opcodes/xtensa-dis.c

   1 /* xtensa-dis.c.  Disassembly functions for Xtensa.
   2    Copyright 2003, 2004 Free Software Foundation, Inc.
   3    Contributed by Bob Wilson at Tensilica, Inc. (bwilson@tensilica.com)
   4
   5    This file is part of GDB, GAS, and the GNU binutils.
   6
   7    GDB, GAS, and the GNU binutils are free software; you can redistribute
   8    them and/or modify them under the terms of the GNU General Public
   9    License as published by the Free Software Foundation; either version 2,
  10    or (at your option) any later version.
  11
  12    GDB, GAS, and the GNU binutils are distributed in the hope that they
  13    will be useful, but WITHOUT ANY WARRANTY; without even the implied
  14    warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15    the GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License along
  18    with this file; see the file COPYING.  If not, write to the Free
  19    Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  20    USA.  */
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <sys/types.h>
  25 #include <string.h>
  26 #include "xtensa-isa.h"
  27 #include "ansidecl.h"
  28 #include "libiberty.h"
  29 #include "sysdep.h"
  30 #include "dis-asm.h"
  31
  32 #include <setjmp.h>
  33
  34 extern xtensa_isa xtensa_default_isa;
  35
  36 #ifndef MAX
  37 #define MAX(a,b) (a > b ? a : b)
  38 #endif
  39
  40 int show_raw_fields;
  41
  42 static int fetch_data
  43   PARAMS ((struct disassemble_info *, bfd_vma));
  44 static void print_xtensa_operand
  45   PARAMS ((bfd_vma, struct disassemble_info *, xtensa_opcode, int, unsigned));
  46
  47 struct dis_private
  48 {
  49   bfd_byte *byte_buf;
  50   jmp_buf bailout;
  51 };
  52
  53
  54 static int
  55 fetch_data (info, memaddr)
  56      struct disassemble_info *info;
  57      bfd_vma memaddr;
  58 {
  59   int length, status = 0;
  60   struct dis_private *priv = (struct dis_private *) info->private_data;
  61   int insn_size = xtensa_isa_maxlength (xtensa_default_isa);
  62
  63   /* Read the maximum instruction size, padding with zeros if we go past
  64      the end of the text section.  This code will automatically adjust
  65      length when we hit the end of the buffer.  */
  66
  67   memset (priv->byte_buf, 0, insn_size);
  68   for (length = insn_size; length > 0; length--)
  69     {
  70       status = (*info->read_memory_func) (memaddr, priv->byte_buf, length,
  71                                           info);
  72       if (status == 0)
  73         return length;
  74     }
  75   (*info->memory_error_func) (status, memaddr, info);
  76   longjmp (priv->bailout, 1);
  77   /*NOTREACHED*/
  78 }
  79
  80
  81 static void
  82 print_xtensa_operand (memaddr, info, opc, opnd, operand_val)
  83      bfd_vma memaddr;
  84      struct disassemble_info *info;
  85      xtensa_opcode opc;
  86      int opnd;
  87      unsigned operand_val;
  88 {
  89   xtensa_isa isa = xtensa_default_isa;
  90   int signed_operand_val;
  91
  92   if (show_raw_fields)
  93     {
  94       if (operand_val < 0xa)
  95         (*info->fprintf_func) (info->stream, "%u", operand_val);
  96       else
  97         (*info->fprintf_func) (info->stream, "0x%x", operand_val);
  98       return;
  99     }
 100
 101   (void) xtensa_operand_decode (isa, opc, opnd, &operand_val);
 102   signed_operand_val = (int) operand_val;
 103
 104   if (xtensa_operand_is_register (isa, opc, opnd) == 0)
 105     {
 106       if (xtensa_operand_is_PCrelative (isa, opc, opnd) == 1)
 107         {
 108           (void) xtensa_operand_undo_reloc (isa, opc, opnd,
 109                                             &operand_val, memaddr);
 110           info->target = operand_val;
 111           (*info->print_address_func) (info->target, info);
 112         }
 113       else
 114         {
 115           if ((signed_operand_val > -256) && (signed_operand_val < 256))
 116             (*info->fprintf_func) (info->stream, "%d", signed_operand_val);
 117           else
 118             (*info->fprintf_func) (info->stream, "0x%x", signed_operand_val);
 119         }
 120     }
 121   else
 122     {
 123       int i = 1;
 124       xtensa_regfile opnd_rf = xtensa_operand_regfile (isa, opc, opnd);
 125       (*info->fprintf_func) (info->stream, "%s%u",
 126                              xtensa_regfile_shortname (isa, opnd_rf),
 127                              operand_val);
 128       while (i < xtensa_operand_num_regs (isa, opc, opnd))
 129         {
 130           operand_val++;
 131           (*info->fprintf_func) (info->stream, ":%s%u",
 132                                  xtensa_regfile_shortname (isa, opnd_rf),
 133                                  operand_val);
 134           i++;
 135         }
 136     }
 137 }
 138
 139
 140 /* Print the Xtensa instruction at address MEMADDR on info->stream.
 141    Returns length of the instruction in bytes.  */
 142
 143 int
 144 print_insn_xtensa (memaddr, info)
 145      bfd_vma memaddr;
 146      struct disassemble_info *info;
 147 {
 148   unsigned operand_val;
 149   int bytes_fetched, size, maxsize, i, n, noperands, nslots;
 150   xtensa_isa isa;
 151   xtensa_opcode opc;
 152   xtensa_format fmt;
 153   struct dis_private priv;
 154   static bfd_byte *byte_buf = NULL;
 155   static xtensa_insnbuf insn_buffer = NULL;
 156   static xtensa_insnbuf slot_buffer = NULL;
 157   int first, first_slot, valid_insn;
 158
 159   if (!xtensa_default_isa)
 160     xtensa_default_isa = xtensa_isa_init (0, 0);
 161
 162   info->target = 0;
 163   maxsize = xtensa_isa_maxlength (xtensa_default_isa);
 164
 165   /* Set bytes_per_line to control the amount of whitespace between the hex
 166      values and the opcode.  For Xtensa, we always print one "chunk" and we
 167      vary bytes_per_chunk to determine how many bytes to print.  (objdump
 168      would apparently prefer that we set bytes_per_chunk to 1 and vary
 169      bytes_per_line but that makes it hard to fit 64-bit instructions on
 170      an 80-column screen.)  The value of bytes_per_line here is not exactly
 171      right, because objdump adds an extra space for each chunk so that the
 172      amount of whitespace depends on the chunk size.  Oh well, it's good
 173      enough....  Note that we set the minimum size to 4 to accomodate
 174      literal pools.  */
 175   info->bytes_per_line = MAX (maxsize, 4);
 176
 177   /* Allocate buffers the first time through.  */
 178   if (!insn_buffer)
 179     {
 180       insn_buffer = xtensa_insnbuf_alloc (xtensa_default_isa);
 181       slot_buffer = xtensa_insnbuf_alloc (xtensa_default_isa);
 182       byte_buf = (bfd_byte *) xmalloc (MAX (maxsize, 4));
 183     }
 184
 185   priv.byte_buf = byte_buf;
 186
 187   info->private_data = (PTR) &priv;
 188   if (setjmp (priv.bailout) != 0)
 189       /* Error return.  */
 190       return -1;
 191
 192   /* Don't set "isa" before the setjmp to keep the compiler from griping.  */
 193   isa = xtensa_default_isa;
 194   size = 0;
 195   nslots = 0;
 196
 197   /* Fetch the maximum size instruction.  */
 198   bytes_fetched = fetch_data (info, memaddr);
 199
 200   /* Copy the bytes into the decode buffer.  */
 201   memset (insn_buffer, 0, (xtensa_insnbuf_size (isa) *
 202                            sizeof (xtensa_insnbuf_word)));
 203   xtensa_insnbuf_from_chars (isa, insn_buffer, priv.byte_buf, bytes_fetched);
 204
 205   fmt = xtensa_format_decode (isa, insn_buffer);
 206   if (fmt == XTENSA_UNDEFINED
 207       || ((size = xtensa_format_length (isa, fmt)) > bytes_fetched))
 208     valid_insn = 0;
 209   else
 210     {
 211       /* Make sure all the opcodes are valid.  */
 212       valid_insn = 1;
 213       nslots = xtensa_format_num_slots (isa, fmt);
 214       for (n = 0; n < nslots; n++)
 215         {
 216           xtensa_format_get_slot (isa, fmt, n, insn_buffer, slot_buffer);
 217           if (xtensa_opcode_decode (isa, fmt, n, slot_buffer)
 218               == XTENSA_UNDEFINED)
 219             {
 220               valid_insn = 0;
 221               break;
 222             }
 223         }
 224     }
 225
 226   if (!valid_insn)
 227     {
 228       (*info->fprintf_func) (info->stream, ".byte %#02x", priv.byte_buf[0]);
 229       return 1;
 230     }
 231
 232   if (nslots > 1)
 233     (*info->fprintf_func) (info->stream, "{ ");
 234
 235   first_slot = 1;
 236   for (n = 0; n < nslots; n++)
 237     {
 238       if (first_slot)
 239         first_slot = 0;
 240       else
 241         (*info->fprintf_func) (info->stream, "; ");
 242
 243       xtensa_format_get_slot (isa, fmt, n, insn_buffer, slot_buffer);
 244       opc = xtensa_opcode_decode (isa, fmt, n, slot_buffer);
 245       (*info->fprintf_func) (info->stream, "%s",
 246                              xtensa_opcode_name (isa, opc));
 247
 248       /* Print the operands (if any).  */
 249       noperands = xtensa_opcode_num_operands (isa, opc);
 250       first = 1;
 251       for (i = 0; i < noperands; i++)
 252         {
 253           if (xtensa_operand_is_visible (isa, opc, i) == 0)
 254             continue;
 255           if (first)
 256             {
 257               (*info->fprintf_func) (info->stream, "\t");
 258               first = 0;
 259             }
 260           else
 261             (*info->fprintf_func) (info->stream, ", ");
 262           (void) xtensa_operand_get_field (isa, opc, i, fmt, n,
 263                                            slot_buffer, &operand_val);
 264
 265           print_xtensa_operand (memaddr, info, opc, i, operand_val);
 266         }
 267     }
 268
 269   if (nslots > 1)
 270     (*info->fprintf_func) (info->stream, " }");
 271
 272   info->bytes_per_chunk = size;
 273   info->display_endian = info->endian;
 274
 275   return size;
 276 }
 277