reasons for rewriting regular memory (was: [ANNOUNCE]: clang compiling ports, take 2)

[perryh at pluto.rain.com]

Matthias Andree <matthias.andree at gmx.de> wrote:
> > I agree, but I can think of another valid exception. System with
> > Hamming correction on the memory, gets a single bit (correctable)
> > error. Need to rewrite the memory contents to reset all the parity
> > bits!
> That's a matter of the EDAC stuff, not the business of applications.

True, but it may explain why clang does not flag "*x = *x;" when it
does flag "x = x;".  A compiler cannot know the context in which the
compiled code will be used.

BTW I agree that an understanding is needed of _why_ the code in
question was included.  I have seen "x = x;" -- x being a formal
parameter -- used to prevent an "unused argument" warning in a
function which did not in fact need the argument in question, but
had to declare it for uniformity with other functions pointed to
by the same function pointer type.