I've always found the name ComputeMaskedBits a bit unintuitive, and since r154011 it's even worse because there is no masking going on whatsoever: http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120402/140280.html Is there any appetite for a global rename to ComputeKnownBits? Or any other better names? Thanks, Jay.