210 lines
5.1 KiB
Plaintext
210 lines
5.1 KiB
Plaintext
@c Copyright 2012
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@c Free Software Foundation, Inc.
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@c This is part of the GAS manual.
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@c For copying conditions, see the file as.texinfo.
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@ifset GENERIC
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@page
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@node XGATE-Dependent
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@chapter XGATE Dependent Features
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@end ifset
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@ifclear GENERIC
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@node Machine Dependencies
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@chapter XGATE Dependent Features
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@end ifclear
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@cindex XGATE support
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@menu
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* XGATE-Opts:: XGATE Options
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* XGATE-Syntax:: Syntax
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* XGATE-Directives:: Assembler Directives
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* XGATE-Float:: Floating Point
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* XGATE-opcodes:: Opcodes
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@end menu
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@node XGATE-Opts
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@section XGATE Options
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@cindex options, XGATE
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@cindex XGATE options
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The Freescale XGATE version of @code{@value{AS}} has a few machine
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dependent options.
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@table @code
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@cindex @samp{-mshort}
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@item -mshort
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This option controls the ABI and indicates to use a 16-bit integer ABI.
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It has no effect on the assembled instructions.
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This is the default.
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@cindex @samp{-mlong}
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@item -mlong
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This option controls the ABI and indicates to use a 32-bit integer ABI.
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@cindex @samp{-mshort-double}
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@item -mshort-double
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This option controls the ABI and indicates to use a 32-bit float ABI.
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This is the default.
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@cindex @samp{-mlong-double}
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@item -mlong-double
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This option controls the ABI and indicates to use a 64-bit float ABI.
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@cindex @samp{--print-insn-syntax}
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@item --print-insn-syntax
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You can use the @samp{--print-insn-syntax} option to obtain the
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syntax description of the instruction when an error is detected.
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@cindex @samp{--print-opcodes}
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@item --print-opcodes
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The @samp{--print-opcodes} option prints the list of all the
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instructions with their syntax. Once the list is printed
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@code{@value{AS}} exits.
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@end table
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@node XGATE-Syntax
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@section Syntax
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@cindex XGATE syntax
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@cindex syntax, XGATE
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In XGATE RISC syntax, the instruction name comes first and it may
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be followed by up to three operands. Operands are separated by commas
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(@samp{,}). @code{@value{AS}} will complain if too many operands are specified
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for a given instruction. The same will happen if you specified too few
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operands.
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@smallexample
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nop
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ldl #23
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CMP R1, R2
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@end smallexample
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@cindex line comment character, XGATE
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@cindex XGATE line comment character
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The presence of a @samp{;} character or a @samp{!} character anywhere
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on a line indicates the start of a comment that extends to the end of
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that line.
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A @samp{*} or a @samp{#} character at the start of a line also
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introduces a line comment, but these characters do not work elsewhere
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on the line. If the first character of the line is a @samp{#} then as
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well as starting a comment, the line could also be logical line number
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directive (@pxref{Comments}) or a preprocessor control command
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(@pxref{Preprocessing}).
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@cindex line separator, XGATE
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@cindex statement separator, XGATE
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@cindex XGATE line separator
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The XGATE assembler does not currently support a line separator
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character.
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@cindex XGATE addressing modes
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@cindex addressing modes, XGATE
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The following addressing modes are understood for XGATE:
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@table @dfn
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@item Inherent
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@samp{}
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@item Immediate 3 Bit Wide
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@samp{#@var{number}}
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@item Immediate 4 Bit Wide
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@samp{#@var{number}}
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@item Immediate 8 Bit Wide
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@samp{#@var{number}}
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@item Monadic Addressing
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@samp{@var{reg}}
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@item Dyadic Addressing
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@samp{@var{reg}, @var{reg}}
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@item Triadic Addressing
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@samp{@var{reg}, @var{reg}, @var{reg}}
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@item Relative Addressing 9 Bit Wide
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@samp{*@var{symbol}}
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@item Relative Addressing 10 Bit Wide
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@samp{*@var{symbol}}
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@item Index Register plus Immediate Offset
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@samp{@var{reg}, (@var{reg}, #@var{number})}
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@item Index Register plus Register Offset
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@samp{@var{reg}, @var{reg}, @var{reg}}
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@item Index Register plus Register Offset with Post-increment
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@samp{@var{reg}, @var{reg}, @var{reg}+}
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@item Index Register plus Register Offset with Pre-decrement
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@samp{@var{reg}, @var{reg}, -@var{reg}}
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The register can be either @samp{R0}, @samp{R1}, @samp{R2}, @samp{R3},
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@samp{R4}, @samp{R5}, @samp{R6} or @samp{R7}.
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@end table
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Convience macro opcodes to deal with 16-bit values have been added.
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@table @dfn
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@item Immediate 16 Bit Wide
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@samp{#@var{number}}, or @samp{*@var{symbol}}
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For example:
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@smallexample
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ldw R1, #1024
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ldw R3, timer
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ldw R1, (R1, #0)
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COM R1
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stw R2, (R1, #0)
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@end smallexample
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@end table
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@node XGATE-Directives
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@section Assembler Directives
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@cindex assembler directives, XGATE
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@cindex XGATE assembler directives
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The XGATE version of @code{@value{AS}} have the following
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specific assembler directives:
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@node XGATE-Float
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@section Floating Point
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@cindex floating point, XGATE
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@cindex XGATE floating point
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Packed decimal (P) format floating literals are not supported(yet).
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The floating point formats generated by directives are these.
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@table @code
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@cindex @code{float} directive, XGATE
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@item .float
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@code{Single} precision floating point constants.
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@cindex @code{double} directive, XGATE
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@item .double
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@code{Double} precision floating point constants.
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@cindex @code{extend} directive XGATE
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@cindex @code{ldouble} directive XGATE
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@item .extend
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@itemx .ldouble
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@code{Extended} precision (@code{long double}) floating point constants.
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@end table
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@need 2000
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@node XGATE-opcodes
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@section Opcodes
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@cindex XGATE opcodes
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@cindex instruction set, XGATE
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