517 lines
12 KiB
C
517 lines
12 KiB
C
/* Print National Semiconductor 32000 instructions for GDB, the GNU debugger.
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Copyright 1986, 1988, 1991, 1992 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
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#include "defs.h"
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#include "symtab.h"
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#include "ns32k-opcode.h"
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#include "gdbcore.h"
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/* 32000 instructions are never longer than this. */
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#define MAXLEN 62
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/* Number of elements in the opcode table. */
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#define NOPCODES (sizeof notstrs / sizeof notstrs[0])
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#define NEXT_IS_ADDR '|'
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/*
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* extract "count" bits starting "offset" bits
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* into buffer
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*/
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int
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bit_extract (buffer, offset, count)
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char *buffer;
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int offset;
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int count;
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{
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int result;
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int mask;
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int bit;
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buffer += offset >> 3;
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offset &= 7;
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bit = 1;
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result = 0;
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while (count--)
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{
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if ((*buffer & (1 << offset)))
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result |= bit;
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if (++offset == 8)
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{
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offset = 0;
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buffer++;
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}
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bit <<= 1;
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}
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return result;
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}
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float
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fbit_extract (buffer, offset, count)
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{
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union {
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int ival;
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float fval;
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} foo;
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foo.ival = bit_extract (buffer, offset, 32);
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return foo.fval;
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}
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double
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dbit_extract (buffer, offset, count)
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{
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union {
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struct {int low, high; } ival;
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double dval;
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} foo;
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foo.ival.low = bit_extract (buffer, offset, 32);
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foo.ival.high = bit_extract (buffer, offset+32, 32);
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return foo.dval;
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}
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sign_extend (value, bits)
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{
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value = value & ((1 << bits) - 1);
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return (value & (1 << (bits-1))
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? value | (~((1 << bits) - 1))
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: value);
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}
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flip_bytes (ptr, count)
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char *ptr;
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int count;
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{
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char tmp;
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while (count > 0)
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{
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tmp = *ptr;
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ptr[0] = ptr[count-1];
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ptr[count-1] = tmp;
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ptr++;
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count -= 2;
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}
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}
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/* Given a character C, does it represent a general addressing mode? */
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#define Is_gen(c) \
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((c) == 'F' || (c) == 'L' || (c) == 'B' \
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|| (c) == 'W' || (c) == 'D' || (c) == 'A')
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/* Adressing modes. */
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#define Adrmod_index_byte 0x1c
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#define Adrmod_index_word 0x1d
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#define Adrmod_index_doubleword 0x1e
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#define Adrmod_index_quadword 0x1f
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/* Is MODE an indexed addressing mode? */
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#define Adrmod_is_index(mode) \
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(mode == Adrmod_index_byte \
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|| mode == Adrmod_index_word \
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|| mode == Adrmod_index_doubleword \
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|| mode == Adrmod_index_quadword)
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/* Print the 32000 instruction at address MEMADDR in debugged memory,
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on STREAM. Returns length of the instruction, in bytes. */
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int
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print_insn (memaddr, stream)
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CORE_ADDR memaddr;
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FILE *stream;
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{
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unsigned char buffer[MAXLEN];
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register int i;
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register unsigned char *p;
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register char *d;
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unsigned short first_word;
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int gen, disp;
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int ioffset; /* bits into instruction */
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int aoffset; /* bits into arguments */
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char arg_bufs[MAX_ARGS+1][ARG_LEN];
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int argnum;
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int maxarg;
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read_memory (memaddr, buffer, MAXLEN);
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first_word = *(unsigned short *) buffer;
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for (i = 0; i < NOPCODES; i++)
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if ((first_word & ((1 << notstrs[i].detail.obits) - 1))
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== notstrs[i].detail.code)
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break;
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/* Handle undefined instructions. */
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if (i == NOPCODES)
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{
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fprintf (stream, "0%o", buffer[0]);
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return 1;
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}
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fprintf (stream, "%s", notstrs[i].name);
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ioffset = notstrs[i].detail.ibits;
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aoffset = notstrs[i].detail.ibits;
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d = notstrs[i].detail.args;
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if (*d)
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{
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/* Offset in bits of the first thing beyond each index byte.
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Element 0 is for operand A and element 1 is for operand B.
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The rest are irrelevant, but we put them here so we don't
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index outside the array. */
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int index_offset[MAX_ARGS];
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/* 0 for operand A, 1 for operand B, greater for other args. */
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int whicharg = 0;
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fputc ('\t', stream);
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maxarg = 0;
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/* First we have to find and keep track of the index bytes,
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if we are using scaled indexed addressing mode, since the index
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bytes occur right after the basic instruction, not as part
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of the addressing extension. */
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if (Is_gen(d[1]))
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{
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int addr_mode = bit_extract (buffer, ioffset - 5, 5);
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if (Adrmod_is_index (addr_mode))
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{
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aoffset += 8;
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index_offset[0] = aoffset;
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}
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}
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if (d[2] && Is_gen(d[3]))
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{
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int addr_mode = bit_extract (buffer, ioffset - 10, 5);
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if (Adrmod_is_index (addr_mode))
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{
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aoffset += 8;
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index_offset[1] = aoffset;
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}
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}
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while (*d)
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{
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argnum = *d - '1';
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d++;
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if (argnum > maxarg && argnum < MAX_ARGS)
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maxarg = argnum;
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ioffset = print_insn_arg (*d, ioffset, &aoffset, buffer,
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memaddr, arg_bufs[argnum],
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index_offset[whicharg]);
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d++;
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whicharg++;
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}
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for (argnum = 0; argnum <= maxarg; argnum++)
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{
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CORE_ADDR addr;
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char *ch, *index ();
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for (ch = arg_bufs[argnum]; *ch;)
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{
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if (*ch == NEXT_IS_ADDR)
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{
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++ch;
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addr = atoi (ch);
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print_address (addr, stream);
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while (*ch && *ch != NEXT_IS_ADDR)
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++ch;
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if (*ch)
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++ch;
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}
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else
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putc (*ch++, stream);
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}
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if (argnum < maxarg)
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fprintf (stream, ", ");
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}
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}
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return aoffset / 8;
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}
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/* Print an instruction operand of category given by d. IOFFSET is
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the bit position below which small (<1 byte) parts of the operand can
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be found (usually in the basic instruction, but for indexed
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addressing it can be in the index byte). AOFFSETP is a pointer to the
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bit position of the addressing extension. BUFFER contains the
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instruction. ADDR is where BUFFER was read from. Put the disassembled
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version of the operand in RESULT. INDEX_OFFSET is the bit position
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of the index byte (it contains garbage if this operand is not a
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general operand using scaled indexed addressing mode). */
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print_insn_arg (d, ioffset, aoffsetp, buffer, addr, result, index_offset)
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char d;
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int ioffset, *aoffsetp;
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char *buffer;
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CORE_ADDR addr;
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char *result;
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int index_offset;
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{
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int addr_mode;
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float Fvalue;
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double Lvalue;
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int Ivalue;
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int disp1, disp2;
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int index;
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switch (d)
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{
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case 'F':
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case 'L':
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case 'B':
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case 'W':
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case 'D':
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case 'A':
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addr_mode = bit_extract (buffer, ioffset-5, 5);
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ioffset -= 5;
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switch (addr_mode)
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{
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case 0x0: case 0x1: case 0x2: case 0x3:
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case 0x4: case 0x5: case 0x6: case 0x7:
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switch (d)
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{
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case 'F':
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case 'L':
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sprintf (result, "f%d", addr_mode);
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break;
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default:
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sprintf (result, "r%d", addr_mode);
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}
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break;
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case 0x8: case 0x9: case 0xa: case 0xb:
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case 0xc: case 0xd: case 0xe: case 0xf:
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disp1 = get_displacement (buffer, aoffsetp);
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sprintf (result, "%d(r%d)", disp1, addr_mode & 7);
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break;
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case 0x10:
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case 0x11:
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case 0x12:
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disp1 = get_displacement (buffer, aoffsetp);
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disp2 = get_displacement (buffer, aoffsetp);
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sprintf (result, "%d(%d(%s))", disp2, disp1,
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addr_mode==0x10?"fp":addr_mode==0x11?"sp":"sb");
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break;
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case 0x13:
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sprintf (result, "reserved");
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break;
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case 0x14:
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switch (d)
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{
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case 'B':
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Ivalue = bit_extract (buffer, *aoffsetp, 8);
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Ivalue = sign_extend (Ivalue, 8);
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*aoffsetp += 8;
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sprintf (result, "$%d", Ivalue);
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break;
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case 'W':
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Ivalue = bit_extract (buffer, *aoffsetp, 16);
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flip_bytes (&Ivalue, 2);
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*aoffsetp += 16;
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Ivalue = sign_extend (Ivalue, 16);
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sprintf (result, "$%d", Ivalue);
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break;
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case 'D':
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Ivalue = bit_extract (buffer, *aoffsetp, 32);
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flip_bytes (&Ivalue, 4);
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*aoffsetp += 32;
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sprintf (result, "$%d", Ivalue);
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break;
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case 'A':
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Ivalue = bit_extract (buffer, *aoffsetp, 32);
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flip_bytes (&Ivalue, 4);
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*aoffsetp += 32;
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sprintf (result, "$|%d|", Ivalue);
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break;
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case 'F':
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Fvalue = fbit_extract (buffer, *aoffsetp, 32);
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flip_bytes (&Fvalue, 4);
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*aoffsetp += 32;
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sprintf (result, "$%g", Fvalue);
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break;
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case 'L':
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Lvalue = dbit_extract (buffer, *aoffsetp, 64);
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flip_bytes (&Lvalue, 8);
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*aoffsetp += 64;
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sprintf (result, "$%g", Lvalue);
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break;
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}
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break;
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case 0x15:
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disp1 = get_displacement (buffer, aoffsetp);
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sprintf (result, "@|%d|", disp1);
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break;
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case 0x16:
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disp1 = get_displacement (buffer, aoffsetp);
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disp2 = get_displacement (buffer, aoffsetp);
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sprintf (result, "EXT(%d) + %d", disp1, disp2);
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break;
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case 0x17:
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sprintf (result, "tos");
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break;
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case 0x18:
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disp1 = get_displacement (buffer, aoffsetp);
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sprintf (result, "%d(fp)", disp1);
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break;
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case 0x19:
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disp1 = get_displacement (buffer, aoffsetp);
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sprintf (result, "%d(sp)", disp1);
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break;
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case 0x1a:
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disp1 = get_displacement (buffer, aoffsetp);
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sprintf (result, "%d(sb)", disp1);
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break;
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case 0x1b:
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disp1 = get_displacement (buffer, aoffsetp);
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sprintf (result, "|%d|", addr + disp1);
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break;
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case 0x1c:
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case 0x1d:
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case 0x1e:
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case 0x1f:
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index = bit_extract (buffer, index_offset - 8, 3);
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print_insn_arg (d, index_offset, aoffsetp, buffer, addr,
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result, 0);
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{
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static char *ind[] = {"b", "w", "d", "q"};
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char *off;
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off = result + strlen (result);
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sprintf (off, "[r%d:%s]", index,
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ind[addr_mode & 3]);
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}
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break;
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}
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break;
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case 'q':
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Ivalue = bit_extract (buffer, ioffset-4, 4);
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Ivalue = sign_extend (Ivalue, 4);
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sprintf (result, "%d", Ivalue);
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ioffset -= 4;
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break;
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case 'r':
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Ivalue = bit_extract (buffer, ioffset-3, 3);
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sprintf (result, "r%d", Ivalue&7);
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ioffset -= 3;
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break;
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case 'd':
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sprintf (result, "%d", get_displacement (buffer, aoffsetp));
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break;
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case 'p':
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sprintf (result, "%c%d%c", NEXT_IS_ADDR,
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addr + get_displacement (buffer, aoffsetp),
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NEXT_IS_ADDR);
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break;
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case 'i':
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Ivalue = bit_extract (buffer, *aoffsetp, 8);
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*aoffsetp += 8;
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sprintf (result, "0x%x", Ivalue);
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break;
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}
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return ioffset;
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}
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get_displacement (buffer, aoffsetp)
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char *buffer;
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int *aoffsetp;
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{
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int Ivalue;
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Ivalue = bit_extract (buffer, *aoffsetp, 8);
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switch (Ivalue & 0xc0)
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{
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case 0x00:
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case 0x40:
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Ivalue = sign_extend (Ivalue, 7);
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*aoffsetp += 8;
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break;
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case 0x80:
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Ivalue = bit_extract (buffer, *aoffsetp, 16);
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flip_bytes (&Ivalue, 2);
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Ivalue = sign_extend (Ivalue, 14);
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*aoffsetp += 16;
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break;
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case 0xc0:
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Ivalue = bit_extract (buffer, *aoffsetp, 32);
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flip_bytes (&Ivalue, 4);
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Ivalue = sign_extend (Ivalue, 30);
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*aoffsetp += 32;
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break;
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}
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return Ivalue;
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}
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/* Return the number of locals in the current frame given a pc
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pointing to the enter instruction. This is used in the macro
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FRAME_FIND_SAVED_REGS. */
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ns32k_localcount (enter_pc)
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CORE_ADDR enter_pc;
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{
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unsigned char localtype;
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int localcount;
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localtype = read_memory_integer (enter_pc+2, 1);
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if ((localtype & 0x80) == 0)
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localcount = localtype;
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else if ((localtype & 0xc0) == 0x80)
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localcount = (((localtype & 0x3f) << 8)
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| (read_memory_integer (enter_pc+3, 1) & 0xff));
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else
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localcount = (((localtype & 0x3f) << 24)
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| ((read_memory_integer (enter_pc+3, 1) & 0xff) << 16)
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| ((read_memory_integer (enter_pc+4, 1) & 0xff) << 8 )
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| (read_memory_integer (enter_pc+5, 1) & 0xff));
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return localcount;
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}
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/*
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* Get the address of the enter opcode for the function
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* containing PC, if there is an enter for the function,
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* and if the pc is between the enter and exit.
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* Returns positive address if pc is between enter/exit,
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* 1 if pc before enter or after exit, 0 otherwise.
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*/
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CORE_ADDR
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ns32k_get_enter_addr (pc)
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CORE_ADDR pc;
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{
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CORE_ADDR enter_addr;
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unsigned char op;
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if (ABOUT_TO_RETURN (pc))
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return 1; /* after exit */
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enter_addr = get_pc_function_start (pc);
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if (pc == enter_addr)
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return 1; /* before enter */
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op = read_memory_integer (enter_addr, 1);
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if (op != 0x82)
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return 0; /* function has no enter/exit */
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return enter_addr; /* pc is between enter and exit */
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}
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