/*

 * Copyright (c) 2008, 2018, 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_FrameMap.hpp"

#include "c1/c1_Instruction.hpp"

#include "c1/c1_LIRAssembler.hpp"

#include "c1/c1_LIRGenerator.hpp"

#include "c1/c1_Runtime1.hpp"

#include "c1/c1_ValueStack.hpp"

#include "ci/ciArray.hpp"

#include "ci/ciObjArrayKlass.hpp"

#include "ci/ciTypeArrayKlass.hpp"

#include "ci/ciUtilities.hpp"

#include "gc/shared/c1/barrierSetC1.hpp"

#include "gc/shared/cardTable.hpp"

#include "gc/shared/cardTableBarrierSet.hpp"

#include "runtime/sharedRuntime.hpp"

#include "runtime/stubRoutines.hpp"

#include "vmreg_arm.inline.hpp"

#ifdef ASSERT

#define __ gen()->lir(__FILE__, __LINE__)->

#else

#define __ gen()->lir()->

#endif

void LIRItem::load_byte_item() {

  load_item();

}

void LIRItem::load_nonconstant() {

  LIR_Opr r = value()->operand();

  if (_gen->can_inline_as_constant(value())) {

    if (!r->is_constant()) {

      r = LIR_OprFact::value_type(value()->type());

    }

    _result = r;

  } else {

    load_item();

  }

}

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

//               LIRGenerator

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

LIR_Opr LIRGenerator::exceptionOopOpr() {

  return FrameMap::Exception_oop_opr;

}

LIR_Opr LIRGenerator::exceptionPcOpr()  {

  return FrameMap::Exception_pc_opr;

}

LIR_Opr LIRGenerator::syncLockOpr()     {

  return new_register(T_INT);

}

LIR_Opr LIRGenerator::syncTempOpr()     {

  return new_register(T_OBJECT);

}

LIR_Opr LIRGenerator::getThreadTemp()   {

  return LIR_OprFact::illegalOpr;

}

LIR_Opr LIRGenerator::atomicLockOpr() {

  return LIR_OprFact::illegalOpr;

}

LIR_Opr LIRGenerator::result_register_for(ValueType* type, bool callee) {

  LIR_Opr opr;

  switch (type->tag()) {

    case intTag:     opr = FrameMap::Int_result_opr;    break;

    case objectTag:  opr = FrameMap::Object_result_opr; break;

    case longTag:    opr = FrameMap::Long_result_opr;   break;

    case floatTag:   opr = FrameMap::Float_result_opr;  break;

    case doubleTag:  opr = FrameMap::Double_result_opr; break;

    case addressTag:

    default: ShouldNotReachHere(); return LIR_OprFact::illegalOpr;

  }

  assert(opr->type_field() == as_OprType(as_BasicType(type)), "type mismatch");

  return opr;

}

LIR_Opr LIRGenerator::rlock_byte(BasicType type) {

  return new_register(T_INT);

}

//--------- loading items into registers --------------------------------

bool LIRGenerator::can_store_as_constant(Value v, BasicType type) const {

#ifdef AARCH64

  if (v->type()->as_IntConstant() != NULL) {

    return v->type()->as_IntConstant()->value() == 0;

  } else if (v->type()->as_LongConstant() != NULL) {

    return v->type()->as_LongConstant()->value() == 0;

  } else if (v->type()->as_ObjectConstant() != NULL) {

    return v->type()->as_ObjectConstant()->value()->is_null_object();

  } else if (v->type()->as_FloatConstant() != NULL) {

    return jint_cast(v->type()->as_FloatConstant()->value()) == 0;

  } else if (v->type()->as_DoubleConstant() != NULL) {

    return jlong_cast(v->type()->as_DoubleConstant()->value()) == 0;

  }

#endif // AARCH64

  return false;

}

bool LIRGenerator::can_inline_as_constant(Value v) const {

  if (v->type()->as_IntConstant() != NULL) {

    return Assembler::is_arith_imm_in_range(v->type()->as_IntConstant()->value());

  } else if (v->type()->as_ObjectConstant() != NULL) {

    return v->type()->as_ObjectConstant()->value()->is_null_object();

#ifdef AARCH64

  } else if (v->type()->as_LongConstant() != NULL) {

    return Assembler::is_arith_imm_in_range(v->type()->as_LongConstant()->value());

#else

  } else if (v->type()->as_FloatConstant() != NULL) {

    return v->type()->as_FloatConstant()->value() == 0.0f;

  } else if (v->type()->as_DoubleConstant() != NULL) {

    return v->type()->as_DoubleConstant()->value() == 0.0;

#endif // AARCH64

  }

  return false;

}

bool LIRGenerator::can_inline_as_constant(LIR_Const* c) const {

  ShouldNotCallThis(); // Not used on ARM

  return false;

}

#ifdef AARCH64

static bool can_inline_as_constant_in_cmp(Value v) {

  jlong constant;

  if (v->type()->as_IntConstant() != NULL) {

    constant = v->type()->as_IntConstant()->value();

  } else if (v->type()->as_LongConstant() != NULL) {

    constant = v->type()->as_LongConstant()->value();

  } else if (v->type()->as_ObjectConstant() != NULL) {

    return v->type()->as_ObjectConstant()->value()->is_null_object();

  } else if (v->type()->as_FloatConstant() != NULL) {

    return v->type()->as_FloatConstant()->value() == 0.0f;

  } else if (v->type()->as_DoubleConstant() != NULL) {

    return v->type()->as_DoubleConstant()->value() == 0.0;

  } else {

    return false;

  }

  return Assembler::is_arith_imm_in_range(constant) || Assembler::is_arith_imm_in_range(-constant);

}

static bool can_inline_as_constant_in_logic(Value v) {

  if (v->type()->as_IntConstant() != NULL) {

    return Assembler::LogicalImmediate(v->type()->as_IntConstant()->value(), true).is_encoded();

  } else if (v->type()->as_LongConstant() != NULL) {

    return Assembler::LogicalImmediate(v->type()->as_LongConstant()->value(), false).is_encoded();

  }

  return false;

}

#endif // AARCH64

LIR_Opr LIRGenerator::safepoint_poll_register() {

  return LIR_OprFact::illegalOpr;

}

static LIR_Opr make_constant(BasicType type, jlong c) {

  switch (type) {

    case T_ADDRESS:

    case T_OBJECT:  return LIR_OprFact::intptrConst(c);

    case T_LONG:    return LIR_OprFact::longConst(c);

    case T_INT:     return LIR_OprFact::intConst(c);

    default: ShouldNotReachHere();

    return LIR_OprFact::intConst(-1);

  }

}

#ifdef AARCH64

void LIRGenerator::add_constant(LIR_Opr src, jlong c, LIR_Opr dest) {

  if (c == 0) {

    __ move(src, dest);

    return;

  }

  BasicType type = src->type();

  bool is_neg = (c < 0);

  c = ABS(c);

  if ((c >> 24) == 0) {

    for (int shift = 0; shift <= 12; shift += 12) {

      int part = ((int)c) & (right_n_bits(12) << shift);

      if (part != 0) {

        if (is_neg) {

          __ sub(src, make_constant(type, part), dest);

        } else {

          __ add(src, make_constant(type, part), dest);

        }

        src = dest;

      }

    }

  } else {

    __ move(make_constant(type, c), dest);

    if (is_neg) {

      __ sub(src, dest, dest);

    } else {

      __ add(src, dest, dest);

    }

  }

}

#endif // AARCH64

void LIRGenerator::add_large_constant(LIR_Opr src, int c, LIR_Opr dest) {

  assert(c != 0, "must be");

#ifdef AARCH64

  add_constant(src, c, dest);

#else

  // Find first non-zero bit

  int shift = 0;

  while ((c & (3 << shift)) == 0) {

    shift += 2;

  }

  // Add the least significant part of the constant

  int mask = 0xff << shift;

  __ add(src, LIR_OprFact::intConst(c & mask), dest);

  // Add up to 3 other parts of the constant;

  // each of them can be represented as rotated_imm

  if (c & (mask << 8)) {

    __ add(dest, LIR_OprFact::intConst(c & (mask << 8)), dest);

  }

  if (c & (mask << 16)) {

    __ add(dest, LIR_OprFact::intConst(c & (mask << 16)), dest);

  }

  if (c & (mask << 24)) {

    __ add(dest, LIR_OprFact::intConst(c & (mask << 24)), dest);

  }

#endif // AARCH64

}

static LIR_Address* make_address(LIR_Opr base, LIR_Opr index, LIR_Address::Scale scale, BasicType type) {

  return new LIR_Address(base, index, scale, 0, type);

}

LIR_Address* LIRGenerator::generate_address(LIR_Opr base, LIR_Opr index,

                                            int shift, int disp, BasicType type) {

  assert(base->is_register(), "must be");

  if (index->is_constant()) {

    disp += index->as_constant_ptr()->as_jint() << shift;

    index = LIR_OprFact::illegalOpr;

  }

#ifndef AARCH64

  if (base->type() == T_LONG) {

    LIR_Opr tmp = new_register(T_INT);

    __ convert(Bytecodes::_l2i, base, tmp);

    base = tmp;

  }

  if (index != LIR_OprFact::illegalOpr && index->type() == T_LONG) {

    LIR_Opr tmp = new_register(T_INT);

    __ convert(Bytecodes::_l2i, index, tmp);

    index = tmp;

  }

  // At this point base and index should be all ints and not constants

  assert(base->is_single_cpu() && !base->is_constant(), "base should be an non-constant int");

  assert(index->is_illegal() || (index->type() == T_INT && !index->is_constant()), "index should be an non-constant int");

#endif

  int max_disp;

  bool disp_is_in_range;

  bool embedded_shift;

#ifdef AARCH64

  int align = exact_log2(type2aelembytes(type, true));

  assert((disp & right_n_bits(align)) == 0, "displacement is not aligned");

  assert(shift == 0 || shift == align, "shift should be zero or equal to embedded align");

  max_disp = (1 << 12) << align;

  if (disp >= 0) {

    disp_is_in_range = Assembler::is_unsigned_imm_in_range(disp, 12, align);

  } else {

    disp_is_in_range = Assembler::is_imm_in_range(disp, 9, 0);

  }

  embedded_shift = true;

#else

  switch (type) {

    case T_BYTE:

    case T_SHORT:

    case T_CHAR:

      max_disp = 256;          // ldrh, ldrsb encoding has 8-bit offset

      embedded_shift = false;

      break;

    case T_FLOAT:

    case T_DOUBLE:

      max_disp = 1024;         // flds, fldd have 8-bit offset multiplied by 4

      embedded_shift = false;

      break;

    case T_LONG:

      max_disp = 4096;

      embedded_shift = false;

      break;

    default:

      max_disp = 4096;         // ldr, ldrb allow 12-bit offset

      embedded_shift = true;

  }

  disp_is_in_range = (-max_disp < disp && disp < max_disp);

#endif // !AARCH64

  if (index->is_register()) {

    LIR_Opr tmp = new_pointer_register();

    if (!disp_is_in_range) {

      add_large_constant(base, disp, tmp);

      base = tmp;

      disp = 0;

    }

    LIR_Address* addr = make_address(base, index, (LIR_Address::Scale)shift, type);

    if (disp == 0 && embedded_shift) {

      // can use ldr/str instruction with register index

      return addr;

    } else {

      LIR_Opr tmp = new_pointer_register();

      __ add(base, LIR_OprFact::address(addr), tmp); // add with shifted/extended register

      return new LIR_Address(tmp, disp, type);

    }

  }

  // If the displacement is too large to be inlined into LDR instruction,

  // generate large constant with additional sequence of ADD instructions

  int excess_disp = disp & ~(max_disp - 1);

  if (excess_disp != 0) {

    LIR_Opr tmp = new_pointer_register();

    add_large_constant(base, excess_disp, tmp);

    base = tmp;

  }

  return new LIR_Address(base, disp & (max_disp - 1), type);

}

LIR_Address* LIRGenerator::emit_array_address(LIR_Opr array_opr, LIR_Opr index_opr, BasicType type) {

  int base_offset = arrayOopDesc::base_offset_in_bytes(type);

  int elem_size = type2aelembytes(type);

  if (index_opr->is_constant()) {

    int offset = base_offset + index_opr->as_constant_ptr()->as_jint() * elem_size;

    return generate_address(array_opr, offset, type);

  } else {

    assert(index_opr->is_register(), "must be");

    int scale = exact_log2(elem_size);

    return generate_address(array_opr, index_opr, scale, base_offset, type);

  }

}

LIR_Opr LIRGenerator::load_immediate(int x, BasicType type) {

  assert(type == T_LONG || type == T_INT, "should be");

  LIR_Opr r = make_constant(type, x);

#ifdef AARCH64

  bool imm_in_range = Assembler::LogicalImmediate(x, type == T_INT).is_encoded();

#else

  bool imm_in_range = AsmOperand::is_rotated_imm(x);

#endif // AARCH64

  if (!imm_in_range) {

    LIR_Opr tmp = new_register(type);

    __ move(r, tmp);

    return tmp;

  }

  return r;

}

void LIRGenerator::increment_counter(address counter, BasicType type, int step) {

  LIR_Opr pointer = new_pointer_register();

  __ move(LIR_OprFact::intptrConst(counter), pointer);

  LIR_Address* addr = new LIR_Address(pointer, type);

  increment_counter(addr, step);

}

void LIRGenerator::increment_counter(LIR_Address* addr, int step) {

  LIR_Opr temp = new_register(addr->type());

  __ move(addr, temp);

  __ add(temp, make_constant(addr->type(), step), temp);

  __ move(temp, addr);

}

void LIRGenerator::cmp_mem_int(LIR_Condition condition, LIR_Opr base, int disp, int c, CodeEmitInfo* info) {

  __ load(new LIR_Address(base, disp, T_INT), FrameMap::LR_opr, info);

  __ cmp(condition, FrameMap::LR_opr, c);

}

void LIRGenerator::cmp_reg_mem(LIR_Condition condition, LIR_Opr reg, LIR_Opr base, int disp, BasicType type, CodeEmitInfo* info) {

  __ load(new LIR_Address(base, disp, type), FrameMap::LR_opr, info);

  __ cmp(condition, reg, FrameMap::LR_opr);

}

bool LIRGenerator::strength_reduce_multiply(LIR_Opr left, int c, LIR_Opr result, LIR_Opr tmp) {

  assert(left != result, "should be different registers");

  if (is_power_of_2(c + 1)) {

#ifdef AARCH64

    __ shift_left(left, log2_intptr(c + 1), result);

    __ sub(result, left, result);

#else

    LIR_Address::Scale scale = (LIR_Address::Scale) log2_intptr(c + 1);

    LIR_Address* addr = new LIR_Address(left, left, scale, 0, T_INT);

    __ sub(LIR_OprFact::address(addr), left, result); // rsb with shifted register

#endif // AARCH64

    return true;

  } else if (is_power_of_2(c - 1)) {

    LIR_Address::Scale scale = (LIR_Address::Scale) log2_intptr(c - 1);

    LIR_Address* addr = new LIR_Address(left, left, scale, 0, T_INT);

    __ add(left, LIR_OprFact::address(addr), result); // add with shifted register

    return true;

  }

  return false;

}

void LIRGenerator::store_stack_parameter(LIR_Opr item, ByteSize offset_from_sp) {

  assert(item->type() == T_INT, "other types are not expected");

  __ store(item, new LIR_Address(FrameMap::SP_opr, in_bytes(offset_from_sp), item->type()));

}

void LIRGenerator::set_card(LIR_Opr value, LIR_Address* card_addr) {

  assert(CardTable::dirty_card_val() == 0,

    "Cannot use ZR register (aarch64) or the register containing the card table base address directly (aarch32) otherwise");

#ifdef AARCH64

  // AARCH64 has a register that is constant zero. We can use that one to set the

  // value in the card table to dirty.

  __ move(FrameMap::ZR_opr, card_addr);

#else // AARCH64

  if((ci_card_table_address_as<intx>() & 0xff) == 0) {

    // If the card table base address is aligned to 256 bytes, we can use the register

    // that contains the card_table_base_address.

    __ move(value, card_addr);

  } else {

    // Otherwise we need to create a register containing that value.

    LIR_Opr tmp_zero = new_register(T_INT);

    __ move(LIR_OprFact::intConst(CardTable::dirty_card_val()), tmp_zero);

    __ move(tmp_zero, card_addr);

  }

#endif // AARCH64

}

void LIRGenerator::CardTableBarrierSet_post_barrier_helper(LIR_OprDesc* addr, LIR_Const* card_table_base) {

  assert(addr->is_register(), "must be a register at this point");

  CardTableBarrierSet* ctbs = barrier_set_cast<CardTableBarrierSet>(BarrierSet::barrier_set());

  CardTable* ct = ctbs->card_table();

  LIR_Opr tmp = FrameMap::LR_ptr_opr;

  // TODO-AARCH64: check performance

  bool load_card_table_base_const = AARCH64_ONLY(false) NOT_AARCH64(VM_Version::supports_movw());

  if (load_card_table_base_const) {

    __ move((LIR_Opr)card_table_base, tmp);

  } else {

    __ move(new LIR_Address(FrameMap::Rthread_opr, in_bytes(JavaThread::card_table_base_offset()), T_ADDRESS), tmp);

  }

#ifdef AARCH64

  LIR_Address* shifted_reg_operand = new LIR_Address(tmp, addr, (LIR_Address::Scale) -CardTable::card_shift, 0, T_BYTE);

  LIR_Opr tmp2 = tmp;

  __ add(tmp, LIR_OprFact::address(shifted_reg_operand), tmp2); // tmp2 = tmp + (addr >> CardTable::card_shift)

  LIR_Address* card_addr = new LIR_Address(tmp2, T_BYTE);

#else

  // Use unsigned type T_BOOLEAN here rather than (signed) T_BYTE since signed load

  // byte instruction does not support the addressing mode we need.

  LIR_Address* card_addr = new LIR_Address(tmp, addr, (LIR_Address::Scale) -CardTable::card_shift, 0, T_BOOLEAN);

#endif

  if (UseCondCardMark) {

    if (ct->scanned_concurrently()) {

      __ membar_storeload();

    }

    LIR_Opr cur_value = new_register(T_INT);

    __ move(card_addr, cur_value);

    LabelObj* L_already_dirty = new LabelObj();

    __ cmp(lir_cond_equal, cur_value, LIR_OprFact::intConst(CardTable::dirty_card_val()));

    __ branch(lir_cond_equal, T_BYTE, L_already_dirty->label());

    set_card(tmp, card_addr);

    __ branch_destination(L_already_dirty->label());

  } else {