https://gcc.gnu.org/bugzilla/show_bug.cgi?id=124336
--- Comment #4 from Uroš Bizjak <ubizjak at gmail dot com> ---
(In reply to Zdenek Sojka from comment #3)
> I think, from the performance point of view, generally the size of the
> memory access should be the same as other accesses to the same memory
> location [rsp+0], in order to allow store-to-load forwarding. (if there are
> such accesses)
This is only a probe insn that accesses the stack at the end of the page:
c: 48 81 ec 00 10 00 00 sub $0x1000,%rsp
13: 83 0c 24 00 orl $0x0,(%rsp)
There is "nothing" at this location, so any kind of STL is not effective.
