https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95123
Alexander Monakov <amonakov at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |amonakov at gcc dot gnu.org
--- Comment #1 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
This is probably due to sel-sched, and very sensitive to compiler revision: I
tried checking with a 20200511 (one day difference) on Compiler Exporer, and
could not reproduce the miscompilation.
If you still have the compiler binary, you can help out by testing with
sel-sched debug counters: if you append -fdbg-cnt=sel_sched_insn_cnt:0 to the
"bad" command line, it should work again (as sel-sched will not move anything),
with -fdbg-cnt=sel_sched_insn_cnt:99999 it should fail. We use this for
isolating a problematic transformation (by bisecting on the counter value).
(other sel-sched debug counters are sel_sched_cnt and sel_sched_region_cnt, but
they are more coarse-grained, by pass and region, instead of insn,
respectively)
