anyone know the origin of the word 'insn'

[Marty Hauff]

I'm in the process of preparing a research paper describing some work I have been doing with GCC and would like to satisfy myself as to where this name came from?  Does any one know? Is it an acronym, abreviation or just someones desire to create a word with one fewer vowel than would be necessary for all of us to know how to pronounce it.

Thanks
Marty