1 /* Table of relaxations for Xtensa assembly.
2 Copyright (C) 2003-2023 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 bool 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 bool 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 */