instrs[i] = ((short*)x)[i];

    }

  }

  NativeIllegalInstruction::insert(x);

}

void Relocation::pd_swap_out_breakpoint(address x, short* instrs, int instrlen) {

  Untested("pd_swap_out_breakpoint");

  assert(NativeIllegalInstruction::instruction_size == sizeof(short), "right address unit for update");

  NativeInstruction* ni = nativeInstruction_at(x);

  *(short*)ni->addr_at(0) = instrs[0];

}

void poll_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {

#ifdef _LP64

  if (!Assembler::is_polling_page_far()) {

    typedef Assembler::WhichOperand WhichOperand;

    WhichOperand which = (WhichOperand) format();

    // This format is imm but it is really disp32

    which = Assembler::disp32_operand;

    address orig_addr = old_addr_for(addr(), src, dest);

    NativeInstruction* oni = nativeInstruction_at(orig_addr);

    int32_t* orig_disp = (int32_t*) Assembler::locate_operand(orig_addr, which);

    // This poll_addr is incorrect by the size of the instruction it is irrelevant

    intptr_t poll_addr = (intptr_t)oni + *orig_disp;

    NativeInstruction* ni = nativeInstruction_at(addr());

    intptr_t new_disp = poll_addr - (intptr_t) ni;

    int32_t* disp = (int32_t*) Assembler::locate_operand(addr(), which);

    * disp = (int32_t)new_disp;

  }

#endif // _LP64

}

void poll_return_Relocation::fix_relocation_after_move(const CodeBuffer* src, CodeBuffer* dest) {

#ifdef _LP64

  if (!Assembler::is_polling_page_far()) {

    typedef Assembler::WhichOperand WhichOperand;

    WhichOperand which = (WhichOperand) format();

    // This format is imm but it is really disp32

    which = Assembler::disp32_operand;

    address orig_addr = old_addr_for(addr(), src, dest);

    NativeInstruction* oni = nativeInstruction_at(orig_addr);

    int32_t* orig_disp = (int32_t*) Assembler::locate_operand(orig_addr, which);

    // This poll_addr is incorrect by the size of the instruction it is irrelevant

    intptr_t poll_addr = (intptr_t)oni + *orig_disp;

    NativeInstruction* ni = nativeInstruction_at(addr());

    intptr_t new_disp = poll_addr - (intptr_t) ni;

    int32_t* disp = (int32_t*) Assembler::locate_operand(addr(), which);

    * disp = (int32_t)new_disp;

  }

#endif // _LP64

}