Signed integer overflow undefined behavior or not?

[deadalnix via Digitalmars-d]

On Friday, 13 November 2015 at 06:46:37 UTC, Ali Çehreli wrote:
> Since it's UB in C and C++, I've heard that both clang and gcc 
> do remove code branches if they can prove that there will be 
> signed overflow. I don't know how or whether that optimization 
> is turned off for D.
>
> Ali

Clang does it, but LLVM IR defines flags for overflow behavior 
and it is up to the frontend to choose which one it want to use.