diff options
Diffstat (limited to 'opcodes/cgen-dis.c')
-rw-r--r-- | opcodes/cgen-dis.c | 61 |
1 files changed, 54 insertions, 7 deletions
diff --git a/opcodes/cgen-dis.c b/opcodes/cgen-dis.c index 8e9fe56..4622c8c 100644 --- a/opcodes/cgen-dis.c +++ b/opcodes/cgen-dis.c @@ -30,7 +30,58 @@ static CGEN_INSN_LIST * hash_insn_array PARAMS ((CGEN_CPU_DESC, const CGEN_INSN *, int, int, CGEN_INSN_LIST **, CGEN_INSN_LIST *)); static CGEN_INSN_LIST * hash_insn_list PARAMS ((CGEN_CPU_DESC, const CGEN_INSN_LIST *, CGEN_INSN_LIST **, CGEN_INSN_LIST *)); static void build_dis_hash_table PARAMS ((CGEN_CPU_DESC)); - + +/* Return the number of decodable bits in this insn. */ +static int +count_decodable_bits (insn) + const CGEN_INSN *insn; +{ + unsigned mask = CGEN_INSN_BASE_MASK (insn); + int bits = 0; + int 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 (hentbuf, insn, htable, hash) + 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. @@ -74,9 +125,7 @@ hash_insn_array (cd, insns, count, entsize, htable, hentbuf) CGEN_INSN_MASK_BITSIZE (insn), big_p); hash = (* cd->dis_hash) (buf, value); - hentbuf->next = htable[hash]; - hentbuf->insn = insn; - htable[hash] = hentbuf; + add_insn_to_hash_chain (hentbuf, insn, htable, hash); } return hentbuf; @@ -114,9 +163,7 @@ hash_insn_list (cd, insns, htable, hentbuf) CGEN_INSN_MASK_BITSIZE (ilist->insn), big_p); hash = (* cd->dis_hash) (buf, value); - hentbuf->next = htable [hash]; - hentbuf->insn = ilist->insn; - htable [hash] = hentbuf; + add_insn_to_hash_chain (hentbuf, ilist->insn, htable, hash); } return hentbuf; |