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improve prog.c and try.sh for 2024/kurdyukov4

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We improve `prog.c` beyond the 4M byte patch to reach 64M bytes.

The `try.sh` is made more robust, detecting both compiler and
executable problems that are **NOT** bugs in the code.

The code is now declared **INABIAF - please DO NOT fix**.
A detailed description of compiler, linker and resource
issues has been added to the `README.md` and `index.html`.
This commit is contained in:
Landon Curt Noll committed 2025-08-06 18:48:05 -07:00
1 parent 6811aa55ae
commit f098cf0872
7 files changed
+569 -83
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2024/kurdyukov4/index.html
+47 -15
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@@ -25,14 +25,14 @@
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@@ -447,7 +447,7 @@
<a class="Right" href="https://github.com/ioccc-src/winner/blob/master/2024/kurdyukov4/prog.c">C code</a>
<a class="Right" href="https://github.com/ioccc-src/winner/blob/master/2024/kurdyukov4/Makefile">Makefile</a>
<a class="Right" href="#inventory">Inventory</a>
<a class="Right" href="https://validator.w3.org/nu/?doc=https%3A%2F%2Fwww.ioccc.org%2F2024%2Fkurdyukov4%2Findex.html">&#x2713;</a>
<a class="Right" href="https://validator.w3.org/nu/?doc=#">&#x2713;</a>
</div>
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@@ -474,14 +474,7 @@ Location: <a href="../../location.html#RU">RU</a> - <em>Russian Federation</em>
<!-- BEFORE: 1st line of markdown file: 2024/kurdyukov4/README.md -->
<h2 id="to-build">To build:</h2>
<pre><code> make all</code></pre>
<h3 id="bugs-and-misfeatures">Bugs and (Mis)features:</h3>
<p>The current status of this entry is:</p>
<blockquote>
<p><strong>STATUS: known bug - please help us fix</strong></p>
</blockquote>
<p>For more detailed information see <a href="../../bugs.html#2024_kurdyukov4">2024/kurdyukov4 in bugs.html</a>.</p>
<p>In fixing this bug you will come to a better appreciation of how the
code was able to process random data files as large as 64K.</p>
<p>XXX - It is necessary to avoid collisions with C keywords when generating names for variables, for example: if do asm int for EOF.</p>
<h2 id="to-use">To use:</h2>
<pre><code> ./prog &lt; data &gt; out.c</code></pre>
<h2 id="try">Try:</h2>
@@ -495,6 +488,45 @@ the resulting program when run:</p>
./out &gt; output</code></pre>
<p>re-assemble the original input <strong>WITHOUT USING ANY LITERALS</strong> in the C code it produced!</p>
<p>You mind may go into a spiral as you attempt to read and understand how this is done. :-)</p>
<h3 id="large-input-size-issues">Large input size issues</h3>
<p>The author, <a href="../../authors.html#Ilya_Kurdyukov">Ilya Kurdyukov</a>, was
kind enough to provide us with an improvement to his amazing code that
allows for larger input sizes. To see what was patched run the following
within the <code>2024/kurdyukov4</code> directory:</p>
<pre><code> make make diff_orig_prog</code></pre>
<p>The above patch extended the original standard input size limit from 128K bytes to 64M bytes.</p>
<p>While the <a href="https://github.com/ioccc-src/winner/blob/master/2024/kurdyukov4/try.sh">2024/kurdyukov4/try.sh</a> script will attempt
to run the code in steps starting from 64K of random data up to 64M bytes of random data,
it is unlikely that you will be able to limitations by the compiler, linker, processor
architecture, memory, system, other resource limits if not run out of patience.</p>
<p>On fairly normal systems, we experienced the following while running
<a href="https://github.com/ioccc-src/winner/blob/master/2024/kurdyukov4/try.sh">2024/kurdyukov4/try.sh</a>:</p>
<pre><code> | random | | C code | compile time | compile time | |
| input | try.sh | size in | clang 17.0.0 | gcc 11.5.0 | |
| bytes | stage | bytes | Apple silicon | x86 64 | notes |
|--------|--------|-----------|---------------|----------------|----------------------------|
| 64K | test3 | 515764 | 10 sec | 75 sec | gcc 7.5x slower than clang |
| 1M | test4 | 3939019 | 80 sec | 1 hour 15 min | gcc 56x slower than clang |
| 4M | test5 | 13296449 | 1 min 50 sec | 14 hour 2 min | gcc 460x slower than clang |
| 16M | test6 | 136786072 | 4 min 40 sec | very long | clang excutable crashes |
| 64M | test7 | 200412713 | 44 min 40 sec | extremely long | clang excutable crashes |</code></pre>
<p>We never had the time nor resources to attempt to compile using <code>gcc(1)</code>, the code needed for
any random input larger than 4M bytes.</p>
<p>For 16M bytes and larger on Apple silicon, for random input size of 16M bytes and 64M bytes,
the <code>clang(1)</code> linker phase issues the following warning:</p>
<blockquote>
<p>ld: warning: atom ‘_main’ … is larger than the max code size between branch island clusters,
this may lead to unreachable branches</p>
</blockquote>
<p>If you attempt to run the <code>clang(1)</code> generated executable anyway, is crashes with:</p>
<blockquote>
<p>segmentation fault</p>
</blockquote>
<p>Compiling <code>gcc(1)</code> with a random input size of 16M bytes and 64M bytes was <strong>never attempted</strong>
because such a compile attempt would <strong>take too long</strong> and require a <strong>large amount of ram</strong>.</p>
<p><strong>PLEASE NOTE</strong>: The above problems are <strong>NOT</strong> code bugs. They represent compiler mis-features,
linker limitations, and/or architecture limitations.</p>
<p><strong>macOS NOTE</strong>: The macOS <code>/usr/bin/gcc</code> is actually <code>clang(1)</code>, and so using <code>gcc(1)</code> under macOS doesn’t count.</p>
<h2 id="authors-remarks">Author’s remarks:</h2>
<h3 id="no-literals-encoder">No Literals Encoder</h3>
<p>This program creates C code that will output the specified data to stdout. There are no literals used in the generated code.</p>
@@ -607,7 +639,7 @@ Jump to: <a href="#">top</a>
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