This syntax for the Motorola 680x0 was developed at mit.
The 680x0 version of
as uses instructions names and
syntax compatible with the Sun assembler. Intervening periods are
ignored; for example, `movl' is equivalent to `mov.l'.
In the following table apc stands for any of the address registers (`%a0' through `%a7'), the program counter (`%pc'), the zero-address relative to the program counter (`%zpc'), a suppressed address register (`%za0' through `%za7'), or it may be omitted entirely. The use of size means one of `w' or `l', and it may be omitted, along with the leading colon, unless a scale is also specified. The use of scale means one of `1', `2', `4', or `8', and it may always be omitted along with the leading colon.
The following addressing modes are understood:
%a6is also known as `%fp', the Frame Pointer.
The number may be omitted.
The onumber or the register, but not both, may be omitted.
The number may be omitted. Omitting the register produces
the Postindex addressing mode.