add m32rx docs

diff --git a/gas/doc/c-m32r.texi b/gas/doc/c-m32r.texi
index f121ede48145a85f2eb5c5c3c41bc82c8290078f..82b5456d126d681e0d3f7e0460dc4cbb84821413 100644 (file)
--- a/gas/doc/c-m32r.texi
+++ b/gas/doc/c-m32r.texi
@@ -1,4 +1,4 @@
-@c Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 1998 Free Software Foundation, Inc.
+@c Copyright (C) 1991, 92-98, 1999 Free Software Foundation, Inc.
 @c This is part of the GAS manual.
 @c For copying conditions, see the file as.texinfo.
 @ifset GENERIC
@@ -11,3 +11,124 @@
 @chapter M32R Dependent Features
 @end ifclear
 
+@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