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.
165 lines
7.4 KiB
HTML
165 lines
7.4 KiB
HTML
<html lang="en">
|
|
<head>
|
|
<title>Sparc-Constants - Using as</title>
|
|
<meta http-equiv="Content-Type" content="text/html">
|
|
<meta name="description" content="Using as">
|
|
<meta name="generator" content="makeinfo 4.7">
|
|
<link title="Top" rel="start" href="index.html#Top">
|
|
<link rel="up" href="Sparc_002dSyntax.html#Sparc_002dSyntax" title="Sparc-Syntax">
|
|
<link rel="prev" href="Sparc_002dRegs.html#Sparc_002dRegs" title="Sparc-Regs">
|
|
<link rel="next" href="Sparc_002dRelocs.html#Sparc_002dRelocs" title="Sparc-Relocs">
|
|
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
|
|
<!--
|
|
This file documents the GNU Assembler "as".
|
|
|
|
Copyright (C) 1991, 92, 93, 94, 95, 96, 97, 98, 99, 2000, 2001, 2002,
|
|
2006, 2007 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 1.1
|
|
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''.
|
|
|
|
man end-->
|
|
<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; }
|
|
--></style>
|
|
</head>
|
|
<body>
|
|
<div class="node">
|
|
<p>
|
|
<a name="Sparc_002dConstants"></a>Next: <a rel="next" accesskey="n" href="Sparc_002dRelocs.html#Sparc_002dRelocs">Sparc-Relocs</a>,
|
|
Previous: <a rel="previous" accesskey="p" href="Sparc_002dRegs.html#Sparc_002dRegs">Sparc-Regs</a>,
|
|
Up: <a rel="up" accesskey="u" href="Sparc_002dSyntax.html#Sparc_002dSyntax">Sparc-Syntax</a>
|
|
<hr><br>
|
|
</div>
|
|
|
|
<h5 class="subsubsection">9.30.3.3 Constants</h5>
|
|
|
|
<p><a name="index-Sparc-constants-1516"></a><a name="index-constants_002c-Sparc-1517"></a>
|
|
Several Sparc instructions take an immediate operand field for
|
|
which mnemonic names exist. Two such examples are <span class="samp">membar</span>
|
|
and <span class="samp">prefetch</span>. Another example are the set of V9
|
|
memory access instruction that allow specification of an
|
|
address space identifier.
|
|
|
|
<p>The <span class="samp">membar</span> instruction specifies a memory barrier that is
|
|
the defined by the operand which is a bitmask. The supported
|
|
mask mnemonics are:
|
|
|
|
<ul>
|
|
<li><span class="samp">#Sync</span> requests that all operations (including nonmemory
|
|
reference operations) appearing prior to the <code>membar</code> must have
|
|
been performed and the effects of any exceptions become visible before
|
|
any instructions after the <code>membar</code> may be initiated. This
|
|
corresponds to <code>membar</code> cmask field bit 2.
|
|
|
|
<li><span class="samp">#MemIssue</span> requests that all memory reference operations
|
|
appearing prior to the <code>membar</code> must have been performed before
|
|
any memory operation after the <code>membar</code> may be initiated. This
|
|
corresponds to <code>membar</code> cmask field bit 1.
|
|
|
|
<li><span class="samp">#Lookaside</span> requests that a store appearing prior to the
|
|
<code>membar</code> must complete before any load following the
|
|
<code>membar</code> referencing the same address can be initiated. This
|
|
corresponds to <code>membar</code> cmask field bit 0.
|
|
|
|
<li><span class="samp">#StoreStore</span> defines that the effects of all stores appearing
|
|
prior to the <code>membar</code> instruction must be visible to all
|
|
processors before the effect of any stores following the
|
|
<code>membar</code>. Equivalent to the deprecated <code>stbar</code> instruction.
|
|
This corresponds to <code>membar</code> mmask field bit 3.
|
|
|
|
<li><span class="samp">#LoadStore</span> defines all loads appearing prior to the
|
|
<code>membar</code> instruction must have been performed before the effect
|
|
of any stores following the <code>membar</code> is visible to any other
|
|
processor. This corresponds to <code>membar</code> mmask field bit 2.
|
|
|
|
<li><span class="samp">#StoreLoad</span> defines that the effects of all stores appearing
|
|
prior to the <code>membar</code> instruction must be visible to all
|
|
processors before loads following the <code>membar</code> may be performed.
|
|
This corresponds to <code>membar</code> mmask field bit 1.
|
|
|
|
<li><span class="samp">#LoadLoad</span> defines that all loads appearing prior to the
|
|
<code>membar</code> instruction must have been performed before any loads
|
|
following the <code>membar</code> may be performed. This corresponds to
|
|
<code>membar</code> mmask field bit 0.
|
|
|
|
</ul>
|
|
|
|
<p>These values can be ored together, for example:
|
|
|
|
<pre class="example"> membar #Sync
|
|
membar #StoreLoad | #LoadLoad
|
|
membar #StoreLoad | #StoreStore
|
|
</pre>
|
|
<p>The <code>prefetch</code> and <code>prefetcha</code> instructions take a prefetch
|
|
function code. The following prefetch function code constant
|
|
mnemonics are available:
|
|
|
|
<ul>
|
|
<li><span class="samp">#n_reads</span> requests a prefetch for several reads, and corresponds
|
|
to a prefetch function code of 0.
|
|
|
|
<p><span class="samp">#one_read</span> requests a prefetch for one read, and corresponds
|
|
to a prefetch function code of 1.
|
|
|
|
<p><span class="samp">#n_writes</span> requests a prefetch for several writes (and possibly
|
|
reads), and corresponds to a prefetch function code of 2.
|
|
|
|
<p><span class="samp">#one_write</span> requests a prefetch for one write, and corresponds
|
|
to a prefetch function code of 3.
|
|
|
|
<p><span class="samp">#page</span> requests a prefetch page, and corresponds to a prefetch
|
|
function code of 4.
|
|
|
|
<p><span class="samp">#invalidate</span> requests a prefetch invalidate, and corresponds to
|
|
a prefetch function code of 16.
|
|
|
|
<p><span class="samp">#unified</span> requests a prefetch to the nearest unified cache, and
|
|
corresponds to a prefetch function code of 17.
|
|
|
|
<p><span class="samp">#n_reads_strong</span> requests a strong prefetch for several reads,
|
|
and corresponds to a prefetch function code of 20.
|
|
|
|
<p><span class="samp">#one_read_strong</span> requests a strong prefetch for one read,
|
|
and corresponds to a prefetch function code of 21.
|
|
|
|
<p><span class="samp">#n_writes_strong</span> requests a strong prefetch for several writes,
|
|
and corresponds to a prefetch function code of 22.
|
|
|
|
<p><span class="samp">#one_write_strong</span> requests a strong prefetch for one write,
|
|
and corresponds to a prefetch function code of 23.
|
|
|
|
<p>Onle one prefetch code may be specified. Here are some examples:
|
|
|
|
<pre class="example"> prefetch [%l0 + %l2], #one_read
|
|
prefetch [%g2 + 8], #n_writes
|
|
prefetcha [%g1] 0x8, #unified
|
|
prefetcha [%o0 + 0x10] %asi, #n_reads
|
|
</pre>
|
|
<p>The actual behavior of a given prefetch function code is processor
|
|
specific. If a processor does not implement a given prefetch
|
|
function code, it will treat the prefetch instruction as a nop.
|
|
|
|
<p>For instructions that accept an immediate address space identifier,
|
|
<code>as</code> provides many mnemonics corresponding to
|
|
V9 defined as well as UltraSPARC and Niagara extended values.
|
|
For example, <span class="samp">#ASI_P</span> and <span class="samp">#ASI_BLK_INIT_QUAD_LDD_AIUS</span>.
|
|
See the V9 and processor specific manuals for details.
|
|
|
|
</ul>
|
|
|
|
</body></html>
|
|
|