On February 11, 2020 9:32:14 PM GMT+01:00, "Uecker, Martin"
<martin.uec...@med.uni-goettingen.de> wrote:
>
>In the following example, it seems
>that 'bar' could be optimized to
>return '1' and every else could be
>optimized away. Or am I missing
>something?
p might be still NULL when bar is called.
Do I need to add
>some specific compiler flags?
-fipa-pta
But we simply do not implement turning pointer dereference into direct accesses
when points to says it would be possible. And yes, the NULL case can probably
be ignored (though we generally support catching NULL dereferences with signal
handlers), or at least speculated away with a well predicted branch.
Any situation where doing the above is profitable?
>
>
>static int a = 1;
>static int *p;
>
>extern
>void foo(void)
>{
> p = &a;
>}
>
>extern
>int bar(void)
>{
> return *p;
>}
>
>
>thank you,
>Martin
