@c Copyright (C) 1991-2014 Free Software Foundation, Inc. @c This is part of the GAS manual. @c For copying conditions, see the file as.texinfo. @ifset GENERIC @page @node Sparc-Dependent @chapter SPARC Dependent Features @end ifset @ifclear GENERIC @node Machine Dependencies @chapter SPARC Dependent Features @end ifclear @cindex SPARC support @menu * Sparc-Opts:: Options * Sparc-Aligned-Data:: Option to enforce aligned data * Sparc-Syntax:: Syntax * Sparc-Float:: Floating Point * Sparc-Directives:: Sparc Machine Directives @end menu @node Sparc-Opts @section Options @cindex options for SPARC @cindex SPARC options @cindex architectures, SPARC @cindex SPARC architectures The SPARC chip family includes several successive versions, using the same core instruction set, but including a few additional instructions at each version. There are exceptions to this however. For details on what instructions each variant supports, please see the chip's architecture reference manual. By default, @code{@value{AS}} assumes the core instruction set (SPARC v6), but ``bumps'' the architecture level as needed: it switches to successively higher architectures as it encounters instructions that only exist in the higher levels. If not configured for SPARC v9 (@code{sparc64-*-*}) GAS will not bump past sparclite by default, an option must be passed to enable the v9 instructions. GAS treats sparclite as being compatible with v8, unless an architecture is explicitly requested. SPARC v9 is always incompatible with sparclite. @c The order here is the same as the order of enum sparc_opcode_arch_val @c to give the user a sense of the order of the "bumping". @table @code @kindex -Av6 @kindex -Av7 @kindex -Av8 @kindex -Aleon @kindex -Asparclet @kindex -Asparclite @kindex -Av9 @kindex -Av9a @kindex -Av9b @kindex -Av9c @kindex -Av9d @kindex -Av9e @kindex -Av9v @kindex -Av9m @kindex -Asparc @kindex -Asparcvis @kindex -Asparcvis2 @kindex -Asparcfmaf @kindex -Asparcima @kindex -Asparcvis3 @kindex -Asparcvis3r @item -Av6 | -Av7 | -Av8 | -Aleon | -Asparclet | -Asparclite @itemx -Av8plus | -Av8plusa | -Av8plusb | -Av8plusc | -Av8plusd | -Av8plusv @itemx -Av9 | -Av9a | -Av9b | -Av9c | -Av9d | -Av9e | -Av9v | -Av9m @itemx -Asparc | -Asparcvis | -Asparcvis2 | -Asparcfmaf | -Asparcima @itemx -Asparcvis3 | -Asparcvis3r Use one of the @samp{-A} options to select one of the SPARC architectures explicitly. If you select an architecture explicitly, @code{@value{AS}} reports a fatal error if it encounters an instruction or feature requiring an incompatible or higher level. @samp{-Av8plus}, @samp{-Av8plusa}, @samp{-Av8plusb}, @samp{-Av8plusc}, @samp{-Av8plusd}, and @samp{-Av8plusv} select a 32 bit environment. @samp{-Av9}, @samp{-Av9a}, @samp{-Av9b}, @samp{-Av9c}, @samp{-Av9d}, @samp{-Av9e}, @samp{-Av9v} and @samp{-Av9m} select a 64 bit environment and are not available unless GAS is explicitly configured with 64 bit environment support. @samp{-Av8plusa} and @samp{-Av9a} enable the SPARC V9 instruction set with UltraSPARC VIS 1.0 extensions. @samp{-Av8plusb} and @samp{-Av9b} enable the UltraSPARC VIS 2.0 instructions, as well as the instructions enabled by @samp{-Av8plusa} and @samp{-Av9a}. @samp{-Av8plusc} and @samp{-Av9c} enable the UltraSPARC Niagara instructions, as well as the instructions enabled by @samp{-Av8plusb} and @samp{-Av9b}. @samp{-Av8plusd} and @samp{-Av9d} enable the floating point fused multiply-add, VIS 3.0, and HPC extension instructions, as well as the instructions enabled by @samp{-Av8plusc} and @samp{-Av9c}. @samp{-Av8pluse} and @samp{-Av9e} enable the cryptographic instructions, as well as the instructions enabled by @samp{-Av8plusd} and @samp{-Av9d}. @samp{-Av8plusv} and @samp{-Av9v} enable floating point unfused multiply-add, and integer multiply-add, as well as the instructions enabled by @samp{-Av8pluse} and @samp{-Av9e}. @samp{-Av8plusm} and @samp{-Av9m} enable the VIS 4.0, subtract extended, xmpmul, xmontmul and xmontsqr instructions, as well as the instructions enabled by @samp{-Av8plusv} and @samp{-Av9v}. @samp{-Asparc} specifies a v9 environment. It is equivalent to @samp{-Av9} if the word size is 64-bit, and @samp{-Av8plus} otherwise. @samp{-Asparcvis} specifies a v9a environment. It is equivalent to @samp{-Av9a} if the word size is 64-bit, and @samp{-Av8plusa} otherwise. @samp{-Asparcvis2} specifies a v9b environment. It is equivalent to @samp{-Av9b} if the word size is 64-bit, and @samp{-Av8plusb} otherwise. @samp{-Asparcfmaf} specifies a v9b environment with the floating point fused multiply-add instructions enabled. @samp{-Asparcima} specifies a v9b environment with the integer multiply-add instructions enabled. @samp{-Asparcvis3} specifies a v9b environment with the VIS 3.0, HPC , and floating point fused multiply-add instructions enabled. @samp{-Asparcvis3r} specifies a v9b environment with the VIS 3.0, HPC, and floating point unfused multiply-add instructions enabled. @samp{-Asparc5} is equivalent to @samp{-Av9m}. @item -xarch=v8plus | -xarch=v8plusa | -xarch=v8plusb | -xarch=v8plusc @itemx -xarch=v8plusd | -xarch=v8plusv | -xarch=v9 | -xarch=v9a @itemx -xarch=v9b | -xarch=v9c | -xarch=v9d | -xarch=v9e | -xarch=v9v | -xarch=v9m @itemx -xarch=sparc | -xarch=sparcvis | -xarch=sparcvis2 @itemx -xarch=sparcfmaf | -xarch=sparcima | -xarch=sparcvis3 @itemx -xarch=sparcvis3r | -xarch=sparc5 For compatibility with the SunOS v9 assembler. These options are equivalent to -Av8plus, -Av8plusa, -Av8plusb, -Av8plusc, -Av8plusd, -Av8plusv, -Av9, -Av9a, -Av9b, -Av9c, -Av9d, -Av9e, -Av9v, -Av9m, -Asparc, -Asparcvis, -Asparcvis2, -Asparcfmaf, -Asparcima, -Asparcvis3, and -Asparcvis3r, respectively. @item -bump Warn whenever it is necessary to switch to another level. If an architecture level is explicitly requested, GAS will not issue warnings until that level is reached, and will then bump the level as required (except between incompatible levels). @item -32 | -64 Select the word size, either 32 bits or 64 bits. These options are only available with the ELF object file format, and require that the necessary BFD support has been included. @end table @node Sparc-Aligned-Data @section Enforcing aligned data @cindex data alignment on SPARC @cindex SPARC data alignment SPARC GAS normally permits data to be misaligned. For example, it permits the @code{.long} pseudo-op to be used on a byte boundary. However, the native SunOS assemblers issue an error when they see misaligned data. @kindex --enforce-aligned-data You can use the @code{--enforce-aligned-data} option to make SPARC GAS also issue an error about misaligned data, just as the SunOS assemblers do. The @code{--enforce-aligned-data} option is not the default because gcc issues misaligned data pseudo-ops when it initializes certain packed data structures (structures defined using the @code{packed} attribute). You may have to assemble with GAS in order to initialize packed data structures in your own code. @cindex SPARC syntax @cindex syntax, SPARC @node Sparc-Syntax @section Sparc Syntax The assembler syntax closely follows The Sparc Architecture Manual, versions 8 and 9, as well as most extensions defined by Sun for their UltraSPARC and Niagara line of processors. @menu * Sparc-Chars:: Special Characters * Sparc-Regs:: Register Names * Sparc-Constants:: Constant Names * Sparc-Relocs:: Relocations * Sparc-Size-Translations:: Size Translations @end menu @node Sparc-Chars @subsection Special Characters @cindex line comment character, Sparc @cindex Sparc line comment character A @samp{!} character appearing anywhere on a line indicates the start of a comment that extends to the end of that line. If a @samp{#} appears as the first character of a line then the whole line is treated as a comment, but in this case the line could also be a logical line number directive (@pxref{Comments}) or a preprocessor control command (@pxref{Preprocessing}). @cindex line separator, Sparc @cindex statement separator, Sparc @cindex Sparc line separator @samp{;} can be used instead of a newline to separate statements. @node Sparc-Regs @subsection Register Names @cindex Sparc registers @cindex register names, Sparc The Sparc integer register file is broken down into global, outgoing, local, and incoming. @itemize @bullet @item The 8 global registers are referred to as @samp{%g@var{n}}. @item The 8 outgoing registers are referred to as @samp{%o@var{n}}. @item The 8 local registers are referred to as @samp{%l@var{n}}. @item The 8 incoming registers are referred to as @samp{%i@var{n}}. @item The frame pointer register @samp{%i6} can be referenced using the alias @samp{%fp}. @item The stack pointer register @samp{%o6} can be referenced using the alias @samp{%sp}. @end itemize Floating point registers are simply referred to as @samp{%f@var{n}}. When assembling for pre-V9, only 32 floating point registers are available. For V9 and later there are 64, but there are restrictions when referencing the upper 32 registers. They can only be accessed as double or quad, and thus only even or quad numbered accesses are allowed. For example, @samp{%f34} is a legal floating point register, but @samp{%f35} is not. Certain V9 instructions allow access to ancillary state registers. Most simply they can be referred to as @samp{%asr@var{n}} where @var{n} can be from 16 to 31. However, there are some aliases defined to reference ASR registers defined for various UltraSPARC processors: @itemize @bullet @item The tick compare register is referred to as @samp{%tick_cmpr}. @item The system tick register is referred to as @samp{%stick}. An alias, @samp{%sys_tick}, exists but is deprecated and should not be used by new software. @item The system tick compare register is referred to as @samp{%stick_cmpr}. An alias, @samp{%sys_tick_cmpr}, exists but is deprecated and should not be used by new software. @item The software interrupt register is referred to as @samp{%softint}. @item The set software interrupt register is referred to as @samp{%set_softint}. The mnemonic @samp{%softint_set} is provided as an alias. @item The clear software interrupt register is referred to as @samp{%clear_softint}. The mnemonic @samp{%softint_clear} is provided as an alias. @item The performance instrumentation counters register is referred to as @samp{%pic}. @item The performance control register is referred to as @samp{%pcr}. @item The graphics status register is referred to as @samp{%gsr}. @item The V9 dispatch control register is referred to as @samp{%dcr}. @end itemize Various V9 branch and conditional move instructions allow specification of which set of integer condition codes to test. These are referred to as @samp{%xcc} and @samp{%icc}. In V9, there are 4 sets of floating point condition codes which are referred to as @samp{%fcc@var{n}}. Several special privileged and non-privileged registers exist: @itemize @bullet @item The V9 address space identifier register is referred to as @samp{%asi}. @item The V9 restorable windows register is referred to as @samp{%canrestore}. @item The V9 savable windows register is referred to as @samp{%cansave}. @item The V9 clean windows register is referred to as @samp{%cleanwin}. @item The V9 current window pointer register is referred to as @samp{%cwp}. @item The floating-point queue register is referred to as @samp{%fq}. @item The V8 co-processor queue register is referred to as @samp{%cq}. @item The floating point status register is referred to as @samp{%fsr}. @item The other windows register is referred to as @samp{%otherwin}. @item The V9 program counter register is referred to as @samp{%pc}. @item The V9 next program counter register is referred to as @samp{%npc}. @item The V9 processor interrupt level register is referred to as @samp{%pil}. @item The V9 processor state register is referred to as @samp{%pstate}. @item The trap base address register is referred to as @samp{%tba}. @item The V9 tick register is referred to as @samp{%tick}. @item The V9 trap level is referred to as @samp{%tl}. @item The V9 trap program counter is referred to as @samp{%tpc}. @item The V9 trap next program counter is referred to as @samp{%tnpc}. @item The V9 trap state is referred to as @samp{%tstate}. @item The V9 trap type is referred to as @samp{%tt}. @item The V9 condition codes is referred to as @samp{%ccr}. @item The V9 floating-point registers state is referred to as @samp{%fprs}. @item The V9 version register is referred to as @samp{%ver}. @item The V9 window state register is referred to as @samp{%wstate}. @item The Y register is referred to as @samp{%y}. @item The V8 window invalid mask register is referred to as @samp{%wim}. @item The V8 processor state register is referred to as @samp{%psr}. @item The V9 global register level register is referred to as @samp{%gl}. @end itemize Several special register names exist for hypervisor mode code: @itemize @bullet @item The hyperprivileged processor state register is referred to as @samp{%hpstate}. @item The hyperprivileged trap state register is referred to as @samp{%htstate}. @item The hyperprivileged interrupt pending register is referred to as @samp{%hintp}. @item The hyperprivileged trap base address register is referred to as @samp{%htba}. @item The hyperprivileged implementation version register is referred to as @samp{%hver}. @item The hyperprivileged system tick offset register is referred to as @samp{%hstick_offset}. Note that there is no @samp{%hstick} register, the normal @samp{%stick} is used. @item The hyperprivileged system tick enable register is referred to as @samp{%hstick_enable}. @item The hyperprivileged system tick compare register is referred to as @samp{%hstick_cmpr}. @end itemize @node Sparc-Constants @subsection Constants @cindex Sparc constants @cindex constants, Sparc Several Sparc instructions take an immediate operand field for which mnemonic names exist. Two such examples are @samp{membar} and @samp{prefetch}. Another example are the set of V9 memory access instruction that allow specification of an address space identifier. The @samp{membar} instruction specifies a memory barrier that is the defined by the operand which is a bitmask. The supported mask mnemonics are: @itemize @bullet @item @samp{#Sync} requests that all operations (including nonmemory reference operations) appearing prior to the @code{membar} must have been performed and the effects of any exceptions become visible before any instructions after the @code{membar} may be initiated. This corresponds to @code{membar} cmask field bit 2. @item @samp{#MemIssue} requests that all memory reference operations appearing prior to the @code{membar} must have been performed before any memory operation after the @code{membar} may be initiated. This corresponds to @code{membar} cmask field bit 1. @item @samp{#Lookaside} requests that a store appearing prior to the @code{membar} must complete before any load following the @code{membar} referencing the same address can be initiated. This corresponds to @code{membar} cmask field bit 0. @item @samp{#StoreStore} defines that the effects of all stores appearing prior to the @code{membar} instruction must be visible to all processors before the effect of any stores following the @code{membar}. Equivalent to the deprecated @code{stbar} instruction. This corresponds to @code{membar} mmask field bit 3. @item @samp{#LoadStore} defines all loads appearing prior to the @code{membar} instruction must have been performed before the effect of any stores following the @code{membar} is visible to any other processor. This corresponds to @code{membar} mmask field bit 2. @item @samp{#StoreLoad} defines that the effects of all stores appearing prior to the @code{membar} instruction must be visible to all processors before loads following the @code{membar} may be performed. This corresponds to @code{membar} mmask field bit 1. @item @samp{#LoadLoad} defines that all loads appearing prior to the @code{membar} instruction must have been performed before any loads following the @code{membar} may be performed. This corresponds to @code{membar} mmask field bit 0. @end itemize These values can be ored together, for example: @example membar #Sync membar #StoreLoad | #LoadLoad membar #StoreLoad | #StoreStore @end example The @code{prefetch} and @code{prefetcha} instructions take a prefetch function code. The following prefetch function code constant mnemonics are available: @itemize @bullet @item @samp{#n_reads} requests a prefetch for several reads, and corresponds to a prefetch function code of 0. @samp{#one_read} requests a prefetch for one read, and corresponds to a prefetch function code of 1. @samp{#n_writes} requests a prefetch for several writes (and possibly reads), and corresponds to a prefetch function code of 2. @samp{#one_write} requests a prefetch for one write, and corresponds to a prefetch function code of 3. @samp{#page} requests a prefetch page, and corresponds to a prefetch function code of 4. @samp{#invalidate} requests a prefetch invalidate, and corresponds to a prefetch function code of 16. @samp{#unified} requests a prefetch to the nearest unified cache, and corresponds to a prefetch function code of 17. @samp{#n_reads_strong} requests a strong prefetch for several reads, and corresponds to a prefetch function code of 20. @samp{#one_read_strong} requests a strong prefetch for one read, and corresponds to a prefetch function code of 21. @samp{#n_writes_strong} requests a strong prefetch for several writes, and corresponds to a prefetch function code of 22. @samp{#one_write_strong} requests a strong prefetch for one write, and corresponds to a prefetch function code of 23. Onle one prefetch code may be specified. Here are some examples: @example prefetch [%l0 + %l2], #one_read prefetch [%g2 + 8], #n_writes prefetcha [%g1] 0x8, #unified prefetcha [%o0 + 0x10] %asi, #n_reads @end example The actual behavior of a given prefetch function code is processor specific. If a processor does not implement a given prefetch function code, it will treat the prefetch instruction as a nop. For instructions that accept an immediate address space identifier, @code{@value{AS}} provides many mnemonics corresponding to V9 defined as well as UltraSPARC and Niagara extended values. For example, @samp{#ASI_P} and @samp{#ASI_BLK_INIT_QUAD_LDD_AIUS}. See the V9 and processor specific manuals for details. @end itemize @node Sparc-Relocs @subsection Relocations @cindex Sparc relocations @cindex relocations, Sparc ELF relocations are available as defined in the 32-bit and 64-bit Sparc ELF specifications. @code{R_SPARC_HI22} is obtained using @samp{%hi} and @code{R_SPARC_LO10} is obtained using @samp{%lo}. Likewise @code{R_SPARC_HIX22} is obtained from @samp{%hix} and @code{R_SPARC_LOX10} is obtained using @samp{%lox}. For example: @example sethi %hi(symbol), %g1 or %g1, %lo(symbol), %g1 sethi %hix(symbol), %g1 xor %g1, %lox(symbol), %g1 @end example These ``high'' mnemonics extract bits 31:10 of their operand, and the ``low'' mnemonics extract bits 9:0 of their operand. V9 code model relocations can be requested as follows: @itemize @bullet @item @code{R_SPARC_HH22} is requested using @samp{%hh}. It can also be generated using @samp{%uhi}. @item @code{R_SPARC_HM10} is requested using @samp{%hm}. It can also be generated using @samp{%ulo}. @item @code{R_SPARC_LM22} is requested using @samp{%lm}. @item @code{R_SPARC_H44} is requested using @samp{%h44}. @item @code{R_SPARC_M44} is requested using @samp{%m44}. @item @code{R_SPARC_L44} is requested using @samp{%l44} or @samp{%l34}. @item @code{R_SPARC_H34} is requested using @samp{%h34}. @end itemize The @samp{%l34} generates a @code{R_SPARC_L44} relocation because it calculates the necessary value, and therefore no explicit @code{R_SPARC_L34} relocation needed to be created for this purpose. The @samp{%h34} and @samp{%l34} relocations are used for the abs34 code model. Here is an example abs34 address generation sequence: @example sethi %h34(symbol), %g1 sllx %g1, 2, %g1 or %g1, %l34(symbol), %g1 @end example The PC relative relocation @code{R_SPARC_PC22} can be obtained by enclosing an operand inside of @samp{%pc22}. Likewise, the @code{R_SPARC_PC10} relocation can be obtained using @samp{%pc10}. These are mostly used when assembling PIC code. For example, the standard PIC sequence on Sparc to get the base of the global offset table, PC relative, into a register, can be performed as: @example sethi %pc22(_GLOBAL_OFFSET_TABLE_-4), %l7 add %l7, %pc10(_GLOBAL_OFFSET_TABLE_+4), %l7 @end example Several relocations exist to allow the link editor to potentially optimize GOT data references. The @code{R_SPARC_GOTDATA_OP_HIX22} relocation can obtained by enclosing an operand inside of @samp{%gdop_hix22}. The @code{R_SPARC_GOTDATA_OP_LOX10} relocation can obtained by enclosing an operand inside of @samp{%gdop_lox10}. Likewise, @code{R_SPARC_GOTDATA_OP} can be obtained by enclosing an operand inside of @samp{%gdop}. For example, assuming the GOT base is in register @code{%l7}: @example sethi %gdop_hix22(symbol), %l1 xor %l1, %gdop_lox10(symbol), %l1 ld [%l7 + %l1], %l2, %gdop(symbol) @end example There are many relocations that can be requested for access to thread local storage variables. All of the Sparc TLS mnemonics are supported: @itemize @bullet @item @code{R_SPARC_TLS_GD_HI22} is requested using @samp{%tgd_hi22}. @item @code{R_SPARC_TLS_GD_LO10} is requested using @samp{%tgd_lo10}. @item @code{R_SPARC_TLS_GD_ADD} is requested using @samp{%tgd_add}. @item @code{R_SPARC_TLS_GD_CALL} is requested using @samp{%tgd_call}. @item @code{R_SPARC_TLS_LDM_HI22} is requested using @samp{%tldm_hi22}. @item @code{R_SPARC_TLS_LDM_LO10} is requested using @samp{%tldm_lo10}. @item @code{R_SPARC_TLS_LDM_ADD} is requested using @samp{%tldm_add}. @item @code{R_SPARC_TLS_LDM_CALL} is requested using @samp{%tldm_call}. @item @code{R_SPARC_TLS_LDO_HIX22} is requested using @samp{%tldo_hix22}. @item @code{R_SPARC_TLS_LDO_LOX10} is requested using @samp{%tldo_lox10}. @item @code{R_SPARC_TLS_LDO_ADD} is requested using @samp{%tldo_add}. @item @code{R_SPARC_TLS_IE_HI22} is requested using @samp{%tie_hi22}. @item @code{R_SPARC_TLS_IE_LO10} is requested using @samp{%tie_lo10}. @item @code{R_SPARC_TLS_IE_LD} is requested using @samp{%tie_ld}. @item @code{R_SPARC_TLS_IE_LDX} is requested using @samp{%tie_ldx}. @item @code{R_SPARC_TLS_IE_ADD} is requested using @samp{%tie_add}. @item @code{R_SPARC_TLS_LE_HIX22} is requested using @samp{%tle_hix22}. @item @code{R_SPARC_TLS_LE_LOX10} is requested using @samp{%tle_lox10}. @end itemize Here are some example TLS model sequences. First, General Dynamic: @example sethi %tgd_hi22(symbol), %l1 add %l1, %tgd_lo10(symbol), %l1 add %l7, %l1, %o0, %tgd_add(symbol) call __tls_get_addr, %tgd_call(symbol) nop @end example Local Dynamic: @example sethi %tldm_hi22(symbol), %l1 add %l1, %tldm_lo10(symbol), %l1 add %l7, %l1, %o0, %tldm_add(symbol) call __tls_get_addr, %tldm_call(symbol) nop sethi %tldo_hix22(symbol), %l1 xor %l1, %tldo_lox10(symbol), %l1 add %o0, %l1, %l1, %tldo_add(symbol) @end example Initial Exec: @example sethi %tie_hi22(symbol), %l1 add %l1, %tie_lo10(symbol), %l1 ld [%l7 + %l1], %o0, %tie_ld(symbol) add %g7, %o0, %o0, %tie_add(symbol) sethi %tie_hi22(symbol), %l1 add %l1, %tie_lo10(symbol), %l1 ldx [%l7 + %l1], %o0, %tie_ldx(symbol) add %g7, %o0, %o0, %tie_add(symbol) @end example And finally, Local Exec: @example sethi %tle_hix22(symbol), %l1 add %l1, %tle_lox10(symbol), %l1 add %g7, %l1, %l1 @end example When assembling for 64-bit, and a secondary constant addend is specified in an address expression that would normally generate an @code{R_SPARC_LO10} relocation, the assembler will emit an @code{R_SPARC_OLO10} instead. @node Sparc-Size-Translations @subsection Size Translations @cindex Sparc size translations @cindex size, translations, Sparc Often it is desirable to write code in an operand size agnostic manner. @code{@value{AS}} provides support for this via operand size opcode translations. Translations are supported for loads, stores, shifts, compare-and-swap atomics, and the @samp{clr} synthetic instruction. If generating 32-bit code, @code{@value{AS}} will generate the 32-bit opcode. Whereas if 64-bit code is being generated, the 64-bit opcode will be emitted. For example @code{ldn} will be transformed into @code{ld} for 32-bit code and @code{ldx} for 64-bit code. Here is an example meant to demonstrate all the supported opcode translations: @example ldn [%o0], %o1 ldna [%o0] %asi, %o2 stn %o1, [%o0] stna %o2, [%o0] %asi slln %o3, 3, %o3 srln %o4, 8, %o4 sran %o5, 12, %o5 casn [%o0], %o1, %o2 casna [%o0] %asi, %o1, %o2 clrn %g1 @end example In 32-bit mode @code{@value{AS}} will emit: @example ld [%o0], %o1 lda [%o0] %asi, %o2 st %o1, [%o0] sta %o2, [%o0] %asi sll %o3, 3, %o3 srl %o4, 8, %o4 sra %o5, 12, %o5 cas [%o0], %o1, %o2 casa [%o0] %asi, %o1, %o2 clr %g1 @end example And in 64-bit mode @code{@value{AS}} will emit: @example ldx [%o0], %o1 ldxa [%o0] %asi, %o2 stx %o1, [%o0] stxa %o2, [%o0] %asi sllx %o3, 3, %o3 srlx %o4, 8, %o4 srax %o5, 12, %o5 casx [%o0], %o1, %o2 casxa [%o0] %asi, %o1, %o2 clrx %g1 @end example Finally, the @samp{.nword} translating directive is supported as well. It is documented in the section on Sparc machine directives. @node Sparc-Float @section Floating Point @cindex floating point, SPARC (@sc{ieee}) @cindex SPARC floating point (@sc{ieee}) The Sparc uses @sc{ieee} floating-point numbers. @node Sparc-Directives @section Sparc Machine Directives @cindex SPARC machine directives @cindex machine directives, SPARC The Sparc version of @code{@value{AS}} supports the following additional machine directives: @table @code @cindex @code{align} directive, SPARC @item .align This must be followed by the desired alignment in bytes. @cindex @code{common} directive, SPARC @item .common This must be followed by a symbol name, a positive number, and @code{"bss"}. This behaves somewhat like @code{.comm}, but the syntax is different. @cindex @code{half} directive, SPARC @item .half This is functionally identical to @code{.short}. @cindex @code{nword} directive, SPARC @item .nword On the Sparc, the @code{.nword} directive produces native word sized value, ie. if assembling with -32 it is equivalent to @code{.word}, if assembling with -64 it is equivalent to @code{.xword}. @cindex @code{proc} directive, SPARC @item .proc This directive is ignored. Any text following it on the same line is also ignored. @cindex @code{register} directive, SPARC @item .register This directive declares use of a global application or system register. It must be followed by a register name %g2, %g3, %g6 or %g7, comma and the symbol name for that register. If symbol name is @code{#scratch}, it is a scratch register, if it is @code{#ignore}, it just suppresses any errors about using undeclared global register, but does not emit any information about it into the object file. This can be useful e.g. if you save the register before use and restore it after. @cindex @code{reserve} directive, SPARC @item .reserve This must be followed by a symbol name, a positive number, and @code{"bss"}. This behaves somewhat like @code{.lcomm}, but the syntax is different. @cindex @code{seg} directive, SPARC @item .seg This must be followed by @code{"text"}, @code{"data"}, or @code{"data1"}. It behaves like @code{.text}, @code{.data}, or @code{.data 1}. @cindex @code{skip} directive, SPARC @item .skip This is functionally identical to the @code{.space} directive. @cindex @code{word} directive, SPARC @item .word On the Sparc, the @code{.word} directive produces 32 bit values, instead of the 16 bit values it produces on many other machines. @cindex @code{xword} directive, SPARC @item .xword On the Sparc V9 processor, the @code{.xword} directive produces 64 bit values. @end table