Re: Number of Bits Needed to Represent a Zero-Offset Integer

[via Digitalmars-d-learn]

On Monday, 19 January 2015 at 13:30:47 UTC, Steven Schveighoffer 
wrote:
http://dlang.org/phobos/core_bitop.html#.bsr
It's actually an intrinsic, reduces to an instruction. Mind the 
requirements for 0.

-Steve

Nice. Is this intrinsic supported for all DMD/GCD/LDC supported 
platforms or do we have to supply fallback logic when bsr is not 
available?