/* Print Motorola 68k instructions for GDB, the GNU debugger.
- Copyright 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
+ Copyright 1986, 1987, 1989, 1991, 1992 Free Software Foundation, Inc.
This file is part of GDB.
#include "symtab.h"
#include "opcode/m68k.h"
#include "gdbcore.h"
+#include "ieee-float.h"
/* Local function prototypes */
char *fpcr_names[] = { "", "fpiar", "fpsr", "fpiar/fpsr", "fpcr",
"fpiar/fpcr", "fpsr/fpcr", "fpiar-fpcr"};
+/* Define accessors for 68K's 1, 2, and 4-byte signed quantities.
+ The _SHIFT values move the quantity to the high order end of an
+ `int' value, so it will sign-extend. Probably a few more casts
+ are needed to make it compile without warnings on finicky systems. */
+#define BITS_PER_BYTE 8
+#define BYTE_SHIFT (BITS_PER_BYTE * ((sizeof (int)) - 1))
+#define WORD_SHIFT (BITS_PER_BYTE * ((sizeof (int)) - 2))
+#define LONG_SHIFT (BITS_PER_BYTE * ((sizeof (int)) - 4))
-#define NEXTBYTE(p) (p += 2, ((char *)p)[-1])
+#define NEXTBYTE(p) (p += 2, ((int)(p[-1]) << BYTE_SHIFT) >> BYTE_SHIFT)
#define NEXTWORD(p) \
- (p += 2, ((((char *)p)[-2]) << 8) + p[-1])
+ (p += 2, (((int)((p[-2] << 8) + p[-1])) << WORD_SHIFT) >> WORD_SHIFT)
#define NEXTLONG(p) \
- (p += 4, (((((p[-4] << 8) + p[-3]) << 8) + p[-2]) << 8) + p[-1])
+ (p += 4, (((int)((((((p[-4] << 8) + p[-3]) << 8) + p[-2]) << 8) + p[-1])) \
+ << LONG_SHIFT) >> LONG_SHIFT)
+/* Ecch -- assumes host == target float formats. FIXME. */
#define NEXTSINGLE(p) \
(p += 4, *((float *)(p - 4)))
#define NEXTDOUBLE(p) \
(p += 8, *((double *)(p - 8)))
-
-#define NEXTEXTEND(p) \
- (p += 12, 0.0) /* Need a function to convert from extended to double
- precision... */
-
-#define NEXTPACKED(p) \
- (p += 12, 0.0) /* Need a function to convert from packed to double
- precision. Actually, it's easier to print a
- packed number than a double anyway, so maybe
- there should be a special case to handle this... */
\f
/* Print the m68k instruction at address MEMADDR in debugged memory,
on STREAM. Returns length of the instruction, in bytes. */
int regno;
register char *regname;
register unsigned char *p1;
- register double flval;
+ double flval;
int flt_p;
switch (*d)
if (place == 'b')
val = NEXTBYTE (p);
else if (place == 'B')
- val = ((char *)buffer)[1];
+ val = NEXTBYTE (buffer); /* from the opcode word */
else if (place == 'w' || place == 'W')
val = NEXTWORD (p);
else if (place == 'l' || place == 'L')
val = NEXTLONG (p);
else if (place == 'g')
{
- val = ((char *)buffer)[1];
+ val = NEXTBYTE (buffer);
if (val == 0)
val = NEXTWORD (p);
else if (val == -1)
break;
case 'x':
- flval = NEXTEXTEND(p);
+ ieee_extended_to_double (ext_format_68881, p, &flval);
+ p += 12;
break;
case 'p':
- flval = NEXTPACKED(p);
+ p += 12;
+ flval = 0; /* FIXME, handle packed decimal someday. */
break;
default:
}
}
else
- abort ();
+ goto de_fault;
break;
- default:
+ default: de_fault:
error ("Invalid arg format in opcode table: \"%c\".", *d);
}