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

/* CGEN generic disassembler support code.
   Copyright (C) 1996-2025 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"
#include "disassemble.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)
{
  CGEN_INSN_LGUINT mask = CGEN_INSN_BASE_MASK (insn);
#if GCC_VERSION >= 3004
  return __builtin_popcount (mask);
#else
  int bits = 0;
  unsigned m;

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

/* 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 preferred.  */

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 [8];
      unsigned long value;
      const CGEN_INSN *insn = &insns[i];
      size_t size;

      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);
      size = CGEN_INSN_MASK_BITSIZE (insn);
      OPCODES_ASSERT (size <= sizeof (buf) * 8);
      bfd_put_bits ((bfd_vma) value, buf, size, 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[8];
      unsigned long value;
      size_t size;

      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);
      size = CGEN_INSN_MASK_BITSIZE (ilist->insn);
      OPCODES_ASSERT (size <= sizeof (buf) * 8);
      bfd_put_bits ((bfd_vma) value, buf, size, 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 preferred 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
	1	/* CGEN generic disassembler support code.
	2	Copyright (C) 1996-2025 Free Software Foundation, Inc.
	3
	4	This file is part of libopcodes.
	5
	6	This library 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	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.
	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.,
	18	51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA. */
	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	#include "disassemble.h"
	28
	29	static CGEN_INSN_LIST * hash_insn_array (CGEN_CPU_DESC, const CGEN_INSN , int, int, CGEN_INSN_LIST , CGEN_INSN_LIST );
	30	static CGEN_INSN_LIST * hash_insn_list (CGEN_CPU_DESC, const CGEN_INSN_LIST , CGEN_INSN_LIST , CGEN_INSN_LIST );
	31	static void build_dis_hash_table (CGEN_CPU_DESC);
	32	static int count_decodable_bits (const CGEN_INSN *);
	33	static void add_insn_to_hash_chain (CGEN_INSN_LIST *,
	34	const CGEN_INSN *,
	35	CGEN_INSN_LIST **,
	36	unsigned int);
	37
	38	/* Return the number of decodable bits in this insn. */
	39	static int
	40	count_decodable_bits (const CGEN_INSN *insn)
	41	{
	42	CGEN_INSN_LGUINT mask = CGEN_INSN_BASE_MASK (insn);
	43	#if GCC_VERSION >= 3004
	44	return __builtin_popcount (mask);
	45	#else
	46	int bits = 0;
	47	unsigned m;
	48
	49	for (m = 1; m != 0; m <<= 1)
	50	{
	51	if (mask & m)
	52	++bits;
	53	}
	54	return bits;
	55	#endif
	56	}
	57
	58	/* Add an instruction to the hash chain. */
	59	static void
	60	add_insn_to_hash_chain (CGEN_INSN_LIST *hentbuf,
	61	const CGEN_INSN *insn,
	62	CGEN_INSN_LIST **htable,
	63	unsigned int hash)
	64	{
	65	CGEN_INSN_LIST *current_buf;
	66	CGEN_INSN_LIST *previous_buf;
	67	int insn_decodable_bits;
	68
	69	/* Add insns sorted by the number of decodable bits, in decreasing order.
	70	This ensures that any insn which is a special case of another will be
	71	checked first. */
	72	insn_decodable_bits = count_decodable_bits (insn);
	73	previous_buf = NULL;
	74	for (current_buf = htable[hash]; current_buf != NULL;
	75	current_buf = current_buf->next)
	76	{
	77	int current_decodable_bits = count_decodable_bits (current_buf->insn);
	78	if (insn_decodable_bits >= current_decodable_bits)
	79	break;
	80	previous_buf = current_buf;
	81	}
	82
	83	/* Now insert the new insn. */
	84	hentbuf->insn = insn;
	85	hentbuf->next = current_buf;
	86	if (previous_buf == NULL)
	87	htable[hash] = hentbuf;
	88	else
	89	previous_buf->next = hentbuf;
	90	}
	91
	92	/* Subroutine of build_dis_hash_table to add INSNS to the hash table.
	93
	94	COUNT is the number of elements in INSNS.
	95	ENTSIZE is sizeof (CGEN_IBASE) for the target.
	96	??? No longer used but leave in for now.
	97	HTABLE points to the hash table.
	98	HENTBUF is a pointer to sufficiently large buffer of hash entries.
	99	The result is a pointer to the next entry to use.
	100
	101	The table is scanned backwards as additions are made to the front of the
	102	list and we want earlier ones to be preferred. */
	103
	104	static CGEN_INSN_LIST *
	105	hash_insn_array (CGEN_CPU_DESC cd,
	106	const CGEN_INSN * insns,
	107	int count,
	108	int entsize ATTRIBUTE_UNUSED,
	109	CGEN_INSN_LIST ** htable,
	110	CGEN_INSN_LIST * hentbuf)
	111	{
	112	int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG;
	113	int i;
	114
	115	for (i = count - 1; i >= 0; --i, ++hentbuf)
	116	{
	117	unsigned int hash;
	118	char buf [8];
	119	unsigned long value;
	120	const CGEN_INSN *insn = &insns[i];
	121	size_t size;
	122
	123	if (! (* cd->dis_hash_p) (insn))
	124	continue;
	125
	126	/* We don't know whether the target uses the buffer or the base insn
	127	to hash on, so set both up. */
	128
	129	value = CGEN_INSN_BASE_VALUE (insn);
	130	size = CGEN_INSN_MASK_BITSIZE (insn);
	131	OPCODES_ASSERT (size <= sizeof (buf) * 8);
	132	bfd_put_bits ((bfd_vma) value, buf, size, big_p);
	133	hash = (* cd->dis_hash) (buf, value);
	134	add_insn_to_hash_chain (hentbuf, insn, htable, hash);
	135	}
	136
	137	return hentbuf;
	138	}
	139
	140	/* Subroutine of build_dis_hash_table to add INSNS to the hash table.
	141	This function is identical to hash_insn_array except the insns are
	142	in a list. */
	143
	144	static CGEN_INSN_LIST *
	145	hash_insn_list (CGEN_CPU_DESC cd,
	146	const CGEN_INSN_LIST *insns,
	147	CGEN_INSN_LIST **htable,
	148	CGEN_INSN_LIST *hentbuf)
	149	{
	150	int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG;
	151	const CGEN_INSN_LIST *ilist;
	152
	153	for (ilist = insns; ilist != NULL; ilist = ilist->next, ++ hentbuf)
	154	{
	155	unsigned int hash;
	156	char buf[8];
	157	unsigned long value;
	158	size_t size;
	159
	160	if (! (* cd->dis_hash_p) (ilist->insn))
	161	continue;
	162
	163	/* We don't know whether the target uses the buffer or the base insn
	164	to hash on, so set both up. */
	165
	166	value = CGEN_INSN_BASE_VALUE (ilist->insn);
	167	size = CGEN_INSN_MASK_BITSIZE (ilist->insn);
	168	OPCODES_ASSERT (size <= sizeof (buf) * 8);
	169	bfd_put_bits ((bfd_vma) value, buf, size, big_p);
	170	hash = (* cd->dis_hash) (buf, value);
	171	add_insn_to_hash_chain (hentbuf, ilist->insn, htable, hash);
	172	}
	173
	174	return hentbuf;
	175	}
	176
	177	/* Build the disassembler instruction hash table. */
	178
	179	static void
	180	build_dis_hash_table (CGEN_CPU_DESC cd)
	181	{
	182	int count = cgen_insn_count (cd) + cgen_macro_insn_count (cd);
	183	CGEN_INSN_TABLE *insn_table = & cd->insn_table;
	184	CGEN_INSN_TABLE *macro_insn_table = & cd->macro_insn_table;
	185	unsigned int hash_size = cd->dis_hash_size;
	186	CGEN_INSN_LIST *hash_entry_buf;
	187	CGEN_INSN_LIST **dis_hash_table;
	188	CGEN_INSN_LIST *dis_hash_table_entries;
	189
	190	/* The space allocated for the hash table consists of two parts:
	191	the hash table and the hash lists. */
	192
	193	dis_hash_table = (CGEN_INSN_LIST **)
	194	xmalloc (hash_size * sizeof (CGEN_INSN_LIST *));
	195	memset (dis_hash_table, 0, hash_size * sizeof (CGEN_INSN_LIST *));
	196	dis_hash_table_entries = hash_entry_buf = (CGEN_INSN_LIST *)
	197	xmalloc (count * sizeof (CGEN_INSN_LIST));
	198
	199	/* Add compiled in insns.
	200	Don't include the first one as it is a reserved entry. */
	201	/* ??? It was the end of all hash chains, and also the special
	202	"invalid insn" marker. May be able to do it differently now. */
	203
	204	hash_entry_buf = hash_insn_array (cd,
	205	insn_table->init_entries + 1,
	206	insn_table->num_init_entries - 1,
	207	insn_table->entry_size,
	208	dis_hash_table, hash_entry_buf);
	209
	210	/* Add compiled in macro-insns. */
	211
	212	hash_entry_buf = hash_insn_array (cd, macro_insn_table->init_entries,
	213	macro_insn_table->num_init_entries,
	214	macro_insn_table->entry_size,
	215	dis_hash_table, hash_entry_buf);
	216
	217	/* Add runtime added insns.
	218	Later added insns will be preferred over earlier ones. */
	219
	220	hash_entry_buf = hash_insn_list (cd, insn_table->new_entries,
	221	dis_hash_table, hash_entry_buf);
	222
	223	/* Add runtime added macro-insns. */
	224
	225	hash_insn_list (cd, macro_insn_table->new_entries,
	226	dis_hash_table, hash_entry_buf);
	227
	228	cd->dis_hash_table = dis_hash_table;
	229	cd->dis_hash_table_entries = dis_hash_table_entries;
	230	}
	231
	232	/* Return the first entry in the hash list for INSN. */
	233
	234	CGEN_INSN_LIST *
	235	cgen_dis_lookup_insn (CGEN_CPU_DESC cd, const char * buf, CGEN_INSN_INT value)
	236	{
	237	unsigned int hash;
	238
	239	if (cd->dis_hash_table == NULL)
	240	build_dis_hash_table (cd);
	241
	242	hash = (* cd->dis_hash) (buf, value);
	243
	244	return cd->dis_hash_table[hash];
	245	}