On Wed, Oct 20, 2021 at 1:14 AM Jeff Law via Gcc-patches <gcc-patches@gcc.gnu.org> wrote: > > > > On 10/18/2021 10:54 PM, apinski--- via Gcc-patches wrote: > > From: Andrew Pinski <apin...@marvell.com> > > > > Instead of putting a full blow DCE after execute_fixup_cfg, it makes sense > > to try to remove the defining statement for the store that is being removed. > > Right now we only handle PHI node statements as there needs no extra checks > > except for it is only used once in the store statement. > > > > gcc/ChangeLog: > > > > * tree-cfg.c (maybe_remove_writeonly_store): Remove defining > > (PHI) statement of the store if possible. > This is the only part that I consider at all controversial. > > Is the case you're trying to handle such that you have to eliminate the > PHI immediately and can't wait until the next DCE pass? > > If so and we want to go this direction, should we pull this out into a > little routine? I'm a bit surprised we don't already have one or more > that do basically the same thing.
We have simple_dce_from_worklist for this which you'd seed with the SSA rhs of the removed stores. Richard. > > Jeff >
