I guess "fold" means do the computation at compile time? No, it is being called with a variable. That is interesting that libc has a gamma function. I will have to track down the implementation ...
-----Original Message----- From: Ian Lance Taylor [mailto:i...@google.com] Sent: Tuesday, November 15, 2011 1:58 AM To: James Hirschorn Cc: gcc@gcc.gnu.org; james.hirsch...@gmail.com Subject: Re: builtin gamma function James Hirschorn <james.hirsch...@hotmail.com> writes: > I have noticed that the builtin gamma function is very accurate and > extremely fast. Can someone tell me where to find the source code for the > implementation? Are you calling it on a constant? Because gcc will fold gamma applied to a constant which meets certain characteristics. If you aren't calling it on a constant, then you are getting the function from your libc. gcc does not itself include an implementation of the gamma function. Ian
