1 /* Print Motorola 68k instructions for GDB, the GNU debugger.
2 Copyright 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
22 #include "opcode/m68k.h"
24 #include "ieee-float.h"
26 /* Local function prototypes */
29 fetch_arg
PARAMS ((unsigned char *, int, int));
32 print_base
PARAMS ((int, int, FILE *));
34 static unsigned char *
35 print_indexed
PARAMS ((int, unsigned char *, CORE_ADDR
, FILE *));
37 static unsigned char *
38 print_insn_arg
PARAMS ((char *, unsigned char *, unsigned char *, CORE_ADDR
,
41 /* 68k instructions are never longer than this many bytes. */
44 /* Number of elements in the opcode table. */
45 #define NOPCODES (sizeof m68k_opcodes / sizeof m68k_opcodes[0])
47 const char * const fpcr_names
[] = {
48 "", "fpiar", "fpsr", "fpiar/fpsr", "fpcr",
49 "fpiar/fpcr", "fpsr/fpcr", "fpiar/fpsr/fpcr"};
51 /* Define accessors for 68K's 1, 2, and 4-byte signed quantities.
52 The _SHIFT values move the quantity to the high order end of an
53 `int' value, so it will sign-extend. Probably a few more casts
54 are needed to make it compile without warnings on finicky systems. */
55 #define BITS_PER_BYTE 8
56 #define BYTE_SHIFT (BITS_PER_BYTE * ((sizeof (int)) - 1))
57 #define WORD_SHIFT (BITS_PER_BYTE * ((sizeof (int)) - 2))
58 #define LONG_SHIFT (BITS_PER_BYTE * ((sizeof (int)) - 4))
60 #define NEXTBYTE(p) (p += 2, ((int)(p[-1]) << BYTE_SHIFT) >> BYTE_SHIFT)
63 (p += 2, (((int)((p[-2] << 8) + p[-1])) << WORD_SHIFT) >> WORD_SHIFT)
66 (p += 4, (((int)((((((p[-4] << 8) + p[-3]) << 8) + p[-2]) << 8) + p[-1])) \
67 << LONG_SHIFT) >> LONG_SHIFT)
69 /* Ecch -- assumes host == target float formats. FIXME. */
70 #define NEXTSINGLE(p) \
71 (p += 4, *((float *)(p - 4)))
73 #define NEXTDOUBLE(p) \
74 (p += 8, *((double *)(p - 8)))
76 /* Print the m68k instruction at address MEMADDR in debugged memory,
77 on STREAM. Returns length of the instruction, in bytes. */
80 print_insn (memaddr
, stream
)
84 unsigned char buffer
[MAXLEN
];
86 register unsigned char *p
;
88 register int bestmask
;
91 read_memory (memaddr
, (char *) buffer
, MAXLEN
);
95 for (i
= 0; i
< NOPCODES
; i
++)
97 register unsigned int opcode
= m68k_opcodes
[i
].opcode
;
98 register unsigned int match
= m68k_opcodes
[i
].match
;
99 if (((0xff & buffer
[0] & (match
>> 24)) == (0xff & (opcode
>> 24)))
100 && ((0xff & buffer
[1] & (match
>> 16)) == (0xff & (opcode
>> 16)))
101 && ((0xff & buffer
[2] & (match
>> 8)) == (0xff & (opcode
>> 8)))
102 && ((0xff & buffer
[3] & match
) == (0xff & opcode
)))
104 /* Don't use for printout the variants of divul and divsl
105 that have the same register number in two places.
106 The more general variants will match instead. */
107 for (d
= m68k_opcodes
[i
].args
; *d
; d
+= 2)
111 /* Don't use for printout the variants of most floating
112 point coprocessor instructions which use the same
113 register number in two places, as above. */
115 for (d
= m68k_opcodes
[i
].args
; *d
; d
+= 2)
119 if (*d
== 0 && match
> bestmask
)
127 /* Handle undefined instructions. */
130 fprintf_filtered (stream
, "0%o", (buffer
[0] << 8) + buffer
[1]);
134 fprintf_filtered (stream
, "%s", m68k_opcodes
[best
].name
);
136 /* Point at first word of argument data,
137 and at descriptor for first argument. */
140 /* Why do this this way? -MelloN */
141 for (d
= m68k_opcodes
[best
].args
; *d
; d
+= 2)
145 if (d
[1] == 'l' && p
- buffer
< 6)
147 else if (p
- buffer
< 4 && d
[1] != 'C' && d
[1] != '8' )
150 if (d
[1] >= '1' && d
[1] <= '3' && p
- buffer
< 4)
152 if (d
[1] >= '4' && d
[1] <= '6' && p
- buffer
< 6)
154 if ((d
[0] == 'L' || d
[0] == 'l') && d
[1] == 'w' && p
- buffer
< 4)
158 d
= m68k_opcodes
[best
].args
;
161 fputs_filtered (" ", stream
);
165 p
= print_insn_arg (d
, buffer
, p
, memaddr
+ p
- buffer
, stream
);
167 if (*d
&& *(d
- 2) != 'I' && *d
!= 'k')
168 fputs_filtered (",", stream
);
173 static unsigned char *
174 print_insn_arg (d
, buffer
, p
, addr
, stream
)
176 unsigned char *buffer
;
177 register unsigned char *p
;
178 CORE_ADDR addr
; /* PC for this arg to be relative to */
182 register int place
= d
[1];
184 register const char *regname
;
185 register unsigned char *p1
;
192 fprintf_filtered (stream
, "ccr");
196 fprintf_filtered (stream
, "sr");
200 fprintf_filtered (stream
, "usp");
205 static struct { char *name
; int value
; } names
[]
206 = {{"sfc", 0x000}, {"dfc", 0x001}, {"cacr", 0x002},
207 {"usp", 0x800}, {"vbr", 0x801}, {"caar", 0x802},
208 {"msp", 0x803}, {"isp", 0x804}};
210 val
= fetch_arg (buffer
, place
, 12);
211 for (regno
= sizeof names
/ sizeof names
[0] - 1; regno
>= 0; regno
--)
212 if (names
[regno
].value
== val
)
214 fprintf_filtered (stream
, names
[regno
].name
);
218 fprintf_filtered (stream
, "%d", val
);
223 val
= fetch_arg (buffer
, place
, 3);
224 /* 0 means 8, except for the bkpt instruction... */
225 if (val
== 0 && d
[1] != 's')
227 fprintf_filtered (stream
, "#%d", val
);
231 val
= fetch_arg (buffer
, place
, 8);
234 fprintf_filtered (stream
, "#%d", val
);
238 val
= fetch_arg (buffer
, place
, 4);
239 fprintf_filtered (stream
, "#%d", val
);
243 fprintf_filtered (stream
, "%s", reg_names
[fetch_arg (buffer
, place
, 3)]);
247 fprintf_filtered (stream
, "%s",
248 reg_names
[fetch_arg (buffer
, place
, 3) + 010]);
252 fprintf_filtered (stream
, "%s", reg_names
[fetch_arg (buffer
, place
, 4)]);
256 fprintf_filtered (stream
, "%s@", reg_names
[fetch_arg (buffer
, place
, 4)]);
260 fprintf_filtered (stream
, "fp%d", fetch_arg (buffer
, place
, 3));
264 val
= fetch_arg (buffer
, place
, 6);
266 fprintf_filtered (stream
, "%s", reg_names
[val
& 7]);
268 fprintf_filtered (stream
, "%d", val
);
272 fprintf_filtered (stream
, "%s@+",
273 reg_names
[fetch_arg (buffer
, place
, 3) + 8]);
277 fprintf_filtered (stream
, "%s@-",
278 reg_names
[fetch_arg (buffer
, place
, 3) + 8]);
283 fprintf_filtered (stream
, "{%s}", reg_names
[fetch_arg (buffer
, place
, 3)]);
284 else if (place
== 'C')
286 val
= fetch_arg (buffer
, place
, 7);
287 if ( val
> 63 ) /* This is a signed constant. */
289 fprintf_filtered (stream
, "{#%d}", val
);
292 error ("Invalid arg format in opcode table: \"%c%c\".",
298 p1
= buffer
+ (*d
== '#' ? 2 : 4);
300 val
= fetch_arg (buffer
, place
, 4);
301 else if (place
== 'C')
302 val
= fetch_arg (buffer
, place
, 7);
303 else if (place
== '8')
304 val
= fetch_arg (buffer
, place
, 3);
305 else if (place
== '3')
306 val
= fetch_arg (buffer
, place
, 8);
307 else if (place
== 'b')
309 else if (place
== 'w')
311 else if (place
== 'l')
314 error ("Invalid arg format in opcode table: \"%c%c\".",
316 fprintf_filtered (stream
, "#%d", val
);
322 else if (place
== 'B')
323 val
= NEXTBYTE (buffer
); /* from the opcode word */
324 else if (place
== 'w' || place
== 'W')
326 else if (place
== 'l' || place
== 'L')
328 else if (place
== 'g')
330 val
= NEXTBYTE (buffer
);
336 else if (place
== 'c')
338 if (buffer
[1] & 0x40) /* If bit six is one, long offset */
344 error ("Invalid arg format in opcode table: \"%c%c\".",
347 print_address (addr
+ val
, stream
);
352 fprintf_filtered (stream
, "%s@(%d)",
353 reg_names
[fetch_arg (buffer
, place
, 3)], val
);
357 fprintf_filtered (stream
, "%s",
358 fpcr_names
[fetch_arg (buffer
, place
, 3)]);
362 val
= fetch_arg (buffer
, 'd', 3); /* Get coprocessor ID... */
363 if (val
!= 1) /* Unusual coprocessor ID? */
364 fprintf_filtered (stream
, "(cpid=%d) ", val
);
366 p
+= 2; /* Skip coprocessor extended operands */
382 val
= fetch_arg (buffer
, 'x', 6);
383 val
= ((val
& 7) << 3) + ((val
>> 3) & 7);
386 val
= fetch_arg (buffer
, 's', 6);
388 /* Get register number assuming address register. */
389 regno
= (val
& 7) + 8;
390 regname
= reg_names
[regno
];
394 fprintf_filtered (stream
, "%s", reg_names
[val
]);
398 fprintf_filtered (stream
, "%s", regname
);
402 fprintf_filtered (stream
, "%s@", regname
);
406 fprintf_filtered (stream
, "%s@+", regname
);
410 fprintf_filtered (stream
, "%s@-", regname
);
415 fprintf_filtered (stream
, "%s@(%d)", regname
, val
);
419 p
= print_indexed (regno
, p
, addr
, stream
);
427 fprintf_filtered (stream
, "@#");
428 print_address (val
, stream
);
433 fprintf_filtered (stream
, "@#");
434 print_address (val
, stream
);
439 print_address (addr
+ val
, stream
);
443 p
= print_indexed (-1, p
, addr
, stream
);
447 flt_p
= 1; /* Assume it's a float... */
466 flval
= NEXTSINGLE(p
);
470 flval
= NEXTDOUBLE(p
);
475 ieee_extended_to_double (&ext_format_68881
, p
, &flval
);
482 flval
= 0; /* FIXME, handle packed decimal someday. */
486 error ("Invalid arg format in opcode table: \"%c%c\".",
489 if ( flt_p
) /* Print a float? */
490 fprintf_filtered (stream
, "#%g", flval
);
492 fprintf_filtered (stream
, "#%d", val
);
496 fprintf_filtered (stream
, "<invalid address mode 0%o>", val
);
508 /* Move the pointer ahead if this point is farther ahead
513 fputs_filtered ("#0", stream
);
518 register int newval
= 0;
519 for (regno
= 0; regno
< 16; ++regno
)
520 if (val
& (0x8000 >> regno
))
521 newval
|= 1 << regno
;
526 for (regno
= 0; regno
< 16; ++regno
)
527 if (val
& (1 << regno
))
531 fputs_filtered ("/", stream
);
533 fprintf_filtered (stream
, "%s", reg_names
[regno
]);
535 while (val
& (1 << (regno
+ 1)))
537 if (regno
> first_regno
)
538 fprintf_filtered (stream
, "-%s", reg_names
[regno
]);
541 else if (place
== '3')
545 val
= fetch_arg (buffer
, place
, 8);
548 fputs_filtered ("#0", stream
);
553 register int newval
= 0;
554 for (regno
= 0; regno
< 8; ++regno
)
555 if (val
& (0x80 >> regno
))
556 newval
|= 1 << regno
;
561 for (regno
= 0; regno
< 8; ++regno
)
562 if (val
& (1 << regno
))
566 fputs_filtered ("/", stream
);
568 fprintf_filtered (stream
, "fp%d", regno
);
570 while (val
& (1 << (regno
+ 1)))
572 if (regno
> first_regno
)
573 fprintf_filtered (stream
, "-fp%d", regno
);
581 error ("Invalid arg format in opcode table: \"%c\".", *d
);
584 return (unsigned char *) p
;
587 /* Fetch BITS bits from a position in the instruction specified by CODE.
588 CODE is a "place to put an argument", or 'x' for a destination
589 that is a general address (mode and register).
590 BUFFER contains the instruction. */
593 fetch_arg (buffer
, code
, bits
)
594 unsigned char *buffer
;
605 case 'd': /* Destination, for register or quick. */
606 val
= (buffer
[0] << 8) + buffer
[1];
610 case 'x': /* Destination, for general arg */
611 val
= (buffer
[0] << 8) + buffer
[1];
616 val
= (buffer
[3] >> 4);
624 val
= (buffer
[2] << 8) + buffer
[3];
629 val
= (buffer
[2] << 8) + buffer
[3];
635 val
= (buffer
[2] << 8) + buffer
[3];
639 val
= (buffer
[4] << 8) + buffer
[5];
644 val
= (buffer
[4] << 8) + buffer
[5];
649 val
= (buffer
[4] << 8) + buffer
[5];
653 val
= (buffer
[2] << 8) + buffer
[3];
658 val
= (buffer
[2] << 8) + buffer
[3];
687 /* Print an indexed argument. The base register is BASEREG (-1 for pc).
688 P points to extension word, in buffer.
689 ADDR is the nominal core address of that extension word. */
691 static unsigned char *
692 print_indexed (basereg
, p
, addr
, stream
)
699 static char *scales
[] = {"", "*2", "*4", "*8"};
700 register int base_disp
;
701 register int outer_disp
;
706 /* Generate the text for the index register.
707 Where this will be output is not yet determined. */
708 sprintf (buf
, "[%s.%c%s]",
709 reg_names
[(word
>> 12) & 0xf],
710 (word
& 0x800) ? 'l' : 'w',
711 scales
[(word
>> 9) & 3]);
713 /* Handle the 68000 style of indexing. */
715 if ((word
& 0x100) == 0)
718 ((word
& 0x80) ? word
| 0xff00 : word
& 0xff)
719 + ((basereg
== -1) ? addr
: 0),
721 fputs_filtered (buf
, stream
);
725 /* Handle the generalized kind. */
726 /* First, compute the displacement to add to the base register. */
733 switch ((word
>> 4) & 3)
736 base_disp
= NEXTWORD (p
);
739 base_disp
= NEXTLONG (p
);
744 /* Handle single-level case (not indirect) */
748 print_base (basereg
, base_disp
, stream
);
749 fputs_filtered (buf
, stream
);
753 /* Two level. Compute displacement to add after indirection. */
759 outer_disp
= NEXTWORD (p
);
762 outer_disp
= NEXTLONG (p
);
765 fprintf_filtered (stream
, "%d(", outer_disp
);
766 print_base (basereg
, base_disp
, stream
);
768 /* If postindexed, print the closeparen before the index. */
770 fprintf_filtered (stream
, ")%s", buf
);
771 /* If preindexed, print the closeparen after the index. */
773 fprintf_filtered (stream
, "%s)", buf
);
778 /* Print a base register REGNO and displacement DISP, on STREAM.
779 REGNO = -1 for pc, -2 for none (suppressed). */
782 print_base (regno
, disp
, stream
)
788 fprintf_filtered (stream
, "%d", disp
);
789 else if (regno
== -1)
790 fprintf_filtered (stream
, "0x%x", disp
);
792 fprintf_filtered (stream
, "%d(%s)", disp
, reg_names
[regno
]);
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