Changeset 609 for branches/GNU/src/binutils/opcodes/cgen-dis.c

Timestamp:

Aug 16, 2003, 6:59:22 PM (22 years ago)

Author:

bird

Message:

binutils v2.14 - offical sources.

File:

• branches/GNU/src/binutils/opcodes/cgen-dis.c (modified) (4 diffs, 1 prop)

branches/GNU/src/binutils/opcodes/cgen-dis.c

@@ -1 +1 @@
 /* CGEN generic disassembler support code.
 
-   Copyright 1996, 1997, 1998, 1999, 2000, 2001
+   Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002
    Free Software Foundation, Inc.
 
@@ -28 +28 @@
 #include "opcode/cgen.h"
 
+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));
+static int               count_decodable_bits PARAMS ((const CGEN_INSN *));
+static void              add_insn_to_hash_chain PARAMS ((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 (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.
 
@@ -71 +131 @@
                     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);
     }
 
@@ -111 +169 @@
                    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);
     }