1 /* GAS interface for targets using CGEN: Cpu tools GENerator.
2 Copyright 1996, 1997, 1998, 1999, 2000, 2001
3 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
23 #include "libiberty.h"
26 #include "cgen-desc.h"
30 #include "dwarf2dbg.h"
32 /* Opcode table descriptor, must be set by md_begin. */
34 CGEN_CPU_DESC gas_cgen_cpu_desc
;
36 /* Callback to insert a register into the symbol table.
37 A target may choose to let GAS parse the registers.
38 ??? Not currently used. */
41 cgen_asm_record_register (name
, number
)
45 /* Use symbol_create here instead of symbol_new so we don't try to
46 output registers into the object file's symbol table. */
47 symbol_table_insert (symbol_create (name
, reg_section
,
48 number
, &zero_address_frag
));
51 /* We need to keep a list of fixups. We can't simply generate them as
52 we go, because that would require us to first create the frag, and
53 that would screw up references to ``.''.
55 This is used by cpu's with simple operands. It keeps knowledge of what
56 an `expressionS' is and what a `fixup' is out of CGEN which for the time
59 OPINDEX is the index in the operand table.
60 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 intially. 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.
131 struct saved_fixups
{
132 struct fixup fixup_chain
[GAS_CGEN_MAX_FIXUPS
];
133 int num_fixups_in_chain
;
136 static struct saved_fixups stored_fixups
[MAX_SAVED_FIXUP_CHAINS
];
139 gas_cgen_initialize_saved_fixups_array ()
142 while (i
< MAX_SAVED_FIXUP_CHAINS
)
143 stored_fixups
[i
++].num_fixups_in_chain
= 0;
147 gas_cgen_save_fixups (int i
)
149 if (i
< 0 || i
>= MAX_SAVED_FIXUP_CHAINS
)
151 as_fatal("index into stored_fixups[] out of bounds");
154 stored_fixups
[i
].num_fixups_in_chain
= num_fixups
;
155 memcpy(stored_fixups
[i
].fixup_chain
, fixups
,
156 sizeof (fixups
[0])*num_fixups
);
161 gas_cgen_restore_fixups (int i
)
163 if (i
< 0 || i
>= MAX_SAVED_FIXUP_CHAINS
)
165 as_fatal("index into stored_fixups[] out of bounds");
168 num_fixups
= stored_fixups
[i
].num_fixups_in_chain
;
169 memcpy(fixups
,stored_fixups
[i
].fixup_chain
,
170 (sizeof (stored_fixups
[i
].fixup_chain
[0]))*num_fixups
);
171 stored_fixups
[i
].num_fixups_in_chain
= 0;
175 gas_cgen_swap_fixups (int i
)
178 struct fixup tmp_fixup
;
180 if (i
< 0 || i
>= MAX_SAVED_FIXUP_CHAINS
)
182 as_fatal("index into stored_fixups[] out of bounds");
188 gas_cgen_restore_fixups (i
);
190 else if (stored_fixups
[i
].num_fixups_in_chain
== 0)
192 gas_cgen_save_fixups (i
);
196 tmp
= stored_fixups
[i
].num_fixups_in_chain
;
197 stored_fixups
[i
].num_fixups_in_chain
= num_fixups
;
200 for (tmp
= GAS_CGEN_MAX_FIXUPS
; tmp
--;)
202 tmp_fixup
= stored_fixups
[i
].fixup_chain
[tmp
];
203 stored_fixups
[i
].fixup_chain
[tmp
] = fixups
[tmp
];
204 fixups
[tmp
] = tmp_fixup
;
209 /* Default routine to record a fixup.
210 This is a cover function to fix_new.
211 It exists because we record INSN with the fixup.
213 FRAG and WHERE are their respective arguments to fix_new_exp.
215 OPINFO is something the caller chooses to help in reloc determination.
217 At this point we do not use a bfd_reloc_code_real_type for
218 operands residing in the insn, but instead just use the
219 operand index. This lets us easily handle fixups for any
220 operand type. We pick a BFD reloc type in md_apply_fix. */
223 gas_cgen_record_fixup (frag
, where
, insn
, length
, operand
, opinfo
, symbol
, offset
)
226 const CGEN_INSN
* insn
;
228 const CGEN_OPERAND
* operand
;
235 /* It may seem strange to use operand->attrs and not insn->attrs here,
236 but it is the operand that has a pc relative relocation. */
238 fixP
= fix_new (frag
, where
, length
/ 8, symbol
, offset
,
239 CGEN_OPERAND_ATTR_VALUE (operand
, CGEN_OPERAND_PCREL_ADDR
),
240 (bfd_reloc_code_real_type
)
241 ((int) BFD_RELOC_UNUSED
242 + (int) operand
->type
));
243 fixP
->fx_cgen
.insn
= insn
;
244 fixP
->fx_cgen
.opinfo
= opinfo
;
249 /* Default routine to record a fixup given an expression.
250 This is a cover function to fix_new_exp.
251 It exists because we record INSN with the fixup.
253 FRAG and WHERE are their respective arguments to fix_new_exp.
255 OPINFO is something the caller chooses to help in reloc determination.
257 At this point we do not use a bfd_reloc_code_real_type for
258 operands residing in the insn, but instead just use the
259 operand index. This lets us easily handle fixups for any
260 operand type. We pick a BFD reloc type in md_apply_fix. */
263 gas_cgen_record_fixup_exp (frag
, where
, insn
, length
, operand
, opinfo
, exp
)
266 const CGEN_INSN
* insn
;
268 const CGEN_OPERAND
* operand
;
274 /* It may seem strange to use operand->attrs and not insn->attrs here,
275 but it is the operand that has a pc relative relocation. */
277 fixP
= fix_new_exp (frag
, where
, length
/ 8, exp
,
278 CGEN_OPERAND_ATTR_VALUE (operand
, CGEN_OPERAND_PCREL_ADDR
),
279 (bfd_reloc_code_real_type
)
280 ((int) BFD_RELOC_UNUSED
281 + (int) operand
->type
));
282 fixP
->fx_cgen
.insn
= insn
;
283 fixP
->fx_cgen
.opinfo
= opinfo
;
288 /* Used for communication between the next two procedures. */
289 static jmp_buf expr_jmp_buf
;
290 static int expr_jmp_buf_p
;
292 /* Callback for cgen interface. Parse the expression at *STRP.
293 The result is an error message or NULL for success (in which case
294 *STRP is advanced past the parsed text).
295 WANT is an indication of what the caller is looking for.
296 If WANT == CGEN_ASM_PARSE_INIT the caller is beginning to try to match
297 a table entry with the insn, reset the queued fixups counter.
298 An enum cgen_parse_operand_result is stored in RESULTP.
299 OPINDEX is the operand's table entry index.
300 OPINFO is something the caller chooses to help in reloc determination.
301 The resulting value is stored in VALUEP. */
304 gas_cgen_parse_operand (cd
, want
, strP
, opindex
, opinfo
, resultP
, valueP
)
305 CGEN_CPU_DESC cd ATTRIBUTE_UNUSED
;
306 enum cgen_parse_operand_type want
;
310 enum cgen_parse_operand_result
*resultP
;
314 /* These are volatile to survive the setjmp. */
315 char * volatile hold
;
316 enum cgen_parse_operand_result
* volatile resultP_1
;
319 static enum cgen_parse_operand_result
*resultP_1
;
321 const char *errmsg
= NULL
;
324 if (want
== CGEN_PARSE_OPERAND_INIT
)
326 gas_cgen_init_parse ();
331 hold
= input_line_pointer
;
332 input_line_pointer
= (char *) *strP
;
334 /* We rely on md_operand to longjmp back to us.
335 This is done via gas_cgen_md_operand. */
336 if (setjmp (expr_jmp_buf
) != 0)
339 input_line_pointer
= (char *) hold
;
340 *resultP_1
= CGEN_PARSE_OPERAND_RESULT_ERROR
;
341 return "illegal operand";
348 *strP
= input_line_pointer
;
349 input_line_pointer
= hold
;
351 /* FIXME: Need to check `want'. */
356 errmsg
= _("illegal operand");
357 *resultP
= CGEN_PARSE_OPERAND_RESULT_ERROR
;
360 errmsg
= _("missing operand");
361 *resultP
= CGEN_PARSE_OPERAND_RESULT_ERROR
;
364 *valueP
= exp
.X_add_number
;
365 *resultP
= CGEN_PARSE_OPERAND_RESULT_NUMBER
;
368 *valueP
= exp
.X_add_number
;
369 *resultP
= CGEN_PARSE_OPERAND_RESULT_REGISTER
;
372 queue_fixup (opindex
, opinfo
, &exp
);
374 *resultP
= CGEN_PARSE_OPERAND_RESULT_QUEUED
;
381 /* md_operand handler to catch unrecognized expressions and halt the
382 parsing process so the next entry can be tried.
384 ??? This could be done differently by adding code to `expression'. */
387 gas_cgen_md_operand (expressionP
)
388 expressionS
*expressionP ATTRIBUTE_UNUSED
;
390 /* Don't longjmp if we're not called from within cgen_parse_operand(). */
392 longjmp (expr_jmp_buf
, 1);
395 /* Finish assembling instruction INSN.
396 BUF contains what we've built up so far.
397 LENGTH is the size of the insn in bits.
398 RELAX_P is non-zero if relaxable insns should be emitted as such.
399 Otherwise they're emitted in non-relaxable forms.
400 The "result" is stored in RESULT if non-NULL. */
403 gas_cgen_finish_insn (insn
, buf
, length
, relax_p
, result
)
404 const CGEN_INSN
*insn
;
405 CGEN_INSN_BYTES_PTR buf
;
408 finished_insnS
*result
;
413 unsigned int byte_len
= length
/ 8;
415 /* ??? Target foo issues various warnings here, so one might want to provide
416 a hook here. However, our caller is defined in tc-foo.c so there
417 shouldn't be a need for a hook. */
419 /* Write out the instruction.
420 It is important to fetch enough space in one call to `frag_more'.
421 We use (f - frag_now->fr_literal) to compute where we are and we
422 don't want frag_now to change between calls.
424 Relaxable instructions: We need to ensure we allocate enough
425 space for the largest insn. */
427 if (CGEN_INSN_ATTR_VALUE (insn
, CGEN_INSN_RELAX
))
428 /* These currently shouldn't get here. */
431 /* Is there a relaxable insn with the relaxable operand needing a fixup? */
434 if (relax_p
&& CGEN_INSN_ATTR_VALUE (insn
, CGEN_INSN_RELAXABLE
))
436 /* Scan the fixups for the operand affected by relaxing
437 (i.e. the branch address). */
439 for (i
= 0; i
< num_fixups
; ++i
)
441 if (CGEN_OPERAND_ATTR_VALUE (cgen_operand_lookup_by_num (gas_cgen_cpu_desc
, fixups
[i
].opindex
),
450 if (relax_operand
!= -1)
458 #ifdef TC_CGEN_MAX_RELAX
459 max_len
= TC_CGEN_MAX_RELAX (insn
, byte_len
);
461 max_len
= CGEN_MAX_INSN_SIZE
;
463 /* Ensure variable part and fixed part are in same fragment. */
464 /* FIXME: Having to do this seems like a hack. */
467 /* Allocate space for the fixed part. */
468 f
= frag_more (byte_len
);
470 /* Create a relaxable fragment for this instruction. */
473 exp
= &fixups
[relax_operand
].exp
;
474 sym
= exp
->X_add_symbol
;
475 off
= exp
->X_add_number
;
476 if (exp
->X_op
!= O_constant
&& exp
->X_op
!= O_symbol
)
478 /* Handle complex expressions. */
479 sym
= make_expr_symbol (exp
);
483 frag_var (rs_machine_dependent
,
484 max_len
- byte_len
/* max chars */,
485 0 /* variable part already allocated */,
486 /* FIXME: When we machine generate the relax table,
487 machine generate a macro to compute subtype. */
493 /* Record the operand number with the fragment so md_convert_frag
494 can use gas_cgen_md_record_fixup to record the appropriate reloc. */
495 old_frag
->fr_cgen
.insn
= insn
;
496 old_frag
->fr_cgen
.opindex
= fixups
[relax_operand
].opindex
;
497 old_frag
->fr_cgen
.opinfo
= fixups
[relax_operand
].opinfo
;
499 result
->frag
= old_frag
;
503 f
= frag_more (byte_len
);
505 result
->frag
= frag_now
;
508 /* If we're recording insns as numbers (rather than a string of bytes),
509 target byte order handling is deferred until now. */
511 cgen_put_insn_value (gas_cgen_cpu_desc
, f
, length
, *buf
);
513 memcpy (f
, buf
, byte_len
);
516 /* Emit DWARF2 debugging information. */
517 dwarf2_emit_insn (byte_len
);
519 /* Create any fixups. */
520 for (i
= 0; i
< num_fixups
; ++i
)
523 const CGEN_OPERAND
*operand
=
524 cgen_operand_lookup_by_num (gas_cgen_cpu_desc
, fixups
[i
].opindex
);
526 /* Don't create fixups for these. That's done during relaxation.
527 We don't need to test for CGEN_INSN_RELAX as they can't get here
530 && CGEN_INSN_ATTR_VALUE (insn
, CGEN_INSN_RELAXABLE
)
531 && CGEN_OPERAND_ATTR_VALUE (operand
, CGEN_OPERAND_RELAX
))
534 #ifndef md_cgen_record_fixup_exp
535 #define md_cgen_record_fixup_exp gas_cgen_record_fixup_exp
538 fixP
= md_cgen_record_fixup_exp (frag_now
, f
- frag_now
->fr_literal
,
539 insn
, length
, operand
,
543 result
->fixups
[i
] = fixP
;
548 result
->num_fixups
= num_fixups
;
553 /* Apply a fixup to the object code. This is called for all the
554 fixups we generated by the call to fix_new_exp, above. In the call
555 above we used a reloc code which was the largest legal reloc code
556 plus the operand index. Here we undo that to recover the operand
557 index. At this point all symbol values should be fully resolved,
558 and we attempt to completely resolve the reloc. If we can not do
559 that, we determine the correct reloc code and put it back in the fixup. */
561 /* FIXME: This function handles some of the fixups and bfd_install_relocation
562 handles the rest. bfd_install_relocation (or some other bfd function)
563 should handle them all. */
566 gas_cgen_md_apply_fix3 (fixP
, valueP
, seg
)
569 segT seg ATTRIBUTE_UNUSED
;
571 char *where
= fixP
->fx_frag
->fr_literal
+ fixP
->fx_where
;
573 /* Canonical name, since used a lot. */
574 CGEN_CPU_DESC cd
= gas_cgen_cpu_desc
;
576 /* FIXME FIXME FIXME: The value we are passed in *valuep includes
577 the symbol values. Since we are using BFD_ASSEMBLER, if we are
578 doing this relocation the code in write.c is going to call
579 bfd_install_relocation, which is also going to use the symbol
580 value. That means that if the reloc is fully resolved we want to
581 use *valuep since bfd_install_relocation is not being used.
582 However, if the reloc is not fully resolved we do not want to use
583 *valuep, and must use fx_offset instead. However, if the reloc
584 is PC relative, we do want to use *valuep since it includes the
585 result of md_pcrel_from. This is confusing. */
587 if (fixP
->fx_addsy
== (symbolS
*) NULL
)
592 else if (fixP
->fx_pcrel
)
596 value
= fixP
->fx_offset
;
597 if (fixP
->fx_subsy
!= (symbolS
*) NULL
)
599 if (S_GET_SEGMENT (fixP
->fx_subsy
) == absolute_section
)
600 value
-= S_GET_VALUE (fixP
->fx_subsy
);
603 /* We don't actually support subtracting a symbol. */
604 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
605 _("expression too complex"));
610 if ((int) fixP
->fx_r_type
>= (int) BFD_RELOC_UNUSED
)
612 int opindex
= (int) fixP
->fx_r_type
- (int) BFD_RELOC_UNUSED
;
613 const CGEN_OPERAND
*operand
= cgen_operand_lookup_by_num (cd
, opindex
);
615 bfd_reloc_code_real_type reloc_type
;
616 CGEN_FIELDS
*fields
= alloca (CGEN_CPU_SIZEOF_FIELDS (cd
));
617 const CGEN_INSN
*insn
= fixP
->fx_cgen
.insn
;
619 /* If the reloc has been fully resolved finish the operand here. */
620 /* FIXME: This duplicates the capabilities of code in BFD. */
622 /* FIXME: If partial_inplace isn't set bfd_install_relocation won't
623 finish the job. Testing for pcrel is a temporary hack. */
626 CGEN_CPU_SET_FIELDS_BITSIZE (cd
) (fields
, CGEN_INSN_BITSIZE (insn
));
627 CGEN_CPU_SET_VMA_OPERAND (cd
) (cd
, opindex
, fields
, (bfd_vma
) value
);
631 CGEN_INSN_INT insn_value
=
632 cgen_get_insn_value (cd
, where
, CGEN_INSN_BITSIZE (insn
));
634 /* ??? 0 is passed for `pc'. */
635 errmsg
= CGEN_CPU_INSERT_OPERAND (cd
) (cd
, opindex
, fields
,
636 &insn_value
, (bfd_vma
) 0);
637 cgen_put_insn_value (cd
, where
, CGEN_INSN_BITSIZE (insn
),
641 /* ??? 0 is passed for `pc'. */
642 errmsg
= CGEN_CPU_INSERT_OPERAND (cd
) (cd
, opindex
, fields
, where
,
646 as_bad_where (fixP
->fx_file
, fixP
->fx_line
, "%s", errmsg
);
652 /* The operand isn't fully resolved. Determine a BFD reloc value
653 based on the operand information and leave it to
654 bfd_install_relocation. Note that this doesn't work when
655 partial_inplace == false. */
657 reloc_type
= md_cgen_lookup_reloc (insn
, operand
, fixP
);
658 if (reloc_type
!= BFD_RELOC_NONE
)
660 fixP
->fx_r_type
= reloc_type
;
664 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
665 _("unresolved expression that must be resolved"));
670 else if (fixP
->fx_done
)
672 /* We're finished with this fixup. Install it because
673 bfd_install_relocation won't be called to do it. */
674 switch (fixP
->fx_r_type
)
677 md_number_to_chars (where
, value
, 1);
680 md_number_to_chars (where
, value
, 2);
683 md_number_to_chars (where
, value
, 4);
686 md_number_to_chars (where
, value
, 8);
689 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
690 _("internal error: can't install fix for reloc type %d (`%s')"),
691 fixP
->fx_r_type
, bfd_get_reloc_code_name (fixP
->fx_r_type
));
697 /* bfd_install_relocation will be called to finish things up. */
700 /* Tuck `value' away for use by tc_gen_reloc.
701 See the comment describing fx_addnumber in write.h.
702 This field is misnamed (or misused :-). */
703 fixP
->fx_addnumber
= value
;
708 /* Translate internal representation of relocation info to BFD target format.
710 FIXME: To what extent can we get all relevant targets to use this? */
713 gas_cgen_tc_gen_reloc (section
, fixP
)
714 asection
* section ATTRIBUTE_UNUSED
;
719 reloc
= (arelent
*) xmalloc (sizeof (arelent
));
721 reloc
->howto
= bfd_reloc_type_lookup (stdoutput
, fixP
->fx_r_type
);
722 if (reloc
->howto
== (reloc_howto_type
*) NULL
)
724 as_bad_where (fixP
->fx_file
, fixP
->fx_line
,
725 _("relocation is not supported"));
729 assert (!fixP
->fx_pcrel
== !reloc
->howto
->pc_relative
);
731 reloc
->sym_ptr_ptr
= (asymbol
**) xmalloc (sizeof (asymbol
*));
732 *reloc
->sym_ptr_ptr
= symbol_get_bfdsym (fixP
->fx_addsy
);
734 /* Use fx_offset for these cases. */
735 if (fixP
->fx_r_type
== BFD_RELOC_VTABLE_ENTRY
736 || fixP
->fx_r_type
== BFD_RELOC_VTABLE_INHERIT
)
737 reloc
->addend
= fixP
->fx_offset
;
739 reloc
->addend
= fixP
->fx_addnumber
;
741 reloc
->address
= fixP
->fx_frag
->fr_address
+ fixP
->fx_where
;