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-rw-r--r--opcodes/cgen-dis.c61
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;