Question about alignment of struct _Unwind_Exception

[Peter Bergner]

On 11/4/20 1:31 PM, Florian Weimer wrote:
>> If I can align the MMA types a different way, then the default
>> alignment will go back to 128 bits, which should "fix" the issue
>> you are seeing.
> 
> x86-64 does this as well if 512-bit vector types exist.  We need to fix
> this in glibc.  (Maybe things work out due to the struct pthread layout
> on x86-64, but it's still a bug.)

I agree GLIBC has a problem here.  That said, GCC should not have changed
the default alignment either.  I just committed a fix to GCC trunk that
reverts the change to BIGGEST_ALIGNMENT and fixes the alignment of the MMA
types a different way.  I will backport the fix to thje GCC 10 release
branch after it's baked a couple of days on trunk.

Peter