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.
8 @chapter TIC6X Dependent Features
11 @node Machine Dependencies
12 @chapter TIC6X Dependent Features
16 @cindex TMS320C6X support
18 * TIC6X Options:: Options
19 * TIC6X Syntax:: Syntax
20 * TIC6X Directives:: Directives
24 @section TIC6X Options
26 @cindex options for TIC6X
31 @cindex @code{-march=} command line option, TIC6X
32 @item -march=@var{arch}
33 Enable (only) instructions from architecture @var{arch}. By default,
34 all instructions are permitted.
36 The following values of @var{arch} are accepted: @code{c62x},
37 @code{c64x}, @code{c64x+}, @code{c67x}, @code{c67x+}, @code{c674x}.
39 @cindex @code{-matomic} command line option, TIC6X
40 @cindex @code{-mno-atomic} command line option, TIC6X
43 Enable or disable the optional C64x+ atomic operation instructions.
44 By default, they are enabled if no @option{-march} option is given, or
45 if an architecture is specified with @option{-march} that implies
46 these instructions are present (currently, there are no such
47 architectures); they are disabled if an architecture is specified with
48 @option{-march} on which the instructions are optional or not
49 present. This option overrides such a default from the architecture,
50 independent of the order in which the @option{-march} or
51 @option{-matomic} or @option{-mno-atomic} options are passed.
53 @cindex @code{-mdsbt} command line option, TIC6X
54 @cindex @code{-mno-dsbt} command line option, TIC6X
57 The @option{-mdsbt} option causes the assembler to generate the
58 @code{Tag_ABI_DSBT} attribute with a value of 1, indicating that the
59 code is using DSBT addressing. The @option{-mno-dsbt} option, the
60 default, causes the tag to have a value of 0, indicating that the code
61 does not use DSBT addressing. The linker will emit a warning if
62 objects of different type (DSBT and non-DSBT) are linked together.
64 @cindex @code{-mpid=} command line option, TIC6X
68 The @option{-mpid=} option causes the assembler to generate the
69 @code{Tag_ABI_PID} attribute with a value indicating the form of data
70 addressing used by the code. @option{-mpid=no}, the default,
71 indicates position-dependent data addressing, @option{-mpid=near}
72 indicates position-independent addressing with GOT accesses using near
73 DP addressing, and @option{-mpid=far} indicates position-independent
74 addressing with GOT accesses using far DP addressing. The linker will
75 emit a warning if objects built with different settings of this option
78 @cindex @code{-mpic} command line option, TIC6X
79 @cindex @code{-mno-pic} command line option, TIC6X
82 The @option{-mpic} option causes the assembler to generate the
83 @code{Tag_ABI_PIC} attribute with a value of 1, indicating that the
84 code is using position-independent code addressing, The
85 @code{-mno-pic} option, the default, causes the tag to have a value of
86 0, indicating position-dependent code addressing. The linker will
87 emit a warning if objects of different type (position-dependent and
88 position-independent) are linked together.
90 @cindex TIC6X big-endian output
91 @cindex TIC6X little-endian output
92 @cindex big-endian output, TIC6X
93 @cindex little-endian output, TIC6X
95 @itemx -mlittle-endian
96 Generate code for the specified endianness. The default is
103 @section TIC6X Syntax
105 @cindex line comment character, TIC6X
106 @cindex TIC6X line comment character
107 The presence of a @samp{;} on a line indicates the start of a comment
108 that extends to the end of the current line. If a @samp{#} or
109 @samp{*} appears as the first character of a line, the whole line is
110 treated as a comment.
112 @cindex line separator, TIC6X
113 @cindex statement separator, TIC6X
114 @cindex TIC6X line separator
115 The @samp{@@} character can be used instead of a newline to separate
118 Instruction, register and functional unit names are case-insensitive.
119 @command{@value{AS}} requires fully-specified functional unit names,
120 such as @samp{.S1}, @samp{.L1X} or @samp{.D1T2}, on all instructions
121 using a functional unit.
123 For some instructions, there may be syntactic ambiguity between
124 register or functional unit names and the names of labels or other
125 symbols. To avoid this, enclose the ambiguous symbol name in
126 parentheses; register and functional unit names may not be enclosed in
129 @node TIC6X Directives
130 @section TIC6X Directives
132 @cindex machine directives, TIC6X
133 @cindex TIC6X machine directives
135 Directives controlling the set of instructions accepted by the
136 assembler have effect for instructions between the directive and any
137 subsequent directive overriding it.
141 @cindex @code{.arch} directive, TIC6X
142 @item .arch @var{arch}
143 This has the same effect as @option{-march=@var{arch}}.
145 @cindex @code{.atomic} directive, TIC6X
146 @cindex @code{.noatomic} directive, TIC6X
149 These have the same effects as @option{-matomic} and
150 @option{-mno-atomic}.
152 @cindex @code{.c6xabi_attribute} directive, TIC6X
153 @item .c6xabi_attribute @var{tag}, @var{value}
154 Set the C6000 EABI build attribute @var{tag} to @var{value}.
156 The @var{tag} is either an attribute number or one of
157 @code{Tag_ISA}, @code{Tag_ABI_wchar_t},
158 @code{Tag_ABI_stack_align_needed},
159 @code{Tag_ABI_stack_align_preserved}, @code{Tag_ABI_DSBT},
160 @code{Tag_ABI_PID}, @code{Tag_ABI_PIC},
161 @code{TAG_ABI_array_object_alignment},
162 @code{TAG_ABI_array_object_align_expected},
163 @code{Tag_ABI_compatibility} and @code{Tag_ABI_conformance}. The
164 @var{value} is either a @code{number}, @code{"string"}, or
165 @code{number, "string"} depending on the tag.
167 @cindex @code{.nocmp} directive, TIC6X
169 Disallow use of C64x+ compact instructions in the current text