gas/config/xtensa-relax.h

   1 /* Table of relaxations for Xtensa assembly.
   2    Copyright (C) 2003-2021 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
  95 {
  96   OP_CONSTANT,
  97   OP_OPERAND,
  98   OP_OPERAND_LOW8,              /* Sign-extended low 8 bits of immed.  */
  99   OP_OPERAND_HI24S,             /* High 24 bits of immed,
 100                                    plus 0x100 if low 8 bits are signed.  */
 101   OP_OPERAND_F32MINUS,          /* 32 - immed.  */
 102   OP_OPERAND_LOW16U,            /* Low 16 bits of immed.  */
 103   OP_OPERAND_HI16U,             /* High 16 bits of immed.  */
 104   OP_LITERAL,
 105   OP_FREEREG,
 106   OP_LABEL
 107 } OpType;
 108
 109 typedef enum cmp_op
 110 {
 111   OP_EQUAL,
 112   OP_NOTEQUAL,
 113 } CmpOp;
 114
 115 struct precondition
 116 {
 117   CmpOp cmp;
 118   int op_num;
 119   OpType typ;                   /* CONSTANT: op_data is a constant.
 120                                    OPERAND: operand op_num must equal op_data.
 121                                    Cannot be LITERAL or LABEL.  */
 122   int op_data;
 123 };
 124
 125
 126 typedef struct build_op BuildOp;
 127
 128 struct build_op
 129 {
 130   int op_num;
 131   OpType typ;
 132   unsigned op_data;             /* CONSTANT: op_data is the value to encode.
 133                                    OPERAND: op_data is the field in the
 134                                    source instruction to take the value from
 135                                    and encode in the op_num field here.
 136                                    LITERAL: op_data is field in the source
 137                                    instruction that is stored in the literal.
 138                                    LABEL: unused.  */
 139   BuildOp *next;
 140 };
 141
 142 typedef struct build_instr BuildInstr;
 143
 144 typedef enum instr_type
 145 {
 146   INSTR_INSTR,
 147   INSTR_LITERAL_DEF,
 148   INSTR_LABEL_DEF
 149 } InstrType;
 150
 151 struct build_instr
 152 {
 153   InstrType typ;
 154   xtensa_opcode opcode;         /* Unused for LITERAL_DEF or LABEL_DEF.  */
 155   BuildOp *ops;
 156   BuildInstr *next;
 157 };
 158
 159 struct transition_rule
 160 {
 161   xtensa_opcode opcode;
 162   PreconditionList *conditions;
 163   ReqOptionList *options;
 164   BuildInstr *to_instr;
 165 };
 166
 167 typedef int (*transition_cmp_fn) (const TransitionRule *,
 168                                   const TransitionRule *);
 169
 170 extern TransitionTable *xg_build_simplify_table (transition_cmp_fn);
 171 extern TransitionTable *xg_build_widen_table (transition_cmp_fn);
 172
 173 extern bfd_boolean xg_has_userdef_op_fn (OpType);
 174 extern long xg_apply_userdef_op_fn (OpType, long);
 175
 176 enum flix_level
 177 {
 178   FLIX_ALL,
 179   FLIX_NO_GENERATE,
 180   FLIX_NONE
 181 };
 182
 183 extern enum flix_level produce_flix;
 184
 185 #endif /* !XTENSA_RELAX_H */