Integer overflow and underflow semantics?

[John Colvin via Digitalmars-d]

On Friday, 18 July 2014 at 08:49:43 UTC, Walter Bright wrote:
> On 7/17/2014 4:56 AM, David Nadlinger wrote:
>> Oh dear, you'd be in for a very nasty surprise if you relied 
>> on this. ;)
>
> When I wrote that part of the spec, it was long before these 
> sorts of optimizations appeared, and it never occurred to me 
> that they would be.

Does the dmd backend do any such optimisations? I assume not.