/* CGEN generic disassembler support code. Copyright (C) 1996-2023 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 #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[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]; }