[Bug rtl-optimization/59461] missed zero-extension elimination in the combiner

[ebotcazou at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=59461

--- Comment #11 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> So are the upper bits for SPARC completely undefined? That would then be the
> major distinction between MIPS and SPARC. The upper bits are defined for MIPS

On the contrary, they are always defined since instructions always operate on
the full 64-bit registers, but they don't matter for 32-bit operations, i.e.
32-bit operations would work the same if they were garbage.