gas/doc/c-rl78.texi

   1 @c Copyright (C) 2011-2015 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 RL78-Dependent
   7 @chapter RL78 Dependent Features
   8 @end ifset
   9 @ifclear GENERIC
  10 @node Machine Dependencies
  11 @chapter RL78 Dependent Features
  12 @end ifclear
  13
  14 @cindex RL78 support
  15 @menu
  16 * RL78-Opts::                   RL78 Assembler Command Line Options
  17 * RL78-Modifiers::              Symbolic Operand Modifiers
  18 * RL78-Directives::             Assembler Directives
  19 * RL78-Syntax::                 Syntax
  20 @end menu
  21
  22 @node RL78-Opts
  23 @section RL78 Options
  24 @cindex options, RL78
  25 @cindex RL78 options
  26
  27 @table @code
  28 @item relax
  29 Enable support for link-time relaxation.
  30
  31 @item mg10
  32 Mark the generated binary as targeting the G10 variant of the RL78
  33 architecture.
  34
  35 @item mg13
  36 Mark the generated binary as targeting the G13 variant of the RL78
  37 architecture.
  38
  39 @item mg14
  40 @itemx mrl78
  41 Mark the generated binary as targeting the G14 variant of the RL78
  42 architecture.  This is the default.
  43
  44 @item m32bit-doubles
  45 Mark the generated binary as one that uses 32-bits to hold the
  46 @code{double} floating point type.  This is the default.
  47
  48 @item m64bit-doubles
  49 Mark the generated binary as one that uses 64-bits to hold the
  50 @code{double} floating point type.
  51
  52 @end table
  53
  54 @node RL78-Modifiers
  55 @section Symbolic Operand Modifiers
  56
  57 @cindex RL78 modifiers
  58 @cindex syntax, RL78
  59
  60 The RL78 has three modifiers that adjust the relocations used by the
  61 linker:
  62
  63 @table @code
  64
  65 @item %lo16()
  66
  67 When loading a 20-bit (or wider) address into registers, this modifier
  68 selects the 16 least significant bits.
  69
  70 @smallexample
  71   movw ax,#%lo16(_sym)
  72 @end smallexample
  73
  74 @item %hi16()
  75
  76 When loading a 20-bit (or wider) address into registers, this modifier
  77 selects the 16 most significant bits.
  78
  79 @smallexample
  80   movw ax,#%hi16(_sym)
  81 @end smallexample
  82
  83 @item %hi8()
  84
  85 When loading a 20-bit (or wider) address into registers, this modifier
  86 selects the 8 bits that would go into CS or ES (i.e. bits 23..16).
  87
  88 @smallexample
  89   mov es, #%hi8(_sym)
  90 @end smallexample
  91
  92 @end table
  93
  94 @node RL78-Directives
  95 @section Assembler Directives
  96
  97 @cindex assembler directives, RL78
  98 @cindex RL78 assembler directives
  99
 100 In addition to the common directives, the RL78 adds these:
 101
 102 @table @code
 103
 104 @item .double
 105 Output a constant in ``double'' format, which is either a 32-bit
 106 or a 64-bit floating point value, depending upon the setting of the
 107 @option{-m32bit-doubles}|@option{-m64bit-doubles} command line
 108 option.
 109
 110 @item .bss
 111 Select the BSS section.
 112
 113 @item .3byte
 114 Output a constant value in a three byte format.
 115
 116 @item .int
 117 @itemx .word
 118 Output a constant value in a four byte format.
 119
 120 @end table
 121
 122 @node RL78-Syntax
 123 @section Syntax for the RL78
 124 @menu
 125 * RL78-Chars::                Special Characters
 126 @end menu
 127
 128 @node RL78-Chars
 129 @subsection Special Characters
 130
 131 @cindex line comment character, RL78
 132 @cindex RL78 line comment character
 133 The presence of a @samp{;} appearing anywhere on a line indicates the
 134 start of a comment that extends to the end of that line.
 135
 136 If a @samp{#} appears as the first character of a line then the whole
 137 line is treated as a comment, but in this case the line can also be a
 138 logical line number directive (@pxref{Comments}) or a preprocessor
 139 control command (@pxref{Preprocessing}).
 140
 141 @cindex line separator, RL78
 142 @cindex statement separator, RL78
 143 @cindex RL78 line separator
 144 The @samp{|} character can be used to separate statements on the same
 145 line.