Author:

• Name: Ilya Kurdyukov
  Location: RU - Russian Federation (Russia)

Award presentation:

Watch the Our Favorite Universe YouTube show for this entry:

IOCCC28 - 2024/kurdyukov4 - Prize in embiggening

To build:

    make all

Bugs and (Mis)features:

The current status of this entry is:

STATUS: INABIAF - please DO NOT fix

For more detailed information see 2024/kurdyukov4 in bugs.html.

To use:

    ./prog < data > out.c

Try:

    ./try.sh

Judges’ remarks:

This program assembles data from standard input and write C code on standard output:

    ./prog < input > out.c

When if you have the patience to compile and if your C compiler does not object, the resulting program when run:

    cc out.c -o out
    ./out > output

re-assemble the original input WITHOUT USING ANY LITERALS in the C code it produced!

You mind may go into a spiral as you attempt to read and understand how this is done. :-)

Large input size issues

The author, Ilya Kurdyukov, 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 2024/kurdyukov4 directory:

    make make diff_orig_prog

The above patch extended the original standard input size limit from 128K bytes to 64M bytes.

While the 2024/kurdyukov4/try.sh 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.

On fairly normal systems, we experienced the following while running 2024/kurdyukov4/try.sh:

    | 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    |

We never had the time nor resources to attempt to compile using gcc(1), the code needed for any random input larger than 4M bytes.

For 16M bytes and larger on Apple silicon, for random input size of 16M bytes and 64M bytes, the clang(1) linker phase issues the following warning:

ld: warning: atom ‘_main’ … is larger than the max code size between branch island clusters, this may lead to unreachable branches

If you attempt to run the clang(1) generated executable anyway, is crashes with:

segmentation fault

Compiling gcc(1) with a random input size of 16M bytes and 64M bytes was never attempted because such a compile attempt would take too long and require a large amount of ram.

PLEASE NOTE: The above problems are NOT code bugs. They represent compiler mis-features, linker limitations, and/or architecture limitations.

macOS NOTE: The macOS /usr/bin/gcc is actually clang(1), and so using gcc(1) under macOS doesn’t count.

Author’s remarks:

No Literals Encoder

This program creates C code that will output the specified data to stdout. There are no literals used in the generated code.

• Binary data is supported.
• If there was a lot of data on the input (even just 64KB), then compiling the generated code can be a good stress test for the compiler.
• Why a spiral? I don’t know, just because it looks cooler this way.

Primary files

• prog.c - entry source code
• Makefile - entry Makefile
• prog.orig.c - original source code
• try.sh - script to try entry

Secondary files

• 2024_kurdyukov4.tar.bz2 - download entry tarball
• README.md - markdown source for this web page
• .entry.json - entry summary and manifest in JSON
• .gitignore - list of files that should not be committed under git
• .path - directory path from top level directory
• index.html - this web page

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