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, 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301,
  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 struct dis_private
  43 {
  44   bfd_byte *byte_buf;
  45   jmp_buf bailout;
  46 };
  47
  48
  49 static int
  50 fetch_data (struct disassemble_info *info, bfd_vma memaddr)
  51 {
  52   int length, status = 0;
  53   struct dis_private *priv = (struct dis_private *) info->private_data;
  54   int insn_size = xtensa_isa_maxlength (xtensa_default_isa);
  55
  56   /* Read the maximum instruction size, padding with zeros if we go past
  57      the end of the text section.  This code will automatically adjust
  58      length when we hit the end of the buffer.  */
  59
  60   memset (priv->byte_buf, 0, insn_size);
  61   for (length = insn_size; length > 0; length--)
  62     {
  63       status = (*info->read_memory_func) (memaddr, priv->byte_buf, length,
  64                                           info);
  65       if (status == 0)
  66         return length;
  67     }
  68   (*info->memory_error_func) (status, memaddr, info);
  69   longjmp (priv->bailout, 1);
  70   /*NOTREACHED*/
  71 }
  72
  73
  74 static void
  75 print_xtensa_operand (bfd_vma memaddr,
  76                       struct disassemble_info *info,
  77                       xtensa_opcode opc,
  78                       int opnd,
  79                       unsigned operand_val)
  80 {
  81   xtensa_isa isa = xtensa_default_isa;
  82   int signed_operand_val;
  83
  84   if (show_raw_fields)
  85     {
  86       if (operand_val < 0xa)
  87         (*info->fprintf_func) (info->stream, "%u", operand_val);
  88       else
  89         (*info->fprintf_func) (info->stream, "0x%x", operand_val);
  90       return;
  91     }
  92
  93   (void) xtensa_operand_decode (isa, opc, opnd, &operand_val);
  94   signed_operand_val = (int) operand_val;
  95
  96   if (xtensa_operand_is_register (isa, opc, opnd) == 0)
  97     {
  98       if (xtensa_operand_is_PCrelative (isa, opc, opnd) == 1)
  99         {
 100           (void) xtensa_operand_undo_reloc (isa, opc, opnd,
 101                                             &operand_val, memaddr);
 102           info->target = operand_val;
 103           (*info->print_address_func) (info->target, info);
 104         }
 105       else
 106         {
 107           if ((signed_operand_val > -256) && (signed_operand_val < 256))
 108             (*info->fprintf_func) (info->stream, "%d", signed_operand_val);
 109           else
 110             (*info->fprintf_func) (info->stream, "0x%x", signed_operand_val);
 111         }
 112     }
 113   else
 114     {
 115       int i = 1;
 116       xtensa_regfile opnd_rf = xtensa_operand_regfile (isa, opc, opnd);
 117       (*info->fprintf_func) (info->stream, "%s%u",
 118                              xtensa_regfile_shortname (isa, opnd_rf),
 119                              operand_val);
 120       while (i < xtensa_operand_num_regs (isa, opc, opnd))
 121         {
 122           operand_val++;
 123           (*info->fprintf_func) (info->stream, ":%s%u",
 124                                  xtensa_regfile_shortname (isa, opnd_rf),
 125                                  operand_val);
 126           i++;
 127         }
 128     }
 129 }
 130
 131
 132 /* Print the Xtensa instruction at address MEMADDR on info->stream.
 133    Returns length of the instruction in bytes.  */
 134
 135 int
 136 print_insn_xtensa (bfd_vma memaddr, struct disassemble_info *info)
 137 {
 138   unsigned operand_val;
 139   int bytes_fetched, size, maxsize, i, n, noperands, nslots;
 140   xtensa_isa isa;
 141   xtensa_opcode opc;
 142   xtensa_format fmt;
 143   struct dis_private priv;
 144   static bfd_byte *byte_buf = NULL;
 145   static xtensa_insnbuf insn_buffer = NULL;
 146   static xtensa_insnbuf slot_buffer = NULL;
 147   int first, first_slot, valid_insn;
 148
 149   if (!xtensa_default_isa)
 150     xtensa_default_isa = xtensa_isa_init (0, 0);
 151
 152   info->target = 0;
 153   maxsize = xtensa_isa_maxlength (xtensa_default_isa);
 154
 155   /* Set bytes_per_line to control the amount of whitespace between the hex
 156      values and the opcode.  For Xtensa, we always print one "chunk" and we
 157      vary bytes_per_chunk to determine how many bytes to print.  (objdump
 158      would apparently prefer that we set bytes_per_chunk to 1 and vary
 159      bytes_per_line but that makes it hard to fit 64-bit instructions on
 160      an 80-column screen.)  The value of bytes_per_line here is not exactly
 161      right, because objdump adds an extra space for each chunk so that the
 162      amount of whitespace depends on the chunk size.  Oh well, it's good
 163      enough....  Note that we set the minimum size to 4 to accomodate
 164      literal pools.  */
 165   info->bytes_per_line = MAX (maxsize, 4);
 166
 167   /* Allocate buffers the first time through.  */
 168   if (!insn_buffer)
 169     {
 170       insn_buffer = xtensa_insnbuf_alloc (xtensa_default_isa);
 171       slot_buffer = xtensa_insnbuf_alloc (xtensa_default_isa);
 172       byte_buf = (bfd_byte *) xmalloc (MAX (maxsize, 4));
 173     }
 174
 175   priv.byte_buf = byte_buf;
 176
 177   info->private_data = (void *) &priv;
 178   if (setjmp (priv.bailout) != 0)
 179       /* Error return.  */
 180       return -1;
 181
 182   /* Don't set "isa" before the setjmp to keep the compiler from griping.  */
 183   isa = xtensa_default_isa;
 184   size = 0;
 185   nslots = 0;
 186
 187   /* Fetch the maximum size instruction.  */
 188   bytes_fetched = fetch_data (info, memaddr);
 189
 190   /* Copy the bytes into the decode buffer.  */
 191   memset (insn_buffer, 0, (xtensa_insnbuf_size (isa) *
 192                            sizeof (xtensa_insnbuf_word)));
 193   xtensa_insnbuf_from_chars (isa, insn_buffer, priv.byte_buf, bytes_fetched);
 194
 195   fmt = xtensa_format_decode (isa, insn_buffer);
 196   if (fmt == XTENSA_UNDEFINED
 197       || ((size = xtensa_format_length (isa, fmt)) > bytes_fetched))
 198     valid_insn = 0;
 199   else
 200     {
 201       /* Make sure all the opcodes are valid.  */
 202       valid_insn = 1;
 203       nslots = xtensa_format_num_slots (isa, fmt);
 204       for (n = 0; n < nslots; n++)
 205         {
 206           xtensa_format_get_slot (isa, fmt, n, insn_buffer, slot_buffer);
 207           if (xtensa_opcode_decode (isa, fmt, n, slot_buffer)
 208               == XTENSA_UNDEFINED)
 209             {
 210               valid_insn = 0;
 211               break;
 212             }
 213         }
 214     }
 215
 216   if (!valid_insn)
 217     {
 218       (*info->fprintf_func) (info->stream, ".byte %#02x", priv.byte_buf[0]);
 219       return 1;
 220     }
 221
 222   if (nslots > 1)
 223     (*info->fprintf_func) (info->stream, "{ ");
 224
 225   first_slot = 1;
 226   for (n = 0; n < nslots; n++)
 227     {
 228       if (first_slot)
 229         first_slot = 0;
 230       else
 231         (*info->fprintf_func) (info->stream, "; ");
 232
 233       xtensa_format_get_slot (isa, fmt, n, insn_buffer, slot_buffer);
 234       opc = xtensa_opcode_decode (isa, fmt, n, slot_buffer);
 235       (*info->fprintf_func) (info->stream, "%s",
 236                              xtensa_opcode_name (isa, opc));
 237
 238       /* Print the operands (if any).  */
 239       noperands = xtensa_opcode_num_operands (isa, opc);
 240       first = 1;
 241       for (i = 0; i < noperands; i++)
 242         {
 243           if (xtensa_operand_is_visible (isa, opc, i) == 0)
 244             continue;
 245           if (first)
 246             {
 247               (*info->fprintf_func) (info->stream, "\t");
 248               first = 0;
 249             }
 250           else
 251             (*info->fprintf_func) (info->stream, ", ");
 252           (void) xtensa_operand_get_field (isa, opc, i, fmt, n,
 253                                            slot_buffer, &operand_val);
 254
 255           print_xtensa_operand (memaddr, info, opc, i, operand_val);
 256         }
 257     }
 258
 259   if (nslots > 1)
 260     (*info->fprintf_func) (info->stream, " }");
 261
 262   info->bytes_per_chunk = size;
 263   info->display_endian = info->endian;
 264
 265   return size;
 266 }
 267