19.5. HPPA Assembler Directives

as for the HPPA supports many additional directives for compatibility with the native assembler. This section describes them only briefly. For detailed information on HPPA-specific assembler directives, see [HP9000 Series 800 Assembly Language Reference Manual] (HP 92432-90001).

as does not support the following assembler directives described in the HP manual:

.endm           .liston
.enter          .locct
.leave          .macro
.listoff

Beyond those implemented for compatibility, as supports one additional assembler directive for the HPPA: .param. It conveys register argument locations for static functions. Its syntax closely follows the .export directive.

These are the additional directives in as for the HPPA:

.block n, .blockz n

Reserve n bytes of storage, and initialize them to zero.

.call

Mark the beginning of a procedure call. Only the special case with no arguments is allowed.

.callinfo [ param=value, … ] [ flag, … ]

Specify a number of parameters and flags that define the environment for a procedure.

param may be any of frame (frame size), entry_gr (end of general register range), entry_fr (end of float register range), entry_sr (end of space register range).

The values for flag are calls or caller (proc has subroutines), no_calls (proc does not call subroutines), save_rp (preserve return pointer), save_sp (proc preserves stack pointer), no_unwind (do not unwind this proc), hpux_int (proc is interrupt routine).

.code

Assemble into the standard section called $TEXT$, subsection $CODE$.

.copyright "string"

In the SOM object format, insert string into the object code, marked as a copyright string.

.copyright "string"

In the ELF object format, insert string into the object code, marked as a version string.

.enter

Not yet supported; the assembler rejects programs containing this directive.

.entry

Mark the beginning of a procedure.

.exit

Mark the end of a procedure.

.export name [ ,typ ] [ ,param=r ]

Make a procedure name available to callers. typ, if present, must be one of absolute, code (ELF only, not SOM), data, entry, data, entry, millicode, plabel, pri_prog, or sec_prog.

param, if present, provides either relocation information for the procedure arguments and result, or a privilege level. param may be argwn (where n ranges from 0 to 3, and indicates one of four one-word arguments); rtnval (the procedure's result); or priv_lev (privilege level). For arguments or the result, r specifies how to relocate, and must be one of no (not relocatable), gr (argument is in general register), fr (in floating point register), or fu (upper half of float register). For priv_lev, r is an integer.

.half n

Define a two-byte integer constant n; synonym for the portable as directive .short.

.import name [ ,typ ]

Converse of .export; make a procedure available to call. The arguments use the same conventions as the first two arguments for .export.

.label name

Define name as a label for the current assembly location.

.leave

Not yet supported; the assembler rejects programs containing this directive.

.origin lc

Advance location counter to lc. Synonym for the {No value for `as'} portable directive .org.

.param name [ ,typ ] [ ,param=r ]

Similar to .export, but used for static procedures.

.proc

Use preceding the first statement of a procedure.

.procend

Use following the last statement of a procedure.

label .reg expr

Synonym for .equ; define label with the absolute expression expr as its value.

.space secname [ ,params ]

Switch to section secname, creating a new section by that name if necessary. You may only use params when creating a new section, not when switching to an existing one. secname may identify a section by number rather than by name.

If specified, the list params declares attributes of the section, identified by keywords. The keywords recognized are spnum=exp (identify this section by the number exp, an absolute expression), sort=exp (order sections according to this sort key when linking; exp is an absolute expression), unloadable (section contains no loadable data), notdefined (this section defined elsewhere), and private (data in this section not available to other programs).

.spnum secnam

Allocate four bytes of storage, and initialize them with the section number of the section named secnam. (You can define the section number with the HPPA .space directive.)

.string "str"

Copy the characters in the string str to the object file. Section 4.6.1.1 Strings, for information on escape sequences you can use in as strings.

Warning! The HPPA version of .string differs from the usual as definition: it does not write a zero byte after copying str.

.stringz "str"

Like .string, but appends a zero byte after copying str to object file.

.subspa name [ ,params ], .nsubspa name [ ,params ]

Similar to .space, but selects a subsection name within the current section. You may only specify params when you create a subsection (in the first instance of .subspa for this name).

If specified, the list params declares attributes of the subsection, identified by keywords. The keywords recognized are quad=expr ("quadrant" for this subsection), align=expr (alignment for beginning of this subsection; a power of two), access=expr (value for "access rights" field), sort=expr (sorting order for this subspace in link), code_only (subsection contains only code), unloadable (subsection cannot be loaded into memory), common (subsection is common block), dup_comm (initialized data may have duplicate names), or zero (subsection is all zeros, do not write in object file).

.nsubspa always creates a new subspace with the given name, even if one with the same name already exists.

.version "str"

Write str as version identifier in object code.