[Bug target/84710] [8 Regression] ICE: RTL check: expected code 'reg', have 'subreg' in rhs_regno, at rtl.h:1896 with -O -fno-forward-propagate

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84710

--- Comment #6 from Zdenek Sojka <zsojka at seznam dot cz> ---
(In reply to Segher Boessenkool from comment #4)
> The testcase has UB of course (d is undefined).

The original testcase had defined behavior. The uninitialized use is the result
of delta/creduce reduction. There was an ICE with the unreduced testcase as
well.