IPA and LTO

[Pierre Vittet]

Hello,

If local_function_and_variable_visibility was not a simple IPA pass it 
would not have been called once per file but once per function (as it is 
with GIMPLE pass).
I feel this is normal that this pass is run 2 times because it is run 
before any link operations.

However, I don't know exactly how and when ld is called and which passes 
run after this.

Pierre Vittet

On 13/07/2011 17:54, AJM-2 wrote:
>
> What you say is in line with my understanding, however when I instrument the
> execute function of ipa-function-and-variable-visibility
> (local_function_and_variable_visibility()) I note that:
>
> gcc -flto a.c b.c
> causes the pass to be called twice (presumably once per file).
>
> If I split the compilation into two stages, then in the link stage
> gcc -flto a.o b.o
> the pass is never called.
>
> Conversely, the gate of IPA-Points-to does seem to be called three times at
> link time (presumably once for each file and then once for all together).  I
> cannot discover the cause of the different behaviours here.
>