Changing -O to be equivalent to -O3

[David Nadlinger]

On Monday, 18 March 2013 at 16:39:14 UTC, John Colvin wrote:
> Far from being documented as equivalent to O3, ldc2 --help says 
> O4 and O5 are "link-time optimization" Is this also incorrect?

Well, it's correct in so far as they were intended for LTO. But 
as far as I remember, they were never implemented, and certainly 
aren't right now.

David