[Bug target/53987] [SH] Unnecessary zero-extensions

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53987

--- Comment #13 from Oleg Endo <olegendo at gcc dot gnu.org> ---
attachment 36309 of PR 67506 is another example.  It contains the following
code sequence:

        mov.b   @r2,r0   <<
        extu.b  r0,r0    << 
        tst     #128,r0
        bt/s    .L11
        extu.w  r0,r2    <<
        mov     r1,r2