[Gcl-devel] Re: sibling call optimization

[Jim Wilson]

Jim Wilson wrote:
> Overall, the -O3 code isn't really much worse than the -O2 code.  In the
> O2 code, calling from LI2->LI1->LI2 involves two sibcalls.  In the -O3
> case, the same sequence involves one regular function call.  Note that
> LI2 is calling itself, not LI1.  This is because LI1 was inlined into
> LI2.  So it is possible that the -O3 code may actually be faster, even
> though it has calls instead of sibcalls.

Except if you are concerned about stack space usage, in which case the 
single regular function call is much worse than two sibcalls.  I was 
only thinking about the speed of the code.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com