1 /* tc-xtensa.h -- Header file for tc-xtensa.c.
2 Copyright (C) 2003, 2004 Free Software Foundation, Inc.
4 This file is part of GAS, the GNU Assembler.
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)
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.
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
24 #ifdef ANSI_PROTOTYPES
29 #error Xtensa support requires BFD_ASSEMBLER
33 #error Xtensa support requires ELF object format
36 #include "xtensa-isa.h"
37 #include "xtensa-config.h"
39 #define TARGET_BYTES_BIG_ENDIAN XCHAL_HAVE_BE
42 /* Maximum number of opcode slots in a VLIW instruction. */
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. */
53 enum xtensa_relax_statesE
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. */
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. */
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
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
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. */
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. */
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. */
96 /* The next fragment would like its first instruction to NOT cross an
97 instruction fetch boundary. */
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
107 /* This will be turned into a NOP or NOP.N if the previous instruction
108 is expanded to negate a loop. */
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. */
116 /* Another fragment could generate an expansion here but has not yet. */
119 /* Expansion has been generated by an instruction that generates a
120 literal. However, the stretch has NOT been reported yet in this
124 /* Expansion has been generated by an instruction that generates a
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. */
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. */
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
146 /* The last instruction in this fragment (at->fr_opcode) contains a
147 literal. It has already been expanded at least 1 step. */
150 /* The last instruction in this fragment (at->fr_opcode) contains a
151 literal. It has already been expanded at least 2 steps. */
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
162 /* This marks the location of a pipeline stall. We can fill these guys
163 in for alignment of any size. */
166 /* This marks the location as unreachable. The assembler may widen or
167 narrow this area to meet alignment requirements of nearby
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. */
179 /* This is used as a stopper to bound the number of steps that
181 #define RELAX_IMMED_MAXSTEPS (RELAX_IMMED_STEP2 - RELAX_IMMED)
183 struct xtensa_frag_type
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.
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. */
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;
200 /* Inhibits relaxation of machine-dependent alignment frags the
201 first time through a relaxation.... */
202 unsigned int relax_seen
: 1;
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;
211 unsigned int is_specific_opcode
: 1; /* also implies no_transform */
213 unsigned int is_align
: 1;
214 unsigned int is_text_align
: 1;
215 unsigned int alignment
: 5;
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;
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
228 /* The destination segment for literal frags. (Note that this is only
229 valid after xtensa_move_literals. */
232 /* For the relaxation scheme, some literal fragments can have their
233 expansions modified by an instruction that relaxes. */
234 int text_expansion
[MAX_SLOTS
];
235 int literal_expansion
[MAX_SLOTS
];
236 int unreported_expansion
;
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
];
245 /* The global aligner needs to walk backward through the list of
246 frags. This field is only valid after xtensa_end. */
251 /* For VLIW support, we need to know what slot a fixup applies to. */
252 typedef struct xtensa_fix_data_struct
255 symbolS
*X_add_symbol
;
256 offsetT X_add_number
;
260 /* Structure to record xtensa-specific symbol information. */
261 typedef struct xtensa_symfield_type
263 unsigned int is_loop_target
: 1;
264 unsigned int is_branch_target
: 1;
265 } xtensa_symfield_type
;
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
;
275 /* Property section types. */
283 typedef struct xtensa_segment_info_struct
285 fragS
*literal_pool_loc
;
286 xtensa_block_info
*blocks
[max_xt_sec
];
287 } xtensa_segment_info
;
290 /* Section renaming is only supported in Tensilica's version of GAS. */
291 #ifdef XTENSA_SECTION_RENAME
292 extern const char *xtensa_section_rename (const char *);
294 /* Tensilica's section renaming feature is not included here. */
295 #define xtensa_section_rename(name) (name)
296 #endif /* XTENSA_SECTION_RENAME */
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
*);
316 #define TARGET_FORMAT xtensa_target_format ()
317 #define TARGET_ARCH bfd_arch_xtensa
318 #define TC_SEGMENT_INFO_TYPE xtensa_segment_info
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)
322 #define TC_FRAG_TYPE struct xtensa_frag_type
323 #define TC_FRAG_INIT(frag) xtensa_frag_init (frag)
324 #define TC_FORCE_RELOCATION(fix) xtensa_force_relocation (fix)
325 #define NO_PSEUDO_DOT xtensa_check_inside_bundle ()
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)
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
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")
340 #define HANDLE_ALIGN(fragP) xtensa_handle_align (fragP)
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. */
347 #define md_post_relax_hook \
351 xtensa_post_relax_hook (); \
352 bfd_map_over_sections (stdoutput, renumber_sections, &i); \
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. */
362 #define md_relax_frag(segment, fragP, stretch) \
363 xtensa_relax_frag (fragP, stretch, &stretched)
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
371 #define TC_LINKRELAX_FIXUP(SEG) 0
372 #define MD_APPLY_SYM_VALUE(FIX) 0
373 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0
376 /* Resource reservation info functions. */
378 /* Returns the number of copies of a particular unit. */
379 typedef int (*unit_num_copies_func
) (void *, xtensa_funcUnit
);
381 /* Returns the number of units the opcode uses. */
382 typedef int (*opcode_num_units_func
) (void *, xtensa_opcode
);
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);
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);
392 /* The above typedefs parameterize the resource_table so that the
393 optional scheduler doesn't need its own resource reservation system.
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):
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
404 Of course the optional scheduler has its own reservation table
407 int opcode_funcUnit_use_unit (void *, xtensa_opcode
, int);
408 int opcode_funcUnit_use_stage (void *, xtensa_opcode
, int);
414 int allocated_cycles
;
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
;
423 resource_table
*new_resource_table
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);
432 #endif /* TC_XTENSA */