Apr 08, 2009 19:30
#define BITCOUNT(x) (((BX_(x)+(BX_(x)>>4)) & 0x0F0F0F0F) % 255)
#define BX_(x) ((x) - (((x)>>1)&0x77777777) \
- (((x)>>2)&0x33333333) \
- (((x)>>3)&0x11111111))
-- really weird C code to count the number of bits in a word
Leave a comment
Comments 3
http://www.amazon.co.uk/Hackers-Delight-Henry-S-Warren/dp/0201914654/ref=sr_1_1?ie=UTF8&s=books&qid=1239216289&sr=8-1
I would lend it to you but I'd probably never see it again! ;)
Reply
Reply
Reply
Leave a comment