An interesting thought hit me when reading this. The "classic" Cray series (Cray-1, X-MP, Y-MP) all have a rather curious instruction generally known as population count. All it does is to take a register and count the number of one bits in it, and return that count. ... Just a thought. It's the only plausable use that I have yet thought of for this instruction. Has anyone else got any ideas?
This instruction would be useful in all sorts of applications. I was just wishing I had such a thing only last week. I had to write a little loop to check the number of bits set in a word. Each bit represented an action, and in my particular case it was an error if more than 1 action was requested. The loop was really a waste when you consider that it could have been done in 1 instruction. tw