> > Well, it's hardly an optimization if it's incorrect, and it seems to be > > incorrect. As the old saying goes, I can make your code infinitely fast > > if you don't care about the results. > > It's incorrect to rely on the extension taking place. It's not incorrect to > do the extension.
The behaviour of extending everything twice (on caller and callee side) was in i386 backend forever. Definitely before concept of partial register stalls as invented. My guess is that it all comes from history that original i386 PS ABI was written with K&R C in mind. I tried to remove the caler side extend in 90s, but it never got into a mainline. Honza > > Richard. > > > Andrew. > > > >
