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Re: [PATCH] re-enable -mabi=no-altivec on powerpc64-linux
On Tue, 2008-02-05 at 11:49 +1030, Alan Modra wrote:
> On Mon, Feb 04, 2008 at 10:30:21AM -0800, Janis Johnson wrote:
> > Before this patch, rs6000_explicit_options.abi was explicitly NOT set
> > for -mabi=no-altivec (by the comment with "???"). Alan, please take a
> > look to see if I broke something for SPE. Perhaps there should be
> > separate fields for altivec_abi and spec_abi?
>
> Well, you've changed the behaviour. I don't know whether that
> qualifies as broken.. I believe the thinking behind the old behaviour
> is that -mabi=no-altivec ought to have no effect on whether the spe
> abi is selected by default or not. After all, if you're compiling for
> spe you don't have altivec hardware and -mabi=no-altivec doesn't
> change the default. (You could argue that -mabi=no-spe similarly
> shouldn't have any effect when compiling for a non-spe processor but
> we don't do that for some reason.)
>
> I do think the code would be simpler if we had separate abi fields.
> -mabi=altivec and -mabi=spe ought to count as explicitly setting both
> fields, but the no- versions ought to just set their own field.
When processing -mabi=no-altivec do we know whether we're generating
spe code so we can just ignore that option? Similarly for
-mabi=no-spe. If not I'll look at splitting the abi field.
Janis