Subversion Repositories open8_urisc

@c Copyright 2010, 2011 Free Software Foundation, Inc.

@c This is part of the GAS manual.

@c For copying conditions, see the file as.texinfo.

@c man end

@ifset GENERIC

@page

@node TIC6X-Dependent

@chapter TIC6X Dependent Features

@end ifset

@ifclear GENERIC

@node Machine Dependencies

@chapter TIC6X Dependent Features

@end ifclear

@cindex TIC6X support

@cindex TMS320C6X support

@menu

* TIC6X Options::            Options

* TIC6X Syntax::             Syntax

* TIC6X Directives::         Directives

@end menu

@node TIC6X Options

@section TIC6X Options

@cindex TIC6X options

@cindex options for TIC6X

@c man begin OPTIONS

@table @gcctabopt

@cindex @code{-march=} command line option, TIC6X

@item -march=@var{arch}

Enable (only) instructions from architecture @var{arch}.  By default,

all instructions are permitted.

The following values of @var{arch} are accepted: @code{c62x},

@code{c64x}, @code{c64x+}, @code{c67x}, @code{c67x+}, @code{c674x}.

@cindex @code{-mdsbt} command line option, TIC6X

@cindex @code{-mno-dsbt} command line option, TIC6X

@item -mdsbt

@itemx -mno-dsbt

The @option{-mdsbt} option causes the assembler to generate the

@code{Tag_ABI_DSBT} attribute with a value of 1, indicating that the

code is using DSBT addressing.  The @option{-mno-dsbt} option, the

default, causes the tag to have a value of 0, indicating that the code

does not use DSBT addressing.  The linker will emit a warning if

objects of different type (DSBT and non-DSBT) are linked together.

@cindex @code{-mpid=} command line option, TIC6X

@item -mpid=no

@itemx -mpid=near

@itemx -mpid=far

The @option{-mpid=} option causes the assembler to generate the

@code{Tag_ABI_PID} attribute with a value indicating the form of data

addressing used by the code.  @option{-mpid=no}, the default,

indicates position-dependent data addressing, @option{-mpid=near}

indicates position-independent addressing with GOT accesses using near

DP addressing, and @option{-mpid=far} indicates position-independent

addressing with GOT accesses using far DP addressing.  The linker will

emit a warning if objects built with different settings of this option

are linked together.

@cindex @code{-mpic} command line option, TIC6X

@cindex @code{-mno-pic} command line option, TIC6X

@item -mpic

@itemx -mno-pic

The @option{-mpic} option causes the assembler to generate the

@code{Tag_ABI_PIC} attribute with a value of 1, indicating that the

code is using position-independent code addressing,  The

@code{-mno-pic} option, the default, causes the tag to have a value of

0, indicating position-dependent code addressing.  The linker will

emit a warning if objects of different type (position-dependent and

position-independent) are linked together.

@cindex TIC6X big-endian output

@cindex TIC6X little-endian output

@cindex big-endian output, TIC6X

@cindex little-endian output, TIC6X

@item -mbig-endian

@itemx -mlittle-endian

Generate code for the specified endianness.  The default is

little-endian.

@end table

@c man end

@node TIC6X Syntax

@section TIC6X Syntax

@cindex line comment character, TIC6X

@cindex TIC6X line comment character

The presence of a @samp{;} on a line indicates the start of a comment

that extends to the end of the current line.  If a @samp{#} or

@samp{*} appears as the first character of a line, the whole line is

treated as a comment.  Note that if a line starts with a @samp{#}

character then it can also be a logical line number directive

(@pxref{Comments}) or a preprocessor control command

(@pxref{Preprocessing}).

@cindex line separator, TIC6X

@cindex statement separator, TIC6X

@cindex TIC6X line separator

The @samp{@@} character can be used instead of a newline to separate

statements.

Instruction, register and functional unit names are case-insensitive.

@command{@value{AS}} requires fully-specified functional unit names,

such as @samp{.S1}, @samp{.L1X} or @samp{.D1T2}, on all instructions

using a functional unit.

For some instructions, there may be syntactic ambiguity between

register or functional unit names and the names of labels or other

symbols.  To avoid this, enclose the ambiguous symbol name in

parentheses; register and functional unit names may not be enclosed in

parentheses.

@node TIC6X Directives

@section TIC6X Directives

@cindex machine directives, TIC6X

@cindex TIC6X machine directives

Directives controlling the set of instructions accepted by the

assembler have effect for instructions between the directive and any

subsequent directive overriding it.

@table @code

@cindex @code{.arch} directive, TIC6X

@item .arch @var{arch}

This has the same effect as @option{-march=@var{arch}}.

@cindex @code{.cantunwind} directive, TIC6X

@item .cantunwind

Prevents unwinding through the current function.  No personality routine

or exception table data is required or permitted.

If this is not specified then frame unwinding information will be

constructed from CFI directives. @pxref{CFI directives}.

@cindex @code{.c6xabi_attribute} directive, TIC6X

@item .c6xabi_attribute @var{tag}, @var{value}

Set the C6000 EABI build attribute @var{tag} to @var{value}.

The @var{tag} is either an attribute number or one of

@code{Tag_ISA}, @code{Tag_ABI_wchar_t},

@code{Tag_ABI_stack_align_needed},

@code{Tag_ABI_stack_align_preserved}, @code{Tag_ABI_DSBT},

@code{Tag_ABI_PID}, @code{Tag_ABI_PIC},

@code{TAG_ABI_array_object_alignment},

@code{TAG_ABI_array_object_align_expected},

@code{Tag_ABI_compatibility} and @code{Tag_ABI_conformance}.  The

@var{value} is either a @code{number}, @code{"string"}, or

@code{number, "string"} depending on the tag.

@cindex @code{.ehtype} directive, TIC6X

@item .ehtype @var{symbol}

Output an exception type table reference to @var{symbol}.

@cindex @code{.endp} directive, TIC6X

@item .endp

Marks the end of and exception table or function.  If preceeded by a

@code{.handlerdata} directive then this also switched back to the previous

text section.

@cindex @code{.handlerdata} directive, TIC6X

@item .handlerdata

Marks the end of the current function, and the start of the exception table

entry for that function.  Anything between this directive and the

@code{.endp} directive will be added to the exception table entry.

Must be preceded by a CFI block containing a @code{.cfi_lsda} directive.

directive.

@cindex @code{.nocmp} directive, TIC6X

@item .nocmp

Disallow use of C64x+ compact instructions in the current text

section.

@cindex @code{.personalityindex} directive, TIC6X

@item .personalityindex @var{index}

Sets the personality routine for the current function to the ABI specified

compact routine number @var{index}

@cindex @code{.personality} directive, TIC6X

@item .personality @var{name}

Sets the personality routine for the current function to @var{name}.

@cindex @code{.scomm} directive, TIC6X

@item .scomm @var{symbol}, @var{size}, @var{align}

Like @code{.comm}, creating a common symbol @var{symbol} with size @var{size}

and alignment @var{align}, but unlike when using @code{.comm}, this symbol

will be placed into the small BSS section by the linker.

@end table