What is the fastest way to transpose the bits in an 8x8 block on bits?

Question

I\'m not sure the exact term for what I\'m trying to do. I have an 8x8 block of bits stored in 8 bytes, each byte stores one row. When

Answer 1

You really want to do something like this with SIMD instructions with something like the GCC vector vector support: http://ds9a.nl/gcc-simd/example.html