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e0001a05 | 1 | /* tc-xtensa.h -- Header file for tc-xtensa.c. |
43cd72b9 | 2 | Copyright (C) 2003, 2004 Free Software Foundation, Inc. |
e0001a05 NC |
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 the Free | |
18 | Software Foundation, 59 Temple Place - Suite 330, Boston, MA | |
19 | 02111-1307, USA. */ | |
20 | ||
21 | #ifndef TC_XTENSA | |
22 | #define TC_XTENSA 1 | |
23 | ||
24 | #ifdef ANSI_PROTOTYPES | |
25 | struct fix; | |
26 | #endif | |
27 | ||
28 | #ifndef BFD_ASSEMBLER | |
29 | #error Xtensa support requires BFD_ASSEMBLER | |
30 | #endif | |
31 | ||
32 | #ifndef OBJ_ELF | |
33 | #error Xtensa support requires ELF object format | |
34 | #endif | |
35 | ||
43cd72b9 | 36 | #include "xtensa-isa.h" |
e0001a05 NC |
37 | #include "xtensa-config.h" |
38 | ||
39 | #define TARGET_BYTES_BIG_ENDIAN XCHAL_HAVE_BE | |
40 | ||
41 | ||
43cd72b9 BW |
42 | /* Maximum number of opcode slots in a VLIW instruction. */ |
43 | #define MAX_SLOTS 31 | |
44 | ||
45 | ||
46 | /* For all xtensa relax states except RELAX_DESIRE_ALIGN and | |
47 | RELAX_DESIRE_ALIGN_IF_TARGET, the amount a frag might grow is stored | |
48 | in the fr_var field. For the two exceptions, fr_var is a float value | |
49 | that records the frequency with which the following instruction is | |
50 | executed as a branch target. The aligner uses this information to | |
51 | tell which targets are most important to be aligned. */ | |
52 | ||
53 | enum xtensa_relax_statesE | |
54 | { | |
55 | RELAX_ALIGN_NEXT_OPCODE, | |
56 | /* Use the first opcode of the next fragment to determine the | |
57 | alignment requirements. This is ONLY used for LOOPs currently. */ | |
58 | ||
59 | RELAX_CHECK_ALIGN_NEXT_OPCODE, | |
60 | /* The next non-empty frag contains a loop instruction. Check to see | |
61 | if it is correctly aligned, but do not align it. */ | |
62 | ||
63 | RELAX_DESIRE_ALIGN_IF_TARGET, | |
64 | /* These are placed in front of labels and converted to either | |
65 | RELAX_DESIRE_ALIGN / RELAX_LOOP_END or rs_fill of 0 before | |
66 | relaxation begins. */ | |
67 | ||
68 | RELAX_ADD_NOP_IF_A0_B_RETW, | |
69 | /* These are placed in front of conditional branches. Before | |
70 | relaxation begins, they are turned into either NOPs for branches | |
71 | immediately followed by RETW or RETW.N or rs_fills of 0. This is | |
72 | used to avoid a hardware bug in some early versions of the | |
73 | processor. */ | |
74 | ||
75 | RELAX_ADD_NOP_IF_PRE_LOOP_END, | |
76 | /* These are placed after JX instructions. Before relaxation begins, | |
77 | they are turned into either NOPs, if the JX is one instruction | |
78 | before a loop end label, or rs_fills of 0. This is used to avoid a | |
79 | hardware interlock issue prior to Xtensa version T1040. */ | |
80 | ||
81 | RELAX_ADD_NOP_IF_SHORT_LOOP, | |
82 | /* These are placed after LOOP instructions and turned into NOPs when: | |
83 | (1) there are less than 3 instructions in the loop; we place 2 of | |
84 | these in a row to add up to 2 NOPS in short loops; or (2) the | |
85 | instructions in the loop do not include a branch or jump. | |
86 | Otherwise they are turned into rs_fills of 0 before relaxation | |
87 | begins. This is used to avoid hardware bug PR3830. */ | |
88 | ||
89 | RELAX_ADD_NOP_IF_CLOSE_LOOP_END, | |
90 | /* These are placed after LOOP instructions and turned into NOPs if | |
91 | there are less than 12 bytes to the end of some other loop's end. | |
92 | Otherwise they are turned into rs_fills of 0 before relaxation | |
93 | begins. This is used to avoid hardware bug PR3830. */ | |
94 | ||
95 | RELAX_DESIRE_ALIGN, | |
96 | /* The next fragment would like its first instruction to NOT cross an | |
97 | instruction fetch boundary. */ | |
98 | ||
99 | RELAX_MAYBE_DESIRE_ALIGN, | |
100 | /* The next fragment might like its first instruction to NOT cross an | |
101 | instruction fetch boundary. These are placed after a branch that | |
102 | might be relaxed. If the branch is relaxed, then this frag will be | |
103 | a branch target and this frag will be changed to RELAX_DESIRE_ALIGN | |
104 | frag. */ | |
105 | ||
106 | RELAX_LOOP_END, | |
107 | /* This will be turned into a NOP or NOP.N if the previous instruction | |
108 | is expanded to negate a loop. */ | |
109 | ||
110 | RELAX_LOOP_END_ADD_NOP, | |
111 | /* When the code density option is available, this will generate a | |
112 | NOP.N marked RELAX_NARROW. Otherwise, it will create an rs_fill | |
113 | fragment with a NOP in it. */ | |
114 | ||
115 | RELAX_LITERAL, | |
116 | /* Another fragment could generate an expansion here but has not yet. */ | |
117 | ||
118 | RELAX_LITERAL_NR, | |
119 | /* Expansion has been generated by an instruction that generates a | |
120 | literal. However, the stretch has NOT been reported yet in this | |
121 | fragment. */ | |
122 | ||
123 | RELAX_LITERAL_FINAL, | |
124 | /* Expansion has been generated by an instruction that generates a | |
125 | literal. */ | |
126 | ||
127 | RELAX_LITERAL_POOL_BEGIN, | |
128 | RELAX_LITERAL_POOL_END, | |
129 | /* Technically these are not relaxations at all but mark a location | |
130 | to store literals later. Note that fr_var stores the frchain for | |
131 | BEGIN frags and fr_var stores now_seg for END frags. */ | |
132 | ||
133 | RELAX_NARROW, | |
134 | /* The last instruction in this fragment (at->fr_opcode) can be | |
135 | freely replaced with a single wider instruction if a future | |
136 | alignment desires or needs it. */ | |
137 | ||
138 | RELAX_IMMED, | |
139 | /* The last instruction in this fragment (at->fr_opcode) contains | |
140 | the value defined by fr_symbol (fr_offset = 0). If the value | |
141 | does not fit, use the specified expansion. This is similar to | |
142 | "NARROW", except that these may not be expanded in order to align | |
143 | code. */ | |
144 | ||
145 | RELAX_IMMED_STEP1, | |
146 | /* The last instruction in this fragment (at->fr_opcode) contains a | |
147 | literal. It has already been expanded at least 1 step. */ | |
148 | ||
149 | RELAX_IMMED_STEP2, | |
150 | /* The last instruction in this fragment (at->fr_opcode) contains a | |
151 | literal. It has already been expanded at least 2 steps. */ | |
152 | ||
153 | RELAX_SLOTS, | |
154 | /* There are instructions within the last VLIW instruction that need | |
155 | relaxation. Find the relaxation based on the slot info in | |
156 | xtensa_frag_type. Relaxations that deal with particular opcodes | |
157 | are slot-based (e.g., converting a MOVI to an L32R). Relaxations | |
158 | that deal with entire instructions, such as alignment, are not | |
159 | slot-based. */ | |
160 | ||
161 | RELAX_FILL_NOP, | |
162 | /* This marks the location of a pipeline stall. We can fill these guys | |
163 | in for alignment of any size. */ | |
164 | ||
165 | RELAX_UNREACHABLE, | |
166 | /* This marks the location as unreachable. The assembler may widen or | |
167 | narrow this area to meet alignment requirements of nearby | |
168 | instructions. */ | |
169 | ||
170 | RELAX_MAYBE_UNREACHABLE, | |
171 | /* This marks the location as possibly unreachable. These are placed | |
172 | after a branch that may be relaxed into a branch and jump. If the | |
173 | branch is relaxed, then this frag will be converted to a | |
174 | RELAX_UNREACHABLE frag. */ | |
175 | ||
176 | RELAX_NONE | |
177 | }; | |
178 | ||
179 | /* This is used as a stopper to bound the number of steps that | |
180 | can be taken. */ | |
181 | #define RELAX_IMMED_MAXSTEPS (RELAX_IMMED_STEP2 - RELAX_IMMED) | |
182 | ||
e0001a05 NC |
183 | struct xtensa_frag_type |
184 | { | |
43cd72b9 BW |
185 | /* Info about the current state of assembly, e.g., transform, |
186 | absolute_literals, etc. These need to be passed to the backend and | |
187 | then to the object file. | |
188 | ||
189 | When is_assembly_state_set is false, the frag inherits some of the | |
190 | state settings from the previous frag in this segment. Because it | |
191 | is not possible to intercept all fragment closures (frag_more and | |
192 | frag_append_1_char can close a frag), we use a pass after initial | |
193 | assembly to fill in the assembly states. */ | |
194 | ||
195 | unsigned int is_assembly_state_set : 1; | |
196 | unsigned int is_no_density : 1; | |
197 | unsigned int is_no_transform : 1; | |
198 | unsigned int use_absolute_literals : 1; | |
199 | ||
200 | /* Inhibits relaxation of machine-dependent alignment frags the | |
201 | first time through a relaxation.... */ | |
202 | unsigned int relax_seen : 1; | |
203 | ||
204 | /* Infomation that is needed in the object file and set when known. */ | |
205 | unsigned int is_literal : 1; | |
206 | unsigned int is_loop_target : 1; | |
207 | unsigned int is_branch_target : 1; | |
208 | unsigned int is_insn : 1; | |
209 | unsigned int is_unreachable : 1; | |
e0001a05 | 210 | |
43cd72b9 | 211 | unsigned int is_specific_opcode : 1; /* also implies no_transform */ |
e0001a05 | 212 | |
43cd72b9 BW |
213 | unsigned int is_align : 1; |
214 | unsigned int is_text_align : 1; | |
215 | unsigned int alignment : 5; | |
216 | ||
217 | /* A frag with this bit set is the first in a loop that actually | |
218 | contains an instruction. */ | |
219 | unsigned int is_first_loop_insn : 1; | |
e0001a05 NC |
220 | |
221 | /* For text fragments that can generate literals at relax time, this | |
222 | variable points to the frag where the literal will be stored. For | |
223 | literal frags, this variable points to the nearest literal pool | |
224 | location frag. This literal frag will be moved to after this | |
225 | location. */ | |
e0001a05 NC |
226 | fragS *literal_frag; |
227 | ||
228 | /* The destination segment for literal frags. (Note that this is only | |
229 | valid after xtensa_move_literals. */ | |
e0001a05 NC |
230 | segT lit_seg; |
231 | ||
232 | /* For the relaxation scheme, some literal fragments can have their | |
233 | expansions modified by an instruction that relaxes. */ | |
43cd72b9 BW |
234 | int text_expansion[MAX_SLOTS]; |
235 | int literal_expansion[MAX_SLOTS]; | |
236 | int unreported_expansion; | |
237 | ||
238 | /* For text fragments that can generate literals at relax time: */ | |
239 | fragS *literal_frags[MAX_SLOTS]; | |
240 | enum xtensa_relax_statesE slot_subtypes[MAX_SLOTS]; | |
241 | symbolS *slot_symbols[MAX_SLOTS]; | |
242 | symbolS *slot_sub_symbols[MAX_SLOTS]; | |
243 | offsetT slot_offsets[MAX_SLOTS]; | |
244 | ||
245 | /* The global aligner needs to walk backward through the list of | |
246 | frags. This field is only valid after xtensa_end. */ | |
247 | fragS *fr_prev; | |
e0001a05 NC |
248 | }; |
249 | ||
43cd72b9 BW |
250 | |
251 | /* For VLIW support, we need to know what slot a fixup applies to. */ | |
252 | typedef struct xtensa_fix_data_struct | |
253 | { | |
254 | int slot; | |
255 | symbolS *X_add_symbol; | |
256 | offsetT X_add_number; | |
257 | } xtensa_fix_data; | |
258 | ||
259 | ||
260 | /* Structure to record xtensa-specific symbol information. */ | |
261 | typedef struct xtensa_symfield_type | |
e0001a05 | 262 | { |
43cd72b9 BW |
263 | unsigned int is_loop_target : 1; |
264 | unsigned int is_branch_target : 1; | |
265 | } xtensa_symfield_type; | |
266 | ||
267 | ||
268 | /* Structure for saving information about a block of property data | |
269 | for frags that have the same flags. The forward reference is | |
270 | in this header file. The actual definition is in tc-xtensa.c. */ | |
271 | struct xtensa_block_info_struct; | |
272 | typedef struct xtensa_block_info_struct xtensa_block_info; | |
273 | ||
e0001a05 | 274 | |
43cd72b9 | 275 | /* Property section types. */ |
e0001a05 NC |
276 | typedef enum |
277 | { | |
e0001a05 | 278 | xt_literal_sec, |
43cd72b9 | 279 | xt_prop_sec, |
e0001a05 NC |
280 | max_xt_sec |
281 | } xt_section_type; | |
282 | ||
283 | typedef struct xtensa_segment_info_struct | |
284 | { | |
285 | fragS *literal_pool_loc; | |
286 | xtensa_block_info *blocks[max_xt_sec]; | |
287 | } xtensa_segment_info; | |
288 | ||
e0001a05 NC |
289 | |
290 | /* Section renaming is only supported in Tensilica's version of GAS. */ | |
43cd72b9 | 291 | #ifdef XTENSA_SECTION_RENAME |
7fa3d080 | 292 | extern const char *xtensa_section_rename (const char *); |
e0001a05 NC |
293 | #else |
294 | /* Tensilica's section renaming feature is not included here. */ | |
295 | #define xtensa_section_rename(name) (name) | |
296 | #endif /* XTENSA_SECTION_RENAME */ | |
297 | ||
298 | ||
7fa3d080 BW |
299 | extern const char *xtensa_target_format (void); |
300 | extern void xtensa_init_fix_data (struct fix *); | |
301 | extern void xtensa_frag_init (fragS *); | |
302 | extern int xtensa_force_relocation (struct fix *); | |
303 | extern void xtensa_frob_label (struct symbol *); | |
304 | extern void xtensa_end (void); | |
305 | extern void xtensa_post_relax_hook (void); | |
306 | extern void xtensa_file_arch_init (bfd *); | |
307 | extern void xtensa_flush_pending_output (void); | |
308 | extern bfd_boolean xtensa_fix_adjustable (struct fix *); | |
309 | extern void xtensa_symbol_new_hook (symbolS *); | |
310 | extern long xtensa_relax_frag (fragS *, long, int *); | |
311 | extern void xtensa_elf_section_change_hook (void); | |
312 | extern int xtensa_unrecognized_line (int); | |
313 | extern bfd_boolean xtensa_check_inside_bundle (void); | |
314 | extern void xtensa_handle_align (fragS *); | |
e0001a05 NC |
315 | |
316 | #define TARGET_FORMAT xtensa_target_format () | |
317 | #define TARGET_ARCH bfd_arch_xtensa | |
318 | #define TC_SEGMENT_INFO_TYPE xtensa_segment_info | |
43cd72b9 BW |
319 | #define TC_SYMFIELD_TYPE struct xtensa_symfield_type |
320 | #define TC_FIX_TYPE xtensa_fix_data | |
321 | #define TC_INIT_FIX_DATA(x) xtensa_init_fix_data (x) | |
e0001a05 NC |
322 | #define TC_FRAG_TYPE struct xtensa_frag_type |
323 | #define TC_FRAG_INIT(frag) xtensa_frag_init (frag) | |
43cd72b9 BW |
324 | #define TC_FORCE_RELOCATION(fix) xtensa_force_relocation (fix) |
325 | #define NO_PSEUDO_DOT xtensa_check_inside_bundle () | |
e0001a05 NC |
326 | #define tc_canonicalize_symbol_name(s) xtensa_section_rename (s) |
327 | #define tc_init_after_args() xtensa_file_arch_init (stdoutput) | |
328 | #define tc_fix_adjustable(fix) xtensa_fix_adjustable (fix) | |
329 | #define tc_frob_label(sym) xtensa_frob_label (sym) | |
43cd72b9 BW |
330 | #define tc_unrecognized_line(ch) xtensa_unrecognized_line (ch) |
331 | #define md_do_align(a,b,c,d,e) xtensa_flush_pending_output () | |
332 | #define md_elf_section_change_hook xtensa_elf_section_change_hook | |
e0001a05 NC |
333 | #define md_elf_section_rename(name) xtensa_section_rename (name) |
334 | #define md_end xtensa_end | |
335 | #define md_flush_pending_output() xtensa_flush_pending_output () | |
336 | #define md_operand(x) | |
337 | #define TEXT_SECTION_NAME xtensa_section_rename (".text") | |
338 | #define DATA_SECTION_NAME xtensa_section_rename (".data") | |
339 | #define BSS_SECTION_NAME xtensa_section_rename (".bss") | |
43cd72b9 | 340 | #define HANDLE_ALIGN(fragP) xtensa_handle_align (fragP) |
e0001a05 NC |
341 | |
342 | ||
343 | /* The renumber_section function must be mapped over all the sections | |
344 | after calling xtensa_post_relax_hook. That function is static in | |
345 | write.c so it cannot be called from xtensa_post_relax_hook itself. */ | |
346 | ||
347 | #define md_post_relax_hook \ | |
348 | do \ | |
349 | { \ | |
350 | int i = 0; \ | |
351 | xtensa_post_relax_hook (); \ | |
352 | bfd_map_over_sections (stdoutput, renumber_sections, &i); \ | |
353 | } \ | |
354 | while (0) | |
355 | ||
356 | ||
357 | /* Because xtensa relaxation can insert a new literal into the middle of | |
358 | fragment and thus require re-running the relaxation pass on the | |
359 | section, we need an explicit flag here. We explicitly use the name | |
360 | "stretched" here to avoid changing the source code in write.c. */ | |
361 | ||
362 | #define md_relax_frag(segment, fragP, stretch) \ | |
363 | xtensa_relax_frag (fragP, stretch, &stretched) | |
364 | ||
365 | ||
366 | #define LOCAL_LABELS_FB 1 | |
367 | #define WORKING_DOT_WORD 1 | |
368 | #define DOUBLESLASH_LINE_COMMENTS | |
369 | #define TC_HANDLES_FX_DONE | |
370 | #define TC_FINALIZE_SYMS_BEFORE_SIZE_SEG 0 | |
43cd72b9 | 371 | #define TC_LINKRELAX_FIXUP(SEG) 0 |
e0001a05 | 372 | #define MD_APPLY_SYM_VALUE(FIX) 0 |
43cd72b9 BW |
373 | #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0 |
374 | ||
375 | ||
376 | /* Resource reservation info functions. */ | |
377 | ||
378 | /* Returns the number of copies of a particular unit. */ | |
379 | typedef int (*unit_num_copies_func) (void *, xtensa_funcUnit); | |
380 | ||
381 | /* Returns the number of units the opcode uses. */ | |
382 | typedef int (*opcode_num_units_func) (void *, xtensa_opcode); | |
383 | ||
384 | /* Given an opcode and an index into the opcode's funcUnit list, | |
385 | returns the unit used for the index. */ | |
386 | typedef int (*opcode_funcUnit_use_unit_func) (void *, xtensa_opcode, int); | |
387 | ||
388 | /* Given an opcode and an index into the opcode's funcUnit list, | |
389 | returns the cycle during which the unit is used. */ | |
390 | typedef int (*opcode_funcUnit_use_stage_func) (void *, xtensa_opcode, int); | |
391 | ||
392 | /* The above typedefs parameterize the resource_table so that the | |
393 | optional scheduler doesn't need its own resource reservation system. | |
394 | ||
395 | For simple resource checking, which is all that happens normally, | |
396 | the functions will be as follows (with some wrapping to make the | |
397 | interface more convenient): | |
398 | ||
399 | unit_num_copies_func = xtensa_funcUnit_num_copies | |
400 | opcode_num_units_func = xtensa_opcode_num_funcUnit_uses | |
401 | opcode_funcUnit_use_unit_func = xtensa_opcode_funcUnit_use->unit | |
402 | opcode_funcUnit_use_stage_func = xtensa_opcode_funcUnit_use->stage | |
403 | ||
404 | Of course the optional scheduler has its own reservation table | |
405 | and functions. */ | |
406 | ||
7fa3d080 BW |
407 | int opcode_funcUnit_use_unit (void *, xtensa_opcode, int); |
408 | int opcode_funcUnit_use_stage (void *, xtensa_opcode, int); | |
43cd72b9 BW |
409 | |
410 | typedef struct | |
411 | { | |
412 | void *data; | |
413 | int cycles; | |
414 | int allocated_cycles; | |
415 | int num_units; | |
416 | unit_num_copies_func unit_num_copies; | |
417 | opcode_num_units_func opcode_num_units; | |
418 | opcode_funcUnit_use_unit_func opcode_unit_use; | |
419 | opcode_funcUnit_use_stage_func opcode_unit_stage; | |
420 | char **units; | |
421 | } resource_table; | |
422 | ||
423 | resource_table *new_resource_table | |
7fa3d080 BW |
424 | (void *, int, int, unit_num_copies_func, opcode_num_units_func, |
425 | opcode_funcUnit_use_unit_func, opcode_funcUnit_use_stage_func); | |
426 | void resize_resource_table (resource_table *, int); | |
427 | void clear_resource_table (resource_table *); | |
428 | bfd_boolean resources_available (resource_table *, xtensa_opcode, int); | |
429 | void reserve_resources (resource_table *, xtensa_opcode, int); | |
430 | void release_resources (resource_table *, xtensa_opcode, int); | |
e0001a05 | 431 | |
e0001a05 | 432 | #endif /* TC_XTENSA */ |