-@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1999, 2000
+@c Copyright 1991, 1992, 1993, 1994, 1995, 1997, 1999, 2000, 2001,
+@c 2002, 2003, 2004
@c Free Software Foundation, Inc.
@c This is part of the GAS manual.
@c For copying conditions, see the file as.texinfo.
* 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
@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. @samp{-mips5}, @samp{-mips32}, @samp{-mips32r2}, and
-@samp{-mips64} correspond to generic @sc{MIPS V}, @sc{MIPS32},
-@sc{MIPS32 Release 2}, and
-@sc{MIPS64} ISA processors, respectively. You can also switch
+@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}.
This tells the assembler to accept MDMX instructions.
@samp{-no-mdmx} 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 -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-vr4122-bugs
-@itemx -no-mfix-vr4122-bugs
-Insert @samp{nop} instructions to avoid errors in certain versions of
-the vr4122 core. This option is intended to be used on GCC-generated
-code: it is not designed to catch errors in hand-written assembler code.
+@item -mfix-vr4120
+@itemx -no-mfix-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
+Insert nops to work around the VR4130 @samp{mflo}/@samp{mfhi} errata.
@item -m4010
@itemx -no-m4010
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
This option is ignored. It is accepted for command-line compatibility with
Generate code to take a break exception rather than a trap exception when an
error is detected. This is the default.
-@item -n
-When this option is used, @code{@value{AS}} will issue a warning every
-time it generates a nop instruction from a macro.
+@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 5, or 32, 32r2, or 64.
+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
in the assembly. The @code{.set nomdmx} directive prevents MDMX
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.
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