gas/doc/c-tic6x.texi

   1 @c Copyright 2010 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 TIC6X-Dependent
   7 @chapter TIC6X Dependent Features
   8 @end ifset
   9 @ifclear GENERIC
  10 @node Machine Dependencies
  11 @chapter TIC6X Dependent Features
  12 @end ifclear
  13
  14 @cindex TIC6X support
  15 @cindex TMS320C6X support
  16 @menu
  17 * TIC6X Options::            Options
  18 * TIC6X Syntax::             Syntax
  19 * TIC6X Directives::         Directives
  20 @end menu
  21
  22 @node TIC6X Options
  23 @section TIC6X Options
  24 @cindex TIC6X options
  25 @cindex options for TIC6X
  26
  27 @table @code
  28
  29 @cindex @code{-march=} command line option, TIC6X
  30 @item -march=@var{arch}
  31 Enable (only) instructions from architecture @var{arch}.  By default,
  32 all instructions are permitted.
  33
  34 The following values of @var{arch} are accepted: @code{c62x},
  35 @code{c64x}, @code{c64x+}, @code{c67x}, @code{c67x+}, @code{c674x}.
  36
  37 @cindex @code{-matomic} command line option, TIC6X
  38 @cindex @code{-mno-atomic} command line option, TIC6X
  39 @item -matomic
  40 @itemx -mno-atomic
  41 Enable or disable the optional C64x+ atomic operation instructions.
  42 By default, they are enabled if no @option{-march} option is given, or
  43 if an architecture is specified with @option{-march} that implies
  44 these instructions are present (currently, there are no such
  45 architectures); they are disabled if an architecture is specified with
  46 @option{-march} on which the instructions are optional or not
  47 present.  This option overrides such a default from the architecture,
  48 independent of the order in which the @option{-march} or
  49 @option{-matomic} or @option{-mno-atomic} options are passed.
  50
  51 @cindex @code{-mdsbt} command line option, TIC6X
  52 @cindex @code{-mno-dsbt} command line option, TIC6X
  53 @item -mdsbt
  54 @itemx -mno-dsbt
  55 The @option{-mdsbt} option causes the assembler to generate the
  56 @code{Tag_ABI_DSBT} attribute with a value of 1, indicating that the
  57 code is using DSBT addressing.  The @option{-mno-dsbt} option, the
  58 default, causes the tag to have a value of 0, indicating that the code
  59 does not use DSBT addressing.  The linker will emit a warning if
  60 objects of different type (DSBT and non-DSBT) are linked together.
  61
  62 @cindex TIC6X big-endian output
  63 @cindex TIC6X little-endian output
  64 @cindex big-endian output, TIC6X
  65 @cindex little-endian output, TIC6X
  66 @item -mbig-endian
  67 @itemx -mlittle-endian
  68 Generate code for the specified endianness.  The default is
  69 little-endian.
  70
  71 @end table
  72
  73 @node TIC6X Syntax
  74 @section TIC6X Syntax
  75
  76 @cindex line comment character, TIC6X
  77 @cindex TIC6X line comment character
  78 The presence of a @samp{;} on a line indicates the start of a comment
  79 that extends to the end of the current line.  If a @samp{#} or
  80 @samp{*} appears as the first character of a line, the whole line is
  81 treated as a comment.
  82
  83 @cindex line separator, TIC6X
  84 @cindex statement separator, TIC6X
  85 @cindex TIC6X line separator
  86 The @samp{@@} character can be used instead of a newline to separate
  87 statements.
  88
  89 Instruction, register and functional unit names are case-insensitive.
  90 @command{@value{AS}} requires fully-specified functional unit names,
  91 such as @samp{.S1}, @samp{.L1X} or @samp{.D1T2}, on all instructions
  92 using a functional unit.
  93
  94 For some instructions, there may be syntactic ambiguity between
  95 register or functional unit names and the names of labels or other
  96 symbols.  To avoid this, enclose the ambiguous symbol name in
  97 parentheses; register and functional unit names may not be enclosed in
  98 parentheses.
  99
 100 @node TIC6X Directives
 101 @section TIC6X Directives
 102
 103 @cindex machine directives, TIC6X
 104 @cindex TIC6X machine directives
 105
 106 Directives controlling the set of instructions accepted by the
 107 assembler have effect for instructions between the directive and any
 108 subsequent directive overriding it.
 109
 110 @table @code
 111
 112 @cindex @code{.arch} directive, TIC6X
 113 @item .arch @var{arch}
 114 This has the same effect as @option{-march=@var{arch}}.
 115
 116 @cindex @code{.atomic} directive, TIC6X
 117 @cindex @code{.noatomic} directive, TIC6X
 118 @item .atomic
 119 @itemx .noatomic
 120 These have the same effects as @option{-matomic} and
 121 @option{-mno-atomic}.
 122
 123 @cindex @code{.c6xabi_attribute} directive, TIC6X
 124 @item .c6xabi_attribute @var{tag}, @var{value}
 125 Set the C6000 EABI build attribute @var{tag} to @var{value}.
 126
 127 The @var{tag} is either an attribute number or one of
 128 @code{Tag_ISA}, @code{Tag_ABI_DSBT} and @code{Tag_ABI_compatibility}.  The
 129 @var{value} is either a @code{number}, @code{"string"}, or
 130 @code{number, "string"} depending on the tag.
 131
 132 @cindex @code{.nocmp} directive, TIC6X
 133 @item .nocmp
 134 Disallow use of C64x+ compact instructions in the current text
 135 section.
 136
 137 @end table