1 @c Copyright (C) 1991-2015 Free Software Foundation, Inc.
2 @c This is part of the GAS manual.
3 @c For copying conditions, see the file as.texinfo.
7 @chapter SPARC Dependent Features
10 @node Machine Dependencies
11 @chapter SPARC Dependent Features
16 * Sparc-Opts:: Options
17 * Sparc-Aligned-Data:: Option to enforce aligned data
18 * Sparc-Syntax:: Syntax
19 * Sparc-Float:: Floating Point
20 * Sparc-Directives:: Sparc Machine Directives
26 @cindex options for SPARC
28 @cindex architectures, SPARC
29 @cindex SPARC architectures
30 The SPARC chip family includes several successive versions, using the same
31 core instruction set, but including a few additional instructions at
32 each version. There are exceptions to this however. For details on what
33 instructions each variant supports, please see the chip's architecture
36 By default, @code{@value{AS}} assumes the core instruction set (SPARC
37 v6), but ``bumps'' the architecture level as needed: it switches to
38 successively higher architectures as it encounters instructions that
39 only exist in the higher levels.
41 If not configured for SPARC v9 (@code{sparc64-*-*}) GAS will not bump
42 past sparclite by default, an option must be passed to enable the
45 GAS treats sparclite as being compatible with v8, unless an architecture
46 is explicitly requested. SPARC v9 is always incompatible with sparclite.
48 @c The order here is the same as the order of enum sparc_opcode_arch_val
49 @c to give the user a sense of the order of the "bumping".
73 @item -Av6 | -Av7 | -Av8 | -Aleon | -Asparclet | -Asparclite
74 @itemx -Av8plus | -Av8plusa | -Av8plusb | -Av8plusc | -Av8plusd | -Av8plusv
75 @itemx -Av9 | -Av9a | -Av9b | -Av9c | -Av9d | -Av9e | -Av9v | -Av9m
76 @itemx -Asparc | -Asparcvis | -Asparcvis2 | -Asparcfmaf | -Asparcima
77 @itemx -Asparcvis3 | -Asparcvis3r
78 Use one of the @samp{-A} options to select one of the SPARC
79 architectures explicitly. If you select an architecture explicitly,
80 @code{@value{AS}} reports a fatal error if it encounters an instruction
81 or feature requiring an incompatible or higher level.
83 @samp{-Av8plus}, @samp{-Av8plusa}, @samp{-Av8plusb}, @samp{-Av8plusc},
84 @samp{-Av8plusd}, and @samp{-Av8plusv} select a 32 bit environment.
86 @samp{-Av9}, @samp{-Av9a}, @samp{-Av9b}, @samp{-Av9c}, @samp{-Av9d},
87 @samp{-Av9e}, @samp{-Av9v} and @samp{-Av9m} select a 64 bit
88 environment and are not available unless GAS is explicitly configured
89 with 64 bit environment support.
91 @samp{-Av8plusa} and @samp{-Av9a} enable the SPARC V9 instruction set with
92 UltraSPARC VIS 1.0 extensions.
94 @samp{-Av8plusb} and @samp{-Av9b} enable the UltraSPARC VIS 2.0 instructions,
95 as well as the instructions enabled by @samp{-Av8plusa} and @samp{-Av9a}.
97 @samp{-Av8plusc} and @samp{-Av9c} enable the UltraSPARC Niagara instructions,
98 as well as the instructions enabled by @samp{-Av8plusb} and @samp{-Av9b}.
100 @samp{-Av8plusd} and @samp{-Av9d} enable the floating point fused
101 multiply-add, VIS 3.0, and HPC extension instructions, as well as the
102 instructions enabled by @samp{-Av8plusc} and @samp{-Av9c}.
104 @samp{-Av8pluse} and @samp{-Av9e} enable the cryptographic
105 instructions, as well as the instructions enabled by @samp{-Av8plusd}
108 @samp{-Av8plusv} and @samp{-Av9v} enable floating point unfused
109 multiply-add, and integer multiply-add, as well as the instructions
110 enabled by @samp{-Av8pluse} and @samp{-Av9e}.
112 @samp{-Av8plusm} and @samp{-Av9m} enable the VIS 4.0, subtract extended,
113 xmpmul, xmontmul and xmontsqr instructions, as well as the instructions
114 enabled by @samp{-Av8plusv} and @samp{-Av9v}.
116 @samp{-Asparc} specifies a v9 environment. It is equivalent to
117 @samp{-Av9} if the word size is 64-bit, and @samp{-Av8plus} otherwise.
119 @samp{-Asparcvis} specifies a v9a environment. It is equivalent to
120 @samp{-Av9a} if the word size is 64-bit, and @samp{-Av8plusa} otherwise.
122 @samp{-Asparcvis2} specifies a v9b environment. It is equivalent to
123 @samp{-Av9b} if the word size is 64-bit, and @samp{-Av8plusb} otherwise.
125 @samp{-Asparcfmaf} specifies a v9b environment with the floating point
126 fused multiply-add instructions enabled.
128 @samp{-Asparcima} specifies a v9b environment with the integer
129 multiply-add instructions enabled.
131 @samp{-Asparcvis3} specifies a v9b environment with the VIS 3.0,
132 HPC , and floating point fused multiply-add instructions enabled.
134 @samp{-Asparcvis3r} specifies a v9b environment with the VIS 3.0, HPC,
135 and floating point unfused multiply-add instructions enabled.
137 @samp{-Asparc5} is equivalent to @samp{-Av9m}.
139 @item -xarch=v8plus | -xarch=v8plusa | -xarch=v8plusb | -xarch=v8plusc
140 @itemx -xarch=v8plusd | -xarch=v8plusv | -xarch=v9 | -xarch=v9a
141 @itemx -xarch=v9b | -xarch=v9c | -xarch=v9d | -xarch=v9e | -xarch=v9v | -xarch=v9m
142 @itemx -xarch=sparc | -xarch=sparcvis | -xarch=sparcvis2
143 @itemx -xarch=sparcfmaf | -xarch=sparcima | -xarch=sparcvis3
144 @itemx -xarch=sparcvis3r | -xarch=sparc5
145 For compatibility with the SunOS v9 assembler. These options are
146 equivalent to -Av8plus, -Av8plusa, -Av8plusb, -Av8plusc, -Av8plusd,
147 -Av8plusv, -Av9, -Av9a, -Av9b, -Av9c, -Av9d, -Av9e, -Av9v, -Av9m,
148 -Asparc, -Asparcvis, -Asparcvis2, -Asparcfmaf, -Asparcima,
149 -Asparcvis3, and -Asparcvis3r, respectively.
152 Warn whenever it is necessary to switch to another level.
153 If an architecture level is explicitly requested, GAS will not issue
154 warnings until that level is reached, and will then bump the level
155 as required (except between incompatible levels).
158 Select the word size, either 32 bits or 64 bits.
159 These options are only available with the ELF object file format,
160 and require that the necessary BFD support has been included.
163 @node Sparc-Aligned-Data
164 @section Enforcing aligned data
166 @cindex data alignment on SPARC
167 @cindex SPARC data alignment
168 SPARC GAS normally permits data to be misaligned. For example, it
169 permits the @code{.long} pseudo-op to be used on a byte boundary.
170 However, the native SunOS assemblers issue an error when they see
173 @kindex --enforce-aligned-data
174 You can use the @code{--enforce-aligned-data} option to make SPARC GAS
175 also issue an error about misaligned data, just as the SunOS
178 The @code{--enforce-aligned-data} option is not the default because gcc
179 issues misaligned data pseudo-ops when it initializes certain packed
180 data structures (structures defined using the @code{packed} attribute).
181 You may have to assemble with GAS in order to initialize packed data
182 structures in your own code.
185 @cindex syntax, SPARC
187 @section Sparc Syntax
188 The assembler syntax closely follows The Sparc Architecture Manual,
189 versions 8 and 9, as well as most extensions defined by Sun
190 for their UltraSPARC and Niagara line of processors.
193 * Sparc-Chars:: Special Characters
194 * Sparc-Regs:: Register Names
195 * Sparc-Constants:: Constant Names
196 * Sparc-Relocs:: Relocations
197 * Sparc-Size-Translations:: Size Translations
201 @subsection Special Characters
203 @cindex line comment character, Sparc
204 @cindex Sparc line comment character
205 A @samp{!} character appearing anywhere on a line indicates the start
206 of a comment that extends to the end of that line.
208 If a @samp{#} appears as the first character of a line then the whole
209 line is treated as a comment, but in this case the line could also be
210 a logical line number directive (@pxref{Comments}) or a preprocessor
211 control command (@pxref{Preprocessing}).
213 @cindex line separator, Sparc
214 @cindex statement separator, Sparc
215 @cindex Sparc line separator
216 @samp{;} can be used instead of a newline to separate statements.
219 @subsection Register Names
220 @cindex Sparc registers
221 @cindex register names, Sparc
223 The Sparc integer register file is broken down into global,
224 outgoing, local, and incoming.
228 The 8 global registers are referred to as @samp{%g@var{n}}.
231 The 8 outgoing registers are referred to as @samp{%o@var{n}}.
234 The 8 local registers are referred to as @samp{%l@var{n}}.
237 The 8 incoming registers are referred to as @samp{%i@var{n}}.
240 The frame pointer register @samp{%i6} can be referenced using
241 the alias @samp{%fp}.
244 The stack pointer register @samp{%o6} can be referenced using
245 the alias @samp{%sp}.
248 Floating point registers are simply referred to as @samp{%f@var{n}}.
249 When assembling for pre-V9, only 32 floating point registers
250 are available. For V9 and later there are 64, but there are
251 restrictions when referencing the upper 32 registers. They
252 can only be accessed as double or quad, and thus only even
253 or quad numbered accesses are allowed. For example, @samp{%f34}
254 is a legal floating point register, but @samp{%f35} is not.
256 Certain V9 instructions allow access to ancillary state registers.
257 Most simply they can be referred to as @samp{%asr@var{n}} where
258 @var{n} can be from 16 to 31. However, there are some aliases
259 defined to reference ASR registers defined for various UltraSPARC
264 The tick compare register is referred to as @samp{%tick_cmpr}.
267 The system tick register is referred to as @samp{%stick}. An alias,
268 @samp{%sys_tick}, exists but is deprecated and should not be used
272 The system tick compare register is referred to as @samp{%stick_cmpr}.
273 An alias, @samp{%sys_tick_cmpr}, exists but is deprecated and should
274 not be used by new software.
277 The software interrupt register is referred to as @samp{%softint}.
280 The set software interrupt register is referred to as @samp{%set_softint}.
281 The mnemonic @samp{%softint_set} is provided as an alias.
284 The clear software interrupt register is referred to as
285 @samp{%clear_softint}. The mnemonic @samp{%softint_clear} is provided
289 The performance instrumentation counters register is referred to as
293 The performance control register is referred to as @samp{%pcr}.
296 The graphics status register is referred to as @samp{%gsr}.
299 The V9 dispatch control register is referred to as @samp{%dcr}.
302 Various V9 branch and conditional move instructions allow
303 specification of which set of integer condition codes to
304 test. These are referred to as @samp{%xcc} and @samp{%icc}.
306 In V9, there are 4 sets of floating point condition codes
307 which are referred to as @samp{%fcc@var{n}}.
309 Several special privileged and non-privileged registers
314 The V9 address space identifier register is referred to as @samp{%asi}.
317 The V9 restorable windows register is referred to as @samp{%canrestore}.
320 The V9 savable windows register is referred to as @samp{%cansave}.
323 The V9 clean windows register is referred to as @samp{%cleanwin}.
326 The V9 current window pointer register is referred to as @samp{%cwp}.
329 The floating-point queue register is referred to as @samp{%fq}.
332 The V8 co-processor queue register is referred to as @samp{%cq}.
335 The floating point status register is referred to as @samp{%fsr}.
338 The other windows register is referred to as @samp{%otherwin}.
341 The V9 program counter register is referred to as @samp{%pc}.
344 The V9 next program counter register is referred to as @samp{%npc}.
347 The V9 processor interrupt level register is referred to as @samp{%pil}.
350 The V9 processor state register is referred to as @samp{%pstate}.
353 The trap base address register is referred to as @samp{%tba}.
356 The V9 tick register is referred to as @samp{%tick}.
359 The V9 trap level is referred to as @samp{%tl}.
362 The V9 trap program counter is referred to as @samp{%tpc}.
365 The V9 trap next program counter is referred to as @samp{%tnpc}.
368 The V9 trap state is referred to as @samp{%tstate}.
371 The V9 trap type is referred to as @samp{%tt}.
374 The V9 condition codes is referred to as @samp{%ccr}.
377 The V9 floating-point registers state is referred to as @samp{%fprs}.
380 The V9 version register is referred to as @samp{%ver}.
383 The V9 window state register is referred to as @samp{%wstate}.
386 The Y register is referred to as @samp{%y}.
389 The V8 window invalid mask register is referred to as @samp{%wim}.
392 The V8 processor state register is referred to as @samp{%psr}.
395 The V9 global register level register is referred to as @samp{%gl}.
398 Several special register names exist for hypervisor mode code:
402 The hyperprivileged processor state register is referred to as
406 The hyperprivileged trap state register is referred to as @samp{%htstate}.
409 The hyperprivileged interrupt pending register is referred to as
413 The hyperprivileged trap base address register is referred to as
417 The hyperprivileged implementation version register is referred
421 The hyperprivileged system tick offset register is referred to as
422 @samp{%hstick_offset}. Note that there is no @samp{%hstick} register,
423 the normal @samp{%stick} is used.
426 The hyperprivileged system tick enable register is referred to as
427 @samp{%hstick_enable}.
430 The hyperprivileged system tick compare register is referred
431 to as @samp{%hstick_cmpr}.
434 @node Sparc-Constants
435 @subsection Constants
436 @cindex Sparc constants
437 @cindex constants, Sparc
439 Several Sparc instructions take an immediate operand field for
440 which mnemonic names exist. Two such examples are @samp{membar}
441 and @samp{prefetch}. Another example are the set of V9
442 memory access instruction that allow specification of an
443 address space identifier.
445 The @samp{membar} instruction specifies a memory barrier that is
446 the defined by the operand which is a bitmask. The supported
451 @samp{#Sync} requests that all operations (including nonmemory
452 reference operations) appearing prior to the @code{membar} must have
453 been performed and the effects of any exceptions become visible before
454 any instructions after the @code{membar} may be initiated. This
455 corresponds to @code{membar} cmask field bit 2.
458 @samp{#MemIssue} requests that all memory reference operations
459 appearing prior to the @code{membar} must have been performed before
460 any memory operation after the @code{membar} may be initiated. This
461 corresponds to @code{membar} cmask field bit 1.
464 @samp{#Lookaside} requests that a store appearing prior to the
465 @code{membar} must complete before any load following the
466 @code{membar} referencing the same address can be initiated. This
467 corresponds to @code{membar} cmask field bit 0.
470 @samp{#StoreStore} defines that the effects of all stores appearing
471 prior to the @code{membar} instruction must be visible to all
472 processors before the effect of any stores following the
473 @code{membar}. Equivalent to the deprecated @code{stbar} instruction.
474 This corresponds to @code{membar} mmask field bit 3.
477 @samp{#LoadStore} defines all loads appearing prior to the
478 @code{membar} instruction must have been performed before the effect
479 of any stores following the @code{membar} is visible to any other
480 processor. This corresponds to @code{membar} mmask field bit 2.
483 @samp{#StoreLoad} defines that the effects of all stores appearing
484 prior to the @code{membar} instruction must be visible to all
485 processors before loads following the @code{membar} may be performed.
486 This corresponds to @code{membar} mmask field bit 1.
489 @samp{#LoadLoad} defines that all loads appearing prior to the
490 @code{membar} instruction must have been performed before any loads
491 following the @code{membar} may be performed. This corresponds to
492 @code{membar} mmask field bit 0.
496 These values can be ored together, for example:
500 membar #StoreLoad | #LoadLoad
501 membar #StoreLoad | #StoreStore
504 The @code{prefetch} and @code{prefetcha} instructions take a prefetch
505 function code. The following prefetch function code constant
506 mnemonics are available:
510 @samp{#n_reads} requests a prefetch for several reads, and corresponds
511 to a prefetch function code of 0.
513 @samp{#one_read} requests a prefetch for one read, and corresponds
514 to a prefetch function code of 1.
516 @samp{#n_writes} requests a prefetch for several writes (and possibly
517 reads), and corresponds to a prefetch function code of 2.
519 @samp{#one_write} requests a prefetch for one write, and corresponds
520 to a prefetch function code of 3.
522 @samp{#page} requests a prefetch page, and corresponds to a prefetch
525 @samp{#invalidate} requests a prefetch invalidate, and corresponds to
526 a prefetch function code of 16.
528 @samp{#unified} requests a prefetch to the nearest unified cache, and
529 corresponds to a prefetch function code of 17.
531 @samp{#n_reads_strong} requests a strong prefetch for several reads,
532 and corresponds to a prefetch function code of 20.
534 @samp{#one_read_strong} requests a strong prefetch for one read,
535 and corresponds to a prefetch function code of 21.
537 @samp{#n_writes_strong} requests a strong prefetch for several writes,
538 and corresponds to a prefetch function code of 22.
540 @samp{#one_write_strong} requests a strong prefetch for one write,
541 and corresponds to a prefetch function code of 23.
543 Onle one prefetch code may be specified. Here are some examples:
546 prefetch [%l0 + %l2], #one_read
547 prefetch [%g2 + 8], #n_writes
548 prefetcha [%g1] 0x8, #unified
549 prefetcha [%o0 + 0x10] %asi, #n_reads
552 The actual behavior of a given prefetch function code is processor
553 specific. If a processor does not implement a given prefetch
554 function code, it will treat the prefetch instruction as a nop.
556 For instructions that accept an immediate address space identifier,
557 @code{@value{AS}} provides many mnemonics corresponding to
558 V9 defined as well as UltraSPARC and Niagara extended values.
559 For example, @samp{#ASI_P} and @samp{#ASI_BLK_INIT_QUAD_LDD_AIUS}.
560 See the V9 and processor specific manuals for details.
565 @subsection Relocations
566 @cindex Sparc relocations
567 @cindex relocations, Sparc
569 ELF relocations are available as defined in the 32-bit and 64-bit
570 Sparc ELF specifications.
572 @code{R_SPARC_HI22} is obtained using @samp{%hi} and @code{R_SPARC_LO10}
573 is obtained using @samp{%lo}. Likewise @code{R_SPARC_HIX22} is
574 obtained from @samp{%hix} and @code{R_SPARC_LOX10} is obtained
575 using @samp{%lox}. For example:
578 sethi %hi(symbol), %g1
579 or %g1, %lo(symbol), %g1
581 sethi %hix(symbol), %g1
582 xor %g1, %lox(symbol), %g1
585 These ``high'' mnemonics extract bits 31:10 of their operand,
586 and the ``low'' mnemonics extract bits 9:0 of their operand.
588 V9 code model relocations can be requested as follows:
592 @code{R_SPARC_HH22} is requested using @samp{%hh}. It can
593 also be generated using @samp{%uhi}.
595 @code{R_SPARC_HM10} is requested using @samp{%hm}. It can
596 also be generated using @samp{%ulo}.
598 @code{R_SPARC_LM22} is requested using @samp{%lm}.
601 @code{R_SPARC_H44} is requested using @samp{%h44}.
603 @code{R_SPARC_M44} is requested using @samp{%m44}.
605 @code{R_SPARC_L44} is requested using @samp{%l44} or @samp{%l34}.
607 @code{R_SPARC_H34} is requested using @samp{%h34}.
610 The @samp{%l34} generates a @code{R_SPARC_L44} relocation because it
611 calculates the necessary value, and therefore no explicit
612 @code{R_SPARC_L34} relocation needed to be created for this purpose.
614 The @samp{%h34} and @samp{%l34} relocations are used for the abs34 code
615 model. Here is an example abs34 address generation sequence:
618 sethi %h34(symbol), %g1
620 or %g1, %l34(symbol), %g1
623 The PC relative relocation @code{R_SPARC_PC22} can be obtained by
624 enclosing an operand inside of @samp{%pc22}. Likewise, the
625 @code{R_SPARC_PC10} relocation can be obtained using @samp{%pc10}.
626 These are mostly used when assembling PIC code. For example, the
627 standard PIC sequence on Sparc to get the base of the global offset
628 table, PC relative, into a register, can be performed as:
631 sethi %pc22(_GLOBAL_OFFSET_TABLE_-4), %l7
632 add %l7, %pc10(_GLOBAL_OFFSET_TABLE_+4), %l7
635 Several relocations exist to allow the link editor to potentially
636 optimize GOT data references. The @code{R_SPARC_GOTDATA_OP_HIX22}
637 relocation can obtained by enclosing an operand inside of
638 @samp{%gdop_hix22}. The @code{R_SPARC_GOTDATA_OP_LOX10}
639 relocation can obtained by enclosing an operand inside of
640 @samp{%gdop_lox10}. Likewise, @code{R_SPARC_GOTDATA_OP} can be
641 obtained by enclosing an operand inside of @samp{%gdop}.
642 For example, assuming the GOT base is in register @code{%l7}:
645 sethi %gdop_hix22(symbol), %l1
646 xor %l1, %gdop_lox10(symbol), %l1
647 ld [%l7 + %l1], %l2, %gdop(symbol)
650 There are many relocations that can be requested for access to
651 thread local storage variables. All of the Sparc TLS mnemonics
656 @code{R_SPARC_TLS_GD_HI22} is requested using @samp{%tgd_hi22}.
658 @code{R_SPARC_TLS_GD_LO10} is requested using @samp{%tgd_lo10}.
660 @code{R_SPARC_TLS_GD_ADD} is requested using @samp{%tgd_add}.
662 @code{R_SPARC_TLS_GD_CALL} is requested using @samp{%tgd_call}.
665 @code{R_SPARC_TLS_LDM_HI22} is requested using @samp{%tldm_hi22}.
667 @code{R_SPARC_TLS_LDM_LO10} is requested using @samp{%tldm_lo10}.
669 @code{R_SPARC_TLS_LDM_ADD} is requested using @samp{%tldm_add}.
671 @code{R_SPARC_TLS_LDM_CALL} is requested using @samp{%tldm_call}.
674 @code{R_SPARC_TLS_LDO_HIX22} is requested using @samp{%tldo_hix22}.
676 @code{R_SPARC_TLS_LDO_LOX10} is requested using @samp{%tldo_lox10}.
678 @code{R_SPARC_TLS_LDO_ADD} is requested using @samp{%tldo_add}.
681 @code{R_SPARC_TLS_IE_HI22} is requested using @samp{%tie_hi22}.
683 @code{R_SPARC_TLS_IE_LO10} is requested using @samp{%tie_lo10}.
685 @code{R_SPARC_TLS_IE_LD} is requested using @samp{%tie_ld}.
687 @code{R_SPARC_TLS_IE_LDX} is requested using @samp{%tie_ldx}.
689 @code{R_SPARC_TLS_IE_ADD} is requested using @samp{%tie_add}.
692 @code{R_SPARC_TLS_LE_HIX22} is requested using @samp{%tle_hix22}.
694 @code{R_SPARC_TLS_LE_LOX10} is requested using @samp{%tle_lox10}.
697 Here are some example TLS model sequences.
699 First, General Dynamic:
702 sethi %tgd_hi22(symbol), %l1
703 add %l1, %tgd_lo10(symbol), %l1
704 add %l7, %l1, %o0, %tgd_add(symbol)
705 call __tls_get_addr, %tgd_call(symbol)
712 sethi %tldm_hi22(symbol), %l1
713 add %l1, %tldm_lo10(symbol), %l1
714 add %l7, %l1, %o0, %tldm_add(symbol)
715 call __tls_get_addr, %tldm_call(symbol)
718 sethi %tldo_hix22(symbol), %l1
719 xor %l1, %tldo_lox10(symbol), %l1
720 add %o0, %l1, %l1, %tldo_add(symbol)
726 sethi %tie_hi22(symbol), %l1
727 add %l1, %tie_lo10(symbol), %l1
728 ld [%l7 + %l1], %o0, %tie_ld(symbol)
729 add %g7, %o0, %o0, %tie_add(symbol)
731 sethi %tie_hi22(symbol), %l1
732 add %l1, %tie_lo10(symbol), %l1
733 ldx [%l7 + %l1], %o0, %tie_ldx(symbol)
734 add %g7, %o0, %o0, %tie_add(symbol)
737 And finally, Local Exec:
740 sethi %tle_hix22(symbol), %l1
741 add %l1, %tle_lox10(symbol), %l1
745 When assembling for 64-bit, and a secondary constant addend is
746 specified in an address expression that would normally generate
747 an @code{R_SPARC_LO10} relocation, the assembler will emit an
748 @code{R_SPARC_OLO10} instead.
750 @node Sparc-Size-Translations
751 @subsection Size Translations
752 @cindex Sparc size translations
753 @cindex size, translations, Sparc
755 Often it is desirable to write code in an operand size agnostic
756 manner. @code{@value{AS}} provides support for this via
757 operand size opcode translations. Translations are supported
758 for loads, stores, shifts, compare-and-swap atomics, and the
759 @samp{clr} synthetic instruction.
761 If generating 32-bit code, @code{@value{AS}} will generate the
762 32-bit opcode. Whereas if 64-bit code is being generated,
763 the 64-bit opcode will be emitted. For example @code{ldn}
764 will be transformed into @code{ld} for 32-bit code and
765 @code{ldx} for 64-bit code.
767 Here is an example meant to demonstrate all the supported
779 casna [%o0] %asi, %o1, %o2
783 In 32-bit mode @code{@value{AS}} will emit:
794 casa [%o0] %asi, %o1, %o2
798 And in 64-bit mode @code{@value{AS}} will emit:
809 casxa [%o0] %asi, %o1, %o2
813 Finally, the @samp{.nword} translating directive is supported
814 as well. It is documented in the section on Sparc machine
818 @section Floating Point
820 @cindex floating point, SPARC (@sc{ieee})
821 @cindex SPARC floating point (@sc{ieee})
822 The Sparc uses @sc{ieee} floating-point numbers.
824 @node Sparc-Directives
825 @section Sparc Machine Directives
827 @cindex SPARC machine directives
828 @cindex machine directives, SPARC
829 The Sparc version of @code{@value{AS}} supports the following additional
833 @cindex @code{align} directive, SPARC
835 This must be followed by the desired alignment in bytes.
837 @cindex @code{common} directive, SPARC
839 This must be followed by a symbol name, a positive number, and
840 @code{"bss"}. This behaves somewhat like @code{.comm}, but the
843 @cindex @code{half} directive, SPARC
845 This is functionally identical to @code{.short}.
847 @cindex @code{nword} directive, SPARC
849 On the Sparc, the @code{.nword} directive produces native word sized value,
850 ie. if assembling with -32 it is equivalent to @code{.word}, if assembling
851 with -64 it is equivalent to @code{.xword}.
853 @cindex @code{proc} directive, SPARC
855 This directive is ignored. Any text following it on the same
856 line is also ignored.
858 @cindex @code{register} directive, SPARC
860 This directive declares use of a global application or system register.
861 It must be followed by a register name %g2, %g3, %g6 or %g7, comma and
862 the symbol name for that register. If symbol name is @code{#scratch},
863 it is a scratch register, if it is @code{#ignore}, it just suppresses any
864 errors about using undeclared global register, but does not emit any
865 information about it into the object file. This can be useful e.g. if you
866 save the register before use and restore it after.
868 @cindex @code{reserve} directive, SPARC
870 This must be followed by a symbol name, a positive number, and
871 @code{"bss"}. This behaves somewhat like @code{.lcomm}, but the
874 @cindex @code{seg} directive, SPARC
876 This must be followed by @code{"text"}, @code{"data"}, or
877 @code{"data1"}. It behaves like @code{.text}, @code{.data}, or
880 @cindex @code{skip} directive, SPARC
882 This is functionally identical to the @code{.space} directive.
884 @cindex @code{word} directive, SPARC
886 On the Sparc, the @code{.word} directive produces 32 bit values,
887 instead of the 16 bit values it produces on many other machines.
889 @cindex @code{xword} directive, SPARC
891 On the Sparc V9 processor, the @code{.xword} directive produces