gas/config/xtensa-relax.h

   1 /* Table of relaxations for Xtensa assembly.
   2    Copyright 2003, 2004, 2007 Free Software Foundation, Inc.
   3
   4    This file is part of GAS, the GNU Assembler.
   5
   6    GAS is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    GAS is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with GAS; see the file COPYING.  If not, write to
  18    the Free Software Foundation, 51 Franklin Street - Fifth Floor, Boston,
  19    MA 02110-1301, USA.  */
  20
  21 #ifndef XTENSA_RELAX_H
  22 #define XTENSA_RELAX_H
  23
  24 #include "xtensa-isa.h"
  25
  26
  27 /* Data structures for the table-driven relaxations for Xtensa processors.
  28    See xtensa-relax.c for details.  */
  29
  30 typedef struct transition_list TransitionList;
  31 typedef struct transition_table TransitionTable;
  32 typedef struct transition_rule TransitionRule;
  33 typedef struct precondition_list PreconditionList;
  34 typedef struct precondition Precondition;
  35
  36 typedef struct req_or_option_list ReqOrOptionList;
  37 typedef struct req_or_option_list ReqOrOption;
  38 typedef struct req_option_list ReqOptionList;
  39 typedef struct req_option_list ReqOption;
  40
  41 struct transition_table
  42 {
  43   int num_opcodes;
  44   TransitionList **table;       /* Possible transitions for each opcode.  */
  45 };
  46
  47 struct transition_list
  48 {
  49   TransitionRule *rule;
  50   TransitionList *next;
  51 };
  52
  53 struct precondition_list
  54 {
  55   Precondition *precond;
  56   PreconditionList *next;
  57 };
  58
  59
  60 /* The required options for a rule are represented with a two-level
  61    structure, with leaf expressions combined by logical ORs at the
  62    lower level, and the results then combined by logical ANDs at the
  63    top level.  The AND terms are linked in a list, and each one can
  64    contain a reference to a list of OR terms.  The leaf expressions,
  65    i.e., the OR options, can be negated by setting the is_true field
  66    to FALSE.  There are two classes of leaf expressions: (1) those
  67    that are properties of the Xtensa configuration and can be
  68    evaluated once when building the tables, and (2) those that depend
  69    of the state of directives or other settings that may vary during
  70    the assembly.  The following expressions may be used in group (1):
  71
  72    IsaUse*:     Xtensa configuration settings.
  73    realnop:     TRUE if the instruction set includes a NOP instruction.
  74
  75    There are currently no expressions in group (2), but they are still
  76    supported since there is a good chance they'll be needed again for
  77    something.  */
  78
  79 struct req_option_list
  80 {
  81   ReqOrOptionList *or_option_terms;
  82   ReqOptionList *next;
  83 };
  84
  85 struct req_or_option_list
  86 {
  87   char *option_name;
  88   bfd_boolean is_true;
  89   ReqOrOptionList *next;
  90 };
  91
  92 /* Operand types and constraints on operands:  */
  93
  94 typedef enum op_type OpType;
  95 typedef enum cmp_op CmpOp;
  96
  97 enum op_type
  98 {
  99   OP_CONSTANT,
 100   OP_OPERAND,
 101   OP_OPERAND_LOW8,              /* Sign-extended low 8 bits of immed.  */
 102   OP_OPERAND_HI24S,             /* High 24 bits of immed,
 103                                    plus 0x100 if low 8 bits are signed.  */
 104   OP_OPERAND_F32MINUS,          /* 32 - immed.  */
 105   OP_OPERAND_LOW16U,            /* Low 16 bits of immed.  */
 106   OP_OPERAND_HI16U,             /* High 16 bits of immed.  */
 107   OP_LITERAL,
 108   OP_LABEL
 109 };
 110
 111 enum cmp_op
 112 {
 113   OP_EQUAL,
 114   OP_NOTEQUAL,
 115 };
 116
 117 struct precondition
 118 {
 119   CmpOp cmp;
 120   int op_num;
 121   OpType typ;                   /* CONSTANT: op_data is a constant.
 122                                    OPERAND: operand op_num must equal op_data.
 123                                    Cannot be LITERAL or LABEL.  */
 124   int op_data;
 125 };
 126
 127
 128 typedef struct build_op BuildOp;
 129
 130 struct build_op
 131 {
 132   int op_num;
 133   OpType typ;
 134   unsigned op_data;             /* CONSTANT: op_data is the value to encode.
 135                                    OPERAND: op_data is the field in the
 136                                    source instruction to take the value from
 137                                    and encode in the op_num field here.
 138                                    LITERAL or LABEL: unused.  */
 139   BuildOp *next;
 140 };
 141
 142 typedef struct build_instr BuildInstr;
 143 typedef enum instr_type InstrType;
 144
 145 enum instr_type
 146 {
 147   INSTR_INSTR,
 148   INSTR_LITERAL_DEF,
 149   INSTR_LABEL_DEF
 150 };
 151
 152 struct build_instr
 153 {
 154   InstrType typ;
 155   xtensa_opcode opcode;         /* Unused for LITERAL_DEF or LABEL_DEF.  */
 156   BuildOp *ops;
 157   BuildInstr *next;
 158 };
 159
 160 struct transition_rule
 161 {
 162   xtensa_opcode opcode;
 163   PreconditionList *conditions;
 164   ReqOptionList *options;
 165   BuildInstr *to_instr;
 166 };
 167
 168 typedef int (*transition_cmp_fn) (const TransitionRule *,
 169                                   const TransitionRule *);
 170
 171 extern TransitionTable *xg_build_simplify_table (transition_cmp_fn);
 172 extern TransitionTable *xg_build_widen_table (transition_cmp_fn);
 173
 174 extern bfd_boolean xg_has_userdef_op_fn (OpType);
 175 extern long xg_apply_userdef_op_fn (OpType, long);
 176
 177 #endif /* !XTENSA_RELAX_H */