This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [patch] tree-ssa-sink.c: Don't restrict immediate uses that weconsider.
On Thu, 2005-04-07 at 14:23 -0400, Kazu Hirata wrote:
> Hi Jeff and Daniel,
>
> > > ie, if we have an immediate use which points
> > > to a phi argument, then well, the object in question better appear in
> > > that phi argument, or else something horribly wrong has happened.
> >
> > It does, just *not as the bare symbol*.
> >
> > IE it's an invariant like &foo_3, instead of just plain foo_3.
> >
> > Thus, the comparison he's removing (which in this case would be &foo_3
> > == foo_3) will fail, and we will get a wrong answer about where we need
> > to sink to.
>
> Assuming foo_3 is an SSA_NAME, do we ever take an address of SSA_NAME?
I honestly don't remember :)
I thought it was possible if they were invariant, but now i'm not so
sure.
Andrew will enlighten us