/*

 * Copyright (c) 2014, Red Hat 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 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 "assembler_aarch64.inline.hpp"

#include "code/vtableStubs.hpp"

#include "interp_masm_aarch64.hpp"

#include "memory/resourceArea.hpp"

#include "oops/compiledICHolder.hpp"

#include "oops/instanceKlass.hpp"

#include "oops/klassVtable.hpp"

#include "runtime/sharedRuntime.hpp"

#include "vmreg_aarch64.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) {

  const int aarch64_code_length = VtableStub::pd_code_size_limit(true);

  VtableStub* s = new(aarch64_code_length) VtableStub(true, vtable_index);

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

  if (s == NULL) {

    return NULL;

  }

  ResourceMark rm;

  CodeBuffer cb(s->entry_point(), aarch64_code_length);

  MacroAssembler* masm = new MacroAssembler(&cb);

#ifndef PRODUCT

  if (CountCompiledCalls) {

    __ lea(r16, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));

    __ incrementw(Address(r16));

  }

#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");

  // get receiver klass

  address npe_addr = __ pc();

  __ load_klass(r16, j_rarg0);

#ifndef PRODUCT

  if (DebugVtables) {

    Label L;

    // check offset vs vtable length

    __ ldrw(rscratch1, Address(r16, Klass::vtable_length_offset()));

    __ cmpw(rscratch1, vtable_index * vtableEntry::size());

    __ br(Assembler::GT, L);

    __ enter();

    __ mov(r2, vtable_index);

    __ call_VM(noreg,

               CAST_FROM_FN_PTR(address, bad_compiled_vtable_index), j_rarg0, r2);

    __ leave();

    __ bind(L);

  }

#endif // PRODUCT

  __ lookup_virtual_method(r16, vtable_index, rmethod);

  if (DebugVtables) {

    Label L;

    __ cbz(rmethod, L);

    __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));

    __ cbnz(rscratch1, L);

    __ stop("Vtable entry is NULL");

    __ bind(L);

  }

  // r0: receiver klass

  // rmethod: Method*

  // r2: receiver

  address ame_addr = __ pc();

  __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));

  __ br(rscratch1);

  __ flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {

    tty->print_cr("vtable #%d at " PTR_FORMAT "[%d] left over: %d",

                  vtable_index, p2i(s->entry_point()),

                  (int)(s->code_end() - s->entry_point()),

                  (int)(s->code_end() - __ pc()));

  }

  guarantee(__ pc() <= s->code_end(), "overflowed buffer");

  s->set_exception_points(npe_addr, ame_addr);

  return s;

}

VtableStub* VtableStubs::create_itable_stub(int itable_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 code_length = VtableStub::pd_code_size_limit(false);

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

  ResourceMark rm;

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

  MacroAssembler* masm = new MacroAssembler(&cb);

#ifndef PRODUCT

  if (CountCompiledCalls) {

    __ lea(r10, ExternalAddress((address) SharedRuntime::nof_megamorphic_calls_addr()));

    __ incrementw(Address(r10));

  }

#endif

  // Entry arguments:

  //  rscratch2: CompiledICHolder

  //  j_rarg0: Receiver

  // Most registers are in use; we'll use r16, rmethod, r10, r11

  const Register recv_klass_reg     = r10;

  const Register holder_klass_reg   = r16; // declaring interface klass (DECC)

  const Register resolved_klass_reg = rmethod; // resolved interface klass (REFC)

  const Register temp_reg           = r11;

  const Register icholder_reg       = rscratch2;

  Label L_no_such_interface;

  __ ldr(resolved_klass_reg, Address(icholder_reg, CompiledICHolder::holder_klass_offset()));

  __ ldr(holder_klass_reg,   Address(icholder_reg, CompiledICHolder::holder_metadata_offset()));

  // 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();

  __ load_klass(recv_klass_reg, j_rarg0);

  // Receiver subtype check against REFC.

  // Destroys recv_klass_reg value.

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

                             recv_klass_reg, resolved_klass_reg, noreg,

                             // outputs:  scan temp. reg1, scan temp. reg2

                             recv_klass_reg, temp_reg,

                             L_no_such_interface,

                             /*return_method=*/false);

  // Get selected method from declaring class and itable index

  __ load_klass(recv_klass_reg, j_rarg0);   // restore recv_klass_reg

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

                       recv_klass_reg, holder_klass_reg, itable_index,

                       // outputs: method, scan temp. reg

                       rmethod, temp_reg,

                       L_no_such_interface);

  // method (rmethod): Method*

  // j_rarg0: receiver

#ifdef ASSERT

  if (DebugVtables) {

    Label L2;

    __ cbz(rmethod, L2);

    __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));

    __ cbnz(rscratch1, L2);

    __ stop("compiler entrypoint is null");

    __ bind(L2);

  }

#endif // ASSERT

  // rmethod: Method*

  // j_rarg0: receiver

  address ame_addr = __ pc();

  __ ldr(rscratch1, Address(rmethod, Method::from_compiled_offset()));

  __ br(rscratch1);

  __ 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.

  __ far_jump(RuntimeAddress(SharedRuntime::get_handle_wrong_method_stub()));

  __ flush();

  if (PrintMiscellaneous && (WizardMode || Verbose)) {

    tty->print_cr("itable #%d at " PTR_FORMAT "[%d] left over: %d",

                  itable_index, p2i(s->entry_point()),

                  (int)(s->code_end() - s->entry_point()),

                  (int)(s->code_end() - __ pc()));

  }

  guarantee(__ pc() <= s->code_end(), "overflowed buffer");

  s->set_exception_points(npe_addr, ame_addr);

  return s;

}

int VtableStub::pd_code_size_limit(bool is_vtable_stub) {

  int size = DebugVtables ? 216 : 0;

  if (CountCompiledCalls)

    size += 6 * 4;

  // FIXME: vtable stubs only need 36 bytes

  if (is_vtable_stub)

    size += 52;

  else

    size += 176;

  return size;

  // In order to tune these parameters, run the JVM with VM options

  // +PrintMiscellaneous and +WizardMode to see information about

  // actual itable stubs.  Run it with -Xmx31G -XX:+UseCompressedOops.

  //

  // If Universe::narrow_klass_base is nonzero, decoding a compressed

  // class can take zeveral instructions.

  //

  // The JVM98 app. _202_jess has a megamorphic interface call.

  // The itable code looks like this:

  //    ldr    xmethod, [xscratch2,#CompiledICHolder::holder_klass_offset]

  //    ldr    x0, [xscratch2]

  //    ldr    w10, [x1,#oopDesc::klass_offset_in_bytes]

  //    mov    xheapbase, #0x3c000000                //   #narrow_klass_base

  //    movk    xheapbase, #0x3f7, lsl #32

  //    add    x10, xheapbase, x10

  //    mov    xheapbase, #0xe7ff0000                //   #heapbase

  //    movk    xheapbase, #0x3f7, lsl #32

  //    ldr    w11, [x10,#vtable_length_offset]

  //    add    x11, x10, x11, uxtx #3

  //    add    x11, x11, #itableMethodEntry::method_offset_in_bytes

  //    ldr    x10, [x11]

  //    cmp    xmethod, x10

  //    b.eq    found_method

  // search:

  //    cbz    x10, no_such_interface

  //    add    x11, x11, #0x10

  //    ldr    x10, [x11]

  //    cmp    xmethod, x10

  //    b.ne    search

  // found_method:

  //    ldr    w10, [x1,#oopDesc::klass_offset_in_bytes]

  //    mov    xheapbase, #0x3c000000                //   #narrow_klass_base

  //    movk    xheapbase, #0x3f7, lsl #32

  //    add    x10, xheapbase, x10

  //    mov    xheapbase, #0xe7ff0000                //   #heapbase

  //    movk    xheapbase, #0x3f7, lsl #32

  //    ldr    w11, [x10,#vtable_length_offset]

  //    add    x11, x10, x11, uxtx #3

  //    add    x11, x11, #itableMethodEntry::method_offset_in_bytes

  //    add    x10, x10, #itentry_off

  //    ldr    xmethod, [x11]

  //    cmp    x0, xmethod

  //    b.eq    found_method2

  // search2:

  //    cbz    xmethod, 0x000003ffa872e6cc

  //    add    x11, x11, #0x10

  //    ldr    xmethod, [x11]

  //    cmp    x0, xmethod

  //    b.ne    search2

  // found_method2:

  //    ldr    w11, [x11,#itableOffsetEntry::offset_offset_in_bytes]

  //    ldr    xmethod, [x10,w11,uxtw]

  //    ldr    xscratch1, [xmethod,#Method::from_compiled_offset]

  //    br    xscratch1

  // no_such_interface:

  //    b      throw_ICCE_entry

}

int VtableStub::pd_code_alignment() { return 4; }