[thirdparty/binutils-gdb.git] / opcodes / cgen-dis.c

/* CGEN generic disassembler support code.
   Copyright (C) 1996-2020 Free Software Foundation, Inc.

   This file is part of libopcodes.

   This library is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3, or (at your option)
   any later version.

   It is distributed in the hope that it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
   License for more details.

   You should have received a copy of the GNU General Public License along
   with this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.  */

#include "sysdep.h"
#include <stdio.h>
#include "ansidecl.h"
#include "libiberty.h"
#include "bfd.h"
#include "symcat.h"
#include "opcode/cgen.h"

static CGEN_INSN_LIST *  hash_insn_array        (CGEN_CPU_DESC, const CGEN_INSN *, int, int, CGEN_INSN_LIST **, CGEN_INSN_LIST *);
static CGEN_INSN_LIST *  hash_insn_list         (CGEN_CPU_DESC, const CGEN_INSN_LIST *, CGEN_INSN_LIST **, CGEN_INSN_LIST *);
static void              build_dis_hash_table   (CGEN_CPU_DESC);
static int		 count_decodable_bits   (const CGEN_INSN *);
static void		 add_insn_to_hash_chain (CGEN_INSN_LIST *,
						 const CGEN_INSN *,
						 CGEN_INSN_LIST **,
						 unsigned int);

/* Return the number of decodable bits in this insn.  */
static int
count_decodable_bits (const CGEN_INSN *insn)
{
  unsigned mask = CGEN_INSN_BASE_MASK (insn);
  int bits = 0;
  unsigned m;

  for (m = 1; m != 0; m <<= 1)
    {
      if (mask & m)
	++bits;
    }
  return bits;
}

/* Add an instruction to the hash chain.  */
static void
add_insn_to_hash_chain (CGEN_INSN_LIST *hentbuf,
			const CGEN_INSN *insn,
			CGEN_INSN_LIST **htable,
			unsigned int hash)
{
  CGEN_INSN_LIST *current_buf;
  CGEN_INSN_LIST *previous_buf;
  int insn_decodable_bits;

  /* Add insns sorted by the number of decodable bits, in decreasing order.
     This ensures that any insn which is a special case of another will be
     checked first.  */
  insn_decodable_bits = count_decodable_bits (insn);
  previous_buf = NULL;
  for (current_buf = htable[hash]; current_buf != NULL;
       current_buf = current_buf->next)
    {
      int current_decodable_bits = count_decodable_bits (current_buf->insn);
      if (insn_decodable_bits >= current_decodable_bits)
	break;
      previous_buf = current_buf;
    }

  /* Now insert the new insn.  */
  hentbuf->insn = insn;
  hentbuf->next = current_buf;
  if (previous_buf == NULL)
    htable[hash] = hentbuf;
  else
    previous_buf->next = hentbuf;
}

/* Subroutine of build_dis_hash_table to add INSNS to the hash table.

   COUNT is the number of elements in INSNS.
   ENTSIZE is sizeof (CGEN_IBASE) for the target.
   ??? No longer used but leave in for now.
   HTABLE points to the hash table.
   HENTBUF is a pointer to sufficiently large buffer of hash entries.
   The result is a pointer to the next entry to use.

   The table is scanned backwards as additions are made to the front of the
   list and we want earlier ones to be prefered.  */

static CGEN_INSN_LIST *
hash_insn_array (CGEN_CPU_DESC cd,
		 const CGEN_INSN * insns,
		 int count,
		 int entsize ATTRIBUTE_UNUSED,
		 CGEN_INSN_LIST ** htable,
		 CGEN_INSN_LIST * hentbuf)
{
  int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG;
  int i;

  for (i = count - 1; i >= 0; --i, ++hentbuf)
    {
      unsigned int hash;
      char buf [4];
      unsigned long value;
      const CGEN_INSN *insn = &insns[i];

      if (! (* cd->dis_hash_p) (insn))
	continue;

      /* We don't know whether the target uses the buffer or the base insn
	 to hash on, so set both up.  */

      value = CGEN_INSN_BASE_VALUE (insn);
      bfd_put_bits ((bfd_vma) value,
		    buf,
		    CGEN_INSN_MASK_BITSIZE (insn),
		    big_p);
      hash = (* cd->dis_hash) (buf, value);
      add_insn_to_hash_chain (hentbuf, insn, htable, hash);
    }

  return hentbuf;
}

/* Subroutine of build_dis_hash_table to add INSNS to the hash table.
   This function is identical to hash_insn_array except the insns are
   in a list.  */

static CGEN_INSN_LIST *
hash_insn_list (CGEN_CPU_DESC cd,
		const CGEN_INSN_LIST *insns,
		CGEN_INSN_LIST **htable,
		CGEN_INSN_LIST *hentbuf)
{
  int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG;
  const CGEN_INSN_LIST *ilist;

  for (ilist = insns; ilist != NULL; ilist = ilist->next, ++ hentbuf)
    {
      unsigned int hash;
      char buf[4];
      unsigned long value;

      if (! (* cd->dis_hash_p) (ilist->insn))
	continue;

      /* We don't know whether the target uses the buffer or the base insn
	 to hash on, so set both up.  */

      value = CGEN_INSN_BASE_VALUE (ilist->insn);
      bfd_put_bits((bfd_vma) value,
		   buf,
		   CGEN_INSN_MASK_BITSIZE (ilist->insn),
		   big_p);
      hash = (* cd->dis_hash) (buf, value);
      add_insn_to_hash_chain (hentbuf, ilist->insn, htable, hash);
    }

  return hentbuf;
}

/* Build the disassembler instruction hash table.  */

static void
build_dis_hash_table (CGEN_CPU_DESC cd)
{
  int count = cgen_insn_count (cd) + cgen_macro_insn_count (cd);
  CGEN_INSN_TABLE *insn_table = & cd->insn_table;
  CGEN_INSN_TABLE *macro_insn_table = & cd->macro_insn_table;
  unsigned int hash_size = cd->dis_hash_size;
  CGEN_INSN_LIST *hash_entry_buf;
  CGEN_INSN_LIST **dis_hash_table;
  CGEN_INSN_LIST *dis_hash_table_entries;

  /* The space allocated for the hash table consists of two parts:
     the hash table and the hash lists.  */

  dis_hash_table = (CGEN_INSN_LIST **)
    xmalloc (hash_size * sizeof (CGEN_INSN_LIST *));
  memset (dis_hash_table, 0, hash_size * sizeof (CGEN_INSN_LIST *));
  dis_hash_table_entries = hash_entry_buf = (CGEN_INSN_LIST *)
    xmalloc (count * sizeof (CGEN_INSN_LIST));

  /* Add compiled in insns.
     Don't include the first one as it is a reserved entry.  */
  /* ??? It was the end of all hash chains, and also the special
     "invalid insn" marker.  May be able to do it differently now.  */

  hash_entry_buf = hash_insn_array (cd,
				    insn_table->init_entries + 1,
				    insn_table->num_init_entries - 1,
				    insn_table->entry_size,
				    dis_hash_table, hash_entry_buf);

  /* Add compiled in macro-insns.  */

  hash_entry_buf = hash_insn_array (cd, macro_insn_table->init_entries,
				    macro_insn_table->num_init_entries,
				    macro_insn_table->entry_size,
				    dis_hash_table, hash_entry_buf);

  /* Add runtime added insns.
     Later added insns will be prefered over earlier ones.  */

  hash_entry_buf = hash_insn_list (cd, insn_table->new_entries,
				   dis_hash_table, hash_entry_buf);

  /* Add runtime added macro-insns.  */

  hash_insn_list (cd, macro_insn_table->new_entries,
		  dis_hash_table, hash_entry_buf);

  cd->dis_hash_table = dis_hash_table;
  cd->dis_hash_table_entries = dis_hash_table_entries;
}

/* Return the first entry in the hash list for INSN.  */

CGEN_INSN_LIST *
cgen_dis_lookup_insn (CGEN_CPU_DESC cd, const char * buf, CGEN_INSN_INT value)
{
  unsigned int hash;

  if (cd->dis_hash_table == NULL)
    build_dis_hash_table (cd);

  hash = (* cd->dis_hash) (buf, value);

  return cd->dis_hash_table[hash];
}
Commit	Line	Data
252b5132	1	/* CGEN generic disassembler support code.
b3adc24a	2	Copyright (C) 1996-2020 Free Software Foundation, Inc.
252b5132	3
9b201bb5	4	This file is part of libopcodes.
252b5132	5
9b201bb5	6	This library is free software; you can redistribute it and/or modify
252b5132	7	it under the terms of the GNU General Public License as published by
9b201bb5	8	the Free Software Foundation; either version 3, or (at your option)
252b5132 RH	9	any later version.
252b5132 RH	10
9b201bb5 NC	11	It is distributed in the hope that it will be useful, but WITHOUT
	12	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	13	or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
	14	License for more details.
252b5132 RH	15
	16	You should have received a copy of the GNU General Public License along
	17	with this program; if not, write to the Free Software Foundation, Inc.,
f4321104	18	51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
252b5132 RH	19
	20	#include "sysdep.h"
	21	#include <stdio.h>
	22	#include "ansidecl.h"
	23	#include "libiberty.h"
	24	#include "bfd.h"
	25	#include "symcat.h"
	26	#include "opcode/cgen.h"
	27
10e05405 MM	28	static CGEN_INSN_LIST * hash_insn_array (CGEN_CPU_DESC, const CGEN_INSN , int, int, CGEN_INSN_LIST , CGEN_INSN_LIST );
	29	static CGEN_INSN_LIST * hash_insn_list (CGEN_CPU_DESC, const CGEN_INSN_LIST , CGEN_INSN_LIST , CGEN_INSN_LIST );
	30	static void build_dis_hash_table (CGEN_CPU_DESC);
	31	static int count_decodable_bits (const CGEN_INSN *);
	32	static void add_insn_to_hash_chain (CGEN_INSN_LIST *,
	33	const CGEN_INSN *,
	34	CGEN_INSN_LIST **,
	35	unsigned int);
1c009264 DB	36
	37	/* Return the number of decodable bits in this insn. */
	38	static int
10e05405	39	count_decodable_bits (const CGEN_INSN *insn)
1c009264 DB	40	{
	41	unsigned mask = CGEN_INSN_BASE_MASK (insn);
	42	int bits = 0;
d8c823c8 MM	43	unsigned m;
d8c823c8 MM	44
1c009264 DB	45	for (m = 1; m != 0; m <<= 1)
	46	{
	47	if (mask & m)
	48	++bits;
	49	}
	50	return bits;
	51	}
	52
43e65147	53	/* Add an instruction to the hash chain. */
1c009264	54	static void
10e05405 MM	55	add_insn_to_hash_chain (CGEN_INSN_LIST *hentbuf,
	56	const CGEN_INSN *insn,
	57	CGEN_INSN_LIST **htable,
	58	unsigned int hash)
1c009264 DB	59	{
	60	CGEN_INSN_LIST *current_buf;
	61	CGEN_INSN_LIST *previous_buf;
	62	int insn_decodable_bits;
	63
	64	/* Add insns sorted by the number of decodable bits, in decreasing order.
	65	This ensures that any insn which is a special case of another will be
	66	checked first. */
	67	insn_decodable_bits = count_decodable_bits (insn);
	68	previous_buf = NULL;
	69	for (current_buf = htable[hash]; current_buf != NULL;
	70	current_buf = current_buf->next)
	71	{
	72	int current_decodable_bits = count_decodable_bits (current_buf->insn);
	73	if (insn_decodable_bits >= current_decodable_bits)
	74	break;
	75	previous_buf = current_buf;
	76	}
	77
	78	/* Now insert the new insn. */
	79	hentbuf->insn = insn;
	80	hentbuf->next = current_buf;
	81	if (previous_buf == NULL)
	82	htable[hash] = hentbuf;
	83	else
	84	previous_buf->next = hentbuf;
	85	}
	86
252b5132 RH	87	/* Subroutine of build_dis_hash_table to add INSNS to the hash table.
	88
	89	COUNT is the number of elements in INSNS.
	90	ENTSIZE is sizeof (CGEN_IBASE) for the target.
	91	??? No longer used but leave in for now.
	92	HTABLE points to the hash table.
	93	HENTBUF is a pointer to sufficiently large buffer of hash entries.
	94	The result is a pointer to the next entry to use.
	95
	96	The table is scanned backwards as additions are made to the front of the
	97	list and we want earlier ones to be prefered. */
	98
	99	static CGEN_INSN_LIST *
10e05405 MM	100	hash_insn_array (CGEN_CPU_DESC cd,
	101	const CGEN_INSN * insns,
	102	int count,
	103	int entsize ATTRIBUTE_UNUSED,
	104	CGEN_INSN_LIST ** htable,
	105	CGEN_INSN_LIST * hentbuf)
252b5132	106	{
17310e56	107	int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG;
252b5132 RH	108	int i;
	109
	110	for (i = count - 1; i >= 0; --i, ++hentbuf)
	111	{
	112	unsigned int hash;
	113	char buf [4];
	114	unsigned long value;
	115	const CGEN_INSN *insn = &insns[i];
	116
	117	if (! (* cd->dis_hash_p) (insn))
	118	continue;
	119
	120	/* We don't know whether the target uses the buffer or the base insn
	121	to hash on, so set both up. */
	122
	123	value = CGEN_INSN_BASE_VALUE (insn);
aed80dae FCE	124	bfd_put_bits ((bfd_vma) value,
	125	buf,
	126	CGEN_INSN_MASK_BITSIZE (insn),
	127	big_p);
252b5132	128	hash = (* cd->dis_hash) (buf, value);
1c009264	129	add_insn_to_hash_chain (hentbuf, insn, htable, hash);
252b5132 RH	130	}
	131
	132	return hentbuf;
	133	}
	134
	135	/* Subroutine of build_dis_hash_table to add INSNS to the hash table.
	136	This function is identical to hash_insn_array except the insns are
	137	in a list. */
	138
	139	static CGEN_INSN_LIST *
10e05405 MM	140	hash_insn_list (CGEN_CPU_DESC cd,
	141	const CGEN_INSN_LIST *insns,
	142	CGEN_INSN_LIST **htable,
	143	CGEN_INSN_LIST *hentbuf)
252b5132	144	{
17310e56	145	int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG;
252b5132 RH	146	const CGEN_INSN_LIST *ilist;
	147
	148	for (ilist = insns; ilist != NULL; ilist = ilist->next, ++ hentbuf)
	149	{
	150	unsigned int hash;
	151	char buf[4];
	152	unsigned long value;
	153
	154	if (! (* cd->dis_hash_p) (ilist->insn))
	155	continue;
	156
	157	/* We don't know whether the target uses the buffer or the base insn
	158	to hash on, so set both up. */
	159
	160	value = CGEN_INSN_BASE_VALUE (ilist->insn);
aed80dae FCE	161	bfd_put_bits((bfd_vma) value,
	162	buf,
	163	CGEN_INSN_MASK_BITSIZE (ilist->insn),
	164	big_p);
252b5132	165	hash = (* cd->dis_hash) (buf, value);
1c009264	166	add_insn_to_hash_chain (hentbuf, ilist->insn, htable, hash);
252b5132 RH	167	}
	168
	169	return hentbuf;
	170	}
	171
	172	/* Build the disassembler instruction hash table. */
	173
	174	static void
10e05405	175	build_dis_hash_table (CGEN_CPU_DESC cd)
252b5132 RH	176	{
	177	int count = cgen_insn_count (cd) + cgen_macro_insn_count (cd);
	178	CGEN_INSN_TABLE *insn_table = & cd->insn_table;
	179	CGEN_INSN_TABLE *macro_insn_table = & cd->macro_insn_table;
	180	unsigned int hash_size = cd->dis_hash_size;
	181	CGEN_INSN_LIST *hash_entry_buf;
	182	CGEN_INSN_LIST **dis_hash_table;
	183	CGEN_INSN_LIST *dis_hash_table_entries;
	184
	185	/* The space allocated for the hash table consists of two parts:
	186	the hash table and the hash lists. */
	187
	188	dis_hash_table = (CGEN_INSN_LIST **)
	189	xmalloc (hash_size * sizeof (CGEN_INSN_LIST *));
	190	memset (dis_hash_table, 0, hash_size * sizeof (CGEN_INSN_LIST *));
	191	dis_hash_table_entries = hash_entry_buf = (CGEN_INSN_LIST *)
	192	xmalloc (count * sizeof (CGEN_INSN_LIST));
	193
	194	/* Add compiled in insns.
	195	Don't include the first one as it is a reserved entry. */
	196	/* ??? It was the end of all hash chains, and also the special
	197	"invalid insn" marker. May be able to do it differently now. */
	198
	199	hash_entry_buf = hash_insn_array (cd,
	200	insn_table->init_entries + 1,
	201	insn_table->num_init_entries - 1,
	202	insn_table->entry_size,
	203	dis_hash_table, hash_entry_buf);
	204
	205	/* Add compiled in macro-insns. */
	206
	207	hash_entry_buf = hash_insn_array (cd, macro_insn_table->init_entries,
	208	macro_insn_table->num_init_entries,
	209	macro_insn_table->entry_size,
	210	dis_hash_table, hash_entry_buf);
	211
	212	/* Add runtime added insns.
	213	Later added insns will be prefered over earlier ones. */
	214
	215	hash_entry_buf = hash_insn_list (cd, insn_table->new_entries,
	216	dis_hash_table, hash_entry_buf);
	217
	218	/* Add runtime added macro-insns. */
	219
	220	hash_insn_list (cd, macro_insn_table->new_entries,
	221	dis_hash_table, hash_entry_buf);
	222
	223	cd->dis_hash_table = dis_hash_table;
	224	cd->dis_hash_table_entries = dis_hash_table_entries;
	225	}
	226
	227	/* Return the first entry in the hash list for INSN. */
	228
	229	CGEN_INSN_LIST *
10e05405	230	cgen_dis_lookup_insn (CGEN_CPU_DESC cd, const char * buf, CGEN_INSN_INT value)
252b5132 RH	231	{
	232	unsigned int hash;
	233
	234	if (cd->dis_hash_table == NULL)
	235	build_dis_hash_table (cd);
	236
	237	hash = (* cd->dis_hash) (buf, value);
	238
	239	return cd->dis_hash_table[hash];
	240	}