src/hotspot/cpu/arm/c1_LIRGenerator_arm.cpp - master - githubmirror/galahad

src/hotspot/cpu/arm/c1_LIRGenerator_arm.cpp
1 338 строк44 KB
Zihao Lin
8370878: C1: Clean up unnecessary ConversionStub constructor
06 ноя 2025, 10:19
06 ноя 2025, 10:19ac9cf5d
/*
 * Copyright (c) 2008, 2025, 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 "asm/macroAssembler.inline.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 "utilities/powerOfTwo.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 {
  return false;
}


bool LIRGenerator::can_inline_as_constant(Value v) const {
  if (v->type()->as_IntConstant() != nullptr) {
    return Assembler::is_arith_imm_in_range(v->type()->as_IntConstant()->value());
  } else if (v->type()->as_ObjectConstant() != nullptr) {
    return v->type()->as_ObjectConstant()->value()->is_null_object();
  } else if (v->type()->as_FloatConstant() != nullptr) {
    return v->type()->as_FloatConstant()->value() == 0.0f;
  } else if (v->type()->as_DoubleConstant() != nullptr) {
    return v->type()->as_DoubleConstant()->value() == 0.0;
  }
  return false;
}


bool LIRGenerator::can_inline_as_constant(LIR_Const* c) const {
  ShouldNotCallThis(); // Not used on ARM
  return false;
}




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);
  }
}



void LIRGenerator::add_large_constant(LIR_Opr src, int c, LIR_Opr dest) {
  assert(c != 0, "must be");
  // 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);
  }
}

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;
  }

  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");

  int max_disp;
  bool disp_is_in_range;
  bool embedded_shift;

  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);

  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(jlong x, BasicType type) {
  assert(type == T_LONG || type == T_INT, "should be");
  LIR_Opr r = make_constant(type, x);
  bool imm_in_range = AsmOperand::is_rotated_imm((unsigned int)(x));
  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, jint c, LIR_Opr result, LIR_Opr tmp) {
  assert(left != result, "should be different registers");
  juint u_value = (juint)c;
  if (is_power_of_2(u_value + 1)) {
    LIR_Address::Scale scale = (LIR_Address::Scale) log2i_exact(u_value + 1);
    LIR_Address* addr = new LIR_Address(left, left, scale, 0, T_INT);
    __ sub(LIR_OprFact::address(addr), left, result); // rsb with shifted register
    return true;
  } else if (is_power_of_2(u_value - 1)) {
    LIR_Address::Scale scale = (LIR_Address::Scale) log2i_exact(u_value - 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;
  } else if (c == -1) {
    __ negate(left, result);
    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 the register containing the card table base address directly");
  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);
  }
}

void LIRGenerator::CardTableBarrierSet_post_barrier_helper(LIR_Opr addr, LIR_Const* card_table_base) {
  assert(addr->is_register(), "must be a register at this point");

  LIR_Opr tmp = FrameMap::LR_ptr_opr;

  bool load_card_table_base_const = 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);
  }

  // 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);
  if (UseCondCardMark) {
    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, L_already_dirty->label());
    set_card(tmp, card_addr);
    __ branch_destination(L_already_dirty->label());
  } else {
    set_card(tmp, card_addr);
  }
}

void LIRGenerator::array_store_check(LIR_Opr value, LIR_Opr array, CodeEmitInfo* store_check_info, ciMethod* profiled_method, int profiled_bci) {
  LIR_Opr tmp1 = FrameMap::R0_oop_opr;
  LIR_Opr tmp2 = FrameMap::R1_oop_opr;
  LIR_Opr tmp3 = LIR_OprFact::illegalOpr;
  __ store_check(value, array, tmp1, tmp2, tmp3, store_check_info, profiled_method, profiled_bci);
}

//----------------------------------------------------------------------
//             visitor functions
//----------------------------------------------------------------------

void LIRGenerator::do_MonitorEnter(MonitorEnter* x) {
  assert(x->is_pinned(),"");
  LIRItem obj(x->obj(), this);
  obj.load_item();
  set_no_result(x);

  LIR_Opr lock = new_pointer_register();
  LIR_Opr hdr  = new_pointer_register();

  CodeEmitInfo* info_for_exception = nullptr;
  if (x->needs_null_check()) {
    info_for_exception = state_for(x);
  }

  CodeEmitInfo* info = state_for(x, x->state(), true);
  monitor_enter(obj.result(), lock, hdr, LIR_OprFact::illegalOpr,
                x->monitor_no(), info_for_exception, info);
}


void LIRGenerator::do_MonitorExit(MonitorExit* x) {
  assert(x->is_pinned(),"");
  LIRItem obj(x->obj(), this);
  obj.dont_load_item();
  set_no_result(x);

  LIR_Opr obj_temp = new_pointer_register();
  LIR_Opr lock     = new_pointer_register();
  LIR_Opr hdr      = new_pointer_register();

  monitor_exit(obj_temp, lock, hdr, atomicLockOpr(), x->monitor_no());
}


// _ineg, _lneg, _fneg, _dneg
void LIRGenerator::do_NegateOp(NegateOp* x) {
#ifdef __SOFTFP__
  address runtime_func = nullptr;
  ValueTag tag = x->type()->tag();
  if (tag == floatTag) {
    runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::fneg);
  } else if (tag == doubleTag) {
    runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dneg);
  }
  if (runtime_func != nullptr) {
    set_result(x, call_runtime(x->x(), runtime_func, x->type(), nullptr));
    return;
  }
#endif // __SOFTFP__
  LIRItem value(x->x(), this);
  value.load_item();
  LIR_Opr reg = rlock_result(x);
  __ negate(value.result(), reg);
}


// for  _fadd, _fmul, _fsub, _fdiv, _frem
//      _dadd, _dmul, _dsub, _ddiv, _drem
void LIRGenerator::do_ArithmeticOp_FPU(ArithmeticOp* x) {
  address runtime_func;
  switch (x->op()) {
    case Bytecodes::_frem:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::frem);
      break;
    case Bytecodes::_drem:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::drem);
      break;
#ifdef __SOFTFP__
    // Call function compiled with -msoft-float.

      // __aeabi_XXXX_glibc: Imported code from glibc soft-fp bundle for calculation accuracy improvement. See CR 6757269.

    case Bytecodes::_fadd:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fadd_glibc);
      break;
    case Bytecodes::_fmul:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fmul);
      break;
    case Bytecodes::_fsub:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fsub_glibc);
      break;
    case Bytecodes::_fdiv:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_fdiv);
      break;
    case Bytecodes::_dadd:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dadd_glibc);
      break;
    case Bytecodes::_dmul:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dmul);
      break;
    case Bytecodes::_dsub:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_dsub_glibc);
      break;
    case Bytecodes::_ddiv:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_ddiv);
      break;
    default:
      ShouldNotReachHere();
#else // __SOFTFP__
    default: {
      LIRItem left(x->x(), this);
      LIRItem right(x->y(), this);
      left.load_item();
      right.load_item();
      rlock_result(x);
      arithmetic_op_fpu(x->op(), x->operand(), left.result(), right.result());
      return;
    }
#endif // __SOFTFP__
  }

  LIR_Opr result = call_runtime(x->x(), x->y(), runtime_func, x->type(), nullptr);
  set_result(x, result);
}


void LIRGenerator::make_div_by_zero_check(LIR_Opr right_arg, BasicType type, CodeEmitInfo* info) {
  assert(right_arg->is_register(), "must be");
  __ cmp(lir_cond_equal, right_arg, make_constant(type, 0));
  __ branch(lir_cond_equal, new DivByZeroStub(info));
}


// for  _ladd, _lmul, _lsub, _ldiv, _lrem
void LIRGenerator::do_ArithmeticOp_Long(ArithmeticOp* x) {
  CodeEmitInfo* info = nullptr;
  if (x->op() == Bytecodes::_ldiv || x->op() == Bytecodes::_lrem) {
    info = state_for(x);
  }

  switch (x->op()) {
    case Bytecodes::_ldiv:
    case Bytecodes::_lrem: {
      LIRItem right(x->y(), this);
      right.load_item();
      make_div_by_zero_check(right.result(), T_LONG, info);
    }
    // Fall through
    case Bytecodes::_lmul: {
      address entry;
      switch (x->op()) {
      case Bytecodes::_lrem:
        entry = CAST_FROM_FN_PTR(address, SharedRuntime::lrem);
        break;
      case Bytecodes::_ldiv:
        entry = CAST_FROM_FN_PTR(address, SharedRuntime::ldiv);
        break;
      case Bytecodes::_lmul:
        entry = CAST_FROM_FN_PTR(address, SharedRuntime::lmul);
        break;
      default:
        ShouldNotReachHere();
        return;
      }
      LIR_Opr result = call_runtime(x->y(), x->x(), entry, x->type(), nullptr);
      set_result(x, result);
      break;
    }
    case Bytecodes::_ladd:
    case Bytecodes::_lsub: {
      LIRItem left(x->x(), this);
      LIRItem right(x->y(), this);
      left.load_item();
      right.load_item();
      rlock_result(x);
      arithmetic_op_long(x->op(), x->operand(), left.result(), right.result(), nullptr);
      break;
    }
    default:
      ShouldNotReachHere();
  }
}


// for: _iadd, _imul, _isub, _idiv, _irem
void LIRGenerator::do_ArithmeticOp_Int(ArithmeticOp* x) {
  bool is_div_rem = x->op() == Bytecodes::_idiv || x->op() == Bytecodes::_irem;
  LIRItem left(x->x(), this);
  LIRItem right(x->y(), this);
  LIRItem* left_arg = &left;
  LIRItem* right_arg = &right;

  // Test if instr is commutative and if we should swap
  if (x->is_commutative() && left.is_constant()) {
    left_arg = &right;
    right_arg = &left;
  }

  if (is_div_rem) {
    CodeEmitInfo* info = state_for(x);
    if (x->op() == Bytecodes::_idiv && right_arg->is_constant() && is_power_of_2(right_arg->get_jint_constant())) {
      left_arg->load_item();
      right_arg->dont_load_item();
      LIR_Opr tmp = LIR_OprFact::illegalOpr;
      LIR_Opr result = rlock_result(x);
      __ idiv(left_arg->result(), right_arg->result(), result, tmp, info);
    } else {
      left_arg->load_item_force(FrameMap::R0_opr);
      right_arg->load_item_force(FrameMap::R2_opr);
      LIR_Opr tmp = FrameMap::R1_opr;
      LIR_Opr result = rlock_result(x);
      LIR_Opr out_reg;
      if (x->op() == Bytecodes::_irem) {
        out_reg = FrameMap::R0_opr;
        __ irem(left_arg->result(), right_arg->result(), out_reg, tmp, info);
      } else { // (x->op() == Bytecodes::_idiv)
        out_reg = FrameMap::R1_opr;
        __ idiv(left_arg->result(), right_arg->result(), out_reg, tmp, info);
      }
      __ move(out_reg, result);
    }


  } else {
    left_arg->load_item();
    if (x->op() == Bytecodes::_imul && right_arg->is_constant()) {
      jint c = right_arg->get_jint_constant();
      if (c > 0 && c < max_jint && (is_power_of_2(c) || is_power_of_2(c - 1) || is_power_of_2(c + 1))) {
        right_arg->dont_load_item();
      } else {
        right_arg->load_item();
      }
    } else {
      right_arg->load_nonconstant();
    }
    rlock_result(x);
    assert(right_arg->is_constant() || right_arg->is_register(), "wrong state of right");
    arithmetic_op_int(x->op(), x->operand(), left_arg->result(), right_arg->result(), LIR_OprFact::nullOpr);
  }
}


void LIRGenerator::do_ArithmeticOp(ArithmeticOp* x) {
  ValueTag tag = x->type()->tag();
  assert(x->x()->type()->tag() == tag && x->y()->type()->tag() == tag, "wrong parameters");
  switch (tag) {
    case floatTag:
    case doubleTag:  do_ArithmeticOp_FPU(x);  return;
    case longTag:    do_ArithmeticOp_Long(x); return;
    case intTag:     do_ArithmeticOp_Int(x);  return;
    default:         ShouldNotReachHere();    return;
  }
}


// _ishl, _lshl, _ishr, _lshr, _iushr, _lushr
void LIRGenerator::do_ShiftOp(ShiftOp* x) {
  LIRItem value(x->x(), this);
  LIRItem count(x->y(), this);

  if (value.type()->is_long()) {
    count.set_destroys_register();
  }

  if (count.is_constant()) {
    assert(count.type()->as_IntConstant() != nullptr, "should be");
    count.dont_load_item();
  } else {
    count.load_item();
  }
  value.load_item();

  LIR_Opr res = rlock_result(x);
  shift_op(x->op(), res, value.result(), count.result(), LIR_OprFact::illegalOpr);
}


// _iand, _land, _ior, _lor, _ixor, _lxor
void LIRGenerator::do_LogicOp(LogicOp* x) {
  LIRItem left(x->x(), this);
  LIRItem right(x->y(), this);

  left.load_item();

  right.load_nonconstant();

  logic_op(x->op(), rlock_result(x), left.result(), right.result());
}


// _lcmp, _fcmpl, _fcmpg, _dcmpl, _dcmpg
void LIRGenerator::do_CompareOp(CompareOp* x) {
#ifdef __SOFTFP__
  address runtime_func;
  switch (x->op()) {
    case Bytecodes::_fcmpl:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::fcmpl);
      break;
    case Bytecodes::_fcmpg:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::fcmpg);
      break;
    case Bytecodes::_dcmpl:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dcmpl);
      break;
    case Bytecodes::_dcmpg:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dcmpg);
      break;
    case Bytecodes::_lcmp: {
        LIRItem left(x->x(), this);
        LIRItem right(x->y(), this);
        left.load_item();
        right.load_nonconstant();
        LIR_Opr reg = rlock_result(x);
         __ lcmp2int(left.result(), right.result(), reg);
        return;
      }
    default:
      ShouldNotReachHere();
  }
  LIR_Opr result = call_runtime(x->x(), x->y(), runtime_func, x->type(), nullptr);
  set_result(x, result);
#else // __SOFTFP__
  LIRItem left(x->x(), this);
  LIRItem right(x->y(), this);
  left.load_item();

  right.load_nonconstant();

  LIR_Opr reg = rlock_result(x);

  if (x->x()->type()->is_float_kind()) {
    Bytecodes::Code code = x->op();
    __ fcmp2int(left.result(), right.result(), reg, (code == Bytecodes::_fcmpl || code == Bytecodes::_dcmpl));
  } else if (x->x()->type()->tag() == longTag) {
    __ lcmp2int(left.result(), right.result(), reg);
  } else {
    ShouldNotReachHere();
  }
#endif // __SOFTFP__
}

LIR_Opr LIRGenerator::atomic_cmpxchg(BasicType type, LIR_Opr addr, LIRItem& cmp_value, LIRItem& new_value) {
  LIR_Opr ill = LIR_OprFact::illegalOpr;  // for convenience
  LIR_Opr tmp1 = LIR_OprFact::illegalOpr;
  LIR_Opr tmp2 = LIR_OprFact::illegalOpr;
  new_value.load_item();
  cmp_value.load_item();
  LIR_Opr result = new_register(T_INT);
  if (type == T_OBJECT || type == T_ARRAY) {
    __ cas_obj(addr, cmp_value.result(), new_value.result(), new_register(T_INT), new_register(T_INT), result);
  } else if (type == T_INT) {
    __ cas_int(addr->as_address_ptr()->base(), cmp_value.result(), new_value.result(), tmp1, tmp1, result);
  } else if (type == T_LONG) {
    tmp1 = new_register(T_LONG);
    __ cas_long(addr->as_address_ptr()->base(), cmp_value.result(), new_value.result(), tmp1, tmp2, result);
  } else {
    ShouldNotReachHere();
  }
  return result;
}

LIR_Opr LIRGenerator::atomic_xchg(BasicType type, LIR_Opr addr, LIRItem& value) {
  bool is_oop = type == T_OBJECT || type == T_ARRAY;
  LIR_Opr result = new_register(type);
  value.load_item();
  assert(type == T_INT || is_oop || (type == T_LONG && VM_Version::supports_ldrexd()), "unexpected type");
  LIR_Opr tmp = (UseCompressedOops && is_oop) ? new_pointer_register() : LIR_OprFact::illegalOpr;
  __ xchg(addr, value.result(), result, tmp);
  return result;
}

LIR_Opr LIRGenerator::atomic_add(BasicType type, LIR_Opr addr, LIRItem& value) {
  LIR_Opr result = new_register(type);
  value.load_item();
  assert(type == T_INT || (type == T_LONG && VM_Version::supports_ldrexd ()), "unexpected type");
  LIR_Opr tmp = new_register(type);
  __ xadd(addr, value.result(), result, tmp);
  return result;
}

void LIRGenerator::do_MathIntrinsic(Intrinsic* x) {
  address runtime_func;
  switch (x->id()) {
    case vmIntrinsics::_dabs: {
#ifdef __SOFTFP__
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dabs);
      break;
#else
      assert(x->number_of_arguments() == 1, "wrong type");
      LIRItem value(x->argument_at(0), this);
      value.load_item();
      __ abs(value.result(), rlock_result(x), LIR_OprFact::illegalOpr);
      return;
#endif // __SOFTFP__
    }
    case vmIntrinsics::_dsqrt:
    case vmIntrinsics::_dsqrt_strict: {
#ifdef __SOFTFP__
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dsqrt);
      break;
#else
      assert(x->number_of_arguments() == 1, "wrong type");
      LIRItem value(x->argument_at(0), this);
      value.load_item();
      __ sqrt(value.result(), rlock_result(x), LIR_OprFact::illegalOpr);
      return;
#endif // __SOFTFP__
    }
    case vmIntrinsics::_dsin:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dsin);
      break;
    case vmIntrinsics::_dcos:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dcos);
      break;
    case vmIntrinsics::_dtan:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dtan);
      break;
    case vmIntrinsics::_dlog:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dlog);
      break;
    case vmIntrinsics::_dlog10:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dlog10);
      break;
    case vmIntrinsics::_dexp:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dexp);
      break;
    case vmIntrinsics::_dpow:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::dpow);
      break;
    default:
      ShouldNotReachHere();
      return;
  }

  LIR_Opr result;
  if (x->number_of_arguments() == 1) {
    result = call_runtime(x->argument_at(0), runtime_func, x->type(), nullptr);
  } else {
    assert(x->number_of_arguments() == 2 && x->id() == vmIntrinsics::_dpow, "unexpected intrinsic");
    result = call_runtime(x->argument_at(0), x->argument_at(1), runtime_func, x->type(), nullptr);
  }
  set_result(x, result);
}

void LIRGenerator::do_FmaIntrinsic(Intrinsic* x) {
  fatal("FMA intrinsic is not implemented on this platform");
}

void LIRGenerator::do_vectorizedMismatch(Intrinsic* x) {
  fatal("vectorizedMismatch intrinsic is not implemented on this platform");
}

void LIRGenerator::do_ArrayCopy(Intrinsic* x) {
  CodeEmitInfo* info = state_for(x, x->state());
  assert(x->number_of_arguments() == 5, "wrong type");
  LIRItem src(x->argument_at(0), this);
  LIRItem src_pos(x->argument_at(1), this);
  LIRItem dst(x->argument_at(2), this);
  LIRItem dst_pos(x->argument_at(3), this);
  LIRItem length(x->argument_at(4), this);

  // We put arguments into the same registers which are used for a Java call.
  // Note: we used fixed registers for all arguments because all registers
  // are caller-saved, so register allocator treats them all as used.
  src.load_item_force    (FrameMap::R0_oop_opr);
  src_pos.load_item_force(FrameMap::R1_opr);
  dst.load_item_force    (FrameMap::R2_oop_opr);
  dst_pos.load_item_force(FrameMap::R3_opr);
  length.load_item_force (FrameMap::R4_opr);
  LIR_Opr tmp =          (FrameMap::R5_opr);
  set_no_result(x);

  int flags;
  ciArrayKlass* expected_type;
  arraycopy_helper(x, &flags, &expected_type);
  __ arraycopy(src.result(), src_pos.result(), dst.result(), dst_pos.result(), length.result(),
               tmp, expected_type, flags, info);
}

void LIRGenerator::do_update_CRC32(Intrinsic* x) {
  fatal("CRC32 intrinsic is not implemented on this platform");
}

void LIRGenerator::do_update_CRC32C(Intrinsic* x) {
  Unimplemented();
}

void LIRGenerator::do_Convert(Convert* x) {
  address runtime_func;
  switch (x->op()) {
    case Bytecodes::_l2f:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::l2f);
      break;
    case Bytecodes::_l2d:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::l2d);
      break;
    case Bytecodes::_f2l:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::f2l);
      break;
    case Bytecodes::_d2l:
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::d2l);
      break;
#ifdef __SOFTFP__
    case Bytecodes::_f2d:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_f2d);
      break;
    case Bytecodes::_d2f:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_d2f);
      break;
    case Bytecodes::_i2f:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_i2f);
      break;
    case Bytecodes::_i2d:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_i2d);
      break;
    case Bytecodes::_f2i:
      runtime_func = CAST_FROM_FN_PTR(address, __aeabi_f2iz);
      break;
    case Bytecodes::_d2i:
      // This is implemented in hard float in assembler on arm but a call
      // on other platforms.
      runtime_func = CAST_FROM_FN_PTR(address, SharedRuntime::d2i);
      break;
#endif // __SOFTFP__
    default: {
      LIRItem value(x->value(), this);
      value.load_item();
      LIR_Opr reg = rlock_result(x);
      __ convert(x->op(), value.result(), reg);
      return;
    }
  }

  LIR_Opr result = call_runtime(x->value(), runtime_func, x->type(), nullptr);
  set_result(x, result);
}


void LIRGenerator::do_NewInstance(NewInstance* x) {
  print_if_not_loaded(x);

  CodeEmitInfo* info = state_for(x, x->state());
  LIR_Opr reg = result_register_for(x->type());  // R0 is required by runtime call in NewInstanceStub::emit_code
  LIR_Opr klass_reg = FrameMap::R1_metadata_opr; // R1 is required by runtime call in NewInstanceStub::emit_code
  LIR_Opr tmp1 = new_register(objectType);
  LIR_Opr tmp2 = new_register(objectType);
  LIR_Opr tmp3 = FrameMap::LR_oop_opr;

  new_instance(reg, x->klass(), x->is_unresolved(), tmp1, tmp2, tmp3,
               LIR_OprFact::illegalOpr, klass_reg, info);

  LIR_Opr result = rlock_result(x);
  __ move(reg, result);
}


void LIRGenerator::do_NewTypeArray(NewTypeArray* x) {
  // Evaluate state_for() first, because it can emit code
  // with the same fixed registers that are used here (R1, R2)
  CodeEmitInfo* info = state_for(x, x->state());
  LIRItem length(x->length(), this);

  length.load_item_force(FrameMap::R2_opr);      // R2 is required by runtime call in NewTypeArrayStub::emit_code
  LIR_Opr len = length.result();

  LIR_Opr reg = result_register_for(x->type());  // R0 is required by runtime call in NewTypeArrayStub::emit_code
  LIR_Opr klass_reg = FrameMap::R1_metadata_opr; // R1 is required by runtime call in NewTypeArrayStub::emit_code

  LIR_Opr tmp1 = new_register(objectType);
  LIR_Opr tmp2 = new_register(objectType);
  LIR_Opr tmp3 = FrameMap::LR_oop_opr;
  LIR_Opr tmp4 = LIR_OprFact::illegalOpr;

  BasicType elem_type = x->elt_type();
  __ metadata2reg(ciTypeArrayKlass::make(elem_type)->constant_encoding(), klass_reg);

  CodeStub* slow_path = new NewTypeArrayStub(klass_reg, len, reg, info);
  __ allocate_array(reg, len, tmp1, tmp2, tmp3, tmp4, elem_type, klass_reg, slow_path);

  LIR_Opr result = rlock_result(x);
  __ move(reg, result);
}


void LIRGenerator::do_NewObjectArray(NewObjectArray* x) {
  // Evaluate state_for() first, because it can emit code
  // with the same fixed registers that are used here (R1, R2)
  CodeEmitInfo* info = state_for(x, x->state());
  LIRItem length(x->length(), this);

  length.load_item_force(FrameMap::R2_opr);           // R2 is required by runtime call in NewObjectArrayStub::emit_code
  LIR_Opr len = length.result();

  CodeEmitInfo* patching_info = nullptr;
  if (!x->klass()->is_loaded() || PatchALot) {
    patching_info = state_for(x, x->state_before());
  }

  LIR_Opr reg = result_register_for(x->type());       // R0 is required by runtime call in NewObjectArrayStub::emit_code
  LIR_Opr klass_reg = FrameMap::R1_metadata_opr;      // R1 is required by runtime call in NewObjectArrayStub::emit_code

  LIR_Opr tmp1 = new_register(objectType);
  LIR_Opr tmp2 = new_register(objectType);
  LIR_Opr tmp3 = FrameMap::LR_oop_opr;
  LIR_Opr tmp4 = LIR_OprFact::illegalOpr;

  CodeStub* slow_path = new NewObjectArrayStub(klass_reg, len, reg, info);
  ciMetadata* obj = ciObjArrayKlass::make(x->klass());
  if (obj == ciEnv::unloaded_ciobjarrayklass()) {
    BAILOUT("encountered unloaded_ciobjarrayklass due to out of memory error");
  }
  klass2reg_with_patching(klass_reg, obj, patching_info);
  __ allocate_array(reg, len, tmp1, tmp2, tmp3, tmp4, T_OBJECT, klass_reg, slow_path);

  LIR_Opr result = rlock_result(x);
  __ move(reg, result);
}


void LIRGenerator::do_NewMultiArray(NewMultiArray* x) {
  Values* dims = x->dims();
  int i = dims->length();
  LIRItemList* items = new LIRItemList(i, i, nullptr);
  while (i-- > 0) {
    LIRItem* size = new LIRItem(dims->at(i), this);
    items->at_put(i, size);
  }

  // Need to get the info before, as the items may become invalid through item_free
  CodeEmitInfo* patching_info = nullptr;
  if (!x->klass()->is_loaded() || PatchALot) {
    patching_info = state_for(x, x->state_before());

    // Cannot re-use same xhandlers for multiple CodeEmitInfos, so
    // clone all handlers (NOTE: Usually this is handled transparently
    // by the CodeEmitInfo cloning logic in CodeStub constructors but
    // is done explicitly here because a stub isn't being used).
    x->set_exception_handlers(new XHandlers(x->exception_handlers()));
  }

  i = dims->length();
  while (i-- > 0) {
    LIRItem* size = items->at(i);
    size->load_item();
    LIR_Opr sz = size->result();
    assert(sz->type() == T_INT, "should be");
    store_stack_parameter(sz, in_ByteSize(i * BytesPerInt));
  }

  CodeEmitInfo* info = state_for(x, x->state());
  LIR_Opr klass_reg = FrameMap::R0_metadata_opr;
  klass2reg_with_patching(klass_reg, x->klass(), patching_info);

  LIR_Opr rank = FrameMap::R2_opr;
  __ move(LIR_OprFact::intConst(x->rank()), rank);
  LIR_Opr varargs = FrameMap::SP_opr;
  LIR_OprList* args = new LIR_OprList(3);
  args->append(klass_reg);
  args->append(rank);
  args->append(varargs);
  LIR_Opr reg = result_register_for(x->type());
  __ call_runtime(Runtime1::entry_for(StubId::c1_new_multi_array_id),
                  LIR_OprFact::illegalOpr, reg, args, info);

  LIR_Opr result = rlock_result(x);
  __ move(reg, result);
}


void LIRGenerator::do_BlockBegin(BlockBegin* x) {
  // nothing to do for now
}


void LIRGenerator::do_CheckCast(CheckCast* x) {
  LIRItem obj(x->obj(), this);
  CodeEmitInfo* patching_info = nullptr;
  if (!x->klass()->is_loaded() || (PatchALot && !x->is_incompatible_class_change_check() && !x->is_invokespecial_receiver_check())) {
    patching_info = state_for(x, x->state_before());
  }

  obj.load_item();

  CodeEmitInfo* info_for_exception =
    (x->needs_exception_state() ? state_for(x) :
                                  state_for(x, x->state_before(), true /*ignore_xhandler*/));

  CodeStub* stub;
  if (x->is_incompatible_class_change_check()) {
    assert(patching_info == nullptr, "can't patch this");
    stub = new SimpleExceptionStub(StubId::c1_throw_incompatible_class_change_error_id,
                                   LIR_OprFact::illegalOpr, info_for_exception);
  } else if (x->is_invokespecial_receiver_check()) {
    assert(patching_info == nullptr, "can't patch this");
    stub = new DeoptimizeStub(info_for_exception,
                              Deoptimization::Reason_class_check,
                              Deoptimization::Action_none);
  } else {
    stub = new SimpleExceptionStub(StubId::c1_throw_class_cast_exception_id,
                                   LIR_OprFact::illegalOpr, info_for_exception);
  }

  LIR_Opr out_reg = rlock_result(x);
  LIR_Opr tmp1 = FrameMap::R0_oop_opr;
  LIR_Opr tmp2 = FrameMap::R1_oop_opr;
  LIR_Opr tmp3 = LIR_OprFact::illegalOpr;

  __ checkcast(out_reg, obj.result(), x->klass(), tmp1, tmp2, tmp3, x->direct_compare(),
               info_for_exception, patching_info, stub, x->profiled_method(), x->profiled_bci());
}


void LIRGenerator::do_InstanceOf(InstanceOf* x) {
  LIRItem obj(x->obj(), this);
  CodeEmitInfo* patching_info = nullptr;
  if (!x->klass()->is_loaded() || PatchALot) {
    patching_info = state_for(x, x->state_before());
  }

  obj.load_item();
  LIR_Opr out_reg = rlock_result(x);
  LIR_Opr tmp1 = FrameMap::R0_oop_opr;
  LIR_Opr tmp2 = FrameMap::R1_oop_opr;
  LIR_Opr tmp3 = LIR_OprFact::illegalOpr;

  __ instanceof(out_reg, obj.result(), x->klass(), tmp1, tmp2, tmp3,
                x->direct_compare(), patching_info, x->profiled_method(), x->profiled_bci());
}

// Intrinsic for Class::isInstance
address LIRGenerator::isInstance_entry() {
  return CAST_FROM_FN_PTR(address, Runtime1::is_instance_of);
}


#ifdef __SOFTFP__
// Turn operator if (f <op> g) into runtime call:
//     call _aeabi_fcmp<op>(f, g)
//     cmp(eq, 1)
//     branch(eq, true path).
void LIRGenerator::do_soft_float_compare(If* x) {
  assert(x->number_of_sux() == 2, "inconsistency");
  ValueTag tag = x->x()->type()->tag();
  If::Condition cond = x->cond();
  address runtime_func;
  // unordered comparison gets the wrong answer because aeabi functions
  //  return false.
  bool unordered_is_true = x->unordered_is_true();
  // reverse of condition for ne
  bool compare_to_zero = false;
  switch (lir_cond(cond)) {
    case lir_cond_notEqual:
      compare_to_zero = true;  // fall through
    case lir_cond_equal:
      runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, __aeabi_fcmpeq):
          CAST_FROM_FN_PTR(address, __aeabi_dcmpeq);
      break;
    case lir_cond_less:
      if (unordered_is_true) {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_fcmplt):
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_dcmplt);
      } else {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, __aeabi_fcmplt):
          CAST_FROM_FN_PTR(address, __aeabi_dcmplt);
      }
      break;
    case lir_cond_lessEqual:
      if (unordered_is_true) {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_fcmple):
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_dcmple);
      } else {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, __aeabi_fcmple):
          CAST_FROM_FN_PTR(address, __aeabi_dcmple);
      }
      break;
    case lir_cond_greaterEqual:
      if (unordered_is_true) {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_fcmpge):
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_dcmpge);
      } else {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, __aeabi_fcmpge):
          CAST_FROM_FN_PTR(address, __aeabi_dcmpge);
      }
      break;
    case lir_cond_greater:
      if (unordered_is_true) {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_fcmpgt):
          CAST_FROM_FN_PTR(address, SharedRuntime::unordered_dcmpgt);
      } else {
        runtime_func = tag == floatTag ?
          CAST_FROM_FN_PTR(address, __aeabi_fcmpgt):
          CAST_FROM_FN_PTR(address, __aeabi_dcmpgt);
      }
      break;
    case lir_cond_aboveEqual:
    case lir_cond_belowEqual:
      ShouldNotReachHere();  // We're not going to get these.
    default:
      assert(lir_cond(cond) == lir_cond_always, "must be");
      ShouldNotReachHere();
  }
  set_no_result(x);

  // add safepoint before generating condition code so it can be recomputed
  if (x->is_safepoint()) {
    increment_backedge_counter(state_for(x, x->state_before()), x->profiled_bci());
    __ safepoint(LIR_OprFact::illegalOpr, state_for(x, x->state_before()));
  }
  // Call float compare function, returns (1,0) if true or false.
  LIR_Opr result = call_runtime(x->x(), x->y(), runtime_func, intType, nullptr);
  __ cmp(lir_cond_equal, result,
         compare_to_zero ?
           LIR_OprFact::intConst(0) : LIR_OprFact::intConst(1));
  profile_branch(x, cond);
  move_to_phi(x->state());
  __ branch(lir_cond_equal, x->tsux());
}
#endif // __SOFTFP__

void LIRGenerator::do_If(If* x) {
  assert(x->number_of_sux() == 2, "inconsistency");
  ValueTag tag = x->x()->type()->tag();

#ifdef __SOFTFP__
  if (tag == floatTag || tag == doubleTag) {
    do_soft_float_compare(x);
    assert(x->default_sux() == x->fsux(), "wrong destination above");
    __ jump(x->default_sux());
    return;
  }
#endif // __SOFTFP__

  LIRItem xitem(x->x(), this);
  LIRItem yitem(x->y(), this);
  LIRItem* xin = &xitem;
  LIRItem* yin = &yitem;
  If::Condition cond = x->cond();

  if (tag == longTag) {
    if (cond == If::gtr || cond == If::leq) {
      cond = Instruction::mirror(cond);
      xin = &yitem;
      yin = &xitem;
    }
    xin->set_destroys_register();
  }

  xin->load_item();
  LIR_Opr left = xin->result();
  LIR_Opr right;

  if (tag == longTag && yin->is_constant() && yin->get_jlong_constant() == 0 &&
      (cond == If::eql || cond == If::neq)) {
    // inline long zero
    right = LIR_OprFact::value_type(yin->value()->type());
  } else {
    yin->load_nonconstant();
    right = yin->result();
  }

  set_no_result(x);

  // add safepoint before generating condition code so it can be recomputed
  if (x->is_safepoint()) {
    increment_backedge_counter_conditionally(lir_cond(cond), left, right, state_for(x, x->state_before()),
        x->tsux()->bci(), x->fsux()->bci(), x->profiled_bci());
    __ safepoint(LIR_OprFact::illegalOpr, state_for(x, x->state_before()));
  }

  __ cmp(lir_cond(cond), left, right);
  profile_branch(x, cond);
  move_to_phi(x->state());
  if (x->x()->type()->is_float_kind()) {
    __ branch(lir_cond(cond), x->tsux(), x->usux());
  } else {
    __ branch(lir_cond(cond), x->tsux());
  }
  assert(x->default_sux() == x->fsux(), "wrong destination above");
  __ jump(x->default_sux());
}


LIR_Opr LIRGenerator::getThreadPointer() {
  return FrameMap::Rthread_opr;
}

void LIRGenerator::trace_block_entry(BlockBegin* block) {
  __ move(LIR_OprFact::intConst(block->block_id()), FrameMap::R0_opr);
  LIR_OprList* args = new LIR_OprList(1);
  args->append(FrameMap::R0_opr);
  address func = CAST_FROM_FN_PTR(address, Runtime1::trace_block_entry);
  __ call_runtime_leaf(func, getThreadTemp(), LIR_OprFact::illegalOpr, args);
}


void LIRGenerator::volatile_field_store(LIR_Opr value, LIR_Address* address,
                                        CodeEmitInfo* info) {
  if (value->is_double_cpu()) {
    assert(address->index()->is_illegal(), "should have a constant displacement");
    LIR_Address* store_addr = nullptr;
    if (address->disp() != 0) {
      LIR_Opr tmp = new_pointer_register();
      add_large_constant(address->base(), address->disp(), tmp);
      store_addr = new LIR_Address(tmp, (intx)0, address->type());
    } else {
      // address->disp() can be 0, if the address is referenced using the unsafe intrinsic
      store_addr = address;
    }
    __ volatile_store_mem_reg(value, store_addr, info);
    return;
  }
  __ store(value, address, info, lir_patch_none);
}

void LIRGenerator::volatile_field_load(LIR_Address* address, LIR_Opr result,
                                       CodeEmitInfo* info) {
  if (result->is_double_cpu()) {
    assert(address->index()->is_illegal(), "should have a constant displacement");
    LIR_Address* load_addr = nullptr;
    if (address->disp() != 0) {
      LIR_Opr tmp = new_pointer_register();
      add_large_constant(address->base(), address->disp(), tmp);
      load_addr = new LIR_Address(tmp, (intx)0, address->type());
    } else {
      // address->disp() can be 0, if the address is referenced using the unsafe intrinsic
      load_addr = address;
    }
    __ volatile_load_mem_reg(load_addr, result, info);
    return;
  }
  __ load(address, result, info, lir_patch_none);
}