gas/doc/c-rl78.texi

   1 @c Copyright 2011
   2 @c Free Software Foundation, Inc.
   3 @c This is part of the GAS manual.
   4 @c For copying conditions, see the file as.texinfo.
   5 @ifset GENERIC
   6 @page
   7 @node RL78-Dependent
   8 @chapter RL78 Dependent Features
   9 @end ifset
  10 @ifclear GENERIC
  11 @node Machine Dependencies
  12 @chapter RL78 Dependent Features
  13 @end ifclear
  14
  15 @cindex RL78 support
  16 @menu
  17 * RL78-Opts::                   RL78 Assembler Command Line Options
  18 * RL78-Modifiers::              Symbolic Operand Modifiers
  19 * RL78-Directives::             Assembler Directives
  20 * RL78-Syntax::                 Syntax
  21 @end menu
  22
  23 @node RL78-Opts
  24 @section RL78 Options
  25 @cindex options, RL78
  26 @cindex RL78 options
  27
  28 The Renesas RL78 port of @code{@value{AS}} has no target-specific
  29 options.
  30
  31 @node RL78-Modifiers
  32 @section Symbolic Operand Modifiers
  33
  34 @cindex RL78 modifiers
  35 @cindex syntax, RL78
  36
  37 The RL78 has three modifiers that adjust the relocations used by the
  38 linker:
  39
  40 @table @code
  41
  42 @item %lo16()
  43
  44 When loading a 20-bit (or wider) address into registers, this modifier
  45 selects the 16 least significant bits.
  46
  47 @smallexample
  48   movw ax,#%lo16(_sym)
  49 @end smallexample
  50
  51 @item %hi16()
  52
  53 When loading a 20-bit (or wider) address into registers, this modifier
  54 selects the 16 most significant bits.
  55
  56 @smallexample
  57   movw ax,#%hi16(_sym)
  58 @end smallexample
  59
  60 @item %hi8()
  61
  62 When loading a 20-bit (or wider) address into registers, this modifier
  63 selects the 8 bits that would go into CS or ES (i.e. bits 23..16).
  64
  65 @smallexample
  66   mov es, #%hi8(_sym)
  67 @end smallexample
  68
  69 @end table
  70
  71 @node RL78-Directives
  72 @section Assembler Directives
  73
  74 @cindex assembler directives, RL78
  75 @cindex RL78 assembler directives
  76
  77 In addition to the common directives, the RL78 adds these:
  78
  79 @table @code
  80
  81 @item .double
  82 Output a constant in ``double'' format, which is a 32-bit floating
  83 point value on RL78.
  84
  85 @item .bss
  86 Select the BSS section.
  87
  88 @item .3byte
  89 Output a constant value in a three byte format.
  90
  91 @item .int
  92 @itemx .word
  93 Output a constant value in a four byte format.
  94
  95 @end table
  96
  97 @node RL78-Syntax
  98 @section Syntax for the RL78
  99 @menu
 100 * RL78-Chars::                Special Characters
 101 @end menu
 102
 103 @node RL78-Chars
 104 @subsection Special Characters
 105
 106 @cindex line comment character, RL78
 107 @cindex RL78 line comment character
 108 The presence of a @samp{;} appearing anywhere on a line indicates the
 109 start of a comment that extends to the end of that line.
 110
 111 If a @samp{#} appears as the first character of a line then the whole
 112 line is treated as a comment, but in this case the line can also be a
 113 logical line number directive (@pxref{Comments}) or a preprocessor
 114 control command (@pxref{Preprocessing}).
 115
 116 @cindex line separator, RL78
 117 @cindex statement separator, RL78
 118 @cindex RL78 line separator
 119 The @samp{|} character can be used to separate statements on the same
 120 line.