Can compiler optimization introduce bugs?

Question

Today I had a discussion with a friend of mine and we debated for a couple of hours about \"compiler optimization\".

I defended the point that sometimes

Answer 1

It's theoretically possible, sure. But if you don't trust the tools to do what they are supposed to do, why use them? But right away, anyone arguing from the position of

"compilers are built by smart people and do smart things" and thus, can never go wrong.

is making a foolish argument.

So, until you have reason to believe that a compiler is doing so, why posture about it?