/*

 * Copyright 2003-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

#include "incls/_precompiled.incl"

#include "incls/_vtableStubs_x86_64.cpp.incl"

// machine-dependent part of VtableStubs: create VtableStub of correct size and

// initialize its code

#define __ masm->

#ifndef PRODUCT

extern "C" void bad_compiled_vtable_index(JavaThread* thread,

                                          oop receiver,

                                          int index);

#endif

VtableStub* VtableStubs::create_vtable_stub(int vtable_index) {

  const int amd64_code_length = VtableStub::pd_code_size_limit(true);

  VtableStub* s = new(amd64_code_length) VtableStub(true, vtable_index);

  ResourceMark rm;

  CodeBuffer cb(s->entry_point(), amd64_code_length);

  MacroAssembler* masm = new MacroAssembler(&cb);

#ifndef PRODUCT

  if (CountCompiledCalls) {

    __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));

  }

#endif

  // get receiver (need to skip return address on top of stack)

  assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

  // Free registers (non-args) are rax, rbx

  // get receiver klass

  address npe_addr = __ pc();

  __ movq(rax, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));

  // compute entry offset (in words)

  int entry_offset =

    instanceKlass::vtable_start_offset() + vtable_index * vtableEntry::size();

#ifndef PRODUCT

  if (DebugVtables) {

    Label L;

    // check offset vs vtable length

    __ cmpl(Address(rax, instanceKlass::vtable_length_offset() * wordSize),

            vtable_index * vtableEntry::size());

    __ jcc(Assembler::greater, L);

    __ movl(rbx, vtable_index);

    __ call_VM(noreg,

               CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, rbx);

    __ bind(L);

  }

#endif // PRODUCT

  // load methodOop and target address

  const Register method = rbx;

  __ movq(method, Address(rax,

                          entry_offset * wordSize +

                          vtableEntry::method_offset_in_bytes()));

  if (DebugVtables) {

    Label L;

    __ cmpq(method, (int)NULL);

    __ jcc(Assembler::equal, L);

    __ cmpq(Address(method, methodOopDesc::from_compiled_offset()), (int)NULL_WORD);

    __ jcc(Assembler::notZero, L);

    __ stop("Vtable entry is NULL");

    __ bind(L);

  }

  // rax: receiver klass

  // rbx: methodOop

  // rcx: receiver

  address ame_addr = __ pc();

  __ jmp( Address(rbx, methodOopDesc::from_compiled_offset()));

  __ flush();

  s->set_exception_points(npe_addr, ame_addr);

  return s;

}

VtableStub* VtableStubs::create_itable_stub(int vtable_index) {

  // Note well: pd_code_size_limit is the absolute minimum we can get

  // away with.  If you add code here, bump the code stub size

  // returned by pd_code_size_limit!

  const int amd64_code_length = VtableStub::pd_code_size_limit(false);

  VtableStub* s = new(amd64_code_length) VtableStub(false, vtable_index);

  ResourceMark rm;

  CodeBuffer cb(s->entry_point(), amd64_code_length);

  MacroAssembler* masm = new MacroAssembler(&cb);

#ifndef PRODUCT

  if (CountCompiledCalls) {

    __ incrementl(ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));

  }

#endif

  // Entry arguments:

  //  rax: Interface

  //  j_rarg0: Receiver

  // Free registers (non-args) are rax (interface), rbx

  // get receiver (need to skip return address on top of stack)

  assert(VtableStub::receiver_location() == j_rarg0->as_VMReg(), "receiver expected in j_rarg0");

  // get receiver klass (also an implicit null-check)

  address npe_addr = __ pc();

  __ movq(rbx, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));

  // If we take a trap while this arg is on the stack we will not

  // be able to walk the stack properly. This is not an issue except

  // when there are mistakes in this assembly code that could generate

  // a spurious fault. Ask me how I know...

  __ pushq(j_rarg1);     // Most registers are in use, so save one

  // compute itable entry offset (in words)

  const int base = instanceKlass::vtable_start_offset() * wordSize;

  assert(vtableEntry::size() * wordSize == 8,

         "adjust the scaling in the code below");

  // Get length of vtable

  __ movl(j_rarg1,

          Address(rbx, instanceKlass::vtable_length_offset() * wordSize));

  __ leaq(rbx, Address(rbx, j_rarg1, Address::times_8, base));

  if (HeapWordsPerLong > 1) {

    // Round up to align_object_offset boundary

    __ round_to_q(rbx, BytesPerLong);

  }

  Label hit, next, entry;

  __ jmpb(entry);

  __ bind(next);

  __ addq(rbx, itableOffsetEntry::size() * wordSize);

  __ bind(entry);

#ifdef ASSERT

    // Check that the entry is non-null

  if (DebugVtables) {

    Label L;

    __ pushq(rbx);

    __ movq(rbx, Address(rbx, itableOffsetEntry::interface_offset_in_bytes()));

    __ testq(rbx, rbx);

    __ jcc(Assembler::notZero, L);

    __ stop("null entry point found in itable's offset table");

    __ bind(L);

    __ popq(rbx);

  }

#endif

  __ cmpq(rax, Address(rbx, itableOffsetEntry::interface_offset_in_bytes()));

  __ jcc(Assembler::notEqual, next);

  // We found a hit, move offset into j_rarg1

  __ movl(j_rarg1, Address(rbx, itableOffsetEntry::offset_offset_in_bytes()));

  // Compute itableMethodEntry

  const int method_offset =

    (itableMethodEntry::size() * wordSize * vtable_index) +

    itableMethodEntry::method_offset_in_bytes();

  // Get methodOop and entrypoint for compiler

  // Get klass pointer again

  __ movq(rax, Address(j_rarg0, oopDesc::klass_offset_in_bytes()));

  const Register method = rbx;

  __ movq(method, Address(rax, j_rarg1, Address::times_1, method_offset));

  // Restore saved register, before possible trap.

  __ popq(j_rarg1);

  // method (rbx): methodOop

  // j_rarg0: receiver

#ifdef ASSERT

    if (DebugVtables) {

      Label L2;

      __ cmpq(method, (int)NULL);

      __ jcc(Assembler::equal, L2);

      __ cmpq(Address(method, methodOopDesc::from_compiled_offset()), (int)NULL_WORD);

      __ jcc(Assembler::notZero, L2);

      __ stop("compiler entrypoint is null");

      __ bind(L2);

    }

#endif // ASSERT

    // rbx: methodOop

    // j_rarg0: receiver

    address ame_addr = __ pc();

    __ jmp(Address(method, methodOopDesc::from_compiled_offset()));

  __ flush();

  s->set_exception_points(npe_addr, ame_addr);

  return s;

}

int VtableStub::pd_code_size_limit(bool is_vtable_stub) {

  if (is_vtable_stub) {

    // Vtable stub size

    return (DebugVtables ? 512 : 24) + (CountCompiledCalls ? 13 : 0);

  } else {

    // Itable stub size

    return (DebugVtables ? 636 : 64) + (CountCompiledCalls ? 13 : 0);

  }

}

int VtableStub::pd_code_alignment() {

  return wordSize;

}