https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92038
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Status|UNCONFIRMED |NEW
Last reconfirmed| |2019-10-10
CC| |jakub at gcc dot gnu.org,
| |rguenth at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is that we initialize the aggregate without initializing the
tail-padding but the ABI says we pass in a 64bit reg which means we load from
the uninitialized padding. RTL opts cannot deal with the partial/piecewise
inits
to elide the local aggregate.
It's not that we don't care but this one is not so easy to fix.
With liveness analysis and some heuristics store-merging could be made to
also initialize the padding.
