1 /* GAS interface for targets using CGEN: Cpu tools GENerator.
2 Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
3 2006 Free Software Foundation, Inc.
5 This file is part of GAS, the GNU Assembler.
7 GAS is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GAS is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GAS; see the file COPYING. If not, write to the Free Software
19 Foundation, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
24 #include "cgen-desc.h"
27 #include "dwarf2dbg.h"
29 static void queue_fixup (int, int, expressionS
*);
31 /* Opcode table descriptor, must be set by md_begin. */
33 CGEN_CPU_DESC gas_cgen_cpu_desc
;
35 /* Callback to insert a register into the symbol table.
36 A target may choose to let GAS parse the registers.
37 ??? Not currently used. */
40 cgen_asm_record_register (name
, number
)
44 /* Use symbol_create here instead of symbol_new so we don't try to
45 output registers into the object file's symbol table. */
46 symbol_table_insert (symbol_create (name
, reg_section
,
47 number
, &zero_address_frag
));
50 /* We need to keep a list of fixups. We can't simply generate them as
51 we go, because that would require us to first create the frag, and
52 that would screw up references to ``.''.
54 This is used by cpu's with simple operands. It keeps knowledge of what
55 an `expressionS' is and what a `fixup' is out of CGEN which for the time
58 OPINDEX is the index in the operand table.
59 OPINFO is something the caller chooses to help in reloc determination. */
68 static struct fixup fixups
[GAS_CGEN_MAX_FIXUPS
];
69 static int num_fixups
;
71 /* Prepare to parse an instruction.
72 ??? May wish to make this static and delete calls in md_assemble. */
75 gas_cgen_init_parse ()
83 queue_fixup (opindex
, opinfo
, expP
)
88 /* We need to generate a fixup for this expression. */
89 if (num_fixups
>= GAS_CGEN_MAX_FIXUPS
)
90 as_fatal (_("too many fixups"));
91 fixups
[num_fixups
].exp
= *expP
;
92 fixups
[num_fixups
].opindex
= opindex
;
93 fixups
[num_fixups
].opinfo
= opinfo
;
97 /* The following functions allow fixup chains to be stored, retrieved,
98 and swapped. They are a generalization of a pre-existing scheme
99 for storing, restoring and swapping fixup chains that was used by
100 the m32r port. The functionality is essentially the same, only
101 instead of only being able to store a single fixup chain, an entire
102 array of fixup chains can be stored. It is the user's responsibility
103 to keep track of how many fixup chains have been stored and which
104 elements of the array they are in.
106 The algorithms used are the same as in the old scheme. Other than the
107 "array-ness" of the whole thing, the functionality is identical to the
110 gas_cgen_initialize_saved_fixups_array():
111 Sets num_fixups_in_chain to 0 for each element. Call this from
112 md_begin() if you plan to use these functions and you want the
113 fixup count in each element to be set to 0 initially. This is
114 not necessary, but it's included just in case. It performs
115 the same function for each element in the array of fixup chains
116 that gas_init_parse() performs for the current fixups.
118 gas_cgen_save_fixups (element):
119 element - element number of the array you wish to store the fixups
120 to. No mechanism is built in for tracking what element
123 gas_cgen_restore_fixups (element):
124 element - element number of the array you wish to restore the fixups
127 gas_cgen_swap_fixups(int element):
128 element - swap the current fixups with those in this element number.
133 struct fixup fixup_chain
[GAS_CGEN_MAX_FIXUPS
];
134 int num_fixups_in_chain
;
137 static struct saved_fixups stored_fixups
[MAX_SAVED_FIXUP_CHAINS
];
140 gas_cgen_initialize_saved_fixups_array ()
144 while (i
< MAX_SAVED_FIXUP_CHAINS
)
145 stored_fixups
[i
++].num_fixups_in_chain
= 0;
149 gas_cgen_save_fixups (i
)
152 if (i
< 0 || i
>= MAX_SAVED_FIXUP_CHAINS
)
154 as_fatal ("index into stored_fixups[] out of bounds");
158 stored_fixups
[i
].num_fixups_in_chain
= num_fixups
;
159 memcpy (stored_fixups
[i
].fixup_chain
, fixups
,
160 sizeof (fixups
[0]) * num_fixups
);
165 gas_cgen_restore_fixups (i
)
168 if (i
< 0 || i
>= MAX_SAVED_FIXUP_CHAINS
)
170 as_fatal ("index into stored_fixups[] out of bounds");
174 num_fixups
= stored_fixups
[i
].num_fixups_in_chain
;
175 memcpy (fixups
, stored_fixups
[i
].fixup_chain
,
176 (sizeof (stored_fixups
[i
].fixup_chain
[0])) * num_fixups
);
177 stored_fixups
[i
].num_fixups_in_chain
= 0;
181 gas_cgen_swap_fixups (i
)
184 if (i
< 0 || i
>= MAX_SAVED_FIXUP_CHAINS
)
186 as_fatal ("index into stored_fixups[] out of bounds");
191 gas_cgen_restore_fixups (i
);
193 else if (stored_fixups
[i
].num_fixups_in_chain
== 0)
194 gas_cgen_save_fixups (i
);
199 struct fixup tmp_fixup
;
201 tmp
= stored_fixups
[i
].num_fixups_in_chain
;
202 stored_fixups
[i
].num_fixups_in_chain
= num_fixups
;
205 for (tmp
= GAS_CGEN_MAX_FIXUPS
; tmp
--;)
207 tmp_fixup
= stored_fixups
[i
].fixup_chain
[tmp
];
208 stored_fixups
[i
].fixup_chain
[tmp
] = fixups
[tmp
];
209 fixups
[tmp
] = tmp_fixup
;
214 /* Default routine to record a fixup.
215 This is a cover function to fix_new.
216 It exists because we record INSN with the fixup.
218 FRAG and WHERE are their respective arguments to fix_new_exp.
220 OPINFO is something the caller chooses to help in reloc determination.
222 At this point we do not use a bfd_reloc_code_real_type for
223 operands residing in the insn, but instead just use the
224 operand index. This lets us easily handle fixups for any
225 operand type. We pick a BFD reloc type in md_apply_fix. */
228 gas_cgen_record_fixup (frag
, where
, insn
, length
, operand
, opinfo
, symbol
, offset
)
231 const CGEN_INSN
* insn
;
233 const CGEN_OPERAND
* operand
;
240 /* It may seem strange to use operand->attrs and not insn->attrs here,
241 but it is the operand that has a pc relative relocation. */
242 fixP
= fix_new (frag
, where
, length
/ 8, symbol
, offset
,
243 CGEN_OPERAND_ATTR_VALUE (operand
, CGEN_OPERAND_PCREL_ADDR
),
244 (bfd_reloc_code_real_type
)
245 ((int) BFD_RELOC_UNUSED
246 + (int) operand
->type
));
247 fixP
->fx_cgen
.insn
= insn
;
248 fixP
->fx_cgen
.opinfo
= opinfo
;
253 /* Default routine to record a fixup given an expression.
254 This is a cover function to fix_new_exp.
255 It exists because we record INSN with the fixup.
257 FRAG and WHERE are their respective arguments to fix_new_exp.
259 OPINFO is something the caller chooses to help in reloc determination.
261 At this point we do not use a bfd_reloc_code_real_type for
262 operands residing in the insn, but instead just use the
263 operand index. This lets us easily handle fixups for any
264 operand type. We pick a BFD reloc type in md_apply_fix. */
267 gas_cgen_record_fixup_exp (frag
, where
, insn
, length
, operand
, opinfo
, exp
)
270 const CGEN_INSN
* insn
;
272 const CGEN_OPERAND
* operand
;
278 /* It may seem strange to use operand->attrs and not insn->attrs here,
279 but it is the operand that has a pc relative relocation. */
280 fixP
= fix_new_exp (frag
, where
, length
/ 8, exp
,
281 CGEN_OPERAND_ATTR_VALUE (operand
, CGEN_OPERAND_PCREL_ADDR
),
282 (bfd_reloc_code_real_type
)
283 ((int) BFD_RELOC_UNUSED
284 + (int) operand
->type
));
285 fixP
->fx_cgen
.insn
= insn
;
286 fixP
->fx_cgen
.opinfo
= opinfo
;
291 /* Used for communication between the next two procedures. */
292 static jmp_buf expr_jmp_buf
;
293 static int expr_jmp_buf_p
;
295 /* Callback for cgen interface. Parse the expression at *STRP.
296 The result is an error message or NULL for success (in which case
297 *STRP is advanced past the parsed text).
298 WANT is an indication of what the caller is looking for.
299 If WANT == CGEN_ASM_PARSE_INIT the caller is beginning to try to match
300 a table entry with the insn, reset the queued fixups counter.
301 An enum cgen_parse_operand_result is stored in RESULTP.
302 OPINDEX is the operand's table entry index.
303 OPINFO is something the caller chooses to help in reloc determination.
304 The resulting value is stored in VALUEP. */
307 gas_cgen_parse_operand (cd
, want
, strP
, opindex
, opinfo
, resultP
, valueP
)
308 CGEN_CPU_DESC cd ATTRIBUTE_UNUSED
;
309 enum cgen_parse_operand_type want
;
313 enum cgen_parse_operand_result
*resultP
;
317 /* These are volatile to survive the setjmp. */
318 char * volatile hold
;
319 enum cgen_parse_operand_result
* volatile resultP_1
;
320 volatile int opinfo_1
;
323 static enum cgen_parse_operand_result
*resultP_1
;
329 if (want
== CGEN_PARSE_OPERAND_INIT
)
331 gas_cgen_init_parse ();
336 hold
= input_line_pointer
;
337 input_line_pointer
= (char *) *strP
;
340 /* We rely on md_operand to longjmp back to us.
341 This is done via gas_cgen_md_operand. */
342 if (setjmp (expr_jmp_buf
) != 0)
345 input_line_pointer
= (char *) hold
;
346 *resultP_1
= CGEN_PARSE_OPERAND_RESULT_ERROR
;
347 return _("illegal operand");
355 *strP
= input_line_pointer
;
356 input_line_pointer
= hold
;
358 #ifdef TC_CGEN_PARSE_FIX_EXP
359 opinfo_1
= TC_CGEN_PARSE_FIX_EXP (opinfo_1
, & exp
);
362 /* FIXME: Need to check `want'. */
367 errmsg
= _("illegal operand");
368 *resultP
= CGEN_PARSE_OPERAND_RESULT_ERROR
;
371 errmsg
= _("missing operand");
372 *resultP
= CGEN_PARSE_OPERAND_RESULT_ERROR
;
375 if (want
== CGEN_PARSE_OPERAND_SYMBOLIC
)
377 *valueP
= exp
.X_add_number
;
378 *resultP
= CGEN_PARSE_OPERAND_RESULT_NUMBER
;
381 *valueP
= exp
.X_add_number
;
382 *resultP
= CGEN_PARSE_OPERAND_RESULT_REGISTER
;
386 queue_fixup (opindex
, opinfo_1
, &exp
);
388 *resultP
= CGEN_PARSE_OPERAND_RESULT_QUEUED
;
395 /* md_operand handler to catch unrecognized expressions and halt the
396 parsing process so the next entry can be tried.
398 ??? This could be done differently by adding code to `expression'. */
401 gas_cgen_md_operand (expressionP
)
402 expressionS
*expressionP ATTRIBUTE_UNUSED
;
404 /* Don't longjmp if we're not called from within cgen_parse_operand(). */
406 longjmp (expr_jmp_buf
, 1);
409 /* Finish assembling instruction INSN.
410 BUF contains what we've built up so far.
411 LENGTH is the size of the insn in bits.
412 RELAX_P is non-zero if relaxable insns should be emitted as such.
413 Otherwise they're emitted in non-relaxable forms.
414 The "result" is stored in RESULT if non-NULL. */
417 gas_cgen_finish_insn (insn
, buf
, length
, relax_p
, result
)
418 const CGEN_INSN
*insn
;
419 CGEN_INSN_BYTES_PTR buf
;
422 finished_insnS
*result
;
427 unsigned int byte_len
= length
/ 8;
429 /* ??? Target foo issues various warnings here, so one might want to provide
430 a hook here. However, our caller is defined in tc-foo.c so there
431 shouldn't be a need for a hook. */
433 /* Write out the instruction.
434 It is important to fetch enough space in one call to `frag_more'.
435 We use (f - frag_now->fr_literal) to compute where we are and we
436 don't want frag_now to change between calls.
438 Relaxable instructions: We need to ensure we allocate enough
439 space for the largest insn. */
441 if (CGEN_INSN_ATTR_VALUE (insn
, CGEN_INSN_RELAXED
))
442 /* These currently shouldn't get here. */
445 /* Is there a relaxable insn with the relaxable operand needing a fixup? */
448 if (relax_p
&& CGEN_INSN_ATTR_VALUE (insn
, CGEN_INSN_RELAXABLE
))
450 /* Scan the fixups for the operand affected by relaxing
451 (i.e. the branch address). */
453 for (i
= 0; i
< num_fixups
; ++i
)
455 if (CGEN_OPERAND_ATTR_VALUE (cgen_operand_lookup_by_num (gas_cgen_cpu_desc
, fixups
[i
].opindex
),
464 if (relax_operand
!= -1)
472 #ifdef TC_CGEN_MAX_RELAX
473 max_len
= TC_CGEN_MAX_RELAX (insn
, byte_len
);
475 max_len
= CGEN_MAX_INSN_SIZE
;
477 /* Ensure variable part and fixed part are in same fragment. */
478 /* FIXME: Having to do this seems like a hack. */
481 /* Allocate space for the fixed part. */
482 f
= frag_more (byte_len
);
484 /* Create a relaxable fragment for this instruction. */
487 exp
= &fixups
[relax_operand
].exp
;
488 sym
= exp
->X_add_symbol
;
489 off
= exp
->X_add_number
;
490 if (exp
->X_op
!= O_constant
&& exp
->X_op
!= O_symbol
)
492 /* Handle complex expressions. */
493 sym
= make_expr_symbol (exp
);
497 frag_var (rs_machine_dependent
,
498 max_len
- byte_len
/* max chars */,
499 0 /* variable part already allocated */,
500 /* FIXME: When we machine generate the relax table,
501 machine generate a macro to compute subtype. */
507 /* Record the operand number with the fragment so md_convert_frag
508 can use gas_cgen_md_record_fixup to record the appropriate reloc. */
509 old_frag
->fr_cgen
.insn
= insn
;
510 old_frag
->fr_cgen
.opindex
= fixups
[relax_operand
].opindex
;
511 old_frag
->fr_cgen
.opinfo
= fixups
[relax_operand
].opinfo
;
513 result
->frag
= old_frag
;
517 f
= frag_more (byte_len
);
519 result
->frag
= frag_now
;
522 /* If we're recording insns as numbers (rather than a string of bytes),
523 target byte order handling is deferred until now. */
525 cgen_put_insn_value (gas_cgen_cpu_desc
, (unsigned char *) f
, length
, *buf
);
527 memcpy (f
, buf
, byte_len
);
530 /* Emit DWARF2 debugging information. */
531 dwarf2_emit_insn (byte_len
);
533 /* Create any fixups. */
534 for (i
= 0; i
< num_fixups
; ++i
)
537 const CGEN_OPERAND
*operand
=
538 cgen_operand_lookup_by_num (gas_cgen_cpu_desc
, fixups
[i
].opindex
);
540 /* Don't create fixups for these. That's done during relaxation.
541 We don't need to test for CGEN_INSN_RELAXED as they can't get here
544 && CGEN_INSN_ATTR_VALUE (insn
, CGEN_INSN_RELAXABLE
)
545 && CGEN_OPERAND_ATTR_VALUE (operand
, CGEN_OPERAND_RELAX
))
548 #ifndef md_cgen_record_fixup_exp
549 #define md_cgen_record_fixup_exp gas_cgen_record_fixup_exp
552 fixP
= md_cgen_record_fixup_exp (frag_now
, f
- frag_now
->fr_literal
,
553 insn
, length
, operand
,
557 result
->fixups
[i
] = fixP
;
562 result
->num_fixups
= num_fixups
;
567 /* Apply a fixup to the object code. This is called for all the
568 fixups we generated by the call to fix_new_exp, above. In the call
569 above we used a reloc code which was the largest legal reloc code
570 plus the operand index. Here we undo that to recover the operand
571 index. At this point all symbol values should be fully resolved,
572 and we attempt to completely resolve the reloc. If we can not do
573 that, we determine the correct reloc code and put it back in the fixup. */
575 /* FIXME: This function handles some of the fixups and bfd_install_relocation
576 handles the rest. bfd_install_relocation (or some other bfd function)
577 should handle them all. */
580 gas_cgen_md_apply_fix (fixP
, valP
, seg
)
583 segT seg ATTRIBUTE_UNUSED
;
585 char *where
= fixP
->fx_frag
->fr_literal
+ fixP
->fx_where
;
586 valueT value
= * valP
;
587 /* Canonical name, since used a lot. */
588 CGEN_CPU_DESC cd
= gas_cgen_cpu_desc
;
590 if (fixP
->fx_addsy
== (symbolS
*) NULL
)
593 /* We don't actually support subtracting a symbol. */
594 if (fixP
->fx_subsy
!= (symbolS
*) NULL
)
595 as_bad_where (fixP
->fx_file
, fixP
->fx_line
, _("expression too complex"));
597 if ((int) fixP
->fx_r_type
>= (int) BFD_RELOC_UNUSED
)
599 int opindex
= (int) fixP
->fx_r_type
- (int) BFD_RELOC_UNUSED
;
600 const CGEN_OPERAND
*operand
= cgen_operand_lookup_by_num (cd
, opindex
);
602 bfd_reloc_code_real_type reloc_type
;
603 CGEN_FIELDS
*fields
= alloca (CGEN_CPU_SIZEOF_FIELDS (cd
));
604 const CGEN_INSN
*insn
= fixP
->fx_cgen
.insn
;
606 /* If the reloc has been fully resolved finish the operand here. */
607 /* FIXME: This duplicates the capabilities of code in BFD. */
609 /* FIXME: If partial_inplace isn't set bfd_install_relocation won't
610 finish the job. Testing for pcrel is a temporary hack. */
613 CGEN_CPU_SET_FIELDS_BITSIZE (cd
) (fields
, CGEN_INSN_BITSIZE (insn
));
614 CGEN_CPU_SET_VMA_OPERAND (cd
) (cd
, opindex
, fields
, (bfd_vma
) value
);
618 CGEN_INSN_INT insn_value
=
619 cgen_get_insn_value (cd
, (unsigned char *) where
,
620 CGEN_INSN_BITSIZE (insn
));
622 /* ??? 0 is passed for `pc'. */
623 errmsg
= CGEN_CPU_INSERT_OPERAND (cd
) (cd
, opindex
, fields
,
624 &insn_value
, (bfd_vma
) 0);
625 cgen_put_insn_value (cd
, (unsigned char *) where
,
626 CGEN_INSN_BITSIZE (insn
), insn_value
);
629 /* ??? 0 is passed for `pc'. */
630 errmsg
= CGEN_CPU_INSERT_OPERAND (cd
) (cd
, opindex
, fields
,
631 (unsigned char *) where
,
635 as_bad_where (fixP
->fx_file
, fixP
->fx_line
, "%s", errmsg
);
641 /* The operand isn't fully resolved. Determine a BFD reloc value
642 based on the operand information and leave it to
643 bfd_install_relocation. Note that this doesn't work when
644 partial_inplace == false. */
646 reloc_type
= md_cgen_lookup_reloc (insn
, operand
, fixP
);
648 if (reloc_type
!= BFD_RELOC_NONE
)
649 fixP
->fx_r_type
= reloc_type
;
652 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
653 _("unresolved expression that must be resolved"));
658 else if (fixP
->fx_done
)
660 /* We're finished with this fixup. Install it because
661 bfd_install_relocation won't be called to do it. */
662 switch (fixP
->fx_r_type
)
665 md_number_to_chars (where
, value
, 1);
668 md_number_to_chars (where
, value
, 2);
671 md_number_to_chars (where
, value
, 4);
674 md_number_to_chars (where
, value
, 8);
677 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
678 _("internal error: can't install fix for reloc type %d (`%s')"),
679 fixP
->fx_r_type
, bfd_get_reloc_code_name (fixP
->fx_r_type
));
684 bfd_install_relocation will be called to finish things up. */
686 /* Tuck `value' away for use by tc_gen_reloc.
687 See the comment describing fx_addnumber in write.h.
688 This field is misnamed (or misused :-). */
689 fixP
->fx_addnumber
= value
;
692 /* Translate internal representation of relocation info to BFD target format.
694 FIXME: To what extent can we get all relevant targets to use this? */
697 gas_cgen_tc_gen_reloc (section
, fixP
)
698 asection
* section ATTRIBUTE_UNUSED
;
703 reloc
= (arelent
*) xmalloc (sizeof (arelent
));
705 reloc
->howto
= bfd_reloc_type_lookup (stdoutput
, fixP
->fx_r_type
);
706 if (reloc
->howto
== (reloc_howto_type
*) NULL
)
708 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
709 _("relocation is not supported"));
713 assert (!fixP
->fx_pcrel
== !reloc
->howto
->pc_relative
);
715 reloc
->sym_ptr_ptr
= (asymbol
**) xmalloc (sizeof (asymbol
*));
716 *reloc
->sym_ptr_ptr
= symbol_get_bfdsym (fixP
->fx_addsy
);
718 /* Use fx_offset for these cases. */
719 if (fixP
->fx_r_type
== BFD_RELOC_VTABLE_ENTRY
720 || fixP
->fx_r_type
== BFD_RELOC_VTABLE_INHERIT
)
721 reloc
->addend
= fixP
->fx_offset
;
723 reloc
->addend
= fixP
->fx_addnumber
;
725 reloc
->address
= fixP
->fx_frag
->fr_address
+ fixP
->fx_where
;
729 /* Perform any cgen specific initialisation.
730 Called after gas_cgen_cpu_desc has been created. */
735 if (flag_signed_overflow_ok
)
736 cgen_set_signed_overflow_ok (gas_cgen_cpu_desc
);
738 cgen_clear_signed_overflow_ok (gas_cgen_cpu_desc
);