> | Yes, very nasty, this code may well be broken by compilers right now. I
> | should report these.
>
> Terminology: when you say "may well be broken by compilers right now",
> it suggests you think the code is correct; but then that does not go
> well with the first part of your sentence...

Sorry, I did not mean to say that the code is correct.

I was trying to say that unlike the LHS signed shift UBs, this one
probably isn't consistently compiled on a single platform as the
optimization level and compiler version and surrounding code changes.

John