/*

 * Copyright (c) 1997, 2016, Oracle and/or its affiliates. All rights reserved.

 * 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 "asm/macroAssembler.inline.hpp"

#include "code/compiledIC.hpp"

#include "code/icBuffer.hpp"

#include "code/nmethod.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/safepoint.hpp"

// ----------------------------------------------------------------------------

#define __ _masm.

address CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf, address mark) {

  // Stub is fixed up when the corresponding call is converted from

  // calling compiled code to calling interpreted code.

  // mov rmethod, 0

  // jmp -4 # to self

  if (mark == NULL) {

    mark = cbuf.insts_mark();  // Get mark within main instrs section.

  }

  // Note that the code buffer's insts_mark is always relative to insts.

  // That's why we must use the macroassembler to generate a stub.

  MacroAssembler _masm(&cbuf);

  address base = __ start_a_stub(to_interp_stub_size());

  int offset = __ offset();

  if (base == NULL) {

    return NULL;  // CodeBuffer::expand failed

  }

  // static stub relocation stores the instruction address of the call

  __ relocate(static_stub_Relocation::spec(mark));

  // static stub relocation also tags the Method* in the code-stream.

  __ mov_metadata(rmethod, (Metadata*)NULL);

  __ movptr(rscratch1, 0);

  __ br(rscratch1);

  assert((__ offset() - offset) <= (int)to_interp_stub_size(), "stub too big");

  __ end_a_stub();

  return base;

}

#undef __

int CompiledStaticCall::to_interp_stub_size() {

  return 7 * NativeInstruction::instruction_size;

}

// Relocation entries for call stub, compiled java to interpreter.

int CompiledStaticCall::reloc_to_interp_stub() {

  return 4; // 3 in emit_to_interp_stub + 1 in emit_call

}

void CompiledDirectStaticCall::set_to_interpreted(const methodHandle& callee, address entry) {

  address stub = find_stub(false /* is_aot */);

  guarantee(stub != NULL, "stub not found");

  if (TraceICs) {

    ResourceMark rm;

    tty->print_cr("CompiledDirectStaticCall@" 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);

#ifndef PRODUCT

  NativeGeneralJump* jump = nativeGeneralJump_at(method_holder->next_instruction_address());

  // read the value once

  volatile intptr_t data = method_holder->data();

  assert(data == 0 || data == (intptr_t)callee(),

         "a) MT-unsafe modification of inline cache");

  assert(data == 0 || jump->jump_destination() == entry,

         "b) MT-unsafe modification of inline cache");

#endif

  // Update stub.

  method_holder->set_data((intptr_t)callee());

  NativeGeneralJump::insert_unconditional(method_holder->next_instruction_address(), entry);

  ICache::invalidate_range(stub, to_interp_stub_size());

  // Update jump to call.

  set_destination_mt_safe(stub);

}

void CompiledDirectStaticCall::set_stub_to_clean(static_stub_Relocation* static_stub) {

  assert (CompiledIC_lock->is_locked() || SafepointSynchronize::is_at_safepoint(), "mt unsafe call");

  // Reset stub.

  address stub = static_stub->addr();

  assert(stub != NULL, "stub not found");

  // Creation also verifies the object.

  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);

  method_holder->set_data(0);

}

//-----------------------------------------------------------------------------

// Non-product mode code

#ifndef PRODUCT

void CompiledDirectStaticCall::verify() {

  // Verify call.

  _call->verify();

  if (os::is_MP()) {

    _call->verify_alignment();

  }

  // Verify stub.

  address stub = find_stub(false /* is_aot */);

  assert(stub != NULL, "no stub found for static call");

  // Creation also verifies the object.

  NativeMovConstReg* method_holder = nativeMovConstReg_at(stub);

  NativeJump*        jump          = nativeJump_at(method_holder->next_instruction_address());

  // Verify state.

  assert(is_clean() || is_call_to_compiled() || is_call_to_interpreted(), "sanity check");

}

#endif // !PRODUCT