| <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> |
| <html> |
| <!-- This file documents the GNU Assembler "as". |
| |
| Copyright (C) 1991-2013 Free Software Foundation, Inc. |
| |
| Permission is granted to copy, distribute and/or modify this document |
| under the terms of the GNU Free Documentation License, Version 1.3 |
| or any later version published by the Free Software Foundation; |
| with no Invariant Sections, with no Front-Cover Texts, and with no |
| Back-Cover Texts. A copy of the license is included in the |
| section entitled "GNU Free Documentation License". |
| --> |
| <!-- Created by GNU Texinfo 5.2, http://www.gnu.org/software/texinfo/ --> |
| <head> |
| <title>Using as: HPPA Directives</title> |
| |
| <meta name="description" content="Using as: HPPA Directives"> |
| <meta name="keywords" content="Using as: HPPA Directives"> |
| <meta name="resource-type" content="document"> |
| <meta name="distribution" content="global"> |
| <meta name="Generator" content="makeinfo"> |
| <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> |
| <link href="index.html#Top" rel="start" title="Top"> |
| <link href="AS-Index.html#AS-Index" rel="index" title="AS Index"> |
| <link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> |
| <link href="HPPA_002dDependent.html#HPPA_002dDependent" rel="up" title="HPPA-Dependent"> |
| <link href="HPPA-Opcodes.html#HPPA-Opcodes" rel="next" title="HPPA Opcodes"> |
| <link href="HPPA-Floating-Point.html#HPPA-Floating-Point" rel="prev" title="HPPA Floating Point"> |
| <style type="text/css"> |
| <!-- |
| a.summary-letter {text-decoration: none} |
| blockquote.smallquotation {font-size: smaller} |
| div.display {margin-left: 3.2em} |
| div.example {margin-left: 3.2em} |
| div.indentedblock {margin-left: 3.2em} |
| div.lisp {margin-left: 3.2em} |
| div.smalldisplay {margin-left: 3.2em} |
| div.smallexample {margin-left: 3.2em} |
| div.smallindentedblock {margin-left: 3.2em; font-size: smaller} |
| div.smalllisp {margin-left: 3.2em} |
| kbd {font-style:oblique} |
| pre.display {font-family: inherit} |
| pre.format {font-family: inherit} |
| pre.menu-comment {font-family: serif} |
| pre.menu-preformatted {font-family: serif} |
| pre.smalldisplay {font-family: inherit; font-size: smaller} |
| pre.smallexample {font-size: smaller} |
| pre.smallformat {font-family: inherit; font-size: smaller} |
| pre.smalllisp {font-size: smaller} |
| span.nocodebreak {white-space:nowrap} |
| span.nolinebreak {white-space:nowrap} |
| span.roman {font-family:serif; font-weight:normal} |
| span.sansserif {font-family:sans-serif; font-weight:normal} |
| ul.no-bullet {list-style: none} |
| --> |
| </style> |
| |
| |
| </head> |
| |
| <body lang="en" bgcolor="#FFFFFF" text="#000000" link="#0000FF" vlink="#800080" alink="#FF0000"> |
| <a name="HPPA-Directives"></a> |
| <div class="header"> |
| <p> |
| Next: <a href="HPPA-Opcodes.html#HPPA-Opcodes" accesskey="n" rel="next">HPPA Opcodes</a>, Previous: <a href="HPPA-Floating-Point.html#HPPA-Floating-Point" accesskey="p" rel="prev">HPPA Floating Point</a>, Up: <a href="HPPA_002dDependent.html#HPPA_002dDependent" accesskey="u" rel="up">HPPA-Dependent</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| <hr> |
| <a name="HPPA-Assembler-Directives"></a> |
| <h4 class="subsection">9.13.5 HPPA Assembler Directives</h4> |
| |
| <p><code>as</code> 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 |
| <cite>HP9000 Series 800 Assembly Language Reference Manual</cite> (HP 92432-90001). |
| </p> |
| <a name="index-HPPA-directives-not-supported"></a> |
| <p><code>as</code> does <em>not</em> support the following assembler directives |
| described in the HP manual: |
| </p> |
| <div class="example"> |
| <pre class="example">.endm .liston |
| .enter .locct |
| .leave .macro |
| .listoff |
| </pre></div> |
| |
| <a name="index-_002eparam-on-HPPA"></a> |
| <p>Beyond those implemented for compatibility, <code>as</code> supports one |
| additional assembler directive for the HPPA: <code>.param</code>. It conveys |
| register argument locations for static functions. Its syntax closely follows |
| the <code>.export</code> directive. |
| </p> |
| <a name="index-HPPA_002donly-directives"></a> |
| <p>These are the additional directives in <code>as</code> for the HPPA: |
| </p> |
| <dl compact="compact"> |
| <dt><code>.block <var>n</var></code></dt> |
| <dt><code>.blockz <var>n</var></code></dt> |
| <dd><p>Reserve <var>n</var> bytes of storage, and initialize them to zero. |
| </p> |
| </dd> |
| <dt><code>.call</code></dt> |
| <dd><p>Mark the beginning of a procedure call. Only the special case with <em>no |
| arguments</em> is allowed. |
| </p> |
| </dd> |
| <dt><code>.callinfo [ <var>param</var>=<var>value</var>, … ] [ <var>flag</var>, … ]</code></dt> |
| <dd><p>Specify a number of parameters and flags that define the environment for a |
| procedure. |
| </p> |
| <p><var>param</var> may be any of ‘<samp>frame</samp>’ (frame size), ‘<samp>entry_gr</samp>’ (end of |
| general register range), ‘<samp>entry_fr</samp>’ (end of float register range), |
| ‘<samp>entry_sr</samp>’ (end of space register range). |
| </p> |
| <p>The values for <var>flag</var> are ‘<samp>calls</samp>’ or ‘<samp>caller</samp>’ (proc has |
| subroutines), ‘<samp>no_calls</samp>’ (proc does not call subroutines), ‘<samp>save_rp</samp>’ |
| (preserve return pointer), ‘<samp>save_sp</samp>’ (proc preserves stack pointer), |
| ‘<samp>no_unwind</samp>’ (do not unwind this proc), ‘<samp>hpux_int</samp>’ (proc is interrupt |
| routine). |
| </p> |
| </dd> |
| <dt><code>.code</code></dt> |
| <dd><p>Assemble into the standard section called ‘<samp>$TEXT$</samp>’, subsection |
| ‘<samp>$CODE$</samp>’. |
| </p> |
| </dd> |
| <dt><code>.copyright "<var>string</var>"</code></dt> |
| <dd><p>In the SOM object format, insert <var>string</var> into the object code, marked as a |
| copyright string. |
| </p> |
| </dd> |
| <dt><code>.copyright "<var>string</var>"</code></dt> |
| <dd><p>In the ELF object format, insert <var>string</var> into the object code, marked as a |
| version string. |
| </p> |
| </dd> |
| <dt><code>.enter</code></dt> |
| <dd><p>Not yet supported; the assembler rejects programs containing this directive. |
| </p> |
| </dd> |
| <dt><code>.entry</code></dt> |
| <dd><p>Mark the beginning of a procedure. |
| </p> |
| </dd> |
| <dt><code>.exit</code></dt> |
| <dd><p>Mark the end of a procedure. |
| </p> |
| </dd> |
| <dt><code>.export <var>name</var> [ ,<var>typ</var> ] [ ,<var>param</var>=<var>r</var> ]</code></dt> |
| <dd><p>Make a procedure <var>name</var> available to callers. <var>typ</var>, if present, must |
| be one of ‘<samp>absolute</samp>’, ‘<samp>code</samp>’ (ELF only, not SOM), ‘<samp>data</samp>’, |
| ‘<samp>entry</samp>’, ‘<samp>data</samp>’, ‘<samp>entry</samp>’, ‘<samp>millicode</samp>’, ‘<samp>plabel</samp>’, |
| ‘<samp>pri_prog</samp>’, or ‘<samp>sec_prog</samp>’. |
| </p> |
| <p><var>param</var>, if present, provides either relocation information for the |
| procedure arguments and result, or a privilege level. <var>param</var> may be |
| ‘<samp>argw<var>n</var></samp>’ (where <var>n</var> ranges from <code>0</code> to <code>3</code>, and |
| indicates one of four one-word arguments); ‘<samp>rtnval</samp>’ (the procedure’s |
| result); or ‘<samp>priv_lev</samp>’ (privilege level). For arguments or the result, |
| <var>r</var> specifies how to relocate, and must be one of ‘<samp>no</samp>’ (not |
| relocatable), ‘<samp>gr</samp>’ (argument is in general register), ‘<samp>fr</samp>’ (in |
| floating point register), or ‘<samp>fu</samp>’ (upper half of float register). |
| For ‘<samp>priv_lev</samp>’, <var>r</var> is an integer. |
| </p> |
| </dd> |
| <dt><code>.half <var>n</var></code></dt> |
| <dd><p>Define a two-byte integer constant <var>n</var>; synonym for the portable |
| <code>as</code> directive <code>.short</code>. |
| </p> |
| </dd> |
| <dt><code>.import <var>name</var> [ ,<var>typ</var> ]</code></dt> |
| <dd><p>Converse of <code>.export</code>; make a procedure available to call. The arguments |
| use the same conventions as the first two arguments for <code>.export</code>. |
| </p> |
| </dd> |
| <dt><code>.label <var>name</var></code></dt> |
| <dd><p>Define <var>name</var> as a label for the current assembly location. |
| </p> |
| </dd> |
| <dt><code>.leave</code></dt> |
| <dd><p>Not yet supported; the assembler rejects programs containing this directive. |
| </p> |
| </dd> |
| <dt><code>.origin <var>lc</var></code></dt> |
| <dd><p>Advance location counter to <var>lc</var>. Synonym for the <code>as</code> |
| portable directive <code>.org</code>. |
| </p> |
| </dd> |
| <dt><code>.param <var>name</var> [ ,<var>typ</var> ] [ ,<var>param</var>=<var>r</var> ]</code></dt> |
| <dd><p>Similar to <code>.export</code>, but used for static procedures. |
| </p> |
| </dd> |
| <dt><code>.proc</code></dt> |
| <dd><p>Use preceding the first statement of a procedure. |
| </p> |
| </dd> |
| <dt><code>.procend</code></dt> |
| <dd><p>Use following the last statement of a procedure. |
| </p> |
| </dd> |
| <dt><code><var>label</var> .reg <var>expr</var></code></dt> |
| <dd><p>Synonym for <code>.equ</code>; define <var>label</var> with the absolute expression |
| <var>expr</var> as its value. |
| </p> |
| </dd> |
| <dt><code>.space <var>secname</var> [ ,<var>params</var> ]</code></dt> |
| <dd><p>Switch to section <var>secname</var>, creating a new section by that name if |
| necessary. You may only use <var>params</var> when creating a new section, not |
| when switching to an existing one. <var>secname</var> may identify a section by |
| number rather than by name. |
| </p> |
| <p>If specified, the list <var>params</var> declares attributes of the section, |
| identified by keywords. The keywords recognized are ‘<samp>spnum=<var>exp</var></samp>’ |
| (identify this section by the number <var>exp</var>, an absolute expression), |
| ‘<samp>sort=<var>exp</var></samp>’ (order sections according to this sort key when linking; |
| <var>exp</var> is an absolute expression), ‘<samp>unloadable</samp>’ (section contains no |
| loadable data), ‘<samp>notdefined</samp>’ (this section defined elsewhere), and |
| ‘<samp>private</samp>’ (data in this section not available to other programs). |
| </p> |
| </dd> |
| <dt><code>.spnum <var>secnam</var></code></dt> |
| <dd><p>Allocate four bytes of storage, and initialize them with the section number of |
| the section named <var>secnam</var>. (You can define the section number with the |
| HPPA <code>.space</code> directive.) |
| </p> |
| <a name="index-string-directive-on-HPPA"></a> |
| </dd> |
| <dt><code>.string "<var>str</var>"</code></dt> |
| <dd><p>Copy the characters in the string <var>str</var> to the object file. |
| See <a href="Strings.html#Strings">Strings</a>, for information on escape sequences you can use in |
| <code>as</code> strings. |
| </p> |
| <p><em>Warning!</em> The HPPA version of <code>.string</code> differs from the |
| usual <code>as</code> definition: it does <em>not</em> write a zero byte |
| after copying <var>str</var>. |
| </p> |
| </dd> |
| <dt><code>.stringz "<var>str</var>"</code></dt> |
| <dd><p>Like <code>.string</code>, but appends a zero byte after copying <var>str</var> to object |
| file. |
| </p> |
| </dd> |
| <dt><code>.subspa <var>name</var> [ ,<var>params</var> ]</code></dt> |
| <dt><code>.nsubspa <var>name</var> [ ,<var>params</var> ]</code></dt> |
| <dd><p>Similar to <code>.space</code>, but selects a subsection <var>name</var> within the |
| current section. You may only specify <var>params</var> when you create a |
| subsection (in the first instance of <code>.subspa</code> for this <var>name</var>). |
| </p> |
| <p>If specified, the list <var>params</var> declares attributes of the subsection, |
| identified by keywords. The keywords recognized are ‘<samp>quad=<var>expr</var></samp>’ |
| (“quadrant” for this subsection), ‘<samp>align=<var>expr</var></samp>’ (alignment for |
| beginning of this subsection; a power of two), ‘<samp>access=<var>expr</var></samp>’ (value |
| for “access rights” field), ‘<samp>sort=<var>expr</var></samp>’ (sorting order for this |
| subspace in link), ‘<samp>code_only</samp>’ (subsection contains only code), |
| ‘<samp>unloadable</samp>’ (subsection cannot be loaded into memory), ‘<samp>comdat</samp>’ |
| (subsection is comdat), ‘<samp>common</samp>’ (subsection is common block), |
| ‘<samp>dup_comm</samp>’ (subsection may have duplicate names), or ‘<samp>zero</samp>’ |
| (subsection is all zeros, do not write in object file). |
| </p> |
| <p><code>.nsubspa</code> always creates a new subspace with the given name, even |
| if one with the same name already exists. |
| </p> |
| <p>‘<samp>comdat</samp>’, ‘<samp>common</samp>’ and ‘<samp>dup_comm</samp>’ can be used to implement |
| various flavors of one-only support when using the SOM linker. The SOM |
| linker only supports specific combinations of these flags. The details |
| are not documented. A brief description is provided here. |
| </p> |
| <p>‘<samp>comdat</samp>’ provides a form of linkonce support. It is useful for |
| both code and data subspaces. A ‘<samp>comdat</samp>’ subspace has a key symbol |
| marked by the ‘<samp>is_comdat</samp>’ flag or ‘<samp>ST_COMDAT</samp>’. Only the first |
| subspace for any given key is selected. The key symbol becomes universal |
| in shared links. This is similar to the behavior of ‘<samp>secondary_def</samp>’ |
| symbols. |
| </p> |
| <p>‘<samp>common</samp>’ provides Fortran named common support. It is only useful |
| for data subspaces. Symbols with the flag ‘<samp>is_common</samp>’ retain this |
| flag in shared links. Referencing a ‘<samp>is_common</samp>’ symbol in a shared |
| library from outside the library doesn’t work. Thus, ‘<samp>is_common</samp>’ |
| symbols must be output whenever they are needed. |
| </p> |
| <p>‘<samp>common</samp>’ and ‘<samp>dup_comm</samp>’ together provide Cobol common support. |
| The subspaces in this case must all be the same length. Otherwise, this |
| support is similar to the Fortran common support. |
| </p> |
| <p>‘<samp>dup_comm</samp>’ by itself provides a type of one-only support for code. |
| Only the first ‘<samp>dup_comm</samp>’ subspace is selected. There is a rather |
| complex algorithm to compare subspaces. Code symbols marked with the |
| ‘<samp>dup_common</samp>’ flag are hidden. This support was intended for "C++ |
| duplicate inlines". |
| </p> |
| <p>A simplified technique is used to mark the flags of symbols based on |
| the flags of their subspace. A symbol with the scope SS_UNIVERSAL and |
| type ST_ENTRY, ST_CODE or ST_DATA is marked with the corresponding |
| settings of ‘<samp>comdat</samp>’, ‘<samp>common</samp>’ and ‘<samp>dup_comm</samp>’ from the |
| subspace, respectively. This avoids having to introduce additional |
| directives to mark these symbols. The HP assembler sets ‘<samp>is_common</samp>’ |
| from ‘<samp>common</samp>’. However, it doesn’t set the ‘<samp>dup_common</samp>’ from |
| ‘<samp>dup_comm</samp>’. It doesn’t have ‘<samp>comdat</samp>’ support. |
| </p> |
| </dd> |
| <dt><code>.version "<var>str</var>"</code></dt> |
| <dd><p>Write <var>str</var> as version identifier in object code. |
| </p></dd> |
| </dl> |
| |
| <hr> |
| <div class="header"> |
| <p> |
| Next: <a href="HPPA-Opcodes.html#HPPA-Opcodes" accesskey="n" rel="next">HPPA Opcodes</a>, Previous: <a href="HPPA-Floating-Point.html#HPPA-Floating-Point" accesskey="p" rel="prev">HPPA Floating Point</a>, Up: <a href="HPPA_002dDependent.html#HPPA_002dDependent" accesskey="u" rel="up">HPPA-Dependent</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="AS-Index.html#AS-Index" title="Index" rel="index">Index</a>]</p> |
| </div> |
| |
| |
| |
| </body> |
| </html> |
