Implementation complexity of bit permutation instructions
Zhihue Shi, R.B. Lee · 2004
Several bit permutation instructions, including GRP, OMFLIP, CROSS, and BFLY, have been proposed recently for efficiently performing arbitrary bit permutations. Previous work has shown that these instructions can accelerate a variety of applications such as block ciphers and sorting algorithms. In this paper, we compare the implementation complexity of these instructions in terms of delay. We use logical effort, a process technology independent method, to estimate the delay of the bit permutation functional units. Our results show that for 64-bit operations, the BFLY instruction is the fastest among these bit permutation instructions; the OMFLIP instruction is next; and the GRP instruction is the slowest.