cefff85550
This had been causing Camellia (the only cipher that uses these macros) to fail when compiling "out-of-the-box" with gcc version "4.3.3-5ubuntu4". I think because the compiler had no idea any memory access was going on in these macros. Adding "memory" as a clobber solves the problem, but is probably overkill. I suspect that if we specify the constraint for y differently, we could get rid of both "memory" and __volatile__, which would allow the compiler to optimize much more. Also, in gcc versions that support it, we should probably use the bswap builtins instead.
See doc/crypt.pdf