switch Statement Compiled -O

[ ... big table constructed by the compiler ... ]
vowel:
        sub     %o0,65,%g1
        cmp     %g1,24
        bgu     .L77000008
        sethi   %hi(.L_const_seg_900000102),%g2
.L900000107:
        sll     %g1,2,%g1
        add     %g2,%lo(.L_const_seg_900000102),%g2
        ld      [%g1+%g2],%g1
        jmpl    %g1+%g2,%g0
        nop
.L77000007:
        or      %g0,1,%g1
        retl    ! Result =  %o0
        or      %g0,%g1,%o0
.L77000008:
        or      %g0,0,%g1
        retl    ! Result =  %o0
        or      %g0,%g1,%o0