C-Reduce

I am C-Reduce, the shrinker of C/C++ programs.

[C-Reduce @creduce]

Always happy to help!

[LaurieWired @lauriewired]

One contestant experimented with C-Reduce; a way to search for C++ programs that create unusual compiler behavior.

Maximizing the fitness function for error as a reward, no templates, no pre-processor hacks.

Just nested parenthesis causing exponential error output!

[Lee Wei @leewei666]

Learn LLVM until I find a compiler job | Day 29

Both creduce and llvm-reduce are still running. Hopefully, the can finish by tomorrow morning.

[Valentin Churavy @vchuravy]

@creduce My favorite version of this is https://t.co/T88Ed79x9y which can take an entire tree of Julia packages and apply creduce to it .

Now I just need to figure out how to use Julia's parser to do smarter rewrites.

[C-Reduce @creduce]

"You can use C-Reduce for any language" by Max Bernstein.
https://t.co/UvbrgsIDZP

[Colin Percival @cperciva]

Running creduce to try to minimize a test case for "clang produces different binaries when building natively on i386 vs cross-building from amd64". Only reduced from 2346 to 1727 lines so far, which makes me think this bug is hard to trigger.

[C-Reduce @creduce]

@_osa1 @cfbolz @mraleph I'm ready when you are!

[C-Reduce @creduce]

@JethroGB @moyix @bjg Actually, C-Reduce has a lot of tactics that are specific to C/C++ code.

If you're reducing something that is not C/C++ code, you can disable all those passes with the `--not-c` command-line option.

[C-Reduce @creduce]

I'll try anything!

[Brendan Dolan-Gavitt @moyix]

Does such a thing as CReduce for a Python script exist? (Or can CReduce be abused into working on Python code?)

[Serpent7776 @serpent7776]

I tried creduce to reduce a segfaulting test case and it reduced it to this 👍 #creduce #screenshotsaturday

[C-Reduce @creduce]

We've all been there.

[C-Reduce @creduce]

I love working the night shift. 🌜
Thanks for the shout out!

[@ericniebler.bsky.social @ericniebler]

@atomgalaxy I reduce a lot of compiler bugs, so I have a system that involves a directory full of stub stdlib/system headers, creduce, and some ready-made scripts.

I also have a 64-core machine. creduce takes it down to ~10k overnight, and I take it from there.

[Paul F. Dietz @PaulFDietz]

@lemire You should use creduce to minimize that.

[C-Reduce @creduce]

Thanks for the shout out!

[furtive pygmy (parody) 💨 @steubens7]

@tom_verbeure creduce is good to know regardless, it's just especially good at this

[C-Reduce @creduce]

@gamefeast @BruceDawson0xB @visualc Thanks for the shout out!

[nobodyreally @gamefeast]

@BruceDawson0xB @visualc You can make minimal repros using creduce fairly easily. Even with msvc, just do it under WSL and take advantage of the fact you can call native win32 programs. No advanced C++ skills necessary

[Varun / 王潤 / げんじ @typesanitizer]

creduce help text:

--shaddap Suppress output about non-fatal internal errors
[..]
--sllooww Try harder to reduce, but perhaps take a long time to do so

[C-Reduce @creduce]

@typesanitizer Oops! My bad. 🙁

Be sure to report the bug!

[Varun / 王潤 / げんじ @typesanitizer]

Expectation: I have a bug, let me try to use C-Reduce to reduce it
Reality: Run into a bug with C-Reduce itself

Happy weekend I guess...

Oh wait, it's just Thursday.

[Eric Eide @eeide]

Hey! Guess what came in the mail today! @sigplan @PLDI @creduce

[C-Reduce @creduce]

💯 https://t.co/8KDo3YjqI9