/*

 * Copyright (c) 1997, 2016, 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/macroAssembler.inline.hpp"

#include "code/codeCache.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.

  // movq rbx, 0

  // jmp -5 # 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());

  if (base == NULL) {

    return NULL;  // CodeBuffer::expand failed.

  }

  // Static stub relocation stores the instruction address of the call.

  __ relocate(static_stub_Relocation::spec(mark, false), Assembler::imm_operand);

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

  __ mov_metadata(rbx, (Metadata*) NULL);  // Method is zapped till fixup time.

  // This is recognized as unresolved by relocs/nativeinst/ic code.

  __ jump(RuntimeAddress(__ pc()));

  assert(__ pc() - base <= to_interp_stub_size(), "wrong stub size");

  // Update current stubs pointer and restore insts_end.

  __ end_a_stub();

  return base;

}

#undef __

int CompiledStaticCall::to_interp_stub_size() {

  return NOT_LP64(10)    // movl; jmp

         LP64_ONLY(15);  // movq (1+1+8); jmp (1+4)

}

// 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

}

#if INCLUDE_AOT

#define __ _masm.

void CompiledStaticCall::emit_to_aot_stub(CodeBuffer &cbuf, address mark) {

  if (!UseAOT) {

    return;

  }

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

  // calling compiled code to calling aot code.

  // movq rax, imm64_aot_code_address

  // jmp  rax

  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_aot_stub_size());

  guarantee(base != NULL, "out of space");

  // Static stub relocation stores the instruction address of the call.

  __ relocate(static_stub_Relocation::spec(mark, true /* is_aot */), Assembler::imm_operand);

  // Load destination AOT code address.

#ifdef _LP64

  __ mov64(rax, CONST64(0));  // address is zapped till fixup time.

#else

  __ movl(rax, 0);  // address is zapped till fixup time.

#endif

  // This is recognized as unresolved by relocs/nativeinst/ic code.

  __ jmp(rax);

  assert(__ pc() - base <= to_aot_stub_size(), "wrong stub size");

  // Update current stubs pointer and restore insts_end.

  __ end_a_stub();

}

#undef __

int CompiledStaticCall::to_aot_stub_size() {

  if (UseAOT) {

    return NOT_LP64(7)    // movl; jmp

           LP64_ONLY(12);  // movq (1+1+8); jmp (2)

  } else {

    return 0;

  }

}

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

int CompiledStaticCall::reloc_to_aot_stub() {

  if (UseAOT) {

    return 2; // 1 in emit_to_aot_stub + 1 in emit_call

  } else {

    return 0;

  }

}

#endif // INCLUDE_AOT

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);

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

#ifdef ASSERT

  // read the value once

  intptr_t data = method_holder->data();

  address destination = jump->jump_destination();

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

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

  assert(destination == (address)-1 || destination == entry,

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

#endif

  // Update stub.

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

  jump->set_jump_destination(entry);

  // 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);

  if (!static_stub->is_aot()) {

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

    jump->set_jump_destination((address)-1);

  }

}

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

// Non-product mode code

#ifndef PRODUCT

void CompiledDirectStaticCall::verify() {

  // Verify call.

  _call->verify();

  if (os::is_MP()) {

    _call->verify_alignment();

  }

#ifdef ASSERT

  CodeBlob *cb = CodeCache::find_blob_unsafe((address) _call);

  assert(cb && !cb->is_aot(), "CompiledDirectStaticCall cannot be used on AOTCompiledMethod");

#endif

  // 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