Question about assembly output

[rsw0x via digitalmars-d-ldc]

Hi,

I noticed that(on x86) using core.bitop in LDC outputs a call 
instead of directly turning them into instructions as both dmd 
and gdc do.

Is this intended behavior?(I'm not a big assembly expert, so this 
could just be a really dumb question on my part.)

example:

LDC
http://goo.gl/T1ZJaD

dmd
http://goo.gl/f1gaOb

gdc
http://goo.gl/RDlP0n