> Note that most other places in force_to_mode optimizing shifts already
> check for non-negative shift amounts; but in this place the check is
> missing.
>
> The following patch adds the check here as well, fixing the undefined
> behaviour (and subsequent bootstrap comparison failure) in my test.
Hello,
in testing a patch on arm-linux-gnueabihf, I ran into a bootstrap comparison
failure that turned out to be caused by a pre-existing bug in common code,
where combine.c code exposed undefined behaviour.
The problem is this code in force_to_mode when simplifying a LSHIFTRT:
/* Here we
