You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
213 lines
9.9 KiB
HTML
213 lines
9.9 KiB
HTML
<!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) 1991-2019 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 6.4, http://www.gnu.org/software/texinfo/ -->
|
|
<head>
|
|
<title>s390 Directives (Using as)</title>
|
|
|
|
<meta name="description" content="s390 Directives (Using as)">
|
|
<meta name="keywords" content="s390 Directives (Using as)">
|
|
<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="S_002f390_002dDependent.html#S_002f390_002dDependent" rel="up" title="S/390-Dependent">
|
|
<link href="s390-Floating-Point.html#s390-Floating-Point" rel="next" title="s390 Floating Point">
|
|
<link href="s390-Literal-Pool-Entries.html#s390-Literal-Pool-Entries" rel="prev" title="s390 Literal Pool Entries">
|
|
<style type="text/css">
|
|
<!--
|
|
a.summary-letter {text-decoration: none}
|
|
blockquote.indentedblock {margin-right: 0em}
|
|
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
|
|
blockquote.smallquotation {font-size: smaller}
|
|
div.display {margin-left: 3.2em}
|
|
div.example {margin-left: 3.2em}
|
|
div.lisp {margin-left: 3.2em}
|
|
div.smalldisplay {margin-left: 3.2em}
|
|
div.smallexample {margin-left: 3.2em}
|
|
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.nolinebreak {white-space: nowrap}
|
|
span.roman {font-family: initial; font-weight: normal}
|
|
span.sansserif {font-family: sans-serif; font-weight: normal}
|
|
ul.no-bullet {list-style: none}
|
|
-->
|
|
</style>
|
|
|
|
|
|
</head>
|
|
|
|
<body lang="en">
|
|
<a name="s390-Directives"></a>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="s390-Floating-Point.html#s390-Floating-Point" accesskey="n" rel="next">s390 Floating Point</a>, Previous: <a href="s390-Syntax.html#s390-Syntax" accesskey="p" rel="prev">s390 Syntax</a>, Up: <a href="S_002f390_002dDependent.html#S_002f390_002dDependent" accesskey="u" rel="up">S/390-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="Assembler-Directives-8"></a>
|
|
<h4 class="subsection">9.40.4 Assembler Directives</h4>
|
|
|
|
<p><code>as</code> for s390 supports all of the standard ELF
|
|
assembler directives as outlined in the main part of this document.
|
|
Some directives have been extended and there are some additional
|
|
directives, which are only available for the s390 <code>as</code>.
|
|
</p>
|
|
<dl compact="compact">
|
|
<dd><a name="index-_002einsn-directive_002c-s390"></a>
|
|
</dd>
|
|
<dt><code>.insn</code></dt>
|
|
<dd><p>This directive permits the numeric representation of an instructions
|
|
and makes the assembler insert the operands according to one of the
|
|
instructions formats for ‘<samp>.insn</samp>’ (<a href="s390-Formats.html#s390-Formats">s390 Formats</a>).
|
|
For example, the instruction ‘<samp>l %r1,24(%r15)</samp>’ could be written as
|
|
‘<samp>.insn rx,0x58000000,%r1,24(%r15)</samp>’.
|
|
<a name="index-_002eshort-directive_002c-s390"></a>
|
|
<a name="index-_002elong-directive_002c-s390"></a>
|
|
<a name="index-_002equad-directive_002c-s390"></a>
|
|
</p></dd>
|
|
<dt><code>.short</code></dt>
|
|
<dt><code>.long</code></dt>
|
|
<dt><code>.quad</code></dt>
|
|
<dd><p>This directive places one or more 16-bit (.short), 32-bit (.long), or
|
|
64-bit (.quad) values into the current section. If an ELF or TLS modifier
|
|
is used only the following expressions are allowed:
|
|
‘<samp>symbol@modifier + constant</samp>’,
|
|
‘<samp>symbol@modifier + label + constant</samp>’, and
|
|
‘<samp>symbol@modifier - label + constant</samp>’.
|
|
The following modifiers are available:
|
|
</p><dl compact="compact">
|
|
<dt><code>@got</code></dt>
|
|
<dt><code>@got12</code></dt>
|
|
<dd><p>The @got modifier can be used for .short, .long and .quad. The @got12
|
|
modifier is synonym to @got. The symbol is added to the GOT. The symbol
|
|
term is replaced with offset from the start of the GOT to the GOT slot for
|
|
the symbol.
|
|
</p></dd>
|
|
<dt><code>@gotoff</code></dt>
|
|
<dd><p>The @gotoff modifier can be used for .short, .long and .quad. The symbol
|
|
term is replaced with the offset from the start of the GOT to the address
|
|
of the symbol.
|
|
</p></dd>
|
|
<dt><code>@gotplt</code></dt>
|
|
<dd><p>The @gotplt modifier can be used for .long and .quad. A procedure linkage
|
|
table entry is generated for the symbol and a jump slot for the symbol
|
|
is added to the GOT. The symbol term is replaced with the offset from the
|
|
start of the GOT to the jump slot for the symbol.
|
|
</p></dd>
|
|
<dt><code>@plt</code></dt>
|
|
<dd><p>The @plt modifier can be used for .long and .quad. A procedure linkage
|
|
table entry us generated for the symbol. The symbol term is replaced with
|
|
the address of the PLT entry for the symbol.
|
|
</p></dd>
|
|
<dt><code>@pltoff</code></dt>
|
|
<dd><p>The @pltoff modifier can be used for .short, .long and .quad. The symbol
|
|
term is replaced with the offset from the start of the PLT to the address
|
|
of the symbol.
|
|
</p></dd>
|
|
<dt><code>@tlsgd</code></dt>
|
|
<dt><code>@tlsldm</code></dt>
|
|
<dd><p>The @tlsgd and @tlsldm modifier can be used for .long and .quad. A
|
|
tls_index structure for the symbol is added to the GOT. The symbol term is
|
|
replaced with the offset from the start of the GOT to the tls_index structure.
|
|
</p></dd>
|
|
<dt><code>@gotntpoff</code></dt>
|
|
<dt><code>@indntpoff</code></dt>
|
|
<dd><p>The @gotntpoff and @indntpoff modifier can be used for .long and .quad.
|
|
The symbol is added to the static TLS block and the negated offset to the
|
|
symbol in the static TLS block is added to the GOT. For @gotntpoff the
|
|
symbol term is replaced with the offset from the start of the GOT to the
|
|
GOT slot, for @indntpoff the symbol term is replaced with the address
|
|
of the GOT slot.
|
|
</p></dd>
|
|
<dt><code>@dtpoff</code></dt>
|
|
<dd><p>The @dtpoff modifier can be used for .long and .quad. The symbol term
|
|
is replaced with the offset of the symbol relative to the start of the
|
|
TLS block it is contained in.
|
|
</p></dd>
|
|
<dt><code>@ntpoff</code></dt>
|
|
<dd><p>The @ntpoff modifier can be used for .long and .quad. The symbol term
|
|
is replaced with the offset of the symbol relative to the TCB pointer.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<p>For more information about the thread local storage modifiers see the
|
|
ELF extension documentation ‘<samp>ELF Handling For Thread-Local Storage</samp>’.
|
|
</p>
|
|
<a name="index-_002eltorg-directive_002c-s390"></a>
|
|
</dd>
|
|
<dt><code>.ltorg</code></dt>
|
|
<dd><p>This directive causes the current contents of the literal pool to be
|
|
dumped to the current location (<a href="s390-Literal-Pool-Entries.html#s390-Literal-Pool-Entries">s390 Literal Pool Entries</a>).
|
|
</p>
|
|
<a name="index-_002emachine-directive_002c-s390"></a>
|
|
</dd>
|
|
<dt><code>.machine <var>STRING</var>[+<var>EXTENSION</var>]…</code></dt>
|
|
<dd>
|
|
<p>This directive allows changing the machine for which code is
|
|
generated. <code>string</code> may be any of the <code>-march=</code>
|
|
selection options, or <code>push</code>, or <code>pop</code>. <code>.machine
|
|
push</code> saves the currently selected cpu, which may be restored with
|
|
<code>.machine pop</code>. Be aware that the cpu string has to be put
|
|
into double quotes in case it contains characters not appropriate
|
|
for identifiers. So you have to write <code>"z9-109"</code> instead of
|
|
just <code>z9-109</code>. Extensions can be specified after the cpu
|
|
name, separated by plus characters. Valid extensions are:
|
|
<code>htm</code>,
|
|
<code>nohtm</code>,
|
|
<code>vx</code>,
|
|
<code>novx</code>.
|
|
They extend the basic instruction set with features from a higher
|
|
cpu level, or remove support for a feature from the given cpu
|
|
level.
|
|
</p>
|
|
<p>Example: <code>z13+nohtm</code> allows all instructions of the z13 cpu
|
|
except instructions from the HTM facility.
|
|
</p>
|
|
<a name="index-_002emachinemode-directive_002c-s390"></a>
|
|
</dd>
|
|
<dt><code>.machinemode string</code></dt>
|
|
<dd><p>This directive allows to change the architecture mode for which code
|
|
is being generated. <code>string</code> may be <code>esa</code>, <code>zarch</code>,
|
|
<code>zarch_nohighgprs</code>, <code>push</code>, or <code>pop</code>.
|
|
<code>.machinemode zarch_nohighgprs</code> can be used to prevent the
|
|
<code>highgprs</code> flag from being set in the ELF header of the output
|
|
file. This is useful in situations where the code is gated with a
|
|
runtime check which makes sure that the code is only executed on
|
|
kernels providing the <code>highgprs</code> feature.
|
|
<code>.machinemode push</code> saves the currently selected mode, which may
|
|
be restored with <code>.machinemode pop</code>.
|
|
</p></dd>
|
|
</dl>
|
|
|
|
<hr>
|
|
<div class="header">
|
|
<p>
|
|
Next: <a href="s390-Floating-Point.html#s390-Floating-Point" accesskey="n" rel="next">s390 Floating Point</a>, Previous: <a href="s390-Syntax.html#s390-Syntax" accesskey="p" rel="prev">s390 Syntax</a>, Up: <a href="S_002f390_002dDependent.html#S_002f390_002dDependent" accesskey="u" rel="up">S/390-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>
|