gcc/regrename.h

   1 /* This file contains definitions for the register renamer.
   2    Copyright (C) 2011-2013 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 struct du_head
  26 {
  27   /* The next chain.  */
  28   struct du_head *next_chain;
  29   /* The first and last elements of this chain.  */
  30   struct du_chain *first, *last;
  31   /* Describes the register being tracked.  */
  32   unsigned regno;
  33   int nregs;
  34
  35   /* A unique id to be used as an index into the conflicts bitmaps.  */
  36   unsigned id;
  37   /* A bitmap to record conflicts with other chains.  */
  38   bitmap_head conflicts;
  39   /* Conflicts with untracked hard registers.  */
  40   HARD_REG_SET hard_conflicts;
  41
  42   /* Nonzero if the chain crosses a call.  */
  43   unsigned int need_caller_save_reg:1;
  44   /* Nonzero if the register is used in a way that prevents renaming,
  45      such as the SET_DEST of a CALL_INSN or an asm operand that used
  46      to be a hard register.  */
  47   unsigned int cannot_rename:1;
  48 };
  49
  50 typedef struct du_head *du_head_p;
  51
  52 /* This struct describes a single occurrence of a register.  */
  53 struct du_chain
  54 {
  55   /* Links to the next occurrence of the register.  */
  56   struct du_chain *next_use;
  57
  58   /* The insn where the register appears.  */
  59   rtx insn;
  60   /* The location inside the insn.  */
  61   rtx *loc;
  62   /* The register class required by the insn at this location.  */
  63   ENUM_BITFIELD(reg_class) cl : 16;
  64 };
  65
  66 /* This struct describes data gathered during regrename_analyze about
  67    a single operand of an insn.  */
  68 typedef struct
  69 {
  70   /* The number of chains recorded for this operand.  */
  71   int n_chains;
  72   /* Holds either the chain for the operand itself, or for the registers in
  73      a memory operand.  */
  74   struct du_chain *chains[MAX_REGS_PER_ADDRESS];
  75   struct du_head *heads[MAX_REGS_PER_ADDRESS];
  76 } operand_rr_info;
  77
  78 /* A struct to hold a vector of operand_rr_info structures describing the
  79    operands of an insn.  */
  80 typedef struct
  81 {
  82   operand_rr_info *op_info;
  83 } insn_rr_info;
  84
  85
  86 extern vec<insn_rr_info> insn_rr;
  87
  88 extern void regrename_init (bool);
  89 extern void regrename_finish (void);
  90 extern void regrename_analyze (bitmap);
  91 extern du_head_p regrename_chain_from_id (unsigned int);
  92 extern int find_best_rename_reg (du_head_p, enum reg_class, HARD_REG_SET *,
  93                                  int);
  94 extern void regrename_do_replace (du_head_p, int);
  95
  96 #endif