| @c Copyright (C) 2012-2016 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 XGATE-Dependent |
| @chapter XGATE Dependent Features |
| @end ifset |
| @ifclear GENERIC |
| @node Machine Dependencies |
| @chapter XGATE Dependent Features |
| @end ifclear |
| |
| @cindex XGATE support |
| @menu |
| * XGATE-Opts:: XGATE Options |
| * XGATE-Syntax:: Syntax |
| * XGATE-Directives:: Assembler Directives |
| * XGATE-Float:: Floating Point |
| * XGATE-opcodes:: Opcodes |
| @end menu |
| |
| @node XGATE-Opts |
| @section XGATE Options |
| |
| @cindex options, XGATE |
| @cindex XGATE options |
| The Freescale XGATE version of @code{@value{AS}} has a few machine |
| dependent options. |
| |
| @table @code |
| |
| @cindex @samp{-mshort} |
| @item -mshort |
| This option controls the ABI and indicates to use a 16-bit integer ABI. |
| It has no effect on the assembled instructions. |
| This is the default. |
| |
| @cindex @samp{-mlong} |
| @item -mlong |
| This option controls the ABI and indicates to use a 32-bit integer ABI. |
| |
| @cindex @samp{-mshort-double} |
| @item -mshort-double |
| This option controls the ABI and indicates to use a 32-bit float ABI. |
| This is the default. |
| |
| @cindex @samp{-mlong-double} |
| @item -mlong-double |
| This option controls the ABI and indicates to use a 64-bit float ABI. |
| |
| @cindex @samp{--print-insn-syntax} |
| @item --print-insn-syntax |
| You can use the @samp{--print-insn-syntax} option to obtain the |
| syntax description of the instruction when an error is detected. |
| |
| @cindex @samp{--print-opcodes} |
| @item --print-opcodes |
| The @samp{--print-opcodes} option prints the list of all the |
| instructions with their syntax. Once the list is printed |
| @code{@value{AS}} exits. |
| |
| @end table |
| |
| @node XGATE-Syntax |
| @section Syntax |
| |
| @cindex XGATE syntax |
| @cindex syntax, XGATE |
| |
| In XGATE RISC syntax, the instruction name comes first and it may |
| be followed by up to three operands. Operands are separated by commas |
| (@samp{,}). @code{@value{AS}} will complain if too many operands are specified |
| for a given instruction. The same will happen if you specified too few |
| operands. |
| |
| @smallexample |
| nop |
| ldl #23 |
| CMP R1, R2 |
| @end smallexample |
| |
| @cindex line comment character, XGATE |
| @cindex XGATE line comment character |
| The presence of a @samp{;} character or a @samp{!} character anywhere |
| on a line indicates the start of a comment that extends to the end of |
| that line. |
| |
| A @samp{*} or a @samp{#} character at the start of a line also |
| introduces a line comment, but these characters do not work elsewhere |
| on the line. If the first character of the line is a @samp{#} then as |
| well as starting a comment, the line could also be logical line number |
| directive (@pxref{Comments}) or a preprocessor control command |
| (@pxref{Preprocessing}). |
| |
| @cindex line separator, XGATE |
| @cindex statement separator, XGATE |
| @cindex XGATE line separator |
| The XGATE assembler does not currently support a line separator |
| character. |
| |
| @cindex XGATE addressing modes |
| @cindex addressing modes, XGATE |
| The following addressing modes are understood for XGATE: |
| @table @dfn |
| @item Inherent |
| @samp{} |
| |
| @item Immediate 3 Bit Wide |
| @samp{#@var{number}} |
| |
| @item Immediate 4 Bit Wide |
| @samp{#@var{number}} |
| |
| @item Immediate 8 Bit Wide |
| @samp{#@var{number}} |
| |
| @item Monadic Addressing |
| @samp{@var{reg}} |
| |
| @item Dyadic Addressing |
| @samp{@var{reg}, @var{reg}} |
| |
| @item Triadic Addressing |
| @samp{@var{reg}, @var{reg}, @var{reg}} |
| |
| @item Relative Addressing 9 Bit Wide |
| @samp{*@var{symbol}} |
| |
| @item Relative Addressing 10 Bit Wide |
| @samp{*@var{symbol}} |
| |
| @item Index Register plus Immediate Offset |
| @samp{@var{reg}, (@var{reg}, #@var{number})} |
| |
| @item Index Register plus Register Offset |
| @samp{@var{reg}, @var{reg}, @var{reg}} |
| |
| @item Index Register plus Register Offset with Post-increment |
| @samp{@var{reg}, @var{reg}, @var{reg}+} |
| |
| @item Index Register plus Register Offset with Pre-decrement |
| @samp{@var{reg}, @var{reg}, -@var{reg}} |
| |
| The register can be either @samp{R0}, @samp{R1}, @samp{R2}, @samp{R3}, |
| @samp{R4}, @samp{R5}, @samp{R6} or @samp{R7}. |
| |
| @end table |
| |
| Convience macro opcodes to deal with 16-bit values have been added. |
| |
| @table @dfn |
| |
| @item Immediate 16 Bit Wide |
| @samp{#@var{number}}, or @samp{*@var{symbol}} |
| |
| For example: |
| |
| @smallexample |
| ldw R1, #1024 |
| ldw R3, timer |
| ldw R1, (R1, #0) |
| COM R1 |
| stw R2, (R1, #0) |
| @end smallexample |
| @end table |
| |
| @node XGATE-Directives |
| @section Assembler Directives |
| |
| @cindex assembler directives, XGATE |
| @cindex XGATE assembler directives |
| |
| The XGATE version of @code{@value{AS}} have the following |
| specific assembler directives: |
| |
| @node XGATE-Float |
| @section Floating Point |
| |
| @cindex floating point, XGATE |
| @cindex XGATE floating point |
| Packed decimal (P) format floating literals are not supported(yet). |
| |
| The floating point formats generated by directives are these. |
| |
| @table @code |
| @cindex @code{float} directive, XGATE |
| @item .float |
| @code{Single} precision floating point constants. |
| |
| @cindex @code{double} directive, XGATE |
| @item .double |
| @code{Double} precision floating point constants. |
| |
| @cindex @code{extend} directive XGATE |
| @cindex @code{ldouble} directive XGATE |
| @item .extend |
| @itemx .ldouble |
| @code{Extended} precision (@code{long double}) floating point constants. |
| @end table |
| |
| @need 2000 |
| @node XGATE-opcodes |
| @section Opcodes |
| |
| @cindex XGATE opcodes |
| @cindex instruction set, XGATE |
| |