[jmorse2]

It's DWARF-5 only: variable values can be expressed in terms of a parameters value on entry to the function. Depending on the circumstances, that value can be recovered from further up the stack frame.

(Ninja edit: although tuning for GDB might coax LLVM to emit the pre-standardised form, without DWARF-5).

[xxpor]

When I have to debug a production crash (compiled with -O3), that's usually what I do today. Basically, the value can be derived from something that's static/global, eventually. Now that I think about it though, I'm kind of surprised gdb hasn't done that for me historically, but maybe the debug info isn't detailed enough and I can do it just because I can read the actual source.