Landon Curt Noll
a9ca93ec47
Add "<!-- BEFORE: 1st line of markdown file: FILE/PATH -->" before the markdown content. This line appears in the generated HTML. Add "<!-- AFTER: last line of markdown file: FILE/PATH -->" after the markdown content. This line appears in the generated HTML. We test a fix relating to problems produced by `pandoc(1)` when footnotes are added at the end of generated HTML. This test is made for `2000/bmeyer/index.html`. Fixed exit 4 in `bin/md2html.sh that should be exit 5. Changed `bin/md2html.sh` VERSION from to "1.3 2024-04-14" to "1.4 2024-04-18". Run `bin/readme2index.sh -v 1 2000/bmeyer` to perform the above.
330 lines
16 KiB
HTML
330 lines
16 KiB
HTML
<!DOCTYPE html>
|
||
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
|
||
<!-- START: two lines up starts content from: inc/top.default.html -->
|
||
|
||
<!-- END: this line ends content from: inc/top.default.html -->
|
||
<!-- START: this line starts content from: inc/head.default.html -->
|
||
|
||
<head>
|
||
<link rel="stylesheet" href="../../ioccc.css">
|
||
<link href="https://fonts.googleapis.com/css2?family=Outfit:wght@100..900&display=swap" rel="stylesheet">
|
||
<meta charset="utf-8">
|
||
<meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
|
||
<title>2015/hou - Most Well-rounded Hash</title>
|
||
<link rel="icon" type="image/x-icon" href="../../favicon.ico">
|
||
<meta name="description" content="2015 IOCCC entry hou - Most Well-rounded Hash">
|
||
<meta name="keywords" content="IOCCC, 2015, IOCCC 2015, IOCCC entry, hou, Most Well-rounded Hash">
|
||
</head>
|
||
|
||
<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
|
||
<!-- !!! DO NOT MODIFY THIS FILE - This file is generated by a tool !!! -->
|
||
<!-- !!! DO NOT MODIFY THIS FILE - This file is generated by a tool !!! -->
|
||
<!-- !!! DO NOT MODIFY THIS FILE - This file is generated by a tool !!! -->
|
||
<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
|
||
|
||
<!-- END: this line ends content from: inc/head.default.html -->
|
||
|
||
<!-- -->
|
||
<!-- This web page was formed via the tool: bin/readme2index.sh -->
|
||
<!-- The content of main section of this web page came from: 2015/hou/README.md -->
|
||
<!-- -->
|
||
|
||
<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
|
||
<!-- !!! Do not modify this web page, instead modify the file: 2015/hou/README.md !!! -->
|
||
<!-- !!! Do not modify this web page, instead modify the file: 2015/hou/README.md !!! -->
|
||
<!-- !!! Do not modify this web page, instead modify the file: 2015/hou/README.md !!! -->
|
||
<!-- !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! -->
|
||
|
||
<!-- Markdown content was converted into HTML via the tool: bin/md2html.sh -->
|
||
|
||
<!-- START: this line starts content from: inc/body.default.html -->
|
||
|
||
<body>
|
||
|
||
<!-- END: this line ends content from: inc/body.default.html -->
|
||
<!-- START: this line starts content from: inc/topbar.default.html -->
|
||
|
||
<div class="theader">
|
||
<nav class="topbar">
|
||
<div class="container">
|
||
<div class="logo">
|
||
IOCCC
|
||
</div>
|
||
|
||
<div class="topbar-items">
|
||
<div class="item">
|
||
<span class="item-header">
|
||
Home
|
||
</span>
|
||
|
||
<div class="sub-item">
|
||
<div class="outfit-font"><a href="../../index.html">IOCCC Home</a></div>
|
||
<div class="outfit-font"><a href="../../years.html">Winning Entries</a></div>
|
||
<div class="outfit-font"><a href="../../authors.html">People who have won</a></div>
|
||
<div class="outfit-font"><a href="../../location.html">Location of authors</a></div>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="item">
|
||
<span class="item-header">
|
||
News
|
||
</span>
|
||
|
||
<div class="sub-item">
|
||
<div class="outfit-font"><a href="../../news.html">IOCCC News</a></div>
|
||
<div class="outfit-font"><a href="../../status.html">Contest status</a></div>
|
||
<div class="outfit-font"><a href="../../next/index.html">Rules and Guidelines</a></div>
|
||
<div class="outfit-font"><a href="../../faq.html#submit">How to enter the IOCCC</a></div>
|
||
<div class="outfit-font"><a href="../../faq.html">FAQ</a></div>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="item">
|
||
<span class="item-header">
|
||
Bugs
|
||
</span>
|
||
|
||
<div class="sub-item">
|
||
<div class="outfit-font"><a href="../../bugs.html">Bugs & (mis)features</a></div>
|
||
<div class="outfit-font"><a href="../../faq.html#fix_an_entry">Fixing IOCCC entries</a></div>
|
||
<div class="outfit-font"><a href="../../faq.html#fix_web_site">Fixing the web site</a></div>
|
||
<div class="outfit-font"><a href="../../faq.html#fix_author">Fixing author info</a></div>
|
||
<div class="outfit-font"><a href="../../thanks-for-help.html">Thanks for the help</a></div>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="item">
|
||
<span class="item-header">
|
||
Judges
|
||
</span>
|
||
|
||
<div class="sub-item">
|
||
<div class="outfit-font"><a href="../../judges.html">The IOCCC Judges</a></div>
|
||
<div class="outfit-font"><a href="../../contact.html">Contacting the IOCCC</a></div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</nav>
|
||
</div>
|
||
|
||
<!-- END: this line ends content from: inc/topbar.default.html -->
|
||
<!-- START: this line starts content from: inc/header.default.html -->
|
||
|
||
<div class="header">
|
||
<img src="../../png/ioccc.png" alt="IOCCC image by Matt Zucker" width=300 height=110>
|
||
<h1>The International Obfuscated C Code Contest</h1>
|
||
<h2>2015/hou - Most Well-rounded Hash</h2>
|
||
</div>
|
||
|
||
<!-- END: this line ends content from: inc/header.default.html -->
|
||
<!-- START: this line starts content from: inc/navbar.mid.html -->
|
||
|
||
<div class="navbar">
|
||
<a class="Left" href="../endoh4/index.html">← endoh4</a>
|
||
<a class="Left" href="../index.html">↑ 2015 ↑</a>
|
||
<a class="Left" href="../howe/index.html">howe →</a>
|
||
<a class="Right" href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/prog.c">C code</a>
|
||
<a class="Right" href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/Makefile">Makefile</a>
|
||
<a class="Right" href="#inventory">Inventory</a>
|
||
<a class="Right" href="https://validator.w3.org/nu/?doc=https%3A%2F%2Fioccc-src.github.io%2Ftemp-test-ioccc%2F2015%2Fhou%2Findex.html">✓</a>
|
||
</div>
|
||
|
||
<!-- END: this line ends content from: inc/navbar.mid.html -->
|
||
<!-- START: this line starts content from: inc/before-content.default.html -->
|
||
|
||
<div class="content" id="content">
|
||
|
||
<!-- END: this line ends content from: inc/before-content.default.html -->
|
||
<!-- START: this line starts content for HTML phase 20 by: bin/output-index-author.sh via bin/md2html.sh -->
|
||
|
||
<!-- START: this line starts content generated by: bin/output-index-author.sh -->
|
||
|
||
<h2 id="author">Author:</h2>
|
||
<ul>
|
||
<li>Name: <a href="../../authors.html#Qiming_HOU">Qiming HOU</a><br>
|
||
Location: <a href="../../location.html#CN">CN</a> - <em>People’s Republic of China</em> (<em>China</em>)</li>
|
||
</ul>
|
||
|
||
<!-- END: next line ends content generated by: bin/output-index-author.sh -->
|
||
|
||
<!-- END: this line ends content for HTML phase 20 by: bin/output-index-author.sh via bin/md2html.sh -->
|
||
<!-- START: this line starts content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
|
||
|
||
<!-- BEFORE: 1st line of markdown file: 2015/hou/README.md -->
|
||
<h2 id="to-build">To build:</h2>
|
||
<pre><code> make</code></pre>
|
||
<h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
|
||
<p>The current status of this entry is:</p>
|
||
<pre><code> STATUS: INABIAF - please **DO NOT** fix</code></pre>
|
||
<p>For more detailed information see <a href="../../bugs.html#2015_hou">2015 hou bugs</a>.</p>
|
||
<h2 id="to-use">To use:</h2>
|
||
<pre><code> echo something | ./prog
|
||
./prog < file</code></pre>
|
||
<h2 id="try">Try:</h2>
|
||
<pre><code> ./try.sh</code></pre>
|
||
<h2 id="judges-remarks">Judges’ remarks:</h2>
|
||
<p>A good start for understanding this entry might be
|
||
<a href="rfc1321.txt">rfc1321.txt</a>. How does it compute this using only a
|
||
single looping construct? The original reference source code for this
|
||
algorithm is about 355 lines of code, yet this entry is only 199 lines with
|
||
one statement per line and it isn’t using lots of macro expansion tricks like
|
||
the reference code!</p>
|
||
<p>Some things that make you go, “huh?”</p>
|
||
<pre><code> ./prog < prog.c | cut -c-5
|
||
./prog < Makefile | cut -c-4</code></pre>
|
||
<p>How are those values magically returned?</p>
|
||
<p>What happens with a large file? Something over 256K.</p>
|
||
<pre><code> ./prog < large_file</code></pre>
|
||
<p>Where does that message come from?</p>
|
||
<h2 id="authors-remarks">Author’s remarks:</h2>
|
||
<p>This looks like a normal C program.</p>
|
||
<p>Almost everything is a <code>double</code>.</p>
|
||
<p>There are tell-tale signs like <code>pow(2,(?/12))</code> and <code>exp(-?*?)</code> (names redacted).
|
||
You can also find a bunch of cosines and polynomial evaluations.</p>
|
||
<p>It looks like a ????? ???????????, right?</p>
|
||
<p>Run and find out.</p>
|
||
<h3 id="why-obfuscated">Why obfuscated</h3>
|
||
<p>Some poor scripting folks only have access to doubles (Jav?script, L?a, BA?IC,
|
||
etc.).</p>
|
||
<p>As a C programmer, I feel obliged to show a gesture of sympathy, to experience
|
||
their pain and provide an answer.</p>
|
||
<p>Except when absolutely necessary (<code>printf</code>, <code>int main()</code>, array indexing), there
|
||
isn’t a single integer. Even <code>getchar()</code> and <code>EOF</code> are immediately converted.</p>
|
||
<p>Since <code>bool</code> counts as an integer type too, there is no boolean either. No
|
||
comparison, no <code>if</code>, no <code>?:</code>, no <code>||</code> <code>&&</code>. Everything is done in a single loop
|
||
that terminates on <code>printf(3)</code>. Straight up arithmetic.</p>
|
||
<p><code>floor(3)</code> and <code>ceil(3)</code> are technically double-to-double functions, but they feel
|
||
like cheating. Yes <code>cos(3)</code>, no <code>floor(3)</code>.</p>
|
||
<h3 id="limitations">Limitations</h3>
|
||
<p>Hard requirements:</p>
|
||
<ul>
|
||
<li><p>The platform must implement the <code>double</code> type as IEEE754-compliant 64-bit
|
||
floating point numbers. The 80-bit intermediate format used by x87 is
|
||
considered as an violation of this. The code should print an error message on
|
||
such platforms.</p></li>
|
||
<li><p>The program must start with the CPU / FPU in round-to-nearest mode.</p></li>
|
||
</ul>
|
||
<p>Soft requirements:</p>
|
||
<ul>
|
||
<li><p>The compiler must respect <code>volatile</code>. The code is formatted to warn about
|
||
that, though.</p></li>
|
||
<li><p>The printed result is only correct on little-endian machines. The program
|
||
takes care to warn about this issue after printing an incorrect big-endian
|
||
result. Error messages become garbled, though.</p></li>
|
||
</ul>
|
||
<p>Tested platforms:</p>
|
||
<ul>
|
||
<li>Linux 3.18.7, Rasperberry Pi 2, clang 3.0-6.2, (works)</li>
|
||
<li>Linux 3.18.7, Rasperberry Pi 2, gcc 4.6.3, (works)</li>
|
||
<li>Mac OS X 10, x64, Apple LLVM version 6.1.0 (clang-602.0.53), (works)</li>
|
||
<li>Windows 8.1, x86, MSVC 2012 (works)</li>
|
||
<li>Windows 8.1, x64, MSVC 2012 (works)</li>
|
||
<li>Windows 8.1, x86, MinGW gcc 4.6.2 (fails, prints error message)</li>
|
||
<li>Windows 8.1, x86, MinGW gcc 4.6.2 with -msse2 -mfpmath=sse (works)</li>
|
||
</ul>
|
||
<!--
|
||
|
||
Copyright © 1984-2024 by Landon Curt Noll. All Rights Reserved.
|
||
|
||
You are free to share and adapt this file under the terms of this license:
|
||
|
||
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
|
||
|
||
For more information, see:
|
||
|
||
https://creativecommons.org/licenses/by-sa/4.0/
|
||
|
||
-->
|
||
<!-- AFTER: last line of markdown file: 2015/hou/README.md -->
|
||
|
||
<!-- END: this line ends content for HTML phase 21 by: bin/pandoc-wrapper.sh via bin/md2html.sh -->
|
||
<!-- START: this line starts content for HTML phase 22 by: bin/output-index-inventory.sh via bin/md2html.sh -->
|
||
|
||
<!-- START: this line starts content generated by: bin/output-index-inventory.sh -->
|
||
|
||
<div id="inventory">
|
||
<h1 id="inventory-for-2015hou">Inventory for 2015/hou</h1>
|
||
</div>
|
||
<p><a href="#top">Jump to top</a></p>
|
||
<h2 id="primary-files">Primary files</h2>
|
||
<ul>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/prog.c">prog.c</a> - entry source</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/Makefile">Makefile</a> - entry Makefile</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/prog.orig.c">prog.orig.c</a> - original source</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/try.sh">try.sh</a> - how to run</li>
|
||
<li><a href="rfc1321.txt">rfc1321.txt</a> - RFC 1321 - MD5 Message-Digest Algorithm</li>
|
||
</ul>
|
||
<h2 id="secondary-files">Secondary files</h2>
|
||
<ul>
|
||
<li><a href="2015_hou.tar.bz2">2015_hou.tar.bz2</a> - download entry tarball</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/README.md">README.md</a> - markdown source for this web page</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/.entry.json">.entry.json</a> - description of entry in JSON</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/.gitignore">.gitignore</a> - list of files that should not be committed under git</li>
|
||
<li><a href="large">large</a> - large input data</li>
|
||
<li><a href="https://github.com/ioccc-src/temp-test-ioccc/blob/master/2015/hou/.path">.path</a> - directory path from top directory</li>
|
||
<li><a href="index.html">index.html</a> - this web page</li>
|
||
</ul>
|
||
|
||
<!-- END: next line ends content generated by: bin/output-index-inventory.sh -->
|
||
|
||
<!-- END: this line ends content for HTML phase 22 by: bin/output-index-inventory.sh via bin/md2html.sh -->
|
||
<!-- START: this line starts content from: inc/after-content.default.html -->
|
||
|
||
</div>
|
||
|
||
<!-- END: this line ends content from: inc/after-content.default.html -->
|
||
<!-- START: this line starts content from: inc/footer.default.html -->
|
||
|
||
<!--
|
||
|
||
Copyright © 1984-2024 by Landon Curt Noll. All Rights Reserved.
|
||
|
||
You are free to share and adapt this file under the terms of this license:
|
||
|
||
Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
|
||
|
||
For more information, see:
|
||
|
||
https://creativecommons.org/licenses/by-sa/4.0/
|
||
|
||
-->
|
||
|
||
<div class="footer">
|
||
<div id="copyright"><h2>Copyright and CC BY-SA 4.0 License</h2></div>
|
||
<p>All IOCCC content including this file and web page are:</p>
|
||
<b> Copyright © 1984-2024 by Landon Curt Noll. <a href="https://creativecommons.org/faq/#what-does-some-rights-reserved-mean">Some Rights Reserved</a>.</b>
|
||
<p>This work is licensed by Landon Curt Noll under:</p>
|
||
<p><b><a href="https://creativecommons.org/licenses/by-sa/4.0/?ref=chooser-v1"
|
||
target="_blank" rel="license noopener noreferrer" style="display:inline-block;"> CC BY-SA 4.0
|
||
<img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
|
||
src="../../png/cc.png"
|
||
alt="cc inside circle symbol">
|
||
<img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
|
||
src="../../png/by.png"
|
||
alt="person inside circle symbol">
|
||
<img style="height:22px!important;margin-left:3px;vertical-align:text-bottom;"
|
||
src="../../png/sa.png"
|
||
alt="arrow looping back on itself inside circle symbol">
|
||
</a></b></p>
|
||
<p>The <b>CC BY-SA 4.0 LEGAL CODE</b> for this license is found under:</p>
|
||
<p> <b><a href="https://creativecommons.org/licenses/by-sa/4.0/legalcode.en">
|
||
https://creativecommons.org/licenses/by-sa/4.0/legalcode.en</a></b></p>
|
||
<p>You should <b>carefully review</b> all of the terms and conditions of the
|
||
<a href="https://creativecommons.org/licenses/by-sa/4.0/legalcode.en">actual license</a>
|
||
before using the licensed material.</p>
|
||
<p>You may wish to review the <b><a href="../../license.html">highlights of some of the key
|
||
features and terms</a></b> of the <a href="https://creativecommons.org/licenses/by-sa/4.0/legalcode.en">actual license</a>.</p>
|
||
<h2>Coda</h2>
|
||
<p><a href="https://validator.w3.org/nu/?doc=https%3A%2F%2Fioccc-src.github.io%2Ftemp-test-ioccc%2F2015%2Fhou%2Findex.html">Nu HTML check this web page</a></p>
|
||
<p><a href="#top">Jump to top</a> <a href="#content">Jump to Content</a> <a href="#inventory">Jump to Inventory</a></p>
|
||
</div>
|
||
|
||
<!-- END: this line ends content from: inc/footer.default.html -->
|
||
<!-- START: this line starts content from: inc/bottom.default.html -->
|
||
|
||
</body>
|
||
</html>
|
||
|
||
<!-- END: this line ends content from: inc/bottom.default.html -->
|