/*

 * Copyright (c) 2016, 2018, Oracle and/or its affiliates. All rights reserved.

 * Copyright (c) 2016, 2018 SAP SE. 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/macroAssembler.inline.hpp"

#include "code/vtableStubs.hpp"

#include "interp_masm_s390.hpp"

#include "memory/resourceArea.hpp"

#include "oops/compiledICHolder.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/klassVtable.hpp"

#include "runtime/sharedRuntime.hpp"

#include "vmreg_s390.inline.hpp"

#ifdef COMPILER2

#include "opto/runtime.hpp"

#endif

#define __ masm->

#ifndef PRODUCT

extern "C" void bad_compiled_vtable_index(JavaThread* thread, oop receiver, int index);

#endif

// Used by compiler only; may use only caller saved, non-argument registers.

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) {

    //               worst case             actual size

    slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);

    slop_bytes += slop_delta;

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

    // Use generic emitter for direct memory increment.

    // Abuse Z_method as scratch register for generic emitter.

    // It is loaded further down anyway before it is first used.

    // No dynamic code size variance here, increment is 1, always.

    __ add2mem_32(Address(Z_R1_scratch), 1, Z_method);

  }

#endif

  assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");

  const Register rcvr_klass   = Z_R1_scratch;

  address        npe_addr     = __ pc(); // npe == NULL ptr exception

  // check if we must do an explicit check (implicit checks disabled, offset too large).

  __ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());

  // Get receiver klass.

  __ load_klass(rcvr_klass, Z_ARG1);

#ifndef PRODUCT

  if (DebugVtables) {

    NearLabel L;

    // Check offset vs vtable length.

    const Register vtable_idx = Z_R0_scratch;

    //               worst case             actual size

    slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(vtable_idx, vtable_index*vtableEntry::size(), true);

    slop_bytes += slop_delta;

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

    assert(Displacement::is_shortDisp(in_bytes(Klass::vtable_length_offset())), "disp to large");

    __ z_cl(vtable_idx, in_bytes(Klass::vtable_length_offset()), rcvr_klass);

    __ z_brl(L);

    __ z_lghi(Z_ARG3, vtable_index);  // Debug code, don't optimize.

    __ call_VM(noreg, CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), Z_ARG1, Z_ARG3, false);

    // Count unused bytes (assume worst case here).

    slop_bytes += 12;

    __ bind(L);

  }

#endif

  int entry_offset = in_bytes(Klass::vtable_start_offset()) +

                     vtable_index * vtableEntry::size_in_bytes();

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

  // Set method (in case of interpreted method), and destination address.

  // Duplicate safety code from enc_class Java_Dynamic_Call_dynTOC.

  if (Displacement::is_validDisp(v_off)) {

    __ z_lg(Z_method/*method oop*/, v_off, rcvr_klass/*class oop*/);

    // Account for the load_const in the else path.

    slop_delta  = __ load_const_size();

  } else {

    // Worse case, offset does not fit in displacement field.

    //               worst case             actual size

    slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_method, v_off, true);

    __ z_lg(Z_method/*method oop*/, 0, Z_method/*method offset*/, rcvr_klass/*class oop*/);

  }

  slop_bytes += slop_delta;

#ifndef PRODUCT

  if (DebugVtables) {

    NearLabel L;

    __ z_ltgr(Z_method, Z_method);

    __ z_brne(L);

    __ stop("Vtable entry is ZERO", 102);

    __ bind(L);

  }

#endif

  // Must do an explicit check if offset too large or implicit checks are disabled.

  address ame_addr = __ pc();

  __ null_check(Z_method, Z_R1_scratch, in_bytes(Method::from_compiled_offset()));

  __ z_lg(Z_R1_scratch, in_bytes(Method::from_compiled_offset()), Z_method);

  __ z_br(Z_R1_scratch);

  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) {

    //               worst case             actual size

    slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::nof_megamorphic_calls_addr(), true);

    slop_bytes += slop_delta;

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

    // Use generic emitter for direct memory increment.

    // Abuse Z_method as scratch register for generic emitter.

    // It is loaded further down anyway before it is first used.

    // No dynamic code size variance here, increment is 1, always.

    __ add2mem_32(Address(Z_R1_scratch), 1, Z_method);

  }

#endif

  assert(VtableStub::receiver_location() == Z_R2->as_VMReg(), "receiver expected in Z_ARG1");

  // Entry arguments:

  //  Z_method: Interface

  //  Z_ARG1:   Receiver

  NearLabel no_such_interface;

  const Register rcvr_klass = Z_tmp_1,

                 interface  = Z_tmp_2;

  // Get receiver klass.

  // Must do an explicit check if offset too large or implicit checks are disabled.

  address npe_addr = __ pc(); // npe == NULL ptr exception

  __ null_check(Z_ARG1, Z_R1_scratch, oopDesc::klass_offset_in_bytes());

  __ load_klass(rcvr_klass, Z_ARG1);

  // Receiver subtype check against REFC.

  __ z_lg(interface, Address(Z_method, CompiledICHolder::holder_klass_offset()));

  __ lookup_interface_method(rcvr_klass, interface, noreg,

                             noreg, Z_R1, no_such_interface, /*return_method=*/ false);

  // Get Method* and entrypoint for compiler

  __ z_lg(interface, Address(Z_method, CompiledICHolder::holder_metadata_offset()));

  __ lookup_interface_method(rcvr_klass, interface, itable_index,

                             Z_method, Z_R1, no_such_interface, /*return_method=*/ true);

#ifndef PRODUCT

  if (DebugVtables) {

    NearLabel ok1;

    __ z_ltgr(Z_method, Z_method);

    __ z_brne(ok1);

    __ stop("method is null", 103);

    __ bind(ok1);

  }

#endif

  address ame_addr = __ pc();

  // Must do an explicit check if implicit checks are disabled.

  if (!ImplicitNullChecks) {

    __ compare64_and_branch(Z_method, (intptr_t) 0, Assembler::bcondEqual, no_such_interface);

  }

  __ z_lg(Z_R1_scratch, in_bytes(Method::from_compiled_offset()), Z_method);

  __ z_br(Z_R1_scratch);

  // Handle IncompatibleClassChangeError in itable stubs.

  __ bind(no_such_interface);

  // more detailed IncompatibleClassChangeError

  // we force re-resolving of the call site by jumping to

  // the "handle wrong method" stub, thus letting the

  // interpreter runtime do all the dirty work.

  //               worst case          actual size

  slop_delta  = __ load_const_size() - __ load_const_optimized_rtn_len(Z_R1_scratch, (long)SharedRuntime::get_handle_wrong_method_stub(), true);

  slop_bytes += slop_delta;

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

  __ z_br(Z_R1_scratch);

  masm->flush();

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

  return s;

}

int VtableStub::pd_code_alignment() {

  // System z cache line size is 256 bytes, but octoword-alignment is quite ok.

  const unsigned int icache_line_size = 32;

  return icache_line_size;

}