Re: Possible GCC optimization bug

On Thu, 12 Feb 2026 at 16:35, Anubis 1101 <[email protected]> wrote:

> That does appear to "fix" it, but it doesn't tell me what was actually
> wrong.
>

It tells you exactly what's wrong. You have undefined behaviour due to
accessing outside an array. That causes the compiler to turn the code into
garbage, because it has undefined behaviour.


> It just corrects the bad addressing and additionally prints out "runtime
> error: index 10 out of bounds for type 'char [10]'"... which, yea, I know
> that. That's half of why I'm here.
>

So stop doing it then.




> If there's something specific I'm doing that's causing it, that's what I'd
> like to know. As far as I can tell, there's no flaw in my code itself.
>

You're accessing data[10] when that is past the end of the array. That
makes the program's behaviour undefined. Anything can happen.

So fix it. Stop accessing past the end of the array.