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.
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.
In my work I have to do that with gcc (in another words i have to
modify the compiler so it makes it)
you said is necessary to have to learn a fair amount of gcc
infrastructure in order to do it. Like what?
greicy
Ian Lance Taylor <iant@xxxxxxxxxx> a écrit :
Greicy.Costa-Marques@xxxxxxx writes:
I'd like to know if is possible to gcc to duplicate a variable? for example
....
int a=2; i have this
i want to do it: int a_1=2, a_2=2;
I have a code in c and i want to modify the gcc so it makes the
duplication of the variable. i like to do it at the level of RTL to
ASM.
I know that there is a function (output_asm_insn) in final.c that
goes from RTL to ASM.
would anyone have any suggestions to do this?
Yes, it is possible. However, you are going to have to learn a fair
amount of gcc infrastructure in order to do it. One important question
is going to be how you know which variable you want to duplicate.
Presumably you don't want to duplicate all variables. Another important
question is what you want to do with the duplicated variable. If you
duplicate the variable in a straightforward way, the duplicate will
simply be removed by the optimization passes.
Ian
