@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1999, 2000, 2001,
-@c 2002, 2003, 2004
+@c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
@c Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
* MIPS option stack:: Directives to save and restore options
* MIPS ASE instruction generation overrides:: Directives to control
generation of MIPS ASE instructions
+* MIPS floating-point:: Directives to override floating-point options
+* MIPS Syntax:: MIPS specific syntactical considerations
@end menu
@node MIPS Opts
@itemx -mips2
@itemx -mips3
@itemx -mips4
-@itemx -mips5
+@itemx -mips5xo
@itemx -mips32
@itemx -mips32r2
@itemx -mips64
@code{.set mips16} at the start of the assembly file. @samp{-no-mips16}
turns off this option.
+@item -mmicromips
+@itemx -mno-micromips
+Generate code for the microMIPS processor. This is equivalent to putting
+@code{.set micromips} at the start of the assembly file. @samp{-mno-micromips}
+turns off this option. This is equivalent to putting @code{.set nomicromips}
+at the start of the assembly file.
+
@item -msmartmips
@itemx -mno-smartmips
Enables the SmartMIPS extensions to the MIPS32 instruction set, which
This tells the assembler to accept MT instructions.
@samp{-mno-mt} turns off this option.
+@item -mmcu
+@itemx -mno-mcu
+Generate code for the MCU Application Specific Extension.
+This tells the assembler to accept MCU instructions.
+@samp{-mno-mcu} turns off this option.
+
@item -mfix7000
@itemx -mno-fix7000
Cause nops to be inserted if the read of the destination register
of an mfhi or mflo instruction occurs in the following two instructions.
+@item -mfix-loongson2f-jump
+@itemx -mno-fix-loongson2f-jump
+Eliminate instruction fetch from outside 256M region to work around the
+Loongson2F @samp{jump} instructions. Without it, under extreme cases,
+the kernel may crash. The issue has been solved in latest processor
+batches, but this fix has no side effect to them.
+
+@item -mfix-loongson2f-nop
+@itemx -mno-fix-loongson2f-nop
+Replace nops by @code{or at,at,zero} to work around the Loongson2F
+@samp{nop} errata. Without it, under extreme cases, cpu might
+deadlock. The issue has been solved in latest loongson2f batches, but
+this fix has no side effect to them.
+
@item -mfix-vr4120
-@itemx -no-mfix-vr4120
+@itemx -mno-fix-vr4120
Insert nops to work around certain VR4120 errata. This option is
intended to be used on GCC-generated code: it is not designed to catch
all problems in hand-written assembler code.
@item -mfix-vr4130
-@itemx -no-mfix-vr4130
+@itemx -mno-fix-vr4130
Insert nops to work around the VR4130 @samp{mflo}/@samp{mfhi} errata.
+@item -mfix-24k
+@itemx -no-mfix-24k
+Insert nops to work around the 24K @samp{eret}/@samp{deret} errata.
+
+@item -mfix-cn63xxp1
+@itemx -mno-fix-cn63xxp1
+Replace @code{pref} hints 0 - 4 and 6 - 24 with hint 28 to work around
+certain CN63XXP1 errata.
+
@item -m4010
@itemx -no-m4010
Generate code for the LSI @sc{r4010} chip. This tells the assembler to
rm9000,
10000,
12000,
+14000,
+16000,
4kc,
4km,
4kp,
4ksd,
m4k,
m4kp,
+m14k,
+m14kc,
24kc,
24kf2_1,
24kf,
74kf,
74kf1_1,
74kf3_2,
+1004kc,
+1004kf2_1,
+1004kf,
+1004kf1_1,
5kc,
5kf,
20kc,
sb1,
sb1a,
loongson2e,
-loongson2f
+loongson2f,
+loongson3a,
+octeon,
+xlr
@end quotation
For compatibility reasons, @samp{@var{n}x} and @samp{@var{b}fx} are
@sc{gnu} @code{@value{AS}}, there is no need for @samp{-nocpp}, because the
@sc{gnu} assembler itself never runs the C preprocessor.
+@item -msoft-float
+@itemx -mhard-float
+Disable or enable floating-point instructions. Note that by default
+floating-point instructions are always allowed even with CPU targets
+that don't have support for these instructions.
+
+@item -msingle-float
+@itemx -mdouble-float
+Disable or enable double-precision floating-point operations. Note
+that by default double-precision floating-point operations are always
+allowed even with CPU targets that don't have support for these
+operations.
+
@item --construct-floats
@itemx --no-construct-floats
-@cindex --construct-floats
-@cindex --no-construct-floats
The @code{--no-construct-floats} option disables the construction of
double width floating point constants by loading the two halves of the
value into the two single width floating point registers that make up
Traditional @sc{mips} assemblers do not support this directive.
+The directive @code{.set micromips} puts the assembler into microMIPS mode,
+in which it will assemble instructions for the microMIPS processor. Use
+@code{.set nomicromips} to return to normal 32 bit mode.
+
+Traditional @sc{mips} assemblers do not support this directive.
+
@node MIPS autoextend
@section Directives for extending MIPS 16 bit instructions
@kindex @code{.insn}
The @code{.insn} directive tells @code{@value{AS}} that the following
-data is actually instructions. This makes a difference in MIPS 16 mode:
-when loading the address of a label which precedes instructions,
-@code{@value{AS}} automatically adds 1 to the value, so that jumping to
-the loaded address will do the right thing.
+data is actually instructions. This makes a difference in MIPS 16 and
+microMIPS modes: when loading the address of a label which precedes
+instructions, @code{@value{AS}} automatically adds 1 to the value, so
+that jumping to the loaded address will do the right thing.
+
+@kindex @code{.global}
+The @code{.global} and @code{.globl} directives supported by
+@code{@value{AS}} will by default mark the symbol as pointing to a
+region of data not code. This means that, for example, any
+instructions following such a symbol will not be disassembled by
+@code{objdump} as it will regard them as data. To change this
+behaviour an optional section name can be placed after the symbol name
+in the @code{.global} directive. If this section exists and is known
+to be a code section, then the symbol will be marked as poiting at
+code not data. Ie the syntax for the directive is:
+
+ @code{.global @var{symbol}[ @var{section}][, @var{symbol}[ @var{section}]] ...},
+
+Here is a short example:
+
+@example
+ .global foo .text, bar, baz .data
+foo:
+ nop
+bar:
+ .word 0x0
+baz:
+ .word 0x1
+
+@end example
@node MIPS option stack
@section Directives to save and restore options
in the assembly. The @code{.set nomt} directive prevents MT
instructions from being accepted.
+@cindex MIPS MCU instruction generation override
+@kindex @code{.set mcu}
+@kindex @code{.set nomcu}
+The directive @code{.set mcu} makes the assembler accept instructions
+from the MCU Application Specific Extension from that point on
+in the assembly. The @code{.set nomcu} directive prevents MCU
+instructions from being accepted.
+
+Traditional @sc{mips} assemblers do not support these directives.
+
+@node MIPS floating-point
+@section Directives to override floating-point options
+
+@cindex Disable floating-point instructions
+@kindex @code{.set softfloat}
+@kindex @code{.set hardfloat}
+The directives @code{.set softfloat} and @code{.set hardfloat} provide
+finer control of disabling and enabling float-point instructions.
+These directives always override the default (that hard-float
+instructions are accepted) or the command-line options
+(@samp{-msoft-float} and @samp{-mhard-float}).
+
+@cindex Disable single-precision floating-point operations
+@kindex @code{.set singlefloat}
+@kindex @code{.set doublefloat}
+The directives @code{.set singlefloat} and @code{.set doublefloat}
+provide finer control of disabling and enabling double-precision
+float-point operations. These directives always override the default
+(that double-precision operations are accepted) or the command-line
+options (@samp{-msingle-float} and @samp{-mdouble-float}).
+
Traditional @sc{mips} assemblers do not support these directives.
+
+@node MIPS Syntax
+@section Syntactical considerations for the MIPS assembler
+@menu
+* MIPS-Chars:: Special Characters
+@end menu
+
+@node MIPS-Chars
+@subsection Special Characters
+
+@cindex line comment character, MIPS
+@cindex MIPS 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{#} appears as the first character of a line, the whole line
+is treated as a comment, but in this case the line can also be a
+logical line number directive (@pxref{Comments}) or a
+preprocessor control command (@pxref{Preprocessing}).
+
+@cindex line separator, MIPS
+@cindex statement separator, MIPS
+@cindex MIPS line separator
+The @samp{;} character can be used to separate statements on the same
+line.
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