1 /* Table of relaxations for Xtensa assembly. 2 Copyright 2003, 2004 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: op_data is the ordinal 139 that identifies the appropriate one, i.e., 140 there can be more than one literal or 141 label in an expansion. */ 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 unsigned id; /* LITERAL_DEF or LABEL_DEF: an ordinal to 159 identify which one. */ 160 xtensa_opcode opcode; /* Unused for LITERAL_DEF or LABEL_DEF. */ 161 BuildOp *ops; 162 BuildInstr *next; 163 }; 164 165 struct transition_rule 166 { 167 xtensa_opcode opcode; 168 PreconditionList *conditions; 169 ReqOptionList *options; 170 BuildInstr *to_instr; 171 }; 172 173 typedef int (*transition_cmp_fn) (const TransitionRule *, 174 const TransitionRule *); 175 176 extern TransitionTable *xg_build_simplify_table (transition_cmp_fn); 177 extern TransitionTable *xg_build_widen_table (transition_cmp_fn); 178 179 extern bfd_boolean xg_has_userdef_op_fn (OpType); 180 extern long xg_apply_userdef_op_fn (OpType, long); 181 182 #endif /* !XTENSA_RELAX_H */ 183