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
;
191 case 'c': /* cache identifier */
193 static char *cacheFieldName
[] = { "NOP", "dc", "ic", "bc" };
194 val
= fetch_arg (buffer
, place
, 2);
195 fprintf_filtered (stream
, cacheFieldName
[val
]);
199 case 'a': /* address register indirect only. Cf. case '+'. */
201 fprintf_filtered (stream
,
203 reg_names
[fetch_arg (buffer
, place
, 3) + 8]);
207 case '_': /* 32-bit absolute address for move16. */
210 fprintf_filtered (stream
, "@#");
211 print_address (val
, stream
);
216 fprintf_filtered (stream
, "ccr");
220 fprintf_filtered (stream
, "sr");
224 fprintf_filtered (stream
, "usp");
229 static struct { char *name
; int value
; } names
[]
230 = {{"sfc", 0x000}, {"dfc", 0x001}, {"cacr", 0x002},
231 {"tc", 0x003}, {"itt0",0x004}, {"itt1", 0x005},
232 {"dtt0",0x006}, {"dtt1",0x007},
233 {"usp", 0x800}, {"vbr", 0x801}, {"caar", 0x802},
234 {"msp", 0x803}, {"isp", 0x804}, {"mmusr",0x805},
235 {"urp", 0x806}, {"srp", 0x807}};
237 val
= fetch_arg (buffer
, place
, 12);
238 for (regno
= sizeof names
/ sizeof names
[0] - 1; regno
>= 0; regno
--)
239 if (names
[regno
].value
== val
)
241 fprintf_filtered (stream
, names
[regno
].name
);
245 fprintf_filtered (stream
, "%d", val
);
250 val
= fetch_arg (buffer
, place
, 3);
251 /* 0 means 8, except for the bkpt instruction... */
252 if (val
== 0 && d
[1] != 's')
254 fprintf_filtered (stream
, "#%d", val
);
258 val
= fetch_arg (buffer
, place
, 8);
261 fprintf_filtered (stream
, "#%d", val
);
265 val
= fetch_arg (buffer
, place
, 4);
266 fprintf_filtered (stream
, "#%d", val
);
270 fprintf_filtered (stream
, "%s", reg_names
[fetch_arg (buffer
, place
, 3)]);
274 fprintf_filtered (stream
, "%s",
275 reg_names
[fetch_arg (buffer
, place
, 3) + 010]);
279 fprintf_filtered (stream
, "%s", reg_names
[fetch_arg (buffer
, place
, 4)]);
283 fprintf_filtered (stream
, "%s@", reg_names
[fetch_arg (buffer
, place
, 4)]);
287 fprintf_filtered (stream
, "fp%d", fetch_arg (buffer
, place
, 3));
291 val
= fetch_arg (buffer
, place
, 6);
293 fprintf_filtered (stream
, "%s", reg_names
[val
& 7]);
295 fprintf_filtered (stream
, "%d", val
);
299 fprintf_filtered (stream
, "%s@+",
300 reg_names
[fetch_arg (buffer
, place
, 3) + 8]);
304 fprintf_filtered (stream
, "%s@-",
305 reg_names
[fetch_arg (buffer
, place
, 3) + 8]);
310 fprintf_filtered (stream
, "{%s}", reg_names
[fetch_arg (buffer
, place
, 3)]);
311 else if (place
== 'C')
313 val
= fetch_arg (buffer
, place
, 7);
314 if ( val
> 63 ) /* This is a signed constant. */
316 fprintf_filtered (stream
, "{#%d}", val
);
319 error ("Invalid arg format in opcode table: \"%c%c\".",
325 p1
= buffer
+ (*d
== '#' ? 2 : 4);
327 val
= fetch_arg (buffer
, place
, 4);
328 else if (place
== 'C')
329 val
= fetch_arg (buffer
, place
, 7);
330 else if (place
== '8')
331 val
= fetch_arg (buffer
, place
, 3);
332 else if (place
== '3')
333 val
= fetch_arg (buffer
, place
, 8);
334 else if (place
== 'b')
336 else if (place
== 'w')
338 else if (place
== 'l')
341 error ("Invalid arg format in opcode table: \"%c%c\".",
343 fprintf_filtered (stream
, "#%d", val
);
349 else if (place
== 'B')
350 val
= NEXTBYTE (buffer
); /* from the opcode word */
351 else if (place
== 'w' || place
== 'W')
353 else if (place
== 'l' || place
== 'L')
355 else if (place
== 'g')
357 val
= NEXTBYTE (buffer
);
363 else if (place
== 'c')
365 if (buffer
[1] & 0x40) /* If bit six is one, long offset */
371 error ("Invalid arg format in opcode table: \"%c%c\".",
374 print_address (addr
+ val
, stream
);
379 fprintf_filtered (stream
, "%s@(%d)",
380 reg_names
[fetch_arg (buffer
, place
, 3)], val
);
384 fprintf_filtered (stream
, "%s",
385 fpcr_names
[fetch_arg (buffer
, place
, 3)]);
389 val
= fetch_arg (buffer
, 'd', 3); /* Get coprocessor ID... */
390 if (val
!= 1) /* Unusual coprocessor ID? */
391 fprintf_filtered (stream
, "(cpid=%d) ", val
);
393 p
+= 2; /* Skip coprocessor extended operands */
410 val
= fetch_arg (buffer
, 'x', 6);
411 val
= ((val
& 7) << 3) + ((val
>> 3) & 7);
414 val
= fetch_arg (buffer
, 's', 6);
416 /* Get register number assuming address register. */
417 regno
= (val
& 7) + 8;
418 regname
= reg_names
[regno
];
422 fprintf_filtered (stream
, "%s", reg_names
[val
]);
426 fprintf_filtered (stream
, "%s", regname
);
430 fprintf_filtered (stream
, "%s@", regname
);
434 fprintf_filtered (stream
, "%s@+", regname
);
438 fprintf_filtered (stream
, "%s@-", regname
);
443 fprintf_filtered (stream
, "%s@(%d)", regname
, val
);
447 p
= print_indexed (regno
, p
, addr
, stream
);
455 fprintf_filtered (stream
, "@#");
456 print_address (val
, stream
);
461 fprintf_filtered (stream
, "@#");
462 print_address (val
, stream
);
467 print_address (addr
+ val
, stream
);
471 p
= print_indexed (-1, p
, addr
, stream
);
475 flt_p
= 1; /* Assume it's a float... */
494 flval
= NEXTSINGLE(p
);
498 flval
= NEXTDOUBLE(p
);
503 ieee_extended_to_double (&ext_format_68881
, p
, &flval
);
510 flval
= 0; /* FIXME, handle packed decimal someday. */
514 error ("Invalid arg format in opcode table: \"%c%c\".",
517 if ( flt_p
) /* Print a float? */
518 fprintf_filtered (stream
, "#%g", flval
);
520 fprintf_filtered (stream
, "#%d", val
);
524 fprintf_filtered (stream
, "<invalid address mode 0%o>", val
);
536 /* Move the pointer ahead if this point is farther ahead
541 fputs_filtered ("#0", stream
);
546 register int newval
= 0;
547 for (regno
= 0; regno
< 16; ++regno
)
548 if (val
& (0x8000 >> regno
))
549 newval
|= 1 << regno
;
554 for (regno
= 0; regno
< 16; ++regno
)
555 if (val
& (1 << regno
))
559 fputs_filtered ("/", stream
);
561 fprintf_filtered (stream
, "%s", reg_names
[regno
]);
563 while (val
& (1 << (regno
+ 1)))
565 if (regno
> first_regno
)
566 fprintf_filtered (stream
, "-%s", reg_names
[regno
]);
569 else if (place
== '3')
573 val
= fetch_arg (buffer
, place
, 8);
576 fputs_filtered ("#0", stream
);
581 register int newval
= 0;
582 for (regno
= 0; regno
< 8; ++regno
)
583 if (val
& (0x80 >> regno
))
584 newval
|= 1 << regno
;
589 for (regno
= 0; regno
< 8; ++regno
)
590 if (val
& (1 << regno
))
594 fputs_filtered ("/", stream
);
596 fprintf_filtered (stream
, "fp%d", regno
);
598 while (val
& (1 << (regno
+ 1)))
600 if (regno
> first_regno
)
601 fprintf_filtered (stream
, "-fp%d", regno
);
609 error ("Invalid arg format in opcode table: \"%c\".", *d
);
612 return (unsigned char *) p
;
615 /* Fetch BITS bits from a position in the instruction specified by CODE.
616 CODE is a "place to put an argument", or 'x' for a destination
617 that is a general address (mode and register).
618 BUFFER contains the instruction. */
621 fetch_arg (buffer
, code
, bits
)
622 unsigned char *buffer
;
633 case 'd': /* Destination, for register or quick. */
634 val
= (buffer
[0] << 8) + buffer
[1];
638 case 'x': /* Destination, for general arg */
639 val
= (buffer
[0] << 8) + buffer
[1];
644 val
= (buffer
[3] >> 4);
652 val
= (buffer
[2] << 8) + buffer
[3];
657 val
= (buffer
[2] << 8) + buffer
[3];
663 val
= (buffer
[2] << 8) + buffer
[3];
667 val
= (buffer
[4] << 8) + buffer
[5];
672 val
= (buffer
[4] << 8) + buffer
[5];
677 val
= (buffer
[4] << 8) + buffer
[5];
681 val
= (buffer
[2] << 8) + buffer
[3];
686 val
= (buffer
[2] << 8) + buffer
[3];
691 val
= (buffer
[1] >> 6);
721 /* Print an indexed argument. The base register is BASEREG (-1 for pc).
722 P points to extension word, in buffer.
723 ADDR is the nominal core address of that extension word. */
725 static unsigned char *
726 print_indexed (basereg
, p
, addr
, stream
)
733 static char *scales
[] = {"", "*2", "*4", "*8"};
734 register int base_disp
;
735 register int outer_disp
;
740 /* Generate the text for the index register.
741 Where this will be output is not yet determined. */
742 sprintf (buf
, "[%s.%c%s]",
743 reg_names
[(word
>> 12) & 0xf],
744 (word
& 0x800) ? 'l' : 'w',
745 scales
[(word
>> 9) & 3]);
747 /* Handle the 68000 style of indexing. */
749 if ((word
& 0x100) == 0)
752 ((word
& 0x80) ? word
| 0xff00 : word
& 0xff)
753 + ((basereg
== -1) ? addr
: 0),
755 fputs_filtered (buf
, stream
);
759 /* Handle the generalized kind. */
760 /* First, compute the displacement to add to the base register. */
767 switch ((word
>> 4) & 3)
770 base_disp
= NEXTWORD (p
);
773 base_disp
= NEXTLONG (p
);
778 /* Handle single-level case (not indirect) */
782 print_base (basereg
, base_disp
, stream
);
783 fputs_filtered (buf
, stream
);
787 /* Two level. Compute displacement to add after indirection. */
793 outer_disp
= NEXTWORD (p
);
796 outer_disp
= NEXTLONG (p
);
799 fprintf_filtered (stream
, "%d(", outer_disp
);
800 print_base (basereg
, base_disp
, stream
);
802 /* If postindexed, print the closeparen before the index. */
804 fprintf_filtered (stream
, ")%s", buf
);
805 /* If preindexed, print the closeparen after the index. */
807 fprintf_filtered (stream
, "%s)", buf
);
812 /* Print a base register REGNO and displacement DISP, on STREAM.
813 REGNO = -1 for pc, -2 for none (suppressed). */
816 print_base (regno
, disp
, stream
)
822 fprintf_filtered (stream
, "%d", disp
);
823 else if (regno
== -1)
824 fprintf_filtered (stream
, "0x%x", disp
);
826 fprintf_filtered (stream
, "%d(%s)", disp
, reg_names
[regno
]);
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