source: trunk/binutils/gas/config/xtensa-relax.h@ 2852

/* Table of relaxations for Xtensa assembly.
   Copyright 2003 Free Software Foundation, Inc.

   This file is part of GAS, the GNU Assembler.

   GAS is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   GAS 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 for more details.

   You should have received a copy of the GNU General Public License
   along with GAS; see the file COPYING.  If not, write to
   the Free Software Foundation, 59 Temple Place - Suite 330, Boston, 
   MA 02111-1307, USA.  */

#ifndef XTENSA_RELAX_H
#define XTENSA_RELAX_H

#include "xtensa-isa.h"


/* Data structures for the table-driven relaxations for Xtensa processors.
   See xtensa-relax.c for details.  */

typedef struct transition_list TransitionList;
typedef struct transition_table TransitionTable;
typedef struct transition_rule TransitionRule;
typedef struct precondition_list PreconditionList;
typedef struct precondition Precondition;

struct transition_table
{
  int num_opcodes;
  TransitionList **table;       /* Possible transitions for each opcode.  */
};

struct transition_list
{
  TransitionRule *rule;
  TransitionList *next;
};

struct precondition_list
{
  Precondition *precond;
  PreconditionList *next;
};


/* Operand types and constraints on operands:  */

typedef enum op_type OpType;
typedef enum cmp_op CmpOp;

enum op_type
{
  OP_CONSTANT,
  OP_OPERAND,
  OP_OPERAND_LOW8,              /* Sign-extended low 8 bits of immed.  */
  OP_OPERAND_HI24S,             /* high 24 bits of immed,
                                   plus 0x100 if low 8 bits are signed.  */
  OP_OPERAND_F32MINUS,          /* 32 - immed.  */
  OP_LITERAL,
  OP_LABEL
};

enum cmp_op
{
  OP_EQUAL,
  OP_NOTEQUAL,
};

struct precondition
{
  CmpOp cmp;
  int op_num;
  OpType typ;                   /* CONSTANT: op_data is a constant.
                                   OPERAND: operand op_num must equal op_data.
                                   Cannot be LITERAL or LABEL.  */
  int op_data;
};

typedef struct build_op BuildOp;

struct build_op
{
  int op_num;
  OpType typ;
  unsigned op_data;             /* CONSTANT: op_data is the value to encode.
                                   OPERAND: op_data is the field in the
                                   source instruction to take the value from
                                   and encode in the op_num field here.
                                   LITERAL or LABEL: op_data is the ordinal
                                   that identifies the appropriate one, i.e.,
                                   there can be more than one literal or
                                   label in an expansion.  */
  BuildOp *next;
};

typedef struct build_instr BuildInstr;
typedef enum instr_type InstrType;

enum instr_type
{
  INSTR_INSTR,
  INSTR_LITERAL_DEF,
  INSTR_LABEL_DEF
};

struct build_instr
{
  InstrType typ;
  unsigned id;                  /* LITERAL_DEF or LABEL_DEF: an ordinal to
                                   identify which one.  */
  xtensa_opcode opcode;         /* unused for LITERAL_DEF or LABEL_DEF.  */
  BuildOp *ops;
  BuildInstr *next;
};

struct transition_rule
{
  xtensa_opcode opcode;
  PreconditionList *conditions;
  BuildInstr *to_instr;
};

extern TransitionTable *xg_build_simplify_table
  PARAMS ((void));
extern TransitionTable *xg_build_widen_table
  PARAMS ((void));

extern bfd_boolean xg_has_userdef_op_fn
  PARAMS ((OpType));
extern long xg_apply_userdef_op_fn
  PARAMS ((OpType, long));

#endif /* !XTENSA_RELAX_H */