

Bit Twiddling Hacks (2005) - thealphanerd
http://graphics.stanford.edu/~seander/bithacks.html

======
fubarred
Neat. Also here's some other sources beyond the usual CS bookshelf suspects:

[http://www.hackersdelight.org/](http://www.hackersdelight.org/)

[http://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html](http://www.inwap.com/pdp10/hbaker/hakmem/hakmem.html)

(We recently had to grab the C standards in order to bust out some integer
under/overflow macros that wouldn't be brittle.)

------
viraptor
There's also a lot of 64-bit hacks on pages related to chess programming (8x8
boards). For example:
[https://chessprogramming.wikispaces.com/Bitboards](https://chessprogramming.wikispaces.com/Bitboards)

And my faviourite bit hack question on SO:
[https://stackoverflow.com/questions/14537831/isolate-
specifi...](https://stackoverflow.com/questions/14537831/isolate-specific-row-
column-diagonal-from-a-64-bit-number)

------
new299
It's an awesome page.

I would guess one of the reasons it's here though is that it's almost required
reading for Google interviews, #DetermineIfPowerOf2 is a particular favorite.

------
drv
Another resource in the same vein (it links to this page, among others):

[http://aggregate.org/MAGIC/](http://aggregate.org/MAGIC/)

------
dang
This has been popular over the years, but hasn't had attention on HN in a
while:

[https://hn.algolia.com/?q=bit+twiddling+hacks#!/story/foreve...](https://hn.algolia.com/?q=bit+twiddling+hacks#!/story/forever/0/bit%20twiddling%20hacks)

We put 2005 on it, though the Internet Archive says there were earlier
versions.

------
aosmith
He should pay bounties in BTC...

