This joke is attributed to Linus Thorvals:

IBM motto: "We found five vowels hiding in a corner, and we used them _all_ for the 'eieio' instruction so that we wouldn't have to use them anywhere else"

Unsourced history of eieio and sex: http://www.mail-archive.com/linux-fbdev@vuser.vu.union.edu/m...

Oh, that eieio. There's another one:

    Description: Enhanced Implementation of Emacs Interpreted Objects
    EIEIO is an Emacs lisp program which implements a controlled
    object-oriented programming methodology following the CLOS
    standard. EIEIO also has object browsing functions, and custom widget
    types. It has a fairly complete manual describing how to use it.
 
    EIEIO is now a part of CEDET (Collection of Emacs Development
    Environment Tools).

Interesting story. Surprised it shot to the top though.

Lightweight enough to be an easy upvote, but hackery enough where you wouldn't feel guilty about upvoting it. It's basically a perfect story.

Yeah, I was amused with that instruction when I was hacking at vxworks and hand modifying a bootloader without source code ... good times ...

This brings back (mostly) fond memories of writing PowerPC assembler many years ago. One thing that seems odd to me is that the author credits Motorola with naming of the eieio instruction. I would have thought that instruction would have been in the original Power instruction set and thus it would have been IBM that named it. Anyone know?

He probably just thinks Moto invented PowerPC.

I've long believed one of the ISA designers was a Japanese, as eieio means kinda hooray in Japanese.

I wonder what they called POPCOUNT.

Sadly, there is no population-count instruction on PowerPC. The closest thing you get is cntlzw (Count Leading Zeroes Word).

> Sadly, there is no population-count instruction on PowerPC

Here is one man's theory as to why:

http://www.moyogo.com/blog/2005/09/secret-opcodes.html

looks like eieio came from IBM...not sure about sex (sign extend) instruction though.

AAA on X86 is not bad.... By the way, i386 NOP is in fact XCHG EAX, EAX