mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-10 03:54:48 +00:00
105 lines
3.1 KiB
Plaintext
105 lines
3.1 KiB
Plaintext
|
@c Copyright 2010, 2011 Free Software Foundation, Inc.
|
||
|
@c This is part of the GAS manual.
|
||
|
@c For copying conditions, see the file as.texinfo.
|
||
|
|
||
|
@node XSTORMY16-Dependent
|
||
|
@chapter XStormy16 Dependent Features
|
||
|
|
||
|
@cindex XStormy16 support
|
||
|
@menu
|
||
|
* XStormy16 Syntax:: Syntax
|
||
|
* XStormy16 Directives:: Machine Directives
|
||
|
* XStormy16 Opcodes:: Pseudo-Opcodes
|
||
|
@end menu
|
||
|
|
||
|
@node XStormy16 Syntax
|
||
|
@section Syntax
|
||
|
@menu
|
||
|
* XStormy16-Chars:: Special Characters
|
||
|
@end menu
|
||
|
|
||
|
@node XStormy16-Chars
|
||
|
@subsection Special Characters
|
||
|
|
||
|
@cindex line comment character, XStormy16
|
||
|
@cindex XStormy16 line comment character
|
||
|
@samp{#} is the line comment character. If a @samp{#} appears as the
|
||
|
first character of a line, the whole line is treated as a comment, but
|
||
|
in this case the line can also be a logical line number directive
|
||
|
(@pxref{Comments}) or a preprocessor control command
|
||
|
(@pxref{Preprocessing}).
|
||
|
|
||
|
@cindex comment character, XStormy16
|
||
|
@cindex XStormy16 comment character
|
||
|
A semicolon (@samp{;}) can be used to start a comment that extends
|
||
|
from wherever the character appears on the line up to the end of the
|
||
|
line.
|
||
|
|
||
|
@cindex line separator, XStormy16
|
||
|
@cindex statement separator, XStormy16
|
||
|
@cindex XStormy16 line separator
|
||
|
|
||
|
The @samp{|} character can be used to separate statements on the same
|
||
|
line.
|
||
|
|
||
|
|
||
|
@node XStormy16 Directives
|
||
|
@section XStormy16 Machine Directives
|
||
|
|
||
|
@cindex machine directives, XStormy16
|
||
|
@cindex XStormy16 machine directives
|
||
|
@table @code
|
||
|
|
||
|
@cindex @code{16bit_pointers} directive, XStormy16
|
||
|
@item .16bit_pointers
|
||
|
Like the @option{--16bit-pointers} command line option this directive
|
||
|
indicates that the assembly code makes use of 16-bit pointers.
|
||
|
|
||
|
@cindex @code{32bit_pointers} directive, XStormy16
|
||
|
@item .32bit_pointers
|
||
|
Like the @option{--32bit-pointers} command line option this directive
|
||
|
indicates that the assembly code makes use of 32-bit pointers.
|
||
|
|
||
|
@cindex @code{.no_pointers} directive, XStormy16
|
||
|
@item .no_pointers
|
||
|
Like the @option{--no-pointers} command line option this directive
|
||
|
indicates that the assembly code does not makes use pointers.
|
||
|
|
||
|
@end table
|
||
|
|
||
|
@node XStormy16 Opcodes
|
||
|
@section XStormy16 Pseudo-Opcodes
|
||
|
|
||
|
@cindex XStormy16 pseudo-opcodes
|
||
|
@cindex pseudo-opcodes for XStormy16
|
||
|
@code{@value{AS}} implements all the standard XStormy16 opcodes.
|
||
|
|
||
|
@code{@value{AS}} also implements the following pseudo ops:
|
||
|
|
||
|
@table @code
|
||
|
|
||
|
@cindex @code{@@lo} pseudo-op, XStormy16
|
||
|
@item @@lo()
|
||
|
Computes the lower 16 bits of the given expression and stores it into
|
||
|
the immediate operand field of the given instruction. For example:
|
||
|
|
||
|
@samp{add r6, @@lo(here - there)}
|
||
|
|
||
|
computes the difference between the address of labels 'here' and
|
||
|
'there', takes the lower 16 bits of this difference and adds it to
|
||
|
register 6.
|
||
|
|
||
|
@cindex @code{@@hi} pseudo-op, XStormy16
|
||
|
@item @@hi()
|
||
|
Computes the higher 16 bits of the given expression and stores it into
|
||
|
the immediate operand field of the given instruction. For example:
|
||
|
|
||
|
@samp{addc r7, @@hi(here - there)}
|
||
|
|
||
|
computes the difference between the address of labels 'here' and
|
||
|
'there', takes the upper 16 bits of this difference, shifts it down 16
|
||
|
bits and then adds it, along with the carry bit, to the value in
|
||
|
register 7.
|
||
|
|
||
|
@end table
|