SPARC Assembly Language Reference Manual

Appendix A Pseudo-Operations

The pseudo-operations listed in this appendix are supported by the SPARC assembler.

A.1 Alphabetized Listing with Descriptions

.alias

Turns off the effect of the preceding .noalias pseudo-op. (Compiler-generated only.)

.align boundary

Aligns the location counter on a boundary where ((“location counter” mod boundary)==0); boundary may be any power of 2.

.ascii string [, string"]

Generates the given sequence(s) of ASCII characters.

.asciz string [, string]*

Generates the given sequence(s) of ASCII characters. This pseudo-op appends a null (zero) byte to each string.

.byte 8bitval [, 8bitval]*

Generates (a sequence of) initialized bytes in the current segment.

.common symbol, size [, sect_name] [, alignment]

Provides a tentative definition of symbol. Size bytes are allocated for the object represented by symbol.

If the symbol is not defined in the input file and is declared to be local to the file, the symbol is allocated in sect_name and its location is optionally aligned to a multiple of alignment. If sect_name is not given, the symbol is allocated in the uninitialized data section (bss). Currently, only .bss is supported for the section name. (.data is not currently supported.)
If the symbol is not defined in the input file and is declared to be global, the SPARC link editor allocates storage for the symbol, depending on the definition of symbol_name in other files. Global is the default binding for common symbols.
If the symbol is defined in the input file, the definition specifies the location of the symbol and the tentative definition is overridden.

.double 0rfloatval [, 0rfloatval]*

Generates (a sequence of) initialized double-precision floating-point values in the current segment. floatval is a string acceptable to atof(3); that is, an optional sign followed by a non-empty string of digits with optional decimal point and optional exponent.

.empty

Suppresses assembler complaints about the next instruction presence in a delay slot when used in the delay slot of a Control Transfer Instruction (CTI).

Some instructions should not be in the delay slot of a CTI. See the SPARC Architecture Manual for details.

.file string

Creates a symbol table entry where string is the symbol name and STT_FILE is the symbol table type. string specifies the name of the source file associated with the object file.

.global symbol [, symbol]* .globl symbol [, symbol]*

Declares each symbol in the list to be global; that is, each symbol is either defined externally or defined in the input file and accessible in other files; default bindings for the symbol are overridden.

A global symbol definition in one file will satisfy an undefined reference to the same global symbol in another file.
Multiple definitions of a defined global symbol is not allowed. If a defined global symbol has more than one definition, an error will occur.
A global psuedo-op oes not need to occur before a definition, or tentative definition, of the specified symbol.

Note –

This pseudo-op by itself does not define the symbol.

.half 16bitval [, 16bitval]*

Generates (a sequence of) initialized halfwords in the current segment. The location counter must already be aligned on a halfword boundary (use .align 2).

.ident string

Generates the null terminated string in a comment section. This operation is equivalent to:

.pushsection .comment

.asciz string

.popsection

.local symbol [, symbol]*

Declares each symbol in the list to be local; that is, each symbol is defined in the input file and not accessible in other files; default bindings for the symbol are overridden. These symbols take precedence over weak and global symbols.

Since local symbols are not accessible to other files, local symbols of the same name may exist in multiple files.

Note –

This pseudo-op by itself does not define the symbol.

.noalias %reg1, %reg2

%reg1 and %reg2 will not alias each other (that is, point to the same destination) until a .alias pseudo-op is issued. (Compiler-generated only.)

.nonvolatile

Defines the end of a block of instruction. The instructions in the block may not be permuted. This pseudo-op has no effect if:

The block of instruction has been previously terminated by a Control Transfer Instruction (CTI) or a label
There is no preceding .volatile pseudo-op

.nword 64bitval [, 64bitval]*

If -xarch=v8/v8plus then assembler interprets the instruction as .word. If -xarch=v9 the assembler interprets the instruction as .xword.

.optim string

This pseudo-op changes the optimization level of a particular function. (Compiler-generated only.)

.popsection

Removes the top section from the section stack. The new section on the top of the stack becomes the current section. This pseudo-op and its corresponding .pushsection command allow you to switch back and forth between the named sections.

.proc n

Signals the beginning of a procedure (that is, a unit of optimization) to the peephole optimizer in the SPARC assembler; n specifies which registers will contain the return value upon return from the procedure. (Compiler-generated only.)

.pushsection sect_name [, attributes]

Moves the named section to the top of the section stack. This new top section then becomes the current section. This pseudo-op and its corresponding .popsection command allow you to switch back and forth between the named sections.

.quad 0rfloatval [, 0rfloatval]*

Generates (a sequence of) initialized quad-precision floating-point values in the current segment. floatval is a string acceptable to atof(3); that is, an optional sign followed by a non-empty string of digits with optional decimal point and optional exponent.

Note –

The .quad command currently generates quad-precision values with only double-precision significance.

.reserve symbol, size [, sect_name [, alignment]]

Defines symbol, and reserves size bytes of space for it in the sect_name. This operation is equivalent to:

	.pushsection	 sect_name

	.align	 alignment
symbol:

	.skip 	 size

	.popsection

If a section is not specified, space is reserved in the current segment.

.section section_name [, attributes]

Makes the specified section the current section.

The assembler maintains a section stack which is manipulated by the section control directives. The current section is the section that is currently on top of the stack. This pseudo-op changes the top of the section stack.

If section_name does not exist, a new section with the specified name and attributes is created.
If section_name is a non-reserved section, attributes must be included the first time it is specified by the .section directive.

See the sections 3.2.2 Predefined User Sections and 3.2.3 Predefined Non-User Sections in Chapter 3, Executable and Linking Format for a detailed description of the reserved sections. See Table 3–2 in Chapter 3, Executable and Linking Format for a detailed description of the section attribute flags.

Attributes can be:

#write | #alloc | #execinstr

.seg section_name

Note –

This pseudo-op is currently supported for compatibility with existing SunOS 4.1 SPARC assembly language programs. This pseudo-op has been replaced by the .section pseudo-op.

Changes the current section to one of the predefined user sections. The assembler will interpret the following SunOS 4.1 SPARC assembly directive: to be the same as the following SunOS 5.x SPARC assembly directive:

 .seg text, .seg data, .seg data1, .seg bss, 

.section .text, .section .data, .section .data1,

.section .bss.

Predefined user section names are changed in SunOS 5.x.

.single 0rfloatval [, 0rfloatval]*

Generates (a sequence of) initialized single-precision floating-point values in the current segment.

Note –

This operation does not align automatically.

.size symbol, expr: Declares the symbol size to be expr. expr must be an absolute expression.

.skip n: Increments the location counter by n, which allocates n bytes of empty space in the current segment.

.stabn <various parameters>: The pseudo-op is used by Solaris 2.x SPARCompilers only to pass debugging information to the symbolic debuggers.

.stabs <various parameters>: The pseudo-op is used by Solaris 2.x SPARCompilers only to pass debugging information to the symbolic debuggers.

.type symbol, type

Declares the type of symbol, where type can be:

#object

#function

#no_type

See Table 3–6 in Chapter 3, Executable and Linking Format, for detailed information on symbols.

.uahalf 16bitval [, 16bitval]*

Generates a (sequence of) 16-bit value(s).

Note –

This operation does not align automatically.

.uaword 32bitval [, 32bitval]*

Generates a (sequence of) 32-bit value(s).

Note –

This operation does not align automatically.

.version string: Identifies the minimum assembler version necessary to assemble the input file. You can use this pseudo-op to ensure assembler-compiler compatibility. If string indicates a newer version of the assembler than this version of the assembler, a fatal error message is displayed and the SPARC assembler exits.

.volatile: Defines the beginning of a block of instruction. The instructions in the section may not be changed. The block of instruction should end at a .nonvolatile pseudo-op and should not contain any Control Transfer Instructions (CTI) or labels. The volatile block of instructions is terminated after the last instruction preceding a CTI or label.

.weak symbol [, symbol]

Declares each symbol in the list to be defined either externally, or in the input file and accessible to other files; default bindings of the symbol are overridden by this directive.

Note the following:

A weak symbol definition in one file will satisfy an undefined reference to a global symbol of the same name in another file.
Unresolved weak symbols have a default value of zero; the link editor does not resolve these symbols.
If a weak symbol has the same name as a defined global symbol, the weak symbol is ignored and no error results.

Note –

This pseudo-op does not itself define the symbol.

.word 32bitval [, 32bitval]*

Generates (a sequence of) initialized words in the current segment.

Note –

This operation does not align automatically.

.xword 64bitval [, 64bitval]*

Generates (a sequence of) initialized 64-bit values in the current segment.

Note –

This operation does not align automatically.

.xstabs <various parameters>

The pseudo-op is used by Solaris 2.x SPARCompilers only to pass debugging information to the symbolic debuggers.

symbol =expr

Assigns the value of expr to symbol.