[Bug rtl-optimization/83393] [8 Regression] wrong code with -O2 -fno-forward-propagate -fno-tree-bit-ccp

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83393

--- Comment #3 from Segher Boessenkool <segher at gcc dot gnu.org> ---
In the original code, r108 as set by insn 14 is dead after insn 16.  The
combination 15->20 should have changed that, but apparently didn't.