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[binutils.git] / gas / config / tc-xtensa.h
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1 /* tc-xtensa.h -- Header file for tc-xtensa.c.
2 Copyright (C) 2003, 2004, 2005 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)
9 any later version.
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, 51 Franklin Street - Fifth Floor, Boston, MA
19 02110-1301, USA. */
21 #ifndef TC_XTENSA
22 #define TC_XTENSA 1
24 struct fix;
26 #ifndef OBJ_ELF
27 #error Xtensa support requires ELF object format
28 #endif
30 #include "xtensa-isa.h"
31 #include "xtensa-config.h"
33 #define TARGET_BYTES_BIG_ENDIAN XCHAL_HAVE_BE
36 /* Maximum number of opcode slots in a VLIW instruction. */
37 #define MAX_SLOTS 15
40 /* For all xtensa relax states except RELAX_DESIRE_ALIGN and
41 RELAX_DESIRE_ALIGN_IF_TARGET, the amount a frag might grow is stored
42 in the fr_var field. For the two exceptions, fr_var is a float value
43 that records the frequency with which the following instruction is
44 executed as a branch target. The aligner uses this information to
45 tell which targets are most important to be aligned. */
47 enum xtensa_relax_statesE
49 RELAX_ALIGN_NEXT_OPCODE,
50 /* Use the first opcode of the next fragment to determine the
51 alignment requirements. This is ONLY used for LOOPs currently. */
53 RELAX_CHECK_ALIGN_NEXT_OPCODE,
54 /* The next non-empty frag contains a loop instruction. Check to see
55 if it is correctly aligned, but do not align it. */
57 RELAX_DESIRE_ALIGN_IF_TARGET,
58 /* These are placed in front of labels and converted to either
59 RELAX_DESIRE_ALIGN / RELAX_LOOP_END or rs_fill of 0 before
60 relaxation begins. */
62 RELAX_ADD_NOP_IF_A0_B_RETW,
63 /* These are placed in front of conditional branches. Before
64 relaxation begins, they are turned into either NOPs for branches
65 immediately followed by RETW or RETW.N or rs_fills of 0. This is
66 used to avoid a hardware bug in some early versions of the
67 processor. */
69 RELAX_ADD_NOP_IF_PRE_LOOP_END,
70 /* These are placed after JX instructions. Before relaxation begins,
71 they are turned into either NOPs, if the JX is one instruction
72 before a loop end label, or rs_fills of 0. This is used to avoid a
73 hardware interlock issue prior to Xtensa version T1040. */
75 RELAX_ADD_NOP_IF_SHORT_LOOP,
76 /* These are placed after LOOP instructions and turned into NOPs when:
77 (1) there are less than 3 instructions in the loop; we place 2 of
78 these in a row to add up to 2 NOPS in short loops; or (2) the
79 instructions in the loop do not include a branch or jump.
80 Otherwise they are turned into rs_fills of 0 before relaxation
81 begins. This is used to avoid hardware bug PR3830. */
83 RELAX_ADD_NOP_IF_CLOSE_LOOP_END,
84 /* These are placed after LOOP instructions and turned into NOPs if
85 there are less than 12 bytes to the end of some other loop's end.
86 Otherwise they are turned into rs_fills of 0 before relaxation
87 begins. This is used to avoid hardware bug PR3830. */
89 RELAX_DESIRE_ALIGN,
90 /* The next fragment would like its first instruction to NOT cross an
91 instruction fetch boundary. */
93 RELAX_MAYBE_DESIRE_ALIGN,
94 /* The next fragment might like its first instruction to NOT cross an
95 instruction fetch boundary. These are placed after a branch that
96 might be relaxed. If the branch is relaxed, then this frag will be
97 a branch target and this frag will be changed to RELAX_DESIRE_ALIGN
98 frag. */
100 RELAX_LOOP_END,
101 /* This will be turned into a NOP or NOP.N if the previous instruction
102 is expanded to negate a loop. */
104 RELAX_LOOP_END_ADD_NOP,
105 /* When the code density option is available, this will generate a
106 NOP.N marked RELAX_NARROW. Otherwise, it will create an rs_fill
107 fragment with a NOP in it. */
109 RELAX_LITERAL,
110 /* Another fragment could generate an expansion here but has not yet. */
112 RELAX_LITERAL_NR,
113 /* Expansion has been generated by an instruction that generates a
114 literal. However, the stretch has NOT been reported yet in this
115 fragment. */
117 RELAX_LITERAL_FINAL,
118 /* Expansion has been generated by an instruction that generates a
119 literal. */
121 RELAX_LITERAL_POOL_BEGIN,
122 RELAX_LITERAL_POOL_END,
123 /* Technically these are not relaxations at all but mark a location
124 to store literals later. Note that fr_var stores the frchain for
125 BEGIN frags and fr_var stores now_seg for END frags. */
127 RELAX_NARROW,
128 /* The last instruction in this fragment (at->fr_opcode) can be
129 freely replaced with a single wider instruction if a future
130 alignment desires or needs it. */
132 RELAX_IMMED,
133 /* The last instruction in this fragment (at->fr_opcode) contains
134 the value defined by fr_symbol (fr_offset = 0). If the value
135 does not fit, use the specified expansion. This is similar to
136 "NARROW", except that these may not be expanded in order to align
137 code. */
139 RELAX_IMMED_STEP1,
140 /* The last instruction in this fragment (at->fr_opcode) contains a
141 literal. It has already been expanded at least 1 step. */
143 RELAX_IMMED_STEP2,
144 /* The last instruction in this fragment (at->fr_opcode) contains a
145 literal. It has already been expanded at least 2 steps. */
147 RELAX_SLOTS,
148 /* There are instructions within the last VLIW instruction that need
149 relaxation. Find the relaxation based on the slot info in
150 xtensa_frag_type. Relaxations that deal with particular opcodes
151 are slot-based (e.g., converting a MOVI to an L32R). Relaxations
152 that deal with entire instructions, such as alignment, are not
153 slot-based. */
155 RELAX_FILL_NOP,
156 /* This marks the location of a pipeline stall. We can fill these guys
157 in for alignment of any size. */
159 RELAX_UNREACHABLE,
160 /* This marks the location as unreachable. The assembler may widen or
161 narrow this area to meet alignment requirements of nearby
162 instructions. */
164 RELAX_MAYBE_UNREACHABLE,
165 /* This marks the location as possibly unreachable. These are placed
166 after a branch that may be relaxed into a branch and jump. If the
167 branch is relaxed, then this frag will be converted to a
168 RELAX_UNREACHABLE frag. */
170 RELAX_NONE
173 /* This is used as a stopper to bound the number of steps that
174 can be taken. */
175 #define RELAX_IMMED_MAXSTEPS (RELAX_IMMED_STEP2 - RELAX_IMMED)
177 struct xtensa_frag_type
179 /* Info about the current state of assembly, e.g., transform,
180 absolute_literals, etc. These need to be passed to the backend and
181 then to the object file.
183 When is_assembly_state_set is false, the frag inherits some of the
184 state settings from the previous frag in this segment. Because it
185 is not possible to intercept all fragment closures (frag_more and
186 frag_append_1_char can close a frag), we use a pass after initial
187 assembly to fill in the assembly states. */
189 unsigned int is_assembly_state_set : 1;
190 unsigned int is_no_density : 1;
191 unsigned int is_no_transform : 1;
192 unsigned int use_longcalls : 1;
193 unsigned int use_absolute_literals : 1;
195 /* Inhibits relaxation of machine-dependent alignment frags the
196 first time through a relaxation.... */
197 unsigned int relax_seen : 1;
199 /* Information that is needed in the object file and set when known. */
200 unsigned int is_literal : 1;
201 unsigned int is_loop_target : 1;
202 unsigned int is_branch_target : 1;
203 unsigned int is_insn : 1;
204 unsigned int is_unreachable : 1;
206 unsigned int is_specific_opcode : 1; /* also implies no_transform */
208 unsigned int is_align : 1;
209 unsigned int is_text_align : 1;
210 unsigned int alignment : 5;
212 /* A frag with this bit set is the first in a loop that actually
213 contains an instruction. */
214 unsigned int is_first_loop_insn : 1;
216 /* A frag with this bit set is a branch that we are using to
217 align branch targets as if it were a normal narrow instruction. */
218 unsigned int is_aligning_branch : 1;
220 /* For text fragments that can generate literals at relax time, this
221 variable points to the frag where the literal will be stored. For
222 literal frags, this variable points to the nearest literal pool
223 location frag. This literal frag will be moved to after this
224 location. */
225 fragS *literal_frag;
227 /* The destination segment for literal frags. (Note that this is only
228 valid after xtensa_move_literals.) This field is also used for
229 LITERAL_POOL_END frags. */
230 segT lit_seg;
232 /* Frag chain for LITERAL_POOL_BEGIN frags. */
233 struct frchain *lit_frchain;
235 /* For the relaxation scheme, some literal fragments can have their
236 expansions modified by an instruction that relaxes. */
237 int text_expansion[MAX_SLOTS];
238 int literal_expansion[MAX_SLOTS];
239 int unreported_expansion;
241 /* For text fragments that can generate literals at relax time: */
242 fragS *literal_frags[MAX_SLOTS];
243 enum xtensa_relax_statesE slot_subtypes[MAX_SLOTS];
244 symbolS *slot_symbols[MAX_SLOTS];
245 offsetT slot_offsets[MAX_SLOTS];
247 /* The global aligner needs to walk backward through the list of
248 frags. This field is only valid after xtensa_end. */
249 fragS *fr_prev;
253 /* For VLIW support, we need to know what slot a fixup applies to. */
254 typedef struct xtensa_fix_data_struct
256 int slot;
257 symbolS *X_add_symbol;
258 offsetT X_add_number;
259 } xtensa_fix_data;
262 /* Structure to record xtensa-specific symbol information. */
263 typedef struct xtensa_symfield_type
265 unsigned int is_loop_target : 1;
266 unsigned int is_branch_target : 1;
267 } xtensa_symfield_type;
270 /* Structure for saving information about a block of property data
271 for frags that have the same flags. The forward reference is
272 in this header file. The actual definition is in tc-xtensa.c. */
273 struct xtensa_block_info_struct;
274 typedef struct xtensa_block_info_struct xtensa_block_info;
277 /* Property section types. */
278 typedef enum
280 xt_literal_sec,
281 xt_prop_sec,
282 max_xt_sec
283 } xt_section_type;
285 typedef struct xtensa_segment_info_struct
287 fragS *literal_pool_loc;
288 xtensa_block_info *blocks[max_xt_sec];
289 } xtensa_segment_info;
292 extern const char *xtensa_target_format (void);
293 extern void xtensa_init_fix_data (struct fix *);
294 extern void xtensa_frag_init (fragS *);
295 extern int xtensa_force_relocation (struct fix *);
296 extern int xtensa_validate_fix_sub (struct fix *);
297 extern void xtensa_frob_label (struct symbol *);
298 extern void xtensa_end (void);
299 extern void xtensa_post_relax_hook (void);
300 extern void xtensa_file_arch_init (bfd *);
301 extern void xtensa_flush_pending_output (void);
302 extern bfd_boolean xtensa_fix_adjustable (struct fix *);
303 extern void xtensa_symbol_new_hook (symbolS *);
304 extern long xtensa_relax_frag (fragS *, long, int *);
305 extern void xtensa_elf_section_change_hook (void);
306 extern int xtensa_unrecognized_line (int);
307 extern bfd_boolean xtensa_check_inside_bundle (void);
308 extern void xtensa_handle_align (fragS *);
309 extern char *xtensa_section_rename (char *);
311 #define TARGET_FORMAT xtensa_target_format ()
312 #define TARGET_ARCH bfd_arch_xtensa
313 #define TC_SEGMENT_INFO_TYPE xtensa_segment_info
314 #define TC_SYMFIELD_TYPE struct xtensa_symfield_type
315 #define TC_FIX_TYPE xtensa_fix_data
316 #define TC_INIT_FIX_DATA(x) xtensa_init_fix_data (x)
317 #define TC_FRAG_TYPE struct xtensa_frag_type
318 #define TC_FRAG_INIT(frag) xtensa_frag_init (frag)
319 #define TC_FORCE_RELOCATION(fix) xtensa_force_relocation (fix)
320 #define TC_FORCE_RELOCATION_SUB_SAME(fix, seg) \
321 (! SEG_NORMAL (seg) || xtensa_force_relocation (fix))
322 #define TC_VALIDATE_FIX_SUB(fix) xtensa_validate_fix_sub (fix)
323 #define NO_PSEUDO_DOT xtensa_check_inside_bundle ()
324 #define tc_canonicalize_symbol_name(s) xtensa_section_rename (s)
325 #define tc_canonicalize_section_name(s) xtensa_section_rename (s)
326 #define tc_init_after_args() xtensa_file_arch_init (stdoutput)
327 #define tc_fix_adjustable(fix) xtensa_fix_adjustable (fix)
328 #define tc_frob_label(sym) xtensa_frob_label (sym)
329 #define tc_unrecognized_line(ch) xtensa_unrecognized_line (ch)
330 #define md_do_align(a,b,c,d,e) xtensa_flush_pending_output ()
331 #define md_elf_section_change_hook xtensa_elf_section_change_hook
332 #define md_end xtensa_end
333 #define md_flush_pending_output() xtensa_flush_pending_output ()
334 #define md_operand(x)
335 #define TEXT_SECTION_NAME xtensa_section_rename (".text")
336 #define DATA_SECTION_NAME xtensa_section_rename (".data")
337 #define BSS_SECTION_NAME xtensa_section_rename (".bss")
338 #define HANDLE_ALIGN(fragP) xtensa_handle_align (fragP)
339 #define MAX_MEM_FOR_RS_ALIGN_CODE 1
342 /* The renumber_section function must be mapped over all the sections
343 after calling xtensa_post_relax_hook. That function is static in
344 write.c so it cannot be called from xtensa_post_relax_hook itself. */
346 #define md_post_relax_hook \
347 do \
349 int i = 0; \
350 xtensa_post_relax_hook (); \
351 bfd_map_over_sections (stdoutput, renumber_sections, &i); \
353 while (0)
356 /* Because xtensa relaxation can insert a new literal into the middle of
357 fragment and thus require re-running the relaxation pass on the
358 section, we need an explicit flag here. We explicitly use the name
359 "stretched" here to avoid changing the source code in write.c. */
361 #define md_relax_frag(segment, fragP, stretch) \
362 xtensa_relax_frag (fragP, stretch, &stretched)
365 #define LOCAL_LABELS_FB 1
366 #define WORKING_DOT_WORD 1
367 #define DOUBLESLASH_LINE_COMMENTS
368 #define TC_HANDLES_FX_DONE
369 #define TC_FINALIZE_SYMS_BEFORE_SIZE_SEG 0
370 #define TC_LINKRELAX_FIXUP(SEG) 0
371 #define MD_APPLY_SYM_VALUE(FIX) 0
372 #define SUB_SEGMENT_ALIGN(SEG, FRCHAIN) 0
375 /* Resource reservation info functions. */
377 /* Returns the number of copies of a particular unit. */
378 typedef int (*unit_num_copies_func) (void *, xtensa_funcUnit);
380 /* Returns the number of units the opcode uses. */
381 typedef int (*opcode_num_units_func) (void *, xtensa_opcode);
383 /* Given an opcode and an index into the opcode's funcUnit list,
384 returns the unit used for the index. */
385 typedef int (*opcode_funcUnit_use_unit_func) (void *, xtensa_opcode, int);
387 /* Given an opcode and an index into the opcode's funcUnit list,
388 returns the cycle during which the unit is used. */
389 typedef int (*opcode_funcUnit_use_stage_func) (void *, xtensa_opcode, int);
391 /* The above typedefs parameterize the resource_table so that the
392 optional scheduler doesn't need its own resource reservation system.
394 For simple resource checking, which is all that happens normally,
395 the functions will be as follows (with some wrapping to make the
396 interface more convenient):
398 unit_num_copies_func = xtensa_funcUnit_num_copies
399 opcode_num_units_func = xtensa_opcode_num_funcUnit_uses
400 opcode_funcUnit_use_unit_func = xtensa_opcode_funcUnit_use->unit
401 opcode_funcUnit_use_stage_func = xtensa_opcode_funcUnit_use->stage
403 Of course the optional scheduler has its own reservation table
404 and functions. */
406 int opcode_funcUnit_use_unit (void *, xtensa_opcode, int);
407 int opcode_funcUnit_use_stage (void *, xtensa_opcode, int);
409 typedef struct
411 void *data;
412 int cycles;
413 int allocated_cycles;
414 int num_units;
415 unit_num_copies_func unit_num_copies;
416 opcode_num_units_func opcode_num_units;
417 opcode_funcUnit_use_unit_func opcode_unit_use;
418 opcode_funcUnit_use_stage_func opcode_unit_stage;
419 unsigned char **units;
420 } resource_table;
422 resource_table *new_resource_table
423 (void *, int, int, unit_num_copies_func, opcode_num_units_func,
424 opcode_funcUnit_use_unit_func, opcode_funcUnit_use_stage_func);
425 void resize_resource_table (resource_table *, int);
426 void clear_resource_table (resource_table *);
427 bfd_boolean resources_available (resource_table *, xtensa_opcode, int);
428 void reserve_resources (resource_table *, xtensa_opcode, int);
429 void release_resources (resource_table *, xtensa_opcode, int);
431 #endif /* TC_XTENSA */