constand folding of functions

Hi!

1) Is it possible that you add round and trunc to llvm::canConstantFoldCallTo
(and the code that actually does the folding)? If I'm not mistaken
they are defined in the C99 standard-

2) Is it possible to pull this out of llvm and make it somehow user-definable?
For example I also want the float functions (e.g. sinf, cosf) to be folded
or any custom function

-Jochen