gas/config/xtensa-relax.h

   1 /* Table of relaxations for Xtensa assembly.
   2    Copyright 2003, 2004, 2005, 2007, 2008, 2009 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 3, 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_FREEREG,
 109   OP_LABEL
 110 };
 111
 112 enum cmp_op
 113 {
 114   OP_EQUAL,
 115   OP_NOTEQUAL,
 116 };
 117
 118 struct precondition
 119 {
 120   CmpOp cmp;
 121   int op_num;
 122   OpType typ;                   /* CONSTANT: op_data is a constant.
 123                                    OPERAND: operand op_num must equal op_data.
 124                                    Cannot be LITERAL or LABEL.  */
 125   int op_data;
 126 };
 127
 128
 129 typedef struct build_op BuildOp;
 130
 131 struct build_op
 132 {
 133   int op_num;
 134   OpType typ;
 135   unsigned op_data;             /* CONSTANT: op_data is the value to encode.
 136                                    OPERAND: op_data is the field in the
 137                                    source instruction to take the value from
 138                                    and encode in the op_num field here.
 139                                    LITERAL: op_data is field in the source
 140                                    instruction that is stored in the literal.
 141                                    LABEL: unused.  */
 142   BuildOp *next;
 143 };
 144
 145 typedef struct build_instr BuildInstr;
 146 typedef enum instr_type InstrType;
 147
 148 enum instr_type
 149 {
 150   INSTR_INSTR,
 151   INSTR_LITERAL_DEF,
 152   INSTR_LABEL_DEF
 153 };
 154
 155 struct build_instr
 156 {
 157   InstrType typ;
 158   xtensa_opcode opcode;         /* Unused for LITERAL_DEF or LABEL_DEF.  */
 159   BuildOp *ops;
 160   BuildInstr *next;
 161 };
 162
 163 struct transition_rule
 164 {
 165   xtensa_opcode opcode;
 166   PreconditionList *conditions;
 167   ReqOptionList *options;
 168   BuildInstr *to_instr;
 169 };
 170
 171 typedef int (*transition_cmp_fn) (const TransitionRule *,
 172                                   const TransitionRule *);
 173
 174 extern TransitionTable *xg_build_simplify_table (transition_cmp_fn);
 175 extern TransitionTable *xg_build_widen_table (transition_cmp_fn);
 176
 177 extern bfd_boolean xg_has_userdef_op_fn (OpType);
 178 extern long xg_apply_userdef_op_fn (OpType, long);
 179
 180 enum flix_level
 181 {
 182   FLIX_ALL,
 183   FLIX_NO_GENERATE,
 184   FLIX_NONE
 185 };
 186
 187 extern enum flix_level produce_flix;
 188
 189 #endif /* !XTENSA_RELAX_H */