The really fun bit is when you explicitly want to force one form or other, for some reason. Usually this is related to instruction length, but occasionally you

The really fun bit is when you explicitly want to force one form or other, for some reason. Usually this is related to instruction length, but occasionally you used to run into times when one form could help avoid a stall. Keeping tricks like that stable and clearly documented is, uh, not for the faint of heart.