/*

 * Copyright (c) 2000, 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 "c1/c1_Compilation.hpp"

#include "c1/c1_Instruction.hpp"

#include "c1/c1_InstructionPrinter.hpp"

#include "c1/c1_LIRAssembler.hpp"

#include "c1/c1_MacroAssembler.hpp"

#include "c1/c1_ValueStack.hpp"

#include "ci/ciInstance.hpp"

#include "runtime/os.hpp"

void LIR_Assembler::patching_epilog(PatchingStub* patch, LIR_PatchCode patch_code, Register obj, CodeEmitInfo* info) {

  // We must have enough patching space so that call can be inserted.

  // We cannot use fat nops here, since the concurrent code rewrite may transiently

  // create the illegal instruction sequence.

  while ((intx) _masm->pc() - (intx) patch->pc_start() < NativeGeneralJump::instruction_size) {

    _masm->nop();

  }

  patch->install(_masm, patch_code, obj, info);

  append_code_stub(patch);

#ifdef ASSERT

  Bytecodes::Code code = info->scope()->method()->java_code_at_bci(info->stack()->bci());

  if (patch->id() == PatchingStub::access_field_id) {

    switch (code) {

      case Bytecodes::_putstatic:

      case Bytecodes::_getstatic:

      case Bytecodes::_putfield:

      case Bytecodes::_getfield:

        break;

      default:

        ShouldNotReachHere();

    }

  } else if (patch->id() == PatchingStub::load_klass_id) {

    switch (code) {

      case Bytecodes::_new:

      case Bytecodes::_anewarray:

      case Bytecodes::_multianewarray:

      case Bytecodes::_instanceof:

      case Bytecodes::_checkcast:

        break;

      default:

        ShouldNotReachHere();

    }

  } else if (patch->id() == PatchingStub::load_mirror_id) {

    switch (code) {

      case Bytecodes::_putstatic:

      case Bytecodes::_getstatic:

      case Bytecodes::_ldc:

      case Bytecodes::_ldc_w:

        break;

      default:

        ShouldNotReachHere();

    }

  } else if (patch->id() == PatchingStub::load_appendix_id) {

    Bytecodes::Code bc_raw = info->scope()->method()->raw_code_at_bci(info->stack()->bci());

    assert(Bytecodes::has_optional_appendix(bc_raw), "unexpected appendix resolution");

  } else {

    ShouldNotReachHere();

  }

#endif

}

PatchingStub::PatchID LIR_Assembler::patching_id(CodeEmitInfo* info) {

  IRScope* scope = info->scope();

  Bytecodes::Code bc_raw = scope->method()->raw_code_at_bci(info->stack()->bci());

  if (Bytecodes::has_optional_appendix(bc_raw)) {

    return PatchingStub::load_appendix_id;

  }

  return PatchingStub::load_mirror_id;

}

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

LIR_Assembler::LIR_Assembler(Compilation* c):

   _compilation(c)

 , _masm(c->masm())

 , _bs(Universe::heap()->barrier_set())

 , _frame_map(c->frame_map())

 , _current_block(NULL)

 , _pending_non_safepoint(NULL)

 , _pending_non_safepoint_offset(0)

{

  _slow_case_stubs = new CodeStubList();

}

LIR_Assembler::~LIR_Assembler() {

}

void LIR_Assembler::check_codespace() {

  CodeSection* cs = _masm->code_section();

  if (cs->remaining() < (int)(NOT_LP64(1*K)LP64_ONLY(2*K))) {

    BAILOUT("CodeBuffer overflow");

  }

}

void LIR_Assembler::append_code_stub(CodeStub* stub) {

  _slow_case_stubs->append(stub);

}

void LIR_Assembler::emit_stubs(CodeStubList* stub_list) {

  for (int m = 0; m < stub_list->length(); m++) {

    CodeStub* s = stub_list->at(m);

    check_codespace();

    CHECK_BAILOUT();

#ifndef PRODUCT

    if (CommentedAssembly) {

      stringStream st;

      s->print_name(&st);

      st.print(" slow case");

      _masm->block_comment(st.as_string());

    }

#endif

    s->emit_code(this);

#ifdef ASSERT

    s->assert_no_unbound_labels();

#endif

  }

}

void LIR_Assembler::emit_slow_case_stubs() {

  emit_stubs(_slow_case_stubs);

}

bool LIR_Assembler::needs_icache(ciMethod* method) const {

  return !method->is_static();

}

int LIR_Assembler::code_offset() const {

  return _masm->offset();

}

address LIR_Assembler::pc() const {

  return _masm->pc();

}

// To bang the stack of this compiled method we use the stack size

// that the interpreter would need in case of a deoptimization. This

// removes the need to bang the stack in the deoptimization blob which

// in turn simplifies stack overflow handling.

int LIR_Assembler::bang_size_in_bytes() const {

  return MAX2(initial_frame_size_in_bytes() + os::extra_bang_size_in_bytes(), _compilation->interpreter_frame_size());

}

void LIR_Assembler::emit_exception_entries(ExceptionInfoList* info_list) {

  for (int i = 0; i < info_list->length(); i++) {

    XHandlers* handlers = info_list->at(i)->exception_handlers();

    for (int j = 0; j < handlers->length(); j++) {

      XHandler* handler = handlers->handler_at(j);

      assert(handler->lir_op_id() != -1, "handler not processed by LinearScan");

      assert(handler->entry_code() == NULL ||

             handler->entry_code()->instructions_list()->last()->code() == lir_branch ||

             handler->entry_code()->instructions_list()->last()->code() == lir_delay_slot, "last operation must be branch");

      if (handler->entry_pco() == -1) {

        // entry code not emitted yet

        if (handler->entry_code() != NULL && handler->entry_code()->instructions_list()->length() > 1) {

          handler->set_entry_pco(code_offset());

          if (CommentedAssembly) {

            _masm->block_comment("Exception adapter block");

          }

          emit_lir_list(handler->entry_code());

        } else {

          handler->set_entry_pco(handler->entry_block()->exception_handler_pco());

        }

        assert(handler->entry_pco() != -1, "must be set now");

      }

    }

  }

}

void LIR_Assembler::emit_code(BlockList* hir) {

  if (PrintLIR) {

    print_LIR(hir);

  }

  int n = hir->length();

  for (int i = 0; i < n; i++) {

    emit_block(hir->at(i));

    CHECK_BAILOUT();

  }

  flush_debug_info(code_offset());

  DEBUG_ONLY(check_no_unbound_labels());

}

void LIR_Assembler::emit_block(BlockBegin* block) {

  if (block->is_set(BlockBegin::backward_branch_target_flag)) {

    align_backward_branch_target();

  }

  // if this block is the start of an exception handler, record the

  // PC offset of the first instruction for later construction of

  // the ExceptionHandlerTable

  if (block->is_set(BlockBegin::exception_entry_flag)) {

    block->set_exception_handler_pco(code_offset());

  }

#ifndef PRODUCT

  if (PrintLIRWithAssembly) {

    // don't print Phi's

    InstructionPrinter ip(false);

    block->print(ip);

  }

#endif /* PRODUCT */

  assert(block->lir() != NULL, "must have LIR");

  X86_ONLY(assert(_masm->rsp_offset() == 0, "frame size should be fixed"));

#ifndef PRODUCT

  if (CommentedAssembly) {

    stringStream st;

    st.print_cr(" block B%d [%d, %d]", block->block_id(), block->bci(), block->end()->printable_bci());

    _masm->block_comment(st.as_string());

  }

#endif

  emit_lir_list(block->lir());

  X86_ONLY(assert(_masm->rsp_offset() == 0, "frame size should be fixed"));

}

void LIR_Assembler::emit_lir_list(LIR_List* list) {

  peephole(list);

  int n = list->length();

  for (int i = 0; i < n; i++) {

    LIR_Op* op = list->at(i);

    check_codespace();

    CHECK_BAILOUT();

#ifndef PRODUCT

    if (CommentedAssembly) {

      // Don't record out every op since that's too verbose.  Print

      // branches since they include block and stub names.  Also print

      // patching moves since they generate funny looking code.

      if (op->code() == lir_branch ||

          (op->code() == lir_move && op->as_Op1()->patch_code() != lir_patch_none)) {

        stringStream st;

        op->print_on(&st);

        _masm->block_comment(st.as_string());

      }

    }

    if (PrintLIRWithAssembly) {

      // print out the LIR operation followed by the resulting assembly

      list->at(i)->print(); tty->cr();

    }

#endif /* PRODUCT */

    op->emit_code(this);

    if (compilation()->debug_info_recorder()->recording_non_safepoints()) {

      process_debug_info(op);

    }

#ifndef PRODUCT

    if (PrintLIRWithAssembly) {

      _masm->code()->decode();

    }

#endif /* PRODUCT */

  }

}

#ifdef ASSERT

void LIR_Assembler::check_no_unbound_labels() {

  CHECK_BAILOUT();

  for (int i = 0; i < _branch_target_blocks.length() - 1; i++) {

    if (!_branch_target_blocks.at(i)->label()->is_bound()) {

      tty->print_cr("label of block B%d is not bound", _branch_target_blocks.at(i)->block_id());

      assert(false, "unbound label");

    }

  }

}

#endif

//----------------------------------debug info--------------------------------

void LIR_Assembler::add_debug_info_for_branch(CodeEmitInfo* info) {

  int pc_offset = code_offset();

  flush_debug_info(pc_offset);

  info->record_debug_info(compilation()->debug_info_recorder(), pc_offset);

  if (info->exception_handlers() != NULL) {

    compilation()->add_exception_handlers_for_pco(pc_offset, info->exception_handlers());

  }

}

void LIR_Assembler::add_call_info(int pc_offset, CodeEmitInfo* cinfo) {

  flush_debug_info(pc_offset);

  cinfo->record_debug_info(compilation()->debug_info_recorder(), pc_offset);

  if (cinfo->exception_handlers() != NULL) {

    compilation()->add_exception_handlers_for_pco(pc_offset, cinfo->exception_handlers());

  }

}

static ValueStack* debug_info(Instruction* ins) {

  StateSplit* ss = ins->as_StateSplit();

  if (ss != NULL) return ss->state();

  return ins->state_before();

}

void LIR_Assembler::process_debug_info(LIR_Op* op) {

  Instruction* src = op->source();

  if (src == NULL)  return;

  int pc_offset = code_offset();

  if (_pending_non_safepoint == src) {

    _pending_non_safepoint_offset = pc_offset;

    return;

  }

  ValueStack* vstack = debug_info(src);

  if (vstack == NULL)  return;

  if (_pending_non_safepoint != NULL) {

    // Got some old debug info.  Get rid of it.

    if (debug_info(_pending_non_safepoint) == vstack) {

      _pending_non_safepoint_offset = pc_offset;

      return;

    }

    if (_pending_non_safepoint_offset < pc_offset) {

      record_non_safepoint_debug_info();

    }

    _pending_non_safepoint = NULL;

  }

  // Remember the debug info.

  if (pc_offset > compilation()->debug_info_recorder()->last_pc_offset()) {

    _pending_non_safepoint = src;

    _pending_non_safepoint_offset = pc_offset;

  }

}

// Index caller states in s, where 0 is the oldest, 1 its callee, etc.

// Return NULL if n is too large.

// Returns the caller_bci for the next-younger state, also.

static ValueStack* nth_oldest(ValueStack* s, int n, int& bci_result) {

  ValueStack* t = s;

  for (int i = 0; i < n; i++) {

    if (t == NULL)  break;

    t = t->caller_state();

  }

  if (t == NULL)  return NULL;

  for (;;) {

    ValueStack* tc = t->caller_state();

    if (tc == NULL)  return s;

    t = tc;

    bci_result = tc->bci();

    s = s->caller_state();

  }

}

void LIR_Assembler::record_non_safepoint_debug_info() {

  int         pc_offset = _pending_non_safepoint_offset;

  ValueStack* vstack    = debug_info(_pending_non_safepoint);

  int         bci       = vstack->bci();

  DebugInformationRecorder* debug_info = compilation()->debug_info_recorder();

  assert(debug_info->recording_non_safepoints(), "sanity");

  debug_info->add_non_safepoint(pc_offset);

  // Visit scopes from oldest to youngest.

  for (int n = 0; ; n++) {

    int s_bci = bci;

    ValueStack* s = nth_oldest(vstack, n, s_bci);

    if (s == NULL)  break;

    IRScope* scope = s->scope();

    //Always pass false for reexecute since these ScopeDescs are never used for deopt

    methodHandle null_mh;

    debug_info->describe_scope(pc_offset, null_mh, scope->method(), s->bci(), false/*reexecute*/);

  }

  debug_info->end_non_safepoint(pc_offset);

}

ImplicitNullCheckStub* LIR_Assembler::add_debug_info_for_null_check_here(CodeEmitInfo* cinfo) {

  return add_debug_info_for_null_check(code_offset(), cinfo);

}

ImplicitNullCheckStub* LIR_Assembler::add_debug_info_for_null_check(int pc_offset, CodeEmitInfo* cinfo) {

  ImplicitNullCheckStub* stub = new ImplicitNullCheckStub(pc_offset, cinfo);

  append_code_stub(stub);

  return stub;

}

void LIR_Assembler::add_debug_info_for_div0_here(CodeEmitInfo* info) {

  add_debug_info_for_div0(code_offset(), info);

}

void LIR_Assembler::add_debug_info_for_div0(int pc_offset, CodeEmitInfo* cinfo) {

  DivByZeroStub* stub = new DivByZeroStub(pc_offset, cinfo);

  append_code_stub(stub);

}

void LIR_Assembler::emit_rtcall(LIR_OpRTCall* op) {

  rt_call(op->result_opr(), op->addr(), op->arguments(), op->tmp(), op->info());

}

void LIR_Assembler::emit_call(LIR_OpJavaCall* op) {

  verify_oop_map(op->info());

  if (os::is_MP()) {

    // must align calls sites, otherwise they can't be updated atomically on MP hardware

    align_call(op->code());

  }

  // emit the static call stub stuff out of line

  emit_static_call_stub();

  CHECK_BAILOUT();

  switch (op->code()) {

  case lir_static_call:

  case lir_dynamic_call:

    call(op, relocInfo::static_call_type);

    break;

  case lir_optvirtual_call:

    call(op, relocInfo::opt_virtual_call_type);

    break;

  case lir_icvirtual_call:

    ic_call(op);

    break;

  case lir_virtual_call:

    vtable_call(op);

    break;

  default:

    fatal("unexpected op code: %s", op->name());

    break;

  }

  // JSR 292

  // Record if this method has MethodHandle invokes.

  if (op->is_method_handle_invoke()) {

    compilation()->set_has_method_handle_invokes(true);

  }

#if defined(X86) && defined(TIERED)

  // C2 leave fpu stack dirty clean it

  if (UseSSE < 2) {

    int i;

    for ( i = 1; i <= 7 ; i++ ) {

      ffree(i);

    }

    if (!op->result_opr()->is_float_kind()) {

      ffree(0);

    }

  }

#endif // X86 && TIERED

}

void LIR_Assembler::emit_opLabel(LIR_OpLabel* op) {

  _masm->bind (*(op->label()));

}

void LIR_Assembler::emit_op1(LIR_Op1* op) {

  switch (op->code()) {

    case lir_move:

      if (op->move_kind() == lir_move_volatile) {

        assert(op->patch_code() == lir_patch_none, "can't patch volatiles");

        volatile_move_op(op->in_opr(), op->result_opr(), op->type(), op->info());

      } else {

        move_op(op->in_opr(), op->result_opr(), op->type(),

                op->patch_code(), op->info(), op->pop_fpu_stack(),

                op->move_kind() == lir_move_unaligned,

                op->move_kind() == lir_move_wide);

      }

      break;

    case lir_roundfp: {

      LIR_OpRoundFP* round_op = op->as_OpRoundFP();

      roundfp_op(round_op->in_opr(), round_op->tmp(), round_op->result_opr(), round_op->pop_fpu_stack());

      break;

    }