-@c Copyright (C) 1991, 92, 93, 94, 95, 1997 Free Software Foundation, Inc.
+@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1999, 2000, 2001,
+@c 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+@c Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
@ifset GENERIC
@cindex MIPS processor
@sc{gnu} @code{@value{AS}} for @sc{mips} architectures supports several
-different @sc{mips} processors, and MIPS ISA levels I through IV. For
-information about the @sc{mips} instruction set, see @cite{MIPS RISC
-Architecture}, by Kane and Heindrich (Prentice-Hall). For an overview
-of @sc{mips} assembly conventions, see ``Appendix D: Assembly Language
-Programming'' in the same work.
+different @sc{mips} processors, and MIPS ISA levels I through V, MIPS32,
+and MIPS64. For information about the @sc{mips} instruction set, see
+@cite{MIPS RISC Architecture}, by Kane and Heindrich (Prentice-Hall).
+For an overview of @sc{mips} assembly conventions, see ``Appendix D:
+Assembly Language Programming'' in the same work.
@menu
* MIPS Opts:: Assembler options
* MIPS Object:: ECOFF object code
* MIPS Stabs:: Directives for debugging information
* MIPS ISA:: Directives to override the ISA level
+* MIPS symbol sizes:: Directives to override the size of symbols
* MIPS autoextend:: Directives for extending MIPS 16 bit instructions
* MIPS insn:: Directive to mark data as an instruction
* 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
@end menu
@node MIPS Opts
tools, which must be configured for one or the other). Use @samp{-EB}
to select big-endian output, and @samp{-EL} for little-endian.
+@item -KPIC
+@cindex PIC selection, MIPS
+@cindex @option{-KPIC} option, MIPS
+Generate SVR4-style PIC. This option tells the assembler to generate
+SVR4-style position-independent macro expansions. It also tells the
+assembler to mark the output file as PIC.
+
+@item -mvxworks-pic
+@cindex @option{-mvxworks-pic} option, MIPS
+Generate VxWorks PIC. This option tells the assembler to generate
+VxWorks-style position-independent macro expansions.
+
@cindex MIPS architecture options
@item -mips1
@itemx -mips2
@itemx -mips3
@itemx -mips4
+@itemx -mips5xo
+@itemx -mips32
+@itemx -mips32r2
+@itemx -mips64
+@itemx -mips64r2
Generate code for a particular MIPS Instruction Set Architecture level.
@samp{-mips1} corresponds to the @sc{r2000} and @sc{r3000} processors,
@samp{-mips2} to the @sc{r6000} processor, @samp{-mips3} to the
@sc{r4000} processor, and @samp{-mips4} to the @sc{r8000} and
-@sc{r10000} processors. You can also switch instruction sets during the
-assembly; see @ref{MIPS ISA,, Directives to override the ISA level}.
+@sc{r10000} processors. @samp{-mips5}, @samp{-mips32}, @samp{-mips32r2},
+@samp{-mips64}, and @samp{-mips64r2}
+correspond to generic
+@sc{MIPS V}, @sc{MIPS32}, @sc{MIPS32 Release 2}, @sc{MIPS64},
+and @sc{MIPS64 Release 2}
+ISA processors, respectively. You can also switch
+instruction sets during the assembly; see @ref{MIPS ISA, Directives to
+override the ISA level}.
@item -mgp32
-Assume that 32-bit general purpose registers are available. This
-affects synthetic instructions such as @code{move}, which will assemble
-to a 32-bit or a 64-bit instruction depending on this flag. On some
-MIPS variants there is a 32-bit mode flag; when this flag is set,
-64-bit instructions generate a trap. Also, some 32-bit OSes only save
-the 32-bit registers on a context switch, so it is essential never to
-use the 64-bit registers.
+@itemx -mfp32
+Some macros have different expansions for 32-bit and 64-bit registers.
+The register sizes are normally inferred from the ISA and ABI, but these
+flags force a certain group of registers to be treated as 32 bits wide at
+all times. @samp{-mgp32} controls the size of general-purpose registers
+and @samp{-mfp32} controls the size of floating-point registers.
+
+The @code{.set gp=32} and @code{.set fp=32} directives allow the size
+of registers to be changed for parts of an object. The default value is
+restored by @code{.set gp=default} and @code{.set fp=default}.
+
+On some MIPS variants there is a 32-bit mode flag; when this flag is
+set, 64-bit instructions generate a trap. Also, some 32-bit OSes only
+save the 32-bit registers on a context switch, so it is essential never
+to use the 64-bit registers.
@item -mgp64
-Assume that 64-bit general purpose registers are available. This is
-provided in the interests of symmetry with -gp32.
+@itemx -mfp64
+Assume that 64-bit registers are available. This is provided in the
+interests of symmetry with @samp{-mgp32} and @samp{-mfp32}.
+
+The @code{.set gp=64} and @code{.set fp=64} directives allow the size
+of registers to be changed for parts of an object. The default value is
+restored by @code{.set gp=default} and @code{.set fp=default}.
@item -mips16
@itemx -no-mips16
Generate code for the MIPS 16 processor. This is equivalent to putting
-@samp{.set mips16} at the start of the assembly file. @samp{-no-mips16}
+@code{.set mips16} at the start of the assembly file. @samp{-no-mips16}
turns off this option.
+@item -msmartmips
+@itemx -mno-smartmips
+Enables the SmartMIPS extensions to the MIPS32 instruction set, which
+provides a number of new instructions which target smartcard and
+cryptographic applications. This is equivalent to putting
+@code{.set smartmips} at the start of the assembly file.
+@samp{-mno-smartmips} turns off this option.
+
+@item -mips3d
+@itemx -no-mips3d
+Generate code for the MIPS-3D Application Specific Extension.
+This tells the assembler to accept MIPS-3D instructions.
+@samp{-no-mips3d} turns off this option.
+
+@item -mdmx
+@itemx -no-mdmx
+Generate code for the MDMX Application Specific Extension.
+This tells the assembler to accept MDMX instructions.
+@samp{-no-mdmx} turns off this option.
+
+@item -mdsp
+@itemx -mno-dsp
+Generate code for the DSP Release 1 Application Specific Extension.
+This tells the assembler to accept DSP Release 1 instructions.
+@samp{-mno-dsp} turns off this option.
+
+@item -mdspr2
+@itemx -mno-dspr2
+Generate code for the DSP Release 2 Application Specific Extension.
+This option implies -mdsp.
+This tells the assembler to accept DSP Release 2 instructions.
+@samp{-mno-dspr2} turns off this option.
+
+@item -mmt
+@itemx -mno-mt
+Generate code for the MT Application Specific Extension.
+This tells the assembler to accept MT instructions.
+@samp{-mno-mt} turns off this option.
+
@item -mfix7000
-@itemx -no-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 -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 -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
@sc{r@var{nnnn}} chip. This tells the assembler to accept instructions
specific to that chip, and to schedule for that chip's hazards.
-@item -mcpu=@var{cpu}
+@item -march=@var{cpu}
Generate code for a particular MIPS cpu. It is exactly equivalent to
@samp{-m@var{cpu}}, except that there are more value of @var{cpu}
understood. Valid @var{cpu} value are:
4010,
4100,
4111,
+vr4120,
+vr4130,
+vr4181,
4300,
4400,
4600,
rm5231,
rm5261,
rm5721,
+vr5400,
+vr5500,
6000,
rm7000,
8000,
-10000
+rm9000,
+10000,
+12000,
+14000,
+16000,
+4kc,
+4km,
+4kp,
+4ksc,
+4kec,
+4kem,
+4kep,
+4ksd,
+m4k,
+m4kp,
+24kc,
+24kf2_1,
+24kf,
+24kf1_1,
+24kec,
+24kef2_1,
+24kef,
+24kef1_1,
+34kc,
+34kf2_1,
+34kf,
+34kf1_1,
+74kc,
+74kf2_1,
+74kf,
+74kf1_1,
+74kf3_2,
+1004kc,
+1004kf2_1,
+1004kf,
+1004kf1_1,
+5kc,
+5kf,
+20kc,
+25kf,
+sb1,
+sb1a,
+loongson2e,
+loongson2f,
+octeon,
+xlr
@end quotation
+For compatibility reasons, @samp{@var{n}x} and @samp{@var{b}fx} are
+accepted as synonyms for @samp{@var{n}f1_1}. These values are
+deprecated.
+
+@item -mtune=@var{cpu}
+Schedule and tune for a particular MIPS cpu. Valid @var{cpu} values are
+identical to @samp{-march=@var{cpu}}.
+
+@item -mabi=@var{abi}
+Record which ABI the source code uses. The recognized arguments
+are: @samp{32}, @samp{n32}, @samp{o64}, @samp{64} and @samp{eabi}.
+
+@item -msym32
+@itemx -mno-sym32
+@cindex -msym32
+@cindex -mno-sym32
+Equivalent to adding @code{.set sym32} or @code{.set nosym32} to
+the beginning of the assembler input. @xref{MIPS symbol sizes}.
@cindex @code{-nocpp} ignored (MIPS)
@item -nocpp
@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
+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
+the double width register. This feature is useful if the processor
+support the FR bit in its status register, and this bit is known (by
+the programmer) to be set. This bit prevents the aliasing of the double
+width register by the single width registers.
+
+By default @code{--construct-floats} is selected, allowing construction
+of these floating point constants.
+
@item --trap
@itemx --no-break
@c FIXME! (1) reflect these options (next item too) in option summaries;
@itemx --no-trap
Generate code to take a break exception rather than a trap exception when an
error is detected. This is the default.
+
+@item -mpdr
+@itemx -mno-pdr
+Control generation of @code{.pdr} sections. Off by default on IRIX, on
+elsewhere.
+
+@item -mshared
+@itemx -mno-shared
+When generating code using the Unix calling conventions (selected by
+@samp{-KPIC} or @samp{-mcall_shared}), gas will normally generate code
+which can go into a shared library. The @samp{-mno-shared} option
+tells gas to generate code which uses the calling convention, but can
+not go into a shared library. The resulting code is slightly more
+efficient. This option only affects the handling of the
+@samp{.cpload} and @samp{.cpsetup} pseudo-ops.
@end table
@node MIPS Object
support C++ debugging). These directives are primarily used by compilers, not
assembly language programmers!
+@node MIPS symbol sizes
+@section Directives to override the size of symbols
+
+@cindex @code{.set sym32}
+@cindex @code{.set nosym32}
+The n64 ABI allows symbols to have any 64-bit value. Although this
+provides a great deal of flexibility, it means that some macros have
+much longer expansions than their 32-bit counterparts. For example,
+the non-PIC expansion of @samp{dla $4,sym} is usually:
+
+@smallexample
+lui $4,%highest(sym)
+lui $1,%hi(sym)
+daddiu $4,$4,%higher(sym)
+daddiu $1,$1,%lo(sym)
+dsll32 $4,$4,0
+daddu $4,$4,$1
+@end smallexample
+
+whereas the 32-bit expansion is simply:
+
+@smallexample
+lui $4,%hi(sym)
+daddiu $4,$4,%lo(sym)
+@end smallexample
+
+n64 code is sometimes constructed in such a way that all symbolic
+constants are known to have 32-bit values, and in such cases, it's
+preferable to use the 32-bit expansion instead of the 64-bit
+expansion.
+
+You can use the @code{.set sym32} directive to tell the assembler
+that, from this point on, all expressions of the form
+@samp{@var{symbol}} or @samp{@var{symbol} + @var{offset}}
+have 32-bit values. For example:
+
+@smallexample
+.set sym32
+dla $4,sym
+lw $4,sym+16
+sw $4,sym+0x8000($4)
+@end smallexample
+
+will cause the assembler to treat @samp{sym}, @code{sym+16} and
+@code{sym+0x8000} as 32-bit values. The handling of non-symbolic
+addresses is not affected.
+
+The directive @code{.set nosym32} ends a @code{.set sym32} block and
+reverts to the normal behavior. It is also possible to change the
+symbol size using the command-line options @option{-msym32} and
+@option{-mno-sym32}.
+
+These options and directives are always accepted, but at present,
+they have no effect for anything other than n64.
+
@node MIPS ISA
@section Directives to override the ISA level
@kindex @code{.set mips@var{n}}
@sc{gnu} @code{@value{AS}} supports an additional directive to change
the @sc{mips} Instruction Set Architecture level on the fly: @code{.set
-mips@var{n}}. @var{n} should be a number from 0 to 4. A value from 1
-to 4 makes the assembler accept instructions for the corresponding
-@sc{isa} level, from that point on in the assembly. @code{.set
-mips@var{n}} affects not only which instructions are permitted, but also
-how certain macros are expanded. @code{.set mips0} restores the
-@sc{isa} level to its original level: either the level you selected with
-command line options, or the default for your configuration. You can
-use this feature to permit specific @sc{r4000} instructions while
-assembling in 32 bit mode. Use this directive with care!
-
-The directive @samp{.set mips16} puts the assembler into MIPS 16 mode,
+mips@var{n}}. @var{n} should be a number from 0 to 5, or 32, 32r2, 64
+or 64r2.
+The values other than 0 make the assembler accept instructions
+for the corresponding @sc{isa} level, from that point on in the
+assembly. @code{.set mips@var{n}} affects not only which instructions
+are permitted, but also how certain macros are expanded. @code{.set
+mips0} restores the @sc{isa} level to its original level: either the
+level you selected with command line options, or the default for your
+configuration. You can use this feature to permit specific @sc{mips3}
+instructions while assembling in 32 bit mode. Use this directive with
+care!
+
+@cindex MIPS CPU override
+@kindex @code{.set arch=@var{cpu}}
+The @code{.set arch=@var{cpu}} directive provides even finer control.
+It changes the effective CPU target and allows the assembler to use
+instructions specific to a particular CPU. All CPUs supported by the
+@samp{-march} command line option are also selectable by this directive.
+The original value is restored by @code{.set arch=default}.
+
+The directive @code{.set mips16} puts the assembler into MIPS 16 mode,
in which it will assemble instructions for the MIPS 16 processor. Use
-@samp{.set nomips16} to return to normal 32 bit mode.
+@code{.set nomips16} to return to normal 32 bit mode.
-Traditional @sc{mips} assemblers do not support this directive.
+Traditional @sc{mips} assemblers do not support this directive.
@node MIPS autoextend
@section Directives for extending MIPS 16 bit instructions
@kindex @code{.set autoextend}
@kindex @code{.set noautoextend}
By default, MIPS 16 instructions are automatically extended to 32 bits
-when necessary. The directive @samp{.set noautoextend} will turn this
-off. When @samp{.set noautoextend} is in effect, any 32 bit instruction
-must be explicitly extended with the @samp{.e} modifier (e.g.,
-@samp{li.e $4,1000}). The directive @samp{.set autoextend} may be used
+when necessary. The directive @code{.set noautoextend} will turn this
+off. When @code{.set noautoextend} is in effect, any 32 bit instruction
+must be explicitly extended with the @code{.e} modifier (e.g.,
+@code{li.e $4,1000}). The directive @code{.set autoextend} may be used
to once again automatically extend instructions when necessary.
This directive is only meaningful when in MIPS 16 mode. Traditional
@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
to change the state of the code which invoked the macro.
Traditional @sc{mips} assemblers do not support these directives.
+
+@node MIPS ASE instruction generation overrides
+@section Directives to control generation of MIPS ASE instructions
+
+@cindex MIPS MIPS-3D instruction generation override
+@kindex @code{.set mips3d}
+@kindex @code{.set nomips3d}
+The directive @code{.set mips3d} makes the assembler accept instructions
+from the MIPS-3D Application Specific Extension from that point on
+in the assembly. The @code{.set nomips3d} directive prevents MIPS-3D
+instructions from being accepted.
+
+@cindex SmartMIPS instruction generation override
+@kindex @code{.set smartmips}
+@kindex @code{.set nosmartmips}
+The directive @code{.set smartmips} makes the assembler accept
+instructions from the SmartMIPS Application Specific Extension to the
+MIPS32 @sc{isa} from that point on in the assembly. The
+@code{.set nosmartmips} directive prevents SmartMIPS instructions from
+being accepted.
+
+@cindex MIPS MDMX instruction generation override
+@kindex @code{.set mdmx}
+@kindex @code{.set nomdmx}
+The directive @code{.set mdmx} makes the assembler accept instructions
+from the MDMX Application Specific Extension from that point on
+in the assembly. The @code{.set nomdmx} directive prevents MDMX
+instructions from being accepted.
+
+@cindex MIPS DSP Release 1 instruction generation override
+@kindex @code{.set dsp}
+@kindex @code{.set nodsp}
+The directive @code{.set dsp} makes the assembler accept instructions
+from the DSP Release 1 Application Specific Extension from that point
+on in the assembly. The @code{.set nodsp} directive prevents DSP
+Release 1 instructions from being accepted.
+
+@cindex MIPS DSP Release 2 instruction generation override
+@kindex @code{.set dspr2}
+@kindex @code{.set nodspr2}
+The directive @code{.set dspr2} makes the assembler accept instructions
+from the DSP Release 2 Application Specific Extension from that point
+on in the assembly. This dirctive implies @code{.set dsp}. The
+@code{.set nodspr2} directive prevents DSP Release 2 instructions from
+being accepted.
+
+@cindex MIPS MT instruction generation override
+@kindex @code{.set mt}
+@kindex @code{.set nomt}
+The directive @code{.set mt} makes the assembler accept instructions
+from the MT Application Specific Extension from that point on
+in the assembly. The @code{.set nomt} directive prevents MT
+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.