mirror of https://github.com/odrling/Aegisub
187 lines
7.5 KiB
HTML
187 lines
7.5 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
|
||
|
|
<html>
|
||
|
|
<head>
|
||
|
|
<title>Frequently Asked Questions (FAQ)</title>
|
||
|
|
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
|
||
|
|
<meta name="Author" content="Mike Pall">
|
||
|
|
<meta name="Copyright" content="Copyright (C) 2005-2017, Mike Pall">
|
||
|
|
<meta name="Language" content="en">
|
||
|
|
<link rel="stylesheet" type="text/css" href="bluequad.css" media="screen">
|
||
|
|
<link rel="stylesheet" type="text/css" href="bluequad-print.css" media="print">
|
||
|
|
<style type="text/css">
|
||
|
|
dd { margin-left: 1.5em; }
|
||
|
|
</style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div id="site">
|
||
|
|
<a href="http://luajit.org"><span>Lua<span id="logo">JIT</span></span></a>
|
||
|
|
</div>
|
||
|
|
<div id="head">
|
||
|
|
<h1>Frequently Asked Questions (FAQ)</h1>
|
||
|
|
</div>
|
||
|
|
<div id="nav">
|
||
|
|
<ul><li>
|
||
|
|
<a href="luajit.html">LuaJIT</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="http://luajit.org/download.html">Download <span class="ext">»</span></a>
|
||
|
|
</li><li>
|
||
|
|
<a href="install.html">Installation</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="running.html">Running</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="extensions.html">Extensions</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="ext_ffi.html">FFI Library</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="ext_ffi_tutorial.html">FFI Tutorial</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_ffi_api.html">ffi.* API</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_ffi_semantics.html">FFI Semantics</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_jit.html">jit.* Library</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_c_api.html">Lua/C API</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="ext_profiler.html">Profiler</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a href="status.html">Status</a>
|
||
|
|
<ul><li>
|
||
|
|
<a href="changes.html">Changes</a>
|
||
|
|
</li></ul>
|
||
|
|
</li><li>
|
||
|
|
<a class="current" href="faq.html">FAQ</a>
|
||
|
|
</li><li>
|
||
|
|
<a href="http://luajit.org/performance.html">Performance <span class="ext">»</span></a>
|
||
|
|
</li><li>
|
||
|
|
<a href="http://wiki.luajit.org/">Wiki <span class="ext">»</span></a>
|
||
|
|
</li><li>
|
||
|
|
<a href="http://luajit.org/list.html">Mailing List <span class="ext">»</span></a>
|
||
|
|
</li></ul>
|
||
|
|
</div>
|
||
|
|
<div id="main">
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Where can I learn more about LuaJIT and Lua?</dt>
|
||
|
|
<dd>
|
||
|
|
<ul style="padding: 0;">
|
||
|
|
<li>The <a href="http://luajit.org/list.html"><span class="ext">»</span> LuaJIT mailing list</a> focuses on topics
|
||
|
|
related to LuaJIT.</li>
|
||
|
|
<li>The <a href="http://wiki.luajit.org/"><span class="ext">»</span> LuaJIT wiki</a> gathers community
|
||
|
|
resources about LuaJIT.</li>
|
||
|
|
<li>News about Lua itself can be found at the
|
||
|
|
<a href="http://www.lua.org/lua-l.html"><span class="ext">»</span> Lua mailing list</a>.
|
||
|
|
The mailing list archives are worth checking out for older postings
|
||
|
|
about LuaJIT.</li>
|
||
|
|
<li>The <a href="http://lua.org"><span class="ext">»</span> main Lua.org site</a> has complete
|
||
|
|
<a href="http://www.lua.org/docs.html"><span class="ext">»</span> documentation</a> of the language
|
||
|
|
and links to books and papers about Lua.</li>
|
||
|
|
<li>The community-managed <a href="http://lua-users.org/wiki/"><span class="ext">»</span> Lua Wiki</a>
|
||
|
|
has information about diverse topics.</li>
|
||
|
|
</ul>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Where can I learn more about the compiler technology used by LuaJIT?</dt>
|
||
|
|
<dd>
|
||
|
|
I'm planning to write more documentation about the internals of LuaJIT.
|
||
|
|
In the meantime, please use the following Google Scholar searches
|
||
|
|
to find relevant papers:<br>
|
||
|
|
Search for: <a href="http://scholar.google.com/scholar?q=Trace+Compiler"><span class="ext">»</span> Trace Compiler</a><br>
|
||
|
|
Search for: <a href="http://scholar.google.com/scholar?q=JIT+Compiler"><span class="ext">»</span> JIT Compiler</a><br>
|
||
|
|
Search for: <a href="http://scholar.google.com/scholar?q=Dynamic+Language+Optimizations"><span class="ext">»</span> Dynamic Language Optimizations</a><br>
|
||
|
|
Search for: <a href="http://scholar.google.com/scholar?q=SSA+Form"><span class="ext">»</span> SSA Form</a><br>
|
||
|
|
Search for: <a href="http://scholar.google.com/scholar?q=Linear+Scan+Register+Allocation"><span class="ext">»</span> Linear Scan Register Allocation</a><br>
|
||
|
|
Here is a list of the <a href="http://article.gmane.org/gmane.comp.lang.lua.general/58908"><span class="ext">»</span> innovative features in LuaJIT</a>.<br>
|
||
|
|
And, you know, reading the source is of course the only way to enlightenment. :-)
|
||
|
|
</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Why do I get this error: "attempt to index global 'arg' (a nil value)"?<br>
|
||
|
|
Q: My vararg functions fail after switching to LuaJIT!</dt>
|
||
|
|
<dd>LuaJIT is compatible to the Lua 5.1 language standard. It doesn't
|
||
|
|
support the implicit <tt>arg</tt> parameter for old-style vararg
|
||
|
|
functions from Lua 5.0.<br>Please convert your code to the
|
||
|
|
<a href="http://www.lua.org/manual/5.1/manual.html#2.5.9"><span class="ext">»</span> Lua 5.1
|
||
|
|
vararg syntax</a>.</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Why do I get this error: "bad FPU precision"?<br>
|
||
|
|
<dt>Q: I get weird behavior after initializing Direct3D.<br>
|
||
|
|
<dt>Q: Some FPU operations crash after I load a Delphi DLL.<br>
|
||
|
|
</dt>
|
||
|
|
<dd>
|
||
|
|
|
||
|
|
DirectX/Direct3D (up to version 9) sets the x87 FPU to single-precision
|
||
|
|
mode by default. This violates the Windows ABI and interferes with the
|
||
|
|
operation of many programs — LuaJIT is affected, too. Please make
|
||
|
|
sure you always use the <tt>D3DCREATE_FPU_PRESERVE</tt> flag when
|
||
|
|
initializing Direct3D.<br>
|
||
|
|
|
||
|
|
Direct3D version 10 or higher do not show this behavior anymore.
|
||
|
|
Consider testing your application with older versions, too.<br>
|
||
|
|
|
||
|
|
Similarly, the Borland/Delphi runtime modifies the FPU control word and
|
||
|
|
enables FP exceptions. Of course this violates the Windows ABI, too.
|
||
|
|
Please check the Delphi docs for the Set8087CW method.
|
||
|
|
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Sometimes Ctrl-C fails to stop my Lua program. Why?</dt>
|
||
|
|
<dd>The interrupt signal handler sets a Lua debug hook. But this is
|
||
|
|
currently ignored by compiled code (this will eventually be fixed). If
|
||
|
|
your program is running in a tight loop and never falls back to the
|
||
|
|
interpreter, the debug hook never runs and can't throw the
|
||
|
|
"interrupted!" error.<br> In the meantime you have to press Ctrl-C
|
||
|
|
twice to get stop your program. That's similar to when it's stuck
|
||
|
|
running inside a C function under the Lua interpreter.</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Why doesn't my favorite power-patch for Lua apply against LuaJIT?</dt>
|
||
|
|
<dd>Because it's a completely redesigned VM and has very little code
|
||
|
|
in common with Lua anymore. Also, if the patch introduces changes to
|
||
|
|
the Lua semantics, these would need to be reflected everywhere in the
|
||
|
|
VM, from the interpreter up to all stages of the compiler.<br> Please
|
||
|
|
use only standard Lua language constructs. For many common needs you
|
||
|
|
can use source transformations or use wrapper or proxy functions.
|
||
|
|
The compiler will happily optimize away such indirections.</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: Lua runs everywhere. Why doesn't LuaJIT support my CPU?</dt>
|
||
|
|
<dd>Because it's a compiler — it needs to generate native
|
||
|
|
machine code. This means the code generator must be ported to each
|
||
|
|
architecture. And the fast interpreter is written in assembler and
|
||
|
|
must be ported, too. This is quite an undertaking.<br>
|
||
|
|
The <a href="install.html">install documentation</a> shows the supported
|
||
|
|
architectures. Other architectures will follow based on sufficient user
|
||
|
|
demand and/or sponsoring.</dd>
|
||
|
|
</dl>
|
||
|
|
|
||
|
|
<dl>
|
||
|
|
<dt>Q: When will feature X be added? When will the next version be released?</dt>
|
||
|
|
<dd>When it's ready.<br>
|
||
|
|
C'mon, it's open source — I'm doing it on my own time and you're
|
||
|
|
getting it for free. You can either contribute a patch or sponsor
|
||
|
|
the development of certain features, if they are important to you.
|
||
|
|
</dd>
|
||
|
|
</dl>
|
||
|
|
<br class="flush">
|
||
|
|
</div>
|
||
|
|
<div id="foot">
|
||
|
|
<hr class="hide">
|
||
|
|
Copyright © 2005-2017 Mike Pall
|
||
|
|
<span class="noprint">
|
||
|
|
·
|
||
|
|
<a href="contact.html">Contact</a>
|
||
|
|
</span>
|
||
|
|
</div>
|
||
|
|
</body>
|
||
|
|
</html>
|