This is the mail archive of the
gcc-help@gcc.gnu.org
mailing list for the GCC project.
Re: duplicate a variable!!!!
On 03/31/2011 11:16 AM, Greicy.Costa-Marques@imag.fr wrote:
>
> Hi, Ian
>
>> One important question
>> is going to be how you know which variable you want to duplicate.
>
> yes, i know which variables i want to duplicate.
>
>> Presumably you don't want to duplicate all variables.
>
> no, i want to duplicate all variables in my code.
Statically-allocated, or even on-stack variables?
>> Another important question is what you want to do with the
>> duplicated variable.
>
> Because I want to harden my code. I'm working with fault injection
> by software and I want to harden my code, and a way of hardening is
> the duplication of variables. And as I still do not know how, I chose
> to start trying for a single variable and after to use the same path
> for all variables in my code.
>
>> If you duplicate the variable in a straightforward way, the duplicate will
>> simply be removed by the optimization passes.
>
> I want the duplication remains after optimization.
I suspect that the easiest way would be to create a volatile copy of
every variable after gimplification, and then fix up all assignemnts
to copy into the volatile.
Andrew.