i386-bugs.html

来自「gcc手册」· HTML 代码 · 共 40 行

HTML
40 行
字号 
<html lang="en">

<head>

<title>Using as</title>

<meta http-equiv="Content-Type" content="text/html">

<meta name="description" content="Using as">

<meta name="generator" content="makeinfo 4.3">

<link href="http://www.gnu.org/software/texinfo/" rel="generator-home">

</head>

<body>

<div class="node">

<p>

Node:<a name="i386-Bugs">i386-Bugs</a>,

Next:<a rel="next" accesskey="n" href="i386-Notes.html#i386-Notes">i386-Notes</a>,

Previous:<a rel="previous" accesskey="p" href="i386-Arch.html#i386-Arch">i386-Arch</a>,

Up:<a rel="up" accesskey="u" href="i386-Dependent.html#i386-Dependent">i386-Dependent</a>

<hr><br>

</div>



<h4 class="section">AT&amp;T Syntax bugs</h4>



   <p>The UnixWare assembler, and probably other AT&amp;T derived ix86 Unix

assemblers, generate floating point instructions with reversed source

and destination registers in certain cases.  Unfortunately, gcc and

possibly many other programs use this reversed syntax, so we're stuck

with it.



   <p>For example



<pre class="smallexample">             fsub %st,%st(3)

     </pre>



<p>results in <code>%st(3)</code> being updated to <code>%st - %st(3)</code> rather

than the expected <code>%st(3) - %st</code>.  This happens with all the

non-commutative arithmetic floating point operations with two register

operands where the source register is <code>%st</code> and the destination

register is <code>%st(i)</code>.



   </body></html>

i386-bugs.html - 源码说明

本页面展示了「gcc手册」中的 i386-bugs.html 源码文件，采用 HTML 编程语言编写，共 40 行代码。您可以在线阅读完整代码内容，也可以返回资源详情页下载完整源码包进行本地学习和开发。

虫虫开发者社区收录了大量与gcc相关的技术资源，包括源代码、技术文档、电路图等，是电子工程师和嵌入式开发者的专业学习平台。

⌨️ 快捷键说明

复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?