gcc/regrename.h

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