On Wed, Apr 08, 2020 at 09:20:07AM -0400, Jason Merrill via Gcc-patches wrote:
> On 4/8/20 4:47 AM, Richard Biener wrote:
> > On Tue, Apr 7, 2020 at 5:01 PM Martin Liška <mli...@suse.cz> wrote:
> > >
> > > Hi.
> > >
> > > The patch allows DCE to remove only replaceable operators new and delete.
> > > That's achieved by proper mark up of all these operators in C++ FE.
> > > The patch also brings all tests we've collected so far for the PR.
> > >
> > > Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
> > >
> > > Ready to be installed?
> >
> > Grepping for uses of DECL_IS_OPERATOR_* reveals you miss comparing
> > the new flag in ipa-icf.c and cgraph node dumping in cgraph.c might want
> > to dump it as well.
> >
> > Otherwise it looks reasonable.
> >
> > So the mid-end parts are OK in case FE people are happy with this solution
> > for GCC 10.
>
> This seems fine for GCC 10, though I wonder about using an attribute for
> DECL_REPLACEABLE_OPERATOR rather than taking a bit in all FUNCTION_DECLs
> that will only ever be set on a small handful.
If it is just for GCC 10 and we'll return the bit back to unused in GCC 11,
I'd think it is acceptable.
> For GCC 11 we probably want to make the distinction Jonathan mentions
> between new-expressions and direct calls to operator new.
Yeah.
Jakub
