[Bug rtl-optimization/83565] RTL combine pass breaks shift result (at least on ia64)

[wilson at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83565

--- Comment #18 from Jim Wilson <wilson at gcc dot gnu.org> ---
SPARC defines WORD_REGISTER_OPERATIONS, and works the same as ia64.  The upper
bits of a 64-bit register after a 32-bit operation are don't care bits.