gas/doc/c-xgate.texi

   1 @c Copyright (C) 2012-2017 Free Software Foundation, Inc.
   2 @c This is part of the GAS manual.
   3 @c For copying conditions, see the file as.texinfo.
   4 @ifset GENERIC
   5 @page
   6 @node XGATE-Dependent
   7 @chapter XGATE Dependent Features
   8 @end ifset
   9 @ifclear GENERIC
  10 @node Machine Dependencies
  11 @chapter XGATE Dependent Features
  12 @end ifclear
  13
  14 @cindex XGATE support
  15 @menu
  16 * XGATE-Opts::                   XGATE Options
  17 * XGATE-Syntax::                 Syntax
  18 * XGATE-Directives::             Assembler Directives
  19 * XGATE-Float::                  Floating Point
  20 * XGATE-opcodes::                Opcodes
  21 @end menu
  22
  23 @node XGATE-Opts
  24 @section XGATE Options
  25
  26 @cindex options, XGATE
  27 @cindex XGATE options
  28 The Freescale XGATE version of @code{@value{AS}} has a few machine
  29 dependent options.
  30
  31 @table @code
  32
  33 @cindex @samp{-mshort}
  34 @item -mshort
  35 This option controls the ABI and indicates to use a 16-bit integer ABI.
  36 It has no effect on the assembled instructions.
  37 This is the default.
  38
  39 @cindex @samp{-mlong}
  40 @item -mlong
  41 This option controls the ABI and indicates to use a 32-bit integer ABI.
  42
  43 @cindex @samp{-mshort-double}
  44 @item -mshort-double
  45 This option controls the ABI and indicates to use a 32-bit float ABI.
  46 This is the default.
  47
  48 @cindex @samp{-mlong-double}
  49 @item -mlong-double
  50 This option controls the ABI and indicates to use a 64-bit float ABI.
  51
  52 @cindex @samp{--print-insn-syntax}
  53 @item --print-insn-syntax
  54 You can use the @samp{--print-insn-syntax} option to obtain the
  55 syntax description of the instruction when an error is detected.
  56
  57 @cindex @samp{--print-opcodes}
  58 @item --print-opcodes
  59 The @samp{--print-opcodes} option prints the list of all the
  60 instructions with their syntax. Once the list is printed
  61 @code{@value{AS}} exits.
  62
  63 @end table
  64
  65 @node XGATE-Syntax
  66 @section Syntax
  67
  68 @cindex XGATE syntax
  69 @cindex syntax, XGATE
  70
  71 In XGATE RISC syntax, the instruction name comes first and it may
  72 be followed by up to three operands. Operands are separated by commas
  73 (@samp{,}). @code{@value{AS}} will complain if too many operands are specified
  74 for a given instruction. The same will happen if you specified too few
  75  operands.
  76
  77 @smallexample
  78 nop
  79 ldl  #23
  80 CMP  R1, R2
  81 @end smallexample
  82
  83 @cindex line comment character, XGATE
  84 @cindex XGATE line comment character
  85 The presence of a @samp{;} character or a @samp{!} character anywhere
  86 on a line indicates the start of a comment that extends to the end of
  87 that line.
  88
  89 A @samp{*} or a @samp{#} character at the start of a line also
  90 introduces a line comment, but these characters do not work elsewhere
  91 on the line.  If the first character of the line is a @samp{#} then as
  92 well as starting a comment, the line could also be logical line number
  93 directive (@pxref{Comments}) or a preprocessor control command
  94 (@pxref{Preprocessing}).
  95
  96 @cindex line separator, XGATE
  97 @cindex statement separator, XGATE
  98 @cindex XGATE line separator
  99 The XGATE assembler does not currently support a line separator
 100 character.
 101
 102 @cindex XGATE addressing modes
 103 @cindex addressing modes, XGATE
 104 The following addressing modes are understood for XGATE:
 105 @table @dfn
 106 @item Inherent
 107 @samp{}
 108
 109 @item Immediate 3 Bit Wide
 110 @samp{#@var{number}}
 111
 112 @item Immediate 4 Bit Wide
 113 @samp{#@var{number}}
 114
 115 @item Immediate 8 Bit Wide
 116 @samp{#@var{number}}
 117
 118 @item Monadic Addressing
 119 @samp{@var{reg}}
 120
 121 @item Dyadic Addressing
 122 @samp{@var{reg}, @var{reg}}
 123
 124 @item Triadic Addressing
 125 @samp{@var{reg}, @var{reg}, @var{reg}}
 126
 127 @item Relative Addressing 9 Bit Wide
 128 @samp{*@var{symbol}}
 129
 130 @item Relative Addressing 10 Bit Wide
 131 @samp{*@var{symbol}}
 132
 133 @item Index Register plus Immediate Offset
 134 @samp{@var{reg}, (@var{reg}, #@var{number})}
 135
 136 @item Index Register plus Register Offset
 137 @samp{@var{reg}, @var{reg}, @var{reg}}
 138
 139 @item Index Register plus Register Offset with Post-increment
 140 @samp{@var{reg}, @var{reg}, @var{reg}+}
 141
 142 @item Index Register plus Register Offset with Pre-decrement
 143 @samp{@var{reg}, @var{reg}, -@var{reg}}
 144
 145 The register can be either @samp{R0}, @samp{R1}, @samp{R2}, @samp{R3},
 146 @samp{R4}, @samp{R5}, @samp{R6} or @samp{R7}.
 147
 148 @end table
 149
 150 Convene macro opcodes to deal with 16-bit values have been added.
 151
 152 @table @dfn
 153
 154 @item Immediate 16 Bit Wide
 155 @samp{#@var{number}}, or @samp{*@var{symbol}}
 156
 157 For example:
 158
 159 @smallexample
 160 ldw R1, #1024
 161 ldw R3, timer
 162 ldw R1, (R1, #0)
 163 COM R1
 164 stw R2, (R1, #0)
 165 @end smallexample
 166 @end table
 167
 168 @node XGATE-Directives
 169 @section Assembler Directives
 170
 171 @cindex assembler directives, XGATE
 172 @cindex XGATE assembler directives
 173
 174 The XGATE version of @code{@value{AS}} have the following
 175 specific assembler directives:
 176
 177 @node XGATE-Float
 178 @section Floating Point
 179
 180 @cindex floating point, XGATE
 181 @cindex XGATE floating point
 182 Packed decimal (P) format floating literals are not supported(yet).
 183
 184 The floating point formats generated by directives are these.
 185
 186 @table @code
 187 @cindex @code{float} directive, XGATE
 188 @item .float
 189 @code{Single} precision floating point constants.
 190
 191 @cindex @code{double} directive, XGATE
 192 @item .double
 193 @code{Double} precision floating point constants.
 194
 195 @cindex @code{extend} directive XGATE
 196 @cindex @code{ldouble} directive XGATE
 197 @item .extend
 198 @itemx .ldouble
 199 @code{Extended} precision (@code{long double}) floating point constants.
 200 @end table
 201
 202 @need 2000
 203 @node XGATE-opcodes
 204 @section Opcodes
 205
 206 @cindex XGATE opcodes
 207 @cindex instruction set, XGATE
 208