> > which shows how the global objects initialization keeps things live.
> > Early optimization turns it into
> >
> > (static initializers for t.C) ()
> > {
> > <bb 2>:
> > NotUsedObject._vptr.CObject = &MEM[(void *)&_ZTV7CObject + 16B];
> > return;
> >
> > }
> >
> > but we don't have any pass removing stores to globals never read. IPA
> > reference computes this
> > in some way but doesn't get to export this in a reasonable way - its
> > transform stage could DSE
> > those though.
>
> We have write only variable detection but
> > NotUsedObject/4 (CObject NotUsedObject) @0x7f70d41fe580
> > Type: variable definition analyzed
> > Visibility: public
> > References:
> > Referring: _Z41__static_initialization_and_destruction_0ii/9 (addr)
> > Availability: not-ready
> > Varpool flags:
>
> it stops on fact believing that address of NotUsedObject is taken. Why it is
> not considered to be load?
Too early dump I guess. At mainline I get empty constructor:
.type _GLOBAL__sub_I_NotUsedObject, @function
_GLOBAL__sub_I_NotUsedObject:
.LFB6:
rep ret
not ideal, but still an improvement ;)
The problem is that write only var is removed only at late optimization
and then it is too late to remove the unreachable function.
Honza
>
> Honza
