On 03/24/2016 02:17 AM, Olivier Hainque wrote:
[snip]
So, aside from the dependency issue which needs to be fixed somehow, I
think it would make sense to consider using a strong blockage mecanism in
expand_epilogue.
That's what we both said here
https://gcc.gnu.org/ml/gcc-patches/2011-11/msg01180.html
and David agreed too
https://gcc.gnu.org/ml/gcc-patches/2011-11/msg01842.html
but if you can have the alias analysis changes accepted that would be
even better.
I'd really like to come to a resolution we're confident is robust,
because these are really very nasty bugs.
The robust solution is to have a scheduling barrier just before the
point where the stack is deallocated.
The alternative some folks have suggested would be for the generic parts
of the compiler to add the scheduling barrier before the stack pointer
adjustment. I wouldn't object to that.
Jeff
