C++ NativeJump::jump_destination方法代码示例

void CompiledDirectStaticCall::set_to_interpreted(const methodHandle& callee, address entry) {
  address stub = find_stub(/*is_aot*/ false);
  guarantee(stub != NULL, "stub not found");

  if (TraceICs) {
    ResourceMark rm;
    tty->print_cr("[email protected]" INTPTR_FORMAT ": set_to_interpreted %s",
                  p2i(instruction_address()),
                  callee->name_and_sig_as_C_string());
  }

  // Creation also verifies the object.
  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub + NativeCall::get_IC_pos_in_java_to_interp_stub());
  NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());

  // A generated lambda form might be deleted from the Lambdaform
  // cache in MethodTypeForm.  If a jit compiled lambdaform method
  // becomes not entrant and the cache access returns null, the new
  // resolve will lead to a new generated LambdaForm.

  assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee() || callee->is_compiled_lambda_form(),
         "a) MT-unsafe modification of inline cache");
  assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,
         "b) MT-unsafe modification of inline cache");

  // Update stub.
  method_holder->set_data((intptr_t)callee());
  jump->set_jump_destination(entry);

  // Update jump to call.
  set_destination_mt_safe(stub);
}

void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {
  address stub = find_stub();
  guarantee(stub != NULL, "stub not found");

  if (TraceICs) {
    ResourceMark rm;
    tty->print_cr("[email protected]" INTPTR_FORMAT ": set_to_interpreted %s",
                  p2i(instruction_address()),
                  callee->name_and_sig_as_C_string());
  }

  // Creation also verifies the object.
  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);
  NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());

  assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(),
         "a) MT-unsafe modification of inline cache");
  assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,
         "b) MT-unsafe modification of inline cache");

  // Update stub.
  method_holder->set_data((intptr_t)callee());
  jump->set_jump_destination(entry);

  // Update jump to call.
  set_destination_mt_safe(stub);
}

address Relocation::pd_call_destination(address orig_addr) {
  intptr_t adj = 0;
  address inst_loc = addr();

  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 = -(inst_loc - orig_addr);
  }
  if (NativeFarCall::is_far_call_at(inst_loc)) {
    NativeFarCall* call = nativeFarCall_at(inst_loc);
    return call->destination() + (intptr_t)(call->is_pcrelative() ? adj : 0);
  } else if (NativeJump::is_jump_at(inst_loc)) {
    NativeJump* jump = nativeJump_at(inst_loc);
    return jump->jump_destination() + (intptr_t)(jump->is_pcrelative() ? adj : 0);
  } else if (NativeConditionalFarBranch::is_conditional_far_branch_at(inst_loc)) {
    NativeConditionalFarBranch* branch = NativeConditionalFarBranch_at(inst_loc);
    return branch->branch_destination();
  } else {
    // There are two instructions at the beginning of a stub, therefore we
    // load at orig_addr + 8.
    orig_addr = nativeCall_at(inst_loc)->get_trampoline();
    if (orig_addr == NULL) {
      return (address) -1;
    } else {
      return (address) nativeMovConstReg_at(orig_addr + 8)->data();
    }
  }
}

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();
  }
}

// Code for unit testing implementation of NativeJump class
void NativeJump::test() {
#ifdef ASSERT
  ResourceMark rm;
  CodeBuffer cb("test", 100, 100);
  MacroAssembler* a = new MacroAssembler(&cb);
  NativeJump* nj;
  uint idx;
  int offsets[] = {
    0x0,
    0xffffffff,
    0x7fffffff,
    0x80000000,
    4096,
    4097,
    0x20,
    0x4000,
  };

  VM_Version::allow_all();

  AddressLiteral al(0x7fffbbbb, relocInfo::external_word_type);
  a->sethi(al, I3);
  a->jmpl(I3, al.low10(), G0, RelocationHolder::none);
  a->delayed()->nop();
  a->sethi(al, I3);
  a->jmpl(I3, al.low10(), L3, RelocationHolder::none);
  a->delayed()->nop();

  nj = nativeJump_at( cb.insts_begin() );
  nj->print();

  nj = nativeJump_at( nj->next_instruction_address() );
  for (idx = 0; idx < ARRAY_SIZE(offsets); idx++) {
    nj->set_jump_destination( nj->instruction_address() + offsets[idx] );
    assert(nj->jump_destination() == (nj->instruction_address() + offsets[idx]), "check unit test");
    nj->print();
  }

  VM_Version::revert();
#endif // ASSERT
}

address InlineCacheBuffer::ic_buffer_entry_point(address code_begin) {
  NativeMovConstReg* move = nativeMovConstReg_at(code_begin);   // creation also verifies the object
  NativeJump*        jump = nativeJump_at(move->next_instruction_address());
  return jump->jump_destination();
}

address InlineCacheBuffer::ic_buffer_entry_point(address code_begin) {
  address jump_address;
  jump_address = code_begin + NativeInstruction::instruction_size;
  NativeJump* jump = nativeJump_at(jump_address);
  return jump->jump_destination();
}