[llvm-commits] [PATCH] Disable ARM partial flag dependency optimization at -Oz

[Renato Golin]

Yup, good to me, too.

On 18 December 2012 21:37, Quentin Colombet <qcolombet at apple.com> wrote:
>
> On Dec 18, 2012, at 1:28 PM, Jim Grosbach <grosbach at apple.com> wrote:
>
> LGTM!
>
> This should work even for the combination of muddles Renato mentions, as
> we're re-initializing the value for each MachineFunction we process.
>
>
> Yes, it should!
>
> Renato, is it ok for you?
>
> -Quentin
>
>
> -Jim
>
> On Dec 18, 2012, at 1:22 PM, Quentin Colombet <qcolombet at apple.com> wrote:
>
> Hi,
>
> Thanks for the reviews.
>
> I'd like Jim's idea about caching the information in a local class variable.
> I've updated the patch accordingly.
>
> New patch attached.
>
> -Quentin
>
> <Thumb2SizeReduction-Oz.patch>
>
> On Dec 18, 2012, at 1:00 PM, Renato Golin <rengolin at systemcall.org> wrote:
>
> On 18 December 2012 20:18, Jim Grosbach <grosbach at apple.com> wrote:
>
> The command line options aren't really available here, and we'd have to
> check for a function-local override anyway, so I don't think that'll work
> out.
>
>
> True, I forgot about that.
>
>
> Is there concern here the potential compile time impact? Accessing the
> attribute list should be pretty quick (a couple of pointer indirections and
> a bit mask).
>
>
> Mainly, yes, but I agree it's not a big problem.
>
>
> If we want, we could cache the value locally in the size reduction pass as a
> local class ivar and initialize it at the start of runOnMachineFunction().
> That would make the access a single pointer indirection off the 'this'
> pointer for the pass.
>
>
> If that pass would only run on a single module, that'd make sense. But
> if you could run it (opt) on a collation of different modules,
> possibly compiled with different flags, than I'd think you'd need the
> full check.
>
> I agree that the lookup is cheap, sorry for having over-complicated things.
> ;)
>
> LGTM.
>
> cheers,
> --renato
>
>
>
>



-- 
cheers,
--renato

http://systemcall.org/