xref: /netbsd-src/external/gpl3/binutils.old/dist/gas/config/tc-xstormy16.c (revision 212397c69a103ae7e5eafa8731ddfae671d2dee7)
1 /* tc-xstormy16.c -- Assembler for the Sanyo XSTORMY16.
2    Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009, 2010
3    Free Software Foundation.
4 
5    This file is part of GAS, the GNU Assembler.
6 
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 3, or (at your option)
10    any later version.
11 
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.
16 
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
19    the Free Software Foundation, 51 Franklin Street - Fifth Floor,
20    Boston, MA 02110-1301, USA.  */
21 
22 #include "as.h"
23 #include "subsegs.h"
24 #include "symcat.h"
25 #include "opcodes/xstormy16-desc.h"
26 #include "opcodes/xstormy16-opc.h"
27 #include "cgen.h"
28 
29 /* Structure to hold all of the different components describing
30    an individual instruction.  */
31 typedef struct
32 {
33   const CGEN_INSN *	insn;
34   const CGEN_INSN *	orig_insn;
35   CGEN_FIELDS		fields;
36 #if CGEN_INT_INSN_P
37   CGEN_INSN_INT         buffer [1];
38 #define INSN_VALUE(buf) (*(buf))
39 #else
40   unsigned char         buffer [CGEN_MAX_INSN_SIZE];
41 #define INSN_VALUE(buf) (buf)
42 #endif
43   char *		addr;
44   fragS *		frag;
45   int                   num_fixups;
46   fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
47   int                   indices [MAX_OPERAND_INSTANCES];
48 }
49 xstormy16_insn;
50 
51 const char comment_chars[]        = ";";
52 const char line_comment_chars[]   = "#";
53 const char line_separator_chars[] = "|";
54 const char EXP_CHARS[]            = "eE";
55 const char FLT_CHARS[]            = "dD";
56 
57 #define O_fptr_symbol	(O_max + 1)
58 
59 #define XSTORMY16_SHORTOPTS ""
60 const char * md_shortopts = XSTORMY16_SHORTOPTS;
61 
62 struct option md_longopts[] =
63 {
64   {NULL, no_argument, NULL, 0}
65 };
66 size_t md_longopts_size = sizeof (md_longopts);
67 
68 int
69 md_parse_option (int    c ATTRIBUTE_UNUSED,
70 		 char * arg ATTRIBUTE_UNUSED)
71 {
72   return 0;
73 }
74 
75 void
76 md_show_usage (FILE * stream)
77 {
78   fprintf (stream, _(" XSTORMY16 specific command line options:\n"));
79 }
80 
81 /* The target specific pseudo-ops which we support.  */
82 const pseudo_typeS md_pseudo_table[] =
83 {
84   { "word",	cons,		4 },
85   { NULL, 	NULL, 		0 }
86 };
87 
88 
89 void
90 md_begin (void)
91 {
92   /* Initialize the `cgen' interface.  */
93 
94   /* Set the machine number and endian.  */
95   gas_cgen_cpu_desc = xstormy16_cgen_cpu_open (CGEN_CPU_OPEN_MACHS, 0,
96 					  CGEN_CPU_OPEN_ENDIAN,
97 					  CGEN_ENDIAN_LITTLE,
98 					  CGEN_CPU_OPEN_END);
99   xstormy16_cgen_init_asm (gas_cgen_cpu_desc);
100 
101   /* This is a callback from cgen to gas to parse operands.  */
102   cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
103 }
104 
105 static bfd_boolean skipping_fptr = FALSE;
106 
107 void
108 md_assemble (char * str)
109 {
110   xstormy16_insn insn;
111   char *    errmsg;
112 
113   /* Make sure that if we had an erroneous input line which triggered
114      the skipping_fptr boolean that it does not affect following lines.  */
115   skipping_fptr = FALSE;
116 
117   /* Initialize GAS's cgen interface for a new instruction.  */
118   gas_cgen_init_parse ();
119 
120   insn.insn = xstormy16_cgen_assemble_insn
121     (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
122 
123   if (!insn.insn)
124     {
125       as_bad ("%s", errmsg);
126       return;
127     }
128 
129   /* Doesn't really matter what we pass for RELAX_P here.  */
130   gas_cgen_finish_insn (insn.insn, insn.buffer,
131 			CGEN_FIELDS_BITSIZE (& insn.fields), 0, NULL);
132 }
133 
134 void
135 md_operand (expressionS * e)
136 {
137   if (*input_line_pointer != '@')
138     return;
139 
140   if (strncmp (input_line_pointer + 1, "fptr", 4) == 0)
141     {
142       input_line_pointer += 5;
143       SKIP_WHITESPACE ();
144       if (*input_line_pointer != '(')
145 	{
146 	  as_bad (_("Expected '('"));
147 	  goto err;
148 	}
149       input_line_pointer++;
150 
151       expression (e);
152 
153       if (*input_line_pointer != ')')
154 	{
155 	  as_bad (_("Missing ')'"));
156 	  goto err;
157 	}
158       input_line_pointer++;
159       SKIP_WHITESPACE ();
160 
161       if (e->X_op != O_symbol)
162 	as_bad (_("Not a symbolic expression"));
163       else if (* input_line_pointer == '-')
164 	/* We are computing the difference of two function pointers
165 	   like this:
166 
167 	    .hword  @fptr (foo) - @fptr (bar)
168 
169 	  In this situation we do not want to generate O_fptr_symbol
170 	  operands because the result is an absolute value, not a
171 	  function pointer.
172 
173 	  We need to make the check here, rather than when the fixup
174 	  is generated as the function names (foo & bar in the above
175 	  example) might be local symbols and we want the expression
176 	  to be evaluated now.  This kind of thing can happen when
177 	  gcc is generating computed gotos.  */
178 	skipping_fptr = TRUE;
179       else if (skipping_fptr)
180 	skipping_fptr = FALSE;
181       else
182         e->X_op = O_fptr_symbol;
183     }
184 
185   return;
186  err:
187   ignore_rest_of_line ();
188 }
189 
190 /* Called while parsing data to create a fixup.
191    Create BFD_RELOC_XSTORMY16_FPTR16 relocations.  */
192 
193 void
194 xstormy16_cons_fix_new (fragS *f,
195 			int where,
196 			int nbytes,
197 			expressionS *exp)
198 {
199   bfd_reloc_code_real_type code;
200 
201   if (exp->X_op == O_fptr_symbol)
202     {
203       switch (nbytes)
204 	{
205  	case 4:
206  	  /* This can happen when gcc is generating debug output.
207  	     For example it can create a stab with the address of
208  	     a function:
209 
210  	     	.stabs	"foo:F(0,21)",36,0,0,@fptr(foo)
211 
212  	     Since this does not involve switching code pages, we
213  	     just allow the reloc to be generated without any
214  	     @fptr behaviour.  */
215  	  exp->X_op = O_symbol;
216  	  code = BFD_RELOC_32;
217  	  break;
218 
219  	case 2:
220  	  exp->X_op = O_symbol;
221  	  code = BFD_RELOC_XSTORMY16_FPTR16;
222  	  break;
223 
224  	default:
225 	  as_bad (_("unsupported fptr fixup size %d"), nbytes);
226 	  return;
227 	}
228     }
229   else if (nbytes == 1)
230     code = BFD_RELOC_8;
231   else if (nbytes == 2)
232     code = BFD_RELOC_16;
233   else if (nbytes == 4)
234     code = BFD_RELOC_32;
235   else
236     {
237       as_bad (_("unsupported fixup size %d"), nbytes);
238       return;
239     }
240 
241   fix_new_exp (f, where, nbytes, exp, 0, code);
242 }
243 
244 /* Called while parsing an instruction to create a fixup.
245    Create BFD_RELOC_XSTORMY16_FPTR16 relocations.  */
246 
247 fixS *
248 xstormy16_cgen_record_fixup_exp (fragS *              frag,
249 				 int                  where,
250 				 const CGEN_INSN *    insn,
251 				 int                  length,
252 				 const CGEN_OPERAND * operand,
253 				 int                  opinfo,
254 				 expressionS *        exp)
255 {
256   fixS *fixP;
257   operatorT op = exp->X_op;
258 
259   if (op == O_fptr_symbol)
260     exp->X_op = O_symbol;
261 
262   fixP = gas_cgen_record_fixup_exp (frag, where, insn, length,
263 				    operand, opinfo, exp);
264 
265   if (op == O_fptr_symbol)
266     {
267       if (operand->type != XSTORMY16_OPERAND_IMM16)
268 	as_bad (_("unsupported fptr fixup"));
269       else
270 	{
271 	  fixP->fx_r_type = BFD_RELOC_XSTORMY16_FPTR16;
272 	  fixP->fx_where += 2;
273 	}
274     }
275 
276   return fixP;
277 }
278 
279 valueT
280 md_section_align (segT segment, valueT size)
281 {
282   int align = bfd_get_section_alignment (stdoutput, segment);
283 
284   return ((size + (1 << align) - 1) & (-1 << align));
285 }
286 
287 symbolS *
288 md_undefined_symbol (char * name ATTRIBUTE_UNUSED)
289 {
290   return 0;
291 }
292 
293 /* Return an initial guess of the length by which a fragment must grow to
294    hold a branch to reach its destination.
295    Also updates fr_type/fr_subtype as necessary.
296 
297    Called just before doing relaxation.
298    Any symbol that is now undefined will not become defined.
299    The guess for fr_var is ACTUALLY the growth beyond fr_fix.
300    Whatever we do to grow fr_fix or fr_var contributes to our returned value.
301    Although it may not be explicit in the frag, pretend fr_var starts with a
302    0 value.  */
303 
304 int
305 md_estimate_size_before_relax (fragS * fragP ATTRIBUTE_UNUSED,
306 			       segT    segment ATTRIBUTE_UNUSED)
307 {
308   /* No assembler relaxation is defined (or necessary) for this port.  */
309   abort ();
310 }
311 
312 /* *fragP has been relaxed to its final size, and now needs to have
313    the bytes inside it modified to conform to the new size.
314 
315    Called after relaxation is finished.
316    fragP->fr_type == rs_machine_dependent.
317    fragP->fr_subtype is the subtype of what the address relaxed to.  */
318 
319 void
320 md_convert_frag (bfd *   abfd ATTRIBUTE_UNUSED,
321 		 segT    sec ATTRIBUTE_UNUSED,
322 		 fragS * fragP ATTRIBUTE_UNUSED)
323 {
324   /* No assembler relaxation is defined (or necessary) for this port.  */
325   abort ();
326 }
327 
328 /* Functions concerning relocs.  */
329 
330 /* The location from which a PC relative jump should be calculated,
331    given a PC relative reloc.  */
332 
333 long
334 md_pcrel_from_section (fixS * fixP, segT sec)
335 {
336   if ((fixP->fx_addsy != (symbolS *) NULL
337        && (! S_IS_DEFINED (fixP->fx_addsy)
338 	   || S_GET_SEGMENT (fixP->fx_addsy) != sec))
339       || xstormy16_force_relocation (fixP))
340     /* The symbol is undefined,
341        or it is defined but not in this section,
342        or the relocation will be relative to this symbol not the section symbol.
343        Let the linker figure it out.  */
344     return 0;
345 
346   return fixP->fx_frag->fr_address + fixP->fx_where;
347 }
348 
349 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
350    Returns BFD_RELOC_NONE if no reloc type can be found.
351    *FIXP may be modified if desired.  */
352 
353 bfd_reloc_code_real_type
354 md_cgen_lookup_reloc (const CGEN_INSN *    insn ATTRIBUTE_UNUSED,
355 		      const CGEN_OPERAND * operand,
356 		      fixS *               fixP)
357 {
358   switch (operand->type)
359     {
360     case XSTORMY16_OPERAND_IMM2:
361     case XSTORMY16_OPERAND_IMM3:
362     case XSTORMY16_OPERAND_IMM3B:
363     case XSTORMY16_OPERAND_IMM4:
364     case XSTORMY16_OPERAND_HMEM8:
365       return BFD_RELOC_NONE;
366 
367     case XSTORMY16_OPERAND_IMM12:
368       fixP->fx_where += 2;
369       return BFD_RELOC_XSTORMY16_12;
370 
371     case XSTORMY16_OPERAND_IMM8:
372     case XSTORMY16_OPERAND_LMEM8:
373       return fixP->fx_pcrel ? BFD_RELOC_8_PCREL : BFD_RELOC_8;
374 
375     case XSTORMY16_OPERAND_IMM16:
376       /* This might have been processed at parse time.  */
377       fixP->fx_where += 2;
378       if (fixP->fx_cgen.opinfo && fixP->fx_cgen.opinfo != BFD_RELOC_NONE)
379 	return fixP->fx_cgen.opinfo;
380       return fixP->fx_pcrel ? BFD_RELOC_16_PCREL : BFD_RELOC_16;
381 
382     case XSTORMY16_OPERAND_ABS24:
383       return BFD_RELOC_XSTORMY16_24;
384 
385     case XSTORMY16_OPERAND_REL8_4:
386       fixP->fx_addnumber -= 2;
387     case XSTORMY16_OPERAND_REL8_2:
388       fixP->fx_addnumber -= 2;
389       fixP->fx_pcrel = 1;
390       return BFD_RELOC_8_PCREL;
391 
392     case XSTORMY16_OPERAND_REL12:
393       fixP->fx_where += 2;
394       /* Fall through...  */
395     case XSTORMY16_OPERAND_REL12A:
396       fixP->fx_addnumber -= 2;
397       fixP->fx_pcrel = 1;
398       return BFD_RELOC_XSTORMY16_REL_12;
399 
400     default : /* avoid -Wall warning */
401       abort ();
402     }
403 }
404 
405 /* See whether we need to force a relocation into the output file.
406    This is used to force out switch and PC relative relocations when
407    relaxing.  */
408 
409 int
410 xstormy16_force_relocation (fixS * fix)
411 {
412   if (fix->fx_r_type == BFD_RELOC_XSTORMY16_FPTR16)
413     return 1;
414 
415   return generic_force_reloc (fix);
416 }
417 
418 /* Return true if a relocation against a symbol may be replaced with
419    a relocation against section+offset.  */
420 
421 bfd_boolean
422 xstormy16_fix_adjustable (fixS * fixP)
423 {
424   /* We need the symbol name for the VTABLE entries.  */
425   if (fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
426       || fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
427     return FALSE;
428 
429   if (fixP->fx_r_type == BFD_RELOC_XSTORMY16_FPTR16)
430     return FALSE;
431 
432   return TRUE;
433 }
434 
435 /* This is a copy of gas_cgen_md_apply_fix, with some enhancements to
436    do various things that would not be valid for all ports.  */
437 
438 void
439 xstormy16_md_apply_fix (fixS *   fixP,
440 			 valueT * valueP,
441 			 segT     seg ATTRIBUTE_UNUSED)
442 {
443   char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
444   valueT value = *valueP;
445   /* Canonical name, since used a lot.  */
446   CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
447 
448   /* md_cgen_lookup_reloc() will adjust this to compensate for where
449      in the opcode the relocation happens, for pcrel relocations.  We
450      have no other way of keeping track of what this offset needs to
451      be.  */
452   fixP->fx_addnumber = 0;
453 
454   /* This port has pc-relative relocs and DIFF_EXPR_OK defined, so
455      it must deal with turning a BFD_RELOC_{8,16,32,64} into a
456      BFD_RELOC_*_PCREL for the case of
457 
458 	.word something-.  */
459   if (fixP->fx_pcrel)
460     switch (fixP->fx_r_type)
461       {
462       case BFD_RELOC_8:
463 	fixP->fx_r_type = BFD_RELOC_8_PCREL;
464 	break;
465       case BFD_RELOC_16:
466 	fixP->fx_r_type = BFD_RELOC_16_PCREL;
467 	break;
468       case BFD_RELOC_32:
469 	fixP->fx_r_type = BFD_RELOC_32_PCREL;
470 	break;
471       case BFD_RELOC_64:
472 	fixP->fx_r_type = BFD_RELOC_64_PCREL;
473 	break;
474       default:
475 	break;
476       }
477 
478   if (fixP->fx_addsy == (symbolS *) NULL)
479     fixP->fx_done = 1;
480 
481   /* We don't actually support subtracting a symbol.  */
482   if (fixP->fx_subsy != (symbolS *) NULL)
483     as_bad_where (fixP->fx_file, fixP->fx_line, _("expression too complex"));
484 
485   if ((int) fixP->fx_r_type >= (int) BFD_RELOC_UNUSED)
486     {
487       int opindex = (int) fixP->fx_r_type - (int) BFD_RELOC_UNUSED;
488       const CGEN_OPERAND *operand = cgen_operand_lookup_by_num (cd, opindex);
489       const char *errmsg;
490       bfd_reloc_code_real_type reloc_type;
491       CGEN_FIELDS *fields = alloca (CGEN_CPU_SIZEOF_FIELDS (cd));
492       const CGEN_INSN *insn = fixP->fx_cgen.insn;
493 
494       /* If the reloc has been fully resolved finish the operand here.  */
495       /* FIXME: This duplicates the capabilities of code in BFD.  */
496       if (fixP->fx_done)
497 	{
498 	  CGEN_CPU_SET_FIELDS_BITSIZE (cd) (fields, CGEN_INSN_BITSIZE (insn));
499 	  CGEN_CPU_SET_VMA_OPERAND (cd) (cd, opindex, fields, (bfd_vma) value);
500 
501 #if CGEN_INT_INSN_P
502 	  {
503 	    CGEN_INSN_INT insn_value =
504 	      cgen_get_insn_value (cd, (unsigned char *) where,
505 				   CGEN_INSN_BITSIZE (insn));
506 
507 	    /* ??? 0 is passed for `pc'.  */
508 	    errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields,
509 						   &insn_value, (bfd_vma) 0);
510 	    cgen_put_insn_value (cd, (unsigned char *) where,
511 				 CGEN_INSN_BITSIZE (insn), insn_value);
512 	  }
513 #else
514 	  /* ??? 0 is passed for `pc'.  */
515 	  errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields,
516 						 (unsigned char *) where,
517 						 (bfd_vma) 0);
518 #endif
519 	  if (errmsg)
520 	    as_bad_where (fixP->fx_file, fixP->fx_line, "%s", errmsg);
521 	}
522 
523       if (fixP->fx_done)
524 	return;
525 
526       /* The operand isn't fully resolved.  Determine a BFD reloc value
527 	 based on the operand information and leave it to
528 	 bfd_install_relocation.  Note that this doesn't work when
529 	 !partial_inplace.  */
530 
531       reloc_type = md_cgen_lookup_reloc (insn, operand, fixP);
532       if (reloc_type != BFD_RELOC_NONE)
533 	fixP->fx_r_type = reloc_type;
534       else
535 	{
536 	  as_bad_where (fixP->fx_file, fixP->fx_line,
537 			_("unresolved expression that must be resolved"));
538 	  fixP->fx_done = 1;
539 	  return;
540 	}
541     }
542   else if (fixP->fx_done)
543     {
544       /* We're finished with this fixup.  Install it because
545 	 bfd_install_relocation won't be called to do it.  */
546       switch (fixP->fx_r_type)
547 	{
548 	case BFD_RELOC_8:
549 	  md_number_to_chars (where, value, 1);
550 	  break;
551 	case BFD_RELOC_16:
552 	  md_number_to_chars (where, value, 2);
553 	  break;
554 	case BFD_RELOC_32:
555 	  md_number_to_chars (where, value, 4);
556 	  break;
557 	case BFD_RELOC_64:
558 	  md_number_to_chars (where, value, 8);
559 	  break;
560 	default:
561 	  as_bad_where (fixP->fx_file, fixP->fx_line,
562 			_("internal error: can't install fix for reloc type %d (`%s')"),
563 			fixP->fx_r_type, bfd_get_reloc_code_name (fixP->fx_r_type));
564 	  break;
565 	}
566     }
567   else
568     {
569       /* bfd_install_relocation will be called to finish things up.  */
570     }
571 
572   /* This is a RELA port.  Thus, it does not need to store a
573      value if it is going to make a reloc.  What's more, when
574      assembling a line like
575 
576      .byte global-0x7f00
577 
578      we'll get a spurious error message if we try to stuff 0x7f00 into
579      the byte.  */
580   if (! fixP->fx_done)
581     *valueP = 0;
582 
583   /* Tuck `value' away for use by tc_gen_reloc.
584      See the comment describing fx_addnumber in write.h.
585      This field is misnamed (or misused :-).  */
586   fixP->fx_addnumber += value;
587 }
588 
589 
590 /* Write a value out to the object file, using the appropriate endianness.  */
591 
592 void
593 md_number_to_chars (char * buf, valueT val, int n)
594 {
595   number_to_chars_littleendian (buf, val, n);
596 }
597 
598 char *
599 md_atof (int type, char * litP, int * sizeP)
600 {
601   return ieee_md_atof (type, litP, sizeP, FALSE);
602 }
603