Edited sentence: Find-first-zero operation, starting from the leftmost bit, is equivalent to computing the base 2 logarithm.This helps computing rapidly such quantities on machines that can run it in their basic instruction set (ex: =clz= in MIPS).Vertical flipping of a one-bit-per-pixel image, or some FFT algorithms, require to flip.When this operation is not available on the processor, it's still possible to proceed by passes, in this example on 32 bits:.the bits of individual words ( becomes