[Bug tree-optimization/40073] Vector short/char shifts generate sub-optimal code

[amylaar at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=40073

--- Comment #13 from Jorn Wolfgang Rennecke <amylaar at gcc dot gnu.org> ---
If the shifted value is 16 bit and int is 32 bit wide, then, depending
on target costs, instead of a vector compare, we might decide to use
a sign extract of bit 4 of the shift count instead.