[LLVMdev] Avoiding Constant Folding

[Duncan Sands]

Hi Cuong,

> I am trying to avoid using stack memory (or mutable variable is the term
> used in the tutorial). I am also trying to optimize the code as much as I
> can before using optimizer passes such as mem2reg (to reduce the compile
> time as well).

I don't think there is much point in avoiding stack variables (using them
makes your life much simpler -> easier to have your front-end be correct;
passes like mem2reg will turn your variables into registers if possible
anyway).  And there's also not much point in trying to keep the bitcode small
so as to speed up the optimizers: it will just make your front-end more
complicated, while probably the gains (if any) are insignificant.  My advice
is to keep your front-end as simple as possible.  You can run some per-function
passes as you output each function, to clean it up and reduce the bitcode size,
for example simplifycfg+scalarrepl+instcombine, if memory usage is a problem.

Ciao, Duncan.