mirror of
https://github.com/autc04/Retro68.git
synced 2024-09-04 22:29:49 +00:00
258 lines
8.7 KiB
Plaintext
258 lines
8.7 KiB
Plaintext
|
@c Copyright 1996, 2000, 2002 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 D10V-Dependent
|
||
|
@chapter D10V Dependent Features
|
||
|
@end ifset
|
||
|
@ifclear GENERIC
|
||
|
@node Machine Dependencies
|
||
|
@chapter D10V Dependent Features
|
||
|
@end ifclear
|
||
|
|
||
|
@cindex D10V support
|
||
|
@menu
|
||
|
* D10V-Opts:: D10V Options
|
||
|
* D10V-Syntax:: Syntax
|
||
|
* D10V-Float:: Floating Point
|
||
|
* D10V-Opcodes:: Opcodes
|
||
|
@end menu
|
||
|
|
||
|
@node D10V-Opts
|
||
|
@section D10V Options
|
||
|
@cindex options, D10V
|
||
|
@cindex D10V options
|
||
|
The Mitsubishi D10V version of @code{@value{AS}} has a few machine
|
||
|
dependent options.
|
||
|
|
||
|
@table @samp
|
||
|
@item -O
|
||
|
The D10V can often execute two sub-instructions in parallel. When this option
|
||
|
is used, @code{@value{AS}} will attempt to optimize its output by detecting when
|
||
|
instructions can be executed in parallel.
|
||
|
@item --nowarnswap
|
||
|
To optimize execution performance, @code{@value{AS}} will sometimes swap the
|
||
|
order of instructions. Normally this generates a warning. When this option
|
||
|
is used, no warning will be generated when instructions are swapped.
|
||
|
@item --gstabs-packing
|
||
|
@item --no-gstabs-packing
|
||
|
@code{@value{AS}} packs adjacent short instructions into a single packed
|
||
|
instruction. @samp{--no-gstabs-packing} turns instruction packing off if
|
||
|
@samp{--gstabs} is specified as well; @samp{--gstabs-packing} (the
|
||
|
default) turns instruction packing on even when @samp{--gstabs} is
|
||
|
specified.
|
||
|
@end table
|
||
|
|
||
|
@node D10V-Syntax
|
||
|
@section Syntax
|
||
|
@cindex D10V syntax
|
||
|
@cindex syntax, D10V
|
||
|
|
||
|
The D10V syntax is based on the syntax in Mitsubishi's D10V architecture manual.
|
||
|
The differences are detailed below.
|
||
|
|
||
|
@menu
|
||
|
* D10V-Size:: Size Modifiers
|
||
|
* D10V-Subs:: Sub-Instructions
|
||
|
* D10V-Chars:: Special Characters
|
||
|
* D10V-Regs:: Register Names
|
||
|
* D10V-Addressing:: Addressing Modes
|
||
|
* D10V-Word:: @@WORD Modifier
|
||
|
@end menu
|
||
|
|
||
|
|
||
|
@node D10V-Size
|
||
|
@subsection Size Modifiers
|
||
|
@cindex D10V size modifiers
|
||
|
@cindex size modifiers, D10V
|
||
|
The D10V version of @code{@value{AS}} uses the instruction names in the D10V
|
||
|
Architecture Manual. However, the names in the manual are sometimes ambiguous.
|
||
|
There are instruction names that can assemble to a short or long form opcode.
|
||
|
How does the assembler pick the correct form? @code{@value{AS}} will always pick the
|
||
|
smallest form if it can. When dealing with a symbol that is not defined yet when a
|
||
|
line is being assembled, it will always use the long form. If you need to force the
|
||
|
assembler to use either the short or long form of the instruction, you can append
|
||
|
either @samp{.s} (short) or @samp{.l} (long) to it. For example, if you are writing
|
||
|
an assembly program and you want to do a branch to a symbol that is defined later
|
||
|
in your program, you can write @samp{bra.s foo}.
|
||
|
Objdump and GDB will always append @samp{.s} or @samp{.l} to instructions which
|
||
|
have both short and long forms.
|
||
|
|
||
|
@node D10V-Subs
|
||
|
@subsection Sub-Instructions
|
||
|
@cindex D10V sub-instructions
|
||
|
@cindex sub-instructions, D10V
|
||
|
The D10V assembler takes as input a series of instructions, either one-per-line,
|
||
|
or in the special two-per-line format described in the next section. Some of these
|
||
|
instructions will be short-form or sub-instructions. These sub-instructions can be packed
|
||
|
into a single instruction. The assembler will do this automatically. It will also detect
|
||
|
when it should not pack instructions. For example, when a label is defined, the next
|
||
|
instruction will never be packaged with the previous one. Whenever a branch and link
|
||
|
instruction is called, it will not be packaged with the next instruction so the return
|
||
|
address will be valid. Nops are automatically inserted when necessary.
|
||
|
|
||
|
If you do not want the assembler automatically making these decisions, you can control
|
||
|
the packaging and execution type (parallel or sequential) with the special execution
|
||
|
symbols described in the next section.
|
||
|
|
||
|
@node D10V-Chars
|
||
|
@subsection Special Characters
|
||
|
@cindex line comment character, D10V
|
||
|
@cindex D10V line comment character
|
||
|
@samp{;} and @samp{#} are the line comment characters.
|
||
|
@cindex sub-instruction ordering, D10V
|
||
|
@cindex D10V sub-instruction ordering
|
||
|
Sub-instructions may be executed in order, in reverse-order, or in parallel.
|
||
|
Instructions listed in the standard one-per-line format will be executed sequentially.
|
||
|
To specify the executing order, use the following symbols:
|
||
|
@table @samp
|
||
|
@item ->
|
||
|
Sequential with instruction on the left first.
|
||
|
@item <-
|
||
|
Sequential with instruction on the right first.
|
||
|
@item ||
|
||
|
Parallel
|
||
|
@end table
|
||
|
The D10V syntax allows either one instruction per line, one instruction per line with
|
||
|
the execution symbol, or two instructions per line. For example
|
||
|
@table @code
|
||
|
@item abs a1 -> abs r0
|
||
|
Execute these sequentially. The instruction on the right is in the right
|
||
|
container and is executed second.
|
||
|
@item abs r0 <- abs a1
|
||
|
Execute these reverse-sequentially. The instruction on the right is in the right
|
||
|
container, and is executed first.
|
||
|
@item ld2w r2,@@r8+ || mac a0,r0,r7
|
||
|
Execute these in parallel.
|
||
|
@item ld2w r2,@@r8+ ||
|
||
|
@itemx mac a0,r0,r7
|
||
|
Two-line format. Execute these in parallel.
|
||
|
@item ld2w r2,@@r8+
|
||
|
@itemx mac a0,r0,r7
|
||
|
Two-line format. Execute these sequentially. Assembler will
|
||
|
put them in the proper containers.
|
||
|
@item ld2w r2,@@r8+ ->
|
||
|
@itemx mac a0,r0,r7
|
||
|
Two-line format. Execute these sequentially. Same as above but
|
||
|
second instruction will always go into right container.
|
||
|
@end table
|
||
|
@cindex symbol names, @samp{$} in
|
||
|
@cindex @code{$} in symbol names
|
||
|
Since @samp{$} has no special meaning, you may use it in symbol names.
|
||
|
|
||
|
@node D10V-Regs
|
||
|
@subsection Register Names
|
||
|
@cindex D10V registers
|
||
|
@cindex registers, D10V
|
||
|
You can use the predefined symbols @samp{r0} through @samp{r15} to refer to the D10V
|
||
|
registers. You can also use @samp{sp} as an alias for @samp{r15}. The accumulators
|
||
|
are @samp{a0} and @samp{a1}. There are special register-pair names that may
|
||
|
optionally be used in opcodes that require even-numbered registers. Register names are
|
||
|
not case sensitive.
|
||
|
|
||
|
Register Pairs
|
||
|
@table @code
|
||
|
@item r0-r1
|
||
|
@item r2-r3
|
||
|
@item r4-r5
|
||
|
@item r6-r7
|
||
|
@item r8-r9
|
||
|
@item r10-r11
|
||
|
@item r12-r13
|
||
|
@item r14-r15
|
||
|
@end table
|
||
|
|
||
|
The D10V also has predefined symbols for these control registers and status bits:
|
||
|
@table @code
|
||
|
@item psw
|
||
|
Processor Status Word
|
||
|
@item bpsw
|
||
|
Backup Processor Status Word
|
||
|
@item pc
|
||
|
Program Counter
|
||
|
@item bpc
|
||
|
Backup Program Counter
|
||
|
@item rpt_c
|
||
|
Repeat Count
|
||
|
@item rpt_s
|
||
|
Repeat Start address
|
||
|
@item rpt_e
|
||
|
Repeat End address
|
||
|
@item mod_s
|
||
|
Modulo Start address
|
||
|
@item mod_e
|
||
|
Modulo End address
|
||
|
@item iba
|
||
|
Instruction Break Address
|
||
|
@item f0
|
||
|
Flag 0
|
||
|
@item f1
|
||
|
Flag 1
|
||
|
@item c
|
||
|
Carry flag
|
||
|
@end table
|
||
|
|
||
|
@node D10V-Addressing
|
||
|
@subsection Addressing Modes
|
||
|
@cindex addressing modes, D10V
|
||
|
@cindex D10V addressing modes
|
||
|
@code{@value{AS}} understands the following addressing modes for the D10V.
|
||
|
@code{R@var{n}} in the following refers to any of the numbered
|
||
|
registers, but @emph{not} the control registers.
|
||
|
@table @code
|
||
|
@item R@var{n}
|
||
|
Register direct
|
||
|
@item @@R@var{n}
|
||
|
Register indirect
|
||
|
@item @@R@var{n}+
|
||
|
Register indirect with post-increment
|
||
|
@item @@R@var{n}-
|
||
|
Register indirect with post-decrement
|
||
|
@item @@-SP
|
||
|
Register indirect with pre-decrement
|
||
|
@item @@(@var{disp}, R@var{n})
|
||
|
Register indirect with displacement
|
||
|
@item @var{addr}
|
||
|
PC relative address (for branch or rep).
|
||
|
@item #@var{imm}
|
||
|
Immediate data (the @samp{#} is optional and ignored)
|
||
|
@end table
|
||
|
|
||
|
@node D10V-Word
|
||
|
@subsection @@WORD Modifier
|
||
|
@cindex D10V @@word modifier
|
||
|
@cindex @@word modifier, D10V
|
||
|
Any symbol followed by @code{@@word} will be replaced by the symbol's value
|
||
|
shifted right by 2. This is used in situations such as loading a register
|
||
|
with the address of a function (or any other code fragment). For example, if
|
||
|
you want to load a register with the location of the function @code{main} then
|
||
|
jump to that function, you could do it as follows:
|
||
|
@smallexample
|
||
|
@group
|
||
|
ldi r2, main@@word
|
||
|
jmp r2
|
||
|
@end group
|
||
|
@end smallexample
|
||
|
|
||
|
@node D10V-Float
|
||
|
@section Floating Point
|
||
|
@cindex floating point, D10V
|
||
|
@cindex D10V floating point
|
||
|
The D10V has no hardware floating point, but the @code{.float} and @code{.double}
|
||
|
directives generates @sc{ieee} floating-point numbers for compatibility
|
||
|
with other development tools.
|
||
|
|
||
|
@node D10V-Opcodes
|
||
|
@section Opcodes
|
||
|
@cindex D10V opcode summary
|
||
|
@cindex opcode summary, D10V
|
||
|
@cindex mnemonics, D10V
|
||
|
@cindex instruction summary, D10V
|
||
|
For detailed information on the D10V machine instruction set, see
|
||
|
@cite{D10V Architecture: A VLIW Microprocessor for Multimedia Applications}
|
||
|
(Mitsubishi Electric Corp.).
|
||
|
@code{@value{AS}} implements all the standard D10V opcodes. The only changes are those
|
||
|
described in the section on size modifiers
|
||
|
|