1  /* This file contains definitions for the register renamer.
       2     Copyright (C) 2011-2023 Free Software Foundation, Inc.
       3  
       4  This file is part of GCC.
       5  
       6  GCC is free software; you can redistribute it and/or modify it under
       7  the terms of the GNU General Public License as published by the Free
       8  Software Foundation; either version 3, or (at your option) any later
       9  version.
      10  
      11  GCC is distributed in the hope that it will be useful, but WITHOUT ANY
      12  WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
      14  for more details.
      15  
      16  You should have received a copy of the GNU General Public License
      17  along with GCC; see the file COPYING3.  If not see
      18  <http://www.gnu.org/licenses/>.  */
      19  
      20  #ifndef GCC_REGRENAME_H
      21  #define GCC_REGRENAME_H
      22  
      23  /* We keep linked lists of DU_HEAD structures, each of which describes
      24     a chain of occurrences of a reg.  */
      25  class du_head
      26  {
      27  public:
      28    /* The next chain.  */
      29    class du_head *next_chain;
      30    /* The first and last elements of this chain.  */
      31    struct du_chain *first, *last;
      32    /* The chain that this chain is tied to.  */
      33    class du_head *tied_chain;
      34    /* Describes the register being tracked.  */
      35    unsigned regno;
      36    int nregs;
      37  
      38    /* A unique id to be used as an index into the conflicts bitmaps.  */
      39    unsigned id;
      40    /* A bitmap to record conflicts with other chains.  */
      41    bitmap_head conflicts;
      42    /* Conflicts with untracked hard registers.  */
      43    HARD_REG_SET hard_conflicts;
      44    /* Which registers are fully or partially clobbered by the calls that
      45       the chain crosses.  */
      46    HARD_REG_SET call_clobber_mask;
      47  
      48    /* A bitmask of ABIs used by the calls that the chain crosses.  */
      49    unsigned int call_abis : NUM_ABI_IDS;
      50    /* Nonzero if the register is used in a way that prevents renaming,
      51       such as the SET_DEST of a CALL_INSN or an asm operand that used
      52       to be a hard register.  */
      53    unsigned int cannot_rename:1;
      54    /* Nonzero if the chain has already been renamed.  */
      55    unsigned int renamed:1;
      56  
      57    /* Fields for use by target code.  */
      58    unsigned int target_data_1;
      59    unsigned int target_data_2;
      60  };
      61  
      62  typedef class du_head *du_head_p;
      63  
      64  /* This struct describes a single occurrence of a register.  */
      65  struct du_chain
      66  {
      67    /* Links to the next occurrence of the register.  */
      68    struct du_chain *next_use;
      69  
      70    /* The insn where the register appears.  */
      71    rtx_insn *insn;
      72    /* The location inside the insn.  */
      73    rtx *loc;
      74    /* The register class required by the insn at this location.  */
      75    ENUM_BITFIELD(reg_class) cl : 16;
      76  };
      77  
      78  /* This struct describes data gathered during regrename_analyze about
      79     a single operand of an insn.  */
      80  struct operand_rr_info
      81  {
      82    /* The number of chains recorded for this operand.  */
      83    short n_chains;
      84    bool failed;
      85    /* Holds either the chain for the operand itself, or for the registers in
      86       a memory operand.  */
      87    struct du_chain *chains[MAX_REGS_PER_ADDRESS];
      88    class du_head *heads[MAX_REGS_PER_ADDRESS];
      89  };
      90  
      91  /* A struct to hold a vector of operand_rr_info structures describing the
      92     operands of an insn.  */
      93  struct insn_rr_info
      94  {
      95    operand_rr_info *op_info;
      96  };
      97  
      98  
      99  extern vec<insn_rr_info> insn_rr;
     100  
     101  extern void regrename_init (bool);
     102  extern void regrename_finish (void);
     103  extern void regrename_analyze (bitmap, bool = true);
     104  extern du_head_p regrename_chain_from_id (unsigned int);
     105  extern int find_rename_reg (du_head_p, enum reg_class, HARD_REG_SET *, int,
     106  			    bool);
     107  extern bool regrename_do_replace (du_head_p, int);
     108  extern reg_class regrename_find_superclass (du_head_p, int *,
     109  					    HARD_REG_SET *);
     110  
     111  #endif