[Bug tree-optimization/93301] Wrong optimization: instability of uninitialized variables leads to nonsense

[vincent-gcc at vinc17 dot net via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93301

--- Comment #16 from Vincent Lefèvre <vincent-gcc at vinc17 dot net> ---
(In reply to Martin Uecker from comment #15)
> I do not think the C standard can be read in a way where reading a variable
> can yield a different value each time (except if the access is UB). For
> unspecified values it talks about "the value chosen in each instance" not
> about "the value chosen for each read of a variable".

But any instance of what? There is no context in the definition (possibly
except the operation that yields the value).