[Bug bootstrap/78390] [7 Regression] Bootstrap failure: match.pd: cannot determine type of operand

[vogt at linux dot vnet.ibm.com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78390

--- Comment #19 from Dominik Vogt <vogt at linux dot vnet.ibm.com> ---
(In reply to Segher Boessenkool from comment #17)
> Combine should probably not try to generate this extract, I wonder if it
> can exist on any target.  So where is it coming from?
> 
> Of course the target should not "successfully" match it ;-)

There is a discussion going on about this issue:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77822

I'm working on an s390[x] patch to reject such combinations, but the middleend
should probably not generate this in the first place.