[RFC][ARM][PR67714] signed char is zero-extended instead of sign-extended

[Kugan]

On 13/01/16 10:19, Jim Wilson wrote:
> On Mon, Jan 11, 2016 at 10:22 PM, kugan
> <kugan.vivekanandarajah@linaro.org> wrote:
>> When promote_function_mode and promote_ssa_mode changes the sign
>> differently, following  is the cause for the problem in PR67714.
> 
>> This is similar to PR65932 where sign change in PROMOTE_MODE causes problem
>> for parameter. But need a different fix there.
> 
> One of the proposed fixes for PR65932 was to make PROMOTE_MODE work
> the same as promote_function_mode.  That should fix both bugs, and
> avoid some of the weirdness necessary to work around the problem where
> they disagree.  However, that fix is stalled, because it causes
> potential performance regressions for some older ARM versions.  I've
> been meaning to look at that again.  It is probably a better fix than
> the one you are proposing here if we can make it work.

Yes, making PROMOTE_MODE to work the same way as in
promote_function_mode in arm will fix this. Can you please point me to
the test cases that are regressing so that I can also start looking at them.

Thanks,
Kugan