<html lang="en">
<head>
<title>Opcodes for i860 - Using as</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="Using as">
<meta name="generator" content="makeinfo 4.13">
<link title="Top" rel="start" href="index.html#Top">
<link rel="up" href="i860_002dDependent.html#i860_002dDependent" title="i860-Dependent">
<link rel="prev" href="Directives_002di860.html#Directives_002di860" title="Directives-i860">
<link rel="next" href="Syntax-of-i860.html#Syntax-of-i860" title="Syntax of i860">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<!--
This file documents the GNU Assembler "as".
Copyright (C) 1991-2015 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''.
-->
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family:serif; font-weight:normal; }
span.sansserif { font-family:sans-serif; font-weight:normal; }
--></style>
</head>
<body>
<div class="node">
<a name="Opcodes-for-i860"></a>
<p>
Next: <a rel="next" accesskey="n" href="Syntax-of-i860.html#Syntax-of-i860">Syntax of i860</a>,
Previous: <a rel="previous" accesskey="p" href="Directives_002di860.html#Directives_002di860">Directives-i860</a>,
Up: <a rel="up" accesskey="u" href="i860_002dDependent.html#i860_002dDependent">i860-Dependent</a>
<hr>
</div>
<h4 class="subsection">9.16.4 i860 Opcodes</h4>
<p><a name="index-opcodes_002c-i860-1170"></a><a name="index-i860-opcodes-1171"></a>All of the Intel i860XR and i860XP machine instructions are supported. Please see
either <em>i860 Microprocessor Programmer's Reference Manual</em> or <em>i860 Microprocessor Architecture</em> for more information.
<h5 class="subsubsection">9.16.4.1 Other instruction support (pseudo-instructions)</h5>
<p>For compatibility with some other i860 assemblers, a number of
pseudo-instructions are supported. While these are supported, they are
a very undesirable feature that should be avoided – in particular, when
they result in an expansion to multiple actual i860 instructions. Below
are the pseudo-instructions that result in expansions.
<ul>
<li>Load large immediate into general register:
<p>The pseudo-instruction <code>mov imm,%rn</code> (where the immediate does
not fit within a signed 16-bit field) will be expanded into:
<pre class="smallexample"> orh large_imm@h,%r0,%rn
or large_imm@l,%rn,%rn
</pre>
<li>Load/store with relocatable address expression:
<p>For example, the pseudo-instruction <code>ld.b addr_exp(%rx),%rn</code>
will be expanded into:
<pre class="smallexample"> orh addr_exp@ha,%rx,%r31
ld.l addr_exp@l(%r31),%rn
</pre>
<p>The analogous expansions apply to <code>ld.x, st.x, fld.x, pfld.x, fst.x</code>, and <code>pst.x</code> as well.
<li>Signed large immediate with add/subtract:
<p>If any of the arithmetic operations <code>adds, addu, subs, subu</code> are used
with an immediate larger than 16-bits (signed), then they will be expanded.
For instance, the pseudo-instruction <code>adds large_imm,%rx,%rn</code> expands to:
<pre class="smallexample"> orh large_imm@h,%r0,%r31
or large_imm@l,%r31,%r31
adds %r31,%rx,%rn
</pre>
<li>Unsigned large immediate with logical operations:
<p>Logical operations (<code>or, andnot, or, xor</code>) also result in expansions.
The pseudo-instruction <code>or large_imm,%rx,%rn</code> results in:
<pre class="smallexample"> orh large_imm@h,%rx,%r31
or large_imm@l,%r31,%rn
</pre>
<p>Similarly for the others, except for <code>and</code> which expands to:
<pre class="smallexample"> andnot (-1 - large_imm)@h,%rx,%r31
andnot (-1 - large_imm)@l,%r31,%rn
</pre>
</ul>
</body></html>