[Bug ipa/123517] [16 regression] infinite loop in ext-dce (due to miscompiling of ext-dce with -O3 -march=native) while compiling _gcov_execl.i since r16-6652

[jamborm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123517

--- Comment #9 from Martin Jambor <jamborm at gcc dot gnu.org> ---
I have bootstrapped the patch (on top of ab6621a77fb) on x86_64-linux before
committing the patch, but this is -O3 -march=native bootstrap, right?  I will
obviously have a look on Monday.

Is the code in comment #3 really a reproducer though?  That does not like
anything IPA-CP would attempt to optimize.