[Bug tree-optimization/110557] [13/14 Regression] Wrong code for x86_64-linux-gnu with -O3 -mavx2: vectorized loop mishandles signed bit-fields

["avieira at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110557

--- Comment #5 from avieira at gcc dot gnu.org ---
Hi Xi,

Feel free to test your patch and submit it to the list for review. I had a look
over and it looks correct to me.

I feel like it also addresses the cases where the bitfield is 'sandwiched'
like:
int x : 7;
ptrdiff_t y : 56;
long long z: 1;

As you left-shift it, and it also addresses the case where you have both
sign-extension and have to widen-it, because you still transform the type into
signed.

But it might be nice to add tests to cover those two, just in case someone
changes this.

In the future, if you do plan to work on something it would be nice to let
people know on the bugzilla ticket (preferably by assigning it to yourself) so
that multiple people don't end up working on the same thing, I had started to
write a patch, but wasn't as far as you and I like your approach :)