[EMAIL PROTECTED] writes: > What? No compiler is smart enough to say, "The program > sets these variables but they are never referenced again. > I'll save time and not set them."
That's actually not true. Many compilers are smart enough to do that, and in fact do that sort of thing. That's what data flow analysis is for. The reason that C has a "volatile" keyword is to inform compilers that there are side effects that are not visible from the code alone in the use of particular variables. That's useful when you don't want sets of registers in hardware optimized away, but it is also of substantial use in preventing the removal via optimization of password zeroing routines. By the way, although C is often too convoluted because of pointer arithmetic for compilers to do good optimizations, many high level languages are not -- you should certainly never assume that operations will not be reordered or removed by an optimizing compiler if you know what is good for you. Perry --------------------------------------------------------------------- The Cryptography Mailing List Unsubscribe by sending "unsubscribe cryptography" to [EMAIL PROTECTED]
