| 1 | /* CGEN generic disassembler support code. |
| 2 | Copyright 1996-2013 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 | |
| 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); |
| 36 | |
| 37 | /* Return the number of decodable bits in this insn. */ |
| 38 | static int |
| 39 | count_decodable_bits (const CGEN_INSN *insn) |
| 40 | { |
| 41 | unsigned mask = CGEN_INSN_BASE_MASK (insn); |
| 42 | int bits = 0; |
| 43 | int m; |
| 44 | for (m = 1; m != 0; m <<= 1) |
| 45 | { |
| 46 | if (mask & m) |
| 47 | ++bits; |
| 48 | } |
| 49 | return bits; |
| 50 | } |
| 51 | |
| 52 | /* Add an instruction to the hash chain. */ |
| 53 | static void |
| 54 | add_insn_to_hash_chain (CGEN_INSN_LIST *hentbuf, |
| 55 | const CGEN_INSN *insn, |
| 56 | CGEN_INSN_LIST **htable, |
| 57 | unsigned int hash) |
| 58 | { |
| 59 | CGEN_INSN_LIST *current_buf; |
| 60 | CGEN_INSN_LIST *previous_buf; |
| 61 | int insn_decodable_bits; |
| 62 | |
| 63 | /* Add insns sorted by the number of decodable bits, in decreasing order. |
| 64 | This ensures that any insn which is a special case of another will be |
| 65 | checked first. */ |
| 66 | insn_decodable_bits = count_decodable_bits (insn); |
| 67 | previous_buf = NULL; |
| 68 | for (current_buf = htable[hash]; current_buf != NULL; |
| 69 | current_buf = current_buf->next) |
| 70 | { |
| 71 | int current_decodable_bits = count_decodable_bits (current_buf->insn); |
| 72 | if (insn_decodable_bits >= current_decodable_bits) |
| 73 | break; |
| 74 | previous_buf = current_buf; |
| 75 | } |
| 76 | |
| 77 | /* Now insert the new insn. */ |
| 78 | hentbuf->insn = insn; |
| 79 | hentbuf->next = current_buf; |
| 80 | if (previous_buf == NULL) |
| 81 | htable[hash] = hentbuf; |
| 82 | else |
| 83 | previous_buf->next = hentbuf; |
| 84 | } |
| 85 | |
| 86 | /* Subroutine of build_dis_hash_table to add INSNS to the hash table. |
| 87 | |
| 88 | COUNT is the number of elements in INSNS. |
| 89 | ENTSIZE is sizeof (CGEN_IBASE) for the target. |
| 90 | ??? No longer used but leave in for now. |
| 91 | HTABLE points to the hash table. |
| 92 | HENTBUF is a pointer to sufficiently large buffer of hash entries. |
| 93 | The result is a pointer to the next entry to use. |
| 94 | |
| 95 | The table is scanned backwards as additions are made to the front of the |
| 96 | list and we want earlier ones to be prefered. */ |
| 97 | |
| 98 | static CGEN_INSN_LIST * |
| 99 | hash_insn_array (CGEN_CPU_DESC cd, |
| 100 | const CGEN_INSN * insns, |
| 101 | int count, |
| 102 | int entsize ATTRIBUTE_UNUSED, |
| 103 | CGEN_INSN_LIST ** htable, |
| 104 | CGEN_INSN_LIST * hentbuf) |
| 105 | { |
| 106 | int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG; |
| 107 | int i; |
| 108 | |
| 109 | for (i = count - 1; i >= 0; --i, ++hentbuf) |
| 110 | { |
| 111 | unsigned int hash; |
| 112 | char buf [4]; |
| 113 | unsigned long value; |
| 114 | const CGEN_INSN *insn = &insns[i]; |
| 115 | |
| 116 | if (! (* cd->dis_hash_p) (insn)) |
| 117 | continue; |
| 118 | |
| 119 | /* We don't know whether the target uses the buffer or the base insn |
| 120 | to hash on, so set both up. */ |
| 121 | |
| 122 | value = CGEN_INSN_BASE_VALUE (insn); |
| 123 | bfd_put_bits ((bfd_vma) value, |
| 124 | buf, |
| 125 | CGEN_INSN_MASK_BITSIZE (insn), |
| 126 | big_p); |
| 127 | hash = (* cd->dis_hash) (buf, value); |
| 128 | add_insn_to_hash_chain (hentbuf, insn, htable, hash); |
| 129 | } |
| 130 | |
| 131 | return hentbuf; |
| 132 | } |
| 133 | |
| 134 | /* Subroutine of build_dis_hash_table to add INSNS to the hash table. |
| 135 | This function is identical to hash_insn_array except the insns are |
| 136 | in a list. */ |
| 137 | |
| 138 | static CGEN_INSN_LIST * |
| 139 | hash_insn_list (CGEN_CPU_DESC cd, |
| 140 | const CGEN_INSN_LIST *insns, |
| 141 | CGEN_INSN_LIST **htable, |
| 142 | CGEN_INSN_LIST *hentbuf) |
| 143 | { |
| 144 | int big_p = CGEN_CPU_INSN_ENDIAN (cd) == CGEN_ENDIAN_BIG; |
| 145 | const CGEN_INSN_LIST *ilist; |
| 146 | |
| 147 | for (ilist = insns; ilist != NULL; ilist = ilist->next, ++ hentbuf) |
| 148 | { |
| 149 | unsigned int hash; |
| 150 | char buf[4]; |
| 151 | unsigned long value; |
| 152 | |
| 153 | if (! (* cd->dis_hash_p) (ilist->insn)) |
| 154 | continue; |
| 155 | |
| 156 | /* We don't know whether the target uses the buffer or the base insn |
| 157 | to hash on, so set both up. */ |
| 158 | |
| 159 | value = CGEN_INSN_BASE_VALUE (ilist->insn); |
| 160 | bfd_put_bits((bfd_vma) value, |
| 161 | buf, |
| 162 | CGEN_INSN_MASK_BITSIZE (ilist->insn), |
| 163 | big_p); |
| 164 | hash = (* cd->dis_hash) (buf, value); |
| 165 | add_insn_to_hash_chain (hentbuf, ilist->insn, htable, hash); |
| 166 | } |
| 167 | |
| 168 | return hentbuf; |
| 169 | } |
| 170 | |
| 171 | /* Build the disassembler instruction hash table. */ |
| 172 | |
| 173 | static void |
| 174 | build_dis_hash_table (CGEN_CPU_DESC cd) |
| 175 | { |
| 176 | int count = cgen_insn_count (cd) + cgen_macro_insn_count (cd); |
| 177 | CGEN_INSN_TABLE *insn_table = & cd->insn_table; |
| 178 | CGEN_INSN_TABLE *macro_insn_table = & cd->macro_insn_table; |
| 179 | unsigned int hash_size = cd->dis_hash_size; |
| 180 | CGEN_INSN_LIST *hash_entry_buf; |
| 181 | CGEN_INSN_LIST **dis_hash_table; |
| 182 | CGEN_INSN_LIST *dis_hash_table_entries; |
| 183 | |
| 184 | /* The space allocated for the hash table consists of two parts: |
| 185 | the hash table and the hash lists. */ |
| 186 | |
| 187 | dis_hash_table = (CGEN_INSN_LIST **) |
| 188 | xmalloc (hash_size * sizeof (CGEN_INSN_LIST *)); |
| 189 | memset (dis_hash_table, 0, hash_size * sizeof (CGEN_INSN_LIST *)); |
| 190 | dis_hash_table_entries = hash_entry_buf = (CGEN_INSN_LIST *) |
| 191 | xmalloc (count * sizeof (CGEN_INSN_LIST)); |
| 192 | |
| 193 | /* Add compiled in insns. |
| 194 | Don't include the first one as it is a reserved entry. */ |
| 195 | /* ??? It was the end of all hash chains, and also the special |
| 196 | "invalid insn" marker. May be able to do it differently now. */ |
| 197 | |
| 198 | hash_entry_buf = hash_insn_array (cd, |
| 199 | insn_table->init_entries + 1, |
| 200 | insn_table->num_init_entries - 1, |
| 201 | insn_table->entry_size, |
| 202 | dis_hash_table, hash_entry_buf); |
| 203 | |
| 204 | /* Add compiled in macro-insns. */ |
| 205 | |
| 206 | hash_entry_buf = hash_insn_array (cd, macro_insn_table->init_entries, |
| 207 | macro_insn_table->num_init_entries, |
| 208 | macro_insn_table->entry_size, |
| 209 | dis_hash_table, hash_entry_buf); |
| 210 | |
| 211 | /* Add runtime added insns. |
| 212 | Later added insns will be prefered over earlier ones. */ |
| 213 | |
| 214 | hash_entry_buf = hash_insn_list (cd, insn_table->new_entries, |
| 215 | dis_hash_table, hash_entry_buf); |
| 216 | |
| 217 | /* Add runtime added macro-insns. */ |
| 218 | |
| 219 | hash_insn_list (cd, macro_insn_table->new_entries, |
| 220 | dis_hash_table, hash_entry_buf); |
| 221 | |
| 222 | cd->dis_hash_table = dis_hash_table; |
| 223 | cd->dis_hash_table_entries = dis_hash_table_entries; |
| 224 | } |
| 225 | |
| 226 | /* Return the first entry in the hash list for INSN. */ |
| 227 | |
| 228 | CGEN_INSN_LIST * |
| 229 | cgen_dis_lookup_insn (CGEN_CPU_DESC cd, const char * buf, CGEN_INSN_INT value) |
| 230 | { |
| 231 | unsigned int hash; |
| 232 | |
| 233 | if (cd->dis_hash_table == NULL) |
| 234 | build_dis_hash_table (cd); |
| 235 | |
| 236 | hash = (* cd->dis_hash) (buf, value); |
| 237 | |
| 238 | return cd->dis_hash_table[hash]; |
| 239 | } |