/*

 * Copyright (c) 2008, 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 "asm/assembler.hpp"

#include "asm/macroAssembler.inline.hpp"

#include "assembler_arm.inline.hpp"

#include "code/vtableStubs.hpp"

#include "interp_masm_arm.hpp"

#include "memory/resourceArea.hpp"

#include "oops/compiledICHolder.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/klassVtable.hpp"

#include "runtime/sharedRuntime.hpp"

#include "vmreg_arm.inline.hpp"

#ifdef COMPILER2

#include "opto/runtime.hpp"

#endif

// 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) {

  // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.

  const int stub_code_length = code_size_limit(true);

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

  // Can be NULL if there is no free space in the code cache.

  if (s == NULL) {

    return NULL;

  }

  // Count unused bytes in instruction sequences of variable size.

  // We add them to the computed buffer size in order to avoid

  // overflow in subsequently generated stubs.

  address   start_pc;

  int       slop_bytes = 0;

  int       slop_delta = 0;

  ResourceMark    rm;

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

  MacroAssembler* masm = new MacroAssembler(&cb);

#if (!defined(PRODUCT) && defined(COMPILER2))

  if (CountCompiledCalls) {

    // Implementation required?

  }

#endif

  assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");

  const Register tmp = Rtemp; // Rtemp OK, should be free at call sites

  address npe_addr = __ pc();

  __ load_klass(tmp, R0);

#ifndef PRODUCT

  if (DebugVtables) {

    // Implementation required?

  }

#endif

  start_pc = __ pc();

  { // lookup virtual method

    int entry_offset = in_bytes(Klass::vtable_start_offset()) + vtable_index * vtableEntry::size_in_bytes();

    int method_offset = vtableEntry::method_offset_in_bytes() + entry_offset;

    assert ((method_offset & (wordSize - 1)) == 0, "offset should be aligned");

    int offset_mask = 0xfff;

    if (method_offset & ~offset_mask) {

      __ add(tmp, tmp, method_offset & ~offset_mask);

    }

    __ ldr(Rmethod, Address(tmp, method_offset & offset_mask));

  }

  slop_delta  = 8 - (int)(__ pc() - start_pc);

  slop_bytes += slop_delta;

  assert(slop_delta >= 0, "negative slop(%d) encountered, adjust code size estimate!", slop_delta);

#ifndef PRODUCT

  if (DebugVtables) {

    // Implementation required?

  }

#endif

  address ame_addr = __ pc();

  __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));

  masm->flush();

  bookkeeping(masm, tty, s, npe_addr, ame_addr, true, vtable_index, slop_bytes, 0);

  return s;

}

VtableStub* VtableStubs::create_itable_stub(int itable_index) {

  // Read "A word on VtableStub sizing" in share/code/vtableStubs.hpp for details on stub sizing.

  const int stub_code_length = code_size_limit(false);

  VtableStub* s = new(stub_code_length) VtableStub(false, itable_index);

  // Can be NULL if there is no free space in the code cache.

  if (s == NULL) {

    return NULL;

  }

  // Count unused bytes in instruction sequences of variable size.

  // We add them to the computed buffer size in order to avoid

  // overflow in subsequently generated stubs.

  address   start_pc;

  int       slop_bytes = 0;

  int       slop_delta = 0;

  ResourceMark    rm;

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

  MacroAssembler* masm = new MacroAssembler(&cb);

#if (!defined(PRODUCT) && defined(COMPILER2))

  if (CountCompiledCalls) {

    // Implementation required?

  }

#endif

  assert(VtableStub::receiver_location() == R0->as_VMReg(), "receiver expected in R0");

  // R0-R3 / R0-R7 registers hold the arguments and cannot be spoiled

  const Register Rclass  = R4;

  const Register Rintf   = R5;

  const Register Rscan   = R6;

  Label L_no_such_interface;

  assert_different_registers(Ricklass, Rclass, Rintf, Rscan, Rtemp);

  start_pc = __ pc();

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

  address npe_addr = __ pc();

  __ load_klass(Rclass, R0);

  // Receiver subtype check against REFC.

  __ ldr(Rintf, Address(Ricklass, CompiledICHolder::holder_klass_offset()));

  __ lookup_interface_method(// inputs: rec. class, interface, itable index

                             Rclass, Rintf, noreg,

                             // outputs: temp reg1, temp reg2

                             noreg, Rscan, Rtemp,

                             L_no_such_interface);

  const ptrdiff_t  typecheckSize = __ pc() - start_pc;

  start_pc = __ pc();

  // Get Method* and entry point for compiler

  __ ldr(Rintf, Address(Ricklass, CompiledICHolder::holder_metadata_offset()));

  __ lookup_interface_method(// inputs: rec. class, interface, itable index

                             Rclass, Rintf, itable_index,

                             // outputs: temp reg1, temp reg2, temp reg3

                             Rmethod, Rscan, Rtemp,

                             L_no_such_interface);

  const ptrdiff_t lookupSize = __ pc() - start_pc;

  // Reduce "estimate" such that "padding" does not drop below 8.

  const ptrdiff_t estimate = 140;

  const ptrdiff_t codesize = typecheckSize + lookupSize;

  slop_delta  = (int)(estimate - codesize);

  slop_bytes += slop_delta;

  assert(slop_delta >= 0, "itable #%d: Code size estimate (%d) for lookup_interface_method too small, required: %d", itable_index, (int)estimate, (int)codesize);

#ifndef PRODUCT

  if (DebugVtables) {

    // Implementation required?

  }

#endif

  address ame_addr = __ pc();

  __ ldr(PC, Address(Rmethod, Method::from_compiled_offset()));

  __ bind(L_no_such_interface);

  // Handle IncompatibleClassChangeError in itable stubs.

  // More detailed error message.

  // We force resolving of the call site by jumping to the "handle

  // wrong method" stub, and so let the interpreter runtime do all the

  // dirty work.

  assert(SharedRuntime::get_handle_wrong_method_stub() != NULL, "check initialization order");

  __ jump(SharedRuntime::get_handle_wrong_method_stub(), relocInfo::runtime_call_type, Rtemp);

  masm->flush();

  bookkeeping(masm, tty, s, npe_addr, ame_addr, false, itable_index, slop_bytes, 0);

  return s;

}

int VtableStub::pd_code_alignment() {

  // ARM32 cache line size is not an architected constant. We just align on word size.

  const unsigned int icache_line_size = wordSize;

  return icache_line_size;

}