[Bug tree-optimization/114403] [14 regression] LLVM miscompiled with -O3 -march=znver2 -fno-vect-cost-model since r14-6822-g01f4251b8775c8

[sjames at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114403

--- Comment #10 from Sam James <sjames at gcc dot gnu.org> ---
Created attachment 57774
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57774&action=edit
EarlyCSE.cpp.cpp.177t.ch_vect-bad

optimize("O2") on `template <typename InputIteratorT>
hash_code hash_combine_range_impl(InputIteratorT first, InputIteratorT last)
works,` but O3 is broken.

Unfortunately, novector pragmas don't work on the while()s in there. I get a
ignored warning.

Attached those dumps w/ -fdbg-cnt=vect_loop:7 (so just the one bad loop). I can
tarball up the 6 vs 7 if useful.

Thanks. Will try disabling those passes next..