[Bug debug/106746] [13 Regression] '-fcompare-debug' failure (length) with -O2 -fsched2-use-superblocks since r13-2041-g6624ad73064de241

[hjl.tools at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106746

--- Comment #10 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Roger Sayle from comment #9)
> I'm curious why the zero_extend behaves so differently to a sign_extend,
> perhaps a  missing simplification or pattern.  Presumably the CONCAT in the
> debug_insn is there whether or not a sign_extend or zero_extend is used?

I think instruction order changes at random when there are debug insns
with CONCAT and CONCATN.