http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55095 --- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2012-10-27 18:39:39 UTC --- (In reply to comment #1) > Is there any function to compute how many bits are required to store a value? For positive values it's easy, something like 1 + (int)log2(value)