/*

 * Copyright (c) 1997, 2013, 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/compiledIC.hpp"

#include "code/icBuffer.hpp"

#include "code/nmethod.hpp"

#include "memory/resourceArea.hpp"

#include "runtime/mutexLocker.hpp"

#include "runtime/safepoint.hpp"

// Release the CompiledICHolder* associated with this call site is there is one.

void CompiledIC::cleanup_call_site(virtual_call_Relocation* call_site) {

  // This call site might have become stale so inspect it carefully.

  NativeCall* call = nativeCall_at(call_site->addr());

  if (is_icholder_entry(call->destination())) {

    NativeMovConstReg* value = nativeMovConstReg_at(call_site->cached_value());

    InlineCacheBuffer::queue_for_release((CompiledICHolder*)value->data());

  }

}

bool CompiledIC::is_icholder_call_site(virtual_call_Relocation* call_site) {

  // This call site might have become stale so inspect it carefully.

  NativeCall* call = nativeCall_at(call_site->addr());

  return is_icholder_entry(call->destination());

}

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

// High-level access to an inline cache. Guaranteed to be MT-safe.

CompiledIC::CompiledIC(nmethod* nm, NativeCall* call)

  : _ic_call(call)

{

  address ic_call = call->instruction_address();

  assert(ic_call != NULL, "ic_call address must be set");

  assert(nm != NULL, "must pass nmethod");

  assert(nm->contains(ic_call), "must be in nmethod");

  // Search for the ic_call at the given address.

  RelocIterator iter(nm, ic_call, ic_call+1);

  bool ret = iter.next();

  assert(ret == true, "relocInfo must exist at this address");

  assert(iter.addr() == ic_call, "must find ic_call");

  if (iter.type() == relocInfo::virtual_call_type) {

    virtual_call_Relocation* r = iter.virtual_call_reloc();

    _is_optimized = false;

    _value = nativeMovConstReg_at(r->cached_value());

  } else {

    assert(iter.type() == relocInfo::opt_virtual_call_type, "must be a virtual call");

    _is_optimized = true;

    _value = NULL;

  }

}

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

#define __ _masm.

void CompiledStaticCall::emit_to_interp_stub(CodeBuffer &cbuf) {

  // 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

  address 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()*2);

  if (base == NULL) return;  // CodeBuffer::expand failed.

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

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

  // Update current stubs pointer and restore insts_end.

  __ end_a_stub();

}

#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

}

void CompiledStaticCall::set_to_interpreted(methodHandle callee, address entry) {

  address stub = find_stub();

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

  if (TraceICs) {

    ResourceMark rm;

    tty->print_cr("CompiledStaticCall@" INTPTR_FORMAT ": set_to_interpreted %s",

                  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());

  assert(method_holder->data() == 0 || method_holder->data() == (intptr_t)callee(),

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

  assert(jump->jump_destination() == (address)-1 || jump->jump_destination() == entry,

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

  // Update stub.

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

  jump->set_jump_destination(entry);

  // Update jump to call.

  set_destination_mt_safe(stub);

}

void CompiledStaticCall::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);

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

  method_holder->set_data(0);

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

}

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

// Non-product mode code

#ifndef PRODUCT

void CompiledStaticCall::verify() {

  // Verify call.

  NativeCall::verify();

  if (os::is_MP()) {

    verify_alignment();

  }

  // Verify stub.

  address stub = find_stub();

  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