137 lines
5.2 KiB
Text
137 lines
5.2 KiB
Text
@c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
|
|
@c This is part of the GAS manual.
|
|
@c For copying conditions, see the file as.texinfo.
|
|
@ifset GENERIC
|
|
@page
|
|
@node M32R-Dependent
|
|
@chapter M32R Dependent Features
|
|
@end ifset
|
|
@ifclear GENERIC
|
|
@node Machine Dependencies
|
|
@chapter M32R Dependent Features
|
|
@end ifclear
|
|
|
|
@c start-sanitize-m32rx
|
|
|
|
@cindex M32R support
|
|
@menu
|
|
* M32R-Opts:: M32R Options
|
|
* M32R-Warnings:: M32R Warnings
|
|
@end menu
|
|
|
|
@node M32R-Opts
|
|
@section M32R Options
|
|
|
|
@cindex options, M32R
|
|
@cindex M32R options
|
|
|
|
The Mitsubishi M32R version of @code{@value{AS}} has a few machine
|
|
dependent options:
|
|
|
|
@table @code
|
|
@item -m32rx
|
|
@cindex @samp{-m32rx} option, M32RX
|
|
@cindex architecture options, M32RX
|
|
@cindex M32R architecture options
|
|
@code{@value{AS}} can assemble code for several different members of the
|
|
Mitsubishi M32R family. Normally the default is to assemble code for
|
|
the M32R microprocessor. This option may be used to change the default
|
|
to the M32RX microprocessor, which adds some more instructions to the
|
|
basic M32R instruction set, and some additional parameters to some of
|
|
the original instructions.
|
|
|
|
@item -warn-explicit-parallel-conflicts
|
|
@cindex @samp{-warn-explicit-parallel-conflicts} option, M32RX
|
|
Instructs @code{@value{AS}} to produce warning messages when
|
|
questionable parallel instructions are encountered. This option is
|
|
enabled by default, but @code{@value{GCC}} disables it when it invokes
|
|
@code{@value{AS}} directly. Questionable instructions are those whoes
|
|
behaviour would be different if they were executed sequentially. For
|
|
example the code fragment @samp{mv r1, r2 || mv r3, r1} produces a
|
|
different result from @samp{mv r1, r2 \n mv r3, r1} since the former
|
|
moves r1 into r3 and then r2 into r1, whereas the later moves r2 into r1
|
|
and r3.
|
|
|
|
@item -Wp
|
|
@cindex @samp{-Wp} option, M32RX
|
|
This is a shorter synonym for the @emph{-warn-explicit-parallel-conflicts}
|
|
option.
|
|
|
|
@item -no-warn-explicit-parallel-conflicts
|
|
@cindex @samp{-no-warn-explicit-parallel-conflicts} option, M32RX
|
|
Instructs @code{@value{AS}} not to produce warning messages when
|
|
questionable parallel instructions are encountered.
|
|
|
|
@item -Wnp
|
|
@cindex @samp{-Wnp} option, M32RX
|
|
This is a shorter synonym for the @emph{-no-warn-explicit-parallel-conflicts}
|
|
option.
|
|
|
|
@end table
|
|
|
|
@node M32R-Warnings
|
|
@section M32R Warnings
|
|
|
|
@cindex warnings, M32R
|
|
@cindex M32R warnings
|
|
|
|
There are several warning and error messages that can be produced by
|
|
@code{@value{AS}} which are specific to the M32R:
|
|
|
|
@table @code
|
|
|
|
@item output of 1st instruction is the same as an input to 2nd instruction - is this intentional ?
|
|
This message is only produced if warnings for explicit parallel
|
|
conflicts have been enabled. It indicates that the assembler has
|
|
encountered a parallel instruction in which the destination register of
|
|
the left hand instruction is used as an input register in the right hand
|
|
instruction. For example in this code fragment
|
|
@samp{mv r1, r2 || neg r3, r1} register r1 is the destination of the
|
|
move instruction and the input to the neg instruction.
|
|
|
|
@item output of 2nd instruction is the same as an input to 1st instruction - is this intentional ?
|
|
This message is only produced if warnings for explicit parallel
|
|
conflicts have been enabled. It indicates that the assembler has
|
|
encountered a parallel instruction in which the destination register of
|
|
the right hand instruction is used as an input register in the left hand
|
|
instruction. For example in this code fragment
|
|
@samp{mv r1, r2 || neg r2, r3} register r2 is the destination of the
|
|
neg instruction and the input to the move instruction.
|
|
|
|
@item instruction @samp{...} is for the M32RX only
|
|
This message is produced when the assembler encounters an instruction
|
|
which is only supported by the M32Rx processor, and the @samp{-m32rx}
|
|
command line flag has not been specified to allow assembly of such
|
|
instructions.
|
|
|
|
@item unknown instruction @samp{...}
|
|
This message is produced when the assembler encounters an instruction
|
|
which it doe snot recognise.
|
|
|
|
@item only the NOP instruction can be issued in parallel on the m32r
|
|
This message is produced when the assembler encounters a parallel
|
|
instruction which does not involve a NOP instruction and the
|
|
@samp{-m32rx} command line flag has not been specified. Only the M32Rx
|
|
processor is able to execute two instructions in parallel.
|
|
|
|
@item instruction @samp{...} cannot be executed in parallel.
|
|
This message is produced when the assembler encounters a parallel
|
|
instruction which is made up of one or two instructions which cannot be
|
|
executed in parallel.
|
|
|
|
@item Instructions share the same execution pipeline
|
|
This message is produced when the assembler encounters a parallel
|
|
instruction whoes components both use the same execution pipeline.
|
|
|
|
@item Instructions write to the same destination register.
|
|
This message is produced when the assembler encounters a parallel
|
|
instruction where both components attempt to modify the same register.
|
|
For example these code fragments will produce this message:
|
|
@samp{mv r1, r2 || neg r1, r3}
|
|
@samp{jl r0 || mv r14, r1}
|
|
@samp{st r2, @@-r1 || mv r1, r3}
|
|
@samp{mv r1, r2 || ld r0, @@r1+}
|
|
@samp{cmp r1, r2 || addx r3, r4} (Both write to the condition bit)
|
|
|
|
@end table
|
|
@c end-sanitize-m32rx
|