On Tue, Jan 31, 2017 at 05:31:41PM +0100, Jakub Jelinek wrote:
> On Tue, Jan 31, 2017 at 12:15:36PM +0100, Martin Jambor wrote:
> > > I've committed it as is, feel free to propose changes. But before that,
> > > we
> > > should figure out what to do with -fipa-cp-alignment. Should it have
> > > Ignore flag and
> > > Does nothing. Preserved for backward compatibility.
> > > description in common.opt, and
> > >
> > > @item -fipa-cp-alignment
> > > @opindex -fipa-cp-alignment
> > > When enabled, this optimization propagates alignment of function
> > > parameters to support better vectorization and string operations.
> > >
> > > This flag is enabled by default at @option{-O2} and @option{-Os}. It
> > > requires that @option{-fipa-cp} is enabled.
> > > @option{-fipa-cp-alignment} is obsolete, use @option{-fipa-bit-cp}
> > > instead.
> > >
> > > removed altogether, or should it say be alias for -fipa-bit-cp?
> >
> > Well, -fipa-bit-cp is a superset of the old -fipa-cp-alignment in the
> > sense that the latter worked only for pointers whereas the former now
> > also operates on integers.
> >
> > We could still refuse to store results of the analysis to pointers if
> > user provided -fno-ipa-cp-alignment, but I do not think it is
> > reasonable. My preference would be to mark it obsolete and document
> > that -fipa-bit-cp should be used instead.
>
> What are obsolete options? Do you mean deprecated or removed?
I am sorry, I got confused by the mail I was quoting. I meant
deprecated, because I thought that was the appropriate thing to do.
However, I personally will not object if we remove it.
> We have ignored options retained just for compatibility that do nothing.
I'll have a look at how it is done and prepare a patch, it may take a
few days though because I am traveling now.
Martin
> -fipa-cp-alignment does nothing right now (nothing ever checks it), but
> it isn't declared as Ignore and is documented (ignored options aren't
> documented). The current state is that e.g. x_flag_ipa_cp_alignment is
> still a field in global_options* etc.
>
> Jakub
