/*

 * Copyright 2005-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 *

 */

inline bool LinearScan::is_processed_reg_num(int reg_num) {

  // rsp and rbp (numbers 6 ancd 7) are ignored

  assert(FrameMap::rsp_opr->cpu_regnr() == 6, "wrong assumption below");

  assert(FrameMap::rbp_opr->cpu_regnr() == 7, "wrong assumption below");

  assert(reg_num >= 0, "invalid reg_num");

  return reg_num < 6 || reg_num > 7;

}

inline int LinearScan::num_physical_regs(BasicType type) {

  // Intel requires two cpu registers for long,

  // but requires only one fpu register for double

  if (type == T_LONG) {

    return 2;

  }

  return 1;

}

inline bool LinearScan::requires_adjacent_regs(BasicType type) {

  return false;

}

inline bool LinearScan::is_caller_save(int assigned_reg) {

  assert(assigned_reg >= 0 && assigned_reg < nof_regs, "should call this only for registers");

  return true; // no callee-saved registers on Intel

}

inline void LinearScan::pd_add_temps(LIR_Op* op) {

  switch (op->code()) {

    case lir_tan:

    case lir_sin:

    case lir_cos: {

      // The slow path for these functions may need to save and

      // restore all live registers but we don't want to save and

      // restore everything all the time, so mark the xmms as being

      // killed.  If the slow path were explicit or we could propagate

      // live register masks down to the assembly we could do better

      // but we don't have any easy way to do that right now.  We

      // could also consider not killing all xmm registers if we

      // assume that slow paths are uncommon but it's not clear that

      // would be a good idea.

      if (UseSSE > 0) {

#ifndef PRODUCT

        if (TraceLinearScanLevel >= 2) {

          tty->print_cr("killing XMMs for trig");

        }

#endif

        int op_id = op->id();

        for (int xmm = 0; xmm < FrameMap::nof_caller_save_xmm_regs; xmm++) {

          LIR_Opr opr = FrameMap::caller_save_xmm_reg_at(xmm);

          add_temp(reg_num(opr), op_id, noUse, T_ILLEGAL);

        }

      }

      break;

    }

  }

}

// Implementation of LinearScanWalker

inline bool LinearScanWalker::pd_init_regs_for_alloc(Interval* cur) {

  if (allocator()->gen()->is_vreg_flag_set(cur->reg_num(), LIRGenerator::byte_reg)) {

    assert(cur->type() != T_FLOAT && cur->type() != T_DOUBLE, "cpu regs only");

    _first_reg = pd_first_byte_reg;

    _last_reg = pd_last_byte_reg;

    return true;

  } else if ((UseSSE >= 1 && cur->type() == T_FLOAT) || (UseSSE >= 2 && cur->type() == T_DOUBLE)) {

    _first_reg = pd_first_xmm_reg;

    _last_reg = pd_last_xmm_reg;

    return true;

  }

  return false;

}

class FpuStackAllocator VALUE_OBJ_CLASS_SPEC {

 private:

  Compilation* _compilation;

  LinearScan* _allocator;

  LIR_OpVisitState visitor;

  LIR_List* _lir;

  int _pos;

  FpuStackSim _sim;

  FpuStackSim _temp_sim;

  bool _debug_information_computed;

  LinearScan*   allocator()                      { return _allocator; }

  Compilation*  compilation() const              { return _compilation; }

  // unified bailout support

  void          bailout(const char* msg) const   { compilation()->bailout(msg); }

  bool          bailed_out() const               { return compilation()->bailed_out(); }

  int pos() { return _pos; }

  void set_pos(int pos) { _pos = pos; }

  LIR_Op* cur_op() { return lir()->instructions_list()->at(pos()); }

  LIR_List* lir() { return _lir; }

  void set_lir(LIR_List* lir) { _lir = lir; }

  FpuStackSim* sim() { return &_sim; }

  FpuStackSim* temp_sim() { return &_temp_sim; }

  int fpu_num(LIR_Opr opr);

  int tos_offset(LIR_Opr opr);

  LIR_Opr to_fpu_stack_top(LIR_Opr opr, bool dont_check_offset = false);

  // Helper functions for handling operations

  void insert_op(LIR_Op* op);

  void insert_exchange(int offset);

  void insert_exchange(LIR_Opr opr);

  void insert_free(int offset);

  void insert_free_if_dead(LIR_Opr opr);

  void insert_free_if_dead(LIR_Opr opr, LIR_Opr ignore);

  void insert_copy(LIR_Opr from, LIR_Opr to);

  void do_rename(LIR_Opr from, LIR_Opr to);

  void do_push(LIR_Opr opr);

  void pop_if_last_use(LIR_Op* op, LIR_Opr opr);

  void pop_always(LIR_Op* op, LIR_Opr opr);

  void clear_fpu_stack(LIR_Opr preserve);

  void handle_op1(LIR_Op1* op1);

  void handle_op2(LIR_Op2* op2);

  void handle_opCall(LIR_OpCall* opCall);

  void compute_debug_information(LIR_Op* op);

  void allocate_exception_handler(XHandler* xhandler);

  void allocate_block(BlockBegin* block);

#ifndef PRODUCT

  void check_invalid_lir_op(LIR_Op* op);

#endif

  // Helper functions for merging of fpu stacks

  void merge_insert_add(LIR_List* instrs, FpuStackSim* cur_sim, int reg);

  void merge_insert_xchg(LIR_List* instrs, FpuStackSim* cur_sim, int slot);

  void merge_insert_pop(LIR_List* instrs, FpuStackSim* cur_sim);

  bool merge_rename(FpuStackSim* cur_sim, FpuStackSim* sux_sim, int start_slot, int change_slot);

  void merge_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, FpuStackSim* sux_sim);

  void merge_cleanup_fpu_stack(LIR_List* instrs, FpuStackSim* cur_sim, BitMap& live_fpu_regs);

  bool merge_fpu_stack_with_successors(BlockBegin* block);

 public:

  LIR_Opr to_fpu_stack(LIR_Opr opr); // used by LinearScan for creation of debug information

  FpuStackAllocator(Compilation* compilation, LinearScan* allocator);

  void allocate();

};