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m68k-opcode.h
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1991-04-07
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/* Opcode table for m68000/m68020 and m68881.
Copyright (C) 1989, Free Software Foundation.
This file is part of GDB, the GNU Debugger and GAS, the GNU Assembler.
Both GDB and GAS are free software; you can redistribute and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 1, or (at your option)
any later version.
GDB and GAS are distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GDB or GAS; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
struct m68k_opcode
{
char *name;
unsigned long opcode;
unsigned long match;
char *args;
};
/* We store four bytes of opcode for all opcodes because that
is the most any of them need. The actual length of an instruction
is always at least 2 bytes, and is as much longer as necessary to
hold the operands it has.
The match component is a mask saying which bits must match
particular opcode in order for an instruction to be an instance
of that opcode.
The args component is a string containing two characters
for each operand of the instruction. The first specifies
the kind of operand; the second, the place it is stored. */
/* Kinds of operands:
D data register only. Stored as 3 bits.
A address register only. Stored as 3 bits.
R either kind of register. Stored as 4 bits.
F floating point coprocessor register only. Stored as 3 bits.
O an offset (or width): immediate data 0-31 or data register.
Stored as 6 bits in special format for BF... insns.
+ autoincrement only. Stored as 3 bits (number of the address register).
- autodecrement only. Stored as 3 bits (number of the address register).
Q quick immediate data. Stored as 3 bits.
This matches an immediate operand only when value is in range 1 .. 8.
M moveq immediate data. Stored as 8 bits.
This matches an immediate operand only when value is in range -128..127
T trap vector immediate data. Stored as 4 bits.
k K-factor for fmove.p instruction. Stored as a 7-bit constant or
a three bit register offset, depending on the field type.
# immediate data. Stored in special places (b, w or l)
which say how many bits to store.
^ immediate data for floating point instructions. Special places
are offset by 2 bytes from '#'...
B pc-relative address, converted to an offset
that is treated as immediate data.
d displacement and register. Stores the register as 3 bits
and stores the displacement in the entire second word.
C the CCR. No need to store it; this is just for filtering validity.
S the SR. No need to store, just as with CCR.
U the USP. No need to store, just as with CCR.
I Coprocessor ID. Not printed if 1. The Coprocessor ID is always
extracted from the 'd' field of word one, which means that an extended
coprocessor opcode can be skipped using the 'i' place, if needed.
s System Control register for the floating point coprocessor.
S List of system control registers for floating point coprocessor.
J Misc register for movec instruction, stored in 'j' format.
Possible values:
000 SFC Source Function Code reg
001 DFC Data Function Code reg
002 CACR Cache Control Register
800 USP User Stack Pointer
801 VBR Vector Base reg
802 CAAR Cache Address Register
803 MSP Master Stack Pointer
804 ISP Interrupt Stack Pointer
L Register list of the type d0-d7/a0-a7 etc.
(New! Improved! Can also hold fp0-fp7, as well!)
The assembler tries to see if the registers match the insn by
looking at where the insn wants them stored.
l Register list like L, but with all the bits reversed.
Used for going the other way. . .
They are all stored as 6 bits using an address mode and a register number;
they differ in which addressing modes they match.
* all (modes 0-6,7.*)
~ alterable memory (modes 2-6,7.0,7.1)(not 0,1,7.~)
% alterable (modes 0-6,7.0,7.1)(not 7.~)
; data (modes 0,2-6,7.*)(not 1)
@ data, but not immediate (modes 0,2-6,7.? ? ?)(not 1,7.?) This may really be ;, the 68020 book says it is
! control (modes 2,5,6,7.*-)(not 0,1,3,4,7.4)
& alterable control (modes 2,5,6,7.0,7.1)(not 0,1,7.? ? ?)
$ alterable data (modes 0,2-6,7.0,7.1)(not 1,7.~)
? alterable control, or data register (modes 0,2,5,6,7.0,7.1)(not 1,3,4,7.~)
/ control, or data register (modes 0,2,5,6,7.0,7.1,7.2,7.3)(not 1,3,4,7.4)
*/
/* JF: for the 68851 */
/*
I didn't use much imagination in choosing the
following codes, so many of them aren't very
mnemonic. -rab
P pmmu register
Possible values:
000 TC Translation Control reg
100 CAL Current Access Level
101 VAL Validate Access Level
110 SCC Stack Change Control
111 AC Access Control
W wide pmmu registers
Possible values:
001 DRP Dma Root Pointer
010 SRP Supervisor Root Pointer
011 CRP Cpu Root Pointer
f function code register
0 SFC
1 DFC
V VAL register only
X BADx, BACx
100 BAD Breakpoint Acknowledge Data
101 BAC Breakpoint Acknowledge Control
Y PSR
Z PCSR
| memory (modes 2-6, 7.*)
*/
/* Places to put an operand, for non-general operands:
s source, low bits of first word.
d dest, shifted 9 in first word
1 second word, shifted 12
2 second word, shifted 6
3 second word, shifted 0
4 third word, shifted 12
5 third word, shifted 6
6 third word, shifted 0
7 second word, shifted 7
8 second word, shifted 10
D store in both place 1 and place 3; for divul and divsl.
b second word, low byte
w second word (entire)
l second and third word (entire)
g branch offset for bra and similar instructions.
The place to store depends on the magnitude of offset.
t store in both place 7 and place 8; for floating point operations
c branch offset for cpBcc operations.
The place to store is word two if bit six of word one is zero,
and words two and three if bit six of word one is one.
i Increment by two, to skip over coprocessor extended operands. Only
works with the 'I' format.
k Dynamic K-factor field. Bits 6-4 of word 2, used as a register number.
Also used for dynamic fmovem instruction.
C floating point coprocessor constant - 7 bits. Also used for static
K-factors...
j Movec register #, stored in 12 low bits of second word.
Places to put operand, for general operands:
d destination, shifted 6 bits in first word
b source, at low bit of first word, and immediate uses one byte
w source, at low bit of first word, and immediate uses two bytes
l source, at low bit of first word, and immediate uses four bytes
s source, at low bit of first word.
Used sometimes in contexts where immediate is not allowed anyway.
f single precision float, low bit of 1st word, immediate uses 4 bytes
F double precision float, low bit of 1st word, immediate uses 8 bytes
x extended precision float, low bit of 1st word, immediate uses 12 bytes
p packed float, low bit of 1st word, immediate uses 12 bytes
*/
#define one(x) ((x) << 16)
#define two(x, y) (((x) << 16) + y)
extern int numopcodes;
extern struct m68k_opcode *endop;
extern struct m68k_opcode m68k_opcodes[];