What's in a name?

Because somebody's going to wonder: rlwinm is a PowerPC machine instruction, the mnemonic standing for “Rotate Left Word Immediate then aNd with Mask”.

The mask in question isn't fully general, of course — this is RISC, so it wouldn't fit — but it can be any contiguous non-empty range of 1 bits, which can wrap around the beginning/end of the word, or not. Thus, things like left and right (logical) shifts, clearing the low or high N bits, and extracting a bitfield from a word are all just special cases of rlwinm.

In other words, it's a fairly elegant generalization of a bunch of related operations which are often considered as separate, and some of which usually require multiple instructions.

(It's also not a terribly common username, and perhaps more importantly it's six characters long.)

Ironically, I haven't really done any assembly or machine-language stuff on PowerPC, whereas I have on x86.

I might eventually decide in something different for the Blog Title, but the domain name will definitely stay.