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- /* CGEN generic disassembler support code.
- Copyright (C) 1996-2022 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)
- {
- unsigned 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[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 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];
- }
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