Hexencoding.sol

pragma solidity ^0.4.0;

contract HexEncoding {

    function hexEncodeTest(address addr) returns (bytes32 ret) {
        uint x = uint(addr) / 2**32;
        
        // Nibble interleave
        x = x & 0x00000000000000000000000000000000ffffffffffffffffffffffffffffffff;
        x = (x | (x * 2**64)) & 0x0000000000000000ffffffffffffffff0000000000000000ffffffffffffffff;
        x = (x | (x * 2**32)) & 0x00000000ffffffff00000000ffffffff00000000ffffffff00000000ffffffff;
        x = (x | (x * 2**16)) & 0x0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff;
        x = (x | (x * 2** 8)) & 0x00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff;
        x = (x | (x * 2** 4)) & 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f;
        
        // Hex encode
        uint h = (x & 0x0808080808080808080808080808080808080808080808080808080808080808) / 8;
        uint i = (x & 0x0404040404040404040404040404040404040404040404040404040404040404) / 4;
        uint j = (x & 0x0202020202020202020202020202020202020202020202020202020202020202) / 2;
        x = x + (h & (i | j)) * 0x27 + 0x3030303030303030303030303030303030303030303030303030303030303030;
        
        // Store and load next batch
        assembly {
            mstore(0, x)
        }
        x = uint(addr) * 2**96;
        
        // Nibble interleave
        x = x & 0x00000000000000000000000000000000ffffffffffffffffffffffffffffffff;
        x = (x | (x * 2**64)) & 0x0000000000000000ffffffffffffffff0000000000000000ffffffffffffffff;
        x = (x | (x * 2**32)) & 0x00000000ffffffff00000000ffffffff00000000ffffffff00000000ffffffff;
        x = (x | (x * 2**16)) & 0x0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff0000ffff;
        x = (x | (x * 2** 8)) & 0x00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff00ff;
        x = (x | (x * 2** 4)) & 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f;
        
        // Hex encode
        h = (x & 0x0808080808080808080808080808080808080808080808080808080808080808) / 8;
        i = (x & 0x0404040404040404040404040404040404040404040404040404040404040404) / 4;
        j = (x & 0x0202020202020202020202020202020202020202020202020202020202020202) / 2;
        x = x + (h & (i | j)) * 0x27 + 0x3030303030303030303030303030303030303030303030303030303030303030;
        
        // Store and hash
        assembly {
            mstore(32, x)
            ret := sha3(0, 40)
        }
    }
}