* Rich Felker: >> If the compiler can handle the zeroing, that would be great, though not >> sure how (some __attribute__((zero)) which generates a type constructor >> for such structure; it kind of departs from what the C language offers). > > The compiler fundamentally can't. At the very least it would require > effective type tracking, which requires shadow memory and is even more > controversial than -fstrict-aliasing (because in a sense it's a > stronger version thereof).
It's possible to do it with the right types. See _Bool on 32-bit Darwin PowerPC for an example, which is four bytes instead of the usual one. Similarly, we could have integer types with trap representations. Whether it is a good idea is a different matter, but the amount of compiler magic required is actually limited. Thanks, Florian
