Re: [avr-gcc-list] memcpy() : problem when passing destination pointer

[Pertti Kellomäki]

Joerg Wunsch wrote:
> Vincent Trouilliez <address@hidden> wrote:
> > IIRC it said volatile must be used to keep the compiler from
> > optimizing away access to a variable that he thinks might be
> > pointless. Like writing a variable that is never read back.
>
> Nope, if the variable is a global one, it will always be written.

I'm not a C expert so I might be out of my depth here, but
wouldn't it be legal for the C compiler to optimize away
even global variables? Some time ago there was some talk
about a possible AVR port of LLVM, and this is exactly the
kind of thing I would expect LLVM's link time optimization
to do.
--
Pertti