1/* tc-ip2k.c -- Assembler for the Scenix IP2xxx.
2   Copyright (C) 2000-2017 Free Software Foundation, Inc.
3
4   This file is part of GAS, the GNU Assembler.
5
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 3, or (at your option)
9   any later version.
10
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.
15
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
18   the Free Software Foundation, 51 Franklin Street - Fifth Floor,
19   Boston, MA 02110-1301, USA.  */
20
21#include "as.h"
22#include "subsegs.h"
23#include "symcat.h"
24#include "opcodes/ip2k-desc.h"
25#include "opcodes/ip2k-opc.h"
26#include "cgen.h"
27#include "elf/common.h"
28#include "elf/ip2k.h"
29
30/* Structure to hold all of the different components describing
31   an individual instruction.  */
32typedef struct
33{
34  const CGEN_INSN *	insn;
35  const CGEN_INSN *	orig_insn;
36  CGEN_FIELDS		fields;
37#if CGEN_INT_INSN_P
38  CGEN_INSN_INT         buffer [1];
39#define INSN_VALUE(buf) (*(buf))
40#else
41  unsigned char         buffer [CGEN_MAX_INSN_SIZE];
42#define INSN_VALUE(buf) (buf)
43#endif
44  char *		addr;
45  fragS *		frag;
46  int                   num_fixups;
47  fixS *                fixups [GAS_CGEN_MAX_FIXUPS];
48  int                   indices [MAX_OPERAND_INSTANCES];
49}
50ip2k_insn;
51
52const char comment_chars[]        = ";";
53const char line_comment_chars[]   = "#";
54const char line_separator_chars[] = "";
55const char EXP_CHARS[]            = "eE";
56const char FLT_CHARS[]            = "dD";
57
58/* Flag to detect when switching to code section where insn alignment is
59   implied.  */
60static int force_code_align = 0;
61
62/* Mach selected from command line.  */
63static int ip2k_mach = 0;
64static unsigned ip2k_mach_bitmask = 0;
65
66
67static void
68ip2k_elf_section_rtn (int i)
69{
70  obj_elf_section(i);
71
72  if (force_code_align)
73    {
74      do_align (1, NULL, 0, 0);
75      force_code_align = 0;
76    }
77}
78
79static void
80ip2k_elf_section_text (int i)
81{
82  obj_elf_text(i);
83
84  do_align (1, NULL, 0, 0);
85  force_code_align = 0;
86}
87
88/* The target specific pseudo-ops which we support.  */
89const pseudo_typeS md_pseudo_table[] =
90{
91    { "text",   ip2k_elf_section_text,  0 },
92    { "sect",   ip2k_elf_section_rtn,   0 },
93    { NULL, 	NULL,			0 }
94};
95
96
97
98enum options
99{
100  OPTION_CPU_IP2022 = OPTION_MD_BASE,
101  OPTION_CPU_IP2022EXT
102};
103
104struct option md_longopts[] =
105{
106  { "mip2022",     no_argument, NULL, OPTION_CPU_IP2022 },
107  { "mip2022ext",  no_argument, NULL, OPTION_CPU_IP2022EXT },
108  { NULL,           no_argument, NULL, 0 },
109};
110size_t md_longopts_size = sizeof (md_longopts);
111
112const char * md_shortopts = "";
113
114int
115md_parse_option (int c ATTRIBUTE_UNUSED, const char * arg ATTRIBUTE_UNUSED)
116{
117  switch (c)
118    {
119    case OPTION_CPU_IP2022:
120      ip2k_mach = bfd_mach_ip2022;
121      ip2k_mach_bitmask = 1 << MACH_IP2022;
122      break;
123
124    case OPTION_CPU_IP2022EXT:
125      ip2k_mach = bfd_mach_ip2022ext;
126      ip2k_mach_bitmask = 1 << MACH_IP2022EXT;
127      break;
128
129    default:
130      return 0;
131    }
132
133  return 1;
134}
135
136void
137md_show_usage (FILE * stream)
138{
139  fprintf (stream, _("IP2K specific command line options:\n"));
140  fprintf (stream, _("  -mip2022               restrict to IP2022 insns \n"));
141  fprintf (stream, _("  -mip2022ext            permit extended IP2022 insn\n"));
142}
143
144
145void
146md_begin (void)
147{
148  /* Initialize the `cgen' interface.  */
149
150  /* Set the machine number and endian.  */
151  gas_cgen_cpu_desc = ip2k_cgen_cpu_open (CGEN_CPU_OPEN_MACHS,
152					  ip2k_mach_bitmask,
153					  CGEN_CPU_OPEN_ENDIAN,
154					  CGEN_ENDIAN_BIG,
155					  CGEN_CPU_OPEN_END);
156  ip2k_cgen_init_asm (gas_cgen_cpu_desc);
157
158  /* This is a callback from cgen to gas to parse operands.  */
159  cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
160
161  /* Set the machine type.  */
162  bfd_default_set_arch_mach (stdoutput, bfd_arch_ip2k, ip2k_mach);
163}
164
165
166void
167md_assemble (char * str)
168{
169  ip2k_insn insn;
170  char * errmsg;
171
172  /* Initialize GAS's cgen interface for a new instruction.  */
173  gas_cgen_init_parse ();
174
175  insn.insn = ip2k_cgen_assemble_insn
176      (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
177
178  if (!insn.insn)
179    {
180      as_bad ("%s", errmsg);
181      return;
182    }
183
184  /* Check for special relocation required by SKIP instructions.  */
185  if (CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_SKIPA))
186    /* Unconditional skip has a 1-bit relocation of the current pc, so
187       that we emit either sb pcl.0 or snb pcl.0 depending on whether
188       the PCL (pc + 2) >> 1 is odd or even.  */
189    {
190      enum cgen_parse_operand_result result_type;
191      bfd_vma value;
192      const char *curpc_plus_2 = ".+2";
193      const char *err;
194
195      err = cgen_parse_address (gas_cgen_cpu_desc, & curpc_plus_2,
196				IP2K_OPERAND_ADDR16CJP,
197				BFD_RELOC_IP2K_PC_SKIP,
198				& result_type, & value);
199      if (err)
200	{
201	  as_bad ("%s", err);
202	  return;
203	}
204    }
205
206  /* Doesn't really matter what we pass for RELAX_P here.  */
207  gas_cgen_finish_insn (insn.insn, insn.buffer,
208			CGEN_FIELDS_BITSIZE (& insn.fields), 1, NULL);
209}
210
211valueT
212md_section_align (segT segment, valueT size)
213{
214  int align = bfd_get_section_alignment (stdoutput, segment);
215
216  return ((size + (1 << align) - 1) & -(1 << align));
217}
218
219
220symbolS *
221md_undefined_symbol (char * name ATTRIBUTE_UNUSED)
222{
223    return 0;
224}
225
226int
227md_estimate_size_before_relax (fragS * fragP ATTRIBUTE_UNUSED,
228			       segT    segment ATTRIBUTE_UNUSED)
229{
230  as_fatal (_("relaxation not supported\n"));
231  return 1;
232}
233
234
235/* *fragP has been relaxed to its final size, and now needs to have
236   the bytes inside it modified to conform to the new size.
237
238   Called after relaxation is finished.
239   fragP->fr_type == rs_machine_dependent.
240   fragP->fr_subtype is the subtype of what the address relaxed to.  */
241
242void
243md_convert_frag (bfd   * abfd  ATTRIBUTE_UNUSED,
244		 segT    sec   ATTRIBUTE_UNUSED,
245		 fragS * fragP ATTRIBUTE_UNUSED)
246{
247}
248
249
250/* Functions concerning relocs.  */
251
252long
253md_pcrel_from (fixS *fixP ATTRIBUTE_UNUSED)
254{
255  abort ();
256}
257
258
259/* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
260   Returns BFD_RELOC_NONE if no reloc type can be found.
261   *FIXP may be modified if desired.  */
262
263bfd_reloc_code_real_type
264md_cgen_lookup_reloc (const CGEN_INSN *    insn     ATTRIBUTE_UNUSED,
265		      const CGEN_OPERAND * operand,
266		      fixS *               fixP     ATTRIBUTE_UNUSED)
267{
268  bfd_reloc_code_real_type result;
269
270  result = BFD_RELOC_NONE;
271
272  switch (operand->type)
273    {
274    case IP2K_OPERAND_FR:
275    case IP2K_OPERAND_ADDR16L:
276    case IP2K_OPERAND_ADDR16H:
277    case IP2K_OPERAND_LIT8:
278      /* These may have been processed at parse time.  */
279      if (fixP->fx_cgen.opinfo != 0)
280	result = fixP->fx_cgen.opinfo;
281      fixP->fx_no_overflow = 1;
282      break;
283
284    case IP2K_OPERAND_ADDR16CJP:
285      result = fixP->fx_cgen.opinfo;
286      if (result == 0 || result == BFD_RELOC_NONE)
287	result = BFD_RELOC_IP2K_ADDR16CJP;
288      fixP->fx_no_overflow = 1;
289      break;
290
291    case IP2K_OPERAND_ADDR16P:
292      result = BFD_RELOC_IP2K_PAGE3;
293      fixP->fx_no_overflow = 1;
294      break;
295
296    default:
297      result = BFD_RELOC_NONE;
298      break;
299    }
300
301  return result;
302}
303
304
305/* Write a value out to the object file, using the appropriate endianness.  */
306
307void
308md_number_to_chars (char * buf, valueT val, int n)
309{
310  number_to_chars_bigendian (buf, val, n);
311}
312
313const char *
314md_atof (int type, char * litP, int *  sizeP)
315{
316  return ieee_md_atof (type, litP, sizeP, TRUE);
317}
318
319
320/* See whether we need to force a relocation into the output file.
321   Force most of them, since the linker's bfd relocation engine
322   understands range limits better than gas' cgen fixup engine.
323   Consider the case of a fixup intermediate value being larger than
324   the instruction it will be eventually encoded within.  */
325
326int
327ip2k_force_relocation (fixS * fix)
328{
329  switch (fix->fx_r_type)
330    {
331    case BFD_RELOC_IP2K_FR9:
332    case BFD_RELOC_IP2K_FR_OFFSET:
333    case BFD_RELOC_IP2K_BANK:
334    case BFD_RELOC_IP2K_ADDR16CJP:
335    case BFD_RELOC_IP2K_PAGE3:
336    case BFD_RELOC_IP2K_LO8DATA:
337    case BFD_RELOC_IP2K_HI8DATA:
338    case BFD_RELOC_IP2K_EX8DATA:
339    case BFD_RELOC_IP2K_LO8INSN:
340    case BFD_RELOC_IP2K_HI8INSN:
341    case BFD_RELOC_IP2K_PC_SKIP:
342    case BFD_RELOC_IP2K_TEXT:
343      return 1;
344
345    case BFD_RELOC_16:
346      if (fix->fx_subsy && S_IS_DEFINED (fix->fx_subsy)
347	  && fix->fx_addsy && S_IS_DEFINED (fix->fx_addsy)
348	  && (S_GET_SEGMENT (fix->fx_addsy)->flags & SEC_CODE))
349	{
350	  fix->fx_r_type = BFD_RELOC_IP2K_TEXT;
351	  return 0;
352	}
353      break;
354
355    default:
356      break;
357    }
358
359  return generic_force_reloc (fix);
360}
361
362void
363ip2k_apply_fix (fixS *fixP, valueT *valueP, segT seg)
364{
365  if (fixP->fx_r_type == BFD_RELOC_IP2K_TEXT
366      && ! fixP->fx_addsy
367      && ! fixP->fx_subsy)
368    {
369      *valueP = ((int)(* valueP)) / 2;
370      fixP->fx_r_type = BFD_RELOC_16;
371    }
372  else if (fixP->fx_r_type == BFD_RELOC_UNUSED + IP2K_OPERAND_FR)
373    {
374      /* Must be careful when we are fixing up an FR.  We could be
375	 fixing up an offset to (SP) or (DP) in which case we don't
376	 want to step on the top 2 bits of the FR operand.  The
377	 gas_cgen_md_apply_fix doesn't know any better and overwrites
378	 the entire operand.  We counter this by adding the bits
379	 to the new value.  */
380      char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
381
382      /* Canonical name, since used a lot.  */
383      CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
384      CGEN_INSN_INT insn_value
385	= cgen_get_insn_value (cd, (unsigned char *) where,
386			       CGEN_INSN_BITSIZE (fixP->fx_cgen.insn));
387      /* Preserve (DP) or (SP) specification.  */
388      *valueP += (insn_value & 0x180);
389    }
390
391  gas_cgen_md_apply_fix (fixP, valueP, seg);
392}
393
394int
395ip2k_elf_section_flags (flagword flags,
396			bfd_vma attr ATTRIBUTE_UNUSED,
397			int type ATTRIBUTE_UNUSED)
398{
399  /* This is used to detect when the section changes to an executable section.
400     This function is called by the elf section processing.  When we note an
401     executable section specifier we set an internal flag to denote when
402     word alignment should be forced.  */
403  if (flags & SEC_CODE)
404    force_code_align = 1;
405
406  return flags;
407}
408
409