Divide & remainder are indeed special cases. 

Gcc's machine description says (paraphrased), and I believe this is
consistent with the Alpha manual, although it's not totally clear:

 The divide and remainder functions always take their inputs from
 t10 and t11, put their output in t12, and clobber
 t9 and at.

That is, it does not clobber t10 and t11, which Chris's routines did.

Also, peeking at the object code for OSF1's libc, the routines do save
and restore t10 and t11.

--
Trevor Blackwell         tlb@eecs.harvard.edu          (617) 495-8912